The rapid decline of the prompt emission in Gamma-Ray Bursts

Many gamma ray bursts (GRBs) have been observed with the Burst-Alert and X-Ray telescopes of the Swift satellite. The successive `pulses' of these GRBs end with a fast decline and a fast spectral softening, until they are overtaken by another pulse, or the last pulse's decline is overtaken by a less rapidly-varying `afterglow'. The fast decline-phase has been attributed, in the currently-explored standard fireball model of GRBs, to `high-latitude' synchrotron emission from a collision of two conical shells. This high latitude emission does not explain the observed spectral softening. In contrast, the temporal behaviour and the spectral evolution during the fast-decline phase agree with the predictions of the cannonball model of GRBs.Comment: Four added figures comparing the evolution of the inferred effective photon spectral index during the fast decline phase of the prompt emission in 14 selected Swift GRBS and the cannonball (CB) model predictio

Immunological Characterization and Neutralizing Ability of Monoclonal Antibodies Directed Against Botulinum Neurotoxin Type H.

BackgroundOnly Clostridium botulinum strain IBCA10-7060 produces the recently described novel botulinum neurotoxin type H (BoNT/H). BoNT/H (N-terminal two-thirds most homologous to BoNT/F and C-terminal one-third most homologous to BoNT/A) requires antitoxin to toxin ratios ≥1190:1 for neutralization by existing antitoxins. Hence, more potent and safer antitoxins against BoNT/H are needed.MethodsWe therefore evaluated our existing monoclonal antibodies (mAbs) to BoNT/A and BoNT/F for BoNT/H binding, created yeast-displayed mutants to select for higher-affinity-binding mAbs by using flow cytometry, and evaluated the mAbs' ability to neutralize BoNT/H in the standard mouse bioassay.ResultsAnti-BoNT/A HCC-binding mAbs RAZ1 and CR2 bound BoNT/H with high affinity. However, only 1 of 6 BoNT/F mAbs (4E17.2A) bound BoNT/H but with an affinity >800-fold lower (equilibrium dissociation binding constant [KD] = 7.56 × 10(-8)M) than its BoNT/F affinity (KD= 9.1 × 10(-11)M), indicating that the N-terminal two-thirds of BoNT/H is immunologically unique. The affinity of 4E17.2A for BoNT/H was increased >500-fold to KD= 1.48 × 10(-10)M (mAb 4E17.2D). A combination of mAbs RAZ1, CR2, and 4E17.2D completely protected mice challenged with 280 mouse median lethal doses of BoNT/H at a mAb dose as low as 5 µg of total antibody.ConclusionsThis 3-mAb combination potently neutralized BoNT/H and represents a potential human antitoxin that could be developed for the prevention and treatment of type H botulism

Adaptive Subcarrier PSK Intensity Modulation in Free Space Optical Systems

We propose an adaptive transmission technique for free space optical (FSO) systems, operating in atmospheric turbulence and employing subcarrier phase shift keying (S-PSK) intensity modulation. Exploiting the constant envelope characteristics of S-PSK, the proposed technique offers efficient utilization of the FSO channel capacity by adapting the modulation order of S-PSK, according to the instantaneous state of turbulence induced fading and a pre-defined bit error rate (BER) requirement. Novel expressions for the spectral efficiency and average BER of the proposed adaptive FSO system are presented and performance investigations under various turbulence conditions and target BER requirements are carried out. Numerical results indicate that significant spectral efficiency gains are offered without increasing the transmitted average optical power or sacrificing BER requirements, in moderate-to-strong turbulence conditions. Furthermore, the proposed variable rate transmission technique is applied to multiple input multiple output (MIMO) FSO systems, providing additional improvement in the achieved spectral efficiency as the number of the transmit and/or receive apertures increases.Comment: Submitted To IEEE Transactions On Communication

Psoriatic Arthritis and Diabetes: A Population-Based Cross-Sectional Study

Background. Diabetes has been associated with psoriasis, but little is known about the association between psoriatic arthritis and diabetes. Methods. Patients diagnosed with psoriatic arthritis by a rheumatologist were compared to age- and sex-matched patients without psoriatic arthritis regarding the prevalence of diabetes in a population-based cross-sectional study using logistic multivariate models. The study was performed utilizing the medical database of Clalit, the largest healthcare provider organization in Israel. Results. The study included 549 patients with psoriatic arthritis ≥21 years and 1,098 patients without psoriatic arthritis. The prevalence of diabetes in patients with psoriatic arthritis was increased as compared to the prevalence in patients without psoriatic arthritis (15.3% versus 10.7%, value = 0.008). The difference was prominent among females (18.7% versus 10.3%, ) but not among males (11.2% in patients with and without psoriatic arthritis, ). In a multivariate analysis, psoriatic arthritis was associated with diabetes among females (OR = 1.60, 95% CI: 1.02–2.52, ) but not among males (OR = 0.71, 95% CI: 0.42–1.22, ). Conclusion. Our study suggests a possible association between psoriatic arthritis and diabetes in women. Women with psoriatic arthritis might be candidates for diabetes screening

Low rate of non-attenders to primary care providers in Israel - a retrospective longitudinal study

BACKGROUND: A model that combines reactive and anticipatory care within routine consultations has become recognized as a cost-effective means of providing preventive health care, challenging the need of the periodic health examination. As such, opportunistic screening may be preferable to organized screening. Provision of comprehensive preventive healthcare within the primary care system depends on regular attendance of the general population to primary care physicians (PCPs). Objectives: To assess the proportion of patients who do not visit a PCP even once during a four-year period, and to describe the characteristics of this population. METHODS: An observational study, based on electronic medical records of 421,012 individuals who were members of one district of Clalit Health Services, the largest health maintenance organization in Israel. RESULTS: The average annual number of visits to PCPs was 7.6 ± 8.7 to 8.3 ± 9.0 (median 5, 25%-75% interval 1–11) and 9.5 ± 10.0 to10.2 ± 10.4 (median 6, 25%-75% interval 1–14) including visits to direct access consultants) in the four years of the study. During the first year of the study 87.2% of the population visited a PCP. During the four year study period, only 1.5% did not visit a PCP even once. In a multivariate analysis having fewer chronic diseases (for each additional chronic disease the OR, 95% CI was 0.40 (0.38¬0.42)), being a new immigrant (OR, 95% CI 2.46 (2.32¬2.62)), and being male (OR, 95% CI 1.66 (1.58¬1.75)) were the strongest predictors of being a non-attender to a PCP for four consecutive years. CONCLUSIONS: The rate of nonattendance to PCPs in Israel is low. Other than new immigrant status, none of the characteristics identified for nonattendance suggest increased need for healthcare services

Is the Hyporheic Zone Relevant beyond the Scientific Community?

Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by multiple scientific disciplines for almost half a century. These previous efforts have shown that the hyporheic zone is a modulator for most metabolic stream processes and serves as a refuge and habitat for a diverse range of aquatic organisms. It also exerts a major control on river water quality by increasing the contact time with reactive environments, which in turn results in retention and transformation of nutrients, trace organic compounds, fine suspended particles, and microplastics, among others. The paper showcases the critical importance of hyporheic zones, both from a scientific and an applied perspective, and their role in ecosystem services to answer the question of the manuscript title. It identifies major research gaps in our understanding of hyporheic processes. In conclusion, we highlight the potential of hyporheic restoration to efficiently manage and reactivate ecosystem functions and services in river corridors. View Full-Tex