Activation of Vav and Ras through the nerve growth factor and B cell receptors by different kinases

Engagement of the B-cell antigen receptor (BCR) or the nerve growth factor receptor (NGFR/TrkA) induces activation of multiple tyrosine kinases, resulting in phosphorylation of numerous intracellular substrates. We show that addition of NGF or anti-IgM antibody leads to the early tyrosine phosphorylation of p95(vav), which is expressed exclusively in hematopoietic cells; NGF, similar to crosslinking the BCR, also results in the rapid activation of Ras. The phosphorylation of Vav and activation of Ras triggered by NGF is mediated through Trk tyrosine kinase, whereas signaling through the BCR uses a different tyrosine kinase. We also show that NGF induces tyrosine phosphorylation of Shc and its association with Grb2. Vav and Ras with the adaptor proteins Shc and Grb2 appear to serve as a link between different receptor-mediated signaling pathways and, in human B cells, may play an important regulatory role in neuroimmune interactions.     

Two-dimensional relativistic longitudinal Green's function in the presence of a moving planar dielectric-magnetic discontinuity

The current contribution is concerned with obtaining the relativistic two-dimensional (three-dimensional in relativity jargon) Green's function of a time-harmonic line current that is embedded in a moving dielectric-magnetic medium with a planar discontinuity. By applying a plane-wave (PW) spectral representation for the relativistic electromagnetic Green's function of a dielectric-magnetic medium that is moving in a uniform velocity, the exact reflected and transmitted (refracted) fields are obtained in the form of a spectral integral over PWs in the so-called laboratory and comoving frames. We investigate these spectral representations, as well as their asymptotic evaluations, and discuss the associated relativistic wave phenomena of direct reflected/transmitted rays and relativistic head waves (lateral waves).     

An equation of turbulent motion in tubes

An equation of turbulent motion in a round cylindrical channel, which involves no empirical quantities, is proposed for the first time. A solution of this equation describes the average velocity profile in all regions of the channel cross section in the entire range of turbulent Reynolds numbers. The computational model is based on taking into account the internal distributed resistance created by a turbulent “vortex backfill.”     

Online monitoring of water toxicity by use of bioluminescent reporter bacterial biochips

We describe a flow-through biosensor for online continuous water toxicity monitoring. At the heart of the device are disposable modular biochips incorporating agar-immobilized bioluminescent recombinant reporter bacteria, the responses of which are probed by single-photon avalanche diode detectors. To demonstrate the biosensor capabilities, we equipped it with biochips harboring both inducible and constitutive reporter strains and exposed it to a continuous water flow for up to 10 days. During these periods we challenged the biosensor with 2-h pulses of water spiked with model compounds representing different classes of potential water pollutants, as well as with a sample of industrial wastewater. The biosensor reporter panel detected all simulated contamination events within 0.5-2.5 h, and its response was indicative of the nature of the contaminating chemicals. We believe that a biosensor of the proposed design can be integrated into future water safety and security networks, as part of an early warning system against accidental or intentional water pollution by toxic chemicals.     

A prospective study of the association between obesity and burnout among apparently healthy men and women.

The authors prospectively tested the hypothesis that obesity predicts burnout and the reverse-causation hypothesis that burnout predicts obesity. Respondents were 724 men and 340 women, apparently healthy employees, who underwent routine periodic health examinations at 2 points of time about 18 months apart. Obesity was assessed by body mass index, waist-hip ratio, and waist circumference. In regression analyses, done separately for men and women, the authors controlled for depressive symptomatology, sport activity, and Time 1 levels of the criterion. The hypothesis that burnout predicts obesity was not supported. The authors found that Time 1 measures of obesity predicted reductions rather than the hypothesized elevations of Time 2 burnout levels. The authors also found that for male respondents with relatively higher levels of Time 1 burnout, the higher their level of Time 1 obesity measure, the lower their level of T2 burnout. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of nanoparticle dispersion in polypropylene by small-angle X-ray scattering

A small-angle X-ray scattering method has been developed for the quantitative evaluation of the effectiveness of nanoparticle dispersion in polymer matrices; it is termed the nanoscale dispersion index. This method was applied to dispersions of nanosized TiO₂ fillers in polypropylene. Master batches prepared with lower filler contents showed better dispersion as evaluated by the nanoscale dispersion index. The addition of 1,3:2,4-di(3,4-dimethylbenzylidene) sorbitol to the compounds did not affect the degree of nanoscale dispersion as estimated by the nanoscale dispersion index. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Hypertension and sickness absence: the role of perceived symptoms

The association between perceived symptoms and absenteeism was examined in five groups of employed adults: normotensives, unaware hypertensives, aware and untreated hypertensives, aware and treated hypertensives, and falsely aware normotensives. Aware hypertensives (untreated and treated) and falsely aware normotensives had a higher average of perceived symptoms than normotensives, whereas unaware hypertensives had lower. The absenteeism rate across the groups showed a similar pattern. A significant interaction of perceived symptoms by study group on absenteeism was uncovered. Hypertensives and falsely aware normotensives who reported a low level of symptoms were not absent more than their normotensive counterparts. However, aware hypertensives and falsely aware normotensives who perceived a high symptoms level showed higher absenteeism than unaware hypertensives and normotensives with a similar level. This suggests that aware hypertensives have a greater tendency than both normotensives and unaware hypertensives to equate their symptoms with ill health and to act accordingly. Special attention should be directed to aware hypertensives who perceive a threat to their health.     

The Association Between Burnout, Depression, Anxiety, and Inflammation Biomarkers: C-Reactive Protein and Fibrinogen in Men and Women.

Following the demonstrated association of employee burnout or vital exhaustion with several risk factors for cardiovascular disease (CVD) and CVD risk, the authors investigated the possibility that one of the mechanisms linking burnout with CVD morbidity is microinflammation, gauged in this study by high-sensitivity C-reactive protein (hs-CRP) and fibrinogen concentrations. Their sample included 630 women and 933 men, all apparently healthy, who underwent periodic health examinations. The authors controlled for possible confounders including 2 other negative affective states: depression and anxiety. In women, burnout was positively associated with hs-CRP and fibrinogen concentrations, and anxiety was negatively associated with them. In men, depression was positively associated with hs-CRP and fibrinogen concentrations, but not with burnout or anxiety. Thus, burnout, depression, and anxiety are differentially associated with microinflammation biomarkers, dependent on gender. (PsycINFO Database Record (c) 2010 APA, all rights reserved)