1,659 research outputs found
Street Outreach Workers: Best Practices and Lessons Learned
Street outreach workers are an important part of the Senator Charles E. Shannon Jr. Community Safety Initiative (CSI) comprehensive gang and youth violence reduction strategy in Massachusetts1. Street outreach involves the use of individuals to “work the streets,” making contact with youth in neighborhoods with high levels of gang activity. These individuals are generally not employed by the criminal justice system agencies but rather are based in community service organizations or other non- governmental agencies. Street outreach workers provide an important bridge between the community, gang-involved youth, and the agencies (whether social service or law enforcement) that respond to the problems of delinquency and gangs. This guide offers information, guidance, and lessons learned from street outreach programs nationally and within the Massachusetts Shannon CSI communities to help guide existing street outreach programs and support communities considering developing new street outreach programs
An experimental and computational investigation of the flow field about a transonic airfoil in supercritical flow with turbulent boundary-layer separation
A combined experimental and computational research program is described for testing and guiding turbulence modeling within regions of separation induced by shock waves incident in turbulent boundary layers. Specifically, studies are made of the separated flow the rear portion of an 18%-thick circular-arc airfoil at zero angle of attack in high Reynolds number supercritical flow. The measurements include distributions of surface static pressure and local skin friction. The instruments employed include highfrequency response pressure cells and a large array of surface hot-wire skin-friction gages. Computations at the experimental flow conditions are made using time-dependent solutions of ensemble-averaged Navier-Stokes equations, plus additional equations for the turbulence modeling
Self-similar structure and experimental signatures of suprathermal ion distribution in inertial confinement fusion implosions
The distribution function of suprathermal ions is found to be self-similar
under conditions relevant to inertial confinement fusion hot-spots. By
utilizing this feature, interference between the hydro-instabilities and
kinetic effects is for the first time assessed quantitatively to find that the
instabilities substantially aggravate the fusion reactivity reduction. The ion
tail depletion is also shown to lower the experimentally inferred ion
temperature, a novel kinetic effect that may explain the discrepancy between
the exploding pusher experiments and rad-hydro simulations and contribute to
the observation that temperature inferred from DD reaction products is lower
than from DT at National Ignition Facility.Comment: Revised version accepted for publication in PRL. "Copyright (2015) by
the American Physical Society.
Vitamin D and Its Effects on Glucose Homeostasis, Cardiovascular Function and Immune Function
In recent years there has been increasing interest in the non-skeletal effects of vitamin D. It has been suggested that vitamin D deficiency may influence the development of diabetes, cardiovascular dysfunction and autoimmune diseases. This review focuses on the current knowledge of the effects of vitamin D and its deficiency on cardiovascular function, glucose homeostasis and immune function, with a particular focus on children. Although, there is good evidence to show that there is an association between vitamin D deficiency and an abnormality of the above systems, there is little evidence to show that vitamin D supplementation leads to an improvement in function, especially in childhood
Involvement of Mhc Loci in immune responses that are not Ir-gene-controlled
Twenty-nine randomly chosen, soluble antigens, many of them highly complex, were used to immunize mice of two strains, C3H and B10.RIII. Lymphnode cells from the immunized mice were restimulated in vitro with the priming antigens and the proliferative response of the cells was determined. Both strains were responders to 28 of 29 antigens. Eight antigens were then used to immunize 11 congenic strains carrying different H-2 haplotypes, and the T-cell proliferative responses of these strains were determined. Again, all the strains responded to seven of the eight antigens. These experiments were then repeated, but this time -antibodies specific for the A (AA) or E (EE) molecules were added to the culture to block the in vitro responsiveness. In all but one of the responses, inhibition with both A-specific and E-specific antibodies was observed. The response to one antigen (Blastoinyces) was exceptional in that some strains were nonresponders to this antigen. Furthermore, the response in the responder strains was blocked with A-specific, but not with E-specific, antibodies. The study demonstrates that responses to antigens not controlled by Irr genes nevertheless require participation of class II Mhc molecules. In contrast to Ir gene-controlled responses involving either the A- or the E-molecule controlling loci (but never both), the responses not Ir-controlled involve participation of both A- and E-controlling loci. The lack of Ir-gene control is probably the result of complexity of the responses to multiple determinants. There is thus no principal difference between responses controlled and those not controlled by Ir genes: both types involve the recognition of the antigen, in the context of Mhc molecules
Autoinducer 2 signalling via the phosphotransferase FruA drives galactose utilization by Streptococcus pneumoniae resulting in hypervirulence
Communication between bacterial cells is crucial for the coordination of
diverse cellular processes that facilitate environmental adaptation and, in the case
of pathogenic species, virulence. This is achieved by the secretion and detection of
small signaling molecules called autoinducers, a process termed quorum sensing. To
date, the only signaling molecule recognized by both Gram-positive and Gramnegative
bacteria is autoinducer 2 (AI-2), synthesized by the metabolic enzyme LuxS
(S-ribosylhomocysteine lyase) as a by-product of the activated methyl cycle. Homologues
of LuxS are ubiquitous in bacteria, suggesting a key role in interspecies, as
well as intraspecies, communication. Gram-negative bacteria sense and respond to
AI-2 via the Lsr ABC transporter system or by the LuxP/LuxQ phosphorelay system.
However, homologues of these systems are absent from Gram-positive bacteria and
the AI-2 receptor is unknown. Here we show that in the major human pathogen
Streptococcus pneumoniae, sensing of exogenous AI-2 is dependent on FruA, a
fructose-specific phosphoenolpyruvate-phosphotransferase system that is highly conserved
in Gram-positive pathogens. Importantly, AI-2 signaling via FruA enables the
bacterium to utilize galactose as a carbon source and upregulates the Leloir pathway,
thereby leading to increased production of capsular polysaccharide and a hypervirulent
phenotype
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