511 research outputs found

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

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    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 νFνpkνpkk\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

    Economic burden of diverticular disease : an observational analysis based on real world data from an Italian region

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    INTRODUCTION: Diverticular disease (DD), a herniation of the colonic mucosa through the muscle layer, covers a wide variety of conditions associated with the presence of diverticula in the colon. The most serious form is an acute episode of diverticulitis, which can lead to hospitalization and surgery with various types of consequences. The main aim of this study is to evaluate the economic burden of hospitalizations arising from acute episodes of diverticulitis using data from the administrative databases used in the Marche region in Italy and, as a secondary objective of this real-world data analysis, to study patient outcome variables following initial hospitalization for diverticulitis. METHOD: A deterministic linkage was performed at individual user level between the different administrative sources of the Marche region through anonymous ID number for a period of analysis between 1 January, 2008 and 31 December, 2014. We enrolled all patients with at least one hospitalization for "diverticulitis of the colon without mention of haemorrhage" (ICD-9-CM code 562.11) or "diverticulitis of the colon with haemorrhage" (ICD-9-CM code 562.13) as primary or secondary diagnosis. For each patient we assessed the cost of hospitalization, of medicines and of specialist services considering a time-scale of one year or cohort analysis 365days after first admission. RESULTS: The total number of residents in the Marche region who had at least one hospitalization for diverticulitis in the period 2008-2014 was 2987 (427 patients a year, corresponding to about 35 patients per 100,000 adult residents); the total number of admissions was 3453 (just over 490 a year). The direct healthcare costs incurred by the Marche region for episodes of diverticulitis in 2008-2014 amounted to approximately €11.4 million (€1.6 million a year), of which €10.9 million (95.5%) for the hospitalizations, € 246,000 (2.1%) for pharmaceutical treatment and €270,000 (2.4%) for specialist outpatient services. The average annual cost per patient was €3826, of which €3653 was for hospitalization, while pharmaceutical expenditure and specialist services accounted for €83 and €90, respectively. The cohort of patients undergoing a first admission for diverticulitis between 2010 and 2013 was made up of 1729 people (54.4% women, mean age 68.9 years), of whom 1500 (86.8%) did not undergo surgery while in hospital. Hospital mortality, recorded only for the over-65 age class, averaged 1.2%; for patients not receiving surgery during the initial hospitalization it was 0.5%, reaching 5.2% in patients undergoing surgery. The percentage of patients with one or more readmissions for diverticulitis within a year of the first was on average 7.8% and in 48% of cases this resulted in surgery. CONCLUSIONS: Our study is the first analysis in Italy to use real-world data to measure the financial impact of diverticular disease. Assuming that the diagnostic and therapeutic behaviour identified in the Marche region could be representative of the situation nationwide, the estimated annual number of hospitalizations in Italy for acute episodes of diverticulitis is 19,000. The total amount of economic resources needed to treat patients suffering from acute episodes of diverticulitis is estimated at €63.5 million a year

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

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    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

    Comparative chloroplast genomics: analyses including new sequences from the angiosperms Nuphar advena and Ranunculus macranthus

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    <p>Abstract</p> <p>Background</p> <p>The number of completely sequenced plastid genomes available is growing rapidly. This array of sequences presents new opportunities to perform comparative analyses. In comparative studies, it is often useful to compare across wide phylogenetic spans and, within angiosperms, to include representatives from basally diverging lineages such as the genomes reported here: <it>Nuphar advena </it>(from a basal-most lineage) and <it>Ranunculus macranthus </it>(a basal eudicot). We report these two new plastid genome sequences and make comparisons (within angiosperms, seed plants, or all photosynthetic lineages) to evaluate features such as the status of <it>ycf15 </it>and <it>ycf68 </it>as protein coding genes, the distribution of simple sequence repeats (SSRs) and longer dispersed repeats (SDR), and patterns of nucleotide composition.</p> <p>Results</p> <p>The <it>Nuphar </it>[GenBank:<ext-link ext-link-type="gen" ext-link-id="NC_008788">NC_008788</ext-link>] and <it>Ranunculus </it>[GenBank:<ext-link ext-link-type="gen" ext-link-id="NC_008796">NC_008796</ext-link>] plastid genomes share characteristics of gene content and organization with many other chloroplast genomes. Like other plastid genomes, these genomes are A+T-rich, except for rRNA and tRNA genes. Detailed comparisons of <it>Nuphar </it>with <it>Nymphaea</it>, another Nymphaeaceae, show that more than two-thirds of these genomes exhibit at least 95% sequence identity and that most SSRs are shared. In broader comparisons, SSRs vary among genomes in terms of abundance and length and most contain repeat motifs based on A and T nucleotides.</p> <p>Conclusion</p> <p>SSR and SDR abundance varies by genome and, for SSRs, is proportional to genome size. Long SDRs are rare in the genomes assessed. SSRs occur less frequently than predicted and, although the majority of the repeat motifs do include A and T nucleotides, the A+T bias in SSRs is less than that predicted from the underlying genomic nucleotide composition. In codon usage third positions show an A+T bias, however variation in codon usage does not correlate with differences in A+T-richness. Thus, although plastome nucleotide composition shows "A+T richness", an A+T bias is not apparent upon more in-depth analysis, at least in these aspects. The pattern of evolution in the sequences identified as <it>ycf15 </it>and <it>ycf68 </it>is not consistent with them being protein-coding genes. In fact, these regions show no evidence of sequence conservation beyond what is normal for non-coding regions of the IR.</p

    Association of Obesity With Colonic Diverticulosis in Women

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    Background & Aims: Obesity has been associated with an increased risk of colonic diverticulosis. Evidence for this association is limited. We assessed whether anthropometric measures of obesity were associated with colonic diverticulosis. Methods: We analyzed data from a prospective study of 623 patients undergoing screening colonoscopies from 2013 through 2015; colonoscopies included examinations for diverticulosis. Body measurements were made the day of the procedure. Multivariate analyses were performed using modified Poisson regression to estimate prevalence ratios (PRs) and 95% CIs while adjusting for confounding variables. All analyses were stratified by sex. Results: Among men, there was no association between any measure of obesity and diverticulosis. After adjustment, women with an obese body mass index (BMI ≥ 30) had an increased risk of any diverticulosis (PR, 1.48; 95% CI, 1.08–2.04) compared with women with a normal body mass index (BMI 18.5–24.9). The strength of this association was greater for more than 5 diverticula (PR, 2.05; 95% CI, 1.23–3.40). There was no significant association between measures of central obesity and diverticulosis in women. Stratified by sex, colonic diverticulosis was significantly less prevalent in women compared with men before the age of 51 years (29% vs 45%, P = .06). The prevalence of diverticulosis did not differ by sex in older age groups. Conclusions: In an analysis of data from 623 patients undergoing screening colonoscopies, we found that obesity (BMI ≥30) significantly increased the risk of colonic diverticulosis in women but not men. Colonic diverticulosis was less prevalent in premenopausal-age women compared with similar-age men. These findings suggest that sex hormones may influence the development of diverticulosis

    Dietary calcium and risk of microscopic colitis

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    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

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    Adult steelhead Oncorhynchus mykiss tagged with archival transmitters primarily migrated through a large river corridor at depths &gt;2 m interspersed with frequent but short (&lt;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
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