Search results for "Isolation"

2014

This paper deals with the fault detection problem for a class of discrete-time wireless networked control systems described by switching topology with uncertainties and disturbances. System states of each individual node are affected not only by its own measurements, but also by other nodes’ measurements according to a certain network topology. As the topology of system can be switched in a stochastic way, we aim to designH∞fault detection observers for nodes in the dynamic time-delay systems. By using the Lyapunov method and stochastic analysis techniques, sufficient conditions are acquired to guarantee the existence of the filters satisfying theH∞performance constraint, and observer gains…

Identification of Cpgp40/15 Type Ib as the Predominant Allele in Isolates of Cryptosporidium spp. from a Waterborne Outbreak of Gastroenteritis in So…

2006

ABSTRACT Cryptosporidium sp. isolates from a waterborne outbreak of diarrhea in France were analyzed by PCR-restriction fragment length polymorphism analysis and sequencing of the Cpgp40/15 locus. Ninety-one percent of the isolates were Cryptosporidium hominis type Ib. The results of this study and those of studies of other outbreaks suggest that the type Ib allele is the predominant allele associated with waterborne cryptosporidiosis.

Survival after pathogen exposure in group-living insects: don't forget the stress of social isolation!

2016

A major cost of group-living is its inherent risk of pathogen infection. To limit this risk, many group-living animals have developed the capability to prophylactically boost their immune system in the presence of group members and/or to mount collective defences against pathogens. These two phenomena, called density-dependent prophylaxis and social immunity, respectively, are often used to explain why, in group-living species, individuals survive better in groups than in isolation. However, this survival difference may also reflect an alternative and often overlooked process: a cost of social isolation on individuals' capability to fight against infections. Here, we disentangled the effect…

Strong reproductive barriers in a narrow hybrid zone of West-Mediterranean green toads (Bufo viridis subgroup) with Plio-Pleistocene divergence

2010

Abstract Background One key question in evolutionary biology deals with the mode and rate at which reproductive isolation accumulates during allopatric speciation. Little is known about secondary contacts of recently diverged anuran species. Here we conduct a multi-locus field study to investigate a contact zone between two lineages of green toads with an estimated divergence time of 2.7 My, and report results from preliminary experimental crosses. Results The Sicilian endemic Bufo siculus and the Italian mainland-origin B. balearicus form a narrow hybrid zone east of Mt. Etna. Despite bidirectional mtDNA introgression over a ca. 40 km North-South cline, no F1 hybrids could be found, and nu…

Sex-pairing pheromones and reproductive isolation in three sympatric Cornitermes species (Isoptera, Termitidae, Syntermitinae)

2011

International audience; The species-specificity of pairing has been studied in three sympatric Neotropical termites: Cornitermes bequaerti, Cornitermes cumulans and Cornitermes silvestrii (Termitidae, Syntermitinae). Bioassays showed that sex attraction was highly species-specific between C. bequaerti and C cumulans but not between C. cumulans and C. silvestrii. The sex-pairing pheromone of the three species is secreted by the tergal glands of female alates. It consists of a common compound (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. In C. bequaerti, this polyunsaturated alcohol is the only compound of the sex-pairing pheromone, whereas it is associated with the oxygenated sesquiterpene (E)-nerolid…

Sexual and postmating reproductive isolation between allopatric Drosophila montana populations suggest speciation potential

2011

This work was funded by a European Commission Research Training Grant RTN2-2001-00049, the Centre of Excellence for Evolutionary Research at the University of Jyväskylä and a Marie Curie Initial Training Network, ‘Understanding the evolutionary origin of biological diversity’ (ITN-2008-213780 SPECIATION) Background: Widely distributed species with populations adapted to different environmental conditions can provide valuable opportunities for tracing the onset of reproductive incompatibilities and their role in the speciation process. Drosophila montana, a D. virilis group species found in high latitude boreal forests in Nearctic and Palearctic regions around the globe, could be an excellen…

Size‐selective harvesting fosters adaptations in mating behaviour and reproductive allocation, affecting sexual selection in fish

2019

The role of sexual selection in the context of harvest-induced evolution is poorly understood. However, elevated and trait-selective harvesting of wild populations may change sexually selected traits, which in turn can affect mate choice and reproduction. We experimentally evaluated the potential for fisheries-induced evolution of mating behaviour and reproductive allocation in fish. We used an experimental system of zebrafish (Danio rerio) lines exposed to large, small or random (i.e. control) size-selective mortality. The large-harvested line represented a treatment simulating the typical case in fisheries where the largest individuals are preferentially harvested. We used a full factoria…

Risk factors for Coronavirus Disease 2019 (COVID-19) severity and mortality among solid cancer patients and impact of the disease on anticancer treat…

2020

Background Cancer patients are thought to have an increased risk of developing severe Coronavirus Disease 2019 (COVID-19) infection and of dying from the disease. In this work, predictive factors for COVID-19 severity and mortality in cancer patients were investigated. Patients and Methods In this large nationwide retro-prospective cohort study, we collected data on patients with solid tumours and COVID-19 diagnosed between March 1 and June 11, 2020. The primary endpoint was all-cause mortality and COVID-19 severity, defined as admission to an intensive care unit (ICU) and/or mechanical ventilation and/or death, was one of the secondary endpoints. Results From April 4 to June 11, 2020, 1289…

Influence of microbial symbionts on insect pheromones

2018

Covering: up to 2018 Pheromones serve as chemical signals between individuals of the same species and play important roles for mate localization and mate choice as well as other social interactions in insects. A growing body of literature indicates that microbial symbionts can modulate their hosts' chemical profiles, mate choice decisions and social behavior. This modulation can occur by the direct biosynthesis of pheromone components or the provisioning of precursors, or through general changes in the metabolite pool of the host and its resource allocation into pheromone production. Here we review and discuss the contexts in which microbial modulation of intraspecific communication in inse…

Removing Batch Effects from Longitudinal Gene Expression - Quantile Normalization Plus ComBat as Best Approach for Microarray Transcriptome Data

2016

International audience; Technical variation plays an important role in microarray-based gene expression studies, and batch effects explain a large proportion of this noise. It is therefore mandatory to eliminate technical variation while maintaining biological variability. Several strategies have been proposed for the removal of batch effects, although they have not been evaluated in large-scale longitudinal gene expression data. In this study, we aimed at identifying a suitable method for batch effect removal in a large study of microarray-based longitudinal gene expression. Monocytic gene expression was measured in 1092 participants of the Gutenberg Health Study at baseline and 5-year fol…