Fermi Large Area Telescope observations of PSR J1836+5925

The discovery of the gamma-ray pulsar PSR J1836+5925, powering the formerly unidentified EGRET source 3EG J1835+5918, was one of the early accomplishments of the Fermi Large Area Telescope (LAT). Sitting 25 degrees off the Galactic plane, PSR J1836+5925 is a 173 ms pulsar with a characteristic age of 1.8 million years, a spindown luminosity of 1.1$\times10^{34}$ erg s$^{-1}$, and a large off-peak emission component, making it quite unusual among the known gamma-ray pulsar population. We present an analysis of one year of LAT data, including an updated timing solution, detailed spectral results and a long-term light curve showing no indication of variability. No evidence for a surrounding pulsar wind nebula is seen and the spectral characteristics of the off-peak emission indicate it is likely magnetospheric. Analysis of recent XMM observations of the X-ray counterpart yields a detailed characterization of its spectrum, which, like Geminga, is consistent with that of a neutron star showing evidence for both magnetospheric and thermal emission.Comment: Accepted to Astrophysical Journa

Biological characteristics and treatment outcomes of metastatic or recurrent neuroendocrine tumors: tumor grade and metastatic site are important for treatment strategy

<p>Abstract</p> <p>Background</p> <p>Studies about the biology, treatment pattern, and treatment outcome of metastatic/recurrent neuroendocrine tumor (NET) have been few.</p> <p>Methods</p> <p>We enrolled patients with metastatic/recurrent NET diagnosed between January 1996 and July 2007 and retrospectively analyzed.</p> <p>Results</p> <p>A total of 103 patients were evaluated. Twenty-six patients (25.2%) had pancreatic NET, 27 (26.2%) had gastrointestinal NET, 2 (1.9%) had lung NET, 28 (27.2%) had NET from other sites, and 20 (19.4%) had NET from unknown origin. The liver was the most common metastatic site (68.9%). Thirty-four patients had grade 1 disease, 1 (1.0%) had grade 2 disease, 15 (14.6%) had grade 3 disease, 9 (8.7%) had large cell disease, and 7 (6.8%) had small cell disease.</p> <p>Sixty-six patients received systemic treatment (interferon, somatostatin analogues or chemotherapy), 64 patients received local treatment (TACE, radiofrequency ablation, metastasectomy, etc.). Thirty-six patients received both systemic and local treatments.</p> <p>Median overall survival (OS) was 29.0 months (95% confidence interval, 25.0-33.0) in the103 patients. OS was significantly influenced by grade (<it>p </it>= .001). OS was 43.0, 23.0, and 29.0 months in patients who received local treatment only, systemic treatment only, and both treatments, respectively (<it>p </it>= .245). The median time-to-progression (TTP) was 6.0 months. Overall response rate was 34.0% and disease-control rate was 64.2%. TTP was influenced by the presence of liver metastasis (<it>p </it>= .011).</p> <p>Conclusions</p> <p>OS of metastatic/recurrent NET was different according to tumor grade. TTP was different according to metastasis site. Therefore, development of optimal treatment strategy based on the characteristics of NET is warranted.</p

Chronic Sub-lethal Effects Observed in Wild-Caught Fishes Following Two Major Oil Spills in the Gulf of Mexico: \u3cem\u3eDeepwater Horizon\u3c/em\u3e and Ixtoc 1

During and subsequent to major oil spill events, considerable attention focuses on charismatic and economic megafauna – and especially fishes – and visual manifestations of impacts upon them. Beginning with a series of tanker accidents occurring in Europe and the USA in the 1970s–1990s, greater awareness of the potential for both acute and chronic sub-lethal impacts on fish populations has focused on exposure to polycyclic aromatic hydrocarbons (PAHs). The ambiguity of acute impacts observed during the Deepwater Horizon and Ixtoc 1 incidents has promoted considerable new research on alternative toxic endpoints that portend short- and long-term sub-lethal outcomes that influence the overall fitness of exposed populations. Laboratory-based exposure studies have traditionally focused on acute mortality-based endpoints (e.g., lethal concentrations at which 50% of the population dies = LC50) and observed at test concentrations normally exceeding environmentally relevant concentrations in real-world spills. Consequently, using laboratory-based toxicity experiments can be problematic inferring impacts on wild fish populations. In this chapter we review historical and more recent information documenting changes in abundance, recruitment, habitat use, population dynamics, trophic changes, and various physiologically based sub-lethal effects on oil-exposed fishes and especially consider research undertaken following the Deepwater Horizon and Ixtoc 1 spills in the Gulf of Mexico