271 research outputs found

    Etude Clinique des niveaux de perturbation de la metacognition, de la cognition sociale et du contrôle exécutif dans la pathologie frontale

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    Recent and convergent studies in neuropsychology have suggested the importance of frontal regions to the integrity of a number of functions such as metamemory capacities, executive functions, and social skills (Theory of Mind : ToM). In this original work, following Stuss et Anderson (2004), we assume a link between disturbances of these functions. We proposed to 16 frontal patients and 20 matched healthy subjects a protocol designed to test metamemory, ToM and executive functions in order to analyze the relations between disturbances of self-awareness (metamemory) and awareness of others (ToM), and cognitive control (executive functions). Our results confirm the importance of frontal lobes on these capacities. No correlation was found between measures of metamemory, measures of ToM and executive scores. The observation of individual profiles emphasizes the existence of dissociations between self awareness and consciousness of the others, and between these two forms of metacognitive control and the executive functioning. These results confirm the importance to engage more studies combining aspects of ToM, metacognition and executive control, to better understand the organization and architecture of the functions supported by frontal lobe

    Single-Cell (Meta-)Genomics of a Dimorphic Candidatus Thiomargarita nelsonii Reveals Genomic Plasticity

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    The genus Thiomargarita includes the world's largest bacteria. But as uncultured organisms, their physiology, metabolism, and basis for their gigantism are not well understood. Thus, a genomics approach, applied to a single Candidatus Thiomargarita nelsonii cell was employed to explore the genetic potential of one of these enigmatic giant bacteria. The Thiomargarita cell was obtained from an assemblage of budding Ca. T. nelsonii attached to a provannid gastropod shell from Hydrate Ridge, a methane seep offshore of Oregon, USA. Here we present a manually curated genome of Bud S10 resulting from a hybrid assembly of long Pacific Biosciences and short Illumina sequencing reads. With respect to inorganic carbon fixation and sulfur oxidation pathways, the Ca. T nelsonii Hydrate Ridge Bud S10 genome was similar to marine sister taxa within the family Beggiatoaceae. However, the Bud S10 genome contains genes suggestive of the genetic potential for lithotrophic growth on arsenite and perhaps hydrogen. The genome also revealed that Bud 510 likely respires nitrate via two pathways: a complete denitrification pathway and a dissimilatory nitrate reduction to ammonia pathway. Both pathways have been predicted, but not previously fully elucidated, in the genomes of other large, vacuolated, sulfur-oxidizing bacteria. Surprisingly, the genome also had a high number of unusual features for a bacterium to include the largest number of metacaspases and introns ever reported in a bacterium. Also present, are a large number of other mobile genetic elements, such as insertion sequence (IS) transposable elements and miniature inverted-repeat transposable elements (MITEs). In some cases, mobile genetic elements disrupted key genes in metabolic pathways. For example, a MITE interrupts hupL, which encodes the large subunit of the hydrogenase in hydrogen oxidation. Moreover, we detected a group I intron in one of the most critical genes in the sulfur oxidation pathway, dsrA. The dsrA group I intron also carried a MITE sequence that, like the hupL MITE family, occurs broadly across the genome. The presence of a high degree of mobile elements in genes central to Thiomargarita's core metabolism has not been previously reported in free-living bacteria and suggests a highly mutable genome

    Public health critical race praxis at the intersection of traffic stops and injury epidemiology

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    Background: Law enforcement traffic stops are one of the most common entryways to the US justice system. Conventional frameworks suggest traffic stops promote public safety by reducing dangerous driving practices and non-vehicular crime with little to no collateral damage to individuals and communities. Critical frameworks interrogate these assumptions, identifying significant individual and community harms that disparately impact Black, Indigenous, and People of Color (BIPOC) and low-income communities. Methods: The Public Health Critical Race Praxis (PHCRP) and multi-level frameworks from community anti-racist training were combined into a structured diagram to guide intervention and research teams in contrasting conventional and critical perspectives on traffic stops. The diagram divides law enforcement and drivers/residents as two separate agent types that interact during traffic stops. These two agent types have different conventional and critical histories, priorities, and perspectives at multiple levels, including individual, interpersonal, institutional, and cultural levels. Conventional solutions (identifying explicitly racist officers, “meet-a-cop” programs, police interaction training for drivers) are born from conventional frameworks (rewarding crime prevention regardless of cost, the war on drugs saves lives, driver behavior perfectionism). While conventional perspectives focus on individual and interpersonal levels, critical perspectives more deeply acknowledge dynamics at institutional and cultural levels. Critical solutions may be hard to discover without critical frameworks, including that law enforcement creates measurable collateral damage and disparate social control effects; neighborhood patrol priorities can be set without community self-determination or accountability and may trump individual and interpersonal dynamics; and the war on drugs is highly racialized and disproportionally enforced through traffic stop programs. Conclusions: Traffic stop enforcement and crash prevention programs that do not deeply and critically consider these dynamics at multiple levels, not just law enforcement-driver interactions at the individual and interpersonal levels, may be at increased risk of propagating histories of BIPOC discrimination. In contrast, public health and transportation researchers and practitioners engaged in crash and injury prevention strategies that employ law enforcement should critically consider disparate history and impacts of law enforcement in BIPOC communities. PHCRP, anti-racism frameworks, and the included diagram may assist them in organizing critical thinking about research studies, interventions, and impacts

    Re-prioritizing traffic stops to reduce motor vehicle crash outcomes and racial disparities

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    Background: Law enforcement traffic stops are one of the most common entryways to the US justice system. Conventional frameworks suggest traffic stops promote public safety by reducing dangerous driving practices and non-vehicular crime. Law enforcement agencies have wide latitude in enforcement, including prioritization of stop types: (1) safety (e.g. moving violation) stops, (2) investigatory stops, or (3) economic (regulatory and equipment) stops. In order to prevent traffic crash fatalities and reduce racial disparities, the police department of Fayetteville, North Carolina significantly re-prioritized safety stops. Methods: Annual traffic stop, motor vehicle crash, and crime data from 2002 to 2016 were combined to examine intervention (2013-2016) effects. Fayetteville was compared against synthetic control agencies built from 8 similar North Carolina agencies by weighted matching on pre-intervention period trends and comparison against post-intervention trends. Results: On average over the intervention period as compared to synthetic controls, Fayetteville increased both the number of safety stops + 121% (95% confidence interval + 17%, + 318%) and the relative proportion of safety stops (+ 47%). Traffic crash and injury outcomes were reduced, including traffic fatalities - 28% (- 64%, + 43%), injurious crashes - 23% (- 49%, + 16%), and total crashes - 13% (- 48%, + 21%). Disparity measures were reduced, including Black percent of traffic stops - 7% (- 9%, - 5%) and Black vs. White traffic stop rate ratio - 21% (- 29%, - 13%). In contrast to the Ferguson Effect hypothesis, the relative de-prioritization of investigatory stops was not associated with an increase in non-traffic crime outcomes, which were reduced or unchanged, including index crimes - 10% (- 25%, + 8%) and violent crimes - 2% (- 33%, + 43%). Confidence intervals were estimated using a different technique and, given small samples, may be asymmetrical. Conclusions: The re-prioritization of traffic stop types by law enforcement agencies may have positive public health consequences both for motor vehicle injury and racial disparity outcomes while having little impact on non-traffic crime

    Block of death-receptor apoptosis protects mouse cytomegalovirus from macrophages and is a determinant of virulence in immunodeficient hosts.

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    The inhibition of death-receptor apoptosis is a conserved viral function. The murine cytomegalovirus (MCMV) gene M36 is a sequence and functional homologue of the human cytomegalovirus gene UL36, and it encodes an inhibitor of apoptosis that binds to caspase-8, blocks downstream signaling and thus contributes to viral fitness in macrophages and in vivo. Here we show a direct link between the inability of mutants lacking the M36 gene (ΔM36) to inhibit apoptosis, poor viral growth in macrophage cell cultures and viral in vivo fitness and virulence. ΔM36 grew poorly in RAG1 knockout mice and in RAG/IL-2-receptor common gamma chain double knockout mice (RAGγC(-/-)), but the depletion of macrophages in either mouse strain rescued the growth of ΔM36 to almost wild-type levels. This was consistent with the observation that activated macrophages were sufficient to impair ΔM36 growth in vitro. Namely, spiking fibroblast cell cultures with activated macrophages had a suppressive effect on ΔM36 growth, which could be reverted by z-VAD-fmk, a chemical apoptosis inhibitor. TNFα from activated macrophages synergized with IFNγ in target cells to inhibit ΔM36 growth. Hence, our data show that poor ΔM36 growth in macrophages does not reflect a defect in tropism, but rather a defect in the suppression of antiviral mediators secreted by macrophages. To the best of our knowledge, this shows for the first time an immune evasion mechanism that protects MCMV selectively from the antiviral activity of macrophages, and thus critically contributes to viral pathogenicity in the immunocompromised host devoid of the adaptive immune system

    High frequency of mitochondrial genome instability in human endometrial carcinomas

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    To investigate the occurrence of somatic mitochondrial DNA (mtDNA) mutations in human primary endometrial carcinomas, we sequenced the D-loop region, the 12S and 16S rRNA genes of mtDNA of cancer tissues and their matched normal controls. About 56% (28 out of 50) of cases carry one or more somatic changes in mtDNA including deletion, point mutation and mitochondrial microsatellite instability (mtMSI), namely the change in length of short base-repetitive sequences of mtDNA. In particular, mtMSI was frequently detected in 89% (25 out of 28) of all the cases carrying somatic changes followed by point mutations (25%; seven out of 28) and deletion (3.5%; one out of 28). The CCCCCTCCCC sequences located in the Hypervariable Regions I and II of the D-loop and 12S rRNA gene are instability hot spot regions in endometrial carcinomas. It is suggested that errors in replication may account for the high frequency of mtMSI in human endometrial carcinomas. The relatively high prevalence of mtMSI may be a potential new tool for detection of endometrial cancer. © 2003 Cancer Research UK.link_to_subscribed_fulltex

    Characterization of human Sec16B: indications of specialized, non-redundant functions

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    The endoplasmic reticulum (ER) represents the entry point into the secretory pathway and from here newly synthesized proteins and lipids are delivered to the Golgi. The selective cargo export from the ER is mediated by COPII-assembly at specific sites of the ER, the so-called transitional ER (tER). The peripheral membrane protein Sec16, first identified in yeast, localizes to transitional ER and plays a key role in organization of these sites. Sec16 defines the tER and is thought to act as a scaffold for the COPII coat assembly. In humans two isoforms of Sec16 are present, the larger Sec16A and the smaller Sec16B. Nevertheless, the functional differences between the two isoforms are ill-defined. Here we describe characterization of the localization and dynamics of Sec16B relative to Sec16A, provide evidence that Sec16B is likely a minor or perhaps specialized form of Sec16, and that it is not functionally redundant with Sec16A

    Unsupervised Analysis of Classical Biomedical Markers: Robustness and Medical Relevance of Patient Clustering Using Bioinformatics Tools

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    Motivation: It has been proposed that clustering clinical markers, such as blood test results, can be used to stratify patients. However, the robustness of clusters formed with this approach to data pre-processing and clustering algorithm choices has not been evaluated, nor has clustering reproducibility. Here, we made use of the NHANES survey to compare clusters generated with various combinations of pre-processing and clustering algorithms, and tested their reproducibility in two separate samples. Method: Values of 44 biomarkers and 19 health/life style traits were extracted from the National Health and Nutrition Examination Survey (NHANES). The 1999–2002 survey was used for training, while data from the 2003–2006 survey was tested as a validation set. Twelve combinations of pre-processing and clustering algorithms were applied to the training set. The quality of the resulting clusters was evaluated both by considering their properties and by comparative enrichment analysis. Cluster assignments were projected to the validation set (using an artificial neural network) and enrichment in health/life style traits in the resulting clusters was compared to the clusters generated from the original training set. Results: The clusters obtained with different pre-processing and clustering combinations differed both in terms of cluster quality measures and in terms of reproducibility of enrichment with health/life style properties. Z-score normalization, for example, dramatically improved cluster quality and enrichments, as compared to unprocessed data, regardless of the clustering algorithm used. Clustering diabetes patients revealed a group of patients enriched with retinopathies. This coul

    Considerations on equity in management of end-stage kidney disease in low- and middle-income countries

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    Achievement of equity in health requires development of a health system in which everyone has a fair opportunity to attain their full health potential. The current, large country-level variation in the reported incidence and prevalence of treated end-stage kidney disease indicates the existence of system-level inequities. Equitable implementation of kidney replacement therapy (KRT) programs must address issues of availability, affordability, and acceptability. The major structural factors that impact equity in KRT in different countries are the organization of health systems, overall health care spending, funding and delivery models, and nature of KRT prioritization (transplantation, hemodialysis or peritoneal dialysis, and conservative care). Implementation of KRT programs has the potential to exacerbate inequity unless equity is deliberately addressed. In this review, we summarize discussions on equitable provision of KRT in low- and middle-income countries and suggest areas for future research
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