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1
Stamatakis, Michail, and Nikos V. Mantzaris. "Intrinsic noise and division cycle effects on an abstract biological oscillator." Chaos: An Interdisciplinary Journal of Nonlinear Science 20, no. 3 (September 2010): 033118. http://dx.doi.org/10.1063/1.3484868.
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COX, D. L., R. ENDRES, R. V. KULKARNI, M. LABUTE, and R. R. P. SINGH. "ELECTRON CORRELATION EFFECTS IN BIOLOGICAL MOLECULES." International Journal of Modern Physics B 16, no. 20n22 (August 30, 2002): 3377. http://dx.doi.org/10.1142/s0217979202014462.
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Allosteric (conformation changing) proteins with transition metal atoms are at the heart of much important biological function (e.g., myoglobin hemoglobin used for storing and transporting oxygen in the bloodstream). In the case of myoglobin and hemoglobin, oxygen ligation to the iron center induces a spin crossover (high to low) coupled to a structural change; apart from the role of Hunds' exchange in the spin crossover, electron interaction effects have been ignored. We argue that the spin crossover/structure change observed in the similarly structured but far simpler cobalt valence tautomer molecules1 necessitates an inclusion of underscreened Kondo like correlations for a complete description of the energetics of the transition and dynamics, e.g., for x-ray absorption data. We carry this study out with Varma-Yafet-Gunnarsson-Schonhammer wave functions, which, in chemistry language, are basis set restricted configuration interaction in character. We briefly review the applicability of such wave functions to the description of the putative Kondo molecules cerocene (Ce[(CH)5]2) and ytterbocene bipyridine (Yb[(CH)5]2(bipy)) and to the problem of electron transfer in biological molecules and organic conductors, where anomalous long range tunneling may occur. Research supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Division of Materials Research.
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Sokolova, Ekaterina, Natalia Menzorova, Victoria Davydova, Alexandra Kuz’mich, Anna Kravchenko, Natalya Mishchenko, and Irina Yermak. "Effects of Carrageenans on Biological Properties of Echinochrome." Marine Drugs 16, no. 11 (November 1, 2018): 419. http://dx.doi.org/10.3390/md16110419.
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Sea urchin pigment echinochrome A (Ech), a water-insoluble compound, is the active substance in the cardioprotective and antioxidant drug Histochrome® (PIBOC FEB RAS, Moscow, Russia). It has been established that Ech dissolves in aqueous solutions of carrageenans (CRGs). Herein, we describe the effects of different types of CRGs on some properties of Ech. Our results showed that CRGs significantly decreased the spermotoxicity of Ech, against the sea urchin S. intermedius sperm. Ech, as well as its complex with CRG, did not affect the division and development of early embryos of the sea urchin. Ech reduced reactive oxygen species production (ROS) in neutrophils, caused by CRG. The obtained complexes of these substances with pro- and anti-activating ROS formation properties illustrate the possibility of modulating the ROS induction, using these compounds. The CRGs stimulate the induction of anti-inflammatory IL-10 synthesis, whereas Ech inhibits this synthesis and increases the production of the pro-inflammatory cytokines IL-6 and TNFα. The inclusion of Ech, in the complex with the CRGs, decreases Ech’s ability to induce the expression of pro-inflammatory cytokines, especially TNFα, and increases the induction of anti-inflammatory cytokine IL-10. Thus, CRGs modify the action of Ech, by decreasing its pro-inflammatory effect. Whereas, the Ech’s protective action towards human epithelial HT-29 cells remains to be unaltered in the complex, with κ/β-CRG, under stress conditions.
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Lock, Judith E. "Transgenerational effects of parent and grandparent gender on offspring development in a biparental beetle species." Biology Letters 8, no. 3 (November 16, 2011): 408–11. http://dx.doi.org/10.1098/rsbl.2011.0920.
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Parental effects on offspring life-history traits are common and increasingly well-studied. However, the extent to which these effects persist into offspring in subsequent generations has received less attention. In this experiment, maternal and paternal effects on offspring and grand-offspring were investigated in the biparental burying beetle Nicrophorus vespilloides , using a split-family design. This allowed the separation of prenatal and postnatal transgenerational effects. Grandparent and parent gender were found to have a cumulative effect on offspring development and may provide a selection pressure on the division of parental investment in biparental species.
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Schlimpert, Susan, Sebastian Wasserstrom, Govind Chandra, Maureen J. Bibb, Kim C. Findlay, Klas Flärdh, and Mark J. Buttner. "Two dynamin-like proteins stabilize FtsZ rings duringStreptomycessporulation." Proceedings of the National Academy of Sciences 114, no. 30 (July 7, 2017): E6176—E6183. http://dx.doi.org/10.1073/pnas.1704612114.
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During sporulation, the filamentous bacteriaStreptomycesundergo a massive cell division event in which the synthesis of ladders of sporulation septa convert multigenomic hyphae into chains of unigenomic spores. This process requires cytokinetic Z-rings formed by the bacterial tubulin homolog FtsZ, and the stabilization of the newly formed Z-rings is crucial for completion of septum synthesis. Here we show that two dynamin-like proteins, DynA and DynB, play critical roles in this process. Dynamins are a family of large, multidomain GTPases involved in key cellular processes in eukaryotes, including vesicle trafficking and organelle division. Many bacterial genomes encode dynamin-like proteins, but the biological function of these proteins has remained largely enigmatic. Using a cell biological approach, we show that the twoStreptomycesdynamins specifically localize to sporulation septa in an FtsZ-dependent manner. Moreover, dynamin mutants have a cell division defect due to the decreased stability of sporulation-specific Z-rings, as demonstrated by kymographs derived from time-lapse images of FtsZ ladder formation. This defect causes the premature disassembly of individual Z-rings, leading to the frequent abortion of septum synthesis, which in turn results in the production of long spore-like compartments with multiple chromosomes. Two-hybrid analysis revealed that the dynamins are part of the cell division machinery and that they mediate their effects on Z-ring stability during developmentally controlled cell division via a network of protein–protein interactions involving DynA, DynB, FtsZ, SepF, SepF2, and the FtsZ-positioning protein SsgB.
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Helanterä, Heikki, Oliver Aehle, Maurice Roux, Jürgen Heinze, and Patrizia d'Ettorre. "Family-based guilds in the ant Pachycondyla inversa." Biology Letters 9, no. 3 (June 23, 2013): 20130125. http://dx.doi.org/10.1098/rsbl.2013.0125.
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High relatedness promotes the evolution of sociality because potentially costly cooperative behaviours are directed towards kin. However, societies, such as those of social insects, also benefit from genetic diversity, e.g. through enhanced disease resistance and division of labour. Effects of genetic diversity have been investigated in a few complex eusocial species. Here, we show that genetically based division of labour may also be important in ‘simple societies’, with fewer individuals and limited morphological caste differentiation. The ponerine ant Pachycondyla inversa has small colonies, headed by several unrelated queens. We show that nest-mate workers from different matrilines engage in different tasks, have distinct chemical profiles and associate preferentially with kin in the nest, while queens and brood stay together. This suggests that genetically based division of labour may precede the evolution of complex eusociality and facilitate the existence of low relatedness societies functioning as associations of distinct families that mutually benefit from group living.
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Dong, Ren G., John Z. Wu, Xueyan S. Xu, Daniel E. Welcome, and Kristine Krajnak. "A Review of Hand–Arm Vibration Studies Conducted by US NIOSH since 2000." Vibration 4, no. 2 (June 15, 2021): 482–528. http://dx.doi.org/10.3390/vibration4020030.
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Studies on hand-transmitted vibration exposure, biodynamic responses, and biological effects were conducted by researchers at the Health Effects Laboratory Division (HELD) of the National Institute for Occupational Safety and Health (NIOSH) during the last 20 years. These studies are systematically reviewed in this report, along with the identification of areas where additional research is needed. The majority of the studies cover the following aspects: (i) the methods and techniques for measuring hand-transmitted vibration exposure; (ii) vibration biodynamics of the hand–arm system and the quantification of vibration exposure; (iii) biological effects of hand-transmitted vibration exposure; (iv) measurements of vibration-induced health effects; (iv) quantification of influencing biomechanical effects; and (v) intervention methods and technologies for controlling hand-transmitted vibration exposure. The major findings of the studies are summarized and discussed.
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Hynd, PI. "Effects of nutrition on wool follicle cell kinetics in sheep differing in efficiency of wool production." Australian Journal of Agricultural Research 40, no. 2 (1989): 409. http://dx.doi.org/10.1071/ar9890409.
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Wide phenotypic variation in fibre output per follicle was generated by selecting sheep (five South Australian strongwool Merinos, one finewool Merino and one Corriedale) on this basis, and by offering these sheep a low-protein diet for 9 weeks, followed by a high-protein diet for a further 8 weeks. Clean wool production was measured over the final 3 weeks of each period, while fibre diameter, the rate of length growth of fibres and a number of follicle characters were measured over the last 7 days of each period. The rate of division of follicle bulb cells and the total volume of the germinative region of the follicle was estimated by image-analysis of bulb sections in skin biopsy samples.With the change from the low-protein diet to the high-protein diet, the rate of clean fleece production was increased by 33% (P<0.002), reflecting an increase in fibre diameter (8%) and rate of length growth of fibres (26%); the volume of the germinative region of the average bulb increased 30% (P<0.012) and the rate of bulb cell division by 35% (P<0.004); cortical cell volume also did not change (923 8m3 v. 965 8m3; the average proportion of fibre cross-sectional area occupied by paracortical cells increased from 0.2 1 to 0.35 ( P < 0.01 0); the proportion of dividing cells entering the fibre cortex ranged from 0.25 to 0.42 (mean, 0.31) between sheep on the low-protein diet, and from 0.22 to 0.39 (mean, 0.32) when the animals were fed the high-protein ration; the effect of diet on cell distribution to fibre and inner root sheath was not significant (P<0.601).Phenotypic differences in fibre output were primarily related to differences in the rate of bulb cell division (r= 0.896, P < 0.001), but inclusion of a term for the proportion of bulb cells entering the fibre cortex, removed an additional, significant proportion of the variance. Cortical cell volume, on the other hand, was poorly related to fibre output.
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Yuan, Jintao, Zhiping Wei, Xinwei Xu, Dickson Kofi Wiredu Ocansey, Xiu Cai, and Fei Mao. "The Effects of Mesenchymal Stem Cell on Colorectal Cancer." Stem Cells International 2021 (July 24, 2021): 1–14. http://dx.doi.org/10.1155/2021/9136583.
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Colorectal cancer (CRC) is a common malignant tumor of the gastrointestinal tract with nonobvious early symptoms and late symptoms of anemia, weight loss, and other systemic symptoms. Its morbidity and fatality rate are next only to gastric cancer, esophageal cancer, and primary liver cancer among digestive malignancies. In addition to the conventional surgical intervention, other therapies such as radiotherapy and chemotherapy and new treatment methods such as biologics and microbiological products have been introduced. As a promising cell therapy, mesenchymal stem cell (MSC) has attracted extensive research attention. MSCs are early undifferentiated pluripotent stem cells, which have the common features of stem cells, including self-replication, self-division, self-renewal, and multidirectional differentiation. MSCs come from a wide range of sources and can be extracted from a variety of tissues such as the bone marrow, umbilical cord, and fat. Current studies have shown that MSCs have a variety of biological functions such as immune regulation, tissue damage repair, and therapeutic effects on tumors such as CRC. This review outlines the overview of MSCs and CRC and summarizes the role of MSC application in CRC.
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Geniole, Shawn N., Valentina Proietti, Brian M. Bird, Triana L. Ortiz, Pierre L. Bonin, Bernard Goldfarb, Neil V. Watson, and Justin M. Carré. "Testosterone reduces the threat premium in competitive resource division." Proceedings of the Royal Society B: Biological Sciences 286, no. 1903 (May 29, 2019): 20190720. http://dx.doi.org/10.1098/rspb.2019.0720.
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Like other animals, humans are sensitive to facial cues of threat. Recent evidence suggests that we use this information to dynamically calibrate competitive decision-making over resources, ceding more to high-threat individuals (who appear more willing/able to retaliate) and keeping more from low-threat individuals. Little is known, however, about the biological factors that support such threat assessment and decision-making systems. In a pre-registered, double-blind, placebo-controlled, cross-over testosterone administration study ( n = 118 men), we show for the first time that testosterone reduces the effects of threat on decision-making: participants ceded more resources to high-threat (versus low-threat) individuals (replicating the ‘threat premium’), but this effect was blunted by testosterone, which selectively reduced the amount of resources ceded to those highest in threat. Thus, our findings suggest that testosterone influences competitive decision-making by recalibrating the integration of threat into the decision-making process.
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Lele, Uttara N., Ulfat I. Baig, and Milind G. Watve. "Phenotypic Plasticity and Effects of Selection on Cell Division Symmetry in Escherichia coli." PLoS ONE 6, no. 1 (January 10, 2011): e14516. http://dx.doi.org/10.1371/journal.pone.0014516.
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Messing, Karen. "Physical Exposures in Work Commonly Done by Women." Canadian Journal of Applied Physiology 29, no. 5 (October 1, 2004): 639–56. http://dx.doi.org/10.1139/h04-041.
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The North American workforce is still highly sex-segregated, with most members of each sex in jobs composed primarily of workers of the same sex. This division is accentuated when jobs involve physical demands. Women have traditionally been assigned to tasks whose physical demands are considered to be light. Nevertheless, these tasks can have biological effects, sometimes serious. Phenomena related to physical demands of women's work can be considered in three categories: (a) musculoskeletal and cardiovascular demands of tasks often assigned to women in factories and service work; (b) sex- and gender-specific effects of toxic substances found in the workplace; and (c) interactions between work and the domestic responsibilities of many women. These phenomena are described, using examples recently gathered from workplaces. Effects of biological sex are distinguished, as far as possible, from effects of gender (social roles). Keywords: ergonomics, gender, occupation, anthropometry, toxicity, repetitive movements, static effort
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Harvey, Emily, Jeffrey Heys, and Tomáš Gedeon. "Quantifying the effects of the division of labor in metabolic pathways." Journal of Theoretical Biology 360 (November 2014): 222–42. http://dx.doi.org/10.1016/j.jtbi.2014.07.011.
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SAKUDA, Shohei, Yoshihiro NISHIMOTO, Mikio OHI, Makoto WATANABE, Seiji TAKAYAMA, Akira ISOGAI, and Yasuhiro YAMADA. "Effects of demethylallosamidin, a potent yeast chitinase inhibitor, on the cell division of yeast." Agricultural and Biological Chemistry 54, no. 5 (1990): 1333–35. http://dx.doi.org/10.1271/bbb1961.54.1333.
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Houx, Peter J., and Jellemer Jolles. "Age-Related Decline of Psychomotor Speed: Effects of Age, Brain Health, Sex, and Education." Perceptual and Motor Skills 76, no. 1 (February 1993): 195–211. http://dx.doi.org/10.2466/pms.1993.76.1.195.
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A cross-sectional study into age-related decline of psychomotor speed is reported. A newly introduced choice response task was used, involving three conditions: simple reaction time (SRT), choice reaction time (CRT), and CRT with stimulus-response incompatibility. Subjects were 247 volunteers, aged 20 to 80 yr. in seven age levels. Although all subjects thought themselves to be normal and healthy, a post hoc division could be made based on biological life events (BLE, mild biological or environmental factors that can hamper optimal brain functioning, such as repeated general anesthesia). Performance was poorer by subjects who had experienced one or more such event: slowing was comparable to the effect of age, especially in the more difficult task conditions. There were significant effects of sex and education, men being consistently faster than women, and more highly educated subjects performing better than subjects with only low or medium education. These findings replicate observations from other test methods. They are also in line with several other studies giving interactions between the effects of aging and physical fitness. This study questions the validity of much research on aging, as the data suggest that a more rigorous health screening for biological life events in subjects recruited from the normal, healthy population can reduce performance effects normally ascribed to aging.
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Ferguson-Gow, Henry, Seirian Sumner, Andrew F. G. Bourke, and Kate E. Jones. "Colony size predicts division of labour in attine ants." Proceedings of the Royal Society B: Biological Sciences 281, no. 1793 (October 22, 2014): 20141411. http://dx.doi.org/10.1098/rspb.2014.1411.
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Division of labour is central to the ecological success of eusocial insects, yet the evolutionary factors driving increases in complexity in division of labour are little known. The size–complexity hypothesis proposes that, as larger colonies evolve, both non-reproductive and reproductive division of labour become more complex as workers and queens act to maximize inclusive fitness. Using a statistically robust phylogenetic comparative analysis of social and environmental traits of species within the ant tribe Attini, we show that colony size is positively related to both non-reproductive (worker size variation) and reproductive (queen–worker dimorphism) division of labour. The results also suggested that colony size acts on non-reproductive and reproductive division of labour in different ways. Environmental factors, including measures of variation in temperature and precipitation, had no significant effects on any division of labour measure or colony size. Overall, these results support the size–complexity hypothesis for the evolution of social complexity and division of labour in eusocial insects. Determining the evolutionary drivers of colony size may help contribute to our understanding of the evolution of social complexity.
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Foster, Warren G. "Advances in understanding the effects of in utero exposure to chemicals." F1000Research 8 (December 17, 2019): 2116. http://dx.doi.org/10.12688/f1000research.21352.1.
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The uterine environment in which a foetus develops is critical to infant, child, and adult health. Adverse intra-uterine environments have been linked to increased risk for neurobehavioral disorders and metabolic and cardiovascular disease. Rapid cell division, tissue growth, differentiation, and organization of major organs are all features rendering the developing foetus sensitive to insult from exogenous chemicals. Therefore, interest in measurement of developmental exposure to environmental chemicals during critical periods of foetal development has grown. However, determining the consequences of developmental exposure to toxic chemicals presents epidemiologists, toxicologists, and regulatory health authorities with numerous important challenges. Improvements in analytical methods have led to greater sensitivity and thus detection of chemical residues at far lower concentrations, yet the biological relevance of the documented exposure is often unknown and difficult to determine. Although the benefit of quantifying exposure during critical windows of development is well recognized, access to appropriate biological fluids at relevant periods of development continues to pose a challenge. Moreover, knowledge gaps in the toxicological data together with lack of mechanistic insight make interpretation difficult and challenge confidence in conclusions of the human health consequences. Herein, a brief overview of several important issues central to understanding the consequences of developmental exposure to environmental toxicants is considered.
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Grundier, W., and F. Keilmann. "Resonant Microwave Effect on Locally Fixed Yeast Microcolonies." Zeitschrift für Naturforschung C 44, no. 9-10 (October 1, 1989): 863–66. http://dx.doi.org/10.1515/znc-1989-9-1028.
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The microwave influence on the growth of yeast cells is studied in a novel experimental set-up designed to observe individual cells growing for several division cycles. The results are in accordance with resonant microwave-induced growth stimulation as observed in our earlier set-up where the turbidity of a stirred suspension of cells was used as the measure of growth. The new experimental set-up is suited to decide on the proposed triplet mechanism of resonant microwave biological effects.
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Vachlova, O. S., and T. A. Oboskalova. "One of the trends of oxidative protection in in vitro fertilization programs." Obstetrics, Gynecology and Reproduction 14, no. 4 (October 14, 2020): 502–14. http://dx.doi.org/10.17749/2313-7347/ob.gyn.rep.2020.140.
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Here we review published data from experimental and clinical international studies examining pathogenetic effects of melatonin upon using programs of In Vitro Fertilization (IVF); highlighting various viewpoints on its biological action as a regulator of circadian rhythms: on the one hand, the inhibitory effect of melatonin on pulsating secretion of gonadotropin-releasing hormone was considered, thereby achieving a contraceptive effect; on the other hand, its ability to induce the secretion of human chorionic gonadotropin ensuring ovulation process, was discussed. We also review the data on melatonin acting as a highly active antioxidant. While using melatonin as a metabolic supplement in IVF programs, its positive effect on oocyte morphology and quality of fertilization, embryo division was observed. Moreover, we also highlight the results of studies examining melatonin-related effects on quality of fertilization and embryo division after adding it to culture medium. Such effects demonstrated dose-depended pattern. Taking into account the data of the analyzed publications, adding exogenous melatonin to culture medium may represent a new strategy for personalized approach to improve outcome of IVF programs. Its effectiveness should be further investigated and considered for introduction within the framework of pregravid preparation.
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Jaffé, Rodolfo, Daniel J. C. Kronauer, F. Bernhard Kraus, Jacobus J. Boomsma, and Robin F. A. Moritz. "Worker caste determination in the army ant Eciton burchellii." Biology Letters 3, no. 5 (July 17, 2007): 513–16. http://dx.doi.org/10.1098/rsbl.2007.0257.
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Elaborate division of labour has contributed significantly to the ecological success of social insects. Division of labour is achieved either by behavioural task specialization or by morphological specialization of colony members. In physical caste systems, the diet and rearing environment of developing larvae is known to determine the phenotype of adult individuals, but recent studies have shown that genetic components also contribute to the determination of worker caste. One of the most extreme cases of worker caste differentiation occurs in the army ant genus Eciton , where queens mate with many males and colonies are therefore composed of numerous full-sister subfamilies. This high intracolonial genetic diversity, in combination with the extreme caste polymorphism, provides an excellent test system for studying the extent to which caste determination is genetically controlled. Here we show that genetic effects contribute significantly to worker caste fate in Eciton burchellii . We conclude that the combination of polyandry and genetic variation for caste determination may have facilitated the evolution of worker caste diversity in some lineages of social insects.
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Eliopoulos, P. A., A. Kapranas, E. G. Givropoulou, and I. C. W. Hardy. "Reproductive efficiency of the bethylid waspCephalonomia tarsalis:the influences of spatial structure and host density." Bulletin of Entomological Research 107, no. 2 (October 3, 2016): 139–47. http://dx.doi.org/10.1017/s0007485316000651.
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AbstractThe parasitoid waspCephalonomia tarsalis(Ashmead) (Hymenoptera: Bethylidae) is commonly present in stored product facilities. While beneficial, it does not provide a high degree of biological pest control against its host, the saw-toothed beetleOryzaephilus surinamensis(L.) (Coleoptera: Silvanidae). A candidate explanation for poor host population suppression is that adult females interfere with each other's foraging and reproductive behavior. We used simple laboratory microcosms to evaluate such mutual interference in terms of its overall effects on offspring production. We varied the density of the hosts and also the spatial structure of the environment, via the extent of population sub-division and the provision of different substrates. Production ofC. tarsalisoffspring was positively influenced by host density and by the isolation of females. With incomplete sub-division within microcosms offspring production was, in contrast, low and even zero. The provision of corrugated paper as a substrate enhanced offspring production and partially mitigated the effects of mutual interference. We recommend simple improvements to mass rearing practice and identify promising areas for further behavioral and chemical studies towards a better understanding of the mechanisms of mutual interference.
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Bouwhuis, Sandra, Simon Verhulst, Christina Bauch, and Oscar Vedder. "Reduced telomere length in offspring of old fathers in a long-lived seabird." Biology Letters 14, no. 6 (June 2018): 20180213. http://dx.doi.org/10.1098/rsbl.2018.0213.
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Evidence for transgenerational effects of senescence, whereby offspring from older parents have a reduced lifetime reproductive success, is increasing. Such effects could arise from compromised germline maintenance in old parents, potentially reflected in reduced telomere length in their offspring. We test the relationship between parental age and offspring early-life telomere length in a natural population of common terns and find a significant negative correlation between paternal age and offspring telomere length. Offspring telomere length is reduced by 35 base pairs for each additional year of paternal age. We find no correlation with maternal age. These results fit with the idea of compromised germline maintenance in males, whose germline stem cells require continued division.
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Franzle, Stefan, and Bernd Markert. "Carcinogenesis and Chemotherapy Viewed from the Perspective of Stoichiometric Network Analysis (SNA): What Can the Biological System of the Elements Contribute to an Understanding of Tumour Induction by Elemental Chemical Noxae (e.g., Ni2+, Cd2+) and to an Understanding of Chemotherapy?" Scientific World JOURNAL 3 (2003): 319–41. http://dx.doi.org/10.1100/tsw.2003.01.
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The biological application of stoichiometric network analysis (SNA) permits an understanding of tumour induction, carcinogenesis, and chemotherapy. Starting from the Biological System of the Elements, which provides a comprehensive treatment of the functions and distributions of chemical (trace) elements in biology, an attempt is made to interrelate the essential feature of biology and — regrettably — of tumour genesis by superimposing SNA reasoning on common features of all crucial biological processes. For this purpose, aspects, effects and drawbacks of autocatalysis (identical reproduction which can occur either under control or without control [in tumours]) are linked with the known facts about element distributions in living beings and about interference of metals with tumours (in terms of both chemotherapy and carcinogenesis). The essential role of autocatalysis in biology and the drawbacks of either controlled or spontaneous cell division can be used to understand crucial aspects of carcinogenesis and chemotherapy because SNA describes and predicts effects of autocatalysis, including phase effects that may be due to some kind of intervention. The SNA-based classifications of autocatalytic networks in cell biology are outlined here to identify new approaches to chemotherapy.
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Wang, Meng, Xin Wang, Yuan Li, Qiang Xiao, Xiao-Hai Cui, Guo-Dong Xiao, Ji-Chang Wang, Chong-Wen Xu, Hong Ren, and Dapeng Liu. "Nutlin-3-Induced Sensitization of Non-Small Cell Lung Cancer Stem Cells to Axitinib-Induced Apoptosis Through Repression of Akt1/Wnt Signaling." Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics 27, no. 9 (September 23, 2019): 987–95. http://dx.doi.org/10.3727/096504018x15424918479652.
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The aim of this study was to investigate the potential biological activities of nutlin-3 in the regulation of growth and proliferation of non-small cell lung cancer (NSCLC) stem cells (CSCs), which may help in sensitizing to axitinib-induced apoptosis. Nutlin-3 induction of p53 expression was used to test its role in controlling the cell division pattern and apoptosis of NSCLC cells. A549 cells and H460 cells were pretreated with nutlin-3 and then treated with either an Akt1 activator or shRNA-GSK3β, to investigate the potential role of p53 sensitization in the biological effects of axitinib. We also determined the expression levels of GSK3β and p-Akt1 in patients with NSCLC and determined their potential association with survival data using Kaplan‐Meier plots and CBIOTAL. Increased p53 expression stimulated the induction of apoptosis by axitinib and promoted asymmetric cell division (ACD) of NSCLC CSCs. The repression of Akt phosphorylation induced by nutlin-3 promoted the ACD of lung CSCs, decreasing the proportion of the stem cell population. In addition to the induction of apoptosis by axitinib through inhibition of Wnt signaling, nutlin-3 treatment further enhanced axitinib-induced apoptosis by inhibiting Akt1/GSK3β/Wnt signaling. The low expression of GSK3β and increased expression of p-Akt in patients with NSCLC were closely associated with the development of NSCLC. TP53 stimulates the induction of apoptosis in NSCLC by axitinib and the ACD of lung CSCs through its regulatory effects on the p53/Akt/GSK3β pathways.
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Pilcher, Jon R. "Biological evidence of past environments and climatic changes." European Review 2, no. 4 (October 1994): 271–78. http://dx.doi.org/10.1017/s1062798700001198.
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This paper will examine some of the types of biological evidence that allow us an insight into past environments and will consider some of the concepts that affect and limit our interpretations of past environments, and through them climatic changes.Scandinavia was the birthplace of palaeoenvironmental studies; basic to these being the concepts of speciation formulated in Uppsala by Linnaeus nearly 250 years ago. Sernander proposed his bog regeneration theories in 1910 and von Post gave his first two lectures on pollen analysis in 1916. Iversen demonstrated how the impact of human activities could be disentangled from climate change and later discussed the effects of lags in the vegetation at the start of the post glacial. These laid the framework for much that I will describe.At the turn of the century the two botanists Blytt and Sernander proposed a sub-division of the recent past (the post glacial period or Holocene as we now call it) on the basis of biological evidence preserved in bogs. They described wood layers in peat bogs and introduced the terms Boreal and Sub-Boreal for the time spanned by the wood layers, and the Atlantic and Sub-Atlantic for what they interpreted as the intervening wetter periods. These wood layers are as obvious now as they were in 1900 and the terms Boreal and Atlantic have gone in and out of fashion over the intervening years.
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Tang, Xiaochao, Dianmei Yu, Haiyan Wang, Wenwen Meng, Yiwen Zhai, Zhixiang Lei, Zhen Liu, and Xianchun Wang. "Pull-Down Assay-Guided Insights into the Effects of Latroeggtoxin-VI on Nerve Cells." Toxins 13, no. 2 (February 12, 2021): 136. http://dx.doi.org/10.3390/toxins13020136.
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Latroeggtoxin-VI (LETX-VI) is a peptide neurotoxin newly found from the eggs of spider L. tredecimguttatus. To explore the mechanism of action of the LETX-VI on nerve cells, the effects of LETX-VI on PC12 cells, a commonly used neuron model, were analyzed using a pull-down assay-guided strategy. LETX-VI was shown to interact with 164 PC12 cell proteins that have diverse molecular functions such as binding, catalysis, regulation, structural activity, etc., thereby extensively affecting the biological processes in the PC12 cells, particularly protein metabolism, response to stimulus, substance transport, and nucleic acid metabolism, with 56.71%, 42.07%, 29.88% and 28.66% of the identified proteins being involved in these biological processes, respectively. By interacting with the relevant proteins, LETX-VI enhanced the synthesis of dopamine; positively regulated cell division and proliferation; and negatively regulated cell cycle arrest, cell death, and apoptotic processes, and therefore has limited cytotoxicity against the PC12 cells, which were further experimentally confirmed. In general, the effects of LETX-VI on PC12 cells are more regulatory than cytotoxic. These findings have deepened our understanding of the action mechanism of LETX-VI on nerve cells and provided valuable clues for further related researches including those on Parkinson’s disease.
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Ganjali, Monireh, Alexander M. Seifalian, and Masoud Mozafari. "Effect of Laser Irradiation on Cell Cycle and Mitosis." Journal of Lasers in Medical Sciences 9, no. 4 (September 17, 2018): 249–53. http://dx.doi.org/10.15171/jlms.2018.45.
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Introduction: In this research, low-level helium-neon (He-Ne) laser irradiation effects on monkey kidney cells (Vero cell line) mitosis were studied. Methods: The experiment was carried out on a monkey kidney cell line "Vero (CCL-81)". This is a lineage of cells used in cell cultures and can be used for efficacy and media testing. The monolayer cells were formed on coating glass in a spectral cuvette (20×20×30 mm). The samples divided into two groups. The first groups as irradiated monolayer cells were exposed by a He-Ne laser (PolyaronNPO, L’vov, Ukraine) with λ=632.8 nm, max power density (P) = 10 mW/cm2 , generating linearly polarized and the second groups as the control monolayer cells were located in a cuvette protected by a lightproof screen from the first cuvette and also from the laser exposure. Then, changing functional activity of the monolayer cells, due to the radiation influence on some physical factors were measured. Results: The results showed that low-intensity laser irradiation in the range of visible red could make meaningful changes in the cell division process (the mitosis activity). These changes depend on the power density, exposure time, the presence of a magnetic field, and the duration of time after exposure termination. The stimulatory effects on the cell division within the power density of 1-6 mW/(cm2 ) and exposure time in the range of 1-10 minutes was studied. It is demonstrated that the increase in these parameters (power density and exposure time) leads to destructing the cell division process. Conclusion: The results are useful to identify the molecular mechanisms caused by low-intensity laser effects on the biological activities of the cells. Thus, this study helps to optimize medical laser technology as well as achieving information on the therapeutic effects of low-intensity lasers.
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Meng, Xiangyu, Lu Wang, Bo Zhu, Jun Zhang, Shuai Guo, Qiang Li, Tao Zhang, Zhichao Zheng, Gang Wu, and Yan Zhao. "Integrated Bioinformatics Analysis of the Clinical Value and Biological Function of ATAD2 in Hepatocellular Carcinoma." BioMed Research International 2020 (May 6, 2020): 1–18. http://dx.doi.org/10.1155/2020/8657468.
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ATPase family AAA domain-containing protein 2 (ATAD2), a chromatin regulator and an oncogenic transcription cofactor, is frequently overexpressed in many cancers, particularly in hepatocellular carcinoma (HCC). By integrating open-access online mRNA datasets and our institutional tissue data on HCC, the clinical role and functions of ATAD2 were analyzed by bioinformatic algorithms. We systematically examined ATAD2 expression in HCC based on a large sample population, integrating data from our institution and the GEO, Oncomine, and TCGA datasets. Aberrant ATAD2 expression related to pathways was identified by bioinformatic algorithms. The effects of ATAD2 downregulation on the cycle cell were also determined. A pooled analysis from 28 datasets indicated that ATAD2 overexpression was found in HCC (SMD=8.88, 95% CI: 5.96–11.81, P<0.001) and was correlated with poor survival. Subgroup analysis of Asian patients with a serum alpha-fetoprotein (AFP) concentration < 200 ng/ml in stage I + II showed that the ATAD2-high group had a more unfavorable overall survival (OS) rate than the ATAD2-low group. The receiver operating characteristic curve indicated that the efficiency of ATAD2 for HCC diagnosis was considerable (area under the curve=0.89, 95% CI: 0.86–0.91). Functional analysis based on bioinformatic algorithms demonstrated that ATAD2 participates in cell division, mitotic nuclear division, DNA replication, repair, and cell cycle processes. ATAD2 knockout in HCC cells downregulated cyclin C and cyclin D1 protein levels and resulted in G1/S phase arrest in vitro. The kinesin family member C1 (KIFC1), shugoshin 1 (SGO1), GINS complex subunit 1 (GINS1), and TPX2 microtubule nucleation factor (TPX2) genes were closely related to ATAD2 upregulation. ATAD2 may interact with TTK protein kinase (TTK) to accelerate HCC carcinogenesis. ATAD2 plays a vital role in HCC carcinogenesis by disturbing the interaction between chromatin proteins and DNA. Targeting ATAD2 represents a promising method for the development of therapeutic treatments for cancer.
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Labeeb, May, Abdelfattah Badr, Soliman A. Haroun, Magdy Z. Mattar, Aziza S. El-Kholy, and Ibrahim M. El-Mehasseb. "Ecofriendly Synthesis of Silver Nanoparticles and Their Effects on Early Growth and Cell Division in Roots of Green Pea (Pisum sativum L.)." Gesunde Pflanzen 72, no. 2 (December 12, 2019): 113–27. http://dx.doi.org/10.1007/s10343-019-00491-5.
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Mogulevtseva, J. A., A. V. Mezentsev, and S. A. Bruskin. "RNAI-MEDIATED SILENCING OF MATRIX METALLOPROTEINASE 1 IN EPIDERMAL KERATINOCYTES INFLUENCES THE BIOLOGICAL EFFECTS OF INTERLEUKIN 17A." Vavilov Journal of Genetics and Breeding 22, no. 4 (July 3, 2018): 425–32. http://dx.doi.org/10.18699/vj18.378.
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Matrix metalloproteinases (MMPs) are important for the pathogenesis of psoriasis and other autoimmune disorders. In the extracellular matrix, accumulation of proinflammatory cytokines, such as interleukin 17A (IL-17A), leads to induction of several MMPs, including MMP1. MMPs change the composition and other properties of the extracellular matrix. These changes facilitate tissue remodeling and promote the development of psoriatic plaques. The aim of this study was to explore how MMP1 silencing might influence the biological effects of IL-17A on migration and proliferation of human epidermal keratinocytes and the expression of genes involved in their division and differentiation. The experiments were performed with MMP1-deficient and control epidermal keratinocytes, HaCaT-MMP1 and HaCaT-KTR, respectively. Cell proliferation and migration were assessed by comparative analysis of the growth curves and scratch assay, respectively. To quantify cell migration, representative areas of cell cultures were photographed at the indicated time points and compared to each other. Changes in gene expression were analyzed by real-time PCR. The obtained results demonstrated that MMP1 silencing in the cells treated with IL-17A resulted in downregulation of MMP9 and -12, FOSL1, CCNA2, IVL, KRT14 and -17 as well as upregulation of MMP2, CCND1 and LOR. Moreover, MMP1 silencing led to a decrease in cell proliferation and an impairment of cell migration. Thus, MMP1-deficiency in epidermal keratinocytes can be beneficial for psoriasis patients that experience an accumulation of IL-17 in lesional skin. Knocking MMP1 down could influence migration and proliferation of epidermal keratinocytes in vivo, as well as help to control the expression of MMP1, -2, -9 и -12, CCNA2, CCND1, KRT14 and -17 that are crucial for the pathogenesis of psoriasis.
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Alesi, Viola, Valeria Orlando, Silvia Genovese, Sara Loddo, Elisa Pisaneschi, Daniele Pompili, Cecilia Surace, et al. "Interstitial 10q21.1q23.31 Duplication due to Meiotic Recombination of a Paternal Balanced Complex Rearrangement: Cytogenetic and Molecular Characterization." Cytogenetic and Genome Research 151, no. 4 (2017): 179–85. http://dx.doi.org/10.1159/000475490.
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Complex chromosomal rearrangements (CCRs) are structural aberrations involving more than 2 chromosomal breakpoints. They are associated with different outcomes depending on the deletion/duplication of genomic material, gene disruption, or position effects. Balanced CCRs can also undergo missegregation during meiotic division, leading to unbalanced derivative chromosomes and, in some cases, to affected offspring. We report on a patient presenting with developmental and speech delay, growth retardation, microcephaly, hypospadias, and dysmorphic features, harboring an interstitial 10q21.1q23.31 duplication, due to recombination of a paternal CCR. Application of several cytogenetic and molecular techniques allowed determining the biological bases of the rearrangement, understanding the underlying chromosomal mechanism, and assessing the reproductive risk.
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Mirza, Amer M., Stephan Gysin, Nisar Malek, Kei-ichi Nakayama, James M. Roberts, and Martin McMahon. "Cooperative Regulation of the Cell Division Cycle by the Protein Kinases RAF and AKT." Molecular and Cellular Biology 24, no. 24 (December 15, 2004): 10868–81. http://dx.doi.org/10.1128/mcb.24.24.10868-10881.2004.
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ABSTRACT The RAS-activated RAF→MEK→extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3′-kinase (PI3′-kinase)→PDK1→AKT signaling pathways are believed to cooperate to promote the proliferation of normal cells and the aberrant proliferation of cancer cells. To explore the mechanisms that underlie such cooperation, we have derived cells harboring conditionally active, steroid hormone-regulated forms of RAF and AKT. These cells permit the assessment of the biological and biochemical effects of activation of these protein kinases either alone or in combination with one another. Under conditions where activation of neither RAF nor AKT alone promoted S-phase progression, coactivation of both kinases elicited a robust proliferative response. Moreover, under conditions where high-level activation of RAF induced G1 cell cycle arrest, activation of AKT bypassed the arrest and promoted S-phase progression. At the level of the cell cycle machinery, RAF and AKT cooperated to induce cyclin D1 and repress p27Kip1 expression. Repression of p27Kip1 was accompanied by a dramatic reduction in KIP1 mRNA and was observed in primary mouse embryo fibroblasts derived from mice either lacking SKP2 or expressing a T187A mutated form of p27Kip1. Consistent with these observations, pharmacological inhibition of MEK or PI3′-kinase inhibited the effects of activated RAS on the expression of p27Kip1 in NIH 3T3 fibroblasts and in a panel of bona fide human pancreatic cancer cell lines. Furthermore, we demonstrated that AKT activation led to sustained activation of cyclin/cdk2 complexes that occurred concomitantly with the removal of RAF-induced p21Cip1 from cyclin E/cdk2 complexes. Cumulatively, these data strongly suggest that the RAF→MEK→ERK and PI3′K→PDK→AKT signaling pathways can cooperate to promote G0→G1→S-phase cell cycle progression in both normal and cancer cells.
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Nunes, R. D. M., I. M. S. Sales, S. I. O. Silva, J. M. C. Sousa, and A. P. Peron. "Antiproliferative and genotoxic effects of nature identical and artificial synthetic food additives of aroma and flavor." Brazilian Journal of Biology 77, no. 1 (March 2017): 150–54. http://dx.doi.org/10.1590/1519-6984.12115.
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Abstract This study aimed to analyze the antiproliferative and genotoxic potential of synthetic food flavorings, nature identical passion fruit and artificial vanilla. This assessment used root meristem cells of Allium cepa L., in exposure times of 24 and 48 hours and using doses of 0.2; 0.4 and 0.6 mL. Roots were fixed in Carnoy’s solution, hydrolyzed in hydrochloric acid, stained with acetic orcein and analyzed with optical microscope at 400× magnification, 5,000 cells for each treatment. For data analysis, it was used Chi-square test at 5%. Doses of 0.2 mL at ET 48 h; 0.4 and 0.6 mL at ET 24 and 48 h of passion fruit flavor, and the three doses of the vanilla flavor at ET 24 and 48 h significantly reduced the cell division rate in the meristems of roots, proving to be cytotoxic. Doses of 0.2; 0.4 and 0.6 mL of the passion fruit additive, and the three doses of vanilla tested, in the two exposure times, induced mitotic spindle changes and micronuclei formation in the cells of the test organism used, proving to be genotoxic. Therefore, under the studied conditions, flavoring solutions of vanilla and passion fruit, marketed nationally and internationally, significantly altered the functioning of the cell cycle in root meristem cells of A. cepa.
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Bashiry, Moein, Hedayat Hoseini, Abdoreza Mohammadi, Ehsan Sadeghi, Nader Karimian-Khosroshahi, Francisco J. Barba, and Amin Mousavi Khaneghah. "Industrial and culinary practice effects on biologically active polyamines level in turkey meat." Quality Assurance and Safety of Crops & Foods 13, no. 2 (May 26, 2021): 67–78. http://dx.doi.org/10.15586/qas.v13i2.775.
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Polyamines, including putrescine, spermidine, and spermine, are biological compounds present in nearly all food items. Their desirable physiological effects include cell division and growth. Hence, are undesirable in the diet of patients with tumor. This study aimed to assess the impact of curing agents (sodium chloride (0–2 g), sodium nitrite (0–200 ppm), sodium polyphosphate (0–0.5 g), and ascorbic acid (0–500 ppm)), cooking (frying (180°C), and boiling (100°C)) on polyamine contents in turkey breast meat using response surface methodology based on central composite design and dispersive liquid-liquid microextraction. Postprocessing changes were investigated using a high-performance liquid chromatography equipped with an ultraviolet detector. Study outcomes showed the presence of sodium chloride, sodium nitrite, and sodium polyphosphate in turkey meat reduced the putrescine and spermine content significantly (P < 0.0001). The addition of ascorbic acid as a curing agent slightly increased the concentration of polyamines, while no significant linear effects were associated with the thermal processes. The study observed that curing agents like sodium chloride, sodium nitrite, sodium polyphosphate, and ascorbic acid at 2 g, 200 ppm, 0.5 g, and 382 ppm, respectively, in frying mode minimized spermine and putrescine content with more than 96% desirability. In conclusion, curing additives and cooking are promising procedures for polyamine reduction in turkey breast meat.
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Barbosa, Egberto Reis, Leonel Tadao Takada, Lilian Regina Gonçalves, Rose Mary Paulo do Nascimento Costa, Laura Silveira-Moriyama, and Hsin Fen Chien. "Botulinum toxin type A in the treatment of hemifacial spasm: an 11-year experience." Arquivos de Neuro-Psiquiatria 68, no. 4 (August 2010): 502–5. http://dx.doi.org/10.1590/s0004-282x2010000400006.
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In order to evaluate the long-term effect of botulinum toxin type A (BTX) in the treatment of hemifacial spasm (HFS), a retrospective analysis of patients treated at the Movement Disorders Unit of the Division of Neurology, Clinical Hospital, University of São Paulo, School of Medicine from 1993 to 2004 was made. A total of 808 injections with BTX were administered to 54 patients with HFS. The mean duration of improvement per application was 3.46 months and the mean rate of improvement using subjective judgement by the patient was of 83%. Adverse effects, mostly minor, were observed in 64.8% of patients at least once along the period of follow-up and the most frequent of them was orbicularis oris paralysis (38.8%). There was no decrement in response when compared the first and the last injection recorded.
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MULNER-LORILLON, Odile, Jean MAROT, Xavier CAYLA, Robert POUHLE, and Robert BELLE. "Purification and characterization of a casein-kinase-II-type enzyme from Xenopus laevis ovary. Biological effects on the meiotic cell division of full-grown oocyte." European Journal of Biochemistry 171, no. 1-2 (January 1988): 107–17. http://dx.doi.org/10.1111/j.1432-1033.1988.tb13765.x.
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Romaña, L. A., P. Brisset, G. Pagano, A. Amoux, Y. Martin, A. Caillot, and R. Loarer. "Use of Radioactive Tracing Techniques to Identify Participate Deposits and Biological Effects of Urban Effluents Discharges from Sewage Outfalls." Water Science and Technology 25, no. 12 (June 1, 1992): 115–22. http://dx.doi.org/10.2166/wst.1992.0343.
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The discharge at sea of domestic effluents can present, in terms of its particulate phase, very different behaviors depending on the quantity discharged, on the type of purification treatment, as well as on the dumping method and on the dumping site. Consequently, it is extremely difficult to identify the relation between the deposits originating from the dumped waste and the modifications undergone by the substrate and by benthic populations. We have therefore focused our efforts on the particular case of East Toulon which is representative of most Mediterranean urban effluents discharges, in order to study the fate and impact of the particulate matter released by the sewage pipe (1,800 m long, 42 m deep) in the area close to its outfall. The first phase consisted in searching for preferential deposit areas with the use of a radioactive tracer (hafnium) injected for 35 consecutive days on a continuous basis at the outlet of the physico-chemical purification plant. This tracer which fixes itself irreversibly on the particulate matter, was systematically tracked on the sea bottom with a sled carrying a nuclear detection probe. This enabled a cartography of deposits to be established both on a temporal (four times) and a spatial basis. A multi-disciplinary sediment survey was then conducted, based on these results. Samples were collected at various distances from the outfall. In addition to standard parameters (particle size, matter content), the main toxicants originating from the discharge were examined. Finally, we used the same samples to carry out toxicological assays on sea urchins, based on sediment-induced alterations in embryogenesis, cell division and fertilization. Our findings revealed a non-monotonous trend in the embryo-toxicity of sediments which was satisfactorily consistent with the preferential deposit area of the (toxic) suspended matter originating from the discharge.
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Walworth, Nathan G., Emily J. Zakem, John P. Dunne, Sinéad Collins, and Naomi M. Levine. "Microbial evolutionary strategies in a dynamic ocean." Proceedings of the National Academy of Sciences 117, no. 11 (March 2, 2020): 5943–48. http://dx.doi.org/10.1073/pnas.1919332117.
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Marine microbes form the base of ocean food webs and drive ocean biogeochemical cycling. Yet little is known about the ability of microbial populations to adapt as they are advected through changing conditions. Here, we investigated the interplay between physical and biological timescales using a model of adaptation and an eddy-resolving ocean circulation climate model. Two criteria were identified that relate the timing and nature of adaptation to the ratio of physical to biological timescales. Genetic adaptation was impeded in highly variable regimes by nongenetic modifications but was promoted in more stable environments. An evolutionary trade-off emerged where greater short-term nongenetic transgenerational effects (low-γ strategy) enabled rapid responses to environmental fluctuations but delayed genetic adaptation, while fewer short-term transgenerational effects (high-γ strategy) allowed faster genetic adaptation but inhibited short-term responses. Our results demonstrate that the selective pressures for organisms within a single water mass vary based on differences in generation timescales resulting in different evolutionary strategies being favored. Organisms that experience more variable environments should favor a low-γ strategy. Furthermore, faster cell division rates should be a key factor in genetic adaptation in a changing ocean. Understanding and quantifying the relationship between evolutionary and physical timescales is critical for robust predictions of future microbial dynamics.
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Lopes, Carla, Sophie Aubert, Fany Bourgois-Rocha, Monia Barnat, Ana Cristina Rego, Nicole Déglon, Anselme L. Perrier, and Sandrine Humbert. "Dominant-Negative Effects of Adult-Onset Huntingtin Mutations Alter the Division of Human Embryonic Stem Cells-Derived Neural Cells." PLOS ONE 11, no. 2 (February 10, 2016): e0148680. http://dx.doi.org/10.1371/journal.pone.0148680.
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Maravelias, Christos D. "Habitat selection and clustering of a pelagic fish: effects of topography and bathymetry on species dynamics." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 3 (March 1, 1999): 437–50. http://dx.doi.org/10.1139/f98-176.
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Two dynamic aspects of the ecology of pelagic fish, distribution and abundance, have been linked to topographic, bathymetric, and biotic factors. The two-stage generalized additive modelling (GAM) approach undertaken in the present study offered biological interpretations of presence/absence of a pelagic fish species as distinguished from abundance (if present) in relation to various abiotic and biotic factors. The data were collected during the ICES coordinated Atlantic herring (Clupea harengus) acoustic surveys (ICES Division IVa) of July 1992, 1994, and 1995 in the northern North Sea. The depth of the water column, the seabed substrate, and zooplankton biomass appeared to be significant factors modulating presence and relative abundance of a pelagic species within the northern North Sea. Results indicated that habitats with the higher probability of finding herring present were those located in shallower waters having a gravel/sand type of seabed that also carried the highest zooplankton abundances. Species clustering was found to be preferentially higher in these habitats. Notwithstanding their pelagic nature, herring exhibit preferences for areas with specific bathymetric, substratum, and zooplanktonic conditions. These preferences are believed to be linked to the oceanography of the North Sea ecosystem.
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Miller, Michael K., and C. Shannon Stokes. "Teenage fertility, socioeconomic status and infant mortality." Journal of Biosocial Science 17, no. 2 (April 1985): 147–55. http://dx.doi.org/10.1017/s0021932000015601.
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SummaryThe paper examines the relationship between infant mortality and a complex measure of socioeconomic status for evidence of diminution. In data on counties in the United States with a minimum of 20 infant deaths over the 5-year period 1971–75, no evidence of a declining relationship between socioeconomic status and infant mortality was found. Both level of community affluence and racial composition of the population exerted direct effects on levels of infant deaths. In addition, both socioeconomic status and racial composition exhibited indirect effects which operated through teenage childbearing. When total infant mortality was subdivided, teenage fertility serves as a mediating variable in the link between socioeconomic status and neonatal mortality, but not for the postneonatal components. Given the nearly equivalent total effect of socioeconomic status on infant mortality, it is concluded that the classic division into neonatal (supposedly a function of biological and genetic agents) and postneonatal (traditionally attributed to social and environmental agents), may be too crude to allow the contemporary effects of the socioenvironmental milieu to be evaluated effectively.
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Kapheim, Karen M., and Makenna M. Johnson. "Support for the reproductive ground plan hypothesis in a solitary bee: links between sucrose response and reproductive status." Proceedings of the Royal Society B: Biological Sciences 284, no. 1847 (January 25, 2017): 20162406. http://dx.doi.org/10.1098/rspb.2016.2406.
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In social bees, foraging behaviour is correlated with reproductive status and sucrose sensitivity via endocrine pathways. This association led to the hypothesis that division of labour in social insect societies is derived from an ancestral ground plan that functions to synchronize dietary preferences with reproductive needs in solitary insects. However, the relationship between these traits is unknown for solitary bees, which represent the ancestral state of social bees. We used the proboscis extension response assay to measure sucrose response among reproductive females of the solitary alkali bee ( Nomia melanderi ) as a function of acute juvenile hormone (JH) treatments and reproductive physiology. We also tested long-term effects of JH on reproductive development in newly emerged females. JH did not have short-term effects on reproductive physiology or sucrose response, but did have significant long-term effects on ovary and Dufour's gland development. Dufour's gland size, not ovary development, was a significant predictor of sucrose response. This provides support for the reproductive ground plan hypothesis, because the Dufour's gland has conserved reproductive functions in bees. Differing results from this study and honeybees suggest independent origins of division of labour may have evolved via co-option of different components of a conserved ground plan.
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Johnson, Madeleine, and Evariste Fongnzossie. "Ethnobotanical Survey of Plants Used as Amulets Among the Banen Ethnic Group in Ndiki Sub-Division (Centre Region of Cameroon)." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 68, no. 4 (2020): 741–53. http://dx.doi.org/10.11118/actaun202068040741.
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An ethnobotanical survey was carried in Ndiki sub-division of the Central Region of Cameroon to collect information on the use of plants in the manufacture of amulets among the Banen ethnic group. Focus group discussions and interviews were carried out from 2004 to 2010 and from 2013 to 2015 with a total of 50 respondents (34 men and 16 female) to gather information about local names of plants used, type of management (wild/cultivated), availability (common, sporadic, rare), existing threats, part(s) used, preparation methods, effects of amulets, associated taboos/beliefs, etc. A total of 11 plant species were recorded as used as amulet. They include Aframomum melegueta (Zingiberaceae), Cissus aralioides (Rubiaceae), Costus afer (Zingiberaceae), Euphorbia kamerunica (Euphorbiaceae), Imperata cylindrica (Poaceae), Kigelia Africana (Bignoniaceae), Morinda morindoides (Bak) Milne-Redh (Rubiaceae), Ornithogalum sp. (Amaryllidaceae), Pentaclethra macrophylla (Mimosaceae), Platycerium angolense (Polypodiaceae), Trachyphrynium braunianum (Maranthaceae). The amulets are used to protect people and their property, inflict sentiments of respect and fear. In case of violation, the perpetrator faces diverse punishments including suddenly seeing a big snake, hearing of a deafening scream in their ears, various evil and skin diseases. He can be healed upon confession of his wrongdoing to the owner of the amulet. This study shows that the traditional knowledge on amulets is an important part of the living habits and culture of Banen people who still have a strong belief in their efficacy.
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Arpağ, Göker, Elizabeth J. Lawrence, Veronica J. Farmer, Sarah L. Hall, and Marija Zanic. "Collective effects of XMAP215, EB1, CLASP2, and MCAK lead to robust microtubule treadmilling." Proceedings of the National Academy of Sciences 117, no. 23 (May 26, 2020): 12847–55. http://dx.doi.org/10.1073/pnas.2003191117.
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Microtubule network remodeling is essential for fundamental cellular processes including cell division, differentiation, and motility. Microtubules are active biological polymers whose ends stochastically and independently switch between phases of growth and shrinkage. Microtubule treadmilling, in which the microtubule plus end grows while the minus end shrinks, is observed in cells; however, the underlying mechanisms are not known. Here, we use a combination of computational and in vitro reconstitution approaches to determine the conditions leading to robust microtubule treadmilling. We find that microtubules polymerized from tubulin alone can treadmill, albeit with opposite directionality and order-of-magnitude slower rates than observed in cells. We then employ computational simulations to predict that the combinatory effects of four microtubule-associated proteins (MAPs), namely EB1, XMAP215, CLASP2, and MCAK, can promote fast and sustained plus-end-leading treadmilling. Finally, we experimentally confirm the predictions of our computational model using a multi-MAP, in vitro microtubule dynamics assay to reconstitute robust plus-end-leading treadmilling, consistent with observations in cells. Our results demonstrate how microtubule dynamics can be modulated to achieve a dynamic balance between assembly and disassembly at opposite polymer ends, resulting in treadmilling over long periods of time. Overall, we show how the collective effects of multiple components give rise to complex microtubule behavior that may be used for global network remodeling in cells.
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Ilak Peršurić, A. S. "Social roles of farmwomen: The case of Croatia." Agricultural Economics (Zemědělská ekonomika) 57, No. 6 (June 28, 2011): 297–307. http://dx.doi.org/10.17221/41/2010-agricecon.
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The article is based on a field research on family farms in Croatia. On a sample of 350 farmwomen their social roles were analysed. The keys of the gender division of typical feminine tasks such as household tasks, family care tasks and the position in the family and on farm was analysed. Through statistical data processing in multivariate matrixes the latent matrix of independent variables: family, progessional position and farm economic status showed significant effects on matrix of dependent variables traditional feminine work, family care tasks and expectations of women hindering farmwoman's possibilities for off farm employment.
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Kovtonyuk, Larisa V., Markus G. Manz, and Hitoshi Takizawa. "Thrombopoietin-Receptor Signalling Induces Proliferation of Dormant HSC." Blood 120, no. 21 (November 16, 2012): 2343. http://dx.doi.org/10.1182/blood.v120.21.2343.2343.
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Abstract Abstract 2343 Lifelong blood production is maintained by a very rare population of self-renewing hematopoietic stem cells (HSCs) in bone marrow (BM). Proliferation, differentiation and survival of HSC toward stepwise hematopoietic cell development needs to be tightly controlled by cell intrinsic and extrinsic factors, as excess or insufficient production of mature blood cells potentially leads to neoplasia or aplasia. HSCs and progenitors (HSPCs) are equipped with cell surface receptors for different cytokines or chemokines (Kaushansky, NEJM 2006), and thus can integrate external signals, leading finally to proliferation and subsequent increase of hematopoietic cells in demand. Some of these regulatory pathways are already exploited in clinical settings: CXCR4 antagonists for HSPC mobilization, human granulocyte colony-stimulating factor (hG-CSF) for HSC mobilization and myeloid regeneration, and thrombopoietin agonists (THPO) for improving thrombocytopenia. However, despite their clinical use, little is known about the influence of these molecules on HSC. We established in vivo HSC divisional tracking with CFSE (5(6)-carboxyfluorescein diacetate N-succinimidyl ester). This allows to track single HSC division with high resolution, and subsequently to test biological activity of HSC-containing fractions (LKS) with different divisional history (Takizawa et al., JEM 2011). Using this system we evaluated the effects of systemic administration of human fms-related tyrosine kinase 3 ligand (hFlt3L), hG-CSF (Filgrastim), CXCR4 antagonist (AMD3100), and the THPO receptor (cMpl) agonist (Romiplostim) on HSC division. CFSE-labeled LKS were transferred into non-irradiated steady-state recipients. The non-dividing cell fraction was defined by the CFSE profile of CD4+CD62L+ T cells. One week after transplantation mice were injected with PBS or respective reagents daily or every other day for over one week. Three weeks after transfer, phenotypic BM analysis demonstrated that most of donor LKS had undergone several divisions while a small fraction of LKS remained undivided in PBS treated control mice (Figure 1a), containing long term self-renewing HSCs with at least 20–30% frequency (Takizawa et al., JEM 2011). Administration of hFlt3L increased the percentage of intermediate (1–5x divided) and fast cycling (>5x divided) LKS, which mainly contains CD150- Flt3+ multipotent progenitor cells (Figure 1b). Upon injections of cMpl agonist all donor LKS divided more than once, leaving no cells in quiescent fraction, with substantial expansion of CD150+ cells in the divided fraction. CXCR4 antagonist and hG-CSF administration had little effect on LKS proliferation. These data suggest that cMpl agonist drives dormant cells into proliferation, whereas hG-CSF has little effect on LKS division. To determine whether cMpl agonist increases the turnover of functionally defined, bona fide HSCs, we performed secondary transplantation of 0–1, 2–4, and ≥5x divided LKS. Twenty fast- (≥5x divided cells at 3 weeks), slow-cycling (2–4x divided) or relatively dormant LKS Flt3- cMpl+ cells (0–1x divided) were sorted from mice treated with PBS or cMpl agonist, and transplanted into lethally irradiated mice. Early results demonstrate increased percentage of secondary recipient engrafted with 2–4x divided cells from primary animals treated with cMpl agonist compared to those cells from PBS treated control Our results thus suggest that cMpl agonists have mitogenic activity not only for megakaryocyte progenitors but also for HSCs. How far this holds true in the human species needs to be determined. However, it should be taken in consideration given clinical data on evolution of pre-existing clonal myeloid diseases under cMpl agonist treatment (Dantoni, ASH abstract 2011), and also when treatment is applied long-term to patients with primary non-clonal hematopoietic diseases as immune thrombocytopenia or aplastic anemia. Disclosures: No relevant conflicts of interest to declare.
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Sipiczki, Matthias. "Metschnikowia pulcherrima and Related Pulcherrimin-Producing Yeasts: Fuzzy Species Boundaries and Complex Antimicrobial Antagonism." Microorganisms 8, no. 7 (July 12, 2020): 1029. http://dx.doi.org/10.3390/microorganisms8071029.
Full textAbstract:
Yeasts affiliated with the Metschnikowia pulcherrima clade (subclade) of the large ascomycetous genus Metschnikowia frequently turn out to produce the characteristic maroon-red pulcherrimin when tested for pigment production and prove to exert antagonistic effects on many types of microorganisms. The determination of the exact taxonomic position of the strains is hampered by the shortage of distinctive morphological and physiological properties of the species of the clade and the lack of rDNA barcode gaps. The rDNA repeats of the type strains of the species are not homogenized and are assumed to evolve by a birth-and-death mechanism combined with reticulation. The taxonomic division is further hampered by the incomplete biological (reproductive) isolation of the species: certain type strains can be hybridized and genome sequencing revealed chimeric genome structures in certain strains that might have evolved from interspecies hybrids (alloploid genome duplication). Various mechanisms have been proposed for the antimicrobial antagonism. One is related to pulcherrimin production. The diffusible precursor of pulcherrimin, the pulcherriminic acid is secreted by the cells into the environment where it forms the insoluble pulcherrimin with the ferric ions. The lack of free iron caused by the immobilization of ferric ions inhibits the growth of many microorganisms. Recent results of research into the complexity of the taxonomic division of the pulcherrimin-producing Metschnikowia yeasts and the mechanism(s) underlying their antimicrobial antagonism are discussed in this review.
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Scobie, DR, PI Hynd, and BP Setchell. "Reduction of synthetic and mitotic activity in the wool follicle by catecholamines." Australian Journal of Agricultural Research 45, no. 6 (1994): 1159. http://dx.doi.org/10.1071/ar9941159.
Full textAbstract:
Literature evidence on the effects of catecholamines on wool growth is scant and the short-term effects have not been investigated. Since catecholamines are relatively short-lived, three approaches were adopted to investigate their effects on cellular events in the wool follicle over periods as short as 4 h. In vitro culture of skin revealed a reduction of DNA synthesis in response to either adrenaline or noradrenaline added to the media (P < 0.001) in a dose-dependent manner (P < 0.001). Intradermal injections of adrenaline and noradrenaline significantly lowered the rate of cell division in wool follicles in comparison with control sites in vivo (P < 0.05). These results indicate that the catecholamines can rapidly lower the rate of proliferative events in the wool follicle. The left superior cervical ganglion was removed from 18 sheep. The animals were exposed to a cold environment and ear temperature was monitored to indicate the likely release of noradrenaline in the skin of the cheeks or adrenaline from the adrenals. With respect to the sympathectomized side, a reduction in ear temperature on the unoperated side was associated with lowered mitotic rate at the unoperated cheek site (P < 0.026). However, when the temperature of the unoperated side was not lowered, mitotic rate was not consistently lower on one side with respect to the other. Physiological levels of noradrenaline therefore mimicked the effects observed during the pharmacological studies, and the catecholamines may therefore play an important role in the regulation of wool growth.
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Robinson, Elva J. H., and Jessica L. Barker. "Inter-group cooperation in humans and other animals." Biology Letters 13, no. 3 (March 2017): 20160793. http://dx.doi.org/10.1098/rsbl.2016.0793.
Full textAbstract:
Social interactions are often characterized by cooperation within groups and conflict or competition between groups. In certain circumstances, however, cooperation can arise between social groups. Here, we examine the circumstances under which inter-group cooperation is expected to emerge and present examples with particular focus on groups in two well-studied but dissimilar taxa: humans and ants. Drivers for the evolution of inter-group cooperation include overarching threats from predators, competitors or adverse conditions, and group-level resource asymmetries. Resources can differ between groups in both quantity and type. Where the difference is in type, inequalities can lead to specialization and division of labour between groups, a phenomenon characteristic of human societies, but rarely seen in other animals. The ability to identify members of one's own group is essential for social coherence; we consider the proximate roles of identity effects in shaping inter-group cooperation and allowing membership of multiple groups. Finally, we identify numerous valuable avenues for future research that will improve our understanding of the processes shaping inter-group cooperation.
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Zöttl, Markus, Jack Thorley, David Gaynor, Nigel C. Bennett, and Tim Clutton-Brock. "Variation in growth of Damaraland mole-rats is explained by competition rather than by functional specialization for different tasks." Biology Letters 12, no. 12 (December 2016): 20160820. http://dx.doi.org/10.1098/rsbl.2016.0820.
Full textAbstract:
In some eusocial insect societies, adaptation to the division of labour results in multimodal size variation among workers. It has been suggested that variation in size and growth among non-breeders in naked and Damaraland mole-rats may similarly reflect functional divergence associated with different cooperative tasks. However, it is unclear whether individual growth rates are multimodally distributed (as would be expected if variation in growth is associated with specialization for different tasks) or whether variation in growth is unimodally distributed, and is related to differences in the social and physical environment (as would be predicted if there are individual differences in growth but no discrete differences in developmental pathways). Here, we show that growth trajectories of non-breeding Damaraland mole-rats vary widely, and that their distribution is unimodal, contrary to the suggestion that variation in growth is the result of differentiation into discrete castes. Though there is no evidence of discrete variation in growth, social factors appear to exert important effects on growth rates and age-specific size, which are both reduced in large social groups.