Type Ia Supernovae as Stellar Endpoints and Cosmological Tools

Empirically, Type Ia supernovae are the most useful, precise, and mature tools for determining astronomical distances. Acting as calibrated candles they revealed the presence of dark energy and are being used to measure its properties. However, the nature of the SN Ia explosion, and the progenitors involved, have remained elusive, even after seven decades of research. But now new large surveys are bringing about a paradigm shift --- we can finally compare samples of hundreds of supernovae to isolate critical variables. As a result of this, and advances in modeling, breakthroughs in understanding all aspects of SNe Ia are finally starting to happen.Comment: Invited review for Nature Communications. Final published version. Shortened, update

ARHGEF7 (BETA-PIX) Acts as Guanine Nucleotide Exchange Factor for Leucine-Rich Repeat Kinase 2

Background: Mutations within the leucine-rich repeat kinase 2 (LRRK2) gene are a common cause of familial and sporadic Parkinson’s disease. The multidomain protein LRRK2 exhibits overall low GTPase and kinase activity in vitro. Methodology/Principal Findings: Here, we show that the rho guanine nucleotide exchange factor ARHGEF7 and the small GTPase CDC42 are interacting with LRRK2 in vitro and in vivo. GTPase activity of full-length LRRK2 increases in the presence of recombinant ARHGEF7. Interestingly, LRRK2 phosphorylates ARHGEF7 in vitro at previously unknown phosphorylation sites. We provide evidence that ARHGEF7 might act as a guanine nucleotide exchange factor for LRRK2 and that R1441C mutant LRRK2 with reduced GTP hydrolysis activity also shows reduced binding to ARHGEF7. Conclusions/Significance: Downstream effects of phosphorylation of ARHGEF7 through LRRK2 could be (i) a feedback control mechanism for LRRK2 activity as well as (ii) an impact of LRRK2 on actin cytoskeleton regulation. A newly identified familial mutation N1437S, localized within the GTPase domain of LRRK2, further underlines the importance of the GTPas

"Now we are in a different time; various bad diseases have come." understanding men's acceptability of male circumcision for HIV prevention in a moderate prevalence setting

Background: Adult male surgical circumcision (MC) has been shown to reduce HIV acquisition in men and is recommended by the WHO for inclusion in comprehensive national HIV prevention programs in high prevalence settings. Only limited research to date has been conducted in countries experiencing moderate burden epidemics, where the acceptability, operational feasibility and potential epidemiological impact of MC remain unclear. Methods. A multi-method qualitative research study was conducted at four sites in Papua New Guinea (PNG), with 24 focus group discussions and 65 in-depth interviews carried out among 276 men. Results: The majority of men were in favour of MC being introduced for HIV prevention in PNG and considered improved genital hygiene, enhanced sexual pleasure and culturally appropriateness key factors in the acceptability of a future intervention. A minority of men were against the introduction of MC, primarily due to concerns regarding sexual risk compensation and that the intervention went against prevailing cultural and religious beliefs. Conclusion: This is one of the first community-based MC acceptability studies conducted in a moderate prevalence setting outside of Africa. Research findings from this study suggest that a future MC program for HIV prevention would be widely accepted by men in PNG

Recent advances in gastrointestinal oncology - updates and insights from the 2009 annual meeting of the American Society of Clinical Oncology

We have reviewed the pivotal presentations related to gastrointestinal malignancies from 2009 annual meeting of the American Society of Clinical Oncology with the theme of "personalizing cancer care". We have discussed the scientific findings and the impact on practice guidelines and ongoing clinical trials. Adding trastuzumab to chemotherapy improved the survival of patients with advanced gastric cancer overexpressing human epidermal growth factor receptor 2. Gemcitabine plus cisplatin has become a new standard for first-line treatment of advanced biliary cancer. Octreotide LAR significantly lengthened median time to tumor progression compared with placebo in patients with metastatic neuroendocrine tumors of the midgut. Addition of oxaliplatin to fluoropyrimidines for preoperative chemoradiotherapy in patients with stage II or III rectal cancer did not improve local tumor response but increased toxicities. Bevacizumab did not provide additional benefit to chemotherapy in adjuvant chemotherapy for stage II or III colon cancer. In patients with resected stage II colon cancer, recurrence score estimated by multigene RT-PCR assay has been shown to provide additional risk stratification. In stage IV colorectal cancer, data have supported the routine use of prophylactic skin treatment in patients receiving antibody against epidermal growth factor receptor, and the use of upfront chemotherapy as initial management in patients with synchronous metastasis without obstruction or bleeding from the primary site

SCAview: an Intuitive Visual Approach to the Integrative Analysis of Clinical Data in Spinocerebellar Ataxias

With SCAview, we present a prompt and comprehensive tool that enables scientists to browse large datasets of the most common spinocerebellar ataxias intuitively and without technical effort. Basic concept is a visualization of data, with a graphical handling and filtering to select and define subgroups and their comparison. Several plot types to visualize all data points resulting from the selected attributes are provided. The underlying synthetic cohort is based on clinical data from five different European and US longitudinal multicenter cohorts in spinocerebellar ataxia type 1, 2, 3, and 6 (SCA1, 2, 3, and 6) comprising > 1400 patients with overall > 5500 visits. First, we developed a common data model to integrate the clinical, demographic, and characterizing data of each source cohort. Second, the available datasets from each cohort were mapped onto the data model. Third, we created a synthetic cohort based on the cleaned dataset. With SCAview, we demonstrate the feasibility of mapping cohort data from different sources onto a common data model. The resulting browser-based visualization tool with a thoroughly graphical handling of the data offers researchers the unique possibility to visualize relationships and distributions of clinical data, to define subgroups and to further investigate them without any technical effort. Access to SCAview can be requested via the Ataxia Global Initiative and is free of charge

Identifying an indoor air exposure limit for formaldehyde considering both irritation and cancer hazards

Formaldehyde is a well-studied chemical and effects from inhalation exposures have been extensively characterized in numerous controlled studies with human volunteers, including asthmatics and other sensitive individuals, which provide a rich database on exposure concentrations that can reliably produce the symptoms of sensory irritation. Although individuals can differ in their sensitivity to odor and eye irritation, the majority of authoritative reviews of the formaldehyde literature have concluded that an air concentration of 0.3 ppm will provide protection from eye irritation for virtually everyone. A weight of evidence-based formaldehyde exposure limit of 0.1 ppm (100 ppb) is recommended as an indoor air level for all individuals for odor detection and sensory irritation. It has recently been suggested by the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP), and the US Environmental Protection Agency (US EPA) that formaldehyde is causally associated with nasopharyngeal cancer (NPC) and leukemia. This has led US EPA to conclude that irritation is not the most sensitive toxic endpoint and that carcinogenicity should dictate how to establish exposure limits for formaldehyde. In this review, a number of lines of reasoning and substantial scientific evidence are described and discussed, which leads to a conclusion that neither point of contact nor systemic effects of any type, including NPC or leukemia, are causally associated with exposure to formaldehyde. This conclusion supports the view that the equivocal epidemiology studies that suggest otherwise are almost certainly flawed by identified or yet to be unidentified confounding variables. Thus, this assessment concludes that a formaldehyde indoor air limit of 0.1 ppm should protect even particularly susceptible individuals from both irritation effects and any potential cancer hazard

Phase transition of charged Black Holes in Brans–Dicke theory through geometrical thermodynamics

In this paper, we take into account black hole solutions of Brans-Dicke-Maxwell theory and investigate their stability and phase transition points. We apply the concept of geometry in thermodynamics to obtain phase transition points and compare its results with those, calculated in canonical ensemble through heat capacity. We show that these black holes enjoy second order phase transitions. We also show that there is a lower bound for the horizon radius of physical charged black holes in Brans-Dicke theory which is originated from restrictions of positivity of temperature. In addition, we find that employing specific thermodynamical metric in the context of geometrical thermodynamics, yields divergencies for thermodynamical Ricci scalar in places of the phase transitions. It will be pointed out that due to characteristics behavior of thermodynamical Ricci scalar around its divergence points, one is able to distinguish the physical limitation point from the phase transitions. In addition, the free energy of these black holes will be obtained and its behavior will be investigated. It will be shown that the behavior of the free energy in the place where the heat capacity diverges, demonstrates second order phase transition characteristics.Comment: 16 pages with 11 captioned figures, new version, accepted in EPJ