840 research outputs found
Earthquake-Induced Lateral Displacement of a Landfill
In the wake of stability failure of the Kettleman Hills Waste Repository on March 19, 1988, the stability of landfill mass in earthquake-prone areas has become an important issue in the community. Based on a proposed landfill site in the Memphis, Tennessee area, this paper studies behaviors of landfills under various landfill and earthquake conditions (height and slope angle of the landfill, average unit weight of the landfill refuse, and peak acceleration and time duration of bedrock motion) by calculating lateral displacements induced by a design earthquake. Results indicate that lateral displacement of a landfill is proportional to the slope angle of the landfill, peak acceleration and time duration of bedrock motion, and is inversely proportional to the average unit weight of the landfill refuse. The slope angle of a landfill and the peak acceleration of bedrock motion have significant influence on the lateral displacement of a landfill compared with landfill height, average unit weight of landfill refuse and time duration of bedrock motion. Results also indicate that some landfill heights should be avoided to diminish landfill resonance, and the maximum slope angle of a landfill under certain seismic conditions depends on the internal friction angle of the landfill refuse. In addition, the lateral displacements calculated from actual and pseudo-accelerations are compared and discussed
Genetic diversity analysis of DRB3.2 in domestic yak (Bos grunniens) in Qinghai-Tibetan Plateau
DRB3 gene has been extensively evaluated as a candidate marker for association with many bovine disease and immunological traits. A hemi-nested polymerase chain reaction-sequencing method was used to investigate the polymorphisms of DRB3.2 gene from 209 individuals in three different domestic yak (Bos grunniens) populations (62 Tianzhu white yaks, 78 Gannan yaks and 69 Datong yaks) from the Qinghai-Tibetan Plateau. Sixty-three polymorphic sites and 143 haplotypes were detected. The percentage of polymorphic sites in Gannan Yak (GNY), Tianzhu white Yak (TWY) and Datong Yak (DTY) were 21.80, 29.95 and 12.95%, while the haplotype diversity were 0.9987, 0.9984 and 0.9855, respectively. At the amino acid level, Glu had the highest content; the percentage was 12.326%, followed by Arg (10.315%), Phe (10.804%), Val (8.346%), Gly (8.315%), Leu (6.606%) and Ala (5.851%), whereas Met and Ile were below than 1%. Only 19 amino acids were found in DTY, Met was lost. Among the synonymous codons, whose third base was G and/or C had a higher usage frequency. Most variability were found in amino acid residues 11, 13, 26, 28, 30, 32, 37, 56, 57, 59, 60, 61, 67, 70, 71, 72, 73 and 74. In GNY, the residues at positions 71, 11 and 72 were highly polymorphic with 8, 7 and 7, at 50, 58, 70, 74 and 78, the residues were selectively polymorphic than other yak populations; the other polymorphic sites were common in the populations. The results of this study indicated that the Chinese domestic yak populations in the Qinghai-Tibetan Plateau have abundant polymorphism in DRB3.2, and the GNY was the highest, followed by TWY and DTY.Key words: Domestic Yak, Hemi-nested PCR, BoLA-DRB3.2, polymorphism
Risk factors for hematemesis in Hoima and Buliisa Districts, Western Uganda, September-October 2015
Introduction: On 17 September 2015, Buliisa District Health Office reported multiple deaths due to haemorrhage to the Uganda Ministry of Health. We conducted an investigation to verify the existence of an outbreak and to identify the disease nature, mode of transmission and risk factors.Methods: We defined a suspected case as onset of hematemesis between 1 June 2015 and 15 October 2015 in a resident of Hoima, Buliisa or neighbouring districts. We identified cases by reviewing medical records and actively searching in the community. We interviewed casepatients and health-care workers and performed descriptive epidemiology to generate hypotheses on possible exposures. In a case-control study we compared exposures between 21 cases and 81 controls, matched by age (± 10 years), sex and village of residence. We collected 22 biological specimens from 19 case-patients to test for Viral Haemorrhagic Fevers (VHF). We analysed the data using the Mantel-Haenszel method to account for the matched study design.Results: We identified 56 cases with onset from June to October (attack rate 15/100,000 in Buliisa District and 5.2/100,000 in Hoima District). The age-specific attack rate was highest in persons aged 31-60 years (15/100,000 in Hoima and 47/100,000 in Buliisa); no persons below 15 years of age had the illness. In the case-control study, 42% (5/12) of cases vs. 0.0% (0/77) of controls had liver disease (ORM-H = ∞; 95%CI = 3.7-∞); 71% (10/14) of cases vs. 35% (28/81) of controls had ulcer disease (ORM-H = 13; 95% CI = 1.6-98); 27% (3/11) of cases vs. 14% (11/81) of controls used indomethacin prior to disease onset (ORM-H = 6.0; 95% CI = 1.0-36). None of the blood samples were positive for any of the VHFs.Conclusion: This reported cluster of hematemesis illness was due to predisposing conditions and use of Non- Steroidal Anti-inflammatory Drugs (NSAID). Health education should be conducted on the danger of NSAIDs misuse, especially in persons with predisposing conditions.Keywords: Hematemesis, outbreak, case-control, Ugand
Microbiology, ecology, and application of the nitrite-dependent anaerobic methane oxidation process
Nitrite-dependent anaerobic methane oxidation (n-damo), which couples the anaerobic oxidation of methane to denitrification, is a recently discovered process mediated by “Candidatus Methylomirabilis oxyfera.” M. oxyfera is affiliated with the “NC10” phylum, a phylum having no members in pure culture. Based on the isotopic labeling experiments, it is hypothesized that M. oxyfera has an unusual intra-aerobic pathway for the production of oxygen via the dismutation of nitric oxide into dinitrogen gas and oxygen. In addition, the bacterial species has a unique ultrastructure that is distinct from that of other previously described microorganisms. M. oxyfera-like sequences have been recovered from different natural habitats, suggesting that the n-damo process potentially contributes to global carbon and nitrogen cycles. The n-damo process is a process that can reduce the greenhouse effect, as methane is more effective in heat-trapping than carbon dioxide. The n-damo process, which uses methane instead of organic matter to drive denitrification, is also an economical nitrogen removal process because methane is a relatively inexpensive electron donor. This mini-review summarizes the peculiar microbiology of M. oxyfera and discusses the potential ecological importance and engineering application of the n-damo process
Epithelial Heat Shock Proteins Mediate the Protective Effects of Limosilactobacillus reuteri in Dextran Sulfate Sodium-Induced Colitis
Defects in gut barrier function are implicated in gastrointestinal (GI) disorders like inflammatory bowel disease (IBD), as well as in systemic inflammation. With the increasing incidence of IBD worldwide, more attention should be paid to dietary interventions and therapeutics with the potential to boost the natural defense mechanisms of gut epithelial cells. The current study aimed to investigate the protective effects of Limosilactobacillus reuteri ATCC PTA 4659 in a colitis mouse model and delineate the mechanisms behind it. Wild-type mice were allocated to the control group; or given 3% dextran sulfate sodium (DSS) in drinking water for 7 days to induce colitis; or administered L. reuteri for 7 days as pretreatment; or for 14 days starting 7 days before subjecting to the DSS. Peroral treatment with L. reuteri improved colitis severity clinically and morphologically and reduced the colonic levels of Tumor necrosis factor-alpha (TNF-alpha) (Tnf), Interleukin 1-beta (Il1 beta), and nterferon-gamma (Ifng), the crucial pro-inflammatory cytokines in colitis onset. It also prevented the CD11b(+)Ly6G(+) neutrophil recruitment and the skewed immune responses in mesenteric lymph nodes (MLNs) of CD11b(+)CD11c(+) dendritic cell (DC) expansion and Foxp3(+)CD4(+) T-cell reduction. Using 16S rRNA gene amplicon sequencing and RT-qPCR, we demonstrated a colitis-driven bacterial translocation to MLNs and gut microbiota dysbiosis that were in part counterbalanced by L. reuteri treatment. Moreover, the expression of barrier-preserving tight junction (TJ) proteins and cytoprotective heat shock protein (HSP) 70 and HSP25 was reduced by colitis but boosted by L. reuteri treatment. A shift in expression pattern was also observed with HSP70 in response to the pretreatment and with HSP25 in response to L. reuteri-DSS. In addition, the changes of HSPs were found to be correlated to bacterial load and epithelial cell proliferation. In conclusion, our results demonstrate that the human-derived L. reuteri strain 4659 confers protection in experimental colitis in young mice, while intestinal HSPs may mediate the probiotic effects by providing a supportive protein-protein network for the epithelium in health and colitis
Experimental treatment of radiation pneumonitis with human umbilical cord mesenchymal stem cells
AbstractObjectiveTo evaluate of the curative effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) on rat acute radiation pneumonitis.MethodsFourty rats were randomly divided into control group, radiation group, stem cell prevention group, stem cell treatment group and prednisone treatment group. All rats except those in the control group were radiated with X ray to establish the acute radiation pneumonitis damage model. The hUC-MSCs cultured in vitro was administrated to the rats of the prevention group via tail vein (1×106 cells/kg BW) 24 h before the radiation, while the same administration was performed in the rats of the treatment group 24 h after the radiation. After 24 h post the radiation, the rats in the radiation group were given 0.4 mL physiological saline, and those in the prednisone group were given 1 mg/kg prednisone. All rats were observed and executed 72 h after the radiation to detect lung histological changes.ResultsAfter the administration of hUC-MSCs, the survival status of the rats in the prevention group and treatment group was obviously better than that in the control group. As shown by the histological staining, the morphology, proliferation activity and bronchial state of lung tissues were better in the prevention group and treatment group than in the control group.ConclusionsThe hUC-MSCs have definite therapeutic effects on acute radiation pneumonitis in rats
Lack of Airborne Transmission during Outbreak of Pandemic (H1N1) 2009 among Tour Group Members, China, June 2009
This outbreak was caused by droplet transmission
Surveillance for selected tobacco-use behaviors—United States, 1900-1994
Problem/Condition: Surveillance of tobacco use is an essential component of any tobacco-control program. The information gathered can be used to guide research initiatives, intervention programs, and policy decisions.
Reporting Periods: This report covers the period 1900–1994 for per capita cigarette consumption; 1965–1991 for trends in cigarette smoking prevalence and cessation; 1974–1991 for trends in the number of cigarettes smoked daily by current smokers; 1987–1991 for recent patterns of tobacco use; 1970, 1987, and 1991 for trends in cigar/pipe smoking and snuff/chewing tobacco use; 1984–1992 for trends in state-specific prevalences of regular cigarette smoking; 1987–1992 for state-specific estimates of smokeless-tobacco use; and 1976–1993 for trends in cigarette smoking among U.S. high school seniors.
Description of Systems: Estimates of cigarette consumption are reported by the U.S. Department of Agriculture, which uses data from the U.S. Department of the Treasury, the U.S. Department of Commerce, the Tobacco Institute, and other sources. The National Health Interview Survey uses household interviews to provide nationally representative estimates (for the civilian, noninstitutionalized population) of cigarette smoking and other behaviors related to tobacco use. The Behavioral Risk Factor Surveillance System uses telephone surveys of civilian, noninstitutionalized adults (³18 years of age) to provide state-specific estimates of current cigarette smoking and use of smokeless tobacco. The University of Michigan’s Institute for Social Research uses school-based, self-administered questionnaires to gather data on cigarette smoking from a representative sample of U.S. high school seniors.
Results: During the period 1900–1963, per capita cigarette consumption increased; after 1964, consumption declined. During the years 1965–1991, current cigarette smoking prevalence among persons ages ³18 years declined overall and in every sociodemographic category examined. Decrease in current smoking prevalence was slow in some groups (e.g., among persons with fewer years of formal education). Both the prevalence of never smoking and the prevalence of cessation increased from 1965 through 1991. The prevalence of current cigarette smoking, any tobacco smoking, and any tobacco use was highest among American Indians/Alaska Natives and non-Hispanic blacks and lowest among Asians/Pacific Islanders. The prevalence of cigar smoking and pipe smoking has declined substantially since 1970. The prevalence of smokeless-tobacco use among white males ages 18–34 years was higher in 1987 and 1991 than in 1970; among persons ³45 years of age, the use of smokeless tobacco was more common among blacks than whites in 1970 and 1987. Cigarette smoking prevalence has decreased in most states. The prevalence of smokeless tobacco use was especially high among men in West Virginia, Montana, and several southern states. From 1984–1993, prevalence of cigarette smoking remained constant among U.S. high school seniors. However, prevalence increased slightly for male seniors and white seniors, decreased slightly for female high school seniors, and decreased sharply for black high school seniors.
Interpretation: With the exceptions of increases in cigarette smoking among white and male high school seniors and in the use of smokeless tobacco among white males ages 18–34 years, reductions in tobacco use occurred in every subgroup examined. This decrease must continue if the national health objectives for the year 2000 are to be reached.
Actions Taken: Surveillance of tobacco use is ongoing. Effective interventions that discourage initiation and encourage cessation are being disseminated throughout the United States
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