324 research outputs found

    Powering down technology

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    This paper will examine the issue of energy consumption resulting from the use of technology. It will identify and evaluate potential solutions currently being deployed by data center managers. In addition, the paper will recommend guidelines for reducing energy consumption for both the individual and business consumer

    L’expĂ©rience professionnelle : expĂ©riences sĂ©dimentĂ©es et expĂ©riences Ă©pisodiques

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    On dĂ©finit ici l’expĂ©rience professionnelle comme ce qui est produit sur l’homme par sa pratique, c’est-Ă -dire par la rĂ©alisation des tĂąches d’un domaine, sur un temps relativement long. On dĂ©fend l’idĂ©e qu’elle prĂ©sente deux modalitĂ©s : les expĂ©riences « sĂ©dimentĂ©es » sont centrĂ©es sur la rĂ©pĂ©tition des tĂąches dans leur variabilité ; les expĂ©riences » épisodiques » sur la singularitĂ© des situations rencontrĂ©es, des cas hors norme aux cas paradigmatiques. On discute l’articulation de ces deux modalitĂ©s, selon les exigences diffĂ©rentes des types de tĂąches dans les domaines de travail. L’analyse de l’expĂ©rience selon ces modalitĂ©s « sĂ©dimentĂ©es » et « épisodiques » articulĂ©es sert Ă  questionner leurs apports Ă  l’évolution des compĂ©tences, Ă  discuter des « pathologies » possibles de l’expĂ©rience, Ă  expliciter des conditions nĂ©cessaires aux acquisitions et Ă  tirer quelques consĂ©quences sur la conception de formations.Professional experience is defined as the product of practice resulting from tasks performed in a given domain of work, over a relatively long period. We put forward the idea that professional experience covers two modalities: “sedimented” experiences are centred on the repetition of tasks in all their variability; “episodic” experiences are centred on the singularity of the situations encountered, from anomalous events to paradigmatic cases. We discuss how these modalities are articulated in relation to the varying demands of the cognitive operations involved in professional tasks (memory, categorisation, analogical reasoning, decision making
). Analysis of experience depending on its “sedimented” and “episodic” modalities is used to question how they contribute to the development of competencies, discuss what may go wrong with the experience, clarify the conditions required for acquiring competencies and draw some conclusions that may prove useful in devising training programmes

    Bone ultrastructure and x-ray microanalysis of aluminum-intoxicated hemodialyzed patients

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    Bone ultrastructure and x-ray microanalysis of aluminum-intoxicated hemodialyzed patients. In hemodialyzed patients aluminum (Al) intoxication may induce osteomalacic lesions which are mainly observed when plasma immunoreactive parathyroid hormone (iPTH) concentrations are low, and osteitis fibrosa absent. In this study, the bone tissue of eight hemodialyzed patients with elevated plasma and bone Al concentrations was examined by histomorphometry, electron microscopy, and x-ray microanalysis. Five patients (group 1) had osteomalacia and minimal osteitis fibrosa, three patients (group 2) had severe osteitis fibrosa. In group 1, Al was concentrated at the mineralizing front, in hexagonal structures measuring 200 to 1,000 Å which also contained phosphorus, but not calcium. Hydroxyapatite needles had a normal aspect. Osteoblasts appeared inactive. In group 2, Al was also present at the mineralizing layer of osteoid, but, in these cases, in small clusters next to abnormal calcium deposits. Osteoblasts appeared very active. Their mitochondria contained calcium and phosphorus granules, or amorphous material, measuring 1,500 to 2,000 Å, emitting x-rays characteristic for Al and phosphorus. These results suggest that secondary hyperparathyroidism, by stimulating the cellular activity, may increase the uptake and release of Al by the osteoblasts. The presence of Al within the mitochondria of these cells may be one of the factors inducing the mineralization defect.Ultrastructure et microanalyse x du tissu osseux de malades hĂ©modialysĂ©s intoxiquĂ©s par l'aluminium. Chez des malades hĂ©modialysĂ©s l'intoxication par l'aluminium (Al) peut induire des lĂ©sions ostĂ©omalaciques qui s'observent principalement quand la concentration plasmatique de l'hormone parathyroĂŻdienne immunorĂ©active (iPTH) est peu augmentĂ©e, et en l'absence d'ostĂ©ite fibreuse. Dans cette Ă©tude le tissu osseux de huit malades hĂ©modialysĂ©s dont la concentration plasmatique et osseuse de l'Al Ă©tait Ă©levĂ©e, a Ă©tĂ© examinĂ© par l'histomorphomĂ©trie, la microscopie Ă©lectronique et la microanalyse x. Cinq malades (groupe 1) avaient une ostĂ©omalacie et des lĂ©sions minimes d'ostĂ©ite fibreuse, trois malades (groupe 2) avaient une ostĂ©ite fibreuse sĂ©vĂšre. Dans le groupe 1, l'Al Ă©tait concentrĂ© entre ostĂ©oĂŻde et tissu minĂ©ralisĂ©, dans des structures hexagonales mesurant 200 Ă  1000 Å, qui contenaient Ă©galement du phosphore, mais pas de calcium. Les aiguilles d'hydroxyapatite avaient un aspect normal. Les ostĂ©oblastes paraissaient peu actifs. Dans le groupe 2, l'Al Ă©tait aussi prĂ©sent entre ostĂ©oĂŻde et tissu minĂ©ralisĂ©, mais, dans ce cas, sous forme de petits amas, prĂšs de dĂ©pĂŽts anormaux de calcium. Les ostĂ©oblastes semblaient trĂšs actifs. Leurs mitochondries contenaient des granules de calcium et de phosphore ou bien du matĂ©riel amorphe, mesurant 1500 Ă  2000 Å, dont l'Ă©mission x Ă©tait caractĂ©ristique de l'Al et du phosphore. Ces rĂ©sultats suggĂšrent que l'hyperparathyroĂŻdie secondaire, en stimulant l'activitĂ© cellulaire, favorise la captation et le dĂ©pĂŽt de l'Al par les ostĂ©oblastes. La prĂ©sence d'Al dans les mitochondries de ces cellules pourrait ĂȘtre un des facteurs Ă  l'origine du trouble de la minĂ©ralisation

    Rare mutations in SQSTM1 modify susceptibility to frontotemporal lobar degeneration

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    Mutations in the gene coding for Sequestosome 1 (SQSTM1) have been genetically associated with amyotrophic lateral sclerosis (ALS) and Paget disease of bone. In the present study, we analyzed the SQSTM1 coding sequence for mutations in an extended cohort of 1,808 patients with frontotemporal lobar degeneration (FTLD), ascertained within the European Early-Onset Dementia consortium. As control dataset, we sequenced 1,625 European control individuals and analyzed whole-exome sequence data of 2,274 German individuals (total n = 3,899). Association of rare SQSTM1 mutations was calculated in a meta-analysis of 4,332 FTLD and 10,240 control alleles. We identified 25 coding variants in FTLD patients of which 10 have not been described. Fifteen mutations were absent in the control individuals (carrier frequency < 0.00026) whilst the others were rare in both patients and control individuals. When pooling all variants with a minor allele frequency < 0.01, an overall frequency of 3.2 % was calculated in patients. Rare variant association analysis between patients and controls showed no difference over the whole protein, but suggested that rare mutations clustering in the UBA domain of SQSTM1 may influence disease susceptibility by doubling the risk for FTLD (RR = 2.18 [95 % CI 1.24-3.85]; corrected p value = 0.042). Detailed histopathology demonstrated that mutations in SQSTM1 associate with widespread neuronal and glial phospho-TDP-43 pathology. With this study, we provide further evidence for a putative role of rare mutations in SQSTM1 in the genetic etiology of FTLD and showed that, comparable to other FTLD/ALS genes, SQSTM1 mutations are associated with TDP-43 pathology

    Persistence and clearance of Ebola virus RNA from seminal fluid of Ebola virus disease survivors: a longitudinal analysis and modelling study

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    Background By January, 2016, all known transmission chains of the Ebola virus disease (EVD) outbreak in west Africa had been stopped. However, there is concern about persistence of Ebola virus in the reproductive tract of men who have survived EVD. We aimed to use biostatistical modelling to describe the dynamics of Ebola virus RNA load in seminal fl uid, including clearance parameters. Methods In this longitudinal study, we recruited men who had been discharged from three Ebola treatment units in Guinea between January and July, 2015. Participants provided samples of seminal fl uid at follow-up every 3–6 weeks, which we tested for Ebola virus RNA using quantitative real-time RT-PCR. Representative specimens from eight participants were then inoculated into immunodefi cient mice to test for infectivity. We used a linear mixed-eff ect model to analyse the dynamics of virus persistence in seminal fl uid over time. Findings We enrolled 26 participants and tested 130 seminal fl uid specimens; median follow up was 197 days (IQR 187–209 days) after enrolment, which corresponded to 255 days (228–287) after disease onset. Ebola virus RNA was detected in 86 semen specimens from 19 (73%) participants. Median duration of Ebola virus RNA detection was 158 days after onset (73–181; maximum 407 days at end of follow-up). Mathematical modelling of the quantitative time-series data showed a mean clearance rate of Ebola virus RNA from seminal fl uid of –0·58 log units per month, although the clearance kinetic varied greatly between participants. Using our biostatistical model, we predict that 50% and 90% of male survivors clear Ebola virus RNA from seminal fl uid at 115 days (90% prediction interval 72–160) and 294 days (212–399) after disease onset, respectively. We also predicted that the number of men positive for Ebola virus RNA in aff ected countries would decrease from about 50 in January 2016, to fewer than 1 person by July, 2016. Infectious virus was detected in 15 of 26 (58%) specimens tested in mice. Interpretation Time to clearance of Ebola virus RNA from seminal fl uid varies greatly between individuals and could be more than 13 months. Our predictions will assist in decision-making about surveillance and preventive measures in EVD outbreaks

    Quaking promotes monocyte differentiation into pro-atherogenic macrophages by controlling pre-mRNA splicing and gene expression

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    A hallmark of inflammatory diseases is the excessive recruitment and influx of monocytes to sites of tissue damage and their ensuing differentiation into macrophages. Numerous stimuli are known to induce transcriptional changes associated with macrophage phenotype, but posttranscriptional control of human macrophage differentiation is less well understood. Here we show that expression levels of the RNA-binding protein Quaking (QKI) are low in monocytes and early human atherosclerotic lesions, but are abundant in macrophages of advanced plaques. Depletion of QKI protein impairs monocyte adhesion, migration, differentiation into macrophages and foam cell formation in vitro and in vivo. RNA-seq and microarray analysis of human monocyte and macrophage transcriptomes, including those of a unique QKI haploinsufficient patient, reveal striking changes in QKI-dependent messenger RNA levels and splicing of RNA transcripts. The biological importance of these transcripts and requirement for QKI during differentiation illustrates a central role for QKI in posttranscriptionally guiding macrophage identity and function.No sponso

    Persistence and clearance of Ebola virus RNA from seminal fluid of Ebola virus disease survivors: a longitudinal analysis and modelling study.

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    BACKGROUND: By January, 2016, all known transmission chains of the Ebola virus disease (EVD) outbreak in west Africa had been stopped. However, there is concern about persistence of Ebola virus in the reproductive tract of men who have survived EVD. We aimed to use biostatistical modelling to describe the dynamics of Ebola virus RNA load in seminal fluid, including clearance parameters. METHODS: In this longitudinal study, we recruited men who had been discharged from three Ebola treatment units in Guinea between January and July, 2015. Participants provided samples of seminal fluid at follow-up every 3-6 weeks, which we tested for Ebola virus RNA using quantitative real-time RT-PCR. Representative specimens from eight participants were then inoculated into immunodeficient mice to test for infectivity. We used a linear mixed-effect model to analyse the dynamics of virus persistence in seminal fluid over time. FINDINGS: We enrolled 26 participants and tested 130 seminal fluid specimens; median follow up was 197 days (IQR 187-209 days) after enrolment, which corresponded to 255 days (228-287) after disease onset. Ebola virus RNA was detected in 86 semen specimens from 19 (73%) participants. Median duration of Ebola virus RNA detection was 158 days after onset (73-181; maximum 407 days at end of follow-up). Mathematical modelling of the quantitative time-series data showed a mean clearance rate of Ebola virus RNA from seminal fluid of -0·58 log units per month, although the clearance kinetic varied greatly between participants. Using our biostatistical model, we predict that 50% and 90% of male survivors clear Ebola virus RNA from seminal fluid at 115 days (90% prediction interval 72-160) and 294 days (212-399) after disease onset, respectively. We also predicted that the number of men positive for Ebola virus RNA in affected countries would decrease from about 50 in January 2016, to fewer than 1 person by July, 2016. Infectious virus was detected in 15 of 26 (58%) specimens tested in mice. INTERPRETATION: Time to clearance of Ebola virus RNA from seminal fluid varies greatly between individuals and could be more than 13 months. Our predictions will assist in decision-making about surveillance and preventive measures in EVD outbreaks. FUNDING: This study was funded by European Union's Horizon 2020 research and innovation programme, Directorate-General for International Cooperation and Development of the European Commission, Institut national de la santé et de la recherche médicale (INSERM), German Research Foundation (DFG), and Innovative Medicines Initiative 2 Joint Undertaking

    Genome-wide association study of placental weight in 65,405 newborns and 113,620 parents reveals distinct and shared genetic influences between placental and fetal growth

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    A well-functioning placenta is essential for fetal and maternal health throughout pregnancy. Using placental weight as a proxy for placental growth, we report genome-wide association analyses in the fetal (n = 65,405), maternal (n = 61,228) and paternal (n = 52,392) genomes, yielding 40 independent association signals. Twenty-six signals are classified as fetal, four maternal and three fetal and maternal. A maternal parent-of-origin effect is seen near KCNQ1. Genetic correlation and colocalization analyses reveal overlap with birth weight genetics, but 12 loci are classified as predominantly or only affecting placental weight, with connections to placental development and morphology, and transport of antibodies and amino acids. Mendelian randomization analyses indicate that fetal genetically mediated higher placental weight is causally associated with preeclampsia risk and shorter gestational duration. Moreover, these analyses support the role of fetal insulin in regulating placental weight, providing a key link between fetal and placental growth
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