Core-Collapse Supernova Simulations including Neutrino Interactions from the Virial EOS

Core-collapse supernova explosions are driven by a central engine that converts a small fraction of the gravitational binding energy released during core collapse to outgoing kinetic energy. The suspected mode for this energy conversion is the neutrino mechanism, where a fraction of the neutrinos emitted from the newly formed protoneutron star are absorbed by and heat the matter behind the supernova shock. Accurate neutrino-matter interaction terms are crucial for simulating these explosions. In this proceedings for IAUS 331, SN 1987A, 30 years later, we explore several corrections to the neutrino-nucleon scattering opacity and demonstrate the effect on the dynamics of the core-collapse supernova central engine via two dimensional neutrino-radiation-hydrodynamics simulations. Our results reveal that the explosion properties are sensitive to corrections to the neutral-current scattering cross section at the 10-20% level, but only for densities at or above $\sim 10^{12}$ g cm$^{-3}$Comment: 6 pages, 3 figures, appears in Proc. IAU Symposium 331, SN 1987A, 30 years later - Cosmic Rays and Nuclei from Supernovae and Their Aftermath

The role of alcohol response phenotypes in the risk for alcohol use disorder

Heavy alcohol use is pervasive and one of our most significant global health burdens. Early theories posited that certain alcohol response phenotypes, notably low sensitivity to alcohol (‘low-level response’) imparts risk for alcohol use disorder (AUD). However, other theories, and newer measures of subjective alcohol responses, have challenged that contention and argued that high sensitivity to some alcohol effects are equally important for AUD risk. This study presents results of a unique longitudinal study in 294 young adult non-dependent drinkers examined with alcohol and placebo testing in the laboratory at initial enrolment and repeated 5 years later, with regular follow-up intervals assessing AUD (trial registration: http://clinicaltrials.gov/ct2/show/NCT00961792). Findings showed that alcohol sedation was negatively correlated with stimulation across the breath alcohol curve and at initial and re-examination testing. A higher rather than lower alcohol response phenotype was predictive of future AUD. The findings underscore a new understanding of factors increasing vulnerability to AUD

Pre-bomb marine reservoir variability in the Kimberley region, Western Australia

New ΔR values are presented for 10 known-age shells from the Kimberley region of northwest Australia. Previous estimates of ΔR for the Kimberley region are based on only 6 individual shell specimens with dates of live collection known only to within 50 yr (Bowman 1985a). Here, we describe the results of our recent attempts to constrain ΔR variability for this region by dating a suite of known-age pre-AD 1950 shell samples from the Australian Museum and Museum Victoria. A regional ΔR of 58 ± 17 14C yr for open waters between Broome and Cape Leveque is recommended based on 7 of these specimens. The criteria used to select shells for dating and inclusion in the regional mean are discussed.Copyright Information: http://www.sherpa.ac.uk/romeo/issn/0033-8222

Gender Specific Effects of Mood on Alcohol Seeking Behaviors: Preliminary Findings using Intravenous Alcohol Self-Administration

Background Although negative mood has long been implicated in differences in alcohol seeking by men and women, little research has used precise, well-controlled laboratory experiments to examine how negative mood affects alcohol-seeking behaviors. Methods A total of 34 (19 women) community-dwelling, alcohol-using adults aged 21 to 32 (mean age = 24.86, SD = 3.40, 74.3% Caucasian; Alcohol Use Disorders Identification Test [AUDIT] = 10.1, SD = 3.4) completed 2 counterbalanced intravenous alcohol self-administration sessions: one under negative mood and one under neutral mood. Fourteen individuals (9 women; mean age = 25.00, SD = 2.77) participated in an alcohol “liking” experiment (i.e., free access [FA] drinking) and 20 individuals (10 women; mean age = 24.77, SD = 3.73) participated in an alcohol “wanting” experiment, in which gaining access to alcohol required progressively effortful work. There was no significant difference between men and women on the AUDIT, t(32) = −0.38, p = 0.71. Results Priming with negative mood induction caused a significant decrease in self-reported mood (mean change = −1.85, t(32) = −6.81, p < 0.001), as intended. In FA, negative mood was associated with a significantly increased peak breath alcohol concentration (BrAC; F = 9.41, p = 0.01), with a trend toward a greater effect in men than in women (F = 2.67, p = 0.13). Negative mood also had a significant effect on peak BrAC achieved in the progressive work paradigm (F = 5.28, p = 0.04), with a significantly stronger effect in men (F = 5.35, p = 0.03) than women; men also trended toward more consistent work for alcohol across both neutral and negative sessions. Conclusions These preliminary findings demonstrate a gender-specific response on how mood affects alcohol seeking and suggest gender-specific interventions to prevent mood-based alcohol consumption

Alcohol Affects the P3 Component of an Adaptive Stop Signal Task ERP

BACKGROUND The P3 component of the event-related potential (ERP) has been particularly useful in alcohol research for identifying endophenotypes of alcohol use disorder (AUD) risk in sober subjects. However, practice and/or fatigue reduces P3 amplitude, limiting the ability to ascertain acute and adaptive effects of alcohol exposure. Here, we report acute alcohol effects on P3 amplitude and latency using an adaptive stop signal task (aSST). METHODS One hundred and forty eight nondependent moderate to heavy social drinkers, age 21 to 27, participated in 2 single-blind, alcohol or placebo, counterbalanced sessions approximately one week apart. During each session, subjects performed an adaptive stop signal task (aSST) at (1) baseline, (2) upon reaching the target 60 mg/dL breath alcohol concentration or at the equivalent time during the placebo session, and (3) approximately 135 minutes later while the breath alcohol concentration was clamped. Here, we report on differences between baseline and first subsequent measurements across the experimental sessions. During each aSST run, the stop signal delay (SSD, the time between stop and go signals) adjusted trial-by-trial based on the subject’s performance. RESULTS The aSST reliably generated a STOP P3 component that did not change significantly with repeated task performance. The pre-infusion SSD distribution was bimodal, with mean values several hundred msec apart (FAST: 153 msec and SLOW: 390 msec). This suggested different response strategies: FAST SSD favoring “going” over “stopping,” and SLOW SSD favoring “stopping” over “going”. Exposure to alcohol at 60 mg/dL differentially affected the amplitude and latency of the STOP P3 according to SSD group. Alcohol significantly reduced P3 amplitude in the SLOW SSD compared to FAST SSD group, but significantly increased P3 latency in the FAST SSD compared to SLOW SSD group. CONCLUSIONS The aSST is a robust and sensitive task for detecting alcohol induced changes in inhibition behavior as measured by the P3 component in a within subject design. Alcohol was associated with P3 component changes which varied by SSD group, suggesting a differential effect as a function of task strategy. Overall, the data support the potential utility of the aSST in the detection of alcohol response related AUD risk

The apéritif effect: Alcohol's effects on the brain's response to food aromas in women

OBJECTIVE: Consuming alcohol prior to a meal (an apéritif) increases food consumption. This greater food consumption may result from increased activity in brain regions that mediate reward and regulate feeding behavior. Using functional magnetic resonance imaging, we evaluated the blood oxygenation level dependent (BOLD) response to the food aromas of either roast beef or Italian meat sauce following pharmacokinetically controlled intravenous infusion of alcohol. METHODS: BOLD activation to food aromas in non-obese women (n = 35) was evaluated once during intravenous infusion of 6% v/v EtOH, clamped at a steady-state breath alcohol concentration of 50 mg%, and once during infusion of saline using matching pump rates. Ad libitum intake of roast beef with noodles or Italian meat sauce with pasta following imaging was recorded. RESULTS: BOLD activation to food relative to non-food odors in the hypothalamic area was increased during alcohol pre-load when compared to saline. Food consumption was significantly greater, and levels of ghrelin were reduced, following alcohol. CONCLUSIONS: An alcohol pre-load increased food consumption and potentiated differences between food and non-food BOLD responses in the region of the hypothalamus. The hypothalamus may mediate the interplay of alcohol and responses to food cues, thus playing a role in the apéritif phenomenon

Global Comparison of Core-Collapse Supernova Simulations in Spherical Symmetry

We present a comparison between several simulation codes designed to study the core-collapse supernova mechanism. We pay close attention to controlling the initial conditions and input physics in order to ensure a meaningful and informative comparison. Our goal is three-fold. First, we aim to demonstrate the current level of agreement between various groups studying the core-collapse supernova central engine. Second, we desire to form a strong basis for future simulation codes and methods to compare to. Lastly, we want this work to be a stepping stone for future work exploring more complex simulations of core-collapse supernovae, i.e., simulations in multiple dimensions and simulations with modern neutrino and nuclear physics. We compare the early (first ~500ms after core bounce) spherically-symmetric evolution of a 20 solar mass progenitor star from six different core-collapse supernovae codes: 3DnSNe-IDSA, AGILE-BOLTZTRAN, FLASH, F{\sc{ornax}}, GR1D, and PROMETHEUS-VERTEX. Given the diversity of neutrino transport and hydrodynamic methods employed, we find excellent agreement in many critical quantities, including the shock radius evolution and the amount of neutrino heating. Our results provide an excellent starting point from which to extend this comparison to higher dimensions and compare the development of hydrodynamic instabilities that are crucial to the supernova explosion mechanism, such as turbulence and convection.Comment: 24 pages, 7 figures, J. Phys. G focus issue on core-collapse supernovae. This document was written collaboratively on Authorea, comments welcome at https://www.authorea.com/users/1943/articles/167397-global-comparison-of-core-collapse-supernova-simulations-in-spherical-symmetr

Pure iterative reconstruction improves image quality in computed tomography of the abdomen and pelvis acquired at substantially reduced radiation doses in patients with active Crohn disease

Objective: We assessed diagnostic accuracy and image quality of modified protocol (MP) computed tomography (CT) of the abdomen and pelvis reconstructed using pure iterative reconstruction (IR) in patients with Crohn disease (CD). Methods: Thirty-four consecutive patients with CD were referred with suspected extramural complications. Two contemporaneous CT datasets were acquired in all patients: standard protocol (SP) and MP. The MP and SP protocols were designed to impart radiation exposures of 10% to 20% and 80% to 90% of routine abdominopelvic CT, respectively. The MP images were reconstructed with model-based IR (MBIR) and adaptive statistical IR (ASIR). Results: The MP-CT and SP-CT dose length product were 88 (58) mGy.cm (1.27 [0.87] mSv) and 303 [204] mGy.cm (4.8 [2.99] mSv), respectively (P < 0.001). Median diagnostic acceptability, spatial resolution, and contrast resolution were significantly higher and subjective noise scores were significantly lower on SP-ASIR 40 compared with all MP datasets. There was perfect clinical agreement between MP-MBIR and SP-ASIR 40 images for detection of extramural complications. Conclusions: Modified protocol CT using pure IR is feasible for assessment of active CD

Role of radiologic imaging in irritable bowel syndrome: evidence-based review

Purpose: To critically evaluate the current literature in an effort to establish the current role of radiologic imaging (computed tomography, magnetic resonance imaging, ultrasonography [US], fluoroscopy, conventional film radiography) in irritable bowel syndrome (IBS). Materials and Methods: The term “irritable bowel syndrome” was used to search Clinical Evidence, UpToDate, Cochrane Library, TRIP, and National Institute for Health and Clinical Excellence databases and the American College of Physicians Journal Club and Evidence-Based Medicine online. PubMed was searched by using medical subject headings (“irritable bowel syndrome;” “colonic diseases, functional;” “diagnosis;” “colonography;” “computed tomographic (CT)”) and the dates January 1, 1985 to July 1, 2010. Appraisal was independently performed by two reviewers who followed the Oxford Centre for Evidence Based Medicine practice criteria. Results: No systematic review (SR) specifically examined radiologic imaging in IBS; however, in the secondary literature, five relevant SRs or guidelines partially addressed this topic. A PubMed search identified 1451 articles, 111 of which at least partially addressed radiologic imaging. Of these, seven valid articles (two SRs and five primary research articles) were identified. The five primary research articles examined either colonic investigations (colonoscopy and barium enema examination) (n = 5) or US (n = 2) or both (n = 2). Structural disease found infrequently in patients with IBS-type symptoms included diverticulosis, colorectal cancer, celiac disease, inflammatory bowel disease, and ovarian cancer. The incidence of structural disease in patients with concerning symptoms was low. Conclusion: Although widely used, there is a surprising paucity of evidence guiding radiologic imaging in IBS. Radiologic imaging may not be required in patients with IBS without potentially concerning symptoms but should be considered where such symptoms exist, and choice of imaging study should be influenced by predominant symptoms. Definitive recommendations must await further research