Stimulatory effect of dihydroxyphenyl compounds on the aerotolerance of Spirillum volutans and Campylobacter fetus subspecies jejuni.

The aerotolerance of the microaerophilic bacterium Spirillum volutans was greatly stimulated in a defined medium by the presence of dihydroxyphenyl ferric iron-binding compounds such as nor-epinephrine at 10(-5) to 10(-6) M. Dihydroxyphenyl compounds at 2 X 10(-4) M, or iron salts (ferrous or ferric) at high concentration, greatly increased the aerotolerance of a strain of Campylobacter fetus subsp. jejuni when grown on streak plates of Brucella agar. The results suggest that the microaerophilism of these organisms might in part be caused by a failure to synthesize microbial ferric iron-binding compounds at sufficient levels to support aerobic growth.     

Beyond ecosystem modeling: A roadmap to community cyberinfrastructure for ecological data‐model integration

In an era of rapid global change, our ability to understand and predict Earth's natural systems is lagging behind our ability to monitor and measure changes in the biosphere. Bottlenecks to informing models with observations have reduced our capacity to fully exploit the growing volume and variety of available data. Here, we take a critical look at the information infrastructure that connects ecosystem modeling and measurement efforts, and propose a roadmap to community cyberinfrastructure development that can reduce the divisions between empirical research and modeling and accelerate the pace of discovery. A new era of data‐model integration requires investment in accessible, scalable, and transparent tools that integrate the expertise of the whole community, including both modelers and empiricists. This roadmap focuses on five key opportunities for community tools: the underlying foundations of community cyberinfrastructure; data ingest; calibration of models to data; model‐data benchmarking; and data assimilation and ecological forecasting. This community‐driven approach is a key to meeting the pressing needs of science and society in the 21st century.     

Certification of Probability of Sterilization of Liquid by Filtration

Four types of hydrosol filters, two reusable (diatomaceous cylinder and fritted-glass funnel) and two disposable (asbestos pad and membrane filter) were challenged with a heavy bacterial suspension to assess their ability to produce sterile filtrates. Two of the four diatomaceous earth filters, the four fritted-glass funnels, and all of the asbestos pads tested generally gave sterile filtrates. However, only one type of filter, one of the membranes in its manufacturer's own holder, consistently gave sterile filtrates. The two other types of membranes usually gave sterile filtrates if tested in one manufacturer's holder, but all types invariably gave contaminated filtrates when tested in another manufacturer's holder. Contaminated filtrates were generally attributed to a poor reusable filter or to a faulty holder used with a disposable filter. If a high degree of certainty is required for sterile heat-labile filtrate, it is suggested that the liquid be passed through two or more filters in a previously tested and proven system.     

18S rDNA的研究进展及其在膜翅目昆虫分子系统学中的应用

本文综述了18S rDNA的研究进展,主要包括了18S rDNA的结构研究,18S rDNA的网络资源利用和18S rDNA在膜翅目昆虫中的应用。     

Acquired Antibody Responses against Plasmodium vivax Infection Vary with Host Genotype for Duffy Antigen Receptor for Chemokines (DARC)

Background

Polymorphism of the Duffy Antigen Receptor for Chemokines (DARC) is associated with susceptibility to and the severity of Plasmodium vivax malaria in humans. P. vivax uses DARC to invade erythrocytes. Individuals lacking DARC are ‘resistant’ to P. vivax erythrocytic infection. However, susceptibility to P. vivax in DARC+ individuals is reported to vary between specific DARC genotypes. We hypothesized that the natural acquisition of antibodies to P. vivax blood stages may vary with the host genotype and the level of DARC expression. Furthermore, high parasitemia has been reported to effect the acquisition of immunity against pre-erythrocytic parasites. We investigated the correlation between host DARC genotypes and the frequency and magnitude of antibodies against P. vivax erythrocytic stage antigens.

Methodology/Findings

We assessed the frequencies and magnitudes of antibody responses against P. vivax and P. falciparum sporozoite and erythrocytic antigens in Colombian donors from malaria-endemic regions. The frequency and level of naturally-acquired antibodies against the P. vivax erythrocytic antigens merozoite surface protein 1 (PvMSP1) and Duffy binding protein (PvDBP) varied with the host DARC genotypes. Donors with one negative allele (FY*B/FY*Bnull and FY*A/FY*Bnull) were more likely to have anti-PvMSP1 and anti-PvDBP antibodies than those with two positive alleles (FY*B/FY*B and FY*A/FY*B). The lower IgG3 and IgG1 components of the total IgG response may account for the decreased responses to P. vivax erythrocytic antigens with FY*A/FY*B and FY*B/FY*B genotypes. No such association was detected with P. falciparum erythrocytic antigens, which does not use DARC for erythrocyte invasion.

Conclusion/Significance

Individuals with higher DARC expression, which is associated with higher susceptibility to P. vivax infection, exhibited low frequencies and magnitudes of P. vivax blood-stage specific antibody responses. This may indicate that one of the primary mechanisms by which P. vivax evades host immunity is through DARC indirectly down-regulating humoral responses against erythrocytic invasion and development.     

Conserved structural motifs in intracellular trafficking pathways: structure of the gammaCOP appendage domain

The formation of coated vesicles is a fundamental step in many intracellular trafficking pathways. COPI and clathrin represent two important and distinct sets of vesicle coating machinery, involved primarily in mediating intra-Golgi and endocytic transport, respectively. Here we identify an important functional region at the carboxyl terminus of the gamma subunit of the COPI complex (gammaCOP) and describe the X-ray crystal structure of this domain at 2.3 A resolution. This domain of gammaCOP exhibits unexpected structural similarity to the carboxyl-terminal appendage domains of the alpha and beta subunits of the AP2 adaptor proteins, integral components of clathrin-coated vesicles. The remarkable structural conservation exhibited by the gammaCOP appendage domain, coupled with functional data and primary sequence analysis, supports a model of COPI function with significant structural and mechanistic parallels to vesicular transport by the clathrin/AP2 system.     

术中静脉不向剂量右美托咪啶对全髋置换术患者术后患者芬太尼静脉自控镇痛效果的影响

目的：观察气管内全身麻醉下行全髋置换术患者,术中静脉应用不同剂量右美托咪定对术后芬太尼静脉自控镇痛效果的影响及相关不良反应发生的情况。方法：选择择期在气管内全麻下行全髋置换术的患者60 例,ASA Ⅰ ～Ⅱ级,年龄47～78 岁,体重42～79 kg。患者随机分组法分为3 组（n=20）：C 组（盐水对照组）、D1 组（右美托咪定0.5 μg/kg 组）和D2 组（右美托咪定1 μg/kg组）,在手术结束前约1 小时按分组分别给予生理盐水和右美托咪啶,术后镇痛使用芬太尼静脉自控镇痛24 h。记录患者术后2h、2～6 h、6～12 h、12～24 h芬太尼的用量;VAS 评分法评估患者术前、术后2 h、6 h、12 h、24 h 时的疼痛程度;记录镇痛期间恶心呕吐、皮肤瘙痒及过度镇静等不良反应发生的情况。结果：术后2h 和术后2～6 h芬太尼用量D1组和D2 组较C 组减少（P＜0.05）,但D1组和D2 组之间比较无差异（P＞0.05）;而术后6～12 和12～24 h三组患者芬太尼用量无差异（P＞0.05）。术后2 h、2～6 hVAS评分D1 组和D2 组较C组减少（P＜0.05）,而D1组和D2 组之间比较无差异（P＞0.05）;术后6～12、12～24 h三组患者VAS 评分无差异（P＞0.05）。与C 组比较,D1 组和D2 组镇痛期间恶心呕吐发生率降低（P＜0.05）,余不良反应各组之间比较无差异（P＞0.05）。结论：气管内全身麻醉下行全髋置换术的患者,术中静脉应用右美托咪啶可在术后6 h内增强芬太尼镇痛的效果减少芬太尼的用量,但增大剂量效果并不增加而作用时间也不延长。     

Depth gradients in food‐web processes linking habitats in large lakes: Lake Superior as an exemplar ecosystem

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