Mechanomyography and oxygen consumption during incremental cycle ergometry

Brucella abortus strain RB51 was recently approved as an official brucellosis calfhood vaccine for cattle by the Animal and Plant Health Inspection Service branch of the United States Department of Agriculture. Currently available serologic surveillance tests for B. abortus do not detect seroconversion following SRB51 vaccination. The purpose of this study was to evaluate a dot-blot assay using gamma-irradiated strain RB51 bacteria for its specificity and sensitivity to detect antibody responses of cattle vaccinated with strain RB51. Dot-blot titers of sera at a recommended dosage (10(10) colony-forming units) were similar to those of sera from cattle vaccinated with similar numbers of B. abortus strain 19 and greater (P < 0.05) than titers of nonvaccinated cattle. In the first 12 weeks after vaccination with 10(10) colony-forming units of strain RB51, the RB51 dot-blot assay had 100% specificity for titers of 80 or less and a 53% sensitivity for titers of 160 or greater. Sensitivity of the RB51 dot-blot assay peaked at 4 weeks after vaccination with 10(10) colony-forming units of strain RB51. Dot-blot responses of sera from cattle vaccinated with a reduced dosage of strain RB51 (10(9) colony-forming units) did not differ (P > 0.05) from titers of sera from nonvaccinated cattle. Following intraconjunctival challenge with B. abortus strain 2308, titers on the RB51 dot-blot assay did not differ (P > 0.05) between nonvaccinated cattle and cattle vaccinated at calfhood with strain 19 or strain RB51.     

The additivity of substrate fragments in enzyme-ligand binding

BACKGROUND: Enzymes have evolved to recognise their target substrates with exquisite selectivity and specificity. Whether fragments of the substrate--perhaps never available to the evolving enzyme--are bound in the same manner as the parent substrate addresses the fundamental basis of specificity. An understanding of the relative contributions of individual portions of ligand molecules to the enzyme-binding interaction may offer considerable insight into the principles of substrate recognition. RESULTS: We report 12 crystal structures of Escherichia coli thymidylate synthase in complexes with available fragments of the substrate (dUMP), both with and without the presence of a cofactor analogue. The structures display considerable fidelity of binding mode and interactions. These complexes reveal several interesting features: the cofactor analogue enhances the localisation of substrate and substrate fragments near the reactive thiol; the ribose moiety reduces local disorder through additional specific enzyme-ligand interactions; the pyrimidine has multiple roles, ranging from stereospecificity to mechanistic competence; and the glycosidic linkage has an important role in the formation of a covalent attachment between substrate and enzyme. CONCLUSIONS: The requirements of ligand-protein binding can be understood in terms of the binding of separate fragments of the ligand. Fragments which are subsystems of the natural substrate for the enzyme confer specific contributions to the binding affinity, orientation or electrostatics of the enzymatic mechanism. This ligand-binding analysis provides a complementary method to the more prevalent approaches utilising site-directed mutagenesis. In addition, these observations suggest a modular approach for rational drug design utilising chemical fragments.     

Matching treatment focus to patient social investment and support: 18-month follow-up results.

Patients were randomly assigned to 1 of 3 treatments: brief broad-spectrum (BBS), extended relationship enhancement (ERE), or extended cognitive–behavioral (ECB). A hierarchical latent growth model was used to analyze the data of 188 patients (82%) followed for 18 months. ERE treatment was significantly more effective in increasing abstinence of patients entering treatment with a network unsupportive of abstinence or with a low level of investment in their network, whereas BBS treatment was more effective for patients with either (a) both a social network unsupportive of abstinence and a low level of network investment or (b) high investment in a network supportive of abstinence. ECB outcomes were neither as good as those matched nor as bad as those mismatched to the different exposures of relationship enhancement. This suggests that dose of relationship enhancement should be determined after assessing patient relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure of a novel phytoecdysteroid,vitexirone, and efficient isolation of phytoecdysteroids fromVitex fisherii

A novel phytoecdysteroid, vitexirone, has been isolated from a MeOH extract of the root bark of the East African medicinal plantVitex fisherii by recycling high-performance liquid chromatography on a semipreparative scale. In addition, three known phytoecdysteroids, 20-hydroxyecdysone, ajugasterone C, and turkesterone, also were isolated. The structure of vitexirone has been established spectroscopically. The position and stereochemistry of the 11--hydroxy group of ajugasterone C and vitexirone were confirmed by the¹H-¹H homonuclear COSY NMR data. These phytoecdysteroids disrupt the molting process of the pink bollwormPectinophora gossypiella.     

白炭黑胎面胶的新一代硅烷偶联剂

填充白炭黑的低滚动阻力轮胎的开发不断获得新进展。与填充普通炭黑的轮胎相比，白炭黑轮胎不仅降低了油耗，而且具有优异的牵引性能和与后者相当的磨耗寿命。高分散性白炭黑和多硫化双-烷氧基硅烷的发展使高填充白炭黑轮胎商品化获得重大突破。炭黑胶料和白炭黑-硅烷胶料的能耗散机理差异很大，     

Optimal classification methods for diagnosing latent skills and misconceptions for option-scored multiple-choice item quizzes

Behaviormetrika - The paper’s extended Diagnostic Classification Modeling setting assumes (a) nominal item (question) coding, thus&nbsp;including multiple-choice (MC) items, and (b)...     

Characterization of Nicalon fibres with varying diameters: Part II Modified Weibull distribution

Diameters vary significantly in a tow of commercial NicalonTM fibres, which is one of the most attractive ceramic reinforcements for structural composites. It was found that the strength distribution of Nicalon fibres could not be adequately characterized using either single- or bi-modal Weibull distribution. A recently proposed modified Weibull distribution can account for the effect of varying diameter in the characterization of fibre strength. To verify the validity of the modified Weibull distribution, comprehensive mechanical testing and fractographic studies have been conducted on Nicalon SiC fibres with diameters varying from 8 to 22 m. The experimental results have been reported in Part I. Part II of this paper further modifies the derivation of the modified Weibull distribution to yield a relationship which is similar in form, but soundly based on experimental findings. Factors considered in the modified Weibull distribution include the dependence of fracture toughness and flaw density on fibre diameter, both of which may vary with fibre diameter, as reported in Part I. Comparison with experimental data shows that the current modified Weibull distribution works very well, while both single-modal and bi-modal Weibull distributions are inadequate for describing Nicalon fibres with varying diameters. © 1998 Chapman & Hall     

Associations in the Course of Personality Disorders and Axis I Disorders Over Time.

In this study, the authors examined time-varying associations between schizotypal (STPD), borderline (BPD), avoidant (AVPD), or obsessive-compulsive (OCPD) personality disorders and co-occurring Axis I disorders in 544 adult participants from the Collaborative Longitudinal Personality Disorders Study. The authors tested predictions of specific longitudinal associations derived from a model of crosscutting psychobiological dimensions (L. J. Siever & K. L. Davis, 1991) with participants with the relevant Axis I disorders. The authors assessed participants at baseline and at 6-, 12-, and 24-month follow-up evaluations. BPD showed significant longitudinal associations with major depressive disorder and posttraumatic stress disorder. AVPD was significantly associated with anxiety disorders (specifically social phobia and obsessive-compulsive disorder). Two of the four personality disorders under examination (STPD and OCPD) showed little or no association with Axis I disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two-Year Stability and Change of Schizotypal, Borderline, Avoidant, and Obsessive-Compulsive Personality Disorders.

The authors examined the stability of schizotypal (STPD), borderline (BPD), avoidant (AVPD) and obsessive-compulsive (OCPD) personality disorders (PDs) over 2 years of prospective multiwave follow-up. Six hundred thirty-three participants recruited at 4 collaborating sites who met criteria for 1 or more of the 4 PDs or for major depressive disorder (MOD) without PD were assessed with semistructured interviews at baseline, 6, 12, and 24 months. Lifetable survival analyses revealed that the PD groups had slower time to remission than the MDD group. Categorically, PD remission rates range from 50% (AVPD) to 61% (STPD) for dropping below diagnostic threshold on a blind 24-month reassessment but range from 23% (STPD) to 38% (OCPD) for a more stringent definition of improvement. Dimensionally, these findings suggest that PDs may be characterized by maladaptive trait constellations that are stable in their structure (individual differences) but can change in severity or expression over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)