Comparison of mechanical ventilatory constraints between continuous and intermittent exercises in healthy prepubescent children.

International audienceBBackground: The aim of this study was to evaluate the occurrence and severity of mechanical ventilatory constraints in healthy prepubescent children during continuous and intermittent exercise. Methods: Twelve prepubescent children (7 - 11 years old) performed 7 exercises on a treadmill: one graded test for the determination of maximal aerobic speed (MAS), three continuous exercises (CE) at 60, 70 and 80% of MAS and three intermittent exercises (IE), alternating 15s of exercise with 15s of passive recovery, at 90, 100 and 110% of MAS. During each CE and IE, tidal flow/volume loops were plotted within a maximal flow/volume loop (MFVL) measured at rest before each exercise. Expiratory flow limitation (expFL expressed in %Vt) was defined as the part of exercise tidal volume (Vt) meeting the boundary of MFVL. Breathing strategy was estimated by measuring inspiratory capacity relative to forced vital capacity and tidal volume relative to inspiratory capacity. Other breathing pattern parameters (ventilation VE, Vt, respiratory frequency f) were continuously recorded during exercise. Results: An "intensity" effect was found for during CE (p<0.001) but not during IE (p=0.08). The increase in was predominantly assumed by an increase in f for both exercise modalities. During each exercise, several children heterogeneously experienced expFL ranging between 10 - 90%Vt. For all exercises, Vt was predominantly regulated by an increase in Vt/IC with no change in IC/FVC from rest to exercise. Finally, no significant "modality" effect was found for mechanical ventilatory constraint parameters (expFL, VT/IC and IV/FVC). Discussion: We could conclude that neither of the modalities studied induced more mechanical ventilatory constraints than the other, but that exercise intensities specific to each modality might be greater sources of exacerbation for mechanical ventilatory constraints

Dietary and lifestyle quality indices with/without physical activity and markers of insulin resistance in European adolescents: the HELENA study

Resistencia a la insulina en adolescente

Valores de referencia para leptina, cortisol, insulina y glucosa entre los adolescentes europeos y su asociación con adiposidad: Estudio Helena

Background and Objective: Adequate concentrations of leptin, cortisol, and insulin are important for a suitable metabolism and development during adolescence. These hormones jointly with glucose play a major role in fat metabolism and development of childhood obesity. Our main objective was to quantify biomarkers as leptin, cortisol, insulin and glucose status in European adolescents to contribute to establish reference ranges. Methods: A representative sample of 927 adolescents (45% males, 14.9±1.2 years for the overall population) from ten European cities of the HELENA study was used to obtain fasting blood samples for these biomarkers. The percentile distributions were computed by sex and age and percentiles were associated with BMI classification. Results: Serum leptin concentration in adolescents varied significantly according to BMI, sex and age (all p<0.001). Cortisol presented a tendency to increase with age, both for females and males, while insulin and glucose were stable with age. Leptin and insulin were highest in obese adolescents (p<0.001), whilst cortisol and glucose did not vary with BMI. Percentiles 5, 25, 50, 75 and 95, 26.70 and 65.33 ng/ml for leptin; 5.00, 8.11, 11.14, 15.00 and 24.51 μg/dl for cortisol and 3.65, 6.15, 8.52, 11.90 and 20.53 μlU/ml for insulin. Conclusions: In adolescents, leptin, cortisol, insulin and glucose concentrations are differently affected by age, sex and BMI. Establishment of reference ranges (percentiles) of these biomarkers would be of great interest when pediatricians have to assess the trend of an adolescent to develop obesity years after.Objetivo: Concentraciones adecuadas de leptina, cortisol e insulina son importantes para un metabolismo normal durante la adolescencia, puesto que valores alterados de estas hormonas, junto con la glucosa, se asocian con el desarrollo de la obesidad infantil. Nuestro principal objetivo fue cuantificar estos marcadores en adolescentes europeos con el fin de establecer rangos de referencia. Métodos: Muestras de sangre procedentes de 927 adolescentes en ayunas (14,9 ± 1,2 años, 45% varones, estudio HELENA), fueron analizadas para cuantificar la leptina, cortisol, insulina y glucosa. Las distribuciones de percentiles se determinaron teniendo en cuenta el sexo y la edad. También se estudió la asociación entre percentiles y la clasificación del IMC. Resultados: La concentración de leptina en suero variaba significativamente con el IMC, el sexo y la edad (todos p<0,001). El cortisol presentó una tendencia a aumentar con la edad, tanto para varones como mujeres, mientras que la insulina y la glucosa eran estables con la edad. La leptina y la insulina fueron más altas en los adolescentes obesos (p <0,001), mientras que el cortisol y glucosa no variaron con el IMC. Los percentiles 5, 25, 50, 75 y 95, para los valores de hormonas fueron, respectivamente: 1.27, 4.06, 11.54, 26.70 y 65.33 ng/ml para la leptina; 5.00, 8.11, 11.14, 15.00 y 24.51 μg/dl para el cortisol y 3.65, 6.15, 8.52, 11.90 y 20.53 μlU/ml de insulina.The HELENA study has taken place with the financial support of the European Community Sixth RTD Framework Programme (Contract FOODCT- 2005-007034). This study was also supported by a grant from the Spanish Ministry of Science and Innovation AGL2007-29784-E

Dysregulation of Ribosome Biogenesis and Translational Capacity Is Associated with Tumor Progression of Human Breast Cancer Cells

Protein synthesis is a fundamental cell process and ribosomes - particularly through the ribosomal RNA that display ribozyme activity - are the main effectors of this process. Ribosome biogenesis is a very complex process involving transcriptional a

Dietary and lifestyle quality indices with/without physical activity and markers of insulin resistance in European adolescents: the HELENA study

Abstract Emerging data indicate that higher levels of insulin resistance (IR) are common among children and adolescents and are related to cardiometabolic risk; therefore, IR requires consideration early in life. In addition, there is a lack of conclusive evidence regarding the role of dietary nutrients on IR. The Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) was conducted in European adolescents aged 12·5 -17·5 years. A total of 637 participants with valid homeostasis model assessment (HOMA) index data and who completed at least a 2 d 24 h dietary recall were included in the study (60 % of the total HELENA-CSS sample). There were two dietary indices calculated, with the only difference between them being the inclusion or not of physical activity (PA). Markers of IR such as HOMA and the quantitative insulin sensitivity check index (QUICKI) were calculated. Pubertal status, BMI and cardiorespiratory fitness (CRF) were measured as potential confounders. The dietary index including PA was inversely associated with HOMA and directly with the QUICKI in females, but not in males, after adjusting for pubertal status, centre, BMI and CRF. In conclusion, the present study indicates that considering PA as part of the dietary index is of relevance as the resulted index is inversely related to IR independently of potential confounders including CRF. Overall, these findings suggest that intervention studies aimed at preventing IR in young people should focus on increasing the quality of the diet and also on including an optimal PA level in healthy adolescents

Relationship between self-reported dietary intake and physical activity levels among adolescents: The HELENA study

Background Evidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. Therefore it is important to investigate associations between dietary and physical activity behavior, the two most important lifestyle behaviors influencing our energy balance and body composition. The objective of the present study is to describe the relationship between energy, nutrient and food intake and the physical activity level among a large group of European adolescents. Methods The study comprised a total of 2176 adolescents (46.2% male) from ten European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Dietary intake and physical activity were assessed using validated 24-h dietary recalls and self-reported questionnaires respectively. Analyses of covariance (ANCOVA) were used to compare the energy and nutrient intake and the food consumption between groups of adolescents with different physical activity levels (1st to 3rd tertile). Results In both sexes no differences were found in energy intake between the levels of physical activity. The most active males showed a higher intake of polysaccharides, protein, water and vitamin C and a lower intake of saccharides compared to less active males. Females with the highest physical activity level consumed more polysaccharides compared to their least active peers. Male and female adolescents with the highest physical activity levels, consumed more fruit and milk products and less cheese compared to the least active adolescents. The most active males showed higher intakes of vegetables and meat, fish, eggs, meat substitutes and vegetarian products compared to the least active ones. The least active males reported the highest consumption of grain products and potatoes. Within the female group, significantly lower intakes of bread and cereal products and spreads were found for those reporting to spend most time in moderate to vigorous physical activity. The consumption of foods from the remaining food groups, did not differ between the physical activity levels in both sexes. Conclusion It can be concluded that dietary habits diverge between adolescents with different self-reported physical activity levels. For some food groups a difference in intake could be found, which were reflected in differences in some nutrient intakes. It can also be concluded that physically active adolescents are not always inclined to eat healthier diets than their less active peers.The HELENA study took place with the financial support of the European Community Sixth RTD Framework Programme (Contract FOOD-CT: 2005-007034). This work was also partially supported by the European Union, in the framework of the Public Health Programme (ALPHA project, Ref: 2006120), the Swedish Council for Working Life and Social Research (FAS), the Spanish Ministry of Education (EX-2007-1124, and EX-2008-0641), and the Spanish Ministry of Health, Maternal, Child Health and Development Network (number RD08/0072) (JPRL, LAM)

Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV

Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated $\mathrm{t}\overline{\mathrm{t}}$ events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The heavy-flavour jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV)

Evidence for the Higgs boson decay to a bottom quark–antiquark pair

info:eu-repo/semantics/publishe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe