Combined observations of meteors by image-orthicon television camera and multi-station radar

Observations from multiple sites of a radar network and by television of 29 individual meteors from February 1969 through June 1970 are reported. Only 12 of the meteors did not appear to fragment over all the observed portion of their trajectories. From these 12, the relation for the radar magnitude to the panchromatic absolute magnitude was found in terms of velocity of the meteor. A very tentative fit to the data on the duration of long enduring echoes versus visual absolute magnitude is made. The exponential decay characteristics of the later parts of several of the light curves are pointed out as possible evidence of mutual coalescence of droplets into which the meteoroid has completely broken

Impact of Obesity on Metabolic Syndrome in Brazilian Adolescents: A Population-Based Study

Universidade Federal de São Paulo, Escola Paulista Med, Dept Postgrad, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pediat, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Endocrinol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Postgrad, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pediat, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Endocrinol, São Paulo, BrazilWeb of Scienc

Association Between Continued Cannabis Use and Risk of Relapse in First-Episode Psychosis: A Quasi-Experimental Investigation Within an Observational Study

IMPORTANCE: Cannabis use after first-episode psychosis is associated with poor outcomes, but the causal nature of this association is unclear. OBJECTIVE: To examine the precise nature of the association between continued cannabis use after the onset of psychosis and risk of relapse of psychosis. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study followed up for at least 2 years after the onset of psychosis 220 patients who presented to psychiatric services in South London, England, from April 12, 2002, to July 26, 2013, with first-episode psychosis. Longitudinal modeling (fixed-effects analysis, cross-lagged path analysis) was used to examine whether the association between changes in cannabis use and risk of relapse over time is the result of shared vulnerability between psychosis and cannabis use, psychosis increasing the risk of cannabis use (reverse causation), or a causal effect of cannabis use on psychosis relapse. INTERVENTIONS: Exposure to cannabis within the first and second years after onset of psychosis. MAIN OUTCOMES AND MEASURES: The main outcome measure was relapse of psychosis, defined as subsequent hospitalization for psychosis. Effect of cannabis use status in the first year (Ct1) and second year (Ct2) and pattern of cannabis use continuation in the first year and second year were modeled for risk of relapse in the first year (Rt1) and risk of relapse in the second year (Rt2) after psychosis onset. RESULTS: A total of 220 patients with first-episode psychosis were included in the analysis (mean [SD] age, 28.62 [8.58] years; age range, 18-65 years; 90 women [40.9%] and 130 men [59.1%]). Fixed-effects models that adjusted for time-variant (other illicit drug use, antipsychotic medication adherence) and time-invariant (eg, genetic or premorbid environment) unobserved confounders revealed that there was an increase in the odds of experiencing a relapse of psychosis during periods of cannabis use relative to periods of no use (odds ratio, 1.13; 95% CI, 1.03-1.24). Change in the pattern of continuation significantly increased the risk (odds ratio, 1.07; 95% CI, 1.02-1.13), suggesting a dose-dependent association. Cross-lagged analysis confirmed that this association reflected an effect of cannabis use on subsequent risk of relapse (Ct1→Rt2: β = 0.44, P = .04) rather than an effect of relapse on subsequent cannabis use (Rt1→Ct2: β = -0.29, P = .59). CONCLUSIONS AND RELEVANCE: These results reveal a dose-dependent association between change in cannabis use and relapse of psychosis that is unlikely to be a result of self-medication or genetic and environmental confounding

The Core-Collapse Supernova Rate in Arp299 Revisited

We present a study of the CCSN rate in nuclei A and B1 of the luminous infrared galaxy Arp299, based on 11 years of Very Large Array monitoring of their radio emission at 8.4 GHz. Significant variations in the nuclear radio flux density can be used to identify the CCSN activity in the absence of high-resolution very long baseline interferometry observations. In the case of the B1-nucleus, the small variations in its measured diffuse radio emission are below the fluxes expected from radio supernovae, thus making it well-suited to detect RSNe through flux density variability. In fact, we find strong evidence for at least three RSNe this way, which results in a lower limit for the CCSN rate of 0.28 +/- 0.16 per year. In the A-nucleus, we did not detect any significant variability and found a SN detection threshold luminosity which allows only the detection of the most luminous RSNe known. Our method is basically blind to normal CCSN explosions occurring within the A-nucleus, which result in too small variations in the nuclear flux density, remaining diluted by the strong diffuse emission of the nucleus itself. Additionally, we have attempted to find near-infrared counterparts for the earlier reported RSNe in the Arp299 nucleus A, by comparing NIR adaptive optics images from the Gemini-N telescope with contemporaneous observations from the European VLBI Network. However, we were not able to detect NIR counterparts for the reported radio SNe within the innermost regions of nucleus A. While our NIR observations were sensitive to typical CCSNe at 300 mas from the centre of the nucleus A, suffering from extinction up to A_v~15 mag, they were not sensitive to such highly obscured SNe within the innermost nuclear regions where most of the EVN sources were detected. (abridged)Comment: 12 pages, 4 figures and 7 tables. Accepted for publication in MNRA

Charged kaon lifetime at KLOE

Preliminary result on the charged kaon lifetime, obtained by the KLOE experiment operating at DA$\Phi$NE, the Frascati $\phi$-factory, is presentedComment: 3 pages, 3 figures, to appear in the proceedings of 42nd Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Aosta Valley, Italy, 10-17 Mar 200