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1
Brawn, Kristin E. (Togue). "An Examination of the Georges River Clam Management Program." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/BrawnKE2002.pdf.
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Spillman, Claire. "A modelling assessment of hydrodynamics and biogeochemistry of the northern Adriatic Sea, and effects on clam dynamics in Barbamarco Lagoon, Italy /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2008.0002.
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Schlechte, John Warren. "Stage-structured analysis and modeling of the Pacific razor clam (Siliqua patula) in a changing environment : investigation of population dynamics and harvest strategies using process models and simulation /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/5277.
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Allsopp, Janet. "'Oocyte maturation in the Manila clam, Tapes philippinarum'." Thesis, Bangor University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357212.
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Strasser, Carly Ann. "Metapopulation dynamics of the softshell clam, Mya arenaria." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43818.
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Thesis (Ph. D.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2008.Includes bibliographical references.
In this dissertation, I explored metapopulation dynamics and population connectivity, with a focus on the softshell clam, Mya arenaria. I first worked towards developing a method for using elemental signatures retained in the larval shell as a tag of natal habitat. I designed and implemented an experiment to determine whether existing methods commonly used for fishes would be applicable to bivalves. I found that the instrumentation and setup I used were not able to isolate and measure the first larval shell of M. arenaria. In concert with developing this method for bivalves, I reared larval M. arenaria in the laboratory under controlled conditions to understand the environmental and biological factors that may influence elemental signatures in shell. My results show that growth rate and age have significant effects on juvenile shell composition, and that temperature and salinity affect larval and juvenile shell composition in variable ways depending on the element evaluated. I also examined the regional patterns of diversity over the current distribution of M. arenaria using the mitochondrial gene, cytochrome oxidase I (COI). I found minimal variability across all populations sampled, suggesting a recent population expansion in the Northwest Atlantic. Finally, I employed theoretical approaches to understand patch dynamics in a two-patch metapopulation when one patch is of high quality and the other low quality. I developed a matrix metapopulation model and compared growth rate elasticity to patch parameters under variable migration scenarios. I then expanded the model to include stochastic disturbance. I found that in many cases, the spatial distribution of individuals within the metapopulation affects whether growth rate is most elastic to parameters in the good or bad patch.
by Carly A. Strasser.
Ph.D.
6
Ivil, Kenneth Douglas. "The genetic basis of carcinogenesis in the clam enterocystoplasty." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1444303/.
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The incidence of carcinoma following enterocystoplasty increases with time and there is an urgent requirement to develop techniques that can identify patients who will develop a life-threatening tumour. Endoscopic biopsies were taken from the ileovesical anastomosis and native bladder remnant (control specimens) of patients who had undergone a clam ileocystoplasty. Fluorescence in-situ hybridisation (FISH), using centromeric probes for chromosomes 8, 9 and 18, was performed on touch sample preparations from biopsies obtained from fifteen patients. Significant aneuploid changes were found at the ileovesical anastomosis in all cases. Chromosome 18 aneuploidy was present in thirteen patients and may prove to be a useful marker of anastomotic instability. FISH was also used to study tissue from a squamous cell clam cancer and demonstrated a large number of polyploid cells (twenty-three percent). A 'silent' p53 point mutation was identified at codon 192 by sequencing deoxyribonucleic acid (DNA) from this tumour. The restriction site mutation (RSM) assay was used to identify rare p53 mutations in DNA extracted from biopsies obtained from thirty-eight patients. The RSM assay studied five known hotspots for mutations of the p53 gene using the restriction enzymes Hha 1 (codon 175), Taq I (codon 213), Hae III (codon 249/250) and Msp I (codons 148 and 282). Early p53 mutations were found at the ileovesical anastomosis at codon 213 (one patient), codon 248 (three patients) and codon 250 (three patients). The mutations were characterised by sequencing the undigested, mutated polymerase chain reaction products obtained by RSM analysis. The anastomosis of patients who have undergone a clam ileocystoplasty is inherently genetically unstable and therefore prone to cancer formation. Both FISH and the RSM assay show promise as screening techniques and may prove to be useful in identifying those patients most at risk of developing a life-threatening tumour.
7
Basheer, Paliakarakadu Assen Muhammed. "#Clam' permeability tests for assessing the durability of concrete." Thesis, Queen's University Belfast, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296792.
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Libelo, Edward Laurence. "Characterization, utilization and treatment of mechanized clam processing wastes." Thesis, Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/80072.
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In response to water quality deterioration caused by clam processing effluent, the Virginia State Water Control Board is imposing much greater effluent discharge limitations on the industry. Meeting these limits will require increased wastewater treatment and decreasing the water volume of water used and the loading of organic material and suspended solids. Disposal of sludges and solid wastes also present problems to the industry. Three processing plants were studied to characterize the nature, sources and variations in waste generation and to evaluate potential solutions.
Wastewater is generated throughout the processing plants from washing operations, from splashing and overflow of tanks and flumes and from cleanup operations. Wastewater generation varied from plant to plant and at each plant over time, ranging from 80,000 gallons to almost 350,000 gallons per day and as high as 40,000 gallons per hour. The organic loading in wastewater ranged as high as 15,000 mg/L COD and averaged 3000-7000 mg/L. Total suspended solids loading ranged as high as 29,000, and were usually between 1,000 and 10,000 mg/L.
Anaerobic digestion and composting of solid wastes were evaluated by bench scale experiments. Anaerobic digestion can provide reduction in COD of 75% and generate usable biogas. Composting can be used to stabilize sludges and solid wastes with destruction of the organic fraction in seven days.
The proposed 90 mg/L BOD and 90 mg/L TSS limitations are not significantly stricter than the limitations imposed on similar plants in other areas.Master of Science
9
Siegrist, Zachary C. Donovan Deborah Anne. "Broad physiological tolerances of the invasive clam Nuttallia obscurata /." Online version, 2010. http://content.wwu.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=330&CISOBOX=1&REC=6.
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Adams, Alison Elizabeth. "Development and application of the Clam for measuring concrete permability." Thesis, Queen's University Belfast, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235845.
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LaBreche, Timothy Merrick Clark. "Toxicity of Copper to Mercenaria mercenaria (Hard Clam)." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/46181.
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Toxicity of copper to larval Mercenaria mercenaria was evaluated with static non-renewal and continuous renewal methods that permitted daily observation of mortality, activity, development, and metamorphosis without subsampling. Clam larvae, 100 - 150 microns, were held for up to two weeks in small, 30 mm, sealed petri plates during static assays with excellent survival of control organisms, low evaporative losses, and relatively low between replicate variability. An eight day LC50 of 12 micrograms / liter for six day old organisms was determined as well as EC50s (active swimming). EC50s at 24 hours were as much as much as seven times lower than LC50s after 24 hours of exposure. Flow - through assays were conducted with a modified petri dish design. Two sections from opposing sides of a 30 mm petri dish were removed and covered with 35 micron polyester screening. This dish (organism dish) was placed in an outer catch dish that captured the effluent toxin as it passed through the screening and routed it to a catch bottle for water quality analysis. The toxicant feed line entered through the catch dish cover and slowly dripped toxin into the organism dish. Water quality in the flow - through assay remained excellent. Survival of control organisms in the flow - through assay was lower than in static assays, but metamorphosis was not delayed as had been observed in static assays. Data variability was low enough that statistical distinctions were made between the effects of copper on metamorphosis. A non-standard "M" shaped survival response was observed in all assays. The responses generating the "M" shaped response in the static petri assay were statistically different from each other. Activity, as judged by swimming, in organisms was not observed to follow the "M" shaped pattern. Instead, it decreased exponentially with increasing copper concentrations. Static experiments with unfed clams, observations of activity, and data from experiments in copper accumulation by algae led to a theory relating the unusual dose response to food consumption and its relationship to the effective dose of copper to which the larval clams were exposed.Master of Science
12
Leal, Ana Maria. "Conditioning of Manila clam broodstock on natural and artificial diets." Thesis, Bangor University, 1994. https://research.bangor.ac.uk/portal/en/theses/conditioning-of-manila-clam-broodstock-on-natural-and-artificial-diets(0ec43f18-fa32-4d46-9dab-e8e7ea2979ee).html.
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Two trials in 1991 and another two in 1992 were carried out on the broodstock conditioning of Manila clams, Tapes philippinarum. The main objective was to manipulate the lipid and polyunsaturated fatty acid content of Manila clam eggs by maintaining broodstock in different dietary regimes. The second objective was to assess dried algae as alternative diets for conditioning broodstock. Clams were brought into the laboratory from the natural environment early in the year, before gametogenesis had started. Supplements of cultured live (Dunaliella tertiolecta, Skeletonema costatum, Tetraselmis suecica and Isochrysis galbana) and dried algae (T. suecica) diets were fed to the broodstock, usually in a range of mixed diets, at rations equivalent to 3% or 6% of the initial dry meat weight of the broodstock in dry weight of algae per day. The microalgae differed in their long-chain polyunsaturated fatty acid content (PUFA). Unfed control clams received only the organic material which remained in the sea water after sand filtration. The nutritional value of these diets in relation to gametogenesis, fecundity, quality of eggs, and viability and growth of larvae were assessed. Dry T. suecica was the same food value as live T. suecica but Manila clams produced more eggs if supplements of live algae were added. The requirement for conditioning Manila clams (32 mm shell length) to spawn with live or dry T. suecica+S. costatum was 500 to 700 "day-degrees" (D°). With dry T. suecica on its own or mixed with I. galbana, S. costatum and D. tertiolecta it was 500 to 600 Do (44 mm shell length). In one trial clams spawned in the tanks (equivalent to 462 Do) before the first attempt to spawn them was made. Successful spawning was dependent on the quantity and quality of the algal diet during gametogenesis. With a 6% food ration, clams fed dry T. suecica+S. costatum or dry T. suecica+l. galbana produced the highest number of eggs (an average of 3.2 and 4.5 million eggs per female, respectively). The average fecundity was 83% lower when the diet was reduced to a 3% food ration. The dry meat weight, condition index and fecundity of fed broodstock were significantly higher than for unfed animals. The quantity of lipid in the eggs, usually between 4 and 9 ng egg-1, was similar whatever the broodstock diet. However, levels of the essential polyunsaturated fatty acids 20: 5w3 and 22: 6w3 in the eggs were low if the broodstock diet was deficient in these PUFAs. Even though diet manipulation caused changes in the fatty acid composition of the eggs, growth and survival of Manila clam larvae was not reduced in a hatchery situation.
13
Kizhakudan, Joe K. "Observations on the population characteristics of the Corbiculid clam Villorita cyprinoides (Gray) in the Chitrapuzha portion of the Vembanad lake." Thesis, Central Marine Fisheries Research Institute, 1993. http://eprints.cmfri.org.in/11068/1/Joe%20K.%20Kizhadudan.pdf.
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Fishery products, being excellent animal protein supplements, can be easily availed by all sections of people and have served to meet the nutritional requirements of population since time immemorial. However, the geometric expansion o f the global population and the slow er growth rate of the world's food production leaves a large gap between the nutritional
demands and supply, especially in the developing and under-developed countries. Pressed by growing needs, man is forever venturing forth to explore and exploit all available natural resources, through techniques old and new, and often creates a situation wherein irrational exploitation tends to deplete their availability to an alarming level. Aquatic resources are
no exception to this case. Several stocks of finfish and shellfish in the presently exploited areas have reached the maximum sustainable levels and there is no scope to step up the production further. To compensate this inadequacy, man has now taken up the task of propagating aquaculture with added impetus.
14
Tonini, Federico. "Bioconcentration of selected personal care products in Ruditapes philippinarum (Manila clam)." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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The Bioconcentration Factor (BCF) is the principal source of information used to assess and regulate the potential hazard and risk for a chemical that has the potential to bioaccumulate in the marine environment, according to the Marine Strategy Framework Directive (MSFD). The main objective of this thesis was to estimate the BCFs of two different emerging contaminants in Ruditapes philippinarum (Manila clam) under controlled laboratory conditions: the UV filter 4-methylbenzylidene camphor (4-MBC) commonly used in skincare products, and the artificial sweetener Acesulfame potassium (ACE-K) used as a food additive. Ruditapes philippinarum organisms were exposed directly to 4-MBC and ACE-K nominal concentration of 1, 10 and 100 μg L-1 during 10 days. Bioconcentration factors (BCFs) were estimated according to 3 different models for both compounds. The 4-MBC estimated BCFs fall in range of 61553 - 539143 L Kg-1, showing that this compound is very bioaccumulative and could also undergo biomagnification in the marine food chain. On the contrary, estimated ACE-K BCF is consistently lower, in order of 7 L Kg-1 for the nominal exposure concentration of 100 μg L-1. The low ACE-K BCF could be explained by its high solubility in water and thus a rapid metabolization by clams during the experiments. In summary, future research focusing on the marine environment is needed on these two emerging compounds.
15
Jackson, Jonathan R. Swann David L. "Feasibility of hard clam, Mercenaria mercenaria, culture in Grand Bay, Alabama." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Fisheries_and_Allied_Aquacultures/Thesis/Jackson_Jonathan_49.pdf.
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Bargione, Giada <1991>. "Multidisciplinary approach to manage the striped venus clam (Chamelea gallina) fisheries." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10331/1/Tesi_PhD_Giada_Bargione.pdf.
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To responsively manage the striped venus clam (Chamelea gallina) fisheries, a multidisciplinary approach has been adopted through the investigation of new and updated biological aspects (e.g. age, growth, reproduction, size at first maturity, fecundity) and the interaction gear- target or non-target species (e.g. reburial ability, survival potential and exerted damage). The striped venus clam is an important socio-economic species in the Italian fishery context, highly regulated by national and international laws aiming at guaranteeing both social and ecological sustainability. Studies on growth and reproduction revealed that the size at first maturity is reached within the first year of life, whereas the present Minimum Conservation Reference Size of 22 mm is reached at two year of age. The annual reproductive cycle, which is driven by rises in seawater temperature and chlorophyll-a concentration, spans during the warmer months (late spring-summer) with multiple spawning events of different intensity occurring over the spawning period, and the number of potentially emitted gametes is positively related to shell size. Reburial tests conducted on undamaged specimens highlighted the ability of clams to rebury in the sediment once discarded, independently from the size. On the other hand, survival experiments in the laboratory and at sea, on both damaged and undamaged individuals, served to demonstrate that the species has a high survival rate, thus supporting the claim that discarded individuals can contribute to restock the natural populations. Moreover, the evaluation and quantification of damage induced by dredging on the discarded macro-benthic fauna living associated with C. gallina highlighted that soft-shelled or soft-bodied species are the most affected by the fishing process and subjected to a higher mortality. All these findings are of pivotal importance to rationally support the management measures to be adopted in the striped venus clam fishery.
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Tisinger, Jessi Lind. "Treatment of clam-processing wastewater using upflow anaerobic sludge blanket (UASB) technology." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10242009-020256/.
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Bollini, Mario Attilio. "The design of scaled robotic end effectors to mimic razor clam burrowing." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54526.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 75).
This thesis reviews the design of two scaled mechanical end effectors that mimic the digging of Ensis directus, the Atlantic Razor Clam. Modeled after a 0.5x Ensis scale device, the end effectors are 1.0x and 2.0x Ensis scale. The end effectors will be coupled to a pneumatic robotic actuator to explore the nondimensional relationships governing the digging dynamics of razor clams in littoral substrates. Such dynamics could be exploited to construct novel mimetic engineering devices which would provide an order-of-magnitude improvement over existing subsea burrowing and anchoring technologies.
by Mario Attilio Bollini.
S.B.
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Smith, Jansen A., Daniel A. Auerbach, Karl W. Flessa, Alexander S. Flecker, and Gregory P. Dietl. "Fossil clam shells reveal unintended carbon cycling consequences of Colorado River management." ROYAL SOC, 2016. http://hdl.handle.net/10150/622496.
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Water management that alters riverine ecosystem processes has strongly influenced deltas and the people who depend on them, but a full accounting of the trade-offs is still emerging. Using palaeoecological data, we document a surprising biogeochemical consequence of water management in the Colorado River basin. Complete allocation and consumptive use of the river's flow has altered the downstream estuarine ecosystem, including the abundance and composition of the mollusc community, an important component in estuarine carbon cycling. In particular, population declines in the endemic Colorado delta clam, Mulinia coloradoensis, from 50-125 individuals m(-2) in the pre-dam era to three individualsm-2 today, have likely resulted in a reduction, on the order of 5900-15 000 tCyr(-1) (4.1-10.6 mol Cm-2 yr(-1)), in the net carbon emissions associated with molluscs. Although this reduction is large within the estuarine system, it is small in comparison with annual global carbon emissions. Nonetheless, this finding highlights the need for further research into the effects of dams, diversions and reservoirs on the biogeochemistry of deltas and estuaries worldwide, underscoring a present need for integrated water and carbon planning.
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Phillips, John Wilfrid. "Mathematical and physical modelling of a floating clam-type wave energy converter." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/8641.
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The original aim of the research project was to investigate the mechanism of power capture from sea waves and to optimise the performance of a vee-shaped floating Wave Energy Converter, the Floating Clam, patented by Francis Farley. His patent was based on the use of a pressurised bag (or ‘reservoir’) to hold the hinged Clam sides apart, so that, as they moved under the action of sea waves, air would be pumped into and out of a further air reservoir via a turbine/generator set, in order to extract power from the system. Such “Clam Action” would result in the lengthening of the resonant period in heave. The flexibility of the air bag supporting the Clam sides was an important design parameter. This was expected to lead to a reduction in the mass (and hence cost) of the Clam as compared with a rigid body. However, the present research has led to the conclusion that the Clam is most effective when constrained in heave and an alternative power take-off is proposed. The theoretical investigations made use of WAMIT, an industry-standard software tool that provides an analysis based on potential flow theory where fluid viscosity is ignored. The WAMIT option of Generalised Modes has been used to model the Clam action. The hydrodynamic coefficients, calculated by WAMIT, have been curve-fitted so that the correct values are available for any chosen wave period. Two bespoke mathematical models have been developed in this work: a frequency domain model, that uses the hydrodynamic coefficients calculated by WAMIT, and a time domain model, linked to the frequency domain model in such a way as to automatically use the same hydrodynamic and hydrostatic data. In addition to modelling regular waves, the time domain model contains an approximate, but most effective method to simulate the behaviour of the Clam in irregular waves, which could be of use in future control system studies. A comprehensive series of wave tank trials has been completed, and vital to their success has been the modification of the wave tank model to achieve very low values of power take-off stiffness through the use of constant force springs, with negligible mechanical friction in the hinge mechanism. Furthermore, the wave tank model has demonstrated its robustness and thus its suitability for use in further test programmes. The thesis concludes with design suggestions for a full-scale device that employs a pulley/counterbalance arrangement to provide a direct connection to turbine/generator sets, giving an efficient drive with low stiffness and inherently very low friction losses. At the current stage of research, the mean annual power capture is estimated as 157.5 kW, wave to wire in a far from energetic 18 kw/m mean annual wave climate, but with scope for improvement, including through control system development.
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Armitage, Thomas M. "A bioeconomic model of the middle Atlantic surf clam (Spisula solidissima) fishery." W&M ScholarWorks, 1985. https://scholarworks.wm.edu/etd/1539616551.
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A bioeconomic simulation model of the middle Atlantic surf clam (Spisula solidissima) fishery has been developed from a survey of biological and econometric relationships. While identifying the biological input parameters available in the literature, the economic submodel of the fishery has been developed with price and landings time series data, and with data obtained through the use of survey questionnaires and interviews with surf clam fishermen and processors. Alternative management scenarios in the fishery have been evaluated from industry costs in both the harvesting and processing sectors and analysis of the demand for raw product confronting surf clam fishermen. Multiple regression analysis of time series data indicates that surf clam ex-vessel prices may be negatively related to surf clam landings whereas hard clam prices are positively related to ex-vessel ocean quahog prices and ex-vessel oyster prices. The strength of this relationship confirms the status of ocean quahogs as very close substitutes for surf clams. The results of case studies using the model suggest that the Mid-Atlantic Fishery Management Council has followed a prudent course of action in managing the surf clam fishery. The model also projects that, (1) larger yield quotas may be possible in the immediate future without jeopardizing surf clam population stability, (2) overcapitalization in the fishery appears to remain a problem, and (3) the economic outlook for the operators of small vessels remains relatively bleak.
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Landry, Shantelle. "Recruitment And Post-Settlement Mortality Of The Soft-Shell Clam, Mya Arenaria." W&M ScholarWorks, 2021. https://scholarworks.wm.edu/etd/1627407484.
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The soft-shell clam, Mya arenaria, is a benthic, filter-feeding, infaunal clam typically found in intertidal and shallow subtidal waters. Chesapeake Bay stocks of M. arenaria have been depleted since the 1960s due to various factors including predation, temperature, low recruitment, habitat loss, disease mortalities, and commercial harvest. As an important prey item for many commercial species, low abundances of these clams are mostly the result of the voracious appetite of the blue crab, Callinectes sapidus. In addition to predation, summer water temperatures in the Chesapeake Bay are likely driving the low abundances of M. arenaria, as water temperatures commonly surpass the optimal thermal range for this species (2 – 28 C). This study addresses several gaps in our understanding of M. arenaria, and the conditions required for an aquaculture industry for this species to be successful in the Chesapeake Bay. A series of caging experiments and mesh experiments were conducted over two years (2018 and 2019) and at two tidal zones (intertidal and subtidal) in Timberneck Creek and Catlett Islands, VA to examine the recruitment and survival of M. arenaria. In 2018, cages were constructed of ¼” (0.63 cm) VEXAR mesh and cut-off 5-gallon buckets and compared to open plots in two seasons, spring and fall. In 2019, cages were constructed of perforated aquatic plant pots with one of two mesh types, netting or VEXAR, and one of two mesh sizes, ¼” or ½”, cable tied over the top of each cage. One open cage (no mesh covering cage) treatment served as a control at each of the tidal zones at each site. There were two replicates of each caging treatment at each site and tidal zone. Each cage was filled with sediment and 10 marked and measured M. arenaria were planted ~2.5 cm in sediment. One cage of each treatment at each site and tidal zone was collected and examined 6 months from deployment date (and the remaining cages one of each treatment) were collected and examined 12 months from deployment date. At each tidal zone, “iButtons” (temperature loggers) were deployed to collect continuous water temperature measurements. In the lab, clams were identified, counted, measured, and analyzed for organic content using standard ash-free dry-weight (AFDW) measurements. The presence of crabs that had entered into cages made a significant difference in the survival of outplanted clams across all treatments for both tidal zones. Net treatments yielded significantly greater densities of recruits as compared to open and VEXAR treatments in both tidal zones. Overall, the presence of caging and netting increased Mya arenaria survival and recruitment. Netting offered enough protection from predators to allow clams to grow to harvestable sizes within six months. Caging mesh type and size played a role in M. arenaria recruitment and survival, with recruits tending to be more abundant in the ¼” net treatments. This study provides evidence that protection by caging and netting increases survival and recruitment of Mya arenaria – indicating that it is possible to have a successful soft-shell clam aquaculture operation developed in the Chesapeake Bay.
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Benvenuto, Chiara. "Precopulatory mate guarding behavior in clam shrimp a case of intersexual conflict /." [Kent, Ohio] : Kent State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1228147845.
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Thesis (Ph.D.)--Kent State University, 2008.Title from PDF t.p. (viewed Jan. 5, 2010). Advisor: Stephen C. Weeks. Keywords: Crustacea, Branchiopoda, clam shrimp, dioecy, androdioecy, intersexual conflict, precopulatory mate guarding, Eulimnadia texana, Limnadia badia, Limnadopsis tatei, Eulimnadia dahli. Includes bibliographical references (p. 164-193).
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Garcia, Manuela Trueban. "Thermal stress in the Antarctic clam Laternula and the temperate mussel Mytilus." Thesis, Swansea University, 2009. https://cronfa.swan.ac.uk/Record/cronfa42570.
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There is ample evidence that a period of global warming is already affecting ecosystems worldwide. In order to predict the effects of a warming climate on organism physiology and biogeography, a description of the mechanisms involved in species responses to elevated temperatures is needed. Comparative studies examining species inhabiting different environments provide important information on the relative susceptibility of ecosystems to climate change. Antarctic marine ectotherms have evolved in a stable cold environment. They live within a narrow thermal window and experience stress with small elevations in temperature. In contrast, temperate intertidal species experience considerable temperature changes on a daily basis. The Antarctic clam Lateniula elliptica and temperate mussel Mytilus edulis were selected as representative species for their respective environments. This thesis presents i) a description of the construction of a cDNA microarray for L. elliptica, ii) analysis of gene expression in L. elliptica upon acute exposure to 3°C, iii) a comparative study between the two species at the protein level via two dimensional electrophoresis, and iv) analysis of corticosteroid synthesis in Mytiliis. Significant changes in the expression of 294 clones, representing 160 transcripts were observed. Of these, 33 were identified by sequence similarity searches and classified to a variety of cellular functions including protein turnover, folding and chaperoning, intracellular signalling and trafficking and cytoskeletal activity. In addition, the expression of 264 and 375 proteins in L. elliptica and M. edulis respectively was studied, 14 and 26 of which presented changes in expression between treatments. Only changes in proteins involved in energy metabolism were detected in both species. A higher level of biological variation in response to stress was observed in M. echilis at the protein level. The relevance of the observed results in determining the relative susceptibility of these species to climate change is discussed.
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Murphy, Anna Elizabeth. "Effects of commercial clam aquaculture on biogeochemical cycling in shallow coastal ecosystems." W&M ScholarWorks, 2015. https://scholarworks.wm.edu/etd/1539616787.
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As the bivalve aquaculture industry expands worldwide, there is growing interest in its use to mitigate coastal eutrophication, the increased supply of organic matter to an ecosystem. Bivalves influence eutrophication by exerting `top-down' control on primary production through feeding while simultaneously influencing local `bottom-up' effects by increasing nutrient recycling. Additionally, nitrogen (N) is removed via harvest and potentially enhanced denitrification (DNF); however, DNF competes for nitrate (NO3-) with dissimilatory nitrate reduction to ammonium (DNRA), an N retention process. Seasonal in situ flux measurements in Cherrystone Inlet, VA, demonstrated that clam aquaculture sediments are a source of ammonium (NH4+), derived from clam excretion and microbial mineralization of clam biodeposits. Macroalgae, which proliferate on predator-exclusion nets utilized by the US clam industry temporarily sequester this regenerated N. Clam cultivation influences eutrophication locally by providing N in excess of macroalgal N demand, facilitating increased macroalgal production. Experiments investigated the competition between DNF and DNRA within clam sediments. at clam beds in Cherrystone Inlet, DNRA was more favored over DNF than at uncultivated sediments, likely due to the availability of labile organic carbon supplied by clams, low nitrate availability, and sulfidic sediments. However, a comparative study across clam aquaculture sites in the Sacca di Goro, Italy, where Ruditapes philippinarum are cultured, and on the Eastern Shore, VA, where Mercenaria mercenaria are cultured, revealed that the competition between DNF and DNRA is highly dependent on the environment and particularly the relative availability of labile carbon to NO3-. DNF exceeded DNRA at sites in the Sacca di Goro with elevated water column NO3-, concurrent with high abundances of a burrowing amphipod (Corophium sp.) that promoted nitrification. DNRA exceeded DNF at the VA sites and in the eastern region of the Sacca di Goro, where clam biomass was high, water column NO3" low, and sediments were generally reduced. Variability in rates across sites highlights the challenge in generalizing about the role of DNF in enhancing N removal across all clam aquaculture locations. An ecosystem-scale C and N budget was constructed for Cherrystone Inlet to understand the influence of clam cultivation on energy flow and eutrophication at a basin-wide scale. Although clam cultivation occupied only 3% of the Inlet's surface area, the clams filtered a volume equivalent to 7-44% of the system daily. Annually, N regeneration at the clam beds was ~3-fold higher than N removed by harvest. Due to the short water residence time, low watershed N load, and close vicinity of clam beds to the mouth of the Inlet, cultivated clams are likely subsidized by phytoplankton from the Chesapeake Bay. Thus, the N regenerated at the clam beds, which fuels macroalgal production would not be present in the system without facilitation by the cultured clams. This study demonstrates that although clams may dampen eutrophication by removing phytoplankton from the water column, high densities of clams can facilitate rapid N turnover through excretion and DNRA, fueling macroalgae, a form of eutrophication. The effect of clam aquaculture on N removal and subsequently organic matter supply is highly dependent on environmental conditions and clam cultivation practices, as well as the scale considered. at a large-scale (e.g. Chesapeake Bay) clam aquaculture is a net sink for N through harvest, however this study suggests that clam aquaculture may increase N and organic matter supply (i.e. macroalgae) on a basin-wide scale (e.g. Cherrystone Inlet).
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Marshall, Robert. "Broodstock conditioning and larval rearing of the geoduck clam (Panopea generosa Gould, 1850)." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/41531.
Full textAbstract:
The aim of this thesis was to identify conditions that optimize Panopea generosa broodstock conditioning and larval growth and survival in a hatchery setting. A series of experiments subjected broodstock (adults) to various levels of key factors [i.e. temperature (Ch. 2), salinity (Ch. 3) and nutrition [ration (Ch. 4) and feed type (Ch. 5)]. A larval experiment examined the effects of stocking density and feed level combinations on growth and survival (Ch. 6).
Broodstock responses were quantified using gravimetric (condition and gonadosomatic indices) and histological techniques (development classification, volume fractions and oocyte diameter). Survival and spawning rates were also examined. Of the temperatures tested (7, 11, 15 and 19˚C) 11˚C had the highest spawning rates (% individuals) and more oocytes follicle⁻¹, than 15 and 19˚C. At 7˚C gonadosomatic indices were highest but this temperature did not produce spawning clams. Gonads degenerated at 19˚C. Among salinities of 17, 20, 24, and 29 gonad sheath thickness and area occupied by gametes increased at 29 but not at 24. Salinities of 17 and 20 were associated with fungal infection and had high mortality rates after 26 d exposure. With higher ration treatments (up to 7.2 × 10⁹ cells clam⁻¹ d⁻¹ [Isochrysis sp. (TISO) and Chaetoceros muelleri, 50:50 by cell count] clams became more spawned. Very high rations (10.0 × 10 ⁹ cells clam⁻¹ d⁻¹) increased mortality. Algal type [Dunaliella tertiolecta, (TISO), C. muelleri and TISO + C. muelleri) had no measurable impact on gonad development based on any of the response variables used. The larval experiment showed that there was a significant interaction between stocking density and feed level with respect to growth and survival. The most efficient treatment was 10 larvae ml⁻¹ fed 5,000 cells larva⁻¹ (TISO) as it had among the highest growth (3.75 μm day⁻¹) and survival (42%) rates but low algal requirements. These findings illustrate reproductive responses of P. generosa that can be applied to a hatchery management strategy.
27
Woods, Helen. "An Examination of Potential Conflict between SAV and Hard Clam Aquaculture in the Lower Chesapeake Bay." W&M ScholarWorks, 2001. http://web.vims.edu/library/Theses/Woods01.pdf.
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Scola, Silvia. "Bioaccumulation of copper (CuONPs vs ionic Copper) from sediments in the clam Scrobicularia plana." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17423/.
Full textAbstract:
Sediments are considered a sink for metals, and nanoparticles transport in environmental is dominated by sedimentation. Consequently organisms that live in the sediments are more exposed to the risks related to exposure and toxicity of engineered nanoparticles (ENPs), especially deposit feeding invertebrates that have body surfaces in direct contacts with sediments and ingest huge amounts of sediment particles, due to the low source of food in sediments. In this study was carried out a 30-day experiment on juveniles of Scrobicularia plana exposed to spiked sediments with two different forms of copper, ionic (CuCl2) and nanoparticle (CuONP), both with low and high exposure. The first aim of this study was to evaluate bioaccumulation kinetics of the two different forms of copper in S. plana, in terms of bioaccumulation in the whole tissue and subcellular fractionation. The second aim was to evaluate the Condition Index of S. plana using the dry flesh weight: dry shell weight ratio condition index. Results of the bioaccumulation kinetics show a significant contamination and bioaccumulation of copper in whole animal tissue, that increased over time; for both copper forms, the organisms exposed to the highest concentrations showed the highest values of metal accumulation. The subcellular fraction results were in agreement with those of the bioaccumulated copper in the whole tissue. The results indicate the ability of the bivalve to detoxify bioaccumulated copper and that the concentration of copper associated to the metabolic available fraction (MAF) increases significantly as the concentration of Cu increases in the sediment. Thus, S. plana bioaccumulates copper, and has the ability to regulate the MAF rather than the total accumulated metal. Data on the Condition Index showed that the high CuCl2 treatment had a toxic effect on the physiological state of the organisms.
29
Narwankar, Shalaka. "Process optimization for microbial safety and sensory evaluation of high pressure processed hard clams (Mercenaria mercenaria)." 2008. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.17362.
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Liang, Hui-Ru, and 梁惠如. "Antitumor compound of freshwater clam." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/88324941178312027840.
Full textAbstract:
碩士國立臺灣海洋大學
食品科學系
93
Abstract Recently, the marine shellfish have shown to inhibit cancer proliferation and other bioactivities. Hard calm, oyster and the abalone have been reported that could suppress the growth of liver carcinoma and gastric carcinoma, as well as antiviral and immunomodulated activities. In addition, local people believe that the soup made with freshwater clam have hepatoprotective activity. Although the freshwater calm aqueous extract has demonstrated to inhibit the proliferation of human liver carcinoma and induce the apoptosis of carcinoma and possess significant hepatoprotective activity, the study of bioactive compounds was not extensive. The goal of this study was to search the bioactive compound based on the anti-cancer activity-guided approach. In the preliminary study, the ethyl acetate fraction after partition with water of freshwater calm methanolic extract induced apoptosis of Hep-J2 cell line. FC-Me-EA was further purified with column chromatography including Al2O3, SiO2 column chromatography and reverse phase high performance liquid chromatography based on bioactivity-guided approach. Different cell-lines including 6KK, HepG2 (human liver hepatoma) and HL-60 (human premyelocytic leukemia) were employed to study the cytotoxicities of fresh-clam extract and used to guide to isolate active fraction. This study demonstrated that the lipophilic fraction of fresh-clam possessed anti-cancer activities. One of fraction 112-5 was demonstrated to have significant anti-hepatoma activity (4 μg/ml). After further purification, a pure compound 200-7 consisting sterol skeleton was obtained.
31
張素容. "Effects of Four Heavy Metals on Susceptibility of Hard Clam (Meretrix lusoria) to Clam Virus." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/34570580600243205808.
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Huang, Sheng-Chia, and 黃聖佳. "Vascular protection on tilapia (Oreochromis spp.) by feeding freshwater clam extract and hydrolysate of clam." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/37911433224609388369.
Full textAbstract:
博士國立臺灣海洋大學
食品科學系
105
The aim of this study is to establish an alternative hyperlipidemia animal model by employing high fat diet fed tilapia (Oreochromis spp.), then applied to evaluate the anti-atherosclerotic activities of Corbicula fluminea extracts. Vascular lipid accumulation and inflammation of tilapia were induced by a high-fat diet (HFD) fed for two weeks. The total cholesterol and low-density lipoprotein (LDL-C) in plasma were significantly (p<0.05) higher (1.7 times) than the control group. Fatty stacking was observed in HFD fed tilapia heart vessel, and the abnormal thickening in aorta intima was 8 time higher than the control group. These results indicated that tilapia fed HFD induced hyperlipidemia and atherosclerosis within 2 weeks. The phenomenon was similar to the atherosclerosis development in mammals. Tilapia fed an HFD supplemented with clam hot-water-extract (FCW), or supplemented with clam residue hydrolysate (FCWR) showed significantly (p<0.05) decreased total cholesterol and triacylglycerol in liver by 34% and 64% respectively, and lowered hepatosomatic index (HSI). The concentrations of cholesterol, triacylglycerol and LDL-C in plasma of HFD-FCW and HFD-FCWR were significantly (p<0.05) lower than the HFD group, being decreased by 20% and 60% respectively. The plasma LDL-C/HDL-C ratio of HFD-FCW and HFD-FCWR group were reduced from 4.91 to 3.76 and 2.81, respectively. Increased total antioxidant activity in plasma, and improved fatty streak were observed in which was induced by HFD. FCWR was more effective in hypolipidemia and atherosclerosis preventive compared to FCW. The total sterol and total phenol content in FCWR was 14 and 4 time higher than in FCW, respectively. Freshwater clam was purified sequentially by ultrafiltration, gel filtration, and RP-HPLC. The fractions FCW-PB-1 and FCWR-SD-1 possessed strong antioxidant activity were subsequently subjected to LC–MS/MS. The molecular weight of FCW-PB-1 has a molecular weight of 1041 Da. FCWR-SD-1 was identified as guanine, and the half inhibitory concentration (IC50) to 15-LOX was 0.21 mg/ml. In conclusion, HFD can induce hyperlipidemia in tilapia, which is the first study using tilapia as an alternative animal model to demonstrate preventive hyperlipidemia. The freshwater clam extracts contained polyphenol, steroid, peptide, and guanine and the components provided antioxidant activity, lowered cholesterol absorption and inhibited LOX activities, thus prevented lipid oxidation and atherosclerosis.
33
Lee, Pai-Yi, and 李珮宜. "Studies on the Availability of Bone Biomaterials by Using Shell from Hard Clam and Freshwater Clam." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/e72k6n.
Full textAbstract:
碩士國立臺灣海洋大學
食品科學系
107
Hard clam and freshwater clam are common fishery product in Taiwan. However, its edible part usually less than 50%. This study was to improve the economic value and the use of hard clam and freshwater clam shell by converting to calcium phosphates as the feasibility of bone biomaterials. Hydroxyapatite (HA) and tricalcium phosphate (TCP) are common synthetic calcium phosphate biomaterials used as bone grafts, due to their similarity to the mineral phase of the bone. TCP was supplemented with magnesium (Mg) to form tricalcium magnesium phosphate (TCMP) which can influence osteoblast and osteoclast activity. In this study, hard clam and freshwater clam shell were converted by two ways, which were hydrothermal reaction and wet chemical precipitation. After a series analysis of X-ray diffraction, fourier transmission infrared spectrometry and scanning electron microscopy, it is found that the raw material was successfully converted to TCP material. HA was obtained one form of TCP compound by hydrothermal reaction and β-tricalcium magnesium phosphate (β-TCMP) was obtained by wet chemical precipitation with adding magnesium oxide. Both product appearances are mostly irregular polygons with high porosity and pore diversity. The inductively coupled plasma-optical emission spectrometry (ICP-OES) showed that both materials were no harmful metal ions to the human body. In the MG-63 cell culture experiment with β-TCMP products obtained from hard clam and freshwater clam shells, MTT assay showed that both materials were not cytotoxic by using soaking solution and tablets of both materials. The differentiation of osteoblasts was elevated by both materials according to the alkaline phosphatase activity test. The result of the mineralization experiment also indicated that both materials promoted cell mineralization. Judging from above results, the synthesized -TCMP materials from hard clam and freshwater clam shells are potential for bone repairing biomaterial.
34
CHEN, YAN-ZHOU, and 陳彥州. "The studies on transcription and rephication processes and guanylyltransferasefinction of clam aguanylyltransferase finction of clam aquareovirus (CAV)." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/14081122540503622269.
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Wu, Yu-Chi, and 吳昱奇. "Fundamental Studies on Hard Clam Mechanical Drying." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/11445373737353617971.
Full textAbstract:
碩士國立中興大學
農業機械工程學系
84
In this research, studies of the optimum drying method for hard clam based on the influences of dried meat's color, cubic measure and rehydration ability which are caused by the various blanching solutions, cooling conditions, drying temperatures and drying methods(hot-air drying or desiccant dehumidification drying), are proposed. Using Newton's law of cooling to the drying results, the mathematic model which can be applied for the practical drying operation will be invtent and the equilibrium ralitive humidity (EMC/ERH) are obtained using an equilibrium ralitive himidity method. Using the regression principle,the model of the relations between EMC and ERH is to be established which can be used for the processing, drying and storing of the hard clam meat. Form the study of the EMC properties, the Oswin equation obtains the better fittings for desorption isotherms whereas the Halsey equation was for adsorption isotherms. For the most appropriate condition of the predrying operation, it is found that the salt water with 1.5% concentration can be used for blanching and iced water for cooling. The experimental results also show that to retain the beat quality of the dried hard clam meat, the optimum drying conditions of the hot air are 40℃for the mono-temperature curing and 40℃-3hrs-65℃ for the dual-temperature curing, respectively. In the desiccant dehumidification drying, a mono- temperature of 40℃ is suggested which can obtain better quality than the hot-air drying and hold a larger drying rate than the 40℃ mono-temperature hot-air ones. It is also found that the model using Newton's law of cooling can precisely predict the moisture content changes.This equation can be provided to be the refrernce for the operation of the drying processes. Keywords ：Hard Clam, Hot Air Drying, Desiccant Dehumidification Drying, Equilibrium Moisture Content,Equilibrium Relative Humidity
36
Huang, Chien-Chih, and 黃建智. "Effects of freshwater clam, hard clam, and oyster on liver damage and fibrosis induced by carbon tetrachloride in rats." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/39811016621468233571.
Full textAbstract:
碩士國立臺灣海洋大學
食品科學系
98
Studies have shown that clam may improve liver function, and the mechanism is, however, still unknown. This study was divided into two parts: 1) the influences of carbohydrates supplementation on CCl4-induced acute liver damage; 2) the influences of clam, hard clam, and oyster supplementation on CCl4-induced chronic liver damage and liver fibrosis. (1) The acute experiment was designed to include the following four groups: A) control (with saline only), B) glucose (2% w/v in saline), C) sucrose (2% w/v in saline), and D) glycogen (2% w/v in saline). Results of the acute study showed that plasma animotransferase activity and TBARS levels significantly decreased after the glucose, sucrose, and glycogen treatment at the 12, 24, and 48 hour marks, respectively. After 48 hours, plasma bilirubin and tumor necrosis factor-α concentration significant decreased, and hepatic TBARS levels increased in rats fed a diet with either glucose, sucrose, or glycogen supplementation. Sucrose supplement significantly increased hepatic total glutathione, glutathione, and glycogen levels. After giving the sucrose treatment to rats with CCl4-induced acute liver damage, it reduced both the blood urea nitrogen and the accumulation of liver triglyceride. The treatments were given with either glycogen or glucose to the rats with CCl4-induced acute liver damage, increasing glycogen concentration and total cholesterol in the liver, respectively. (2) The chronic experiment was designed to include the following seven groups: A) control with olive oil, B) CCl4 only, C) silymarin with CCl4, D) clam with CCl4, E) oyster with CCl4, F) hard clam with CCl4, and G) glucose with CCl4. Groups of clam, oyster, hard clam, and glucose fed rats increased the concentration of plasma albumin, glucose, and blood urea nitrogen in CCl4-induced chronic liver damage cases. Moreover, they lowered the activity of plasma ALT and both the concentration ammonia and TBRAS, and also increased the contents of total cholesterol and reduced the concentration of bile acid in stool. Results of the chronic study showed that plasma TGF-beta1 and insulin concentration, hepatic glycogen in hard clam, oyster, and glucose groups significantly decreased. The plasma TNF-alpha and bilirubin in all the groups significantly decreased, which also increased the weight, bowel movements, and triglyceride concentration in the rats with CCl4-induced chronic liver damage, except the glucose group. Glucose, oyster, clam, and hard clam supplements may significantly impede the progression of liver fibrosis, hepatomegaly, and fat accumulation. Oyster and hard clams can reduce the concentration of plasma total cholesterol in rats with CCl4-induced chronic liver damage. Hard clam and glucose can impede splenomegaly, whereas hard clams can reduce the concentration of plasma triglycerides and creatinine. Hard clams, oysters, and glucose function as well as clams in liver protection. In conclusion, the results indicates that Hard clams, oysters, and clam which contains sufficient carbohydrates play an critical role in liver protection.
37
邱亦奇. "Effects of Zing, Cadium, Copper and Clam Birnavirus on Hard Clam (Meretrix Lusoria): Oxygen Consumption and Susceptibility to Virus Infection." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/19116457486795605568.
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Li, Chih-Ting, and 李致廷. "Studies on Antioxidative Activity of Water Extracts and Bactericidal Effects of Calcinated Powders of Hard Clam and Freshwater Clam Shells." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/72819811026319089079.
Full textAbstract:
碩士國立臺灣海洋大學
食品科學系
101
The composition of bivalve shells includes about 96% - 98% inorganic compounds (mainly CaCO3) and 2% - 3% organic compounds. The purpose of this study was to investigate the antioxidative activities of water soluble extracts and the bactericidal effects of calcinated powders from the most abundant freshwater bivalve, freshwater clam (Corbicula fluminea), and seawater bivalve, hard clam (Meretrix lusoria), in Taiwan. In the first part of this study, first of all, the shells of hard clam and freshwater clam were cleaned-up and then crushed to a powder. An equal weight of deionized water was added to the powder and extracted at 130℃ and 1.5 atm for 60 min. The extract solution was filtered and dialyzed. Finally, the solution was lyophilized and employed as the water extract of freshwater clam shells (FSE) and hard clams (HSE). The protein content of HSE and FSE was about 17.37% and 12.43%, respectively. The peptide (&;lt; 6 kDa) content of HSE and FSE was about 11.78% and 9.11%, respectively. Either FSE or FSE didn’t contain carbohydrates and polyphenols. Both HSE and FSE solutions were weak basic. The amino acid composition of FSE and HSE was mainly glycine. Aspartic acid, tyrosine and phenylalanine were also rich. In the antioxidant activity study, the IC50 (half maximal inhibitory concentration) value of DPPH (1,1-diphenyl-2- picrylhydrazyl) scavenging activity of FSE was about 124.70 μg/ml. HSE didn’t have DPPH radical scavenging activity. The IC50 values of Fe2+-inhibition of FSE and HSE were 1.36 and 0.25 mg/ml, respectively. The reducing power of FSE was five times more than HSE. There was no significant difference of ABTS+ scavenging activity between FSE and HSE at low concentrations. In the cell experiments, the cell viability of CCD966SK cells was not affected by FSE or HSE treatment. Furthermore, H2O2-induced oxidative stress in CCD966SK cells was reduced by FSE treatment, but not by HSE treatment. In the second part of this study, freshwater clam shell powder (FSP) and hard clam shell powder (HSP) was calcinated at 1,050℃ for 24 hr, and the yields of calcinated FSP (CFSP) and calcinated HSP (CHSP) were both about 45%. The main composition of CFSP and CHSP was converted to CaO from CaCO3. On the other side, the particle sizes were also decreased. Both of CFSP and CHSP was strong basic (pH 11.5-12.4). After 6 days storage, the pH of CFSP and CHSP suspended solutions were not changed significantly. Bacterial counts of Proteus vulgaris and Bacillus subtilis were reduced about 7 log CFU/ml by either 0.1% (w/v) CFSP or CHSP for 3 min immersion. Bacterial counts of Staphylococcus capitis were reduced about 7 log CFU/ml by 0.5% (w/v) either CFSP or CHSP for 3 min immersion. Finally, bacterial counts of Listeria monocytogenes were reduced about 6.25-7.42 log CFU/ml by either 1% (w/v) CFSP or CHSP for 3 min immersion. Oppositely, neither HSP nor FSP had no bactericidal effect. Hence, antioxidant activities were found in both HSE and FSE, which can be used for skin protection materials. Bactericidal effects were found in both CFSP and CHSP solutions, which can be used as food cleaners.
39
Tu, Chia-Ming, and 涂家銘. "Effect of clam extracts on hepatic stellate cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/10883178844635813150.
Full textAbstract:
碩士中國醫藥大學
生物科技學系碩士班
98
The freshwater clam is a widely-consumed shellfish and is used as a remedy for liver injury and anti-alcoholic toxicity in Asia. The hepatic stellate cells (HSCs) are central for the development of fibrosis during liver injury. The HSCs transit from quiescent type to activated type which is characterized by upregulation of alpha-smooth muscle actin (α-SMA) expression and extracellular matrix secretion in hepatic fibrosis. The tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) were increased in activated HSCs. The aim of this study was to investigate the effect of clam extracts on the HSCs. Activated HSCs were incubated with clam extracts. After 5 days incubation, the clam extracts significantly inhibited activated HSCs proliferation and cause cell cycle arrest in G2/M phase. Reverse transcriptase polymerasechain reaction (RT-PCR) or western blotting revealed that the expression of α-SMA and type I collagen in activated HSC were decreased. Clam extracts could also inhibit TNF-α and TGF-β mRNA expression in activated HSCs. These results suggest that clam extracts could inhibit activation of HSCs.
40
Rosa, Inês Correia. "The asian clam-dispersal, impacts and potential benefits." Doctoral thesis, 2013. https://repositorio-aberto.up.pt/handle/10216/74500.
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Rosa, Inês Correia. "The asian clam-dispersal, impacts and potential benefits." Tese, 2013. https://repositorio-aberto.up.pt/handle/10216/74500.
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42
Suja, N. "Studies on the reproduction of Marcia opima (Gmelin)." Thesis, 2002. http://eprints.cmfri.org.in/7134/1/TH-110.pdf.
Full textAbstract:
The annual reproductive cycle of the clam, Marcia opima (Gmelin)
from two geographically separated populations at Tuticorin and Ashtamudi was
studied. It was observed that M. opima spawns twice a year at both the places.
But the spawning periods are May to June and November to December at
Tuticorin and March to May and November to January at Ashtamudi. Fully
matured condition of the clam was associated with an increase in the values of
gonad index and condition factor and a decrease in the digestive gland index. A
slight increase in temperature initiated the spawning activity of M. opima at both
the places. The sex ratio at Ashtamudi showed a male dominance. Attempts to
induce the maturation of dams showed that fed clams matured faster than the
unfed. The gonad index, condition factor and oocyte diameter of clams, kept at
28°C with proper feed was more than that kept at 23°C. Spawning and larval
rearing of M. opima were successfully carried out in the hatchery. The settlement
of larvae took place on 11111 day. On day 75, the spats attained an average size of
2.81 x 2.37mm. The growth and survival of spats at varying salinities was
studied. Maximum growth rate and 100% survival of spat was reported at salinity
25 %0. During biochemical analysis, it was noticed that protein level increases to
maximum in the fully matured clams. A low level of carbohydrate was observed
during gametogenesis. Lipid level was more in the female gonad than the male
gonad. Studies revealed that wet meat weight of clam is directly related to
oxygen consumption, ammonia excretion and protein catabolism. The clam
fishery at Tuticorin bay constituted a number of species like Marcia opima,
Semele striata, Mesodesma glabratum, Gafrarium tumidum, Mactra cuneata and
Paphia sp. Allometric relationships of M. opima from both the sites showed a
correlation coefficient near to unity between various morphological
characteristics. Parasitic infestation was observed in the clams during some
months of the sampling period in both the populations.
43
Panikkar, Preetha. "Studies on the effect of temperature and salinity on growth and feeding rate of the black clam Villorita cyprinoides (Gray)." Thesis, 1990. http://eprints.cmfri.org.in/11106/1/Preetha%20Panikar.pdf.
Full textAbstract:
Clams are perhaps the most widely distributed and utilized aquatic invertebrates providing protein-rich food in much greater abundance than mussels and oysters. In India,
their exploitation at present is limited to the natural
resources which may get depleted in course of time. Clam
culture has not been taken up in our country on any commercial
or semi-commercial scale, though there is scope for it because
of the availability of vast stretches of suitable areas as well
as seed clams, either from nature or by producing them in
hatcheries. Such a proposition may become imperative in
future since the demand for more food has to be met by resorting to new methods for augmenting food production.
44
Regunathan, C. "A study on the black clam villorita cyprinoides (Gray) as protein source in prawn diet." Thesis, 1992. http://eprints.cmfri.org.in/11120/1/Regunathan%20C..pdf.
Full textAbstract:
With the situation that the production by capture fisheries has
reached or is reaching a state of maximum exploitation , it is rightly presumed that there would be a decline in production. In context with this situation, aquaculture has been found to be a supplementary source to cater to the increasing world needs for fisheries products. This has led to the upsurge in aquaculture practices in many countries including India.
45
Hsiao, An-Chu, and 蕭安助. "The influence of temperature and salinity on growth and metabolism of bivalves Meretrix lusoria（hard clam）and Psammotaea virescens（soft clam）." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/74451271325904495091.
Full textAbstract:
碩士國立嘉義大學
水產生物學系研究所
94
Abstract This thesis studied the influences of salinity and quality of the substrate on the growth, burying behavior, and physiology of hard clam (Meretrix lusoria) and soft clam (Psammotaea virescens) at high temperature to improve the management of the aqua-farm. M. lusoria is the most important pond-culture clam in Taiwan, its growth was retarded or somatic index was reduced during high temperature season. Summer is also rainy season, sudden heavy rain often made hurt of the cultured clams. P. virescens, lives in the estuary, may adapt well to high temperature and low salinity conditions. Whether these two clams may be cultured in turn to conform to seasonal change was also discussed. When water temperature was higher than 30 ℃, oxygen consumptions of the clams at various salinity condition declined. The results of the studies showed that the hard clams could grow well at high temperature, if the quality of the substrate was good and the salinity was maintained in 20~25 ppt. At this salinity condition, the clams buried into sand most quickly, had the highest filtering rate and excreted the largest amount of nitrogen. Oxygen consumption of the soft clams did not differ significantly at 27 ℃, 30 ℃, and 33℃. The soft clams grew better under the condition of 27 ℃, salinity 15~20 ppt, and the more aging substrate, and buried into sand most quickly at salinity 15~20 ppt. The filtering rate declined at temperature higher than 27 ℃, and was highest at salinity 10~20 ppt. Higher temperature and salinity made less excretion of nitrogen. The clams, had been acclimated at salinity 30 ppt for 7 days, were subjected to the water of 10 ppt. The osmosis of the hard clams balanced to the environment after 9~10 hours at 30~ 33 ℃, and 24 hours at 27 ℃. The osmosis of the soft clams balanced to the environment after 7 hours at 27~ 30 ℃, and 23 hours at 27 ℃. The results showed that the hard clams suited higher salinity than the soft clams did, but the soft clams adapted to sudden change of salinity better than the hard clams. The soft clams grew better at low temperature, but earth temperature might be cooler than upper high temperature water. The more aging substrate made the soft clams grew better, organic matter might make sand easier to bury into and acted as sediment food resource.
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Stirling, David. "Mechanized clam harvesting for coastal British Columbia: environmental implications." Thesis, 2011. http://hdl.handle.net/1828/3774.
Full textAbstract:
For certain shellfish species, a mechanical harvester has the potential to greatly reduce harvesting costs. Traditionally, hand rakes are used in shellfish harvesting in British Columbia. In order to determine if it is environmentally feasible to use a mechanical harvester, an environmental assessment on mechanical harvesting and traditional harvesting needs to occur for comparison. In July 2008, a preliminary oceanographic assessment was conducted at three study sites in Baynes Sound. Each of the three study sites contained a mechanical and manual harvest plot and reference stations. Sampling stations were established at fixed positions within each plot and at four positions along a downstream transect (following the dominant current direction.) Surveys were conducted 24 hours pre-harvest, immediately post-harvest, and 24 hours post-harvest. Parameters included in situ sediment sulphides, eH (REDOX), sediment grain size (SGS), visual condition (digital imagery), sedimentation (silt flux) and sediment macro-fauna. Results show only localized environmental effects associated with each harvest approach; with no significant difference documented between the manual and mechanical harvesting methods on the study beaches. These results indicate the use of a mechanical shellfish harvester is as environmentally sound as the traditional method of hand harvesting, and poses no additional environmental risks. Introducing mechanization in shellfish harvesting will allow shellfish producers to reduce costs and increase profits, making the British Columbian shellfish industry more competitive with other suppliers.Graduate
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Chaio, Li Min, and 趙立民. "Purification and Characterization of Amylase from Fresh Water Clam." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/81788935779893473595.
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CHEN, LI-ZHEN, and 陳麗貞. "The genetic variations of Taiwanese hard clam, Meretrix lusoria." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/77044438836380888384.
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Liu, Pi-Yu, and 劉碧玉. "Antihyperglycemic Effect of Hydrolysate of Chlorella and Freshwater Clam." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/29311886720431019642.
Full textAbstract:
碩士國立臺灣海洋大學
食品科學系
100
pulverized chlorella and freshwater clam were used as new material in this study. Pulverized chlorella were hydrolyzed by cellulase and protease at 50℃ for 3 hours. The freshwater clam muscle was extracted using hot water. The residual meat was first freeze-dried, then hydrolyzed at 50oC by protease to obtain freshwater clam hydrolysate. The inhibitory effect of Chlorella (CH) and freshwater clam hydrolysates (PX) on activity of α-glucosidase and DPP4 (dipepidy peptidase 4) were investigated, and the physiological effect on regulation of blood sugar was also evaluated. Pulverized chlorella hydrolysate was separated into five fractions by size exclusion chromatography on a Sephadex G-25 gel with BPG column. The fraction P2 (M.W.=860-740 Da) and P4 (M.W.=350-300 Da) of hydrolysate showed the higher inhibition on α-glucosidase (AG) with IC50 being 1.42 and 3.62 mg/ml, respectively. The fraction P4 was further analyzed by RP-HPLC with HILIC column, the peak H2 had the better inhibitory activity againt AG. Freshwater clam hydrosate was filtered with membrane cut-off at 1000 Da. The IC50 of filtered (M.W. < 1000 Da) against AG and DPP4 were 25.69 and 8.54 mg/ml, respectively. After 8 weeks of feeding the type 2 diabetic rats induced by STZ with CH/PX reduced 11.6 and 10.5% plasma sugar at the 60 and 120 minutes in glucose tolerance test. Diabetic rats fed CH, PX and CH/PX siginifcantly decreased plasma glucose by 8.1, 3.7 and 9.6%, plasma total cholesterol (24.2, 37.3 and 29.1%, respectively) and triglyceride (5.3, 12.6 and 8.8%, respectively) in fasting. Plasma insulin and HOMA-IR (homeostatic model assessment insulin resistance ) levels decreased by 38.0 and 51.95%, respectively, in diabetic rats fed with CH/PX.
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Yu-Chen-Wu and 吳宇晨. "A Study On Clam Production Area Development In Taixi." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8cgf3g.
Full textAbstract:
碩士國立臺北科技大學
經營管理系碩士班
105
The new south policy is the current trade policy direction of Taiwan. This research is mainly aimed at analyzing the breeding area of Taixihaipu in Yunlin County, exploring the direction of trade, how to enhance the competitiveness of farmers and provide them Fisheries industry development of the operators reference. This paper integrates past arguments and literature on scholars related to clam culture, and explores the actual business model and development of clams breeding industry by conducting field interviews with farmers and related exporters and related experts. Oriented, hoping to find the breeding industry should be to strengthen the development of the main points to enhance the overall competitiveness of the aquaculture industry. This study summarizes the following suggestions: the traditional aquaculture industry can move towards the internationalization of the ranks: First, to the aquaculture industrys recommendations: 1. Product refined, 2. Develop their own brand, 3. Group of operations; Second, to the governments recommendations: 1. Implementation of the license system and brand counseling, 2. Strengthen the local production and marketing classes to form a special producing areas, 3. Encourage the development of product added value,4.Provide timely assistance.