A transformation for L\'evy processes with one-sided jumps and applications

The aim of this work is to extend and study a family of transformations between Laplace exponents of L\'evy processes which have been introduced recently in a variety of different contexts by Patie, Kyprianou and Patie, and, Gnedin, as well as in older work of Urbanik . We show how some specific instances of this mapping prove to be useful for a variety of applications

Polyethylene glycol and prevalence of colorectal adenomas : Population-based study of 1165 patients undergoing colonoscopy

Background and aim — Dietary polyethylene glycol (PEG) is extraordinarily potent in the chemoprevention of experimental colon carcinogenesis. PEG is used to treat constipation in France and in the USA. French laxatives include Forlax® (PEG4000), Movicol® and Transipeg® (PEG3350), and Idrocol® (pluronic F68). This study tests the hypothesis that use of a PEG-based laxative might reduce the prevalence of colorectal tumors. Methods — In this population-based study, consecutive patients attending for routine total colonoscopy were enrolled during four months by the gastroenterologists of Indre-et-Loire. They were asked if they had previously taken a laxative or a NSAID. Age, gender, previous polyps, family history of colorectal cancer, constipation, digestive symptoms were also recorded. Tumors found during colonoscopy were categorized histologically. Results — Records from 1165 patients fulfilled the inclusion criteria, 607 women and 498 men, mean age 58.3. Among those, 813 had no tumor, 329 had adenomas, and 23 had carcinomas. In a univariate analysis, older age, male gender, lack of digestive symptom, and previous polyps were more common in patients with colorectal tumors. In contrast, previous Forlax® intake was more common in tumor-free patients (odds ratio (OR) any use/no use, 0.52; 95% confidence interval, 0.27-0.94). More people used Forlax®, which contains a higher dose of PEG than the other PEGlaxatives, whose ORs were smaller than one, but did not reach significance. In multivariate analysis, older age and male gender were associated with higher risk, and NSAIDs use with lower risk, of colorectal tumors. Conclusion — Forlax® users had a halved risk of colorectal tumors in univariate analysis, which suggests that PEG may prevent carcinogenesis

Genomic organization of the KTX2 gene, encoding a `short' scorpion toxin active on K+ channels

AbstractA single intron of 87 bp, close to the region encoding the C-terminal part of the signal peptide, was found in the gene of the `short' scorpion toxin kaliotoxin 2 of Androctonus australis acting on various types of K+ channels. Its A+T content was particularly high (up to 86%). By walking and ligation-mediated PCR, the promoter sequences of the kaliotoxin 2 gene of Androctonus australis were studied. The transcription unit of the gene is 390 bp long. Consensus sequences were identified. The genes of `short' scorpion toxins active on K+ channels are organized similarly to those of the `long' scorpion toxins active on Na+ channels and not like those of structurally related insect defensins, which are intronless

Association between reported exposure to road traffic and respiratory symptoms in children: evidence of bias

Background Many studies showing effects of traffic-related air pollution on health rely on self-reported exposure, which may be inaccurate. We estimated the association between self-reported exposure to road traffic and respiratory symptoms in preschool children, and investigated whether the effect could have been caused by reporting bias. Methods In a random sample of 8700 preschool children in Leicestershire, UK, exposure to road traffic and respiratory symptoms were assessed by a postal questionnaire (response rate 80%). The association between traffic exposure and respiratory outcomes was assessed using unconditional logistic regression and conditional regression models (matching by postcode). Results Prevalence odds ratios (95% confidence intervals) for self-reported road traffic exposure, comparing the categories ‘moderate' and ‘dense', respectively, with ‘little or no' were for current wheezing: 1.26 (1.13-1.42) and 1.30 (1.09-1.55); chronic rhinitis: 1.18 (1.05-1.31) and 1.31 (1.11-1.56); night cough: 1.17 (1.04-1.32) and 1.36 (1.14-1.62); and bronchodilator use: 1.20 (1.04-1.38) and 1.18 (0.95-1.46). Matched analysis only comparing symptomatic and asymptomatic children living at the same postcode (thus exposed to similar road traffic) showed similar ORs, suggesting that parents of children with respiratory symptoms reported more road traffic than parents of asymptomatic children. Conclusions Our study suggests that reporting bias could explain some or even all the association between reported exposure to road traffic and disease. Over-reporting of exposure by only 10% of parents of symptomatic children would be sufficient to produce the effect sizes shown in this study. Future research should be based only on objective measurements of traffic exposur

Subseries/Subepochs approved as a formal rank in the international stratigraphic guide

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Aubry, M., Head, M. J., Piller, W. E., & Berggren, W. A. Subseries/Subepochs approved as a formal rank in the international stratigraphic guide. Episodes, 43(4), (2020): 1041-1044, doi:10.18814/epiiugs/2020/020066.The International Subcommission on Stratigraphic Classification, as the constituent body of the International Commission on Stratigraphy (ICS) responsible for the International Stratigraphic Guide, has voted to include the subseries/ subepoch as a formal rank in the next edition of the Guide. This acknowledges the recent ratification of formal subseries and their corresponding stages for the Holocene Series/Epoch but allows individual subcommissions within ICS the freedom to decide whether or not to adopt this rank for their particular stratigraphic/time interval.We are grateful to the ISSC membership for discussions and to Secretary Jochen Erbacher for organizing the vote; to Mike Walker for sharing an unpublished manuscript with us; to the many colleagues who have expressed their support for formalization of subseries; and to Dennis Kent and an anonymous reviewer for their reviews of the manuscript

A cross-sectional survey of supports for evidence-informed decision-making in healthcare organisations: a research protocol

Background: This protocol builds on the development of a) a framework that identified the various supports (i.e. positions, activities, interventions) that a healthcare organisation or health system can implement for evidence-informed decision-making (EIDM) and b) a qualitative study that showed the current mix of supports that some Canadian healthcare organisations have in place and the ones that are perceived to facilitate the use of research evidence in decision-making. Based on these findings, we developed a web survey to collect cross-sectional data about the specific supports that regional health authorities and hospitals in two Canadian provinces (Ontario and Quebec) have in place to facilitate EIDM. Methods/design This paper describes the methods for a cross-sectional web survey among 32 regional health authorities and 253 hospitals in the provinces of Quebec and Ontario (Canada) to collect data on the current mix of organisational supports that these organisations have in place to facilitate evidence-informed decision-making. The data will be obtained through a two-step survey design: a 10-min survey among CEOs to identify key units and individuals in regard to our objectives (step 1) and a 20-min survey among managers of the key units identified in step 1 to collect information about the activities performed by their unit regarding the acquisition, assessment, adaptation and/or dissemination of research evidence in decision-making (step 2). The study will target three types of informants: CEOs, library/documentation centre managers and all other key managers whose unit is involved in the acquisition, assessment, adaptation/packaging and/or dissemination of research evidence in decision-making. We developed an innovative data collection system to increase the likelihood that only the best-informed respondent available answers each survey question. The reporting of the results will be done using descriptive statistics of supports by organisation type and by province. Discussion This study will be the first to collect and report large-scale cross-sectional data on the current mix of supports health system organisations in the two most populous Canadian provinces have in place for evidence-informed decision-making. The study will also provide useful information to researchers on how to collect organisation-level data with reduced risk of self-reporting bias

Unwanted sexual experiences among adolescents: shedding light on the gray zone between consensual and non-consensual sex

This study aimed at exploring adolescents' perceptions of unwanted sexual experiences (USE) in order to set up definitions, categories, and boundaries on the continuum between consensual and non-consensual sex. Methods: We conducted a qualitative thematic analysis of four focus group discussions gathering a total of 29 male and female adolescents aged 16-20 years. Results: Analysis of participants' discourse revealed three main characteristics that define USE, namely, regret, as most situations discussed were said to be acceptable or not in terms of whether there were regrets after the fact; misperception of sexual intent; and lack of communication between partners. Conclusions: Our findings revealed that health professionals should be aware of the subtle aspects identifying USE when screening for situations that can have adverse psychological consequences. Where prevention is concerned, it appears important to address these aspects of USE in sex education classe

Evolutionary changes in the notochord genetic toolkit: a comparative analysis of notochord genes in the ascidian Ciona and the larvacean Oikopleura

<p>Abstract</p> <p>Background</p> <p>The notochord is a defining feature of the chordate clade, and invertebrate chordates, such as tunicates, are uniquely suited for studies of this structure. Here we used a well-characterized set of 50 notochord genes known to be targets of the notochord-specific Brachyury transcription factor in one tunicate, <it>Ciona intestinalis </it>(Class Ascidiacea), to begin determining whether the same genetic toolkit is employed to build the notochord in another tunicate, <it>Oikopleura dioica </it>(Class Larvacea). We identified <it>Oikopleura </it>orthologs of the <it>Ciona </it>notochord genes, as well as lineage-specific duplicates for which we determined the phylogenetic relationships with related genes from other chordates, and we analyzed their expression patterns in <it>Oikopleura </it>embryos.</p> <p>Results</p> <p>Of the 50 <it>Ciona </it>notochord genes that were used as a reference, only 26 had clearly identifiable orthologs in <it>Oikopleura</it>. Two of these conserved genes appeared to have undergone <it>Oikopleura</it>- and/or tunicate-specific duplications, and one was present in three copies in <it>Oikopleura</it>, thus bringing the number of genes to test to 30. We were able to clone and test 28 of these genes. Thirteen of the 28 <it>Oikopleura </it>orthologs of <it>Ciona </it>notochord genes showed clear expression in all or in part of the <it>Oikopleura </it>notochord, seven were diffusely expressed throughout the tail, six were expressed in tissues other than the notochord, while two probes did not provide a detectable signal at any of the stages analyzed. One of the notochord genes identified, <it>Oikopleura netrin</it>, was found to be unevenly expressed in notochord cells, in a pattern reminiscent of that previously observed for one of the <it>Oikopleura </it><it>Hox </it>genes.</p> <p>Conclusions</p> <p>A surprisingly high number of <it>Ciona </it>notochord genes do not have apparent counterparts in <it>Oikopleura</it>, and only a fraction of the evolutionarily conserved genes show clear notochord expression. This suggests that <it>Ciona </it>and <it>Oikopleura</it>, despite the morphological similarities of their notochords, have developed rather divergent sets of notochord genes after their split from a common tunicate ancestor. This study demonstrates that comparisons between divergent tunicates can lead to insights into the basic complement of genes sufficient for notochord development, and elucidate the constraints that control its composition.</p