驱捕叉角羚的方法

本文介绍美国西部捕捉叉角羚的简易方法--驱捕法。主要论述了围捕设计,聚群技术和捕捉步骤。作者指出,围捕圈要选择在叉角羚集中的方圆8公里内。围捕圈包括翼栏、隐蔽处、围捕栏及围捕栏内的捕捉栏。围捕栏要设置在山脊或隆起地形物之后,以免被驱入的动物发现。另外,围捕圈的入口应确定在盛行风的30度范围内,以便直升飞机在风里工作时能得到最大的机动性。围捕栏内的捕捉栏,便于人们能从较大动物群中分出可以控制一定数量的动物进行捕捉。这个结构能使捕捉动物更容易。适时使用直升飞机及人与人拉起粗帆布形成的人列,是将动物驱入围捕栏的有效手段。此外,捕捉叉角羚时,2个人对付1个动物,能保证捕捉人员和叉角羚均不受伤害。 作者报道了1980-1985年中,每年的11-2月,用此方法成功地活捕到2110只叉角羚,与围捕直接有关的动物死亡仅2.2%。对107头叉角羚进行追踪生物遥测的结果表明,围捕后的死亡率极小以至勿需考虑。用此方法,能在2天内从建起围捕栏,捕捉、标记60-100多只成体叉角羚,然后拆除。 作者认为此项围捕方法,与以前报道过的方法比较,能在较短时间内以最小死亡率捕获到较大数量的叉角羚。     

Large-scale identification of polymorphic microsatellites using an <Emphasis Type="Italic">in silico</Emphasis> approach

Background  

Simple Sequence Repeat (SSR) or microsatellite markers are valuable for genetic research. Experimental methods to develop SSR markers are laborious, time consuming and expensive. In silico approaches have become a practicable and relatively inexpensive alternative during the last decade, although testing putative SSR markers still is time consuming and expensive. In many species only a relatively small percentage of SSR markers turn out to be polymorphic. This is particularly true for markers derived from expressed sequence tags (ESTs). In EST databases a large redundancy of sequences is present, which may contain information on length-polymorphisms in the SSR they contain, and whether they have been derived from heterozygotes or from different genotypes. Up to now, although a number of programs have been developed to identify SSRs in EST sequences, no software can detect putatively polymorphic SSRs.     

Mental practice-based rehabilitation training to improve arm function and daily activity performance in stroke patients: a randomized clinical trial

Background  

Over 50% of patients with upper limb paresis resulting from stroke face long-term impaired arm function and ensuing disability in daily life. Unfortunately, the number of effective treatments aimed at improving arm function due to stroke is still low. This study aims to evaluate a new therapy for improving arm function in sub-acute stroke patients based on mental practice theories and functional task-oriented training, and to study the predictors for a positive treatment result. It is hypothesized that a six-week, mental practice-based training program (additional to regular therapy) targeting the specific upper extremity skills important to the individual patient will significantly improve both arm function and daily activity performance, as well as being cost effective.     

PTP1B inhibitors: synthesis and evaluation of difluoro-methylenephosphonate bioisosteres on a sulfonamide scaffold

We have synthesized and evaluated a series of triaryl sulfonamide-based PTP1B inhibitors in which a difluoro-methylenephosphonate group of a potent lead has been replaced by potential bioisosteric replacements. Several mono- or di-charged compounds (8a, 8b, and 15a) were shown exhibit inhibitory activity in the low micromolar range, demonstrating the feasibility of using this approach in identifying non-phosphonate pTyr mimetics in a small molecular scaffold. These results also provide a useful indication of the relative effectiveness of these pTyr mimetics.     

Synthesis of Dideoxymycobactin Antigens Presented by CD1a Reveals T Cell Fine Specificity for Natural Lipopeptide Structures

Mycobacterium tuberculosis survival in cells requires mycobactin siderophores. Recently, the search for lipid antigens presented by the CD1a antigen-presenting protein led to the discovery of a mycobactin-like compound, dideoxymycobactin (DDM). Here we synthesize DDMs using solution phase and solid phase peptide synthesis chemistry. Comparison of synthetic standards to natural mycobacterial mycobactins by nuclear magnetic resonance and mass spectrometry allowed identification of an unexpected α-methyl serine unit in natural DDM. This finding further distinguishes these pre-siderophores as foreign compounds distinct from conventional peptides, and we provide evidence that this chemical variation influences the T cell response. One synthetic DDM recapitulated natural structures and potently stimulated T cells, making it suitable for patient studies of CD1a in infectious disease. DDM analogs differing in the stereochemistry of their butyrate or oxazoline moieties were not recognized by human T cells. Therefore, we conclude that T cells show precise specificity for both arms of the peptide, which are predicted to lie at the CD1a-T cell receptor interface.Pathogens are detected by the host when antigenic molecules directly contact immune receptors during the early stages of infection. The strategy of intracellular infection allows viruses, certain bacteria and protozoa to partially cloak themselves from the immune response by physically encapsulating their antigens within host cells. Intracellular residence also takes advantage of immune tolerance mechanisms that prevent autoimmune destruction of self. T cells play a central role in immunity to intracellular pathogens because they can respond to antigens that are generated inside cells and then transported to the surface of infected cells after binding to antigen-presenting molecules. The antigen-presenting molecules encoded in the major histocompatibility complex are widely known for presenting peptide fragments of proteins (1). More recently, human and mouse members of the CD1 (cluster of differentiation 1) system have been shown to present small amphipathic molecules, including a variety of membrane lipids, glycolipids, and lipopeptides, greatly expanding the molecular structures recognized by the cellular immune system (2, 3).Among human CD1 proteins (CD1a, CD1b, CD1c, CD1d, and CD1e), each CD1 isoform is expressed on a different spectrum of antigen-presenting cells. Human CD1a proteins are distinguished from other CD1 proteins by high expression levels on the surface of intradermal Langerhans cells, which play a role in barrier immune function (4). Human T cell clones have been shown to directly recognize CD1a proteins in the presence of exogenous foreign antigens (5) or in the presence of sulfatide and other self lipids (6, 7), suggesting a role for CD1a in T cell activation. In addition, mycobacteria and other intracellular pathogens have been shown to increase CD1a expression in lesions found in leprosy and tuberculosis patients, implying a possible role for CD1a in the response to infection, especially at mucosal or skin sites (8–10). Analysis of the molecular target recognized by CD1a-restricted T cell clone (CD8-2) allowed the identification of a foreign antigen presented by CD1a as dideoxymycobactin (DDM) (11).²Mycobactin binds iron to promote Mycobacterium tuberculosis survival. DDM was initially isolated (11) from antigenic lipid extracts of M. tuberculosis, a pathogen that kills ∼1.7 million humans annually on a worldwide basis (12). The determination of DDM structure was based on mass spectrometric and NMR studies of limiting amounts of natural material derived from the pathogenic organisms, so that not all elements of its chemical structure could be formally determined. Instead, its assigned structure was facilitated by obvious parallels of dideoxymycobactin with mycobactin, a lipopeptide siderophore (13, 14). Iron is required for reduction-oxidation reactions involving respiration and other basic metabolic pathways in bacterial pathogens (13). Environmental mycobacteria have at least two iron uptake pathways, but mycobactin and the related molecule carboxymycobactin represent the only known dedicated iron uptake pathway for pathogenic species like M. tuberculosis (15, 16). Highlighting the physiological importance of the mycobactin pathway, deletion of mycobactin synthase B limits M. tuberculosis survival in cells (13, 14). Also, mammalian innate immune systems produce siderocalin, a 20-kDa lipocalin that binds both ferric and apo siderophores, preventing their uptake and subsequent iron delivery to microbes (17–20). The small available yields of natural material highlighted the need for a straightforward method to synthesize DDM for studies of its role in mycobacterial iron acquisition and testing T cell responses in human populations, as well as to provide authentic standards to investigate unknown aspects of natural DDM stereochemistry. Here we report two syntheses for production of DDM in solution phase and solid phase. Comparison of synthetic and natural DDMs gives unexpected insight into the stereochemical structures of the methylserine, oxazoline, and butyrate moieties of DDM and provides direct evidence that the T cell response is highly specific for a unique aspect of DDM structure that protrudes from the surface of the CD1a-DDM complexes.     

The genus Teliocrinus (Crinoidea,Echinodermata): a key taxon among pentacrinid stalked crinoids

The main characters of the stalked crinoids of the family Pentacrinitidae attributed to the genus Teliocrinus are re‐evaluated from a quantitative study of phenotype variation, new observations on arm and stalk articulations, and observation of ontogenetic trends. All of the specimens collected in the northern Indian Ocean belong to the same species, i.e. Teliocrinus springeri (Clark, 1909). However, two phenotypes living at different depths remain valid as subspecies: Teliocrinus springeri springeri (Clark, 1909) and Teliocrinus springeri liliaceus (Clark, 1909). Teliocrinus shares several ontogenetic trends with Endoxocrinus, especially in nonfunctional brachial articulations and stalk symplexies. Its assignment to the Diplocrininae is confirmed. A discussion of its affinities with pentacrinid fossil genera in which the crown is well preserved suggests that Diplocrininae could have first appeared during the Lower Cretaceous. A shortening of brachitaxes and a paedomorphic trend of stalk symplexies are the main other evolutionary traits. Nonfunctional articulations are frequently found at the paedomorphic pole of the heterochronic gradient, without clear derived characters. Classification of pentacrinids mainly based on such symplesiomorphy or paedomorphic characters must be definitively abandoned. However, in post‐Palaeozoic stalked crinoids the scarcity of well‐preserved fossils, the high frequency of paedomorphy, and convergent adaptive characters makes phylogenetic reconstruction only based on morphological characters very difficult and speculative. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 22–39.     

A Neuro-Muscular Elasto-Dynamic Model of the Human Arm Part 2: Musculotendon Dynamics and Related Stress Effects

In this paper we develop an elasto-dynamic model of the human arm that includes effects of neuro-muscular control uponelastic deformation in the limb.The elasto-dynamic model of the arm is based on hybrid parameter multiple body systemvariational projection principles presented in the companion paper.Though the technique is suitable for detailed bone and jointmodeling,we present simulations for simplified geometry of the bones,discretized as Rayleigh beams with elongation,whileallowing for large deflections.Motion of the upper extremity is simulated by incorporating muscle forces derived from aHill-type model of musculotendon dynamics.The effects of muscle force are modeled in two ways.In one approach,aneffective joint torque is calculated by multiplying the muscle force by a joint moment ann.A second approach models themuscle as acting along a straight line between the origin and insertion sites of the tendon.Simple arm motion is simulated byutilizing neural feedback and feedforward control.Simulations illustrate the combined effects of neural control strategies,models of muscle force inclusion,and elastic assumptions on joint trajectories and stress and strain development in the bone andtendon.     

Comparison of linkage disequilibrium and haplotype diversity on macro- and microchromosomes in chicken

Background

Toll like receptors (TLR) play the central role in the recognition of pathogen associated molecular patterns (PAMPs). Mutations in the TLR1, TLR2 and TLR4 genes may change the ability to recognize PAMPs and cause altered responsiveness to the bacterial pathogens.

Results

The study presents association between TLR gene mutations and increased susceptibility to Mycobacterium avium subsp. paratuberculosis (MAP) infection. Novel mutations in TLR genes (TLR1- Ser150Gly and Val220Met; TLR2 – Phe670Leu) were statistically correlated with the hindrance in recognition of MAP legends. This correlation was confirmed subsequently by measuring the expression levels of cytokines (IL-4, IL-8, IL-10, IL-12 and IFN-γ) in the mutant and wild type moDCs (mocyte derived dendritic cells) after challenge with MAP cell lysate or LPS. Further in silico analysis of the TLR1 and TLR4 ectodomains (ECD) revealed the polymorphic nature of the central ECD and irregularities in the central LRR (leucine rich repeat) motifs.

Conclusion

The most critical positions that may alter the pathogen recognition ability of TLR were: the 9^th amino acid position in LRR motif (TLR1–LRR10) and 4^th residue downstream to LRR domain (exta-LRR region of TLR4). The study describes novel mutations in the TLRs and presents their association with the MAP infection.     

Do synovial biopsies help to support evidence for involvement of innate immunity in the immunopathology of Beh?et's disease?

Behçet's disease is a complex vasculitis of unknown etiology. Abundant neutrophils suggest the involvement of innate immunity. Cytokines are skewed to the T-helper-1 pattern. Few sterile organs are easily accessible for analysis in Behçet's disease. Cañete and coworkers identify inflamed joints as a feasible model and suggest the involvement of innate immunity in Behçet's disease.