1,162 research outputs found
NLO corrections to the polarized Drell-Yan cross section in proton-proton collisions
We present the full next-to-leading order (NLO) corrected inclusive cross
section for massive lepton pair production in longitudinally polarized
proton-proton collisions. All QCD partonic subprocesses have been included
provided the lepton pair is created by a virtual photon, which is a valid
approximation for . Like in unpolarized proton-proton
scattering the dominant subprocess is given by the -channel so that
massive lepton pair production provides us with an excellent method to measure
the spin density of the gluon. Using our calculations we give predictions for
the longitudinal spin asymmetry measurements at the RHIC.Comment: 4 pages, LaTeX, 2 Postscript figures. Talk presented at the 6th
International Symposium on Radiative Corrections "RADCOR 2002" and 6th
Zeuthen Workshop on Elementary Particle Theory. Kloster Banz, Germany,
September 8-13, 200
NNLO Corrections to the Polarized Drell-Yan Coefficient Function
We present the full next-to-next-to-leading order (NNLO) corrections to the
coefficient function for the polarized cross section of
the Drell-Yan process. We study the effect of these corrections on the process
at an C.M. energy . All QCD partonic
subprocesses have been included provided the lepton pair is created by a
virtual photon, which is a valid approximation for a lepton pair invariant mass
. For this reaction the dominant subprocess is given by and its higher order corrections so that it provides us with an
excellent tool to measure the polarized sea-quark densities.Comment: 5 pages, 5 figures, 7th DESY Workshop on Elementary Particle Theory,
Loops and Legs in Quantum Field Theory, Zinnowitz, Germany, April 25-30, 200
Lipids driving protein structure? Evolutionary adaptations in Kir channels
Many eukaryotic channels, transporters and receptors are activated by phosphatidyl inositol bisphosphate (PIP(2)) in the membrane, and every member of the eukaryotic inward rectifier potassium (Kir) channel family requires membrane PIP(2) for activity. In contrast, a bacterial homolog (KirBac1.1) is specifically inhibited by PIP(2). We speculate that a key evolutionary adaptation in eukaryotic channels is the insertion of additional linkers between trans-membrane and cytoplasmic domains, revealed by new crystal structures, that convert PIP(2) inhibition to activation. Such an adaptation may reflect a novel evolutionary drive to protein structure,; one that was necessary to permit channel function within the highly negatively charged membranes that evolved in the eukaryotic lineage
Sumoylation of LAP1 is involved in the HDAC4-mediated repression of COX-2 transcription
CEBPB, one of the CEBP family members, is a crucial regulator of gene expression during innate immunity, inflammatory responses and adipogenesis. In this study, the EGF-induced increase of CEBPB mRNA is shown to be coincident with the decrease of COX-2 mRNA. We identified that all of the individual CEBPB isoforms, LAP1, LAP2 and LIP, attenuate EGF-induced COX-2 promoter activity. Although increased sumoylation of both LAP1 and LAP2 is observed during the lagging stage of EGF treatment, only the sumoylated LAP1, but not the sumoylated LAP2, is responsible for COX-2 gene repression. In addition, EGF treatment can regulate the nucleocytoplasmic redistribution of HDAC4 and SUMO1. We further demonstrated by loss-of- and gain-of-function approaches that HDAC4 can be a negative regulator while inactivating COX-2 transcription. The sumoylation mutant LAP1, LAP1K174A, exhibits an attenuated ability to interact with HDAC4, and increased COX-2 promoter activity. Furthermore, the in vivo DNA binding assay demonstrated that LAP1K174A and CEBPDK120A, sumoylation-defective CEBPD mutants, attenuate the binding of HDAC4 on the COX-2 promoter. In light of the above, our data suggest that the suCEBPD and suLAP1 are involved in the repression of COX-2 transcription through the recruitment of HDAC4
Predictors of physical activity for weekdays and weekends among adolescent – a cross-sectional study in Sarawak, Malaysia
This study aimed to describe the patterns of physical activities both at weekends and on weekdays and to identify their associated factors.
Material/Methods This was a cross-sectional study conducted among secondary school students aged 13-15
years old in Kuching Division, Sarawak, Malaysia. A self-administered questionnaire was used to collect socio-demographic information and to measure perceived barriers, self-efficacies and social influences. Anthropometric measurements were taken and used to
determine BMI-for-age, while pedometers were used to assess the physical activity levels. Data were analyzed using SPSS.
Results A total of 474 students from six secondary schools participated. About 16% of the respondents
were overweight and obese, majority of them males. The mean BMI was 21.21±12.93, higher among males. The mean steps per day were 6251.37±3085.31, with weekends
recorded a higher number of steps. The number of steps among males was higher than among females. On weekdays, self-motivation scores significantly predicted the participants’number of steps/physical activity rate (b = 521.43, 95% CI -72.78 to 1050.19). At weekends, lack of interest and knowledge scores (b = -427.82, 95% CI -837.72 to 17.92) and making choices scores (b = 737.41, 95% CI -197.94 to 1276.88) were significant to predict the number of steps/physical activity levels.
Conclusions These findings indicated the importance of investigating predictors of physical activity for weekdays and weekends. Thus, efforts should focus on how to motivate adolescents to be more physically active targeting the identified predictors for weekdays and week
ends
Perceptions of receiving bad news about cancer among bone cancer patients in Sarawak General Hospital - A descriptive study
Perceptions of exclusive breastfeeding among Bidayuh mothers in Sarawak, Malaysia: a qualitative study
Despite its benefits, exclusive breast feeding is not widely practised in Malaysia. As the decision for exclusive breastfeeding is influenced by social and cultural context, it is important to conduct studies in different societies in Malaysia. This qualitative study aimed to explore the perceptions of exclusive breastfeeding among Bidayuh women in Sarawak, Malaysia. Methods: A purposive sample of Bidayuh women who exclusively breastfed their infants for at least three months were recruited from one rural village in one sub-district of Kuching. An in-depth interview asked participants to respond to an open-ended questionnaire designed to elicit perception/challenges and motivating factors to continue exclusive breastfeeding. Results: Participants believed that it was their responsibility to breastfeed and breast milk was regarded as a gift from God with goodness that brought a proud and joyful experience. Breastfeeding also strengthened the mother-infant's physical and emotional bonding. Social support was important to ensure the continuation of exclusive breast feeding. Conclusion: Health care workers should emphasise these perceptions in their teaching and continue to provide support for exclusive breast feeding. More studies in other ethnic groups in Malaysia are recommended so as to provide relevant content for health care professionals to frame health education and promotion of exclusive breastfeeding within a culturally meaningful context
Disordered eating and body image issues and their associated factors among adolescents in urban secondary schools in Sarawak, Malaysia
Eating disorders are common health issues among the adolescents. The objective of this study was to determine the prevalence of eating disorders and their relationship with body mass index, body part satisfaction and perception on body weight among urban secondary school children. It was a cross-sectional study conducted in Kuching, Sarawak. Data was collected using a self-administered questionnaire that consist of the Eating
Attitude Test-26 (EAT-26), perception on body part satisfaction and body weight, and anthropometric measurement.
Data was entered and analysed using SPSS version 22. A
total of 329 respondents participated in this study with
59% females and 60.5% Malays. There were 14.3% of the
respondents overweight and obese, with higher percentage
among males (19.3%). About 18.5% of the respondents
were found to be at risk of eating disorders with higher
prevalence among males (19.3%). More females reported
to have higher prevalence of body part dissatisfaction
(46.9%) and body weight (37.6%) compared to males
(40%, 28.1%). The statistical results indicated there were significant associations between EAT-26 and body mass index (BMI) (p = 0.039), body part satisfaction (p = 0.004), and perception of body weight (p = 0.038). Eating disorders are becoming more prevalent amongst adolescents, particularly among males. As eating disorder are strongly associated with adolescent mental and physical health, intervention programme on their developmental challenges and issues for both males and females should be in place particularly in the school education syllabus
Environment factors associated with adolescents body mass index, physical activity and physical fitness in Kuching South City, Sarawak - a cross-sectional study
Impact of HONO sources on the performance of mesoscale air quality models
Nitrous acid (HONO) photolysis constitutes a primary source of OH in the early morning, which leads to
changes in model gas-phase and particulate matter concentrations. However, state-of-the-art models of
chemical mechanisms share a common representation of gas-phase chemistry leading to HONO that fails
in reproducing the observed profiles. Hence, there is a growing interest in improving the definition of
additional HONO sources within air quality models, i.e. direct emissions or heterogeneous reactions. In
order to test their feasibility under atmospheric conditions, the WRF-ARW/HERMES/CMAQ modeling
system is applied with high horizontal resolution (4 4 km2) to Spain for November 24e27, 2008. HONO
modeled sources include: (1) direct emissions from on-road transport; NO2 hydrolysis on aerosol and
ground surfaces, the latter with (2) kinetics depending exclusively on available surfaces for reaction and
(3) refined kinetics considering also relative humidity dependence; and (4) photoenhanced NO2
reduction on ground surfaces. The DOMINO measurement campaign performed in El Arenosillo
(Southern Spain) provides valuable HONO observations. Modeled HONO results are consistently below
observations, even when the most effective scenario is assessed, corresponding to contributions of direct
emissions and NO2 hydrolysis with the simplest kinetics parameterization. With the additional sources of
HONO, PM2.5 predictions can be up to 14% larger in urban areas. Quantified impacts on secondary
pollutants have to be taken as a low threshold, due to the proven underestimation of HONO levels. It is
fundamental to improve HONO sources definition within air quality models, both for the scientific
community and decision makers.Peer ReviewedPostprint (published version
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