151 research outputs found

    Search for Oscillation of the Electron-Capture Decay Probability of 142^{142}Pm

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    We have searched for time modulation of the electron capture decay probability of 142^{142}Pm in an attempt to confirm a recent claim from a group at the Gesellschaft f\"{u}r Schwerionenforschung (GSI). We produced 142^{142}Pm via the 124^{124}Sn(23^{23}Na, 5n)142^{142}Pm reaction at the Berkeley 88-Inch Cyclotron with a bombardment time short compared to the reported modulation period. Isotope selection by the Berkeley Gas-filled Separator is followed by implantation and a long period of monitoring the 142^{142}Nd Kα_{\alpha} x-rays from the daughter. The decay time spectrum of the x-rays is well-described by a simple exponential and the measured half-life of 40.68(53) seconds is consistent with the accepted value. We observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by Litvinov {\it et al.} (Phys. Lett. B 664 (2008) 162; arXiv:0801.2079 [nucl-ex]). A literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in 142^{142}Eu electron-capture decay. A reanalysis of the published data shows no oscillatory behavior.Comment: 12 pages (double-spaced), 6 figure

    Physical fitness reference standards for preschool children: the PREFIT project

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    Objectives: Reference values are necessary for classifying children, for health screening, and for early prevention as many non-communicable diseases aggravate during growth and development. While physical fitness reference standards are available in children aged 6 and older, such information is lacking in preschool children. Therefore, the purposes of this study were (1) to provide sex-and age-specific physical fitness reference standards for Spanish preschool children; and (2) to study sex differences across this age period and to characterise fitness performance throughout the preschool period. Design: Cross-sectional. Methods: A total of 3179 preschool children (1678 boys) aged 2.8–6.4 years old from Spain were included in the present study. Physical fitness was measured using the PREFIT battery. Results: Age- and sex-specific percentiles for the physical fitness components are provided. Boys performed better than girls in the cardiorespiratory fitness, muscular strength, and speed-agility tests over the whole preschool period studied and for the different percentiles. In contrast, girls performed slightly better than boys in the balance test. Older children had better performance in all fitness tests than their younger counterparts. Conclusions: Our study provides age- and sex-specific physical fitness reference standards in preschool children allowing interpretation of fitness assessment. Sexual dimorphism in fitness tests exists already at preschool age, and these differences become larger with age. These findings will help health, sport, and school professionals to identify preschool children with a high/very low fitness level, to examine changes in fitness over time, and to analyse those changes obtained due to intervention effects.The PREFIT project takes place thanks to the funding linked to the Ramón y Cajal grant held by FBO (RYC-2011-09011). CC-S is supported by a grant from the Spanish Ministry of Economy and Competitiveness (BES-2014-068829). JRR and FBO are supported by grants from the Spanish Ministry of Science and Innovation (RYC-2010-05957 and RYC-2011-09011, respectively). In addition, this study was further supported by the University of Granada, Plan Propio de Investigación 2016, Excellence actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES). Additional funding from the SAMID III network, RETICS, funded by the PNI+D+I 2017-2021 (Spain), ISCIII- Sub-Directorate General for Research Assessment and Promotion, the European Regional Development Fund (ERDF) (Ref. RD16/0022), the EXERNET Research Network on Exercise and Health in Special Populations (DEP2005-00046/ACTI), the University of the Basque Country (GIU14/21), and the University of Zaragoza (JIUZ-2014-BIO-08)

    Further Experimental Studies of Two-Body Radiative \Upsilon Decays

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    Continuing our studies of radiative Upsilon(1S) decays, we report on a search for Upsilon to gamma eta and Upsilon to gamma f_{J}(2220) in 61.3 pb^{-1} of e^{+}e^{-} data taken with the CLEO II detector at the Cornell Electron Storage Ring. For the gamma eta search the three decays of the eta meson to pi^{+}pi^{-}pi^{0}, pi^{0}pi^{0}pi^{0}, and gamma gamma were investigated. We found no candidate events in the two (3\pi)^{0} modes and no significant excess over expected backgrounds in the gamma gamma mode to set a limit on the branching fraction of B(Upsilon to gamma eta) < 2.1 x 10^{-5} at 90% C.L. The three charged two-body final states h h-bar (h = pi^{+}, K^{+}, p) were investigated for f_{J}(2220) production, with one, one, and two events found, respectively. Limits at 90% C.L. of B(\Upsilon to gamma f_{J}) x B(f_{J} to h h-bar) ~ 1.5 x 10^{-5} have been set for each of these modes. We compare our results to measurements of other radiative Upsilon decays, to measurements of radiative J/psi decays, and to theoretical predictions.Comment: 19 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review

    Reexamining radiative decays of 1−−1^{--} quarkonium into η′\eta' and η\eta

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    Recently CLEO has studied the radiative decay of Υ\Upsilon into η′\eta' and an upper limit for the decay has been determined. Confronting with this upper limit,most of theoretical predictions for the decay fails. After briefly reviewing these predictions we re-examine the decay by separating nonperturbative effect related to the quarkonium and that related to η′\eta' or η\eta, in which the later is parameterized by distribution amplitudes of gluons in η′\eta'. With this factorization approach we obtain theoretical predictions which are in agreement with experiment. Uncertainties in our predictions are discussed. The possibly largest uncertainties are from relativistic corrections for J/ΨJ/\Psi and the value of the charm quark mass. We argue that the effect of these uncertainties can be reduced by using quarkonium masses instead of using quark masses. An example of the reduction is shown with an attempt to explain the violation of the famous 14% rule in radiative decays of charmonia.Comment: 9 Pages, Latex fil

    Prevalence of severe/morbid obesity and other weight status and anthropometric reference standards in Spanish preschool children: The PREFIT project

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    BACKGROUND: Childhood obesity has become a major health problem in children under the age of 5 years. Providing reference standards would help paediatricians to detect and/or prevent health problems related to both low and high levels of body mass and to central adiposity later in life. Therefore, the aim of this study was to examine the prevalence of different weight status categories and to provide sex- and age-specific anthropometry reference standards for Spanish preschool children. METHODS: A total of 3178 preschool children (4.59±0.87 years old) participated in this study. Prevalence of different degrees of obesity (mild, severe, and morbid) and other weight status categories were determined. RESULTS: Reference standards were obtained. Prevalence of overweight and obese preschool children in the Spanish population ranged from 21.4 to 34.8%. Specifically, the obesity prevalence was 3.5, 1.2, and 1.3% of these subjects were categorized as mild, severe, and morbid obese. Sex- and age-specific reference standards for anthropometric parameters are provided for every 0.25 years (i.e. every trimester of life). CONCLUSION: Our results show a high prevalence of overweight/obese preschoolers. The provided sex- and age-specific anthropometric reference standards could help paediatricians to track and monitor anthropometric changes at this early stage in order to prevent overweight/obesity.We thank the participation of the preschoolers, parents, and teachers in this study. We are grateful to Ms. Carmen Sainz-Quinn for assistance with the English language. This work is part of a Ph.D. Thesis conducted in the Biomedicine Doctoral Studies of the University of Granada, Spain. The PREFIT project takes place owing to the funding of the Ramón y Cajal grant held by FBO (RYC-2011-09011). C.C.-S. is supported by a grant from the Spanish Ministry of Economy and Competitiveness (BES-2014-068829). E.G.A. and F.B.O. are supported by a grant from the Spanish Ministry of Science and Innovation (RYC-2014-16390 and RYC-2011-09011, respectively). C.A.-B., A.P.-B., and G.S.-D. are supported by the Spanish Ministry of Education (FPU13/03137, FPU15/ 05337, and FPU13/04365, respectively). Additional funding was obtained from the University of Granada, Plan Propio de Investigación 2016, Excellence actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES) and by the Junta de Andalucia, Consejería de Conocimiento, Investigación y Universidades. In addition, funding was provided by the SAMID III network, RETICS, the PN I+D+I 2017-2021 (Spain), ISCIII-Sub-Directorate General for Research Assessment and Promotion, the European Regional Development Fund (ERDF) (RD16/0022, SOMM17/6107/UGR), the EXERNET Research Network on Exercise and Health in Special Populations (DEP2005- 00046/ACTI), the University of the Basque Country (GIU14/21), and the University of Zaragoza (JIUZ-2014-BIO-08)

    Polymorphic Allele of Human IRGM1 Is Associated with Susceptibility to Tuberculosis in African Americans

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    An ancestral polymorphic allele of the human autophagy-related gene IRGM1 is associated with altered gene expression and a genetic risk for Crohn's Disease (CD). We used the single nucleotide polymorphism rs10065172C/T as a marker of this polymorphic allele and genotyped 370 African American and 177 Caucasian tuberculosis (TB) cases and 180 African American and 110 Caucasian controls. Among African Americans, the TB cases were more likely to carry the CD-related T allele of rs10065172 (odds ratio of 1.54; 95% confidence interval, 1.17–2.02; P<0.01) compared to controls. Our finding suggests that this CD-related IRGM1 polymorphic allele is also associated with human susceptibility to TB disease among African Americans

    Percentile reference values for anthropometric body composition indices in European children from the IDEFICS study

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    INTRODUCTION: To characterise the nutritional status in children with obesity or wasting conditions, European anthropometric reference values for body composition measures beyond the body mass index (BMI) are needed. Differentiated assessment of body composition in children has long been hampered by the lack of appropriate references. OBJECTIVES: The aim of our study is to provide percentiles for body composition indices in normal weight European children, based on the IDEFICS cohort (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS). METHODS: Overall 18 745 2.0-10.9-year-old children from eight countries participated in the study. Children classified as overweight/obese or underweight according to IOTF (N = 5915) were excluded from the analysis. Anthropometric measurements (BMI (N = 12 830); triceps, subscapular, fat mass and fat mass index (N = 11 845-11 901); biceps, suprailiac skinfolds, sum of skinfolds calculated from skinfold thicknesses (N = 8129-8205), neck circumference (N = 12 241); waist circumference and waist-to-height ratio (N = 12 381)) were analysed stratified by sex and smoothed 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile curves were calculated using GAMLSS. RESULTS: Percentile values of the most important anthropometric measures related to the degree of adiposity are depicted for European girls and boys. Age-and sex-specific differences were investigated for all measures. As an example, the 50th and 99th percentile values of waist circumference ranged from 50.7-59.2 cm and from 51.3-58.7 cm in 4.5-to < 5.0-year-old girls and boys, respectively, to 60.6-74.5 cm in girls and to 59.9-76.7 cm in boys at the age of 10.5-10.9 years. CONCLUSION: The presented percentile curves may aid a differentiated assessment of total and abdominal adiposity in European children

    Autophagy Gene Variant IRGM −261T Contributes to Protection from Tuberculosis Caused by Mycobacterium tuberculosis but Not by M. africanum Strains

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    The human immunity-related GTPase M (IRGM) has been shown to be critically involved in regulating autophagy as a means of disposing cytosolic cellular structures and of reducing the growth of intracellular pathogens in vitro. This includes Mycobacterium tuberculosis, which is in agreement with findings indicating that M. tuberculosis translocates from the phagolysosome into the cytosol of infected cells, where it becomes exposed to autophagy. To test whether IRGM plays a role in human infection, we studied IRGM gene variants in 2010 patients with pulmonary tuberculosis (TB) and 2346 unaffected controls. Mycobacterial clades were classified by spoligotyping, IS6110 fingerprinting and genotyping of the pks1/15 deletion. The IRGM genotype −261TT was negatively associated with TB caused by M. tuberculosis (OR 0.66, CI 0.52–0.84, Pnominal 0.0009, Pcorrected 0.0045) and not with TB caused by M. africanum or M. bovis (OR 0.95, CI 0.70–1.30. P 0.8). Further stratification for mycobacterial clades revealed that the protective effect applied only to M. tuberculosis strains with a damaged pks1/15 gene which is characteristic for the Euro-American (EUAM) subgroup of M. tuberculosis (OR 0.63, CI 0.49–0.81, Pnominal 0.0004, Pcorrected 0.0019). Our results, including those of luciferase reporter gene assays with the IRGM variants −261C and −261T, suggest a role for IRGM and autophagy in protection of humans against natural infection with M. tuberculosis EUAM clades. Moreover, they support in vitro findings indicating that TB lineages capable of producing a distinct mycobacterial phenolic glycolipid that occurs exclusively in strains with an intact pks1/15 gene inhibit innate immune responses in which IRGM contributes to the control of autophagy. Finally, they raise the possibility that the increased frequency of the IRGM −261TT genotype may have contributed to the establishment of M. africanum as a pathogen in the West African population

    Strain-Specific Differences in the Genetic Control of Two Closely Related Mycobacteria

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    The host response to mycobacterial infection depends on host and pathogen genetic factors. Recent studies in human populations suggest a strain specific genetic control of tuberculosis. To test for mycobacterial-strain specific genetic control of susceptibility to infection under highly controlled experimental conditions, we performed a comparative genetic analysis using the A/J- and C57BL/6J-derived recombinant congenic (RC) mouse panel infected with the Russia and Pasteur strains of Mycobacterium bovis Bacille Calmette Guérin (BCG). Bacillary counts in the lung and spleen at weeks 1 and 6 post infection were used as a measure of susceptibility. By performing genome-wide linkage analyses of loci that impact on tissue-specific bacillary burden, we were able to show the importance of correcting for strain background effects in the RC panel. When linkage analysis was adjusted on strain background, we detected a single locus on chromosome 11 that impacted on pulmonary counts of BCG Russia but not Pasteur. The same locus also controlled the splenic counts of BCG Russia but not Pasteur. By contrast, a locus on chromosome 1 which was indistinguishable from Nramp1 impacted on splenic bacillary counts of both BCG Russia and Pasteur. Additionally, dependent upon BCG strain, tissue and time post infection, we detected 9 distinct loci associated with bacillary counts. Hence, the ensemble of genetic loci impacting on BCG infection revealed a highly dynamic picture of genetic control that reflected both the course of infection and the infecting strain. This high degree of adaptation of host genetics to strain-specific pathogenesis is expected to provide a suitable framework for the selection of specific host-mycobacteria combinations during co-evolution of mycobacteria with humans
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