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1.
1. Lysosome-rich fractions were obtained from foetal liver tissues as early as 35 days uterine age. Foetal lysosomes showed the same ;structure-linked latency' and acid hydrolytic potentiality characteristic of their adult counterparts. 2. The osmotic stability of lysosome-rich fraction from foetal guinea-pig liver tissue was greater than that of the corresponding adult lysosome fractions, p-nitrophenyl-phosphatase being used as marker enzyme. 3. The observation was confirmed by using beta-glycerophosphatase and phenolphthalein beta-glucuronidase as alternative marker enzymes. p-Nitrophenyl phosphate and beta-glycerophosphate appear to act as substrates for the same enzyme. 4. By using p-nitrophenylphosphatase activity measurements it was shown that the osmotic stability of foetal lysosomal fractions decreased with increasing foetal age, but at no time achieved the degree of osmotic instability characteristic of adult lysosomal fractions. 5. The correlation of these findings with the intracellular environment of lysosomes is discussed.  相似文献   
2.
The Latin American literature on Conditional Cash Transfer (CCT) welfare programs has typically involved the quantitative evaluation of social and economic impact, with fewer studies addressing the qualitative and gendered impacts of CCTs. Drawing from ethnographic fieldwork in poor squatter settlement communities in Uruguay, this article explores the everyday social realities of poor single mothers who have been disconnected from their kinship networks and must rely on CCT payments for survival. I locate these women's experiences within the third‐way neoliberal discourses of ‘empowerment’, ‘participation’ and ‘self‐help’ espoused by the state, and the various structural conditions, including crime, violence and unequal gender relations, that impact negatively on women's abilities to comply with their social and civic duties. I argue that rather than producing responsible and empowered subjects, Uruguay's recent CCT welfare program has paradoxically limited some women's participation in civic and public life and reproduced their dependent relations with men.  相似文献   
3.
Stress granules (SGs) are dynamic cytosolic aggregates containing messenger ribonucleoproteins and target poly-adenylated (A)-mRNA. A key component of SGs is Ras-GAP SH3 domain binding protein-1 (G3BP1), which in part mediates protein-protein and protein-RNA interactions. SGs are modulated during infection by several viruses, however, the function and significance of this process remains poorly understood. In this study, we investigated the interplay between SGs and Coxsackievirus type B3 (CVB3), a member of the Picornaviridae family. Our studies demonstrated that SGs were formed early during CVB3 infection; however, G3BP1-positive SGs were actively disassembled at 5 hrs post-infection, while poly(A)-positive RNA granules persisted. Furthermore, we confirmed G3BP1 cleavage by 3Cpro at Q325. We also demonstrated that overexpression of G3BP1-SGs negatively impacted viral replication at the RNA, protein, and viral progeny levels. Using electron microscopy techniques, we showed that G3BP1-positive SGs localized near mitochondrial surfaces. Finally, we provided evidence that the C-terminal cleavage product of G3BP1 inhibited SG formation and promoted CVB3 replication. Taken together, we conclude that CVB3 infection selectively targets G3BP1-SGs by cleaving G3BP1 to produce a dominant-negative fragment that further inhibits G3BP1-SG formation and facilitates viral replication.  相似文献   
4.
Accumulating evidence suggests that dysregulation of placental DNA methylation (DNAm) is a mechanism linking maternal weight during pregnancy to metabolic programming outcomes. The common marmoset, Callithrix jaccus, is a platyrrhine primate species that has provided much insight into studies of the primate placenta, maternal condition, and metabolic programming, yet the relationships between maternal weight and placental DNAm are unknown. Here, we report genome-wide DNAm from term marmoset placentas using reduced representation bisulfite sequencing. We identified 74 genes whose DNAm pattern is associated with maternal weight during gestation. These genes are predominantly involved in energy metabolism and homeostasis, including the regulation of glycolytic and lipid metabolic processes pathways.  相似文献   
5.
Although the importance of signals involved in species recognition and sexual selection to speciation is widely recognized, the processes that underlie signal divergence are still a matter of debate. Several possible processes have been hypothesized, including genetic drift, arbitrary sexual selection, and adaptation to local signaling environments. We use comparative analyses to investigate whether the remarkable geographic variation of dewlap phenotype in a Hispaniolan trunk Anolis lizard (A. distichus) is a result of adaptive signal divergence to heterogeneous environments. We recover a repeated pattern of divergence in A. distichus dewlap color, pattern, and size with environmental variation across Hispaniola. These results are aligned with ecological models of signal divergence and provide strong evidence for dewlap adaptation to local signaling environments. We also find that A. distichus dewlaps vary with the environment in a different manner to other previously studied anoles, thus expanding upon previous predictions on the direction dewlaps will diverge in perceptual color space in response to the environment.  相似文献   
6.
While much is known about adult obesity in nonhuman primates, very little is known regarding development of childhood adiposity. As small monkeys that are easy to handle and have a relatively fast life history, common marmoset monkeys (Callithrix jacchus) offer interesting opportunities to examine the question of fat versus lean mass growth in a nonhuman primate. This article provides an overview of our understanding of early life growth in mass in marmoset monkeys, based primarily upon our past 20 years of research, culminating in our recent findings on early life obesity in this species. Common marmosets display variance in early life growth patterns that is related to both pre‐ and postnatal factors and the marmoset uterine environment is exquisitely designed to reflect resources available for the gestation of multiple offspring, making them an interesting model of developmental programming. We have demonstrated that obesity can be generated in very early life in captive marmosets, with excess adiposity evident by one month of age, making this species a potentially valuable model in which to study pediatric obesity and its sequelae. Birth weight is associated with adiposity in animals vulnerable to obesity. Early life exposure to higher fat diets enhances the chances of postweaning obesity development. However, overall higher food consumption is also associated with obesity development at later ages. One unexpected finding in our studies has been the relatively high body fat percentage of neonatal (12–18%) marmosets suggesting that hypotheses regarding the uniqueness of high human neonatal adiposity merit further examination. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
7.
We wish to report the synthesis of new tetradentate ligands in less than 3 h in good to excellent yields from a commercially available compound using microwave-assisted technology. First tests of complexation showed a high ability of these ligands to chelate 64Cu(II) in very diluted medium. These new systems have the potential to be used for nuclear medicine and particularly for PET-imaging.  相似文献   
8.
9.
Background Focus on the placenta as an agent of fetal development and offspring health outcomes is growing. Primate research facilities or zoos may collect and fix placental tissue for long‐term storage, but little is known about the effects of formalin fixation on the non‐human primate placenta. Methods We obtained 48 vervet monkey placentas from the St. Kitts Biomedical Research Foundation. We investigated via correlation coefficients and ANOVAs the effects of gestational age and original fresh weight on weight change due to fixation. We also used linear regression models to determine whether fixed tissue weight was predictive of fresh weight and gestational age. Results Although the vervet monkey placenta is described as bidiscoid, 14.6% of the placentas in this sample were fused into a single mass. A decrease in weight was the most common response to formalin fixation, with the greatest degree of loss experienced by the heaviest placentas (ANOVA, F = 5.99, P = 0.005). Gestational age was unrelated to weight change. Those placentas that increased in weight had the lowest fresh weights. Fixed weights significantly predicted both fresh weight and gestational age (r2 = 0.78, P < 0.00001; r2 = 0.76, P < 0.00001, respectively). Conclusions This paper adds to a sparse literature on the vervet monkey placenta. That fixed placentas are excellent predictors of both fresh weight and gestational age suggests that banked tissue may be a valuable resource for reconstructing aspects of individual life history, although caution must be exercised given the variability of weight change as a function of original placental size.  相似文献   
10.
Sea ice conditions in the Antarctic affect the life cycle of the emperor penguin (Aptenodytes forsteri). We present a population projection for the emperor penguin population of Terre Adélie, Antarctica, by linking demographic models (stage‐structured, seasonal, nonlinear, two‐sex matrix population models) to sea ice forecasts from an ensemble of IPCC climate models. Based on maximum likelihood capture‐mark‐recapture analysis, we find that seasonal sea ice concentration anomalies (SICa) affect adult survival and breeding success. Demographic models show that both deterministic and stochastic population growth rates are maximized at intermediate values of annual SICa, because neither the complete absence of sea ice, nor heavy and persistent sea ice, would provide satisfactory conditions for the emperor penguin. We show that under some conditions the stochastic growth rate is positively affected by the variance in SICa. We identify an ensemble of five general circulation climate models whose output closely matches the historical record of sea ice concentration in Terre Adélie. The output of this ensemble is used to produce stochastic forecasts of SICa, which in turn drive the population model. Uncertainty is included by incorporating multiple climate models and by a parametric bootstrap procedure that includes parameter uncertainty due to both model selection and estimation error. The median of these simulations predicts a decline of the Terre Adélie emperor penguin population of 81% by the year 2100. We find a 43% chance of an even greater decline, of 90% or more. The uncertainty in population projections reflects large differences among climate models in their forecasts of future sea ice conditions. One such model predicts population increases over much of the century, but overall, the ensemble of models predicts that population declines are far more likely than population increases. We conclude that climate change is a significant risk for the emperor penguin. Our analytical approach, in which demographic models are linked to IPCC climate models, is powerful and generally applicable to other species and systems.  相似文献   
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