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Sample records for case-control analysis nested

  1. Comparison of nested case-control and survival analysis methodologies for analysis of time-dependent exposure

    Directory of Open Access Journals (Sweden)

    Platt Robert W

    2005-01-01

    Full Text Available Abstract Background Epidemiological studies of exposures that vary with time require an additional level of methodological complexity to account for the time-dependence of exposure. This study compares a nested case-control approach for the study of time-dependent exposure with cohort analysis using Cox regression including time-dependent covariates. Methods A cohort of 1340 subjects with four fixed and seven time-dependent covariates was used for this study. Nested case-control analyses were repeated 100 times for each of 4, 8, 16, 32, and 64 controls per case, and point estimates were compared to those obtained using Cox regression on the full cohort. Computational efficiencies were evaluated by comparing central processing unit times required for analysis of the cohort at sizes 1, 2, 4, 8, 16, and 32 times its initial size. Results Nested case-control analyses yielded results that were similar to results of Cox regression on the full cohort. Cox regression was found to be 125 times slower than the nested case-control approach (using four controls per case. Conclusions The nested case-control approach is a useful alternative for cohort analysis when studying time-dependent exposures. Its superior computational efficiency may be particularly useful when studying rare outcomes in databases, where the ability to analyze larger sample sizes can improve the power of the study.

  2. [Analysis suspected allergic factors to shenqi fuzheng injection based on prescription sequence analysis and nested case control study].

    Science.gov (United States)

    Ai, Qing-Hua; Zeng, Xian-Bin; Xie, Yan-Ming; Yang, Wei

    2014-09-01

    This study based on twenty 3A grade hospital information system (HIS) database in China, adopt toprescription sequence analysis (PSA) with nested case control study (NCCS) to analysis mainly suspected allergy factor of Shenqi Fuzheng injection (Shenqi Fuzheng). Study design according to start to stop using Shenqi Fuzheng whether using dexamethasone injection will crowd divided into cases group and control group, each case matched 4 controls were selected, two groups according to the ratio of the age and sex matched well. Square test, Fisher exact test, single factor and multiple factor logistic regression were used to analyze data Condition on admission, allergic history, dosage and drug combinations were taken into account in cases of suspected allergic reactions. After analysis in two subgroups we found that the single dose (P = 0.000 2) and the combined use of matrine (P marketing Chinese medicine injection. PMID:25532396

  3. Analysis of the joint effects of radon exposure and smoking on lung cancer risk in three nested case-control studies in Europe

    International Nuclear Information System (INIS)

    Full text: Objectives: Three case-control studies nested in the French (Fr), German (Ge) and Czech (Cz) cohorts of uranium miners were conducted in the frame of a European research Project, named Alpha-Risk, on the quantification of risks associated with multiple radiation exposures. These case-control studies aimed at assessing the effect of protracted radon exposure on lung cancer risk taking into account individual tobacco consumption. Material and methods: In the three case-control studies, cases were miners of the corresponding cohort who died of lung cancer (100, 704, 672 cases for the Fr, Ge and Cz study, respectively). For each case, controls were randomly matched on birth period and attained age at the time of death of the corresponding case (500, 1398 and 1491 controls for the Fr, Ge and Cz study, respectively). Cumulated radon exposure during employment was obtained from ambient and individual measurements for the Fr and Cz studies, and from a job exposure matrix for the Ge study. Smoking habits were retrospectively determined from medical archives and questionnaires applied in face-to-face interviews, phone calls or mailings. Analysis was performed by conditional logistic regression using a linear excess relative risk (ERR) model. A multiplicative model was fitted to assess the joint effect of radon exposure and smoking on lung cancer risk. Results: Smoking status was established for 62, 421, and 672 cases and 320, 620, and 1491 controls for the Fr, Ge, and Cz study, respectively. Two categories ('ever smokers' vs. 'never smokers') were defined. The percentages of 'ever-smokers' were 90%, 95%, and 92% for the cases and 73%, 75%, and 73% for the controls, for the Fr, Ge and Cz study, respectively. Mean five-year lagged cumulated radon exposures were 115, 717 and 174 working level months (WLM) for the cases, and 71, 505 and 118 WLM for the controls, for the Fr, Ge and Cz study, respectively. The excess relative risk per WLM (ERR/WLM) was 0.98% with a 95

  4. Maximum likelihood estimation for Cox's regression model under nested case-control sampling

    DEFF Research Database (Denmark)

    Scheike, Thomas Harder; Juul, Anders

    2004-01-01

    Nested case-control sampling is designed to reduce the costs of large cohort studies. It is important to estimate the parameters of interest as efficiently as possible. We present a new maximum likelihood estimator (MLE) for nested case-control sampling in the context of Cox's proportional hazard...

  5. Nested case-control study on the risk factors of colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Kun Chen; Jian Cai; Xi-Yong Liu; Xi-Yuan Ma; Kai-Yan Yao; Shu Zheng

    2003-01-01

    AIM: To investigate the risk factors of colon cancer andrectal cancer.METHODS: A nested case-control study was conducted ina cohort of 64 693 subjects who participated in a colorectalcancer screening program from 1989 to 1998 in Jiashancounty, Zhejiang, China. 196 cases of colorectal cancer weredetected from 1990 to 1998 as the case group and 980non-colorectal cancer subjects, matched with factors of age,gender, resident location, were randomly selected from the64 693 cohort as controls. By using univariate analysis andmutivariate conditional logistic regression analysis, the oddsratio (OR) and its 95 % confidence interval (95 %CI) werecalculated between colorectal cancer and personal habits,dietary factors, as well as intestinal related symptoms.RESULTS: The mutivariate analysis results showed that aftermatched with age, sex and resident location, mucous bloodstool history and mixed sources of drinking water were closelyassociated with colon cancer and rectal cancer, OR values forthe mucous blood stool history were 3.508 (95 %CI: 1.370-8.985) and 2.139 (95 %CI: 1.040-4.402) respectively; for themixed drinking water sources, 2.387 (95 %CI: 1.243-4.587)and 1.951 (95 %CI: 1.086-3.506) respectively. All reachedthe significant level with a P-value less than 0.05.CONCLUSION: The study suggested that mucous bloodstool history and mixed sources of drinking water were therisk factors of colon cancer and rectal cancer. There was noany significant association between dietary habits and theincidence of colorectal cancer.

  6. Trimethoprim-sulfamethoxazole induced hyperkalaemia in elderly patients receiving spironolactone: nested case-control study

    OpenAIRE

    Antoniou, Tony; Gomes, Tara; Mamdani, Muhammad M.; Yao, Zhan; Hellings, Chelsea; Garg, Amit X.; Matthew A Weir; Juurlink, David N.

    2011-01-01

    Objectives To characterise the risk of admission to hospital for hyperkalaemia in elderly patients treated with trimethoprim-sulfamethoxazole in combination with spironolactone. Design Population based nested case-control study. Setting Ontario, Canada, from 1 April 1992 to 1 March 2010. Participants Cases were residents of Ontario aged 66 years or above receiving chronic treatment with spironolactone and admitted to hospital with hyperkalaemia within 14 days of receiving a prescription for e...

  7. Partially Linear Single Index Cox Regression Model in Nested Case-Control Studies

    OpenAIRE

    Shang, Shulian; Liu, Mengling; Zeleniuch-Jacquotte, Anne; Clendenen, Tess V; Krogh, Vittorio; Hallmans, Goran; Lu, Wenbin

    2013-01-01

    The nested case-control (NCC) design is widely used in epidemiologic studies as a cost-effective subcohort sampling method to study the association between a disease and its potential risk factors. NCC data are commonly analyzed using Thomas' partial likelihood approach under the Cox proportional hazards model assumption. However, the linear modeling form in the Cox model may be insufficient for practical applications, especially when there are a large number of risk factors under investigati...

  8. Serum Taurine and Stroke Risk in Women: A Prospective, Nested Case-Control Study

    OpenAIRE

    Fen Wu; Koenig, Karen L; Anne Zeleniuch-Jacquotte; Saran Jonas; Yelena Afanasyeva; Wójcik, Oktawia P.; Max Costa; Yu Chen

    2016-01-01

    Background Taurine (2-aminoethanesulfonic acid), a conditionally essential sulfur-containing amino acid, is mainly obtained from diet in humans. Experimental studies have shown that taurine’s main biological actions include bile salt conjugation, blood pressure regulation, anti-oxidation, and anti-inflammation. Methods We conducted a prospective case-control study nested in the New York University Women’s Health Study, a cohort study involving 14,274 women enrolled since 1985. Taurine was mea...

  9. ESTIMATING HAZARD RATIOS IN NESTED CASE-CONTROL STUDIES BY MANTEL-HAENSZEL METHOD

    Institute of Scientific and Technical Information of China (English)

    张忠占

    2001-01-01

    In this article, a class of Mantel-Haenszel type estimators of hazard ratios in proportional hazards model is presented for simple nested case-control study. The estimators have the form of the Mantel-Haenszel estimator of odds ratios, and it is shown that the estimators are dually consistent, and asymptotically normal. Dually consistently estimated covariance matrices of the proposed estimators are also developed. An example is given to illustrate the estimators.

  10. Columnar cell lesions and subsequent breast cancer risk: a nested case-control study

    OpenAIRE

    Aroner, Sarah A.; Collins, Laura Christine; Schnitt, Stuart Jay; Connolly, James Leo; Colditz, Graham A; Tamimi, Rulla May

    2010-01-01

    Introduction: Histologic and genetic evidence suggests that at least some columnar cell lesions (CCL) of the breast represent precursor lesions in the low-grade breast neoplasia pathway. However, the risk of subsequent breast cancer associated with the presence of CCL in a benign breast biopsy is poorly understood.Methods The authors examined the association between the presence of CCL and subsequent breast cancer risk in a nested case-control study of benign breast disease (BBD) and breast c...

  11. Selecting controls for assessing interaction in nested case-control studies

    International Nuclear Information System (INIS)

    Two methods for selecting controls in nested case-control studies, matching on X and counter matching on X, are compared when interest is in interaction between a risk factor X measured in the full cohort and another risk factor Z measured only in the case-control sample. This is important because matching provides efficiency gains relative to random sampling when X is uncommon and the interaction is positive (greater than multiplicative), whereas counter matching is generally efficient compared to random sampling. Matching and counter matching were compared to each other and to random sampling of controls for dichotomous X and Z. Comparison was by simulation, using as an example a published study of radiation and other risk factors for breast cancer in the Japanese atomic-bomb survivors, and by asymptotic relative efficiency calculations for a wide range of parameters specifying the prevalence of X and Z as well as the levels of correlation and interaction between them. Focus was on analyses utilizing general models for the joint risk of X and Z. Counter-matching performed better than matching or random sampling in terms of efficiency for inference about interaction in the case of a rare risk factor X and uncorrelated risk factor Z. Further, more general, efficiency calculations demonstrated that counter-matching is generally efficient relative to matched case-control designs for studying interaction. Because counter-matched designs may be analyzed using standard statistical methods and allow investigation of confounding of the effect of X, whereas matched designs require a non-standard approach when fitting general risk models and do not allow investigating the adjusted risk of X, it is concluded that counter-matching on X can be a superior alternative to matching on X in nested case-control studies of interaction when X is known at the time of case-control sampling. (author)

  12. Neonatal Mortality Risk Factors in a Rural Part of Iran: A Nested Case-Control Study

    OpenAIRE

    Chaman, R. (PhD); K Holakouie Naieni; B. Golestan; H Nabavizadeh; M. Yunesian

    2009-01-01

    "nBackground: Due to complex causal framework of neonatal mortality, improvement of this health indicator is quite gradual and it's decreasing trend is not as great as other health indicators such as infant and under 5 mortality rates.This study was conducted to evaluate neonatal mortality risk factors based on nested case-control design."nMethods:  The study population was 6900 neonates who were born in rural areas of Kohgiluyeh and Boyerahmad province (South of Iran)...

  13. Suicide by people in a community justice pathway: population-based nested case-control study.

    Science.gov (United States)

    King, Carlene; Senior, Jane; Webb, Roger T; Millar, Tim; Piper, Mary; Pearsall, Alison; Humber, Naomi; Appleby, Louis; Shaw, Jenny

    2015-08-01

    The elevated risk of suicide in prison and after release is a well-recognised and serious problem. Despite this, evidence concerning community-based offenders' suicide risk is sparse. We conducted a population-based nested case-control study of all people in a community justice pathway in England and Wales. Our data show 13% of general population suicides were in community justice pathways before death. Suicide risks were highest among individuals receiving police cautions, and those having recent, or impending prosecution for sexual offences. Findings have implications for the training and practice of clinicians identifying and assessing suicidality, and offering support to those at elevated risk.

  14. Antipsychotic Medications and Risk of Acute Coronary Syndrome in Schizophrenia: A Nested Case-Control Study

    Science.gov (United States)

    Liu, Hsing-Cheng; Yang, Shu-Yu; Liao, Ya-Tang; Chen, Chiao-Chicy; Kuo, Chian-Jue

    2016-01-01

    Background This study assessed the risk of developing acute coronary syndrome requiring hospitalization in association with the use of certain antipsychotic medications in schizophrenia patients. Methods A nationwide cohort of 31,177 inpatients with schizophrenia between the ages of 18 and 65 years whose records were enrolled in the National Health Insurance Research Database in Taiwan from 2000 to 2008 and were studied after encrypting the identifications. Cases (n = 147) were patients with subsequent acute coronary syndrome requiring hospitalization after their first psychiatric admission. Based on a nested case-control design, each case was matched with 20 controls for age, sex and the year of first psychiatric admission using risk-set sampling. The effects of antipsychotic agents on the development of acute coronary syndrome were assessed using multiple conditional logistic regression and sensitivity analyses to confirm any association. Results We found that current use of aripiprazole (adjusted risk ratio [RR] = 3.68, 95% CI: 1.27–10.64, p<0.05) and chlorpromazine (adjusted RR = 2.96, 95% CI: 1.40–6.24, p<0.001) were associated with a dose-dependent increase in the risk of developing acute coronary syndrome. Although haloperidol was associated with an increased risk (adjusted RR = 2.03, 95% CI: 1.20–3.44, p<0.01), there was no clear dose-dependent relationship. These three antipsychotic agents were also associated with an increased risk in the first 30 days of use, and the risk decreased as the duration of therapy increased. Sensitivity analyses using propensity score-adjusted modeling showed that the results were similar to those of multiple regression analysis. Conclusions Patients with schizophrenia who received aripiprazole, chlorpromazine, or haloperidol could have a potentially elevated risk of developing acute coronary syndrome, particularly at the start of therapy. PMID:27657540

  15. Cardiovascular drugs and the risk of suicide: a nested case-control study

    DEFF Research Database (Denmark)

    Callréus, Torbjörn; Agerskov Andersen, Ulla; Hallas, Jesper;

    2007-01-01

    OBJECTIVE: During the past 30 years, various cardiovascular drugs have been implicated as causes of depression or suicide. Although the evidence for causal relationships has generally been conflicting, both beta-blockers and angiotensin-converting-enzyme inhibitors (ACE-inhibitors) have been...... related to depression. Lipid-lowering therapies and calcium-channel blockers have also been linked to an increased risk of suicide. In this study, we investigated the possible association between the use of cardiovascular drugs and suicide using population-based register data. METHODS: We performed...... a nested case-control study in the county of Funen, Denmark, that consisted of 743 cases of completed suicide identified in a Death Registry for the period 1991-1998 and 14,860 age- and sex-matched controls. Information on previous drug use was retrieved from prescription data and the association between...

  16. Assessing adherence in the CAPRISA 004 tenofovir gel HIV prevention trial: results of a nested case-control study.

    Science.gov (United States)

    MacQueen, Kathleen M; Weaver, Mark A; van Loggerenberg, Francois; Succop, Stacey; Majola, Nelisle; Taylor, Doug; Karim, Quarraisha Abdool; Karim, Salim Abdool

    2014-05-01

    Adherence undeniably impacts product effectiveness in microbicide trials, but the connection has proven challenging to quantify using routinely collected behavioral data. We explored this relationship using a nested case-control study in the CAPRISA 004 Tenofovir (TFV) gel HIV prevention trial. Detailed 3-month recall data on sex events, condom and gel use were collected from 72 incident cases and 205 uninfected controls. We then assessed how the relationship between self-reported adherence and HIV acquisition differed between the TFV and placebo gel groups, an interaction effect that should exist if effectiveness increases with adherence. The CAPRISA 004 trial determined that randomization to TFV gel was associated with a significant reduction in risk of HIV acquisition. In our nested case-control study, however, we did not observe a meaningful decrease in the relative odds of infection-TFV versus placebo-as self-reported adherence increased. To the contrary, exploratory sub-group analysis of the case-control data identified greater evidence for a protective effect of TFV gel among participants reporting less than 80 % adherence to the protocol-defined regimen (odds ratio (OR) 0.30; 95 % CI 0.11-0.78) than among those reporting ≥ 80 % adherence (Odds Ratio 0.81; 95 % CI 0.34-1.92). The small number of cases may have inhibited our ability to detect the hypothesized interaction between adherence and effectiveness. Nonetheless, our results re-emphasize the challenges faced by investigators when adherence may be miss-measured, miss-reported, or confounded with the risk of HIV. PMID:24647763

  17. Helicobacter pylori infection and gastric cancer: evidence fron a retrospective cohort study and nested case-control study in China

    Institute of Scientific and Technical Information of China (English)

    Run-Tian Wang; Chou-Wen Zhu; Hai Yu; Yu-Jun Cong; Sbu Zheng; Bing-Quan Wu; Tao Wang; Kun Chen; Ji-Yao Wang; Jie-Ping Zhang; San-Ren Lin; Yi-Min Zhu; Wen-Ming Zhang; Yu-Xin Cao

    2002-01-01

    AIM: To explore the association between Helicobacter pylori (Hp) infection and risk of gastric cancer in China. METHODS: Utilizing gastroendoscopic biospsy tissue banks accumulated from1980 to1988 in Shandong, Zhejiang, and Jiangsu, where stomach cancer incidence was high, during stomach cancer screening conducted by Health Science Center of Peking University, School of Medicine of Zhejiang University, and Zhongshan Hospital of Fudan University. Warthin Starry silver staining method was applied to determine H. pyloriinfection status of biopsies collected during gastroendoscopic examination. In the retrospective study, the subjects were divided into two cohorts, the exposure cohort was positive H. pyloriinfection, and the non-exposure cohort was negative. Death from stomach cancer was determined as the outcome of the study. Logistic regression and Cox regression were applied to analyze the association between Helicobacterpyloriinfection and gastric cancer risk. In the nested case-control study, there were 28 deaths from gastric cancer in the fields of Muping, Shandong province, and Zhoushan, Zhejiang provinces. 4 controls were matched to each case on the basis of age (±5 years old), sex, residential place at the same time entered into the study. Conditional logistic regression analysis was used to analyze the data.RESULTS: There were a total of 2 719 subjects (male 1 399,female 1 320) with gastroendoscopic biopsies stored available treated as a cohort. H. pyloripositive cohort included 1 671 subjects (61.5 %) and H. pylorinegative cohort 1 048 subjects(38.5 %). These subjects were followed up for 1-19 years, averaged 10.88 years. The outcome of death from stomach cancer in the exposure cohort was 33, and in the non-exposure cohort 11. After adjustment for age and sex, RR=1.9850 (P=0.0491), 95 % CI was 1.0026, and 3.9301. The results of conditional logistic regression showed an OR of 4.467 and 95 % CI of 1.161, and 17.190 for the nested case control study

  18. Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study.

    Science.gov (United States)

    Lopez-del Burgo, Cristina; Gea, Alfredo; de Irala, Jokin; Martínez-González, Miguel A; Chavarro, Jorge E; Toledo, Estefania

    2015-08-01

    The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72-1.51). No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72-1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82-1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84-1.64) was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women's fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously.

  19. Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study

    Directory of Open Access Journals (Sweden)

    Cristina Lopez-del Burgo

    2015-07-01

    Full Text Available The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72–1.51. No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72–1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82–1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84–1.64 was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women’s fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously.

  20. Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study

    Science.gov (United States)

    Lopez-del Burgo, Cristina; Gea, Alfredo; de Irala, Jokin; Martínez-González, Miguel A.; Chavarro, Jorge E.; Toledo, Estefania

    2015-01-01

    The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72–1.51). No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72–1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82–1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84–1.64) was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women’s fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously. PMID:26225997

  1. Varenicline and Risk of Self-Harm: A Nested Case-Control Study

    Science.gov (United States)

    Martins, Diana; Yao, Zhan; Mamdani, Muhammad M.; Juurlink, David N.; Gomes, Tara; Antoniou, Tony

    2016-01-01

    Background Smoking remains a serious public health concern. Pharmacotherapy for smoking cessation, including bupropion and varenicline, are proven means to increase quit rates. Post-marketing reports describing suicidal behaviours have raised concerns about the safety of varenicline. However, whether varenicline imparts a higher risk of suicide relative to bupropion remains uncertain. Methods A population-based nested case-control study in Ontario, Canada, from April 1, 2011 to March 31, 2015 was conducted. Subjects were residents of Ontario aged 18 years and older with publicly funded drug coverage receiving either bupropion or varenicline for smoking cessation. We defined cases were those with a hospitalization or emergency department visit for suicide or non-fatal self-harm within 90 days of treatment. For each case, we identified up to fifty controls from the same cohort matched on age, sex, history of self-harm, use of selected psychotropic medications, alcohol abuse and prior admission to a mental health unit. Adjusted odds ratio were used to compare the risk of suicide/self-harm of varenicline to bupropion. Results We identified 331 cases and 5,346 matched-controls. Following adjustment for potential confounders, we found that varenicline was not associated with an increased risk of suicide/self-harm relative to bupropion (adjusted odds ratio 1.15; 95% confidence interval 0.71 to 1.87). Interpretation Treatment with varenicline does not appear to significantly increase the risk of suicide or self-harm relative to bupropion. PMID:27662654

  2. HLA-DR and -DQ eplet mismatches and transplant glomerulopathy: a nested case-control study.

    Science.gov (United States)

    Sapir-Pichhadze, R; Tinckam, K; Quach, K; Logan, A G; Laupacis, A; John, R; Beyene, J; Kim, S J

    2015-01-01

    We conducted a nested case-control study from a cohort of adult kidney transplant recipients to assess the risk of transplant glomerulopathy (TG) as a function of donor and recipient HLA-DR and -DQ incompatibility at the eplet level. Cases (n = 52) were defined as patients diagnosed with transplant glomerulopathy based on biopsies showing glomerular basement membrane duplication without immune complex deposition. Controls (n = 104) with a similar follow-up from transplantation were randomly selected from the remaining cohort. HLAMatchmaker was used to ascertain the number of DRB1/3/4/5, DQA1 and DQB1 related eplet mismatches (eplet load). Multivariable conditional logistic regression models demonstrated an increase in the odds of TG (odds ratios [OR] of 2.84 [95% confidence interval (CI): 1.03, 7.84] and 4.62 [95% CI: 1.51, 14.14]) in the presence of 27-43 and >43 HLA-DR + DQ related eplet mismatches versus <27 eplet mismatches, respectively. When the eplet load was modeled as a continuous variable, the OR for TG was 1.25 (95% CI: 1.04, 1.50) for every 10 additional HLA-DR + DQ eplet mismatches. Our study suggests that minimization of HLA-DR + DQ eplet mismatches may decrease the incidence of transplant glomerulopathy diagnosed by indication biopsies. The role of eplet immunogenicity/antigenicity as determinants of allograft outcomes requires further study. PMID:25521856

  3. Neonatal Mortality Risk Factors in a Rural Part of Iran: A Nested Case-Control Study

    Directory of Open Access Journals (Sweden)

    R Chaman

    2009-03-01

    Full Text Available "nBackground: Due to complex causal framework of neonatal mortality, improvement of this health indicator is quite gradual and it's decreasing trend is not as great as other health indicators such as infant and under 5 mortality rates.This study was conducted to evaluate neonatal mortality risk factors based on nested case-control design."nMethods:  The study population was 6900 neonates who were born in rural areas of Kohgiluyeh and Boyerahmad province (South of Iran. They were under follow up till the end of neonatal period and the outcome of interest was neonatal death. By using risk set sampling method, 97 cases and 97 controls were selected in study cohort."nResults: Prematurity (OR= 5.57, LBW (OR= 7.68, C-section (OR= 7.27, birth rank more than 3 (OR=6.95 and birth spac­ing less than 24 months (OR= 4.65 showed significant statistical association (P< 0.05 with neonatal mortality. The Popula­tion Attributable Fraction (PAF was 0.45 for LBW, 0.40 for prematurity, 0.28 for C-section, 0.30 for birth rank more than 3, and 0.16 for birth spacing less than 24 months."nConclusion: Prematurity, low birth weight, C-section, birth spacing less than 24 months and birth rank more than 3 are impor­tant risk factors for neonatal mortality.

  4. Stroke and plasma markers of milk fat intake – a prospective nested case-control study

    Directory of Open Access Journals (Sweden)

    Weinehall Lars

    2009-05-01

    Full Text Available Abstract Background Dairy products are high in saturated fat and are traditionally a risk factor for vascular diseases. The fatty acids 15:0 and 17:0 of plasma lipids are biomarkers of milk fat intake. The aim of the present study was to evaluate the risk of a first-ever stroke in relation to the plasma milk fat biomarkers. Methods A prospective case-control study was nested within two population based health surveys in Northern Sweden. Among 129 stroke cases and 257 matched controls, plasma samples for fatty acid analyses were available in 108 cases and 216 control subjects. Proportions of 15:0 and 17:0 of plasma lipids, weight, height, blood lipids, blood pressures, and lifestyle data were employed in conditional logistic regression modelling. Results The proportions of fatty acids 17:0 and 15:0+17:0 of total plasma phospholipids were significantly higher in female controls than cases, but not in men. 17:0 and 15:0+17:0 were significantly and inversely related to stroke in the whole study sample as well as in women. The standardised odds ratio (95% CI in women to have a stroke was 0.41 (0.24–0.69 for 17:0 in plasma phospholipids. Adjustment for traditional cardiovascular risk factors, physical activity and diet had marginal effects on the odds ratios. A similar, but non-significant, trend was seen in men. Conclusion It is hypothesised that dairy or milk fat intake may be inversely related to the risk of a first event of stroke. The intriguing results of this study should be interpreted with caution. Follow up studies with greater power, and where intakes are monitored both by dietary recordings and fatty acid markers are needed.

  5. Cardiovascular safety of celecoxib in acute myocardial infarction patients: a nested case-control study

    Directory of Open Access Journals (Sweden)

    Josiane Courteau

    2009-04-01

    Full Text Available The objective was to measure the impact of exposure to coxibs and non-steroidal anti-inflammatory drugs (NSAID on morbidity and mortality in older patients with acute myocardial infarction (AMI. A nested case-control study was carried out using an exhaustive population-based cohort of patients aged 66 years and older living in Quebec (Canada who survived a hospitalization for AMI (ICD-9 410 between 1999 and 2002. The main variables were all-cause and cardiovascular (CV death, subsequent hospital admission for AMI, and a composite end-point including recurrent AMI or CV death. Conditional logistic regressions were used to estimate the risk of mortality and morbidity. A total of 19,823 patients aged 66 years and older survived hospitalization for AMI in the province of Quebec between 1999 and 2002. After controlling for covariables, the risk of subsequent AMI and the risk of composite end-point were increased by the use of rofecoxib. The risk of subsequent AMI was particularly high for new rofecoxib users (HR 2.47, 95% CI 1.57-3.89. No increased risk was observed for celecoxib users. No increased risk of CV death was observed for patients exposed to coxibs or NSAIDs. Patients newly exposed to NSAIDs were at an increased risk of death (HR 2.22, 95% CI 1.30-3.77 and of composite end-point (HR 2.28, 95% CI 1.35-3.84. Users of rofecoxib and NSAIDs, but not celecoxib, were at an increased risk of recurrent AMI and of composite end-point. Surprisingly, no increased risk of CV death was observed. Further studies are needed to better understand these apparently contradictory results.

  6. Epidemiological adaptation of quartz exposure modeling in Swedish aluminum foundries: nested case-control study on lung cancer.

    Science.gov (United States)

    Westberg, Håkan B; Bellander, Tom

    2003-12-01

    In a recent cohort study in aluminum foundries and remelting plants an unexpectedly high risk of lung cancer was found in workers in sand foundries. On the basis of present and historical measurement data, we developed a statistical model for exposure to total dust and crystalline quartz for different jobs and time periods. Cumulative dose estimates of total dust and crystalline quartz were calculated and used in a nested case-control study in the cohort. From the cohort of foundry workers (n = 5016), 46 cases of lung cancer were identified. The final analysis was performed on 31 cases and 233 controls with one year or more of employment. Historical measurement data from the 1960s and onward were collected, totaling 203 total dust and 103 crystalline quartz exposure observations. Regression models, using the determinants of job title, time period, type of foundry, and size of production, were developed for assessing historical total dust and crystalline quartz air concentrations. These estimates were used to calculate individual cumulative exposure in the case-control study. In the multiple linear regression analysis, the determinants explained much of the variations in dust level (r(2) = 0.58). The explained variation in crystalline quartz was much lower (r(2) = 0.13). The regression coefficients for the type of foundry, time period, and size of production were statistically significant for total dust. On the basis of the regression analysis, the final models were used to calculate individual cumulative exposures. The calculated cumulative dust and quartz exposures averaged 33 mg/m(3) * year and 0.42 mg/m(3) * year, respectively. The odds ratios (ORs) were not significant, but showed dose-response trends for both dust and crystalline quartz. PMID:14612297

  7. A nested case-control approach to interactions between radiation dose and other factors as causes of cancer

    International Nuclear Information System (INIS)

    Often a nested case-control study is the most practicable approach to estimating the interaction of two cancer risk factors in a large cohort. If one of the factors has already been evaluated for the entire cohort, however, more information is already available about its relationship to risk than could be obtained from a nested study. A modified case-control approach is proposed, in which information about the second, unknown factor is sought for cases and controls matched on the first factor. The approach requires, for interaction models other than the multiplicative, a nonstandard analytical approach incorporating cohort-based information about the first factor. The problem is discussed in the context of breast cancer risk in a defined cohort of female Japanese atomic bomb survivors, in relation to radiation dose and reproductive history. (author)

  8. Risk of miscarriage among users of corticosteroid hormones: a population-based nested case-control study

    OpenAIRE

    Bjørn AM; Nielsen RB; Nørgaard M; Nohr EA; Ehrenstein V

    2013-01-01

    Anne-Mette B Bjørn,1 Rikke B Nielsen,1 Mette Nørgaard,1 Ellen A Nohr,2 Vera Ehrenstein11Department of Clinical Epidemiology, 2Section for Epidemiology, Department of Public Health, Aarhus University Hospital, Aarhus, DenmarkBackground: The purpose of this nested case-control study in Denmark was to study the association between use of corticosteroids and risk of miscarriage.Methods: We identified prescriptions for corticosteroids before the miscarriage/index date. We est...

  9. Trimethoprim-sulfamethoxazole induced hyperkalaemia in elderly patients receiving spironolactone: nested case-control study

    Science.gov (United States)

    Gomes, Tara; Mamdani, Muhammad M; Yao, Zhan; Hellings, Chelsea; Garg, Amit X; Weir, Matthew A; Juurlink, David N

    2011-01-01

    Objectives To characterise the risk of admission to hospital for hyperkalaemia in elderly patients treated with trimethoprim-sulfamethoxazole in combination with spironolactone. Design Population based nested case-control study. Setting Ontario, Canada, from 1 April 1992 to 1 March 2010. Participants Cases were residents of Ontario aged 66 years or above receiving chronic treatment with spironolactone and admitted to hospital with hyperkalaemia within 14 days of receiving a prescription for either trimethoprim-sulfamethoxazole, amoxicillin, norfloxacin, or nitrofurantoin. Up to four controls for each case were identified from the same cohort, matched on age, sex, and presence or absence of chronic kidney disease and diabetes, and required to have received one of the study antibiotics within 14 days before the case’s index date. Main outcome measures Odds ratio for association between admission to hospital with hyperkalaemia and receipt of a study antibiotic in the preceding 14 days, adjusted for conditions and drugs that may influence risk of hyperkalaemia. Results During the 18 year study period, 6903 admissions for hyperkalaemia were identified, 306 of which occurred within 14 days of antibiotic use. Of these, 248 (81%) cases were matched to 783 controls. 10.8% (17 859/165 754) of spironolactone users received at least one prescription for trimethoprim-sulfamethoxazole. Compared with amoxicillin, prescription of trimethoprim-sulfamethoxazole was associated with a marked increase in the risk of admission to hospital for hyperkalaemia (adjusted odds ratio 12.4, 95% confidence interval 7.1 to 21.6). The population attributable fraction was 59.7%, suggesting that approximately 60% of all cases of hyperkalaemia in older patients taking spironolactone and treated with an antibiotic for a urinary tract infection could be avoided if trimethoprim-sulfamethoxazole was not prescribed. Treatment with nitrofurantoin was also associated with an increase in the risk of

  10. A nested case-control study on female breast cancer risk among medical diagnostic X-ray workers in China

    International Nuclear Information System (INIS)

    Objectives: To research whether prolonged or repeated low-level ionizing radiation can induce female breast cancer or not and to investigate other risk factors related to breast cancer risk, a nested case-control study was done. Methods: 30 cases of breast cancers were enrolled in the study, 4 normal persons were selected from X-ray workers as controls to match each case. Logistic regression model was used for risk analysis. Results: 1) Accumulative breast dose is a significant risk factor, odds ratio (OR) between two dose levels (10c Gy) is 1.73 (95%CI = 1.05-2.84). 2) ORs of other two factors, obesity and family history of breast cancer, are 4.07 (P = 0.01) and 26.67 (P = 0.024) respectively. 3) Interaction may exist between occupational X-ray exposure and obesity or non-lactation. Conclusions: Longtime and low-level occupational X-ray exposure may relate to excess risk of female breast cancer among medical diagnostic X-ray workers. Family history of breast cancer and obesity are also the significant risk factors of the cancer. The existence of obesity and non-lactation may enhance the effect of radiation-induced breast cancer

  11. Blood fatty acid patterns are associated with prostate cancer risk in a prospective nested case-control study

    Science.gov (United States)

    Yang, Meng; Ayuningtyas, Azalea; Kenfield, Stacey A.; Sesso, Howard D.; Campos, Hannia; Ma, Jing; Stampfer1, Meir J.; Chavarro, Jorge E.

    2016-01-01

    Background Circulating fatty acids are highly correlated with each other and analyzing fatty acid patterns could better capture their interactions and their relation to prostate cancer. We aimed to assess the associations between data-derived blood fatty acid patterns and prostate cancer risk. Methods We conducted a nested case-control study in the Physicians’ Health Study. Fatty acids levels were measured in whole blood samples of 476 cases and their matched controls by age and smoking status. Fatty acid patterns were identified using principal component analysis. Conditional logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI). Results Two patterns explaining 40.9% of total variation in blood fatty acid levels were identified. Pattern 1, which mainly reflects polyunsaturated fatty acid metabolism, was suggestively positively related to prostate cancer risk (ORquintile 5 vs. quintile 1=1.37, 95%CI=0.91–2.05, Ptrend=0.07). Pattern 2, which largely reflects de novo lipogenesis, was significantly associated with higher prostate cancer risk (ORquintile5 vs quintile1=1.63, 95%CI=1.04–2.55, Ptrend=0.02). This association was similar across tumor stage, grade, clinical aggressiveness categories and follow-up time. Conclusion The two patterns of fatty acids we identified were consistent with known interactions between fatty acid intake and metabolism. A pattern suggestive of higher activity in the de novo lipogenesis pathway was related to higher risk of prostate cancer. PMID:27488836

  12. Change in fracture risk and fracture pattern after bariatric surgery: nested case-control study

    Science.gov (United States)

    Rousseau, Catherine; Jean, Sonia; Gamache, Philippe; Lebel, Stéfane; Mac-Way, Fabrice; Biertho, Laurent; Michou, Laëtitia

    2016-01-01

    Objective To investigate whether bariatric surgery increases the risk of fracture. Design Retrospective nested case-control study. Setting Patients who underwent bariatric surgery in the province of Quebec, Canada, between 2001 and 2014, selected using healthcare administrative databases. Participants 12 676 patients who underwent bariatric surgery, age and sex matched with 38 028 obese and 126 760 non-obese controls. Main outcome measures Incidence and sites of fracture in patients who had undergone bariatric surgery compared with obese and non-obese controls. Fracture risk was also compared before and after surgery (index date) within each group and by type of surgery from 2006 to 2014. Multivariate conditional Poisson regression models were adjusted for fracture history, number of comorbidities, sociomaterial deprivation, and area of residence. Results Before surgery, patients undergoing bariatric surgery (9169 (72.3%) women; mean age 42 (SD 11) years) were more likely to fracture (1326; 10.5%) than were obese (3065; 8.1%) or non-obese (8329; 6.6%) controls. A mean of 4.4 years after surgery, bariatric patients were more susceptible to fracture (514; 4.1%) than were obese (1013; 2.7%) and non-obese (3008; 2.4%) controls. Postoperative adjusted fracture risk was higher in the bariatric group than in the obese (relative risk 1.38, 95% confidence interval 1.23 to 1.55) and non-obese (1.44, 1.29 to 1.59) groups. Before surgery, the risk of distal lower limb fracture was higher, upper limb fracture risk was lower, and risk of clinical spine, hip, femur, or pelvic fractures was similar in the bariatric and obese groups compared with the non-obese group. After surgery, risk of distal lower limb fracture decreased (relative risk 0.66, 0.56 to 0.78), whereas risk of upper limb (1.64, 1.40 to 1.93), clinical spine (1.78, 1.08 to 2.93), pelvic, hip, or femur (2.52, 1.78 to 3.59) fractures increased. The increase in risk of fracture reached significance only for

  13. The association between component malalignment and post-operative pain following navigation-assisted total knee arthroplasty: results of a cohort/nested case-control study.

    Science.gov (United States)

    Czurda, Thomas; Fennema, Peter; Baumgartner, Martin; Ritschl, Peter

    2010-07-01

    Previous studies have noted an adverse relationship between implant malalignment during total knee arthroplasty (TKA) and post-operative pain. Although some evidence exists indicating that computer-assisted surgical navigation for TKA can improve the accuracy of component alignment, its impact on clinical outcomes is currently unknown. The dual goals of the present cohort/nested case-control study were to (1) compare self-reported responses to the Western Ontario-McMaster Osteoarthritis Index (WOMAC) questionnaire between computer-assisted TKA (123 patients) using the imageless PiGalileo navigation system and conventional TKA (207 patients) [cohort analysis], and (2) to investigate a potential association between malalignment and post-operative pain in 19 painful knees and 19 asymptomatic knees obtained from the cohort analysis using matched sampling [nested case-control study]. In the cohort analysis, a relevant but non-significant (P = 0.06) difference in the occurrence of chronic pain was observed between the navigated (12%) and conventional arms (20%). Median post-operative WOMAC pain score was 100 (range, 50-100) in the conventional group and 100 (range, 65-100) in the navigated group. However, the Mann-Whitney test revealed a significant difference in favor of the navigated group (P = 0.01). In the nested case-control analysis, radiological outcomes and computer tomography (CT) measurements of femoral rotation were compared between the groups. The CT rotation measurements yielded evidence of a relationship between post-operative pain and incorrect rotational alignment of the femoral component of more than 3 degrees (OR: 7; 95% CI: 1.2-42; P = .033). In conclusion, there was no clinical benefit to computer-assisted navigation; however, a statistically significant relationship was observed between incorrect rotational alignment of the femoral component and symptoms of post-operative pain following TKA.

  14. A nested case-control study of maternal-neonatal transmission of hepatitis B virus in a Chinese population

    Institute of Scientific and Technical Information of China (English)

    Li-Zhang Chen; Wen-Qi Zhou; Shu-Shan Zhao; Zhi-Yu Liu; Shi-Wu Wen

    2011-01-01

    AIM: To examine the determinants of maternal-neo?natal transmission of hepatitis B virus (HBV).METHODS: A nested case-control study was conducted in Changsha, Hunan, People's Republic of China from January 1, 2005 to September 31, 2006. To avoid po?tential maternal blood contamination, we collected vein blood of newborns immediately after birth and before initial hepatitis B vaccination to determine the HBV in?fection status of the newborn. For each HBsAg-positive infant, one HBsAg-negative infant born to an HBsAg-positive mother was matched by hospital at birth (same), gender (same), and date of birth (within 1 mo). A face-to-face interview was conducted to collect clinical and epidemiological data. Conditional logistic regression analysis was used to estimate the independent effects of various determinants on maternal-neonatal transmis?sion of HBV.RESULTS: A total of 141 HBsAg-positive infants and 141 individually matched HBsAg-negative infants were included in the final analysis. Maternal first-degree family history of HBV infection, intrahepatic cholesta-sis, and premature rupture of membranes were risk factors for perinatal transmission of HBV, whereas sys?tematic treatment and HBV immunoglobulin injections for mothers with HBV infection were protective factors for maternal-neonatal transmission of HBV, after ad?justment for potential confounding factors.CONCLUSION: For HBsAg-positive mothers, system?atic treatment, HBV immunoglobulin administration, and controlling intrahepatic cholestasis and pregnancy complications may reduce the incidence of perinatal transmission of HBV.

  15. Lung cancer risk, exposure to radon and tobacco consumption in a nested case-control study of French uranium miners

    International Nuclear Information System (INIS)

    Introduction: A nested case-control study was conducted among the French uranium miners cohort in order to assess the effect of protract ed radon exposure on lung cancer risk taking into account tobacco consumption. Material and methods: One hundred uranium miners employed by the French company CEA-COGEMA and who died of a lung cancer between 1980 and 1994 were identified as cases among the cohort. For each case, five controls were randomly matched on birth period and attained age at the time of death of the corresponding case. Cumulated radon exposure during employment was reconstructed for each of these 100 cases and 500 controls. Smoking habits were retrospectively determined from three complementary sources: 1) medical files, 2) forms filled in by occupational physicians and 3) questionnaires applied in face-to-face interviews, phone calls or mailings. Analysis was performed by conditional logistic regression using a linear excess relative risk (ERR) model. A multiplicative model was fitted to assess the joint effect of radon exposure and smoking on lung cancer risk. Results: Smoking status was established for 62 cases and 320 controls and two categories ('ever smokers' vs. 'never smokers') were defined. Ninety percent of the cases and 73% of the controls were classified as 'ever smokers'. Mean five-year lagged cumulated radon exposures were 82.0 and 47.6 working level months (WLM) for the cases and the controls, respectively. The excess relative risk per WLM (ERR/WLM) was 1.1% with a 95%-confidence interval (CI) of 0.2-2.0%. When adjusting for smoking, radon exposure effect was little modified (ERR/WLM = 0.8%, 95% -CI = 0.1- 2.8%). The effect of smoking on lung cancer risk was comparable to results reported in previous miners cohorts (OR = 3.04, 95% -CI = 1.20-7.70). Discussion: A consequent effort was carried out to collect smoking status from three sources for the miners included in this nested case-control study. This analysis shows that, when adjusting on

  16. Use of Hypoprothrombinemia-Inducing Cephalosporins and the Risk of Hemorrhagic Events: A Nationwide Nested Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Li-Ju Chen

    Full Text Available Existing data regarding the risk of hemorrhagic events associated with exposure to hypoprothrombinemia-inducing cephalosporins are limited by the small sample size. This population-based study aimed to examine the association between exposure to hypoprothrombinemia-inducing cephalosporins and hemorrhagic events using National Health Insurance Research Database in Taiwan.A nationwide nested case-control study.National Health Insurance Research database.We conducted a nested case-control study within a cohort of 6191 patients who received hypoprothrombinemia-inducing cephalosporins and other antibiotics for more than 48 hours. Multivariable conditional logistic regressions were used to calculate the adjusted odds ratio (aOR and 95% confidence interval (CI for hemorrhagic events associated with exposure to hypoprothrombinemia-inducing cephalosporins (overall, cumulative dose measured as defined daily dose (DDD, and individual cephalosporins.Within the cohort, we identified 704 patients with hemorrhagic events and 2816 matched controls. Use of hypoprothrombinemia-inducing cephalosporins was associated with increased risk of hemorrhagic events (aOR, 1.71; 95% CI, 1.42-2.06, which increased with higher cumulative doses (5 DDDs, aOR 1.89. The aOR for individual cephalosporin was 2.88 (95% CI, 2.08-4.00, 1.35 (1.09-1.67 and 4.57 (2.63-7.95 for cefmetazole, flomoxef, and cefoperazone, respectively. Other risk factors included use of anticoagulants (aOR 2.08 [95% CI, 1.64-2.63], liver failure (aOR 1.69 [1.30-2.18], poor nutritional status (aOR 1.41 [1.15-1.73], and history of hemorrhagic events (aOR 2.57 [1.94-3.41] 6 months prior to the index date.Use of hypoprothrombinemia-inducing cephalosporins increases risk of hemorrhagic events. Close watch for hemorrhagic events is recommended when prescribing these cephalosporins, especially in patients who are at higher risk.

  17. Disentangling the Association between Statins, Cholesterol, and Colorectal Cancer: A Nested Case-Control Study

    Science.gov (United States)

    Mamtani, Ronac; Lewis, James D.; Scott, Frank I.; Ahmad, Tariq; Goldberg, David S.; Datta, Jashodeep; Yang, Yu-Xiao; Boursi, Ben

    2016-01-01

    Background Several prior studies have found an association between statin use and reduced risk of colorectal cancer. We hypothesized that these findings may be due to systematic bias and examined the independent association of colorectal cancer risk with statin use, serum cholesterol, and change in cholesterol concentration. Methods and Findings 22,163 colorectal cancer cases and 86,538 matched controls between 1995 and 2013 were identified within The Health Improvement Network (THIN) a population-representative database. Conditional logistic regression models estimated colorectal cancer risk with statin use, serum total cholesterol (mmol/L), and change in total cholesterol level. We confirmed a decreased risk of colorectal cancer with statin use (long-term: odds ratio [OR], 0.95; 95% confidence interval [CI], 0.91–0.99; short-term: OR, 0.92; 95% CI, 0.85–0.99). However, to assess whether the observed association may result from indication bias, a subgroup analysis was conducted among patients prescribed a statin. In this subgroup (n = 5,102 cases, n = 19,032 controls), 3.1% of case subjects and 3.1% of controls discontinued therapy. The risk of colorectal cancer was not significantly different among those who continued statin therapy and those who discontinued (OR, 0.98; 95% CI, 0.79–1.22). Increased serum cholesterol was independently associated with decreased risk of colorectal cancer (OR, 0.89 per mmol/L increase; 95% CI, 0.87–0.91); the association was only present if serum cholesterol was measured near the cancer diagnosis (24 mo: OR, 0.98; 95% CI, 0.93–1.03). Decreases in serum total cholesterol >1 mmol/L ≥1 year prior to cancer diagnosis were associated with subsequent colorectal cancer (statin users: OR, 1.25; 95 CI%, 1.03–1.53; nonusers: OR, 2.36; 95 CI%, 1.78–3.12). As an observational study, limitations included incomplete data and residual confounding. Conclusions Although the risk of colorectal cancer was lower in statin users versus

  18. Circulating C-Reactive Protein Concentrations and Risks of Colon and Rectal Cancer : A Nested Case-Control Study Within the European Prospective Investigation into Cancer and Nutrition

    NARCIS (Netherlands)

    Aleksandrova, Krasimira; Jenab, Mazda; Boeing, Heiner; Jansen, Eugene; Bueno-de-Mesquita, H. Bas; Rinaldi, Sabina; Riboli, Elio; Overvad, Kim; Dahm, Christina C.; Olsen, Anja; Tjonneland, Anne; Boutron-Ruault, Marie-Christine; Clavel-Chapelon, Francoise; Morois, Sophie; Palli, Domenico; Krogh, Vittorio; Tumino, Rosario; Vineis, Paolo; Panico, Salvatore; Kaaks, Rudolf; Rohrmann, Sabine; Trichopoulou, Antonia; Lagiou, Pagona; Trichopoulos, Dimitrios; van Duijnhoven, Fraenzel J. B.; Leufkens, Anke M.; Peeters, Petra H.; Rodriguez, Laudina; Bonet, Catalina; Sanchez, Maria-Jose; Dorronsoro, Miren; Navarro, Carmen; Barricarte, Aurelio; Palmqvist, Richard; Hallmans, Goran; Khaw, Kay-Tee; Wareham, Nicholas; Allen, Naomi E.; Spencer, Elizabeth; Romaguera, Dora; Norat, Teresa; Pischon, Tobias

    2010-01-01

    The authors investigated associations between serum C-reactive protein (CRP) concentrations and colon and rectal cancer risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (1992-2003) among 1,096 incident cases and 1,096 controls selected using

  19. Lack of Significant Effects of Chlamydia trachomatis Infection on Cervical Adenocarcinoma Risk: Nested Case-Control Study

    Science.gov (United States)

    Smelov, Vitaly; Gheit, Tarik; Sundström, Karin; Ploner, Alexander; McKay-Chopin, Sandrine; Eklund, Carina; Tommasino, Massimo; Dillner, Joakim

    2016-01-01

    Background A role of Chlamydia trachomatis in HPV-induced cervical carcinogenesis has been reported for cervical cancer but studies on cervical adenocarcinoma are limited. Methods A total of 1,553 cervical smears taken up to 26 years before diagnosis in a large population-based nested case-control study of cervical adenocarcinoma (AC, 132 cases with matched controls), and adenocarcinoma in situ (AIS, 159 cases with matched controls) were tested for C. trachomatis and HPV DNA by a type-specific PCR bead-based multiplex genotyping (TS-MPG) assay. Results Only 1.7% of samples were positive for C. trachomatis, with no significant differences between AC/AIS cases and controls. HPV-positivity was detected in 49.3% of C. trachomatis-negative and 65.4% C. trachomatis-positive samples, respectively. Conclusions A large prospective study did not find any risk for cervical adenocarcinoma and/or AIS conferred by C. trachomatis infection. Impact C. trachomatis appears not to be involved in cervical adenocarcinomas. PMID:27227411

  20. Lack of Significant Effects of Chlamydia trachomatis Infection on Cervical Adenocarcinoma Risk: Nested Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Vitaly Smelov

    Full Text Available A role of Chlamydia trachomatis in HPV-induced cervical carcinogenesis has been reported for cervical cancer but studies on cervical adenocarcinoma are limited.A total of 1,553 cervical smears taken up to 26 years before diagnosis in a large population-based nested case-control study of cervical adenocarcinoma (AC, 132 cases with matched controls, and adenocarcinoma in situ (AIS, 159 cases with matched controls were tested for C. trachomatis and HPV DNA by a type-specific PCR bead-based multiplex genotyping (TS-MPG assay.Only 1.7% of samples were positive for C. trachomatis, with no significant differences between AC/AIS cases and controls. HPV-positivity was detected in 49.3% of C. trachomatis-negative and 65.4% C. trachomatis-positive samples, respectively.A large prospective study did not find any risk for cervical adenocarcinoma and/or AIS conferred by C. trachomatis infection.C. trachomatis appears not to be involved in cervical adenocarcinomas.

  1. Risk of Prostate Cancer after Trans Urethral Resection of BPH: A Cohort and Nested Case-Control Study

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Camilla T., E-mail: Camilla.thellenberg@onkologi.umu.se [Department of Radiation Sciences, Oncology, Umeå University, SE-901 87 Umeå (Sweden); Wiklund, Fredrik; Grönberg, Henrik [Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm SE-171 77 (Sweden); Bergh, Anders [Department of Medical Biosciences, Pathology, Umeå University, SE-901 87 Umeå (Sweden); Melin, Beatrice [Department of Radiation Sciences, Oncology, Umeå University, SE-901 87 Umeå (Sweden)

    2011-11-08

    Epidemiological and experimental evidence suggests that inflammation plays a role in both prostate cancer (PCa) and benign prostate hyperplasia (BPH). This study evaluates the risk of PC after transurethral resection (TURP) for BPH and estimates the PCa risk related to presence of inflammation in the resected material. The Pathology Department at the University Hospital of Umeå (Umeå, Sweden) identified BPH cases (n = 7,901) that underwent TURP between 1982 and 1997. Using these pathological specimens, we compared the incidence of PCa in the cohort to the population and calculated the standardized incidence and mortality ratios (SIR and SMR). Inflammation, the androgen receptor (AR), and p53 were evaluated in a nested case-control study of 201 cases and controls. Inflammation was graded severe or mild-moderate. In the follow-up period after TURP, cases developed prostate cancer and the controls did not. After TURP, SIR for prostate cancer increased [1.26, CI 95% (1.17–1.35) ], whereas SMR decreased [0.59, CI 95% (0.47–0.73) ]. Presence of inflammation at the time of TURP did not differ between cases and controls nor were there differences in p53 or AR staining. The data suggest a small increased risk of PCa after TURP and decreased PCa mortality. Inflammation at the time of TURP is not associated with PCa risk in this material. The increased PCa risk may be attributed to increased surveillance and PSA screening.

  2. Risk of Prostate Cancer after Trans Urethral Resection of BPH: A Cohort and Nested Case-Control Study

    International Nuclear Information System (INIS)

    Epidemiological and experimental evidence suggests that inflammation plays a role in both prostate cancer (PCa) and benign prostate hyperplasia (BPH). This study evaluates the risk of PC after transurethral resection (TURP) for BPH and estimates the PCa risk related to presence of inflammation in the resected material. The Pathology Department at the University Hospital of Umeå (Umeå, Sweden) identified BPH cases (n = 7,901) that underwent TURP between 1982 and 1997. Using these pathological specimens, we compared the incidence of PCa in the cohort to the population and calculated the standardized incidence and mortality ratios (SIR and SMR). Inflammation, the androgen receptor (AR), and p53 were evaluated in a nested case-control study of 201 cases and controls. Inflammation was graded severe or mild-moderate. In the follow-up period after TURP, cases developed prostate cancer and the controls did not. After TURP, SIR for prostate cancer increased [1.26, CI 95% (1.17–1.35) ], whereas SMR decreased [0.59, CI 95% (0.47–0.73) ]. Presence of inflammation at the time of TURP did not differ between cases and controls nor were there differences in p53 or AR staining. The data suggest a small increased risk of PCa after TURP and decreased PCa mortality. Inflammation at the time of TURP is not associated with PCa risk in this material. The increased PCa risk may be attributed to increased surveillance and PSA screening

  3. Use of antipsychotics and risk of venous thromboembolism in postmenopausal women. A population-based nested case-control study.

    Science.gov (United States)

    Wang, Meng-Ting; Liou, Jun-Ting; Huang, Yun-Wen; Lin, Chen Wei; Wu, Gwo-Jang; Chu, Che-Li; Yeh, Chin-Bin; Wang, Yun-Han

    2016-06-01

    Despite continued uncertainty of venous thromboembolism (VTE) caused from antipsychotic agents, this safety issue has not been examined in postmenopausal women, a population with high usages of antipsychotics and at high risk for VTE. We assessed whether antipsychotic use was associated with an increased VTE risk in women after menopause. We conducted a nested case-control study of all Taiwanese women aged ≥ 50 years (n = 316,132) using a nationwide healthcare claims database between 2000 and 2011. All newly diagnosed VTE patients treated with an anticoagulant or thrombectomy surgery were identified as cases (n = 2,520) and individually matched to select controls (n = 24,223) by cohort entry date, age, cancer diagnosis and major surgery procedure. The odds ratios (ORs) and 95 % confidence interval (CI) of VTE associated with antipsychotics were estimated by multivariate conditional logistic regressions. Current use of antipsychotics was associated with a 1.90-fold (95 % CI = 1.64-2.19) increased VTE risk compared with nonuse in postmenopausal women. The VTE risk existed in a dose-dependent fashion (test for trend, p 30 days. In conclusion, current use of antipsychotics is significantly associated with a dose-dependent increased risk of VTE in postmenopausal women, especially for those currently taking high-dose or receiving parenteral antipsychotics. PMID:26941052

  4. Understanding non-compliance to colorectal cancer screening: a case control study, nested in a randomised trial [ISRCTN83029072

    Directory of Open Access Journals (Sweden)

    Borgia Piero

    2005-12-01

    Full Text Available Abstract Background The major limit to colorectal cancer screening effectiveness is often low compliance. We studied the reasons for non compliance and determinants of compliance to faecal occult blood tests in Lazio, Italy. Methods This is a case-control study nested within a trial that tested the effect of type of test and provider on colorectal cancer screening compliance. Non compliant trial subjects were classified as cases, and compliant subjects were classified as controls. We sampled 600 cases and 600 controls matched by their general practitioner, half were invited for screening at the hospital, and the other half directly at their general practitioner's office. Cases and controls answered questions on: distance from test provider, logistical problems, perception of colorectal cancer risk, confidence in screening efficacy, fear of results, presence of colorectal cancer in the family, and gastrointestinal symptoms. Results About 31% of cases never received the letter offering free screening, and 17% of the sampled population had already been screened. The first reported reason for non-compliance was "lack of time" (30%; the major determinant of compliance was the distance from the test provider: odds ratio >30 minutes vs Conclusion To increase compliance, screening programmes must involve test providers who are geographically close to the target population.

  5. Risk of Prostate Cancer after Trans Urethral Resection of BPH: A Cohort and Nested Case-Control Study

    Directory of Open Access Journals (Sweden)

    Beatrice Melin

    2011-11-01

    Full Text Available Epidemiological and experimental evidence suggests that inflammation plays a role in both prostate cancer (PCa and benign prostate hyperplasia (BPH. This study evaluates the risk of PC after transurethral resection (TURP for BPH and estimates the PCa risk related to presence of inflammation in the resected material. The Pathology Department at the University Hospital of Umeå (Umeå, Sweden identified BPH cases (n = 7,901 that underwent TURP between 1982 and 1997. Using these pathological specimens, we compared the incidence of PCa in the cohort to the population and calculated the standardized incidence and mortality ratios (SIR and SMR. Inflammation, the androgen receptor (AR, and p53 were evaluated in a nested case-control study of 201 cases and controls. Inflammation was graded severe or mild-moderate. In the follow-up period after TURP, cases developed prostate cancer and the controls did not. After TURP, SIR for prostate cancer increased [1.26, CI 95% (1.17–1.35], whereas SMR decreased [0.59, CI 95% (0.47–0.73]. Presence of inflammation at the time of TURP did not differ between cases and controls nor were there differences in p53 or AR staining. The data suggest a small increased risk of PCa after TURP and decreased PCa mortality. Inflammation at the time of TURP is not associated with PCa risk in this material. The increased PCa risk may be attributed to increased surveillance and PSA screening.

  6. Lung Cancer Risk from Occupational and Environmental Radon and Role of Smoking in Two Czech Nested Case-Control Studies

    Directory of Open Access Journals (Sweden)

    Ladislav Tomasek

    2013-03-01

    Full Text Available The aim of the present study was to evaluate the risk of lung cancer from combined exposure to radon and smoking. Methodologically, it is based on case-control studies nested within two Czech cohort studies of nearly 11,000 miners followed-up for mortality in 1952–2010 and nearly 12,000 inhabitants exposed to high levels of radon in homes, with mortality follow-up in 1960–2010. In addition to recorded radon exposure, these studies use information on smoking collected from the subjects or their relatives. A total of 1,029 and 370 cases with smoking information have been observed in the occupational and environmental (residential studies, respectively. Three or four control subjects have been individually matched to cases according to sex, year of birth, and age. The combined effect from radon and smoking is analyzed in terms of geometric mixture models of which the additive and multiplicative models are special cases. The resulting models are relatively close to the additive interaction (mixing parameter 0.2 and 0.3 in the occupational and residential studies, respectively. The impact of the resulting model in the residential radon study is illustrated by estimates of lifetime risk in hypothetical populations of smokers and non-smokers. In comparison to the multiplicative risk model, the lifetime risk from the best geometric mixture model is considerably higher, particularly in the non-smoking population.

  7. Corticosteroid Risk Function of Severe Infection in Primary Immune Thrombocytopenia Adults. A Nationwide Nested Case-Control Study.

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    Guillaume Moulis

    Full Text Available Corticosteroid (CS-related infection risk in immune thrombocytopenia (ITP is unknown. The aim of this study was to assess the adjusted CS risk function of severe infection in persistent or chronic primary ITP adults. We designed a nested case-control study in the FAITH cohort. This cohort is built through the French national health insurance database named SNIIRAM and includes all treated incident persistent or chronic primary ITP adults in France (ENCePP n°4574. Patients who entered the FAITH cohort between 2009 and 2012 were eligible (n = 1805. Cases were patients with infection as primary diagnosis code during hospitalization. Index date was the date of first hospitalization for infection. A 2:1 matching was performed on age and entry date in the cohort. Various CS exposure time-windows were defined: current user, exposure during the 1/3/6 months preceding index date and from the entry date. CS doses were converted in prednisone equivalent (PEQ. The cumulative CS doses were averaged in each time-window to obtain daily PEQ dosages. Each CS exposure definition was assessed using multivariate conditional regression models. During the study period, 161 cases (9 opportunistic occurred. The model with the best goodness of fit was CS exposure during the month before the index date (OR: 2.48, 95% CI: 1.61-3.83. The dose-effect relation showed that the risk existed from averaged daily doses ≥5 mg PEQ (vs. <5 mg: 2.09, 95% CI: 1.17-3.71. The risk of infection was mainly supported by current or recent exposure to CS, even with low doses.

  8. Impact of Urate Level on Cardiovascular Risk in Allopurinol Treated Patients. A Nested Case-Control Study.

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    Kasper Søltoft Larsen

    Full Text Available Gout gives rise to increased risk of cardiovascular events. Gout attacks can be effectively prevented with urate lowering drugs, and allopurinol potentially reduces cardiovascular risk. What target level of urate is required to reduce cardiovascular risk is not known.To investigate the effect of achieving target plasma urate with allopurinol on cardiovascular outcomes in a case-control study nested within long-term users of allopurinol.We identified long-term users of allopurinol in Funen County, Denmark. Among these, we identified all cases of cardiovascular events and sampled 4 controls to each case from the same population. The cases and controls were compared with respect to whether they reached a urate target below 0.36 mmol/l on allopurinol. The derived odds ratios were controlled for potential confounders available from data on prescriptions, laboratory values and in- and outpatient contacts.No association between treatment-to-target urate level and cardiovascular events were found (adjusted odds ratio of 1.01, 95% confidence interval 0.79-1.28. No significant effect was seen in any subgroup defined by age, gender, renal function, allopurinol dose or the achieved urate level. Overall, the doses of allopurinol used in this study were low (mean ≈ 140 mg/day.We were unable to demonstrate a link between achieved urate level in patients treated with allopurinol and risk of cardiovascular events. Possible explanations include that allopurinol doses higher than those used in this study are required to achieve cardiovascular risk reduction or that the cardiovascular effect of allopurinol is not mediated through low urate levels. It remains to be seen whether allopurinol has a dose-response relationship with cardiovascular events at higher doses.

  9. Diabetes mellitus increases the prevalence of anemia in patients with chronic kidney disease: A nested case-control study

    Science.gov (United States)

    Loutradis, Charalampos; Skodra, Alexandra; Georgianos, Panagiotis; Tolika, Panagiota; Alexandrou, Dimitris; Avdelidou, Afroditi; Sarafidis, Pantelis A

    2016-01-01

    AIM: To compare anemia prevalence between matched chronic kidney disease (CKD) patients with and without diabetes mellitus (DM) and to assess factors associated with anemia development. METHODS: This is a nested case-control study of 184 type-2 diabetic and 184 non-diabetic CKD patients from a prospectively assembled database of a Nephrology outpatient clinic, matched for gender, age and estimated glomerular filtration rate (eGFR). Prevalence of anemia (hemoglobin: Men: < 13 g/dL, women: < 12 g/dL and/or use of recombinant erythropoietin) was examined in comparison, in the total population and by CKD Stage. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with anemia. RESULTS: The total prevalence of anemia was higher in diabetics (47.8% vs 33.2%, P = 0.004). Accordingly, prevalence was higher in diabetics in CKD Stage 3 (53.5% vs 33.1%, P < 0.001) and particularly in Stage 3a (60.4% vs 26.4%, P < 0.001), whereas it was non-significantly higher in Stage 4 (61.3% vs 48.4%; P = 0.307). Serum ferritin was higher in diabetics in total and in CKD stages, while serum iron was similar between groups. In multivariate analyses, DM (OR = 2.206, 95%CI: 1.196-4.069), CKD Stages 3a, 3b, 4 (Stage 4: OR = 12.169, 95%CI: 3.783-39.147) and serum iron (OR = 0.976, 95%CI: 0.968-0.985 per mg/dL increase) were independently associated with anemia. CONCLUSION: Prevalence of anemia progressively increases with advancing stages of CKD and is higher in diabetic than matched non-diabetic CKD patients and diabetes is independently associated with anemia occurrence. Detection and treatment of anemia in diabetic CKD patients should be performed earlier than non-diabetic counterparts. PMID:27458564

  10. Oncogenic CagA promotes gastric cancer risk via activating ERK signaling pathways: a nested case-control study.

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    Jae Jeong Yang

    Full Text Available BACKGROUND: CagA cellular interaction via activation of the ERK signaling pathway may be a starting point in the development of gastric cancer. This study aimed to evaluate whether genes involved in ERK downstream signaling pathways activated by CagA are susceptible genetic markers for gastric cancer. METHODS: In the discovery phase, a total of 580 SNPs within +/-5 kbp of 30 candidate genes were genotyped to examine an association with gastric cancer risk in the Korean Multi-center Cancer Cohort (100 incident gastric cancer case-control sets. The most significant SNPs (raw or permutated p value<0.02 identified in the discovery analysis were re-evaluated in the extension phase using unconditional logistic regression model (400 gastric cancer case-control sets. Combined analyses including pooled- and meta-analysis were conducted to summarize all the results. RESULTS: 24 SNPs in eight genes (ERK, Dock180, C3G, Rap1, Src, CrkL, Mek and Crk were significantly associated with gastric cancer risk in the individual SNP analyses in the discovery phase (p<0.05. In the extension analyses, ERK rs5999749, Dock180 rs4635002 and C3G rs7853122 showed marginally significant gene-dose effects for gastric cancer. Consistently, final combined analysis presented the SNPs as significantly associated with gastric cancer risk (OR = 1.56, [95% CI: 1.19-2.06], OR = 0.61, [95% CI: 0.43-0.87], OR = 0.59, [95% CI: 0.54-0.76], respectively. CONCLUSIONS: Our findings suggest that ERK rs5999749, Dock180 rs4635002 and C3G rs7853122 are genetic determinants in gastric carcinogenesis.

  11. Risk of hip fractures associated with benzodiazepines: Applying common protocol to a multi-database nested case-control study. The protect project

    OpenAIRE

    Requena, Gema; Logie, John; González-González, Rocío; Gardarsdottir, Helga; Afonso, Ana; Souverein, Patrick C.; Merino, Elisa Martin; Boudiaf, Nada; Huerta, Consuelo; Bate, Andrew; Alvarez, Yolanda; García-Rodríguez, Luis A; Reynolds, Robert; Schlienger, Raymond G.; De Groot, Mark C.H.

    2014-01-01

    Background: The association between benzodiazepines (BZD) and hip fractures has been estimated in several observational studies although diverse methodologies and definitions have hampered comparability. Objectives: To evaluate the discrepancies in the risk estimates of hip/femur fractures associated with BDZs across different databases and to assess the impact of different matching strategies. Methods: A case control study nested in a cohort of BZD users, examining their association with the...

  12. Plasma carotenoids, retinol, and tocopherols and postmenopausal breast cancer risk in the Multiethnic Cohort Study: a nested case-control study

    OpenAIRE

    Epplein, Meira; Shvetsov, Yurii B.; Wilkens, Lynne R.; Franke, Adrian A.; Cooney, Robert V.; Le Marchand, Loïc; Brian E Henderson; Kolonel, Laurence N; Goodman, Marc T.

    2009-01-01

    Introduction Assessments by the handful of prospective studies of the association of serum antioxidants and breast cancer risk have yielded inconsistent results. This multiethnic nested case-control study sought to examine the association of plasma carotenoids, retinol, and tocopherols with postmenopausal breast cancer risk. Methods From the biospecimen subcohort of the Multiethnic Cohort Study, 286 incident postmenopausal breast cancer cases were matched to 535 controls on age, sex, ethnicit...

  13. Serum α-Tocopherol and γ-Tocopherol Concentrations and Prostate Cancer Risk in the PLCO Screening Trial: A Nested Case-Control Study

    OpenAIRE

    Weinstein, Stephanie J.; Ulrike Peters; Jiyoung Ahn; Friesen, Marlin D.; Elio Riboli; Hayes, Richard B; Demetrius Albanes

    2012-01-01

    BACKGROUND: Vitamin E compounds exhibit prostate cancer preventive properties experimentally, but serologic investigations of tocopherols, and randomized controlled trials of supplementation in particular, have been inconsistent. Many studies suggest protective effects among smokers and for aggressive prostate cancer, however. METHODS: We conducted a nested case-control study of serum α-tocopherol and γ-tocopherol and prostate cancer risk in the Prostate, Lung, Colorectal and Ovarian Cancer S...

  14. Lack of association between serological evidence of past Coxiella burnetii infection and incident ischaemic heart disease: nested case-control study.

    OpenAIRE

    Amouyel Philippe; Bingham Annie; Ducimetiere Pierre; Yarnell John WG; Woodside Jayne V; Wyatt Dorothy E; O'Neill Hugh J; Coyle Peter V; McKenna James P; Murray Liam J; McCaughey Conall; Montaye Michele; Arveiler Dominique; Haas Bernadette; Ferrieres Jean

    2005-01-01

    Abstract Background Coxiella burnetii causes the common worldwide zoonotic infection, Q fever. It has been previously suggested that patients who had recovered from acute Q fever (whether symptomatic or otherwise) may be at increased risk of ischaemic heart disease. We undertook this study to determine if past infection with Coxiella burnetii, the aetiological agent of Q fever, is a risk factor for the subsequent development of ischaemic heart disease. Methods A nested case-control study with...

  15. The relationship between asthma and depression in primary care patients: a historical cohort and nested case control study.

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    Paul Walters

    Full Text Available BACKGROUND AND OBJECTIVES: Asthma and depression are common health problems in primary care. Evidence of a relationship between asthma and depression is conflicting. OBJECTIVES: to determine 1. The incidence rate and incidence rate ratio of depression in primary care patients with asthma compared to those without asthma, and 2. The standardized mortality ratio of depressed compared to non-depressed patients with asthma. METHODS: A historical cohort and nested case control study using data derived from the United Kingdom General Practice Research Database. PARTICIPANTS: 11,275 incident cases of asthma recorded between 1/1/95 and 31/12/96 age, sex and practice matched with non-cases from the database (ratio 1:1 and followed up through the database for 10 years. 1,660 cases were matched by date of asthma diagnosis with 1,660 controls. MAIN OUTCOME MEASURES: number of cases diagnosed with depression, the number of deaths over the study period. RESULTS: The rate of depression in patients with asthma was 22.4/1,000 person years and without asthma 13.8 /1,000 person years. The incident rate ratio (adjusted for age, sex, practice, diabetes, cardiovascular disease, cerebrovascular disease, smoking was 1.59 (95% CI 1.48-1.71. The increased rate of depression was not associated with asthma severity or oral corticosteroid use. It was associated with the number of consultations (odds ratio per visit 1.09; 95% CI 1.07-1.11. The age and sex adjusted standardized mortality ratio for depressed patients with asthma was 1.87 (95% CI: 1.54-2.27. CONCLUSIONS: Asthma is associated with depression. This was not related to asthma severity or oral corticosteroid use but was related to service use. This suggests that a diagnosis of depression is related to health seeking behavior in patients with asthma. There is an increased mortality rate in depressed patients with asthma. The cause of this needs further exploration. Consideration should be given to case-finding for

  16. Cancer and frailty in older adults: a nested case-control study of the Mexican Health and Aging Study

    Science.gov (United States)

    Pérez-Zepeda, Mario Ulises; Cárdenas-Cárdenas, Eduardo; Cesari, Matteo; Navarrete-Reyes, Ana Patricia; Gutiérrez-Robledo, Luis Miguel

    2016-01-01

    Purpose Understanding how the convergence between chronic and complex diseases—such as cancer—and emerging conditions of older adults—such as frailty—takes place would help in halting the path that leads to disability in this age group. The objective of this manuscript is to describe the association between a past medical history of cancer and frailty in Mexican older adults. Methods This is a nested in cohort case-control study of the Mexican Health and Aging Study. Frailty was categorized by developing a 55-item frailty index that was also used to define cases in two ways: incident frailty (incident >0.25 frailty index score) and worsening frailty (negative residuals from a regression between 2001 and 2012 frailty index scores). Exposition was defined as self-report of cancer between 2001 and 2012. Older adults with a cancer history were further divided into recently diagnosed (10 years from the initial diagnosis). Odds ratios were estimated by fitting a logistic regression adjusted for confounding variables. Results Out of a total of 8022 older adults with a mean age of 70.6 years, the prevalence of a past medical history of cancer was 3.6 % (n = 288). Among these participants, 45.1 % had been diagnosed with cancer more than 10 years previously. A higher risk of incident frailty compared to controls [odds ratio (OR) 1.53 (95 % confidence interval (CI) 1.04–2.26, p = 0.03); adjusted model OR 1.74 (95 % CI 1.15–2.61, p = 0.008)] was found in the group with a recent cancer diagnosis. Also, an inverse association between a remote cancer diagnosis and worsening frailty was found [OR = 0.56 (95 % CI 0.39–0.8), p = 0.002; adjusted model OR 0.61 (95 % CI 0.38–0.99, p = 0.046)]. Conclusions Cancer is associated with a higher frailty index, with a potential relevant role of the time that has elapsed since the cancer diagnosis. Implications for cancer survivors Cancer survivors may be more likely to develop frailty or worsening of the health status at an

  17. Perinatal Mortality Magnitude, Determinants and Causes in West Gojam: Population-Based Nested Case-Control Study

    Science.gov (United States)

    Yirgu, Robel; Molla, Mitike; Sibley, Lynn; Gebremariam, Abebe

    2016-01-01

    Introduction In Ethiopia, even if a significant reduction in child mortality is recorded recently, perinatal mortality rate is still very high. This study assessed the magnitude, determinants and causes of perinatal death in West Gojam zone, Ethiopia. Methods and materials A nested case control study was conducted on 102 cases (mothers who lost their newborns for perinatal death) and 204 controls (mothers who had live infants in the same year) among a cohort of 4097 pregnant mothers in three districts of the West Gojam zone, from Feb 2011 to Mar 2012. Logistic regression models were used to identify the independent determinant factors for perinatal mortality. The World Health Organization verbal autopsy instrument for neonatal death was used to collect mortality data and cause of death was assigned by a pediatrician and a neonatologist. Result Perinatal mortality rate was 25.1(95% CI 20.3, 29.9) per 1000 live and stillbirths. Primiparous mothers had a higher risk of losing their newborn babies for perinatal death than mothers who gave birth to five or more children (AOR = 3.15, 95% CI 1.03–9.60). Babies who were born to women who had a previous history of losing their baby to perinatal death during their last pregnancy showed higher odds of perinatal death than their counterparts (AOR = 9.55, 95% CI 4.67–19.54). Preterm newborns were more at risk for perinatal death (AOR = 9.44, 95%CI 1.81–49.22) than term babies. Newborns who were born among a household of more than two had a lesser risk of dying during the perinatal period as compared to those who were born among a member of only two. Paradoxically, home delivery was found to protect against perinatal death (AOR = 0.07 95% CI, 0.02–0.24) in comparison to institutional delivery. Bacterial sepsis, birth asphyxia and obstructed labour were among the leading causes of perinatal death. Conclusion Perinatal mortality rate remains considerably high, but proper maternal and child health care services can

  18. A nested case-control study of leukocyte mitochondrial DNA copy number and renal cell carcinoma in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.

    Science.gov (United States)

    Hofmann, Jonathan N; Hosgood, H Dean; Liu, Chin-San; Chow, Wong-Ho; Shuch, Brian; Cheng, Wen-Ling; Lin, Ta-Tsung; Moore, Lee E; Lan, Qing; Rothman, Nathaniel; Purdue, Mark P

    2014-05-01

    Mitochondrial DNA (mtDNA) is vulnerable to mutations, and the number of copies of mtDNA per cell may increase to compensate for DNA damage. Case-control studies have reported associations between altered mtDNA copy number and risk of renal cell carcinoma (RCC); however, this association has not been investigated prospectively. We conducted a nested case-control study (252 cases and 504 controls) of RCC risk in relation to pre-diagnostic leukocyte mtDNA copy number in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. mtDNA copy number was measured in triplicate using a fluorescence-based quantitative PCR assay; samples from 22 cases and 36 controls could not be assayed, leaving 230 cases and 468 controls for analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. High mtDNA copy number was associated with an increased risk of RCC, both overall (highest quartile versus lowest: OR = 2.0, 95% CI = 1.2-3.2; P trend = 0.002) and among cases diagnosed ≥6 years after blood collection (OR = 2.6, 95% CI = 1.4-5.0; P trend = 0.003). These findings did not differ significantly by sex, body mass index, history of hypertension or smoking status (P interaction ≥ 0.3). Results of this study suggest that high pre-diagnostic leukocyte mtDNA copy number, a suspected marker of oxidative DNA damage and mitochondrial dysfunction, is associated with increased future RCC risk. PMID:24398668

  19. Young people's risk of suicide attempts after contact with a psychiatric department - a nested case-control design using Danish register data

    DEFF Research Database (Denmark)

    Christiansen, Erik; Juul Larsen, Kim

    2012-01-01

    Background:  There seems to be an increased risk of children and adolescents committing or attempting suicide after contact with a psychiatric department. Children and adolescents living in families with low socio-economic status (SES) might have an especially increased suicide attempt risk....... Methods:  A complete extraction of Danish register data for every individual born in the period 1983-1989 was made. Of these 403,431 individuals, 3,465 had attempted suicide. In order to control for confounder effects from gender, age and calendar-time, a nested case-control study was designed. A total...... population of 72,765 individuals was used to analyze the risk of suicide attempts after contact with a psychiatric department. The case-control data were analyzed using conditional logistic regression. Results:  This study shows that a child/adolescent's risk of suicide attempt peaks immediately after...

  20. Acrylamide and glycidamide hemoglobin adducts and epithelial ovarian cancer: a nested case-control study in non-smoking postmenopausal women from the EPIC cohort

    Science.gov (United States)

    Obón-Santacana, Mireia; Lujan-Barroso, Leila; Travis, Ruth C.; Freisling, Heinz; Ferrari, Pietro; Severi, Gianluca; Baglietto, Laura; Boutron-Ruault, Marie-Christine; Fortner, Renée T.; Ose, Jennifer; Boeing, Heiner; Menéndez, Virginia; Sánchez-Cantalejo, Emilio; Chamosa, Saioa; Huerta Castaño, José María; Ardanaz, Eva; Khaw, Kay-Tee; Wareham, Nick; Merritt, Melissa A.; Gunter, Marc J.; Trichopoulou, Antonia; Papatesta, Eleni-Maria; Klinaki, Eleni; Saieva, Calogero; Tagliabue, Giovanna; Tumino, Rosario; Sacerdote, Carlotta; Mattiello, Amalia; Bueno-de-Mesquita, H.B.; Peeters, Petra H.; Onland-Moret, N. Charlotte; Idahl, Annika; Lundin, Eva; Weiderpass, Elisabete; Vesper, Hubert W.; Riboli, Elio; Duell, Eric J

    2015-01-01

    Background Acrylamide was classified as ‘probably carcinogenic to humans (group 2A)’ by the International Agency for Research on Cancer. Epithelial ovarian cancer (EOC) is the fourth cause of cancer mortality in women. Five epidemiological studies have evaluated the association between EOC risk and dietary acrylamide intake assessed using food frequency questionnaires, and one nested case-control study evaluated hemoglobin adducts of acrylamide (HbAA) and its metabolite glycidamide (HbGA) and EOC risk; the results of these studies were inconsistent. Methods A nested case-control study in non-smoking postmenopausal women (334 cases, 417 controls) was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Unconditional logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between HbAA, HbGA, HbAA+HbGA, and HbGA/HbAA and EOC and invasive serous EOC risk. Results No overall associations were observed between biomarkers of acrylamide exposure analyzed in quintiles and EOC risk; however, positive associations were observed between some middle quintiles of HbGA and HbAA+HbGA. Elevated but non-statistically significant ORs for serous EOC were observed for HbGA and HbAA+HbGA (ORQ5vsQ1:1.91, 95%CI:0.96-3.81 and ORQ5vsQ1:1.90, 95%CI:0.94-3.83, respectively); however, no linear dose-response trends were observed. Conclusion This EPIC nested case-control study failed to observe a clear association between biomarkers of acrylamide exposure and the risk of EOC or invasive serous EOC. Impact It is unlikely that dietary acrylamide exposure increases ovarian cancer risk; however, additional studies with larger sample size should be performed to exclude any possible association with EOC risk. PMID:26376083

  1. Anti-Tuberculosis Drug Induced Hepatotoxicity among TB/HIV Co-Infected Patients at Jimma University Hospital, Ethiopia: Nested Case-Control Study

    OpenAIRE

    Alima Hassen Ali; Tefera Belachew; Alemeshet Yami; Wubeante Yenet Ayen

    2013-01-01

    BACKGROUND: This study was carried out to determine the incidence and predictors of anti-tuberculosis drug induced hepatotoxicity among TB/HIV co-infected patients at Jimma University Hospital, Ethiopia. METHODS/PRINCIPAL FINDINGS: A nested case-control study was conducted by reviewing charts of all TB/HIV co-infected patients who commenced anti-TB treatment from January 2008 to December 2011 at Jimma University Hospital. Patients who had developed hepatotoxicity after at least 5 days of stan...

  2. Impact of Circulating Vitamin D Binding Protein Levels on the Association Between 25-Hydroxyvitamin D and Pancreatic Cancer Risk: A Nested Case-Control Study

    OpenAIRE

    Weinstein, Stephanie J.; Stolzenberg-Solomon, Rachael Z; Kopp, William; Rager, Helen; Virtamo, Jarmo; Albanes, Demetrius

    2012-01-01

    High concentrations of circulating 25-hydroxyvitamin D [25(OH)D] have been associated with elevated pancreatic cancer risk. As this is contrary to an expected inverse association between vitamin D status and cancer, we examined whether vitamin D binding protein (DBP), the primary carrier of vitamin D compounds in circulation, plays a role in this relationship. Prediagnostic serum DBP and 25(OH)D were studied in relation to risk of pancreatic cancer in a nested case-control study of 234 pancre...

  3. Innate immunity and non-Hodgkin's lymphoma (NHL related genes in a nested case-control study for gastric cancer risk.

    Directory of Open Access Journals (Sweden)

    Sue K Park

    Full Text Available OBJECTIVE: Genetic variants regulating the host immune system may contribute to the susceptibility for the development of gastric cancer. Little is known about the role of the innate immunity- and non-Hodgkin's lymphoma (NHL-related genes for gastric cancer risk. This nested case-control study was conducted to identify candidate genes for gastric cancer risk for future studies. METHODS: In the Discovery phase, 3,072 SNPs in 203 innate immunity- and 264 NHL-related genes using the Illumine GoldenGateTM OPA Panel were analyzed in 42 matched case-control sets selected from the Korean Multi-center Cancer Cohort (KMCC. Six significant SNPs in four innate immunity (DEFA6, DEFB1, JAK3, and ACAA1 and 11 SNPs in nine NHL-related genes (INSL3, CHMP7, BCL2L11, TNFRSF8, RAD50, CASP7, CHUK, CD79B, and CLDN9 with a permutated p-value <0.01 were re-genotyped in the Replication phase among 386 cases and 348 controls. Odds ratios (ORs for gastric cancer risk were estimated adjusting for age, smoking status, and H. pylori and CagA sero-positivity. Summarized ORs in the total study population (428 cases and 390 controls are presented using pooled- and meta-analyses. RESULTS: Four SNPS had no heterogeneity across the phases: in the meta-analysis, DEFA6 rs13275170 and DEFB1 rs2738169 had both a 1.3-fold increased odds ratio (OR for gastric cancer (95% CIs = 1.1-1.6; and 1.1-1.5, respectively. INSL3 rs10421916 and rs11088680 had both a 0.8-fold decreased OR for gastric cancer (95% CIs = 0.7-0.97; and 0.7-0.9, respectively. CONCLUSIONS: Our findings suggest that certain variants in the innate immunity and NHL-related genes affect the gastric cancer risk, perhaps by modulating infection-inflammation-immunity mechanisms that remain to be defined.

  4. Effectiveness of the 10-Valent Pneumococcal Conjugate Vaccine (PCV-10) in Children in Chile: A Nested Case-Control Study Using Nationwide Pneumonia Morbidity and Mortality Surveillance Data

    Science.gov (United States)

    Toscano, Cristiana M.; Alencar, Gizelton P.; Alvarez, Andrés; Valenzuela, Maria T.; Andrus, Jon; del Aguila, Roberto; Hormazábal, Juan C.; Araya, Pamela; Pidal, Paola; Matus, Cuauhtemoc R.; de Oliveira, Lucia H.

    2016-01-01

    Background The ten-valent pneumococcal conjugate vaccine (PCV10) was introduced into the Chilean National Immunization Program (NIP) in January 2011 with a 3+1 schedule (2, 4, 6 and 12 months) without catch-up vaccination. We evaluated the effectiveness of PCV10 on pneumonia morbidity and mortality among infants during the first two years after vaccine introduction. Methods This is a population-based nested case-control study using four merged nationwide case-based electronic health data registries: live birth, vaccination, hospitalization and mortality. Children born in 2010 and 2011 were followed from two moths of age for a period of two years. Using four different case definitions of pneumonia hospitalization and/or mortality (all-cause and pneumonia related deaths), all cases and four randomly selected matched controls per case were selected. Controls were matched to cases on analysis time. Vaccination status was then assessed. Vaccine effectiveness (VE) was estimated using conditional logistic regression. Results There were a total of 497,996 children in the 2010 and 2011 Chilean live-birth cohorts. PCV10 VE was 11.2% (95%CI 8.5–13.6) when all pneumonia hospitalizations and deaths were used to define cases. VE increased to 20.7 (95%CI 17.3–23.8) when ICD10 codes used to denote viral pneumonia were excluded from the case definition. VE estimates on pneumonia deaths and all-cause deaths were 71.5 (95%CI 9.0–91.8) and 34.8 (95% CI 23.7–44.4), respectively. Conclusion PCV10 vaccination substantially reduced the number of hospitalizations due to pneumonia and deaths due to pneumonia and to all-causes over this study period. Our findings also reinforce the importance of having quality health information systems for measuring VE. PMID:27058873

  5. Organochlorine exposures influence on breast cancer risk and survival according to estrogen receptor status: a Danish cohort-nested case-control study

    Directory of Open Access Journals (Sweden)

    Rank Fritz

    2001-07-01

    Full Text Available Abstract Background The relationship between breast cancer and organochlorine exposure is controversial and complex. As estrogen receptor positive and negative breast cancer may represent different entities of the disease, this study was undertaken to evaluate organochlorines influence on breast cancer risk and survival according to receptor status. Methods The background material stems from the Copenhagen City Heart Study (Denmark 1976-78. The breast cancer risk was investigated in a cohort nested case-control design including 161 cases and twice as many breast cancer free controls. The cases served as a cohort in the survival analysis. Serum organochlorine concentrations were determined by gaschromotography. Results The observed increased breast cancer risk associated with exposure to dieldrin derived from women who developed an estrogen receptor negative (ERN tumor (Odds ratio [OR] I vs. IV quartile, 7.6, 95% confidence interval [95% CI] 1.4-46.1, p-value for linear trend 0.01. Tumors in women with the highest dieldrin serum level were larger and more often spread at the time of diagnosis than ERP tumors. The risk of dying was for the remaining evaluated compounds higher among patients with ERP breast cancer when compared to those with ERN. In the highest quartile of polychlorinated biphenyls (ΣPCB it was more than 2-fold increased (Relative risk [RR] I vs. IV quartile, 2.5, 95% CI 1.1-5.7, but no dose-response relation was apparent. Conclusion The results do not suggest that exposure to potential estrogenic organochlorines leads to development of an ERP breast cancer. A possible adverse effect on prognosis of hormone-responsive breast cancers needs to be clarified.

  6. Beta-Blockers, Trimethoprim-Sulfamethoxazole, and the Risk of Hyperkalemia Requiring Hospitalization in the Elderly: A Nested Case-Control Study

    Science.gov (United States)

    Weir, Matthew A.; Juurlink, David N.; Gomes, Tara; Mamdani, Muhammad; Hackam, Daniel G.; Jain, Arsh K.

    2010-01-01

    Background and objectives: The simultaneous use of beta adrenergic receptor blockers (β-blockers) and trimethoprim-sulfamethoxazole (TMP-SMX) may confer a high risk of hyperkalemia. Design, setting, participants, & measurements: Two nested case-control studies were conducted to examine the association between hospitalization for hyperkalemia and the use of TMP-SMX in older patients receiving β-blockers. Linked health administrative records from Ontario, Canada, were used to assemble a cohort of 299,749 β-blockers users, aged 66 years or older and capture data regarding medication use and hospital admissions for hyperkalemia. Results: Over the study period from 1994 to 2008, 189 patients in this cohort were hospitalized for hyperkalemia within 14 days of receiving a study antibiotic. Compared with amoxicillin, the use of TMP-SMX was associated with a substantially greater risk of hyperkalemia requiring hospital admission (adjusted odds ratio, 5.1; 95% confidence interval [CI], 2.8 to 9.4). No such risk was identified with ciprofloxacin, norfloxacin, or nitrofurantoin. When dosing was considered, the association was greater at higher doses of TMP-SMX. When the primary analysis was repeated in a cohort of non-β-blocker users, the risk of hyperkalemia comparing TMP-SMX to amoxicillin was not significantly different from that found among β-blocker users. Conclusions: Although TMP-SMX is associated with an increased risk of hyperkalemia in older adults, these findings show no added risk when used in combination with β-blockers. PMID:20595693

  7. Organochlorine exposures influence on breast cancer risk and survival according to estrogen receptor status: a Danish cohort-nested case-control study

    International Nuclear Information System (INIS)

    The relationship between breast cancer and organochlorine exposure is controversial and complex. As estrogen receptor positive and negative breast cancer may represent different entities of the disease, this study was undertaken to evaluate organochlorines influence on breast cancer risk and survival according to receptor status. The background material stems from the Copenhagen City Heart Study (Denmark 1976-78). The breast cancer risk was investigated in a cohort nested case-control design including 161 cases and twice as many breast cancer free controls. The cases served as a cohort in the survival analysis. Serum organochlorine concentrations were determined by gaschromotography. The observed increased breast cancer risk associated with exposure to dieldrin derived from women who developed an estrogen receptor negative (ERN) tumor (Odds ratio [OR] I vs. IV quartile, 7.6, 95% confidence interval [95% CI] 1.4-46.1, p-value for linear trend 0.01). Tumors in women with the highest dieldrin serum level were larger and more often spread at the time of diagnosis than ERP tumors. The risk of dying was for the remaining evaluated compounds higher among patients with ERP breast cancer when compared to those with ERN. In the highest quartile of polychlorinated biphenyls (ΣPCB) it was more than 2-fold increased (Relative risk [RR] I vs. IV quartile, 2.5, 95% CI 1.1-5.7), but no dose-response relation was apparent. The results do not suggest that exposure to potential estrogenic organochlorines leads to development of an ERP breast cancer. A possible adverse effect on prognosis of hormone-responsive breast cancers needs to be clarified

  8. Exposure to bisphosphonates and risk of cancer: a protocol for nested case-control studies using the QResearch primary care database.

    Science.gov (United States)

    Vinogradova, Yana; Coupland, Carol; Hippisley-Cox, Julia

    2012-01-01

    Introduction Bisphosphonates are becoming a common treatment for osteoporosis particularly after discovery of the association between hormone replacement therapy and increased risk of breast cancer. As osteoporosis develops with age, treatment is a long-term intervention. Randomised control trials typically have limited follow-up times, which restricts investigation of the effects of the drugs on risk of primary cancers. A few observational studies have demonstrated a reduced risk of breast cancer and possibly of endometrial cancer in bisphosphonate users. Two epidemiological studies have studied the effect of the drugs on oesophageal cancer but did not reach any definite conclusions. So far, no effects on colorectal and stomach cancer have been shown. This study will investigate the association of bisphosphonates with risks of the 10 most common primary cancers. Methods and analysis A series of nested case-control studies will be based on the general population using records from 660 UK general practices within the QResearch Database. Cases will be patients with primary cancers diagnosed between 1996 and 2011. Each case will be matched by age, sex, practice and calendar year to five controls, who are alive and registered with the practice at the time of diagnosis of the case. Exposure to bisphosphonates will be defined as at least one prescription during the study period. For the most common cancers with substantial numbers of observations, the effect of the duration of the treatment and different types of bisphosphonates will be studied. Conditional logistic regression will be applied to produce ORs adjusted for smoking status, socioeconomic status, ethnicity, cancer-specific co-morbidities and use of other medications. PMID:22240651

  9. Anti-tuberculosis drug induced hepatotoxicity among TB/HIV co-infected patients at Jimma University Hospital, Ethiopia: nested case-control study.

    Directory of Open Access Journals (Sweden)

    Alima Hassen Ali

    Full Text Available BACKGROUND: This study was carried out to determine the incidence and predictors of anti-tuberculosis drug induced hepatotoxicity among TB/HIV co-infected patients at Jimma University Hospital, Ethiopia. METHODS/PRINCIPAL FINDINGS: A nested case-control study was conducted by reviewing charts of all TB/HIV co-infected patients who commenced anti-TB treatment from January 2008 to December 2011 at Jimma University Hospital. Patients who had developed hepatotoxicity after at least 5 days of standard doses of anti-TB drug therapy were labeled as "cases" and those without hepatotoxicity were "controls". Each case with anti-TB drug induced hepatotoxicity was compared with 3 controls selected randomly from the cohort. From a cohort of 296 TB/HIV co-infected patients 8 were excluded from the study as the causality between anti-TB drugs and hepatotoxicity was not confirmed, 33 had developed hepatotoxicity. On bivariate logistic regression analysis, body mass index (BMI <18.5 Kg/m(2 [P = 0.01; OR (95%CI: 3.6 (1.4-9.5], disseminated pulmonary TB [P = 0.00; OR (95%CI: 5.6 (2.2-14.6], CD4 count ≤50 [P = 0.016; OR (95%CI: 3.6(1.27-10.23] and WHO stage 4 [P = 0.004, OR (95%CI: 3.8 (1.68-8.77] were significantly associated with anti-TB drug induced hepatotoxicity. Predictor variables with p-value <0.05 by bivariate analysis were analyzed using multivariable logistic regression analysis and identified disseminated pulmonary TB [P = 0.001; AOR (95%CI = 5.6 (2.1-15.0] and BMI <18.5 [P = 0.014; AOR (95%CI= 3.6 (1.3-10.1] as independent predictors of anti-TB drug induced hepatotoxicity. CONCLUSIONS: The incidence of anti-TB drug induced hepatotoxicity was 11.5%. The results suggest that in the presence of disseminated pulmonary TB and/or BMI <18.5 Kg/m(2, TB/HIV co-infected patients should be closely followed for the occurrence of hepatotoxicity during the intensive phase of TB treatment to prevent morbidity and mortality.

  10. Case-control analysis of paternal age and trisomic anomalies

    NARCIS (Netherlands)

    De Souza, E.; Morris, Joan K.

    2010-01-01

    Objectives To determine whether older paternal age increases the risk of fathering a pregnancy with Patau (trisomy 13), Edwards (trisomy 18), Klinefelter (XXY) or XYY syndrome. Design Case-control: cases with each of these syndromes were matched to four controls with Down syndrome from within the sa

  11. Atopy and new-onset asthma in young Danish farmers and CD14, TLR2, and TLR4 genetic polymorphisms: a nested case-control study

    DEFF Research Database (Denmark)

    Smit, L A M; Bongers, S I M; Ruven, H J T;

    2007-01-01

    BACKGROUND: Evidence exists that exposure to high levels of microbial agents such as endotoxin in the farm environment decreases the risk of atopic sensitization. Genetic variation in innate immunity genes may modulate the response to microbial agents and thus influence susceptibility to asthma...... and atopy. OBJECTIVE: To study potential associations between single nucleotide polymorphisms (SNPs) in CD14, Toll-like receptor 2 (TLR2), and TLR4 genes, and atopy and new-onset asthma in young farmers. METHODS: A nested case-control study was conducted within a cohort of 1901 young Danish farmers. We....../-651 promoter polymorphisms are associated with atopy prevalence among young adults exposed to farm environments. Udgivelsesdato: 2007-Nov...

  12. Antipsychotic polypharmacy and risk of death from natural causes in patients with schizophrenia: a population-based nested case-control study

    DEFF Research Database (Denmark)

    Baandrup, Lone; Gasse, Christiane; Jensen, Vibeke;

    2010-01-01

    OBJECTIVE: Concomitant prescription of more than 1 antipsychotic agent (antipsychotic polypharmacy) in the treatment of schizophrenia is prevalent, although monotherapy is generally recommended. Mortality from natural causes is markedly increased in schizophrenia, and the role of polypharmacy...... remains controversial. The objective was to investigate if antipsychotic polypharmacy is associated with the excess mortality from natural causes among patients with schizophrenia. METHOD: A population-based nested case-control study was conducted using patient data from January 1, 1996, to December 31...... hours) was associated with increased risk of natural death in patients with schizophrenia treated with antipsychotics (OR = 1.78 [95% CI, 1.25-2.52]). CONCLUSIONS: Antipsychotic polypharmacy did not contribute to the excess mortality from natural causes in middle-aged patients with schizophrenia. The...

  13. Second Malignant Neoplasms in Digestive Organs After Childhood Cancer: A Cohort-Nested Case-Control Study

    International Nuclear Information System (INIS)

    Purpose: Cancers of the digestive system constitute a major risk for childhood cancer survivors treated with radiotherapy once they reach adulthood. The aim of this study was to determine therapy-related risk factors for the development of a second malignancy in the digestive organs (SMDO) after a childhood cancer. Methods and Materials: Among 4,568 2-year survivors of a childhood solid cancer diagnosed before 17 years of age at eight French and British centers, and among 25,120 patients diagnosed as having a malignant neoplasm before the age of 20 years, whose data were extracted from the Nordic Cancer Registries, we matched 58 case patients (41 men and 17 women) of SMDO and 167 controls, in their respective cohort, for sex, age at first cancer, calendar year of occurrence of the first cancer, and duration of follow-up. The radiation dose received at the site of each second malignancy and at the corresponding site of its matched control was estimated. Results: The risk of developing a SMDO was 9.7-fold higher in relation to the general populations in France and the United Kingdom. In the case-control study, a strong dose–response relationship was estimated, compared with that in survivors who had not received radiotherapy; the odds ratio was 5.2 (95% CI, 1.7–16.0) for local radiation doses between 10 and 29 Gy and 9.6 (95% CI, 2.6–35.2) for doses equal to or greater than 30 Gy. Chemotherapy was also found to increase the risk of developing SMDO. Conclusions: This study confirms that childhood cancer treatments strongly increase the risk of SMDO, which occur only after a very long latency period.

  14. Does a more refined assessment of exposure to bitumen fume and confounders alter risk estimates from a nested case-control study of lung cancer among European asphalt workers?

    DEFF Research Database (Denmark)

    Agostini, Michela; Ferro, Gilles; Burstyn, Igor;

    2013-01-01

    To investigate whether a refined assessment of exposure to bitumen fume among workers in the European asphalt industry within a nested case-control study resulted in a different interpretation pertaining to risk of lung cancer mortality compared with the cohort study.......To investigate whether a refined assessment of exposure to bitumen fume among workers in the European asphalt industry within a nested case-control study resulted in a different interpretation pertaining to risk of lung cancer mortality compared with the cohort study....

  15. Searching for early breast cancer biomarkers by serum protein profiling of pre-diagnostic serum; a nested case-control study

    International Nuclear Information System (INIS)

    Serum protein profiles have been investigated frequently to discover early biomarkers for breast cancer. So far, these studies used biological samples collected at or after diagnosis. This may limit these studies' value in the search for cancer biomarkers because of the often advanced tumor stage, and consequently risk of reverse causality. We present for the first time pre-diagnostic serum protein profiles in relation to breast cancer, using the Prospect-EPIC (European Prospective Investigation into Cancer and nutrition) cohort. In a nested case-control design we compared 68 women diagnosed with breast cancer within three years after enrollment, with 68 matched controls for differences in serum protein profiles. All samples were analyzed with SELDI-TOF MS (surface enhanced laser desorption/ionization time-of-flight mass spectrometry). In a subset of 20 case-control pairs, the serum proteome was identified and relatively quantified using isobaric Tags for Relative and Absolute Quantification (iTRAQ) and online two-dimensional nano-liquid chromatography coupled with tandem MS (2D-nanoLC-MS/MS). Two SELDI-TOF MS peaks with m/z 3323 and 8939, which probably represent doubly charged apolipoprotein C-I and C3a des-arginine anaphylatoxin (C3adesArg), were higher in pre-diagnostic breast cancer serum (p = 0.02 and p = 0.06, respectively). With 2D-nanoLC-MS/MS, afamin, apolipoprotein E and isoform 1 of inter-alpha trypsin inhibitor heavy chain H4 (ITIH4) were found to be higher in pre-diagnostic breast cancer (p < 0.05), while alpha-2-macroglobulin and ceruloplasmin were lower (p < 0.05). C3adesArg and ITIH4 have previously been related to the presence of symptomatic and/or mammographically detectable breast cancer. We show that serum protein profiles are already altered up to three years before breast cancer detection

  16. Spatial analysis of childhood cancer: a case/control study.

    Directory of Open Access Journals (Sweden)

    Rebeca Ramis

    Full Text Available Childhood cancer was the leading cause of death among children aged 1-14 years for 2012 in Spain. Leukemia has the highest incidence, followed by tumors of the central nervous system (CNS and lymphomas (Hodgkin lymphoma, HL, and Non-Hodgkin's lymphoma, NHL. Spatial distribution of childhood cancer cases has been under concern with the aim of identifying potential risk factors.The two objectives are to study overall spatial clustering and cluster detection of cases of the three main childhood cancer causes, looking to increase etiological knowledge.We ran a case-control study. The cases were children aged 0 to 14 diagnosed with leukemia, lymphomas (HL and NHL or CNS neoplasm in five Spanish regions for the period 1996-2011. As a control group, we used a sample from the Birth Registry matching every case by year of birth, autonomous region of residence and sex with six controls. We geocoded and validated the address of the cases and controls. For our two objectives we used two different methodologies. For the first, for overall spatial clustering detection, we used the differences of K functions from the spatial point patterns perspective proposed by Diggle and Chetwynd and the second, for cluster detection, we used the spatial scan statistic proposed by Kulldorff with a level for statistical significance of 0.05.We had 1062 cases of leukemia, 714 cases of CNS, 92 of HL and 246 of NHL. Accordingly we had 6 times the number of controls, 6372 controls for leukemia, 4284 controls for CNS, 552 controls for HL and 1476 controls for NHL. We found variations in the estimated empirical D(s for the different regions and cancers, including some overall spatial clustering for specific regions and distances. We did not find statistically significant clusters.The variations in the estimated empirical D(s for the different regions and cancers could be partially explained by the differences in the spatial distribution of the population; however, according to the

  17. Plasmodium falciparum infection patterns since birth and risk of severe malaria: a nested case-control study in children on the coast of Kenya.

    Directory of Open Access Journals (Sweden)

    Klara Lundblom

    Full Text Available Children in malaria endemic areas acquire immunity to severe malaria faster than to mild malaria. Only a minority of children suffers from severe malaria and it is not known what determines this. The aim of this study was to establish how P. falciparum infections during the first years of life affect the risk of severe malaria. A matched case-control study was nested within a large birth cohort set up to study the immunoepidemiology of pneumococci on the Kenyan coast. Infection patterns in three-monthly blood samples in cohort children admitted to hospital with severe malaria were compared to controls matched on age, residential location and time of sampling. P. falciparum detected at least once from birth conferred an increased risk of severe malaria and particularly if multiclonal infections, as characterized by genotyping of a polymorphic antigen gene, were ever detected. The results show for the first time that children with severe malaria have more infections early in life compared to community controls. These findings provide important insights on the immunity to severe disease, knowledge essential for the development of a vaccine against severe malaria.

  18. Use of non-steroidal anti-inflammatory drugs and prostate cancer risk: a population-based nested case-control study.

    Directory of Open Access Journals (Sweden)

    Salaheddin M Mahmud

    Full Text Available BACKGROUND: Despite strong laboratory evidence that non-steroidal anti-inflammatory drugs (NSAIDs could prevent prostate cancer, epidemiological studies have so far reported conflicting results. Most studies were limited by lack of information on dosage and duration of use of the different classes of NSAIDs. METHODS: We conducted a nested case-control study using data from Saskatchewan Prescription Drug Plan (SPDP and Cancer Registry to examine the effects of dose and duration of use of five classes of NSAIDs on prostate cancer risk. Cases (N = 9,007 were men aged ≥40 years diagnosed with prostatic carcinoma between 1985 and 2000, and were matched to four controls on age and duration of SPDP membership. Detailed histories of exposure to prescription NSAIDs and other drugs were obtained from the SPDP. RESULTS: Any use of propionates (e.g., ibuprofen, naproxen was associated with a modest reduction in prostate cancer risk (Odds ratio = 0.90; 95%CI 0.84-0.95, whereas use of other NSAIDs was not. In particular, we did not observe the hypothesized inverse association with aspirin use (1.01; 0.95-1.07. There was no clear evidence of dose-response or duration-response relationships for any of the examined NSAID classes. CONCLUSIONS: Our findings suggest modest benefits of at least some NSAIDs in reducing prostate cancer risk.

  19. Antenatal HIV-1 RNA load and timing of mother to child transmission; a nested case-control study in a resource poor setting

    Directory of Open Access Journals (Sweden)

    Chirenje Mike Z

    2010-08-01

    Full Text Available Abstract Objective To determine HIV-1 RNA load during the third trimester of pregnancy and evaluate its effect on in utero and intra-partum/postpartum transmissions in a breastfeeding population. Design A nested case-control study within a PMTCT cohort of antiretroviral therapy naive pregnant women and their infants. Methods A case was a mother who transmitted HIV-1 to her infant (transmitter who was matched to one HIV-1 positive but non-transmitting mother (control. Results From a cohort of 691 pregnant women, 177 (25.6% were HIV-1 positive at enrolment and from these 29 (23% transmitted HIV-1 to their infants, 10 and 19 during in utero and intra-partum/postpartum respectively. Twenty-four mothers sero-converted after delivery and three transmitted HIV-1 to their infants. Each unit increase in log10 viral load was associated with a 178 cells/mm3 and 0.2 g/dL decrease in TLC and hemoglobin levels, p = 0.048 and 0.021 respectively, and a 29% increase in the risk of transmission, p = 0.023. Intra-partum/postpartum transmitters had significantly higher mean viral load relative to their matched controls, p = 0.034. Conclusion Antenatal serum HIV-1 RNA load, TLC and hemoglobin levels were significantly associated with vertical transmission but this association was independent of transmission time. This finding supports the rationale for preventive strategies designed to reduce vertical transmission by lowering maternal viral load.

  20. Gene × Gene interaction between MnSOD and GPX-1 and breast cancer risk: a nested case-control study

    International Nuclear Information System (INIS)

    Germ-line mutations in genes such as BRCA1, BRCA2, and ATM can cause a substantial increase in risk of breast cancer. However, these mutations are rare in the general population, and account for little of the incidence of sporadic breast cancer in the general population. Therefore, research has been focused on examining associations between common polymorphisms and breast cancer risk. To date, few associations have been described. This has led to the hypothesis that breast cancer is a complex disease, whereby a constellation of very low penetrance alleles need to be carried to present a risk phenotype. Polymorphisms in the manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPX-1) genes have been proposed as low penetrance alleles, and have not been clearly associated with breast cancer. We investigated whether variants at both polymorphisms, while not independently associated with breast cancer risk, could influence breast cancer risk when considered together. A case-control study nested within the Nurses' Health Study was performed comparing 1262 women diagnosed with breast cancer to 1533 disease free women. The MnSOD (Val16Ala, rs1799725) and GPX-1 (Pro198Leu, rs1050450) were genotyped via TaqMan assay. Disease risk was evaluated using logistic regression. While neither allele alone shows any change in breast cancer risk, an increase in the risk of breast cancer (OR 1.87, 95% CI 1.09 – 3.19) is observed in individuals who carry both the Ala16Ala genotype of MnSOD and the Leu198Leu genotype of GPX-1. Polymorphisms in the GPX-1 and MnSOD genes are associated with an increased risk of breast cancer

  1. Inhaled Corticosteroids Use Is Not Associated With an Increased Risk of Pregnancy-Induced Hypertension and Gestational Diabetes Mellitus: Two Nested Case-Control Studies.

    Science.gov (United States)

    Lee, Chang-Hoon; Kim, Jimin; Jang, Eun Jin; Lee, Joon-Ho; Kim, Yun Jung; Choi, Seongmi; Kim, Deog Kyeom; Yim, Jae-Joon; Yoon, Ho Il

    2016-05-01

    There have been concerns that systemic corticosteroid use is associated with pregnancy-induced hypertension (PIH) and diabetes mellitus. However, the relationship between inhaled corticosteroids (ICSs) and the risk of PIH has not been fully examined, and there was no study investigating the association between ICS use and the development of gestational diabetes mellitus (GDM). The aims of the study are to determine whether the use of ICSs during pregnancy increases the risk of PIH and GDM in women.We conducted 2 nested case-control studies utilizing the nationwide insurance claims database of the Health Insurance Review and Assessment Service (Seoul, Republic of Korea), in which 1,306,281 pregnant women who delivered between January 1, 2009 and December 31, 2011 were included. Among them, PIH cases and GDM cases were identified and matched controls were included. Conditional logistic regression analyses adjusted by other concomitant drugs use during and before pregnancy and confounding covariates including comorbidities were performed.Total 43,908 PIH cases and 219,534 controls, and 34,190 GDM cases and 170,934 control subjects were identified. When other concomitant drugs use during pregnancy was adjusted, ICS use was associated with an increased rate of PIH (adjusted odds ratio, 1.40 [95% CI, 1.05-1.87]). ICS medication possession ratios and cumulative doses were associated with an increased risk of PIH. However, the statistical significance was not found in other models. In both unadjusted and adjusted multivariable models, ICSs use was not associated with increase in the risk of GDM.ICSs use is not associated with an increased risk of PIH and GDM. PMID:27258493

  2. Low-Grade Inflammation, Oxidative Stress and Risk of Invasive Post-Menopausal Breast Cancer - A Nested Case-Control Study from the Malmo Diet and Cancer Cohort.

    Directory of Open Access Journals (Sweden)

    Joana A Dias

    Full Text Available Although cancer promotes inflammation, the role of inflammation in tumor-genesis is less well established. The aim was to examine if low-grade inflammation is related to post-menopausal breast cancer risk, and if obesity modifies this association.In the Malmö Diet and Cancer cohort, a nested case-control study was defined among 8,513 women free of cancer and aged 55-73 years at baseline (1991-96; 459 were diagnosed with invasive breast cancer during follow-up (until December 31st, 2010. In laboratory analyses of blood from 446 cases, and 885 controls (matched on age and date of blood sampling we examined systemic inflammation markers: oxidized (ox-LDL, interleukin (IL-1β, IL-6, IL-8, tumor necrosis factor (TNF-α, white blood cells, lymphocytes and neutrophils. Odds ratios (OR and 95% confidence intervals (CI for breast cancer risk was calculated using multivariable conditional logistic regression.Inverse associations with breast cancer were seen in fully-adjusted models, for 2nd and 3rd tertiles of ox-LDL, OR (95% CI: 0.65 (0.47-0.90, 0.63 (0.45-0.89 respectively, p-trend = 0.01; and for the 3rd tertile of TNF-α, 0.65 (0.43-0.99, p-trend = 0.04. In contrast, those in the highest IL-1β category had higher risk, 1.71 (1.05-2.79, p-trend = 0.01. Obesity did not modify associations between inflammation biomarkers and breast cancer.Our study does not suggest that low-grade inflammation increase the risk of post-menopausal breast cancer.

  3. Acrylamide and glycidamide hemoglobin adduct levels and endometrial cancer risk: A nested case-control study in nonsmoking postmenopausal women from the EPIC cohort.

    Science.gov (United States)

    Obón-Santacana, Mireia; Freisling, Heinz; Peeters, Petra H; Lujan-Barroso, Leila; Ferrari, Pietro; Boutron-Ruault, Marie-Christine; Mesrine, Sylvie; Baglietto, Laura; Turzanski-Fortner, Renee; Katzke, Verena A; Boeing, Heiner; Quirós, J Ramón; Molina-Portillo, Elena; Larrañaga, Nerea; Chirlaque, María-Dolores; Barricarte, Aurelio; Khaw, Kay-Tee; Wareham, Nick; Travis, Ruth C; Merritt, Melissa A; Gunter, Marc J; Trichopoulou, Antonia; Lagiou, Pagona; Naska, Androniki; Palli, Domenico; Sieri, Sabina; Tumino, Rosario; Fiano, Valentina; Galassom, Rocco; Bueno-de-Mesquita, H B As; Onland-Moret, N Charlotte; Idahl, Annika; Lundin, Eva; Weiderpass, Elisabete; Vesper, Hubert; Riboli, Elio; Duell, Eric J

    2016-03-01

    Acrylamide, classified in 1994 by IARC as "probably carcinogenic to humans," was discovered in 2002 in some heat-treated, carbohydrate-rich foods. Four prospective studies have evaluated the association between dietary acrylamide intake and endometrial cancer (EC) risk with inconsistent results. The purpose of this nested case-control study, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, was to evaluate, for the first time, the association between hemoglobin adducts of acrylamide (HbAA) and glycidamide (HbGA) and the risk of developing EC in non-smoking postmenopausal women. Hemoglobin adducts were measured in red blood cells by HPLC/MS/MS. Four exposure variables were evaluated: HbAA, HbGA, their sum (HbAA+HbGA), and their ratio (HbGA/HbAA). The association between hemoglobin adducts and EC was evaluated using unconditional multivariable logistic regression models, and included 383 EC cases (171 were type-I EC), and 385 controls. Exposure variables were analyzed in quintiles based on control distributions. None of the biomarker variables had an effect on overall EC (HRHbAA;Q5vsQ1 : 0.84, 95%CI: 0.49-1.48; HRHbGA;Q5vsQ1 : 0.94, 95%CI: 0.54-1.63) or type-I EC risk. Additionally, none of the subgroups investigated (BMI acrylamide or glycidamide were not associated with EC or type-I EC risk in 768 nonsmoking postmenopausal women from the EPIC cohort.

  4. Bridging ImmunoGenomic Data Analysis Workflow Gaps (BIGDAWG): An integrated case-control analysis pipeline.

    Science.gov (United States)

    Pappas, Derek J; Marin, Wesley; Hollenbach, Jill A; Mack, Steven J

    2016-03-01

    Bridging ImmunoGenomic Data-Analysis Workflow Gaps (BIGDAWG) is an integrated data-analysis pipeline designed for the standardized analysis of highly-polymorphic genetic data, specifically for the HLA and KIR genetic systems. Most modern genetic analysis programs are designed for the analysis of single nucleotide polymorphisms, but the highly polymorphic nature of HLA and KIR data require specialized methods of data analysis. BIGDAWG performs case-control data analyses of highly polymorphic genotype data characteristic of the HLA and KIR loci. BIGDAWG performs tests for Hardy-Weinberg equilibrium, calculates allele frequencies and bins low-frequency alleles for k×2 and 2×2 chi-squared tests, and calculates odds ratios, confidence intervals and p-values for each allele. When multi-locus genotype data are available, BIGDAWG estimates user-specified haplotypes and performs the same binning and statistical calculations for each haplotype. For the HLA loci, BIGDAWG performs the same analyses at the individual amino-acid level. Finally, BIGDAWG generates figures and tables for each of these comparisons. BIGDAWG obviates the error-prone reformatting needed to traffic data between multiple programs, and streamlines and standardizes the data-analysis process for case-control studies of highly polymorphic data. BIGDAWG has been implemented as the bigdawg R package and as a free web application at bigdawg.immunogenomics.org.

  5. A pooled analysis of case-control studies of thyroid cancer - I. Methods

    NARCIS (Netherlands)

    Negri, E; Ron, E; Franceschi, S; Dal Maso, L; Mark, SD; Preston-Martin, S; McTiernan, A; Kolonel, L; Kleinerman, R; Land, C; Jin, F; Wingren, G; Galanti, MR; Hallquist, A; Glattre, E; Lund, E; Levi, F; Linos, D; Braga, C; La Vecchia, C

    1999-01-01

    Objective. Because the etiology of thyroid cancer is not well described, we conducted a pooled analysis of all published case-control studies, as well as two identified unpublished studies. This paper describes the major characteristics of the 14 studies included in the analysis, as well as the stat

  6. Excess body iron and the risk of type 2 diabetes mellitus: a nested case-control in the PREDIMED (PREvention with MEDiterranean Diet) study.

    Science.gov (United States)

    Arija, Victoria; Fernández-Cao, José C; Basora, Josep; Bulló, Mònica; Aranda, Nuria; Estruch, Ramón; Martínez-González, Miguel A; Salas-Salvadó, Jordi

    2014-12-14

    A prospective nested case-control study within the PREvention with MEDiterranean Diet (PREDIMED) was conducted to evaluate the relationship between excess body Fe (measured as serum ferritin (SF), soluble transferrin receptor (sTfR) and sTfR:ferritin ratio) and the risk of type 2 diabetes mellitus (T2DM) in a Mediterranean population at a high risk of CVD, without T2DM at the start of the study. The study contained 459 subjects, 153 with incident T2DM (cases) and 306 without incident T2DM (controls). The follow-up period was for 6.0 (interquartile range 3.9-6.5) years. For each incident diabetic subject, two subjects were selected as controls who were matched broadly for age as well as for sex, intervention group and BMI. We observed a relationship between SF values >257 μg/l in males and >139 μg/l in females and the risk of T2DM, following adjustment in the conditional logistic regression model for high-sensitivity C-reactive protein, fasting glucose and other components of the metabolic syndrome (OR 3.62, 95% CI 1.32, 19.95; P= 0.022). We also found an association between low sTfR:ferritin ratio levels and the incidence of T2DM (OR 3.02, 95% CI 1.09, 8.39; P= 0.042), but no association with sTfR (OR 1.29, 95% CI 0.51, 3.23; P= 0.722). Oxidative stress has been hypothesised to contribute to the development of insulin resistance and β-cell dysfunction, the two key events in the clinical development of T2DM. Following adjustment for other risk factors for T2DM, excess body Fe (measured as SF and sTfR:ferritin ratio) was associated with an increased risk of developing T2DM in a Mediterranean population at a high risk of CVD.

  7. Interactions between genetic admixture, ethnic identity, APOE genotype and dementia prevalence in an admixed Cuban sample; a cross-sectional population survey and nested case-control study

    Directory of Open Access Journals (Sweden)

    Hernandez Milagros

    2011-03-01

    Full Text Available Abstract Background The prevalence and incidence of dementia are low in Nigeria, but high among African-Americans. In these populations there is a high frequency of the risk-conferring APOE-e4 allele, but the risk ratio is less than in Europeans. In an admixed population of older Cubans we explored the effects of ethnic identity and genetic admixture on APOE genotype, its association with dementia, and dementia prevalence. Methods A cross-sectional catchment area survey of 2928 residents aged 65 and over, with a nested case-control study of individual admixture. Dementia diagnosis was established using 10/66 Dementia and DSM-IV criteria. APOE genotype was determined in 2520 participants, and genetic admixture in 235 dementia cases and 349 controls. Results Mean African admixture proportions were 5.8% for 'white', 28.6% for 'mixed' and 49.6% for 'black' ethnic identities. All three groups were substantially admixed with considerable overlap. African admixture was linearly related to number of APOE-e4 alleles. One or more APOE-e4 alleles was associated with dementia in 'white' and 'black' but not 'mixed' groups but neither this, nor the interaction between APOE-e4 and African admixture (PR 0.52, 95% CI 0.13-2.08 were statistically significant. Neither ethnic identity nor African admixture was associated with dementia prevalence when assessed separately. However, considering their joint effects African versus European admixture was independently associated with a higher prevalence, and 'mixed' or 'black' identity with a lower prevalence of dementia. Conclusions APOE genotype is strongly associated with ancestry. Larger studies are needed to confirm whether the concentration of the high-risk allele in those with African ancestry is offset by an attenuation of its effect. Counter to our hypothesis, African admixture may be associated with higher risk of dementia. Although strongly correlated, effects of admixture and ethnic identity should be

  8. Early Urinary Markers of Diabetic Kidney Disease: A Nested Case-Control Study From the Diabetes Control and Complications Trial (DCCT)

    Science.gov (United States)

    Kern, Elizabeth O; Erhard, Penny; Sun, Wanjie; Genuth, Saul; Weiss, Miriam F

    2010-01-01

    Background Urinary markers were tested as predictors of macroalbuminuria or microalbuminuria in type 1 diabetes. Study Design Nested case:control of participants in the Diabetes Control and Complications Trial (DCCT) Setting & Participants Eighty-seven cases of microalbuminuria were matched to 174 controls in a 1:2 ratio, while 4 cases were matched to 4 controls in a 1:1 ratio, resulting in 91 cases and 178 controls for microalbuminuria. Fifty-five cases of macroalbuminuria were matched to 110 controls in a 1:2 ratio. Controls were free of micro/macroalbuminuria when their matching case first developed micro/macroalbuminuria. Predictors Urinary N-acetyl-β-D-glucosaminidase, pentosidine, AGE fluorescence, albumin excretion rate (AER) Outcomes Incident microalbuminuria (two consecutive annual AER > 40 but 300 mg/day) Measurements Stored urine samples from DCCT entry, and 1–9 years later when macroalbuminuria or microalbuminuria occurred, were measured for the lysosomal enzyme, N-acetyl-β-D-glucosaminidase, and the advanced glycosylation end-products (AGEs) pentosidine and AGE-fluorescence. AER and adjustor variables were obtained from the DCCT. Results Sub-microalbuminuric levels of AER at baseline independently predicted microalbuminuria (adjusted OR 1.83; p<.001) and macroalbuminuria (adjusted OR 1.82; p<.001). Baseline N-acetyl-β-D-glucosaminidase independently predicted macroalbuminuria (adjusted OR 2.26; p<.001), and microalbuminuria (adjusted OR 1.86; p<.001). Baseline pentosidine predicted macroalbuminuria (adjusted OR 6.89; p=.002). Baseline AGE fluorescence predicted microalbuminuria (adjusted OR 1.68; p=.02). However, adjusted for N-acetyl-β-D-glucosaminidase, pentosidine and AGE-fluorescence lost predictive association with macroalbuminuria and microalbuminuria, respectively. Limitations Use of angiotensin converting-enzyme inhibitors was not directly ascertained, although their use was proscribed during the DCCT. Conclusions Early in type 1 diabetes

  9. Serum α-tocopherol and γ-tocopherol concentrations and prostate cancer risk in the PLCO Screening Trial: a nested case-control study.

    Directory of Open Access Journals (Sweden)

    Stephanie J Weinstein

    Full Text Available BACKGROUND: Vitamin E compounds exhibit prostate cancer preventive properties experimentally, but serologic investigations of tocopherols, and randomized controlled trials of supplementation in particular, have been inconsistent. Many studies suggest protective effects among smokers and for aggressive prostate cancer, however. METHODS: We conducted a nested case-control study of serum α-tocopherol and γ-tocopherol and prostate cancer risk in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, with 680 prostate cancer cases and 824 frequency-matched controls. Multivariate-adjusted, conditional logistic regression models were used to estimate odds ratios (OR and 95% confidence intervals (CIs for tocopherol quintiles. RESULTS: Serum α-tocopherol and γ-tocopherol were inversely correlated (r = -0.24, p<0.0001. Higher serum α-tocopherol was associated with significantly lower prostate cancer risk (OR for the highest vs. lowest quintile = 0.63, 95% CI 0.44-0.92, p-trend 0.05. By contrast, risk was non-significantly elevated among men with higher γ-tocopherol concentrations (OR for the highest vs. lowest quintile = 1.35, 95% CI 0.92-1.97, p-trend 0.41. The inverse association between prostate cancer and α-tocopherol was restricted to current and recently former smokers, but was only slightly stronger for aggressive disease. By contrast, the increased risk for higher γ-tocopherol was more pronounced for less aggressive cancers. CONCLUSIONS: Our findings indicate higher α-tocopherol status is associated with decreased risk of developing prostate cancer, particularly among smokers. Although two recent controlled trials did not substantiate an earlier finding of lower prostate cancer incidence and mortality in response to supplementation with a relatively low dose of α-tocopherol, higher α-tocopherol status may be beneficial with respect to prostate cancer risk among smokers. Determining what stage of prostate cancer

  10. Early elevation of serum MMP-3 and MMP-12 predicts protection from World Trade Center-lung injury in New York City Firefighters: a nested case-control study.

    Directory of Open Access Journals (Sweden)

    Sophia Kwon

    Full Text Available OBJECTIVE: After 9/11/2001, some Fire Department of New York (FDNY workers had excessive lung function decline. We hypothesized that early serum matrix metalloproteinases (MMP expression predicts World Trade Center-Lung Injury (WTC-LI years later. METHODS: This is a nested case-control analysis of never-smoking male firefighters with normal pre-exposure Forced Expiratory Volume in one second (FEV1 who had serum drawn up to 155 days post 9/11/2001. Serum MMP-1, 2,3,7,8, 9, 12 and 13 were measured. Cases of WTC-LI (N = 70 were defined as having an FEV1 one standard deviation below the mean (FEV1 ≤ 77% at subspecialty pulmonary evaluation (SPE which was performed 32 months (IQR 21-53 post-9/11. Controls (N = 123 were randomly selected. We modeled MMP's ability as a predictor of cases status with logistic regression adjusted for time to blood draw, exposure intensity, weight gain and pre-9/11 FEV1. RESULTS: Each log-increase in MMP-3 and MMP-12 showed reduced odds of developing WTC-LI by 73% and 54% respectively. MMP-3 and MMP-12 consistently clustered together in cases, controls, and the cohort. Increasing time to blood draw significantly and independently increased the risk of WTC-LI. CONCLUSIONS: Elevated serum levels of MMP-3 and MMP-12 reduce the risk of developing WTC-LI. At any level of MMP-3 or 12, increased time to blood draw is associated with a diminished protective effect.

  11. Early Elevation of Serum MMP-3 and MMP-12 Predicts Protection from World Trade Center-Lung Injury in New York City Firefighters: A Nested Case-Control Study

    Science.gov (United States)

    Echevarria, Ghislaine C.; Comfort, Ashley L.; Naveed, Bushra; Prezant, David J.; Rom, William N.; Nolan, Anna

    2013-01-01

    Objective After 9/11/2001, some Fire Department of New York (FDNY) workers had excessive lung function decline. We hypothesized that early serum matrix metalloproteinases (MMP) expression predicts World Trade Center-Lung Injury (WTC-LI) years later. Methods This is a nested case-control analysis of never-smoking male firefighters with normal pre-exposure Forced Expiratory Volume in one second (FEV1) who had serum drawn up to 155 days post 9/11/2001. Serum MMP-1, 2,3,7,8, 9, 12 and 13 were measured. Cases of WTC-LI (N = 70) were defined as having an FEV1 one standard deviation below the mean (FEV1≤77%) at subspecialty pulmonary evaluation (SPE) which was performed 32 months (IQR 21–53) post-9/11. Controls (N = 123) were randomly selected. We modeled MMP's ability as a predictor of cases status with logistic regression adjusted for time to blood draw, exposure intensity, weight gain and pre-9/11 FEV1. Results Each log-increase in MMP-3 and MMP-12 showed reduced odds of developing WTC-LI by 73% and 54% respectively. MMP-3 and MMP-12 consistently clustered together in cases, controls, and the cohort. Increasing time to blood draw significantly and independently increased the risk of WTC-LI. Conclusions Elevated serum levels of MMP-3 and MMP-12 reduce the risk of developing WTC-LI. At any level of MMP-3 or 12, increased time to blood draw is associated with a diminished protective effect. PMID:24146820

  12. A Note on Penalized Regression Spline Estimation in the Secondary Analysis of Case-Control Data

    KAUST Repository

    Gazioglu, Suzan

    2013-05-25

    Primary analysis of case-control studies focuses on the relationship between disease (D) and a set of covariates of interest (Y, X). A secondary application of the case-control study, often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated due to the case-control sampling, and to avoid the biased sampling that arises from the design, it is typical to use the control data only. In this paper, we develop penalized regression spline methodology that uses all the data, and improves precision of estimation compared to using only the controls. A simulation study and an empirical example are used to illustrate the methodology.

  13. Lung cancer risk among bricklayers in a pooled analysis of case-control studies.

    NARCIS (Netherlands)

    Consonni, Dario; De Matteis, Sara; Olsson, Ann; Pesch, Beate; Kromhout, Hans; Straif, Kurt; Brüning, Thomas

    2014-01-01

    OBJECTIVES: Bricklayers may be exposed to several lung carcinogens, including crystalline silica and asbestos. Previous studies reported an excess of lung cancer among these workers. We examined lung cancer risk among bricklayers within SYNERGY, a large international pooled analysis of case-control

  14. Robust estimation for homoscedastic regression in the secondary analysis of case-control data

    KAUST Repository

    Wei, Jiawei

    2012-12-04

    Primary analysis of case-control studies focuses on the relationship between disease D and a set of covariates of interest (Y, X). A secondary application of the case-control study, which is often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated owing to the case-control sampling, where the regression of Y on X is different from what it is in the population. Previous work has assumed a parametric distribution for Y given X and derived semiparametric efficient estimation and inference without any distributional assumptions about X. We take up the issue of estimation of a regression function when Y given X follows a homoscedastic regression model, but otherwise the distribution of Y is unspecified. The semiparametric efficient approaches can be used to construct semiparametric efficient estimates, but they suffer from a lack of robustness to the assumed model for Y given X. We take an entirely different approach. We show how to estimate the regression parameters consistently even if the assumed model for Y given X is incorrect, and thus the estimates are model robust. For this we make the assumption that the disease rate is known or well estimated. The assumption can be dropped when the disease is rare, which is typically so for most case-control studies, and the estimation algorithm simplifies. Simulations and empirical examples are used to illustrate the approach.

  15. Oral Bisphosphonates and Upper Gastrointestinal Cancer Risks in Asians with Osteoporosis: A Nested Case-Control Study Using National Retrospective Cohort Sample Data from Korea.

    Directory of Open Access Journals (Sweden)

    Sun-Young Jung

    Full Text Available Bisphosphonate can irritate the gastrointestinal mucosa and increase the risk of esophageal or gastric cancer. The relatively high prevalence of upper gastrointestinal cancers and the widespread use of bisphosphonate in Korea call for further investigation. We conducted a case-control study to evaluate the risk of esophageal or gastric cancer after exposure to oral bisphosphonates in Korean patients with osteoporosis.We used the National Health Insurance Service-National Sample Cohort database of Korea from 2002 to 2013. Among osteoporotic patients (>40 years, cases were defined as incident diagnosis of esophageal or gastric cancer between 2006 and 2013. For each case, four controls were matched for age, sex, and income level by type of insurance. We categorized bisphosphonate use as non-user, recent user, past user, and past and recent user, depending on prescription in two periods (1 to 2 years and 2 to 4 years prior to the index date. We also assessed the duration of bisphosphonate use by measuring cumulative duration of exposure (CDE. To examine the association between oral bisphosphonates and esophageal or gastric cancer, we estimated adjusted odds ratios (aORs and 95% confidence intervals (CIs using conditional logistic regression analysis, adjusting for concomitant diseases.A total of 1,708 cases and 6,832 controls were identified. The aORs (95% CIs of recent, past, and continuous bisphosphonate use compared to non-users were 1.18 (0.93-1.51, 1.04 (0.83-1.29, and 1.25 (0.95-1.58, respectively. In addition, no significant association was observed by CDE, even when different outcome definitions were applied.This study did not prove an increased risk of esophageal or gastric cancer risk associated with bisphosphonate use, with respect to both risk windows and duration of exposure, in an Asian population-based, real-world setting.

  16. Powerful SNP-Set Analysis for Case-Control Genome-wide Association Studies

    OpenAIRE

    Wu, Michael C.; Kraft, Peter; Epstein, Michael P.; Deanne M Taylor; Chanock, Stephen J.; Hunter, David J.; Lin, Xihong

    2010-01-01

    GWAS have emerged as popular tools for identifying genetic variants that are associated with disease risk. Standard analysis of a case-control GWAS involves assessing the association between each individual genotyped SNP and disease risk. However, this approach suffers from limited reproducibility and difficulties in detecting multi-SNP and epistatic effects. As an alternative analytical strategy, we propose grouping SNPs together into SNP sets on the basis of proximity to genomic features su...

  17. Nested sampling applied in Bayesian room-acoustics decay analysis.

    Science.gov (United States)

    Jasa, Tomislav; Xiang, Ning

    2012-11-01

    Room-acoustic energy decays often exhibit single-rate or multiple-rate characteristics in a wide variety of rooms/halls. Both the energy decay order and decay parameter estimation are of practical significance in architectural acoustics applications, representing two different levels of Bayesian probabilistic inference. This paper discusses a model-based sound energy decay analysis within a Bayesian framework utilizing the nested sampling algorithm. The nested sampling algorithm is specifically developed to evaluate the Bayesian evidence required for determining the energy decay order with decay parameter estimates as a secondary result. Taking the energy decay analysis in architectural acoustics as an example, this paper demonstrates that two different levels of inference, decay model-selection and decay parameter estimation, can be cohesively accomplished by the nested sampling algorithm. PMID:23145609

  18. Plasma carotenoids, vitamin C, retinol and tocopherols levels and pancreatic cancer risk within the European Prospective Investigation into Cancer and Nutrition: a nested case-control study: plasma micronutrients and pancreatic cancer risk.

    Science.gov (United States)

    Jeurnink, Suzanne M; Ros, Martine M; Leenders, Max; van Duijnhoven, Franzel J B; Siersema, Peter D; Jansen, Eugene H J M; van Gils, Carla H; Bakker, Marije F; Overvad, Kim; Roswall, Nina; Tjønneland, Anne; Boutron-Ruault, Marie-Christine; Racine, Antoine; Cadeau, Claire; Grote, Verena; Kaaks, Rudolf; Aleksandrova, Krasimira; Boeing, Heiner; Trichopoulou, Antonia; Benetou, Vasiliki; Valanou, Elisavet; Palli, Domenico; Krogh, Vittorio; Vineis, Paolo; Tumino, Rosario; Mattiello, Amalia; Weiderpass, Elisabete; Skeie, Guri; Castaño, José María Huerta; Duell, Eric J; Barricarte, Aurelio; Molina-Montes, Esther; Argüelles, Marcial; Dorronsoro, Mire; Johansen, Dorthe; Lindkvist, Björn; Sund, Malin; Crowe, Francesca L; Khaw, Kay-Tee; Jenab, Mazda; Fedirko, Veronika; Riboli, E; Bueno-de-Mesquita, H B

    2015-03-15

    Evidence of a protective effect of several antioxidants and other nutrients on pancreatic cancer risk is inconsistent. The aim of this study was to investigate the association for prediagnostic plasma levels of carotenoids, vitamin C, retinol and tocopherols with risk of pancreatic cancer in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC). 446 incident exocrine pancreatic cancer cases were matched to 446 controls by age at blood collection, study center, sex, date and time of blood collection, fasting status and hormone use. Plasma carotenoids (α- and β-carotene, lycopene, β-cryptoxanthin, canthaxanthin, zeaxanthin and lutein), α- and γ-tocopherol and retinol were measured by reverse phase high-performance liquid chromatography and plasma vitamin C by a colorimetric assay. Incidence rate ratios (IRRs) with 95% confidence intervals (95%CIs) for pancreatic cancer risk were estimated using a conditional logistic regression analysis, adjusted for smoking status, smoking duration and intensity, waist circumference, cotinine levels and diabetes status. Inverse associations with pancreatic cancer risk were found for plasma β-carotene (IRR highest vs. lowest quartile 0.52, 95%CI 0.31-0.88, p for trend = 0.02), zeaxanthin (IRR highest vs. lowest quartile 0.53, 95%CI 0.30-0.94, p for trend = 0.06) and α-tocopherol (IRR highest vs. lowest quartile 0.62, 95%CI 0.39-0.99, p for trend = 0.08. For α- and β-carotene, lutein, sum of carotenoids and γ-tocopherol, heterogeneity between geographical regions was observed. In conclusion, our results show that higher plasma concentrations of β-carotene, zeaxanthin and α-tocopherol may be inversely associated with risk of pancreatic cancer, but further studies are warranted.

  19. Concurrent use of diuretics, angiotensin converting enzyme inhibitors, and angiotensin receptor blockers with non-steroidal anti-inflammatory drugs and risk of acute kidney injury: nested case-control study

    Science.gov (United States)

    Lapi, Francesco; Azoulay, Laurent; Yin, Hui; Nessim, Sharon J

    2013-01-01

    Objectives To assess whether a double therapy combination consisting of diuretics, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers with addition of non-steroidal anti-inflammatory drugs (NSAIDs) and the triple therapy combination of two of the aforementioned antihypertensive drugs to which NSAIDs are added are associated with an increased risk of acute kidney injury. Design Retrospective cohort study using nested case-control analysis. Setting General practices contributing data to the UK Clinical Practice Research Datalink linked to the Hospital Episodes Statistics database. Participants A cohort of 487 372 users of antihypertensive drugs. Main outcome measures Rate ratios with 95% confidence intervals of acute kidney injury associated with current use of double and triple therapy combinations of antihypertensive drugs with NSAIDs. Results During a mean follow-up of 5.9 (SD 3.4) years, 2215 cases of acute kidney injury were identified (incidence rate 7/10 000 person years). Overall, current use of a double therapy combination containing either diuretics or angiotensin converting enzyme inhibitors or angiotensin receptor blockers with NSAIDs was not associated with an increased rate of acute kidney injury. In contrast, current use of a triple therapy combination was associated with an increased rate of acute kidney injury (rate ratio 1.31, 95% confidence interval 1.12 to 1.53). In secondary analyses, the highest risk was observed in the first 30 days of use (rate ratio 1.82, 1.35 to 2.46). Conclusions A triple therapy combination consisting of diuretics with angiotensin converting enzyme inhibitors or angiotensin receptor blockers and NSAIDs was associated with an increased risk of acute kidney injury. The risk was greatest at the start of treatment. Although antihypertensive drugs have cardiovascular benefits, vigilance may be warranted when they are used concurrently with NSAIDs. PMID:23299844

  20. A nested case-control study of intrauterine exposure to persistent organochlorine pollutants in relation to risk of type 1 diabetes.

    OpenAIRE

    Anna Rignell-Hydbom; Maria Elfving; Ivarsson, Sten A.; Christian Lindh; Jönsson, Bo A. G.; Per Olofsson; Lars Rylander

    2010-01-01

    BACKGROUND: The incidence of type 1 diabetes in Europe is increasing at a rate of about 3% per year and there is also an increasing incidence throughout the world. Type 1 diabetes is a complex disease caused by multiple genetic and environmental factors. Persistent organochlorine pollutants (POPs) have been suggested as a triggering factor for developing childhood type 1 diabetes. The aim of this case-control study was to assess possible impacts of in utero exposure to POPs on type 1 diabetes...

  1. A FORTRAN program for stratified analysis of data from case-control studies.

    Science.gov (United States)

    Koepsell, T D

    1983-04-01

    Stratification of study subjects by one or more covariates is a commonly accepted method for dealing with confounding and effect modification in epidemiologic case-control studies. A flexible FORTRAN program is described which facilitates simultaneous stratification by several covariates and which produces summary odds ratio estimates and chi-square statistics by the Mantel-Haenszel method. It also facilitates detection of effect modification by each covariate considered individually. Straightforward means are provided for the user to modify input data before analysis or to exclude certain subjects from analysis, simulating such capabilities in larger statistical packages.

  2. A nested case-control study of adjuvant hormonal therapy persistence and compliance, and early breast cancer recurrence in women with stage I-III breast cancer

    OpenAIRE

    Bennett, Kathleen

    2013-01-01

    PUBLISHED Background: Non-persistence and non-compliance are common in women prescribed hormonal therapy for breast cancer, but little is known about their influence on recurrence. Methods: A nested case–control study of associations between hormonal therapy non-persistence and non-compliance and the risk of early recurrence in women with stage I–III breast cancer was undertaken. Cases, defined as women with a breast cancer recurrence within 4 years of hormonal therapy initiati...

  3. Structural analysis of raw and commercial farm edible bird nests.

    Science.gov (United States)

    Kew, P E; Wong, S F; Lim, P K; Mak, J W

    2014-03-01

    Edible bird nests (EBNs) are consumed worldwide for various health benefits. EBNs are nests built from the saliva of swiftlets of Aerodramus species. The global market for EBNs is on the rise, especially from Hong Kong and mainland China. In the past, EBNs were harvested mainly from natural caves; however in the recent years, there has been a rapid growth of swiftlet farming. Little is known about the actual composition of EBNs except for protein, carbohydrate, ash and lipid contents, amino acids, vitamins and macro/ micronutrients. Besides the biochemical components of EBNs, are there any other structures that are associated with EBNs? This paper reports on the structural analysis of raw unprocessed farm and processed commercial EBNs. The raw EBNs were purchased from swiftlet farms in five locations in Peninsula Malaysia: Kuala Sanglang (Perlis; 6° 16' 0"N, 100° 12' 0"E), Pantai Remis (Perak; 4º 27' 0" N, 100º 38' 0" E), Kluang (Johor; 02º 012 303N 103º 192 583E), Kajang (Selangor; 2º 59' 0"N, 101º 47' 0"E) and Kota Bharu (Kelantan; 6º 8' 0"N, 102º 15' 0"E). The commercial nests were purchased from five different Chinese traditional medicinal shops (Companies A-E). A portion of each EBN was randomly broken into small fragments, attached to carbon tape and coated with gold and palladium particles for examination and photography under a scanning electron microscope. Structural analysis revealed the presence of mites, fungi, bacteria and feather strands on both the raw and commercial nests. Mite eggshells and faecal pellets, and body parts of other arthropods were seen only in the raw nests. The commercial nests had a variety of unidentified structures and substances coated on the nests' surfaces that were not found on the raw nests. The presence of these contaminants may jeopardise the quality of EBNs and pose health risks to consumers. Further identification of the mites and their allergens, fungi and bacteria are on-going and will be reported separately

  4. Death of a Son is Associated With Risk of Suicide Among Parous Women in Taiwan: A Nested Case-Control Study

    OpenAIRE

    Chen, Chih-Cheng; Kuo, Chien-Chun; Wu, Trong-Neng; Yang, Chun-Yuh

    2012-01-01

    Background The impact of the sex of a deceased child on maternal suicide has not been studied. We examined whether the death of a child, especially a son, increased the risk of suicide among parous Taiwanese women. Methods This matched case-control study was done within a cohort of 1 292 462 Taiwanese women who experienced a first and singleton childbirth between 1 January 1978 and 31 December 1987 and were followed up until 31 December 2008. From the cohort, 2701 suicide cases were identifie...

  5. The use of the bootstrap in the analysis of case-control studies with missing data

    DEFF Research Database (Denmark)

    Siersma, Volkert Dirk; Johansen, Christoffer

    2004-01-01

    nonparametric bootstrap, bootstrap confidence intervals, missing values, multiple imputation, matched case-control study......nonparametric bootstrap, bootstrap confidence intervals, missing values, multiple imputation, matched case-control study...

  6. A nested case-control study of intrauterine exposure to persistent organochlorine pollutants in relation to risk of type 1 diabetes.

    Directory of Open Access Journals (Sweden)

    Anna Rignell-Hydbom

    Full Text Available BACKGROUND: The incidence of type 1 diabetes in Europe is increasing at a rate of about 3% per year and there is also an increasing incidence throughout the world. Type 1 diabetes is a complex disease caused by multiple genetic and environmental factors. Persistent organochlorine pollutants (POPs have been suggested as a triggering factor for developing childhood type 1 diabetes. The aim of this case-control study was to assess possible impacts of in utero exposure to POPs on type 1 diabetes. METHODOLOGY/ PRINCIPAL FINDINGS: The study was performed as a case-control study within a biobank in Malmö, a city located in the Southern part of Sweden. The study included 150 cases (children who had their diagnosis mostly before 18 years of age and 150 controls, matched for gender and day of birth. 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153 and the major DDT metabolite 1,1-dichloro-2,2-bis (p-chlorophenyl-ethylene (p,p'-DDE were used as a biomarkers for POP exposure. When comparing the quartile with the highest maternal serum concentrations of PCB-153 with the other quartiles, an odds ratio (OR of 0.73 (95% confidence interval [CI] 0.42, 1.27 was obtained. Similar results was obtained for p,p'-DDE (OR 0.56, 95% CI 0.29, 1.08. CONCLUSIONS: The hypothesis that in utero exposure to POPs will trigger the risk for developing type 1 diabetes was not supported by the results. The risk estimates did, although not statistically significant, go in the opposite direction. However, it is not reasonable to believe that exposure to POPs should protect against type 1 diabetes.

  7. Analysis of Case-Control Studies of Genetic and Environmental Factors With Missing Genetic Information and Haplotype-phase Ambiguity

    OpenAIRE

    Spinka, Christine; Carroll, Raymond J.; Chatterjee, Nilanjan

    2005-01-01

    Case-control studies of unrelated subjects are now widely used to study the role of genetic susceptibility and gene-environment interactions in the etiology of complex diseases. Exploiting an assumption of gene-environment independence, and treating the distribution of the environmental exposures to be completely nonparametric, Chatterjee and Carroll (2005) recently developed an efficient retrospective maximum-likelihood method for analysis of case-control studies. In this article, we develop...

  8. Incorporating single-locus tests into haplotype cladistic analysis in case-control studies.

    Directory of Open Access Journals (Sweden)

    Jianfeng Liu

    2007-03-01

    Full Text Available In case-control studies, genetic associations for complex diseases may be probed either with single-locus tests or with haplotype-based tests. Although there are different views on the relative merits and preferences of the two test strategies, haplotype-based analyses are generally believed to be more powerful to detect genes with modest effects. However, a main drawback of haplotype-based association tests is the large number of distinct haplotypes, which increases the degrees of freedom for corresponding test statistics and thus reduces the statistical power. To decrease the degrees of freedom and enhance the efficiency and power of haplotype analysis, we propose an improved haplotype clustering method that is based on the haplotype cladistic analysis developed by Durrant et al. In our method, we attempt to combine the strengths of single-locus analysis and haplotype-based analysis into one single test framework. Novel in our method is that we develop a more informative haplotype similarity measurement by using p-values obtained from single-locus association tests to construct a measure of weight, which to some extent incorporates the information of disease outcomes. The weights are then used in computation of similarity measures to construct distance metrics between haplotype pairs in haplotype cladistic analysis. To assess our proposed new method, we performed simulation analyses to compare the relative performances of (1 conventional haplotype-based analysis using original haplotype, (2 single-locus allele-based analysis, (3 original haplotype cladistic analysis (CLADHC by Durrant et al., and (4 our weighted haplotype cladistic analysis method, under different scenarios. Our weighted cladistic analysis method shows an increased statistical power and robustness, compared with the methods of haplotype cladistic analysis, single-locus test, and the traditional haplotype-based analyses. The real data analyses also show that our proposed method

  9. Incorporating single-locus tests into haplotype cladistic analysis in case-control studies.

    Science.gov (United States)

    Liu, Jianfeng; Papasian, Chris; Deng, Hong-Wen

    2007-03-23

    In case-control studies, genetic associations for complex diseases may be probed either with single-locus tests or with haplotype-based tests. Although there are different views on the relative merits and preferences of the two test strategies, haplotype-based analyses are generally believed to be more powerful to detect genes with modest effects. However, a main drawback of haplotype-based association tests is the large number of distinct haplotypes, which increases the degrees of freedom for corresponding test statistics and thus reduces the statistical power. To decrease the degrees of freedom and enhance the efficiency and power of haplotype analysis, we propose an improved haplotype clustering method that is based on the haplotype cladistic analysis developed by Durrant et al. In our method, we attempt to combine the strengths of single-locus analysis and haplotype-based analysis into one single test framework. Novel in our method is that we develop a more informative haplotype similarity measurement by using p-values obtained from single-locus association tests to construct a measure of weight, which to some extent incorporates the information of disease outcomes. The weights are then used in computation of similarity measures to construct distance metrics between haplotype pairs in haplotype cladistic analysis. To assess our proposed new method, we performed simulation analyses to compare the relative performances of (1) conventional haplotype-based analysis using original haplotype, (2) single-locus allele-based analysis, (3) original haplotype cladistic analysis (CLADHC) by Durrant et al., and (4) our weighted haplotype cladistic analysis method, under different scenarios. Our weighted cladistic analysis method shows an increased statistical power and robustness, compared with the methods of haplotype cladistic analysis, single-locus test, and the traditional haplotype-based analyses. The real data analyses also show that our proposed method has practical

  10. Association between Herpesviruses and Chronic Periodontitis: A Meta-Analysis Based on Case-Control Studies

    Science.gov (United States)

    Wong, May. Chun. Mei; Feng, Xi-Ping; Lu, Hai-Xia; Xu, Wei

    2015-01-01

    Objective Numerous studies have investigated the associations between herpesviruses and chronic periodontitis; however, the results remain controversial. To derive a more precise estimation, a meta-analysis on all available studies was performed to identify the association between herpesviruses and chronic periodontitis. Methods A computerized literature search was conducted in December 2014 to identify eligible case-control studies from the PUBMED and EMBASE databases according to inclusion and exclusion criteria. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were used to assess the association between herpesviruses and risk of chronic periodontitis. A fixed or random effects model was determined based on a heterogeneity test. Sensitivity analysis was conducted to investigate stability and reliability. Publication bias was investigated using the Begg rank correlation test and Egger's funnel plot. Results Ten eligible studies were included to investigate the association between Epstein–Barr virus (EBV) and chronic periodontitis. The results showed that EBV has a significant association with chronic periodontitis compared with periodontally healthy group (OR = 5.74, 95% CI = 2.53–13.00, Pherpesvirus 7 (HHV-7) and chronic periodontitis risk (OR = 1.00, 95% CI = 0.21–4.86). Conclusion The findings of this meta-analysis suggest that two members of the herpesvirus family, EBV and HCMV, are significantly associated with chronic periodontitis. There is insufficient evidence to support associations between HSV, HHV-7 and chronic periodontitis. PMID:26666412

  11. Analysis of Case-Control Association Studies: SNPs, Imputation and Haplotypes

    KAUST Repository

    Chatterjee, Nilanjan

    2009-11-01

    Although prospective logistic regression is the standard method of analysis for case-control data, it has been recently noted that in genetic epidemiologic studies one can use the "retrospective" likelihood to gain major power by incorporating various population genetics model assumptions such as Hardy-Weinberg-Equilibrium (HWE), gene-gene and gene-environment independence. In this article we review these modern methods and contrast them with the more classical approaches through two types of applications (i) association tests for typed and untyped single nucleotide polymorphisms (SNPs) and (ii) estimation of haplotype effects and haplotype-environment interactions in the presence of haplotype-phase ambiguity. We provide novel insights to existing methods by construction of various score-tests and pseudo-likelihoods. In addition, we describe a novel two-stage method for analysis of untyped SNPs that can use any flexible external algorithm for genotype imputation followed by a powerful association test based on the retrospective likelihood. We illustrate applications of the methods using simulated and real data. © Institute of Mathematical Statistics, 2009.

  12. Nested sampling as a tool for LISA data analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gair, Jonathan R [Institute of Astronomy, Madingley Road, CB3 0HA, Cambridge (United Kingdom); Feroz, Farhan; Graff, Philip; Hobson, Michael P [Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Babak, Stanislav; Petiteau, Antoine [Max-Planck-Institut fuer Gravitationsphysik, Am Muehlenberg 1, 14476, Potsdam (Germany); Porter, Edward K, E-mail: jgair@ast.cam.ac.u [APC, UMR 7164, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)

    2010-05-01

    Nested sampling is a technique for efficiently computing the probability of a data set under a particular hypothesis, also called the Bayesian Evidence or Marginal Likelihood, and for evaluating the posterior. MULTINEST is a multi-modal nested sampling algorithm which has been designed to efficiently explore and characterize posterior probability surfaces containing multiple secondary solutions. We have applied the MULTINEST algorithm to a number of problems in gravitational wave data analysis. In this article, we describe the algorithm and present results for several applications of the algorithm to analysis of mock LISA data. We summarise recently published results for a test case in which we searched for two non-spinning black hole binary merger signals in simulated LISA data. We also describe results obtained with MULTINEST in the most recent round of the Mock LISA Data Challenge (MLDC), in which the algorithm was used to search for and characterise both spinning supermassive black hole binary inspirals and bursts from cosmic string cusps. In all these applications, the algorithm found the correct number of signals and efficiently recovered the posterior probability distribution. Moreover, in most cases the waveform corresponding to the best a-posteriori parameters had an overlap in excess of 99% with the true signal.

  13. Nested sampling as a tool for LISA data analysis

    International Nuclear Information System (INIS)

    Nested sampling is a technique for efficiently computing the probability of a data set under a particular hypothesis, also called the Bayesian Evidence or Marginal Likelihood, and for evaluating the posterior. MULTINEST is a multi-modal nested sampling algorithm which has been designed to efficiently explore and characterize posterior probability surfaces containing multiple secondary solutions. We have applied the MULTINEST algorithm to a number of problems in gravitational wave data analysis. In this article, we describe the algorithm and present results for several applications of the algorithm to analysis of mock LISA data. We summarise recently published results for a test case in which we searched for two non-spinning black hole binary merger signals in simulated LISA data. We also describe results obtained with MULTINEST in the most recent round of the Mock LISA Data Challenge (MLDC), in which the algorithm was used to search for and characterise both spinning supermassive black hole binary inspirals and bursts from cosmic string cusps. In all these applications, the algorithm found the correct number of signals and efficiently recovered the posterior probability distribution. Moreover, in most cases the waveform corresponding to the best a-posteriori parameters had an overlap in excess of 99% with the true signal.

  14. Semantic Analysis of Virtual Classes and Nested Classes

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Virtual classes and nested classes are distinguishing features of BETA. Nested classes originated from Simula, but until recently they have not been part of main stream object- oriented languages. C++ has a restricted form of nested classes and they were included in Java 1.1. Virtual classes is the...... classes and parameterized classes have been made. Although virtual classes and nested classes have been used in BETA for more than a decade, their implementation has not been published. The purpose of this paper is to contribute to the understanding of virtual classes and nested classes by presenting the...

  15. Source attribution of human salmonellosis using a meta-analysis of case-control studies of sporadic infections

    DEFF Research Database (Denmark)

    Coutinho Calado Domingues, Ana Rita; Pires, Sara Monteiro; Hisham Beshara Halasa, Tariq;

    2012-01-01

    Salmonella is an important cause of human illness. Disease is frequently associated with foodborne transmission, but other routes of exposure are recognized. Identifying sources of disease is essential for prioritizing public health interventions. Numerous case-control studies of sporadic...... salmonellosis have been published, often using different methodologies and settings. Systematic reviews consist of a formal process for literature review focused on a research question. With the objective of identifying the most important risk factors for salmonellosis, we performed a systematic review of case......-control studies and a meta-analysis of obtained results. Thirty-five Salmonella case-control studies were identified. In the meta-analysis, heterogeneity between studies and possible sources of bias were investigated, and pooled odds ratios estimated. Results suggested that travel, predisposing factors, eating...

  16. Management of Esophageal Carcinoma Associated with Cirrhosis: A Retrospective Case-Control Analysis

    Directory of Open Access Journals (Sweden)

    Florence Trivin

    2009-01-01

    Full Text Available Objectives. Esophageal carcinoma and cirrhosis have the overlapping etiologic factors. Methods. In a retrospective analysis conducted in 2 Breton institutions we wanted to asses the frequency of this association and the outcome of these patients in a case-control study where each case (cirrhosis and esophageal cancer was paired with two controls (esophageal cancer. Results. In a 10-year period, we have treated 958 esophageal cancer patients; 26 (2.7% had a cirrhosis. The same treatments were proposed to the 2 groups; cases received nonsignificantly different radiation and chemotherapy dose than controls. Severe toxicities and deaths were more frequent among the cases. At the end of the treatment 58% of the cases and 67% of the controls were in complete remission; median and 2-year survival were not different between the 2 groups. All 4 Child-Pugh B class patients experienced severe side effects and 2 died during the treatment. Conclusions. This association is surprisingly infrequent in our population! Child-Pugh B patients had a dismal prognosis and a bad tolerance to radiochemotherapy; Child-Pugh A patients have the same tolerance and the same prognosis as controls and the evidence of a well-compensated cirrhosis has not modified our medical options.

  17. Tissue-type plasminogen activator and C-reactive protein in acute coronary heart disease. A nested case-control study

    DEFF Research Database (Denmark)

    Gram, J; Bladbjerg, E-M; Møller, L;

    2000-01-01

    .005) and it was present in both the 7-9 years follow-up cohort (CRP: P = 0.014; t-PA: P = 0.001) and the 15 years follow-up cohort (CRP: P = 0.027; t-PA: P = 0.012). The best predictor of CRP was t-PA, whilst the best predictor of t-PA was triglycerides. In a logistic regression analysis model, t-PA still came out...... as independent predictor of coronary heart disease, whilst such a significance disappeared for CRP. With the use of ROC curves we determined that AUC for t-PA was 0.62, and for CRP 0.59, indicating that none of these two analytes has a high prognostic power in predicting future coronary events in an initially...

  18. Maternal age and Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

    NARCIS (Netherlands)

    W.A. Rocca; C.M. van Duijn (Cock); D.G. Clayton (David); V. Chandra; L. Fratiglioni (Laura); A.B. Graves; A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; J.A. Mortimer; S.L. Shalat; H. Soininen; A. Hofman (Albert)

    1991-01-01

    textabstractTo investigate the possible association between Alzheimer's disease and late maternal age at index birth, we conducted a collaborative re-analysis of existing case-control data sets. Of the 11 studies participating in the EURODEM project, four were included in the analyses regarding mate

  19. Interaction between genetic and environmental risk factors for Alzheimer's disease: a re-analysis of case-control studies

    NARCIS (Netherlands)

    C.M. van Duijn (Cock); D.G. Clayton (David); V. Chandra; L. Fratiglioni (Laura); A.B. Graves; A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; J.A. Mortimer; W.A. Rocca; S.L. Shalat; H. Soininen; A. Hofman (Albert)

    1994-01-01

    textabstractTo study the interaction among genetic and environmental risk factors, a reanalysis of case-control studies of Alzheimer's disease (AD) was conducted based on the original data of all studies carried out to January 1, 1990. Seven studies were included in the present analysis, comprising

  20. Head trauma as a risk factor for Alzheimer's disease: A collaborative re-analysis of case-control studies

    NARCIS (Netherlands)

    J.A. Mortimer; C.M. van Duijn (Cock); V. Chandra; L. Fratiglioni (Laura); A.B. Graves; A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; W.A. Rocca; S.L. Shalat; H. Soininen; A. Hofman (Albert)

    1991-01-01

    textabstractA re-analysis of the data from 11 case-control studies was performed to investigate the association between head trauma and Alzheimer's disease (AD). To increase comparability of studies, exposures were limited to head trauma with loss of consciousness (hereafter referred to as 'head tra

  1. Pregnancy associated nasopharyngeal carcinoma: A retrospective case-control analysis of maternal survival outcomes

    International Nuclear Information System (INIS)

    Background: Pregnancy-associated nasopharyngeal carcinoma (PANPC) has been associated with poor survival. Recent advances in radiation technology and imaging techniques, and the introduction of chemotherapy have improved survival in nasopharyngeal carcinoma (NPC); however, it is not clear whether these changes have improved survival in PANPC. Therefore, the purpose of this study was to compare five-year maternal survival in patients with PANPC and non-pregnant patients with NPC. Methods: After adjusting for age, stage and chemotherapy mode, we conducted a retrospective case-control study among 36 non-metastatic PANPC patients and 36 non-pregnant NPC patients (control group) who were treated at our institution between 2000 and 2010. Results: The median age of both groups was 30 years (range, 23–35 years); median follow-up for all patients was 70 months. Locoregionally-advanced disease accounted for 83.3% of all patients with PANPC and 92.9% of patients who developed NPC during pregnancy. In both the PANPC and control groups, 31 patients (86.1%) received chemotherapy and all patients received definitive radiotherapy. The five-year rates for overall survival (70% vs. 78%, p = 0.72), distant metastasis-free survival (79% vs. 76%, p = 0.77), loco-regional relapse-free survival (97% vs. 91%, p = 0.69) and disease-free survival (69% vs. 74%, p = 0.98) were not significantly different between the PANPC and control groups. Multivariate analysis using a Cox proportional hazards model revealed that only N-classification was significantly associated with five-year OS. Conclusion: This study demonstrates that, in the modern treatment era, pregnancy itself may not negatively influence survival outcomes in patients with NPC; however, pregnancy may delay the diagnosis of NPC

  2. Estudo caso-controle com resposta multinomial: uma proposta de análise Case-control studies with multinomial responses: a proposal for analysis

    Directory of Open Access Journals (Sweden)

    Ana Carolina Cintra Nunes Mafra

    2010-03-01

    Full Text Available Este estudo revisa alguns artigos com delineamento do tipo caso-controle em que se tem os casos classificados em dois ou mais tipos. A aplicação de modelos para respostas multinomiais e a adequabilidade destes aos estudos caso-controle é discutida. Dentre os ajustes possíveis, argumenta-se que o modelo logístico Politômico é o mais indicado para a obtenção de medidas epidemiológicas de risco e associação neste tipo de delineamento. Como ilustração, apresenta-se uma aplicação desse modelo em um estudo caso-controle de base populacional, comparando os resultados com aqueles obtidos em um ajuste logístico binomial. A abordagem multinomial possibilita investigar, em uma única análise, a ocorrência de associações entre co-variáveis e uma ou algumas das classes de casos estudados, abrindo a possibilidade, de grande interesse epidemiológico, de identificação de fatores de risco e de proteção individualizados para cada subgrupo de interesse.This study reviews articles on case-control studies in which the cases were classified in two or more types. Application of multinomial models and their adequacy for case-control studies are discussed. Among the available multinomial adjustments, we argue that the polytomous logistic model is the most suitable for obtaining epidemiological measures of risk and association in case-control studies. By way of illustration, we present an application of this model in a population-based case-control study, comparing the results with those obtained in a binomial logistic model. The multinomial approach allows investigating, in a single analysis, the occurrence of associations between covariates and more or more subclasses of cases, thus providing the epidemiologically relevant possibility of identifying individualized risk and protective factors for each subclass.

  3. Recreational physical activity and epithelial ovarian cancer: a case-control study, systematic review, and meta-analysis.

    Science.gov (United States)

    Olsen, Catherine M; Bain, Christopher J; Jordan, Susan J; Nagle, Christina M; Green, Adèle C; Whiteman, David C; Webb, Penelope M

    2007-11-01

    It remains unclear whether physical activity is associated with epithelial ovarian cancer risk. We therefore examined the association between recreational physical activity and risk of ovarian cancer in a national population-based case-control study in Australia. We also systematically reviewed all the available evidence linking physical activity with ovarian cancer to provide the best summary estimate of the association. The case-control study included women ages 18 to 79 years with a new diagnosis of invasive (n=1,269) or borderline (n=311) epithelial ovarian cancer identified through a network of clinics, physicians, and state cancer registries throughout Australia. Controls (n=1,509) were randomly selected from the national electoral roll and were frequency matched to cases by age and state. For the systematic review, we identified eligible studies using Medline, the ISI Science Citation Index, and manual review of retrieved references, and included all case-control or cohort studies that permitted assessment of an association between physical activity (recreational/occupational/sedentary behavior) and histologically confirmed ovarian cancer. Meta-analysis was restricted to the subset of these studies that reported on recreational physical activity. In our case-control study, we observed weakly inverse or null associations between recreational physical activity and risk of epithelial ovarian cancer overall. There was no evidence that the effects varied by tumor behavior or histologic subtype. Twelve studies were included in the meta-analysis, which gave summary estimates of 0.79 (95% confidence interval, 0.70-0.85) for case-control studies and 0.81 (95% confidence interval, 0.57-1.17) for cohort studies for the risk of ovarian cancer associated with highest versus lowest levels of recreational physical activity. Thus, pooled results from observational studies suggest that a modest inverse association exists between level of recreational physical activity and

  4. Meta-Analysis of a Multi-Ethnic, Breast Cancer Case-Control Targeted Sequencing Study

    OpenAIRE

    Ablorh, Akweley

    2015-01-01

    Breast cancer, the most commonly diagnosed cancer in American women, is a heritable disease with nearly one hundred known genetic risk factors. Using next generation sequencing, we explored the contribution of genetics at 12 GWAS-identified loci to breast cancer susceptibility in a multi-ethnic breast cancer case-control study. Methods: The study population consists of 4,611 breast cancer cases and controls (2,316 cases and 2,295 controls) from four mutually exclusive ethnicities: Africa...

  5. Breast cancer in the Thai Cohort Study: An exploratory case-control analysis

    OpenAIRE

    Jordan, Susan; Lim, Lynette; Vilainerun, Duangkae; Banks, Emily; Sripaiboonkij, Nintita; Seubsman, Sam-ang; Sleigh, Adrian; Bain, Christopher

    2009-01-01

    Breast cancer incidence may be increasing in Thailand but very little research has assessed core breast cancer risk factors in this country. We used baseline questionnaire data from a national cohort study of Thai Open University students in an exploratory case-control study of breast cancer. The study included 43 female cases and 860 age-matched controls selected from the remaining 47,271 female cohort participants. Odds ratios and 95% confidence intervals were calculated using conditional l...

  6. CYP1A1, GSTM1 and GSTT1 genetic polymorphisms and gastric cancer risk among Japanese: A nested case-control study within a large-scale population-based prospective study.

    Science.gov (United States)

    Hidaka, Akihisa; Sasazuki, Shizuka; Matsuo, Keitaro; Ito, Hidemi; Charvat, Hadrien; Sawada, Norie; Shimazu, Taichi; Yamaji, Taiki; Iwasaki, Motoki; Inoue, Manami; Tsugane, Shoichiro

    2016-08-15

    Cytochrome P450 (CYP) 1A1 and glutathione S-transferases (GST) M1 and T1 are major enzymes in the carcinogen metabolizing pathway. We examined the association between single nucleotide polymorphisms (SNPs) of CYP1A1 (rs4646421, rs4646422 and rs1048943), GSTM1 and GSTT1 and gastric cancer risk in Japan. This is a nested case-control study (457 cases and 457 matched controls) of our population-based cohort involving 36,745 subjects who answered a baseline questionnaire and supplied blood samples. The odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated using conditional logistic regression models. We found that CYP1A1 (rs4646422) variant allele was associated with a statistically significant increased risk of gastric cancer compared with the homozygous wild-type genotype (OR = 1.65; 95% CI = 1.17-2.32). GSTM1 null, GSTT1 null and GSTM1/T1 both or either null genotypes were associated with increased risk, but not statistically significantly. Combination of the CYP1A1 (rs4646422) variant allele and GSTM1/T1 both or either null genotypes was associated with a statistically significant increased risk compared with the combination of the CYP1A1 homozygous wild-type genotype and the GSTM1/T1 both active genotypes. In addition, compared with CYP1A1 (rs4646422) homozygous wild-type genotypes in those who were never-smokers, CYP1A1 variant alleles in those who smoked ≥30 pack-years were associated with an increased risk; neither gene-gene nor gene-environment interactions were significant. The CYP1A1 (rs4646422) polymorphism might be involved in gastric carcinogenesis among the Japanese population. PMID:27062139

  7. Cow's milk consumption, HLA-DQB1 genotype, and type 1 diabetes: a nested case-control study of siblings of children with diabetes. Childhood diabetes in Finland study group.

    Science.gov (United States)

    Virtanen, S M; Läärä, E; Hyppönen, E; Reijonen, H; Räsänen, L; Aro, A; Knip, M; Ilonen, J; Akerblom, H K

    2000-06-01

    The evidence for the putative role of cow's milk in the development of type 1 diabetes is controversial. We studied infant feeding patterns and childhood diet by structured questionnaire (n = 725) and HLA-DQB1 genotype by a polymerase chain reaction-based method (n = 556) in siblings of affected children and followed them for clinical type 1 diabetes. In a nested case-control design in a population who had both dietary and genetic data available, we selected as cases those siblings who progressed to clinical diabetes during the follow-up period (n = 33). For each case, we chose as matched control subjects siblings who fulfilled the following criteria: same sex, age within 1 year, not from the same family, the start of the follow-up within 6 months of that of the respective case, and being at risk for type 1 diabetes at the time the case presented with that disease (n = 254). The median follow-up time was 9.7 years (range 0.2-11.3). Early age at introduction of cow's milk supplements was not significantly associated with progression to clinical type 1 diabetes (relative risk adjusted for matching factors, maternal education, maternal and child's ages, childhood milk consumption, and genetic susceptibility markers was 1.60 [95% CI 0.5-5.1]). The estimated relative risk of childhood milk consumption for progression to type 1 diabetes was 5.37 (1.6-18.4) when adjusted for the matching and aforementioned sociodemographic factors, age at introduction of supplementary milk feeding, as well as for genetic susceptibility markers. In conclusion, our results provide support for the hypothesis that high consumption of cow's milk during childhood can be diabetogenic in siblings of children with type 1 diabetes. However, further studies are needed to assess the possible interaction between genetic disease susceptibility and dietary exposures in the development of this disease. PMID:10866042

  8. The prevalence of lacunar infarct decreases with aging in the elderly: a case-controlled analysis

    Directory of Open Access Journals (Sweden)

    Cai Z

    2016-05-01

    Full Text Available Zhiyou Cai,1 Wenbo He,1 Chuan-yong Peng,2 Jin Zhou,2 Qi-lan Xu,2 Zong-shan Wu2 1Department of Neurology, Renmin Hospital, Hubei University of Medicine, Shiyan Renmin Hospital, Shiyan, Hubei Province, 2The Examination Center of Magnetic Resonance Imaging, the Lu’an Affiliated Hospital of Anhui Medical University, Lu’an People’s Hospital, Lu’an, Anhui Province, People’s Republic of China Background and purpose: Lacunar infarct (LI is well known as a heterogeneous primary disorder of cerebral small vessel. Compelling results have demonstrated that age is a risk factor to the prevalence of LI. However, the relationship between age and the prevalence of LI remains obscure. It is essential to note the relationship between age and the prevalence of LI through more clinical data. Methods: A total of 3,500 patients were included in the case-controlled study. All data were collected from the Examination Center of Magnetic Resonance Imaging, Lu’an People’s Hospital from January 2014 to December 2015. A primary discharge diagnosis of LI was done, and all subjects were evaluated as retrospective data. The relationship between the risk factors and the prevalence of diabetes and the relationship between age and the prevalence of diabetes was analyzed. A chi-square test was used to analyze the associations between different variables. A one-way analysis of variance was used to test the equality of three or more means at one time by using variances. Statistical significance was defined as a P-value of <0.05. Results: The one-way analysis of variance demonstrated that the prevalence of LI increased with age before 60 years and decreased with age after 69 years. The same results were found in both the male and the female subjects. These results showed that the age-related risk factors (hypertension, diabetes, cerebral infarct, cardiovascular diseases, smoking, and drinking have no relationship with the prevalence of LI on the basis of age. There is

  9. A method for detecting epistasis in genome-wide studies using case-control multi-locus association analysis

    OpenAIRE

    Galan Jose; Quintas Antonio; Royo Jose; Sáez María; Bermudo Fernando; González-Pérez Antonio; Gayán Javier; Morón Francisco; Ramirez-Lorca Reposo; Real Luis; Ruiz Agustín

    2008-01-01

    Abstract Background The difficulty in elucidating the genetic basis of complex diseases roots in the many factors that can affect the development of a disease. Some of these genetic effects may interact in complex ways, proving undetectable by current single-locus methodology. Results We have developed an analysis tool called Hypothesis Free Clinical Cloning (HFCC) to search for genome-wide epistasis in a case-control design. HFCC combines a relatively fast computing algorithm for genome-wide...

  10. High Sodium Intake Is Associated With Self-Reported Rheumatoid Arthritis: A Cross Sectional and Case Control Analysis Within the SUN Cohort.

    Science.gov (United States)

    Salgado, Eva; Bes-Rastrollo, Maira; de Irala, Jokin; Carmona, Loreto; Gómez-Reino, Juan J

    2015-09-01

    Sodium intake is a potential environmental factor for immune-mediated inflammatory diseases. The aim of this study is to investigate the association of sodium intake with rheumatoid arthritis. We performed a cross-sectional study nested in a highly educated cohort investigating dietary habits as determinants of disease. Daily sodium intake in grams per day was estimated from a validated food frequency questionnaire. We identified prevalent self-reported cases of rheumatoid arthritis. Logistic regression models were used to estimate the odds ratio for rheumatoid arthritis by sodium intake adjusting for confounders. Linear trend tests and interactions between variables were explored. Sensitivity analyses included age- and sex-matched case-control study, logistic multivariate model adjusted by residuals, and analysis excluding individuals with prevalent diabetes or cardiovascular disease. The effective sample size was 18,555 individuals (mean age 38-years old, 60% women) including 392 self-reported rheumatoid arthritis. Median daily sodium intake (estimated from foods plus added salt) was 3.47 (P25-75: 2.63-4.55) grams. Total sodium intake in the fourth quartile showed a significant association with rheumatoid arthritis (fully adjusted odds ratio 1.5; 95% CI 1.1-2.1, P for trend = 0.02). Never smokers with high sodium intake had higher association than ever smokers with high sodium intake (P for interaction = 0.007). Dose-dependent association was replicated in the case-control study. High sodium intake may be associated with a diagnosis of rheumatoid arthritis. This confirms previous clinical and experimental research. PMID:26376372

  11. Association analysis of PALB2 and BRCA2 in bipolar disorder and schizophrenia in a scandinavian case-control sample

    DEFF Research Database (Denmark)

    Tesli, Martin; Athanasiu, Lavinia; Mattingsdal, Morten;

    2010-01-01

    ,868/2,938) and the STEP-UCL/ED-DUB-STEP2 study (n¿=¿2,558/3,274) in a meta-analysis which revealed a P-value of 1.2¿×¿10(-5) for association between PALB2 SNP rs420259 and BD (n¿=¿5,547/20,241). Neither the PALB2 SNP rs420259 nor the BRCA2 SNP rs9567552 were nominally significantly associated with the SCZ...... (Nominal P¿=¿0.00043). Additionally, we replicated the association between PALB2 SNP rs420259 and BD (Nominal P¿=¿0.025). We then combined our sample with another Nordic case-control sample (n¿=¿435/11,491) from Iceland, and added results from the Wellcome Trust Case Control Consortium (WTCCC) (n¿=¿1...

  12. Multilevel Analysis Methods for Partially Nested Cluster Randomized Trials

    Science.gov (United States)

    Sanders, Elizabeth A.

    2011-01-01

    This paper explores multilevel modeling approaches for 2-group randomized experiments in which a treatment condition involving clusters of individuals is compared to a control condition involving only ungrouped individuals, otherwise known as partially nested cluster randomized designs (PNCRTs). Strategies for comparing groups from a PNCRT in the…

  13. A population-based nested case control study on recurrent pneumonias in children with severe generalized cerebral palsy: ethical considerations of the design and representativeness of the study sample

    Directory of Open Access Journals (Sweden)

    Benninga Marc A

    2005-07-01

    Full Text Available Abstract Background In children with severe generalized cerebral palsy, pneumonias are a major health issue. Malnutrition, dysphagia, gastro-oesophageal reflux, impaired respiratory function and constipation are hypothesized risk factors. Still, no data are available on the relative contribution of these possible risk factors in the described population. This paper describes the initiation of a study in 194 children with severe generalized cerebral palsy, on the prevalence and on the impact of these hypothesized risk factors of recurrent pneumonias. Methods/Design A nested case-control design with 18 months follow-up was chosen. Dysphagia, respiratory function and constipation will be assessed at baseline, malnutrition and gastro-oesophageal reflux at the end of the follow-up. The study population consists of a representative population sample of children with severe generalized cerebral palsy. Inclusion was done through care-centres in a predefined geographical area and not through hospitals. All measurements will be done on-site which sets high demands on all measurements. If these demands were not met in "gold standard" methods, other methods were chosen. Although the inclusion period was prolonged, the desired sample size of 300 children was not met. With a consent rate of 33%, nearly 10% of all eligible children in the Netherlands are included (n = 194. The study population is subtly different from the non-participants with regard to severity of dysphagia and prevalence rates of pneumonias and gastro-oesophageal reflux. Discussion Ethical issues complicated the study design. Assessment of malnutrition and gastro-oesophageal reflux at baseline was considered unethical, since these conditions can be easily treated. Therefore, we postponed these diagnostics until the end of the follow-up. In order to include a representative sample, all eligible children in a predefined geographical area had to be contacted. To increase the consent rate, on

  14. Urinary amino acid alterations in 3-year-old children with neurodevelopmental effects due to perinatal dioxin exposure in Vietnam: a nested case-control study for neurobiomarker discovery.

    Directory of Open Access Journals (Sweden)

    Muneko Nishijo

    Full Text Available In our previous study of 3-year-old children in a dioxin contamination hot spot in Vietnam, the high total dioxin toxic equivalent (TEQ-PCDDs/Fs-exposed group during the perinatal period displayed lower Bayley III neurodevelopmental scores, whereas the high 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD-exposed group displayed increased autistic traits. In autistic children, urinary amino acid profiles have revealed metabolic alterations in the amino acids that serve as neurotransmitters in the developing brain. Therefore, our present study aimed to investigate the use of alterations in urinary amino acid excretion as biomarkers of dioxin exposure-induced neurodevelopmental deficits in highly exposed 3-year-old children in Vietnam. A nested case-control study of urinary analyses was performed for 26 children who were selected from 111 3-year-old children whose perinatal dioxin exposure levels and neurodevelopmental status were examined in follow-up surveys conducted in a dioxin contaminated hot spot. We compared urinary amino acid levels between the following 4 groups: (1 a high TEQ-PCDDs/Fs and high TCDD-exposed group; (2 a high TEQ-PCDDs/Fs but low TCDD-exposed group; (3 a low TEQ-PCDDs/Fs exposed and poorly developed group; and (4 a low TEQ-PCDDs/Fs exposed and well-developed group. Urinary levels of histidine and tryptophan were significantly decreased in the high TEQ-PCDDs/Fs and high TCDD group, as well as in the high TEQ-PCDDs/Fs but low TCDD group, compared with the low TEQ-PCDDs/Fs and well-developed group. However, the ratio of histidine to glycine was significantly lower only in the high TEQ-PCDDs/Fs and high TCDD group. Furthermore, urinary histidine levels and the ratio of histidine to glycine were significantly correlated with neurodevelopmental scores, particularly for language and fine motor skills. These results indicate that urinary histidine is specifically associated with dioxin exposure-induced neurodevelopmental deficits

  15. Fish intake and ovarian cancer risk: a meta-analysis of 15 case-control and cohort studies.

    Directory of Open Access Journals (Sweden)

    Pei-yue Jiang

    Full Text Available BACKGROUND: Previous epidemiological studies have shown that fish consumption may modify the risk of ovarian cancer. However, these studies yielded controversial results. The present meta-analysis was undertaken to evaluate the relationship between fish intake and ovarian cancer risk. METHODS: A literature search was carried out using Pubmed, Embase, and Cochrane Library Central database for all relevant studies up to August 2013. We pooled the relative risks (RR from individual studies using fixed-effect or random-effect model, and carried out heterogeneity and publication bias analyses. RESULTS: A total of 15 (ten case-control, and five cohort studies were included in the present meta-analysis, representing data for 889,033 female subjects and 6,087 ovarian cancer cases. We found that total fish intake was not significantly associated with the risk of ovarian cancer among cohort studies (RR = 1.04 95% CI [0.89, 1.22] as well as case-control studies (RR = 0.90, 95% CI [0.73,1.12]. There was no evidence of publication bias as suggested by Begg's test (P = 0.55 and Egger's test(P = 0.29. CONCLUSIONS: The present meta-analysis showed that total fish consumption was not significantly associated with the risk of ovarian cancer. Further analysis on different fish species and food preparation methods should be conducted in future studies.

  16. Nested cladistic analysis indicates population fragmentation shapes genetic diversity in a freshwater mussel.

    Science.gov (United States)

    Turner, T F; Trexler, J C; Harris, J L; Haynes, J L

    2000-01-01

    Recently developed phylogeographic analyses that incorporate genealogical relationships of alleles offer the exciting prospect of disentangling historical from contemporary events. However, the relative advantages and shortfalls of this approach remain to be studied. We compared the nested cladistic method to the more traditional analysis of variance approach in a study of intraspecific genetic variation in the freshwater mussel, Lampsilis hydiana. We surveyed 257 specimens for nucleotide sequence level variation in a fragment of the mitochondrial 16S rRNA gene. When compared side by side, nested cladistic analysis and analysis of molecular variance (AMOVA) identified fragmentation of Arkansas river populations from remaining populations to the southwest. Nested cladistic analysis identified a second, more recent separation of Ouachita and Upper Saline river populations that was not detected by AMOVA. Differences among analytical methods probably arise from treatment of spatial hierarchical information: hierarchical groups emerge via a parsimony criterion in nested cladistic analysis but must be specified a priori in AMOVA. Both methods identified significant genetic structure among localities within hierarchical groups. Results from AMOVA suggested little gene flow among local populations with an island model. However, inferences about process that gave rise to patterns at this level were not possible in nested cladistic analysis, because an ancestral (interior) haplotype was not observed for a key one-step clade in the parsimony network. Our results suggest that, under some circumstances, nested cladistic analysis has lower power than more traditional analysis of variance to infer processes at the local population level. PMID:10655229

  17. Catastrophic health expenditure: a comparative analysis of empty-nest and non-empty-nest households with seniors in Shandong, China

    Science.gov (United States)

    Yang, Tingting; Chu, Jie; Zhou, Chengchao; Medina, Alexis; Li, Cuicui; Jiang, Shan; Zheng, Wengui; Sun, Liyuan; Liu, Jing

    2016-01-01

    Objective The aim of this study was to compare the catastrophic health expenditure (CHE) prevalence and its determinants between empty-nest and non-empty-nest elderly households. Setting Shandong province of China. Participants A total of 2761 elderly households are included in the analysis. Results CHE incidence among elderly households was 44.9%. The CHE incidence of empty-nest singles (59.3%, p=0.000, OR=3.19) and empty-nest couples (52.9%, p=0.000, OR=2.45) are both statistically higher than that of non-empty-nest elderly households (31.4%). An inverse association was observed between CHE incidence and income level in all elderly household types. Factors including 1 or more household elderly members with non-communicable chronic diseases in the past 6 months, 1 or more elderly household members being hospitalised in the past year and lower household income, are significant risk factors for CHE in all 3 household types (p<0.05). Health insurance status was found to be a significant determinant of CHE among empty-nest singles and non-empty-nest households (p<0.05). Conclusions CHE incidence among elderly households is high in China. Empty-nest households are at higher risk for CHE than non-empty-nest households. Based on these findings, we suggest that special insurance be developed to broaden the coverage of health services and heighten the reimbursement rate for empty-nest elderly in the existing health insurance schemes. Financial and social protection interventions are also essential for identified at-risk subgroups among different types of elderly households. PMID:27381206

  18. Source attribution of human campylobacteriosis using a meta-analysis of case-control studies of sporadic infections

    DEFF Research Database (Denmark)

    Coutinho Calado Domingues, Ana Rita; Pires, Sara Monteiro; Hisham Beshara Halasa, Tariq;

    2012-01-01

    for investigated risk factors were collected and analysed. In the meta-analysis, heterogeneity between the studies and possible sources of bias were investigated, and pooled odds ratios for identified risk factors were estimated. Results suggest that travelling abroad, eating undercooked chicken, environmental...... important sources of human disease is essential for prioritizing food safety interventions and setting public health goals. Numerous case-control studies of sporadic infections of campylobacteriosis have been published. These studies investigated a variety of potential risk factors for disease, often using...... different methodologies and settings. Systematic reviews (SRs) consist of a formal process for literature review focused on a specific research question, and include the identification of relevant literature, quality assessment of relevant studies, summarization or statistical analysis of data...

  19. Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies.

    Science.gov (United States)

    Taylor, Luke E; Swerdfeger, Amy L; Eslick, Guy D

    2014-06-17

    There has been enormous debate regarding the possibility of a link between childhood vaccinations and the subsequent development of autism. This has in recent times become a major public health issue with vaccine preventable diseases increasing in the community due to the fear of a 'link' between vaccinations and autism. We performed a meta-analysis to summarise available evidence from case-control and cohort studies on this topic (MEDLINE, PubMed, EMBASE, Google Scholar up to April, 2014). Eligible studies assessed the relationship between vaccine administration and the subsequent development of autism or autism spectrum disorders (ASD). Two reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus with another author. Five cohort studies involving 1,256,407 children, and five case-control studies involving 9,920 children were included in this analysis. The cohort data revealed no relationship between vaccination and autism (OR: 0.99; 95% CI: 0.92 to 1.06) or ASD (OR: 0.91; 95% CI: 0.68 to 1.20), nor was there a relationship between autism and MMR (OR: 0.84; 95% CI: 0.70 to 1.01), or thimerosal (OR: 1.00; 95% CI: 0.77 to 1.31), or mercury (Hg) (OR: 1.00; 95% CI: 0.93 to 1.07). Similarly the case-control data found no evidence for increased risk of developing autism or ASD following MMR, Hg, or thimerosal exposure when grouped by condition (OR: 0.90, 95% CI: 0.83 to 0.98; p=0.02) or grouped by exposure type (OR: 0.85, 95% CI: 0.76 to 0.95; p=0.01). Findings of this meta-analysis suggest that vaccinations are not associated with the development of autism or autism spectrum disorder. Furthermore, the components of the vaccines (thimerosal or mercury) or multiple vaccines (MMR) are not associated with the development of autism or autism spectrum disorder.

  20. Thymidylate synthase genetic polymorphisms and cancer risk:a meta-analysis of 37 case-control studies

    Institute of Scientific and Technical Information of China (English)

    TANG Jian; WANG Pei-pei; ZHUANG Yan-yan; CHEN Wen-jie; HUANG Feng-ting; ZHANG Shi-neng

    2012-01-01

    Background Several studies have evaluated the association between polymorphisms of thymidylate synthase (TS)and cancer risk in diverse populations but with conflicting results.By pooling the relatively small samples in each study,it is possible to evaluate the association using a meta-analysis.Methods A comprehensive search was conducted to identify all case-control studies on TS on a 28-bp tandem repeats in 5′untranslated region (5′UTR) and a 6-bp insertion (ins) and deletion (del) mutation in 3′UTR of the gene and cancer risk.Meta-analysis was conducted using a fixed and random effect model.Results Our meta-analysis on a total of 13307 cancer cases and 18226 control subjects from 37 published case-control studies showed no significant association between the risk of cancer and the 5′UTR 28-bp tandem repeats polymorphism (3R/3R vs.2R/2R:OR=1.06,95% CI,0.93-1.20) or the 3′UTR 6-bp ins/del polymorphism (del6/del6 vs.ins6/ins6:0R=0.93,95% CI,0.81-1.08) with significant between-study heterogeneity.In the cancer type- and ethnic subgroup-stratification analyses,we did not find any association between TS polymorphisms and cancer risk either.Conclusion TS 5′UTR 28-bp tandem repeats and 3′UTR 6-bp ins/del polymorphisms may not be associated with cancer risk.

  1. Reproductive factors related to the risk of colorectal cancer by subsite: a case-control analysis

    OpenAIRE

    Yoo, K-Y; Tajima, K.; M. Inoue; Takezaki, T.; Hirose, K.; Hamajima, N; Park, S.K.; Kang, D. H.; Kato, T; Hirai, T

    1999-01-01

    The authors hypothesized that reproductive factors of colorectal cancer, which are probably mediated by endogenous hormones, would differ according to colonic subsite. Information on reproductive factors was obtained from 372 female colorectal cancer cases (113 proximal colon, 126 distal colon, 133 rectum) and 31 061 cancer-free controls at the Aichi Cancer Center Hospital, Japan, between 1988 and 1995. Multiple logistic analysis showed that late age at interview, family history of colorectal...

  2. Cigarette smoking and risk of ovarian cancer: a pooled analysis of 21 case-control studies

    OpenAIRE

    Faber, Mette T.; Kjær, Susanne K.; Dehlendorff, Christian; Chang-Claude, Jenny; Klaus K. Andersen; Høgdall, Estrid; Webb, Penelope M.; Jordan, Susan J; Rossing, Mary Anne; Doherty, Jennifer A; Lurie, Galina; Pamela J Thompson; Carney, Michael E; Goodman, Marc T.; Ness, Roberta B.

    2013-01-01

    Purpose The majority of previous studies have observed an increased risk of mucinous ovarian tumors associated with cigarette smoking, but the association with other histological types is unclear. In a large pooled analysis, we examined the risk of epithelial ovarian cancer associated with multiple measures of cigarette smoking with a focus on characterizing risks according to tumor behavior and histology. Methods We used data from 21 case–control studies of ovarian cancer (19,066...

  3. SENSITIVE NUMERICAL SIMULATION AND ANALYSIS OF RAINSTORM USING NESTED WRF MODEL

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-chang; HUANG Si-xun; LI Yi

    2006-01-01

    Nowadays, the nested grid model is widely used to increase the resolution of numerical model.An attempt to investigate the influence of the newly developed nesting technique of WRF model on the mesoscale numerical simulation of severe storm is described in this article.The results of sensitivity tests infer that the WRF model give more accurate and vivid prediction of severe storm with nesting scheme.As is shown in the tests, simulating value of the precipitation centers using nesting scheme are larger than those without using nesting scheme, which indicates that the simulating precipitation of nested storm is closer to the real rainfall.And there is obvious improvement of distribution of rain area and position of precipitation centers.According to the high resolution output data of the WRF model, deep and detailed analysis of characters of the mesoscale system that triggers the rainstorm is reported in this article, and the thermal and dynamical characters of this Meiyu front severe storm are also discussed.

  4. 吸烟与原发性肝癌关系的巢式病例对照研究%Cigarette smoking and primary liver cancer risk: a nested case-control study in Shanghai

    Institute of Scientific and Technical Information of China (English)

    张薇; 高玉堂; 王学励; 张玉兰; Jian-min Yuan

    2009-01-01

    Objective To evaluate the association between cigarette smoking and risk of primary liver cancer (PLC) among middle-aged and elderly men in urban Shanghai. Methods A nested case- control study was conducted based on a cohort of 18 244 men who were 45-64 years of age in 1986-1989 and had no history of cancer at recruitment in Shanghai. As of Dec 31, 2000, a total of 213 incident cases of PLC were identified. 1094 matched controls were randomly selected among the cohort subjects who were free of cancer and alive at the time of cancer diagnosis of the index case. The matching criteria were date of birth (within 2 years), date of biospsy specimen collection (within 1 month), and neighborhood of residence at recruitment. Conditional logistic regression models were used to estimate adjusted odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Results After controlling for potential confounders, cigarette smoking (ever vs. never) was associated with risk of PLC (OR=1.91; 95% CI:1.28-2.86). Risk of PLC increased with increasing number of cigarettes smoked per day, as well as duration of cigarette smoking,pack-years of cigarettes consumed over lifetime and earlier age started smoking. The ORs were 2.16 (95%CI=1.37~3.40), 2.14(95%CI=1.18~3.87), 2.12(95%CI=1.21~3.74) and 2.57 (95% CI=1.50~4.40) for men who smoked 20 cigarettes or more daily, smoked for 40 or more years, consumed more than 37 pack-years of cigarettes, and began smoking before 20 years of age, respectively. Conclusion This study confirms that cigarette smoking is an independent risk factor for primary liver cancer among males in Shanghai.%目的 分析吸烟与上海市区中老年男性原发性肝癌的关系.方法 应用巢式病例对照研究方法,对一个18 244名男性队列随访11年,以队列中213例新发肝癌患者作为病例组,按照患者年龄、采样日期、同居住区等配对条件,从队列中随机抽取1094名健康人作为对照组.使用配

  5. Mapping sleeping bees within their nest: spatial and temporal analysis of worker honey bee sleep.

    Directory of Open Access Journals (Sweden)

    Barrett Anthony Klein

    Full Text Available Patterns of behavior within societies have long been visualized and interpreted using maps. Mapping the occurrence of sleep across individuals within a society could offer clues as to functional aspects of sleep. In spite of this, a detailed spatial analysis of sleep has never been conducted on an invertebrate society. We introduce the concept of mapping sleep across an insect society, and provide an empirical example, mapping sleep patterns within colonies of European honey bees (Apis mellifera L.. Honey bees face variables such as temperature and position of resources within their colony's nest that may impact their sleep. We mapped sleep behavior and temperature of worker bees and produced maps of their nest's comb contents as the colony grew and contents changed. By following marked bees, we discovered that individuals slept in many locations, but bees of different worker castes slept in different areas of the nest relative to position of the brood and surrounding temperature. Older worker bees generally slept outside cells, closer to the perimeter of the nest, in colder regions, and away from uncapped brood. Younger worker bees generally slept inside cells and closer to the center of the nest, and spent more time asleep than awake when surrounded by uncapped brood. The average surface temperature of sleeping foragers was lower than the surface temperature of their surroundings, offering a possible indicator of sleep for this caste. We propose mechanisms that could generate caste-dependent sleep patterns and discuss functional significance of these patterns.

  6. Reduced Serum Level of Interleukin-10 is Associated with Cerebral Infarction: A Case-Control and Meta-Analysis Study.

    Science.gov (United States)

    Zhu, Yifei; Yang, Haiqing; Diao, Zengyan; Li, Yi; Yan, Chuanzhu

    2016-05-01

    IL-10 expression limits inflammation and restricts the size of CNS damage from stroke. In this study, we examined the correlation between cerebral infarction (CI) and serum levels of interleukin-10 (IL-10) using a combination of case-control study and meta-analysis of published data, with an aim of understanding the relevance of serum IL-10 levels to CI development. This study enrolled a total of 169 CI patients admitted to the Second Hospital of Hebei Medical University between May 2011 and November 2014. During the same period, a group of 145 individuals were recruited at the same hospital as healthy controls after thorough physical examination. Serum IL-10 levels were measured by enzyme-linked immunosorbent assay (ELISA). SPSS 19.0 (IBM, 2010, Chicago, IL, USA) and Comprehensive Meta-Analysis 2.0 (CMA 2.0) software were used for data analysis. Serum levels of IL-10 (pg/mL) were significantly lower in CI patients when compared to healthy controls (15.36 ± 3.21 vs. 21.64 ± 5.17, t = 13.12, P  0.05). Logistic regression analysis indicated that, with the exception of triglyceride (TG) and uric acid (UA) levels (both P > 0.05), the other seven parameters, including fasting blood glucose (FPG), total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), creatinine (Cr), systolic blood pressure (SBP), and diastolic blood pressure (DBP), strongly correlated with CI development (all P relationship in Asians (SMD = 2.522, 95 % CI 0.468~4.576, P = 0.016) but not in Caucasians (P > 0.05). Our study provided convincing evidence that the patients with CI exhibit consistently reduced serum levels of IL-10, and IL-10 may be a major player in the development and progression of CI. PMID:26253723

  7. Analysis of eight genes modulating interferon gamma and human genetic susceptibility to tuberculosis: a case-control association study

    Directory of Open Access Journals (Sweden)

    Hoal Eileen G

    2010-06-01

    Full Text Available Abstract Background Interferon gamma is a major macrophage-activating cytokine during infection with Mycobacterium tuberculosis, the causative pathogen of tuberculosis, and its role has been well established in animal models and in humans. This cytokine is produced by activated T helper 1 cells, which can best deal with intracellular pathogens such as M. tuberculosis. Based on the hypothesis that genes which regulate interferon gamma may influence tuberculosis susceptibility, we investigated polymorphisms in eight candidate genes. Methods Fifty-four polymorphisms in eight candidate genes were genotyped in over 800 tuberculosis cases and healthy controls in a population-based case-control association study in a South African population. Genotyping methods used included the SNPlex Genotyping System™, capillary electrophoresis of fluorescently labelled PCR products, TaqMan® SNP genotyping assays or the amplification mutation refraction system. Single polymorphisms as well as haplotypes of the variants were tested for association with TB using statistical analyses. Results A haplotype in interleukin 12B was nominally associated with tuberculosis (p = 0.02, but after permutation testing, done to assess the significance for the entire analysis, this was not globally significant. In addition a novel allele was found for the interleukin 12B D5S2941 microsatellite. Conclusions This study highlights the importance of using larger sample sizes when attempting validation of previously reported genetic associations. Initial studies may be false positives or may propose a stronger genetic effect than subsequently found to be the case.

  8. Case-control analysis of breast cancer in a screened population: implications for the assessment of environmental exposure risk factors

    International Nuclear Information System (INIS)

    The appropriateness of using epidemiologic data from screened populations is investigated. Particular emphasis is given to design advantages and disadvantages of case-control studies using such data, statistical issues that arise in their analysis, and implications for testing hypotheses concerning environmental exposures. Concepts and techniques are illustrated with a recently completed study of breast cancer among screenees. Adjustment of odds ratios for number of screenings, symptomticity and year of first screening was necessary to avoid bias. When case subgroups are compared by classical methods, it should be done directly, rather than indirectly to controls, otherwise spurious trends may appear that are the result of the choice of baseline exposure group rather than risk differences. The multiple logistic model was used to adjust for many factors simultaneously and to model interaction between study factors. It is shown how careful interpretation of logistic regression parameters enables one to design a unified test to compare case subgroups simultaneously to one another and to controls and to test for initiation and promotion of cancer by environmental risk factors

  9. A method for detecting epistasis in genome-wide studies using case-control multi-locus association analysis

    Directory of Open Access Journals (Sweden)

    Galan Jose

    2008-07-01

    Full Text Available Abstract Background The difficulty in elucidating the genetic basis of complex diseases roots in the many factors that can affect the development of a disease. Some of these genetic effects may interact in complex ways, proving undetectable by current single-locus methodology. Results We have developed an analysis tool called Hypothesis Free Clinical Cloning (HFCC to search for genome-wide epistasis in a case-control design. HFCC combines a relatively fast computing algorithm for genome-wide epistasis detection, with the flexibility to test a variety of different epistatic models in multi-locus combinations. HFCC has good power to detect multi-locus interactions simulated under a variety of genetic models and noise conditions. Most importantly, HFCC can accomplish exhaustive genome-wide epistasis search with large datasets as demonstrated with a 400,000 SNP set typed on a cohort of Parkinson's disease patients and controls. Conclusion With the current availability of genetic studies with large numbers of individuals and genetic markers, HFCC can have a great impact in the identification of epistatic effects that escape the standard single-locus association analyses.

  10. Risk of multiple myeloma in rheumatoid arthritis: a meta-analysis of case-control and cohort studies.

    Directory of Open Access Journals (Sweden)

    Kaini Shen

    Full Text Available multiple myeloma is a malignant neoplasm of plasma cells mainly affecting elderly patients. Despite the wealth of information available on therapeutic strategies, the etiology and pathogenesis of myeloma remain unclear. In the current study, a meta-analysis was conducted to assess the possible association between rheumatoid arthritis and myeloma.a literature search was conducted with PubMed, EMBASE and Web of Science for relevant studies published by December 25, 2013. Additionally, we searched annual meeting abstracts of the American Society of Hematology from 2004 to 2013. Only original studies that investigated the association between rheumatoid arthritis and myeloma were included. In total, 8 case-control and 10 cohort studies were identified for analysis.the meta-estimate of the association between rheumatoid arthritis and myeloma was 1.14 (95% CI, 0.97-1.33 overall, with significant heterogeneity among studies. The relationship between myeloma and other autoimmune diseases was additionally examined from available data. Our results showed that myeloma risk is increased 1.31 to 1.65-fold in pernicious anemia and 1.36 to 2.30-fold in ankylosing spondylitis patients.Rheumatoid arthritis does not appear to alter the risk of myeloma, while between-study heterogeneity analyses suggest caution in the interpretation of results. Pernicious anemia and ankylosing spondylitis may be potential risk factors for myeloma development. Future large-scale epidemiological studies with reliable exposure biomarkers are necessary to establish the possible contribution of autoimmune disorders to multiple myeloma.

  11. Evaluation of the landscape surrounding northern bobwhite nest sites: A multiscale analysis

    Science.gov (United States)

    White, C.G.; Schweitzer, Sara H.; Moore, C.T.; Parnell, I.B.; Lewis-Weis, L.A.

    2005-01-01

    Implementation of the Conservation Reserve Program (CRP) altered the interspersion and abundance of patches of different land-cover types in landscapes of the southeastern United States. Because northern bobwhites (Colinus virginianus) are experiencing significant population declines throughout most of their range, including the Southeast, it is critical to understand the impacts of landscape-scale changes in habitat on their reproductive rates. Our objective was to identify components of landscape structure important in predicting nest site selection by bobwhites at different spatial scales in the Upper Coastal Plain of Georgia. We used a Geographic Information System (GIS) and spatial analysis software to calculate metrics of landscape structure near bobwhite nest sites. Logistic regression was used to model the relationship of nest sites to structure within the surrounding landscape at 4 spatial scales. We found that patch density and open-canopy planted pine were consistently important predictor variables at multiple scales, and other variables were important at various scales. The density of different patch types could be increased by thinning rows of pines in large monotypic stands of closed-canopy planted pine stands. Thinning and creating openings in CRP pine plantations should provide increased nesting opportunities for bobwhites. We interpret the support for other variables in our analysis as an indication that various patch configuration lead to different combinations of landscape structure that provide an acceptable range of habitat conditions for bobwhites.

  12. Motor vehicle crashes in diabetic patients with tight glycemic control: a population-based case control analysis.

    Directory of Open Access Journals (Sweden)

    Donald A Redelmeier

    2009-12-01

    Full Text Available BACKGROUND: Complications from diabetes mellitus can compromise a driver's ability to safely operate a motor vehicle, yet little is known about whether euglycemia predicts normal driving risks among adults with diabetes. We studied the association between glycosylated hemoglobin (HbA1c and the risk of a motor vehicle crash using a population-based case control analysis. METHODS AND FINDINGS: We identified consecutive drivers reported to vehicle licensing authorities between January 1, 2005 to January 1, 2007 who had a diagnosis of diabetes mellitus and a HbA1c documented. The risk of a crash was calculated taking into account potential confounders including blood glucose monitoring, complications, and treatments. A total of 57 patients were involved in a crash and 738 were not involved in a crash. The mean HbA1c was lower for those in a crash than controls (7.4% versus 7.9%, unpaired t-test, p = 0.019, equal to a 26% increase in the relative risk of a crash for each 1% reduction in HbA1c (odds ratio = 1.26, 95% confidence interval 1.03-1.54. The trend was evident across the range of HbA1c values and persisted after adjustment for measured confounders (odds ratio = 1.25, 95% confidence interval 1.02-1.55. The two other significant risk factors for a crash were a history of severe hypoglycemia requiring outside assistance (odds ratio = 4.07, 95% confidence interval 2.35-7.04 and later age at diabetes diagnosis (odds ratio per decade = 1.29, 95% confidence interval 1.07-1.57. CONCLUSIONS: In this selected population, tighter glycemic control, as measured by the HbA1c, is associated with an increased risk of a motor vehicle crash.

  13. 4-nitroquinoline-1-oxide-induced mutagen sensitivity and risk of cutaneous melanoma: a case-control analysis.

    Science.gov (United States)

    Wang, Li-E; Li, Chunying; Xiong, Ping; Gershenwald, Jeffrey E; Prieto, Victor G; Duvic, Madeleine; Lee, Jeffrey E; Grimm, Elizabeth A; Hsu, Tao C; Wei, Qingyi

    2016-04-01

    Mutagen sensitivity assay, which measures the enhanced cellular response to DNA damage induced in vitro by mutagens/carcinogens, has been used in the study of cancer susceptibility. 4-Nitroquinoline-1-oxide (4-NQO), an ultraviolet (UV) radiation-mimetic chemical, can produce chromosomal breaks in mammalian cells and induce cancer. Given the potential role of 4-NQO as the experimental mutagen substituting for UV as the etiological carcinogen of cutaneous melanoma (CM), we tested the hypothesis that cellular sensitivity to 4-NQO is associated with the risk of developing CM in a case-control study of 133 patients with primary CM and 176 cancer-free controls. Short-term blood cultures were treated with 4-NQO at a final concentration of 10 μmol/l for 24 h and scored chromatid breaks in 50 well-spread metaphases. Multivariate logistic regression was used to calculate odds ratios and 95% confidence intervals. We found that the log-transformed frequency of chromatid breaks was significantly higher in 133 patients than in 176 controls (P=0.004) and was associated with an increased risk for CM (adjusted odds ratio=1.78, 95% confidence interval: 1.12-2.84) after adjustment for age and sex. Moreover, as the chromatid break values increased, the risk for CM increased in a dose-dependent manner (P(trend)=0.003). Further analysis explored a multiplicative interaction between the sensitivity to 4-NQO and a family history of skin cancer (P(interaction)=0.004) on the risk of CM. Therefore, our findings suggest that sensitivity to 4-NQO may be a risk factor for the risk of CM, which is more sensitive than UV-induced chromotid breaks.

  14. Familial aggregation of Alzheimer's disease and related disorders: A collaborative re-analysis of case-control studies

    NARCIS (Netherlands)

    C.M. van Duijn (Cock); D.G. Clayton (David); V. Chandra; L. Fratiglioni (Laura); A.B. Graves; A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; J.A. Mortimer; W.A. Rocca; S.L. Shalat; H. Soininen; A. Hofman (Albert)

    1991-01-01

    textabstractCase-control studies of Alzheimer's disease were re-analysed to examine the association of Alzheimer's disease with family history in first degree relatives of dementia, Down's syndrome and Parkinson's disease. Overall, the relative risk of Alzheimer's disease for those with at least one

  15. Chlamydia trachomatis and invasive cervical cancer: a pooled analysis of the IARC multicentric case-control study.

    NARCIS (Netherlands)

    Smith, J.S.; Bosetti, C; Munoz, N.; Herrero, R; Bosch, F.X.; Eluf-Neto, J; Meijer, C.J.L.M.; Brule, van den AJ; Franceschi, S; Peeling, RW

    2004-01-01

    To determine whether Chlamydia trachomatis infection is consistently associated with an increased risk of invasive cervical carcinoma (ICC) after accounting for the strong effect of human papillomavirus (HPV) infection, a case-control study of 1,238 cases of ICC and 1,100 control women from 7 countr

  16. Alcohol-related breast cancer in postmenopausal women - effect of CYP19A1, PPARG and PPARGC1A polymorphisms on female sex-hormone levels and interaction with alcohol consumption and NSAID usage in a nested case-control study and a randomised controlled trial

    DEFF Research Database (Denmark)

    Kopp, Tine Iskov; Jensen, Ditte Marie; Ravn-Haren, Gitte;

    2016-01-01

    19A1 is associated with risk of BC in a case-control study group nested within the Danish "Diet, Cancer and Health" cohort (ncases = 687 and ncontrols = 687) and searched for gene-gene interaction between CYP19A1 and PPARGC1A, and CYP19A1 and PPARG, and gene-alcohol and gene-NSAID interactions....... Association between the CYP19A1 polymorphisms and hormone levels was also examined among 339 non-HRT users. Incidence rate ratios were calculated based on Cox' proportional hazards model. Furthermore, we performed a pilot randomised controlled trial to determine the effect of the PPARG Pro(12)Ala polymorphism......Alcohol consumption is associated with increased risk of breast cancer (BC), and the underlying mechanism is thought to be sex-hormone driven. In vitro and observational studies suggest a mechanism involving peroxisome proliferator-activated receptor gamma (PPARγ) in a complex with peroxisome...

  17. The effects of interaction between familial and reproductive factors on breast cancer risk: a combined analysis of seven case-control studies.

    OpenAIRE

    Andrieu, N; Smith, T; Duffy, S.; Zaridze, D. G.; Renaud, R.; Rohan, T.; Gerber, M; Luporsi, E.; Lê, M.; Lee, H. P.; Lifanova, Y.; Day, N.E.

    1998-01-01

    In this paper, a combined analysis was performed to study the interaction between familial risk and reproductive life factors. In particular, the interaction between familial risk and breast cell mitotic activity (BCMA), as assessed by duration of ovarian activity, was investigated because of the potential importance of mitotic activity on genetically susceptible cells. The present analysis included 3152 cases and 4404 controls in seven case-control studies from four countries. The interactio...

  18. Occupational Lifting Tasks and Retinal Detachment in Non-Myopics and Myopics: Extended Analysis of a Case-Control Study

    OpenAIRE

    Mattioli, Stefano; Curti, Stefania; De Fazio, Rocco; Mt Cooke, Robin; Zanardi, Francesca; Bonfiglioli, Roberta; Farioli, Andrea; Violante, Francesco S

    2012-01-01

    Objectives Lifting heavy weights involves the Valsalva manoeuvre, which leads to intraocular pressure spikes. We used data from a case-control study to further investigate the hypothesis that occupational lifting is a risk factor for retinal detachment. Methods The study population included 48 cases (patients operated for retinal detachment) and 84 controls (outpatients attending an eye clinic). The odds ratios (OR) of idiopathic retinal detachment were estimated with a logistic regression mo...

  19. A case-control association study and family-based expression analysis of the bipolar disorder candidate gene PI4K2B

    OpenAIRE

    Houlihan, Lorna; Christoforou, A.; Arbuckle, M I; Torrance, H. S.; Anderson, S. M.; Muir, Walter,; Porteous, D. J.; Blackwood, D H; Evans, K.L.

    2009-01-01

    Bipolar disorder, schizophrenia and recurrent major depression are complex psychiatric illnesses with a substantial, yet unknown genetic component. Linkage of bipolar disorder and recurrent major depression with markers on chromosome 4p15–p16 has been identified in a large Scottish family and three smaller families. Analysis of haplotypes in the four chromosome 4p-linked families, identified two regions, each shared by three of the four families, which are also supported by a case-control ass...

  20. DNA fingerprinting analysis in the solitary bee Megachile rotundata: variability and nest mate genetic relationships.

    Science.gov (United States)

    Blanchetot, A

    1992-08-01

    The most conventional approach for evaluating genetic variability in an insect population involves assessing the degree of enzyme polymorphism. Hymenoptera display a relatively low level of genetic variability compared with most insect species. DNA probes consisting of tandemly repeated sequences are powerful tools for detecting polymorphisms when employed to develop DNA fingerprinting (DNAfp) profiles in a wide range of organisms. This report describes genetic variability in the solitary bee species Megachile rotundata as assessed by DNAfp using the M13 sequence and a synthetic oligonucleotide sequence homologous to a hypervariable region of the alpha-globin gene. DNAfp comparisons among offspring were used to analyze genealogical structure in M. rotundata nests. The results indicate that polyandry, by a large number of males, is not a common phenomenon in M. rotundata bee species. In the present analysis, it is likely that the broods raised in single nests are mostly the offspring of one singly mated female. However, the data does not preclude that for certain nests two males could have been involved in the mating process. PMID:1526476

  1. Insertion/deletion polymorphism in intron 16 of ACE gene in idiopathic recurrent spontaneous abortion: case-control study, systematic review and meta-analysis.

    Science.gov (United States)

    Pereza, Nina; Ostojić, Saša; Zdravčević, Matea; Volk, Marija; Kapović, Miljenko; Peterlin, Borut

    2016-02-01

    The insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin I-converting enzyme gene (ACE) has been extensively studied as a predisposing factor for idiopathic recurrent spontaneous abortion (IRSA). A case-control study including 149 women with ≥3 spontaneous abortions and 149 controls was performed to test the association of ACE I/D polymorphism with IRSA. A systematic review was conducted of previous case-control studies, with strict selection criteria for meta-analyses. We also aimed to evaluate the potential differences in summary estimates between studies defining IRSA as ≥2 and ≥3 spontaneous abortions. Genotyping was performed by PCR, and systematic review conducted using PubMed and Scopus. There was no association of the polymorphism with IRSA in Slovenian women. Sixteen case-control studies, showing substantial differences regarding IRSA definition and selection criteria for women were identified. Meta-analysis was performed and included four studies defining IRSA as ≥2 spontaneous abortions and the current study, which defined IRSA as ≥3 spontaneous abortions. Based on random effects model, meta-analysis conducted on 1192 patients and 736 controls showed no association with IRSA under dominant(DD+IDvsII) and recessive(DDvsID+II) genetic models. Well-designed studies are needed to evaluate the role of ACE I/D polymorphism in IRSA defined as ≥3 spontaneous abortions. PMID:26673102

  2. Risk factors for campylobacteriosis of chicken, ruminant, and environmental origin: a combined case-control and source attribution analysis.

    Directory of Open Access Journals (Sweden)

    Lapo Mughini Gras

    Full Text Available BACKGROUND: Campylobacteriosis contributes strongly to the disease burden of food-borne pathogens. Case-control studies are limited in attributing human infections to the different reservoirs because they can only trace back to the points of exposure, which may not point to the original reservoirs because of cross-contamination. Human Campylobacter infections can be attributed to specific reservoirs by estimating the extent of subtype sharing between strains from humans and reservoirs using multilocus sequence typing (MLST. METHODOLOGY/PRINCIPAL FINDINGS: We investigated risk factors for human campylobacteriosis caused by Campylobacter strains attributed to different reservoirs. Sequence types (STs were determined for 696 C. jejuni and 41 C. coli strains from endemic human cases included in a case-control study. The asymmetric island model, a population genetics approach for modeling Campylobacter evolution and transmission, attributed these cases to four putative animal reservoirs (chicken, cattle, sheep, pig and to the environment (water, sand, wild birds considered as a proxy for other unidentified reservoirs. Most cases were attributed to chicken (66% and cattle (21%, identified as the main reservoirs in The Netherlands. Consuming chicken was a risk factor for campylobacteriosis caused by chicken-associated STs, whereas consuming beef and pork were protective. Risk factors for campylobacteriosis caused by ruminant-associated STs were contact with animals, barbecuing in non-urban areas, consumption of tripe, and never/seldom chicken consumption. Consuming game and swimming in a domestic swimming pool during springtime were risk factors for campylobacteriosis caused by environment-associated STs. Infections with chicken- and ruminant-associated STs were only partially explained by food-borne transmission; direct contact and environmental pathways were also important. CONCLUSION/SIGNIFICANCE: This is the first case-control study in which risk

  3. The Role of Colour Doppler And Spectral Flow Analysis In Pregnancy Induced Hypertension: A Case Control Study

    Directory of Open Access Journals (Sweden)

    Hinal Bhagat

    2015-03-01

    Full Text Available Background: The use of Doppler ultrasound to study blood flow in Obstetrics is of major importance because fetal inaccessibility precludes many other methods of study of fetal circulation. This study was undertaken to assess the role of Doppler in management of Pregnancy induced Hypertension. Methodology: The present case-control study was conducted in the department of Radiology, Govt. Medical College and New Civil Hospital, Surat. Details of obstetric history, age, last menstrual date and underlying risk factor, Doppler study of umbilical artery, fetal middle cerebral artery, both maternal uterine arteries and Ductus venosus was done. Parameters in form of Resistive index (RI, Pulsatility index (PI and systolic/diastolic ratio (S/D of all four arteries were taken. Results: It was observed that 55% cases with pregnancy induced hypertension developed IUGR fetuses while 2% of the IUGR fetus was present in control group. There were 41 (54% cases with IUGR fetuses. Out of which 28 (68% cases with IUGR had fetoplacental Doppler abnormality. 13 cases had abnormally low PI of MCA with normal umbilical arterial Doppler indices, out of which 12 patients had abnormal fetal outcome. Conclusion: By examining the maternal vessels using Doppler ultrasound it is possible to determine, the risk of complication developing in the course of pregnancy long before clinical signs of preeclampsia appear so that therapeutic measures may be undertaken early. [Natl J Med Res 2015; 5(1.000: 57-60

  4. Risk factors associated with hantavirosis fatality: a regional analysis from a case-control study in Brazil

    Directory of Open Access Journals (Sweden)

    Maria Cristina Antunes Willemann

    2014-01-01

    Full Text Available Introduction: In Brazil, hantavirus cardiopulmonary syndrome (HCPS has a high lethality rate that varies by region. This study aimed to identify the risk factors associated with fatal hantavirosis. Methods: This study was a case-control study that included all laboratory confirmed cases of hantavirosis. The cases were stratified by the different Brazilian regions using data from the Notifiable Diseases Information System. “Cases” were patients who progressed to death, whereas “controls” were patients who were cured. The odds ratio (OR and the adjusted OR were calculated. Results: Overall, 158 cases and 281 controls were included in this study. In the Midwest region, the cases were 60% less likely to present with flank pain, and the time between the beginning of symptoms and death was shorter than the time between the beginning of symptoms and a cure. In the Southeast region, the cases were 60% less likely to present with thrombocytopenia or reside in rural areas compared to those who progressed to a cure. Additionally, the cases sought medical assistance, notification and investigation more quickly than the controls. In the Southern region, the cases that died were 70% less likely to be male compared to the controls. Conclusions: HCPS manifests with nonspecific symptoms, and there are few published studies related to the condition, so determining a patient's therapeutic strategy is difficult. This study presents findings from different Brazilian regions and highlights the need for further investigations to improve comprehension about regional risk factors associated with hantavirosis and to reduce morbimortality.

  5. Alcohol-related breast cancer in postmenopausal women - effect of CYP19A1, PPARG and PPARGC1A polymorphisms on female sex-hormone levels and interaction with alcohol consumption and NSAID usage in a nested case-control study and a randomised controlled trial

    DEFF Research Database (Denmark)

    Kopp, Tine Iskov; Jensen, Ditte Marie; Ravn-Haren, Gitte;

    2016-01-01

    Alcohol consumption is associated with increased risk of breast cancer (BC), and the underlying mechanism is thought to be sex-hormone driven. In vitro and observational studies suggest a mechanism involving peroxisome proliferator-activated receptor gamma (PPARγ) in a complex with peroxisome......19A1 is associated with risk of BC in a case-control study group nested within the Danish "Diet, Cancer and Health" cohort (ncases = 687 and ncontrols = 687) and searched for gene-gene interaction between CYP19A1 and PPARGC1A, and CYP19A1 and PPARG, and gene-alcohol and gene-NSAID interactions...... and the PPARγ stimulator Ibuprofen on sex-hormone levels following alcohol intake in postmenopausal women (n = 25) using linear regression. Genetic variations in CYP19A1 were associated with hormone levels (estrone: P rs11070844 = 0.009, estrone sulphate: P rs11070844 = 0.01, P rs749292 = 0.004, P rs...

  6. Association between LGALS2 3279C>T and coronary artery disease: A case-control study and a meta-analysis

    Science.gov (United States)

    LIAN, JIANGFANG; FANG, PEILIANG; DAI, DONGJUN; BA, YANNA; YANG, XI; HUANG, XIAOYAN; LI, JUNXIN; CHEN, XIAOLIANG; GUO, JIAN; GUAN, FENG; PENG, PING; ZHAO, RUOCHI; ZHANG, SHANGSHI; GAO, FANG; TANG, LINLIN; ZHANG, CHENG; JI, HUIHUI; HONG, QINGXIAO; YE, HUADAN; XU, LIMIN; ZHONG, QILONG; LIU, PANPAN; ZHOU, JIANQING; DUAN, SHIWEI

    2014-01-01

    Coronary artery disease (CAD) has become the main cause of mortality worldwide. Lectin galactoside-binding soluble-2 (LGALS2) is involved in the cytokine lymphotoxin-α (LTA) cascade that may influence the progress of CAD. The aim of the present study was to assess the association between the LGALS2 3279C>T (rs7291467) polymorphism and CAD. A total of 562 cases and 572 controls were recruited to examine the association. A systematic meta-analysis was performed to evaluate the contribution of LGALS2 3279C>T polymorphism to the risk of CAD among 12,093 cases and 11,020 controls. There was no significant association found in the present case-control study. However, the meta-analysis showed that LGALS2 3279C>T played a protective role in CAD [P=0.008, odds ratio (OR), 0.90; 95% confidence interval (95% CI), 0.82–0.97] and particularly in the Asian population (P=0.006; OR, 0.82; 95% CI, 0.71–0.94). The present case-control study did not find a significant association between LGALS2 3279C>T and CAD in the Eastern Han Chinese population. However, the meta-analysis indicated that LGALS2 3279C>T played a protective role in CAD, suggesting an ethnic difference in the association of the locus with CAD. PMID:25279163

  7. Preliminary nitrite, nitrate and colour analysis of Malaysian edible bird’s nest

    Directory of Open Access Journals (Sweden)

    Meei Chien Quek

    2015-05-01

    Full Text Available The high nitrite content in edible bird’s nests is a major concern to the local swiftlet industry. It lowers the price of the edible bird’s nests and it brings severe health hazards to consumers and farmers. This research investigated the nitrite and nitrate contents of eight types of local edible bird’s nests by using ion chromatography system and evaluating its colour using the CIE system in L∗a∗b∗ parameters. The nitrite content obtained ranged from 5.7 μg/g for the house nests to 843.8 μg/g for the cave nests. The nitrate content for the house and cave nests was 98.2 μg/g and 36,999.4 μg/g, respectively. The cave nests with darker and redder colour had higher nitrite and nitrate contents than the brighter and more yellow house nests. This likely suggests that the nitrite and nitrate contents have correlations with edible bird’s nests colour. Correlations studies suggested that the nitrite content had high correlations with colour parameters, L∗a∗b∗ of edible bird’s nests at significant level of P < 0.10. These findings suggest that edible bird’s nests’ colour may be a useful indicator for measuring nitrite and nitrate contaminations.

  8. Association, characterisation and meta-analysis of SNPs linked to general reading ability in a German dyslexia case-control cohort.

    Science.gov (United States)

    Müller, Bent; Wilcke, Arndt; Czepezauer, Ivonne; Ahnert, Peter; Boltze, Johannes; Kirsten, Holger

    2016-01-01

    Dyslexia is a severe disorder in the acquisition of reading and writing. Several studies investigated the role of genetics for reading, writing and spelling ability in the general population. However, many of the identified SNPs were not analysed in case-control cohorts. Here, we investigated SNPs previously linked to reading or spelling ability in the general population in a German case-control cohort. Furthermore, we characterised these SNPs for functional relevance with in silico methods and meta-analysed them with previous studies. A total of 16 SNPs within five genes were included. The total number of risk alleles was higher in cases than in controls. Three SNPs were nominally associated with dyslexia: rs7765678 within DCDC2, and rs2038137 and rs6935076 within KIAA0319. The relevance of rs2038137 and rs6935076 was further supported by the meta-analysis. Functional profiling included analysis of tissue-specific expression, annotations for regulatory elements and effects on gene expression levels (eQTLs). Thereby, we found molecular mechanistical implications for 13 of all 16 included SNPs. SNPs associated in our cohort showed stronger gene-specific eQTL effects than non-associated SNPs. In summary, our results validate SNPs previously linked to reading and spelling in the general population in dyslexics and provide insights into their putative molecular pathomechanisms. PMID:27312598

  9. Association, characterisation and meta-analysis of SNPs linked to general reading ability in a German dyslexia case-control cohort

    Science.gov (United States)

    Müller, Bent; Wilcke, Arndt; Czepezauer, Ivonne; Ahnert, Peter; Boltze, Johannes; Kirsten, Holger; Friederici, Angela D.; Emmrich, Frank; Brauer, Jens; Wilcke, Arndt; Neef, Nicole; Boltze, Johannes; Skeide, Michael; Kirsten, Holger; Schaadt, Gesa; Müller, Bent; Kraft, Indra; Czepezauer, Ivonne; Dörr, Liane

    2016-01-01

    Dyslexia is a severe disorder in the acquisition of reading and writing. Several studies investigated the role of genetics for reading, writing and spelling ability in the general population. However, many of the identified SNPs were not analysed in case-control cohorts. Here, we investigated SNPs previously linked to reading or spelling ability in the general population in a German case-control cohort. Furthermore, we characterised these SNPs for functional relevance with in silico methods and meta-analysed them with previous studies. A total of 16 SNPs within five genes were included. The total number of risk alleles was higher in cases than in controls. Three SNPs were nominally associated with dyslexia: rs7765678 within DCDC2, and rs2038137 and rs6935076 within KIAA0319. The relevance of rs2038137 and rs6935076 was further supported by the meta-analysis. Functional profiling included analysis of tissue-specific expression, annotations for regulatory elements and effects on gene expression levels (eQTLs). Thereby, we found molecular mechanistical implications for 13 of all 16 included SNPs. SNPs associated in our cohort showed stronger gene-specific eQTL effects than non-associated SNPs. In summary, our results validate SNPs previously linked to reading and spelling in the general population in dyslexics and provide insights into their putative molecular pathomechanisms. PMID:27312598

  10. ERAP1 variants are associated with ankylosing spondylitis in East Asian population: a new Chinese case-control study and meta-analysis of published series.

    Science.gov (United States)

    Chen, C; Zhang, X

    2015-06-01

    Endoplasmic reticulum aminopeptidase 1 (ERAP1) has been confirmed to be associated with ankylosing spondylitis (AS) in Caucasian. However, whether they are associated with AS in East Asian population remains unidentified. We investigated this relationship by a new Chinese case-control study and a meta-analysis of published series. 368 cases and 460 controls were recruited in the Chinese case-control study. Genotyping was completed using the chip-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Allelic associations were analysed using contingency tables. In the meta-analysis, up to 2748 cases and 2774 controls from seven different studies and the new Chinese study were combined using Review Manager software version 5.1.1. Mantel-Haenszel or Inverse Variance test was used to calculate fixed or random-effects pooled ORs. In the new Chinese study, strong association with AS was observed for marker rs10050860, rs27434 and rs1065407 at P value of ERAP1 variants are associated with AS in East Asian population, indicating a common pathogenic mechanism for AS in East Asians and Caucasians. PMID:25817437

  11. Post hoc Analysis for Detecting Individual Rare Variant Risk Associations Using Probit Regression Bayesian Variable Selection Methods in Case-Control Sequencing Studies.

    Science.gov (United States)

    Larson, Nicholas B; McDonnell, Shannon; Albright, Lisa Cannon; Teerlink, Craig; Stanford, Janet; Ostrander, Elaine A; Isaacs, William B; Xu, Jianfeng; Cooney, Kathleen A; Lange, Ethan; Schleutker, Johanna; Carpten, John D; Powell, Isaac; Bailey-Wilson, Joan; Cussenot, Olivier; Cancel-Tassin, Geraldine; Giles, Graham; MacInnis, Robert; Maier, Christiane; Whittemore, Alice S; Hsieh, Chih-Lin; Wiklund, Fredrik; Catolona, William J; Foulkes, William; Mandal, Diptasri; Eeles, Rosalind; Kote-Jarai, Zsofia; Ackerman, Michael J; Olson, Timothy M; Klein, Christopher J; Thibodeau, Stephen N; Schaid, Daniel J

    2016-09-01

    Rare variants (RVs) have been shown to be significant contributors to complex disease risk. By definition, these variants have very low minor allele frequencies and traditional single-marker methods for statistical analysis are underpowered for typical sequencing study sample sizes. Multimarker burden-type approaches attempt to identify aggregation of RVs across case-control status by analyzing relatively small partitions of the genome, such as genes. However, it is generally the case that the aggregative measure would be a mixture of causal and neutral variants, and these omnibus tests do not directly provide any indication of which RVs may be driving a given association. Recently, Bayesian variable selection approaches have been proposed to identify RV associations from a large set of RVs under consideration. Although these approaches have been shown to be powerful at detecting associations at the RV level, there are often computational limitations on the total quantity of RVs under consideration and compromises are necessary for large-scale application. Here, we propose a computationally efficient alternative formulation of this method using a probit regression approach specifically capable of simultaneously analyzing hundreds to thousands of RVs. We evaluate our approach to detect causal variation on simulated data and examine sensitivity and specificity in instances of high RV dimensionality as well as apply it to pathway-level RV analysis results from a prostate cancer (PC) risk case-control sequencing study. Finally, we discuss potential extensions and future directions of this work. PMID:27312771

  12. Spatial analysis of lung, colorectal, and breast cancer on Cape Cod: An application of generalized additive models to case-control data

    Directory of Open Access Journals (Sweden)

    Aschengrau Ann

    2005-06-01

    Full Text Available Abstract Background The availability of geographic information from cancer and birth defect registries has increased public demands for investigation of perceived disease clusters. Many neighborhood-level cluster investigations are methodologically problematic, while maps made from registry data often ignore latency and many known risk factors. Population-based case-control and cohort studies provide a stronger foundation for spatial epidemiology because potential confounders and disease latency can be addressed. Methods We investigated the association between residence and colorectal, lung, and breast cancer on upper Cape Cod, Massachusetts (USA using extensive data on covariates and residential history from two case-control studies for 1983–1993. We generated maps using generalized additive models, smoothing on longitude and latitude while adjusting for covariates. The resulting continuous surface estimates disease rates relative to the whole study area. We used permutation tests to examine the overall importance of location in the model and identify areas of increased and decreased risk. Results Maps of colorectal cancer were relatively flat. Assuming 15 years of latency, lung cancer was significantly elevated just northeast of the Massachusetts Military Reservation, although the result did not hold when we restricted to residences of longest duration. Earlier non-spatial epidemiology had found a weak association between lung cancer and proximity to gun and mortar positions on the reservation. Breast cancer hot spots tended to increase in magnitude as we increased latency and adjusted for covariates, indicating that confounders were partly hiding these areas. Significant breast cancer hot spots were located near known groundwater plumes and the Massachusetts Military Reservation. Discussion Spatial epidemiology of population-based case-control studies addresses many methodological criticisms of cluster studies and generates new exposure

  13. Risk factors for human salmonellosis originating from pigs, cattle, broiler chickens and egg laying hens: a combined case-control and source attribution analysis.

    Directory of Open Access Journals (Sweden)

    Lapo Mughini-Gras

    Full Text Available Several case-control studies have investigated risk factors for human salmonellosis while others have used Salmonella subtyping to attribute human infections to different food and animal reservoirs. This study combined case-control and source attribution data into a single analysis to explore risk factors at the point of exposure for human salmonellosis originating from four putative food-producing animal reservoirs (pigs, cattle, broilers and layers/eggs in the Netherlands. We confirmed that most human cases (∼ 90% were attributable to layers/eggs and pigs. Layers/eggs and broilers were the most likely reservoirs of salmonellosis in adults, in urban areas, and in spring/summer, whereas pigs and cattle were the most likely reservoirs of salmonellosis in children, in rural areas, and in autumn/winter. Several reservoir-specific risk factors were identified. Not using a chopping board for raw meat only and consuming raw/undercooked meat were risk factors for infection with salmonellas originating from pigs, cattle and broilers. Consuming raw/undercooked eggs and by-products were risk factors for layer/egg-associated salmonellosis. Using antibiotics was a risk factor for pig- and cattle-associated salmonellosis and using proton-pump inhibitors for salmonellosis attributable to any reservoir. Pig- and cattle-associated infections were also linked to direct contact with animals and environmental exposure (e.g. playing in sandboxes. Eating fish, meat in pastry, and several non-meat foods (fruit, vegetables and pasteurized dairy products were protective factors. Consuming pork and occupational exposure to animals and/or raw meats were protective against layer/egg-associated salmonellosis. We concluded that individuals acquiring salmonellosis from different reservoirs have different associated risk factors, suggesting that salmonellas may infect humans through various transmission pathways depending on their original reservoirs. The outcome of

  14. Polymorphisms in thymidylate synthase gene and susceptibility to breast cancer in a Chinese population: a case-control analysis

    Directory of Open Access Journals (Sweden)

    Liu Jiyong

    2006-05-01

    Full Text Available Abstract Background Accumulative evidence suggests that low folate intake is associated with increased risk of breast cancer. Polymorphisms in genes involved in folate metabolism may influence DNA methylation, nucleotide synthesis, and thus individual susceptibility to cancer. Thymidylate synthase (TYMS is a key enzyme that participates in folate metabolism and catalyzes the conversion of dUMP to dTMP in the process of DNA synthesis. Two potentially functional polymorphisms [a 28-bp tandem repeat in the TYMS 5'-untranslated enhanced region (TSER and a 6-bp deletion/insertion in the TYMS 3'-untranslated region (TS 3'-UTR] were suggested to be correlated with alteration of thymidylate synthase expression and associated with cancer risk. Methods To test the hypothesis that polymorphisms of the TYMS gene are associated with risk of breast cancer, we genotyped these two polymorphisms in a case-control study of 432 incident cases with invasive breast cancer and 473 cancer-free controls in a Chinese population. Results We found that the distribution of TS3'-UTR (1494del6 genotype frequencies were significantly different between the cases and controls (P = 0.026. Compared with the TS3'-UTR del6/del6 wild-type genotype, a significantly reduced risk was associated with the ins6/ins6 homozygous variant genotype (adjusted OR = 0.58, 95% CI = 0.35–0.97 but not the del6/ins6 genotype (OR = 1.09, 95% CI = 0.82–1.46. Furthermore, breast cancer risks associated with the TS3'-UTR del6/del6 genotype were more evident in older women, postmenopausal subjects, individuals with a younger age at first-live birth and individuals with an older age at menarche. However, there was no evidence for an association between the TSER polymorphism and breast cancer risks. Conclusion These findings suggest that the TS3'-UTR del6 polymorphism may play a role in the etiology of breast cancer. Further larger population-based studies as well as functional evaluation of the

  15. Functional analysis of the newly established plants induced by nesting gulls on Riou archipelago (Marseille, France)

    Science.gov (United States)

    Vidal, Eric; Médail, Frédéric; Tatoni, Thierry; Vidal, Patrick; Roche, Philip

    1998-06-01

    The recent population explosion of Yellow-legged gulls ( Larus cachinnans), nesting on the Riou archipelago, off Marseille (France), has perturbed the flora and the vegetation of this site. The present study consists of a functional approach to the newly established plant species through an analysis of some of their vital attributes. Small islets appear to be more affected by floristic turnover than larger islands. In some cases, more than 50 % of the current flora was not present 35 years ago. The newly established taxa show special adaptations to the severe ecological pressure induced by gull colonies and to the characteristics of the Mediterranean climate. These plant species are mostly therophytes or hemicryptophytes and have a ruderal or a stress-tolerant strategy. Gulls' contribution to propagule dispersal from the continent appears to be very slight, dispersal by wind being the prevalent mode.

  16. Preliminary nitrite, nitrate and colour analysis of Malaysian edible bird’s nest

    OpenAIRE

    Meei Chien Quek; Nyuk Ling Chin; Yus Aniza Yusof; Sheau Wei Tan; Chung Lim Law

    2015-01-01

    The high nitrite content in edible bird’s nests is a major concern to the local swiftlet industry. It lowers the price of the edible bird’s nests and it brings severe health hazards to consumers and farmers. This research investigated the nitrite and nitrate contents of eight types of local edible bird’s nests by using ion chromatography system and evaluating its colour using the CIE system in L∗a∗b∗ parameters. The nitrite content obtained ranged from 5.7 μg/g for the house nests to 843.8 μg...

  17. Human Mammary Tumor Virus (HMTV Infection and Risk of Human Breast Cancer: An Adaptive Meta-Analysis for Case-Control Studies

    Directory of Open Access Journals (Sweden)

    Jong-Myon Bae

    2016-03-01

    Full Text Available Objective: There is ongoing debate about the association between Human Mammary Tumor Virus (HMTV infection and breast cancer. A systematic review (SR published in 2014 revealed that there was a statistically significant association. However, there was suspected duplication of the studies selected in that SR, and it also presented the need for a more detailed subgroup analysis by region. Therefore, the present study repeated the meta-analysis with the addition of relevant papers published before October 2015. Methods: Using the papers selected for the previous SR, a list was made of the references, and the “cited articles” and “similar articles” provided by PubMed. Of these, we only selected case-control studies that used PCR to detect the HMTV gene in tissue. The criterion for duplication was papers that showed identical researcher names or affiliated institutions. Among duplicated papers, the one with the largest number of samples was chosen. The meta-analysis was used to obtain summary odds ratio (SOR and 95% confidence interval (CI. Results: A total of 13 case-control studies were selected. The total number of the case and control groups was 1,878 and 1,204 persons, respectively. The results of the meta-analysis for these 13 papers showed that HMTV infection increased the risk of breast cancer (SOR=8.37, 95% CI: 2.29-23.39; I-squared = 98.4%. Conclusion: In the sub-group analysis, there was statistical significance for North America, the Mediterranean, and Australia. The results of this study support the claim that HMTV infection increases the risk of human breast cancer.

  18. Olive oil consumption and risk of CHD and/or stroke: a meta-analysis of case-control, cohort and intervention studies.

    Science.gov (United States)

    Martínez-González, Miguel A; Dominguez, Ligia J; Delgado-Rodríguez, Miguel

    2014-07-28

    Increasing evidence suggests that the Mediterranean diet can reduce the risk of CVD. Olive oil is the hallmark of this dietary pattern. We conducted a meta-analysis of case-control, prospective cohort studies and a randomised controlled trial investigating the specific association between olive oil consumption and the risk of CHD (101,460 participants) or stroke (38,673 participants). The results of all observational studies were adjusted for total energy intake. The random-effects model assessing CHD as an outcome showed a relative risk (RR) of 0.73 (95% CI 0.44, 1.21) in case-control studies and 0.96 (95% CI 0.78, 1.18) in cohort studies for a 25 g increase in olive oil consumption. In cohort studies, the random-effects model assessing stroke showed a RR of 0.74 (95% CI 0.60, 0.92). The random-effects model combining all cardiovascular events (CHD and stroke) showed a RR of 0.82 (95% CI 0.70, 0.96). Evidence of heterogeneity was apparent for CHD, but not for stroke. Both the Egger test (P= 0.06) and the funnel plot suggested small-study effects. Available studies support an inverse association of olive oil consumption with stroke (and with stroke and CHD combined), but no significant association with CHD. This finding is in agreement with the recent successful results of the PREDIMED randomised controlled trial.

  19. Postmarketing analysis of medicines: methodology and value of the spanish case-control study and surveillance system in preventing birth defects.

    Science.gov (United States)

    Martínez-Frías, María Luisa

    2007-01-01

    There are many surveillance systems of congenital defects all over the world; several of them have developed specific approaches to generate and test selected hypotheses regarding human teratogens. However, to the best of our knowledge, none of them have a permanent and systematised programme for the study of the risk and safety of drugs. The aim of this article is to describe the research programme on the potential effects of drugs in pregnancy followed by the Spanish Collaborative Study of Congenital Malformations (ECEMC), which is a permanent ongoing case-control study and surveillance system. The programme to analyse drugs includes a continuous and systematic study on the potential effects of medicines used during pregnancy. This programme has several characteristics that make it different from other current systems: (i) the collection of numerous datapoints (up to 312 per infant) in a case-control design; (ii) the use of a versatile and specific coding of birth defects; (iii) a specific programme for the continuous analysis of the potential effects of each type of drugs used during pregnancy that has been developed specifically for the ECEMC methodology, including its dysmorphological coding system. The description of the ECEMC's approach to surveillance of the effects of drug use during pregnancy may help researches in this area, particularly those using data from birth defects registries. PMID:17408307

  20. Nesting phenology of marine turtles: insights from a regional comparative analysis on green turtle (Chelonia mydas.

    Directory of Open Access Journals (Sweden)

    Mayeul Dalleau

    Full Text Available Changes in phenology, the timing of seasonal activities, are among the most frequently observed responses to environmental disturbances and in marine species are known to occur in response to climate changes that directly affects ocean temperature, biogeochemical composition and sea level. We examined nesting seasonality data from long-term studies at 8 green turtle (Chelonia mydas rookeries that include 21 specific nesting sites in the South-West Indian Ocean (SWIO. We demonstrated that temperature drives patterns of nesting seasonality at the regional scale. We found a significant correlation between mean annual Sea Surface Temperature (SST and dates of peak nesting with rookeries exposed to higher SST having a delayed nesting peak. This supports the hypothesis that temperature is the main factor determining peak nesting dates. We also demonstrated a spatial synchrony in nesting activity amongst multiple rookeries in the northern part of the SWIO (Aldabra, Glorieuses, Mohéli, Mayotte but not with the eastern and southern rookeries (Europa, Tromelin, differences which could be attributed to females with sharply different adult foraging conditions. However, we did not detect a temporal trend in the nesting peak date over the study period or an inter-annual relation between nesting peak date and SST. The findings of our study provide a better understanding of the processes that drive marine species phenology. The findings will also help to predict their ability to cope with climate change and other environmental perturbations. Despite demonstrating this spatial shift in nesting phenology, no trend in the alteration of nesting dates over more than 20 years was found.

  1. Triangular Nests!

    Science.gov (United States)

    Powell, R. I.

    2002-01-01

    Shows how integer-sided triangles can be nested, each nest having a single enclosing isosceles triangle. Brings to light what can be seen as a relatively simple generalization of Pythagoras' theorem, a result that should be readily accessible to many secondary school pupils. (Author/KHR)

  2. Association between mitogen-activated protein kinase kinase kinase 1 polymorphisms and breast cancer susceptibility: a meta-analysis of 20 case-control studies.

    Directory of Open Access Journals (Sweden)

    Qiaoli Zheng

    Full Text Available BACKGROUND: The genome-wide single-nucleotide polymorphisms (SNPs profiles can be used as diagnostic markers for human cancers. The associations between mitogen-activated protein kinase kinase kinase 1 (MAP3K1 SNPs rs889312 A>C, rs16886165 T>G and breast cancer risk have been widely evaluated, but the results were inconsistent. To derive a conclusive assessment of the associations, we performed a meta-analysis by combining data from all eligible case-control studies up to date. METHODS: By searching PubMed, ISI web of knowledge, Embase and Cochrane databases, we identified all eligible studies published before September 2013. Odds ratios (ORs with 95% confidence intervals (CIs were used to assess the strength of associations in fixed-effect or random-effect model. False-positive report probability (FPRP was calculated to confirm the significance of the results. RESULTS: A total of 59670 cases in 20 case-control studies were included in this meta-analysis. Significant associations with breast cancer risk were observed for SNPs rs889312 and rs16886165 polymorphisms with a per-allele OR of 1.11 (95% CI: 1.09-1.13 and 1.14 (95% CI: 1.09-1.20 respectively. For rs889312, in subgroup analysis by ethnicity, significant associations were identified in Europeans and Asians, but not in Africans. When stratified by estrogen receptor (ER expression status, rs889312 was associated with both ER-positive and ER-negative breast cancers. Results from the FPRP analyses were consistent with and supportive to the above results. CONCLUSIONS: The present meta-analysis suggests that rs889312-C allele and rs16886165-G allele might be risk factors for breast cancer, especially in Europeans and Asians.

  3. Design and Analysis of a Nested Halbach Permanent Magnet Magnetic Refrigerator

    Science.gov (United States)

    Tura, Armando

    A technology with the potential to create efficient and compact refrigeration devices is an active magnetic regenerative refrigerator (AMRR). AMRRs exploit the magnetocaloric effect displayed by magnetic materials whereby a reversible temperature change is induced when the material is exposed to a change in applied magnetic field. By using the magnetic materials in a regenerator as the heat storage medium and as the means of work input, one creates an active magnetic regenerator (AMR). Although several laboratory devices have been developed, no design has yet demonstrated the performance, reliability, and cost needed to compete with traditional vapor compression refrigerators. There are many reasons for this and questions remain as to the actual potential of the technology. The objective of the work described in this thesis is to quantify the actual and potential performance of a permanent magnet AMR system. A specific device configuration known as a dual-nested-Halbach system is studied in detail. A laboratory scale device is created and characterized over a wide range of operating parameters. A numerical model of the device is created and validated against experimental data. The resulting model is used to create a cost-minimization tool to analyze the conditions needed to achieve specified cost and efficiency targets. Experimental results include cooling power, temperature span, pumping power and work input. Although the magnetocaloric effect of gadolinium is small, temperature spans up to 30 K are obtained. Analysis of power input shows that the inherent magnetic work is a small fraction of the total work input confirming the assumption that potential cycle efficiencies can be large. Optimization of the device generates a number of areas for improvement and specific results depend upon targeted temperature spans and cooling powers. A competitive cost of cooling from a dual-nested-Halbach configuration is challenging and will depend on the ability to create

  4. Are MTHFR C677T and MTRR A66G Polymorphisms Associated with Overweight/Obesity Risk? From a Case-Control to a Meta-Analysis of 30,327 Subjects

    Directory of Open Access Journals (Sweden)

    Shu-Jun Fan

    2015-05-01

    Full Text Available Several studies have examined the associations of methylenetetrahydrofolate reductase (MTHFR C677T and methionine synthase reductase (MTRR A66G polymorphisms with being overweight/obesity. However, the results are still controversial. We therefore conducted a case-control study (517 cases and 741 controls in a Chinese Han population and then performed a meta-analysis by combining previous studies (5431 cases and 24,896 controls. In our case-control study, the MTHFR C677T polymorphism was not significantly associated with being overweight/obesity when examining homozygous codominant, heterozygous codominant, dominant, recessive and allelic genetic models. The following meta-analysis confirmed our case-control results. Heterogeneity was minimal in the overall analysis, and sensitivity analyses and publication bias tests indicated that the meta-analytic results were reliable. Similarly, both the case-control study and meta-analysis found no significant association between the MTRR A66G polymorphism and being overweight/obesity. However, sensitivity analyses showed that the associations between the MTRR A66G polymorphism and being overweight/obesity became significant in the dominant, heterozygous codominant and allelic models after excluding our case-control study. The results from our case-control study and meta-analysis suggest that both of the two polymorphisms are not associated with being overweight/obesity. Further large-scale population-based studies, especially for the MTRR A66G polymorphism, are still needed to confirm or refute our findings.

  5. Epstein-Barr Virus-Positive Diffuse Large B-Cell Lymphoma in the Elderly: A Matched Case-Control Analysis.

    Directory of Open Access Journals (Sweden)

    Chen-Ge Song

    Full Text Available Epstein-Barr virus (EBV-positive diffuse large B-cell lymphoma (DLBCL in the elderly has rarely been reported. This study aimed to explore the clinical characteristics and prognosis of this entity.In situ hybridization (ISH analysis of Epstein-Barr virus (EBV and immunohistochemistry was performed in 230 tumor specimens from consecutive de novo DLBCL patients over 50 years old. A matched-case control analysis (1:3 was utilized to compare EBV-positive and EBV-negative DLBCL in the elderly.A total of 16 patients (7.0% were diagnosed with EBV-positive DLBCL. Of these 16 cases, the median age was 62 years, with a male to female ratio of 11:5. Elderly EBV-positive DLBCL patients had a higher incidence of non-germinal center B-cell (non-GCB subtypes (87.5% and high Ki67 (75% and CD30 expression (93.8%. For EBV-positive patients undergoing initial chemotherapy, 7 of 16 (43.8% had complete remission, 2 (12.5% had partial remission, 2 (12.5% had stable disease, and 5 (31.3% had progressive disease. The median overall survival was 9 months for the EBV-positive patients. A matched-case control analysis suggested that EBV-positive patients had inferior survival outcomes compared with EBV-negative patients (3-year progression-free survival [PFS]: 25% vs. 76.7%, respectively; 3-year overall survival [OS]: 25% vs. 77.4%, respectively; P<0.001.EBV-positive DLBCL of the elderly is associated with an inferior clinical course and inferior survival outcomes. The role of EBV in this disease and the optimal management of this subgroup warrants further investigation.

  6. A matched nested case-control study on the risk factors of metabolic syndrome among male criminal policemen%男性刑警代谢综合征危险因素的巢式病例对照研究

    Institute of Scientific and Technical Information of China (English)

    宋富军; 汤乃军; 李树新; 于浩; 陈曦; 宋光新

    2013-01-01

    Objective To explore the risk factors and their differences of metabolic syndrome (MS) on male criminal police,thereby provide the scientific basis to make prevention and control strategies about the metabolic syndrome for the criminal police career.Methods Based on physical examination data of criminal police in 2010,439 patients with MS (CDS) were randomly selected as cases.And as the 1:2 matched nested case-control study,878 health controls were employed,which were matched with on the basis of sex and age (±1 year).An face-to-face epidemiological investigations on the past exposure status of several possible risk factors was conducted,such as the family history of hypertension and other social economic status,as well as body height and weight,waist circumference,blood pressure,serum lipid and plasma sugar.and the data were analyzed with logistic regression.Results 1317 cases were surveyed,through single factor logistic regression analysis found that 12 factors are related to exposure.Multivariate logistic regression analysis suggested that six factors,such as stress events (OR=1.989,95%CI:1.467~2.696),snoring (OR=1.672,95%CI:1.218~2.294),sweets (OR=0.562,95%CI:0.412~0.766),meat and products (0R=1.494,95%CI:1.065~2.094),siting after dinner for more than 3 h (OR=1.399,95%CI:1.023~1.915).Conclusions MS has become a important public health problems among criminal police.For their professional special,a series of bad habits,unhealthy life style and psychological problems became important risk factors of MS on criminal police.Targeted prevention and control measures should be taken to reduce the incidence of MS.%目的 探讨男性刑警代谢综合征(MS)的危险因素,为制定刑警职业人群代谢综合征的预防与控制策略提供科学依据.方法 以某市刑警2010年体检资料为基础,根据2004年中华医学会糖尿病分会制定的MS工作定义(CDS标准),随机抽取新确诊的439名MS患者为病例组;采用1:2配比

  7. Absenteísmo-doença, modelo demanda-controle e suporte social: um estudo caso-controle aninhado em uma coorte de trabalhadores de hospitais, Santa Catarina, Brasil Sickness-absenteeism, job demand-control model, and social support: a case-control study nested in a cohort of hospital workers, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Kleber dos Santos

    2011-12-01

    the second highest HTL among civil servants in the state, especially those working in hospitals. This is a case-control study nested in a cohort of hospital workers followed up between 07/01/2008 and 06/30/2009. The workers with HTL in this period were selected as cases and those without HTL were selected as cases matched by sex, age and working sector. The outcome was the duration of HTL and the exposure variables were JDC and supervisor and coworker social support. We used both primary and secondary data, zero-inflated negative binomial regression analysis, and socioeconomic and occupation variables in the adjustments. The data used for analysis included 425 participants (144 cases; 281 controls. Low coworker support added 2,04 (95% confidence interval (CI: 1,05-3,93 HTL days. This effect increased to 2,68 days (95% CI: 1,37-5,27 when combined with low job strain and raised 78% (95% CI: 1,02-3,12 more than JDC with high coworker support combined with high strain (iso-strain. This study uncovered the importance of coworker support for the duration of sickness-absenteeism and suggested its use for the interventions aiming to decrease the duration of HTL.

  8. The Associations between VEGF Gene Polymorphisms and Diabetic Retinopathy Susceptibility: A Meta-Analysis of 11 Case-Control Studies

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    Liyuan Han

    2014-01-01

    Full Text Available Aims. Published data on the associations of VEGF polymorphisms with diabetic retinopathy (DR susceptibility are inconclusive. A systematic meta-analysis was undertaken to clarify this topic. Methods. Data were collected from the following electronic databases: PubMed, Embase, OVID, Web of Science, Elsevier Science Direct, Excerpta Medica Database (EMBASE, and Cochrane Library with the last report up to January 10, 2014. ORs and 95% CIs were calculated for VEGF–2578C/A (rs699947, –1154G/A (rs1570360, –460T/C (rs833061, −634G>C (rs2010963, and +936C/T (rs3025039 in at least two published studies. Meta-analysis was performed in a fixed/random effect model by using the software STATA 12.0. Results. A total of 11 studies fulfilling the inclusion criteria were included in this meta-analysis. A significant relationship between VEGF+936C/T (rs3025039 polymorphism and DR was found in a recessive model (OR = 3.19, 95% CI = 1.20–8.41, and P(z=0.01 in Asian and overall populations, while a significant association was also found between –460T/C (rs833061 polymorphism and DR risk under a recessive model (OR = 2.12, 95% CI = 1.12–4.01, and P(z=0.02. Conclusions. Our meta-analysis demonstrates that +936C/T (rs3025039 is likely to be associated with susceptibility to DR in Asian populations, and the recessive model of –460T/C (rs833061 is associated with elevated DR susceptibility.

  9. Nested Cohort

    Science.gov (United States)

    NestedCohort is an R software package for fitting Kaplan-Meier and Cox Models to estimate standardized survival and attributable risks for studies where covariates of interest are observed on only a sample of the cohort.

  10. Genetic analysis of the vitamin D receptor gene in two epithelial cancers: melanoma and breast cancer case-control studies

    International Nuclear Information System (INIS)

    Vitamin D serum levels have been found to be related to sun exposure and diet, together with cell differentiation, growth control and consequently, cancer risk. Vitamin D receptor (VDR) genotypes may influence cancer risk; however, no epidemiological studies in sporadic breast cancer (BC) or malignant melanoma (MM) have been performed in a southern European population. In this study, the VDR gene has been evaluated in two epithelial cancers BC and MM. We have conducted an analysis in 549 consecutive and non-related sporadic BC cases and 556 controls, all from the Spanish population, and 283 MM cases and 245 controls. Genotyping analyses were carried out on four putatively functional SNPs within the VDR gene. An association with the minor allele A of the non-synonymous SNP rs2228570 (rs10735810, FokI, Met1Thr) was observed for BC, with an estimated odds ratio (OR) of 1.26 (95% CI = 1.02–1.57; p = 0.036). The synonymous variant rs731236 (TaqI) appeared to be associated with protection from BC (OR = 0.80, 95%CI = 0.64–0.99; p = 0.047). No statistically significant associations with MM were observed for any SNP. Nevertheless, sub-group analyses revealed an association between rs2228570 (FokI) and absence of childhood sunburns (OR = 0.65, p = 0.003), between the 3'utr SNP rs739837 (BglI) and fair skin (OR = 1.31, p = 0.048), and between the promoter SNP rs4516035 and the more aggressive tumour location in head-neck and trunk (OR = 1.54, p = 0.020). In summary, we observed associations between SNPs in the VDR gene and BC risk, and a comprehensive analysis using clinical and tumour characteristics as outcome variables has revealed potential associations with MM. These associations required confirmation in independent studies

  11. Analysis of the wood duck nesting box program on Wapanocca National Wildlife Refuge: 1977 - 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The wood duck nesting box program on Wapanocca National Wildlife Refuge has undergone transition and expansion throughout the years. These changes have occurred as...

  12. A case-control study of maternal periconceptual and pregnancy recreational drug use and fetal malformation using hair analysis.

    Directory of Open Access Journals (Sweden)

    Anna L David

    Full Text Available OBJECTIVE: Maternal recreational drug use may be associated with the development of fetal malformations such as gastroschisis, brain and limb defects, the aetiology due to vascular disruption during organogenesis. Using forensic hair analysis we reported evidence of recreational drug use in 18% of women with a fetal gastroschisis. Here we investigate this association in a variety of fetal malformations using the same method. METHODS: In a multi-centre study, women with normal pregnancies (controls and those with fetal abnormalities (cases gave informed consent for hair analysis for recreational drug metabolites using mass spectrometry. Hair samples cut at the root were tested in sections corresponding to 3 month time periods (pre and periconceptual period. RESULTS: Women whose fetus had gastroschisis, compared to women with a normal control fetus, were younger (mean age 23.78 ± SD4.79 years, 18-37 vs 29.79 ± SD6 years, 18-42, p = 0.00001, were more likely to have evidence of recreational drug use (15, 25.4% vs 21, 13%, OR2.27, 95thCI 1.08-4.78, p = 0.028, and were less likely to report periconceptual folic acid use (31, 53.4% vs 124, 77.5%, OR0.33, 95thCI 0.18-0.63, p = 0.001. Age-matched normal control women were no less likely to test positive for recreational drugs than women whose fetus had gastroschisis. After accounting for all significant factors, only young maternal age remained significantly associated with gastroschisis. Women with a fetus affected by a non-neural tube central nervous system (CNS anomaly were more likely to test positive for recreational drugs when compared to women whose fetus was normal (7, 35% vs 21, 13%, OR3.59, 95th CI1.20-10.02, p = 0.01. CONCLUSIONS: We demonstrate a significant association between non neural tube CNS anomalies and recreational drug use in the periconceptual period, first or second trimesters, but we cannot confirm this association with gastroschisis. We confirm the association of

  13. A case-control analysis of smoking and breast cancer in African American women: findings from the AMBER Consortium.

    Science.gov (United States)

    Park, Song-Yi; Palmer, Julie R; Rosenberg, Lynn; Haiman, Christopher A; Bandera, Elisa V; Bethea, Traci N; Troester, Melissa A; Viscidi, Emma; Kolonel, Laurence N; Olshan, Andrew F; Ambrosone, Christine B

    2016-06-01

    Recent population studies suggest a role of smoking in the etiology of breast cancer, but few have been conducted among African American women. In a collaborative project of four large studies, we examined associations between smoking measures and breast cancer risk by menopause and hormone receptor status [estrogen receptor-positive (ER+), ER-negative (ER-) and triple-negative (ER-, PR-, HER2-)]. The study included 5791 African American women with breast cancer and 17376 African American controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in multivariable logistic regression analysis with adjustment for study and risk factors. Results differed by menopausal status. Among postmenopausal women, positive associations were observed for long duration and greater pack-years of smoking: relative to never smoking, fully adjusted ORs were 1.14 (95% CI: 1.03-1.26) for duration ≥20 years and 1.16 (95% CI: 1.01-1.33) for ≥20 pack-years. By contrast, inverse associations were observed among premenopausal women, with ORs of 0.80 (95% CI: 0.68-95) for current smoking and 0.81 (95% CI: 0.69-0.96) for former smoking, without trends by duration. Associations among postmenopausal women were somewhat stronger for ER+ breast cancer. The findings suggest that the relation of cigarette smoking to breast cancer risk in African American women may vary by menopausal status and breast cancer subtype. PMID:27207658

  14. Woven signatures: Image analysis of weaverbird nests reveals signature weave patterns

    OpenAIRE

    Bailey, Ida; Backes, A; Walsh, Patrick; Morgan, Kate V.; Meddle, Simone; Healy, Susan D.

    2015-01-01

    In nature, many animals build structures that can be readily measured at the scale of their gross morphology (e.g. length, volume and weight). Capturing individuality as can be done with the structures designed and built by human architects or artists, however, is more challenging. Here, we tested whether computer-aided image texture classification approaches can be used to describe textural variation in the nests of weaverbirds (Ploceus species) in order to attribute nests to the individual ...

  15. Genetic polymorphism in HLA-G 3'UTR 14-bp ins/del and risk of cancer: a meta-analysis of case-control study.

    Science.gov (United States)

    Li, Tao; Huang, Haohai; Liao, Dan; Ling, Huahuang; Su, Bingguang; Cai, Maode

    2015-08-01

    Accumulating evidence has suggested that the human leucocyte antigen-G (HLA-G) 14 bp ins/del polymorphism might be related to cancer susceptibility. However, epidemiologic findings have been inconsistent. Therefore, we performed a meta-analysis of case-control study to derive a more precise estimation of this association. Electronic databases were searched to identify all eligible studies of HLA-G 14 bp ins/del polymorphism and cancer risk. Odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated to evaluate the strength of the association in fixed-effects model or random-effects model according to heterogeneity. Publication bias, sensitivity analysis and subgroup analyses based on cancer type, ethnicity, source of controls and sample size were also performed. A total of 14 case-control studies, involving 2,757 cases and 3,972 controls, were included in the present meta-analysis. The pooled analysis showed that there is no significant relationship between the HLA-G 14 bp ins/del polymorphism and cancer susceptibility under the genetic models (for the allele model del vs. ins: OR 1.13, 95 % CI 1.00-1.27; for the homozygote comparison model del/del vs. ins/ins: OR 1.22, 95 % CI 0.95-1.56; for the dominant model del/del + ins/del vs. ins/ins: OR 1.15, 95 % CI 0.94-1.42; for recessive model del/del vs. ins/del + ins/ins: OR 1.13, 95 % CI 0.96-1.34; respectively). Subgroup analyses indicated significant association among breast cancer, population based control and the large sample size group in some genetic models. Our investigations demonstrate that genotypes for the HLA-G 14 bp ins/del polymorphism may be not associated with overall cancer risk. In a subgroup meta-analysis, however, HLA-G 14-bp ins/del polymorphism might contribute to breast cancer susceptibility.

  16. Hawaii ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seabird nesting colonies in coastal Hawaii. Vector points in this data set represent locations of...

  17. Louisiana ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seabird and wading bird nesting colonies in coastal Louisiana. Vector points in this data set...

  18. Molecular analysis of dolphin morbillivirus: A new sensitive detection method based on nested RT-PCR.

    Science.gov (United States)

    Centelleghe, Cinzia; Beffagna, Giorgia; Zanetti, Rossella; Zappulli, Valentina; Di Guardo, Giovanni; Mazzariol, Sandro

    2016-09-01

    Cetacean Morbillivirus (CeMV) has been identified as the most pathogenic virus for cetaceans. Over the past three decades, this RNA virus has caused several outbreaks of lethal disease in odontocetes and mysticetes worldwide. Isolation and identification of CeMV RNA is very challenging in whales because of the poor preservation status frequently shown by tissues from stranded animals. Nested reverse transcription polymerase chain reaction (nested RT-PCR) is used instead of conventional RT-PCR when it is necessary to increase the sensitivity and the specificity of the reaction. This study describes a new nested RT-PCR technique useful to amplify small amounts of the cDNA copy of Cetacean morbillivirus (CeMV) when it is present in scant quantity in whales' biological specimens. This technique was used to analyze different tissues (lung, brain, spleen and other lymphoid tissues) from one under human care seal and seven cetaceans stranded along the Italian coastline between October 2011 and September 2015. A well-characterized, 200 base pair (bp) fragment of the dolphin Morbillivirus (DMV) haemagglutinin (H) gene, obtained by nested RT-PCR, was sequenced and used to confirm DMV positivity in all the eight marine mammals under study. In conclusion, this nested RT-PCR protocol can represent a sensitive detection method to identify CeMV-positive, poorly preserved tissue samples. Furthermore, this is also a rather inexpensive molecular technique, relatively easy to apply. PMID:27220282

  19. Traditional Dietary Pattern Increases Risk of Prostate Cancer in Argentina: Results of a Multilevel Modeling and Bias Analysis from a Case-Control Study

    Directory of Open Access Journals (Sweden)

    Camila Niclis

    2015-01-01

    Full Text Available There is increasing evidence that dietary habits play a role in prostate cancer (PC occurrence. Argentinean cancer risk studies require additional attention because of the singular dietary pattern of this population. A case-control study (147 PC cases, 300 controls was conducted in Córdoba (Argentina throughout 2008–2013. A principal component factor analysis was performed to identify dietary patterns. A mixed logistic regression model was applied, taking into account family history of cancer. Possible bias was evaluated by probabilistic bias analysis. Four dietary patterns were identified: Traditional (fatty red meats, offal, processed meat, starchy vegetables, added sugars and sweets, candies, fats, and vegetable oils, Prudent (nonstarchy vegetables, whole grains, Carbohydrate (sodas/juices and bakery products, and Cheese (cheeses. High adherence to the Traditional (OR 2.82, 95%CI: 1.569–5.099 and Carbohydrate Patterns (OR 2.14, 95%CI: 1.470–3.128 showed a promoting effect for PC, whereas the Prudent and Cheese Patterns were independent factors. PC occurrence was also associated with family history of PC. Bias adjusted ORs indicate that the validity of the present study is acceptable. High adherence to characteristic Argentinean dietary patterns was associated with increased PC risk. Our results incorporate original contributions to knowledge about scenarios in South American dietary patterns and PC occurrence.

  20. A hybrid Bayesian hierarchical model combining cohort and case-control studies for meta-analysis of diagnostic tests: Accounting for partial verification bias.

    Science.gov (United States)

    Ma, Xiaoye; Chen, Yong; Cole, Stephen R; Chu, Haitao

    2014-05-26

    To account for between-study heterogeneity in meta-analysis of diagnostic accuracy studies, bivariate random effects models have been recommended to jointly model the sensitivities and specificities. As study design and population vary, the definition of disease status or severity could differ across studies. Consequently, sensitivity and specificity may be correlated with disease prevalence. To account for this dependence, a trivariate random effects model had been proposed. However, the proposed approach can only include cohort studies with information estimating study-specific disease prevalence. In addition, some diagnostic accuracy studies only select a subset of samples to be verified by the reference test. It is known that ignoring unverified subjects may lead to partial verification bias in the estimation of prevalence, sensitivities, and specificities in a single study. However, the impact of this bias on a meta-analysis has not been investigated. In this paper, we propose a novel hybrid Bayesian hierarchical model combining cohort and case-control studies and correcting partial verification bias at the same time. We investigate the performance of the proposed methods through a set of simulation studies. Two case studies on assessing the diagnostic accuracy of gadolinium-enhanced magnetic resonance imaging in detecting lymph node metastases and of adrenal fluorine-18 fluorodeoxyglucose positron emission tomography in characterizing adrenal masses are presented.

  1. CD20-negative de novo diffuse large B-cell lymphoma in HIV-negative patients: A matched case-control analysis in a single institution

    Directory of Open Access Journals (Sweden)

    Li Ya-Jun

    2012-05-01

    Full Text Available Abstract Background HIV-negative, CD20-negative de novo diffuse large B-cell lymphoma (DLBCL patients has rarely been reported. To elucidate the nature of this entity, we retrospectively reviewed the data of 1,456 consecutive de novo DLBCL patients who were treated at Sun Yat-Sen University Cancer Center between January 1999 and March 2011. Methods The pathologic characteristics of CD20-negative patients, clinical features, response to initial treatment, and outcomes of 28 patients with available clinical data (n = 21 were reviewed. Then, a matched case-control (1:3 analysis was performed to compare patients with CD20-negative and -positive DLBCL. Results The median age of the 28 CD20-negative DLBCL patients was 48 years, with a male-female ratio of 20:8. Seventeen of 22 (77.3% CD20-negative DLBCL cases were of the non-germinal centre B-cell (non-GCB subtype. High Ki67 expression (≥80%, an index of cell proliferation, was demonstrated in 17 of 24 (70.8% cases. Extranodal involvement (≥ 1 site was observed in 76.2% of the patients. Following initial therapy, 9 of 21 (42.9% cases achieved complete remission, 4 (19% achieved partial remission, 1 (4.8% had stable disease, and 7 (33.3% had disease progression. The median overall survival was 23 months. The 3-year progression-free survival (PFS and overall survival (OS rates were 30.5% and 35%, respectively. A matched case-control analysis showed that patients with CD20-negative and -positive DLBCL did not exhibit a statistically significant difference with respect to the main clinical characteristics (except extranodal involvement, whereas the patients with CD20-positive DLBCL had a better survival outcome with 3-year PFS (P = 0.008 and OS (P = 0.008 rates of 52% and 74.1%, respectively. Conclusions This study suggests that HIV-negative, CD20-negative de novo DLBCL patients have a higher proportion of non-GCB subtype, a higher proliferation index, more frequent extranodal involvement, a poorer

  2. Prediabetes Is Associated with HNF-4α P2 Promoter Polymorphism rs1884613: A Case-Control Study in Han Chinese Population and an Updated Meta-Analysis

    Science.gov (United States)

    Wang, Changyi; Chen, Sihan; Zhang, Tao; Chen, Zhongwei; Liu, Shengyuan; Peng, Xiaolin; Ma, Jianping; Zhong, Xiaohong; Yan, Yanqiong; Tang, Linlin; Mai, Yifeng; Han, Liyuan

    2014-01-01

    Background. Controversy remains for the association between hepatocyte nuclear factor 4α (HNF-4α) P2 promoter polymorphism rs1884613 and type 2 diabetes (T2D). There was no association test of this polymorphism with prediabetes and T2D in the Chinese population. Moreover, an updated meta-analysis in various ethnic groups is needed to establish the contribution of rs1884613 to T2D risk. Methods. Using the Sequenom MassARRAY platform approach, we genotyped rs1884613 of HNF-4α in the P2 promoter region among 490 T2D patients, 471 individuals with prediabetes, and 575 healthy controls. All the individuals were recruited from 16 community health service centers in Nanshan district in Shenzhen province. Using STATA 11.0 software, meta-analysis was performed to summarize the overall contribution of rs1884613 to T2D risk. Results. Polymorphism rs1884613 was associated with genetic susceptibility to prediabetes in the whole samples (OR = 1.40, 95% CI = 1.16–1.68, P = 0.0001) and the female subgrouped samples (OR = 1.48, 95% CI = 1.14–1.92, P = 0.003) after adjusting for age and body mass index (BMI). In contrast, there was no association of rs1884613 with T2D in the whole samples and male in our case-control study and meta-analysis. Conclusions. Our results suggest that rs1884613 contributes to susceptibility to prediabetes, whereas this polymorphism may not play an important role in the development of T2D. PMID:25400315

  3. Prediabetes Is Associated with HNF-4α P2 Promoter Polymorphism rs1884613: A Case-Control Study in Han Chinese Population and an Updated Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Changyi Wang

    2014-01-01

    Full Text Available Background. Controversy remains for the association between hepatocyte nuclear factor 4α (HNF-4α P2 promoter polymorphism rs1884613 and type 2 diabetes (T2D. There was no association test of this polymorphism with prediabetes and T2D in the Chinese population. Moreover, an updated meta-analysis in various ethnic groups is needed to establish the contribution of rs1884613 to T2D risk. Methods. Using the Sequenom MassARRAY platform approach, we genotyped rs1884613 of HNF-4α in the P2 promoter region among 490 T2D patients, 471 individuals with prediabetes, and 575 healthy controls. All the individuals were recruited from 16 community health service centers in Nanshan district in Shenzhen province. Using STATA 11.0 software, meta-analysis was performed to summarize the overall contribution of rs1884613 to T2D risk. Results. Polymorphism rs1884613 was associated with genetic susceptibility to prediabetes in the whole samples (OR = 1.40, 95% CI = 1.16–1.68, P=0.0001 and the female subgrouped samples (OR = 1.48, 95% CI = 1.14–1.92, P=0.003 after adjusting for age and body mass index (BMI. In contrast, there was no association of rs1884613 with T2D in the whole samples and male in our case-control study and meta-analysis. Conclusions. Our results suggest that rs1884613 contributes to susceptibility to prediabetes, whereas this polymorphism may not play an important role in the development of T2D.

  4. Nasopharyngeal Case-Control Study

    Science.gov (United States)

    A case-control study conducted in Taiwan between 1991-1994 among approximately 1,000 individuals to examine the role of viral, environmental, and genetic factors associated with the development of nasopharyngeal carcinoma

  5. Application of nested PCR-DGGE (denaturing gradient gel electrophoresis) for the analysis of ciliate communities in soils.

    Science.gov (United States)

    Shimano, Satoshi; Sambe, Mitsuo; Kasahara, Yasuhiro

    2012-01-01

    Ciliates play important roles as prey and predators in ecosystems. Changes in the ciliate community can affect the composition and population of microfauna and microflora in ecosystems. To investigate the structure of ciliate communities, we developed a nested PCR-DGGE method, which combines a universal eukaryotic-specific primer set in the first PCR step with a ciliate-specific primer set in the second PCR step, to amplify 18S rRNA genes from ciliates. The 300 bp DGGE fragments generated more bands on the gel than the 600 bp DGGE fragments. Prior to bead beating, DNA extraction of ciliates from soil samples was optimized with a combination of freeze-thaw cycles and ultrasonication. We applied this nested PCR-DGGE method to agricultural soils amended with 0, 120, 300, and 600 t ha⁻¹ year⁻¹ of livestock slurry. The results from the DGGE profiles and principal component analysis (PCA) revealed that the supplement of slurry to soils influenced the ciliate communities. From phylogenetic analysis, 108 DGGE bands were assigned to six classes, which included Spirotrichea and Colpodea, of the subphylum Intramacronucleata, and one class of the subphylum Postciliodesmatophora. These results indicated that a wide variety of taxonomic groups were detected by DGGE profiling. Thus, the nested PCR-DGGE method described here could clearly differentiate between ciliate communities within soil samples and allowed for the phylogenetic identification of these ciliates at the class level.

  6. Analysis of microbial communities in doenjang, a Korean fermented soybean paste, using nested PCR-denaturing gradient gel electrophoresis.

    Science.gov (United States)

    Kim, Tae-Woon; Lee, Jun-Hwa; Kim, Sung-Eon; Park, Min-Hee; Chang, Hae Choon; Kim, Hae-Yeong

    2009-05-31

    Doenjang is a traditional Korean fermented soybean paste that provides a major source of protein. The microbial diversity of 10 samples of doenjang (5 commercially manufactured products and 5 homemade products) was investigated using nested PCR-denaturing gradient gel electrophoresis (DGGE). In the first step, the nearly complete 16S rRNA and 18S rRNA genes were amplified using universal primers. Subsequently, these products were used as a template in a nested PCR to obtain fragments suitable for DGGE. The bacterial DGGE profile targeting the V3 region of the 16S rRNA gene indicated that lactic acid bacteria such as Leuconostoc mesenteroide, Tetragenococcus halophilus, and Enterococcus faecium were the predominant species. However, bands corresponding to Bacillus species, known to be the main organisms in doenjang, were not detected under the conditions described above. When selective PCR was conducted using a primer specific for Bacillus species, Bacillus subtilis and B. licheniformis were detected in several doenjang samples. In analysis of fungi, Mucor plumbeus, Aspergillus oryzae, and Debaryomyces hansenii were the most common species in the doenjang samples. On the basis of DGGE, a few differences in community structure were found for different samples. Also, cluster analysis of the DGGE profile revealed that the microbial diversity did not differ clearly between commercially manufactured and homemade products. The nested PCR-DGGE technique was used for the first time in this study to asses a microbial community in doenjang and proved to be effective in profiling microbial diversity. PMID:19324443

  7. Genetic association between NFKB1 −94 ins/del ATTG Promoter Polymorphism and cancer risk: a meta-analysis of 42 case-control studies

    Science.gov (United States)

    Wang, Duan; Xie, Tianhang; Xu, Jin; Wang, Haoyang; Zeng, Weinan; Rao, Shuquan; Zhou, Kai; Pei, Fuxing; Zhou, Zongke

    2016-01-01

    Accumulating evidences have indicated that the functional -94 ins/del ATTG polymorphism in the promoter region of human nuclear factor-kappa B1 (NFKB1) gene may be associated with cancer risk. However, some studies yielded conflicting results. To clarify precise association, we performed a comprehensive meta-analysis of 42 case-control studies involving 43,000 subjects (18,222 cases and 24,778 controls). The overall results suggested that the -94 ins/del ATTG polymorphism had a decreased risk for cancer, reaching significant levels in five genetic models (dominant model: OR = 0.86, 95% CI = 0.79–0.95, P = 0.002; recessive model: OR = 0.84, 95% CI = 0.74–0.94, P = 0.003; homozygous model: OR = 0.77, 95% CI = 0.66–0.90, P = 0.001; heterozygous model: OR = 0.90, 95% CI = 0.83–0.98, P = 0.011; allelic model: OR = 0.89, 95% CI = 0.83–0.96, P = 0.002). Furthermore, the -94 ins/del ATTG polymorphism could confer a decreased or increased risk for cancer development among Asians and Caucasians, respectively. Additionally, the stratification analysis revealed a significant association between the variant and decreased risk of oral, ovarian, and nasopharyngeal cancer in Asians. After we adjusted p values using the Benjamini-Hochberg false discovery rate method to account for multiple comparisons, these associations remained. PMID:27443693

  8. Exposure to ionizing radiation during dental X-rays is not associated with risk of developing meningioma: a meta-analysis based on seven case-control studies.

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    Ping Xu

    Full Text Available Many observational studies have found that exposure to dental X-rays is associated with the risk of development of meningioma. However, these findings are inconsistent. We conducted a meta-analysis to assess the relationship between exposure to dental X-rays and the risk of development of meningioma.The PubMed and EMBASE databases were searched to identify eligible studies. Summary odds ratio (OR estimates and 95% confidence intervals (95% CIs were used to compute the risk of meningioma development according to heterogeneity. Subgroup and sensitivity analyses were performed to further explore the potential heterogeneity. Finally, publication bias was assessed.Seven case-control studies involving 6,174 patients and 19,459 controls were included in the meta-analysis. Neither exposure to dental X-rays nor performance of full-mouth panorex X-rays was associated with an increased risk of development of meningioma (overall: OR, 0.97; 95% CI, 0.70-1.32; dental X-rays: OR, 1.05; 95% CI, 0.89-1.25; panorex X-rays: OR, 1.01; 95% CI, 0.76-1.34. However, exposure to bitewing X-rays was associated with a slightly increased risk of development of meningioma (OR, 1.73; 95% CI, 1.28-2.34. Similar results were obtained in the subgroup and sensitivity analyses. Little evidence of publication bias was observed.Based on the currently limited data, there is no association between exposure to dental X-rays and the risk of development of meningioma. However, these results should be cautiously interpreted because of the heterogeneity among studies. Additional large, high-quality clinical trials are needed to evaluate the association between exposure to dental X-rays and the risk of development of meningioma.

  9. Nested Sequents

    CERN Document Server

    Brünnler, Kai

    2010-01-01

    We see how nested sequents, a natural generalisation of hypersequents, allow us to develop a systematic proof theory for modal logics. As opposed to other prominent formalisms, such as the display calculus and labelled sequents, nested sequents stay inside the modal language and allow for proof systems which enjoy the subformula property in the literal sense. In the first part we study a systematic set of nested sequent systems for all normal modal logics formed by some combination of the axioms for seriality, reflexivity, symmetry, transitivity and euclideanness. We establish soundness and completeness and some of their good properties, such as invertibility of all rules, admissibility of the structural rules, termination of proof-search, as well as syntactic cut-elimination. In the second part we study the logic of common knowledge, a modal logic with a fixpoint modality. We look at two infinitary proof systems for this logic: an existing one based on ordinary sequents, for which no syntactic cut-eliminatio...

  10. A meta-analysis of lesser prairie-chicken nesting and brood-rearing habitats: implications for habitat management

    Science.gov (United States)

    Hagen, Christian A.; Grisham, Blake A.; Boal, Clint W.; Haukos, David A.

    2013-01-01

    The distribution and range of lesser prairie-chicken (Tympanuchus pallidicinctus) has been reduced by >90% since European settlement of the Great Plains of North America. Currently, lesser prairie-chickens occupy 3 general vegetation communities: sand sagebrush (Artemisia filifolia), sand shinnery oak (Quercus havardii), and mixed-grass prairies juxtaposed with Conservation Reserve Program grasslands. As a candidate for protection under the Endangered Species Act, there is a need for a synthesis that characterizes habitat structure rangewide. Thus, we conducted a meta-analysis of vegetation characteristics at nest sites and brood habitats to determine whether there was an overall effect (Hedges' d) of habitat selection and to estimate average (95% CI) habitat characteristics at use sites. We estimated effect sizes (di) from the difference between use (nests and brood sites) and random sampling sites for each study (n = 14), and derived an overall effect size (d++). There was a general effect for habitat selection as evidenced by low levels of variation in effect sizes across studies and regions. There was a small to medium effect (d++) = 0.20-0.82) of selection for greater vertical structure (visual obstruction) by nesting females in both vegetation communities, and selection against bare ground (d++ = 0.20-0.58). Females with broods exhibited less selectivity for habitat components except for vertical structure. The variation of d++ was greater during nesting than brooding periods, signifying a seasonal shift in habitat use, and perhaps a greater range of tolerance for brood-rearing habitat. The overall estimates of vegetation cover were consistent with those provided in management guidelines for the species.

  11. The role of WWOX polymorphisms on COPD susceptibility and pulmonary function traits in Chinese: a case-control study and family-based analysis

    Science.gov (United States)

    Xie, Chenli; Chen, Xiaoliang; Qiu, Fuman; Zhang, Lisha; Wu, Di; Chen, Jiansong; Yang, Lei; Lu, Jiachun

    2016-01-01

    Single nucleotide polymorphisms (SNPs) in the WW domain containing oxidoreductase (WWOX) gene were recently identified to be quantitative trait loci for lung function and thus likely to be susceptible biomarkers for COPD. However, the associations between WWOX SNPs and COPD risk are still unclear. Here, by conducting a two-center case-control study including 1511 COPD cases and 1677 controls and a family-based analysis comprising 95 nuclear pedigrees, we tested the associations between five SNPs that are rs10220974C >T, rs3764340C >G, rs12918952G >A, rs383362G >T, rs12828G >A of WWOX and COPD risk as well as the hereditary inclination of these loci among COPD families. We found that the SNP rs383362G >T was significantly associated with an increased risk of COPD in a T allele-number dependent-manner (OR = 1.30, 95%CI = 1.11 - 1.52). The T allele was more prone to over transmit to sick children and sibs than the G allele (Z = 2.900, P = 0.004). Moreover, the forced expiratory volume in one second/forced vital capacity (FEV1/FVC), FEV1/predicted-FEV1 and annual FEV1 also significantly decreased in the rs383362T carriers compared to the rs383362GG carriers. For other SNPs, no significant association was observed for COPD and pulmonary function. Taken together, our data demonstrated that the SNP rs383362G >T of WWOX plays a role in COPD inheritance. PMID:26902998

  12. TNF-α -308 G > A (rs1800629) Polymorphism is Associated with Celiac Disease: A Meta-analysis of 11 Case-Control Studies

    Science.gov (United States)

    Khan, Saif; Mandal, Raju K.; Jawed, Arshad; Dar, Sajad A.; Wahid, Mohd; Panda, Aditya K.; Areeshi, Mohammed Y.; Ahmed Khan, Md. Ekhlaque; Haque, Shafiul

    2016-09-01

    Celiac disease (CD) remains one of the most significant autoimmune diseases worldwide. The pathogenesis of CD is not clearly understood and is probably attributed to genomic variations and host genetic make-up. Case-control and cohort studies of the association between the TNF-α -308 G > A (rs1800629) polymorphism and CD susceptibility have yielded inconsistent results. In this study, PubMed, EMBASE, and Google Scholar web-databases were searched for pertinent reports showing association of TNF-α -308 G > A gene with CD risk. A total of eleven reports involving 1774 controls and 1147 CD cases were included. Significant associations in four genetic models, viz. variant allele (A vs. G: p = 0.001 OR = 2.051, 95% CI = 1.452-2.895), variant homozygous (AA vs. GG: p = 0.001 OR = 6.626, 95% CI = 3.569-12.300), recessive (AA vs. GG + AG: p = 0.001 OR = 4.766, 95% CI = 3.177-7.152) and dominant (AA + AG vs. GG: p = 0.008 OR = 1.910, 95% CI = 1.181-3.088) were found in comparison with wild type homozygous GG genotype. However, heterozygous genetic model did not show any association. Sensitivity analysis revealed stable and statistically robust results. Our results suggest that TNF-α -308 G > A gene polymorphism significantly contributes to CD susceptibility.

  13. TNF-α -308 G > A (rs1800629) Polymorphism is Associated with Celiac Disease: A Meta-analysis of 11 Case-Control Studies.

    Science.gov (United States)

    Khan, Saif; Mandal, Raju K; Jawed, Arshad; Dar, Sajad A; Wahid, Mohd; Panda, Aditya K; Areeshi, Mohammed Y; Ahmed Khan, Md Ekhlaque; Haque, Shafiul

    2016-01-01

    Celiac disease (CD) remains one of the most significant autoimmune diseases worldwide. The pathogenesis of CD is not clearly understood and is probably attributed to genomic variations and host genetic make-up. Case-control and cohort studies of the association between the TNF-α -308 G > A (rs1800629) polymorphism and CD susceptibility have yielded inconsistent results. In this study, PubMed, EMBASE, and Google Scholar web-databases were searched for pertinent reports showing association of TNF-α -308 G > A gene with CD risk. A total of eleven reports involving 1774 controls and 1147 CD cases were included. Significant associations in four genetic models, viz. variant allele (A vs. G: p = 0.001; OR = 2.051, 95% CI = 1.452-2.895), variant homozygous (AA vs. GG: p = 0.001; OR = 6.626, 95% CI = 3.569-12.300), recessive (AA vs. GG + AG: p = 0.001; OR = 4.766, 95% CI = 3.177-7.152) and dominant (AA + AG vs. GG: p = 0.008; OR = 1.910, 95% CI = 1.181-3.088) were found in comparison with wild type homozygous GG genotype. However, heterozygous genetic model did not show any association. Sensitivity analysis revealed stable and statistically robust results. Our results suggest that TNF-α -308 G > A gene polymorphism significantly contributes to CD susceptibility. PMID:27597177

  14. Obsessive-Compulsive Disorder and quality of life outcomes: protocol for a systematic review and meta-analysis of cross-sectional case-control studies

    Directory of Open Access Journals (Sweden)

    Anna Coluccia

    2015-06-01

    Full Text Available Background. Obsessive-compulsive Disorder (OCD is a chronic disabling psychological condition, which can severely affect quality of life (QOL. Growing interest has been dedicated to assessing which domains of QOL are more severely affected in patients with OCD. However, research yielded conflicting findings. Investigating QOL in OCD could suggest the need for integration of interventions aimed at improving those specific domains more severely impaired by obsessions and compulsions.Methods. We will conduct a systematic review of cross-sectional case-control studies according to PRISMA guidelines, where patients with a primary OCD diagnosis were compared on QOL outcomes with healthy controls. Primary objectives will be to examine differences in QOL outcomes between patients with OCD and healthy controls, and to assess which QOL domains are more severely impaired in patients compared with controls, particularly subjective well-being, social and interpersonal functioning, work functioning, and family functioning. Subsequently, the study will investigate potential moderators of QOL in OCD, including participants characteristics (age, sex, presence of comorbid personality disorders, OCD symptom severity, severity of concurrent depressive symptoms, duration of OCD symptoms, and generational cohort, and study characteristics (date of publication and methodological quality of the studies. Online databases will be searched (PsycINFO, PubMED, Science Direct, Cinahl, Biological Abstracts, Psyclit, Embase, The Cochrane Central Register of Controlled Trials, and Google Scholar. To locate unpublished records, conference abstracts, doctoral dissertations and theses will be handsearched, and experts will be contacted. Statistical analyses will be performed though random effect model meta-analysis. Risk of bias assessments will be conducted using the instrument Methodological Index for Non-Randomized Studies.

  15. A nested case-control study on the influencing factors of tuberculosis among people living with HIV/AIDS in Hunan province%湖南省HIV/AIDS人群结核发病影响因素的巢式病例对照研究

    Institute of Scientific and Technical Information of China (English)

    陈梦施; 杨华林; 陈艳芳; 谭红专; 白丽琼; 张艳辉; 刘军; 李桂平

    2010-01-01

    Objective To determine the risk factors related to tuberculosis infection among people living with HIV/AIDS and to develop strategies for preventing the co-infection.Methods A 1:2matched nested case-control study was carried out to analyze the influencing factors of tuberculosis among people living with HIV/AIDS.Results 1018 people living with HIV/AIDS were followed up for one year with a total number of 736.75 person-years,among them 62 tuberculosis cases were diagnosed.The incidence density of tuberculosis among people living with HIV/AIDS was 8.42 persons per 100 person-years.Factors as education level(OR=0.483),vaccination history of Bacille Calmette Guerin(OR=0.561),CD_4~+ count T-lymphocyte(OR=0.356),unemployment(OR=1.976),living alone(OR=2.646),and smoking(OR=2.215)were significantly related to the prevalence of tuberculosis among people living with HIV/AIDS.Conclusion High education level,with vaccination history of Bacille Calmette Guerin and high level of CD_4~+ T-lymphocyte count were protective factors while being unemployed,living alone,and smoking habit were risk factors related to the prevalence of tuberculosis among people living with HIV/AIDS.%目的 探讨HIV/AIDS人群发生结核病的危险因素.方法 采用1:2匹配的巢式病例对照研究方法分析HIV/AIDS人群发生结核的危险因素.结果 对1018例未患结核的HIV/AIDS人群随访观察1年,累计观察736.75人年,共检查出结核病患者62例,HIV/AIDS人群结核病发病密度为8.42人/100人年(62人/736.75人年).文化程度(OR=0.483)、卡介苗接种史(OR=0.561)、CD_4~+T淋巴细胞数(OR=0.356)、无业(OR=1.976)、单身(OR=2.646)和吸烟(OR=2.215)等因素与HIV/AIDS人群发生结核病有关.结论 文化程度高、有卡介苗接种史和CD_4~+T淋巴细胞数高是HIV/AIDS人群患结核病的保护因素;无业、单身和吸烟是HIV/AIDS人群患结核病的危险因素.

  16. A nested case-control study on the relationship between depression and relapse in patients with condyloma acuminatum%尖锐湿疣患者的抑郁情绪与治疗后复发关联的巢式病例对照研究

    Institute of Scientific and Technical Information of China (English)

    姚海燕; 郑莉; 包满珍

    2011-01-01

    Objective To explore the relationship between depression and relapse irt patients with condyloma acuminatum (CA) prospectively.Methods Using nested case-control study, the depression score was measured prospectively in a CA patient cohort, and 46 cases with relapse of CA and 46 controls without relapse of CA matched for gender and age ( ± 5 a) were recruited in follow-up phase.Conditional Logistic regression models were constructed to estimate OR and 95% CI.Results Compared with matched controls, the cases with relapse of CA in 3 month follow-up phase showed higher depression score significantly (t = 6.77, P< 0.001 ).After adjustment for the course of the disease, mild depression ( OR = 1.13,95 % CI = 1.01 ~ 1.58), moderate depression ( OR = 2.31,95% CI = 1.12 ~ 2.84), and major depression ( OR = 4.1O,95% CI = 2.69~ 5.85 ) were significantly associated with relapse of CA and a clear dose-response effect was also observed.Conclusions The prevention and treatment of depression are beneficial to the decrease of relapse incidence in patients with CA.%目的 前瞻性地探讨尖锐湿疣(condyloma acuminatum,CA)患者就诊时的抑郁状态与治疗后复发的关系.方法 采用巢氏病例对照研究的方法,先对160名门诊接受治疗的CA患者近1周的抑郁状态进行测定,并采用抑郁自评量表进行评分,以3个月随诊期间出现的46名CA复发患者组成病例组,从同期未复发的患者中选择对照,对照与病例按1∶1匹配性别、年龄(±5岁).应用条件Logistic回归模型计算OR值及其95% CI,分析就诊时CA患者的抑郁状态与治疗后病情复发的关系.结果 CA复发病例的抑郁评分高于同期未复发病例的抑郁评分,且差异有统计学意义(t=6.77,P<0.001).调整病程对抑郁与CA复发可能造成的影响后,轻度抑郁(50~59)、中度抑郁(60~69)和重度抑郁(70~)与CA复发关联的OR值及95% CI分别为1.13(1.01~1.58)、2.31(1.12~2.84)和4.10(2.69~5

  17. The effect of health-facility admission and skilled birth attendant coverage on maternal survival in India: a case-control analysis.

    Directory of Open Access Journals (Sweden)

    Ann L Montgomery

    Full Text Available BACKGROUND: Research in areas of low skilled attendant coverage found that maternal mortality is paradoxically higher in women who seek obstetric care. We estimated the effect of health-facility admission on maternal survival, and how this effect varies with skilled attendant coverage across India. METHODS/FINDINGS: Using unmatched population-based case-control analysis of national datasets, we compared the effect of health-facility admission at any time (antenatal, intrapartum, postpartum on maternal deaths (cases to women reporting pregnancies (controls. Probability of maternal death decreased with increasing skilled attendant coverage, among both women who were and were not admitted to a health-facility, however, the risk of death among women who were admitted was higher (at 50% coverage, OR = 2.32, 95% confidence interval 1.85-2.92 than among those women who were not; while at higher levels of coverage, the effect of health-facility admission was attenuated. In a secondary analysis, the probability of maternal death decreased with increasing coverage among both women admitted for delivery or delivered at home but there was no effect of admission for delivery on mortality risk (50% coverage, OR = 1.0, 0.80-1.25, suggesting that poor quality of obstetric care may have attenuated the benefits of facility-based care. Subpopulation analysis of obstetric hemorrhage cases and report of 'excessive bleeding' in controls showed that the probability of maternal death decreased with increasing skilled attendant coverage; but the effect of health-facility admission was attenuated (at 50% coverage, OR = 1.47, 0.95-1.79, suggesting that some of the effect in the main model can be explained by women arriving at facility with complications underway. Finally, highest risk associated with health-facility admission was clustered in women with education ≤ 8 years. CONCLUSIONS: The effect of health-facility admission did vary by skilled attendant coverage, and

  18. Single nucleotide polymorphisms in candidate genes and dengue severity in children: a case-control, functional and meta-analysis study.

    Science.gov (United States)

    Xavier-Carvalho, Caroline; Gibson, Gerusa; Brasil, Patrícia; Ferreira, Ralph X; de Souza Santos, Reinaldo; Gonçalves Cruz, Oswaldo; de Oliveira, Solange Artimos; de Sá Carvalho, Marília; Pacheco, Antonio G; Kubelka, Claire F; Moraes, Milton O

    2013-12-01

    Dengue is an arthropod-borne emerging viral disease with high morbidity and mortality risk in tropical countries like Brazil. Clinical manifestations are vast, ranging from asymptomatic to most severe forms of dengue such as shock. Previous data have shown that host genetics play a role in disease susceptibility and severity. Herein, we have tested the association of single nucleotide polymorphisms (SNPs) at TNF, IL10, MIF, DCSIGN, CLEC5A, NOD2, CCR5 and MRC1 as candidate genes using a matched case-control study design including 88 severe children cases of dengue patients and 335 healthy unrelated subjects that was also separated in IgG(+) and IgG(-) controls. We demonstrated that the TT genotype of CLEC5A SNP (rs1285933 C>T) is associated with dengue severity (OR=2.25; p=0.03) and that GG genotype of -336G>A DCSIGN (CD209) SNP is associated with protection to severe dengue (OR=0.12; p=0.04). Both comparisons were borderline significant when cases were compared with IgG(+) controls subgroup. Nevertheless, genotype-phenotype correlation was also assessed using serum levels of TNF from infected patients at the onset of dengue fever, and CT/TT carriers in CLEC5A secreted higher levels of TNF than CC individuals in 5-7 days of infection. No significant difference was observed in TNF levels between genotypes GG versus AG/AA at DCSIGN promoter. Next, we performed a meta-analysis retrieving results from the literature for -336G>A DCSIGN and -308G>A TNF SNPs demonstrating that the consensus estimates of these SNPs indicated no association with dengue severity (when compared to Dengue fever) in the overall analysis. But, a subgroup analysis in the -336G>A DCSIGN, the G allele was associated with severe dengue susceptibility in Asians (ORallele=2.77; p=0.0001; ORcarriers=2.99; p=0.0001) and protection in Brazilians (ORallele=0.66; p=0.013). In summary, our results suggest that genetic variations at CLEC5A increase the risk and regulate TNF secretion in dengue severity among

  19. Association of p53 codon72 Arg>Pro polymorphism with susceptibility to nasopharyngeal carcinoma: evidence from a case-control study and meta-analysis.

    Science.gov (United States)

    Sahu, S K; Chakrabarti, S; Roy, S D; Baishya, N; Reddy, R R; Suklabaidya, S; Kumar, A; Mohanty, S; Maji, S; Suryanwanshi, A; Rajasubramaniam, S; Asthana, M; Panda, A K; Singh, S P; Ganguly, S; Shaw, O P; Bichhwalia, A K; Sahoo, P K; Chattopadhyay, N R; Chatterjee, K; Kundu, C N; Das, A K; Kannan, R; Zorenpuii; Zomawia, E; Sema, S A; Singh, Y I; Ghosh, S K; Sharma, K; Das, B S; Choudhuri, T

    2016-01-01

    Tumor suppressor p53 is a critical player in the fight against cancer as it controls the cell cycle check point, apoptotic pathways and genomic stability. It is known to be the most frequently mutated gene in a wide variety of human cancers. Single-nucleotide polymorphism of p53 at codon72 leading to substitution of proline (Pro) in place of arginine (Arg) has been identified as a risk factor for development of many cancers, including nasopharyngeal carcinoma (NPC). However, the association of this polymorphism with NPC across the published literature has shown conflicting results. We aimed to conduct a case-control study for a possible relation of p53 codon72 Arg>Pro polymorphism with NPC risk in underdeveloped states of India, combine the result with previously available records from different databases and perform a meta-analysis to draw a more definitive conclusion. A total of 70 NPC patients and 70 healthy controls were enrolled from different hospitals of north-eastern India. The p53 codon72 Arg>Pro polymorphism was typed by polymerase chain reaction, which showed an association with NPC risk. In the meta-analysis consisting of 1842 cases and 2330 controls, it was found that individuals carrying the Pro allele and the ProPro genotype were at a significantly higher risk for NPC as compared with those with the Arg allele and the ArgArg genotype, respectively. Individuals with a ProPro genotype and a combined Pro genotype (ProPro+ArgPro) also showed a significantly higher risk for NPC over a wild homozygote ArgArg genotype. Additionally, the strength of each study was tested by power analysis and genotype distribution by Hardy-Weinberg equilibrium. The outcome of the study indicated that both allele frequency and genotype distribution of p53 codon72 Arg>Pro polymorphism were significantly associated with NPC risk. Stratified analyses based on ethnicity and source of samples supported the above result. PMID:27159678

  20. Lung cancer risk among cooks when accounting for tobacco smoking : a pooled analysis of case-control studies from Europe, Canada, New Zealand, and China

    NARCIS (Netherlands)

    Bigert, Carolina; Gustavsson, Per; Straif, Kurt; Pesch, Beate; Brüning, Thomas; Kendzia, Benjamin; Schüz, Joachim; Stücker, Isabelle; Guida, Florence; Brüske, Irene; Wichmann, Heinz-Erich; Pesatori, Angela C; Landi, Maria Teresa; Caporaso, Neil; Tse, Lap Ah; Yu, Ignatius Tak-sun; Siemiatycki, Jack; Pintos, Javier; Merletti, Franco; Mirabelli, Dario; Simonato, Lorenzo; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Tardón, Adonina; Zaridze, David; Field, John; 't Mannetje, Andrea; Pearce, Neil; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Dumitru, Rodica Stanescu; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Boffetta, Paolo; Forastiere, Francesco; Bueno-de-Mesquita, Bas; Peters, Susan; Vermeulen, Roel; Kromhout, Hans; Olsson, Ann C

    2015-01-01

    OBJECTIVES: To investigate the risk of lung cancer among cooks, while controlling for smoking habits. METHODS: We used data from the SYNERGY project including pooled information on lifetime work histories and smoking habits from 16 case-control studies conducted in Europe, Canada, New Zealand, and C

  1. Towards the identification of a new taphonomic agent: An analysis of bone accumulations obtained from modern Egyptian vulture (Neophron percnopterus) nests

    OpenAIRE

    Sanchis Serra, Alfred; Real Margalef, Cristina; Morales Pérez, Juan Vicente; Pérez Ripoll, Manuel; Tormo Cuñat, Carmen; Carrión Marco, Yolanda; Pérez Jordà, Guillem; Ribera Gómez, Agustín; Bolufer i Marques, Joaquim; Villaverde Bonilla, Valentín

    2014-01-01

    This paper presents the results of a study of bones recovered in various current Egyptian vulture (Neophron percnopterus) nests in a Mediterranean region of the Iberian Peninsula. The Egyptian vulture, a diurnal, scavenging, rupicolous bird of prey, is one of four vulture species that currently inhabit the Iberian Peninsula. An analysis of the remains found in the nests confirms that it has a heterogeneous diet that includes remains from human activities (butchery and food production) and the...

  2. Nest marking behavior and chemical composition of olfactory cues involved in nest recognition in Megachile rotundata.

    Science.gov (United States)

    Guédot, Christelle; Buckner, James S; Hagen, Marcia M; Bosch, Jordi; Kemp, William P; Pitts-Singer, Theresa L

    2013-08-01

    In-nest observations of the solitary bee, Megachile rotundata (F.), revealed that nesting females apply olfactory cues to nests for nest recognition. On their way in and out of the nest, females drag the abdomen along the entire length of the nest, and sometimes deposit fluid droplets from the tip of the abdomen. The removal of bee-marked sections of the nest resulted in hesitation and searching behavior by females, indicating the loss of olfactory cues used for nest recognition. Chemical analysis of female cuticles and the deposits inside marked nesting tubes revealed the presence of hydrocarbons, wax esters, fatty aldehydes, and fatty alcohol acetate esters. Chemical compositions were similar across tube samples, but proportionally different from cuticular extracts. These findings reveal the importance of lipids as chemical signals for nest recognition and suggest that the nest-marking cues are derived from a source in addition to, or other than, the female cuticle. PMID:23905742

  3. Spatial analysis of lung, colorectal, and breast cancer on Cape Cod: An application of generalized additive models to case-control data

    OpenAIRE

    Aschengrau Ann; Weinberg Janice; Webster Thomas; Vieira Verónica; Ozonoff David

    2005-01-01

    Abstract Background The availability of geographic information from cancer and birth defect registries has increased public demands for investigation of perceived disease clusters. Many neighborhood-level cluster investigations are methodologically problematic, while maps made from registry data often ignore latency and many known risk factors. Population-based case-control and cohort studies provide a stronger foundation for spatial epidemiology because potential confounders and disease late...

  4. Polymorphisms of genes coding for ghrelin and its receptor in relation to anthropometry, circulating levels of IGF-I and IGFBP-3, and breast cancer risk : a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)

    NARCIS (Netherlands)

    Dossus, Laure; Mckay, James D.; Canzian, Federico; Wilkening, Stefan; Rinaldi, Sabina; Biessy, Carine; Olsen, Anja; Tjonneland, Anne; Jakobsen, Marianne U.; Overvad, Kim; Clavel-Chapelon, Francoise; Boutron-Ruault, Marie-Christine; Fournier, Agnes; Linseisen, Jakob; Lukanova, Annekatrin; Boeing, Heiner; Fisher, Eva; Trichopoulou, Antonia; Georgila, Christina; Trichopoulos, Dimitrios; Palli, Domenico; Krogh, Vittorio; Tumino, Rosario; Vineis, Paolo; Quiros, Jose Ramon; Sala, Nuria; Martinez-Garcia, Carmen; Dorronsoro, Miren; Chirlaque, Maria-Dolores; Barricarte, Aurelio; van Duijnhoven, Franzel J. B.; Bueno-de-Mesquita, H. B.; van Gils, Carla H.; Peeters, Petra H. M.; Hallmans, Goran; Lenner, Per; Bingham, Sheila; Khaw, Kay Tee; Key, Tim J.; Travis, Ruth C.; Ferrari, Pietro; Jenab, Mazda; Riboli, Elio; Kaaks, Rudolf

    2008-01-01

    Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, has two major functions: the stimulation of the growth hormone production and the stimulation of food intake. Accumulating evidence also suggests a role of ghrelin in cancer development. We conducted a case-control study on

  5. Estimating the spatial scale of herbicide and soil interactions by nested sampling, hierarchical analysis of variance and residual maximum likelihood

    International Nuclear Information System (INIS)

    An unbalanced nested sampling design was used to investigate the spatial scale of soil and herbicide interactions at the field scale. A hierarchical analysis of variance based on residual maximum likelihood (REML) was used to analyse the data and provide a first estimate of the variogram. Soil samples were taken at 108 locations at a range of separating distances in a 9 ha field to explore small and medium scale spatial variation. Soil organic matter content, pH, particle size distribution, microbial biomass and the degradation and sorption of the herbicide, isoproturon, were determined for each soil sample. A large proportion of the spatial variation in isoproturon degradation and sorption occurred at sampling intervals less than 60 m, however, the sampling design did not resolve the variation present at scales greater than this. A sampling interval of 20-25 m should ensure that the main spatial structures are identified for isoproturon degradation rate and sorption without too great a loss of information in this field. - Estimating the spatial scale of herbicide and soil interactions by nested sampling.

  6. Analysis of bacterial and fungal communities in Japanese- and Chinese-fermented soybean pastes using nested PCR-DGGE.

    Science.gov (United States)

    Kim, Tae Woon; Lee, Jun-Hwa; Park, Min-Hee; Kim, Hae-Yeong

    2010-05-01

    The microbial diversity of Japanese- and Chinese-fermented soybean pastes was investigated using nested PCR-denaturing gradient gel electrophoresis (DGGE). Five Japanese-fermented soybean paste samples and three Chinese-fermented soybean paste samples were analyzed for bacteria and fungi. Extracted DNA was used as a template for PCR to amplify 16S rRNA and 18S rRNA genes. The nearly complete 16S rRNA and 18S rRNA genes were amplified using universal primers, and the resulting products were subsequently used as a template in a nested PCR to obtain suitable fragments for DGGE. Tetragenococcus halophilus and Staphylococcus gallinarum were found to dominate the bacterial microbiota in Japanese samples, whereas Bacillus sp. was detected as the predominant species in Chinese samples. DGGE analysis of fungi in soybean pastes determined the presence of Aspergillus oryzae and Zygosaccharomyces rouxii in most of the Chinese and Japanese samples. Some differences were observed in the bacterial diversity of Japanese- and Chinese-fermented soybean pastes. PMID:19924476

  7. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies

    Directory of Open Access Journals (Sweden)

    Heng-feng Yuan

    2016-02-01

    Full Text Available The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p<0.001, a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p<0.01 and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01. The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings.

  8. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies.

    Science.gov (United States)

    Yuan, Heng-Feng; Zhang, Jing; Guo, Chang-An; Yan, Zuo-Qin

    2016-02-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p <0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p <0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings. PMID:26934241

  9. ZDHHC8 as a candidate gene for schizophrenia: Analysis of a putative functional intronic marker in case-control and family-based association studies

    Directory of Open Access Journals (Sweden)

    Jabs Burkhard

    2005-10-01

    Full Text Available Abstract Background The chromosome 22q11 region is proposed as a major candidate locus for susceptibility genes to schizophrenia. Recently, the gene ZDHHC8 encoding a putative palmitoyltransferase at 22q11 was proposed to increase liability to schizophrenia based on both animal models and human association studies by significant over-transmission of allele rs175174A in female, but not male subjects with schizophrenia. Methods Given the genetic complexity of schizophrenia and the potential genetic heterogeneity in different populations, we examined rs175174 in 204 German proband-parent triads and in an independent case-control study (schizophrenic cases: n = 433; controls: n = 186. Results In the triads heterozygous parents transmitted allele G preferentially to females, and allele A to males (heterogeneity χ2 = 4.43; p = 0.035. The case-control sample provided no further evidence for overall or gender-specific effects regarding allele and genotype frequency distributions. Conclusion The findings on rs175174 at ZDHHC8 are still far from being conclusive, but evidence for sexual dimorphism is moderate, and our data do not support a significant genetic contribution of rs175174 to the aetiopathogenesis of schizophrenia.

  10. American Samoa ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for nesting birds in American Samoa. Vector points in this data set represent locations of nesting...

  11. Western Alaska ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for nesting birds in Western Alaska. Vector points in this data set represent locations of nesting birds....

  12. 早产危险因素的病例对照研究%A case-control study: multivariate analysis of risk factors of preterm birth

    Institute of Scientific and Technical Information of China (English)

    朱娟; 赵庆国; 徐龙昌; 李兵

    2011-01-01

    目的 通过分析早产危险因素,探讨降低早产发生率的干预措施.方法 采用病例对照研究方法,对2009年6月~2009年9月广州市某助产机构分娩的133例早产产妇及随机选择的293例足月产妇进行问卷调查和病例摘录,采用卡方检验进行单因素分析筛选出早产危险因素;多因素非条件Logistic回归进一步筛选早产的主要危险因素.结果 产妇高龄、文化程度低、家庭收入低及孕期使用电脑、有生殖系统感染、阴道流血、孕期体重增长低是早产危险因素,产妇有家族早产史、死胎史、既往早产史、多胎妊娠、胎膜早破、胎盘异常、羊水异常及孕次多会增加早产的风险(P<0.05),使用溶剂洗手和孕期使用空调为早产的保护性因素(均P<0.05).多因素Logistic回归分析各危险因素结果显示:发生早产的OR分别为:双胎妊娠19.161(95%CI:5.734~64.030),胎膜早破10.208 (95%CI:5.316~19.603),死胎史5.839 (95%CI:1.503~22.681),胎盘异常4.571(95%CI:1.734~11.989),孕期阴道流血2.894 (95%CI:1.387~6.040);早产保护因素的OR为:家庭收入高0.672(95%CI:0.492~0.918),孕期体重增长较多0.550(95%CI:0.335~0.905).结论 产妇有双胎妊娠、胎膜早破、死胎史、胎盘异常、孕期阴道流血为早产的主要危险因素,加强孕期健康教育、改善经济状况以及重视围产保健,对减少早产的发生至关重要.%Objective To investigate and analyze maternal biological factors, socio-economic factors and environmental exposures associated with preterm birth and to explore interventions to reduce incidence of preterm birth. Methods In case controll study method, 133 women who delivered in a midwifery institution in Guangzhou city over a period from June to September, 2009 and 293 term pregnant women who were randomly selected in the same period and same hospital were investigated with a questionnaire and their medical records were reviewed and extracted

  13. Protective and risk factors in amateur equestrians and description of injury patterns: A retrospective data analysis and a case - control survey

    Directory of Open Access Journals (Sweden)

    Schötzau Andreas

    2011-02-01

    Full Text Available Abstract Background In Switzerland there are about 150,000 equestrians. Horse related injuries, including head and spinal injuries, are frequently treated at our level I trauma centre. Objectives To analyse injury patterns, protective factors, and risk factors related to horse riding, and to define groups of safer riders and those at greater risk Methods We present a retrospective and a case-control survey at conducted a tertiary trauma centre in Bern, Switzerland. Injured equestrians from July 2000 - June 2006 were retrospectively classified by injury pattern and neurological symptoms. Injured equestrians from July-December 2008 were prospectively collected using a questionnaire with 17 variables. The same questionnaire was applied in non-injured controls. Multiple logistic regression was performed, and combined risk factors were calculated using inference trees. Results Retrospective survey A total of 528 injuries occured in 365 patients. The injury pattern revealed as follows: extremities (32%: upper 17%, lower 15%, head (24%, spine (14%, thorax (9%, face (9%, pelvis (7% and abdomen (2%. Two injuries were fatal. One case resulted in quadriplegia, one in paraplegia. Case-control survey 61 patients and 102 controls (patients: 72% female, 28% male; controls: 63% female, 37% male were included. Falls were most frequent (65%, followed by horse kicks (19% and horse bites (2%. Variables statistically significant for the controls were: Older age (p = 0.015, male gender (p = 0.04 and holding a diploma in horse riding (p = 0.004. Inference trees revealed typical groups less and more likely to suffer injury. Conclusions Experience with riding and having passed a diploma in horse riding seem to be protective factors. Educational levels and injury risk should be graded within an educational level-injury risk index.

  14. -251 T/A polymorphism of the interleukin-8 gene and cancer risk: a HuGE review and meta-analysis based on 42 case-control studies.

    Science.gov (United States)

    Wang, Na; Zhou, Rongmiao; Wang, Chunmei; Guo, Xiaoqing; Chen, Zhifeng; Yang, Shan; Li, Yan

    2012-03-01

    The -251T/A (rs4073), a single nucleotide polymorphism, has been identified in the promoter region of the interleukin-8 (IL-8) gene. It's presence could influence the production of IL-8 protein by regulating the transcriptional activity of the gene. A large number of studies have been performed to evaluate the role of -251T/A polymorphism on various cancers, with inconsistent results being reported. In this paper, we summarized 13,189 cases and 16,828 controls from 42 case-control studies and attempted to assess the susceptibility of -251T/A polymorphism to cancers by a comprehensive meta-analysis. Pooled odds ratios and 95% confidence intervals were calculated by using the random-effects model. Publication bias, subgroup, and sensitivity analysis were also performed. Results showed that the carriers of the -251A allele had about a 12-21% increased risk for the reviewed cancer, in total. The carriers of -251A had an elevated risk to breast cancer, gastric cancer and nasopharyngeal cancer and a reduced risk to prostate cancer, but no evidence was found to indicate that the -251A allele predisposed its carriers to colorectal and lung cancers. When stratified separately by 'racial descent' and 'study design', it was found that the carriers of the -251A allele among the African group, Asian group and hospital-based case-control study group were at a higher risk for cancer, but not in European group and population-based case-control study. These results show that -251A allele is susceptible in the development of low-penetrance cancers.

  15. A Cladistic Analysis of Phenotypic Associations with Haplotypes Inferred from Restriction Endonuclease Mapping or DNA Sequencing. V. Analysis of Case/Control Sampling Designs: Alzheimer's Disease and the Apoprotein E Locus

    Science.gov (United States)

    Templeton, A. R.

    1995-01-01

    Present-day associations between haplotypes at a candidate locus and phenotypes exist when phenotypically important mutations occurred at some point during the evolution of the current array of genetic variation. A cladistic statistical design can be defined that focuses power by using the evolutionary history of the candidate DNA region. This paper shows how cladistic methodology is used for the analysis of case/control data, a common sampling design in genetic/disease association studies. A worked example is presented of the associations for sporadic early and late-onset forms of Alzheimer's disease with the 19q13.2 chromosomal region that includes the loci for apoproteins E, CI, and CII. This analysis confirms earlier reports of a strong association of the ApoE &4 allele with Alzheimer's disease but indicates that it is premature to condsider this association causal, particularly for early onset cases. Associations were also found with the &2 allele, as previously reported, and with the 1 allele at the ApoCI locus. However, this analysis indicates that it is inappropriate both statistically and medically to use single markers as risk predictors when haplotype data are available, even when the mutation leading to the marker is identified as having a strong phenotypic association. PMID:7635303

  16. A nested case-control study on the relationship between occupational physical activity,heredity factors and metabolic syndrome%职业体力活动和遗传因素与代谢综合征关系的巢式病例对照研究

    Institute of Scientific and Technical Information of China (English)

    董建梅; 王临池; 陈秋; 俞浩; 杨婕; 郭志荣; 武鸣; 陈晓东

    2010-01-01

    with eases by region,gender and age (±2 years).In total,389 MS patients and 389 eontrols were recruited as study subjects.Nested ease-control study was applied for the present analysis.TaqMan fluorescence probe method was used to detect the genetic polymorphism of PPARα intron 1A/C (rs135539).Results (1)Compared to low physical activity group,the subjects with heavy physical activity were positively associated with MS (OR=2.18,95%CI:1.08-4.38).(2)The subjects,with a family history of hypertension (OR= 1.44,95% CI:1.02-2.03 )or type 2 diabetes (OR=3.25,95CI:1.28-8.20),were significantly indreased the occurrence of MS.(3)The genotype(AA,AC,CC) of PPARα intron 1A/C was not found to be related to MS.The OR of AC and CC genotype (compared to the genotype AA) were 0.98(95%CI:0.70-1.36) and 0.75 (95% CI:0.44-1.29) ,respectively.(4) Effect modifications were observed between family history of hypertension and moderate physical activity (OR=2.47,95% CI:1.00-6.06 ) or heavy physical activity (OR=3.82,95%CI:1.31-11.15) on the development of MS.Conclusion Heavy physical activity,with family history of hypertension or type 2 diabetes,seemed to be positively correlated with the risk of MS.Effect modifications were observed between occupational physical activity and family history of hypertension which might be associated with an increased risk of MS.

  17. Are signalized intersections with cycle tracks safer? A case-control study based on automated surrogate safety analysis using video data.

    Science.gov (United States)

    Zangenehpour, Sohail; Strauss, Jillian; Miranda-Moreno, Luis F; Saunier, Nicolas

    2016-01-01

    Cities in North America have been building bicycle infrastructure, in particular cycle tracks, with the intention of promoting urban cycling and improving cyclist safety. These facilities have been built and expanded but very little research has been done to investigate the safety impacts of cycle tracks, in particular at intersections, where cyclists interact with turning motor-vehicles. Some safety research has looked at injury data and most have reached the conclusion that cycle tracks have positive effects of cyclist safety. The objective of this work is to investigate the safety effects of cycle tracks at signalized intersections using a case-control study. For this purpose, a video-based method is proposed for analyzing the post-encroachment time as a surrogate measure of the severity of the interactions between cyclists and turning vehicles travelling in the same direction. Using the city of Montreal as the case study, a sample of intersections with and without cycle tracks on the right and left sides of the road were carefully selected accounting for intersection geometry and traffic volumes. More than 90h of video were collected from 23 intersections and processed to obtain cyclist and motor-vehicle trajectories and interactions. After cyclist and motor-vehicle interactions were defined, ordered logit models with random effects were developed to evaluate the safety effects of cycle tracks at intersections. Based on the extracted data from the recorded videos, it was found that intersection approaches with cycle tracks on the right are safer than intersection approaches with no cycle track. However, intersections with cycle tracks on the left compared to no cycle tracks seem to be significantly safer. Results also identify that the likelihood of a cyclist being involved in a dangerous interaction increases with increasing turning vehicle flow and decreases as the size of the cyclist group arriving at the intersection increases. The results highlight the

  18. Nested Fixed Depth Fluidic Sampler and At Tank Analysis System Deployment Strategy and Plan

    Energy Technology Data Exchange (ETDEWEB)

    REICH, F.R.

    2000-02-01

    Under the Hanford Site River Protection Project (RPP) privatization strategy, the U.S. Department of Energy (DOE) Office of River Protection (ORP) requires the CH2M Hill Hanford Group, Inc. (CHG) to supply tank waste to the privatization contractor, BNFL Inc. (BNFL), for separation and/or treatment and immobilization (vitrification). Three low-activity waste (LAW) specification envelopes represent the range of liquid waste types in the large, Hanford Site underground waste storage tanks. The CHG also is expected to supply high-level waste (HLW) separation and/or treatment and disposal. The HLW envelope is an aqueous slurry of insoluble suspended solids (sludge). The Phase 1 demonstration will extend over 24 years (1996 through 2019) and will be used to resolve technical uncertainties. About one-tenth of the total Hanford Site tank waste, by mass, will be processed during this period. This document provides a strategy and top-level implementation plan for demonstrating and deploying an alternative sampling technology. The alternative technology is an improvement to the current grab sampling and core sampling approaches that are planned to be used to support the RPP privatization contract. This work also includes adding the capability for some at-tank analysis to enhance the potential of this new technology to meet CHG needs. The first application is to LAW and HLW feed staging for privatization; the next is to support cross-site waste transfer from 200 West Area tanks.

  19. Simulated nest study guide

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The instructions outlined here will provide uniform methods for measuring total predator activity in blocks of nesting cover or at special kinds of nest sites. The...

  20. Recruitment study nest card

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a survey on waterfowl nests in Stillwater Wildlife Management Area. Visits were made to each nest on an approximately weekly basis, and the stage of the...

  1. PyMultiNest: Python interface for MultiNest

    Science.gov (United States)

    Buchner, Johannes

    2016-06-01

    PyMultiNest provides programmatic access to MultiNest (ascl:1109.006) and PyCuba, integration existing Python code (numpy, scipy), and enables writing Prior & LogLikelihood functions in Python. PyMultiNest can plot and visualize MultiNest's progress and allows easy plotting, visualization and summarization of MultiNest results. The plotting can be run on existing MultiNest output, and when not using PyMultiNest for running MultiNest.

  2. A Case-Control Study and Meta-Analysis Reveal BDNF Val66Met Is a Possible Risk Factor for PTSD

    Directory of Open Access Journals (Sweden)

    Dagmar Bruenig

    2016-01-01

    Full Text Available Posttraumatic stress disorder (PTSD is a debilitating condition that develops in some people after exposure to a traumatic event. Brain-derived neurotrophic factor (BDNF is highly expressed in the mammalian brain and is thought to be involved in learning and memory processes. A nonsynonymous polymorphism in the BDNF gene, rs6265 (Val66Met, has been hypothesised to be associated with PTSD. Association studies examining the Val66Met polymorphism and PTSD have been inconclusive, likely due to the variability in type of trauma exposure analysed. Vietnam veterans (n=257 screened for PTSD and controlled for trauma exposure were genotyped for BDNF Val66Met. The association was not significant so we incorporated our data into a meta-analysis to obtain greater statistical power. A comprehensive search of more than 1237 articles revealed eight additional studies suitable for meta-analysis (n=3625. A random-effects meta-analysis observed a potential protective factor of the Val/Val genotype. After removing two studies with violation of Hardy-Weinberg equilibrium, findings for the Val/Val genotype reached significance. Subgroup analyses confirmed a trend for this finding. Limitations of some studies that inform this meta-analysis include poorly screened controls and a lack of examination of population stratification. Effectively designed studies should inform this line of research in the future.

  3. Automated Forensic Animal Family Identification by Nested PCR and Melt Curve Analysis on an Off-the-Shelf Thermocycler Augmented with a Centrifugal Microfluidic Disk Segment.

    Science.gov (United States)

    Keller, Mark; Naue, Jana; Zengerle, Roland; von Stetten, Felix; Schmidt, Ulrike

    2015-01-01

    Nested PCR remains a labor-intensive and error-prone biomolecular analysis. Laboratory workflow automation by precise control of minute liquid volumes in centrifugal microfluidic Lab-on-a-Chip systems holds great potential for such applications. However, the majority of these systems require costly custom-made processing devices. Our idea is to augment a standard laboratory device, here a centrifugal real-time PCR thermocycler, with inbuilt liquid handling capabilities for automation. We have developed a microfluidic disk segment enabling an automated nested real-time PCR assay for identification of common European animal groups adapted to forensic standards. For the first time we utilize a novel combination of fluidic elements, including pre-storage of reagents, to automate the assay at constant rotational frequency of an off-the-shelf thermocycler. It provides a universal duplex pre-amplification of short fragments of the mitochondrial 12S rRNA and cytochrome b genes, animal-group-specific main-amplifications, and melting curve analysis for differentiation. The system was characterized with respect to assay sensitivity, specificity, risk of cross-contamination, and detection of minor components in mixtures. 92.2% of the performed tests were recognized as fluidically failure-free sample handling and used for evaluation. Altogether, augmentation of the standard real-time thermocycler with a self-contained centrifugal microfluidic disk segment resulted in an accelerated and automated analysis reducing hands-on time, and circumventing the risk of contamination associated with regular nested PCR protocols.

  4. Association of sulfotransferase SULT1A1 with breast cancer risk: a meta-analysis of case-control studies with subgroups of ethnic and menopausal statue

    OpenAIRE

    Shao Zhimin; Shen Zhenzhou; Yan Tingting; Zhou Liheng; Jiang Yiwei; Lu Jinsong

    2010-01-01

    Abstract Background Sulfotransferase (SULT) plays an important role in the formation of estrogen which is usually conferred as a risk factor for breast cancer. Polymorphism of the SULT1A1 may be closely associated with breast cancer. However, studies on the association between polymorphism and breast cancer have yielded inconsistent results. We performed a meta-analysis including ethnic subgroup and menopausal statue subgroup to investigate the association of SULT1A1 Arg213His polymorphism wi...

  5. Association Between XRCC3 Thr241Met Polymorphism and Risk of Breast Cancer: Meta-Analysis of 23 Case-Control Studies

    OpenAIRE

    Chai, Fan; Liang, Yan; Li CHEN; Zhang, Fan; Jiang, Jun

    2015-01-01

    Background Studies have shown that gene and environmental factors, such as BRCA1/2 mutations, ionized radiation, and chemical carcinogens, are related with breast cancer. X-ray repair cross-complementing group 3 (XRCC3) is involved in homologous repair of double DNA breaks. It was reported that Thr241Met single-nucleotide polymorphism (SNP) in XRCC3 is associated with increased risk of breast cancer. However, the finding remains controversial. The current meta-analysis aims to determine wheth...

  6. A fully-automated software pipeline for integrating breast density and parenchymal texture analysis for digital mammograms: parameter optimization in a case-control breast cancer risk assessment study

    Science.gov (United States)

    Zheng, Yuanjie; Wang, Yan; Keller, Brad M.; Conant, Emily; Gee, James C.; Kontos, Despina

    2013-02-01

    Estimating a woman's risk of breast cancer is becoming increasingly important in clinical practice. Mammographic density, estimated as the percent of dense (PD) tissue area within the breast, has been shown to be a strong risk factor. Studies also support a relationship between mammographic texture and breast cancer risk. We have developed a fullyautomated software pipeline for computerized analysis of digital mammography parenchymal patterns by quantitatively measuring both breast density and texture properties. Our pipeline combines advanced computer algorithms of pattern recognition, computer vision, and machine learning and offers a standardized tool for breast cancer risk assessment studies. Different from many existing methods performing parenchymal texture analysis within specific breast subregions, our pipeline extracts texture descriptors for points on a spatial regular lattice and from a surrounding window of each lattice point, to characterize the local mammographic appearance throughout the whole breast. To demonstrate the utility of our pipeline, and optimize its parameters, we perform a case-control study by retrospectively analyzing a total of 472 digital mammography studies. Specifically, we investigate the window size, which is a lattice related parameter, and compare the performance of texture features to that of breast PD in classifying case-control status. Our results suggest that different window sizes may be optimal for raw (12.7mm2) versus vendor post-processed images (6.3mm2). We also show that the combination of PD and texture features outperforms PD alone. The improvement is significant (p=0.03) when raw images and window size of 12.7mm2 are used, having an ROC AUC of 0.66. The combination of PD and our texture features computed from post-processed images with a window size of 6.3 mm2 achieves an ROC AUC of 0.75.

  7. CYP1A2 rs762551 polymorphism contributes to cancer susceptibility: a meta-analysis from 19 case-control studies

    Directory of Open Access Journals (Sweden)

    Wang Hongge

    2012-11-01

    Full Text Available Abstract Background Genetic polymorphism (rs762551A>C in gene encoding cytochrome P450 1A2 (CYP1A2 has been shown to influence the inducibility of CYP1A2 expression and thus might be associated with risk of several types of human cancer. However, the results of previous studies on the associations of this polymorphism with risk of cancer are not all consistent. To clarify the potential contribution of CYP1A2 rs762551 to cancer risk, we performed a meta-analysis of the published case–control studies. Methods We used PubMed, Embase, OVID, ScienceDirect, and Chinese National Knowledge Infrastructure databases to identify the related publications for this meta-analysis. The pooled odds ratio (OR and 95% confidence interval (CI were calculated using random effect model to evaluate the association of rs762551 with cancer risk. A χ2-based Q-test was used to examine the heterogeneity assumption and the funnel plot and Egger’s test were used to examine the potential publication bias. The leave-one-out sensitivity analysis was conducted to determine whether our assumptions or decisions have a major effect on the results of the review. Results Our analysis of 19 eligible case–control studies showed a significant association between rs762551C variant with risk of cancer in the genetic model of CC versus AA (OR = 1.30, 95% CI = 1.02-1.64 and the dominant model (OR = 1.19, 95% CI = 1.04-1.36. In subgroup analysis based on ethnicity, the rs762551CC genotype was associated with increased cancer risk (OR = 1.29, 95% CI = 1.27-1.63 in co-dominate model and OR = 1.17, 95% CI = 1.02-1.34 in dominant model in Caucasians, but not in Asians and the mixed population. Conclusion These results suggested that CYP1A2 rs762551 polymorphism is likely to be associated with susceptibility to cancer in Caucasians.

  8. Prediabetes Is Associated with HNF-4α P2 Promoter Polymorphism rs1884613: A Case-Control Study in Han Chinese Population and an Updated Meta-Analysis

    OpenAIRE

    Changyi Wang; Sihan Chen; Tao Zhang; Zhongwei Chen; Shengyuan Liu; Xiaolin Peng; Jianping Ma; Xiaohong Zhong; Yanqiong Yan; Linlin Tang; Yifeng Mai; Liyuan Han; Shiwei Duan

    2014-01-01

    Background. Controversy remains for the association between hepatocyte nuclear factor 4α (HNF-4α) P2 promoter polymorphism rs1884613 and type 2 diabetes (T2D). There was no association test of this polymorphism with prediabetes and T2D in the Chinese population. Moreover, an updated meta-analysis in various ethnic groups is needed to establish the contribution of rs1884613 to T2D risk. Methods. Using the Sequenom MassARRAY platform approach, we genotyped rs1884613 of HNF-4α in the P2 promoter...

  9. Association of Adiponectin SNP+45 and SNP+276 with Type 2 Diabetes in Han Chinese Populations: A Meta-Analysis of 26 Case-Control Studies

    OpenAIRE

    Yiping Li; Xianli Li; Li Shi; Man Yang; Ying Yang; Wenyu Tao; Lei Shi; Yuxin Xiong; Ying Zhang; Yufeng Yao

    2011-01-01

    Recently, many studies have reported that the SNP+45(T>G) and SNP+276(G>T) polymorphisms in the adiponectin gene are associated with type 2 diabetes (T2DM) in the Chinese Han population. However, the previous studies yielded many conflicting results. Thus, a meta-analysis of the association of the adiponectin gene with T2DM in the Chinese Han population is required. In the current study, we first determined the distribution of the adiponectin SNP+276 polymorphism in T2DM and nondiabetes (NDM)...

  10. Sulfotransferase SULT1A1 Arg213His polymorphism with cancer risk: a meta-analysis of 53 case-control studies.

    Directory of Open Access Journals (Sweden)

    Juanjuan Xiao

    Full Text Available BACKGROUND: The SULT1A1 Arg213His (rs9282861 polymorphism is reported to be associated with many kinds of cancer risk. However, the findings are conflicting. For better understanding this SNP site and cancer risk, we summarized available data and performed this meta-analysis. METHODS: Data were collected from the following electronic databases: PubMed, Web of Knowledge and CNKI. The association was assessed by odd ratio (OR and the corresponding 95% confidence interval (95% CI. RESULTS: A total of 53 studies including 16733 cancer patients and 23334 controls based on the search criteria were analyzed. Overall, we found SULT1A1 Arg213His polymorphism can increase cancer risk under heterozygous (OR  1.09, 95% CI = 1.01-1.18, P = 0.040, dominant (OR = 1.10, 95% CI = 1.01-1.19, P = 0.021 and allelic (OR = 1.08, 95% CI = 1.02-1.16, P = 0.015 models. In subgroup analyses, significant associations were observed in upper aero digestive tract (UADT cancer (heterozygous model: OR = 1.62, 95% CI = 1.11-2.35, P = 0.012; dominant model: OR = 1.63, 95% CI = 1.13-2.35, P = 0.009; allelic model: OR = 1.52, 95% CI = 1.10-2.11, P = 0.012 and Indians (recessive model: OR = 1.93, 95% CI = 1.22-3.07, P = 0.005 subgroups. Hospital based study also showed marginally significant association. In the breast cancer subgroup, ethnicity and publication year revealed by meta-regression analysis and one study found by sensitivity analysis were the main sources of heterogeneity. The association between SULT1A1 Arg213His and breast cancer risk was not significant. No publication bias was detected. CONCLUSIONS: The present meta-analysis suggests that SULT1A1 Arg213His polymorphism plays an important role in carcinogenesis, which may be a genetic factor affecting individual susceptibility to UADT cancer. SULT1A1 Arg213His didn't show any association with breast cancer, but the possible risk in Asian population needs further investigation.

  11. Meta-analysis of the association between COX-2 polymorphisms and risk of colorectal cancer based on case-control studies.

    Directory of Open Access Journals (Sweden)

    Qiliu Peng

    Full Text Available OBJECTIVE: Cyclooxygenase-2 (COX-2 is an inducible enzyme converting arachidonic acid to prostaglandins and playing important roles in inflammatory diseases as well as tumor development. Previous studies investigating the association between COX-2 polymorphisms and colorectal cancer (CRC risk reported conflicting results. We performed a meta-analysis of all available studies to explore this association. METHODS: All studies published up to October 2013 on the association between COX-2 polymorphisms and CRC risk were identified by searching electronic databases PubMed, EMBASE, and Cochrane library. The association between COX-2 polymorphisms and CRC risk was assessed by odds ratios (ORs together with their 95% confidence intervals (CIs. RESULTS: Ten studies with 6,774 cases and 9,772 controls were included for -1195A>G polymorphism, 13 studies including 6,807 cases and 10,052 controls were available for -765G>C polymorphism, and 8 studies containing 5,121 cases and 7,487 controls were included for 8473T>C polymorphism. With respect to -765G>C polymorphism, we did not find a significant association with CRC risk when all eligible studies were pooled into the meta-analysis. However, in subgroup analyses by ethnicity and cancer location, with a Bonferroni corrected alpha of 0.05/2, statistical significant increased CRC risk was found in the Asian populations (dominant model CC+CG vs. GG: OR = 1.399, 95%CI: 1.113-1.760, P = 0.004 and rectum cancer patients (CC vs. GG: OR = 2.270, 95%CI: 1.295-3.980, P = 0.004; Recessive model CC vs. CG+GG: OR = 2.269, 95%CI: 1.297-3.970, P = 0.004. In subgroup analysis according to source of control, no significant association was detected. With respect to -1195A>G and 8473T>C polymorphisms, no significant association with CRC risk was demonstrated in the overall and subgroup analyses. CONCLUSIONS: The present meta-analysis suggests that the COX-2 -765G>C polymorphism may be a risk factor for

  12. The tryptophan hydroxylase 1 (TPH1) gene, schizophrenia susceptibility, and suicidal behavior: a multi-centre case-control study and meta-analysis

    DEFF Research Database (Denmark)

    Saetre, Peter; Lundmark, Per; Wang, August;

    2010-01-01

    affected individuals having attempted suicide at least once and patients with no history of suicide attempts (P = 0.84). A systematic literature review and meta-analysis support the A218C polymorphism as a susceptibility locus for schizophrenia (odds ratio 1.17, 95% confidence interval 1......Serotonin (5-hydroxytryptamin; 5-HT) alternations has since long been suspected in the pathophysiology of schizophrenia. Tryptophan hydroxylase (tryptophan 5-monooxygenase; TPH) is the rate-limiting enzyme in the biosynthesis of 5-HT, and sequence variation in intron 6 of the TPH1 gene has been...

  13. Nested Canalizing Functions and Their Networks

    CERN Document Server

    Kadelka, Claus; Adeyeye, John O; Laubenbacher, Reinhard

    2014-01-01

    The concept of a nested canalizing Boolean function has been studied over the last decade in the context of understanding the regulatory logic of molecular interaction networks, such as gene regulatory networks. Such networks are predominantly governed by nested canalizing functions. Derrida values are frequently used to analyze the robustness of a Boolean network to perturbations. This paper introduces closed formulas for the calculation of Derrida values of networks governed by Boolean nested canalizing functions, which previously required extensive simulations. Recently, the concept of nested canalizing functions has been generalized to include multistate functions, and a recursive formula has been derived for their number, as a function of the number of variables. This paper contains a detailed analysis of the class of nested canalizing functions over an arbitrary finite field. In addition, the concept of nested canalization is further generalized and closed formulas for the number of such generalized fun...

  14. Matrix metalloproteinase-9 and -2 and tissue inhibitor of matrix metalloproteinase-2 in invasive pituitary adenomas: A systematic review and meta-analysis of case-control trials.

    Science.gov (United States)

    Liu, Hong-Yan; Gu, Wei-Jun; Wang, Cheng-Zhi; Ji, Xiao-Jian; Mu, Yi-Ming

    2016-06-01

    The extracellular matrix is important for tumor invasion and metastasis. Normal function of the extracellular matrix depends on the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The objective of this meta-analysis was to assess the relationship between expression of MMP-9, MMP-2, and TIMP-2 and invasion of pituitary adenomas.We searched Pubmed, Embase, and the Chinese Biomedical Database up to October 2015. RevMan 5.1 software (Cochrane Collaboration, Copenhagen, Denmark) was used for statistical analysis. We calculated the standardized mean difference (SMD) for data expressed as mean ± standard deviation because of the difference in the detection method.Twenty-four studies (1320 patients) were included. MMP-9 expression was higher in the patients with invasive pituitary adenomas (IPAs) than patients with noninvasive pituitary adenomas (NIPAs) with detection methods of IHC [odds ratio (OR) = 5.48, 95% confidence interval (CI) = 2.61-11.50, P reverse transcriptase-polymerase chain reaction (SMD = 2.28, 95% CI = 0.91-3.64, P = 0.001). MMP-2 expression was also increased in patients with IPAs at the protein level (OR = 3.58, 95% CI = 1.63-7.87, P = 0.001), and RNA level (SMD = 3.91, 95% CI = 1.52-6.29, P = 0.001). Meta-analysis showed that there was no difference in TIMP-2 expression between invasive and NIPAs at the protein level (OR = 0.38, 95% CI = 0.06-2.26, P = 0.29). MMP-9 expression in prolactinomas and nonfunctioning pituitary adenomas was also no difference (OR = 1.03, 95% CI = 0.48-2.20, P = 0.95).The results indicated that MMP-9 and -2 may be correlated with invasiveness of pituitary adenomas, although their relationship with functional status of pituitary adenomas is still not clear. TIMP-2 expression in IPAs needs to be investigated further. PMID:27310993

  15. Association of CDKN2BAS Polymorphism rs4977574 with Coronary Heart Disease: A Case-Control Study and a Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Yi Huang

    2014-09-01

    Full Text Available The goal of our study was to explore the significant association between a non-protein coding single nucleotide polymorphism (SNP rs4977574 of CDKN2BAS gene and coronary heart disease (CHD. A total of 590 CHD cases and 482 non-CHD controls were involved in the present association study. A strong association of rs4977574 with CHD was observed in females (genotype: p = 0.002; allele: p = 0.002, odd ratio (OR = 1.57, 95% confidential interval (CI = 1.18–2.08. Moreover, rs4977574 was more likely to be a risk variant of CHD under the recessive model in females (χ2 = 10.29, p = 0.003, OR = 2.14, 95% CI = 1.31–2.77. A breakdown analysis by age had shown that there was an 87% increased risk of CHD for females younger than 65 years (genotype: χ2 = 14.64, degrees of freedom (df = 2, p = 0.0002; allele: χ2 = 11.31, df = 1, p = 0.0008, OR = 1.87, 95% CI = 1.30–2.70. Similar observation was also found in males younger than 65 years (genotype: χ2 = 8.63, df = 2, p = 0.04; allele: χ2 = 7.55, df = 1, p = 0.006, OR = 1.45, 95% CI = 1.11–1.90. p values were adjusted by age, sex, smoking, high density lipoprotein cholesterol (HDL-C and low density lipoprotein cholesterol (LDL-C. Meta-analysis of 23 studies among 36,452 cases and 39,781 controls showed a strong association between rs4977574 and the risk of CHD (p < 0.0001, OR = 1.27, 95% CI = 1.22–1.31.

  16. Case-control study of mesothelioma in the shipyard industry

    International Nuclear Information System (INIS)

    A nested case-control study was undertaken to investigate the relationship between occupational exposures to asbestos and low-level gamma radiation and mesothelioma. One hundred nineteen cases and four hundred fifty-two latency-matched controls were selected. Analyses were conducted using the conditional maximum likelihood estimate of the odds ratio and conditional logistic regression for matched sets. The results from the analyses revealed a relationship between asbestos exposure and mesothelioma; the strength of this relationship increased with the intensity and duration of the asbestos exposure. Exposure to low-level gamma radiation was also associated with an increased risk of mesothelioma. There was no interaction between asbestos and radiation. Shipyard employment in non-asbestos jobs and male gender were also found to be associated with mesothelioma

  17. A cladistic analysis of phenotypic associations with haplotypes inferred from restriction endonuclease mapping. 4. Nested analyses with cladogram uncertainty and recombination

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, A.R. (Washington Univ., St. Louis, MO (United States)); Sing, C.F. (Univ. of Michigan, Ann Arbor (United States))

    1993-06-01

    The authors previously developed an analytical strategy based on cladistic theory to identify subsets of haplotypes that are associated with significant phenotypic deviations. Their initial approach was limited to segments of DNA in which little recombination occurs. In such cases, a cladogram can be constructed from the restriction site data to estimate the evolutionary steps that interrelate the observed haplotypes to one another. The cladogram is then used to define a nested statistical design for identifying mutational steps associated with significant phenotypic deviations. The central assumption behind this strategy is that a mutation responsible for a particular phenotypic effect is embedded within the evolutionary history that is represented by the cladogram. The power of this approach depends on the accuracy of the cladogram in portraying the evolutionary history of the DNA region. This accuracy can be diminished both by recombination and by uncertainty in the estimated cladogram topology. In a previous paper, the authors presented an algorithm for estimating the set of likely cladograms and recombination events. In this paper they present an algorithm for defining a nested statistical design under cladogram uncertainty and recombination. Given the nested design, phenotypic associations can be examined using either a nested analysis of variance (for haploids or homozygous strains) or permutation testing (for outcrossed, diploid gene regions). In this paper they extend this analytical strategy to include categorical phenotypes in addition to quantitative phenotypes. Some worked examples are presented using Drosophila data sets. These examples illustrate that having some recombination may actually enhance the biological inferences that may be derived from a cladistic analysis. In particular, recombination can be used to assign a physical localization to a given subregion for mutations responsible for significant phenotypic effects. 14 refs., 10 figs., 7 figs.

  18. A cladistic analysis of phenotypic associations with haplotypes inferred from restriction endonuclease mapping. IV. Nested analyses with cladogram uncertainty and recombination.

    Science.gov (United States)

    Templeton, A R; Sing, C F

    1993-06-01

    We previously developed an analytical strategy based on cladistic theory to identify subsets of haplotypes that are associated with significant phenotypic deviations. Our initial approach was limited to segments of DNA in which little recombination occurs. In such cases, a cladogram can be constructed from the restriction site data to estimate the evolutionary steps that interrelate the observed haplotypes to one another. The cladogram is then used to define a nested statistical design for identifying mutational steps associated with significant phenotypic deviations. The central assumption behind this strategy is that a mutation responsible for a particular phenotypic effect is embedded within the evolutionary history that is represented by the cladogram. The power of this approach depends on the accuracy of the cladogram in portraying the evolutionary history of the DNA region. This accuracy can be diminished both by recombination and by uncertainty in the estimated cladogram topology. In a previous paper, we presented an algorithm for estimating the set of likely claodgrams and recombination events. In this paper we present an algorithm for defining a nested statistical design under cladogram uncertainty and recombination. Given the nested design, phenotypic associations can be examined using either a nested analysis of variance (for haploids or homozygous strains) or permutation testing (for outcrossed, diploid gene regions). In this paper we also extend this analytical strategy to include categorical phenotypes in addition to quantitative phenotypes. Some worked examples are presented using Drosophila data sets. These examples illustrate that having some recombination may actually enhance the biological inferences that may derived from a cladistic analysis. In particular, recombination can be used to assign a physical localization to a given subregion for mutations responsible for significant phenotypic effects.

  19. The association between XRCC1 Arg399Gln polymorphism and risk of leukemia in different populations: a meta-analysis of case-control studies

    Directory of Open Access Journals (Sweden)

    Wang F

    2015-11-01

    Full Text Available Fang Wang,1,2,* Qian Zhao,1,2,* Hai-rong He,3 Ya-jing Zhai,4 Jun Lu,3 Hai-bo Hu,1 Jin-song Zhou,1 Yong-hua Yang,5 Yuan-jie Li1 1Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Centre, 2College of Pharmacy, Xi’an Medical University, 3Clinical Research Center, 4Department of Pharmacy, 5Department of Pediatrics, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, People’s Republic of China *These authors contributed equally to this work Background: Associations between Arg399Gln single-nucleotide polymorphism (SNP in the XRCC1 gene and leukemia susceptibility have been studied extensively, however, the results are inconsistent. The aim of this study was to determine these associations using meta-analytical methods.Methods: A meta-analysis was performed to examine the associations between XRCC1 Arg399Gln SNP and leukemia risk. A literature search of PubMed and Web of Science databases was conducted to identify relevant studies published up to March 10, 2015. The references of the retrieved articles were also screened. All the statistical analyses were conducted using Review Manager software.Results: The XRCC1 Arg399Gln SNP was found to be associated with increased childhood risk of acute lymphoblastic leukemia among Asians under the dominant (odds ratio [OR] 2.11, 95% confidence interval [CI] 1.50–2.97, P<0.0001, allele contrast (OR 1.72, 95% CI 1.33–2.23, P<0.0001, and homozygote contrast (OR 2.34, 95% CI 1.25–4.36, P=0.008 models. However, no association was found in Caucasians between the SNP and risk of either chronic myeloid leukemia or chronic lymphocytic leukemia under any contrast model.Conclusion: The findings of the current meta-analysis indicate that the XRCC1 Arg399Gln SNP is a risk factor for childhood lymphoblastic leukemia in Asians. Keywords: Arg399Gln, AML, ALL, CML, CLL, susceptibility

  20. Genetic predisposition to fracture non-union: a case control study of a preliminary single nucleotide polymorphisms analysis of the BMP pathway

    Directory of Open Access Journals (Sweden)

    Giannoudis Peter V

    2011-02-01

    Full Text Available Abstract Background Despite the known multi-factorial nature of atrophic fracture non-unions, a possible genetic predisposition for the development of this complication after long bone fractures remains unknown. This pilot study aimed to address this issue by performing a preliminary SNP analysis of specific genes known to regulate fracture healing. Methods A total of fifteen SNPs within four genes of the Bone Morphogenetic Protein (BMP pathway (BMP-2, BMP-7, NOGGIN and SMAD6 were examined, in 109 randomly selected patients with long bone fractures as a result of motor vehicle accident, fall or direct blow. There were sixty-two patients with atrophic non-union and forty-seven patients (54 fractures with uneventful fracture union. Overall SNPs frequencies were computed with respect to patient's age, gender, smoking habits, fracture-associated parameters and the use of nonsteroidal anti-inflammatory drugs (NSAIDs, and tested for their association to the impaired bone healing process, using binary logistic regression (STATA 11.1; StataCorp, Texas USA. Results Statistical analysis revealed age to be an important covariate in the development of atrophic non-union (p = 0.01, OR 1.05 [per year], and two specific genotypes (G/G genotype of the rs1372857 SNP, located on NOGGIN and T/T genotype of the rs2053423 SNP, located on SMAD6 to be associated with a greater risk of fracture non-union (p = 0.02, OR 4.56 and p = 0.04, OR 10.27, respectively, after adjustment for age. Conclusions This is the first clinical study to investigate the potential existence of genetic susceptibility to fracture non-union. Even though no concrete conclusions can be obtained from this pilot study, our results indicate the existence of a potential genetically predetermined impairment within the BMP signalling cascade, initiated after a fracture and when combined with other risk factors could synergistically increase the susceptibility of a patient to develop non-union. Further

  1. Association of XPC Gene Polymorphisms with Colorectal Cancer Risk in a Southern Chinese Population: A Case-Control Study and Meta-Analysis.

    Science.gov (United States)

    Hua, Rui-Xi; Zhu, Jinhong; Jiang, Dan-Hua; Zhang, Shao-Dan; Zhang, Jiang-Bo; Xue, Wen-Qiong; Li, Xi-Zhao; Zhang, Pei-Fen; He, Jing; Jia, Wei-Hua

    2016-01-01

    Xeroderma pigmentosum group C (XPC) is a key component of the nucleotide excision repair (NER) pathway. Dysfunctional XPC protein may impair NER-mediated DNA repair capacity and further lead to genomic instability and carcinogenesis. Two common nonsynonymous polymorphisms in the XPC gene, Lys939Gln (rs2228001 A > C) and Ala499Val (rs2228000 C > T), have been investigated in various types of cancer. We genotyped these two polymorphisms in 1141 cases with histologically confirmed colorectal cancer (CRC) and 1173 healthy controls to explore their causative association with CRC susceptibility. Overall, no association was observed between these two variants and the risk of CRC. Our meta-analysis also confirmed a lack of overall association. Stratified analyses were performed by age, gender, smoking status, pack-year, drinking status, tumor sites, and Duke's stages. We found that XPC Lys939Gln polymorphism was significantly associated with an increased CRC risk in subjects at 57 years of age or younger (adjusted odds ratio (OR) = 1.37, 95% confidence interval (CI) = 1.004-1.86, p = 0.047) and non-drinkers (adjusted OR = 1.53, 95% CI = 1.10-2.12, p = 0.011). Our results indicated that XPC Lys939Gln may be a low-penetrance CRC susceptibility polymorphism. Our findings warrant further validation. PMID:27669310

  2. Percutaneous ethanol injection therapy is comparable to radiofrequency ablation in hepatocellular carcinoma smaller than 1.5 cm: A matched case-control comparative analysis.

    Science.gov (United States)

    Yu, Su Jong; Yoon, Jung-Hwan; Lee, Jeong Min; Lee, Jae Young; Kim, Se Hyung; Cho, Young Youn; Yoo, Jeong-Ju; Lee, Minjong; Lee, Dong Hyeon; Cho, Yuri; Cho, Eun Ju; Lee, Jeong-Hoon; Kim, Yoon Jun; Kim, Chung Yong

    2016-08-01

    Although percutaneous ethanol injection therapy (PEIT) is best indicated for patients with small hepatocellular carcinoma (HCC), the survival advantage of PEIT needs confirmation in real-world practice. This study was approved by the institutional review board, and the informed consent was waived. The study included 535 consecutive patients with newly diagnosed early stage (Barcelona Clinic Liver Cancer [BCLC] 0 or A) HCC who underwent initially radiofrequency ablation (RFA) (n = 288) or PEIT (n = 247) from January 2005 to December 2010. The primary outcome was overall survival (OS) and the secondary outcome was time to progression (TTP). The longest diameters of tumors of the groups differed significantly and larger for RFA group than PEIT group (P < 0.001; 1.94 ± 0.65 cm vs 1.60 ± 0.50 cm, respectively). The 5-year OS rates were 72.2% in the RFA group and 67.4% in the PEIT group (P = 0.608). Even after propensity score matching, OS rates between the 2 groups were similar (5-year OS: 72.8% with RFA [n = 175] and 68.0% with PEIT [n = 175]) (P = 0.709). Moreover, in patients with the longest diameter of tumors (≤1.5 cm), multivariate Cox regression analysis showed that the treatment modality was not a significant prognosticator for OS (hazard ratio [HR], 1.690; 95% confidence interval [CI], 0.828-3.449; P = 0.149) and time to progression (HR, 1.160; 95% CI, 0.773-1.740; P = 0.474). PEIT and RFA show equal effectiveness in treating HCCs <1.5 cm in terms of OS and time to progression. PMID:27583865

  3. Autonomic dysfunction in mild cognitive impairment: evidence from power spectral analysis of heart rate variability in a cross-sectional case-control study.

    Directory of Open Access Journals (Sweden)

    Paola Nicolini

    Full Text Available Mild cognitive impairment (MCI is set to become a major health problem with the exponential ageing of the world's population. The association between MCI and autonomic dysfunction, supported by indirect evidence and rich with clinical implications in terms of progression to dementia and increased risk of mortality and falls, has never been specifically demonstrated.To conduct a comprehensive assessment of autonomic function in subjects with MCI by means of power spectral analysis (PSA of heart rate variability (HRV at rest and during provocative manoeuvres.This cross-sectional study involved 80 older outpatients (aged ≥ 65 consecutively referred to a geriatric unit and diagnosed with MCI or normal cognition (controls based on neuropsychological testing. PSA was performed on 5-minute electrocardiographic recordings under three conditions--supine rest with free breathing (baseline, supine rest with paced breathing at 12 breaths/minute (parasympathetic stimulation, and active standing (orthosympathetic stimulation--with particular focus on the changes from baseline to stimulation of indices of sympathovagal balance: normalized low frequency (LFn and high frequency (HFn powers and the LF/HF ratio. Blood pressure (BP was measured at baseline and during standing. Given its exploratory nature in a clinical population the study included subjects on medications with a potential to affect HRV.There were no significant differences in HRV indices between the two groups at baseline. MCI subjects exhibited smaller physiological changes in all three HRV indices during active standing, consistently with a dysfunction of the orthosympathetic system. Systolic BP after 10 minutes of standing was lower in MCI subjects, suggesting dysautonomia-related orthostatic BP dysregulation.Our study is novel in providing evidence of autonomic dysfunction in MCI. This is associated with orthostatic BP dysregulation and the ongoing follow-up of the study population will

  4. Association of sulfotransferase SULT1A1 with breast cancer risk: a meta-analysis of case-control studies with subgroups of ethnic and menopausal statue

    Directory of Open Access Journals (Sweden)

    Shao Zhimin

    2010-07-01

    Full Text Available Abstract Background Sulfotransferase (SULT plays an important role in the formation of estrogen which is usually conferred as a risk factor for breast cancer. Polymorphism of the SULT1A1 may be closely associated with breast cancer. However, studies on the association between polymorphism and breast cancer have yielded inconsistent results. We performed a meta-analysis including ethnic subgroup and menopausal statue subgroup to investigate the association of SULT1A1 Arg213His polymorphism with breast cancer. Methods PubMed, EBSCO and Web of Science databases were searched for the correlative articles up to January 2010 (10362 breast cancer patients and 14250 controls. The risk (odds ratio, OR was used to estimate the association between SULT1A1 polymorphism and breast cancer risk. All of the data from each study use either fixed-effects or random-effects. Results We found that SULT1A1 Arg213His had no exact effect to increase the risk of breast cancer (OR = 1.07, 95% CI: 0.97-1.17, P = 0.164, but it did increase the risk of breast cancer among postmenopausal women in the dominant model (OR = 1.28, 95%CI: 1.04-1.58, P = 0.019. No similar effect was found among premenopausal breast cancer women (OR = 1.06, 95%CI: 0.88-1.27, P = 0.537. There was a significant increase in breast cancer risk among Asian women (OR = 2.03, 95% CI: 1.00-4.14, P = 0.051 but not Caucasian women in recessive model. There was publication bias among postmenopausal women subgroup (P = 0.002, however by using the trim and fill method, if the publication bias was the only source of the funnel plot asymmetry, it needed two more studies to be symmetrical. The value of Log OR did not change too much after the adjustment and the fail-safe number of missing studies that would bring the P-value changed was 17. Conclusions We concluded that the polymorphism of SULT1A1 Arg213His might be one of the high risk factors for breast cancer in Asian women and in postmenopausal women for all

  5. Morphology of nested fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Srolovitz, D.J.; Safran, S.A.; Homyonfer, M.; Tenne, R. (Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100 (Israel))

    1995-03-06

    We introduce a continuum model which shows that dislocations and/or grain boundaries are intrinsic features of nested fullerenes whose thickness exceeds a critical value to relieve the large inherent strains in these structures. The ratio of the thickness to the radius of the nested fullerenes is determined by the ratio of the surface to curvature and dislocation (or grain boundary) energies. Confirming experimental evidence is presented for nested fullerenes with small thicknesses and with spherosymmetric shapes.

  6. Nesting Probabilistic Inference

    CERN Document Server

    Mantadelis, Theofrastos

    2011-01-01

    When doing inference in ProbLog, a probabilistic extension of Prolog, we extend SLD resolution with some additional bookkeeping. This additional information is used to compute the probabilistic results for a probabilistic query. In Prolog's SLD, goals are nested very naturally. In ProbLog's SLD, nesting probabilistic queries interferes with the probabilistic bookkeeping. In order to support nested probabilistic inference we propose the notion of a parametrised ProbLog engine. Nesting becomes possible by suspending and resuming instances of ProbLog engines. With our approach we realise several extensions of ProbLog such as meta-calls, negation, and answers of probabilistic goals.

  7. 脑肿瘤与手机使用病例对照研究的Meta分析%Brain tumor and mobile phone use: meta-analysis of case-control studies

    Institute of Scientific and Technical Information of China (English)

    常勇; 吴磊; 彭晓武; 宋世震; 梅勇; 叶方立

    2012-01-01

    目的 评价手机使用与脑肿瘤危险性的联系.方法 采用Meta分析方法对2000年至2011年发表的关于脑肿瘤与手机使用相关的病例对照研究文献进行定量分析.结果 13篇病例对照研究文献纳入,规律使用手机者未见脑瘤危险性增高;而长期使用手机10年以上者与脑肿瘤发生存在关联(OR=1.ll,95% CI:1.01~1.22),长期同侧使用手机发生脑肿瘤危险性增加32%(OR=1.32,95% CI:1.14~1.54).结论 规律使用手机并不增高脑肿瘤发生的风险,长期使用手机可能增加脑肿瘤发生的风险,但分析中的偏倚与混杂因子可能影响因果关系的解释.%Objective To evaluate the association between mobile phone use and brain tumor risk. Methods Meta-analysis method was used to analyze the case-control studies on association between brain tumor and mobile phone use, the data were searched from 2000 to 2011. Results A total of 13 case-control studies were included. Analysis findings showed no increase in risk for regular mobile phone user was seen. A somewhat increased risk was found for long-term mobile phone (0R=1.11; 95% CI: 1.01-1.22). There were suggestions of an increased risk of brain tumor for ipsilateral exposures in 10 years or more (OR=1.32; 95% CI: 1.14—1.54). Conclusion Overall, no increase in risk of brain tumor was observed among uses regular using mobile phone. There were suggestions of an increased risk of brain tumor with long-term heavy use of mobile phone, but biases and confounding factors may prevent a causal interpretation.

  8. 利用光谱分析技术探测红火蚁蚁巢%Detection of Solenopsis invicta nest using spectrum analysis technology

    Institute of Scientific and Technical Information of China (English)

    吴伟斌; 支磊; 洪添胜; 许益镌; 曾玲; 黄双萍; 邓小玲

    2013-01-01

    . Research on the detection method of a Solenopsis invicta nest to eliminate Solenopsis invicta from the source is of practical significance to the prevention of a Solenopsis invicta disaster. Therefore, finding out the location of a nest of Solenopsis invicta is of more practical value than only exterminating Solenopsis invicta. The feasibility of detection of a nest of Solenopsis invicta based on spectrum analysis technology was examined by using an optical spectrum instrument with reflect characteristics. A differential coefficient method and a logarithmic method to analyze original spectral reflectivity were used. The method of using character factors was studied to get the best waveband for distinguishing the ant nest from other things. An Eculidean distance method was used to calculate the average distance, and effective band of the nest of Solenopsis invicta’s recognized effect. In addition, the average of the Euclidean distance of different features is greater than the average of the Euclidean distance of the same feature, and the samples, which were collected and measured by the laboratory hyper-spectral imager to verify the reliability of the selected band. Finally, the results were compared with the traditional method. We randomly selected eight sample points in the Wushan Square of South China Agricultural University. Using the traditional method and a spectrum analytical method to prove it, we got the same result. However, it is more convenient and faster to get the information by using the spectrum analytical method. As a result, the effective wavebands to recognize the Solenopsis invicta nest mostly concentrate on 701-1 510 nm, which are mainly red light bands and near-infrared bands. Additionally, the observation shows that the original spectrum and the logarithmic method could be used to distinguish the nest of Solenopsis invicta from common soil and grass. Moreover, the latter can make it clearer than the others, while the spectrum first

  9. Spatial analysis of toxic emissions in LCA: a sub-continental nested USEtox model with freshwater archetypes.

    Science.gov (United States)

    Kounina, Anna; Margni, Manuele; Shaked, Shanna; Bulle, Cécile; Jolliet, Olivier

    2014-08-01

    This paper develops continent-specific factors for the USEtox model and analyses the accuracy of different model architectures, spatial scales and archetypes in evaluating toxic impacts, with a focus on freshwater pathways. Inter-continental variation is analysed by comparing chemical fate and intake fractions between sub-continental zones of two life cycle impact assessment models: (1) the nested USEtox model parameterized with sub-continental zones and (2) the spatially differentiated IMPACTWorld model with 17 interconnected sub-continental regions. Substance residence time in water varies by up to two orders of magnitude among the 17 zones assessed with IMPACTWorld and USEtox, and intake fraction varies by up to three orders of magnitude. Despite this variation, the nested USEtox model succeeds in mimicking the results of the spatially differentiated model, with the exception of very persistent volatile pollutants that can be transported to polar regions. Intra-continental variation is analysed by comparing fate and intake fractions modelled with the a-spatial (one box) IMPACT Europe continental model vs. the spatially differentiated version of the same model. Results show that the one box model might overestimate chemical fate and characterisation factors for freshwater eco-toxicity of persistent pollutants by up to three orders of magnitude for point source emissions. Subdividing Europe into three archetypes, based on freshwater residence time (how long it takes water to reach the sea), improves the prediction of fate and intake fractions for point source emissions, bringing them within a factor five compared to the spatial model. We demonstrated that a sub-continental nested model such as USEtox, with continent-specific parameterization complemented with freshwater archetypes, can thus represent inter- and intra-continental spatial variations, whilst minimizing model complexity. PMID:24815341

  10. Frog Foam Nest Protein Diversity and Synthesis.

    Science.gov (United States)

    Hissa, Denise Cavalcante; Bezerra, Walderly Melgaço; Freitas, Cléverson Diniz Teixeira De; Ramos, Márcio Viana; Lopes, José Luiz De Souza; Beltramini, Leila Maria; Roberto, Igor Joventino; Cascon, Paulo; Melo, Vânia Maria Maciel

    2016-08-01

    Some amphibian species have developed a breeding strategy in which they deposit their eggs in stable foam nests to protect their eggs and larvae. The frog foam nests are rich in proteins (ranaspumin), especially surfactant proteins, involved in the production of the foam nest. Despite the ecological importance of the foam nests for evolution and species conservation, the biochemical composition, the long-term stability and even the origin of the components are still not completely understood. Recently we showed that Lv-RSN-1, a 23.5-kDa surfactant protein isolated from the nest of the frog Leptodacylus vastus, presents a structural conformation distinct from any protein structures yet reported. So, in the current study we aimed to reveal the protein composition of the foam nest of L. vastus and further characterize the Lv-RSN-1. Proteomic analysis showed the foam nest contains more than 100 of proteins, and that Lv-RSN-1 comprises 45% of the total proteins, suggesting a key role in the nest construction and stability. We demonstrated by Western blotting that Lv-RSN-1 is mainly produced only by the female in the pars convoluta dilata, which highlights the importance of the female preservation for conservation of species that depend on the production of foam nests in the early stages of development. Overall, our results showed the foam nest of L. vastus is composed of a great diversity of proteins and that besides Lv-RSN-1, the main protein in the foam, other proteins must have a coadjuvant role in building and stability of the nest. PMID:27460953

  11. [Analysis of different methods of extracting DNA from paraffin-embedded tissues and the application of nest PCR].

    Science.gov (United States)

    Yan, Limin; Sun, Baocun; Zhao, Xiulan; Liu, Zenghui; Song, Wenjing

    2011-08-01

    The aim of this research was to explore the most optimal method of DNA extraction from formalin-fixed, paraffin-embedded (FFPE) tissues, and to improve the amplification of long fragments with the method. Three methods, one step method, phenol-chloroform extraction method, and genomic DNA purification kit method, were employed to extract DNA from twenty normal thyroid tissues which were fixed with formalin and embedded with paraffin. The highest proportionality of OD260/OD280 in the examples was obtained by phenol-chloroform extraction method, 1.703 +/- 0.086, compared to the results of the other two methods. As for the long DNA segments amplification, the achievement ratio of one step method, phenol-chloroform extraction method and genomic DNA purification kit method were 0%, 5% and 10%, respectively, by traditional PCR method, but 0%, 95% and 85% respectively by the nest PCR. We have found that the best process of extracting DNA from FFPE is digesting by proteinase K and purifying by phenol-chloroform, and it is effective to amplify long DNA segments from FFPE by nest PCR.

  12. Correlation between low development quotient of children and first-trimester serum level of free fatty acids in mothers: a nested case-control study%儿童低发育商与母亲孕早期血清游离脂肪酸关系

    Institute of Scientific and Technical Information of China (English)

    孙蕾; 刘开永; 盛杰; 陶芳标; 郝加虎; 王磊; 蔡传兰

    2013-01-01

    were significant differences in the levels of polyunsaturated fatty acis (PUFA),ω-3PUFA,ω-6PUFA,docosapentaenoic acid (DPA),docosahexaenoic acid (DHA),eicosapentaenoic acid (EPA),EPA + DHA,DHA + anachidonic acid (AA) between the cases and the controls (P < 0.05 for all).High level of EPA served as a protective factor of child low development quotient (odds ratio [OR] =0.37,95 % confidence interval [95 % CI]:0.17-0.79).Correlation analysis demonstrated that there were relationships between EPA and DPA (r =0.608),DHA (r =0.659),AA (r =0.605),and DHA + AA (r =0.676).The level of EPA in maternal serum showed a downward trend with the reduced frequency of fish and other seafood intake (F =3.410,P =0.019).Conclusion The study suggests that there is an association of child's low development quotient with the lack of PUFA supplement of the pregnancy woman.Pregnant women should supplement PUFA to ensure normal mental development of the infant.

  13. Breast cancer risk among Finnish cabin attendants: a nested case-control study

    OpenAIRE

    Kojo, K; Pukkala, E.; Auvinen, A.

    2005-01-01

    Background: Earlier studies have found increased breast cancer risk among female cabin crew. This has been suggested to reflect lifestyle factors (for example, age at first birth), other confounding factors (for example, age at menarche), or occupational factors such as exposure to cosmic radiation and circadian rhythm alterations due to repeated jet lag.

  14. Impact of urate level on cardiovascular risk in allopurinol treated patients. A nested case control study

    DEFF Research Database (Denmark)

    Larsen, Kasper Søltoft; Pottegård, Anton; Lindegaard, H. M.;

    2015-01-01

    Background: Gout gives rise to increased risk of adverse cardiovascular outcomes. Gout attacks can be effectively prevented with urate lowering drugs such as allopurinol, and allopurinol further potentially reduces the cardiovascular risk. Whether treatment to a target level of uric acid.......36 mmol/l on allopurinol. The derived odds ratios were controlled for potential confounders available from data on prescriptions, laboratory values or in- and outpatient contacts. Results: No association of treatment-to-target urate level below 0.36 mmol/l and cardiovascular events were found. Adjusted...

  15. Multilocus Heterozygosity and Coronary Heart Disease: Nested Case-Control Studies in Men and Women

    DEFF Research Database (Denmark)

    Mukamal, Kenneth J.; Jensen, Majken K.; Pers, Tune Hannes;

    2015-01-01

    Background: Generalized allelic heterozygosity has been proposed to improve reproductive fitness and has been associated with higher blood pressure, but its association with chronic disease is not well characterized. Methods: Using the Affymetrix Genome-Wide Human 6.0 array, we performed whole...... with 931 matched controls. We examined the relationship of genome-wide heterozygosity with risk of incident of CHD and with baseline levels of cardiovascular risk factors. Results: In both cohorts, approximately 227650 (SD 2000) SNPs were heterozygous. The number of heterozygous SNPs was not related...

  16. Do chimpanzees build comfortable nests?

    Science.gov (United States)

    Stewart, Fiona A; Pruetz, Jill D; Hansell, Mike H

    2007-08-01

    Nests built by wild chimpanzees (Pan troglodytes verus) were studied at the Fongoli research site in southeastern Senegal from January 2004-May 2004 to investigate the role of comfort in nest building behavior by relating measures of nest comfort and building effort. Nest comfort across zones of the nest surface were compared with construction effort for 25 nests. Several variables of nest comfort were assessed: (1) physical discomfort, (2) visible discomfort, and (3) softness. Physical discomfort was used as a representative measure of nest discomfort. Building effort was measured by (1) construction force, (2) complexity, and (3) added material. Spearman rank correlations compared Effort and Comfort measures for both whole nests and central versus edge zones. The results show that construction force and complexity do not influence comfort of the nest as a whole. Greater Construction force correlates with more nest edge discomfort, yet the central area shows no difference. More complex nests do result in a more comfortable central area in the nest. Nests built with greater force may result in more discomfort, whereas complexity may allow chimpanzees to maintain comfort in a central area for sleep. Chimpanzees may place additional leaves or twigs over hard branches, protruding from the nest surface after construction, to increase comfort of the central nest area. Functions of chimpanzee nest building are likely to be several, but these results suggest comfort is a factor in nest building behavior. PMID:17358021

  17. 一种“用例+控例”驱动的软件分析与设计方法%"Use Case+Control Case" Driven Approach for Software Analysis and Design

    Institute of Scientific and Technical Information of China (English)

    刘春; 张伟; 赵海燕; 金芝

    2013-01-01

    As software systems and their operational environments become more and more complex,the topic of software dependability has attracted more and more attention.The software analysis and design are both required to focus on the functionality and the dependability.However,there still lacks an effective approach to consider the functionality and the dependability simultaneously during software analysis and design.Based on cybernetics,this paper proposes a "use case+control case" driven approach for software analysis and design,which aims to address the software functionality and dependability under a unified framework.During requirements analysis,the "use case+control case" model supports the co-modeling of the functional requirements and the dependability requirements.During system design,the design techniques proposed by ICONIX approach are extended to identify the functionality objects that realize the use cases,and the dependability objects that realize the control cases.A case is also used to illustrate the feasibility of the proposed approach.%随着软件本身及其运行环境的日益复杂,软件可信性引起人们越来越多的关注.软件的分析与设计也越来越需要综合考虑软件的功能性和可信性.然而,如何在软件的分析与设计过程中综合考虑软件的功能性和可信性,目前仍然缺乏系统而有效的方法.基于控制论,提出了一种基于“用例+控例”的方法,以在软件的分析与设计过程中综合考虑软件的功能性和可信性.在需求分析阶段,“用例+控例”模型支持需求工程师在同一个模型中自然地表达软件系统的功能性需求和可信性需求.在系统设计阶段,扩展了ICONIX开发方法的用例驱动的系统设计技术,用以分别识别实现用例的功能对象和实现控例的可信保障对象,以最终构建出既满足功能性需求又满足可信性需求的对象模型.应用一个实例来说明所提出方法的可行性.

  18. Duration of Diabetes and Pancreatic Cancer in a Case-Control Study in the Midwest and the Iowa Women's Health Study (IWHS Cohort

    Directory of Open Access Journals (Sweden)

    Sarah A Henry

    2013-05-01

    Full Text Available Context Studies have shown a relationship between history of diabetes and the risk of pancreatic cancer; however, the temporal relation between diabetes and pancreatic cancer is not clearly established. Objectives Diabetes and diabetes duration were examined in relation to pancreatic cancer in a population-based case-control study and prospective cohort. Methods Case-control study: pancreatic cancer cases (n=200 from the Midwest were frequency matched by age and sex to population controls (n=673. Logistic regression yielded odds ratios (ORs and 95% confidence intervals (95% CI. Iowa Women’s Health Study (IWHS cohort: 292 incident pancreatic cancer cases occurred between 1986-2008 among 36,084 post-menopausal, initially cancer-free women. Diabetes status and diagnosis age were ascertained at baseline and follow-ups. Proportional hazards regression yielded hazard ratios (HR, 95% CI for pancreatic cancer in relation to baseline diabetes. Time-dependent analyses accounted for diabetes diagnosed after baseline. A nested-case control analysis assessed diabetes duration as a risk factor. Results In the case-control study, compared to participants without diabetes, the multivariate ORs (95% CI for pancreatic cancer were 2.35 (1.24-4.47 for those with diabetes and 4.00 (0.94-16.9, 2.79 (0.97-8.04, and 2.40 (0.97-5.98 for diabetes durations of 2-5 years, 5.1-10 years, and more than 10 years, respectively. In IWHS, compared to no diabetes, multivariate-adjusted HRs for pancreatic cancer were 1.86 (1.23-2.83 for baseline diabetes and 1.94 (1.40-2.69 adding diabetes during follow-up. In an IWHS nested case-control analysis, ORs were 1.70 (0.78- 3.67, 2.62 (1.48-4.65, and 2.10 (1.36-3.24 for diabetes durations of 2-5 years, 5.1-10 years and more than 10 years, respectively, versus no diabetes. Conclusions Diabetes is associated with pancreatic cancer risk and this is similar across different duration categories.

  19. High Prevalence of Human Papillomavirus in Colorectal Cancer in Hispanics: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Raul D. Bernabe-Dones

    2016-01-01

    Full Text Available The role of Human Papillomavirus (HPV in colorectal carcinogenesis remains elusive. Based on the high incidence of HPV-associated malignancies among Puerto Rican Hispanics, this study aimed to assess the prevalence of HPV infection and viral integration in colorectal tissues in order to evaluate its putative role in colorectal cancer (CRC. In this case-control study, the prevalence of HPV infection in CRC (cases n = 45 and normal colon mucosa from cancer-free subjects (controls n = 36 was assessed by a nested PCR strategy. HPV-16 genotyping was performed in HPV-positive tissues and the physical status of the HPV-16 genome was determined by E2 detection. HPV was detected in 19 of 45 (42.2% CRC cases (mean age 61.1 ± 10.7 years, 24 males and in 1 of 36 (2.8% controls (mean age 60.9 ± 9.6 years, 24 males with an OR = 25.58 (95% CI 3.21 to 203.49. HPV-16 was detected in 63.2% of the HPV-positive colorectal tumors; genome integration was observed in all HPV-16 positive cases. This is the first report showing the high prevalence of HPV infections in Caribbean Hispanic colorectal tumors. Despite evidence of HPV integration into the host genome, further mechanistic analysis examining HPV oncoprotein expression and the putative role of these oncoproteins in colorectal carcinogenesis is warranted.

  20. High Prevalence of Human Papillomavirus in Colorectal Cancer in Hispanics: A Case-Control Study

    Science.gov (United States)

    Bernabe-Dones, Raul D.; Gonzalez-Pons, Maria; Villar-Prados, Alejandro; Lacourt-Ventura, Mercedes; Rodríguez-Arroyo, Heriberto; Fonseca-Williams, Sharon; Velazquez, Francisco E.; Diaz-Algorri, Yaritza; Lopez-Diaz, Sofia M.; Rodríguez, Nayra; Yamamura, Yasuhiro; Cruz-Correa, Marcia

    2016-01-01

    The role of Human Papillomavirus (HPV) in colorectal carcinogenesis remains elusive. Based on the high incidence of HPV-associated malignancies among Puerto Rican Hispanics, this study aimed to assess the prevalence of HPV infection and viral integration in colorectal tissues in order to evaluate its putative role in colorectal cancer (CRC). In this case-control study, the prevalence of HPV infection in CRC (cases n = 45) and normal colon mucosa from cancer-free subjects (controls n = 36) was assessed by a nested PCR strategy. HPV-16 genotyping was performed in HPV-positive tissues and the physical status of the HPV-16 genome was determined by E2 detection. HPV was detected in 19 of 45 (42.2%) CRC cases (mean age 61.1 ± 10.7 years, 24 males) and in 1 of 36 (2.8%) controls (mean age 60.9 ± 9.6 years, 24 males) with an OR = 25.58 (95% CI 3.21 to 203.49). HPV-16 was detected in 63.2% of the HPV-positive colorectal tumors; genome integration was observed in all HPV-16 positive cases. This is the first report showing the high prevalence of HPV infections in Caribbean Hispanic colorectal tumors. Despite evidence of HPV integration into the host genome, further mechanistic analysis examining HPV oncoprotein expression and the putative role of these oncoproteins in colorectal carcinogenesis is warranted. PMID:26904111

  1. Facial dermatosis associated with Demodex: a case-control study*

    OpenAIRE

    Zhao, Ya-e; Peng, Yan; Wang, Xiang-lan; Wu, Li-ping; Wang, Mei; Yan, Hu-ling; XIAO, SHENG-XIANG

    2011-01-01

    Demodex has been considered to be related with multiple skin disorders, but controversy persists. In this case-control study, a survey was conducted with 860 dermatosis patients aged 12 to 84 years in Xi’an, China to identify the association between facial dermatosis and Demodex. Amongst the patients, 539 suffered from facial dermatosis and 321 suffered from non-facial dermatosis. Demodex mites were sampled and examined using the skin pressurization method. Multivariate regression analysis wa...

  2. Association between the European GWAS-identified susceptibility locus at chromosome 4p16 and the risk of atrial septal defect: a case-control study in Southwest China and a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Li Zhao

    Full Text Available Atrial septal defect (ASD is the third most frequent type of congenital heart anomaly, featuring shunting of blood between the two atria. Gene-environment interaction remains to be an acknowledged cause for ASD occurrence. A recent European genome-wide association study (GWAS of congenital heart disease (CHD identified 3 susceptibility SNPs at chromosome 4p16 associated with ASD: rs870142, rs16835979 and rs6824295. A Chinese-GWAS of CHD conducted in the corresponding period did not reveal the 3 susceptibility SNPs, but reported 2 different risk SNPs: rs2474937 and rs1531070. Therefore, we aimed to investigate the associations between the 3 European GWAS-identified susceptibility SNPs and ASD risk in the Han population in southwest China. Additionally, to increase the robustness of our current analysis, we conducted a meta-analysis combining published studies and our current case-control study. We performed association, linkage disequilibrium, and haplotype analysis among the 3 SNPs in 190 ASD cases and 225 age-, sex-, and ethnicity-matched healthy controls. Genotype and allele frequencies among the 3 SNPs showed statistically significant differences between the cases and controls. Our study found that individuals carrying the allele T of rs870142, the allele A of rs16835979, and the allele T of rs6824295 had a respective 50.1% (odds ratio (OR = 1.501, 95% confidence interval (CI = 1.122-2.009, PFDR-BH = 0.018, 48.5% (OR = 1.485, 95%CI = 1.109-1.987, PFDR-BH = 0.012, and 38.6% (OR = 1.386, 95%CI = 1.042-1.844, PFDR-BH = 0.025 increased risk to develop ASD than wild-type allele carriers in our study cohort. In the haplotype analysis, we identified a disease-risk haplotype (TAT (OR = 1.540, 95%CI = 1.030-2.380, PFDR-BH = 0.016. Our meta-analysis also showed that the investigated SNP was associated with ASD risk (combined OR (95%CI = 1.35 (1.24-1.46, P < 0.00001. Our study provides compelling evidence to motivate better understanding of the etiology

  3. Analysis of bacterial community structures in two sewage treatment plants with different sludge properties and treatment performance by nested PCR-DGGE method

    Institute of Scientific and Technical Information of China (English)

    LIU Xin-chun; ZHANG Yu; YANG Min; WANG Zhen-yu; LV Wen-zhou

    2007-01-01

    The bacterial community structures in two sewage treatment plants with different processes and performance were investigated by denaturing gradient gel electrophoresis (DGGE) of nested polymerase chain reaction (nested PCR) amplified 16S rRNA gene fragments with group-specific primers. Samples of raw sewage and treated effluents were amplified using the whole-cell PCR method, and the activated sludge samples were amplified using the extracted genomic DNA before the PCR products were loaded on the same DGGE gel for bacterial community analysis. Ammonia-oxidizing bacterial and actinomycetic community analysis were also carried out to investigate the relationship between specific population structures and system or sludge performance. The two plants demonstrated a similarity in bacterial community structures of raw sewage and activated sludge, but they had different effluent populations. Many dominant bacterial populations of raw sewage did not appear in the activated sludge samples, suggesting that the dominant bacterial populations in raw sewage might not play an important role during wastewater treatment. Although the two plants had different sludge properties in terms of settleability and foam forming ability, they demonstrated similar actinomycetic community structures. For activated sludge with bad settling performance, the treated water presented a similar DGGE pattern with that of activated sludge, indicating the nonselective washout of bacteria from the system. The plant with better ammonium removal efficiency showed higher ammonia-oxidizing bacteria (AOB) species richness. Analysis of sequencing results showed that the major populations in raw sewage were uncultured bacterium, while in activated sludge the predominant populations were beta proteobacteria.

  4. Serenbe Nest Cottages

    Energy Technology Data Exchange (ETDEWEB)

    Butler, T. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Curtis, O. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Kim, E. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Roberts, S. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Stephenson, R. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

    2012-12-01

    As part of the NAHB Research Center Industry Partnership, Southface partnered with Martin Dodson Builders and the Serenbe community on the construction of a new test home in the suburbs of Atlanta, GA, in the mixed humid climate zone. The most recent subdivision within the Serenbe community, the Nest, will contain 15 small footprint cottage-style homes, and Southface has selected Lot Nine, as the test home for this study. This Nest subdivision serves as a project showcase for both the builder partner and the Serenbe community as a whole. The planning and design incorporated into the Nest cottages will be implemented in each home within the subdivision. These homes addresses Building America savings targets and serve as a basis of design for other homes Martin Dodson plans to build within the Serenbe community.

  5. Serenbe Nest Cottages

    Energy Technology Data Exchange (ETDEWEB)

    Butler, T.; Curtis, O.; Kim, E.; Roberts, S.; Stephenson, R.

    2012-12-01

    As part of the NAHB Research Center Industry Partnership, Southface partnered with Martin Dodson Builders and the Serenbe community on the construction of a new test home in the suburbs of Atlanta, GA in the mixed humid climate zone. The most recent subdivision within the Serenbe community, the Nest, will contain 15 small footprint cottage style homes, and Southface has selected Lot Nine, as the test home for this study. This Nest subdivision serves as a project showcase for both the builder partner and the Serenbe community as a whole. The planning and design incorporated into the Nest cottages will be implemented in each home within the subdivision. These homes addresses Building America Savings targets and serve as a basis of design for other homes Martin Dodson plans to build within the Serenbe community.

  6. Metodologia caso-controle em epidemiologia de doenças cardiovasculares: II - Análise de dados Case-control design in cardiovascular disease epidemiology: II - Analysis of data

    Directory of Open Access Journals (Sweden)

    Suzana Alves de Moraes

    1998-02-01

    Full Text Available A larga difusão, nos últimos anos, de softwares estatísticos indicados para análises multivariadas, aliada à facilidade de seu manuseio, poderá conduzir os usuários à obtenção de estimativas enganosas caso não se conheçam os pressupostos teóricos necessários para o emprego destas técnicas. Com o propósito de se destacar alguns desses pressupostos, apresentam-se as etapas executadas para a análise dos dados de um estudo caso-controle, conduzido no Município de São Paulo, entre março de 1993 e fevereiro de 1994, cujo objetivo foi testar a associação do diabetes mellitus com a doença isquêmica do coração após o ajustamento para possíveis variáveis de confusão e/ou modificadoras de efeito. Para uma melhor visualização didática desses pressupostos metodológicos são destacadas quatro etapas fundamentais durante a fase de análise dos dados: a construção do banco de dados; b cálculo do poder estatístico; c categorização e codificação das variáveis e d a escolha do modelo de regressão logística multivariada.The widespread distribution of statistical software recommended for multivariate analysis as well as the ease in handling it can lead the users into adopting wrong measures if they do not pay attention to the theoretical principles behind those methods. With a view to bringing out some of these principles some steps for the data analysis of a case-control study undertaken in the city of S. Paulo-Brazil from March, 1993 to February, 1994 in order to test the association between diabetes mellitus and ischaemic heart disease after adjusting for potential confounders and/or modifiers of effect are presented. Methodologic issues are emphasized in the development of four steps: a the data bank structure; b the calculation of statistical power; c the definition of variables strata and codification and d the choice of the logistic regression method.

  7. Birds build camouflaged nests

    OpenAIRE

    Bailey, Ida Elizabeth; Muth, Felicity; Morgan, Kate; Meddle, Simone L.; Healy, Susan Denise

    2014-01-01

    This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) (BB/I019502/1 to S.D.H. and S.L.M.) and by Roslin Institute Strategic Grant funding from the BBSRC (to S.L.M). It is assumed that many birds attempt to conceal their nests by using camouflage. To our knowledge, however, no previous experimental studies have explicitly tested this assumption. To explore whether birds choose materials that match the background colors of nest sites to reduce the cons...

  8. Fatores associados à rosácea em amostras populacionais do Sul do Brasil: análise de estudos casos-controles Factors associated with rosacea in population samples of Southern Brazil: analysis of case-control studies

    Directory of Open Access Journals (Sweden)

    Renan Rangel Bonamigo

    2008-10-01

    Full Text Available FUNDAMENTOS: A rosácea é dermatose que apresenta uma série de variáveis associadas a seu surgimento. A maioria dos estudos é proveniente dos Estados Unidos da América e de países europeus, sendo escasso o conhecimento produzido e publicado acerca da doença no Hemisfério Sul, particularmente no Brasil. OBJETIVOS: Descrever os principais fatores clínicos e histopatológicos associados à rosácea em amostras populacionais do sul do Brasil. MÉTODOS: Dois estudos casos-controles realizados em seqüência, com análise univariada e bivariada, utilizando-se p BACKGROUND: Rosacea is a dermatosis that has many factors associated with its onset. Most studies on this condition come from the United States and European countries, with little information produced and published about the disease in the Southern hemisphere, particularly in Brazil. OBJECTIVES: To describe the main clinical and histopathological factors associated with rosacea in population samples from southern Brazil. METHODS: Two case-control studies performed sequentially, with univariate and bivariate analysis, using p<0.05 for statistical significance (Chi-square test and Mantel-Haenzel, for stratifications RESULTS: Rosacea is most frequent among women and in the age range of 40-50 years. Almost all cases have phototypes II and III. The inflammatory forms of rosacea are more often diagnosed than the vascular form and there is an association with serological positivity to Helicobacter pylori and with histopathological presence of Demodex folliculorum (p<0.05. Emotional and climatic changes, exposure to the sun and intake of alcoholic beverages were the main factors described as provoking or worsening the disease. CONCLUSIONS: We have obtained an overview of rosacea in a sample of the southern population of Brazil. While some data are similar to those already described internationally, other aspects, such as economic issues and the factors described as provoking or worsening the

  9. Bed-sharing in the absence of hazardous circumstances: is there a risk of sudden infant death syndrome? An analysis from two case-control studies conducted in the UK.

    Directory of Open Access Journals (Sweden)

    Peter S Blair

    Full Text Available OBJECTIVE: The risk of sudden infant death syndrome (SIDS among infants who co-sleep in the absence of hazardous circumstances is unclear and needs to be quantified. DESIGN: Combined individual-analysis of two population-based case-control studies of SIDS infants and controls comparable for age and time of last sleep. SETTING: Parents of 400 SIDS infants and 1386 controls provided information from five English health regions between 1993-6 (population: 17.7 million and one of these regions between 2003-6 (population:4.9 million. RESULTS: Over a third of SIDS infants (36% were found co-sleeping with an adult at the time of death compared to 15% of control infants after the reference sleep (multivariate OR = 3.9 [95% CI: 2.7-5.6]. The multivariable risk associated with co-sleeping on a sofa (OR = 18.3 [95% CI: 7.1-47.4] or next to a parent who drank more than two units of alcohol (OR = 18.3 [95% CI: 7.7-43.5] was very high and significant for infants of all ages. The risk associated with co-sleeping next to someone who smoked was significant for infants under 3 months old (OR = 8.9 [95% CI: 5.3-15.1] but not for older infants (OR = 1.4 [95% CI: 0.7-2.8]. The multivariable risk associated with bed-sharing in the absence of these hazards was not significant overall (OR = 1.1 [95% CI: 0.6-2.0], for infants less than 3 months old (OR = 1.6 [95% CI: 0.96-2.7], and was in the direction of protection for older infants (OR = 0.1 [95% CI: 0.01-0.5]. Dummy use was associated with a lower risk of SIDS only among co-sleepers and prone sleeping was a higher risk only among infants sleeping alone. CONCLUSION: These findings support a public health strategy that underlines specific hazardous co-sleeping environments parents should avoid. Sofa-sharing is not a safe alternative to bed-sharing and bed-sharing should be avoided if parents consume alcohol, smoke or take drugs or if the infant is pre-term.

  10. Feathering Your Nest

    Science.gov (United States)

    Nabors, Martha L.; Edwards, Linda Carol; Decker, Suzanne

    2010-01-01

    The first-grade classroom was like a natural history museum. Bird nests of every shape and size lay on top of bookshelves that lined two walls. Methods students, who were visiting the classroom in preparation for the science lessons they would teach there, were immediately inspired by the collection. They used the collection as a springboard for…

  11. Case-control study on factors associated with crown fractures in the primary dentition

    Directory of Open Access Journals (Sweden)

    Patrícia CORRÊA-FARIA

    2015-01-01

    Full Text Available The purpose of the present study was to identify the factors associated with dental trauma in preschool children. This case-control study was nested in a population-based cross-sectional study involving a random sample of 301 children one to five years of age in the city of Diamantina, Brazil. The case group was made up of children with at least one fractured deciduous tooth, and the control group was made up of children with no deciduous tooth fracture. The two groups were matched for age in a proportion of one control for every case. The dependent variable was “dental trauma,” diagnosed according to the criteria proposed by Andreasen and Andreasen. The independent variables were overjet, measured and considered accentuated when surpassing 3 mm, and lip coverage, classified as adequate or inadequate. Clinical oral examinations were performed by calibrated dentists. The parents provided information on the socioeconomic indicators. Statistical analysis involved the McNemar test and logistic regression. Each group (case and control was composed of 92 children. In the bivariate analysis, traumatic dental injury (TDI was associated with overjet > 3 mm (p = 0.001, inadequate lip coverage (p < 0.001, mother's schooling (p = 0.028 and household income (p < 0.001. In the multivariate analysis, only inadequate lip coverage was associated with TDI (OR: 5.35; 95% CI: 1.37-20.85. In conclusion, the case group children had a 5.3 - fold more likely chance of presenting inadequate lip coverage, compared with the control children.

  12. Choroidal thickness and central serous chorioretinopathy:a case-control study and Meta-analysis%脉络膜厚度与CSCR的病例对照研究与Meta分析

    Institute of Scientific and Technical Information of China (English)

    叶汉元; 杨安怀

    2015-01-01

    目的:定量分析中心性浆液性脉络膜视网膜病变( central serous chorioretinopathy,CSCR)患者黄斑中心凹下脉络膜厚度( subfoveal choroidal thickness,SFCT)改变。  方法:采用病例对照研究及Meta分析。连续的CSCR患者46例纳入研究,CSCR患者散瞳后前置镜眼底检查,荧光素眼底血管造影和吲哚菁绿血管造影检查确诊。选择同期年龄、性别、屈光度及眼轴匹配的正常人62例62眼作为正常对照组。用加强成像深度扫描OCT检测并比较CSCR组及对照组SFCT。单因素和多因素分析 SFCT 与各临床资料之间的关系。 Meta分析用Stata软件计算两组之间的加权均数差。  结果:CSCR患者的平均SFCT为397.34±83.91μm,正常对照组为274.48±62.57μm。 CSCR组SFCT较对照组明显增厚,差异有统计学意义(P  结论:CSCR患者黄斑中央凹下脉络膜较正常眼厚,增厚的SFCT与CSCR诊断存在相关性。%AIM:To investigate the changes of subfoveal choroidal thickness ( SFCT ) in central serous chorioretinopathy ( CSCR) eyes and to compare them with normal control eyes. METHODS: This was a case-control study and a Meta-analysis. Forty - six CSCR patients diagnosed by the fundus pre - set lens, fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were enrolled in this study. Sixty two age-, sex-, diopter- and axial length-matched 62 normal subjects ( 62 eyes ) were enrolled in this study as the control group. Using enhanced depth imaging optical coherence tomography ( EDI-OCT) , SFCT of CSCR eyes and normal control eyes were measured and compared. Univariate and multivariate linear regression analysis were performed to assess the association between SFCT and clinical factors. The Meta - analysis were conducted using the Stata software package to calculate the summary weighted mean differences ( WMDs) . RESULTS:The mean SFCT of the CSCR group and the normal control group was 397. 34±83. 91μm and

  13. Why Wasp Foundresses Change Nests: Relatedness, Dominance, and Nest Quality

    OpenAIRE

    Perttu Seppä; Queller, David C; Strassmann, Joan E.

    2012-01-01

    The costs and benefits of different social options are best understood when individuals can be followed as they make different choices, something that can be difficult in social insects. In this detailed study, we follow overwintered females of the social wasp Polistes carolina through different nesting strategies in a stratified habitat where nest site quality varies with proximity to a foraging area, and genetic relatedness among females is known. Females may initiate nests, join nests temp...

  14. The Case-Control Analysis of Gallstone Incidence in Cangzhou%沧州市胆道结石发病情况的病例对照分析

    Institute of Scientific and Technical Information of China (English)

    芮晨; 张卫东; 芮炳峰

    2012-01-01

    Objective Through exploring the risk factors of gallstone,to provide the health education information of reducing gallstone incidence and change improper behavior for relevant people, and to make the reference of relevant prevention and control strategy. Methods 86 gallstone cases from 1164 cases in 40 -60 people were analyzed through case-control study and logistic regression analysis to find the risk factors. Results By single factor analysis,the difference had statistical significance in family history of cholecystitis, history of disease about gallstone, taking greasy food, taking animal organs, gender, and smoking. By PAR analysis, history of disease about gallstone, symptom of gallstone in family, taking animal organs, body mass index, meal pattern, and greasy food can cause gallstone with higher probability. Conclusion The gallstone risk factors were gender, family history, taking greasy food and irregular diet,and they were independent factors. Rational dietary structure,regular diet, weight control,exercise, and drinking tea were benefit to prevent the incidence of gallstone.%目的 探讨胆石症患病的危险因素,为该人群提供降低胆结石发病、改变不良行为提供健康教育信息,也为制定相关预防和控制策略提供参考依据.方法 分析沧州市1164例40 ~ 60岁体检人群的86例胆结石病例,通过病例对照分析方法,并采用条件Logistic回归分析胆石症的危险因素.结果 单因素分析胆囊炎家族史、胆囊炎史、喜食油腻食物、喜食动物内脏、女性性别、吸烟有统计学意义.人群归因危险度分析胆囊炎史、家族患胆石症、喜食动物内脏、体质指数、用餐无规律、油腻食物等因素引发胆石症的概率较高.结论 女性、家族史、喜食油腻食物、用餐不规律是胆结石的危险因素,并且其作用相对独立;合理膳食结构、规律进食、控制体重、适当运动、饮茶有助于预防胆石症的发生.

  15. Case-control design as investigative approach to assessing cancer etiology: development and future perspectives.

    Science.gov (United States)

    Kocic, B; Filipovic, S; Petrovic, B; Nikolic, M

    2012-01-01

    The case-control method evolved out of analyses of series of cases. The analytic form of the case-control study can be found in the 19th century medical literature, but did not appear to be viewed as a special or distinct methodology. The first modern case-control study was the Janet Lane-Claypon's study of breast cancer in 1926, but the design was used only sporadically in medicine until 1950, when 4 published casecontrol studies linked smoking and lung cancer. These 1950s studies synthesized the essential elements of the case-control comparison, produced a conceptual shift within epidemiology, and laid the foundation for the rapid development of the case-control design in the subsequent half century. The powerful consistency of these case-control studies, and the replication of their findings in later prospective studies, promoted the general acceptance of the case-control study as a scientific tool in clinical research. Newer case-control studies have benefited from the advances in design, execution and analysis since 1950s. These advances include more rigorous selection and matching of case and control population, improved interviewing techniques, location of the design within a general framework of epidemiologic strategies for relating exposure to disease, understanding of the measures of effect, and application of increasingly sophisticated statistical procedures to findings. This review traces the development and future perspectives of the case-control design to assessing cancer etiology. With illustrations drawn primarily from the literature on its use and the value of its results to unravelling the etiology of malignant diseases, we tried to explore if the case-control approach firmly ensconced in epidemiology as investigational tool and rivals in importance the more straightforward cohort approach. PMID:23033277

  16. Preliminary Evaluation of a Nest Usage Sensor to Detect Double Nest Occupations of Laying Hens

    Directory of Open Access Journals (Sweden)

    Mauro Zaninelli

    2015-01-01

    Full Text Available Conventional cage systems will be replaced by housing systems that allow hens to move freely. These systems may improve hens’ welfare, but they lead to some disadvantages: disease, bone fractures, cannibalism, piling and lower egg production. New selection criteria for existing commercial strains should be identified considering individual data about laying performance and the behavior of hens. Many recording systems have been developed to collect these data. However, the management of double nest occupations remains critical for the correct egg-to-hen assignment. To limit such events, most systems adopt specific trap devices and additional mechanical components. Others, instead, only prevent these occurrences by narrowing the nest, without any detection and management. The aim of this study was to develop and test a nest usage “sensor”, based on imaging analysis, that is able to automatically detect a double nest occupation. Results showed that the developed sensor correctly identified the double nest occupation occurrences. Therefore, the imaging analysis resulted in being a useful solution that could simplify the nest construction for this type of recording system, allowing the collection of more precise and accurate data, since double nest occupations would be managed and the normal laying behavior of hens would not be discouraged by the presence of the trap devices.

  17. Preliminary evaluation of a nest usage sensor to detect double nest occupations of laying hens.

    Science.gov (United States)

    Zaninelli, Mauro; Costa, Annamaria; Tangorra, Francesco Maria; Rossi, Luciana; Agazzi, Alessandro; Savoini, Giovanni

    2015-01-01

    Conventional cage systems will be replaced by housing systems that allow hens to move freely. These systems may improve hens' welfare, but they lead to some disadvantages: disease, bone fractures, cannibalism, piling and lower egg production. New selection criteria for existing commercial strains should be identified considering individual data about laying performance and the behavior of hens. Many recording systems have been developed to collect these data. However, the management of double nest occupations remains critical for the correct egg-to-hen assignment. To limit such events, most systems adopt specific trap devices and additional mechanical components. Others, instead, only prevent these occurrences by narrowing the nest, without any detection and management. The aim of this study was to develop and test a nest usage "sensor", based on imaging analysis, that is able to automatically detect a double nest occupation. Results showed that the developed sensor correctly identified the double nest occupation occurrences. Therefore, the imaging analysis resulted in being a useful solution that could simplify the nest construction for this type of recording system, allowing the collection of more precise and accurate data, since double nest occupations would be managed and the normal laying behavior of hens would not be discouraged by the presence of the trap devices. PMID:25629704

  18. Simulated nests in wildlife management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Many of us have studied game bird nests. Usually we hoped to learn something about nesting cover, cover management and the birds and animals which seemed to eat the...

  19. Nested Hierarchical Dirichlet Processes.

    Science.gov (United States)

    Paisley, John; Wang, Chong; Blei, David M; Jordan, Michael I

    2015-02-01

    We develop a nested hierarchical Dirichlet process (nHDP) for hierarchical topic modeling. The nHDP generalizes the nested Chinese restaurant process (nCRP) to allow each word to follow its own path to a topic node according to a per-document distribution over the paths on a shared tree. This alleviates the rigid, single-path formulation assumed by the nCRP, allowing documents to easily express complex thematic borrowings. We derive a stochastic variational inference algorithm for the model, which enables efficient inference for massive collections of text documents. We demonstrate our algorithm on 1.8 million documents from The New York Times and 2.7 million documents from Wikipedia. PMID:26353240

  20. Provenance for Nested Subqueries

    OpenAIRE

    Glavic, B; Alonso, G

    2009-01-01

    Data provenance is essential in applications such as scientific computing, curated databases, and data warehouses. Several systems have been developed that provide provenance functionality for the relational data model. These systems support only a subset of SQL, a severe limitation in practice since most of the application domains that benefit from provenance information use complex queries. Such queries typically involve nested subqueries, aggregation and/or user defined functions. Without ...

  1. PyNEST: A Convenient Interface to the NEST Simulator.

    Science.gov (United States)

    Eppler, Jochen Martin; Helias, Moritz; Muller, Eilif; Diesmann, Markus; Gewaltig, Marc-Oliver

    2008-01-01

    The neural simulation tool NEST (http://www.nest-initiative.org) is a simulator for heterogeneous networks of point neurons or neurons with a small number of compartments. It aims at simulations of large neural systems with more than 10(4) neurons and 10(7) to 10(9) synapses. NEST is implemented in C++ and can be used on a large range of architectures from single-core laptops over multi-core desktop computers to super-computers with thousands of processor cores. Python (http://www.python.org) is a modern programming language that has recently received considerable attention in Computational Neuroscience. Python is easy to learn and has many extension modules for scientific computing (e.g. http://www.scipy.org). In this contribution we describe PyNEST, the new user interface to NEST. PyNEST combines NEST's efficient simulation kernel with the simplicity and flexibility of Python. Compared to NEST's native simulation language SLI, PyNEST makes it easier to set up simulations, generate stimuli, and analyze simulation results. We describe how PyNEST connects NEST and Python and how it is implemented. With a number of examples, we illustrate how it is used. PMID:19198667

  2. 病例对照Meta分析显示男性乳腺癌与女性乳腺癌预后相同%A meta-analysis based on case-control studies shows the similar prognosis between male and female patients with breast cancer

    Institute of Scientific and Technical Information of China (English)

    Feifei Zhou; Rong Huang; Jun Jiang; Fang Wang; Wenzhuo He; Guifang Guo; Liangping Xia

    2011-01-01

    Objective: Male breast cancer (MBC) is a rare disease, and studies to compare the prognosis between the MBC and female breast cancer (FBC) available now were case-control studies and population-based studies, however, with controversial outcomes. To further investigate whether sex affects the prognosis of breast cancer, we performed a meta-analysis based on all the peered papers. Methods: The PubMed database was screened. Subsequently, the hazard ratios (HRs) for overall survival (OS) and disease special survival (DSS), were pooled using the Review Manager 5.0 package. Results: This study comprised of 254 MBC and 733 FBC patients enrolled in six case-control studies. There was no statistically significant heterogeneity among the trials for either outcome variable. The pooled HR showed that there was no significant difference in 5-year or 10-year DSS (HR: 1.25, 95% CI: 0.76-2.08; HR: 1.04, 95% CI: 0.66-1.59) and 5-year or 10-year OS (HR: 0.76, 95%CI: 0.51-1.14; HR: 0.74, 95% CI: 0.54-1.02) between MBCs and FBCs. Conclusion: MBC and FBC with similar prognosis are found in this meta-analysis based on only case-control studies which matched main potential prognostic factors such as age, clinical stage, and time at diagnosis.

  3. Diets of nesting laughing gulls (Larus atricilla) at the Virginia Coast Reserve: observations from stable isotope analysis.

    Science.gov (United States)

    Knoff, A J; Macko, S A; Erwin, R M

    2001-01-01

    Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia Coast Reserve estuarine system. As earlier traditional diet studies found evidence of individual dietary specialization within gull populations, this study used stable isotope analysis to assess specialization in a coastal Laughing Gull population. Specifically, blood, muscle, and feather isotope values indicated significant intrapopulation dietary specialization. Some gulls relied more heavily on estuarine prey (mean blood delta13C = -17.5, delta15N = 12.6, and delta34S = 9.3), whereas others appeared to consume more foods of marine origin (mean blood delta13C = -19.4, delta15N = 14.8, and delta34S = 10.4). It is important to account for such dietary variability when assessing trophic linkages in dynamic estuarine systems. PMID:11558657

  4. Analysis of the lettuce data from the variable pressure growth chamber at NASA Johnson Space Center: A three-stage nested design model

    Science.gov (United States)

    Lee, Tze-San

    1992-01-01

    A model of three-stage nested experimental design was applied to analyze the lettuce data obtained from the variable pressure growth chamber test bed at NASA-Johnson Space Center. From the results of an application of the analysis of variance and covariance on the data set, it was noted that all of the (uncontrollable) factors, Side, Zone, Height and (controllable) PAR (photosynthetically active radiation), had nonhomogeneous effects on the dry weight of the edible biomass of lettuce per pot. Incidentally, the variations accountable to the (uncontrollable) factorial heterogeneities are merely 9 percent and 17 percent of the total variation for both the first and second crop test, respectively. After adjusting for the PAR as a covariate in the no-intercept model, the accountable variations to all the four factors are 94 percent and 92 percent for the first and the second crop test, respectively. With the use of a no-intercept simple linear regression model, the accountable variations to the factor PAR are 92 percent and 90 percent for the first and the second crop test, respectively. Evidently, the (controllable) factor PAR is the dominating one.

  5. A case-control study on the causes of new HIV infection among heroin addicts attendees at the methadone maintenance treatment clinics

    Institute of Scientific and Technical Information of China (English)

    王常合

    2014-01-01

    Objective To explore the routes and factors associated with HIV new infection of heroin addicts who had been attending the methadone maintenance treatment(MMT)program.Methods A 1∶1 nested case-control study was implemented with the cases(new HIV infections)and controls(HIV negative)selected from the treatment cohort of China MMT clients.Questionnaire

  6. Woodpigeons nesting in association with hobby falcons: advantages and choice rules.

    Science.gov (United States)

    Bogliani; Sergio; Tavecchia

    1999-01-01

    Many bird species nest in close association with other bolder and more aggressive birds which provide protection against nest predators. The woodpigeons, Columba palumbus, that nest in poplar plantations in Northern Italy are found almost exclusively clumped around hobby, Falco subbuteo, nests. Woodpigeons settle in the area and build their nests after the hobby has started nesting. We carried out experiments with dummy nests and observations on woodpigeon nests. Dummy woodpigeon nests placed near a hobby's nest suffered less depredation by hooded crows, Corvus corone cornix, than those placed far from it. A logistic regression analysis showed that three variables, hobby nesting stage, distance from the hobby's nest and the hobby's aggressiveness, influenced the probability of nest predation. The degree of protection varied during the hobby's nesting period and was highest when chicks were in the nest. The hobby's aggressiveness against intruders varied both between and within individuals during different nesting phases. The predation rate of dummy nests associated with the falcon was negatively correlated with the aggressiveness score of the hobby during the 6 days of dummy nest exposure. Observations on real nests showed that woodpigeons selected hobbies that had a high fledging success, and a more vigorous defensive behaviour. Clues that would allow woodpigeons to choose the best protector may be early nesting by the hobby and its aggressiveness. Hobbies preyed on adult woodpigeons, but the risk incurred by the woodpigeons was low compared with the very high risk of nest predation in this area. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10053079

  7. Nested Canalyzing, Unate Cascade, and Polynomial Functions.

    Science.gov (United States)

    Jarrah, Abdul Salam; Raposa, Blessilda; Laubenbacher, Reinhard

    2007-09-15

    This paper focuses on the study of certain classes of Boolean functions that have appeared in several different contexts. Nested canalyzing functions have been studied recently in the context of Boolean network models of gene regulatory networks. In the same context, polynomial functions over finite fields have been used to develop network inference methods for gene regulatory networks. Finally, unate cascade functions have been studied in the design of logic circuits and binary decision diagrams. This paper shows that the class of nested canalyzing functions is equal to that of unate cascade functions. Furthermore, it provides a description of nested canalyzing functions as a certain type of Boolean polynomial function. Using the polynomial framework one can show that the class of nested canalyzing functions, or, equivalently, the class of unate cascade functions, forms an algebraic variety which makes their analysis amenable to the use of techniques from algebraic geometry and computational algebra. As a corollary of the functional equivalence derived here, a formula in the literature for the number of unate cascade functions provides such a formula for the number of nested canalyzing functions.

  8. Where to nest? Ecological determinants of chimpanzee nest abundance and distribution at the habitat and tree species scale.

    Science.gov (United States)

    Carvalho, Joana S; Meyer, Christoph F J; Vicente, Luis; Marques, Tiago A

    2015-02-01

    Conversion of forests to anthropogenic land-uses increasingly subjects chimpanzee populations to habitat changes and concomitant alterations in the plant resources available to them for nesting and feeding. Based on nest count surveys conducted during the dry season, we investigated nest tree species selection and the effect of vegetation attributes on nest abundance of the western chimpanzee, Pan troglodytes verus, at Lagoas de Cufada Natural Park (LCNP), Guinea-Bissau, a forest-savannah mosaic widely disturbed by humans. Further, we assessed patterns of nest height distribution to determine support for the anti-predator hypothesis. A zero-altered generalized linear mixed model showed that nest abundance was negatively related to floristic diversity (exponential form of the Shannon index) and positively with the availability of smaller-sized trees, reflecting characteristics of dense-canopy forest. A positive correlation between nest abundance and floristic richness (number of plant species) and composition indicated that species-rich open habitats are also important in nest site selection. Restricting this analysis to feeding trees, nest abundance was again positively associated with the availability of smaller-sized trees, further supporting the preference for nesting in food tree species from dense forest. Nest tree species selection was non-random, and oil palms were used at a much lower proportion (10%) than previously reported from other study sites in forest-savannah mosaics. While this study suggests that human disturbance may underlie the exclusive arboreal nesting at LCNP, better quantitative data are needed to determine to what extent the construction of elevated nests is in fact a response to predators able to climb trees. Given the importance of LCNP as refuge for Pan t. verus our findings can improve conservation decisions for the management of this important umbrella species as well as its remaining suitable habitats. PMID:25224379

  9. Intelligent nesting system

    Directory of Open Access Journals (Sweden)

    Đuričić Zoran

    2003-01-01

    Full Text Available The economy of the process for the manufacture of parts from sheet metal plates depends on successful solution of the process of cutting various parts from sheet metal plates. Essentially, the problem is to arrange contours within a defined space so that they take up minimal surface. When taken in this way, the considered problem assumes a more general nature; it refers to the utilization of a flat surface, and it can represent a general principle of arranging 2D contours on a certain surface. The paper presents a conceptual solution and a prototypal intelligent nesting system for optimal cutting. The problem of nesting can generally be divided into two intellectual phases: recognition and classification of shapes, and arrangement of recognized shapes on a given surface. In solving these problems, methods of artificial intelligence are applied. In the paper, trained neural network is used for recognition of shapes; on the basis of raster record of a part's drawing, it recognizes the part's shape and which class it belongs to. By means of the expert system, based on rules defined on the basis of acquisition of knowledge from manufacturing sections, as well as on the basis of certain mathematical algorithms, parts are arranged on the arrangement surface. Both systems can also work independently, having been built on the modular principle. The system uses various product models as elements of integration for the entire system. .

  10. PyNEST: a convenient interface to the NEST simulator

    Directory of Open Access Journals (Sweden)

    Jochen M Eppler

    2009-01-01

    Full Text Available The neural simulation tool NEST (http://www.nest-initiative.org is a simulator for heterogeneous networks of point neurons or neurons with a small number of compartments. It aims at simulations of large neural systems with more than 10^4 neurons and 10^7 to 10^9 synapses. NEST is implemented in C++ and can be used on a large range of architectures from single-core laptops over multi-core desktop computers to super-computers with thousands of processor cores. Python (http://www.python.org is a modern programming language that has recently received considerable attention in Computational Neuroscience. Python is easy to learn and has many extension modules for scientific computing (e.g. http://www.scipy.org. In this contribution we describe PyNEST, the new user interface to NEST. PyNEST combines NEST’s efficient simulation kernel with the simplicity and flexibility of Python. Compared to NEST’s native simulation language SLI, PyNEST makes it easier to set up simulations, generate stimuli, and analyze simulation results. We describe how PyNEST connects NEST and Python and how it is implemented. With a number of examples, we illustrate how it is used.

  11. The cavity-nest ant Temnothorax crassispinus prefers larger nests

    OpenAIRE

    Mitrus, S.

    2014-01-01

    Colonies of the ant Temnothorax crassispinus inhabit mostly cavities in wood and hollow acorns. Typically in the field, nest sites that can be used by the ant are a limited resource. In a field experiment, it was investigated whether the ants prefer a specific size of nest, when different ones are available. In July 2011, a total of 160 artificial nests were placed in a beech-pine forest. Four artificial nests (pieces of wood with volume cavities, ca 415, 605, 730, and 980 mm3, respectively) ...

  12. Habitat fragmentation reduces nest survival in an Afrotropical bird community in a biodiversity hotspot

    Science.gov (United States)

    Newmark, W.D.; Stanley, T.R.

    2011-01-01

    Ecologists have long hypothesized that fragmentation of tropical landscapes reduces avian nest success. However, this hypothesis has not been rigorously assessed because of the difficulty of finding large numbers of well-hidden nests in tropical forests. Here we report that in the East Usambara Mountains in Tanzania, which are part of the Eastern Arc Mountains, a global biodiversity hotspot, that daily nest survival rate and nest success for seven of eight common understory bird species that we examined over a single breeding season were significantly lower in fragmented than in continuous forest, with the odds of nest failure for these seven species ranging from 1.9 to 196.8 times higher in fragmented than continuous forest. Cup-shaped nests were particularly vulnerable in fragments. We then examined over six breeding seasons and 14 study sites in a multivariable survival analysis the influence of landscape structure and nest location on daily nest survival for 13 common species representing 1,272 nests and four nest types (plate, cup, dome, and pouch). Across species and nest types, area, distance of nest to edge, and nest height had a dominant influence on daily nest survival, with area being positively related to nest survival and distance of nest to edge and nest height being both positively and negatively associated with daily nest survival. Our results indicate that multiple environmental factors contribute to reduce nest survival within a tropical understory bird community in a fragmented landscape and that maintaining large continuous forest is important for enhancing nest survival for Afrotropical understory birds.

  13. On the evolution of clutch size and nest size in passerine birds.

    Science.gov (United States)

    Slagsvold, T

    1989-05-01

    I examined the hypothesis that the clutch size of some altricial birds may be limited by over-crowding of the nestlings in the nest, by comparing data on different species of European passerines. Large-sized birds build, relative to the body, larger nests than small-sized birds, both as regards the inner and the outer nest widths and as regards edge breadth; only inner nestcup depth did not change relatively to body size. Nest size also varied in relation to nesting place. Birds with open nests built off the ground had a rather narrow nestcup, whereas those with a domed nest, or which nest in a cavity, had a wide nestcup. When only open-nesters were compared, birds nesting on, or close to, the ground tended to have a wider nestcup than birds nesting above the ground. Inner nestcup width was correlated with the amount of mosses and lichens used in building the nest; the more of such materials the narrower the nestcup. The three variables: standardised body size, nesting place, and type of nesting material used accounted for 92% of the overall variation observed in inner nestcup width. When controlling for adult body size, clutch size was positively correlated with the size of the nestcup. A multiple regression analysis showed that relative nestcup depth, nest site, and type of nesting materials used, accounted for 64% of the overall variation in clutch size. PMID:23921394

  14. A Two-Stage Penalized Logistic Regression Approach to Case-Control Genome-Wide Association Studies

    Directory of Open Access Journals (Sweden)

    Jingyuan Zhao

    2012-01-01

    Full Text Available We propose a two-stage penalized logistic regression approach to case-control genome-wide association studies. This approach consists of a screening stage and a selection stage. In the screening stage, main-effect and interaction-effect features are screened by using L1-penalized logistic like-lihoods. In the selection stage, the retained features are ranked by the logistic likelihood with the smoothly clipped absolute deviation (SCAD penalty (Fan and Li, 2001 and Jeffrey’s Prior penalty (Firth, 1993, a sequence of nested candidate models are formed, and the models are assessed by a family of extended Bayesian information criteria (J. Chen and Z. Chen, 2008. The proposed approach is applied to the analysis of the prostate cancer data of the Cancer Genetic Markers of Susceptibility (CGEMS project in the National Cancer Institute, USA. Simulation studies are carried out to compare the approach with the pair-wise multiple testing approach (Marchini et al. 2005 and the LASSO-patternsearch algorithm (Shi et al. 2007.

  15. Using Artificial Nests to Study Nest Predation in Birds

    Science.gov (United States)

    Belthoff, James R.

    2005-01-01

    A simple and effective field exercise that demonstrates factors affecting predation on bird nests is described. With instructor guidance, students in high school biology or college-level biology, ecology, animal behavior, wildlife management or ornithology laboratory courses can collaborate to design field experiments related to nest depredation.

  16. What Multilevel Parallel Programs do when you are not Watching: A Performance Analysis Case Study Comparing MPI/OpenMP, MLP, and Nested OpenMP

    Science.gov (United States)

    Jost, Gabriele; Labarta, Jesus; Gimenez, Judit

    2004-01-01

    With the current trend in parallel computer architectures towards clusters of shared memory symmetric multi-processors, parallel programming techniques have evolved that support parallelism beyond a single level. When comparing the performance of applications based on different programming paradigms, it is important to differentiate between the influence of the programming model itself and other factors, such as implementation specific behavior of the operating system (OS) or architectural issues. Rewriting-a large scientific application in order to employ a new programming paradigms is usually a time consuming and error prone task. Before embarking on such an endeavor it is important to determine that there is really a gain that would not be possible with the current implementation. A detailed performance analysis is crucial to clarify these issues. The multilevel programming paradigms considered in this study are hybrid MPI/OpenMP, MLP, and nested OpenMP. The hybrid MPI/OpenMP approach is based on using MPI [7] for the coarse grained parallelization and OpenMP [9] for fine grained loop level parallelism. The MPI programming paradigm assumes a private address space for each process. Data is transferred by explicitly exchanging messages via calls to the MPI library. This model was originally designed for distributed memory architectures but is also suitable for shared memory systems. The second paradigm under consideration is MLP which was developed by Taft. The approach is similar to MPi/OpenMP, using a mix of coarse grain process level parallelization and loop level OpenMP parallelization. As it is the case with MPI, a private address space is assumed for each process. The MLP approach was developed for ccNUMA architectures and explicitly takes advantage of the availability of shared memory. A shared memory arena which is accessible by all processes is required. Communication is done by reading from and writing to the shared memory.

  17. Jordan Isomorphisms on Nest Subalgebras

    Directory of Open Access Journals (Sweden)

    Aili Yang

    2015-01-01

    Full Text Available This paper is devoted to the study of Jordan isomorphisms on nest subalgebras of factor von Neumann algebras. It is shown that every Jordan isomorphism ϕ between the two nest subalgebras algMβ and algMγ is either an isomorphism or an anti-isomorphism.

  18. Combined effect of tobacco smoking and alcohol drinking in the risk of head and neck cancers: a re-analysis of case-control studies using bi-dimensional spline models.

    Science.gov (United States)

    Dal Maso, Luigino; Torelli, Nicola; Biancotto, Elisa; Di Maso, Matteo; Gini, Andrea; Franchin, Gianni; Levi, Fabio; La Vecchia, Carlo; Serraino, Diego; Polesel, Jerry

    2016-04-01

    The synergistic effect of tobacco smoking and alcohol consumption on the risk of head and neck cancers has been mainly investigated as a cross-product of categorical exposure, thus leading to loss of information. We propose a bi-dimensional logistic spline model to investigate the interacting dose-response relationship of two continuous exposures (i.e., ethanol intake and tobacco smoking) on the risk of head and neck cancers, representing results through three-dimensional graphs. This model was applied to a pool of hospital-based case-control studies on head and neck cancers conducted in Italy and in the Vaud Swiss Canton between 1982 and 2000, including 1569 cases and 3147 controls. Among never drinkers and for all levels of ethanol intake, the risk of head and neck cancers steeply increased with increasing smoking intensity, starting from 1 cigarette/day. The risk associated to ethanol intake increased with incrementing exposure among smokers, and a threshold effect at approximately 50 g/day emerged among never smokers. Compared to abstainers from both tobacco and alcohol consumption, the combined exposure to ethanol and/or cigarettes led to a steep increase of cancer risk up to a 35-fold higher risk (95 % confidence interval 27.30-43.61) among people consuming 84 g/day of ethanol and 10 cigarettes/day. The highest risk was observed at the highest levels of alcohol and tobacco consumption. Our findings confirmed a combined effect of tobacco smoking and alcohol drinking on head and neck cancers risk, providing evidence that bi-dimensional spline models could be a feasible and flexible method to explore the pattern of risks associated to two interacting continuous-exposure variables.

  19. Combined effect of tobacco smoking and alcohol drinking in the risk of head and neck cancers: a re-analysis of case-control studies using bi-dimensional spline models.

    Science.gov (United States)

    Dal Maso, Luigino; Torelli, Nicola; Biancotto, Elisa; Di Maso, Matteo; Gini, Andrea; Franchin, Gianni; Levi, Fabio; La Vecchia, Carlo; Serraino, Diego; Polesel, Jerry

    2016-04-01

    The synergistic effect of tobacco smoking and alcohol consumption on the risk of head and neck cancers has been mainly investigated as a cross-product of categorical exposure, thus leading to loss of information. We propose a bi-dimensional logistic spline model to investigate the interacting dose-response relationship of two continuous exposures (i.e., ethanol intake and tobacco smoking) on the risk of head and neck cancers, representing results through three-dimensional graphs. This model was applied to a pool of hospital-based case-control studies on head and neck cancers conducted in Italy and in the Vaud Swiss Canton between 1982 and 2000, including 1569 cases and 3147 controls. Among never drinkers and for all levels of ethanol intake, the risk of head and neck cancers steeply increased with increasing smoking intensity, starting from 1 cigarette/day. The risk associated to ethanol intake increased with incrementing exposure among smokers, and a threshold effect at approximately 50 g/day emerged among never smokers. Compared to abstainers from both tobacco and alcohol consumption, the combined exposure to ethanol and/or cigarettes led to a steep increase of cancer risk up to a 35-fold higher risk (95 % confidence interval 27.30-43.61) among people consuming 84 g/day of ethanol and 10 cigarettes/day. The highest risk was observed at the highest levels of alcohol and tobacco consumption. Our findings confirmed a combined effect of tobacco smoking and alcohol drinking on head and neck cancers risk, providing evidence that bi-dimensional spline models could be a feasible and flexible method to explore the pattern of risks associated to two interacting continuous-exposure variables. PMID:25855002

  20. PyNEST: a convenient interface to the NEST simulator

    OpenAIRE

    Eppler, Jochen M; Moritz Helias; Eilif Muller; Markus Diesmann; Marc-Oliver Gewaltig

    2008-01-01

    The neural simulation tool NEST (http://www.nest-initiative.org) is a simulator for heterogeneous networks of point neurons or neurons with a small number of compartments. It aims at simulations of large neural systems with more than 10^4 neurons and 10^7 to 10^9 synapses. NEST is implemented in C++ and can be used on a large range of architectures from single-core laptops over multi-core desktop computers to super-computers with thousands of processor cores. Python (http://www.python.org) i...

  1. Hospital visitors as controls in case-control studies

    Directory of Open Access Journals (Sweden)

    Gulnar Azevedo S Mendonça

    2001-10-01

    Full Text Available OBJECTIVE: Selecting controls is one of the most difficult tasks in the design of case-control studies. Hospital controls may be inadequate and random controls drawn from the base population may be unavailable. The aim was to assess the use of hospital visitors as controls in a case-control study on the association of organochlorinated compounds and other risk factors for breast cancer conducted in the main hospital of the "Instituto Nacional de Câncer" -- INCA (National Cancer Institute in Rio de Janeiro (Brazil. METHODS: The study included 177 incident cases and 377 controls recruited among female visitors. Three different models of control group composition were compared: Model 1, with all selected visitors; Model 2, excluding women visiting relatives with breast cancer; and Model 3, excluding all women visiting relatives with any type of cancer. Odds ratios (OR and 95% confidence intervals were calculated to test the associations. RESULTS: Age-adjusted OR for breast cancer associated with risk factors other than family history of cancer, except smoking and breast size, were similar in the three models. Regarding family history of all cancers, except for breast cancer, there was a decreased risk in Models 1 and 2, while in Model 3 there was an increased risk, but not statistically significant. Family history of breast cancer was a risk factor in Models 2 and 3, but no association was found in Model 1. In multivariate analysis a significant risk of breast cancer was found when there was a family history of breast cancer in Models 2 and 3 but not in Model 1. CONCLUSIONS: These results indicate that while investigating risk factors unrelated to family history of cancer, the use of hospital visitors as controls may be a valid and feasible alternative.

  2. Hospital visitors as controls in case-control studies

    Directory of Open Access Journals (Sweden)

    Mendonça Gulnar Azevedo S

    2001-01-01

    Full Text Available OBJECTIVE: Selecting controls is one of the most difficult tasks in the design of case-control studies. Hospital controls may be inadequate and random controls drawn from the base population may be unavailable. The aim was to assess the use of hospital visitors as controls in a case-control study on the association of organochlorinated compounds and other risk factors for breast cancer conducted in the main hospital of the "Instituto Nacional de Câncer" -- INCA (National Cancer Institute in Rio de Janeiro (Brazil. METHODS: The study included 177 incident cases and 377 controls recruited among female visitors. Three different models of control group composition were compared: Model 1, with all selected visitors; Model 2, excluding women visiting relatives with breast cancer; and Model 3, excluding all women visiting relatives with any type of cancer. Odds ratios (OR and 95% confidence intervals were calculated to test the associations. RESULTS: Age-adjusted OR for breast cancer associated with risk factors other than family history of cancer, except smoking and breast size, were similar in the three models. Regarding family history of all cancers, except for breast cancer, there was a decreased risk in Models 1 and 2, while in Model 3 there was an increased risk, but not statistically significant. Family history of breast cancer was a risk factor in Models 2 and 3, but no association was found in Model 1. In multivariate analysis a significant risk of breast cancer was found when there was a family history of breast cancer in Models 2 and 3 but not in Model 1. CONCLUSIONS: These results indicate that while investigating risk factors unrelated to family history of cancer, the use of hospital visitors as controls may be a valid and feasible alternative.

  3. Multiple Sclerosis Associated Risk Factors: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Jalal POOROLAJAL

    2015-11-01

    Full Text Available Background: Hamadan Province is one of the high-risk regions in Iran for Multiple sclerosis (MS. A majority of the epidemiological studies conducted in Iran addressing MS are descriptive. This study was conducted to assess MS and its associated risk factors in Hamadan Province, the west of Iran.Methods: This case-control study compared 100 patients with MS (case group and 100 patients with acute infectious diseases (control group from September 2013 to March 2014. A checklist was used to assess the demographic, medical, and family history of the patients. The Friedman-Rosenman questionnaire was also used to assess personality type. Statistical analysis was performed using logistic regression model with Stata 11 software program.Results: The adjusted odds ratio (OR estimate of MS was 4.37 (95% CI: 2.33, 8.20 for females compared to males; 0.15 (95% CI: 0.06, 0.43 for people aged above 50 years compared to aged 14 to 29 years; 0.44 (95% CI: 0.21, 0.91 for overweight or obese people compared to normal weights. Crude OR indicated a significant association between the occurrence of MS and exclusive breast feeding, season of birth, and smoking. However, the association was not statistically significant after adjustment for other covariates.Conclusion: The risk of MS is significantly lower in male gender, obese/overweight, and old people. Furthermore, non-smoking, non-exclusive breast-feeding, and born in autumn may increase the risk of MS but need further investigation. However, long-term large prospective cohort studies are needed to investigate the true effect of the potential risk factors on MS. Keywords: Multiple sclerosis, Risk factors, Case-control study, Iran

  4. A hospital-based case-control study of non-Hodgkin lymphoid neoplasms in Shanghai: analysis of environmental and occupational risk factors by subtypes of the WHO classification.

    Science.gov (United States)

    Wong, Otto; Harris, Fran; Armstrong, Thomas W; Hua, Fu

    2010-03-19

    The objectives were (1) to investigate potential environmental and occupational risk factors of non-Hodgkin lymphoid neoplasms (NHLN), and (2) to explore the relationships between risk factors and NHLN subtypes according to the World Health Organization (WHO) classification. The investigation was a hospital-based case-control study consisting of 649 newly diagnosed NHLN cases (August 2003 through January 2008) and 1298 individually gender-age-matched patient controls at 25 hospitals in Shanghai. A 17-page questionnaire was used to obtain information on demographics, medical history, family history, lifestyle risk factors, employment history, residential history, and occupational and non-occupational exposures. Certain occupations of interest triggered a second questionnaire, which was occupation-specific and asked for more details about jobs, tasks, materials used and work environment. Exposure assessments were based on the questionnaires, on-site workplace investigations, data published in the Chinese literature, historical exposure measurements maintained by government health agencies, and expert opinions of a panel of local scientists who were familiar with workplaces in Shanghai. Risk estimates (odds ratios and 95% confidence intervals) of individual risk factors were calculated using conditional logistic regression models. A number of potential environmental and occupational risk factors were associated with an increased risk of NHLN (all subtypes combined) and/or individual subtypes; including home/workplace renovation, living on a farm, planting crops, raising livestock or animals, farm workers, fabric sewing and cutting workers, welders and sheet metal workers, masonry and plastering workers, product and chemical testing workers, toy manufacturing, agriculture industry, and beauty salon. Exposures associated with an increased risk of NHLN (all subtypes combined) and/or individual subtypes included benzene, solvents, petroleum fuels, metals, insecticides

  5. Bristol Bay, Alaska Subarea ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for nesting seabirds (alcids, pelagic birds), gulls, terns, diving birds, and raptors in the Bristol Bay...

  6. Terrestrial LiDAR-based automated counting of swiftlet nests in the caves of Gomantong, Sabah, Borneo.

    OpenAIRE

    McFarlane, Donald A.; Warren Roberts; Manfred Buchroithner; Guy Van Rentergem; Joyce Lundberg; Stefan Hautz

    2015-01-01

    High resolution terrestrial laser scanning (TLS) within the Simud Hitam cave, Gomantong, has proven successful at discriminating the nests of black-nest swiftlets from roosting bats in high, inaccessible locations. TLS data was imported into ArcGIS software, allowing for semi-automated counting of nests. Spatial analysis of nest locations has established a maximum packing density of 268 nests/m2 in optimum locations, which correspond to roof slopes of >20 degrees. Rhinolophid bats roost adjac...

  7. Nested subgraphs of complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Corominas-Murtra, Bernat; Sole, Ricard V [ICREA-Complex Systems Lab, Universitat Pompeu Fabra, Dr Aiguader 80, 08003 Barcelona (Spain); Mendes, Jose F F [Departamento de Fisica da Universidade de Aveiro, 3810-193 Aveiro (Portugal)], E-mail: bernat.corominas@upf.edu

    2008-09-26

    We analytically explore the scaling properties of a general class of nested subgraphs in complex networks, which includes the K-core and the K-scaffold, among others. We name such a class of subgraphs K-nested subgraphs since they generate families of subgraphs such that ...S{sub K+1}(G) subset or equal S{sub K}(G) subset or equal S{sub K-1}(G).... Using the so-called configuration model it is shown that any family of nested subgraphs over a network with diverging second moment and finite first moment has infinite elements (i.e. lacking a percolation threshold). Moreover, for a scale-free network with the above properties, we show that any nested family of subgraphs is self-similar by looking at the degree distribution. Both numerical simulations and real data are analyzed and display good agreement with our theoretical predictions.

  8. The association between household socioeconomic position and prevalent tuberculosis in Zambia: a case-control study.

    Directory of Open Access Journals (Sweden)

    Delia Boccia

    Full Text Available BACKGROUND: Although historically tuberculosis (TB has been associated with poverty, few analytical studies from developing countries have tried to: 1. assess the relative impact of poverty on TB after the emergence of HIV; 2. explore the causal mechanism underlying this association; and 3. estimate how many cases of TB could be prevented by improving household socioeconomic position (SEP. METHODS AND FINDINGS: We undertook a case-control study nested within a population-based TB and HIV prevalence survey conducted in 2005-2006 in two Zambian communities. Cases were defined as persons (15+ years of age culture positive for M. tuberculosis. Controls were randomly drawn from the TB-free participants enrolled in the prevalence survey. We developed a composite index of household SEP combining variables accounting for four different domains of household SEP. The analysis of the mediation pathway between household SEP and TB was driven by a pre-defined conceptual framework. Adjusted Population Attributable Fractions (aPAF were estimated. Prevalent TB was significantly associated with lower household SEP [aOR = 6.2, 95%CI: 2.0-19.2 and aOR = 3.4, 95%CI: 1.8-7.6 respectively for low and medium household SEP compared to high]. Other risk factors for prevalent TB included having a diet poor in proteins [aOR = 3.1, 95%CI: 1.1-8.7], being HIV positive [aOR = 3.1, 95%CI: 1.7-5.8], not BCG vaccinated [aOR = 7.7, 95%CI: 2.8-20.8], and having a history of migration [aOR = 5.2, 95%CI: 2.7-10.2]. These associations were not confounded by household SEP. The association between household SEP and TB appeared to be mediated by inadequate consumption of protein food. Approximately the same proportion of cases could be attributed to this variable and HIV infection (aPAF = 42% and 36%, respectively. CONCLUSIONS: While the fight against HIV remains central for TB control, interventions addressing low household SEP and, especially food

  9. Breast cancer risk associated with different HRT formulations: a register-based case-control study

    OpenAIRE

    Thai Do; Möhner Sabine; Heinemann Lothar AJ; Dinger Juergen C; Assmann Anita

    2006-01-01

    Abstract Background Previous epidemiological studies have inconsistently shown a modestly increased breast cancer risk associated with hormone replacement therapy (HRT). Limited information is available about different formulations – particularly concerning different progestins. Methods A case-control study was performed within Germany in collaboration with regional cancer registries and tumor centers. Up to 5 controls were matched breast cancer cases. Conditional logistic regression analysis...

  10. Risk Factors For Ectopic Pregnancy : A Case Control Study

    Directory of Open Access Journals (Sweden)

    Deshmukh J.S

    1999-01-01

    Full Text Available Research question: Which are the risk factors for ectopic pregnancy . Objective: To study the strength of association between hypothesised risk factors and ectopic pregnancy. Study design: Unmatched case- control study. Setting: Government Medical College, Hospital, Nagpur. Participants: 133 cases of ectopic pregnancy and equal number of controls (non pregnant women admitted to study hospital. Study variables : Pelvic inflammatory diseases, sexually transmitted diseases, IUD use at conception , past use of IUD, prior ectopic pregnancy, OC pills use at the time of conception, past use of OC pills, induced abortion, spontaneous abortion, infertility and pelvic and abdominal surgery. Statistical analysis: Odds ratios & their 95% CI, Pearson’s chi square test, unconditional logistic regression analysis and population attributable risk proportion. Results : Use of IUD at conception, prior ectopic pregnancy , pelvic inflammatory disease, sexually transmitted diseases, infertility, OC pills use at the time of conception, past use of IUD and induced abortion were found to be significantly associated with ectopic pregnancy. Conclusion: Identification of these risk factors for etopic pregnancy shall help in early detection and appropriate management in an individual case and it may help in devising a comprehensive preventive strategy for ectopic pregnancy

  11. Diagnóstico e genotipagem do vírus da pseudoraiva por nested-PCR e análise de restrição enzimática Diagnosis and genotyping of pseudorabies virus by nested-PCR and restriction enzyme analysis

    Directory of Open Access Journals (Sweden)

    Antônio Augusto Fonseca Júnior

    2010-04-01

    virus isolation, DNA purification enzyme restriction analysis and a long electrophoresis. The aim of this research was to describe a faster and more sensitive method to detect and genotype PrV based on nested-PCR and restriction enzyme analysis. Twenty PrV isolates from south and southeast regions of Brazil, and the standard strain Shope were grown in PK-15 cells and submitted to PCR for glycoprotein E gene amplification. Additionally were tested 75 clinical samples (swine brain, with 25 positives for virus isolation and seroneutralization, and 50 negatives from a flock free PR with negative results in seroneutralization test. There was 100% of agreement between results of nested-PCR and virus isolation and seroneutralization and all samples detected were classified as genotype II. The nested-PCR, combined with restriction enzyme analysis, was able to detect and genotype PrV in 1-2 days with a sensitivity of 10-1,3 TCID50 mL-1. It was faster than classical methods described in the literature that require at least 7 days to be completed.

  12. DIAMONDS: A new Bayesian nested sampling tool

    CERN Document Server

    Corsaro, Enrico

    2015-01-01

    In the context of high-quality asteroseismic data provided by the NASA Kepler mission, we developed a new code, termed Diamonds (high-DImensional And multi-MOdal NesteD Sampling), for fast Bayesian parameter estimation and model comparison by means of the Nested Sampling Monte Carlo (NSMC) algorithm, an efficient and powerful method very suitable for high-dimensional problems (like the peak bagging analysis of solar-like oscillations) and multi-modal problems (i.e. problems that show multiple solutions). We applied the code to the peak bagging analysis of solar-like oscillations observed in a challenging F-type star. By means of Diamonds one is able to detect the different backgrounds in the power spectrum of the star (e.g. stellar granulation and faculae activity) and to understand whether one or two oscillation peaks can be identified or not. In addition, we demonstrate a novel approach to peak bagging based on multimodality, which is able to reduce significantly the number of free parameters involved in th...

  13. Hospital visitors as controls in case-control studies

    OpenAIRE

    Gulnar Azevedo S Mendonça; José Eluf-Neto

    2001-01-01

    OBJECTIVE: Selecting controls is one of the most difficult tasks in the design of case-control studies. Hospital controls may be inadequate and random controls drawn from the base population may be unavailable. The aim was to assess the use of hospital visitors as controls in a case-control study on the association of organochlorinated compounds and other risk factors for breast cancer conducted in the main hospital of the "Instituto Nacional de Câncer" -- INCA (National Cancer Institute) in ...

  14. Nest poaching in Neotropical parrots

    Science.gov (United States)

    Wright, T.F.; Toft, C.A.; Enkerlin-Hoeflich, E.; Gonzalez-Elizondo, J.; Albornoz, M.; Rodriguez-Ferraro, A.; Rojas-Suarez, F.; Sanz, V.; Trujillo, A.; Beissinger, S.R.; Berovides A., V.; Galvez A., X.; Brice, A.T.; Joyner, K.; Eberhard, J.; Gilardi, J.; Koenig, S.E.; Stoleson, S.; Martuscelli, P.; Meyers, J.M.; Renton, K.; Rodriguez, A.M.; Sosa-Asanza, A.C.; Vilella, F.J.; Wiley, J.W.

    2001-01-01

    Although the poaching of nestlings for the pet trade is thought to contribute to the decline of many species of parrots, its effects have been poorly demonstrated. We calculated rates of mortality due to nest poaching in 23 studies of Neotropical parrots, representing 4024 nesting attempts in 21 species and 14 countries. We also examined how poaching rates vary with geographic region, presence of active protection programs, conservation status and economic value of a species, and passage of the U.S. Wild Bird Conservation Act. The average poaching rate across all studies was 30% of all nests observed. Thirteen studies reported poaching rates of >20%, and four reported rates of >70%. Only six studies documented no nest poaching. Of these, four were conducted on islands in the Caribbean region, which had significantly lower poaching rates than the mainland Neotropics. The other two studies that showed no poaching were conducted on the two species with the lowest economic value in our sample (U.S. retail price). In four studies that allowed direct comparison between poaching at sites with active nest protection versus that at unprotected sites, poaching rates were significantly lower at protected sites, suggesting that active protection efforts can be effective in reducing nest poaching. In those studies conducted both before and after the passage of the U.S. Wild Bird Conservation Act, poaching rates were found to be significantly lower following its enactment than in the period before. This result supports the hypothesis that the legal and illegal parrot trades are positively related, rather than inversely related as has been suggested by avicultural interests. Overall, our study indicates that poaching of parrot nestlings for economic gain is a widespread and biologically significant source of nest mortality in Neotropical parrots.

  15. Violence against Women and Gastroschisis: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Daniel Ruiz

    2013-10-01

    Full Text Available Background: Gastroschisis, a birth defect characterized by herniated fetal abdominal wall, occurs more commonly in infants born to teenage and young mothers. Ischemia of the vascular vitelline vessels is the likely mechanism of pathogenesis. Given that chronic stress and violence against women are risk factors for cardiovascular disease we explored whether these may represent risk factors for gastroschisis, when they occur during pregnancy. A case-control study was conducted, with 15 incident cases of children born with gastroschisis in the Region of Murcia, Spain, from December 2007 to June 2013. Forty concurrent controls were recruited at gestation weeks 20–24 or post-partum. All mothers of cases and controls completed a comprehensive, in-person, ‘green sheet’ questionnaire on environmental exposures. Results: Mothers of children with gastroschisis were younger, smoked more cigarettes per week relative to controls, were exposed to higher amounts of illegal drugs, and suffered from domestic violence more frequently than the controls. Multivariable logistic regression analysis highlights periconceptional ‘gender-related violence’ (OR: 16.6, 95% CI 2.7 to 101.7 and younger maternal age (OR 1.1, 95% CI 1.0–1.3. Conclusions: Violence against pregnant women is associated with birth defects, and should be studied in more depth as a cause-effect teratogenic. Psychosocial risk factors, including gender-based violence, are important for insuring the health and safety of the pregnant mother and the fetus.

  16. REPRODUCTIVE FACTORS AND COLORECTAL CANCER RISK. Case - control study.

    Directory of Open Access Journals (Sweden)

    Adriana Ruseva

    2015-02-01

    Full Text Available Colorectal cancer is one of the most common cancers worldwide. The role of the female sex hormones in the etiology of the disease is very intriguing. Reproductive factors are surrogate measure of lifetime exposition to the sex hormones. Purpose: Our aim is to investigate the association between the reproductive factors and colorectal carcinoma risk. Materials and methods: We include 234 Bulgarian women in our study – 117 cases with colorectal cancer and the same number of healthy controls. Cases are divided into three groups according to the localization of the tumor. We conduct case-control study, using questionnaires about reproductive factors. We use the following statistical methods – descriptive, variational analysis, binary logistic regression. Results: We observed that only the age at menopause is associated with colorectal cancer risk, and this factor has strongest protective effect in the proximal colon (95% CI - 0,051-0,781, OR – 0,200, p – 0,021. Conclusion: Analyzing our data we observed that among Bulgarian women the only reproductive factor that show association with the risk of colorectal cancer is the age at menopause.

  17. Utilização de estratificação e modelo de regressão logística na análise de dados de estudos caso-controle Using of stratification and the logistic regression model in the analysis of data of case-control studies

    Directory of Open Access Journals (Sweden)

    Suely Godoy Agostinho Gimeno

    1995-08-01

    Full Text Available Exemplifica-se a aplicação de análise multivariada, por estratificação e com regressão logística, utilizando dados de um estudo caso-controle sobre câncer de esôfago. Oitenta e cinco casos e 292 controles foram classificados segundo sexo, idade e os hábitos de beber e de fumar. As estimativas por ponto dos odds ratios foram semelhantes, sendo as duas técnicas consideradas complementares.Data of a case-control study of esophageal cancer were used as an example of the use of multivariate analysis with stratification and logistic regression. Eighty-five cases and 292 controls were classified according to sex, age and smoking and drinking habits. The point estimates of the odds ratios were similar, and the techniques were considered complementary.

  18. Successful nesting behavior of Puerto Rican parrots

    Science.gov (United States)

    Wilson, K.A.; Field, R.; Wilson, M.H.

    1995-01-01

    We analyzed nesting behavior of five pairs of the endangered Puerto Rican Parrot (Amazona vittata) during eight successful nesting attempts. Each stage of the nesting cycle (egg laying, incubation, early chick rearing, and late chick rearing) was characterized by distinct trends or levels of behavior. During egg laying, female attentiveness to tile nest increased, and male attentiveness decreased. Throughout incubation and the first several days of early chick rearing, females were highly attentive to their nests, whereas males rarely entered the nest cavities. Female attentiveness then began to decline. Male attentiveness to the nest was sporadic until chicks were 10-12 days old. when all males began to enter their nests at least once each day. During late chick rearing, both male and female attentiveness were erratic and highly variable. Biologists may be able to use these results to identify nest problems and the need for management intervention when patterns of nest attentiveness deviate from the limits described in this study..

  19. Frequent Use of Antibiotics Is Associated with Colorectal Cancer Risk : Results of a Nested Case-Control Study

    NARCIS (Netherlands)

    Dik, Vincent K; van Oijen, Martijn G H; Smeets, Hugo M.; Siersema, Peter D

    2016-01-01

    BACKGROUND: Microbiotical dysbiosis induced by a Western diet seems to be associated with an increased risk of developing colorectal cancer (CRC). Few other factors with an effect on the colonic microbiota and their association with CRC have been evaluated. AIM: We investigated whether the use of an

  20. Early pregnancy IGF-I and placental GH and risk of epithelial ovarian cancer: A nested case-control study.

    Science.gov (United States)

    Schock, Helena; Fortner, Renée T; Surcel, Heljä-Marja; Grankvist, Kjell; Pukkala, Eero; Lehtinen, Matti; Lundin, Eva

    2015-07-15

    Insulin-like growth factor-I (IGF-I) signaling may promote ovarian tumor development by exerting mitotic, antiapoptotic and proangiogenic effects. During pregnancy, maternal production of IGF-I is regulated by placental growth hormone (GH). Parity is an established protective factor for ovarian cancer, however, no prior study has evaluated placental GH and IGF-I in pregnancy and epithelial ovarian cancer (EOC). Prior prospective studies on the association between IGF-I and EOC in nonpregnant populations were inconclusive and did not address associations in subtypes of EOC. Among members of the Finnish Maternity Cohort and the Northern Sweden Maternity Cohort, we identified 1,045 EOC cases, diagnosed after recruitment (1975-2008) and before March 2011 and 2,658 individually matched controls. Placental GH and IGF-I were measured in serum from the last pregnancy before EOC diagnosis or selection as control. We used conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for tertiles and a doubling of hormone concentrations. Higher IGF-I was associated with a nonsignificant decrease in risk for invasive [ORT3 vs. T1 : 0.79 (0.62-1.02); ptrend  = 0.07] and endometrioid tumors [ORT3 vs. T1 : 0.55 (0.28-1.07); ptrend  = 0.07]. The protective association between higher IGF-I levels and risk of invasive EOC was stronger in analyses limited to women aged study provides the first data on placental GH and IGF-I in pregnancy and EOC risk overall and by subtype. Our data suggest higher IGF-I levels in pregnancy may be associated with lower risk of invasive and endometrioid EOC. PMID:25516257

  1. The Diesel Exhaust in Miners study: a nested case-control study of lung cancer and diesel exhaust

    NARCIS (Netherlands)

    Silverman, D.T.; Samanic, C.; Lubin, J.H.; Blair, A.; Stewart, P.A.; Vermeulen, R.; Schleiff, P.L.; Travis, W.D.; Ziegler, R.; Wacholder, S.; Attfield, M.D.

    2012-01-01

    BACKGROUND Most studies of the association between diesel exhaust exposure and lung cancer suggest a modest, but consistent, increased risk. However, to our knowledge, no study to date has had quantitative data on historical diesel exposure coupled with adequate sample size to evaluate the exposure-

  2. The plasma leptin/adiponectin ratio predicts first cardiovascular event in men : A prospective nested case-control study

    NARCIS (Netherlands)

    Kappelle, Paul J. W. H.; Dullaart, Robin P. F.; van Beek, Andre P.; Hillege, Hans L.; Wolffenbuttel, Bruce H. R.

    2012-01-01

    Objective: The plasma leptin/adiponectin (L/A) ratio has been proposed as a preferential marker of atherosclerosis susceptibility compared to leptin and adiponectin alone. We determined the extent to which the L/A ratio predicts incident cardiovascular disease (CVD) taking account of clinical risk f

  3. Impact of Urate Level on Cardiovascular Risk in Allopurinol Treated Patients. A Nested Case-Control Study

    DEFF Research Database (Denmark)

    Søltoft Larsen, Kasper; Pottegård, Anton; Lindegaard, Hanne M;

    2016-01-01

    BACKGROUND: Gout gives rise to increased risk of cardiovascular events. Gout attacks can be effectively prevented with urate lowering drugs, and allopurinol potentially reduces cardiovascular risk. What target level of urate is required to reduce cardiovascular risk is not known. OBJECTIVES......, laboratory values and in- and outpatient contacts. RESULTS: No association between treatment-to-target urate level and cardiovascular events were found (adjusted odds ratio of 1.01, 95% confidence interval 0.79-1.28). No significant effect was seen in any subgroup defined by age, gender, renal function...

  4. Prodromal symptoms and early detection of Parkinson's disease in general practice: a nested case-control study

    NARCIS (Netherlands)

    Plouvier, A.O.A.; Hameleers, R.J.M.G.; Heuvel, E.A. van den; Bor, H.H.; Olde Hartman, T.C.; Bloem, B.R.; Weel, C. van; Lagro-Janssen, A.

    2014-01-01

    BACKGROUND: Timely diagnosis of Parkinson's disease (PD), facilitating early intervention, depends largely on the GP's awareness of early symptomatology. For general practice, it is unknown which prodromal symptoms (symptoms preceding the typical motor symptoms of PD) demand the GP's alertness. OBJE

  5. Predictive value of prostate-specific antigen for prostate cancer: a nested case-control study in EuroSIDA

    Directory of Open Access Journals (Sweden)

    Leah Shepherd

    2014-11-01

    Full Text Available Introduction: Although prostate cancer (PCa incidence is lower in HIV+ men than in HIV− men, the usefulness of prostate-specific antigen (PSA screening in this population is not well defined and may have higher false negative rates than in HIV− men. We aimed to describe the kinetics and predictive value of PSA in HIV+ men. Methods: Men with PCa (n=21 and up to two matched controls (n=40 with prospectively stored plasma samples before PCa (or matched date in controls were selected. Cases and controls were matched on date of first and last sample, age, region of residence and CD4 count at first sample date. Total PSA (tPSA, free PSA (fPSA, testosterone and sex hormone binding globulin (SHBG were measured. Conditional logistic regression models investigated associations between markers and PCa. Sensitivity and specificity of using tPSA >4 µg/L to predict PCa was calculated. Mixed models were used to describe kinetics. Results: Sixty-one men were included with a median six (IQR 2–9 years follow-up. Time between last sample and PCa was seven (4–11 months. Cases and controls were well matched at first sample, with a median age of 51 (IQR 48–57 and CD4 of 437 (243–610 cells/mm3. Median tPSA [2.8 (IQR: 1.6–4.6 and 0.8 (0.5–1.2 µg/L] and fPSA [0.4 (0.2–0.8 and 0.3 (0.2–0.4 µg/L] levels were higher in cases than controls at first sample. Both tPSA and fPSA increased significantly over time in cases (Figure 1, to a median at last sample of 6.1 (4.7–9.5 and 0.9 (0.6–1.3 µg/L, respectively, but were stable in controls, with a median at last sample of 0.8 (0.5–1.4 and 0.2 (0.2–0.4 µg/L (Figure. Higher levels of tPSA and fPSA were associated with higher odds of PCa at first sample [OR for 2-fold higher 4.7 (CI: 1.7–12.9 and 5.4 (1.7–17.4]. Elevated tPSA values in cases were detectable ≥5 years before PCa (p0.7. The most informative predictor of PCa was tPSA (AUC=0.9, followed by fPSA (0.8. Testosterone (AUC = 0.5 and SHBG (0.5 were poor predictors of PCa. Overall, tPSA level >4 µg/L had 99% specificity and 37% sensitivity. Performance was best in the year prior to PCa (specificity: 99%, sensitivity: 88%. Conclusions: PSA was highly predictive of PCa in HIV+ men. Our results indicate that PSA screening in HIV+ men may be useful, and further work is needed to identify potentially age-related cut-offs to maximize sensitivity and specificity to identify those for further evaluation at early stages of PCa.

  6. A nested case-control study of the risk of suicide attempts after discharge from psychiatric care

    DEFF Research Database (Denmark)

    Christiansen, Erik; Jensen, Børge

    2008-01-01

    abuse with mental illness raised risk in an additive way. We found only small gender differences in risk. In order to lower the risk of suicide attempts, we need to improve after-care when discharging from psychiatric care. A differentiation between the possibilities of after-care for different mental...

  7. Effect of consanguinity on birth defects in Saudi women; results from a nested case-control study

    DEFF Research Database (Denmark)

    Majeed-Saidan, Muhammad Ali; Ammari, Amer N; AlHashem, Amal M;

    2015-01-01

    BACKGROUND: The role of consanguinity in the etiology of structural birth defects outside of chromosomal and inherited disorders has always been debated. We studied the independent role of consanguinity on birth defects in Saudi women with a high prevalence of consanguineous marriages. METHODS: T...

  8. The Association Between Potentially Inappropriate Prescribing and Medication-Related Hospital Admissions in Older Patients: A Nested Case Control Study

    NARCIS (Netherlands)

    van der Stelt, C.A.K.; Vermeulen Windsant-van den Tweel, A.M.A.; Egberts, A.C.G.; van den Bemt, P.M.L.A.; Leendertse, A.J.; Hermens, W.A.J.J.; van Marum, R.J.; Derijks, Jeroen

    2016-01-01

    Introduction: Medication-related problems can cause serious adverse drug events (ADEs) that may lead to hospitalization of the patient. There are multiple screening methods to detect and reduce potentially inappropriate medications (PIMs) and potential prescribing omissions (PPOs). Whether this will

  9. Long-term psychosocial sequelae of stillbirth: phase II of a nested case-control cohort study.

    Science.gov (United States)

    Turton, Penelope; Evans, Chris; Hughes, Patricia

    2009-02-01

    Stillbirth is associated with increased psychological morbidity in the subsequent pregnancy and puerperium. This study aimed to assess longer-term psychological and social outcomes of stillbirth and to identify factors associated with adverse outcome. We conducted seven-year follow-up of a cohort of women who were initially assessed during and after a pregnancy subsequent to stillbirth, together with pair-matched controls. All women were living with a partner at baseline and none had live children. Measured outcomes at follow-up included depression, posttraumatic stress disorder (PTSD) and partnership breakdown. Comparison variables included social and psychological factors and, for the stillbirth group, factors relating to the lost pregnancy. There were no differences between groups in case level psychological morbidity, but significantly higher levels of PTSD symptoms persisted in stillbirth group mothers who had case level PTSD 7 years earlier. Stillbirth group mothers were more likely to have experienced subsequent partnership breakdown. In the stillbirth group such breakdown was associated with having held the stillborn infant and having had case-level PTSD. Interpretations and clinical implications of these findings are discussed.

  10. Determinants of visual outcomes in femtosecond laser assisted cataract surgery and phacoemulsification: A nested case control study

    Directory of Open Access Journals (Sweden)

    Rajiv Khandekar

    2015-01-01

    Conclusion: Visual outcomes at 6-8 weeks following CE were not different from FLACS. Visual outcomes following FLACS and CE were not influenced by the operating surgeon or severity of the cataract. The time required for FLACS was greater than that required for CE.

  11. DNA Methylation in Pre-Diagnostic Serum Samples of Breast Cancer Cases: Results of a Nested Case-Control Study

    OpenAIRE

    Brooks, Jennifer D.; Cairns, Paul; Shore, Roy E.; Klein, Catherine B.; Wirgin, Isaac; Afanasyeva, Yelena; Zeleniuch-Jacquotte, Anne

    2010-01-01

    Promoter methylation of tumor-suppressor genes is a frequent and early event in breast carcinogenesis. Paired tumor tissue and serum samples from women with breast cancer show that promoter methylation is detectable in both sample types, with good concordance. This suggests the potential for these serum markers to be used for breast cancer detection.

  12. No relationship between TNF-α genetic variants and combination antiretroviral therapy-related lipodystrophy syndrome in HIV type 1-infected patients: a case-control study and a meta-analysis.

    Science.gov (United States)

    Veloso, Sergi; Olona, Montserrat; Peraire, Joaquim; Viladés, Consuelo; Pardo, Pedro; Domingo, Pere; Asensi, Victor; Broch, Montserrat; Aguilar, Carmen; López-Dupla, Miguel; Aragonés, Gerard; Garcia-Pardo, Graciano; Sirvent, Joan-Josep; Vendrell, Joan; Richart, Cristóbal; Vidal, Francesc

    2011-02-01

    Tumor necrosis factor alpha (TNF-α) is thought to be involved in the pathogenic and metabolic events associated with HIV-1 infection. We assessed whether carriage of the TNF-α gene promoter single nucleotide polymorphism (SNP) is associated with lipodystrophy and metabolic derangements in HIV-1-infected patients treated with cART. We also assessed variations in TNF-α receptor plasma levels. The study group comprised 286 HIV-1-infected patients (133 with and 153 without lipodystrophy) and 203 uninfected controls (UC). TNF-α -238G > A, -308G > A, and -863 C > A SNP were assessed using PCR-RFLPs on white cell DNA. Plasma sTNF-α R1 and R2 levels were measured by ELISA. Student's t test, the χ(2) test, Pearson correlations, and the logistic regression test were performed for statistical analysis. The TNF-α -308G > A SNP was significantly associated with lipodystrophy in the univariate analysis (p = 0.04). This association, however, was no longer significant in the multivariate analysis. A meta-analysis of the published literature and our own data, which included 284 patients with lipodystrophy and 338 without lipodystrophy, showed that there was no relationship between the TNF-α -238G > A and -308G > A SNP and lipodystrophy (p > 0.05 for all comparisons). HIV-1-infected patients had greater sTNF-α R2 plasma levels than UC (p = 0.001) whereas sTNF-α R1 and R2 levels were not significantly different in both the HIV-1-infected cohorts, lipodystrophy vs. nonlipodystrophy (p = NS). In our cohort of white Spaniards the TNF-α -238G > A, -308G > A, and -863C > A SNP were not associated with lipodystrophy in HIV-1-infected patients treated with cART. This finding was replicated in a meta-analysis of the published data, which showed no associations between the TNF-α -238G > A and -308G > A SNP and lipodystrophy. In HIV-1-infected patients under cART there is a systemic overproduction of sTNF-α R2, which is unrelated to

  13. Nest Survival of American Coots Relative to Grazing, Burning, and Water Depths

    Directory of Open Access Journals (Sweden)

    Jane E. Austin

    2011-12-01

    Full Text Available Water and emergent vegetation are key features influencing nest site selection and success for many marsh-nesting waterbirds. Wetland management practices such as grazing, burning, and water-level manipulations directly affect these features and can influence nest survival. We used model selection and before-after-control-impact approaches to evaluate the effects of water depth and four common land-management practices or treatments, i.e., summer grazing, fall grazing, fall burning, and idle (no active treatment on nest survival of American coots (Fulica americana nesting at Grays Lake, a large montane wetland in southeast Idaho. The best model included the variables year × treatment, and quadratic functions of date, water depth, and nest age; height of vegetation at the nest did not improve the best model. However, results from the before-after-control-impact analysis indicate that management practices affected nest success via vegetation and involved interactions of hydrology, residual vegetation, and habitat composition. Nest success in idled fields changed little between pre- and post-treatment periods, whereas nest success declined in fields that were grazed or burned, with the most dramatic declines the year following treatments. The importance of water depth may be amplified in this wetland system because of rapid water-level withdrawal during the nesting season. Water and land-use values for area ranchers, management for nesting waterbirds, and long-term wetland function are important considerations in management of water levels and vegetation.

  14. Can selection on nest size from nest predation explain the latitudinal gradient in clutch size?

    Science.gov (United States)

    Biancucci, L.; Martin, T.E.

    2010-01-01

    1. Latitudinal variation in clutch sizes of birds is a well described, but poorly understood pattern. Many hypotheses have been proposed, but few have been experimentally tested, and none have been universally accepted by researchers. 2. The nest size hypothesis posits that higher nest predation in the tropics favours selection for smaller nests and thereby constrains clutch size by shrinking available space for eggs and/or nestlings in the nest. We tested this hypothesis with an experiment in a tropical forest and a comparative study between temperate and tropical field sites. 3. Specifically, we tested if: (i) predation increased with nest size; (ii) tropical birds had smaller nests controlled for body size; and (iii) clutch size was explained by nest size controlled for body size. 4. Experimental swapping of nests of different sizes showed that nest predation increased with nest size in the tropical site. Moreover, nest predation rates were higher in species with larger nests in both sites. However, nest size, corrected for body mass and phylogeny, did not differ between sites and was not related to clutch size between sites. 5. Hence, nest predation can exert selection on nest size as predicted by the hypothesis. Nest size increased with adult body mass, such that adult size might indirectly influence reproductive success through effects on nest size and nest predation risk. Ultimately, however, selection from nest predation on nest size does not explain the smaller clutch sizes typical of the tropics.

  15. No contribution of angiotensin-converting enzyme (ACE) gene variants to severe obesity: a model for comprehensive case/control and quantitative cladistic analysis of ACE in human diseases.

    Science.gov (United States)

    Bell, Christopher G; Meyre, David; Petretto, Enrico; Levy-Marchal, Claire; Hercberg, Serge; Charles, Marie Aline; Boyle, Cliona; Weill, Jacques; Tauber, Maïte; Mein, Charles A; Aitman, Timothy J; Froguel, Philippe; Walley, Andrew J

    2007-03-01

    Candidate gene analyses are often inconclusive owing to genetic or phenotypic heterogeneity, low statistical power, selection of nonfunctional SNPs, and inadequate statistical analysis of the genetic architecture. Angiotensin-converting enzyme (ACE) is involved in adipocyte growth and function and the ACE-processed angiotensin II inhibits adipocyte differentiation. Associations between body mass index (BMI) and ACE polymorphisms have been reported in general populations, but the contribution to severe obesity of this gene, which is located under an obesity genome-scan linkage peak on 17q23, is unknown. ACE is one of the most studied genes and markers responsible for variation in circulating ACE enzyme levels have been extensively characterised. Eight of these variants were genotyped in 1054 severely obese cases and 918 nonobese controls, as well as 116 nuclear families from the genome scan (n=447), enabling the known clades to be inferred. Qualitative analysis of individual single-nucleotide polymorphisms (SNPs), haplotypes, clades, and diploclades demonstrated no significant associations (P<0.05) after minimal correction for multiple testing. Quantitative analysis of clades and diploclades for BMI, waist-to-hip ratio, or ZBMI in children were also not significant. This rigorous, large-scale study of common, well-defined, severe polygenic obesity provides strong evidence that functionally relevant sequence variation in ACE, whether it is defined at the level of SNPs, haplotypes, or clades, is not associated with severe obesity in French Caucasians. Such a study design exemplifies the strategy needed to clearly define the contribution of the ACE gene to the plethora of complex genetic diseases where weak associations have been previously reported.

  16. Factors associated with tuberculosis treatment default in an endemic area of the Brazilian Amazon: a case control-study.

    Directory of Open Access Journals (Sweden)

    Marlucia da Silva Garrido

    Full Text Available SETTING: Treatment default is a serious problem in tuberculosis control because it implies persistence of infection source, increased mortality, increased relapse rates and facilitates the development of resistant strains. OBJECTIVE: This study analyzed tuberculosis treatment default determinants in the Amazonas State to contribute in planning appropriate control interventions. DESIGN: Observational study with a retrospective cohort using Brazilian Disease Notification System data from 2005 to 2010. A nested case control study design was used. Patients defaulting from treatment were considered as 'cases' and those completing treatment as 'controls'. In the analysis, 11,312 tuberculosis patients were included, 1,584 cases and 9,728 controls. RESULTS: Treatment default was observed to be associated to previous default (aOR 3.20; p<0.001, HIV positivity (aOR 1.62; p<0.001, alcoholism (aOR 1.51; p<0.001, low education level (aOR 1.35; p<0.001 and other co-morbidities (aOR 1.31; p = 0.05. Older patients (aOR 0.98; p = 0.001 and DOT (aOR 0,72; p<0.01 were considered as protective factor for default. CONCLUSIONS: Associated factors should be considered in addressing care and policy actions to tuberculosis control. Information on disease and treatment should be intensified and appropriate to the level of education of the population, in order to promote adherence to treatment and counter the spread of multidrug resistance to anti-TB drugs.

  17. Vitamin D status during pregnancy and the risk of subsequent postpartum depression: a case-control study.

    Directory of Open Access Journals (Sweden)

    Nina O Nielsen

    Full Text Available Epidemiological studies have provided evidence of an association between vitamin D insufficiency and depression and other mood disorders, and a role for vitamin D in various brain functions has been suggested. We hypothesized that low vitamin D status during pregnancy might increase the risk of postpartum depression (PPD. The objective of the study was thus to determine whether low vitamin D status during pregnancy was associated with postpartum depression. In a case-control study nested in the Danish National Birth Cohort, we measured late pregnancy serum concentrations of 25[OH]D3 in 605 women with PPD and 875 controls. Odds ratios [OR for PPD were calculated for six levels of 25[OH]D3. Overall, we found no association between vitamin D concentrations and risk of PPD (p = 0.08. Compared with women with vitamin D concentrations between 50 and 79 nmol/L, the adjusted odds ratios for PPD were 1.35 (95% CI: 0.64; 2.85, 0.83 (CI: 0.50; 1.39 and 1.13 (CI: 0.84; 1.51 among women with vitamin D concentrations < 15 nmol/L, 15-24 nmol/L and 25-49 nmol/L, respectively, and 1.53 (CI: 1.04; 2.26 and 1.89 (CI: 1.06; 3.37 among women with vitamin D concentrations of 80-99 nmol/L and ≥ 100 nmol/L, respectively. In an additional analysis among women with sufficient vitamin D (≥ 50 nmol/L, we observed a significant positive association between vitamin D concentrations and PPD. Our results did not support an association between low maternal vitamin D concentrations during pregnancy and risk of PPD. Instead, an increased risk of PPD was found among women with the highest vitamin D concentrations.

  18. Nested Dynamic Condition Response Graphs

    DEFF Research Database (Denmark)

    Hildebrandt, Thomas; Mukkamala, Raghava Rao; Slaats, Tijs

    2012-01-01

    We present an extension of the recently introduced declarative process model Dynamic Condition Response Graphs ( DCR Graphs) to allow nested subgraphs and a new milestone relation between events. The extension was developed during a case study carried out jointly with our industrial partner...... Exformatics, a danish provider of case and workflow management systems. We formalize the semantics by giving first a map from Nested to (flat) DCR Graphs with milestones, and then extending the previously given mapping from DCR Graphs to Buchi-automata to include the milestone relation....

  19. Efficient use of iterative solvers in nested topology optimization

    DEFF Research Database (Denmark)

    Amir, Oded; Stolpe, Mathias; Sigmund, Ole

    2009-01-01

    In the nested approach to structural optimization, most of the computational effort is invested in the solution of the finite element analysis equations. In this study, it is suggested to reduce this computational cost by using an approximation to the solution of the nested problem, generated by a...... Krylov subspace iterative solver. By choosing convergence criteria for the iterative solver that are strongly related to the optimization objective and to the design sensitivities, it is possible to terminate the iterative solution of the nested equations earlier compared to traditional convergence...... measures. The approximation is shown to be sufficiently accurate for the practical purpose of optimization even though the nested equation system is not solved accurately. The approach is tested on several medium-scale topology optimization problems, including three dimensional minimum compliance problems...

  20. Application of nested sampling in statistical physics: the Potts model

    CERN Document Server

    Pfeifenberger, Manuel J

    2016-01-01

    We present a systematic benchmark study of the nested sampling algorithm on the basis of the Potts model. This model exhibits a first order phase transition for $q>4$ at the critical temperature. The numerical evaluation of the partition function and thermodynamic observables, which involves high dimensional sums of sharply structured multi-modal density functions, represents a major challenge to most standard numerical techniques, such as Markov Chain Monte Carlo. Nested sampling, on the other hand, is particularly suited for such problems. In this paper we will employ both, nested sampling and thermodynamic integration to evaluate the partition function of the Potts model. In both cases individual moves are based on Swendsen-Wang updates. A autocorrelation time analysis of both algorithms shows that the severe slowing down of thermodynamic integration around the critical temperature does not occur in nested sampling. In addition we show, how thermodynamic variables can be computed with high accuracy from th...

  1. Human Papillomavirus Infection and Increased Risk of HIV Acquisition:A Meta-analysis of Case-control Studies%女性 HPV 感染人群发生 HIV 感染风险的荟萃分析

    Institute of Scientific and Technical Information of China (English)

    薛渊; 徐虹; 沈俐

    2016-01-01

    目的:研究女性人群感染人类乳头瘤病毒(human papillomavirus,HPV)后继发人类免疫缺陷病毒(human immu-nodeficiency virus,HIV)感染的风险。方法检索 Pubmed,EMBASE,Coehrane Library,中国知网,万方数据库,中国生物医学文献数据库等,按制定的纳入及排除标准筛选并评价文献质量。收集有关女性人群 HPV 感染后继发 HIV 感染的研究文献,由2名研究者独立提取数据并进行方法学评估,采用 RevMan5.1软件进行荟萃分析。结果纳入符合标准的文献共6篇,均为随机对照试验,研究对象共计9606例。HPV 感染的女性继发 HIV 感染的风险加倍(OR=2.02,95% CI:1.48~2.77)。其中高危型和低危型 HPV 感染患者发生 HIV 感染的相对危险度分别为 OR=2.50,95% CI:1.73~3.61和 OR=2.10,95% CI:1.48~2.96。结论对所选取文献的荟萃分析提示 HPV 感染的女性患者继发 HIV 感染的风险增加,HPV 疫苗可能对 HIV 感染有一定的预防作用。%Objective To evaluate the impact of human papillomavirus(HPV)infection on the risk of HIV acquisition in the female group.Methods Searched PubMed,EMbase,Coehrane Library,CNKI,wanfang database and Chinese Biomedical Lit-erature Database etc for articles about HIV-acquisition in HPV infected female patients.The quality of the literature were e-valuated according to standards of inclusion and exclusion.Data was extracted and methodologically quality evaluated by two independent investigators.Meta-analysis was accomplished using RevMan4.2 software.Results 6 articles were included,all of them were randomized controlled trials,a total of 9 606 cases studied.HIV infection risk was doubled in women with any HPV infection(OR= 2.02,95% CI:1.48 ~ 2.77),demonstrating High-risk HPV-positive (OR= 2.50,95% CI:1.73 ~3.61)and low-risk HPV-positive (OR=2.10,95% CI:1.48~2.96)respectively.Funnel plot analysis revealed no signifi-cant publication

  2. Patterns of magpie nest utilization by a nesting raptor community in a secondary forest

    Institute of Scientific and Technical Information of China (English)

    Tong Zhou; Haitao Wang; Yu Liu; Fumin Lei; Wei Gao

    2009-01-01

    For a total of 9 years, we examined the patterns of a nesting raptor community that utilized European Magpie (Pica pica) nests in the Zuojia Natural Reserve, northeast China. Eight raptor species and two other bird species were recorded nesting in magpie nests. The reuse rate of abandoned magpie nests was 51.6%, and the number of reused nests was positively correlated with their availability. Raptors utilized 83.3% of the reused abandoned magpie nests. Nests followed for more than 1 year were reused by raptors an average of 1.13 times. Inter-specific nest usurpation was common, with 17.3% of new magpie nests being usurped by raptors, and four cases of usurpation occurred among different raptor species. At the community level, 8 of 11 raptor species took over magpie nests to breed in the study area, and 91.9% of their nests came from magpie nests. European Magpies represent the core species in the nest web of the local raptor community that utilizes magpie nests. At the forest stand level, closer proximity to forest edges and greater distances from occupied raptor nests were the best predictors of nest reuse. At the nest-site level, arbor density and canopy coverage were the best predictors of nest reuse.

  3. Unusual raptor nests around the world

    Science.gov (United States)

    Ellis, D.H.; Craig, T.; Craig, E.; Postupalsky, S.; LaRue, C.T.; Nelson, R.W.; Anderson, D.W.; Henny, C.J.; Watson, J.; Millsap, B.A.; Dawson, J.W.; Cole, K.L.; Martin, E.M.; Margalida, A.; Kung, P.

    2009-01-01

    From surveys in many countries, we report raptors using unusual nesting materials (e.g., paper money, rags, metal, antlers, and large bones) and unusual nesting situations. For example, we documented nests of Steppe Eagles Aquila nipalensis and Upland Buzzards Buteo hemilasius on the ground beside well-traveled roads, Saker Falcon Falco cherrug eyries in attics and a cistern, and Osprey Pandion haliaetus nests on the masts of boats and on a suspended automobile. Other records include a Golden Eagle A. chrysaetos nest 7.0 m in height, believed to be the tallest nest ever described, and, for the same species, we report nesting in rudimentary nests. Some nest sites are within a few meters of known predators or competitors. These unusual observations may be important in revealing the plasticity of a species' behavioral repertoire. ?? 2009 The Raptor Research Foundation, Inc.

  4. Exceptional longevity and muscle and fitness related genotypes: a functional in vitro analysis and case-control association replication study with SNPs THRH rs7832552, IL6 rs1800795 and ACSL1 rs6552828

    Directory of Open Access Journals (Sweden)

    Noriyuki eFuku

    2015-05-01

    Full Text Available There are several gene variants that are candidates to influence functional capacity in long-lived individuals. As such, their potential association with exceptional longevity (EL, i.e., reaching 100+ years deserves analysis. Among them are rs7832552 in the thyrotropin-releasing hormone receptor (TRHR gene, rs1800795 in the interleukin-6 (IL6 gene and rs6552828 in the coenzyme A synthetase long-chain 1 (ACSL1 gene. To gain insight into their functionality (which is yet unknown, here we determined for the first time luciferase gene reporter activity at the muscle tissue level in rs7832552 and rs6552828. We then compared allele/genotype frequencies of the 3 abovementioned variants among centenarians [n=138, age range 100-111 years (114 women] and healthy controls [n=334, 20-50 years (141 women] of the same ethnic and geographic origin (Spain. We also studied healthy centenarians [n=79, 100-104 years (40 women] and controls [n=316, 27-81 years (156 women] from Italy, and centenarians [n=742, 100-116 years (623 women] and healthy controls [n=499, 23-59 years (356 women] from Japan. The THRH rs7832552 T-allele and ACSL1 rs6552828 A-allele up-regulated luciferase activity compared to the C and G-allele, respectively (P≤0.001. Yet we found no significant association of EL with rs7832552, rs1800795 or rs6552828 in any of the 3 cohorts. Further research is needed with larger cohorts of centenarians of different origin as well as with younger old people.

  5. Matched case-control studies: a review of reported statistical methodology

    Directory of Open Access Journals (Sweden)

    Niven DJ

    2012-04-01

    Full Text Available Daniel J Niven1, Luc R Berthiaume2, Gordon H Fick1, Kevin B Laupland11Department of Critical Care Medicine, Peter Lougheed Centre, Calgary, 2Department of Community Health Sciences, University of Calgary, Calgary, Alberta, CanadaBackground: Case-control studies are a common and efficient means of studying rare diseases or illnesses with long latency periods. Matching of cases and controls is frequently employed to control the effects of known potential confounding variables. The analysis of matched data requires specific statistical methods.Methods: The objective of this study was to determine the proportion of published, peer reviewed matched case-control studies that used statistical methods appropriate for matched data. Using a comprehensive set of search criteria we identified 37 matched case-control studies for detailed analysis.Results: Among these 37 articles, only 16 studies were analyzed with proper statistical techniques (43%. Studies that were properly analyzed were more likely to have included case patients with cancer and cardiovascular disease compared to those that did not use proper statistics (10/16 or 63%, versus 5/21 or 24%, P = 0.02. They were also more likely to have matched multiple controls for each case (14/16 or 88%, versus 13/21 or 62%, P = 0.08. In addition, studies with properly analyzed data were more likely to have been published in a journal with an impact factor listed in the top 100 according to the Journal Citation Reports index (12/16 or 69%, versus 1/21 or 5%, P ≤ 0.0001.Conclusion: The findings of this study raise concern that the majority of matched case-control studies report results that are derived from improper statistical analyses. This may lead to errors in estimating the relationship between a disease and exposure, as well as the incorrect adaptation of emerging medical literature.Keywords: case-control, matched, dependent data, statistics

  6. Analysis of risk factors for upper gastrointestinal cancer in China: a multicentric population-based case-control study%上消化道三种恶性肿瘤的危险因素分析

    Institute of Scientific and Technical Information of China (English)

    陈万青; 贺宇彤; 孙喜斌; 温登瑰; 陈志峰; 赵德利

    2011-01-01

    Objective To explore the major risk factors for upper gastrointestinal cancer in high occurrence areas of esophageal and gastric cancer in China. Methods Four high occurrence areas of esophageal cancer, namely Cixian and Shexian from Hebei province, Linxian from Henan province, Feicheng from Shandong province, and Zhuanghe from Liaoning province, which is a high occurrence area of gastric cancer,were selected for the study. The newly-diagnosed cases whose date of onset were after January 1st,2009 were selected from the Cancer Registration Database in each district, and 751 cases diagnosed as cancers in lower segment of esophagus, cardiac and other subsite of stomach were randomly recruited. 2253 matched controls were selected to pair the cases at the ratio of 3: 1. The relative information of the study objects were collected from the face-to-face interviews with trained staff by designed questionnaires, and the data was input by EpiData software. Statistic software SPSS 13.0 was applied to conduct both univariate and multivariate logistic regression analysis to evaluate odd ratios (OR) and 95% confident interval (CI).Results As univariate analysis shown,66 objects in case group had irregular diet habit; while 90 in control group had ( OR= 3. 177;95% CI: 2. 127 - 4.745). A higher percentage in case group (83 objects)preferred fried food in comparison with only 214 in control group did (OR= 3. 190; 95% CI: 2.061 -4. 927). 369 objects in case group, but only 119 in control group had history of gastrointestinal diseases ( OR = 14. 660; 95% CI: 11. 342 - 18. 948 ). 282 objects in case group had history of gastroesophageal reflux disease (GERD) ,which was much higher than the percentage in control group (432 objects),with OR =3. 137 (95% CI: 2. 546 -3. 864). All the above factors could increase the risk for upper gastrointestinal cancer. 387 objects in case group and 1278 in control group reported they preferred fresh vegetables in daily diet,which was found to be a

  7. 社区空巢老人心理弹性特征的潜在类别分析%Latent class analysis on resilience characteristics of empty-nest elderly in community

    Institute of Scientific and Technical Information of China (English)

    张杰; 张静平; 王安妮; 苏盼

    2016-01-01

    目的 采用探索性潜在类别分析的方法对社区空巢老人心理弹性的特征进行分析,为不同特征群体实施针对性的干预措施提供依据.方法 采用问卷调查法,使用自编空巢老人一般资料调查表、Connor和Davidson心理弹性量表(CD-RISC)中文版对203名社区空巢老人进行调查,利用统计软件Mplus7.0对心理弹性的特征进行探索性潜在类别分析.结果 通过分析发现,社区空巢老人的心理弹性状况具有明显的分组特征,统计指标(AIC,BIC,Entropy等)支持了3个潜在类别的模型(P=0.006),根据每个类别在问卷各个条目上的条件概率,分别命名为高弹性组[54例(26.6%)],低耐压弹性组[82例(40.4%)],低弹性组[67例(33.0%)].进一步的研究发现:高弹性组与低弹性组类别中空巢老人在年龄构成上差异有统计学意义(P.<0.05),低耐压弹性组与低弹性组类别中的空巢老人在性别构成比例上差异有统计学意义(P<0.05).结论 社区空巢老人的心理弹性特征可分为3个类别,各类别的性别、年龄所占的比例不同.%Objective To analyze the characteristics of resilience among empty-nest elderly in community with exploratory latent class analysis method and provide a basis for making targeted intervention measures according to different characteristics.Methods This study enrolled 203 empty-nest elderly people as the study respondents.The general information,resilience of empty-nest elderly were investigated using the general information questionnaire,Connor-Davidson resilience scale in Chinese version.Latent class analyze (Mplus 7.0) was used to discuss the characteristics of resilience among empty-nest elderly.Results The results showed that the resilience of empty-nest elderly had obvious group characteristics and the statistical indicators(AIC,BIC,Entropy and so on) can support the three categories of potential model(P=0.006).Based on the conditional probability on the various

  8. Instantiation Schemes for Nested Theories

    CERN Document Server

    Echenim, Mnacho

    2011-01-01

    This paper investigates under which conditions instantiation-based proof procedures can be combined in a nested way, in order to mechanically construct new instantiation procedures for richer theories. Interesting applications in the field of verification are emphasized, particularly for handling extensions of the theory of arrays.

  9. Nested Narratives Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Andrew T.; Pattengale, Nicholas D.; Forsythe, James C.; Carvey, Bradley John

    2015-02-01

    In cybersecurity forensics and incident response, the story of what has happened is the most impor- tant artifact yet the one least supported by tools and techniques. Existing tools focus on gathering and manipulating low-level data to allow an analyst to investigate exactly what happened on a host system or a network. Higher-level analysis is usually left to whatever ad hoc tools and techniques an individual may have developed. We discuss visual representations of narrative in the context of cybersecurity incidents with an eye toward multi-scale illustration of actions and actors. We envision that this representation could smoothly encompass individual packets on a wire at the lowest level and nation-state-level actors at the highest. We present progress to date, discuss the impact of technical risk on this project and highlight opportunities for future work.

  10. Nest- and colony-mate recognition in polydomous colonies of meat ants ( Iridomyrmex purpureus)

    Science.gov (United States)

    van Wilgenburg, E.; Ryan, D.; Morrison, P.; Marriott, P. J.; Elgar, M. A.

    2006-07-01

    Workers of polydomous colonies of social insects must recognize not only colony-mates residing in the same nest but also those living in other nests. We investigated the impact of a decentralized colony structure on colony- and nestmate recognition in the polydomous Australian meat ant ( Iridomyrmex purpureus). Field experiments showed that ants of colonies with many nests were less aggressive toward alien conspecifics than those of colonies with few nests. In addition, while meat ants were almost never aggressive toward nestmates, they were frequently aggressive when confronted with an individual from a different nest within the same colony. Our chemical analysis of the cuticular hydrocarbons of workers using a novel comprehensive two-dimensional gas chromatography technique that increases the number of quantifiable compounds revealed both colony- and nest-specific patterns. Combined, these data indicate an incomplete transfer of colony odor between the nests of polydomous meat ant colonies.

  11. Effect of heterogeneity of nest boxes on occurrence of gregarious nesting in laying hens

    DEFF Research Database (Denmark)

    Clausen, Tina; Riber, Anja Brinch

    2012-01-01

    Gregarious nesting, where hens select already occupied nest boxes even when other nest boxes are unoccupied, is an unwanted behaviour in laying hens that may reduce animal welfare and pose a financial cost to the producer. It has been suggested that gregarious nesting is caused by the difficulties...... nesting was higher in experimental groups compared to control groups (P right were higher compared to nest boxes positioned...

  12. Risk Factors For Coronary Heart Disease : A Case Control Study

    Directory of Open Access Journals (Sweden)

    Zodpey Sanjay P

    1998-01-01

    Full Text Available Research question: What is the role of different risk factors in causation of CHD. Objective: To identify the risk factors contributing to the outcome of CHD. Design: Pair matched case-control study. Setting: Government Medical college, Nagpur, India, a tertiary care hospital. Participants: The study included 294 incident cases of CHD diagnosed by standard criteria. Each case was pair matched with one control for age and sex. Controls were selected from subjects attending the hospital for conditions other than CHD. Main Outcome Measure: CHD. Study variable: Socio-economic status (SES, physical inactivity (PI, family history of CHD, type A personality (TAP, cigarette smoking (CS, alcohol consumption (AC, obesity, oral contraceptive use (OC use, diabetes mellitus (DM, hypertension (HT and total serum cholesterol TSC. Results: On univariate analysis all the 11 risk factors were significantly associated with CHD. Conditional multiple logistic regression identified significant association of SES (OR 2.92, 95% CI 2.28-3.73, PI (OR 2.03, 95% CI 1.56-2.62, OC use (OR 3.96, 95% CI 1.11-14.02, obesity (OR 1.62, 95% CI 1.15-2.27, DM (OR 2.17, 95% CI 1.13-4.13, HT (OR 4.23, 95% CI 2.56-6399, TSC (OR 3.84, 95% CI 2.58-5.72 and CHD. Estimates of attributable risk proportion and population attributable risk proportion for the significant factors confirmed their etiological role and impact of these factors on the development of CHD in this population. Conclusion: This study identified significance of SES, PI, OC use, obesity, DM, HT and TSC in multivariate environment in the outcome of CHD.

  13. Toxocariasis in waste pickers: a case control seroprevalence study.

    Directory of Open Access Journals (Sweden)

    Cosme Alvarado-Esquivel

    Full Text Available BACKGROUND: The epidemiology of Toxocara infection in humans in Mexico has been poorly explored. There is a lack of information about Toxocara infection in waste pickers. AIMS: Determine the seroepidemiology of Toxocara infection in waste pickers. METHODS: Through a case control study design, the presence of anti-Toxocara IgG antibodies was determined in 90 waste pickers and 90 age- and gender-matched controls using an enzyme-linked immunoassay. Associations of Toxocara exposure with socio-demographic, work, clinical, and behavioral data of the waste pickers were also evaluated. RESULTS: The seroprevalence of anti-Toxocara IgG antibodies was significantly higher in waste pickers (12/90: 13% than in control subjects (1/90: 1% (OR = 14; 95% CI: 2-288. The seroprevalence was not influenced by socio-demographic or work characteristics. In contrast, increased seroprevalence was found in waste pickers suffering from gastritis, and reflex and visual impairments. Multivariate analysis showed that Toxocara exposure was associated with a low frequency of eating out of home (OR = 26; 95% CI: 2-363 and negatively associated with consumption of chicken meat (OR = 0.03; 95% CI: 0.003-0.59. Other behavioral characteristics such as animal contacts or exposure to soil were not associated with Toxocara seropositivity. CONCLUSIONS: 1 Waste pickers are a risk group for Toxocara infection. 2 Toxocara is impacting the health of waste pickers. This is the first report of Toxocara exposure in waste pickers and of associations of gastritis and reflex impairment with Toxocara seropositivity. Results warrant for further research.

  14. Lupus Myocarditis: A Case-Control Study from China

    Institute of Scientific and Technical Information of China (English)

    Li Zhang; Yan-Lin Zhu; Meng-Tao Li; Na Gao; Xin You; Qing-Jun Wu; Jin-Mei Su

    2015-01-01

    Background:Myocarditis is an uncommon but serious manifestation of systemic lupus erythematosus (SLE).This study aimed to investigate clinical characteristics and outcomes of lupus myocarditis (LM) and to determine risk factors of LM in hospitalized Chinese patients with SLE.Methods:We conducted a retrospective case-control study.A total of 25 patients with LM from 2001 to 2012 were enrolled as the study group,and 1 O0 patients with SLE but without LM were randomly pooled as the control group.Univariable analysis was performed using Chi-square tests for categorical variables,and the Student's t-test or Mann-Whitney U-test was performed for continuous variables according to the normality.Results:LM presented as the initial manifestation of SLE in 7 patients (28%) and occurred mostly at earlier stages compared to the controls (20.88 ± 35.73 vs.44.08 ± 61.56 months,P =0.008).Twenty-one patients (84%) experienced episodes of symptomatic heart failure.Echocardiography showed that 23 patients (92%) had decreased left ventricular ejection fraction (<50%) and all patients had wall motion abnormalities.A high SLE Disease Activity Index was the independent risk factor in the development of LM (odds ratio =1.322,P < 0.001).With aggressive immunosuppressive therapies,most patients achieved satisfactory outcome.The in-hospital mortality was not significantly higher in the LM group than in the controls (4% vs.2%,P =0.491).Conclusions:LM could result in cardiac dysfunction and even sudden death.High SLE disease activity might potentially predict the occurrence of LM at the early stage of SLE.Characteristic echocardiographic findings could confirm the diagnosis of LM.Early aggressive immunosuppressive therapy could improve the cardiac outcome of LM.

  15. Influence of Habitat Types on Prairie Nesting Waterfowl Nest Density and Nest Success in Northeastern North Dakota, 2010 – 2013

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Nest density and nest success of ducks in native and non-native grasslands within the Devils Lake WMD, Northeastern North Dakota. Waterfowl representing 8 species...

  16. Egg Reflectance Analysis of Several Alpine Meadow Nesting Passerines%高寒草甸几种雀形目鸟类的卵反射率分析

    Institute of Scientific and Technical Information of China (English)

    孙嘉辰; 褚晖; 刘力华; 赵亮

    2014-01-01

    To explore the potential relevance between egg coloration and incubation temperature in breeding seasons of Passeriformes,from 2010 to 2013,eggs of 9 species of Passeriformes were collected from alpine meadow and the egg reflectance were measured,respectively.The spectral range were 400 ~ 750 nm (visible light) and 750 ~ 1050 nm (near infrared spectrum).The mean egg reflectance in the two spectral range were 0.066 and 0.123,and the NIR reflectance was significantly different from the visible light reflectance,indicated that the heat control mechanism of eggshell is favored by passerines nesting in alpine meadow.Significant difference was also found in egg reflectance in the NIR range of different nest types,but not in the visible fight range,suggesting different nest environments affected incubation temperature differently.Results also indicated no significant difference in egg color among 8 species except black redstart (Phoenicurus ochruros),suggesting predation pressure drived selection of crypsis eggshell coloration; but from the perspective of thermoregulation,there was significant difference in the NIR reflectance,which explained the breeding ecology in the alpine meadow favored plain but thermoregulatable eggshell colours instead of conspicuous ones.%于2010 ~2013年的繁殖季节,在中国科学院海北高寒草甸生态系统定位站收集了9种青藏高原常见雀形目鸟类的卵,分别进行了反射率测量.测量光谱范围为可见光(400 ~ 750 nm)和短波近红外(750 ~ 1050 nm).卵在两个波段光谱的反射率分别是0.066和0.123,二者差异极显著.在可见光范围内,除赭红尾鸲Phoenicurus ochruros的波峰在绿色光范围内,其他物种都在黄色光范围内;在短波近红外范围内,反射率明显分为3个组,以角百灵和小云雀的地面开放巢较高,黄嘴朱顶雀和黄腹柳莺的灌丛巢较低,其他种居中;开放巢及封闭巢的卵反射率在可见光范围无显著差异,但在短波

  17. Importance Nested Sampling and the MultiNest Algorithm

    CERN Document Server

    Feroz, F; Cameron, E; Pettitt, A N

    2013-01-01

    Bayesian inference involves two main computational challenges. First, in estimating the parameters of some model for the data, the posterior distribution may well be highly multi-modal: a regime in which the convergence to stationarity of traditional Markov Chain Monte Carlo (MCMC) techniques becomes incredibly slow. Second, in selecting between a set of competing models the necessary estimation of the Bayesian evidence for each is, by definition, a (possibly high-dimensional) integration over the entire parameter space; again this can be a daunting computational task, although new Monte Carlo (MC) integration algorithms offer solutions of ever increasing efficiency. Nested sampling (NS) is one such contemporary MC strategy targeted at calculation of the Bayesian evidence, but which also enables posterior inference as a by-product, thereby allowing simultaneous parameter estimation and model selection. The widely-used MultiNest algorithm presents a particularly efficient implementation of the NS technique for...

  18. Case-control analysis of paternal age and trisomic anomalies

    DEFF Research Database (Denmark)

    De Souza, E; Morris, David Jackson; Garne, Ester

    2010-01-01

    To determine whether older paternal age increases the risk of fathering a pregnancy with Patau (trisomy 13), Edwards (trisomy 18), Klinefelter (XXY) or XYY syndrome.......To determine whether older paternal age increases the risk of fathering a pregnancy with Patau (trisomy 13), Edwards (trisomy 18), Klinefelter (XXY) or XYY syndrome....

  19. Spatial Analysis of Childhood Cancer: A Case/Control Study

    OpenAIRE

    Rebeca Ramis; Diana Gómez-Barroso; Ibon Tamayo; Javier García-Pérez; Antonio Morales; Elena Pardo Romaguera; Gonzalo López-Abente

    2015-01-01

    Background Childhood cancer was the leading cause of death among children aged 1-14 years for 2012 in Spain. Leukemia has the highest incidence, followed by tumors of the central nervous system (CNS) and lymphomas (Hodgkin lymphoma, HL, and Non-Hodgkin’s lymphoma, NHL). Spatial distribution of childhood cancer cases has been under concern with the aim of identifying potential risk factors. Objective The two objectives are to study overall spatial clustering and cluster detection of cases of t...

  20. Responding to obesity in Brazil: understanding the international and domestic politics of policy reform through a nested analytic approach to comparative analysis.

    Science.gov (United States)

    Gómez, Eduardo J

    2015-02-01

    Why do governments pursue obesity legislation? And is the case of Brazil unique compared with other nations when considering the politics of policy reform? Using a nested analytic approach to comparative research, I found that theoretical frameworks accounting for why nations implement obesity legislation were not supported with cross-national statistical evidence. I then turned to the case of Brazil's response to obesity at three levels of government, national, urban, and rural, to propose alternative hypotheses for why nations pursue obesity policy. The case of Brazil suggests that the reasons that governments respond are different at these three levels. International forces, historical institutions, and social health movements were factors that prompted national government responses. At the urban and rural government levels, receiving federal financial assistance and human resource support appeared to be more important. The case of Brazil suggests that the international and domestic politics of responding to obesity are highly complex and that national and subnational political actors have different perceptions and interests when pursuing obesity legislation.

  1. [Benton Lake nest survey results 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This dataset is nest survey results from Benton Lake National Wildlife Refuge from highland habitats and island habitats, and also includes a chart of duck nest...

  2. A case-control study of the relationship between hepatitis B virus DNA level and risk of hepatocellular carcinoma in Qidong, China

    Institute of Scientific and Technical Information of China (English)

    Tao-Tao Liu; Ying Fang; Hui Xiong; Tao-Yang Chen; Zheng-Pin Ni; Jian-Feng Luo; Nai-Qing Zhao; Xi-Zhong Shen

    2008-01-01

    AIM: To investigate the role of hepatitis B virus (HBV)replication in the development of hepatocellular carcinoma (HCC), a nested case-control study was performed to study the relationship between HBV DNA level and risk of HCC.METHODS: One hundred and seventy cases of HCC and 276 control subjects free of HCC and cirrhosis were selected for this study. Serum HBV DNA level was measured using fluorescein quantitative polymerase chain reaction at study entry and the last visit.RESULTS: In a binary unconditional logistic regression analysis adjusted for age, cigarette smoking, alcohol consumption and family history of chronic liver diseases,the adjusted odds ratios (95% confidence intervals) of HCC in patients with increasing HBV DNA level were 2.834 (1.237-6.492), 48.403 (14.392-162.789), 42.252(14.784-120.750), and 14.819 (6.992-31.411) for HBV DNA levels ≥ 104 to < 105; ≥ 105 to < 105; ≥ 106 to < 107;≥ 107 copies/mL, respectively. Forty-six HCC cases were selected to compare the serums viral loads of HBV DNA at study entry with those at the last visit. The HBV DNA levels measured at the two time points did not differ significantly.CONCLUSION: The findings of this study provide strong longitudinal evidence of an increased risk of HCC associated with persistent elevation of serum HBV DNA level in the 104-107 range.

  3. Occupational exposures and non-Hodgkin's lymphoma: Canadian case-control study

    OpenAIRE

    Spinelli John J; Dosman James A; McDuffie Helen H; Karunanayake Chandima P; Pahwa Punam

    2008-01-01

    Abstract Background The objective was to study the association between Non-Hodgkin's Lymphoma (NHL) and occupational exposures related to long held occupations among males in six provinces of Canada. Methods A population based case-control study was conducted from 1991 to 1994. Males with newly diagnosed NHL (ICD-10) were stratified by province of residence and age group. A total of 513 incident cases and 1506 population based controls were included in the analysis. Conditional logistic regre...

  4. The design and function of birds' nests

    OpenAIRE

    Mainwaring, Mark C.; Hartley, Ian R.; Lambrechts, Marcel M.; Deeming, D Charles

    2014-01-01

    All birds construct nests in which to lay eggs and/or raise offspring. Traditionally, it was thought that natural selection and the requirement to minimize the risk of predation determined the design of completed nests. However, it is becoming increasingly apparent that sexual selection also influences nest design. This is an important development as while species such as bowerbirds build structures that are extended phenotypic signals whose sole purpose is to attract a mate, nests contain eg...

  5. The design and function of birds’ nests

    OpenAIRE

    Mainwaring, Mark; Hartley, Ian; Lambrechts, Marcel; Deeming, Charles

    2014-01-01

    All birds construct nests in which to lay eggs and/or raise offspring. Traditionally, it was thought that natural selection and the requirement to minimize the risk of predation determined the design of completed nests. However, it is becoming increasingly apparent that sexual selection also influences nest design. This is an important development as while species such as bowerbirds build structures that are extended phenotypic signals whose sole purpose is to attract a mate, nests cont...

  6. Nested Quantum Error Correction Codes

    CERN Document Server

    Wang, Zhuo; Fan, Hen; Vedral, Vlatko

    2009-01-01

    The theory of quantum error correction was established more than a decade ago as the primary tool for fighting decoherence in quantum information processing. Although great progress has already been made in this field, limited methods are available in constructing new quantum error correction codes from old codes. Here we exhibit a simple and general method to construct new quantum error correction codes by nesting certain quantum codes together. The problem of finding long quantum error correction codes is reduced to that of searching several short length quantum codes with certain properties. Our method works for all length and all distance codes, and is quite efficient to construct optimal or near optimal codes. Two main known methods in constructing new codes from old codes in quantum error-correction theory, the concatenating and pasting, can be understood in the framework of nested quantum error correction codes.

  7. Teaching Ecological Concepts with Mud Dauber Nests.

    Science.gov (United States)

    Matthews, Robert W.; Matthews, Janice R.

    1999-01-01

    Contends that mud dauber nests--which are widely available, safe, inexpensive, and easy to use--offer a novel and highly motivating way to teach ecological concepts to life science students at many grade levels. Presents background information for teachers, details classroom-tested methods for nest dissection, provides keys to nest contents, and…

  8. Supramolecular nesting of cyclic polymers

    Science.gov (United States)

    Kondratuk, Dmitry V.; Perdigão, Luís M. A.; Esmail, Ayad M. S.; O'Shea, James N.; Beton, Peter H.; Anderson, Harry L.

    2015-04-01

    Advances in template-directed synthesis make it possible to create artificial molecules with protein-like dimensions, directly from simple components. These synthetic macromolecules have a proclivity for self-organization that is reminiscent of biopolymers. Here, we report the synthesis of monodisperse cyclic porphyrin polymers, with diameters of up to 21 nm (750 C-C bonds). The ratio of the intrinsic viscosities for cyclic and linear topologies is 0.72, indicating that these polymers behave as almost ideal flexible chains in solution. When deposited on gold surfaces, the cyclic polymers display a new mode of two-dimensional supramolecular organization, combining encapsulation and nesting; one nanoring adopts a near-circular conformation, thus allowing a second nanoring to be captured within its perimeter, in a tightly folded conformation. Scanning tunnelling microscopy reveals that nesting occurs in combination with stacking when nanorings are deposited under vacuum, whereas when they are deposited directly from solution under ambient conditions there is stacking or nesting, but not a combination of both.

  9. Early life course risk factors for childhood obesity: the IDEFICS case-control study.

    Directory of Open Access Journals (Sweden)

    Karin Bammann

    Full Text Available BACKGROUND: The early life course is assumed to be a critical phase for childhood obesity; however the significance of single factors and their interplay is not well studied in childhood populations. OBJECTIVES: The investigation of pre-, peri- and postpartum risk factors on the risk of obesity at age 2 to 9. METHODS: A case-control study with 1,024 1:1-matched case-control pairs was nested in the baseline survey (09/2007-05/2008 of the IDEFICS study, a population-based intervention study on childhood obesity carried out in 8 European countries in pre- and primary school settings. Conditional logistic regression was used for identification of risk factors. RESULTS: For many of the investigated risk factors, we found a raw effect in our study. In multivariate models, we could establish an effect for gestational weight gain (adjusted OR = 1.02; 95%CI 1.00-1.04, smoking during pregnancy (adjusted OR = 1.48; 95%CI 1.08-2.01, Caesarian section (adjusted OR = 1.38; 95%CI 1.10-1.74, and breastfeeding 4 to 11 months (adjusted OR = 0.77; 95%CI 0.62-0.96. Birth weight was related to lean mass rather than to fat mass, the effect of smoking was found only in boys, but not in girls. After additional adjustment for parental BMI and parental educational status, only gestational weight gain remained statistically significant. Both, maternal as well as paternal BMI were the strongest risk factors in our study, and they confounded several of the investigated associations. CONCLUSIONS: Key risk factors of childhood obesity in our study are parental BMI and gestational weight gain; consequently prevention approaches should target not only children but also adults. The monitoring of gestational weight seems to be of particular importance for early prevention of childhood obesity.

  10. Nest Material Shapes Eggs Bacterial Environment

    Science.gov (United States)

    Ruiz-Castellano, Cristina; Tomás, Gustavo; Ruiz-Rodríguez, Magdalena; Martín-Gálvez, David; Soler, Juan José

    2016-01-01

    Selective pressures imposed by pathogenic microorganisms to embryos have selected in hosts for a battery of antimicrobial lines of defenses that includes physical and chemical barriers. Due to the antimicrobial properties of volatile compounds of green plants and of chemicals of feather degrading bacteria, the use of aromatic plants and feathers for nest building has been suggested as one of these barriers. However, experimental evidence suggesting such effects is scarce in the literature. During two consecutive years, we explored experimentally the effects of these nest materials on loads of different groups of bacteria (mesophilic bacteria, Enterobacteriaceae, Staphylococcus and Enterococcus) of eggshells in nests of spotless starlings (Sturnus unicolor) at the beginning and at the end of the incubation period. This was also explored in artificial nests without incubation activity. We also experimentally increased bacterial density of eggs in natural and artificial nests and explored the effects of nest lining treatments on eggshell bacterial load. Support for the hypothetical antimicrobial function of nest materials was mainly detected for the year and location with larger average values of eggshell bacterial density. The beneficial effects of feathers and plants were more easily detected in artificial nests with no incubation activity, suggesting an active role of incubation against bacterial colonization of eggshells. Pigmented and unpigmented feathers reduced eggshell bacterial load in starling nests and artificial nest boxes. Results from artificial nests allowed us to discuss and discard alternative scenarios explaining the detected association, particularly those related to the possible sexual role of feathers and aromatic plants in starling nests. All these results considered together confirm the antimicrobial functionality mainly of feathers but also of plants used as nest materials, and highlight the importance of temporally and geographically

  11. Nest structure and communal nesting in Euglossa (Glossura) annectans Dressler (Hymenoptera, Apidae, Euglossini)

    OpenAIRE

    Carlos Alberto Garófalo; Evandro Camillo; Solange Cristina Augusto; Bartira Maria Vieira de Jesus; José Carlos Serrano

    1998-01-01

    Three nests of Euglossa (Glossura) annectans Dressier, 1982 were obtained from trap nests at Serra do Japi, Jundiai, São Paulo State, Brazil. The bees nested in bamboo cane (one nest) and in wooden-boxes (two nests). Solitary (two cases) and pleometrotic (one case) foundations were observed. Two nests were re-used once by two females working in each of them. Re-using females that shared the nests were of the same generation and each built, provisioned and oviposited in her own cells, characte...

  12. Efficient use of iterative solvers in nested topology optimization

    DEFF Research Database (Denmark)

    Amir, Oded; Stolpe, Mathias; Sigmund, Ole

    2010-01-01

    In the nested approach to structural optimization, most of the computational effort is invested in the solution of the analysis equations. In this study, it is suggested to reduce this computational cost by using an approximation to the solution of the analysis problem, generated by a Krylov...... subspace iterative solver. By choosing convergence criteria for the iterative solver that are strongly related to the optimization objective and to the design sensitivities, it is possible to terminate the iterative solution of the nested equations earlier compared to traditional convergence measures. The...... approximation is computationally shown to be sufficiently accurate for the purpose of optimization though the nested equation system is not necessarily solved accurately. The approach is tested on several large-scale topology optimization problems, including minimum compliance problems and compliant mechanism...

  13. How Predation Risk Shapes Avian Nest Site Selection and Processes Underlying Nest Predation Patterns

    OpenAIRE

    Latif, Quresh Shabbir

    2009-01-01

    Given the importance of nest predation to avian fitness, ornithologists expect birds to select nest sites that minimize predation risk. Despite numerous studies contributing to a large body of literature, how predation shapes avian nest site selection is not well understood largely because studies rarely examine the processes underlying either nest site selection or predation risk. I investigated how predation shapes nest site selection for a population of Yellow Warblers with an eye for the ...

  14. Resistance to gray leaf spot of maize: genetic architecture and mechanisms elucidated through nested association mapping and near-isogenic line analysis.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Benson

    2015-03-01

    Full Text Available Gray leaf spot (GLS, caused by Cercospora zeae-maydis and Cercospora zeina, is one of the most important diseases of maize worldwide. The pathogen has a necrotrophic lifestyle and no major genes are known for GLS. Quantitative resistance, although poorly understood, is important for GLS management. We used genetic mapping to refine understanding of the genetic architecture of GLS resistance and to develop hypotheses regarding the mechanisms underlying quantitative disease resistance (QDR loci. Nested association mapping (NAM was used to identify 16 quantitative trait loci (QTL for QDR to GLS, including seven novel QTL, each of which demonstrated allelic series with significant effects above and below the magnitude of the B73 reference allele. Alleles at three QTL, qGLS1.04, qGLS2.09, and qGLS4.05, conferred disease reductions of greater than 10%. Interactions between loci were detected for three pairs of loci, including an interaction between iqGLS4.05 and qGLS7.03. Near-isogenic lines (NILs were developed to confirm and fine-map three of the 16 QTL, and to develop hypotheses regarding mechanisms of resistance. qGLS1.04 was fine-mapped from an interval of 27.0 Mb to two intervals of 6.5 Mb and 5.2 Mb, consistent with the hypothesis that multiple genes underlie highly significant QTL identified by NAM. qGLS2.09, which was also associated with maturity (days to anthesis and with resistance to southern leaf blight, was narrowed to a 4-Mb interval. The distance between major leaf veins was strongly associated with resistance to GLS at qGLS4.05. NILs for qGLS1.04 were treated with the C. zeae-maydis toxin cercosporin to test the role of host-specific toxin in QDR. Cercosporin exposure increased expression of a putative flavin-monooxygenase (FMO gene, a candidate detoxification-related gene underlying qGLS1.04. This integrated approach to confirming QTL and characterizing the potential underlying mechanisms advances the understanding of QDR and will

  15. Toxocariasis in Waste Pickers: A Case Control Seroprevalence Study

    OpenAIRE

    Alvarado-Esquivel, Cosme

    2013-01-01

    Background The epidemiology of Toxocara infection in humans in Mexico has been poorly explored. There is a lack of information about Toxocara infection in waste pickers. Aims Determine the seroepidemiology of Toxocara infection in waste pickers. Methods Through a case control study design, the presence of anti-Toxocara IgG antibodies was determined in 90 waste pickers and 90 age- and gender-matched controls using an enzyme-linked immunoassay. Associations of Toxocara exposure with socio-demog...

  16. Reproductive Risk Factors for Breast Cancer: A Case Control Study

    OpenAIRE

    Meshram II; Hiwarkar PA; Kulkarni PN

    2009-01-01

    Background: Breast cancer is second most important cancer among Indian women. Although risk factors are not much prevalent as in western countries, incidence rate is increasing in India. The study was undertaken to study various risk factors associated with breast cancer. Methods: A hospital based group matched case control study was undertaken to identify risk factors. The study consisted of 105 hospitalized cases confirmed on histopathology and 210 group matched controls selected from urban...

  17. Mind wandering and driving: a responsibility case-control study

    OpenAIRE

    GALERA, Cédric; Orriols, Ludivine; M'BAILARA, Katia; LABOREY, Magali; Contrand, Benjamin; RIBEREAU-GAYON, Régis; Masson, Françoise; Bakiri, Sarah; GABAUDE, Catherine; Fort, Alexandra; MAURY, Bertrand; Lemercier, Céline; Cours, Maurice; BOUVARD, Manuel-Pierre; LAGARDE, Emmanuelle

    2012-01-01

    Objective To assess the association between mind wandering (i.e. thinking unrelated to the task at hand) and the risk of being responsible for the crash. Design Responsibility case-control study. Setting Adult emergency department of the Bordeaux University hospital (France) from April 2010 to August 2011. Participants 955 injured drivers presenting as a result of motor vehicle crash. Main outcome measures The main outcome variable was responsibility for the crash. Exposures were mind wanderi...

  18. Violence against Women and Gastroschisis: A Case-Control Study

    OpenAIRE

    Daniel Ruiz; Maria Teresa Martínez-Ros; Alberto Cárceles-Alvarez; Perales, Joseph E.; Diana Carolina Jaimes-Vega; Alicia Cánovas-Conesa; Virtudes Gomaríz-Peñalver; Soldin, Offie P.; Miguel Felipe Sánchez-Sauco; Juan Antonio Ortega-García

    2013-01-01

    Background: Gastroschisis, a birth defect characterized by herniated fetal abdominal wall, occurs more commonly in infants born to teenage and young mothers. Ischemia of the vascular vitelline vessels is the likely mechanism of pathogenesis. Given that chronic stress and violence against women are risk factors for cardiovascular disease we explored whether these may represent risk factors for gastroschisis, when they occur during pregnancy. A case-control study was conducted, with 15 incident...

  19. On combining family and case-control studies.

    Science.gov (United States)

    Pfeiffer, Ruth M; Pee, David; Landi, Maria T

    2008-11-01

    Studies to detect genetic association with disease can be family-based, often using families with multiple affected members, or population based, as in population-based case-control studies. If data on both study types are available from the same population, it is useful to combine them to improve power to detect genetic associations. Two aspects of the data need to be accommodated, the sampling scheme and potential residual correlations among family members. We propose two approaches for combining data from a case-control study and a family study that collected families with multiple cases. In the first approach, we view a family as the sampling unit and specify the joint likelihood for the family members using a two-level mixed effects model to account for random familial effects and for residual genetic correlations among family members. The ascertainment of the families is accommodated by conditioning on the ascertainment event. The individuals in the case-control study are treated as families of size one, and their unconditional likelihood is combined with the conditional likelihood for the families. This approach yields subject specific maximum likelihood estimates of covariate effects. In the second approach, we view an individual as the sampling unit. The sampling scheme is accommodated using two-phase sampling techniques, marginal covariate effects are estimated, and correlations among family members are accounted for in the variance calculations. The models are compared in simulations. Data from a case-control and a family study from north-eastern Italy on melanoma and a low-risk melanoma-susceptibility gene, MC1R, are used to illustrate the approaches. PMID:18454494

  20. Risk factors for ovarian cancer: a case-control study.

    OpenAIRE

    Booth, M.; Beral, V; SMITH, P.

    1989-01-01

    A hospital-based case-control study of ovarian cancer was conducted in London and Oxford between October 1978 and February 1983. Menstrual characteristics, reproductive and contraceptive history and history of exposure to various environmental factors were compared between 235 women with histologically diagnosed epithelial ovarian cancer and 451 controls. High gravidity, hysterectomy, female sterilisation and oral contraceptive use were associated with a reduced risk of ovarian cancer. Infert...

  1. Smoking and high-risk mammographic parenchymal patterns: a case-control study

    International Nuclear Information System (INIS)

    ,13,14,15]. There are no published studies that assessed the relationship between smoking and mammographic parenchymal patterns. To evaluate whether mammographic parenchymal patterns as classified by Wolfe, which have been positively associated with breast cancer risk, are affected by smoking. In this case-control study, nested within the European Prospective Investigation on Cancer in Norfolk (EPIC-Norfolk) cohort [16], the association between smoking habits and mammographic parenchymal patterns are examined. The full results will be published elsewhere. Study subjects were members of the EPIC cohort in Norwich who also attended the prevalence screening round at the Norwich Breast Screening Centre between November 1989 and December 1997, and were free of breast cancer at that screening. Cases were defined as women with a P2/DY Wolfe's mammographic parenchymal pattern on the prevalence screen mammograms. A total of 203 women with P2/DY patterns were identified as cases and were individually matched by date of birth (within 1 year) and date of prevalence screening (within 3 months) with 203 women with N1/P1 patterns who served as control individuals. Two views, the mediolateral and craniocaudal mammograms, of both breasts were independently reviewed by two of the authors (ES and RW) to determine the Wolfe mammographic parenchymal pattern. Considerable information on health and lifestyle factors was available from the EPIC Health and Lifestyle Questionnaire [16]. In the present study we examined the subjects' personal history of benign breast diseases, menstrual and reproductive factors, oral contraception and hormone replacement therapy, smoking, and anthropometric information such as body mass index and waist:hip ratio. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated by conditional logistic regression [17], and were adjusted for possible confounding factors. The characteristics of the cases and controls are presented in Table 1. Cases were

  2. Assessment of global phase uncertainty in case-control studies

    Directory of Open Access Journals (Sweden)

    van Houwelingen Hans C

    2009-09-01

    Full Text Available Abstract Background In haplotype-based candidate gene studies a problem is that the genotype data are unphased, which results in haplotype ambiguity. The measure 1 quantifies haplotype predictability from genotype data. It is computed for each individual haplotype, and for a measure of global relative efficiency a minimum value is suggested. Alternatively, we developed methods directly based on the information content of haplotype frequency estimates to obtain global relative efficiency measures: and based on A- and D-optimality, respectively. All three methods are designed for single populations; they can be applied in cases only, controls only or the whole data. Therefore they are not necessarily optimal for haplotype testing in case-control studies. Results A new global relative efficiency measure was derived to maximize power of a simple test statistic that compares haplotype frequencies in cases and controls. Application to real data showed that our proposed method gave a clear and summarizing measure for the case-control study conducted. Additionally this measure might be used for selection of individuals, who have the highest potential for improving power by resolving phase ambiguity. Conclusion Instead of using relative efficiency measure for cases only, controls only or their combined data, we link uncertainty measure to case-control studies directly. Hence, our global efficiency measure might be useful to assess whether data are informative or have enough power for estimation of a specific haplotype risk.

  3. Correlation between periodontal disease and onset of coronary heart disease: a Meta-analysis based on 37 case-control studies%牙周病与冠心病发病相关性:一项基于37个病例-对照研究的Meta分析

    Institute of Scientific and Technical Information of China (English)

    毛敏; 杨勇; 曾宪涛; 郭毅; 施俊; 李娟

    2012-01-01

    Objective To review the relationship between periodontal disease and onset risk of coronary heart disease ( CHD ) by using Meta-analysis method. Methods The case-control studies about the relationship between periodontal disease and onset risk of CHD were retrieved from PnbMed, Embase, China National Network Knowledge Infrastructure ( CNKI) , Chinese BioMedical Literature Database ( CBM ) , VIP Database and WanFang Database by two reviewers independently. The quality evaluation and data extraction were performed in the literature accorded with inclusion criterion by applying NOS standard, and then the Mate-analysis was conducted by using CMA v2 software. The level of evidence was graded by using GRADE system. Results There were totally 37 case-control studies included, and 18 in Chinese and 19 in English. The results of Meta-analysis showed that periodontal disease increased 3.76 times in the incidence of CHD ( OR=3.167 95%CI: 2.15-6.58, P<0.001 ) , and sensitivity analysis showed the results was stable. The results of subgroup analysis according to whether traditional risk factors were corrected showed that the incidence of CHD was still up to 2.78 times after correcting ( OR=2.78, 95%CI: 2.09-3.68, P<0.001 ) . The grade of evidence was low in GRADE system and publication bias was slight. Conclusion Periodontal disease is an independent and significant risk factor to CHD. More studies should be further conducted according to the clinical grading of periodontal disease and clinical subtypes of CHD.%目的 采用Meta分析的方法评价牙周病与冠心病(CHD)的发病风险关系.方法 由两名评价者独立检索PubMed、Embase、中国知网、中国生物医学文献数据库、维普及万方数据库中公开发表的探讨牙周炎与CHD发病风险关系病例-对照研究,对符合纳入标准的文献采用NOS标准进行质量评价、数据提取后采用CMA v2软件进行Meta分析,并采用GRADE系统进行证据评级.结果

  4. Nest placement by azure-winged magpies (Cyanopica cyana)

    OpenAIRE

    Redondo, T.; Hidalgo de Trucios, S.J.; Medina, Rosario

    1989-01-01

    Nest site selection of Azure-winged Magpies (Cyanopica cyana) was studied in relation to their proximity to the nests of Japanese Lesser Sparrowhawks (Accipiter gularis). Magpies used nest sites that were more concealed when not nesting in ssociation with the hawk, and nests with a higher rate of leaf cover were less frequently depredated. Magpies preferred to nest close to hawk nests, and such siteshad higher breeding success. However, Azure-winged Magpies nested in places with l...

  5. Nested and Dynamic Contract Boundaries

    Science.gov (United States)

    Strickland, T. Stephen; Felleisen, Matthias

    Previous work on software contracts assumes fixed and statically known boundaries between the parties to a contract. Implementations of contract monitoring systems rely on this assumption to explain the nature of contract violations and to assign blame to violators. In this paper, we explain how to implement arbitrary, nested, and dynamic contract boundaries with two examples. First, we add nestable contract regions to a static, first-order module system. Second, we show that even a dynamic, higher-order, and hierarchical module system can be equipped with software contracts that support precise blame assignment.

  6. Varmelagring i neste generasjon vedovner

    OpenAIRE

    Antonsen, Orjan

    2013-01-01

    Instituttet for energi- og prosessteknikk er involvert innen forskning og utvikling av neste generasjons vedovner. Et av målene for slike vedovner er at de skal ha en vesentlig jevnere effektavgivelse enn dagens løsninger. Dette krever at det benyttes et varmelager sammen med ovnen.I denne oppgaven er et varmelagersystem bestående av en fordamper og en kondensator undersøkt. Veken, en sentral komponent i fordamperen, og dens egenskaper preges i stor grad av produ...

  7. Nested-cone transformer antenna

    Science.gov (United States)

    Ekdahl, Carl A.

    1991-01-01

    A plurality of conical transmission lines are concentrically nested to form n output antenna for pulsed-power, radio-frequency, and microwave sources. The diverging conical conductors enable a high power input density across a bulk dielectric to be reduced below a breakdown power density at the antenna interface with the transmitting medium. The plurality of cones maintain a spacing between conductors which minimizes the generation of high order modes between the conductors. Further, the power input feeds are isolated at the input while enabling the output electromagnetic waves to add at the transmission interface. Thus, very large power signals from a pulse rf, or microwave source can be radiated.

  8. Nest predation and reproductive traits in small passerines: a comparative approach

    Science.gov (United States)

    Yanes, Miguel; Suárez, Francisco

    Nest predation can be a decisive factor in the evolution of bird reproduction strategies. This paper compares several reproductive traits in small passerines on the Iberian Peninsula (n=31) with the probability of daily nest survival from predation. We consider the phylogenetic relationships between species by means of an analysis according to three models of evolutionary change: Brownian, punctuational and GRAFEN'S arbitrary. In this comparative evolutionary scenario, clutch size, egg volume and incubation period appear not to change in relation to nest predation, while the nestling phase duration is a positively-related parameter to daily nest survival from predation. These results are consistent for all models of evolutionary change. Thus, from the perspective of nest predation, the nestling period is the most important evolutionary parameter in small passerines. A hypothetical influence of nest predation on passerine clutch and egg size should only be regarded as an indirect factor, linked to the relationship between these parameters and the duration of the nestling period.

  9. Interaction and Its Solution in Individual Matching Case-control Study

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective To indicate the deficiency of the classical method for analyzing data on individual matching case-control study in consideration of the interaction between the study factor (exposure) and the matching factor, and to find out a proper method for handling this deficiency. Method First, experimental data with 50 pairs of cases and controls were used for strata analysis according to the values of a matching factor to illustrate the possible interaction between a risk factor (exposure) and the matching factor. Second, a detailed procedure was proposed for analyzing such data. Results Interaction between the study factor and matching factor was demonstrated by using strata analysis and unconditional logistic regression analysis. Therefore the results from the classical analysis for such data might be incorrect. Conclusion Data from individual matching case-control study design should be dealt with strata analysis or multivariate analysis to explore and evaluate the possible interaction between the study factor and matching factor. The conclusion would be valid only after such analysis is conducted.

  10. Adipokines as Possible New Predictors of Cardiovascular Diseases: A Case Control Study

    Directory of Open Access Journals (Sweden)

    Laura Pala

    2012-01-01

    Full Text Available Background and Aims. The secretion of several adipocytokines, such as adiponectin, retinol-binding protein 4 (RBP4, adipocyte fatty acid binding protein (aFABP, and visfatin, is altered in subjects with abdominal adiposity; these endocrine alterations could contribute to increased cardiovascular risk. The aim of the study was to assess the relationship among adiponectin, RBP4, aFABP, and visfatin, and incident cardiovascular disease. Methods and Results. A case-control study, nested within a prospective cohort, on 2945 subjects enrolled for a diabetes screening program was performed. We studied 18 patients with incident fatal or nonfatal IHD (Ischemic Heart Disease or CVD (Cerebrovascular Disease, compared with 18 matched control subjects. Circulating adiponectin levels were significantly lower in cases of IHD with respect to controls. Circulating RBP4 levels were significantly increased in CVD and decreased in IHD with respect to controls. Circulating aFABP4 levels were significantly increased in CVD, while no difference was associated with IHD. Circulating visfatin levels were significantly lower in cases of both CVD and IHD with respect to controls, while no difference was associated with CVD. Conclusions. The present study confirms that low adiponectin is associated with increased incidents of IHD, but not CVD, and suggests, for the first time, a major effect of visfatin, aFABP, and RBP4 in the development of cardiovascular disease.

  11. ANALYSIS OF CRYPTOSPORIDIUM SSU rRNA GENE BY NESTED PCR-RFLP%隐孢子虫SSU rRNA基因的巢式PCR-RFLP分析

    Institute of Scientific and Technical Information of China (English)

    姚龙泉; 张西臣; Lihua Xiao; 吴涛; 李建华; 尹继刚

    2004-01-01

    目的建立用巢式聚合酶链反应(Nested PCR)- 限制片段长度多态性(Restriction fragment length polymorphism,RFLP)检测、鉴别微小隐孢子虫(Cryptospordium parvum)和安氏隐孢子虫(C. andersoni)的方法. 方法用巢式PCR技术扩增长春市人和牛粪便中C. parvum与C. andersoni的Small-Subunit rRNA (SSU rRNA)部分基因,并克隆和测序.扩增产物分别用SspⅠ和VspⅠ单酶切,进行RFLP分析,并与GenBank上的17株隐孢子虫相应序列进行对比分析和系统发育分析. 结果 C. parvum HCC1、C. parvum BOCC1和C. andersoni BOCC1扩增产物片段大小分别为830 bp、830 bp和828 bp,经SspⅠ和VspⅠ分别单酶切后形成2种不同的RFLP图谱,根据RFLP图谱可鉴别C. parvum与C. andersoni.序列分析结果显示,C. parvum HCC1与国外牛源C. parvum BOH6、C. parvum GCH1、鹿源C. parvum DR1相应序列同源性均为99.3%;C. parvum BOCC1与国外牛源C. parvum BOH6、C. parvum GCH1、鹿源C. parvum DR1相应序列同源性均为99.5%;C. andersoni BOCC1与国外C. andersoni相应序列同源性为99.9%.系统发育分析结果显示,隐孢子虫虫种形成了2个群,1个群包括C. parvum、C. baileyi、C. meleagridis、C. felis和C. wrairi,另1个群包括C. andersoni、C. muris和C. serpentis. 结论用巢式PCR技术可扩增隐孢子虫基因组DNA中特异片段,根据RFLP图谱可鉴别C. parvum和C. andersoni,表明本实验建立的检测、鉴别C. parvum和C. andersoni的巢式PCR- RFLP方法有效,为我国隐孢子虫分类、隐孢子虫病的分子流行病学研究和诊断打下了良好基础.

  12. Hydrodynamic modeling of Singapore's coastal waters: Nesting and model accuracy

    Science.gov (United States)

    Hasan, G. M. Jahid; van Maren, Dirk Sebastiaan; Ooi, Seng Keat

    2016-01-01

    The tidal variation in Singapore's coastal waters is influenced by large-scale, complex tidal dynamics (by interaction of the Indian Ocean and the South China Sea) as well as monsoon-driven low frequency variations, requiring a model with large spatial coverage. Close to the shores, the complex topography, influenced by headlands and small islands, requires a high resolution model to simulate tidal dynamics. This can be achieved through direct nesting or multi-scale nesting, involving multiple model grids. In this paper, we investigate the effect of grid resolution and multi-scale nesting on the tidal dynamics in Singapore's coastal waters, by comparing model results with observations using different statistical techniques. The results reveal that the intermediate-scale model is generally sufficiently accurate (equal to or better than the most refined model), but also that the most refined model is only more accurate when nested in the intermediate scale model (requiring multi-scale nesting). This latter is the result of the complex tidal dynamics around Singapore, where the dominantly diurnal tidal currents are decoupled from the semi-diurnal water level variations. Furthermore, different techniques to quantify model accuracy (harmonic analysis, basic statistics and more complex statistics) are inconsistent in determining which model is more accurate.

  13. Nest site characteristics and nest loss of Marsh Grassbird at Zhalong National Nature Reserve, China

    Institute of Scientific and Technical Information of China (English)

    Qiang Wang; Xuehong Zhou; Fengshan Li; Yuming Zhang; Feng Li

    2015-01-01

    The Marsh Grassbird Locustella pryeri is an uncommon songbird endemic to East Asia. Suitable nest-site selection can minimize nest loss, especially for open-cup and ground nesting passerines. We located and mon-itored 66 Marsh Grassbird nests during 2004–2006 in Zhalong National Nature Reserve, northeast China, to identify characteristics of preferred nest sites. Marsh Grassbird nested mainly at sites with dense vegetation cover, high undergrowth and dry standing reed stalks, as well as small shallow ponds or rivers. Nests were more successful when they were placed higher above ground in patches with greater litter thickness. Predation and flooding were the leading causes of nest failure, accounting for at least 33 and 25% of 24 nests lost, respectively. We ad-vocate retention of some unharvested reed patches and implementation of irrigation strategies that avoid increas-ing water levels during the breeding period (May–July) of Marsh Grassbirds.

  14. Nest-site selection pattern of Grusjaponensis in Zhalong Nature Reserve of northeast China

    Institute of Scientific and Technical Information of China (English)

    WU Qing-ming; ZOU Hong-fei

    2011-01-01

    Nest-site selection patterns of Red-crowned cranes (Grus japonensis) and the effects of environmental variables were studied during the years of 2002-2008 in Zhalong Nature Reserve, Qiqihar city,northeast China. The nest-site selection pattern of Red-crowned cranes included two orders and three choices: the choice of nest-site habitat type within the macro-habitat order, nest zone selection and nest-site micro-habitat selection within the micro-habitat order. Various habitats (such as Carex swamps and reed fire districts) can be selected as the nest sites for Red-crowned cranes, of which reed swamps (93.15%) are given a preference. Factor Analysis reveals that the micro-habitat selection are affected by four main factors: fire, security (concealment / disturbance),incubation (conditions, nest-material), and food. Further analysis reveals that Red-crowned cranes have certain adaptability to the changes of nesting habitat quality in the Zhalong wetlands. In conclusion, fire, reeds,and water were the most important variables for nest-site habitat selection of Red-crowned Cranes in Zhalong Nature Reserve.

  15. Polytypic Functions Over Nested Datatypes

    Directory of Open Access Journals (Sweden)

    Ralf Hinze

    1999-12-01

    Full Text Available The theory and practice of polytypic programming is intimately connected with the initial algebra semantics of datatypes. This is both a blessing and a curse. It is a blessing because the underlying theory is beautiful and well developed. It is a curse because the initial algebra semantics is restricted to so-called regular datatypes. Recent work by R. Bird and L. Meertens [3] on the semantics of non-regular or nested datatypes suggests that an extension to general datatypes is not entirely straightforward. Here we propose an alternative that extends polytypism to arbitrary datatypes, including nested datatypes and mutually recursive datatypes. The central idea is to use rational trees over a suitable set of functor symbols as type arguments for polytypic functions. Besides covering a wider range of types the approach is also simpler and technically less involving than previous ones. We present several examples of polytypic functions, among others polytypic reduction and polytypic equality. The presentation assumes some background in functional and in polytypic programming. A basic knowledge of monads is required for some of the examples.

  16. Nest architecture shapes the collective behaviour of harvester ants.

    Science.gov (United States)

    Pinter-Wollman, Noa

    2015-10-01

    Structures influence how individuals interact and, therefore, shape the collective behaviours that emerge from these interactions. Here I show that the structure of a nest influences the collective behaviour of harvester ant colonies. Using network analysis, I quantify nest architecture and find that as chamber connectivity and redundancy of connections among chambers increase, so does a colony's speed of recruitment to food. Interestingly, the volume of the chambers did not influence speed of recruitment, suggesting that the spatial organization of a nest has a greater impact on collective behaviour than the number of workers it can hold. Thus, by changing spatial constraints on social interactions organisms can modify their behaviour and impact their fitness.

  17. Exploring Multi-Modal Distributions with Nested Sampling

    CERN Document Server

    Feroz, F

    2013-01-01

    In performing a Bayesian analysis, two difficult problems often emerge. First, in estimating the parameters of some model for the data, the resulting posterior distribution may be multi-modal or exhibit pronounced (curving) degeneracies. Secondly, in selecting between a set of competing models, calculation of the Bayesian evidence for each model is computationally expensive using existing methods such as thermodynamic integration. Nested Sampling is a Monte Carlo method targeted at the efficient calculation of the evidence, but also produces posterior inferences as a by-product and therefore provides means to carry out parameter estimation as well as model selection. The main challenge in implementing Nested Sampling is to sample from a constrained probability distribution. One possible solution to this problem is provided by the Galilean Monte Carlo (GMC) algorithm. We show results of applying Nested Sampling with GMC to some problems which have proven very difficult for standard Markov Chain Monte Carlo (MC...

  18. Historical versus contemporary climate forcing on the annual nesting variability of loggerhead sea turtles in the Northwest Atlantic Ocean.

    Directory of Open Access Journals (Sweden)

    Michael D Arendt

    Full Text Available A recent analysis suggested that historical climate forcing on the oceanic habitat of neonate sea turtles explained two-thirds of interannual variability in contemporary loggerhead (Caretta caretta sea turtle nest counts in Florida, where nearly 90% of all nesting by this species in the Northwest Atlantic Ocean occurs. Here, we show that associations between annual nest counts and climate conditions decades prior to nest counts and those conditions one year prior to nest counts were not significantly different. Examination of annual nest count and climate data revealed that statistical artifacts influenced the reported 31-year lag association with nest counts. The projected importance of age 31 neophytes to annual nest counts between 2020 and 2043 was modeled using observed nest counts between 1989 and 2012. Assuming consistent survival rates among cohorts for a 5% population growth trajectory and that one third of the mature female population nests annually, the 41% decline in annual nest counts observed during 1998-2007 was not projected for 2029-2038. This finding suggests that annual nest count trends are more influenced by remigrants than neophytes. Projections under the 5% population growth scenario also suggest that the Peninsular Recovery Unit could attain the demographic recovery criteria of 106,100 annual nests by 2027 if nest counts in 2019 are at least comparable to 2012. Because the first year of life represents only 4% of the time elapsed through age 31, cumulative survival at sea across decades explains most cohort variability, and thus, remigrant population size. Pursuant to the U.S. Endangered Species Act, staggered implementation of protection measures for all loggerhead life stages has taken place since the 1970s. We suggest that the 1998-2007 nesting decline represented a lagged perturbation response to historical anthropogenic impacts, and that subsequent nest count increases since 2008 reflect a potential recovery response.

  19. Historical versus contemporary climate forcing on the annual nesting variability of loggerhead sea turtles in the Northwest Atlantic Ocean.

    Science.gov (United States)

    Arendt, Michael D; Schwenter, Jeffrey A; Witherington, Blair E; Meylan, Anne B; Saba, Vincent S

    2013-01-01

    A recent analysis suggested that historical climate forcing on the oceanic habitat of neonate sea turtles explained two-thirds of interannual variability in contemporary loggerhead (Caretta caretta) sea turtle nest counts in Florida, where nearly 90% of all nesting by this species in the Northwest Atlantic Ocean occurs. Here, we show that associations between annual nest counts and climate conditions decades prior to nest counts and those conditions one year prior to nest counts were not significantly different. Examination of annual nest count and climate data revealed that statistical artifacts influenced the reported 31-year lag association with nest counts. The projected importance of age 31 neophytes to annual nest counts between 2020 and 2043 was modeled using observed nest counts between 1989 and 2012. Assuming consistent survival rates among cohorts for a 5% population growth trajectory and that one third of the mature female population nests annually, the 41% decline in annual nest counts observed during 1998-2007 was not projected for 2029-2038. This finding suggests that annual nest count trends are more influenced by remigrants than neophytes. Projections under the 5% population growth scenario also suggest that the Peninsular Recovery Unit could attain the demographic recovery criteria of 106,100 annual nests by 2027 if nest counts in 2019 are at least comparable to 2012. Because the first year of life represents only 4% of the time elapsed through age 31, cumulative survival at sea across decades explains most cohort variability, and thus, remigrant population size. Pursuant to the U.S. Endangered Species Act, staggered implementation of protection measures for all loggerhead life stages has taken place since the 1970s. We suggest that the 1998-2007 nesting decline represented a lagged perturbation response to historical anthropogenic impacts, and that subsequent nest count increases since 2008 reflect a potential recovery response. PMID:24339901

  20. Birds' nesting parameters in four forest types in the Pantanal wetland.

    Science.gov (United States)

    Pinho, J B; Marini, M A

    2014-11-01

    We tested the heterogeneity/productivity hypothesis with respect to the abundance and richness of birds and the vegetation density hypothesis with respect to birds' nest predation rates, and determined the relative importance of forested vegetation formations for the conservation of birds in the Pantanal. We estimated the apparent nesting success, and the abundance and richness of nesting birds' in four forest types, by monitoring nests during two reproductive seasons in four forested physiognomies (two high productivity/heterogeneity evergreen forests = Cambará and Landi; two low productivity/heterogeneity dry forests = Cordilheira and Carvoeiro) in the Pantanal wetland in Poconé, State of Mato Grosso, Brazil. We found 381 nests of 46 species (35 Passeriformes and 11 non-Passeriformes) in the four forest types. Of these, we monitored 220 active nests belonging to 44 species, 101 during the reproductive season of 2001 and 119 in 2002. We supported the productivity/heterogeneity hypothesis since the two evergreen forests had higher nest abundance and one of them (Cambará) had higher nesting species richness than the dry forests. The number of nests found in each habitat differed with most nests monitored in the Cambará forest (82%), followed by Landi (9%), Cordilheira (6%) and Carvoeiro (3%) forests. The total number of nests monitored was significantly higher in evergreen forests than in dry forests. Also, more species nested in evergreen (37 species) than in dry (16 species) forests. A Correspondence Analysis revealed that only Carvoeiros had a different nesting bird community. The overall apparent nesting success of 220 nests was 26.8%. We did not support the vegetation density hypothesis since nest predation rates were similar between evergreen (73.5%) and dry (70%) forests, and were higher in the Landi (85%) than in the other three forests (69.2 to 72.2%). Our data indicate that Cambará forests seem to be a key nesting habitat for many bird species of the

  1. Copper accumulation by stickleback nests containing spiggin.

    Science.gov (United States)

    Pinho, G L L; Martins, C M G; Barber, I

    2016-07-01

    The three-spined stickleback is a ubiquitous fish of marine, brackish and freshwater ecosystems across the Northern hemisphere that presents intermediate sensitivity to copper. Male sticklebacks display a range of elaborate reproductive behaviours that include nest construction. To build the nests, each male binds nesting material together using an endogenous glycoprotein nesting glue, known as 'spiggin'. Spiggin is a cysteine-rich protein and, therefore, potentially binds heavy metals present in the environment. The aim of this study was to investigate the capacity of stickleback nests to accumulate copper from environmental sources. Newly built nests, constructed by male fish from polyester threads in laboratory aquaria, were immersed in copper solutions ranging in concentration from 21.1-626.6 μg Cu L(-1). Bundles of polyester threads from aquaria without male fish were also immersed in the same copper solutions. After immersion, nests presented higher amounts of copper than the thread bundles, indicating a higher capacity of nests to bind this metal. A significant, positive correlation between the concentration of copper in the exposure solution and in the exposed nests was identified, but there was no such relationship for thread bundles. Since both spiggin synthesis and male courtship behaviour are under the control of circulating androgens, we predicted that males with high courtship scores would produce and secrete high levels of the spiggin protein. In the present study, nests built by high courtship score males accumulated more copper than those built by low courtship score males. Considering the potential of spiggin to bind metals, the positive relationship between fish courtship and spiggin secretion seems to explain the higher amount of copper on the nests from the fish showing high behaviour scores. Further work is now needed to determine the consequences of the copper binding potential of spiggin in stickleback nests for the health and survival of

  2. Nested Focusing Optics for Compact Neutron Sources

    Science.gov (United States)

    Nabors, Sammy A.

    2015-01-01

    NASA's Marshall Space Flight Center, the Massachusetts Institute of Technology (MIT), and the University of Alabama Huntsville (UAH) have developed novel neutron grazing incidence optics for use with small-scale portable neutron generators. The technology was developed to enable the use of commercially available neutron generators for applications requiring high flux densities, including high performance imaging and analysis. Nested grazing incidence mirror optics, with high collection efficiency, are used to produce divergent, parallel, or convergent neutron beams. Ray tracing simulations of the system (with source-object separation of 10m for 5 meV neutrons) show nearly an order of magnitude neutron flux increase on a 1-mm diameter object. The technology is a result of joint development efforts between NASA and MIT researchers seeking to maximize neutron flux from diffuse sources for imaging and testing applications.

  3. Struggling doctors in specialist training: a case control study

    DEFF Research Database (Denmark)

    O'Neill, Lotte; Norberg, Karen; Thomsen, Maria;

    health professionals, and as the gold standard for educational supervision.2,4-6 Therefore, the aim of this study was to examine: if strugglers in specialist training (cases) tended to struggle already in medical school or not compared to controls (non-strugglers), and which performance indicators during...... not identified as cases in the case extraction period. We aimed at a case-control ratio of 1:4 and intend to match on graduation year. Ten different performance measures relating to medical school admission, first year performance and overall program performances will be examined, such as: pre-university exam...

  4. Nest predation risk influences a cavity-nesting passerine during the post-hatching care period.

    Science.gov (United States)

    Yoon, Jongmin; Kim, Byung-Su; Joo, Eun-Jin; Park, Shi-Ryong

    2016-01-01

    Some nest predators visually assess parental activities to locate a prey nest, whereas parents modify fitness-related traits to reduce the probability of nest predation, and/or nestlings fledge early to escape the risky nest environment. Here, we experimentally tested if the parental and fledging behaviours of oriental tits (Parus minor) that bred in the nest-box varied with cavity conditions associated with nest predation risk during the nestling period. The entrance of experimental nest-boxes was enlarged to create a long-term risk soon after clutch competition. A short-term risk, using simulated playbacks with a coexisting control bird and avian nest predator sound, was simultaneously applied to the nest-boxes whether or not the long-term risk existed. We found that the parents reduced their hourly feeding trips, and the nestlings fledged early with the long-term risk, although the nest mortality of the two nest-box types was low and did not differ. While this study presents a portion of prey-predator interactions with the associated uncertainties, our results highlight that the entrance size of cavities for small hole-nesting birds may play an important role in determining their fitness-related traits depending upon the degree of perceived risk of nest predation. PMID:27553176

  5. Inverse Association of Serum Docosahexaenoic Acid With Newly Diagnosed Hypertension: A Community-based Case-control Study.

    Science.gov (United States)

    Yang, Bo; Ding, Fang; Wang, Feng-Lei; Yu, Wei; Li, Duo

    2016-02-01

    Observational studies on circulating fatty acid (FA) and primary prevention of hypertension have yielded inconsistent results, and the association among the Chinese population is not fully clear. The aim of the study was to discern important FAs that can discriminate hypertensive patients from normotensive persons, and investigate associations between the important FAs and risk of hypertension.We conducted a case-control study nested within a community-based cohort of 2447 Chinese participants aged 35 to 79 years who completed a baseline assessment between October 2012 and April 2013. In all, 480 patients with newly diagnosed hypertension were identified at baseline and 480 normotensive individuals were randomly selected as matched normotensive controls. Controls were individually matched to cases by age (±2 y), sex, and recruitment center, with a 1:1 case-to-control ratio. Serum FA profile was compared between cases and controls by orthogonal partial least squares-discriminant analyses. Odds ratio (OR) with 95% confidence interval (CI) for newly diagnosed hypertension was estimated by a conditional logistical analysis.After adjustment for body mass index, education, profession, family history of hypertension, salt intake, heart rate, blood lipids, and fasting glucose levels, serum FA profile in hypertensive patients was typically characterized by higher 16:0 and 16:1n-7, and lower 18:2n-6 and 22:6n-3, compared with normotensive controls. Docosahexaenoic acid (22:6n-3) and palmitoleic acid (16:1n-7) were identified as the important FA contributing most to the intergroup separations. When comparing the highest and lowest quartile of FA composition, newly diagnosed hypertension was negatively associated with 22:6n-3 (OR 0.65; 95% CI, 0.45-0.93; P for trend = 0.02), but positively associated with 16:1n-7 (OR 2.14; 95% CI, 1.46-3.12; P for trend < 0.001). The associations remained pronounced after multiple adjustments and in further stratified analyses

  6. Nest distribution and nest habitat of the Tibetan Partridge (Perdix hodgsoniae) near Lhasa, Tibet

    Institute of Scientific and Technical Information of China (English)

    Tsering; Dorge; G?ran; H?gstedt; Terje; Lislevand

    2014-01-01

    Background: Little is hitherto known about the breeding ecology of the Tibetan Partridge(Perdix hodgsoniae)which is endemic to the Tibetan plateau. Here we describe nest densities, inter-nest distances and general nest site characteristics in this gallinaceous bird species and explore the possibilities that certain shrub and plant types are preferred as nest surroundings.Method: A total of 56 nests were found over three breeding seasons near Lhasa, Tibet. Nest site characteristics were compared with random control plots and the proportions of specific plant species covering nests were compared with their estimated general occurrence in the study area.Results: Nest density in the two years with highest search effort was estimated at 1.43/km2 and 1.04/km2 but was clearly higher in the part of the study area facing north(1.86–2.35/km2) than that facing south(0.11–0.34/ km2). The average nearest neighbour distance of nests was about 300 m. Nests were situated in relatively lush vegetation and covered by a total of eight shrub species and three herbs. In contrast to previous reports, Caragana shrub did not constitute an important part of the nest habitat. The flowering, non-thorny bush Potentilla fruticosa was significantly over-represented as nest cover, while Rhododendron nivale was similarly under-represented. Nest bush foliage covered a larger area of ground, and the shrub surrounding nests was generally denser, than in control samples. Also, nests were placed closer to paths and in areas with lower densities of Yak(Bos grunniens) dung than in control samples.Except that soil temperatures were lower on nest sites than on control sites, micro-climate variables measured in this study did not differ between nest sites and control plots.Conclusions: Opportunity for nest concealment is probably an important quality of the nest habitat in Tibetan Partridges, yet it is unclear why the species should prefer P. fruticosa as nest cover. It is possible that nest sites are

  7. Nest distribution and nest habitat of the Tibetan Partridge (Perdix hodgsoniae) near Lhasa, Tibet

    Institute of Scientific and Technical Information of China (English)

    Tsering Dorge; Gran Hgstedt; Terje Lislevand

    2014-01-01

    Background:Little is hitherto known about the breeding ecology of the Tibetan Partridge (Perdix hodgsoniae) which is endemic to the Tibetan plateau. Here we describe nest densities, inter-nest distances and general nest site characteristics in this gallinaceous bird species and explore the possibilities that certain shrub and plant types are preferred as nest surroundings. Method:A total of 56 nests were found over three breeding seasons near Lhasa, Tibet. Nest site characteristics were compared with random control plots and the proportions of specific plant species covering nests were compared with their estimated general occurrence in the study area. Results:Nest density in the two years with highest search effort was estimated at 1.43/km2 and 1.04/km2 but was clearly higher in the part of the study area facing north (1.86–2.35/km2) than that facing south (0.11–0.34/km2). The average nearest neighbour distance of nests was about 300 m. Nests were situated in relatively lush vegetation and covered by a total of eight shrub species and three herbs. In contrast to previous reports, Caragana shrub did not constitute an important part of the nest habitat. The flowering, non-thorny bush Potentil a fruticosa was significantly over-represented as nest cover, while Rhododendron nivale was similarly under-represented. Nest bush foliage covered a larger area of ground, and the shrub surrounding nests was generally denser, than in control samples. Also, nests were placed closer to paths and in areas with lower densities of Yak (Bos grunniens) dung than in control samples. Except that soil temperatures were lower on nest sites than on control sites, micro-climate variables measured in this study did not differ between nest sites and control plots. Conclusions:Opportunity for nest concealment is probably an important quality of the nest habitat in Tibetan Partridges, yet it is unclear why the species should prefer P. fruticosa as nest cover. It is possible that nest sites

  8. Optimal Nesting for Continuous Shape Stamping Processes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper discusses the optimal nesting problem for minimizing the scrap in continuous shape stamping processes. The shape sliding technique is used to propose a new approach, OVERLAP-and-ESCAPE, to solve the problem of continuously nesting shapes onto a metal coil of fixed or selectable width. The approach is used to construct the objective function of the mathematical model of the problem using the Simulated Annealing Algorithm to determine the globally minimal configurations for the nesting problems. Some representative cases are studied and the results are encouraging. An automatic nesting software package for manufacturing bicycle chain link blanks is also described.

  9. Blue jays nest in an unusual structure

    Science.gov (United States)

    Muths, Erin L.; Lyons, Curtis P.; Sedgwick, James A.

    2007-01-01

    We describe a successful Blue Jay (Cyanocitta cristata) nest in an unusual structure on the side of a building.  The nest was located near the edge of the species' range along the Front Range of the Rocky Mountains in Colorado.  The nest was completely obvious, suggesting that the structure itself provided adequate cover and sercurity for the jays.  Blue Jays appear to be declining in some areas of the United States such as the Southeast.  Structures such as the one we describe may be more useful in attracting Blue Jays than the nesting platforms available commercially.

  10. The design and function of birds' nests.

    Science.gov (United States)

    Mainwaring, Mark C; Hartley, Ian R; Lambrechts, Marcel M; Deeming, D Charles

    2014-10-01

    All birds construct nests in which to lay eggs and/or raise offspring. Traditionally, it was thought that natural selection and the requirement to minimize the risk of predation determined the design of completed nests. However, it is becoming increasingly apparent that sexual selection also influences nest design. This is an important development as while species such as bowerbirds build structures that are extended phenotypic signals whose sole purpose is to attract a mate, nests contain eggs and/or offspring, thereby suggesting a direct trade-off between the conflicting requirements of natural and sexual selection. Nest design also varies adaptively in order to both minimize the detrimental effects of parasites and to create a suitable microclimate for parents and developing offspring in relation to predictable variation in environmental conditions. Our understanding of the design and function of birds' nests has increased considerably in recent years, and the evidence suggests that nests have four nonmutually exclusive functions. Consequently, we conclude that the design of birds' nests is far more sophisticated than previously realized and that nests are multifunctional structures that have important fitness consequences for the builder/s. PMID:25505520

  11. Nest survival is influenced by parental behaviour and heterospecifics in a mixed-species colony

    Science.gov (United States)

    Brussee, Brianne E.; Coates, Peter S.; Hothem, Roger L.; Howe, Kristy; Casazza, Michael L.; Eadie, John M.

    2016-01-01

    Studies of avian nest success often focus on examining influences of variation in environmental and seasonal factors. However, in-depth evaluations can also incorporate variation in individual incubation behaviour to further advance our understanding of avian reproductive ecology. We examined these relationships in colonially nesting Black-crowned Night-Herons Nycticorax nycticorax using intensive video-monitoring methods to quantify incubation behaviours. We modelled nest survival as a function of both extrinsic factors and incubation behaviours over a 3-year period (2010–12) on Alcatraz Island, USA. Model-averaged parameter estimates indicated that nest survival increased as a function of greater incubation constancy (% of time spent incubating eggs within a 24-h period), and average daily precipitation throughout the nesting stage. Common Ravens Corvus corax are the only known nest predator of Night-Herons on Alcatraz Island, as on many other coastal Pacific islands. We also investigated the effects of heterospecific nesting of California Gulls Larus californicus and Western Gulls Larus occidentalis in a mixed-species colony with Night-Herons, based on nesting proximity data collected over a 2-year period (2011–12). This second analysis indicated that, in addition to incubation behaviours, nesting heterospecifics are an important factor for explaining variation in Night-Heron nest survival. However, contrary to our original expectation, we found that Night-Herons experienced increased nest survival with increasing distance from gull colony boundaries. These results may apply to other areas with multiple colonial nesting species and similar predator communities and climatic patterns.

  12. Interaction between genetic and environmental risk factors for Alzheimer's disease: A reanalysis of case-control studies

    NARCIS (Netherlands)

    C.M. van Duijn (Cock); D.G. Clayton (David); V. Chandra; L. Fratiglioni (Laura); A.B. Graves; A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; J.A. Mortimer; W.A. Rocca (Walter); S.L. Shalat; H. Soininen (H.); A. Hofman (Albert)

    1994-01-01

    textabstractTo study the interaction among genetic and environmental risk factors, a reanalysis of case-control studies of Alzheimer's disease (AD) was conducted based on the original data of all studies carried out to January 1, 1990. Seven studies were included in the present analysis, comprising

  13. Nested Inequalities Among Divergence Measures

    CERN Document Server

    Taneja, Inder Jeet

    2011-01-01

    In this paper we have considered a single inequality having 11 known divergence measures. This inequality include measures like: Jeffryes-Kullback-Leiber J-divergence, Jensen-Shannon divergence (Burbea-Rao, 1982), arithmetic-geometric mean divergence (Taneja, 1995), Hellinger discrimination, symmetric chi-square divergence, triangular discrimination, etc. All these measures are well-known in the literature on Information theory and Statistics. This sequence of 11 measures also include measures due to Kumar and Johnson (2005) and Jain and Srivastava (2007). Three measures arising due to some mean divergences also appears in this inequality. Based on non-negative differences arising due to this single inequality of 11 measures, we have put more than 40 divergence measures in nested or sequential form. Idea of reverse inequalities is also introduced.

  14. Nested trampoline resonators for optomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, M. J., E-mail: mweaver@physics.ucsb.edu; Pepper, B.; Luna, F.; Perock, B. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Buters, F. M.; Eerkens, H. J.; Welker, G.; Heeck, K.; Man, S. de [Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, 2333 CA Leiden (Netherlands); Bouwmeester, D. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, 2333 CA Leiden (Netherlands)

    2016-01-18

    Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating trampoline resonators made from low pressure chemical vapor deposition Si{sub 3}N{sub 4} with a distributed Bragg reflector mirror. We design a nested double resonator structure with 80 dB of mechanical isolation from the mounting surface at the inner resonator frequency, and we demonstrate up to 45 dB of isolation at lower frequencies in agreement with the design. We reliably fabricate devices with mechanical quality factors of around 400 000 at room temperature. In addition, these devices were used to form optical cavities with finesse up to 181 000 ± 1000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators.

  15. Nested Trampoline Resonators for Optomechanics

    CERN Document Server

    Weaver, Matthew J; Luna, Fernando; Buters, Frank M; Eerkens, Hedwig J; Welker, Gesa; Perock, Blaise; Heeck, Kier; de Man, Sven; Bouwmeester, Dirk

    2015-01-01

    Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating novel trampoline resonators made from low pressure chemical vapor deposition (LPCVD) Si$_3$N$_4$ with a distributed bragg reflector (DBR) mirror. We construct a nested double resonator structure that generates approximately 80 dB of mechanical isolation from the mounting surface, eliminating the strong mounting dependence of the quality factor observed with single resonators. With the consistency provided by this isolation scheme we reliably fabricate devices with mechanical quality factors of around 400,000 at room temperature. In addition these devices were used to form optical cavities with finesse up to 181,000 $\\pm$ 1,000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators.

  16. Nested trampoline resonators for optomechanics

    International Nuclear Information System (INIS)

    Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating trampoline resonators made from low pressure chemical vapor deposition Si3N4 with a distributed Bragg reflector mirror. We design a nested double resonator structure with 80 dB of mechanical isolation from the mounting surface at the inner resonator frequency, and we demonstrate up to 45 dB of isolation at lower frequencies in agreement with the design. We reliably fabricate devices with mechanical quality factors of around 400 000 at room temperature. In addition, these devices were used to form optical cavities with finesse up to 181 000 ± 1000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators

  17. Does heavy physical exertion trigger myocardial infarction? A case-crossover analysis nested in a population-based case-referent study.

    Science.gov (United States)

    Hallqvist, J; Möller, J; Ahlbom, A; Diderichsen, F; Reuterwall, C; de Faire, U

    2000-03-01

    To study possible triggering of first events of acute myocardial infarction by heavy physical exertion, the authors conducted a case-crossover analysis (1993-1994) within a population-based case-referent study in Stockholm County, Sweden (the Stockholm Heart Epidemiology Program). Interviews were carried out with 699 myocardial infarction patients after onset of the disease. These cases represented 47 percent of all cases in the study base, and 70 percent of all nonfatal cases. The relative risk from vigorous exertion was 6.1 (95% confidence interval: 4.2, 9.0). The rate difference was 1.5 per million person-hours, and the attributable proportion was 5.7 percent. The risk was modified by physical fitness, with an increased risk being seen among sedentary subjects as in earlier studies, but the data also suggested a U-shaped association. In addition, the trigger effect was modified by socioeconomic status. Premonitory symptoms were common, and this implies risks of reverse causation bias and misclassification of case exposure information that require methodological consideration. Different techniques (the use of the usual-frequency type of control information, a pair-matched analysis, and a standard case-referent analysis) were applied to overcome the threat of misclassification of control exposure information. A case-crossover analysis in a random sample of healthy subjects resulted in a relative risk close to unity, as expected.

  18. 1989 Waterfowl Nesting Study and Nesting Summary 1984-1989 : Big Stone National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The 1989 nesting season marked the sixth consecutive and final year that Big Stone personnel have conducted waterfowl nesting research. In addition, an experimental...

  19. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: New Hampshire: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for nesting birds in New Hampshire. Vector points in this data set represent locations of nesting osprey...

  20. Cancer and polluted work places: a case-control study.

    Science.gov (United States)

    Kjuus, H; Lislerud, A; Lyngdal, P T; Omland, H; Stave, O; Langård, S

    1982-02-01

    The possible association between selected cancers and polluted work places has been studied in a hospital-based, case-control study. By dividing all jobs in the participants working career into "polluted" and "clean", a crude measure for the total industrial exposure a worker experiences throughout his life was established. Among 103 age-matched, case-control pairs the overall estimated relative risk (RR) for exposed subjects (greater than or equal to 10 years in a polluted work place) of developing cancer compared to nonexposed (less than 10 years in a polluted work place) was 1.1. The only subgroup where a significant difference was found between the cases and the controls was the lung cancer subgroup (RR = 4.0, p = 0.02, two-tailed). When the 30 lung cancer cases were compared to an alternative control group consisting of 60 subjects matched for age and smoking habits, an estimated RR of 4.5 was found. A moderate, but not significant association between lung cancer and definite asbestos exposure was also found (RR: 2.3). As most workers are exposed to a variety of industrial agents throughout their working careers, further development of methods for characterizing combined exposures are needed, both for retrospective and prospective purposes. PMID:7068240

  1. Genetic Polymorphisms of Infectious Diseases in Case-Control Studies

    Directory of Open Access Journals (Sweden)

    Antonio G. Pacheco

    2009-01-01

    Full Text Available In the past decade, genetic epidemiological analyses in infectious diseases have increased drastically since the publication of human genome and all the subsequent projects analyzing human diversity at molecular level. The great majority of studies use classical epidemiological designs applied to genetic data, and more than 80% of published studies use population-based case-control designs with widely spread genetic markers in human genome, like short tandem repeats (STR or single nucleotide polymorphisms (SNP, in genes chosen by their physiological association with the disease (candidate genes. Even though genetic data is less prone to several bias issues inherent to case-control studies, some care has to be taken when designing, performing, analyzing and interpreting results from such studies. Here we discuss some basic concepts of genetics and epidemiology as a departure to evaluate and review every step that should be followed to design, conduct, analyze, interpret and present data from those studies, using particularities of infectious diseases, especially leprosy and tuberculosis as models.

  2. Waterbird nest-site selection is influenced by neighboring nests and island topography

    Science.gov (United States)

    Hartman, Christopher; Ackerman, Josh; Takekawa, John Y.; Herzog, Mark

    2016-01-01

    Avian nest-site selection is influenced by factors operating across multiple spatial scales. Identifying preferred physical characteristics (e.g., topography, vegetation structure) can inform managers to improve nesting habitat suitability. However, social factors (e.g., attraction, territoriality, competition) can complicate understanding physical characteristics preferred by nesting birds. We simultaneously evaluated the physical characteristics and social factors influencing selection of island nest sites by colonial-nesting American avocets (Recurvirostra americana) and Forster's terns (Sterna forsteri) at 2 spatial scales in San Francisco Bay, 2011–2012. At the larger island plot (1 m2) scale, we used real-time kinematics to produce detailed topographies of nesting islands and map the distribution of nests. Nesting probability was greatest in island plots between 0.5 m and 1.5 m above the water surface, at distances plots increased up to a peak of 11–12 tern nests, and then decreased thereafter. Yet, avocets were less likely to nest in plots adjacent to plots with nesting avocets, suggesting an influence of intra-specific territoriality. At the smaller microhabitat scale, or the area immediately surrounding the nest, we compared topography, vegetation, and distance to nearest nest between nest sites and paired random sites. Topography had little influence on selection of the nest microhabitat. Instead, nest sites were more likely to have vegetation present, and greater cover, than random sites. Finally, avocet, and to a lesser extent tern, nest sites were closer to other active conspecific or heterospecific nests than random sites, indicating that social attraction played a role in selection of nest microhabitat. Our results demonstrate key differences in nest-site selection between co-occurring avocets and terns, and indicate the effects of physical characteristics and social factors on selection of nesting habitat are dependent on the spatial scale

  3. Florida harvester ant nest architecture, nest relocation and soil carbon dioxide gradients.

    Science.gov (United States)

    Tschinkel, Walter R

    2013-01-01

    Colonies of the Florida harvester ant, Pogonomyrmex badius, excavate species-typical subterranean nests up the 3 m deep with characteristic vertical distribution of chamber area/shape, spacing between levels and vertical arrangement of the ants by age and brood stage. Colonies excavate and occupy a new nest about once a year, and doing so requires that they have information about the depth below ground. Careful excavation and mapping of vacated and new nests revealed that there was no significant difference between the old and new nests in any measure of nest size, shape or arrangement. Colonies essentially built a replicate of the just-vacated nest (although details differed), and they did so in less than a week. The reason for nest relocation is not apparent. Tschinkel noted that the vertical distribution of chamber area, worker age and brood type was strongly correlated to the soil carbon dioxide gradient, and proposed that this gradient serves as a template for nest excavation and vertical distribution. To test this hypothesis, the carbon dioxide gradient of colonies that were just beginning to excavate a new nest was eliminated by boring 6 vent holes around the forming nest, allowing the soil CO2 to diffuse into the atmosphere and eliminating the gradient. Sadly, neither the nest architecture nor the vertical ant distribution of vented nests differed from either unvented control or from their own vacated nest. In a stronger test, workers excavated a new nest under a reversed carbon dioxide gradient (high concentration near the surface, low below). Even under these conditions, the new and old nests did not differ significantly, showing that the soil carbon dioxide gradient does not serve as a template for nest construction or vertical worker distribution. The possible importance of soil CO2 gradients for soil-dwelling animals is discussed.

  4. Adaptive nest clustering and density-dependent nest survival in dabbling ducks

    Science.gov (United States)

    Ringelman, Kevin M.; Eadie, John M.; Ackerman, Joshua T.

    2014-01-01

    Density-dependent population regulation is observed in many taxa, and understanding the mechanisms that generate density dependence is especially important for the conservation of heavily-managed species. In one such system, North American waterfowl, density dependence is often observed at continental scales, and nest predation has long been implicated as a key factor driving this pattern. However, despite extensive research on this topic, it remains unclear if and how nest density influences predation rates. Part of this confusion may have arisen because previous studies have studied density-dependent predation at relatively large spatial and temporal scales. Because the spatial distribution of nests changes throughout the season, which potentially influences predator behavior, nest survival may vary through time at relatively small spatial scales. As such, density-dependent nest predation might be more detectable at a spatially- and temporally-refined scale and this may provide new insights into nest site selection and predator foraging behavior. Here, we used three years of data on nest survival of two species of waterfowl, mallards and gadwall, to more fully explore the relationship between local nest clustering and nest survival. Throughout the season, we found that the distribution of nests was consistently clustered at small spatial scales (˜50–400 m), especially for mallard nests, and that this pattern was robust to yearly variation in nest density and the intensity of predation. We demonstrated further that local nest clustering had positive fitness consequences – nests with closer nearest neighbors were more likely to be successful, a result that is counter to the general assumption that nest predation rates increase with nest density.

  5. Livestock grazing and trampling of birds' nests: an experiment using artificial nests

    OpenAIRE

    Mandema, Freek S.; Tinbergen, Joost M.; Ens, Bruno J.; Bakker, Jan P.

    2013-01-01

    The purpose of this study is to experimentally determine the differences between four grazing treatments on the trampling of nests. Additionally, we examine to what extent the trampling probability of nests is higher close to a source of fresh water. We compare the trampling of artificial nests in five different grazing treatments in an experimental design. We use buried clay pigeon targets as artificial mimics of bird nests to obtain reliable estimates of trampling risk and compare these wit...

  6. Risk factors for basal cell carcinoma in the UK: case-control study in 806 patients.

    OpenAIRE

    Lear, J T; Tan, B B; Smith, A.G.; Bowers, W.; Jones, P W; Heagerty, A.H.; Strange, R.C.; Fryer, A A

    1997-01-01

    Basal cell carcinoma (BCC) is the commonest malignant neoplasm in white people. We present a large UK case-control study in which conditional logistic regression analysis of age-matched and gender-matched data sets was used to compare, first, cases with controls (n = 403) and second, patients having multiple BCC with those having a single BCC (n = 278). Eye/hair colour, occupation, skin type, social class, tumour site at presentation and smoking history were assessed. Social class 1/2, skin t...

  7. Primary postpartum haemorrhage in an Australian tertiary hospital: a case-control study.

    Science.gov (United States)

    Henry, Amanda; Birch, Mary-Rose; Sullivan, Elizabeth A; Katz, Sue; Wang, Yueping Alex

    2005-06-01

    The present study aimed to determine the incidence of primary postpartum haemorrhage (PPH) after vaginal birth at an Australian tertiary hospital, and to investigate risk factors for primary PPH at this hospital. A case-control study of women delivering vaginally at a tertiary hospital from February to June 2003 was performed. Demographic, antenatal, intrapartum, treatment and outcome data were abstracted from patient records. The study population comprised 125 cases and 125 controls, with a primary PPH rate of 12.1 per 100 vaginal births. Risk factors on multivariate analysis were past history of PPH, second stage labour > 60 min, forceps delivery, and incomplete placenta/ragged membranes. PMID:15904450

  8. Network-based model of the growth of termite nests

    Science.gov (United States)

    Eom, Young-Ho; Perna, Andrea; Fortunato, Santo; Darrouzet, Eric; Theraulaz, Guy; Jost, Christian

    2015-12-01

    We present a model for the growth of the transportation network inside nests of the social insect subfamily Termitinae (Isoptera, termitidae). These nests consist of large chambers (nodes) connected by tunnels (edges). The model based on the empirical analysis of the real nest networks combined with pruning (edge removal, either random or weighted by betweenness centrality) and a memory effect (preferential growth from the latest added chambers) successfully predicts emergent nest properties (degree distribution, size of the largest connected component, average path lengths, backbone link ratios, and local graph redundancy). The two pruning alternatives can be associated with different genuses in the subfamily. A sensitivity analysis on the pruning and memory parameters indicates that Termitinae networks favor fast internal transportation over efficient defense strategies against ant predators. Our results provide an example of how complex network organization and efficient network properties can be generated from simple building rules based on local interactions and contribute to our understanding of the mechanisms that come into play for the formation of termite networks and of biological transportation networks in general.

  9. Development with age of nest box use and gregarious nesting in laying hens

    DEFF Research Database (Denmark)

    Riber, Anja Brinch

    2010-01-01

    in position (left + corner, middle, and right). Nesting behaviour was video recorded for 5 days in each of five distinct periods: age 20, 26, 32, 38, and 44 weeks. The total number of visits and the number of gregarious visits were higher in the left nest box than in the other two nest boxes at all ages...

  10. Livestock grazing and trampling of birds' nests : an experiment using artificial nests

    NARCIS (Netherlands)

    Mandema, Freek S.; Tinbergen, Joost M.; Ens, Bruno J.; Bakker, Jan P.

    2013-01-01

    The purpose of this study is to experimentally determine the differences between four grazing treatments on the trampling of nests. Additionally, we examine to what extent the trampling probability of nests is higher close to a source of fresh water. We compare the trampling of artificial nests in f

  11. Nesting Ecology of Hawksbill Sea Turtles (Eretmochelys imbricata) on Utila, Honduras

    Science.gov (United States)

    Damazo, Lindsey Renee Eggers

    The hawksbill sea turtle (Eretmochelys imbricata) has a circumtropical distribution and plays an important role in maintaining the health of coral reefs. Unfortunately, hawksbill populations have been decimated, and estimated numbers in the Caribbean are less than 10% of populations a century ago. The hawksbill is considered Critically Endangered, and researchers are coordinating worldwide efforts to protect this species. One country where we lack knowledge regarding hawksbills is Honduras. This study aimed to increase our understanding of hawksbill nesting ecology in Caribbean Honduras. Characteristics of hawksbill nesting activity and a nesting beach on the island of Utila were elucidated using satellite telemetry, beach profiling, vegetation surveys, beach monitoring, and nest temperature profiles. We affixed satellite transmitters to two nesting hawksbills, and found the turtles migrated to different countries. One turtle traveled 403 km to a bay in Mexico, and the other traveled 181 km to a Marine Protected Area off Belize. This study presents the first description of hawksbill migration routes from Honduras, facilitating protection efforts for turtles that traverse international waters. To investigate nesting beach and turtle characteristics, we conducted beach monitoring during the 2012 nesting season. Nesting turtle carapace sizes were similar to worldwide values, but hatchlings were heavier. To measure nest temperatures, we placed thermocouple data loggers in four nests and four pseudo-nests. Data suggested metabolic heating may be maintaining nest temperatures above the pivotal temperature. However, large temperature fluctuations corresponding to rainfall from Hurricane Ernesto (as determined using a time series cross-correlation analysis) make it difficult to predict sex ratios, and underscore the impact stochastic events can have on nest temperatures. We created topographic and substrate profiles of the beach, and found it was 475 m long, yet hawksbills

  12. Conservation significance of alternative nests of golden eagles

    Directory of Open Access Journals (Sweden)

    Brian A. Millsap

    2015-01-01

    Full Text Available Golden eagles (Aquila chrysaetos are long-lived raptors that maintain nesting territories that may be occupied for a century or longer. Within occupied nesting territories there is one nest in which eagles lay their eggs in a given year (i.e., the used nest, but there are usually other nests (i.e., alternative nests. Conservation plans often protect used nests, but not alternative nests or nesting territories that appear vacant. Our objective is to review literature on golden eagle use of alternative nests and occupancy of nesting territories to determine if alternative nests are biologically significant and warrant greater conservation consideration. Our review shows that: (1 alternative nests or their associated habitat are most often in core areas of golden eagle nesting territories; (2 alternative nests likely will become used in the future; (3 probability of an alternative nest becoming used is greatest where prey availability is high and alternative nest sites are limited; (4 likelihood of annual occupancy or reoccupancy of golden eagle nesting territories is high; and (5 prey availability is the most important determinant of nesting territory occupancy and breeding activity. We recommend alternative nests be treated with the same deference as used nests in land use planning.

  13. Nesting Activity and Behavior of Osmia cornifrons (Hymenoptera: Megachilidae Elucidated Using Videography

    Directory of Open Access Journals (Sweden)

    Matthew I. McKinney

    2012-01-01

    Full Text Available Osmia cornifrons Radoszkowski (Hymenoptera: Megachilidae is utilized as an alternate pollinator to Apis mellifera L. (Hymenoptera: Apidae in early-season fruit crops. This study was conducted to investigate nesting activities and associated behaviors of O. cornifrons. Osmia cornifrons nesting activity was recorded by using a digital video recorder with infrared cameras. Nesting behavior of ten female O. cornifrons was observed, and the number of nesting trips per hour was recorded. Trends in daily activity were determined with regression analysis, and chi square analysis was used to determine if O. cornifrons spent a greater amount of time performing certain activities. The percentage of time required to gather nesting resources and complete nest construction activities was recorded from the video footage. Results of this study showed that pollen gathering was the most time-consuming gathering activity, requiring 221.6±28.69 min per cell and cell provisioning was the most time-consuming intranest activity, requiring 28.9 min ± 3.97 min. We also found that O. cornifrons activity was correlated with time of day, temperature, and precipitation. Various nesting behaviors, including cell provisioning and partitioning, oviposition, grooming, resting and sleeping, nest-searching, and repairing behaviors, are described in this paper.

  14. Rheumatoid Arthritis - Neuropsychology, Depression and Anxiety. A case - control study -120 Portuguese Female subjects.

    Directory of Open Access Journals (Sweden)

    Luis Maia

    2012-07-01

    Full Text Available Objectives: Impact of Rheumatoid Arthritis in cognitive functions has not been well acknowledged in Portugal. With this original article we intended to elucidate this problem in this specific country. Methods: We measured the results of 60 Rheumatoid Arthritis female patients (study group, comparing every patient in a case control paired plan (years in school and age, with control subjects (n = 60, in a total of 120 subjects. All participants were evaluated with Paced Auditory Selective Attention Test, Word List Generation Test, Luria Nebraska Neuropsychological Battery, a Portuguese depressive screening test (IACLIDE, STAI (anxiety trace and trait test and the Mini Mental state examination.Results: The outcomes demonstrate, for the first conclusive time in Portuguese patients, the occurrence of main deficits in terms of cognitive functioning (measured by a variety ofneuropsychological tests, and depressive and anxietysymptomatology. Conclusion: This article asset the need to pay attention in psychoeducational, psychotherapeutic and cognitive stimulation, and reinforcement of neuropsychological intervention in these types of patients.Objectivos: O impacto da artrite reumatóide nas funçõescognitivas não tem sido bem reconhecido em Portugal. Com este artigo original pretendemos elucidar este problema neste país específico.Métodos: Avaliámos os resultados de 60 pacientes femininos com artrite reumatóide (grupo de estudo, comparando cada paciente num estudo de caso-controle, emparelhando ossujeitos com Artrite Reumatóide (60 sujeitos com 60 pacientes Artrite Reumatóide, nas variáveis anos de escolaridade eidade (a variável género era uma constante = feminino.Todos os participantes foram avaliados com o Teste de Atenção Auditiva Selectiva (PASAT, teste de geração de lista de palavras, Bateria Neuropsicológica de Luria Nebraska, um teste português de despistagem de sintomatologia depressiva (IACLIDE, um teste de rastreamento de tra

  15. Conservation significance of alternative nests of golden eagles

    OpenAIRE

    Brian A. Millsap; Teryl G. Grubb; Robert K. Murphy; Ted Swem; James W. Watson

    2015-01-01

    Golden eagles (Aquila chrysaetos) are long-lived raptors that maintain nesting territories that may be occupied for a century or longer. Within occupied nesting territories there is one nest in which eagles lay their eggs in a given year (i.e., the used nest), but there are usually other nests (i.e., alternative nests). Conservation plans often protect used nests, but not alternative nests or nesting territories that appear vacant. Our objective is to review literature on golden eagle use of ...

  16. Case-control study of dementia of the Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    French, L.R.; Schuman, L.M.; Mortimer, J.A.; Hutton, J.T.; Boatman, R.A.; Christians, B.

    1985-03-01

    A case-control study to assess factors of possible etiologic significance to dementia of the Alzheimer type was conducted with 78 male cases diagnosed in 1979-1982 at the Veterans Administration Medical Center in Minneapolis, Minnesota and age-race-sex-matched hospital and neighborhood controls (14 of 16 autopsied cases were histopathologically confirmed). Information was obtained on variables relevant to vital, genetic, and immunologic hypotheses, and on possible occupational and environmental exposures, drug use, psychologic stress, smoking, and alcohol consumption. The only major difference between patients with dementia of the Alzheimer type and controls was a significantly greater occurrence of antecedent head trauma in the patients (odds ratio = 4.50). This finding is consistent with the literature on posttraumatic dementia but its importance is presently unclear.

  17. Olive ridley sea turtle hatching success as a function of the microbial abundance in nest sand at Ostional, Costa Rica.

    Directory of Open Access Journals (Sweden)

    Vanessa S Bézy

    Full Text Available Several studies have suggested that significant embryo mortality is caused by microbes, while high microbial loads are generated by the decomposition of eggs broken by later nesting turtles. This occurs commonly when nesting density is high, especially during mass nesting events (arribadas. However, no previous research has directly quantified microbial abundance and the associated effects on sea turtle hatching success at a nesting beach. The aim of this study was to test the hypothesis that the microbial abundance in olive ridley sea turtle nest sand affects the hatching success at Ostional, Costa Rica. We applied experimental treatments to alter the microbial abundance within the sand into which nests were relocated. We monitored temperature, oxygen, and organic matter content throughout the incubation period and quantified the microbial abundance within the nest sand using a quantitative polymerase chain reaction (qPCR molecular analysis. The most successful treatment in increasing hatching success was the removal and replacement of nest sand. We found a negative correlation between hatching success and fungal abundance (fungal 18S rRNA gene copies g(-1 nest sand. Of secondary importance in determining hatching success was the abundance of bacteria (bacterial 16S rRNA gene copies g(-1 g(-1 nest sand. Our data are consistent with the hypothesis that high microbial activity is responsible for the lower hatching success observed at Ostional beach. Furthermore, the underlying mechanism appears to be the deprivation of oxygen and exposure to higher temperatures resulting from microbial decomposition in the nest.

  18. Case-control association studies with matching and genomic controlling.

    Science.gov (United States)

    Lee, Wen-Chung

    2004-07-01

    Family-based association studies have gained in popularity for mapping disease-susceptibility gene(s) of complex diseases. However, recruiting family controls is often more difficult than recruiting unrelated controls. The author proposes a case-control study, where the possible biases due to population stratification are controlled by matching in the design stage and by genomic controlling in the data-analytic stage. The matching is based on a set of "stratum-delineating variables," such as, race, ethnicity, nationality, ancestry, and birthplace; and the genomic controlling is based on typing a number of null markers across the genome and applying the principle of multiplicative scaling of chi-square distribution. It pays to match carefully to have a higher proportion of correctly matched sets, as computer simulation showed that this would increase the power of the study. If matching is crude, one loses power but still has the correct type I error rate after genomic controlling. Power studies showed that the numbers of affected subjects required for the pair-matched study are comparable to those required by the case-parents design, if the study was conducted in a homogeneous population. As the (control-to-case) matching ratio increases, the number of affected subjects required decreases. With matching ratio tending toward infinity, the number required shrinks roughly by half. The case-control study with matching and genomic controlling frees us from family bondage, and the genetic problem as complicated as mapping genes can now be studied using simple epidemiologic methods. PMID:15185398

  19. Lesser prairie-chicken nest site selection, microclimate, and nest survival in association with vegetation response to a grassland restoration program

    Science.gov (United States)

    Boal, Clint W.; Grisham, Blake A.; Haukos, David A.; Zavaleta, Jennifer C.; Dixon, Charles

    2014-01-01

    Climate models predict that the region of the Great Plains Landscape Conservation Cooperative (GPLCC) will experience increased maximum and minimum temperatures, reduced frequency but greater intensity of precipitation events, and earlier springs. These climate changes along with different landscape management techniques may influence the persistence of the lesser prairie-chicken (Tympanuchus pallidicinctus), a candidate for protection under the Endangered Species Act and a priority species under the GPLCC, in positive or negative ways. The objectives of this study were to conduct (1) a literature review of lesser prairie-chicken nesting phenology and ecology, (2) an analysis of thermal aspects of lesser prairie-chicken nest microclimate data, and (3) an analysis of nest site selection, nest survival, and vegetation response to 10 years of tebuthiuron and/or grazing treatments. We found few reports in the literature containing useful data on the nesting phenology of lesser prairie-chickens; therefore, managers must rely on short-term observations and measurements of parameters that provide some predictive insight into climate impacts on nesting ecology. Our field studies showed that prairie-chickens on nests were able to maintain relatively consistent average nest temperature of 31 °C and nest humidities of 56.8 percent whereas average external temperatures (20.3–35.0 °C) and humidities (35.2–74.9 percent) varied widely throughout the 24 hour (hr) cycle. Grazing and herbicide treatments within our experimental areas were designed to be less intensive than in common practice. We determined nest locations by radio-tagging hen lesser prairie-chickens captured at leks, which are display grounds at which male lesser prairie-chickens aggregate and attempt to attract a female for mating. Because nest locations selected by hen lesser prairie-chicken are strongly associated with the lek at which they were captured, we assessed nesting habitat use on the basis of hens

  20. Simple Algorithms to Calculate Asymptotic Null Distributions of Robust Tests in Case-Control Genetic Association Studies in R

    Directory of Open Access Journals (Sweden)

    Wing Kam Fung

    2010-02-01

    Full Text Available The case-control study is an important design for testing association between genetic markers and a disease. The Cochran-Armitage trend test (CATT is one of the most commonly used statistics for the analysis of case-control genetic association studies. The asymptotically optimal CATT can be used when the underlying genetic model (mode of inheritance is known. However, for most complex diseases, the underlying genetic models are unknown. Thus, tests robust to genetic model misspecification are preferable to the model-dependant CATT. Two robust tests, MAX3 and the genetic model selection (GMS, were recently proposed. Their asymptotic null distributions are often obtained by Monte-Carlo simulations, because they either have not been fully studied or involve multiple integrations. In this article, we study how components of each robust statistic are correlated, and find a linear dependence among the components. Using this new finding, we propose simple algorithms to calculate asymptotic null distributions for MAX3 and GMS, which greatly reduce the computing intensity. Furthermore, we have developed the R package Rassoc implementing the proposed algorithms to calculate the empirical and asymptotic p values for MAX3 and GMS as well as other commonly used tests in case-control association studies. For illustration, Rassoc is applied to the analysis of case-control data of 17 most significant SNPs reported in four genome-wide association studies.

  1. Nest structure and communal nesting in Euglossa (Glossura annectans Dressler (Hymenoptera, Apidae, Euglossini

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Garófalo

    1998-01-01

    Full Text Available Three nests of Euglossa (Glossura annectans Dressier, 1982 were obtained from trap nests at Serra do Japi, Jundiai, São Paulo State, Brazil. The bees nested in bamboo cane (one nest and in wooden-boxes (two nests. Solitary (two cases and pleometrotic (one case foundations were observed. Two nests were re-used once by two females working in each of them. Re-using females that shared the nests were of the same generation and each built, provisioned and oviposited in her own cells, characterizing a communal association. The brood development period was related to climatic conditions. Natural enemies included Anthrax oedipus oedipus Fabricius, 1805 (Bombyliidae, Coelioxys sp. (Megachilidae and Melittobia sp. (Eulophidae.

  2. Urine Nested Polymerase Chain Reaction in Neonatal Septicemia.

    Science.gov (United States)

    Das, B K; Suri, Shipra; Nath, Gopal; Prasad, Rajniti

    2015-08-01

    This cross-sectional study was done to evaluate diagnostic efficacy of urine nested polymerase chain reaction (PCR) using broad-range 16SrDNA PCR-based amplification, followed by restriction analysis and sequencing in neonatal septicemia. The study included 50 babies; 48% had vaginal delivery, 46% were preterm, 20% had a history of prolonged rupture of membranes and 56% were low birth weight (≤2500 g). Clinical presentations were lethargy (96%), respiratory distress (80%) and bleeding diathesis (16%). Absolute neutrophil count <1800/mm(3) was observed in 60%, and positive C-reactive protein in 46%. Thirty neonates had positive blood culture, and Klebsiella pneumoniae (22%) was the predominant organism. Nested urine PCR was positive in 38 (76%) and detected bacterial DNA in 8 neonates with negative blood cultures. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of nested PCR were 100, 60, 78.9, 100 and 84%, respectively, compared with blood culture. Nested PCR can detect most bacteria in single assay and identify unusual and unexpected causal agents.

  3. Body Mass Index, Smoking and Hypertensive Disorders during Pregnancy: A Population Based Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Thuridur A Gudnadóttir

    Full Text Available While obesity is an indicated risk factor for hypertensive disorders of pregnancy, smoking during pregnancy has been shown to be inversely associated with the development of preeclampsia and gestational hypertension. The purpose of this study was to investigate the combined effects of high body mass index and smoking on hypertensive disorders during pregnancy. This was a case-control study based on national registers, nested within all pregnancies in Iceland 1989-2004, resulting in birth at the Landspitali University Hospital. Cases (n = 500 were matched 1:2 with women without a hypertensive diagnosis who gave birth in the same year. Body mass index (kg/m2 was based on height and weight at 10-15 weeks of pregnancy. We used logistic regression models to calculate odds ratios and corresponding 95% confidence intervals as measures of association, adjusting for potential confounders and tested for additive and multiplicative interactions of body mass index and smoking. Women's body mass index during early pregnancy was positively associated with each hypertensive outcome. Compared with normal weight women, the multivariable adjusted odds ratio for any hypertensive disorder was 1.8 (95% confidence interval, 1.3-2.3 for overweight women and 3.1 (95% confidence interval, 2.2-4.3 for obese women. The odds ratio for any hypertensive disorder with obesity was 3.9 (95% confidence interval 1.8-8.6 among smokers and 3.0 (95% confidence interval 2.1-4.3 among non-smokers. The effect estimates for hypertensive disorders with high body mass index appeared more pronounced among smokers than non-smokers, although the observed difference was not statistically significant. Our findings may help elucidate the complicated interplay of these lifestyle-related factors with the hypertensive disorders during pregnancy.

  4. Antidepressant-warfarin interaction and associated gastrointestinal bleeding risk in a case-control study.

    Directory of Open Access Journals (Sweden)

    Hedi Schelleman

    Full Text Available BACKGROUND: Bleeding is the most common and worrisome adverse effect of warfarin therapy. One of the factors that might increase bleeding risk is initiation of interacting drugs that potentiate warfarin. We sought to evaluate whether initiation of an antidepressant increases the risk of hospitalization for gastrointestinal bleeding in warfarin users. METHODOLOGY/PRINCIPAL FINDINGS: Medicaid claims data (1999-2005 were used to perform an observational case-control study nested within person-time exposed to warfarin in those ≥18 years. In total, 430,455 warfarin users contributed 407,370 person-years of warfarin use. The incidence rate of hospitalization for GI bleeding among warfarin users was 4.48 per 100 person-years (95% CI, 4.42-4.55. Each gastrointestinal bleeding cases was matched to 50 controls based on index date and state. Warfarin users had an increased odds ratio of gastrointestinal bleeding upon initiation of citalopram (OR = 1.73 [95% CI, 1.25-2.38], fluoxetine (OR = 1.63 [95% CI, 1.11-2.38], paroxetine (OR = 1.64 [95% CI, 1.27-2.12], amitriptyline (OR = 1.47 [95% CI, 1.02-2.11]. Also mirtazapine, which is not believed to interact with warfarin, increased the risk of GI bleeding (OR = 1.75 [95% CI, 1.30-2.35]. CONCLUSIONS/SIGNIFICANCE: Warfarin users who initiated citalopram, fluoxetine, paroxetine, amitriptyline, or mirtazapine had an increased risk of hospitalization for gastrointestinal bleeding. However, the elevated risk with mirtazapine suggests that a drug-drug interaction may not have been responsible for all of the observed increased risk.

  5. A case-control study: occupational cooking and the risk of uveal melanoma

    Directory of Open Access Journals (Sweden)

    Marr Anja

    2010-10-01

    Full Text Available Abstract Background A European-wide population based case-control study (European rare cancer study undertaken in nine European countries examined risk factors for uveal melanoma. They found a positive association between cooks and the risk of uveal melanoma. In our study we examine whether cooks or people who worked in cook related jobs have an increased uveal melanoma risk. Methods We conducted a case-control study during 2002 and 2005. Overall, 1653 eligible subjects (age range: 20-74 years, living in Germany participated. Interviews were conducted with 459 incident uveal melanoma cases, 827 population controls, 180 ophthalmologist controls and 187 sibling controls. Data on occupational exposure were obtained from a self-administered postal questionnaire and a computer-assisted telephone interview. We used conditional logistic regression to estimate odds ratios adjusting for the matching factors. Results Overall, we did not observe an increased risk of uveal melanoma among people who worked as cooks or who worked in cook related jobs. When we restricted the source population of our study to the population of the Federal State of Northrhine-Westphalia, we observed an increased risk among subjects who were categorized as cooks in the cases-control analysis. Conclusion Our results are in conflict with former results of the European rare cancer study. Considering the rarity of the disease laboratory in vitro studies of human uveal melanoma cell lines should be done to analyze potential exposure risk factors like radiation from microwaves, strong light from incandescent ovens, or infrared radiation.

  6. Association between smoking habits and acne vulgaris. A case-control study

    Directory of Open Access Journals (Sweden)

    Alice Mannocci

    2012-09-01

    Full Text Available

    Background: acne vulgaris, is one of the most common skin disorder. Previous studies about the role of smoke in the pathogenesis of acne reported contradictory results. The aim of this study was to conduct a case-control study investigating the relationship between tobacco smoking and acne.

    Methods: a case-control study was performed during the period September 2009 - February 2010. A questionnaire was administrated to each participant, to assess the association acne - smoke. Cases were outpatients of the Dermatologic Ambulatory of the “Fiorini” Hospital, Sapienza University of Rome (Italy. Controls were age and gender-matched to the cases. The ratio cases-controls was 1:2. A univariate and a multiple logistic regression analysis were conducted; Odds Ratio (OR and the relative 95% confidence interval (95%CI were assessed. The statistical significance was set at p < 0.05.

    Results: crude OR for the association acne - smoke was 7.26 (IC=2.27-23.18; adjusted OR for sex and age was 5.47 (IC=1.67-17.97. Of 93 cases, 6 had a severe grade of acne (6.5%, 19 had an intermediate grade of acne (20.4%, and 68 had a mild grade of acne (73.1%. No one of the smokers had a severe grade of acne, one had an intermediate grade of acne and 11 had mild acne; these differences are not statistically significant.

    Conclusions: the association between acne and smoke shows an increased risk (OR=7.26 with a statistically significant CI. Moreover, people ≥ 18 years of age have twice the risk compared to persons < 18 years of age (OR=2.31.

  7. Diabetes mellitus and arsenic exposure: a second look at case-control data from a Swedish copper smelter.

    OpenAIRE

    Rahman, M.; Axelson, O

    1995-01-01

    OBJECTIVES--To find out whether a newly found association between diabetes mellitus and arsenic in drinking water in Taiwan could be reproduced in copper smelters with arsenic exposure. METHODS--Extended analysis of a previous case-control study from 1978 was based on death records and objective exposure information from the company. The final analysis included only those employed at the smelter. Cases were 12 people with diabetes mellitus on the death certificate and those for whom there was...

  8. Marbled Murrelets Select Distinctive Nest Trees within Old-Growth Forest Patches

    Directory of Open Access Journals (Sweden)

    Michael P. Silvergieter

    2011-12-01

    Full Text Available The coastal old-growth forests of North America's Pacific Coast are renowned both for their commercial and ecological value. This study adds to growing evidence that selective harvesting of the largest trees may have a disproportionate ecological impact. Marbled Murrelets (Brachyramphus marmoratus, a threatened species, nest almost exclusively in these old-growth forests. Detailed knowledge of nesting habitat selection provides guidance for habitat management and conservation. Habitat selection for this species has been studied at a variety of scales using ground and remote methods. However, because Marbled Murrelet nesting activity is limited to a single mossy platform on a single tree, we investigated nest tree selection within old-growth forest patches, using a set of 59 forest patches containing active nests. Nest trees were usually distinctive compared with neighboring trees in the surrounding 25 m radius patch. They averaged 15 to 20% taller than neighboring trees depending on region, had significantly larger stem diameters, more potential nesting platforms, and more moss. They had the most extreme values of height and width about three times as often as expected by chance. An analysis of moss platform use as a function of number of platforms per platform tree suggests that murrelets select individual platforms, rather than platform trees per se. Nonetheless, highly selective logging practices that remove high-value trees from stands may also remove trees most likely to be selected by nesting murrelets.

  9. 1988 Duck nesting study: Stillwater Wildlife Management Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — During the summer, 1988, we conducted a duck nesting study to determine nest success for ducks at Stillwater Wildlife Management Area (WMA). We calculated nest...

  10. Emperor penguins nesting on Inaccessible Island

    Science.gov (United States)

    Jonkel, G.M.; Llano, G.A.

    1975-01-01

    Emperor penguins were observed nesting on Inaccessible I. during the 1973 winter. This is the southernmost nesting of emperor penguins thus far recorded; it also could be the first record of emperors attempting to start a new rookery. This site, however, may have been used by emperors in the past. The closest reported nesting of these penguins to Inaccessible I. is on the Ross Ice Shelf east of Cape Crozier. With the exception of the Inaccessible I. record, there is little evidence that emperor penguins breed in McMurdo Sound proper.

  11. The nest as fortress: Defensive behavior of Polybia emaciata, a mud-nesting eusocial wasp

    Directory of Open Access Journals (Sweden)

    Sean O'Donnell

    2002-02-01

    Full Text Available The swarm-founding wasp Polybia emaciata is unusual among eusocial Vespidae because it uses mud, rather than wood pulp, as its primary nest construction material. Polybia emaciata nests are more durable than similarly sized paper nests. We tested the hypothesis that the defensive behavior of this wasp may have been modified to take advantage of their strong nests in defense against vertebrate attacks. We simulated vertebrate disturbances by tapping on, and breathing in, P. emaciata. nests and similarly sized P. occidentalis paper nests in the same location at the same time. Polybia emaciata. responses to disturbance were qualitatively different from those of P. occidentalis. The latter exit the nest and attack, while P. emaciata. workers typically fled or entered the nest, attacking only after repeated and extended disturbances. We conclude that durable nest material may permit predator avoidance behavior in P. emaciata.. We compare the defensive responses of P. emaciata. workers with those of other swarm-founding Vespidae, and discuss several selective forces that could cause the evolution of species variation in nest defense behavior.

  12. Differentiating nest sites characteristics of four sympatric cavity-nesting birds

    Directory of Open Access Journals (Sweden)

    Chunfa Zhou

    2012-11-01

    Full Text Available Diverse group of cavity-nesting birds inhabit secondary forests of northeastern China, accounting for about one-third of breeding avian species. We examined differences in nest-site characteristics amongfour cavity-nesting birds, including two cavity excavators (i.e., great spotted woodpecker [Dendrocopos major] and grey-headed woodpecker [Picus canus] and two secondary cavity-nesters (i.e., yellow-rumped flycatcher [Ficedula zanthopygia] and Eurasian nuthatch [Sitta europaea] in Dagang Forestry Farm, Jilin Province, China. We detected total 160 active hole nests in the breeding season of 2008, including 58 nests of cavity excavators and 102 of secondary cavity-nesters. Secondary cavity-nesters tend to prefer Salix pierotii for nestingtrees, but the excavators not. Picus canus used south-facing cavities, which may have been due to thermal advantages. Nest tree and nest-site quadrat characteristics were different between the two excavator species. Specifically, there were significant differences in the entrance diameter and cavity inner diameter between the nest sites of Dendrocopos major and Picus canus, and the entrance length and canopy height of nest tree between Ficedula zanthopygia and Sitta europaea. The characteristics at the scale of nest tree were important for distinguishing nest sites for cavity excavators as well as secondary cavity-nesters. Discriminant analyses illustrated that Ficedula zanthopygia and Sitta europaea used cavities excavated by Dendrocopos major and Picus canus, respectively. Differences in size of nesting holes excavated by different woodpeckers could affect the usage of nest sites by secondary cavity-nesters, which may have an impact on avian community structure in secondary forests.

  13. Repeatability of nest morphology in African weaver birds

    OpenAIRE

    Walsh, Patrick T.; Hansell, Mike; Borello, Wendy D.; Healy, Susan D.

    2009-01-01

    It is generally assumed that birds build nests according to a genetic 'template', little influenced by learning or memory. One way to confirm the role of genetics in nest building is to assess the repeatability of nest morphology with repeated nest attempts. Solitary weaver birds, which build multiple nests in a single breeding season, are a useful group with which to do this. Here we show that repeatability of nest morphology was low, but significant, in male Southern Masked weaver birds and...

  14. Nest Construction by a Ground-nesting Bird Represents a Potential Trade-off Between Egg Crypticity and Thermoregulation

    Science.gov (United States)

    Predation selects against conspicuous colors in bird eggs and nests, while thermoregulatory constraints select for nest building behavior that regulates incubation temperatures. We present results that reveal a trade-off between nest crypticity and thermoregulation of eggs base...

  15. Cackling Canada goose nesting populations, Yukon Delta

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Number of potential territories, number of cackling Canada Goose nests, and percent occupancy of available territories from CCG plots on the Yukon Delta National...

  16. Alcid Nesting Habitat on the Maine Coast

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Maine supports an extensive seabird population because of the abundance of relatively inaccessible rocky coastal islands which are ideal nesting grounds for many...

  17. Annual survival of Florida nesting loggerheads

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 30 PAT tags were deployed on nesting loggerhead turtles at Juno Beach, FL in June 2012. There have been three premature pop-offs, one of which appeared to be a...

  18. Starling nest box monitoring [Rocky Mountain Arsenal

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document described the standard operating procedures for observing and recording data collected from starling nest box monitoring at the Rocky Mountain...

  19. Nesting Loggerhead Sea Turtle Activity Report 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper presents results from the sixth annual study of nesting along the Atlantic Oceanfront by the loggerhead sea turtle (Caretta carettd) in Virginia Beach,...

  20. Nesting Loggerhead Sea Turtle Activity Report 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper presents results from the seventh annual study (using Army Corp of Engineers funds;) of nesting along the Atlantic Ocean coastline by the loggerhead sea...

  1. Field guide for use of simulated nests

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Several years experience with use of dummy nests demonstrated that they provide a useful tool in measuring the total activity by eggeating birds and animals over a...

  2. Island's terns nest again after unsuccessful start

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — For five consecutive summers the Trustees of Reservations have directed a program on Nantucket for the protection of the terns which nest in several colonies around...

  3. Nesting Loggerhead Sea Turtle Activity Report 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper presents results from the 9th Annual Study (using Army Corp of Engineers funds) of nesting by the Atlantic loggerhead sea turtle (Caretta caretta) along...

  4. A Bayesian hierarchical approach for combining case-control and prospective studies.

    Science.gov (United States)

    Müller, P; Parmigiani, G; Schildkraut, J; Tardella, L

    1999-09-01

    Motivated by the absolute risk predictions required in medical decision making and patient counseling, we propose an approach for the combined analysis of case-control and prospective studies of disease risk factors. The approach is hierarchical to account for parameter heterogeneity among studies and among sampling units of the same study. It is based on modeling the retrospective distribution of the covariates given the disease outcome, a strategy that greatly simplifies both the combination of prospective and retrospective studies and the computation of Bayesian predictions in the hierarchical case-control context. Retrospective modeling differentiates our approach from most current strategies for inference on risk factors, which are based on the assumption of a specific prospective model. To ensure modeling flexibility, we propose using a mixture model for the retrospective distributions of the covariates. This leads to a general nonlinear regression family for the implied prospective likelihood. After introducing and motivating our proposal, we present simple results that highlight its relationship with existing approaches, develop Markov chain Monte Carlo methods for inference and prediction, and present an illustration using ovarian cancer data. PMID:11315018

  5. Shrinkage Estimators for Robust and Efficient Inference in Haplotype-Based Case-Control Studies

    KAUST Repository

    Chen, Yi-Hau

    2009-03-01

    Case-control association studies often aim to investigate the role of genes and gene-environment interactions in terms of the underlying haplotypes (i.e., the combinations of alleles at multiple genetic loci along chromosomal regions). The goal of this article is to develop robust but efficient approaches to the estimation of disease odds-ratio parameters associated with haplotypes and haplotype-environment interactions. We consider "shrinkage" estimation techniques that can adaptively relax the model assumptions of Hardy-Weinberg-Equilibrium and gene-environment independence required by recently proposed efficient "retrospective" methods. Our proposal involves first development of a novel retrospective approach to the analysis of case-control data, one that is robust to the nature of the gene-environment distribution in the underlying population. Next, it involves shrinkage of the robust retrospective estimator toward a more precise, but model-dependent, retrospective estimator using novel empirical Bayes and penalized regression techniques. Methods for variance estimation are proposed based on asymptotic theories. Simulations and two data examples illustrate both the robustness and efficiency of the proposed methods.

  6. Sialolithiasis is associated with nephrolithiasis: a case-control study.

    Science.gov (United States)

    Wu, Chuan-Chang; Hung, Shih-Han; Lin, Herng-Ching; Lee, Cha-Ze; Lee, Hsin-Chien; Chung, Shiu-Dong

    2016-05-01

    Conclusions This study demonstrates an association between sialolithiasis and nephrolithiasis. The results call for more awareness of this association among physicians and patients with nephrolithiasis. Objective Very few empirical studies have been conducted to explore the potential association between sialolithiasis and nephrolithiasis. As such, the association between sialolithiasis and nephrolithiasis still remains unclear. This study aimed to explore the possible association between sialolithiasis and nephrolithiasis using a population-based dataset. Methods Using data from the Taiwan Longitudinal Health Insurance Database 2005, this case-control study identified 966 patients with sialolithiasis as cases and 2898 sex- and age-matched subjects without sialolithiasis as controls. Conditional logistic regressions were conducted to examine the association of sialolithiasis with previously diagnosed nephrolithiasis. Results Out of 3864 sampled patients, 165 (4.27%) had prior nephrolithiasis. Using Chi-square test, it was found that there was a significant difference in the prevalence of prior nephrolithiasis between the cases and controls (10.25% vs 2.28%, p nephrolithiasis for cases was 4.74 (95% CI = 3.41-6.58, p < 0.001) when compared to controls after adjusting for monthly income, geographic location, urbanization level of residence, diabetes, hypertension, heart failure, chronic renal disease, and tobacco use. PMID:26808906

  7. Ovarian endometriomas and IVF: a retrospective case-control study

    Directory of Open Access Journals (Sweden)

    Guidetti Daniela

    2011-06-01

    Full Text Available Abstract We performed this retrospective case-control study analyzing 428 first-attempt in vitro fertilization (IVF cycles, among which 254 involved women with a previous or present diagnosis of ovarian endometriosis. First, the results of these 254 cycles were compared with 174 cycles involving patients with proven non-endometriotic tubal infertility having similar age and body mass index. Women with ovarian endometriosis had a significantly higher cancellation rate, but similar pregnancy, implantation and delivery rates as patients with tubal infertility. Second, among the women with ovarian endometriosis, the women with a history of laparoscopic surgery for ovarian endometriomas prior to IVF and no visual endometriosis at ovum pick-up (n = 112 were compared with the non-operated women and visual endometriomas at ovum pick-up (n = 142. Patients who underwent ovarian surgery before IVF had significantly shorter period, lower antral follicle count and required higher gonadotropin doses than patients with non-operated endometriomas. The two groups of women with a previous or present ovarian endometriosis did, however, have similar pregnancy, implantation and live birth rates. In conclusion, ovarian endometriosis does not reduce IVF outcome compared with tubal factor. Furthermore, laparoscopic removal of endometriomas does not improve IVF results, but may cause a decrease of ovarian responsiveness to gonadotropins.

  8. Potential risk factors for diabetic neuropathy: a case control study

    Directory of Open Access Journals (Sweden)

    Nooraei Mahdi

    2005-12-01

    Full Text Available Abstract Background Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. Methods In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography. The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI, blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. Results Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, Conclusion In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.

  9. A CASE-CONTROL EPIDEMIOLOGIC STUDY OF ENDOMETRIOSIS

    Institute of Scientific and Technical Information of China (English)

    韩美玲; 潘凌亚; 吴葆桢; 边旭明

    1994-01-01

    A case-control study involving 203 cases of pelvic endometriosis seen from 1987-1989,and 406 randomly selected and age-matched community controls was conducted in order to provide information relevant to effective prophylxaix of the disease.The diagnosis was confirmed by pathology from laparotomy and/or laproscopy.A questionnaire focused on menstrual,marital and reproductive status,professional exposurs and physical activities,and the results were analyzed by a conditional logistic regression model.Women characterized by earlier menarche (≤12 years)and longer period(≥8 days)were found to be saaociated with an elevated incurring risk,and a trend of increasing risk associated with primary dysmenorrhea(RR=2.1 for mild to moderate and RR=5.2 for severe dysmenorrhea),energetic physical activity during menstruation(RR=2.1),and allergic diathesis (RR=1.8)was seen.An inverse relationship was observed between the number of pregnancies and risk of endometrio-sis,and the protective effect was most significant when only the number of full-term pregnancies was counted.The risk factors of endometriosis are discussed,and intensive treatment of primary dysmenorrhea and avoidance of strenuous exercise during menstruation are identified as important as important measures in the prevention of endometriosis.

  10. A case-control study of asthma and ovarian cancer.

    Science.gov (United States)

    Elmasri, Wafic M; Tran, Therese H; Mulla, Zuber D

    2010-01-01

    Epidemiologic studies have found inverse associations between allergy and the development of certain tumors. The authors sought to determine if there was an association between asthma and ovarian cancer. A case-control study was conducted using Florida hospital data (year 2001). Discharge diagnoses were coded using the ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification). Cases were 1,582 women whose principal discharge diagnosis was a malignant neoplasm of the ovary. Two control series were used: 4,744 women whose principal diagnosis was an upper limb bone fracture, and 21,830 women whose principal diagnosis was an acute myocardial infarction. Odds ratios (ORs) adjusted for age, race-ethnicity, Medicaid status, obesity, and smoking were calculated. Cases were 30% less likely than fracture control to be asthmatics (adjusted OR = 0.70, 95% confidence interval [CI]: 0.49-0.99, p = .04). Similarly, cases when compared to acute myocardial infarction controls were significantly less likely to have asthma (adjusted OR = 0.62, 95% CI: 0.45-0.87, p = .005). The results of this statewide exploratory study suggest that individuals with asthma may have a lower risk of developing ovarian cancer than nonasthmatics. PMID:20439229

  11. A case-control study of visual acuity in onychocryptosis.

    LENUS (Irish Health Repository)

    Hogan, Aisling M

    2012-02-01

    BACKGROUND: There are many theories surrounding the etiology of ingrown toenails (IGTN). Few factors have been formally assessed, but it is widely accepted that a poor nail cutting technique has a causative role. AIM: To investigate the hypothesis that decreased visual acuity may lead to inadequate nail cutting and the formation of IGTN. METHODS: A prospective case-control study was performed. Near and distance visual acuity were tested on a population with IGTN (n = 19) and compared with that of an age- and sex-matched control cohort (n = 24) who underwent epidermal cyst excision in the same tertiary referral center. Comparisons of visual acuity were made between groups by Mann-Whitney U-test. Differences were taken to be significant if P < 0.05. Institutional Review Board approval was sought and granted. RESULTS: No significant difference in visual acuity (near or distance) was demonstrated between patients with IGTN and the control group (P = 0.33). CONCLUSION: Visual acuity does not appear to play a significant role in the development of IGTN.

  12. Linear Maps Preserving Idempotence on Nest Algebras

    Institute of Scientific and Technical Information of China (English)

    Jian Lian CUI; Jin Chuan HOU

    2004-01-01

    In this paper, we discuss the rank-1-preserving linear maps on nest algebras of Hilbertspace operators. We obtain several characterizations of such linear maps and apply them to show that a weakly continuous linear bijection on an atomic nest algebra is idempotent preserving if and only if it is a Jordan homomorphism, and in turn, if and only if it is an automorphism or an anti-automorphism.

  13. Malaria diagnosis from pooled blood samples: comparative analysis of real-time PCR, nested PCR and immunoassay as a platform for the molecular and serological diagnosis of malaria on a large-scale

    Directory of Open Access Journals (Sweden)

    Giselle FMC Lima

    2011-09-01

    Full Text Available Malaria diagnoses has traditionally been made using thick blood smears, but more sensitive and faster techniques are required to process large numbers of samples in clinical and epidemiological studies and in blood donor screening. Here, we evaluated molecular and serological tools to build a screening platform for pooled samples aimed at reducing both the time and the cost of these diagnoses. Positive and negative samples were analysed in individual and pooled experiments using real-time polymerase chain reaction (PCR, nested PCR and an immunochromatographic test. For the individual tests, 46/49 samples were positive by real-time PCR, 46/49 were positive by nested PCR and 32/46 were positive by immunochromatographic test. For the assays performed using pooled samples, 13/15 samples were positive by real-time PCR and nested PCR and 11/15 were positive by immunochromatographic test. These molecular methods demonstrated sensitivity and specificity for both the individual and pooled samples. Due to the advantages of the real-time PCR, such as the fast processing and the closed system, this method should be indicated as the first choice for use in large-scale diagnosis and the nested PCR should be used for species differentiation. However, additional field isolates should be tested to confirm the results achieved using cultured parasites and the serological test should only be adopted as a complementary method for malaria diagnosis.

  14. Barriers to colorectal cancer screening: A case-control study

    Institute of Scientific and Technical Information of China (English)

    Shan-Rong Cai; Su-Zhan Zhang; Shu Zheng; Hong-Hong Zhu

    2009-01-01

    AIM:To investigate barriers to colorectal cancer (CRC) screening in a community population. METHODS:We conducted a community-based case-control study in an urban Chinese population by questionnaire. Cases were selected from those completing both a fecal occult blood test (FOBT) case and colonoscopy in a CRC screening program in 2004. Control groups were matched by gender, age group and community. Control 1 included those having a positive FOBT but refusing a colonoscopy. Control 2 included those who refused both an FOBT and colonoscopy. RESULTS:The impact of occupation on willingness to attend a colorectal screening program differed by gender. P for heterogeneity was 0.009 for case vs control group 1, 0.01 for case versus control group 2, and 0.80 for control group 1 vs 2. Poor awareness of CRC and its screening program, characteristics of screening tests, and lack of time affected the screening rate. Financial support, fear of pain and bowel preparation were barriers to a colonoscopy as a screening test. Eighty-two percent of control group 1 and 87.1% of control group 2 were willing attend if the colonoscopy was free, but only 56.3% and 53.1%,respectively, if it was self-paid. Multivariate odds ratios for case vs control group 1 were 0.10 among those unwilling to attend a free colonoscopy and 0.50 among those unwilling to attend a self-paid colonoscopy. CONCLUSION:Raising the public awareness of CRC and its screening, integrating CRC screening into the health care system, and using a painless colonoscopy would increase its screening rate.

  15. Case-control study of fetal microchimerism and breast cancer.

    Directory of Open Access Journals (Sweden)

    Vijayakrishna K Gadi

    Full Text Available BACKGROUND: Prior pregnancy is known to protect against development of breast cancer. Recent studies have demonstrated that pregnancy has the capacity to establish small numbers of immunologically active fetal-derived cells in the mother, a phenomenon known as fetal microchimerism (FMc. We asked whether presence of FMc, routinely acquired during pregnancy, is a protective factor for breast cancer. METHODOLOGY/PRINCIPAL FINDINGS: DNA extracts from peripheral blood specimens were obtained from a population-based case-control study of risk factors for breast cancer in women 21 to 45 years old. Specimens were tested with quantitative PCR for presence and concentrations of male DNA presumed to derive from prior pregnancies with a male fetus. Odds ratios (OR and 95% confidence intervals (CI were estimated with consideration of multiple established reproductive and environmental risk factors for breast cancer. FMc results were generated on 99 parous women, 54 with primary invasive breast cancer and 45 general population controls. FMc prevalence was 56% (25/45 and 26% (14/54 in controls and cases, respectively. Women harboring FMc were less likely to have had breast cancer (OR = 0.29, 95% CI 0.11-0.83; p = 0.02, adjusting for age, number of children, birth of a son, history of miscarriage, and total DNA tested. In addition, FMc concentrations were higher in controls versus cases (p = 0.01. Median concentrations were 2 (0-78 and 0 (0-374 fetal genomes/10(6 maternal genomes in controls and cases, respectively. CONCLUSIONS: Results suggest that the enigma of why some parous women are not afforded protection from breast cancer by pregnancy might in part be explained by differences in FMc. Mechanistic studies of FMc-derived protection against breast cancer are warranted.

  16. Risk factors for psoriasis: A case-control study.

    Science.gov (United States)

    Jankovic, Slavenka; Raznatovic, Milena; Marinkovic, Jelena; Jankovic, Janko; Maksimovic, Natasa

    2009-06-01

    A case-control study of 110 consecutive psoriatic outpatients and 200 unmatched controls was carried out in order to analyze the association of psoriasis with smoking habits, alcohol consumption, family history of psoriasis and stressful life events. Stressful life events were assessed with Paykel's Interview for Recent Life Events, a semi-structured interview covering 63 life events. According to our results, the risk of psoriasis is higher in urban dwellers (odds ratio [OR] = 3.61; 95% confidence interval [CI] = 0.99-13.18), patients who were divorced (OR = 5.69; 95% CI = 2.26-14.34) and those exposed to environmental tobacco smoke at home (OR = 2.29; 95% CI = 1.12-4.67). Alcohol consumption (OR = 2.55; 95% CI = 1.26-5.17), family history of psoriasis (OR = 33.96; 95% CI = 14.14-81.57) and change in work conditions (OR = 8.34; 95% CI = 1.86-37.43) are also risk factors for psoriasis. Separate analyses for men and women showed that the risk of developing psoriasis was stronger in men with a family history of psoriasis (OR = 30.39; 95% CI = 6.72-137.42) than in women (OR = 16.99; 95% CI = 7.21-40.07). The effect of environmental tobacco smoke at home was found only in women (OR = 2.44; 95% CI = 1.26-4.73). Future well-designed epidemiological studies need to be performed in order to determine whether lifestyle factors and stress could be risk factors triggering or aggravating psoriasis.

  17. Evaluation of Candidate Genes in Case-Control Studies: A Statistical Method to Account for Related Subjects

    OpenAIRE

    Slager, S. L.; Schaid, D J

    2001-01-01

    Traditional case-control studies provide a powerful and efficient method for evaluation of association between candidate genes and disease. The sampling of cases from multiplex pedigrees, rather than from a catchment area, can increase the likelihood that genetic cases are selected. However, use of all the related cases without accounting for their biological relationship can increase the type I error rate of the statistical test. To overcome this problem, we present an analysis method that i...

  18. A Ten-Year Case-Control Study of Passive Smoke Exposure as a Risk Factor for Pertussis in Children.

    Science.gov (United States)

    Schmidt, Mark A; Kurosky, Samantha K; Mullooly, John P; Chun, Colleen; Weinmann, Sheila

    2015-01-01

    The authors conducted a matched case-control study of laboratory-confirmed pertussis cases, occurring from 1/1/1996 to 12/31/2005, in children up to 12 years of age who were members of a large managed care organization. Sixty-five laboratoryconfirmed cases of pertussis were identified. Using multivariable conditional logistic regression analysis, the authors did not detect a statistically significant association between pertussis and household passive exposure to cigarette smoking.

  19. Risk factors for cancer cervix among rural women of a hilly state: A case-control study

    OpenAIRE

    Anita Thakur; Bhupender Gupta; Anmol Gupta; Raman Chauhan

    2015-01-01

    In Himachal Pradesh, cancer cervix is a major public health problem since it ranks as the number one female cancer. A case-control study of 226 newly diagnosed, histopathologically confirmed cases of cancer cervix and equal number of matched controls was conducted at Regional Cancer Center, Himachal Pradesh during the period from July 2008 to October 2009 with the objective to study the common factors associated with cancer cervix. Univariate analysis identified 10 risk factors associated sig...

  20. The mathematics of non-linear metrics for nested networks

    Science.gov (United States)

    Wu, Rui-Jie; Shi, Gui-Yuan; Zhang, Yi-Cheng; Mariani, Manuel Sebastian

    2016-10-01

    Numerical analysis of data from international trade and ecological networks has shown that the non-linear fitness-complexity metric is the best candidate to rank nodes by importance in bipartite networks that exhibit a nested structure. Despite its relevance for real networks, the mathematical properties of the metric and its variants remain largely unexplored. Here, we perform an analytic and numeric study of the fitness-complexity metric and a new variant, called minimal extremal metric. We rigorously derive exact expressions for node scores for perfectly nested networks and show that these expressions explain the non-trivial convergence properties of the metrics. A comparison between the fitness-complexity metric and the minimal extremal metric on real data reveals that the latter can produce improved rankings if the input data are reliable.