82 research outputs found

    A ten thousand frames per second readout MAPS for the EUDET beam telescope

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    Designed and manufactured in a commercial CMOS 0.35 μm OPTO process for equipping the EUDET beam telescope, MIMOSA26 is the first reticule size pixel sensor with digital output and integrated zero suppression. It features a matrix of pixels with 576 rows and 1152 columns, covering an active area of ~224 mm2. A single point resolution of about 4 μm was obtained with a pixel pitch of 18.4 μm. Its architecture allows a fast readout frequency of ~10 k frames/s. The paper describes the chip design, test and major characterisation outcome

    CD4saurus Rex &HIVelociraptor vs. development of clinically useful immunological markers: a Jurassic tale of frozen evolution

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    One of the most neglected areas of everyday clinical practice for HIV physicians is unexpectedly represented by CD4 T cell counts when used as an aid to clinical decisions. All who care for HIV patients believe that CD4+ T cell counts are a reliable method to evaluate a patient immune status. There is however a fatalistic acceptance that besides its general usefulness, CD4+ T cell counts have relevant clincal and immunological limits. Shortcomings of CD4 counts appear in certain clinical scenarios including identification of immunological nonresponders, subsequent development of cancer on antiretroviral teatment, failure on tretment simplification. Historical and recently described parameters might be better suited to advise management of patients at certain times during their disease history. Immunogenotypic parameters and innate immune parameters that define progression as well as immune parameters associated with immune recovery are available and have not been introduced into validation processes in larger trials. The scientific and clinical community needs an effort in stimulating clinical evolution of immunological tests beyond "CD4saurus Rex" introducing new parameters in the clinical arena after appropriate validatio

    Policy implementation and priorities to create healthy food environments using the Healthy Food Environment Policy Index (Food-EPI): A pooled level analysis across eleven European countries

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    Background: Food environments have been recognised as highly influential on population diets. Government policies have great potential to create healthy food environments to promote healthy diets. This study aimed to evaluate food environment policy implementation in European countries and identify priority actions for governments to create healthy food environments. Methods: The Healthy Food Environment Policy Index (Food-EPI) was used to evaluate the level of food environment policy and infrastructure support implementation in Estonia, Finland, Germany, Ireland, Italy, the Netherlands, Norway, Poland, Portugal, Slovenia, and Spain in 20192021. Evidence of implementation of food environment policies was compiled in each country and validated by government officials. National experts evaluated the implementation of policies and identified priority recommendations. Findings: Finland had the highest proportion (32%, n = 7/22) of policies shaping food environments with a high level of implementation. Slovenia and Poland had the highest proportion of policies rated at very low implementation (42%, n = 10/24 and 36%, n = 9/25 respectively). Policies regarding food provision, promotion, retail, funding, monitoring, and health in all policies were identified as the most important gaps across the European countries. Experts recommended immediate action on setting standards for nutrients of concern in processed foods, improvement of school food environments, fruit and vegetable subsidies, unhealthy food and beverage taxation, and restrictions on unhealthy food marketing to children. Interpretation: Immediate implementation of policies and infrastructure support that prioritize action towards healthy food environments is urgently required to tackle the burden of obesity and diet-related non-communicable diseases in Europe. Funding: This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 774548 and from the Joint Programming Initiative A Healthy Diet for a Healthy Life. (c) 2022 The Author(s

    High dietary diversity is associated with obesity in Sri Lankan adults: An evaluation of three dietary scores.

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    Background: Dietary diversity is recognized as a key element of a high quality diet. However, diets that offer a greater variety of energy-dense foods could increase food intake and body weight. The aim of this study was to explore association of diet diversity with obesity in Sri Lankan adults. Methods: Six hundred adults aged > 18 years were randomly selected by using multi-stage stratified sample. Dietary intake assessment was undertaken by a 24 hour dietary recall. Three dietary scores, Dietary Diversity Score (DDS), Dietary Diversity Score with Portions (DDSP) and Food Variety Score (FVS) were calculated. Body mass index (BMI) ≥ 25 kg.m−2 is defined as obese and Asian waist circumference cut-offs were used diagnosed abdominal obesity. Results: Mean of DDS for men and women were 6.23 and 6.50 (p=0.06), while DDSP was 3.26 and 3.17 respectively (p=0.24). FVS values were significantly different between men and women 9.55 and 10.24 (p=0.002). Dietary diversity among Sri Lankan adults was significantly associated with gender, residency, ethnicity, education level but not with diabetes status. As dietary scores increased, the percentage consumption was increased in most of food groups except starches. Obese and abdominal obese adults had the highest DDS compared to non-obese groups (p<0.05). With increased dietary diversity the level of BMI, waist circumference and energy consumption was significantly increased in this population. Conclusion: Our data suggests that dietary diversity is positively associated with several socio-demographic characteristics and obesity among Sri Lankan adults. Although high dietary diversity is widely recommended, public health messages should emphasize to improve dietary diversity in selective food items

    A Reduction in Ribonucleotide Reductase Activity Slows Down the Chromosome Replication Fork but Does Not Change Its Localization

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    BACKGROUND:It has been proposed that the enzymes of nucleotide biosynthesis may be compartmentalized or concentrated in a structure affecting the organization of newly replicated DNA. Here we have investigated the effect of changes in ribonucleotide reductase (RNR) activity on chromosome replication and organization of replication forks in Escherichia coli. METHODOLOGY/PRINCIPAL FINDINGS:Reduced concentrations of deoxyribonucleotides (dNTPs) obtained by reducing the activity of wild type RNR by treatment with hydroxyurea or by mutation, resulted in a lengthening of the replication period. The replication fork speed was found to be gradually reduced proportionately to moderate reductions in nucleotide availability. Cells with highly extended C periods showed a "delay" in cell division i.e. had a higher cell mass. Visualization of SeqA structures by immunofluorescence indicated no change in organization of the new DNA upon moderate limitation of RNR activity. Severe nucleotide limitation led to replication fork stalling and reversal. Well defined SeqA structures were not found in situations of extensive replication fork repair. In cells with stalled forks obtained by UV irradiation, considerable DNA compaction was observed, possibly indicating a reorganization of the DNA into a "repair structure" during the initial phase of the SOS response. CONCLUSION/SIGNIFICANCE:The results indicate that the replication fork is slowed down in a controlled manner during moderate nucleotide depletion and that a change in the activity of RNR does not lead to a change in the organization of newly replicated DNA. Control of cell division but not control of initiation was affected by the changes in replication elongation

    A Biodiverse Rich Environment Does Not Contribute to a Better Diet: A Case Study from DR Congo

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    The potential of biodiversity to increase and sustain nutrition security is increasingly recognized by the international research community. To date however, dietary assessment studies that have assessed how biodiversity actually contributes to human diets are virtually absent. This study measured the contribution of wild edible plants (WEP) to the dietary quality in the high biodiverse context of DR Congo. The habitual dietary intake was estimated from 2 multiple-pass 24 h dietary recalls for 363 urban and 129 rural women. All WEP were collected during previous ethnobotanical investigations and identified and deposited in the National Botanical Garden of Belgium (BR). Results showed that in a high biodiverse region with precarious food security, WEP are insufficiently consumed to increase nutrition security or dietary adequacy. The highest contribution came from Dacryodes edulis in the village sample contributing 4.8% of total energy intake. Considering the nutrient composition of the many WEP available in the region and known by the indigenous populations, the potential to increase nutrition security is vast. Additional research regarding the dietary contribution of agricultural biodiversity and the nutrient composition of WEP would allow to integrate them into appropriate dietary guidelines for the region and pave the way to domesticate the most interesting WEP

    The Stringent Response and Cell Cycle Arrest in Escherichia coli

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    The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes upon arrest. Nucleoids of these cells are decondensed; in the absence of the ability to synthesize ppGpp, nucleoids become highly condensed, similar to that seen after treatment with the translational inhibitor chloramphenicol. After induction of the stringent response, while regions corresponding to the origins of replication segregate, the termini remain colocalized in wild-type cells. In contrast, cells arrested by rifampicin and cephalexin do not show colocalized termini, suggesting that the stringent response arrests chromosome segregation at a specific point. Release from starvation causes rapid nucleoid reorganization, chromosome segregation, and resumption of replication. Arrest of replication and inhibition of colony formation by ppGpp accumulation is relieved in seqA and dam mutants, although other aspects of the stringent response appear to be intact. We propose that DNA methylation and SeqA binding to non-origin loci is necessary to enforce a full stringent arrest, affecting both initiation of replication and chromosome segregation. This is the first indication that bacterial chromosome segregation, whose mechanism is not understood, is a step that may be regulated in response to environmental conditions

    Cell Size and the Initiation of DNA Replication in Bacteria

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    In eukaryotes, DNA replication is coupled to the cell cycle through the actions of cyclin-dependent kinases and associated factors. In bacteria, the prevailing view, based primarily from work in Escherichia coli, is that growth-dependent accumulation of the highly conserved initiator, DnaA, triggers initiation. However, the timing of initiation is unchanged in Bacillus subtilis mutants that are ∼30% smaller than wild-type cells, indicating that achievement of a particular cell size is not obligatory for initiation. Prompted by this finding, we re-examined the link between cell size and initiation in both E. coli and B. subtilis. Although changes in DNA replication have been shown to alter both E. coli and B. subtilis cell size, the converse (the effect of cell size on DNA replication) has not been explored. Here, we report that the mechanisms responsible for coordinating DNA replication with cell size vary between these two model organisms. In contrast to B. subtilis, small E. coli mutants delayed replication initiation until they achieved the size at which wild-type cells initiate. Modest increases in DnaA alleviated the delay, supporting the view that growth-dependent accumulation of DnaA is the trigger for replication initiation in E. coli. Significantly, although small E. coli and B. subtilis cells both maintained wild-type concentration of DnaA, only the E. coli mutants failed to initiate on time. Thus, rather than the concentration, the total amount of DnaA appears to be more important for initiation timing in E. coli. The difference in behavior of the two bacteria appears to lie in the mechanisms that control the activity of DnaA
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