413 research outputs found
A polarized version of the CCFM equation for gluons
A derivation for a polarized CCFM evolution equation which is suitable to
describe the scaling behavior of the the unintegrated polarized gluon density
is given. We discuss the properties of this polarized CCFM equation and compare
it to the standard CCFM equation in the unpolarized case.Comment: 15 pages, 6 figures, RevTeX, some minor typos corrected, version to
appear in Phys. Rev.
Characterising WIMPs at a future Linear Collider
We investigate the prospects for detecting and measuring the parameters of
WIMP dark matter in a model independent way at the International Linear
Collider. The signal under study is direct WIMP pair production with associated
initial state radiation . The analysis
accounts for the beam energy spectrum of the ILC and the dominant machine
induced backgrounds. The influence of the detector parameters are incorporated
by full simulation and event reconstruction within the framework of the ILD
detector concept. We show that by using polarised beams, the detection
potential is significantly increased by reduction of the dominant SM background
of radiative neutrino production . The
dominant sources of systematic uncertainty are the precision of the
polarisation measurement and the shape of the beam energy spectrum. With an
integrated luminosity of 500 fb the helicity structure of the interaction
involved can be inferred, and the masses and cross-sections can be measured
with a relative accuracy of the order of 1 %.Comment: 20 pages, 11 figure
Measurement of the open-charm contribution to the diffractive proton structure function
Production of D*+/-(2010) mesons in diffractive deep inelastic scattering has
been measured with the ZEUS detector at HERA using an integrated luminosity of
82 pb^{-1}. Diffractive events were identified by the presence of a large
rapidity gap in the final state. Differential cross sections have been measured
in the kinematic region 1.5 < Q^2 < 200 GeV^2, 0.02 < y < 0.7, x_{IP} < 0.035,
beta 1.5 GeV and |\eta(D*+/-)| < 1.5. The measured cross
sections are compared to theoretical predictions. The results are presented in
terms of the open-charm contribution to the diffractive proton structure
function. The data demonstrate a strong sensitivity to the diffractive parton
densities.Comment: 35 pages, 11 figures, 6 table
The effects of COVID-19 on child mental health:Biannual assessments up to April 2022 in a clinical and two general population samples
BACKGROUND: The COVID-19 pandemic has had an acute impact on child mental and social health, but long-term effects are still unclear. We examined how child mental health has developed since the start of the COVID-19 pandemic up to 2 years into the pandemic (April 2022).METHODS: We included children (age 8-18) from two general population samples (N = 222-1333 per measurement and N = 2401-13,362 for pre-covid data) and one clinical sample receiving psychiatric care (N = 334-748). Behavioral questionnaire data were assessed five times from April 2020 till April 2022 and pre-pandemic data were available for both general population samples. We collected parent-reported data on internalizing and externalizing problems with the Brief Problem Monitor and self-reported data on Anxiety, Depressive symptoms, Sleep-related impairments, Anger, Global health, and Peer relations with the Patient-Reported Outcomes Measurement Information System (PROMIS®).RESULTS: In all samples, parents reported overall increased internalizing problems, but no increases in externalizing problems, in their children. Children from the general population self-reported increased mental health problems from before to during the pandemic on all six PROMIS domains, with generally worst scores in April 2021, and scores improving toward April 2022 but not to pre-pandemic norms. Children from the clinical sample reported increased mental health problems throughout the pandemic, with generally worst scores in April 2021 or April 2022 and no improvement. We found evidence of minor age effects and no sex effects.CONCLUSIONS: Child mental health in the general population has deteriorated during the first phase of the COVID-19 pandemic, has improved since April 2021, but has not yet returned to pre-pandemic levels. Children in psychiatric care show worsening of mental health problems during the pandemic, which has not improved since. Changes in child mental health should be monitored comprehensively to inform health care and policy.</p
Integrative multi-omics analysis of childhood aggressive behavior
This study introduces and illustrates the potential of an integrated multi-omics approach in investigating the underlying biology of complex traits such as childhood aggressive behavior. In 645 twins (cases = 42%), we trained single- and integrative multi-omics models to identify biomarkers for subclinical aggression and investigated the connections among these biomarkers. Our data comprised transmitted and two non-transmitted polygenic scores (PGSs) for 15 traits, 78,772 CpGs, and 90 metabolites. The single-omics models selected 31 PGSs, 1614 CpGs, and 90 metabolites, and the multi-omics model comprised 44 PGSs, 746 CpGs, and 90 metabolites. The predictive accuracy for these models in the test (N = 277, cases = 42%) and independent clinical data (N = 142, cases = 45%) ranged from 43 to 57%. We observed strong connections between DNA methylation, amino acids, and parental non-transmitted PGSs for ADHD, Autism Spectrum Disorder, intelligence, smoking initiation, and self-reported health. Aggression-related omics traits link to known and novel risk factors, including inflammation, carcinogens, and smoking.Analytical BioScience
Heritability of urinary amines, organic acids, and steroid hormones in children
Variation in metabolite levels reflects individual differences in genetic and environmental factors. Here, we investigated the role of these factors in urinary metabolomics data in children. We examined the effects of sex and age on 86 metabolites, as measured on three metabolomics platforms that target amines, organic acids, and steroid hormones. Next, we estimated their heritability in a twin cohort of 1300 twins (age range: 5.7-12.9 years). We observed associations between age and 50 metabolites and between sex and 21 metabolites. The monozygotic (MZ) and dizygotic (DZ) correlations for the urinary metabolites indicated a role for non-additive genetic factors for 50 amines, 13 organic acids, and 6 steroids. The average broad-sense heritability for these amines, organic acids, and steroids was 0.49 (range: 0.25-0.64), 0.50 (range: 0.33-0.62), and 0.64 (range: 0.43-0.81), respectively. For 6 amines, 7 organic acids, and 4 steroids the twin correlations indicated a role for shared environmental factors and the average narrow-sense heritability was 0.50 (range: 0.37-0.68), 0.50 (range; 0.23-0.61), and 0.47 (range: 0.32-0.70) for these amines, organic acids, and steroids. We conclude that urinary metabolites in children have substantial heritability, with similar estimates for amines and organic acids, and higher estimates for steroid hormones.Analytical BioScience
Forward jet production in deep inelastic ep scattering and low-x parton dynamics at HERA
Differential inclusive jet cross sections in neutral current deep inelastic
ep scattering have been measured with the ZEUS detector. Three phase-space
regions have been selected in order to study parton dynamics where the effects
of BFKL evolution might be present. The measurements have been compared to the
predictions of leading-logarithm parton shower Monte Carlo models and
fixed-order perturbative QCD calculations. In the forward region, QCD
calculations at order alpha_s^1 underestimate the data up to an order of
magnitude at low x. An improved description of the data in this region is
obtained by including QCD corrections at order alpha_s^2, which account for the
lowest-order t-channel gluon-exchange diagrams, highlighting the importance of
such terms in parton dynamics at low x.Comment: 25 pages, 4 figure
Inter-method reliability of the modified Rankin Scale in patients with subarachnoid hemorrhage
Background and objectives The modified Rankin Scale (mRS) is one of the most frequently used outcome measures in trials in patients with an aneurysmal subarachnoid hemorrhage (aSAH). The assessment method of the mRS is often not clearly described in trials, while the method used might influence the mRS score. The aim of this study is to evaluate the inter-method reliability of different assessment methods of the mRS.Methods This is a prospective, randomized, multicenter study with follow-up at 6 weeks and 6 months. Patients aged >= 18 years with aSAH were randomized to either a structured interview or a self-assessment of the mRS. Patients were seen by a physician who assigned an mRS score, followed by either the structured interview or the self-assessment. Inter-method reliability was assessed with the quadratic weighted kappa score and percentage of agreement. Assessment of feasibility of the self-assessment was done by a feasibility questionnaire.Results The quadratic weighted kappa was 0.60 between the assessment of the physician and structured interview and 0.56 between assessment of the physician and self-assessment. Percentage agreement was, respectively, 50.8 and 19.6%. The assessment of the mRS through a structured interview and by self-assessment resulted in systematically higher mRS scores than the mRS scored by the physician. Self-assessment of the mRS was proven feasible.Discussion The mRS scores obtained with different assessment methods differ significantly. The agreement between the scores is low, although the reliability between the assessment methods is good. This should be considered when using the mRS in clinical trials.Scientific Assessment and Innovation in Neurosurgical Treatment Strategie
Megakaryocyte lineage development is controlled by modulation of protein acetylation
Treatment with lysine deacetylase inhibitors (KDACi) for haematological malignancies, is accompanied by haematological side effects including thrombocytopenia, suggesting that modulation of protein acetylation affects normal myeloid development, and specifically megakaryocyte development. In the current study, utilising ex-vivo differentiation of human CD34+ haematopoietic progenitor cells, we investigated the effects of two functionally distinct KDACi, valproic acid (VPA), and nicotinamide (NAM), on megakaryocyte differentiation, and lineage choice decisions. Treatment with VPA increased the number of megakaryocyte/erythroid progenitors (MEP), accompanied by inhibition of megakaryocyte differentiation, whereas treatment with NAM accelerated megakaryocyte development, and stimulated polyploidisation. Treatment with bot
Development of a heptaplex PCR assay for identification of Staphylococcus aureus and CoNS with simultaneous detection of virulence and antibiotic resistance genes
Background
Staphylococcal toxicity and antibiotic resistance (STAAR) have been menacing public health. Although vancomycin-resistant Staphylococcus aureus (VRSA) is currently not as widespread as methicillin-resistant S. aureus (MRSA), genome evolution of MRSA into VRSA, including strains engineered within the same patient under anti-staphylococcal therapy, may build up to future public health concern. To further complicate diagnosis, infection control and anti-microbial chemotherapy, non-sterile sites such as the nares and the skin could contain both S. aureus and coagulase-negative staphylococci (CoNS), either of which could harbour mecA the gene driving staphylococcal methicillin-resistance and required for MRSA-VRSA evolution.
Results
A new heptaplex PCR assay has been developed which simultaneously detects seven markers for: i) eubacteria (16S rRNA), ii) Staphylococcus genus (tuf), iii) Staphylococcus aureus (spa), iv) CoNS (cns), v) Panton-Valentine leukocidin (pvl), vi) methicillin resistance (mecA), and vii) vancomycin resistance (vanA). Following successful validation using 255 reference bacterial strains, applicability to analyse clinical samples was evaluated by direct amplification in spiked blood cultures (n = 89) which returned 100 % specificity, negative and positive predictive values. The new assay has LoD of 1.0x103 CFU/mL for the 16S rRNA marker and 1.0x104 CFU/mL for six other markers and completes cycling in less than one hour.
Conclusion
The speed, sensitivity (100 %), NPV (100 %) and PPV (100 %) suggest the new heptaplex PCR assay could be easily integrated into a routine diagnostic microbiology workflow. Detection of the cns marker allows for unique identification of CoNS in mono-microbial and in poly-microbial samples containing mixtures of CoNS and S. aureus without recourse to the conventional elimination approach which is ambiguous. In addition to the SA-CoNS differential diagnostic essence of the new assay, inclusion of vanA primers will allow microbiology laboratories to stay ahead of the emerging MRSA-VRSA evolution. To the best of our knowledge, the new heptaplex PCR assay is the most multiplexed among similar PCR-based assays for simultaneous detection of STAAR
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