Codon usage bias and the evolution of influenza A viruses. Codon Usage Biases of Influenza Virus

Background  

The influenza A virus is an important infectious cause of morbidity and mortality in humans and was responsible for 3 pandemics in the 20^th century. As the replication of the influenza virus is based on its host's machinery, codon usage of its viral genes might be subject to host selection pressures, especially after interspecies transmission. A better understanding of viral evolution and host adaptive responses might help control this disease.     

Blood parasites of Nearctic-Neotropical migrant passerine birds during spring trans-Gulf migration: impact on host body condition

To test the hypothesis that migrants infected with blood parasites arrive on the northern coast of the Gulf of Mexico in poorer condition than uninfected birds, we examined 1705 migrant passerine birds representing 54 species of 11 families from 2 Gulf Coast sites for blood parasites. Three hundred and sixty (21.1%) were infected with 1 or more species of 4 genera of blood parasites. The prevalence of parasites was as follows: Haemoproteus spp. (11.7%), Plasmodium spp. (6.7%), Leucocytozoon spp. (1.3%), and Trypanosoma spp. (1.2%). Both prevalence and density of Haemoproteus spp. infection varied among species. We found no relationship of gender or age with the prevalence of Haemoproteus spp. infection or Plasmodium spp. infection, with the exception of the orchard oriole (Icterus spurius) for which older birds were more likely to be infected with Haemoproteus spp. than younger birds. We also found that scarlet tanagers and summer tanagers infected with species of Haemoproteus have lower fat scores than uninfected individuals and that rose-breasted grosbeaks and Baltimore orioles infected with Haemoproteus spp. have a smaller mean body mass than uninfected individuals. Blood parasites do seem to pose a physiological cost for Neotropical migrant passerines and may be important components of the ecology of these species.     

Vesicle-associated membrane protein-2 (VAMP2) mediates cAMP-stimulated renin release in mouse juxtaglomerular cells

Renin is essential for blood pressure control. Renin is stored in granules in juxtaglomerular (JG) cells, located in the pole of the renal afferent arterioles. The second messenger cAMP stimulates renin release. However, it is unclear whether fusion and exocytosis of renin-containing granules is involved. In addition, the role of the fusion proteins, SNAREs (soluble N-ethylmaleimide-sensitive factor attachment proteins), in renin release from JG cells has not been studied. The vesicle SNARE proteins VAMP2 (vesicle associated membrane protein 2) and VAMP3 mediate cAMP-stimulated exocytosis in other endocrine cells. Thus, we hypothesized that VAMP2 and/or -3 mediate cAMP-stimulated renin release from JG cells. By fluorescence-activated cell sorting, we isolated JG cells expressing green fluorescent protein and compared the relative abundance of VAMP2/3 in JG cells versus total mouse kidney mRNA by quantitative PCR. We found that VAMP2 and VAMP3 mRNA are expressed and enriched in JG cells. Confocal imaging of primary cultures of JG cells showed that VAMP2 (but not VAMP3) co-localized with renin-containing granules. Cleavage of VAMP2 and VAMP3 with tetanus toxin blocked cAMP-stimulated renin release from JG cells by ~50% and impaired cAMP-stimulated exocytosis by ~50%, as monitored with FM1-43. Then we specifically knocked down VAMP2 or VAMP3 by adenoviral-mediated delivery of short hairpin silencing RNA. We found that silencing VAMP2 blocked cAMP-induced renin release by ~50%. In contrast, silencing VAMP3 had no effect on basal or cAMP-stimulated renin release. We conclude that VAMP2 and VAMP3 are expressed in JG cells, but only VAMP2 is targeted to renin-containing granules and mediates the stimulatory effect of cAMP on renin exocytosis.     

Links between plant and fungal communities across a deforestation chronosequence in the Amazon rainforest

Understanding the interactions among microbial communities, plant communities and soil properties following deforestation could provide insights into the long-term effects of land-use change on ecosystem functions, and may help identify approaches that promote the recovery of degraded sites. We combined high-throughput sequencing of fungal rDNA and molecular barcoding of plant roots to estimate fungal and plant community composition in soil sampled across a chronosequence of deforestation. We found significant effects of land-use change on fungal community composition, which was more closely correlated to plant community composition than to changes in soil properties or geographic distance, providing evidence for strong links between above- and below-ground communities in tropical forests.     

Unique Antibody Responses to Malondialdehyde-Acetaldehyde (MAA)-Protein Adducts Predict Coronary Artery Disease

Malondialdehyde-acetaldehyde adducts (MAA) have been implicated in atherosclerosis. The purpose of this study was to investigate the role of MAA in atherosclerotic disease. Serum samples from controls (n = 82) and patients with; non-obstructive coronary artery disease (CAD), (n = 40), acute myocardial infarction (AMI) (n = 42), or coronary artery bypass graft (CABG) surgery due to obstructive multi-vessel CAD (n = 72), were collected and tested for antibody isotypes to MAA-modifed human serum albumin (MAA-HSA). CAD patients had elevated relative levels of IgG and IgA anti-MAA, compared to control patients (p<0.001). AMI patients had a significantly increased relative levels of circulating IgG anti-MAA-HSA antibodies as compared to stable angina (p<0.03) or CABG patients (p<0.003). CABG patients had significantly increased relative levels of circulating IgA anti-MAA-HSA antibodies as compared to non-obstructive CAD (p<0.001) and AMI patients (p<0.001). Additionally, MAA-modified proteins were detected in the tissue of human AMI lesions. In conclusion, the IgM, IgG and IgA anti-MAA-HSA antibody isotypes are differentially and significantly associated with non-obstructive CAD, AMI, or obstructive multi-vessel CAD and may serve as biomarkers of atherosclerotic disease.     

Novel Engineered Nanocrystalline Ultra-hydrophilic Hard Ceramic Coatings for Attachment and Growth of Bone Marrow Stromal Cells

This article has no abstract.     

基于Agent模型的生态公平指数构建与模拟

伴随着社会经济的发展,社会公平逐渐成为热点话题。社会公平问题不但体现在社会现象上,还对生态系统起着重要的影响。通过构建资本交换自主体模型,模拟社会财富分配动态过程,可观测资本交换熵指数变化情况,从而解释熵增原理。除此以外,不同系统的最终状态能达到的最大熵指数不同,用熵增原理与本文构建的最大熵指数模型可以对系统的生态公平进行纵向或横向评价。构建的资本交换熵模型也可以证明最大熵原理,同时,财富集中的现象将会使生态环境的选择权完全交予富人群体,影响可持续发展。     

The molecular basis of potassium nutrition in plants

Over the last five years, the cloning and characterization of K⁺ transport genes corresponding to K⁺ channels (KAT1, AKT1, KST1, AKT2), associated subunits (KAB1) and a high-affinity transporter (HKT1) has opened up important new avenues for research on plant K⁺ nutrition. With the abundance of molecular data now available it seems timely to link this information with the wealth of data previously accumulated on the physiology of plant K⁺ acquisition. The ultimate goal of all this research is to gain a better understanding of K⁺ transport and nutrition in the intact plant. Thus it is important to begin to integrate the molecular research with results from biochemical and physiological research conducted at the cellular, root and whole plant levels. This article will focus on describing the features of the cloned K⁺ transporters and their possible roles in mediating high- and low-affinity K⁺ uptake from the soil, as well as how K⁺ acquisition may be regulated.Abbreviations NEM N-ethyl maleimide - PCMBS p-chloromercuribenzene sulphonic acid     

On processing field and culture samples of desmids (Desmidiales,chlorophyta) for scanning electron microscopy

A procedure is outlined for preparing both field collected and laboratory grown desmid populations for scanning electron microscopy which avoids the use of the potentially hazardous chemicals glutaraldehyde and osmium tetroxide and reduces preparation time substantially. FAA is utilized both in fixation and mucilage removal, and living material can be prepared for critical point drying in as little as 90 min. Limitations of this procedure are outlined briefly and the use of SEM material in systematic studies is commented upon.