Search results for "Process"

Stochastic sampling effects favor manual over digital contact tracing.

2020

Isolation of symptomatic individuals, tracing and testing of their nonsymptomatic contacts are fundamental strategies for mitigating the current COVID-19 pandemic. The breaking of contagion chains relies on two complementary strategies: manual reconstruction of contacts based on interviews and a digital (app-based) privacy-preserving contact tracing. We compare their effectiveness using model parameters tailored to describe SARS-CoV-2 diffusion within the activity-driven model, a general empirically validated framework for network dynamics. We show that, even for equal probability of tracing a contact, manual tracing robustly performs better than the digital protocol, also taking into accou…

2016

The growth of next-generation sequencing (NGS) datasets poses a challenge to the alignment of reads to reference genomes in terms of alignment quality and execution speed. Some available aligners have been shown to obtain high quality mappings at the expense of long execution times. Finding fast yet accurate software solutions is of high importance to research, since availability and size of NGS datasets continue to increase. In this work we present an efficient parallelization approach for NGS short-read alignment on multi-core clusters. Our approach takes advantage of a distributed shared memory programming model based on the new UPC++ language. Experimental results using the CUSHAW3 alig…

State transition identification in multivariate time series (STIMTS) applied to rotational jump trajectories from single molecules

2018

Time resolved data from single molecule experiments often suffer from contamination with noise due to a low signal level. Identifying a proper model to describe the data thus requires an approach with sufficient model parameters without misinterpreting the noise as relevant data. Here, we report on a generalized data evaluation process to extract states with piecewise constant signal level from simultaneously recorded multivariate data, typical for multichannel single molecule experiments. The method employs the minimum description length principle to avoid overfitting the data by using an objective function, which is based on a tradeoff between fitting accuracy and model complexity. We val…

On the growth and form of cortical convolutions

2016

International audience; The rapid growth of the human cortex during development is accompanied by the folding of the brain into a highly convoluted structure1-3. Recent studies have focused on the genetic and cellular regulation of cortical growth4-8, but understanding the formation of the gyral and sulcal convolutions also requires consideration of the geometry and physical shaping of the growing brain9-15. To study this, we use magnetic resonance images to build a 3D-printed layered gel mimic of the developing smooth fetal brain; when immersed in a solvent, the outer layer swells relative to the core, mimicking cortical growth. This relative growth puts the outer layer into mechanical com…

The role of spatial structure in the evolution of viral innate immunity evasion: A diffusion-reaction cellular automaton model

2020

Most viruses have evolved strategies for preventing interferon (IFN) secretion and evading innate immunity. Recent work has shown that viral shutdown of IFN secretion can be viewed as a social trait, since the ability of a given virus to evade IFN-mediated immunity depends on the phenotype of neighbor viruses. Following this idea, we investigate the role of spatial structure in the evolution of innate immunity evasion. For this, we model IFN signaling and viral spread using a spatially explicit approximation that combines a diffusion-reaction model and cellular automaton. Our results indicate that the benefits of preventing IFN secretion for a virus are strongly determined by spatial struct…

Stimulation of natural killer cells with rhCD137 ligand enhances tumor-targeting antibody efficacy in gastric cancer

2018

Although many anticancer agents for gastric cancer have been developed, the prognosis for many patients remains poor. Recently, costimulatory immune molecules that reactivate antitumor immune responses by utilizing the host immune system have attracted attention as new therapeutic strategies. CD137 is a costimulatory molecule that reportedly potentiates the antitumor activity of tumor-targeting monoclonal antibodies (mAbs) by enhancing antibody-dependent cellular cytotoxicity. However, it remains unclear whether CD137 stimulates tumor-regulatory activity in gastric cancer. In this study, we investigated the antitumor effects of CD137 stimulation on gastric cancer cells administered tumor-ta…

Metal homeostasis regulators suppress FRDA phenotypes in a drosophila model of the disease

2016

Friedreich's ataxia (FRDA), the most commonly inherited ataxia in populations of European origin, is a neurodegenerative disorder caused by a decrease in frataxin levels. One of the hallmarks of the disease is the accumulation of iron in several tissues including the brain, and frataxin has been proposed to play a key role in iron homeostasis. We found that the levels of zinc, copper, manganese and aluminum were also increased in a Drosophila model of FRDA, and that copper and zinc chelation improve their impaired motor performance. By means of a candidate genetic screen, we identified that genes implicated in iron, zinc and copper transport and metal detoxification can restore frataxin def…

Transcriptional Differences between Diapausing and Non-Diapausing D. montana Females Reared under the Same Photoperiod and Temperature

2016

Background A wide range of insects living at higher latitudes enter diapause at the end of the warm season, which increases their chances of survival through harsh winter conditions. In this study we used RNA sequencing to identify genes involved in adult reproductive diapause in a northern fly species, Drosophila montana. Both diapausing and non-diapausing flies were reared under a critical day length and temperature, where about half of the emerging females enter diapause enabling us to eliminate the effects of varying environmental conditions on gene expression patterns of the two types of female flies. Results RNA sequencing revealed large differences between gene expression patterns of…

Interactions between odorants and glutathione transferases in the human olfactory cleft

2020

AbstractXenobiotic metabolizing enzymes and other proteins, including odorant-binding proteins located in the nasal epithelium and mucus, participate in a series of processes modulating the concentration of odorants in the environment of olfactory receptors (ORs) and finely impact odor perception. These enzymes and transporters are thought to participate in odorant degradation or transport. Odorant biotransformation results in 1) changes in the odorant quantity up to their clearance and the termination of signaling and 2) the formation of new odorant stimuli (metabolites). Enzymes, such as cytochrome P450 and glutathione transferases (GSTs), have been proposed to participate in odorant clea…

Deviance sensitivity in the auditory cortex of freely moving rats.

2018

Deviance sensitivity is the specific response to a surprising stimulus, one that violates expectations set by the past stimulation stream. In audition, deviance sensitivity is often conflated with stimulus-specific adaptation (SSA), the decrease in responses to a common stimulus that only partially generalizes to other, rare stimuli. SSA is usually measured using oddball sequences, where a common (standard) tone and a rare (deviant) tone are randomly intermixed. However, the larger responses to a tone when deviant does not necessarily represent deviance sensitivity. Deviance sensitivity is commonly tested using a control sequence in which many different tones serve as the standard, eliminat…