Effect of Ethnicity and Geographical Location on Body Weight,Dietary Restraint,and Abnormal Eating Attitudes

Previous studies have examined the effect of ethnicity on obesity, concerns about shape and weight, and attitudes about eating. We hypothesized that geographical location would also influence these variables, and that students growing up in the northern part of the United States and attending northern colleges would differ from students from the South. To examine this, we studied a random sample of 275 African-Americans (AA) and 224 white college students in the entering class of two northern colleges (University of Pittsburgh or University of Massachusetts) or two southern colleges (Augusta or Paine College). All subjects were weighed and completed the Revised Restraint Scale and the EAT-26. AA women were heavier than white women, with no differences due to geographical location. Despite being thinner, white women reported more dietary restraint than AA women. This difference between AA and white women was apparent in both northern and southern college students. In contrast, geographical location was the strongest determinant of bulimic attitudes; both men and women at northern colleges reported higher bulimia scores than those at southern schools. Thus ethnicity appears to be a major determinant of body weight and attitudes about shape and dieting, whereas geographical location appears to exert greater influence on bulimic attitudes.     

BLOEM: A spatially explicit model of bioenergy and carbon capture and storage,applied to Brazil

Bioenergy could play a major role in decarbonizing energy systems in the context of the Paris Agreement. Large-scale bioenergy deployment could be related to sustainability issues and requires major infrastructure investments. It, therefore, needs to be studied carefully. The Bioenergy and Land Optimization Spatially Explicit Model (BLOEM) presented here allows for assessing different bioenergy pathways while encompassing various dimensions that influence their optimal deployment. In this study, BLOEM was applied to the Brazilian context by coupling it with the Brazilian Land Use and Energy Systems (BLUES) model. This allowed investigating the most cost-effective ways of attending future bioenergy supply projections and studying the role of recovered degraded pasture lands in improving land availability in a sustainable and competitive manner. The results show optimizing for limiting deforestation and minimizing logistics costs results in different outcomes. It also indicates that recovering degraded pasture lands is attractive from both logistics and climate perspectives. The systemic approach of BLOEM provides spatial results, highlighting the trade-offs between crop allocation, land use and the logistics dynamics between production, conversion, and demand, providing valuable insights for regional and national climate policy design. This makes it a useful tool for mapping sustainable bioenergy value chain pathways.     

Parasitism, developmental plasticity and bilateral asymmetry of wing feathers in alpine swift, Apus melba, nestlings

The hypothesis that developmental instability is a cost of developmental plasticity is explored using the alpine swift ( Apus melba ) as a model organism. In a previous study, experimentally parasitized nestlings showed a reduced wing growth rate in the first half of the rearing period when parasites were abundant (i.e. peak infestation) and an accelerated growth rate (i.e. compensatory growth) in the second half when parasites decreased in number. This suggests that alpine swifts are able to adjust growth rate in relation to variation in parasite loads. Because developmental plasticity may entail fitness costs, the energy required to sustain compensatory growth may be invested at the expense of developmental stability, potentially resulting in larger deviations from symmetry in paired, bilateral traits (i.e. fluctuating asymmetry, FA). This hypothesis predicts higher FA in parasitized than deparasitized nestlings because of compensatory growth, and hence individuals sustaining the highest level of compensatory growth rate should exhibit the highest FA levels. Another non-mutually exclusive hypothesis argues that parasites directly cause FA by diverting energy required by host for maintenance and growth, and predicts that individuals suffering the most from parasitism during peak infestation should exhibit the highest FA levels. The present study shows that wing feathers of experimentally parasitized nestlings were more asymmetrical than those of experimentally deparasitized ones 50 days after hatching. Furthermore, in parasitized individuals FA was negatively correlated with wing growth rate during the period of peak infestation but not during the period of compensatory growth. These findings suggest that developmental homeostasis is more sensitive to parasites than to compensatory growth.     

Geographic variation in sexual dimorphism in the barn owl Tyto alba: a role for direct selection or genetic correlation?

Geographic variation in sexually selected traits is commonly attributed to geographic variation in the net benefit accrued from bearing such traits. Although natural and sexual selection are potentially important in shaping geographic variation, genetic constraints may also play a role. Although a genetic correlation between two traits may itself be the outcome of natural or sexual selection, it may indirectly reinforce the establishment and maintenance of cline variation with respect to one particular trait when across the cline different values of other traits are selected. Using the barn owl Tyto alba, a species in which the plumage of females is more reddish‐brown and more marked with black spots than that of males, I report results that are consistent with the hypothesis that both direct selection and genetic constraints may help establish and maintain cline variation in sexual dichromatism. In this species, inter‐individual variation in plumage coloration and spottiness has a genetic basis, and these traits are not sensitive to the environment. Data, based on the measurement of skin specimens, is consistent with the hypothesis that the stronger European cline variation in male spottiness than in female spottiness depends on the combined effects of (1) the similar cline variation in male and female plumage coloration and (2) the more intense phenotypic correlation between plumage coloration and spottiness in males (darker birds are more heavily spotted in the two sexes, but especially males) which is a general feature among the globally distributed barn owls. In northern Europe, male and female T. a. guttata are reddish‐brown and heavily spotted, and in southern Europe male and female T. a. alba are white, but only females display many spots. Here, I discuss the relative importance of direct selection, genetic correlation and the post‐ice age invasion of Europe by T. alba, in generating sex‐specific cline variation in plumage spottiness and non‐sex‐specific cline variation in plumage coloration.     

Construction and characterization of two rice bacterial artificial chromosome libraries from the parents of a permanent recombinant inbred mapping population

Rice is a leading grain crop and the staple food for over half of the world population. Rice is also an ideal species for genetic and biological studies of cereal crops and other monocotyledonous plants because of its small genome and well developed genetic system. To facilitate rice genome analysis leading to physical mapping, the identification of molecular markers closely linked to economic traits, and map-based cloning, we have constructed two rice bacterial artificial chromosome (BAC) libraries from the parents of a permanent mapping population (Lemont and Teqing) consisting of 400 F9 recombinant inbred lines (RILs). Lemont (japonica) and Teqing (indica) represent the two major genomes of cultivated rice, both are leading commercial varieties and widely used germplasm in rice breeding programs. The Lemont library contains 7296 clones with an average insert size of 150 kb, which represents 2.6 rice haploid genome equivalents. The Teqing library contains 14208 clones with an average insert size of 130 kb, which represents 4.4. rice haploid genome equivalents. Three single-copy DNA probes were used to screen the libraries and at least two overlapping BAC clones were isolated with each probe from each library, ranging from 45 to 260 kb in insert size. Hybridization of BAC clones with chloroplast DNA probes and fluorescent in situ hybridization using BAC DNA as probes demonstrated that both libraries contain very few clones of chloroplast DNA origin and are likely free of chimeric clones. These data indicate that both BAC libraries should be suitable for map-based cloning of rice genes and physical mapping of the rice genome.     

Do NOE distances contain enough information to assess the relative populations of multi-conformer structures?

Summary The feasibility of determining the relative populations of multi-conformer structures from NOE-derived distances alone is assessed. Without cross-validation of the NOE restraints, any population ratio can be refined to a similar quality of the fit. Complete cross-validation provides a less biased measure of fit and allows the estimation of the correct population ratio when used in conjunction with very tight distance restraints. With the qualitative distance restraints most commonly used in NMR structure determination, cross-validation is unsuccessful in providing the correct answer. Other experimental sources are therefore needed to determine relative populations of multi-conformer structures.To whom correspondence should be addressed.     

Gene identification in a complex chromosomal continuum by local genomic cross-referencing

Most higher plants have complex genomes containing large quantities of repetitive DNA interspersed with low-copy-number sequences. Many of these repetitive DNAs are mobile and have homology to RNAs in various cell types. This can make it difficult to identify the genes in a long chromosomal continuum. It was decided to use genic sequence conservation and grass genome co-linearity as tools for gene identification. A bacterial artificial chromosome (BAC) clone containing sorghum genomic DNA was selected using a maize Adh1 probe. The 165 kb sorghum BAC was tested for hybridization to a set of clones representing the contiguous 280 kb of DNA flanking maize Adh1. None of the repetitive maize DNAs hybridized, but most of the low-copy-number sequences did. A low-copy-number sequence that did cross-hybridize was found to be a gene, while one that did not was found to be a low-copy-number retrotransposon that was named Reina. Regions of cross-hybridization were co-linear between the two genomes, but closer together in the smaller sorghum genome. These results indicate that local genomic cross-referencing by hybridization of orthologous clones can be an efficient and rapid technique for gene identification and studies of genome organization.     

Characterization of phospholipase A2 activation by plasmin in cultured bovine endothelial cells

Treatment of cultured bovine carotid artery endothelial cells with 0.1 µM human plasmin has been reported to induce a receptor-mediated short burst of arachidonate release, which is a pertussis toxin-sensitive and extracellular calcium-dependent reaction. Plasmin-induced calcium influx in cells was significantly inhibited by pretreatment with pertussis toxin, indicating that the former was coupled with a pertussis toxin-sensitive guanosine 5-triphosphate (GTP)-binding protein. Plasmin significantly induced the formation of lysophosphatidylcholine but not lysophosphatidylethanolamine. A cellular phospholipase A₂ with an arachidonyl specificity at the sn-2 position of phosphatidylcholine, which required submicromolar calcium, was identified as a cytosolic phospholipase A₂ by immunoblot analysis. By a cell-free enzyme activity assay and immunoblot analysis, plasmin was found to induce a translocation of the cytosolic phospholipase A₂ from the cytosol to the membrane. Taken together, the results suggest that plasmin bound to its putative receptor and activated a GTP-binding protein coupled to calcium influx channel, followed by translocation and activation of cytosolic phospholipase A₂ in endothelial cells.     

Hydrogen Peroxide Induces a Long-Lasting Inhibition of the Ca2+-Dependent Glutamate Release in Cerebrocortical Synaptosomes Without Interfering with Cytosolic Ca2+

Abstract: We studied the action of H₂O₂ on the exocytosis of glutamate by cerebrocortical synaptosomes. The treatment of synaptosomes with H₂O₂ (50–150 µ M ) for a few minutes results in a long-lasting depression of the Ca²⁺-dependent exocytosis of glutamate, induced by KCl or by the K⁺-channel inhibitor 4-aminopyridine. The energy state of synaptosomes, as judged by the level of phosphocreatine and the ATP/ADP ratio, was not affected by H₂O₂, although a transient decrease was observed after the treatment. H₂O₂ did not promote peroxidation, as judged by the formation of malondialdehyde. In indo-1-loaded synaptosomes, the treatment with H₂O₂ did not modify significantly the KCl-induced increase of [Ca²⁺]_i. H₂O₂ inhibited exocytosis also when the latter was induced by increasing [Ca²⁺]_i with the Ca²⁺ ionophore ionomycin. The effects of H₂O₂ were unchanged in the presence of superoxide dismutase and the presence of the Fe³⁺ chelator deferoxamine. These results appear to indicate that H₂O₂, apparently without damaging the synaptosomes, induces a long-lasting inhibition of the exocytosis of glutamate by acting directly on the exocytotic process.