Relevance of the antibody response against human immunodeficiency virus type 1 envelope to vaccine design

Understanding the antibody response in HIV-1 infection is important to vaccine design. We have studied the antibody response to HIV-1 envelope at the molecular level and determined the characteristics of neutralizing and non-neutralizing antibodies. These antibodies were isolated from phage display libraries prepared from long-term seropositive asymptomatic individuals. The HIV-1 envelope is presented to the immune system in several antigenically distinct configurations: unprocessed gp160, gp120 and gp41 subunits and native envelope, each of which may be important in eliciting an antibody response in HIV-1 infection. The antibodies tested characteristically had poor affinities for native envelope as expressed on the surface of virions or infected cells, but had high affinities against non-native forms of HIV-1 envelope (viral debris). An exceptionally potent neutralizing antibody in contrast, bound native envelope with equivalent or somewhat higher affinity than this. This indicates that the antibody response in HIV-1 infection is principally elicited by viral debris rather than virions, and that these antibodies bind and neutralize viruses sub-optimally. Potential vaccines should be designed to elicit responses against native envelope.     

A reexamination of the relation between halo error and accuracy.

The traditional assumption has been that halo error is negatively related to accuracy of ratings. W. H. Cooper (1981) evaluated this assumption by examining correlation coefficients between measures of accuracy and halo error from five earlier studies of performance and trait ratings. Because the correlation coefficients were typically positive, Cooper concluded that a "paradoxical" positive relation exists between halo error and accuracy. However, there is no paradox; some of these positive correlation coefficients were between halo error and inaccuracy, whereas others were based on analyses that did not take into consideration negative halo errors. When analyses that correct these problems were performed on two sets of data (R. Tallarigo, 1986, n?=?107; R. J. Vance, K. W. Kuhnert, & J. L. Farr, 1978, n?=?112), all significant (p?negative. The use of halo error measures, the possibility of negative halo errors, and implications of the results for rater training are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of fabrication procedure on the electrochemical performance of Ag/AgCl reference electrodes

The influence of several parameters in the preparation procedure of thermal–electrolytic Ag/AgCl electrodes on the resulting electrode performance has been studied. In particular, we report the effect on electrode performance of subtle variations in the preparation of silver oxide paste used for electrode manufacture, in thermal annealing conditions employed and in the procedure for electrochemically converting a fraction of the electrode from silver to silver chloride. Scanning electron microscopy and electrochemical impedance spectroscopy have been used to study the characteristics of the electrodes produced. This work reveals a correlation between the electrochemical behaviour and surface physical characteristics – in particular electrode porosity. The outputs of this study have positive implications for improving the accuracy and comparability of primary pH measurement.     

"Environmental and personal determinants of support perceptions: Three generalizability studies.": Correction.

Reports an error in the original article by B. Lakey et al (Journal of Personality & Social Psychology, 1996 [Jun], Vol 70(6), 1270–1280. On page 1274, the degrees of freedom for several of the terms were incorrectly reported. In addition, the first author's name in the reference citation for Gurung et al. (1994) on p. 1279 contained a typographical error. (The following abstract of this article originally appeared in record 1996-01769-014). The extent to which perceived social support reflects characteristics of the environment, the personality of the perceiver, and their interaction is unknown. This article shows how the methods of generalizability theory can be used to address these questions. When participants rate the same targets on the targets' supportiveness, generalizability theory provides methods for determining the extent to which support judgments are determined by effects due to targets (supporters), perceivers, and their interaction. In 3 studies, each source of variance made significant contributions to support judgments, with the Perceivers–Supporters interaction, characteristics of supporters, and biases of perceivers making the largest contributions, respectively. The implications for theoretical models of perceived support are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reactivity of Candida albicans germ tubes with salivary secretory IgA

Salivary secretory IgA (sIgA) has been shown to react with a group of heat shock mannoproteins preferentially expressed on yeast cells grown at 37 degrees C. Since at this temperature C. albicans can induce germ tubes, we explored the role of germ tube induction on human salivary sIgA reactivity in both germinative and agerminative C. albicans strains, in an attempt to investigate whether the germ tube expressed the heat shock mannoproteins reactive with sIgA. The reactivity with sIgA of the agerminative strain, grown at 25 and 37 degrees C for different times, was measured spectrofluorometrically and was fairly constant with time. Yeast cells grown at 37 degrees C tended to be more reactive than those grown at 25 degrees C. In contrast, when compared with the yeast cells of the germinative strain grown at 25 degrees C, there was a statistically significant decrease in reactivity with sIgA during germ tube formation. Serum IgA and IgG did not show statistically significant changes in reactivity with C. albicans during germination, suggesting differences in reactivity with C. albicans cell wall antigens between mucosal and systemic humoral responses. Cell wall mannoproteins of molecular masses > 60 kDa were characterized by Western blotting as responsible for the decrease in sIgA reactivity observed in the germ tube, and the fall in sIgA reactivity was related to the release of cell wall mannoproteins into the culture medium. The release of these mannoproteins may be a mechanism whereby C. albicans avoids the action of sIgA, and it may play an important role in the post-parasite relationship in oral candidiasis.     

Modeling of laser annealing

Processes inducing micro- and nano-structural modifications of materials play a crucial role in the advanced technology. In particular, laser irradiation attracts a great interest as a tool for the localized thermal treatment (laser thermal annealing) when the global heating of the sample could be detrimental. With the expansion of the application fields, a research effort is required to understand the kinetics in systems subjected to extreme transient excitations induced by the interaction with the laser light. Modeling and simulations cover a relevant part of this research effort. In this paper we review the current status of the laser annealing modeling. The theoretical analysis will be restricted to the heating stage of the irradiation, i.e. the ultrafast energy transfer from the electronic states to the lattice vibrations will not be considered. Therefore, the timescale of the process must be larger than ～1 ns. Models, numerical methods and applications to the experiments will be presented to deal with different questions. Among them: the simulation of the thermal field when the heat absorption depends consistently on the temperature, the prediction of a phase change kinetics in a melting process including the redistribution of alloyed systems, the damage evolution in the transient non-uniform thermal field promoted by the irradiation induced kinetics, the related dopant activation kinetics. Numerical techniques include: continuum, kinetic Monte Carlo and molecular dynamics approaches.     

Use of a non-conventional synthetic basestock in the formulation of high-quality engine oils

Research has been undertaken to identify new synthetic basestocks, to be used alone or with polyalphaolefins, for the formulation of high-quality engine oils. Basestock selection was limited to products not normally used in the synthesis of ester-type basestocks. A non-conventional product was identified: a carbonic ester of synthetic alcohols. A complete engine oil has been formulated using this basestock and submitted to a full test programme. The results are reported.     

Human Serine Racemase Weakly Binds the Third PDZ Domain of PSD-95

Human serine racemase (hSR) is a pyridoxal-5′-phosphate (PLP)-dependent dimer that catalyzes the formation of D-serine from L-serine, as well as the dehydration of both L- and D-serine to pyruvate and ammonia. As D-serine is a co-agonist of N-methyl-D-aspartate receptors (NMDARs), hSR is a key enzyme in glutamatergic neurotransmission. hSR activity is finely regulated by Mg²⁺, ATP, post-translational modifications, and the interaction with protein partners. In particular, the C-terminus of murine SR binds the third PDZ domain (PDZ3) of postsynaptic density protein 95 (PSD-95), a member of the membrane-associated guanylate kinase (MAGUK) family involved in the trafficking and localization of glutamate receptors. The structural details of the interaction and the stability of the complex have not been elucidated yet. We evaluated the binding of recombinant human PSD-95 PDZ3 to hSR by glutaraldehyde cross-linking, pull-down assays, isothermal titration calorimetry, nuclear magnetic resonance, and enzymatic assays. Overall, a weak interaction was observed, confirming the binding for the human orthologs but supporting the hypothesis that a third protein partner (i.e., stargazin) is required for the regulation of hSR activity by PSD-95 and to stabilize their interaction.     

A note on state individual differences in accuracy of response imagery: aftereffects and reminiscence

In two sessions, separated by 7 days, subjects imagined themselves performing a tracking task under a massed practice schedule. After conditions of interpolated rest and no-rest, which were counterbalanced across sessions, subjects actually performed the tracking task. During imagery practice, subjects verbally reported the temporal component of the task. The temporal accuracy of verbal reports varied widely across subjects, but not within subjects. Furthermore, a performance gain was demonstrated as a function of interpolated rest versus no-rest (reminiscence effect). Finally, the accuracy of verbal reports predicted imagery aftereffects, but not reminiscence effects.