1,676 research outputs found
Recommended from our members
Native American-White differences in adult health
textThe goal of this work is to document the health gaps between Native
Americans and non-Hispanic Whites using a recent, consistent, and national-level
dataset—the National Health Interview Survey. I find that Native Americans have
poorer self-reported health and more activity limitations than Whites; Native
Americans are more likely to have no doctor visits than Whites; Native
Americans spend more days in bed than Whites. Further, Native American-White
differences in activity limitations and bed days are completely mediated by
socioeconomic factors. SES also accounts for a large portion of the racial gap in
self-reported health and physician utilization. The racial gap in self-reported
health between Native Americans and Whites narrows with age. However, similar
patterns for activity limitations, bed days, and doctor visits are not observed.
Although it is found that Native Americans living in metropolitan areas have
better self-reported health than Native Americans living in non-metropolitan
areas, non-MSA Native Americans are less likely to have an activity limitation
and more likely to have no doctor visits than MSA Native Americans. With the
exception of doctor visits, the health gaps between Native Americans and Whites
in non-MSA areas are narrower than those in MSA areas. When SES or health
variables are controlled, all racial gaps in non-MSA areas are narrower than those
in MSA areas. With respect to mortality, Native Americans are found to have a
higher risk than Whites and the risk of death for Native Americans versus Whites
declines with age. Compared to Whites, Native Americans are less likely to drink
but they are more likely to drink heavily. Generally, Native Americans are more
likely to smoke than Whites; however, they do not necessarily smoke more
heavily than Whites, especially after controlling for SES. Native Americans are
more likely to be physically inactive compared to non-Hispanic Whites.Sociolog
Two component dark matter with multi-Higgs portals
With the assistance of two extra groups, i.e., an extra hidden gauge group
and a global group, we propose a two component dark matter
(DM) model. After the symmetry being broken, we obtain
both the vector and scalar DM candidates. The two DM candidates communicate
with the standard model (SM) via three Higgs as multi-Higgs portals. The three
Higgs are mixing states of the SM Higgs, the Higgs of the hidden sector and
real part of a supplement complex scalar singlet. We study relic density and
direct detection of DM in three scenarios. The resonance behaviors and
interplay between the two component DM candidates are represented through
investigating of the relic density in the parameter spaces of the two DMs
masses. The electroweak precision parameters constrains the two Higgs portals
couplings ( and ). The relevant vacuum stability and
naturalness problem in the parameter space of and are
studied as well. The model could alleviate these two problems in some parameter
spaces under the constraints of electroweak precision observables and Higgs
indirect search.Comment: 27 pages, 16 figures. Version accepted for publication in JHE
Prevalence and Anthropometric Risk of Metabolic Syndrome in Taiwanese Adolescents
Background. To evaluate the prevalence and the importance of anthropometric indexes on metabolic syndrome (MetS) among young adolescents in Taiwan. Methods. We conducted a cross sectional survey to obtain a representative sampling among Taipei adolescents in 2003, totally enrolled of 1,562 adolescents (764 boys and 798 girls) from age 11 to 15. We used modified NCEP-ATP III criteria to diagnose metabolic syndrome in young adolescents including: blood pressure ≧90th percentile, fasting glucose ≧90th, TG ≧ 90th, HDL-C ≦ 10th, and BMI or WC ≧ 90th according to age and gender specific recommendations.
Results. The overall prevalence of MetS was 4.8% for boys and 3.9% for girls. BMI and WC were significantly associated with MetS for both boys and girls, even after adjusting for age, cigarette smoking, alcohol drinking and pubertal status. However, after further adjusting for BMI or WC, WC for boys (OR = 1.14, 95% CI = 1.05–1.24) and BMI for girls (OR = 1.36, 95% CI = 1.13–1.64) were significantly associated with MetS.
Conclusions. Adolescents with abnormal BMI or waist circumference had 10 to 20 times higher odds of MetS when compared to normal subjects. Obesity, either general or central adiposity, may play an important role in the development of MetS among adolescents
Predicting the continuance usage of information systems: A comparison of three alternative models
This study examines the explanatory power of three prospective models in predicting users¡¦ continuous adoption of information system. The three models include: Expectation-Confirmation Theory Model (ECTM, Model 1), the integration of ECTM with Technology Acceptance Model (ECT-TAM, Model 2), and a hybrid model integrating ECT, TAM and emotions (Model 3). Three hundred and fifty web portal site users were obtained from a survey. Data analysis using LISREL shows that all three models meet the various goodness-of-fit criteria. In terms of variance explained for intention to continue IS usage, all three models perform equally well. As for the explanatory power of satisfaction, Model 3 has the highest R2 (71%), followed by Model 2 (69%), and Model 1 (68%). This result confirms the erstwhile discussion of continuance intention behavior in which adding emotion factors to the cognitive process model will enhance the predictive power of the satisfaction.
Neutron star phase transition as the origin for the fast radio bursts and soft gamma-ray repeaters of SGR J1935+2154
Magnetars are believed as neutron stars (NSs) with strong magnetic fields.
X-ray flares and fast radio bursts (FRBs) have been observed from the magnetar
(soft gamma-ray repeater, SGR J1935+2154). We propose that the phase transition
of the NS can power the FRBs and SGRs.Based on the equation of state provided
by the MIT bag model and the mean field approximation, we solve the
Tolman-Oppenheimer-Volkoff equations to get the NS structure. With spin-down of
the NS, the hadronic shell gradually transfers to the quark shell.The
gravitational potential energy released by one time of the phase transition can
be achieved. The released energy, time interval between two successive phase
transitions, and glitch are all consistent with the observations of the FRBs
and the X-ray flares from SGR J1935+2154. We conclude that the phase transition
of an NS is a plausible mechanism to power the SGRs as well as the repeating
FRBs.Comment: 11 pages, 3 figure
Polymicrobial bloodstream infection involving Aeromonas species: Analysis of 62 cases
AbstractObjectiveTo better understand Aeromonas-involved polymicrobial bacteremia (AIPMB).Materials and MethodsWe conducted a retrospective analysis of patients with AIPMB admitted to three large referral hospitals in Taiwan between 2001 and 2008.ResultsOf a total of 62 patients with AIPMB, 22 had healthcare-associated infection and 40 had community-acquired infection. Enterobacteriaceae was the most common concurrent pathogen (82%). The leading underlying diseases/conditions in the affected patients were solid cancers (45%), recent gastric acid suppressant therapy (39%) and liver cirrhosis (26%). More than 95% of the Aeromonas isolates were susceptible to an aminoglycoside, a third- or fourth-generation cephalosporin, imipenem or ciprofloxacin. Antibiotic susceptibilities did not significantly differ between Aeromonas isolates in patients with healthcare-associated AIPMBs and those in patients with community-acquired AIPMBs. Coinfection with Enterobacteriaceae occurred more commonly in community-acquired AIPMB (93% vs. 64%; p=0.012).ConclusionsAIPMB occurred commonly in patients with liver cirrhosis, solid cancers or recent gastric acid suppressant therapy. Enterobacteriaceae were the most common concurrent pathogens. Similar antibiotic profiles were found in Aeromonas isolates of healthcare-associated and community-acquired AIPMBs
Understanding variation in transcription factor binding by modeling transcription factor genome-epigenome interactions
Despite explosive growth in genomic datasets, the methods for studying epigenomic mechanisms of gene regulation remain primitive. Here we present a model-based approach to systematically analyze the epigenomic functions in modulating transcription factor-DNA binding. Based on the first principles of statistical mechanics, this model considers the interactions between epigenomic modifications and a cis-regulatory module, which contains multiple binding sites arranged in any configurations. We compiled a comprehensive epigenomic dataset in mouse embryonic stem (mES) cells, including DNA methylation (MeDIP-seq and MRE-seq), DNA hydroxymethylation (5-hmC-seq), and histone modifications (ChIP-seq). We discovered correlations of transcription factors (TFs) for specific combinations of epigenomic modifications, which we term epigenomic motifs. Epigenomic motifs explained why some TFs appeared to have different DNA binding motifs derived from in vivo (ChIP-seq) and in vitro experiments. Theoretical analyses suggested that the epigenome can modulate transcriptional noise and boost the cooperativity of weak TF binding sites. ChIP-seq data suggested that epigenomic boost of binding affinities in weak TF binding sites can function in mES cells. We showed in theory that the epigenome should suppress the TF binding differences on SNP-containing binding sites in two people. Using personal data, we identified strong associations between H3K4me2/H3K9ac and the degree of personal differences in NFκB binding in SNP-containing binding sites, which may explain why some SNPs introduce much smaller personal variations on TF binding than other SNPs. In summary, this model presents a powerful approach to analyze the functions of epigenomic modifications. This model was implemented into an open source program APEG (Affinity Prediction by Epigenome and Genome, http://systemsbio.ucsd.edu/apeg)
De novo characterization of a whitefly transcriptome and analysis of its gene expression during development
<p>Abstract</p> <p>Background</p> <p>Whitefly (<it>Bemisia tabaci</it>) causes extensive crop damage throughout the world by feeding directly on plants and by vectoring hundreds of species of begomoviruses. Yet little is understood about its genes involved in development, insecticide resistance, host range plasticity and virus transmission.</p> <p>Results</p> <p>To facilitate research on whitefly, we present a method for <it>de novo </it>assembly of whitefly transcriptome using short read sequencing technology (Illumina). In a single run, we produced more than 43 million sequencing reads. These reads were assembled into 168,900 unique sequences (mean size = 266 bp) which represent more than 10-fold of all the whitefly sequences deposited in the GenBank (as of March 2010). Based on similarity search with known proteins, these analyses identified 27,290 sequences with a cut-off E-value above 10<sup>-5</sup>. Assembled sequences were annotated with gene descriptions, gene ontology and clusters of orthologous group terms. In addition, we investigated the transcriptome changes during whitefly development using a tag-based digital gene expression (DGE) system. We obtained a sequencing depth of over 2.5 million tags per sample and identified a large number of genes associated with specific developmental stages and insecticide resistance.</p> <p>Conclusion</p> <p>Our data provides the most comprehensive sequence resource available for whitefly study and demonstrates that the Illumina sequencing allows <it>de novo </it>transcriptome assembly and gene expression analysis in a species lacking genome information. We anticipate that next generation sequencing technologies hold great potential for the study of the transcriptome in other non-model organisms.</p
Recommended from our members
Understanding Variation in Transcription Factor Binding by Modeling Transcription Factor Genome-Epigenome Interactions
Despite explosive growth in genomic datasets, the methods for studying epigenomic mechanisms of gene regulation remain primitive. Here we present a model-based approach to systematically analyze the epigenomic functions in modulating transcription factor-DNA binding. Based on the first principles of statistical mechanics, this model considers the interactions between epigenomic modifications and a cis-regulatory module, which contains multiple binding sites arranged in any configurations. We compiled a comprehensive epigenomic dataset in mouse embryonic stem (mES) cells, including DNA methylation (MeDIP-seq and MRE-seq), DNA hydroxymethylation (5-hmC-seq), and histone modifications (ChIP-seq). We discovered correlations of transcription factors (TFs) for specific combinations of epigenomic modifications, which we term epigenomic motifs. Epigenomic motifs explained why some TFs appeared to have different DNA binding motifs derived from in vivo (ChIP-seq) and in vitro experiments. Theoretical analyses suggested that the epigenome can modulate transcriptional noise and boost the cooperativity of weak TF binding sites. ChIP-seq data suggested that epigenomic boost of binding affinities in weak TF binding sites can function in mES cells. We showed in theory that the epigenome should suppress the TF binding differences on SNP-containing binding sites in two people. Using personal data, we identified strong associations between H3K4me2/H3K9ac and the degree of personal differences in NFκB binding in SNP-containing binding sites, which may explain why some SNPs introduce much smaller personal variations on TF binding than other SNPs. In summary, this model presents a powerful approach to analyze the functions of epigenomic modifications. This model was implemented into an open source program APEG (Affinity Prediction by Epigenome and Genome, http://systemsbio.ucsd.edu/apeg).</p
Nocturnal CPAP improves walking capacity in COPD patients with obstructive sleep apnoea
BACKGROUND: Exercise limitation is an important issue in patients with chronic obstructive pulmonary disease (COPD), and it often co-exists with obstructive sleep apnoea (overlap syndrome). This study examined the effects of nocturnal continuous positive airway pressure (CPAP) treatment on walking capacity in COPD patients with or without obstructive sleep apnoea. METHODS: Forty-four stable moderate-to-severe COPD patients were recruited and completed this study. They all underwent polysomnography, CPAP titration, accommodation, and treatment with adequate pressure. The incremental shuttle walking test was used to measure walking capacity at baseline and after two nights of CPAP treatment. Urinary catecholamine and heart rate variability were measured before and after CPAP treatment. RESULTS: After two nights of CPAP treatment, the apnoea-hypopnoea index and oxygen desaturation index significantly improved in both overlap syndrome and COPD patients, however these changes were significantly greater in the overlap syndrome than in the COPD group. Sleep architecture and autonomic dysfunction significantly improved in the overlap syndrome group but not in the COPD group. CPAP treatment was associated with an increased walking capacity from baseline from 226.4 ± 95.3 m to 288.6 ± 94.6 m (P < 0.05), and decreased urinary catecholamine levels, pre-exercise heart rate, oxygenation, and Borg scale in the overlap syndrome group. An improvement in the apnoea-hypopnoea index was an independent factor associated with the increase in walking distance (r = 0.564). CONCLUSION: Nocturnal CPAP may improve walking capacity in COPD patients with overlap syndrome. TRIAL REGISTRATION: NCT0091426
- …