Optical Spectral Variability of the Very-High-Energy Gamma-Ray Blazar 1ES 1011+496

We present results of five years of optical (UBVRI) observations of the very-high-energy gamma-ray blazar 1ES 1011+496 at the MDM Observatory. We calibrated UBVRI magnitudes of five comparison stars in the field of the object. Most of our observations were done during moderately faint states of 1ES 1011+496 with R > 15.0. The light curves exhibit moderate, closely correlated variability in all optical wavebands on time scales of a few days. A cross-correlation analysis between optical bands does not show significant evidence for time lags. We find a positive correlation (Pearson's r = 0.57; probability of non-correlation P(>r) ~ 4e-8) between the R-band magnitude and the B - R color index, indicating a bluer-when-brighter trend. Snap-shot optical spectral energy distributions (SEDs) exhibit a peak within the optical regime, typically between the V and B bands. We find a strong (r = 0.78; probability of non-correlation P (>r) ~ 1e-15) positive correlation between the peak flux and the peak frequency, best fit by a relation $\nu F_{\nu}^{\rm pk} \propto \nu_{\rm pk}^k$ with k = 2.05 +/- 0.17. Such a correlation is consistent with the optical (synchrotron) variability of 1ES 1011+496 being primarily driven by changes in the magnetic field.Comment: Accepted for publication in ApJ. 16 pages, including 7 figure

Distribution and Characteristics of Colonic Diverticula in a United States Screening Population

Colonic diverticula are the most common finding from colonoscopy examinations. Little is known about the distribution of colonic diverticula, which are responsible for symptomatic and costly diverticular disease. We aimed to assess the number, location, and characteristics of colonic diverticula in a large US screening population

Neutron generator power supply modeling in EMMA

Sandia National Laboratories has prime responsibility for neutron generator design and manufacturing, and is committed to developing predictive tools for modeling neutron generator performance. An important aspect of understanding component performance is explosively driven ferroelectric power supply modeling. EMMA (ElectroMechanical Modeling in ALEGRA) is a three dimensional compile time version of Sandia`s ALEGRA code. The code is built on top of the general ALEGRA framework for parallel shock-physics computations but also includes additional capability for modeling the electric potential field in dielectrics. The overall package includes shock propagation due to explosive detonation, depoling of ferroelectric ceramics, electric field calculation and coupling with a general lumped element circuit equation system. The AZTEC parallel iterative solver is used to solve for the electric potential. The DASPK differential algebraic equation package is used to solve the circuit equation system. Sample calculations are described

Dietary calcium and risk of microscopic colitis

BACKGROUND: Microscopic colitis is an increasingly common cause of watery diarrhea particularly in older individuals. The role of diet in microscopic colitis has received little study. METHODS: We conducted a case-control study at a single institution enrolling patients referred for elective, outpatient colonoscopy for diarrhea. Patients were classified as microscopic colitis cases or non-microscopic colitis controls following review of colon biopsies by one research pathologist. Study subjects were interviewed by a trained telephone interviewer using a validated food frequency questionnaire. Adherent microbes were evaluated from colonic biopsies using 16s rRNA sequencing. RESULTS: The study population included 106 microscopic colitis cases and 215 controls. Compared to controls, the cases were older, better educated and more likely to be female. Microscopic colitis cases had lower body mass index (BMI) and were more likely to have lost weight. Subjects in the highest quartile of dietary calcium intake had a lower risk of microscopic colitis compared to the lowest quartile, adjusted odds ratio 0.22, 95% confidence interval 0.07-0.76). The findings were not explained by dairy intake, body mass index or weight loss. We found that dietary calcium intake had significant associations with the abundance of Actinobacteria and Coriobacteriales in the microbial community of colonic biopsies. CONCLUSIONS: Compared to patients with diarrhea, microscopic colitis cases had lower intake of dietary calcium. Diet can be associated with alterations in the gut microbiota and with luminal factors that could affect risk for microscopic colitis

Migration depths of adult steelhead Oncorhynchus mykiss in relation to dissolved gas supersaturation in a regulated river system

Adult steelhead Oncorhynchus mykiss tagged with archival transmitters primarily migrated through a large river corridor at depths >2 m interspersed with frequent but short (<5 min) periods closer to the surface. The recorded swimming depths and behaviours probably provided adequate hydrostatic compensation for the supersaturated dissolved gas conditions encountered and probably limited development of gas bubble disease (GBD). Results parallel those from a concurrent adult Chinook salmon Oncorhynchus tshawytscha study, except O. mykiss experienced greater seasonal variability and were more likely to have depth uncompensated supersaturation exposure in some dam tailraces, perhaps explaining the higher incidence of GBD in this species

Risk Factors for Hemorrhoids on Screening Colonoscopy

BackgroundConstipation, a low fiber diet, sedentary lifestyle and gravidity are commonly assumed to increase the risk of hemorrhoids. However, evidence regarding these factors is limited. We examined the association between commonly cited risk factors and the prevalence of hemorrhoids.MethodsWe performed a cross sectional study of participants who underwent a colonoscopy in a colorectal adenoma prevention trial and who had a detailed assessment of bowel habits, diet and activity. The presence of hemorrhoids was extracted from the subjects’ colonoscopy reports. We used logistic regression to estimate odds ratios and 95% confidence intervals while adjusting for age and sex.ResultsThe study included 2,813 participants. Of these, 1,074 had hemorrhoids recorded. Constipation was associated with an increased prevalence of hemorrhoids (OR 1.43, 95% CI 1.11, 1.86). Of the fiber subtypes, high grain fiber intake was associated with a reduced risk (OR for quartile 4 versus quartile 1 = 0.78, 95% CI 0.62, 0.98). We found no association when comparing gravid and nulligravida women (OR 0.93, 95% CI 0.62–1.40). Sedentary behavior was associated with a reduced risk (OR 0.80, 95% CI 0.65–0.98), but not physical activity (OR 0.83, 95% CI 0.66–1.03). Neither being overweight nor obese was associated with the presence of hemorrhoids (OR 0.89, 95% CI 0.72–1.09 and OR 0.86, 95% CI 0.70–1.06).ConclusionsConstipation is associated with an increased risk of hemorrhoids. Gravidity and physical activity do not appear to be associated. High grain fiber intake and sedentary behavior are associated with a decreased risk of hemorrhoids

Quality of life following radiofrequency ablation of dysplastic Barrett’s esophagus

The impact of the diagnosis and treatment of dysplastic Barrett’s esophagus (BE) on quality of life (QoL) is poorly understood. This study assessed the influence of dysplastic BE on QoL and evaluated if endoscopic treatment of dysplastic BE with radiofrequency ablation (RFA) improves QoL

Evaluation of Euler Fluxes for Hypersonic Heating Computations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83575/1/AIAA-41605-439.pd