Germanium Detector with Internal Amplification for Investigation of Rare Processes

Device of new type is suggested - germanium detector with internal amplification. Such detector having effective threshold about 10 eV opens up fresh opportunity for investigation of dark matter, measurement of neutrino magnetic moment, of neutrino coherent scattering at nuclei and for study of solar neutrino problem. Construction of germanium detector with internal amplification and perspectives of its use are described.Comment: 13 pages, latex, 3 figures, report at NANP-99, International Conference on Non-Accelerator Physics, Dubna, Russia, June 29- July 3, 1999. To be published in the Proceeding

Waxing Monkey Frogs in the Wild

This is where the abstract of this record would appear. This is only demonstration data

Exosomes containing HIV protein Nef reorganize lipid rafts potentiating inflammatory response in bystander cells.

HIV infection has a profound effect on "bystander" cells causing metabolic co-morbidities. This may be mediated by exosomes secreted by HIV-infected cells and containing viral factors. Here we show that exosomes containing HIV-1 protein Nef (exNef) are rapidly taken up by macrophages releasing Nef into the cell interior. This caused down-regulation of ABCA1, reduction of cholesterol efflux and sharp elevation of the abundance of lipid rafts through reduced activation of small GTPase Cdc42 and decreased actin polymerization. Changes in rafts led to re-localization of TLR4 and TREM-1 to rafts, phosphorylation of ERK1/2, activation of NLRP3 inflammasome, and increased secretion of pro-inflammatory cytokines. The effects of exNef on lipid rafts and on inflammation were reversed by overexpression of a constitutively active mutant of Cdc42. Similar effects were observed in macrophages treated with exosomes produced by HIV-infected cells or isolated from plasma of HIV-infected subjects, but not with exosomes from cells and subjects infected with ΔNef-HIV or uninfected subjects. Mice injected with exNef exhibited monocytosis, reduced ABCA1 in macrophages, increased raft abundance in monocytes and augmented inflammation. Thus, Nef-containing exosomes potentiated pro-inflammatory response by inducing changes in cholesterol metabolism and reorganizing lipid rafts. These mechanisms may contribute to HIV-associated metabolic co-morbidities

Ecology of Aedes Mosquitoes, the Major Vectors of Arboviruses in Human Population

Aedes aegypti (Stegomyia) has been human vectors for many human diseases globally. In recent years, dengue virus has been diagnosed in different regions such as Asia and Latin America vectored by Aedes spp. mosquitoes. Dengue cases have been reported again in the several parts of African and other continental hospital. The different types of breeding sites have been found to be abundant in both urban and rural areas. The abundance of adult Ae. aegypti and habitat productivity in different settings escalates the risk of dengue transmission if viruses are found in asymptomatic population. The insecticide resistance has been found to occur in the wild population of Aedes aegypti to insecticides commonly used for indoor residual spray and long-lasting insecticidal net treatments. The control of human vector population is still a challenge as the vector has a diurnal feeding and outdoor resting behavior. Environmental management is still the best practice to be adopted in many countries for Aedes aegypti control. The currently discovered dengue vaccine might be an immediate arsenal for the community immunization

Long-term changes of serum chemokine levels in vaccinated military personnel

BACKGROUND: Members of the United States Armed Forces receive a series of vaccinations during their course of service. To investigate the influence of multiple vaccinations on innate immunity, we measured concentrations of a panel of immunomodulatory and pro-inflammatory cytokines in serum samples from a group of such individuals. RESULTS: Significantly increased levels of macrophage inflammatory protein 1α (MIP-1α), MIP-1β and interleukin 8 (IL-8) were detected. Since these cytokines are known to have anti-human immunodeficiency virus (HIV) activity, we tested the effect of serum from these individuals on HIV-1 infectivity and susceptibility of their peripheral blood mononuclear cells (PBMCs) to HIV-1 infection in vitro. Sera from vaccinated military personnel inhibited, and their PBMCs were partially resistant to, infection by HIV-1 strains tropic to CCR5 (R5), but not to CXCR4 (X4), chemokine receptor. CONCLUSION: These findings demonstrate that increased anti-HIV chemokines can be detected in vaccine recipients up to 68 weeks following immunization

Emergence of Minor Populations of Human Immunodeficiency Virus Type 1 Carrying the M184V and L90M Mutations in Subjects Undergoing Structured Treatment Interruptions

The use of structured treatment interruption (STI) in human immunodeficiency virus (HIV)-infected subjects is currently being studied as an alternative therapeutic strategy for HIV-1. The potential risk for selection of drug-resistant HIV-1 variants during STI is unknown and remains a concern. Therefore, the emergence of drug resistance in sequential plasma samples obtained from 28 subjects with chronic HIV infection was studied. They underwent 4 cycles of 2-week STI, followed by 8-week retreatment with highly active antiretroviral therapy identical to that used before STI, and they had never failed treatment before undergoing STI. At week 40, treatment was stopped for a longer period. Minor populations of drug-resistant variants were detected by quantitative real-time polymerase chain reaction, by use of allele-discriminating oligonucleotides for 2 key resistance mutations: L90M (protease) and M184V (reverse transcriptase). The approximate discriminative power was 0.1%. In 14 of 25 and in 3 of 25 subjects, the M184V and the L90M mutations, respectively, were detected as minor populations, at different times during STI. Overall, these results indicate that, in subjects undergoing multiple STIs, HIV-1 variants carrying drug-resistance mutations can emerge during periods of increased HIV-1 replicatio

Neutrino scattering on polarized electron target and neutrino magnetic moment

The completed and proposed experiments for the measurement of the neutrino magnetic moment are discussed. To improve the sensitivity of the search for the neutrino magnetic moment we suggest to use a polarized electron target in the processes of neutrino (antineutrino) -- electron scattering. It is shown that in this case the weak interaction term in the total cross section is few times smaller comparing with unpolarized case, but the electromagnetic term does not depend on electron polarization.Comment: 12 pages, 7 figures. Talk given at the XXVIII ITEP Winter School of Physics, Snegiri, Russia, February 22 - March 1, 200

Large-Mass Ultra-Low Noise Germanium Detectors: Performance and Applications in Neutrino and Astroparticle Physics

A new type of radiation detector, a p-type modified electrode germanium diode, is presented. The prototype displays, for the first time, a combination of features (mass, energy threshold and background expectation) required for a measurement of coherent neutrino-nucleus scattering in a nuclear reactor experiment. The device hybridizes the mass and energy resolution of a conventional HPGe coaxial gamma spectrometer with the low electronic noise and threshold of a small x-ray semiconductor detector, also displaying an intrinsic ability to distinguish multiple from single-site particle interactions. The present performance of the prototype and possible further improvements are discussed, as well as other applications for this new type of device in neutrino and astroparticle physics (double-beta decay, neutrino magnetic moment and WIMP searches).Comment: submitted to Phys. Rev.