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1
Mukhtar, Wan Maisarah, Siti Nadiah Latib, Razman Mohd Halim, and Affa Rozana Abdul Rashid. "Graphene Based Macrobend Unclad SMF for Monitoring pH Level in Aqueous Environment." Solid State Phenomena 307 (July 2020): 78–83. http://dx.doi.org/10.4028/www.scientific.net/ssp.307.78.
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Partial unclad fibers with diameters ranging from d=121μm to d=125μm were fabricated using standard telecommunications optical fiber (SMF28) via low cost mechanical swipe-off technique. Graphene oxide (GO) was deposited using drop casting method on the outer side of the partial unclad SMF. IR laser with excitation wavelengths of λ=1310nm and λ=1550nm were launched along the graphene-coated SMF. The sensitivity of graphene based macrobend unclad SMFs were investigated by introducing two different pH of aqueous environment with values of 3.5 (acidic) and 12.5 (alkaline) that acted as sensing media. The optimum power loss was obtained as smallest diameter of partial unclad SMF with d=121μm was appointed. As uncoated SMF was replaced with the GO coated SMF which had been immersed into 3.5pH liquid solution, it was found that the optical power losses were increased about 6.79dBm and 5.15dBm using laser with λ1=1310nm and λ2=1550nm respectively. The uncoated SMFs experienced the increment of power losses about 2.11dBm and 5.15dBm as they were soaked into the solution with pH=12.5 using similar laser of λ1 and λ2. It is noteworthy to highlight the significant of graphene’s employment on macrobend unclad SMF by using λ1=1310nm in which better sensitivity and selectivity represented by maximum changes of power losses were apparently observed for both solutions. The usage of λ=1550nm exhibited poor selectivity where the partial unclad SMF unable to differentiate two contrasting pH solution. In conclusion, graphene based macrobend fiber optic sensor for pH detection was successfully developed by employing partial unclad SMF with cladding diameter of d=121μm and laser wavelength of λ=1310nm due to the enhancement of evanescent field’s strength.
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Sulendre, Marsetyo, Takdir, Harper, and Poppi. "High Level of Energy and Protein Supplementation Effect on Feed Intake and Liveweight Gain of Bali Bulls Fed Elephant Grass." Proceedings 36, no. 1 (February 12, 2020): 91. http://dx.doi.org/10.3390/proceedings2019036091.
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This research was carried out on-farm at Malonas village, Central Sulawesi, Indonesia to examine the effect of high level supplementation of by-products formulated for high ME and CP. Feed intake, faecal pH and liveweight gain of Bali bulls was observed. The basal diet was elephant grass, and supplements were rice bran (RB), cassava (C), palm kernel meal (PKM), gliricidia (G) and urea. Fifty Bali bulls (weight 168±4.48 kg) were housed in individual pens for 18 weeks (2 introductory and 16 experimental) and allocated into five treatments: A= elephant grass (EG) ad libitum, B= EG offered at 1%W/d, plus 2.5%W/d mixed RB:G, (1:1), C = EG offered at 1%W/d plus 2.5%W/d mixed RB:PKM(1:1), D = EG offered at 1%W/d plus 2.5%W/d mixed C:G (1:1), E = EG offered at 1%W/d plus 2.5%W/d mixed C+ urea: PKM (1:1). Faecal pH was measured at weeks 3, 9 and 15. Bali bulls fed B, C, D and E, consumed supplement at the rate of 2.15, 2.19, 2.09 and 2.29 %W/d, respectively. Total feed intake was 2.47, 2.98, 2.99, 2.93, 3.13%W/d, liveweight gain was 0.30, 0.57, 0.60, 0.66, 0.69 g/d and faecal pH was 6.93, 6.76, 6.65, 6.45, 6.33 for treatment A, B, C, D, and E, respectively. Supplementation increased significantly (P<0.05) total feed intake, liveweight gain, but reduced faecal pH. The highest total feed intake and liveweight gain was achieved by treatment E. It is concluded that cassava can be provided at 1.15%W/d in combination with protein supplement for high liveweight gain of Bali bulls.
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Wang, Rui, Fei Liu, and Li Hong Qin. "Influence of pH and Nitrate on Perchlorate Biological Reduction." Advanced Materials Research 356-360 (October 2011): 303–8. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.303.
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The pH and nitrate effect on the anaerobic biological reduction of perchlorate using acetate as carbon source was studied. Perchlorate reduction occurred throughout the pH range from 6.0 to 9.0. However, initiation of perchlorate reduction was rapid under neutral pH conditions. At initial pH 7, perchlorate reduction followed pseudo-first-order with the reaction rate constants was 0.3732 d-1 and the half-life time was 1.85 d. In the absence and presence of nitrate, the kinetics of perchlorate reduction with the reaction rate constants were 0.3229 d-1 and 0.2307 d-1 (after a lag phase for 3 d), the half-life time were 2.1 d and 6 d. With multiple additions of nitrate, perchlorate removal was observed with a longer lag period, the consequent production of high level nitrite may delay perchlorate degradation.
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BUCHANAN, R. L., M. H. GOLDEN, and R. C. WHITING. "Differentiation of the Effects of pH and Lactic or Acetic Acid Concentration on the Kinetics of Listeria Monocytogenes Inactivation." Journal of Food Protection 56, no. 6 (June 1, 1993): 474–78. http://dx.doi.org/10.4315/0362-028x-56.6.474.
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The effects of pH and lactic acid or acetic acid concentration on Listeria monocytogenes inactivation were studied in brain heart infusion broth using a three strain mixture. Combinations of lactic acid/sodium lactate and acetic acid/sodium acetate were used to achieve concentrations of 0.1, 0.5, 1.0, and 2,0 M in conjunction with pH values of 4.0, 5.0, 6.0, and 7.0. Cultures adjusted with HCl to pH 3.0 to 7.0 in 0.5 pH unit intervals were used as 0.0 M controls. Each pH/concentration combination was inoculated to a level of 108 CFU/ml and incubated at 28°C for up to 60 d. Bacterial populations were determined periodically by plate counts. Inactivation was exponential after an initial lag period. Survivor curves (log# versus time) were fitted using a linear model that incorporated a lag period. The model was subsequently used to calculate D values and “time to a 4-D (99.99%) inactivation” (t4-D); t4-D values were directly related to pH and inversely related to acid concentration. At acid/pH combinations that supported growth, the level of the organism increased slightly (2- to 10-fold) before declining. In the HCl-adjusted controls with pH's ≤5.5, the rate of inactivation was linearly related to pH. In the presence of the monocarboxylic acids, the duration of the lag period and the rate of inactivation were dependent on the pH, as well as the identity and concentration of acid. 4-D inactivation times were related to the level of undissociated lactic and acetic acids. That relationship was described by the equations, t4-D = exp (−0.1773*LA0.5 + 7.3482) and t4-D = exp (−0.1468*AA0.5 + 7.3905) for lactic and acetic acids, respectively, where LA and AA are mM of undissociated acid. These relationships were used in conjunction with the Henderson-Hasselback equation to develop a model for predicting the rate of inactivation as a function of pH and total organic acid concentration.
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Antanaitis, Ramūnas, Vida Juozaitienė, Dovilė Malašauskienė, and Mindaugas Televičius. "Inline Reticulorumen pH as an Indicator of Cows Reproduction and Health Status." Sensors 20, no. 4 (February 14, 2020): 1022. http://dx.doi.org/10.3390/s20041022.
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Our study hypothesis is that the interline registered pH of the cow reticulum can be used as an indicator of health and reproductive status. The main objective of this study was to examine the relationship of pH, using the indicators of the automatic milking system (AMS), with some parameters of cow blood components. The following four main groups were used to classify cow health status: 15–30 d postpartum, 1–34 d after insemination, 35 d after insemination (not pregnant), and 35 d (pregnant). Using the reticulum pH assay, the animals were categorized as pH < 6.22 (5.3% of cows), pH 6.22–6.42 (42.1% of cows), pH 2.6–6.62 (21.1% of cows), and pH > 6.62 (10.5% of cows). Using milking robots, milk yield, fat protein, lactose level, somatic cell count, and electron conductivity were registered. Other parameters assessed included the temperature and pH of the contents of reticulorumens. Assessment of the aforementioned parameters was done using specific smaX-tec boluses. Blood gas parameters were assessed using a blood gas analyzer (EPOC (Siemens Healthcare GmbH, Erlangen, Germany). The study findings indicated that pregnant cows have a higher pH during insemination than that of non-pregnant ones. It was also noted that cows with a low fat/protein ratio, lactose level, and high SCC had low reticulorumen pH. They also had the lowest blood pH. It was also noted that, with the increase of reticulorumen pH, there was an increased level of blood potassium, a high hematocrit, and low sodium and carbon dioxide saturation.
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Tamam, Evsen, and Ilser Turkyilmaz. "Effects of pH and Elevated Glucose Levels on the Electrochemical Behavior of Dental Implants." Journal of Oral Implantology 40, no. 2 (April 1, 2014): 153–59. http://dx.doi.org/10.1563/aaid-joi-d-11-00083.
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Implant failure is more likely to occur in persons with medically compromising systemic conditions, such as diabetes related to high blood glucose levels and inflammatory diseases related to pH levels lower than those in healthy people. The aim of this study was to investigate the effects of lower pH level and simulated- hyperglycemia on implant corrosion as these effects are critical to biocompatibility and osseointegration. The electrochemical corrosion properties of titanium implants were studied in four different solutions: Ringer's physiological solution at pH = 7.0 and pH = 5.5 and Ringer's physiological solution containing 15 mM dextrose at pH = 7 and pH = 5.5. Corrosion behaviors of dental implants were determined by cyclic polarization test and electrochemical impedance spectroscopy. Surface alterations were studied using a scanning electron microscope. All test electrolytes led to apparent differences in corrosion behavior of the implants. The implants under conditions of test exhibited statistically significant increases in Icorr from 0.2372 to 1.007 μAcm−2, corrosion rates from 1.904 to 8.085 mpy, and a decrease in polarization resistances from 304 to 74 Ω. Implants in dextrose-containing solutions were more prone to corrosion than those in Ringer's solutions alone. Increasing the acidity also yielded greater corrosion rates for the dextrose-containing solutions and the solutions without dextrose.
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Furukawa, R., J. E. Wampler, and M. Fechheimer. "Measurement of the cytoplasmic pH of Dictyostelium discoideum using a low light level microspectrofluorometer." Journal of Cell Biology 107, no. 6 (December 1, 1988): 2541–49. http://dx.doi.org/10.1083/jcb.107.6.2541.
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Pyranine was employed as a sensitive pH indicator in a low light level microspectrofluorometer. The in vivo and in vitro standard curves of the 460/410-nm fluorescence excitation ratio of pyranine as a function of pH are identical. Therefore, pyranine is specifically sensitive to cytoplasmic pH in Dictyostelium. The cytoplasmic pH of single cells in a population of Dictyostelium discoideum amoebae was obtained for the first time. The median cytoplasmic pH of vegetative amoebae was 7.19. Carbonyl cyanide m-chlorophenylhydrazone, a mitochondrial uncoupler and a protonophore, lowered the median cytoplasmic pH to 6.12 when the extracellular pH was 6.1. This result is in accord with the protonophore activity of carbonyl cyanide m-chlorophenylhydrazone. Interest in the cytoplasmic pH of Dictyostelium has been greatly stimulated by the theory that cytoplasmic acidification promotes development of pre-stalk cells, while cytoplasmic alkalinization favors the pre-spore pathway (Gross, J. D., J. Bradbury, R. R. Kay, M. J. Peacey. 1983. Nature (Lond.). 303:244-245). The theory postulates that diethylstilbestrol (DES), an inducer of stalk cell differentiation and a plasma membrane proton translocating ATPase inhibitor, should cause acidification of the cytosol. Previous measurements of the effects of stalk cell inducers including DES on intracellular pH using 31P nuclear magnetic resonance measurements have failed to confirm the predictions of the theory, and have suggested that significant modification of the model may be required. Using pyranine as the pH indicator, we find that the median cytoplasmic pH in cells treated with 10 microM DES dropped from 7.19 to pH 6.02. This effect is consistent with the pharmacological action of DES and with the proposal that DES, a stalk cell inducer, should acidify the cytosol. These results provide direct support for the theory that cytoplasmic pH is an essential regulator of the developmental pathway in Dictyostelium.
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Limbach, Joseph R., Estefania Pérez Calvo, and Hans H. Stein. "259 Effects of dietary crude protein level on growth performance, fecal score, gastrointestinal pH, and blood characteristics in weanling pigs fed antibiotic-free diets." Journal of Animal Science 98, Supplement_3 (November 2, 2020): 91–92. http://dx.doi.org/10.1093/jas/skaa054.159.
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Abstract Reducing dietary CP with crystalline AA supplementation has been proposed as a nutritional strategy to control post-weaning diarrhea in response to global concerns about negative effects of sub-therapeutic use of antibiotics. One hundred eighty weaned pigs (5.53 ± 0.88 kg) were randomly allotted to 3 treatments with 12 replicate pens per treatment for 28 d. Treatments included antibiotic-free, corn-soybean meal diets containing 22% and 19% CP, adequate in AA, and a 16% CP diet that provided AA below the requirement. Daily feed provisions and pig weights were recorded weekly. Fecal scores were assessed every other day. Blood samples were collected on d 1, 6, 13, 20, and 27 and 1 pig per pen was euthanized on d 12. Data for growth performance, fecal scores, and intestinal pH were analyzed by contrast statements and data for blood characteristics were analyzed using repeated measures. Results indicated that reducing dietary CP linearly (P ≤ 0.05) reduced overall ADG, G:F, body weight, and fecal scores of pigs. Reduction in dietary CP resulted in greater reduction in BUN after d 13 (treatment × day interaction, P ≤ 0.05). Total protein, albumin, and vitamin A and E in serum were lowest (P ≤ 0.05) on d 13, and pigs fed 16% CP had reduced (P ≤ 0.05) albumin compared with pigs fed other diets. The pH in the ileum was reduced (P ≤ 0.05) as dietary CP decreased but pH in the colon of pigs fed 19% CP was the lowest (P < 0.05) at d 13. In conclusion, reducing CP to 19% and 16% in antibiotic-free diets for weanling pigs reduces fecal score without impairing the growth performance during the first 14 d after weaning. However, additional strategies are needed to maintain growth performance during the next two weeks.
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Rana, Neha, Brent A. Sellers, Jason A. Ferrell, Gregory E. MacDonald, Maria L. Silveira, and Joao M. Vendramini. "Impact of Soil pH on Bahiagrass Competition with Giant Smutgrass (Sporobolus indicusvar.pyramidalis) and Small Smutgrass (Sporobolus indicusvar.indicus)." Weed Science 61, no. 1 (March 2013): 109–16. http://dx.doi.org/10.1614/ws-d-12-00070.1.
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Smutgrass is an invasive, well-rooted perennial that has long been recognized as an aggressive weed throughout Florida and in the subtropical regions of the United States. Small smutgrass and giant smutgrass are the two predominant smutgrass varieties found in Florida. The native soil pH of Florida flatwoods is 4.5 to 5.0 which is lower than the level of soil pH recommended for optimum bahiagrass growth. Therefore, replacement series experiments were conducted in a greenhouse in 2010 and 2011 to compare the competitive ability of bahiagrass with each of the two varieties of smutgrass at three levels of soil pH (4.5, 5.5, and 6.5), two densities; 4 (low) and 8 (high) plants pot−1, and at five planting ratios of 100 : 0, 75 : 25, 50 : 50, 25 : 75, and 0 : 100. Relative competitive ability and aggressivity of giant smutgrass was greater than bahiagrass across all pH levels and densities, whereas relative competitive ability and aggressivity of bahiagrass was greater than small smutgrass in all pH levels and densities, except at pH 6.5. At pH 5.5, biomass accumulation of giant smutgrass was at least 73% higher than bahiagrass, whereas small smutgrass biomass was at least 46% lower than bahiagrass at equal planting ratios of both low and high densities. Differential responses were observed on bahiagrass competitive ability with small and giant smutgrass. Amending soil pH is not a likely option to increase the growth and competitive ability of bahiagrass over giant smutgrass. However, for small smutgrass, it is likely to increase the aggressivity of bahiagrass in bahiagrass–small smutgrass mixture, unless the soil pH is raised above 5.5.
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Ohler, Tracy A., and Cary A. Mitchell. "734 PB 026 EFFECT OF CO2 LEVEL ON COWPEA CANOPY PHOTOSYNTHESIS AND GROWTH." HortScience 29, no. 5 (May 1994): 538b—538. http://dx.doi.org/10.21273/hortsci.29.5.538b.
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The vigorous growth habit and tolerances to heat, water, and acid stresses suggest cowpea as a candidate species for Controlled Ecological Life-Support Systems (CELSS). The low fat, high protein, moderate carbohydrate content of the edible leaves and seeds complement cereal grains in the vegetarian diets planned for CELSS. Cowpea canopy densities of 3.6, 7.2, 10.7, and 14.3 plants·m-2 were grown under CO2 levels of 400 or 1200 μl·l-1. Plants were grown in a deep-batch recirculating hydroponic system. pH was maintained at 5.5 by a pH controller with an in-line electrode. The nutrient solution was replaced as needed and sampled weekly for analysis by inductively coupled plasmaatomic emission spectrometry. Fluorescent lights provided 674±147 μmol·m-2s-1 PAR for an 8-hour photoperiod. Day/night temperature was maintained at 27/25°C. CO2 draw-down within the growth chamber was measured to calculate net photosynthesis. Power consumption was metered and canopy quantum efficiency was calculated. Crop yield rate (g·m-2·d-1). harvest index (% edible biomass), and yield efficiency (edible g·m-2·d-1·(nonedible g)-1) were determined to evaluate the productivity of cowpea for a CELSS. This study was supported by NASA Grant NAGW-2329.
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Tanaka, Keiichiro, Hisashi Hashimoto, and Takao Ohki. "Lactate Levels in Bowel Strangulation With Experimental Animal Model." International Surgery 100, no. 2 (February 1, 2015): 240–43. http://dx.doi.org/10.9738/intsurg-d-13-00211.1.
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Bowel strangulation is a common disease and often requires an urgent operation. Our previous report showed that lactate concentration in the blood is a good predictive marker for emergency. However, the alteration in lactate levels during the course of bowel strangulation remains unclear. We have investigated the progressive increase of lactate after induction of bowel strangulation with animal experiments. Thirty-six mice were randomly divided into 6 groups: 0, 8, 16, 24, 48, and 72 hours after operation. Under anesthesia, laparotomy was performed and a 5-cm segment of terminal ileum with the mesenteric artery and veins was ligated to create a strangulation obstruction. After operation, the arterial blood was collected and lactate concentration and pH were measured using a blood gas analyzer. Lactate concentration in the 8-hour group was markedly increased, while pH decreased significantly (P < 0.05). Lactate concentrations were kept at a high level from 8 to 72 hours after operation. The time lag between strangulation and an increase of lactate is 8 hours. Our study is the first report of a bowel strangulation mouse model. Therefore, it would be possible to find a more specific marker of bowel strangulation using our experimental model.
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Johnson, W. Carroll, Timothy L. Grey, and David Kissel. "Interactive Effects of Soil pH, Halosulfuron Rate, and Application Method on Carryover to Turnip Green and Cabbage." Weed Technology 24, no. 2 (June 2010): 160–64. http://dx.doi.org/10.1614/wt-d-09-00047.1.
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Field studies were conducted in 2006 and 2007 to evaluate the tolerance of autumn-planted cabbage and turnip green to halosulfuron applied the previous spring to cantaloupe. Main plots were three levels of soil pH: maintained at a natural pH level, pH raised with Ca(OH)2, and pH lowered with Al2(SO4)3. Subplots were a factorial arrangement of two halosulfuron application methods and three halosulfuron rates. Halosulfuron application methods were PPI or POST after transplanting to the edges of mulch-covered seedbeds. Halosulfuron rates were 35 and 70 g ai/ha, along with a nontreated control. Cantaloupe were transplanted, maintained weed-free, and evaluated for yield response. After cantaloupe harvest, direct-seeded turnip green and transplanted cabbage were established in September of each year and evaluated for crop tolerance and yield. Data indicated nonsignificant main effects of soil pH and halosulfuron application method on cantaloupe yield. However, in 2007 cantaloupe yields were significantly reduced, by 16 and 20% for halosulfuron applied at 35 and 70 g/ha, respectively. For all turnip green and cabbage response parameters, interactions were nonsignificant between application method and rate, soil pH and rate, and soil pH and application method, along with the three-way interaction. After 6 mo, there was no evidence of stunting from halosulfuron carryover in 2006 to direct-seeded turnip green and in both years to transplanted cabbage. Visual estimates of stunting to direct-seeded turnip green ranged from 9 to 16% for halosulfuron at 35 and 70 g/ha, respectively, in 2007, but all stunting was transient and turnip green yield was not affected.
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Tsuboi, M., K. Harasawa, T. Izawa, T. Komabayashi, H. Fujinami, and K. Suda. "Intralysosomal pH and release of lysosomal enzymes in the rat liver after exhaustive exercise." Journal of Applied Physiology 74, no. 4 (April 1, 1993): 1628–34. http://dx.doi.org/10.1152/jappl.1993.74.4.1628.
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The mechanism underlying exhaustive exercise-induced release of lysosomal enzymes was studied in the rat liver. Exhaustive exercise resulted in the release of beta-glucuronidase and cathepsin D, but not beta-glucosidase and acid phosphatase, into the blood and cytosol, suggesting that the release of lysosomal enzymes is not due to disruption of lysosomal membranes. The intralysosomal pH of the liver, which was approximately 5.5 at the resting level, rose significantly after exhaustive exercise to pH 6.3. In vitro, beta-glucuronidase and cathepsin D were released at an intralysosomal pH exceeding 6.2. In contrast, beta-glucosidase and acid phosphatase were not released. The elevation of intralysosomal pH reduced the aggregation of beta-glucuronidase and cathepsin D. The rate of ammonia accumulation increased markedly in the lysosome-enriched subcellular fraction after exercise. There was a positive relationship between the rate of ammonia accumulation and the elevation of intralysosomal pH in vitro. Lysosomes isolated after exhaustive exercise showed significantly increased osmotic fragility. Our findings suggest that, during exhaustive exercise, the accumulation of ammonia in lysosomes leads to the elevation of intralysosomal pH, resulting in the reduced aggregation of certain lysosomal enzymes. Thus, less aggregated lysosomal enzymes may be released into the cytosol through the lysosomal membrane, the permeability of which has been increased.
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Steingraeber, Mark T., and William H. Gingerich. "Hatching, growth, ion accumulation, and skeletal ossification of brook trout (Salvelinus fontinalis) alevins in acidic soft waters." Canadian Journal of Zoology 69, no. 8 (August 1, 1991): 2266–76. http://dx.doi.org/10.1139/z91-317.
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Brook trout eyed eggs and subsequent alevins were exposed to pH 5.0, 6.5, and 7.0 in soft reconstituted water and to pH 8.2 in hard well water for up to 72 d. Hatching was delayed and hatching success reduced (p < 0.05) in eyed eggs exposed to pH 5.0 and 6.5. Alevin growth was not affected. Fish in all treatments rapidly accumulated monovalent ions in a similar pattern and in the order of Na+ > K+ > Cl− during yolk absorption and early exogenous feeding. Whole-body monovalent ion concentrations were reduced for short periods during yolk absorption in alevins exposed to pH 6.5 and throughout most of the experiment for those exposed to pH 5.0. Whole-body Mg2+ concentrations were not affected by treatment pH and remained near their median hatch level throughout the exposure. The whole-body concentration of Ca2+ was reduced in fish exposed to pH 5.0, particularly near the end of the experiment. Calcium accumulation in fish was influenced by the interaction of pH and time at pH 5.0 but not at the other pH levels. Alevins exposed to pH 5.0 experienced delayed ossification of skeletal structures associated with feeding, respiration, and locomotion that usually persisted for up to 10 d. The detection of skeletal abnormalities early in life might aid in identifying fish populations at risk in acidified waters.
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Krise, William F., and James W. Meade. "Effects of Low-Level Gas Supersaturation on Lake Trout (Salvelinus namaycush)." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 4 (April 1, 1988): 666–74. http://dx.doi.org/10.1139/f88-080.
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Eggs, eleutheroembryos, and alevins of lake trout (Salvelinus namaycush) were reared in 1 of 10 levels of total gas pressure (TCP) ranging from 13 to 81 mm Hg (ΔP) above ambient barometric pressure. Rearing water was soft (30–40 mg CaCO3/L, pH 6.8), temperature was 9.3 °C, and the exogenous feeding portion of the test lasted 98 d. The supersaturation levels tested had no effect on the total survival of eggs, eleutheroembryos, or alevins, and condition factor and mean weight of fish in each treatment were statistically unchanged at the end of the study. Most of the fish that died during the feeding trial were small, had a below-average condition factor, and showed petechial hemorrhaging in the abdominal region. Length frequency distributions differed significantly among treatment groups after 56 d of feeding and remained different through 98 d. There was no difference in weight gain, condition factor, food conversion, and mortality, indicating that these measures are not useful for predicting or monitoring effects within the range of gas levels tested. The estimated incipient lowest level of effect of gas supersaturation remains unclear. A conservative recommendation of maximum supersaturation levels for small lake trout would be in the lower treatment levels used in this study.
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CUPPETT, S. L., J. I. GRAY, J. J. PESTKA, A. M. BOOREN, J. F. PRICE, and C. L. KUTIL. "Effect of Salt Level and Nitrite on Toxin Production by Clostridium botulinum Type E Spores in Smoked Great Lakes Whitefish1." Journal of Food Protection 50, no. 3 (March 1, 1987): 212–17. http://dx.doi.org/10.4315/0362-028x-50.3.212.
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The effect of salt level and nitrite on botulinal safety of smoked whitefish was investigated. An average water-phase (wp) salt concentration of 4.4% inhibited outgrowth of Clostridium botulinum type E spores (103 spores/g) for over 35 d in temperature-abused (27°C) smoked whitefish. Incorporation of nitrite (220 mg/kg) during brining to the smoked salted (4.4%, wp) whitefish inhibited toxin production for 56 d at 27°C. An average salt concentration of 6.2% (wp), with or without nitrite, totally inhibited toxin production for the duration of the study (83 d). The effect of pH and water activity in temperature-abused smoked whitefish as a means of controlling toxin production by C. botulinum type E spores was evaluated.
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Albenzio, Marzia, Antonella Santillo, Mariangela Caroprese, Rosaria Marino, Giovanni Annicchiarico, and Agostino Sevi. "Effects of ventilation rate and of dietary protein level in an intensive dairy sheep system on the features of Canestrato Pugliese cheese." Journal of Dairy Research 74, no. 1 (September 15, 2006): 26–33. http://dx.doi.org/10.1017/s0022029906002111.
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Effects of ventilation rate and of dietary protein level in an intensive dairy sheep system on the features of Canestrato Pugliese cheese were studied. Cheeses were manufactured from the bulk milk obtained from ewes subjected to four different experimental treatments: (1) low dietary crude protein (CP) of 13% in dry matter (DM) at a low ventilation rate (23·5 m3/h per ewe) (LPLV); (2) low dietary CP at a moderate ventilation rate (47 m3/h per ewe) (LPMV), (3) moderate dietary CP of 16% DM at a low ventilation rate (MPLV); and (4) moderate dietary CP dietary at a moderate ventilation rate (MPMV). Bulk milk and cheeses (at 1, 15, 45 and 90 d of ripening) were analysed for chemical composition, N fractions and plasmin-plasminogen activities. The pH 4·6-soluble and insoluble N fractions were analysed by urea-PAGE. Bulk milk from ewes receiving the low CP diet displayed higher casein and lower urea contents. Ewes subjected to the low ventilation rate displayed a higher plasminogen activity in milk, whereas no differences emerged among treatments in the conversion of zymogen to plasmin. During ripening the plasmin-plasminogen system in cheese did not display significant changes across treatments. At 90 d of ripening, the cheese produced with milk from ewes receiving the low CP diet and exposed to the low ventilation rate displayed more markedly stained bands in the area of γ-caseins in pH 4·6-insoluble N fraction. As from 15 d of ripening, the pH 4·6-soluble fraction showed a greater number of bands in the LPMV and MPMV than in the LPLV and MPLV cheeses. The results showed that Canestrato Pugliese cheese manufactured with milk from ewes fed the low CP diet and exposed to the moderate ventilation rate was characterized by higher protein and casein content in the fresh cheese and by a greater proteolysis after 90 d of ripening.
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Furukawa, R., J. E. Wampler, and M. Fechheimer. "Cytoplasmic pH of Dictyostelium discoideum amebae during early development: identification of two cell subpopulations before the aggregation stage." Journal of Cell Biology 110, no. 6 (June 1, 1990): 1947–54. http://dx.doi.org/10.1083/jcb.110.6.1947.
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Development of the cellular slime mold Dictyostelium discoideum is initiated by the removal of nutrients, and results in formation of a mature fruiting body composed of two cell types, the stalk and spore cells. A considerable body of evidence supports the hypothesis that cytoplasmic pH may be an essential regulator of the choice to differentiate in either the prestalk or prespore pathway. We have devised methods for measurement and analysis of intracellular pH in developing Dictyostelium amebae in order to assess directly the potential role of cytoplasmic pH in regulating the pathway of differentiation. The intracellular pH of single D. discoideum amebae during development and in intact slugs has been measured using the pH-sensitive indicator pyranine in a low light level microspectrofluorometer. We have used the ATP-mediated loading method to introduce pyranine into these cells. Cells loaded by the ATP method appear healthy, have no detectable defects in development, and exhibit a similar population distribution of intracellular pH to those loaded by sonication. The intracellular pH of populations comprised of single amebae was found to undergo a transient acidification during development resulting in a bimodal distribution of intracellular pH. The subpopulations were characterized by fitting two gaussian distributions to the data. The number of cells in the acidic intracellular pH subpopulation reached a maximum 4 h after initiation of development, and had returned to a low level by 7 h of development. In addition, a random sample of single amebae within a slug had a median intracellular pH of 7.2, nearly identical to the median pH (7.19) of similarly treated vegetative cells. No gradient of intracellular pH along the anterior to posterior axis of the slug was detected. Our data demonstrate the existence of two distinct subpopulations of cells before the aggregation stage of development in Dictyostelium, and offers support for the hypothesis that changes in intracellular pH contribute to development in D. discoideum.
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Sousa, Jhone de, Joao Vendramini, Philipe Moriel, Hiran da Silva, Joao Sanchez, and Luciano de Sousa. "PSVII-11 Monensin and supplementation level effects on ruminal parameters and in-situ disappearance of steers receiving bermudagrass." Journal of Animal Science 97, Supplement_3 (December 2019): 299. http://dx.doi.org/10.1093/jas/skz258.604.
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Abstract The objective of this study was to evaluate the effects of monensin and supplementation level on bermudagrass (Cynodon dactylon) in situ disappearance and ruminal parameters. The experiment was conducted in Ona, FL. Treatments were the factorial arrangement of 2 supplementation levels [0.4 (low) or 4 kg/d (high)] and 2 monensin levels (20 mg/kg of the DM intake or no monensin) distributed in a latin square design. Four rumen-cannulated steers were used with 10-d adaptation and 3-d incubation and collection periods. Samples were incubated in the rumen with nylon bags and analyzed for DM, CP, and NDF disappearance. Rumen fluid was collected for 3 d during the incubation period and analyzed for pH, ammonia, propionate, lactate, and butyrate. There was no effect (P > 0.05) of monensin on potential DM, CP, and NDF disappearance; however, greater supplementation level increased (P < 0.03) potential DM disappearance (64 vs. 61%) and NDF disappearance (60 vs. 57%). Steers receiving greater supplementation level had greater (P = 0.01) total DMI (1.4 vs. 1.0% BW) but there was no difference in forage DMI (P = 0.72, mean = 1.0 ± 0.1% BW). There was a monensin × supplementation level interaction on ruminal propionate concentration. The interaction occurred because there was no effect (P = 0.64) of monensin with low supplementation (mean = 12 ± 1.2 mol/100 mol); however, monensin increased propionate on high supplementation from 15 to 19 mol/100 mol. There was an increase (P < 0.05) in ruminal ammonia (from 1.9 to 4.4 mg/100 ml) and lactate (from 60 to 64 mol/100 mol) from low to high supplementation. Rumen pH and butyrate were not affected by monensin or supplementation (P > 0.12). Monensin did not change forage disappearance parameters but increased ruminal propionate production in steers receiving greater amount of concentrate.
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Del Pozo, Buensuceso Fernandez, Pilar Gaya, Margarita Medina, M. Asunción Rodríguez-Marín, and Manuel Nuñez. "Changes in chemical and rheological characteristics of La Serena ewes' milk cheese during ripening." Journal of Dairy Research 55, no. 3 (August 1988): 457–64. http://dx.doi.org/10.1017/s0022029900028715.
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SummaryCasein breakdown and free fatty acids formation were studied in ten batches of La Serena cheese throughout a 60 d ripening period. A rapid degradation of αs1-casein occurred, with only 18·6% residual αs1-casein being detected in 60 d-old cheese, whereas 49·5% β-casein remained unattacked. High pH values, low NaCl-in-moisture concentrations and high moisture contents enhanced proteolysis. Lac-tobacilli and yeasts were the only microbial groups which significantly influenced αs1-casein breakdown, and only yeasts affected β-casein hydrolysis. No significant effect of chemical characteristics or microbial groups on FFA levels was detected, an average level of 12·7 mequiv./100 g fat being recorded for 60 d cheese. Rheological characteristics of the cheese reached their minimum values after 15–30 d of ripening and were dependent on αs1- and β-casein breakdown, pH value, NaCl-in-moisture concentration and moisture content.
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Alava, Erin N., Eduardo I. Alava, Cody A. Welchons, Joel V. Yelich, and Matthew J. Hersom. "Effect of increased inclusion of dried distillers grain supplement on adaptation, intake, digestibility, and rumen parameters in steers consuming bermudagrass round bale silage." Translational Animal Science 3, no. 1 (January 1, 2019): 29–41. http://dx.doi.org/10.1093/tas/txz007.
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Abstract Eight ruminally cannulated beef steers were used to evaluate forage intake and physiological response during adaptation to a diet consisting of bermudagrass round bale silage (RBS) and dried distillers grains (DDG) and in a second experiment the effect of level of DDG supplementation on RBS forage intake, digestibility, and rumen parameters. The adaptation experiment was designed to simulate a 14-d step-up process. Initially steers received ad libitum RBS, on d 4 steers were offered 1.13 kg of DDG daily and every 4 d daily DDG offered was increased by 1.13 kg. Blood and rumen fluid samples were collected before feeding (0 h) and 6, 12, 24 (before feeding), and 36 h after every diet change. The digestibility experiment was conducted as an 8 × 4 Latin square with four periods. Treatments included RBS only and DDG supplement levels of 0.33%, 0.66%, and 1.0% of body weight (RBS + 0.33, +0.66, and 1.0, respectively). Collection periods consisted of 21 d to determine dry matter intake [DMI], digestibility, and collect rumen fluid samples. During adaptation, level of DDG did not (P = 0.42) affect RBS DMI. Mean ruminal pH was greater (P < 0.05) for RBS only compared with diets with DDG. When steers were offered 3.39 or 4.52 kg/d of DDG rumen NH3-N concentration was greater (P ≤ 0.05) compared with other levels of DDG or RBS alone. Mean nonesterified fatty acid and plasma urea N concentrations varied among levels of DDG offered. In the digestibility experiment forage DMI, total DMI, and total tract apparent digestibility exhibited a quadratic (P ≤ 0.05) response to level of DDG offered. Mean ruminal pH responded in a quadratic manner (P = 0.03) and was greater for RBS only compared with RBS plus DDG at any level. Mean ruminal NH3-N concentration tended (P = 0.07) to respond in a cubic manner as DDG amount offered increased. Physiological responses during adaptation to DDG over 14 d resembled responses previously observed after long-term DDG supplementation. Offering DDG up to 1% of body weight did depress forage DMI and ruminal pH but increased total DMI, diet digestibility, and ruminal NH3-N concentration.
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Elia, Alice, Karine Ferrand, and Karel Lemmens. "Determination of the Forward Dissolution Rate for International Simple Glass in Alkaline Solutions." MRS Advances 2, no. 12 (2017): 661–67. http://dx.doi.org/10.1557/adv.2016.672.
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ABSTRACTThe International Simple Glass (ISG) is considered as reference benchmark glass and is used in the frame of an international collaboration for the study of the dissolution mechanisms of high-level vitrified nuclear waste.In this work the forward dissolution rate of the ISG was determined in different alkaline solutions, as a simulation of the disposal conditions foreseen by the Belgian concept for geological disposal of vitrified waste. The determination of the forward dissolution rate was done by measuring the Si released from the glass in solution in tests performed at 30 °C in four different KOH solutions with pH varying from 9 to 14 and in artificial cementitious water at pH 13.5.The forward dissolution rates determined for the ISG in high pH solutions are in good agreement with the results obtained for a lower pH range.The rates obtained in this study, moreover, were compared with the rates measured in the same conditions for SON68 glass from a previous work. The values obtained for the two glasses are comparable in artificial cementitious water and in KOH at moderately alkaline pH. At higher pH, ISG glass shows a lower forward dissolution rate with respect to SON68 (0.20 g·m-2·d for ISG and 0.35 g·m-2 d for SON68 at pH 14).
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ASPLUND, KRISTIINA, ESKO NURMI, JORMA HIRN, TIMO HIRVI, and PAULI HILL. "Survival of Yersinia enterocolitica in Fermented Sausages Manufactured With Different Levels of Nitrite and Different Starter Cultures." Journal of Food Protection 56, no. 8 (August 1, 1993): 710–12. http://dx.doi.org/10.4315/0362-028x-56.8.710.
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The ability of Yersinia enterocolitica 0:3 to grow and survive during the manufacture of fermented sausages made with 0, 50, 80, 100, and 120 mg/kg added sodium nitrite and three different commercial starter cultures was determined. The sausage mass was inoculated to contain 1.7 × 105 of Y. enterocolitica per g. Yersinia was not detected after 28 d in sausages made with 80, 100, or 120 mg/kg of sodium nitrite. All sausages manufactured without or with 50 mg/kg sodium nitrite harbored Yersinia during the test period of 35 d. The highest level of Yersinia (5.9 log10 CFU/g) was detected in sausages made with no sodium nitrite and with Pediococcus acidilactici ©. In sausages made with Lactobacillus pentosus (A), the level of Yersinia was less than 2.0 log10 CFU/g. In sausages made with Lactobacillus plantarum (B) and 50 mg/kg sodium nitrite, the level of Yersinia was 2.9 log10 CFU/g. The pH values made with starters A, B, and C reached the pH values of 4.9, 5.2, and 5.4, respectively.
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Wright, J. K., and R. Seckler. "The lactose/H+ carrier of Escherichia coli: lac YUN mutation decreases the rate of active transport and mimics an energy-uncoupled phenotype." Biochemical Journal 227, no. 1 (April 1, 1985): 287–97. http://dx.doi.org/10.1042/bj2270287.
Full textAbstract:
The Escherichia coli K12 strain X71-54 carries the lac YUN allele, coding for a lactose/H+ carrier defective in the accumulation of a number of galactosides [Wilson, Kusch & Kashket (1970) Biochem. Biophys. Res. Commun. 40, 1409-1414]. Previous studies proposed that the lower accumulation in the mutant be due to a faulty coupling of H+ and galactoside fluxes via the carrier. Immunochemical characterization of the carriers in membranes from mutant and parent strains with an antibody directed against the C-terminal decapeptide of the wild-type carrier leads to the conclusion that the mutant carrier is similar to the wild-type in terms of apparent Mr, C-terminal sequence, and level of incorporation into the membrane. The pH-dependence of galactoside transport was compared in the mutant and the parent. At pH 8.0-9.0, mutant and parent behave similarly with respect to the accumulation of beta-D-galactosyl 1-thio-beta-D-galactoside and to the ability to grow on the carrier substrate melibiose. At pH 6.0, both the maximal velocity for active transport and the level of accumulation of beta-D-galactosyl-1-thio-beta-D-galactoside are lower in the mutant. The mutant also is unable to grow on melibiose at pH 5.5. However, at pH 6.0 and low galactoside concentrations, the symport stoichiometry is 0.90 H+ per galactoside in the mutant as compared with 1.07 in the parent. These observations suggest that symport is normal in the mutant and that the lower rate of transport in the mutant is responsible for the phenotype. At higher galactoside concentrations, accumulation is determined not only thermodynamically but also kinetically, contrary to a simple interpretation of the chemiosmotic theory. Therefore lower rates of active transport can mimic the effect of uncoupling H+ and galactoside symport. Examination of countertransport in poisoned cells at pH 6.0 reveals that the rate constants for the reorientation of the loaded and unloaded carrier are altered in the mutant. The reorientation of the unloaded carrier is slower in the mutant. However, the reorientation of the galactoside-H+-carrier complex is slower for substrates like melibiose, but faster for substrates like lactose. These findings suggest that lactose-like and melibiose-like substrates interact with the carrier in slightly different ways.
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Stephen, Alison M., H. S. Wiggins, H. N. Englyst, T. J. Cole, B. J. Wayman, and J. H. Cummings. "The effect of age, sex and level of intake of dietary fibre from wheat on large-bowel function in thirty healthy subjects." British Journal of Nutrition 56, no. 2 (September 1986): 349–61. http://dx.doi.org/10.1079/bjn19860116.
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1. To evaluate the effect of age, sex and level of intake on the colonic response to wheat fibre, thirty healthy volunteers aged 17–62 years (nineteen men, eleven women) recruited from a local industry, were divided into four groups and given a controlled diet for two 3-week periods. The diet contained white bread during one period or one of four different amounts of bran-enriched wholemeal bread during the other (30, 60, 110, 170 g/d).2. Wide variation was observed between subjects in stool weight on the basal diet and in response to wheat fibre. Stepwise regression analysis showed that the variation in stool weight was significantly related to sex (t4.0, P <0.001) but not to age, height, weight or energy:fibre intakes on the basal diet. Stool weight in men (162(SE 11) g/d) was approximately double that in women (83(SE 11) g/d). Transit time and stool weight were closely related and the effect of sex on stool weight could be explained entirely by differences in transit.4. Faecal carbohydrate excretion increased with the addition of bran mainly due to increased amounts of cellulose and pentose (arabinose+xylose), whilst digestibility of dietary non-starch polysaccharide fell from 77.6 (SE 2.3)% on the white bread diet to 65.6 (SE 2.4)% with the added bran (t 7.4, P < 0.01, n26).5. Faecal pH was more acid in men than in women and was related to methane production. Methane producers had higher faecal pH than non-producers (7.06 (SE 0.1 1) v. 6.65 (SE O.1)), lower stool weight (g/d; 93 (SE 12) v. 156 (SE 13)) and slower transit times (h; 84.6 (SE 11.7) v. 48.6 (SE 6.6)).6. These studies show that, when on similar diets, women have much lower stool weights and slower transit times than men. Furthermore, within the range of amounts of wheat fibre used in this and other published work, stool weight increases in linear proportion to the dose of fibre added to the diet. Methane excretion in breath is associated in this group of subjects with slow transit time and high faecal pH.
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Kula, E., and L. Menšík. "Earthworms (Lumbricidae) of an air-polluted area affected by ameliorative liming." Journal of Forest Science 57, No. 5 (May 16, 2011): 210–18. http://dx.doi.org/10.17221/17/2010-jfs.
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The study was aimed at the area of the Krušné hory Mts. with stands of substitute species, soils disturbed by long-term acidification and affected repeatedly by aerial ameliorative liming. Ten species of earthworms were recorded. The highest abundance was shown by earthworms of Dendrobaena attemsi, Dendrobaena octaedra and Dendrobaena vejdovskyi, which are considered to be acidotolerant being, however, monitored in the high and balanced abundance at pH 2.8–6.2. Ubiquitous species developed in soils of markedly lower pH, viz. Lumbricus rubellus (2.8–5.6), Aporrectodea caliginosa (3.1–5.5), and Octolasion lacteum (3.2–5.2). Dendrobaena attemsi responded positively to low saturation of the base-exchange complex, low C/N ratio and high content of phosphorus, and negatively to the high level of calcium. D. octaedra responded positively to the higher level of calcium and D. vejdovskyi to the higher content of potassium.
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De Ondiz, A., M. Avilés, F. A. Garca-Vázquez, C. Carrasco, L. Grullón, and S. Ruiz. "223 ENZYMATIC ACTIVITY LEVEL OF DIFFERENT GLYCOSIDASES IN INTACT AND ACROSOME-REACTED PORCINE SPERM." Reproduction, Fertility and Development 20, no. 1 (2008): 191. http://dx.doi.org/10.1071/rdv20n1ab223.
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The sperm–egg interactions are species-specific forms of cell recognition and the binding event which are a necessary prerequisite for fertilization (Park et al. 2002 Anim. Reprod. Sci. 72, 83–94). Glycosidase enzymes that remove carbohydrates could play an important role in the reproductive tract, modulating decisive physiological events mediated by carbohydrates, which play a key role in sperm–oocyte recognition. The aim of this study was to analyze the presence of the glycosidases α-D-mannosidase, α-L-fucosidase, β-D-glucosaminidase, and β-D-galactosaminidase in intact and acrosome-reacted sperm from fertile matured boars. Sperm were washed three times in PBS by centrifugation at 800g for 10 min. The pelleted sperm were resuspended in the same buffer to obtain a final concentration of 250 � 106 spermatozoa mL–1. The acrosome reaction was induced by incubation of the sperm with 10 µm of calcium ionophore A23187 at 37�C for 30 min. Different enzymes were detected by incubating 8 µL (for α-Dmannosidase) or 80 αL (for the rest of the enzymes) of sperm sample with the corresponding substrate conjugated to 4-methylumbelliferil for 2 h at 37�C in PBS at pH 7.3. Fluorescences were read on a Fluostar Galaxy fluorimeter (BMG LabTech GmbH, Offenburg, Germany), using wavelengths of 340 and 450 nm for excitation and emission, respectively, and were corrected by subtracting tissue and substrate blanks. The results were analyzed using a one way ANOVA. An average of fluorescence units of 9685.86 � 1081.75, 7394.63 � 874.29, 3154.17 � 514.10, and 1666.40 � 117.86 was detected in the intact sperm sample for the α-D-mannosidase, α-L-fucosidase, β-D-glucosaminidase, and β-D-galactosaminidase, respectively. For the acrosome-reacted sperm sample (60–65% acrosome-reacted sperm in the samples measured by fluorescence microscope), an average of 9756.14 � 1011.45, 7026.93 � 771.48, 1185.70 � 277.51, and 1111.60 � 176.70 for α-D-mannosidase, α-L-fucosidase, β-D-glucosaminidase, and β-D-galactosaminidase, respectively. Statistically significant differences (P < 0.05) between intact and acrosome-reacted sperm were detected only for the β-D-glucosaminidase and β-D-galactosaminidase. These results suggest that the four different enzymes detected are mainly present in the sperm plasma membrane. Under the conditions used in this study, α-D-mannosidase is the main enzyme activity present in the sperm. Importantly, β-D-glucosaminidase and β-D-galactosaminidase activity detected in the intact sperm is decreased after the induction of the acrosome reaction.
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Demirkan, H. B., O. Yilmaz, C. Çoker, M. Gümüstekin, J. Batu, M. Bülbül, T. Canda, and M. Alakavuklar. "The influence of partial hepatectomy (PH) on pharmacokinetics of docetaxel (D) in sprague-dawley rats (SDR) with experimental mammary neoplasm models (EMNM)." Journal of Clinical Oncology 24, no. 18_suppl (June 20, 2006): 12021. http://dx.doi.org/10.1200/jco.2006.24.18_suppl.12021.
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12021 Background: Docetaxel (Taxotere-Aventis) is used in the treatment of breast, lung, head and neck, prostate and ovarian cancers. Recently, PH for isolated hepatic metastases of breast cancer has been reported in Japan and France. PH is an experimental model of hepatic insufficiency. Therefore we aimed to study the influence of PH on pharmacokinetics of D in SDR with EMNM. Methods: After the approval of Local Ethical Commitee on Laboratory Animal Researches, 40 female 50-day-old SDR were injected with 50 mg/kg body weight N-nitroso-N-methylurea (NMU) in 09% NaCL solution intraperitoneally. 5 female 50-day-old SDR were only injected with 09% NaCL solution intraperitoneally. After 6-months follow-up period for the formation of EMNM, 8 rats in the Group D+H were hepatectomized partially. Baseline venous blood samples were taken. 24 hours after PH, 6 rats were alive. There were 8 rats in the Group D (without hepatectomy). Before chemotherapy and 1 hour after intravenous infusion of 5 mg/kg body weight D, blood samples were taken for biochemical analyses from both groups. 5., 15., 30. minutes and 1., 2., 4., 5. hours after D infusion, arterial blood samples were taken for pharmacokinetic analyses. Biochemical and Pharmacokinetic tests (BPT) were done by auto-analyzer Hitachi Modular Analytic and HPLC (High Performance Liquid Chromatography) respectively. Area under the concentration-time curve [AUC (0–60)] was determined for each group. Statistical analyses were done by SPSS 11.0 for Windows at the 5% significance level. Results: PH affected liver functions and serum albumin levels negatively (p = 0.028). Although D infusion didn’t affect serum ALT and bilirubine levels, low serum albumin was detected 1 hour after chemotherapy in both groups (p= 0.028 and p= 0.030). AUC(0–60) of plasma D in hepatectomized rats were greater than the other group (p = 0.015). Conclusion: During the treatment of cancer patients in posthepatectomy period with taxanes (D), dose adjustment must be done. In both groups, statistically significant low serum albumin after D infusion may be as a result of decreased intertitial fluid pressure, albumin extravasation and edema formation caused by taxanes. Physiological and preventive studies are needed. No significant financial relationships to disclose.
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Minotti, J. R., E. C. Johnson, T. L. Hudson, R. R. Sibbitt, L. E. Wise, E. Fukushima, and M. V. Icenogle. "Forearm metabolic asymmetry detected by 31P-NMR during submaximal exercise." Journal of Applied Physiology 67, no. 1 (July 1, 1989): 324–29. http://dx.doi.org/10.1152/jappl.1989.67.1.324.
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This study evaluated the relationship of skeletal muscle energy metabolism to forearm blood flow and muscle mass in the dominant (D) and nondominant (ND) forearms of normal subjects. 31P-Magnetic resonance spectroscopy was used to determine intracellular pH and the ratio of inorganic phosphate to phosphocreatine (Pi/PCr), an index of energy metabolism. Forearm blood flow and muscle mass were measured by venous occlusion plethysmography and magnetic resonance imaging, respectively. Metabolic measurements and flow were determined at rest and during submaximal exercise in both forearms. After a warm-up period, six normal right-handed male subjects performed 7.5 min of wrist flexion exercise in the magnet (1 contraction every 5 s), first with the ND forearm and then with the D forearm, at 23, 46, and 69 J/min. At rest, there were no differences between forearms in Pi/PCr or pH. However, at each work load the D forearm demonstrated significantly lower Pi/PCr and higher pH than the ND forearm. Blood flow was not significantly different between the forearms at rest or during exercise. Because these subjects were not engaged in unilateral arm training, we conclude that 1) Pi/PCr is lower and pH is higher in the D compared with the ND forearm in normal subjects during submaximal exercise, 2) these differences are independent of muscle mass and blood flow, and 3) the cumulative effect of long-term, low-level daily activity provides an adequate training stimulus for muscular metabolic adaptations.
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Lang, Harvey J., Claire-Lise Rosenfield, and David Wm Reed. "Response of Ficus benjamina and Dracaena marginata to Iron Stress." Journal of the American Society for Horticultural Science 115, no. 4 (July 1990): 589–92. http://dx.doi.org/10.21273/jashs.115.4.589.
Full textAbstract:
Ficus benjamina L. and Dracaena marginata Lam. were grown in a modified Hoagland's nutrient solution containing either 0, 0.22 or 5.52 mg Fe3+/liter (HEEDTA or EDTA). F. benjamina grew well at all Fe levels and showed mild chlorosis only at 0 mg Fe/liter. For D. marginata, growth decreased and chlorosis increased as solution Fe level decreased. F. benjamina exhibited a high capacity for Fe3+ reduction, which increased as Fe level decreased, reaching a maximum below 0.06 mg·liter-1 D. marginata exhibited a low capacity for Fe3+ reduction, which was slightly enhanced at 0.1 to 0.15 mg·liter-1. In both species, reduction occurred in the presence of roots, with minimal reduction in their absence. This result indicates that Fe3+ is reduced at the root surface and not by reductants released into the solution. F. benjamina increasingly lowered pH as solution Fe decreased, and always lowered pH more than D. marginata at all Fe levels. Total and extractable Fe concentration of leaves did not correlate well with chlorosis, whereas total Fe content per plant correlated highly with chlorosis. Chemical names used: N-hydroxyethyl-ethylenediamine-triacetic acid (HEEDTA), ethylenediamine tetraacetic acid (EDTA).
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Brunelle, Patrick, Christian Schöneich, and Arvi Rauk. "One-electron oxidation of methionine peptides — Stability of the three-electron S—N(amide) bond." Canadian Journal of Chemistry 84, no. 6 (June 1, 2006): 893–904. http://dx.doi.org/10.1139/v06-079.
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The possibility of sulfur–nitrogen (S—N) three-electron bond formation in a one-electron oxidized methionine peptide model was investigated computationally following the detection of such species in pulse radiolysis experiments (C. Schöneich, D. Pogocki, G.L. Hug, and K. Bobrowski. J. Am. Chem. Soc. 125, 13700 (2003)). Geometry optimiza tions were carried out at the B3LYP/6-31G(d) level of theory. Relative free energies in aqueous solution at pH 7 were predicted for all intermediates with enthalpy evaluations at the CCSD(T)/6-31+G(d′) level and free energies of solvation predicted using a continuum model (CPCM). Both the initial oxidation product and the intermediate formed at higher pH were identified as cyclic S—N bonded species in which the intramolecular three-electron interaction is between the S atom and the π orbital of the amide group. TD-B3LYP calculations of the UV spectra support the assignments. A mechanism for the conversion to the most stable α-C-centered radical is proposed. The mechanism involves a novel deprotonation–reprotonation via an intermediate backbone-delocalized radical anion.Key words: methionine oxidation, three-electron bonding, S—N bonding, B3LYP.
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Lopes, Laiane Antunes, Paula Kern Novelli, Roberto Fernandez-Lafuente, Paulo Waldir Tardioli, and Raquel Lima Camargo Giordano. "Glyoxyl-Activated Agarose as Support for Covalently Link Novo-Pro D: Biocatalysts Performance in the Hydrolysis of Casein." Catalysts 10, no. 5 (April 25, 2020): 466. http://dx.doi.org/10.3390/catal10050466.
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This study aimed to evaluate the performance of a commercial protease (Novo-Pro D (NPD)), both in soluble and immobilized forms, in the hydrolysis of proteins (using casein as model protein). Immobilization of the protease NPD on 6% agarose activated with glyoxyl groups for 24 h at 20 °C and pH 10.0 allowed preparing immobilized biocatalyst with around 90% immobilization yield, 92% recovered activity versus small substrate, and a thermal stability 5.3-fold higher than the dialyzed soluble enzyme at 50 °C and pH 8.0. Immobilization times longer than 24 h lead to a decrease in the recovered activity and did not improve the biocatalyst stability. At 50 °C and pH 6.5, the immobilized NPD was around 20-fold more stable than the dialyzed soluble protease. Versus casein, the immobilized NDP presented a 10% level of activity, but it allowed hydrolyzing casein (26 g/L) at 50 °C and pH 6.5 up to a 40% degree of hydrolysis (DH) after 2 h reaction, while under the same conditions, only a 34% DH was achieved with soluble NPD. In addition, the immobilized NPD showed good reusability, maintaining the DH of casein for at least ten 2h-reaction batches.
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McCormick, Nicole E., Scott A. Halperin, Song F., and Lee. "Regulation of d-alanylation of lipoteichoic acid in Streptococcus gordonii." Microbiology 157, no. 8 (August 1, 2011): 2248–56. http://dx.doi.org/10.1099/mic.0.048140-0.
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d-Alanyl esters on lipoteichoic acid (LTA) are involved in adhesion, biofilm formation, resistance to cationic antimicrobial peptides, and immune stimulation. There is evidence that bacteria can modulate the level of d-alanyl esters on LTA in response to challenge, but the mechanism of regulation appears to be different among bacteria. In this study, expression of the dlt operon responsible for d-alanylation of LTA was examined in the commensal bacterium Streptococcus gordonii. dlt expression was assessed using the dlt promoter–lacZ reporter gene assay, LTA d-alanine content measurements and dlt mRNA quantification. The results showed that dlt expression was growth phase-dependent, with the greatest expression at the mid-exponential phase of growth. In contrast to Staphylococcus aureus, dlt expression in Strep. gordonii was not affected by the exogenous addition of Mg2+ or K+. Interestingly, dlt expression was upregulated under acidic conditions or when cells were stressed with polymyxin B, indicating that cell envelope stress may be a signal for dlt expression. In view of these results, mutants defective in the cell envelope stress LiaSR two-component regulatory system were constructed. The liaS and liaR mutants showed an increase in dlt expression over the parent strain at neutral pH. The mutants failed to respond to low pH and polymyxin B stress; dlt expression remained the same in the presence or absence of these stresses. These results suggest that dlt expression in Strep. gordonii is regulated by the LiaSR regulatory system in response to environmental signals such as pH and polymyxin B. The regulation appears to be complex, involving both repression and activation mechanisms.
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Lagos, Vanessa, Mike R. Bedford, and Hans H. Stein. "61 Effects of Reducing the Concentration of Ca and P and Increasing Microbial Phytase on Gastric Ph, Fecal Score, Growth Performance, and Bone Ash of Weanling Pigs." Journal of Animal Science 99, Supplement_1 (May 1, 2021): 44–45. http://dx.doi.org/10.1093/jas/skab054.077.
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Abstract An experiment was conducted to test the hypothesis that lowering dietary Ca and P reduces gastric pH and diarrhea of weanling pigs, but microbial phytase overcomes negative effects of low Ca and P on growth performance and bone ash. A total of 320 weanling pigs (6.35 ± 0.87 kg) were allotted to 8 corn-soybean meal-based diets in a randomized complete block design with 5 pigs/pen. Two phase 1 (d 1 to 14) control diets contained 100 or 50% of total Ca and digestible P relative to the requirement, and 6 diets in which 500, 2,000, or 16,000 units/kg of phytase was added to each control diet were formulated. Common diets were fed in phases 2 (d 15 to 27) and 3 (d 28 to 42). Fecal scores were recorded in phase 1 and growth performance data were recorded within each phase. Gastric pH was measured in 1 pig/pen on d 14; on d 14 and 42, the right femur of 1 pig/pen was collected. Data were analyzed using contrast statements in SAS. Results indicated that during phase 1, lowering Ca and P did not reduce gastric pH or fecal score, but the 50%-diets reduced (P < 0.05) average daily gain and average daily feed intake of pigs compared with the 100%-diets (Table 1). Phytase above 500 units/kg increased (P < 0.05) gain:feed ratio and tended (P < 0.10) to decrease gastric pH. Pigs fed the 50%-diets had reduced (P < 0.05) bone ash at d 14 and 42 compared with pigs fed the 100%-diets regardless of phytase inclusion level. In conclusion, reducing Ca and P in diets for weanling pigs does not decrease gastric pH or fecal score, but compromises growth performance and bone mineralization. However, super-dosing of phytase increases G:F of pigs regardless of dietary Ca and P concentration.
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Wang, Hongchun, Bing Zhang, Liyao Dong, and Yuanlai Lou. "Seed Germination Ecology of Catchweed Bedstraw (Galium aparine)." Weed Science 64, no. 4 (December 2016): 634–41. http://dx.doi.org/10.1614/ws-d-15-00129.1.
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The influence of temperature, light, solution pH, water stress, salt stress, and burial depth on seed germination and seedling emergence of catchweed bedstraw and the sensitivity of that weed to commonly available herbicides in China were studied in laboratory and greenhouse. Germination occurred at day/night temperatures from 5/0 C to 30/25 C, with optimum germination at 15/10 C. Catchweed bedstraw germinated equally well under a 12-h photoperiod and continuous darkness; however, a 24-h photoperiod inhibited seed germination. Catchweed bedstraw seed is moderately sensitive to osmotic potential and salt stress, with 15 and 3% germination rates at an osmotic potential of −0.5 Mpa and salinity level of 120 mM, respectively. Maximum seed germination was observed in near neutral pH; germination was greater than 80% over a broad pH range from 5 to 8. Seedling emergence of the seeds buried at a depth of 1 cm was higher (74%) than those placed on the soil surface (20%), but declined with burial depth increasing. Few (10%) seedlings emerged when seeds were placed at a depth of 5 cm. Bensulfuron-methyl, and ethametsulfuron-methyl applied PRE and tribenuron-methyl, fluroxypyr, and florasulam applied POST can be used to provide greater than 80% control of catchweed bedstraw. The results of this study have contributed to more complete understanding of the germination and emergence of catchweed bedstraw.
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Liu, Chun Shuang, Ai Jie Wang, and Chao Cheng Zhao. "Innovative Integrated Reactor System for Carbon, Sulfur and Nitrogen Removal Based on Biological Phase-Separation." Advanced Materials Research 518-523 (May 2012): 2547–52. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.2547.
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An innovative biological wastewater treatment system for the removal of organic carbon, sulfur and nitrogen was developed based on biological phase-separation principle. This system consists of three reactors integrated together i.e. sulfate reduction and organic matter removal (SR-CR), autotrophic and heterotrophic denitrifying sulfide removal (A&H-DSR) and nitrification (AN) reactors. In this system, the operational parameters for successful bio-phase separation are sulfate and organic loading rate, hydraulic retention time (HRT), COD/SO42-ratio and pH for the SR-CR reactor, and sulfide and nitrate loading rate, HRT, pH, S2-/NO3-ratio and COD/NO3-for the A&H-DSR reactor. The results from a laboratory scale system demonstrated that for the SR-CR reactor, the optimal operating conditions were HRT≥24 h; sulfate and organic loading rate ≤7.5 kg SO42-/m3•d and ≤10 kgCOD/m3•d; COD/SO42-≥2; and pH ≥6.5. For A&H-DSR process, the optimal conditions are sulfide loading rate ≤6.0kg S2-/m3•d; nitrate loading rate ≤3.5 kg NO3-/m3•d; S2-/NO3-≥1; COD/NO3-≥1.25:1; and pH≥7.5. Under such conditions, high sulfate, ammonia and organic matter removal of 99%, 90% and 99% were achieved, respectively. In this case, the elemental sulfur (S0) reclamation efficiency reached 6.0 kg S0/m3•d, around 20 times higher than the maximum level as referred in the literatures. DGGE profiling indicated that the predominant functional organisms of Clostridiaceae sp., Desulfomicrobium sp., Methanosaeta sp. dominated in the SR-CR reactor, and Sulfurovum sp., Pseudomonas aeruginosa and Denitratisoma sp. in the A&H-DSR reactor. These species played essential role in metabolic functions in each bio-phase.
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Tran Thi Thuy, Tien, Krishnan Kannoorpatti, Anna Padovan, and Suresh Thennadil. "Effect of Alkaline Artificial Seawater Environment on the Corrosion Behaviour of Duplex Stainless Steel 2205." Applied Sciences 10, no. 15 (July 22, 2020): 5043. http://dx.doi.org/10.3390/app10155043.
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Sulphate reducing bacteria (SRB) can be found in alkaline environments. Due to their metabolite products such as hydrogen sulphide, the corrosion behaviour of materials in alkaline environments may be affected by the presence of SRB. This study focuses on the investigation of corrosion behaviour of duplex stainless steel DSS 2205 in nutrient rich artificial seawater containing SRB species, Desulfovibrio vulgaris, at different alkaline conditions with pH range from 7 to 10. The open circuit potential value (OCP), sulphide level and pH were recorded daily. Confocal laser scanning microscopy (CLSM) was used to study the adhesion of SRB on the DSS 2205 surface. Electrochemical impedance spectroscopy (EIS) was used to study the properties of the biofilm. Potentiodynamic polarization was used to study the corrosion behaviour of material. Inductively coupled plasma mass was used to measure the concentration of cations Fe, Ni, Mo, Mn in the experimental solution after 28 days. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used for surface analysis. The results showed that D. vulgaris are active in an alkaline environment with pH 7–9. However, at pH 10, D. vulgaris activity exhibited an 8-day lag. The corrosion rate of DSS 2205 at pH 9 was higher than at other pH environments due to a higher dissolved concentration of hydrogen sulphide.
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Mu, J., F. Jin, J. Wang, N. Zheng, and Y. Cong. "Effects of CO<sub>2</sub>-driven ocean acidification on early life stages of marine medaka (<i>Oryzias melastigma</i>)." Biogeosciences Discussions 12, no. 1 (January 5, 2015): 1–20. http://dx.doi.org/10.5194/bgd-12-1-2015.
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Abstract. The potential effects of elevated CO2 level and reduced carbonate saturation state in marine environment on fishes and other non-calcified organisms are still poorly known. In present study, we investigated the effects of ocean acidification on embryogenesis and organogenesis of newly hatched larvae of marine medaka (Oryzias melastigma) after 21 d exposure of eggs to different artificially acidified seawater (pH 7.6 and 7.2, respectively), and compared with those in control group (pH 8.2). Results showed that CO2-driven seawater acidification (pH 7.6 and 7.2) had no detectable effect on hatching time, hatching rate, and heart rate of embryos. However, the deformity rate of larvae in pH 7.2 treatment was significantly higher than that in control treatment. The left and right sagitta areas did not differ significantly from each other in each treatment. However, the mean sagitta area of larvae in pH 7.6 treatment was significantly smaller than that in the control (p = 0.024). These results suggest that although marine medaka might be more tolerant of elevated CO2 than some other fishes, the effect of elevated CO2 level on the calcification of otolith is likely to be the most susceptibly physiological process of pH regulation in early life stage of marine medaka.
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Lin, Xiajing, Zhongyong Gou, Yibing Wang, Long Li, Qiuli Fan, Fayuan Ding, Chuntian Zheng, and Shouqun Jiang. "Effects of Dietary Iron Level on Growth Performance, Immune Organ Indices and Meat Quality in Chinese Yellow Broilers." Animals 10, no. 4 (April 12, 2020): 670. http://dx.doi.org/10.3390/ani10040670.
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The objective of three trials was to investigate the effects of dietary Fe on growth performance, immune organ indices and meat quality of Chinese yellow broilers during the whole growth period. A total of 1440 1-day-old, 1440 22-day-old, and 1080 43-day-old Lingnan yellow male broilers were randomly assigned to one of six dietary treatments with six replicates per treatment (40 birds per replicate for both 1 to 21 d and 22 to 42 d, 30 birds for 43 to 63 d). Additional Fe (0, 20, 40, 60, 80, and 100 mg/kg) was added as FeSO4 • H2O to the three basal diets (calculated Fe 50 mg/kg, analyzed 48.3, 49.1, 48.7 mg/kg, respectively). The calculated final dietary Fe concentrations in Starter, Grower and Finisher phases were 50, 70, 90, 110, 130, and 150 mg/kg. The results showed that average daily gain (ADG), average daily feed intake (ADFI) and feed conversion rate (FCR) of the broilers were not influenced by the different levels of Fe (p> 0.05). Weight indices of the spleen, thymus and bursa of Fabricius were not influenced (p > 0.05) by the different levels of Fe during three 21-day experimental periods. Hematocrit, and Fe contents of the liver and kidney were not affected by different levels of Fe (p> 0.05). The diet with 150 mg/kg of Fe increased the a* (relative redness) value of breast muscle compared to the 50 and 70 mg/kg diets at 24 h post mortem (p< 0.05). The diet with 90 mg/kg Fe increased the pH of breast muscle compared to broilers fed 50 or 150 mg/kg Fe (p < 0.05) 45 min after slaughter. The diet with 90 mg/kg Fe decreased drip loss of breast muscle compared to 150 mg/kg Fe (p< 0.05). These data suggest that feeding yellow-feathered broilers on a conventional corn-soy based diet satisfies their requirements without additional Fe at ages 1 to 21, and 22 to 42 d, while 90 mg/kg in the finisher phase improved meat quality, and from the QP (quadratic polynomial) models of the key meat quality variables, pH of breast muscle and drip loss of breast muscle, the optimal dietary Fe level was 89 to 108 mg/kg, and daily Fe fed allowance was 11 to 13 mg in the finisher phase (43 to 63 d).
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Paleari, R., C. Arcelloni, R. Paroni, I. Fermo, and A. Mosca. "Chromatofocusing and isoelectric focusing in immobilized pH gradients compared for characterization of human hemoglobin variants." Clinical Chemistry 35, no. 3 (March 1, 1989): 425–30. http://dx.doi.org/10.1093/clinchem/35.3.425.
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Abstract We compared the performance of two highly resolving methods, chromatofocusing (CRF) and isoelectric focusing in immobilized pH gradients (IPGF), for the separation of human hemoglobin variants. Lysates containing 13 different hemoglobins, including variants of clinical and geographical importance, and four electrophoretically "silent" variants (Hb Brockton, Hb Cheverly, Hb Köln, and Hb Waco) were analyzed. Both techniques showed a good intrarun precision (CV = 0.87% for CRF, 0.27% for IPGF) and high and similar resolving power (0.010 pH units, with the pH gradients used in this work). The use of an ultranarrow IPGF range (pH 7.15-7.35; pH gradient = 0.019 pH/cm) allowed the resolution between Hb Brockton, Hb Köln, and Hb A. In some cases (Hb D-Los Angeles, Hb F, Hb Waco), the variants were separated from Hb A in different orders, depending on which technique was used, probably because of the different analytical principles of the two methods. As a second-level test, both procedures are informative for characterization of human hemoglobin variants.
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García, Jousy, Juan Carlos González, María Inés Frascaroli, Silvia García, Patricia Blanes, Isabel Correia, João Costa Pessoa, and Luis F. Sala. "Spectroscopic studies of vanadium biosorption on different types of carbohydrate biomass." Canadian Journal of Chemistry 91, no. 3 (March 2013): 186–95. http://dx.doi.org/10.1139/cjc-2012-0208.
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The biosorption potential of different types of carbohydrate biomass is investigated to evaluate their application to purify water contaminated by vanadium in environmentally relevant oxidation states (VIV and VV). Spectroscopic studies were done by electron paramagnetic resonance (EPR), vanadium nuclear magnetic resonance (51V NMR), circular dichroism (CD), and electronic absorption in the visible range (vis). Both d-galacturonic and d-glucuronic acids are major components of plant cellular wall polysaccharides. The interaction of VIV with the model ligands d-galacturonic and d-glucuronic acids showed that complexation starts at low pH values (pH 3) and that carboxylate and sugar–OH groups, as well as water molecules, are involved in the coordination. At pH > 4.5, coordination promotes the sugar–OH deprotonation and new species form with the ligand chelating the metal ion via oxygen atoms of carboxylate and of adjacent sugar–O− donors. The studies with pectin and citric acid show the ability of both compounds to partially reduce VV to VIV in solution and the EPR parameters suggest coordination of carboxylate, sugar–OH, and water molecules. The interaction of VV with biomass from different sources shows that grapefruit, orange peel, and plane tree fruit are the most suitable candidates for the biosorption of vanadium. Studies with VV and grapefruit (or the grainless stalk of corn) indicate that the reduction takes place at the “surface” of the solid. EPR studies on the interaction of VIV with different carbohydrate biomass show their ability to complex high amounts of VIV. We propose that the biosorption mechanism, when the biomass is in contact with VV species, involves sorption, reduction, and retention at the surface level of VIV coordinated by oxygen donors of the biomass. When the interaction starts with VIV, the main process just involves the uptake of the metal ion at the surface level.
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Zhao, Jian Hui, Ning Li, and Yong Feng Li. "Improvement of Organic Loading Rate on Hydrogen Production Using Continuous Stirred Tank." Advanced Materials Research 805-806 (September 2013): 1382–86. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.1382.
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The influence of organic loading rates (OLRs) on the production of fermentation hydrogen was investigated in a continuous stirred tank reactor (CSTR) with brown sugar water as the fermentation substrate, and sewage sludge as the initiation of reaction. Six OLRs were examined, ranging from 12 kg/m3·d to 32 kg/m3·d. The biogas and hydrogen production rates continuously increased with increasing OLR (12 kg/m3·d to 32 kg/m3·d).It reached a maximum production rate of 18.6L/d and a hydrogen production rate of 6.4L/d at OLR= 32 kg/m3·d. Compared with the initial 12kg/m3·d, gas production improved by 89% and 87%, respectively. During system operation, the reactor could maintain a high hydrogen production rate of ethanol-type fermentation by adding a certain amount of NaOH in the reactor to regulate the pH level.
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Bradford, David F., Christina Swanson, and Malcolm S. Gordon. "Effects of low pH and aluminum on amphibians at high elevation in the Sierra Nevada, California." Canadian Journal of Zoology 72, no. 7 (July 1, 1994): 1272–79. http://dx.doi.org/10.1139/z94-169.
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At high elevation in the Sierra Nevada of California, surface waters are extremely low in acid-neutralizing capacity and thus may be vulnerable to changes in water chemistry due to acid deposition. The present study assesses the sensitivity of embryos and hatchling larvae of two Sierran amphibians, Pseudacris regilla (Pacific chorus frog) and Ambystoma macrodactylum (long-toed salamander), to low pH and an elevated level of dissolved aluminum. The populations of these two species are not known to be declining at present. These findings are compared with results for two other Sierran amphibians, Rana muscosa (mountain yellow-legged frog) and Bufo canorus (Yosemite toad), both of which reportedly have declined substantially in numbers in recent years. Embryos and hatchlings of P. regilla and A. macrodactylum were kept for 7 d in reconstituted soft water at pH 4.0–6.0 (inorganic monomeric aluminum effectively 0 or 39–80 μg/L at pH ≥ 4.9), and subsequently for a post-treatment period of up to 16 d in reconstituted soft water at pH 6.0 (no aluminum). LC50 pH values for post-treatment survival averaged 4.3 for embryos and tadpoles of both species. The estimated extreme pH for Sierra Nevada surface water, 5.0, did not cause a significant reduction in survival for either life stage of either species, and sublethal effects on body size and hatching time were not evident at pH ≥ 5.0. Aluminum also did not affect survival of either species, although sublethal effects were evident as reduced body size of A. macrodactylum larvae and earlier hatching in P. regilla. Pseudacris regilla and A. macrodactylum were not consistently more tolerant of low pH than R. muscosa and B. canorus. However, the latter two species show sublethal effects of low pH at pH ≥ 5.0, whereas the former two do not.
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Ntougias, Spyridon, Constantinos Fasseas, and Georgios I. Zervakis. "Olivibacter sitiensis gen. nov., sp. nov., isolated from alkaline olive-oil mill wastes in the region of Sitia, Crete." International Journal of Systematic and Evolutionary Microbiology 57, no. 2 (February 1, 2007): 398–404. http://dx.doi.org/10.1099/ijs.0.64561-0.
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A novel, Gram-negative, non-motile, non-sporulating, rod-shaped bacterium isolated from a viscous two-phase olive-oil mill waste (‘alpeorujo’) is described. The strain, designated AW-6T, is an obligate aerobe, forming irregular, pigmented creamy white colonies. The pH and temperature ranges for growth were pH 5–8 and 5–45 °C, with optimal pH and temperature for growth of pH 6–7 and 28–32 °C, respectively. Strain AW-6T was chemo-organotrophic and utilized mostly d(+)-glucose, protocatechuate and d(+)-xylose, followed by l-cysteine, d(−)-fructose, d(+)-galactose, l-histidine, lactose, sorbitol and sucrose. Menaquinone-7 was detected in the respiratory chain of strain AW-6T. The major fatty acids of strain AW-6T were C16 : 1 ω7c and/or iso-C15 : 0 2-OH, iso-C15 : 0, iso-C17 : 0 3-OH and C16 : 0. The closest phylogenetic relative of strain AW-6T was clone BIti35 (89.7 % 16S rRNA gene sequence similarity), while Sphingobacterium thalpophilum DSM 11723T was the closest recognized relative within the Sphingobacteriaceae (88.2 % similarity). Strain AW-6T showed a low level of DNA–DNA relatedness to S. thalpophilum DSM 11723T (33.8–37.0 %). The DNA G+C content of strain AW-6T was 45.6 mol%. Physiological and chemotaxonomic data further confirmed the distinctiveness of strain AW-6T from members of the genera Sphingobacterium and Pedobacter. Thus, strain AW-6T is considered to represent a novel species of a new genus within the family Sphingobacteriaceae, for which the name Olivibacter sitiensis gen. nov., sp. nov. is proposed. The type strain is AW-6T (=DSM 17696T=CECT 7133T).
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MAIJALA, RIITTA L., SUSANNA H. EEROLA, MATTI A. AHO, and JORMA A. HIRN. "The Effect of GDL-induced pH Decrease on the Formation of Biogenic Amines in Meat." Journal of Food Protection 56, no. 2 (February 1, 1993): 125–29. http://dx.doi.org/10.4315/0362-028x-56.2.125.
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The effect of pH on the formation of biogenic amines has mainly been studied in broths in which pH has been fixed before incubation. However, in the fermentation of dry sausage, pH quite rapidly decreases from the initial value to a certain level. In this study glucono-delta-lactone (GDL) was used to decrease pH in meat, Six minced meat samples were each divided into three portions (A–C): 0% (A), 0.5% (B), or 1.0% (C) of GDL was added and the samples were incubated at 20–22°C for 7 d. The amounts of biogenic amines (histamine, tyramine, putrescine, cadaverine, phenylethylamine, tryptamine, spermine, and spermidine) as well as pH, water activity, and the bacterial counts of lactic acid bacteria, fecal streptococci, coliforms, and total plate count were measured. Addition of GDL resulted in a significant decrease in pH and in the levels of histamine and putrescine as well as in the levels of fecal streptococci, coliforms, and total plate counts. Of 87 fecal streptococci, seven Enterococcus faecalis strains produced tyramine. All the coliforms and related strains isolated from violet red bile agar produced tyramine, putrescine, and cadaverine on agar plates. However, the proportion of histamine-positive strains of these strains, especially Hafnia alvei, increased from 0 to 57% during the incubation. The rate and level of pH decrease clearly affected amine formation in meat, indicating that the levels of, e.g., histamine produced could be decreased by optimizing the pH decrease during fermentation. Addition of GDL facilitates study of the effect of pH decrease without interactions between the starter culture and contaminant flora.
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Kirwan, Stuart, Tommy Boland, Eleonora Serra, Gaurav Rajauria, and Karina Pierce. "413 Effect of chitosan inclusion and dietary crude protein level on rumen fermentation in beef heifers fed a total mixed ration." Journal of Animal Science 97, Supplement_3 (December 2019): 166–67. http://dx.doi.org/10.1093/jas/skz258.343.
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Abstract Chitosan (N-acetyl-D-glucosamine polymer) is a natural biopolymer, which is the second most abundant organic compound on earth, found in lower plants and some arthropods and crustaceans. Studies with ruminants have shown that supplementing with chitosan can alter ruminal fermentation, including higher propionate concentration and lower acetate to propionate ratio, improving the energy efficiency within the rumen though data on nitrogen metabolism is lacking. Therefore, the objective of this study was to evaluate the effects of chitosan with different dietary crude protein (CP) inclusion on rumen fermentation in beef heifers. Eight ruminally cannulated Belgian Blue x Holstein Friesian heifers (752 ± 52Kg BW) were allocated one of four dietary treatments in a 2 x 2 factorial Latin Square design (n = 8). Diets were offered as total mixed ration (TMR) consisting of grass silage plus concentrate. Diets were offered once daily ad libitum. Dietary treatments were as follows: high CP (16%) +/- chitosan (10g kg-1 DMI) supplementation (HP+) or (HP-) and low CP (12%) +/- chitosan supplementation (LP+) or (LP-). Experimental periods were 25d in duration (14 d dietary adaptation and 10 d sampling). Rumen fluid was collected via cannula every 2 h post feeding for analysis of ruminal pH, ammonia (NH3) and volatile fatty acids (VFA) over a 48-hour period. Data was analysed using Proc Mixed procedure in SAS. Significant differences were considered when P < 0.05. Dietary treatment had no effect on ruminal pH (P > 0.05). Chitosan supplementation had no effect on ruminal NH3 and VFA concentrations (P > 0.05), whereas, animals offered 16% CP had higher concentrations of ruminal NH3 (P < 0.001). In conclusion, supplementing a TMR diet fed to beef heifers with chitosan had no effect on rumen fermentation. However, reducing dietary CP concentration fed to beef animals resulted in lower rumen NH3 concentrations.
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Barton, Bruce A., Gary S. Weirter, and Cars B. Schreck. "Effect of Prior Acid Exposure on Physiological Responses of Juvenile Rainbow Trout (Salmo gairdneri) to Acute Handling Stress." Canadian Journal of Fisheries and Aquatic Sciences 42, no. 4 (April 1, 1985): 710–17. http://dx.doi.org/10.1139/f85-091.
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Acid-stressed fish appear to be more sensitive to additional stressors than unstressed fish. When juvenile rainbow trout, Salmo gairdneri, were exposed to acid conditions (pH 5.7–4.7) for 5 d, plasma cortisol was affected only slightly during the initial hours of exposure, but plasma glucose and hematocrit increased, and plasma sodium decreased. However, when fish held at pH 4.7 were subsequently subjected to a 30-s handling stress, poststress plasma cortisol rose to a peak level of more than twice that in handled fish held at ambient pH (6.6). Effects of handling on plasma glucose or sodium were not apparent against levels already altered by the chronic acid exposure, judging by the corticosteroid response, we conclude that the acid-stressed fish were more sensitive to additional handling, even though they appeared to be physiologically normal after 5 d. Thus, as a management consideration, when fish are stocked in acidified waters, care should be taken to avoid situations where the fish may encounter additional disturbances in the new environment. Plasma glucose and sodium were better indicators of chronic acid stress alone than plasma cortisol, but the greater cortisol response to handling at low pH may be a useful method of detecting increased interrenal activity during early stages of environmental acidification.
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Cooper, Helen L., Donald C. Potts, and Adina Paytan. "Effects of elevated pCO2 on the survival, growth, and moulting of the Pacific krill species, Euphausia pacifica." ICES Journal of Marine Science 74, no. 4 (March 7, 2016): 1005–12. http://dx.doi.org/10.1093/icesjms/fsw021.
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While ocean acidification (OA) is expected to have wide-ranging negative effects on marine species, organisms currently living in variable pH environments that expose them intermittently to pH values approaching those predicted for the future, may be better adapted to tolerate prolonged exposure to high pCO2 levels caused by OA. Seasonal upwelling brings low pH water to the surface along the Pacific Coast of North America. In Monterey Bay, California Euphausia pacifica, a key species supporting a diverse multi-trophic-level ecosystem, currently experiences broad pCO2 and pH ranges due to both diel vertical migrations and seasonal upwelling. We determined tolerances of E. pacifica to prolonged exposure to pH levels predicted for 2100 by maintaining adults at two pCO2 levels (380 and 1200 µatm) for 2 months. Rates of survival and moulting were the same at both pCO2 levels. High pCO2 slowed growth in all size classes. In additional experiments to determine pCO2 threshold levels above which E. pacifica is adversely affected, survival was not affected down to pH 6.96 (6050 µatm), but declined rapidly at pH 6.92 (7228 µatm) and lower, with 100% mortality within 10 d at pH 6.89.
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Nimir, Hassan I., Ahmed Hamza, and Ibnelwaleed A. Hussein. "Development of Greener D-Metal Inorganic Crosslinkers for Polymeric Gels Used in Water Control in Oil and Gas Applications." Energies 13, no. 16 (August 18, 2020): 4262. http://dx.doi.org/10.3390/en13164262.
Full textAbstract:
Crosslinkable polymers, such as polyacrylamide (PAM), are widely applied for water control in oil and gas reservoirs. Organic and inorganic crosslinkers are used to formulate a gel with PAM. Although chromium has a high level of toxicity, it has been implemented as an effective crosslinker combined with carboxylates because of the controllability of crosslinking time at low temperatures. The objective of this work was to develop greener d-metal inorganic crosslinkers based on cobalt, copper, and nickel to replace chromium for application at reservoir conditions. The obtained results showed that the gelation chemistry of the developed systems depends on the metal charge density. The gelation of PAM with d-metals depends on pH and temperature for low- and high-charge density, respectively. Cobalt (II) acetate (CoAc) was effective at high temperatures (130–150 °C) and forms (4% CoAc + 9%PAM) stable, and strong gels at a pH > 7 with a storage modulus exceeding 4300 Pa. However, Nickel Acetate and Cupper Acetate formed stable weak gels at low temperatures (50–70 °C) and a pH > 6 and gel decomposition was observed upon increasing the temperature. The developed formulations were compatible with low-salinity water (1000 ppm NaCl).
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WHITEFORD, Craig C., Christie BEST, Andrius KAZLAUSKAS, and Emin T. ULUG. "D-3 phosphoinositide metabolism in cells treated with platelet-derived growth factor." Biochemical Journal 319, no. 3 (November 1, 1996): 851–60. http://dx.doi.org/10.1042/bj3190851.
Full textAbstract:
Despite extensive analysis of phosphoinositide 3-hydroxykinases (PI 3-kinases) at the molecular level, comparatively little is known about the mechanisms by which products of these enzymes exert their expected second-messenger functions. This study examines the metabolism of D-3 phosphoinositides in mouse Ph-N2 fibroblasts lacking the platelet-derived growth factor (PDGF) α-receptor. Treatment of these cultures with BB PDGF, but not AA PDGF, resulted in transient activation of PI 3-kinase activity measured in vitro. Treatment of myo-[3H]inositol-labelled Ph-N2 cells with BB PDGF resulted in the rapid induction of PtdIns(3,4)P2 and PtdIns(3,4,5)P3 and, to a smaller extent, PtdIns3P. The appearance of PtdIns(3,4,5)P3 preceded that of PtdIns(3,4)P2 and PtdIns3P after the addition of PDGF, suggesting that PtdIns(4,5)P2 is the preferred substrate of the agonist-stimulated PI 3-kinase in intact cells. Treatment of both resting and PDGF-stimulated cells with the fungal metabolite wortmannin resulted in pronounced, selective effects on the levels of all D-3 phosphoinositides. Kinetic studies with this PI 3-kinase inhibitor revealed the presence of at least two independent routes for the biosynthesis of D-3 phosphoinositides in PDGF-treated cells.