Using the entire history in the analysis of nested case cohort samples.

PubMed

Rivera, C L; Lumley, T

2016-08-15

Countermatching designs can provide more efficient estimates than simple matching or case-cohort designs in certain situations such as when good surrogate variables for an exposure of interest are available. We extend pseudolikelihood estimation for the Cox model under countermatching designs to models where time-varying covariates are considered. We also implement pseudolikelihood with calibrated weights to improve efficiency in nested case-control designs in the presence of time-varying variables. A simulation study is carried out, which considers four different scenarios including a binary time-dependent variable, a continuous time-dependent variable, and the case including interactions in each. Simulation results show that pseudolikelihood with calibrated weights under countermatching offers large gains in efficiency if compared to case-cohort. Pseudolikelihood with calibrated weights yielded more efficient estimators than pseudolikelihood estimators. Additionally, estimators were more efficient under countermatching than under case-cohort for the situations considered. The methods are illustrated using the Colorado Plateau uranium miners cohort. Furthermore, we present a general method to generate survival times with time-varying covariates. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The History of Stuttering by 7 Years of Age: Follow-Up of a Prospective Community Cohort

ERIC Educational Resources Information Center

Kefalianos, Elaina; Onslow, Mark; Packman, Ann; Vogel, Adam; Pezic, Angela; Mensah, Fiona; Conway, Laura; Bavin, Edith; Block, Susan; Reilly, Sheena

2017-01-01

Purpose: For a community cohort of children confirmed to have stuttered by the age of 4 years, we report (a) the recovery rate from stuttering, (b) predictors of recovery, and (c) comorbidities at the age of 7 years. Method: This study was nested in the Early Language in Victoria Study. Predictors of stuttering recovery included child, family, and…

Historical versus Contemporary Climate Forcing on the Annual Nesting Variability of Loggerhead Sea Turtles in the Northwest Atlantic Ocean

PubMed Central

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

Historical versus contemporary climate forcing on the annual nesting variability of loggerhead sea turtles in the Northwest Atlantic Ocean.

PubMed

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.

Climate and predation dominate juvenile and adult recruitment in a turtle with temperature-dependent sex determination.

PubMed

Schwanz, Lisa E; Spencer, Ricky-John; Bowden, Rachel M; Janzen, Fredric J

2010-10-01

Conditions experienced early in life can influence phenotypes in ecologically important ways, as exemplified by organisms with environmental sex determination. For organisms with temperature-dependent sex determination (TSD), variation in nest temperatures induces phenotypic variation that could impact population growth rates. In environments that vary over space and time, how does this variation influence key demographic parameters (cohort sex ratio and hatchling recruitment) in early life stages of populations exhibiting TSD? We leverage a 17-year data set on a population of painted turtles, Chrysemys picta, to investigate how spatial variation in nest vegetation cover and temporal variation in climate influence early life-history demography. We found that spatial variation in nest cover strongly influenced nest temperature and sex ratio, but was not correlated with clutch size, nest predation, total nest failure, or hatching success. Temporal variation in climate influenced percentage of total nest failure and cohort sex ratio, but not depredation rate, mean clutch size, or mean hatching success. Total hatchling recruitment in a year was influenced primarily by temporal variation in climate-independent factors, number of nests constructed, and depredation rate. Recruitment of female hatchlings was determined by stochastic variation in nest depredation and annual climate and also by the total nest production. Overall population demography depends more strongly on annual variation in climate and predation than it does on the intricacies of nest-specific biology. Finally, we demonstrate that recruitment of female hatchlings translates into recruitment of breeding females into the population, thus linking climate (and other) effects on early life stages to adult demographics.

Risk of intracerebral hemorrhage associated with phenprocoumon exposure: a nested case-control study in a large population-based German database.

PubMed

Behr, Sigrid; Andersohn, Frank; Garbe, Edeltraut

2010-07-01

Intracerebral hemorrhage (ICH) is the most serious complication of oral anticoagulation. This study investigated the risk of ICH for phenprocoumon which is the most widely used oral anticoagulant in Germany. We conducted a nested case-control study in a cohort of 13.4 million insurants of 4 German statutory health insurances (SHIs) who were continuously enrolled for 6 months prior to cohort entry. Cases were patients hospitalized for ICH. Ten controls were matched to each case by SHI, birth year, and sex using incidence density sampling. Rate ratios (RR) of ICH for current phenprocoumon use as compared to non-use were estimated from odds ratios calculated by conditional logistic regression analyses considering multiple risk factors. Analysis of the full cohort revealed a strong increase in incidence of ICH with increasing age. In the nested case-control study including 8138 cases of ICH and 81,373 matched controls, we observed an increased risk of ICH for current phenprocoumon exposure that varied with age. The phenprocoumon-associated risk of ICH was lower in older age groups with RRs from 4.20 (95% confidence interval (CI) 2.44-7.21) for phenprocoumon users less than 55 years of age to 2.43 (95%CI, 1.81-3.27) for those older than 85 years. Our study confirmed known risk factors of ICH. Phenprocoumon exposure was associated with an increased risk of ICH. The interaction of risk for phenprocoumon with age was unexpected and needs further study. (c) 2010 John Wiley & Sons, Ltd.

The effectiveness of emergency nurse practitioner service in the management of patients presenting to rural hospitals with chest pain: a multisite prospective longitudinal nested cohort study.

PubMed

Roche, Tina E; Gardner, Glenn; Jack, Leanne

2017-06-27

Health reforms in service improvement have included the use of nurse practitioners. In rural emergency departments, nurse practitioners work to the full scope of their expanded role across all patient acuities including those presenting with undifferentiated chest pain. Currently, there is a paucity of evidence regarding the effectiveness of emergency nurse practitioner service in rural emergency departments. Inquiry into the safety and quality of the service, particularly regarding the management of complex conditions is a priority to ensure that this service improvement model meets health care needs of rural communities. This study used a prospective, longitudinal nested cohort study of rural emergency departments in Queensland, Australia. Sixty-one consecutive adult patients with chest pain who presented between November 2014 and February 2016 were recruited into the study cohort. A nested cohort of 41 participants with suspected or confirmed acute coronary syndrome were identified. The primary outcome was adherence to guidelines and diagnostic accuracy of electrocardiograph interpretation for the nested cohort. Secondary outcomes included service indicators of waiting times, diagnostic accuracy as measured by unplanned representation rates, satisfaction with care, quality-of-life, and functional status. Data were examined and compared for differences for participants managed by emergency nurse practitioners and those managed in the standard model of care. The median waiting time was 8.0 min (IQR 20) and length-of-stay was 100.0 min (IQR 64). Participants were 2.4 times more likely to have an unplanned representation if managed by the standard service model. The majority of participants (91.5%) were highly satisfied with the care that they received, which was maintained at 30-day follow-up measurement. In the evaluation of quality of life and functional status, summary scores for the SF-12 were comparable with previous studies. No differences were demonstrated between service models. There was a high level of adherence to clinical guidelines for the emergency nurse practitioner service model and a concomitant high level of diagnostic accuracy. Nurse practitioner service demonstrated comparable effectiveness to that of the standard care model in the evaluation of the service indicators and patient reported outcomes. These findings provide a foundation for the beginning evaluation of rural emergency nurse practitioner service in the delivery of safe and effective beyond the setting of minor injury and illness presentations. Australian New Zealand Clinical Trials Registry, ACTRN12616000823471 (Retrospectively registered).

Review of the literature on benzene exposure and leukemia subtypes.

PubMed

Schnatter, A Robert; Rosamilia, Kim; Wojcik, Nancy C

2005-05-30

The epidemiologic literature on benzene exposure and leukemia in the MEDLINE and TOXNET databases was examined through October 2004 using the keywords "benzene", "leukemia" and "adverse health effects". This search was complemented by reviewing the reference lists from extant literature reviews and criteria documents on benzene. Published studies were characterized according to the type of industry studied and design, exposure assessment, disease classification, and control for confounding variables. Study design consisted of either cohort studies or case-control studies, which were further categorized into population-based and nested case-control studies. Disease classification considered the source of diagnostic information, whether there was clinical confirmation from medical records or histopathological, morphological and/or cytogenetic reviews, and as to whether the International Classification of Diseases (ICD) or the French-American-British (FAB) schemes were used (no studies used the Revised European-American Lymphoma (REAL) classification scheme). Nine cohort and 13 case-control studies met inclusion criteria for this review. High and significant acute myeloid leukemia risks with positive dose response relationships were identified across study designs, particularly in the "well-conducted" cohort studies and especially in more highly exposed workers in rubber, shoe, and paint industries. Risks for chronic lymphocytic leukemia (CLL) tended to show elevations in nested case-control studies, with possible dose response relationships in at least two of the three studies. However, cohort studies on CLL show no such risks. Data for chronic myeloid leukemia and acute lymphocytic leukemia are sparse and inconclusive.

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

PubMed

Scheike, Thomas H; Juul, Anders

2004-04-01

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 hazards model. The MLE is computed by the EM-algorithm, which is easy to implement in the proportional hazards setting. Standard errors are estimated by a numerical profile likelihood approach based on EM aided differentiation. The work was motivated by a nested case-control study that hypothesized that insulin-like growth factor I was associated with ischemic heart disease. The study was based on a population of 3784 Danes and 231 cases of ischemic heart disease where controls were matched on age and gender. We illustrate the use of the MLE for these data and show how the maximum likelihood framework can be used to obtain information additional to the relative risk estimates of covariates.

Dairy products and risk of hepatocellular carcinoma: the European Prospective Investigation into Cancer and Nutrition.

PubMed

Duarte-Salles, Talita; Fedirko, Veronika; Stepien, Magdalena; Trichopoulou, Antonia; Bamia, Christina; Lagiou, Pagona; Lukanova, Annekatrin; Trepo, Elisabeth; Overvad, Kim; Tjønneland, Anne; Halkjaer, Jytte; Boutron-Ruault, Marie-Christine; Racine, Antoine; Cadeau, Claire; Kühn, Tilman; Aleksandrova, Krasimira; Trichopoulos, Dimitrios; Tsiotas, Konstantinos; Boffetta, Paolo; Palli, Domenico; Pala, Valeria; Tumino, Rosario; Sacerdote, Carlotta; Panico, Salvatore; Bueno-de-Mesquita, H B as; Dik, Vincent K; Peeters, Petra H; Weiderpass, Elisabete; Torhild Gram, Inger; Hjartåker, Anette; Ramón Quirós, Jose; Fonseca-Nunes, Ana; Molina-Montes, Esther; Dorronsoro, Miren; Navarro Sanchez, Carmen; Barricarte, Aurelio; Lindkvist, Björn; Sonestedt, Emily; Johansson, Ingegerd; Wennberg, Maria; Khaw, Kay-Tee; Wareham, Nick; Travis, Ruth C; Romieu, Isabelle; Riboli, Elio; Jenab, Mazda

2014-10-01

Intake of dairy products has been associated with risk of some cancers, but findings are often inconsistent and information on hepatocellular carcinoma (HCC) risk is limited, particularly from prospective settings. The aim of our study was to investigate the association between consumption of total and specific dairy products (milk/cheese/yogurt) and their components (calcium/vitamin D/fats/protein), with first incident HCC (N(cases) = 191) in the European Prospective Investigation into Cancer and Nutrition cohort, including a nested case-control subset (N(cases) = 122) with the assessment of hepatitis B virus/hepatitis C virus infections status, liver damage and circulating insulin-like growth factor (IGF)-I levels. For cohort analyses, multivariable-adjusted Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CI). For nested case-control analyses, conditional logistic regression was used to calculate odds ratios and 95% CI. A total of 477,206 participants were followed-up for an average of 11 years (person-years follow-up = 5,415,385). In the cohort study, a significant positive HCC risk association was observed for total dairy products (highest vs. lowest tertile, HR = 1.66, 95% CI: 1.13-2.43; p(trend) = 0.012), milk (HR = 1.51, 95% CI: 1.02-2.24; p(trend) = 0.049), and cheese (HR = 1.56, 95% CI: 1.02-2.38; p(trend) = 0.101), but not yogurt (HR = 0.94, 95% CI: 0.65-1.35). Dietary calcium, vitamin D, fat and protein from dairy sources were associated with increased HCC risk, whereas the same nutrients from nondairy sources showed inverse or null associations. In the nested case-control study, similar results were observed among hepatitis-free individuals. Results from this large prospective cohort study suggest that higher consumption of dairy products, particularly milk and cheese, may be associated with increased HCC risk. Validation of these findings in other populations is necessary. Potential biologic mechanisms require further exploration. © 2014 UICC.

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

PubMed Central

Epplein, Meira; Shvetsov, Yurii B; Wilkens, Lynne R; Franke, Adrian A; Cooney, Robert V; Le Marchand, Loïc; Henderson, Brian E; 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, ethnicity, study location (Hawaii or California), smoking status, date/time of collection and hours of fasting. We measured prediagnostic circulating levels of individual carotenoids, retinol, and tocopherols. Conditional logistic regression was used to compute odds ratios and 95% confidence intervals. Results Women with breast cancer tended to have lower levels of plasma carotenoids and tocopherols than matched controls, but the differences were not large or statistically significant and the trends were not monotonic. No association was seen with retinol. A sensitivity analysis excluding cases diagnosed within 1 year after blood draw did not alter the findings. Conclusions The lack of significant associations in this multiethnic population is consistent with previously observed results from less racially-diverse cohorts and serves as further evidence against a causal link between plasma micronutrient concentrations and postmenopausal breast cancer risk. PMID:19619335

Benign Breast Disease: Toward Molecular Prediction of Breast Cancer Risk

DTIC Science & Technology

2006-06-01

with benign breast disease ( BBD ) (1967-1991); 2) the application of potential biomarkers of risk to this archival tissue set; and 3) the discovery...of new, potentially relevant biomarkers of risk in fresh and frozen specimens of BBD . The Center includes a multi-institutional team of basic...State). I. Task 1: Establish Retrospective Cohort of BBD and Nested Case-Control Study A. Complete cohort follow-up We provide here an update of

Comparing the cohort design and the nested case–control design in the presence of both time-invariant and time-dependent treatment and competing risks: bias and precision

PubMed Central

Austin, Peter C; Anderson, Geoffrey M; Cigsar, Candemir; Gruneir, Andrea

2012-01-01

Purpose Observational studies using electronic administrative healthcare databases are often used to estimate the effects of treatments and exposures. Traditionally, a cohort design has been used to estimate these effects, but increasingly, studies are using a nested case–control (NCC) design. The relative statistical efficiency of these two designs has not been examined in detail. Methods We used Monte Carlo simulations to compare these two designs in terms of the bias and precision of effect estimates. We examined three different settings: (A) treatment occurred at baseline, and there was a single outcome of interest; (B) treatment was time varying, and there was a single outcome; and C treatment occurred at baseline, and there was a secondary event that competed with the primary event of interest. Comparisons were made of percentage bias, length of 95% confidence interval, and mean squared error (MSE) as a combined measure of bias and precision. Results In Setting A, bias was similar between designs, but the cohort design was more precise and had a lower MSE in all scenarios. In Settings B and C, the cohort design was more precise and had a lower MSE in all scenarios. In both Settings B and C, the NCC design tended to result in estimates with greater bias compared with the cohort design. Conclusions We conclude that in a range of settings and scenarios, the cohort design is superior in terms of precision and MSE. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22653805

The use of antidepressants and the risk of haemorrhagic stroke: a nested case control study

PubMed Central

Douglas, Ian; Smeeth, Liam; Irvine, David

2011-01-01

AIM To investigate whether selective serotonin re-uptake inhibitor (SSRI) use is associated with an increased risk of haemorrhagic stroke in a cohort of antidepressant users. METHODS We conducted a case control study, nested within a cohort of antidepressant users in the United Kingdom General Practice Research Database. A cohort of 365 195 patients prescribed either an SSRI or tricyclic antidepressant between 1992 and 2006 was identified. Three hundred and fifty-seven cases of haemorrhagic stroke were observed and 1631 control patients without haemorrhagic stroke were selected. RESULTS The primary analysis showed no evidence of an association between current SSRI or TCA use and haemorrhagic stroke. Current use of an SSRI compared with no use at the time of haemorrhagic stroke was associated with an adjusted odds ratio of 1.11 (95% confidence interval (CI) 0.82, 1.50). For current tricyclic use the equivalent odds ratio was 0.73 (0.52, 1.02). There was no evidence that prior cerebrovascular events modified the effect of either SSRIs or TCAs. CONCLUSIONS We found no evidence that SSRIs are associated with an increased risk of haemorrhagic stroke, regardless of prior history of cerebrovascular events. PMID:21143507

Exposure assessment for a nested case-control study of lung cancer among European asphalt workers.

PubMed

Agostini, Michela; Ferro, Gilles; Olsson, Ann; Burstyn, Igor; De Vocht, Frank; Hansen, Johnni; Lassen, Christina Funch; Johansen, Christoffer; Kjaerheim, Kristina; Langard, Sverre; Stucker, Isabelle; Ahrens, Wolfgang; Behrens, Thomas; Lindbohm, Marja-Liisa; Heikkilä, Pirjo; Heederik, Dick; Portengen, Lützen; Shaham, Judith; Boffetta, Paolo; Kromhout, Hans

2010-10-01

Development of a method for retrospective assessment of exposure to bitumen fume, bitumen condensate, organic vapour, polycyclic aromatic hydrocarbons, and co-exposures to known or suspected lung carcinogens for a nested case-control study of lung cancer mortality among European asphalt workers. Company questionnaires and structured questionnaires used in interviews and industry-specific job-exposure matrices (JEMs) were elaborated and applied. Three sources of information were eventually used for exposure assessment and assignment: (i) data obtained in cohort phase, (ii) data from living subjects, next-of-kin, and fellow-workers questionnaires, and (iii) JEMs for bitumen exposure by inhalation and via skin and co-exposures to known or suspected lung carcinogens within and outside cohort companies. Inhalation and dermal exposure estimates for bitumen were adjusted for time trends, time spent in a job, and other determinants of exposure (e.g. oil gravel paving). Clothing patterns, personal protective devices, and personal hygiene were taken into consideration while estimating dermal exposure. Occupational exposures could be assessed for 433 cases and 1253 controls for relevant time periods. Only 43% of work histories were spent inside original asphalt and construction companies. A total of 95.8% of job periods in cohort companies could be coded at a more detailed level. Imputation of work time and 'hygienic behaviour' multipliers was needed for <10% of work history years. Overall, downward trends in exposure were present and differences existed between countries and companies. As expected, correlations were strongest (r > 0.7) among bitumen-related agents, while correlations between coal tar, bitumen-related agents, and established lung carcinogens were weaker (r < 0.4). A systematic and detailed approach was developed to estimate inhalation and dermal exposure for a nested case-control study among asphalt workers.

On estimation of linear transformation models with nested case–control sampling

PubMed Central

Liu, Mengling

2011-01-01

Nested case–control (NCC) sampling is widely used in large epidemiological cohort studies for its cost effectiveness, but its data analysis primarily relies on the Cox proportional hazards model. In this paper, we consider a family of linear transformation models for analyzing NCC data and propose an inverse selection probability weighted estimating equation method for inference. Consistency and asymptotic normality of our estimators for regression coefficients are established. We show that the asymptotic variance has a closed analytic form and can be easily estimated. Numerical studies are conducted to support the theory and an application to the Wilms’ Tumor Study is also given to illustrate the methodology. PMID:21912975

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

PubMed Central

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

Exposure to Radiofrequency Electromagnetic Fields and Sleep Quality: A Prospective Cohort Study

PubMed Central

Mohler, Evelyn; Frei, Patrizia; Fröhlich, Jürg; Braun-Fahrländer, Charlotte; Röösli, Martin

2012-01-01

Background There is persistent public concern about sleep disturbances due to radiofrequency electromagnetic field (RF-EMF) exposure. The aim of this prospective cohort study was to investigate whether sleep quality is affected by mobile phone use or by other RF-EMF sources in the everyday environment. Methods We conducted a prospective cohort study with 955 study participants aged between 30 and 60 years. Sleep quality and daytime sleepiness was assessed by means of standardized questionnaires in May 2008 (baseline) and May 2009 (follow-up). We also asked about mobile and cordless phone use and asked study participants for consent to obtain their mobile phone connection data from the mobile phone operators. Exposure to environmental RF-EMF was computed for each study participant using a previously developed and validated prediction model. In a nested sample of 119 study participants, RF-EMF exposure was measured in the bedroom and data on sleep behavior was collected by means of actigraphy during two weeks. Data were analyzed using multivariable regression models adjusted for relevant confounders. Results In the longitudinal analyses neither operator-recorded nor self-reported mobile phone use was associated with sleep disturbances or daytime sleepiness. Also, exposure to environmental RF-EMF did not affect self-reported sleep quality. The results from the longitudinal analyses were confirmed in the nested sleep study with objectively recorded exposure and measured sleep behavior data. Conclusions We did not find evidence for adverse effects on sleep quality from RF-EMF exposure in our everyday environment. PMID:22624036

"What Do These Words Mean?": A Qualitative Approach to Explore Oral Health Literacy in Vietnamese Immigrant Mothers in Australia

ERIC Educational Resources Information Center

Arora, Amit; Nguyen, Deon; Do, Quang Vinh; Nguyen, Bao; Hilton, Glen; Do, Loc Giang; Bhole, Sameer

2014-01-01

Objective: This study, nested within a large cohort study, sought to explore how well Vietnamese mothers with pre-school children understood the dental health education material commonly available in New South Wales, Australia. Design: Qualitative research. Setting: Home-based interviews. Method: Vietnamese-speaking mothers ("n" = 24)…

A review of published analyses of case-cohort studies and recommendations for future reporting.

PubMed

Sharp, Stephen J; Poulaliou, Manon; Thompson, Simon G; White, Ian R; Wood, Angela M

2014-01-01

The case-cohort study design combines the advantages of a cohort study with the efficiency of a nested case-control study. However, unlike more standard observational study designs, there are currently no guidelines for reporting results from case-cohort studies. Our aim was to review recent practice in reporting these studies, and develop recommendations for the future. By searching papers published in 24 major medical and epidemiological journals between January 2010 and March 2013 using PubMed, Scopus and Web of Knowledge, we identified 32 papers reporting case-cohort studies. The median subcohort sampling fraction was 4.1% (interquartile range 3.7% to 9.1%). The papers varied in their approaches to describing the numbers of individuals in the original cohort and the subcohort, presenting descriptive data, and in the level of detail provided about the statistical methods used, so it was not always possible to be sure that appropriate analyses had been conducted. Based on the findings of our review, we make recommendations about reporting of the study design, subcohort definition, numbers of participants, descriptive information and statistical methods, which could be used alongside existing STROBE guidelines for reporting observational studies.

Methodologic considerations in the design and analysis of nested case-control studies: association between cytokines and postoperative delirium.

PubMed

Ngo, Long H; Inouye, Sharon K; Jones, Richard N; Travison, Thomas G; Libermann, Towia A; Dillon, Simon T; Kuchel, George A; Vasunilashorn, Sarinnapha M; Alsop, David C; Marcantonio, Edward R

2017-06-06

The nested case-control study (NCC) design within a prospective cohort study is used when outcome data are available for all subjects, but the exposure of interest has not been collected, and is difficult or prohibitively expensive to obtain for all subjects. A NCC analysis with good matching procedures yields estimates that are as efficient and unbiased as estimates from the full cohort study. We present methodological considerations in a matched NCC design and analysis, which include the choice of match algorithms, analysis methods to evaluate the association of exposures of interest with outcomes, and consideration of overmatching. Matched, NCC design within a longitudinal observational prospective cohort study in the setting of two academic hospitals. Study participants are patients aged over 70 years who underwent scheduled major non-cardiac surgery. The primary outcome was postoperative delirium from in-hospital interviews and medical record review. The main exposure was IL-6 concentration (pg/ml) from blood sampled at three time points before delirium occurred. We used nonparametric signed ranked test to test for the median of the paired differences. We used conditional logistic regression to model the risk of IL-6 on delirium incidence. Simulation was used to generate a sample of cohort data on which unconditional multivariable logistic regression was used, and the results were compared to those of the conditional logistic regression. Partial R-square was used to assess the level of overmatching. We found that the optimal match algorithm yielded more matched pairs than the greedy algorithm. The choice of analytic strategy-whether to consider measured cytokine levels as the predictor or outcome-- yielded inferences that have different clinical interpretations but similar levels of statistical significance. Estimation results from NCC design using conditional logistic regression, and from simulated cohort design using unconditional logistic regression, were similar. We found minimal evidence for overmatching. Using a matched NCC approach introduces methodological challenges into the study design and data analysis. Nonetheless, with careful selection of the match algorithm, match factors, and analysis methods, this design is cost effective and, for our study, yields estimates that are similar to those from a prospective cohort study design.

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

PubMed

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

2015-07-27

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.

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

PubMed Central

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

Symptoms of anxiety and depression during pregnancy and their association with low birth weight in Chinese women: a nested case control study.

PubMed

Yang, Shaoping; Yang, Rong; Liang, Shengwen; Wang, Jing; Weaver, Nancy L; Hu, Ke; Hu, Ronghua; Trevathan, Edwin; Huang, Zhen; Zhang, Yiming; Yin, Ting; Chang, Jen Jen; Zhao, Jinzhu; Shen, Longjiao; Dong, Guanghui; Zheng, Tongzhang; Xu, Shunqing; Qian, Zhengmin; Zhang, Bin

2017-04-01

This study is a nested case control study from a population-based cohort study conducted in Wuhan, China. The aim is to estimate the association between symptoms of depression during pregnancy (DDP), anxiety during pregnancy(ADP), and depression with anxiety during pregnancy (DADP) and low birth weight (LBW) and to examine the extent to which preterm birth (PTB) moderates these associations. Logistic regression analyses were used to model associations between DDP, ADP, and DADP and LBW. Models were stratified by the presence or absence of PTB to examine moderating effects. From the cohort study, 2853 had a LBW baby (cases); 5457 pregnant women served as controls. Women with DDP or ADP only were not at higher risk of having a LBW baby, but DADP was associated with increased risk of LBW (crude OR 1.41, 95% CI 1.17-1.70; adjusted OR 1.29, 95% CI 1.07-1.57), and the significant association was particularly evident between DADP and LBW in PTB, but not in full-term births. Our data suggests that DADP is related to an increased risk of LBW and that this association is most present in PTBs.

Risk of acute liver injury associated with use of antibiotics. Comparative cohort and nested case-control studies using two primary care databases in Europe.

PubMed

Brauer, Ruth; Douglas, Ian; Garcia Rodriguez, Luis Alberto; Downey, Gerald; Huerta, Consuelo; de Abajo, Francisco; Bate, Andrew; Feudjo Tepie, Maurille; de Groot, Mark C H; Schlienger, Raymond; Reynolds, Robert; Smeeth, Liam; Klungel, Olaf; Ruigómez, Ana

2016-03-01

To assess the impact of varying study designs, exposure and outcome definitions on the risk of acute liver injury (ALI) associated with antibiotic use. The source population comprised of patients registered in two primary care databases, in the UK and in Spain. We identified a cohort consisting of new users of antibiotics during the study period (2004-2009) and non-users during the study period or in the previous year. Cases with ALI were identified within this cohort and classified as definite or probable, based on recorded medical information. The relative risk (RR) of ALI associated with antibiotic use was computed using Poisson regression. For the nested case-control analyses, up to five controls were matched to each case by age, sex, date and practice (in CPRD) and odds ratios (OR) were computed with conditional logistic regression. The age, sex and year adjusted RRs of definite ALI in the current antibiotic use periods was 10.04 (95% CI: 6.97-14.47) in CPRD and 5.76 (95% CI: 3.46-9.59) in BIFAP. In the case-control analyses adjusting for life-style, comorbidities and use of medications, the OR of ALI for current users of antibiotics was and 5.7 (95% CI: 3.46-9.36) in CPRD and 2.6 (95% CI: 1.26-5.37) in BIFAP. Guided by a common protocol, both cohort and case-control study designs found an increased risk of ALI associated with the use of antibiotics in both databases, independent of the exposure and case definitions used. However, the magnitude of the risk was higher in CPRD compared to BIFAP. Copyright © 2016 John Wiley & Sons, Ltd.

The Differential Effects of Preschool: Evidence from Virginia

ERIC Educational Resources Information Center

Huang, Francis L.; Invernizzi, Marcia A.; Drake, E. Allison

2012-01-01

This study investigated the differential and persistent effects of a state-funded pre-K program, the Virginia Preschool Initiative (VPI). We analyzed data from a cohort of over 60,000 students nested in approximately 1000 schools from the beginning of kindergarten to the end of first grade using two-level hierarchical logistic regression models.…

Excessive nest building is a unique behavioural phenotype in the deer mouse model of obsessive-compulsive disorder.

PubMed

Wolmarans, De Wet; Stein, Dan J; Harvey, Brian H

2016-09-01

Obsessive-compulsive disorder (OCD) is a phenotypically heterogeneous condition characterised by time-consuming intrusive thoughts and/or compulsions. Irrespective of the symptom type diagnosed, the severity of OCD is characterised by heterogeneity in symptom presentation that complicates diagnosis and treatment. Heterogeneity of symptoms would be invaluable in an animal model. Nest building behaviour forms part of the normal behavioural repertoire of rodents and demonstrates profound between-species differences. However, it has been proposed that within-species differences in nest building behaviour (i.e. aberrant vs. normal nest building) may resemble obsessive-compulsive-like symptoms. In an attempt to investigate whether other obsessive-compulsive-like behaviours are present in an animal model of OCD, or if aberrant nest building behaviour may represent a unique obsessive-compulsive phenotype in such a model, the current study assessed nest building behaviour in high (H, viz obsessive-compulsive) and non (N, viz normal) stereotypical deer mice. Subsequently, 12 N and H animals, respectively, were provided with an excess of cotton wool daily for one week prior to and following four weeks of high-dose oral escitalopram treatment (50 mg/kg/day). Data from the current investigation demonstrate daily nesting activity to be highly variable in deer mice, with stereotypy and nest building being independent behaviours. However, we identified unique aberrant large nest building behaviour in 30% of animals from both cohorts that was attenuated by escitalopram to pre-treatment nesting scores of the larger group. In summary, behavioural and drug-treatment evidence confirms that deer mouse behaviour does indeed resemble symptom heterogeneity related to OCD, and as such expands its face and predictive validity for the disorder. © The Author(s) 2016.

Brief Report: Maternal Smoking during Pregnancy and Autism Spectrum Disorders

ERIC Educational Resources Information Center

Lee, Brian K.; Gardner, Renee M.; Dal, Henrik; Svensson, Anna; Galanti, Maria Rosaria; Rai, Dheeraj; Dalman, Christina; Magnusson, Cecilia

2012-01-01

Prenatal exposure to tobacco smoke is suggested as a potential risk factor for autism spectrum disorders (ASD). Previous epidemiological studies of this topic have yielded mixed findings. We performed a case-control study of 3,958 ASD cases and 38,983 controls nested in a large register-based cohort in Sweden. ASD case status was measured using a…

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

PubMed Central

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

The relationship between weight gain during pregnancy and urinary tract infections in pregnant women of Shahrekord, by using the "Nested case-control study", in 2013.

PubMed

Rejali, Mehri; Ahmadi, Seyede Soghra; Hassanzadeh, Akbar; Yazdani, Rezvan; Ahmadi, Seyede Nafiseh

2015-01-01

Pregnancy is one of the most important and risky periods in mothers and the fetus life, which plays a key role in health and social activity of the person, family and community. This study is trying to see if there is a relation between increasing weight and urinary tract infection (UTI) in pregnancy by using the open nested case-control study in the city of Shahrekord. In a nested case-control study, one cohort including 832 patients was examined until week 26 to 30 of pregnancy and their UTIs were studied. The required information was collected by examining the health records of pregnant women and completion of the data registration forms. Data collection was controlled by using SPSS and analyzed by using an independent t-test, Chi-square test, Pearson correlation and logistic regression. According to the results of the cohort study with 832 individuals, average weight gain of the group with a UTI was 11.13 ± 3.9 kg and it was 10.63 ± 3.9 kg in the group without UTI, showing no statistically significant difference (P = 0.245). According to the results, genitourinary problems had the highest predictive value for UTIs and the numbers of infertility and the childbirth variables were in the second and third positions, respectively. According to the results study we can conclude that screening and treatment of UTIs have been on time and appropriate in health systems of the city of Shahrekord which have lead to the reduction of infant and maternal diseases even with the condition in having no UTI, and continuing this process for screening and treatment is recommended.

Cohort profile: Pacific Islands Families (PIF) growth study, Auckland, New Zealand

PubMed Central

Rush, E; Oliver, M; Plank, L D; Taylor, S; Iusitini, L; Jalili-Moghaddam, S; Savila, F; Paterson, J; Tautolo, E

2016-01-01

Purpose This article profiles a birth cohort of Pacific children participating in an observational prospective study and describes the study protocol used at ages 14–15 years to investigate how food and activity patterns, metabolic risk and family and built environment are related to rates of physical growth of Pacific children. Participants From 2000 to 2015, the Pacific Islands Families Study has followed, from birth, the growth and development of over 1000 Pacific children born in Auckland, New Zealand. In 2014, 931 (66%) of the original cohort had field measures of body composition, blood pressure and glycated haemoglobin. A nested subsample (n=204) was drawn by randomly selecting 10 males and 10 females from each decile of body weight. These participants had measurement of body composition by dual-energy X-ray absorptiometry, food frequency, 6 min walk test and accelerometer-determined physical activity and sedentary behaviours, and blood biomarkers for metabolic disease such as diabetes. Built environment variables were generated from individual addresses. Findings to date Compared to the Centres for Disease Control and Prevention (CDC) reference population with mean SD scores (SDS) of 0, this cohort of 931 14-year-olds was taller, weighed more and had a higher body mass index (BMI) (mean SDS height >0.6, weight >1.6 and BMI >1.4). 7 of 10 youth were overweight or obese. The nested-sampling frame achieved an even distribution by body weight. Future plans Cross-sectional relationships between body size, fatness and growth rate, food patterns, activity patterns, pubertal development, risks for diabetes and hypertension and the family and wider environment will be examined. In addition, analyses will investigate relationships with data collected earlier in the life course and measures of the cohort in the future. Understanding past and present influences on child growth and health will inform timely interventions to optimise future health and reduce inequalities for Pacific people. PMID:27807091

A review of epidemiological data on epilepsy, phenobarbital, and risk of liver cancer.

PubMed

La Vecchia, Carlo; Negri, Eva

2014-01-01

Phenobarbital is not genotoxic, but has been related to promotion of liver cancer (as well as inhibition) in rodents. In October 2012, we carried out a systematic literature search in the Medline database and searched reference lists of retrieved publications. We identified 15 relevant papers. Epidemiological data on epileptics/anticonvulsant use and liver cancer were retrieved from eight reports from seven cohort (record linkage) studies of epileptics, and data on phenobarbital use from a pharmacy-based record linkage investigation of patients treated with phenobarbital (three reports), plus a case-control study nested in one of the cohort studies and including information on phenobarbital use. Of the studies of cancer in epileptics, two showed no excess risk of liver cancer. A long-term (1933-1984) Danish cohort study of epileptics found relative risks (RRs) of 4.7 [95% confidence interval (CI) 3.2-6.8] of liver cancer and of 2.2 (95% CI 1.2-3.5) of biliary tract cancers. Such apparent excess risks could, however, be largely or completely attributed to thorotrast, a contrast medium used in the past in epileptic patients for cerebral angiography. A Finnish cohort study of epileptics obtained an RR of 1.7 (95% CI 1.2-2.4). Such an apparent excess risk, however, was not related to phenobarbital or to any specific anticonvulsant drug. The long-term follow-up of two UK cohorts found some excess risk of liver cancer among severe, but not among mild, epileptics. Some excess risk of liver cancer was also found in cohort studies of patients hospitalized for epilepsy in Sweden and Taiwan, in the absence, however, of association with any specific drugs. A UK General Practice database, comparing epileptics treated with valproate with unexposed ones, found a very low incidence of liver cancer. Of the studies of cancer in patients treated with phenobarbital, a large US pharmacy-based cohort investigation showed no excess risk of liver cancer. In a case-control study, nested in the Danish cohort of epileptics, no association was observed between phenobarbital and liver cancer among patients who had not received thorotrast (RR=1.0 for liver and 0.8 for biliary tract cancers). Thus, some, although not all, studies reported excess risk of all cancers and liver cancer in severe, but not in milder epileptics. There is no evidence of a specific role of phenobarbital in human liver cancer risk, but data on the topic are limited.

The relationship between weight gain during pregnancy and urinary tract infections in pregnant women of Shahrekord, by using the “Nested case-control study”, in 2013

PubMed Central

Rejali, Mehri; Ahmadi, Seyede Soghra; Hassanzadeh, Akbar; Yazdani, Rezvan; Ahmadi, Seyede Nafiseh

2015-01-01

Background and Objectives: Pregnancy is one of the most important and risky periods in mothers and the fetus life, which plays a key role in health and social activity of the person, family and community. This study is trying to see if there is a relation between increasing weight and urinary tract infection (UTI) in pregnancy by using the open nested case-control study in the city of Shahrekord. Materials and Methods: In a nested case-control study, one cohort including 832 patients was examined until week 26 to 30 of pregnancy and their UTIs were studied. The required information was collected by examining the health records of pregnant women and completion of the data registration forms. Data collection was controlled by using SPSS and analyzed by using an independent t-test, Chi-square test, Pearson correlation and logistic regression. Results: According to the results of the cohort study with 832 individuals, average weight gain of the group with a UTI was 11.13 ± 3.9 kg and it was 10.63 ± 3.9 kg in the group without UTI, showing no statistically significant difference (P = 0.245). According to the results, genitourinary problems had the highest predictive value for UTIs and the numbers of infertility and the childbirth variables were in the second and third positions, respectively. Conclusion: According to the results study we can conclude that screening and treatment of UTIs have been on time and appropriate in health systems of the city of Shahrekord which have lead to the reduction of infant and maternal diseases even with the condition in having no UTI, and continuing this process for screening and treatment is recommended. PMID:27462626

Birth Order and Educational Achievement in Adolescence and Young Adulthood

ERIC Educational Resources Information Center

Fergusson, David M.; Horwood, L. John; Boden, Joseph M.

2006-01-01

This paper examines the relationship between birth order and later educational outcomes in a birth cohort of more than 1,000 New Zealand young adults studied to the age of twenty-five. Being later born was associated with gaining fewer educational qualifications at secondary level and beyond. The use of nested models to control for the confounding…

Relative Immaturity and ADHD: Findings from Nationwide Registers, Parent- and Self-Reports

ERIC Educational Resources Information Center

Halldner, Linda; Tillander, Annika; Lundholm, Cecilia; Boman, Marcus; Långström, Niklas; Larsson, Henrik; Lichtenstein, Paul

2014-01-01

Background: We addressed if immaturity relative to peers reflected in birth month increases the likelihood of ADHD diagnosis and treatment. Methods: We linked nationwide Patient and Prescribed Drug Registers and used prospective cohort and nested case-control designs to study 6-69 year-old individuals in Sweden from July 2005 to December 2009…

`Special agents' trigger social waves in giant honeybees ( Apis dorsata)

NASA Astrophysics Data System (ADS)

Schmelzer, Evelyn; Kastberger, Gerald

2009-12-01

Giant honeybees ( Apis dorsata) nest in the open and have therefore evolved a variety of defence strategies. Against predatory wasps, they produce highly coordinated Mexican wavelike cascades termed ‘shimmering’, whereby hundreds of bees flip their abdomens upwards. Although it is well known that shimmering commences at distinct spots on the nest surface, it is still unclear how shimmering is generated. In this study, colonies were exposed to living tethered wasps that were moved in front of the experimental nest. Temporal and spatial patterns of shimmering were investigated in and after the presence of the wasp. The numbers and locations of bees that participated in the shimmering were assessed, and those bees that triggered the waves were identified. The findings reveal that the position of identified trigger cohorts did not reflect the experimental path of the tethered wasp. Instead, the trigger centres were primarily arranged in the close periphery of the mouth zone of the nest, around those parts where the main locomotory activity occurs. This favours the ‘special-agents’ hypothesis that suggest that groups of specialized bees initiate the shimmering.

Leukemia and brain tumors in Norwegian railway workers, a nested case-control study.

PubMed

Tynes, T; Jynge, H; Vistnes, A I

1994-04-01

In an attempt to assess whether exposure to electromagnetic fields on Norwegian railways induces brain tumors or leukemia, the authors conducted a nested case-control study of railway workers based on incident cases from the Cancer Registry of Norway in a cohort of 13,030 male Norwegian railway workers who had worked on either electric or non-electric railways. The cohort comprised railway line, outdoor station, and electricity workers. The case series comprised 39 men with brain tumors and 52 men with leukemia (follow-up, 1958-1990). Each case was matched on age with four or five controls selected from the same cohort. The exposure of each study subject to electric and magnetic fields was evaluated from cumulative exposure measures based on present measurements and historical data. Limited information on potential confounders such as creosote, solvents, and herbicides was also collected; information on whether the subject had smoked was obtained by interviews with the subjects or work colleagues. The case-control analysis showed that men employed on electric railways, compared with non-electric ones, had an odds ratio for leukemia of 0.70 (adjusted for smoking) and an odds ratio for brain tumor of 0.87. No significant trend was shown for exposure to either magnetic or electric fields. These results do not support an association between exposure to 16 2/3-Hertz electric or magnetic fields and the risk for leukemia or brain tumors.

Regular Use of Aspirin or Non-Aspirin Nonsteroidal Anti-Inflammatory Drugs Is Not Associated With Risk of Incident Pancreatic Cancer in Two Large Cohort Studies.

PubMed

Khalaf, Natalia; Yuan, Chen; Hamada, Tsuyoshi; Cao, Yin; Babic, Ana; Morales-Oyarvide, Vicente; Kraft, Peter; Ng, Kimmie; Giovannucci, Edward; Ogino, Shuji; Stampfer, Meir; Cochrane, Barbara B; Manson, JoAnn E; Clish, Clary B; Chan, Andrew T; Fuchs, Charles S; Wolpin, Brian M

2018-04-01

Use of aspirin and/or non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) reduces the risk of several cancers, but it is not clear if use of these drugs is associated with risk of pancreatic cancer. We evaluated aspirin and non-aspirin NSAID use and risk of pancreatic adenocarcinoma in 141,940 participants from the Health Professionals Follow-up Study and Nurses' Health Study using multivariable-adjusted Cox proportional hazards regression. We considered several exposure classifications to model differing lag times between NSAID exposure and cancer development. We also conducted a nested case-control study of participants from 3 prospective cohorts using conditional logistic regression to evaluate pre-diagnosis levels of plasma salicylurate, a major metabolite of aspirin, in 396 pancreatic cancer cases and 784 matched individuals without pancreatic cancer (controls). In the prospective cohort study, 1122 participants developed pancreatic adenocarcinoma over 4.2 million person-years. Use of aspirin or non-aspirin NSAIDs was not associated with pancreatic cancer risk, even after considering several latency exposure classifications. In a pre-planned subgroup analysis, regular aspirin use was associated with reduced pancreatic cancer risk among participants with diabetes (relative risk, 0.71; 95% CI, 0.54-0.94). In the nested case-control study, pre-diagnosis levels of salicylurate were not associated with pancreatic cancer risk (odds ratio, 1.08; 95% CI, 0.72-1.61; P trend 0.81; comparing participants in the highest quintile with those in the lowest quintile of plasma salicylurate). Regular aspirin or non-aspirin NSAID use was not associated with future risk of pancreatic cancer in participants from several large prospective cohort studies. A possible reduction in risk for pancreatic cancer among people with diabetes who regularly use aspirin should be further examined in preclinical and human studies. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Physical exercise and pelvic girdle pain in pregnancy: A nested case-control study within the Danish National Birth Cohort.

PubMed

Andersen, Linda Kahr; Backhausen, Mette; Hegaard, Hanne Kristine; Juhl, Mette

2015-12-01

Pelvic girdle pain is a frequent cause of sick leave among pregnant women in Denmark. Studies regarding prevention of pelvic girdle pain are sparse. The aim of this study was to examine the association between physical exercise and pelvic girdle pain in pregnancy. A nested case-control study within the Danish National Birth Cohort (n = 5304). This study used self-reported data on pelvic girdle pain obtained from an interview six months after childbirth. Information on physical exercise was obtained from the pregnancy interview around gestational week 16. The association was estimated using logistic regression analysis. Physical exercise in pregnancy was associated with decreased risk of overall pelvic girdle pain (OR = 0.87; 95% CI: 0.77-0.99, p = 0.028). Tests for trend indicated decreasing odds for pelvic girdle pain with increasing number of hours per week spent on exercise (p < 0.001). Compared to no exercise, swimming was associated with a decreased risk of pelvic girdle pain (OR = 0.73; 95% CI: 0.58-0.91, p = 0.005). The findings suggest a possible protective effect of physical exercise on pelvic girdle pain during pregnancy. Copyright © 2015 Elsevier B.V. All rights reserved.

Multidisciplinary design and analytic approaches to advance prospective research on the multilevel determinants of child health.

PubMed

Johnson, Sara B; Little, Todd D; Masyn, Katherine; Mehta, Paras D; Ghazarian, Sharon R

2017-06-01

Characterizing the determinants of child health and development over time, and identifying the mechanisms by which these determinants operate, is a research priority. The growth of precision medicine has increased awareness and refinement of conceptual frameworks, data management systems, and analytic methods for multilevel data. This article reviews key methodological challenges in cohort studies designed to investigate multilevel influences on child health and strategies to address them. We review and summarize methodological challenges that could undermine prospective studies of the multilevel determinants of child health and ways to address them, borrowing approaches from the social and behavioral sciences. Nested data, variation in intervals of data collection and assessment, missing data, construct measurement across development and reporters, and unobserved population heterogeneity pose challenges in prospective multilevel cohort studies with children. We discuss innovations in missing data, innovations in person-oriented analyses, and innovations in multilevel modeling to address these challenges. Study design and analytic approaches that facilitate the integration across multiple levels, and that account for changes in people and the multiple, dynamic, nested systems in which they participate over time, are crucial to fully realize the promise of precision medicine for children and adolescents. Copyright © 2017 Elsevier Inc. All rights reserved.

The worsening factors of dengue hemorrhagic fever (DHF) based on cohort study with nested case-control in a tertiary hospital

NASA Astrophysics Data System (ADS)

Lardo, S.; Soesatyo, M. H. N. E.; Juffrie; Umniyati, S. R.

2018-03-01

The clinical pathway of DHF has a broad pathophysiological and pathogenesis spectrum. Clinical and laboratory characteristics are some of the parameters to determine the factors that contribute to the worsening of the disease. The objective of this study is to determine the clinical and laboratory characteristics which contribute to the worsening of DHF. The study had been conducted from January 2012-December 2014 at the general ward of the Internal Medicine Department, Indonesia Army Central Hospital Gatot Soebroto. There were 101 male patients (64.7%) and 55 female patients (35.3 %) ages ranging from 14 - 62 years old. The diagnosis was divided into: 124 patients DHF grade I, 6 DHF grade II, 20 DHF grade III and 6 with dengue shock syndrome (DSS) patients. Clinically and statistically, there were 4 variables apparently found with the severity of DHF, as follows: decreased appetite with p = 0.007 (OR 4.87), hepatomegaly with p = 0.009 (OR 27.00), systolic blood pressure with p = 0.037 (OR 0.95), and initial thrombocyte with p = 0.000 (OR 0.97). This cohort and nested case-control study found that worsening of DHF is related with decreased appetite, hepatomegaly, systolic blood pressure and initial thrombocyte count.

Does malocclusion influence the adolescent's satisfaction with appearance? A cross-sectional study nested in a Brazilian birth cohort.

PubMed

Peres, Karen Glazer; Barros, Aluísio J D; Anselmi, Luciana; Peres, Marco Aurélio; Barros, Fernando C

2008-04-01

To test whether malocclusion had an impact on adolescents' appearance satisfaction regardless of other physical aspects. A cross-sectional study nested in a birth cohort study was carried out in Pelotas, Brazil. A random sample of 900 15-year-old adolescents was selected. WHO criteria were used to define malocclusion and a questionnaire was administered including self-reported skin colour and appearance satisfaction. Dental caries were assessed. Height and weight were measured and body mass index calculated. Data concerning gender and socioeconomic characteristics were obtained from the cohort's perinatal study. Adjusted analyses including all confounding variables investigated were performed using Poisson regression with robust variance in order to identify the potential risk factors for appearance dissatisfaction. All analyses were carried out separately by gender. The sample included 867 individuals, 54.1% men. The prevalence of moderate or severe malocclusion was 30.6% (95% CI: 26.5-34.7) among boys, and 32.8% (95% CI: 28.2-37.4) among girls (P = 0.524). Dissatisfaction with appearance was reported by 29.8% of the boys and by 46.5% of the girls (P < 0.001). A positive association between malocclusion and appearance dissatisfaction, controlling for other physical, dental caries and socioeconomic characteristics was observed only in girls [prevalence ratio = 1.4 (1.3-1.7)]. Malocclusion is a common condition and is positively associated with appearance dissatisfaction in adolescent girls. The effect of different types of malocclusion on appearance dissatisfaction should be the focus of further investigation.

Density-dependent effects on growth, body size, and clutch size in Black Brant

USGS Publications Warehouse

Sedinger, James S.; Lindberg, Mark S.; Person, Brian T.; Eichholz, Michael W.; Herzog, Mark P.; Flint, Paul L.

1998-01-01

We documented gosling size in late summer, adult body size, and clutch size of known-age Black Brant (Branta bernicla nigricans) females nesting on the Tutakoke River colony between 1986 and 1995. During this period, the colony increased from 1,100 to >5,000 nesting pairs. Gosling mass at 30 days of age declined from 764 ± SE of 13 g and 723 ± 15 g for males and females, respectively, in the 1986 cohort, to 665 ± 18 g and 579 ± 18 g in the 1994 cohort. Gosling size was directly negatively correlated with number of Black Brant broods. We detected no trend in adult body size for individuals from these cohorts; in fact, adults from the 1992 and 1994 cohorts had the largest overall masses. Clutch size increased with age from 3.4 eggs for 2-year-old females to 4.4 eggs for 5-year-old females. Clutch size declined during the study by 0.20 (3-year-old females) to 0.45 (2-year-old females) eggs. Clutch size did not decline between the 1986 and 1990 cohorts for females that were >5 years old. Our results for clutch size and gosling size are similar to those recorded for Lesser Snow Geese (Chen caerulescens caerulescens). Our failure to detect a trend in adult body size, however, differs from the response of other geese to increasing population density. We interpret this difference in effects of density on adult size between Black Brant and other geese as an indication of stronger selection against the smallest individuals in Black Brant relative to other species of geese.

Risk of Injurious Fall and Hip Fracture up to 26 y before the Diagnosis of Parkinson Disease: Nested Case-Control Studies in a Nationwide Cohort.

PubMed

Nyström, Helena; Nordström, Anna; Nordström, Peter

2016-02-01

Low muscle strength has been found in late adolescence in individuals diagnosed with Parkinson disease (PD) 30 y later. This study investigated whether this lower muscle strength also may translate into increased risks of falling and fracture before the diagnosis of PD. Among all Swedish citizens aged ≥50 y in 2005, two nested case-control cohorts were compiled. In cohort I, individuals diagnosed with PD during 1988-2012 (n = 24,412) were matched with up to ten controls (n = 243,363), and the risk of fall-related injuries before diagnosis of PD was evaluated. In cohort II, individuals with an injurious fall in need of emergency care during 1988-2012 (n = 622,333) were matched with one control (n = 622,333), and the risk of PD after the injurious fall was evaluated. In cohort I, 18.0% of cases and 11.5% of controls had at least one injurious fall (p < 0.001) prior to PD diagnosis in the case. Assessed by conditional logistic regression analysis adjusted for comorbid diagnoses and education level, PD was associated with increased risks of injurious fall up to 10 y before diagnosis (odds ratio [OR] 1.19, 95% CI 1.08-1.31; 7 to <10 y before diagnosis) and hip fracture ≥15 y before diagnosis (OR 1.36, 95% CI 1.10-1.69; 15-26 y before diagnosis). In cohort II, 0.7% of individuals with an injurious fall and 0.5% of controls were diagnosed with PD during follow-up (p < 0.001). The risk of PD was increased for up to 10 y after an injurious fall (OR 1.18, 95% CI 1.02-1.37; 7 to <10 y after diagnosis). An important limitation is that the diagnoses were obtained from registers and could not be clinically confirmed for the study. The increased risks of falling and hip fracture prior to the diagnosis of PD may suggest the presence of clinically relevant neurodegenerative impairment many years before the diagnosis of this disease.

A nested case-control study of polychlorinated biphenyls, organochlorine pesticides, and thyroid cancer in the Janus Serum Bank cohort.

PubMed

Lerro, Catherine C; Jones, Rena R; Langseth, Hilde; Grimsrud, Tom K; Engel, Lawrence S; Sjödin, Andreas; Choo-Wosoba, Hyoyoung; Albert, Paul; Ward, Mary H

2018-04-23

Polychlorinated biphenyls (PCBs) and organochlorine pesticides have been associated with altered thyroid hormone levels in humans, but their relationship with thyroid cancer is unknown. We conducted a nested case-control study of thyroid cancer in the Norwegian Janus Serum Bank cohort using pre-diagnostic blood samples from 1972 to 1985. Incident thyroid cancer (n = 108) was ascertained through 2008. Controls were matched 2:1 by age, date of blood draw, gender, and county. We used gas chromatography/mass spectrometry to quantify 36 PCB congeners and metabolites of pesticides DDT, chlordane, hexachlorocyclohexane, and hexachlorobenzene. PCBs and pesticide metabolites were evaluated individually and summed by degree of chlorination and parent compound, respectively. Odds ratios (OR) and 95% confidence intervals (CI) were computed using conditional logistic regression per specified increase in lipid-adjusted concentration. We additionally stratified analyses by birth cohort (1923-1932, 1933-1942, 1943-1957). Increasing concentration of DDT metabolites (OR per 1000 ng/g = 0.80, 95%CI = 0.66-0.98) was inversely associated with thyroid cancer. Associations for PCBs were null or in inverse direction. We observed interactions for total PCBs, moderately-chlorinated PCBs, and chlordane metabolites with birth cohort (p ≤ 0.04). Among participants born 1943-1957, total PCBs (OR per 100 ng/g = 1.25, 95%CI = 1.00-1.56), moderately-chlorinated PCBs (OR per 100 ng/g = 1.31, 95%CI = 1.01-1.70), and chlordane metabolites (OR per 10 ng/g = 1.78, 95%CI = 1.09-2.93) were positively associated with thyroid cancer. For individuals born before 1943, associations were generally null or in the inverse direction. Emissions of PCBs and OC pesticides varied over time. Different risk patterns by birth cohort suggest the potential importance of timing of exposure in thyroid cancer risk. Further evaluation of these associations is warranted. Published by Elsevier Inc.

Mortality from Circulatory System Diseases among French Uranium Miners: A Nested Case-Control Study.

PubMed

Drubay, Damien; Caër-Lorho, Sylvaine; Laroche, Pierre; Laurier, Dominique; Rage, Estelle

2015-05-01

A significant association has been observed between radon exposure and cerebrovascular disease (CeVD) mortality among French uranium miners, but risk factors for circulatory system diseases (CSD) have not been previously considered. We conducted new analyses in the recently updated (through 2007) French cohort of uranium miners (n = 5,086), which included 442 deaths from CSD, 167 of them from ischemic heart disease (IHD) and 105 from CeVD. A nested case-control study was then set up to collect and investigate the influence of these risk factors on the relationships between mortality from CSD and occupational external gamma ray and internal ionizing radiation exposure (radon and long-lived radionuclides) in this updated cohort. The nested case-control study included miners first employed after 1955, still employed in 1976 and followed up through 2007. Individual information about CSD risk factors was collected from medical files for the 76 deaths from CSD (including 26 from IHD and 16 from CeVD) and 237 miners who had not died of CSD by the end of follow-up. The exposure-risk relationships were assessed with a Cox proportional hazard model weighted by the inverse sampling probability. A significant increase in all CSD and CeVD mortality risks associated with radon exposure was observed in the total cohort [hazard ratios: HRCSD/100 working level months (WLM) = 1.11, 95% confidence interval (1.01; 1.22) and HRCeVD/100 WLM = 1.25 (1.09; 1.43), respectively]. A nonsignificant exposure-risk relationship was observed for every type of cumulative ionizing radiation exposure and every end point [e.g., HRCSD/100WLM = 1.43 (0.71; 2.87)]. The adjustment for each CSD risk factor did not substantially change the exposure-risk relationships. When the model was adjusted for overweight, hypertension, diabetes, hypercholesterolemia and smoking status, the HR/100WLM for CSD, for example, was equal to 1.21 (0.54; 2.75); and when it was adjusted for risk factors selected with the Akaike information criterion, it was equal to 1.44 (0.66; 3.14). To our knowledge, this is the first study to use a uranium miner cohort to consider the major standard CSD risk factors in assessing the relationships between ionizing radiation exposure and the risk of death from these diseases. These results suggest that the significant relationship between CeVD risk and radon exposure observed in the total French cohort is probably not affected by the CSD risk factors. Extending the collection of information about CSD risk factors to a larger subsample would be useful to confirm this result.

Prenatal exposure to glycol ethers and cryptorchidism and hypospadias: a nested case-control study.

PubMed

Warembourg, Charline; Botton, Jérémie; Lelong, Nathalie; Rouget, Florence; Khoshnood, Babak; Le Gléau, Florent; Monfort, Christine; Labat, Laurence; Pierre, Fabrice; Heude, Barbara; Slama, Rémy; Multigner, Luc; Charles, Marie-Aline; Cordier, Sylvaine; Garlantézec, Ronan

2018-01-01

Glycol ethers (GE) are oxygenated solvents frequently found in occupational and consumer products. Some of them are well-known testicular and developmental animal toxicants. This study aims to evaluate the risk of male genital anomalies in association with prenatal exposure to GE using urinary biomarkers of exposure. We conducted a case-control study nested in two joint mother-child cohorts (5303 pregnant women). Cases of cryptorchidism and hypospadias were identified at birth and confirmed during a 2-year follow-up period (n=14 cryptorchidism and n=15 hypospadias). Each case was matched to three randomly selected controls within the cohorts for region of inclusion and gestational age at urine sampling. Concentrations of five GE acidic metabolites were measured in spot maternal urine samples collected during pregnancy. ORs were estimated with multivariate conditional logistic regressions including a Firth's penalisation. Detection rates of urinary GE metabolites ranged from 8% to 93% and only two were sufficiently detected (>33%) in each cohort to be studied: methoxyacetic acid (MAA) and phenoxyacetic acid (PhAA). A significantly higher risk of hypospadias was associated with the highest tertile of exposure to MAA: OR (95% CI) 4.5(1.4 to 23.4). No association were observed with urinary concentration of PhAA, nor with the risk of cryptorchidism. In view of the toxicological plausibility of our results, this study, despite its small sample size, raises concern about the potential developmental toxicity of MAA on the male genital system and calls for thorough identification of current sources of exposure to MAA. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Cohort profile: Pacific Islands Families (PIF) growth study, Auckland, New Zealand.

PubMed

Rush, E; Oliver, M; Plank, L D; Taylor, S; Iusitini, L; Jalili-Moghaddam, S; Savila, F; Paterson, J; Tautolo, E

2016-11-02

This article profiles a birth cohort of Pacific children participating in an observational prospective study and describes the study protocol used at ages 14-15 years to investigate how food and activity patterns, metabolic risk and family and built environment are related to rates of physical growth of Pacific children. From 2000 to 2015, the Pacific Islands Families Study has followed, from birth, the growth and development of over 1000 Pacific children born in Auckland, New Zealand. In 2014, 931 (66%) of the original cohort had field measures of body composition, blood pressure and glycated haemoglobin. A nested subsample (n=204) was drawn by randomly selecting 10 males and 10 females from each decile of body weight. These participants had measurement of body composition by dual-energy X-ray absorptiometry, food frequency, 6 min walk test and accelerometer-determined physical activity and sedentary behaviours, and blood biomarkers for metabolic disease such as diabetes. Built environment variables were generated from individual addresses. Compared to the Centres for Disease Control and Prevention (CDC) reference population with mean SD scores (SDS) of 0, this cohort of 931 14-year-olds was taller, weighed more and had a higher body mass index (BMI) (mean SDS height >0.6, weight >1.6 and BMI >1.4). 7 of 10 youth were overweight or obese. The nested-sampling frame achieved an even distribution by body weight. Cross-sectional relationships between body size, fatness and growth rate, food patterns, activity patterns, pubertal development, risks for diabetes and hypertension and the family and wider environment will be examined. In addition, analyses will investigate relationships with data collected earlier in the life course and measures of the cohort in the future. Understanding past and present influences on child growth and health will inform timely interventions to optimise future health and reduce inequalities for Pacific people. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Lysophosphatidic Acid and Apolipoprotein A1 Predict Increased Risk of Developing World Trade Center Lung Injury: A Nested Case-Control Study

PubMed Central

Tsukiji, Jun; Cho, Soo Jung; Echevarria, Ghislaine C.; Kwon, Sophia; Joseph, Phillip; Schenck, Edward J.; Naveed, Bushra; Prezant, David J.; Rom, William N.; Schmidt, Ann Marie; Weiden, Michael D.; Nolan, Anna

2014-01-01

Rationale Metabolic syndrome, inflammatory and vascular injury markers measured in serum after WTC exposures predict abnormal FEV1. We hypothesized that elevated LPA levels predict FEV1

Inhaled Corticosteroid Use in Chronic Obstructive Pulmonary Disease and Risk of Pneumonia: A Nested Case-Control Population-based Study in Lazio (Italy)-The OUTPUL Study.

PubMed

Cascini, Silvia; Kirchmayer, Ursula; Belleudi, Valeria; Bauleo, Lisa; Pistelli, Riccardo; Di Martino, Mirko; Formoso, Giulio; Davoli, Marina; Agabiti, Nera

2017-06-01

Inhaled corticosteroid (ICS) use in chronic obstructive pulmonary disease (COPD) patients is associated with a reduction of exacerbations and a potential risk of pneumonia. The objective was to determine if ICS use, with or without long-acting β 2 -agonist, increases pneumonia risk in COPD patients. A cohort study was performed using linked hospital and drug prescription databases in the Lazio region. Patients (45+) discharged with COPD in 2006-2009 were enrolled and followed from cohort entry until first admission for pneumonia, death or study end, 31 December, 2012. A nested case-control approach was used to estimate the rate ratio (RR) associated with current or past use of ICS adjusted for age, gender, number of exacerbations in the previous year and co-morbidities. Current users were defined as patients with their last ICS prescribed in the 60 days prior to the event. Past users were those with the last prescription between 61 and 365 days before the event. Current use was classified into three levels (high, medium, low) according to the medication possession ratio. Among the cohort of 19288 patients, 3141 had an event of pneumonia (incidence rate for current use 87/1000py, past use 32/1000py). After adjustment, patients with current use were 2.29 (95% confidence interval [CI]: 1.99-2.63) times more likely to be hospitalised for pneumonia with respect to no use; for past use RR was 1.23 (95% CI: 1.07-1.42). For older patients (80+), the rate was higher than that for younger patients. ICS use was associated with an excess risk of pneumonia. The effect was greatest for higher doses and in the very elderly.

The ANDROMEDA prospective cohort study: predictive value of combined criteria to tailor breast cancer screening and new opportunities from circulating markers: study protocol.

PubMed

Giordano, Livia; Gallo, Federica; Petracci, Elisabetta; Chiorino, Giovanna; Segnan, Nereo

2017-11-22

In recent years growing interest has been posed on alternative ways to screen women for breast cancer involving different imaging techniques or adjusting screening interval by breast cancer risk estimates. A new research area is studying circulating microRNAs as molecular biomarkers potentially useful for non invasive early detection together with the analysis of single-nucleotide polymorphisms (SNPs). The Andromeda study is a prospective cohort study on women attending breast cancer screening in a northern Italian area. The aims of the study are: 1) to define appropriate women risk-based stratifications for personalized screening considering different factors (reproductive, family and biopsy history, breast density, lifestyle habits); 2) to evaluate the diagnostic accuracy of selected circulating microRNAs in a case-control study nested within the above mentioned cohort. About 21,000 women aged 46-67 years compliant to screening mammography are expected to be enrolled. At enrolment, information on well-known breast cancer risk factors and life-styles habits are collected through self-admistered questionnaires. Information on breast density and anthropometric measurements (height, weight, body composition, and waist circumference) are recorded. In addition, women are requested to provide a blood sample for serum, plasma and buffy-coat storing for subsequent molecular analyses within the nested case-control study. This investigation will be performed on approximately 233 cases (screen-detected) and 699 matched controls to evaluate SNPs and circulating microRNAs. The whole study will last three years and the cohort will be followed up for ten years to observe the onset of new breast cancer cases. Nowadays women undergo the same screening protocol, independently of their breast density and their individual risk to develop breast cancer. New criteria to better stratify women in risk groups could enable the screening strategies to target high-risk women while reducing interventions in those at low-risk. In this frame the present study will contribute in identifying the feasibility and impact of implementing personalized breast cancer screening. NCT02618538 (retrospectively registered on 27-11-2015.).

Training for Defense? From Stochastic Traits to Synchrony in Giant Honey Bees (Apis dorsata).

PubMed

Weihmann, Frank; Hoetzl, Thomas; Kastberger, Gerald

2012-08-30

In Giant Honey Bees, abdomen flipping happens in a variety of contexts. It can be either synchronous or cascaded, such as in the collective defense traits of shimmering and rearing-up, or it can happen as single-agent behavior. Abdomen flipping is also involved in flickering behavior, which occurs regularly under quiescent colony state displaying singular or collective traits, with stochastic, and (semi-) synchronized properties. It presumably acts via visual, mechanoceptive, and pheromonal pathways and its goals are still unknown. This study questions whether flickering is preliminary to shimmering which is subject of the fs (flickering-shimmering)-transition hypothesis? We tested the respective prediction that trigger sites (ts) at the nest surface (where shimmering waves had been generated) show higher flickering activity than the alternative non-trigger sites (nts). We measured the flickering activity of ts- and nts-surface bees from two experimental nests, before and after the colony had been aroused by a dummy wasp. Arousal increased rate and intensity of the flickering activity of both ts- and nts cohorts (P < 0.05), whereby the flickering intensity of ts-bees were higher than that of nts-bees (P < 0.05). Under arousal, the colonies also increased the number of flickering-active ts- and nts-cohorts (P < 0.05). This provides evidence that cohorts which are specialist at launching shimmering waves are found across the quiescent nest zone. It also proves that arousal may reinforce the responsiveness of quiescent curtain bees for participating in shimmering, practically by recruiting additional trigger site bees for expanding repetition of rate and intensity of shimmering waves. This finding confirms the fs-transition hypothesis and constitutes evidence that flickering is part of a basal colony-intrinsic information system. Furthermore, the findings disprove that the muscle activity associated with flickering would heat up the surface bees. Hence, surface bees are not actively contributing to thermoregulation.

Training for Defense? From Stochastic Traits to Synchrony in Giant Honey Bees (Apis dorsata)

PubMed Central

Weihmann, Frank; Hoetzl, Thomas; Kastberger, Gerald

2012-01-01

In Giant Honey Bees, abdomen flipping happens in a variety of contexts. It can be either synchronous or cascaded, such as in the collective defense traits of shimmering and rearing-up, or it can happen as single-agent behavior. Abdomen flipping is also involved in flickering behavior, which occurs regularly under quiescent colony state displaying singular or collective traits, with stochastic, and (semi-) synchronized properties. It presumably acts via visual, mechanoceptive, and pheromonal pathways and its goals are still unknown. This study questions whether flickering is preliminary to shimmering which is subject of the fs (flickering-shimmering)-transition hypothesis? We tested the respective prediction that trigger sites (ts) at the nest surface (where shimmering waves had been generated) show higher flickering activity than the alternative non-trigger sites (nts). We measured the flickering activity of ts- and nts-surface bees from two experimental nests, before and after the colony had been aroused by a dummy wasp. Arousal increased rate and intensity of the flickering activity of both ts- and nts cohorts (P < 0.05), whereby the flickering intensity of ts-bees were higher than that of nts-bees (P < 0.05). Under arousal, the colonies also increased the number of flickering-active ts- and nts-cohorts (P < 0.05). This provides evidence that cohorts which are specialist at launching shimmering waves are found across the quiescent nest zone. It also proves that arousal may reinforce the responsiveness of quiescent curtain bees for participating in shimmering, practically by recruiting additional trigger site bees for expanding repetition of rate and intensity of shimmering waves. This finding confirms the fs-transition hypothesis and constitutes evidence that flickering is part of a basal colony-intrinsic information system. Furthermore, the findings disprove that the muscle activity associated with flickering would heat up the surface bees. Hence, surface bees are not actively contributing to thermoregulation. PMID:26466631

Extreme developmental temperatures result in morphological abnormalities in painted turtles (Chrysemys picta): a climate change perspective.

PubMed

Telemeco, Rory S; Warner, Daniel A; Reida, Molly K; Janzen, Fredric J

2013-06-01

Increases in extreme environmental events are predicted to be major results of ongoing global climate change and may impact the persistence of species. We examined the effects of heat and cold waves during embryonic development of painted turtles (Chrysemys picta) in natural nests on the occurrence of abnormal shell morphologies in hatchlings. We found that nests exposed to extreme hot temperatures for >60 h produced more hatchlings with abnormalities than nests exposed to extreme hot temperatures for shorter periods, regardless of whether or not nesting females displayed abnormal morphologies. We observed no effect of extreme cold nest temperatures on the occurrence of hatchlings with abnormalities. Moreover, the frequency of nesting females with abnormal shell morphologies was approximately 2-fold lower than that of their offspring, suggesting that such abnormalities are negatively correlated with survival and fitness. Female turtles could potentially buffer their offspring from extreme heat by altering aspects of nesting behavior, such as choosing shadier nesting sites. We addressed this hypothesis by examining the effects of shade cover on extreme nest temperatures and the occurrence of hatchling abnormalities. While shade cover was negatively correlated with the occurrence of extreme hot nest temperatures, it was not significantly correlated with abnormalities. Therefore, female choice of shade cover does not appear to be a viable target for selection to reduce hatchling abnormalities. Our results suggest that increases in the frequency and intensity of heat waves associated with climate change might perturb developmental programs and thereby reduce the fitness of entire cohorts of turtles. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

Risk factors for Staphylococcus aureus postpartum breast abscess.

PubMed

Branch-Elliman, Westyn; Golen, Toni H; Gold, Howard S; Yassa, David S; Baldini, Linda M; Wright, Sharon B

2012-01-01

Staphylococcus aureus (SA) breast abscesses are a complication of the postpartum period. Risk factors for postpartum SA breast abscesses are poorly defined, and literature is conflicting. Whether risk factors for methicillin-resistant SA (MRSA) and methicillin-susceptible SA (MSSA) infections differ is unknown. We describe novel risk factors associated with postpartum breast abscesses and the changing epidemiology of this infection. We conducted a cohort study with a nested case-control study (n = 216) involving all patients with culture-confirmed SA breast abscess among >30 000 deliveries at our academic tertiary care center from 2003 through 2010. Data were collected from hospital databases and through abstraction from medical records. All SA cases were compared with both nested controls and full cohort controls. A subanalysis was completed to determine whether risk factors for MSSA and MRSA breast abscess differ. Univariate analysis was completed using Student's t test, Wilcoxon rank-sum test, and analysis of variance, as appropriate. A multivariable stepwise logistic regression was used to determine final adjusted results for both the case-control and the cohort analyses. Fifty-four cases of culture-confirmed abscess were identified: 30 MRSA and 24 MSSA. Risk factors for postpartum SA breast abscess in multivariable analysis include in-hospital identification of a mother having difficulty breastfeeding (odds ratio, 5.00) and being a mother employed outside the home (odds ratio, 2.74). Risk factors did not differ between patients who developed MRSA and MSSA infections. MRSA is an increasingly important pathogen in postpartum women; risk factors for postpartum SA breast abscess have not changed with the advent of community-associated MRSA.

Core Outcomes in Ventilation Trials (COVenT): protocol for a core outcome set using a Delphi survey with a nested randomised trial and observational cohort study.

PubMed

Blackwood, Bronagh; Ringrow, Suzanne; Clarke, Mike; Marshall, John; Rose, Louise; Williamson, Paula; McAuley, Danny

2015-08-20

Among clinical trials of interventions that aim to modify time spent on mechanical ventilation for critically ill patients there is considerable inconsistency in chosen outcomes and how they are measured. The Core Outcomes in Ventilation Trials (COVenT) study aims to develop a set of core outcomes for use in future ventilation trials in mechanically ventilated adults and children. We will use a mixed methods approach that incorporates a randomised trial nested within a Delphi study and a consensus meeting. Additionally, we will conduct an observational cohort study to evaluate uptake of the core outcome set in published studies at 5 and 10 years following core outcome set publication. The three-round online Delphi study will use a list of outcomes that have been reported previously in a review of ventilation trials. The Delphi panel will include a range of stakeholder groups including patient support groups. The panel will be randomised to one of three feedback methods to assess the impact of the feedback mechanism on subsequent ranking of outcomes. A final consensus meeting will be held with stakeholder representatives to review outcomes. The COVenT study aims to develop a core outcome set for ventilation trials in critical care, explore the best Delphi feedback mechanism for achieving consensus and determine if participation increases use of the core outcome set in the long term.

Decision-Making Involvement and Prediction of Adherence in Youth With Type 1 Diabetes: A Cohort Sequential Study.

PubMed

Miller, Victoria A; Jawad, Abbas F

2018-05-17

To assess developmental trajectories of decision-making involvement (DMI), defined as the ways in which parents and children engage each other in decision-making about illness management, in youth with type 1 diabetes (T1D) and examine the effects of DMI on levels of and changes in adherence with age. Participants included 117 youth with T1D, enrolled at ages 8-16 years and assessed five times over 2 years. The cohort sequential design allowed for the approximation of the longitudinal curve from age 8 to 19 from overlapping cohort segments. Children and parents completed the Decision-Making Involvement Scale, which yields subscales for different aspects of DMI, and a self-report adherence questionnaire. Mixed-effects growth curve modeling was used for analysis, with longitudinal measures nested within participant and participants nested within cohort. Most aspects of DMI (Parent Express, Parent Seek, Child Express, and Joint) increased with child age; scores on some child report subscales (Parent Express, Child Seek, and Joint) decreased after age 12-14 years. After accounting for age, Child Seek, Child Express, and Joint were associated with overall higher levels of adherence in both child (estimates = 0.08-0.13, p < .001) and parent (estimates = 0.07- 0.13, p < .01) report models, but they did not predict changes in adherence with age. These data suggest that helping children to be more proactive in T1D discussions, by encouraging them to express their opinions, share information, and solicit guidance from parents, is a potential target for interventions to enhance effective self-management.

Validation and clinical application of a molecular method for the identification of Cryptococcus neoformans/Cryptococcus gattii complex DNA in human clinical specimens.

PubMed

Rivera, Vanessa; Gaviria, Marcela; Muñoz-Cadavid, Cesar; Cano, Luz; Naranjo, Tonny

2015-01-01

The diagnosis of cryptococcosis is usually performed based on cultures of tissue or body fluids and isolation of the fungus, but this method may require several days. Direct microscopic examination, although rapid, is relatively insensitive. Biochemical and immunodiagnostic rapid tests are also used. However, all of these methods have limitations that may hinder final diagnosis. The increasing incidence of fungal infections has focused attention on tools for rapid and accurate diagnosis using molecular biological techniques. Currently, PCR-based methods, particularly nested, multiplex and real-time PCR, provide both high sensitivity and specificity. In the present study, we evaluated a nested PCR targeting the gene encoding the ITS-1 and ITS-2 regions of rDNA in samples from a cohort of patients diagnosed with cryptococcosis. The results showed that in our hands, this Cryptococcus nested PCR assay has 100% specificity and 100% sensitivity and was able to detect until 2 femtograms of Cryptococcus DNA. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

Genetic causes of intellectual disability in a birth cohort: a population-based study.

PubMed

Karam, Simone M; Riegel, Mariluce; Segal, Sandra L; Félix, Têmis M; Barros, Aluísio J D; Santos, Iná S; Matijasevich, Alicia; Giugliani, Roberto; Black, Maureen

2015-06-01

Intellectual disability affects approximately 1-3% of the population and can be caused by genetic and environmental factors. Although many studies have investigated the etiology of intellectual disability in different populations, few studies have been performed in middle-income countries. The present study estimated the prevalence of genetic causes related to intellectual disability in a cohort of children from a city in south Brazil who were followed from birth. Children who showed poor performance in development and intelligence tests at the ages of 2 and 4 were included. Out of 4,231 liveborns enrolled in the cohort, 214 children fulfilled the inclusion criteria. A diagnosis was established in approximately 90% of the children evaluated. Genetic causes were determined in 31 of the children and 19 cases remained unexplained even after extensive investigation. The overall prevalence of intellectual disability in this cohort due to genetic causes was 0.82%. Because this study was nested in a cohort, there were a large number of variables related to early childhood and the likelihood of information bias was minimized by collecting information with a short recall time. This study was not influenced by selection bias, allowing identification of intellectual disability and estimation of the prevalence of genetic causes in this population, thereby increasing the possibility of providing appropriate management and/or genetic counseling. © 2015 Wiley Periodicals, Inc.

A Case–Control Study of Lung Cancer Nested in a Cohort of European Asphalt Workers

PubMed Central

Olsson, Ann; Kromhout, Hans; Agostini, Michela; Hansen, Johnni; Lassen, Christina Funch; Johansen, Christoffer; Kjaerheim, Kristina; Langård, Sverre; Stücker, Isabelle; Ahrens, Wolfgang; Behrens, Thomas; Lindbohm, Marja-Liisa; Heikkilä, Pirjo; Heederik, Dick; Portengen, Lützen; Shaham, Judith; Ferro, Gilles; de Vocht, Frank; Burstyn, Igor; Boffetta, Paolo

2010-01-01

Background We conducted a nested case–control study in a cohort of European asphalt workers in which an increase in lung cancer risk has been reported among workers exposed to airborne bitumen fume, although potential bias and confounding were not fully addressed. Objective We investigated the contribution of exposure to bitumen, other occupational agents, and tobacco smoking to the risk of lung cancer among asphalt workers. Methods Cases were cohort members in Denmark, Finland, France, Germany, the Netherlands, Norway, and Israel who had died of lung cancer between 1980 and the end of follow-up (2002–2005). Controls were individually matched in a 3:1 ratio to cases on year of birth and country. We derived exposure estimates for bitumen fume and condensate, organic vapor, and polycyclic aromatic hydrocarbons, as well as for asbestos, crystalline silica, diesel motor exhaust, and coal tar. Odds ratios (ORs) were calculated for ever-exposure, duration, average exposure, and cumulative exposure after adjusting for tobacco smoking and exposure to coal tar. Results A total of 433 cases and 1,253 controls were included in the analysis. The OR was 1.12 [95% confidence interval (CI), 0.84–1.49] for inhalation exposure to bitumen fume and 1.17 (95% CI, 0.88–1.56) for dermal exposure to bitumen condensate. No significant trend was observed between lung cancer risk and duration, average exposure, or cumulative exposure to bitumen fume or condensate. Conclusions We found no consistent evidence of an association between indicators of either inhalation or dermal exposure to bitumen and lung cancer risk. A sizable proportion of the excess mortality from lung cancer relative to the general population observed in the earlier cohort phase is likely attributable to high tobacco consumption and possibly to coal tar exposure, whereas other occupational agents do not appear to play an important role. PMID:20529766

Sarcosine and other metabolites along the choline oxidation pathway in relation to prostate cancer--a large nested case-control study within the JANUS cohort in Norway.

PubMed

de Vogel, Stefan; Ulvik, Arve; Meyer, Klaus; Ueland, Per Magne; Nygård, Ottar; Vollset, Stein Emil; Tell, Grethe S; Gregory, Jesse F; Tretli, Steinar; Bjørge, Tone

2014-01-01

Methyl group donors and intermediates of one-carbon metabolism affect DNA synthesis and DNA methylation, and may thereby affect prostate carcinogenesis. Choline, the precursor of betaine, and the one-carbon metabolite sarcosine have been associated with increased prostate cancer risk. Within JANUS, a prospective cohort in Norway (n = 317,000) with baseline serum samples, we conducted a nested case-control study among 3,000 prostate cancer cases and 3,000 controls. Using conditional logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) for prostate cancer risk were estimated according to quintiles of circulating betaine, dimethylglycine (DMG), sarcosine, glycine and serine. High sarcosine and glycine concentrations were associated with reduced prostate cancer risk of borderline significance (sarcosine: highest vs. lowest quintile OR = 0.86, CI = 0.72-1.01, p(trend) = 0.03; glycine: OR = 0.83, CI = 0.70-1.00, p(trend) = 0.07). Serum betaine, DMG and serine were not associated with prostate cancer risk. However, individuals with a high glycine/serine ratio were at decreased prostate cancer risk (OR = 0.74, CI = 0.69-0.85, p(trend) < 0.001). This population-based study suggested that men with high serum sarcosine or glycine concentrations have modestly reduced prostate cancer risk. Ratios of metabolites reflecting one-carbon balance may be associated with prostate cancer risk, as demonstrated for the glycine/serine ratio, and should be explored in future studies. © 2013 UICC.

Effectiveness of a computerised system of patient education in clinical practice: a longitudinal nested cohort study.

PubMed

Su, Chia-Hsien; Li, Tsai-Chung; Cho, Der-Yang; Ma, Wei-Fen; Chang, Yu-Shan; Lee, Tsung-Han; Huang, Li-Chi

2018-05-03

Developing electronic health record information systems is an international trend for promoting the integration of health information and enhancing the quality of medical services. Patient education is a frequent intervention in nursing care, and recording the amount and quality of patient education have become essential in the nursing record. The aims of this study are (1): to develop a high-quality Patient Education Assessment and Description Record System (PEADRS) in the electronic medical record (2); to examine the effectiveness of the PEADRS on documentation and nurses' satisfaction (3); to facilitate communication and cooperation between professionals. A quasi-experimental design and random sampling will be used. The participants are nurses who are involved in patient education by using traditional record or the PEADRS at a medical centre. A prospective longitudinal nested cohort study will be conducted to compare the effectiveness of the PEADRS, including (1): the length of nursing documentation (2); satisfaction with using the PEADRS; and (3) the benefit to professional cooperation. Patient privacy will be protected according to Electronic Medical Record Management Practices of the hospital. This study develops a patient education digital record system, which would profit the quality of clinical practice in health education. The results will be published in peer-reviewed journals and will be presented at scientific conferences. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Proton-pump inhibitors are associated with a reduced risk for bleeding and perforated gastroduodenal ulcers attributable to non-steroidal anti-inflammatory drugs: a nested case-control study

PubMed Central

Vonkeman, Harald E; Fernandes, Robert W; van der Palen, Job; van Roon, Eric N; van de Laar, Mart AFJ

2007-01-01

Treatment with non-steroidal anti-inflammatory drugs (NSAIDs) is hampered by gastrointestinal ulcer complications, such as ulcer bleeding and perforation. The efficacy of proton-pump inhibitors in the primary prevention of ulcer complications arising from the use of NSAIDs remains unproven. Selective cyclooxygenase-2 (COX-2) inhibitors reduce the risk for ulcer complications, but not completely in high-risk patients. This study determines which patients are especially at risk for NSAID ulcer complications and investigates the effectiveness of different preventive strategies in daily clinical practice. With the use of a nested case-control design, a large cohort of NSAID users was followed for 26 months. Cases were patients with NSAID ulcer complications necessitating hospitalisation; matched controls were selected from the remaining cohort of NSAID users who did not have NSAID ulcer complications. During the observational period, 104 incident cases were identified from a cohort of 51,903 NSAID users with 10,402 patient years of NSAID exposure (incidence 1% per year of NSAID use, age at diagnosis 70.4 ± 16.7 years (mean ± SD), 55.8% women), and 284 matched controls. Cases were characterised by serious, especially cardiovascular, co-morbidity. In-hospital mortality associated with NSAID ulcer complications was 10.6% (incidence 21.2 per 100,000 NSAID users). Concomitant proton-pump inhibitors (but not selective COX-2 inhibitors) were associated with a reduced risk for NSAID ulcer complications (the adjusted odds ratio 0.33; 95% confidence interval 0.17 to 0.67; p = 0.002). Especially at risk for NSAID ulcer complications are elderly patients with cardiovascular co-morbidity. Proton-pump inhibitors are associated with a reduced risk for NSAID ulcer complications. PMID:17521422

Microbiota-Dependent Marker TMAO Is Elevated in Silent Ischemia but Is Not Associated With First-Time Myocardial Infarction in HIV Infection.

PubMed

Haissman, Judith M; Knudsen, Andreas; Hoel, Hedda; Kjær, Andreas; Kristoffersen, Ulrik S; Berge, Rolf K; Katzenstein, Terese L; Svardal, Asbjørn; Ueland, Thor; Aukrust, Pål; Lebech, Anne-Mette; Nielsen, Susanne D; Trøseid, Marius

2016-02-01

HIV infection is associated with increased risk of coronary heart disease beyond that explained by traditional risk factors, and altered gut microbiota has been proposed as a potential trigger. Trimethylamine-N-oxide (TMAO) is a proatherogenic substance formed in the liver from trimethylamine, exclusively generated by gut microbiota from dietary phosphatidylcholine. We aimed to investigate whether TMAO is associated with subclinical and clinical coronary heart disease in HIV infection. Two previously described cohorts were examined as follows: (1) cross-sectional cohort of HIV-infected persons and uninfected controls with known atherosclerotic plaque burden as assessed by myocardial perfusion scintigraphy, coronary artery calcium score, and intima-media thickness and (2) nested case-control study of HIV-infected persons with first-time myocardial infarction (MI) compared with HIV-infected persons without MI, assessed at 4 time points from before initiation of antiretroviral therapy (ART) to last sample before the case's MI (median: 51, range: 0-239 days). There was no difference in plasma TMAO when comparing HIV-infected persons and uninfected controls. TMAO was elevated in HIV-infected persons with myocardial perfusion defects but was not associated with coronary artery calcium score, intima media thickness, or Framingham risk score. In the nested case control study, plasma TMAO was not associated with first-time MI. However, TMAO increased after ART introduction and was associated with the use of protease inhibitors in both cohorts. TMAO was elevated in HIV-infected persons with myocardial perfusion defects, but was not associated with first-time MI. Our data question TMAO as a useful biomarker of cardiovascular risk in HIV infection, at least in ART-treated individuals.

Case-control study of male germ cell tumors nested in a cohort of car-manufacturing workers: Findings from the occupational history.

PubMed

Langner, Ingo; Schmeisser, Nils; Mester, Birte; Behrens, Thomas; Gottlieb, Andrea; Ahrens, Wolfgang

2010-10-01

To examine whether the previously observed excess risk of male germ cell cancer in a cohort of car-manufacturing workers can be attributed to occupational activities inside and/or outside the car industry. A nested case-control study among workers in six plants included 205 cases of germ cell cancer and 1,105 controls, individually matched by year of birth (±2 years). Job periods of the individual occupational histories were coded based on the International Standard Classification of Occupations (ISCO) and the industrial classification of economic activities (NACE). Odds ratios (ORs) and corresponding 95%-confidence intervals (CI) for ever-never and cumulative employment were calculated by conditional multivariate logistic regression adjusted for cryptorchidism. Significantly increased risks were observed for machinery fitters and assemblers (A) (OR = 1.8, 95% CI 1.25-2.53) and "workers not elsewhere classified" (OR = 2.10, 95% CI 1.27-3.54), but no trend was observed for employment duration in either occupational group. Stratification of job group A by metal-cutting and non-cutting jobs yielded ORs of 1.87 (95% CI 1.31-2.67) and of 1.24 (95% CI 0.68-2.28), respectively. Among "plumbers, welders, sheet & structural metal workers" (adjusted OR 1.4, 95% CI 0.99-1.95) only "structural metal preparers and erectors" showed a substantially increased risk (OR = 2.30; 95% CI 1.27-4.27). Our results do not fully explain the increased incidence of germ cell cancer in the cohort, but support previous findings showing increased risks among metal workers. These risks were most strongly pronounced in metal-cutting activities. © 2010 Wiley-Liss, Inc.

Genetic Variations in Mitochondria and Prostate Cancer Aggressiveness and Progression in Caucasian and African American Men

DTIC Science & Technology

2015-09-01

cancer, including renal cell carcinoma, non-Hodgkin lymphoma , breast cancer, esophageal adenocarcinoma, lung cancer, colorectal cancer, and...Bassig BA, Seow WJ, Hu W, Purdue MP, Huang WY, et al. Mitochondrial DNA copy number and chronic lymphocytic leukemia/small lymphocytic lymphoma risk...Mitochondrial DNA copy number and future risk of B-cell lymphoma in a nested case-control study in the prospective EPIC cohort. Blood. 2014;124(4):530-5

Freshman year mental health symptoms and level of adaptation as predictors of Internet addiction: a retrospective nested case-control study of male Chinese college students.

PubMed

Yao, Bin; Han, Wei; Zeng, Lingxia; Guo, Xiong

2013-12-15

A retrospective nested case-control study was designed to explore whether freshman year mental health status and level of adaptation are predictors of Internet addiction. The study cohort was 977 college students at a university in northwest China. In the first college year, the students' mental health status and adaptation level were assessed using the Chinese College Student Mental Health Scale (CCSMHS) and the Chinese College Student Adjustment Scale (CCSAS). In the following 1-3 years, 62 Internet-addicted subjects were identified using Young's 8-item diagnostic questionnaire. Controls were matched for demographic characteristics. Using logistic regression analysis, freshman year mental health status, including factors such as somatization, anxiety, depression and self-contempt, and freshman year adaptive problems were found to be causal factors and predictors of Internet addiction. Freshman with features of depression, learning maladaptation and dissatisfaction could be an important target-intervention population for reducing Internet addiction. © 2013 Elsevier Ireland Ltd. All rights reserved.

Reproductive biology and genetic diversity of the green turtle (Chelonia mydas) in Vamizi island, Mozambique.

PubMed

Anastácio, Rita; Santos, Camila; Lopes, Cardoso; Moreira, Helena; Souto, Luis; Ferrão, Jorge; Garnier, Julie; Pereira, Mário J

2014-01-01

Vamizi, an Island located in the Western Indian Ocean, is visited by a small and not fully characterized green turtle (Chelonia mydas (L.)) population. This population is threatened by natural hazards and several human activities, which are used to identify conservation priorities for marine turtles. It was our aim to contribute to the knowledge of marine turtles that nest in Vamizi, with respect to its regional management, and to an area that may possibly be included on the UNESCO World Heritage List due to its potential Outstanding Universal Value. Here, we evaluate the nesting parameters (incubation period, clutch size, hatching and emergence successes rates) and patterns over an 8-year (2003 - 2010) conservation program. We also present the results of genetic diversity based on the analysis of approximately an 850 pb fragment of the mitochondrial DNA control region. We found that Vamizi beaches host a small number of nesting females, approximately 52 per year, but these have shown a reduction in their length. High hatching success (88.5 ± SD 17.2%, N = 649), emergence success rates (84.5 ± SD 20.4%, N = 649) were observed, and genetic diversity (N = 135), with 11 haplotypes found (7 new). It was also observed, in the later years of this study, a reduction in the incubation period, a dislocation of the nesting peak activity and an increase in the number of flooded nests and an increase of the number of nests in areas with lower human activity. Some resilience and behavioral plasticity seems to occur regarding human territory occupancy and climate changes. However, regardless of the results, aspects like what seems to be the reduction of some cohorts, the number of flooded nests and the diminishing of the incubation period (East and South facing beaches), show that conservation efforts have to be improved.

From Advance Euthanasia Directive to Euthanasia: Stable Preference in Older People?

PubMed

Bolt, Eva E; Pasman, H Roeline W; Deeg, Dorly J H; Onwuteaka-Philipsen, Bregje D

2016-08-01

To determine whether older people with advance directive for euthanasia (ADEs) are stable in their advance desire for euthanasia in the last years of life, how frequently older people with an ADE eventually request euthanasia, and what factors determine this. Mortality follow-back study nested in a cohort study. The Netherlands. Proxies of deceased members of a cohort representative of Dutch older people (n = 168) and a cohort of people with advance directives (n = 154). Data from cohort members (possession of ADE) combined with after-death proxy information on cohort members' last 3 months of life. Multiple logistic regression analysis was performed on determinants of a euthanasia request in individuals with an ADE. Response rate was 65%. One hundred forty-two cohort members had an ADE at baseline. Three months before death, 87% remained stable in their desire for euthanasia; 47% eventually requested euthanasia (vs 6% without an ADE), and 16% died after euthanasia. People with an ADE were more likely to request euthanasia if they worried about loss of dignity. The majority of older adults who complete an ADE will have a stable preference over time, but an advance desire for euthanasia does not necessarily result in a euthanasia request. Writing an ADE may reflect a person's need for reassurance that they can request euthanasia in the future. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Mediterranean diet and telomere length in Nurses' Health Study: population based cohort study.

PubMed

Crous-Bou, Marta; Fung, Teresa T; Prescott, Jennifer; Julin, Bettina; Du, Mengmeng; Sun, Qi; Rexrode, Kathryn M; Hu, Frank B; De Vivo, Immaculata

2014-12-02

To examine whether adherence to the Mediterranean diet was associated with longer telomere length, a biomarker of aging. Population based cohort study. Nurses' Health Study, an ongoing prospective cohort study of 121,700 nurses enrolled in 1976; in 1989-90 a subset of 32,825 women provided blood samples. 4676 disease-free women from nested case-control studies within the Nurses' Health Study with telomere length measured who also completed food frequency questionnaires. Association between relative telomere lengths in peripheral blood leukocytes measured by quantitative real time polymerase chain reaction and Alternate Mediterranean Diet score calculated from self reported dietary data. Greater adherence to the Mediterranean diet was associated with longer telomeres after adjustment for potential confounders. Least squares mean telomere length z scores were -0.038 (SE 0.035) for the lowest Mediterranean diet score groups and 0.072 (0.030) for the highest group (P for trend = 0.004). In this large study, greater adherence to the Mediterranean diet was associated with longer telomeres. These results further support the benefits of adherence to the Mediterranean diet for promoting health and longevity. © Crous-Bou et al 2014.

RISK FACTORS FOR SLOW GAIT SPEED: A NESTED CASE-CONTROL SECONDARY ANALYSIS OF THE MEXICAN HEALTH AND AGING STUDY.

PubMed

Pérez-Zepeda, M U; González-Chavero, J G; Salinas-Martinez, R; Gutiérrez-Robledo, L M

2015-01-01

Physical performance tests play a major role in the geriatric assessment. In particular, gait speed has shown to be useful for predicting adverse outcomes. However, risk factors for slow gait speed (slowness) are not clearly described. To determine risk factors associated with slowness in Mexican older adults. A two-step process was adopted for exploring the antecedent risk factors of slow gait speed. First, the cut-off values for gait speed were determined in a representative sample of Mexican older adults. Then, antecedent risk factors of slow gait speed (defined using the identified cut-points) were explored in a nested, cohort case-control study. One representative sample of a cross-sectional survey for the first step and the Mexican Health and Aging Study (a cohort characterized by a 10-year follow-up). A 4-meter usual gait speed test was conducted. Lowest gender and height-stratified groups were considered as defining slow gait speed. Sociodemographic characteristics, comorbidities, psychological and health-care related variables were explored to find those associated with the subsequent development of slow gait speed. Unadjusted and adjusted logistic regression models were performed. In the final model, age, diabetes, hypertension, and history of fractures were associated with the development of slow gait speed. Early identification of subjects at risk of developing slow gait speed may halt the path to disability due to the robust association of this physical performance test with functional decline.

Myeloid leukaemia in systemic lupus erythematosus--a nested case-control study based on Swedish registers.

PubMed

Löfström, Björn; Backlin, Carin; Sundström, Christer; Hellström-Lindberg, Eva; Ekbom, Anders; Lundberg, Ingrid E

2009-10-01

To assess the risk factors for leukaemic transformation and myeloid leukaemia in patients with SLE. A national SLE cohort identified through SLE discharge diagnoses in the Swedish hospital discharge register during 1964 to 1995 (n = 6438) was linked to the national cancer register. A nested case-control study in SLE patients who developed acute or chronic myeloid leukaemia was performed with SLE patients without malignancy as controls. Medical records from cases and controls were reviewed and bone marrow specimens were re-evaluated. A Medline search of previously published cases of SLE and myeloid leukaemia was performed. After confirmation of SLE diagnosis according to the ACR criteria, eight patients with SLE and myeloid leukaemia and 18 SLE controls were included in the study. Preceding leucopenia was significantly associated with leukaemia development, whereas other SLE manifestations were not. Two cases had a preceding bone marrow confirming myelodysplastic syndrome (MDS). Only two cases were significantly treated with cyclophosphamide or AZA. A Medline search resulted in only 15 previously published cases of coincident SLE and myeloid leukaemia. Preceding MDS was reported in five of these, whereas only eight had been treated with cytotoxic drugs. Low-dose chemotherapy was not a major cause of myeloid malignancy in our population-based cohort of SLE patients nor in the reported cases from literature. Leucopenia was a risk factor for myeloid leukaemia development and an MDS was frequently seen. Therefore bone marrow investigation should be considered in SLE patients with long-standing leucopenia and anaemia.

Healthy Dental Pulp Oxygen Saturation Rates in Subjects with Homozygous Sickle Cell Anemia: A Cross-Sectional Study Nested in a Cohort.

PubMed

Souza, Soraia de Fátima Carvalho; Thomaz, Erika Bárbara Abreu Fonseca; Costa, Cyrene Piazera Silva

2017-12-01

To compare the percentage of arterial oxygen saturation (SpO 2 ) in healthy teeth with confirmed pulp vitality between individuals with sickle cell anemia (HbSS) and normal hemoglobin A (HbAA). This is a cross-sectional study nested within a cohort. Samples (n = 2543) comprised teeth with intact crowns and pulp vitality confirmed by thermal sensitivity tests and no history of caries, periodontal disease, or dental trauma. A total of 728 teeth of 113 individuals with HbSS and 1815 teeth of 246 individuals with HbAA were evaluated. Data analysis was performed using the χ 2 and Mann-Whitney tests and Spearman correlation analysis (α = 0.05). The study groups were comparable in terms of age, race, and sex (P > .05). Subjects with HbSS exhibited lower median SpO 2 levels in the body and upper teeth, excluding canines, than subjects with HbAA (P < .05). There were no significant differences in the evaluated parameters between the 2 groups (P > .05). Compared with individuals with HbAA, those with HbSS exhibited lower SpO 2 in maxillary teeth with confirmed pulp vitality, except in the canines. There was no correlation between SpO 2 levels of the body and dental pulp in individuals with HbSS or HbAA. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Long-term health experience of jet engine manufacturing workers: VIII. glioblastoma incidence in relation to workplace experiences with parts and processes.

PubMed

Marsh, Gary M; Youk, Ada O; Buchanich, Jeanine M; Downing, Sarah; Kennedy, Kathleen J; Esmen, Nurtan A; Hancock, Roger P; Lacey, Steven E; Pierce, Jennifer S; Fleissner, Mary Lou

2013-06-01

To determine whether glioblastoma (GB) incidence rates among jet engine manufacturing workers were associated with workplace experiences with specific parts produced and processes performed. Subjects were 210,784 workers employed between 1952 and 2001. We conducted nested case-control and cohort incidence studies with focus on 277 GB cases. We estimated time experienced with 16 part families, 4 process categories, and 32 concurrent part-process combinations with 20 or more GB cases. In both the cohort and case-control studies, none of the part families, process categories, or both considered was associated with increased GB risk. If not due to chance alone, the not statistically significantly elevated GB rates in the North Haven plant may reflect external occupational factors or nonoccupational factors unmeasured in the current evaluation.

Spatial gender-age-period-cohort analysis of pancreatic cancer mortality in Spain (1990–2013)

PubMed Central

Etxeberria, Jaione; Goicoa, Tomás; López-Abente, Gonzalo; Riebler, Andrea

2017-01-01

Recently, the interest in studying pancreatic cancer mortality has increased due to its high lethality. In this work a detailed analysis of pancreatic cancer mortality in Spanish provinces was performed using recent data. A set of multivariate spatial gender-age-period-cohort models was considered to look for potential candidates to analyze pancreatic cancer mortality rates. The selected model combines features of APC (age-period-cohort) models with disease mapping approaches. To ensure model identifiability sum-to-zero constraints were applied. A fully Bayesian approach based on integrated nested Laplace approximations (INLA) was considered for model fitting and inference. Sensitivity analyses were also conducted. In general, estimated average rates by age, cohort, and period are higher in males than in females. The higher differences according to age between males and females correspond to the age groups [65, 70), [70, 75), and [75, 80). Regarding the cohort, the greatest difference between men and women is observed for those born between the forties and the sixties. From there on, the younger the birth cohort is, the smaller the difference becomes. Some cohort differences are also identified by regions and age-groups. The spatial pattern indicates a North-South gradient of pancreatic cancer mortality in Spain, the provinces in the North being the ones with the highest effects on mortality during the studied period. Finally, the space-time evolution shows that the space pattern has changed little over time. PMID:28199327

Genetic causes of intellectual disability in a birth cohort: A population‐based study

PubMed Central

Riegel, Mariluce; Segal, Sandra L.; Félix, Têmis M.; Barros, Aluísio J. D.; Santos, Iná S.; Matijasevich, Alicia; Giugliani, Roberto; Black, Maureen

2015-01-01

Intellectual disability affects approximately 1–3% of the population and can be caused by genetic and environmental factors. Although many studies have investigated the etiology of intellectual disability in different populations, few studies have been performed in middle‐income countries. The present study estimated the prevalence of genetic causes related to intellectual disability in a cohort of children from a city in south Brazil who were followed from birth. Children who showed poor performance in development and intelligence tests at the ages of 2 and 4 were included. Out of 4,231 liveborns enrolled in the cohort, 214 children fulfilled the inclusion criteria. A diagnosis was established in approximately 90% of the children evaluated. Genetic causes were determined in 31 of the children and 19 cases remained unexplained even after extensive investigation. The overall prevalence of intellectual disability in this cohort due to genetic causes was 0.82%. Because this study was nested in a cohort, there were a large number of variables related to early childhood and the likelihood of information bias was minimized by collecting information with a short recall time. This study was not influenced by selection bias, allowing identification of intellectual disability and estimation of the prevalence of genetic causes in this population, thereby increasing the possibility of providing appropriate management and/or genetic counseling. © 2015 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc. PMID:25728503

Blood Erythrocyte Concentrations of Cadmium and Lead and the Risk of B-Cell Non-Hodgkin’s Lymphoma and Multiple Myeloma: A Nested Case-Control Study

PubMed Central

Porta, Miquel; Bergdahl, Ingvar A.; Palli, Domenico; Johansson, Ann-Sofie; Botsivali, Maria; Vineis, Paolo; Vermeulen, Roel; Kyrtopoulos, Soterios A.; Chadeau-Hyam, Marc

2013-01-01

Background Cadmium (Cd) and lead (Pb) are hypothesised to be risk factors for non-Hodgkin’s lymphoma (NHL), a group of haematological malignancies with a suspected environmental aetiology. Within the EnviroGenoMarkers study we utilised pre-diagnostic erythrocyte concentrations of Cd and Pb to determine whether exposure was associated with risk of B-cell NHL and multiple myeloma. Methods 194 incident cases of B-cell NHL and 76 cases of multiple myeloma diagnosed between 1990 and 2006 were identified from two existing cohorts; EPIC-Italy and the Northern Sweden Health and Disease Study. Cases were matched to healthy controls by centre, age, gender and date of blood collection. Cd and Pb were measured in blood samples provided at recruitment using inductively coupled plasma-mass spectrometry. Logistic regression was applied to assess the association with risk. Analyses were stratified by cohort and gender and by subtype where possible. Results There was little evidence of an increased risk of B-cell NHL or multiple myeloma with exposure to Cd (B-cell NHL: OR 1.09 95%CI 0.61, 1.93, MM: OR 1.16 95% CI: 0.40, 3.40 ) or Pb (B-cell NHL: 0.93 95% CI 0.43, 2.02, multiple myeloma: OR 1.63 95%CI 0.45, 5.94) in the total population when comparing the highest to the lowest quartile of exposure. However, gender and cohort specific differences in results were observed. In females the risk of B-cell NHL was more than doubled in those with a body burden of Cd >1µg/L (OR 2.20 95%CI; 1.04, 4.65). Conclusions This nested case-control study does not support a consistent positive association between Cd or Pb and NHL, but there is some indication of a gender specific effect suggesting further research is warranted. PMID:24312375

Lung cancer among newspaper printers exposed to ink mist: a study of trade union members in Manchester, England.

PubMed Central

Leon, D A; Thomas, P; Hutchings, S

1994-01-01

A nested case-control study of lung cancer among men exposed to ink mist in newspaper production with rotary letterpress technology is presented. It is based within a historical cohort of 9232 printing workers in Manchester (1949-63). Men who operated newspaper rotary letterpress machines had a lung cancer standardised mortality ratio (SMR) of 179 (95% confidence interval (95% CI) 144-218) when compared with rates for England and Wales for the follow up period 1950-83. When adjustment was made for the higher rates in the local area, the SMR was reduced to 122 (95% CI 98-148). The nested case control study was based on 110 lung cancer cases (1949-86) and 316 matched controls. Duration of work in a rotary letterpress machine room was positively associated with risk of lung cancer (chi 2 linear trend = 3.30, p = 0.07); mean with 30 or more years duration of exposure had a risk of 1.73 (95% CI 0.94-3.17), relative to those with less than 20 years of exposure. Adjustment for period of first exposure in a machine room reduced the strength of the positive duration effect. The magnitude of the SMRs found in the cohort study could be explained by confounding with smoking. The duration effect seen in the case-control study, however, suggests that there may be a real effect of exposure to letterpress ink mists. This is biologically plausible, as benzo[a]pyrene, a known human carcinogen, has been found in appreciable concentrations in the atmosphere of rotary letterpress machine rooms. PMID:8111469

Performance of Disease Risk Score Matching in Nested Case-Control Studies: A Simulation Study.

PubMed

Desai, Rishi J; Glynn, Robert J; Wang, Shirley; Gagne, Joshua J

2016-05-15

In a case-control study, matching on a disease risk score (DRS), which includes many confounders, should theoretically result in greater precision than matching on only a few confounders; however, this has not been investigated. We simulated 1,000 hypothetical cohorts with a binary exposure, a time-to-event outcome, and 13 covariates. Each cohort comprised 2 subcohorts of 10,000 patients each: a historical subcohort and a concurrent subcohort. DRS were estimated in the historical subcohorts and applied to the concurrent subcohorts. Nested case-control studies were conducted in the concurrent subcohorts using incidence density sampling with 2 strategies-matching on age and sex, with adjustment for additional confounders, and matching on DRS-followed by conditional logistic regression for 9 outcome-exposure incidence scenarios. In all scenarios, DRS matching yielded lower average standard errors and mean squared errors than did matching on age and sex. In 6 scenarios, DRS matching also resulted in greater empirical power. DRS matching resulted in less relative bias than did matching on age and sex at lower outcome incidences but more relative bias at higher incidences. Post-hoc analysis revealed that the effect of DRS model misspecification might be more pronounced at higher outcome incidences, resulting in higher relative bias. These results suggest that DRS matching might increase the statistical efficiency of case-control studies, particularly when the outcome is rare. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cardiac glycosides use and the risk of lung cancer: a nested case-control study.

PubMed

Couraud, Sébastien; Azoulay, Laurent; Dell'Aniello, Sophie; Suissa, Samy

2014-08-08

Two studies have reported statistically significant associations between the use of cardiac glycosides (CGs) and an increased risk of lung cancer. However, these studies had a number of methodological limitations. Thus, the objective of this study was to assess this association in a large population-based cohort of patients. We used the United Kingdom Clinical Practice Research Datalink (CPRD) to identify a cohort of patients, at least 40 years of age, newly-diagnosed with heart failure, or supra-ventricular arrhythmia. A nested case-control analysis was conducted where each incident case of lung cancer identified during follow-up was randomly matched with up to 10 controls. Exposure to CGs was assessed in terms of ever use, cumulative duration of use and cumulative dose. Rate ratios (RRs) with 95% confidence intervals (CIs) were estimated using conditional logistic regression after adjusting for potential confounders. A total of 129,002 patients were included, and followed for a mean (SD) of 4.7 (3.8) years. During follow-up, 1237 patients were newly-diagnosed with lung cancer. Overall, ever use of CGs was not associated with an increased risk of lung cancer when compared to never use (RR = 1.09, 95% CI: 0.94-1.26). In addition, no dose-response relationship was observed in terms of cumulative duration of use and cumulative dose with all RRs around the null value across quartile categories. The results of this large population-based study indicate that the use of CGs is not associated with an increased risk of lung cancer.

Biomarker discovery study design for type 1 diabetes in The Environmental Determinants of Diabetes in the Young (TEDDY) study.

PubMed

Lee, Hye-Seung; Burkhardt, Brant R; McLeod, Wendy; Smith, Susan; Eberhard, Chris; Lynch, Kristian; Hadley, David; Rewers, Marian; Simell, Olli; She, Jin-Xiong; Hagopian, Bill; Lernmark, Ake; Akolkar, Beena; Ziegler, Anette G; Krischer, Jeffrey P

2014-07-01

The Environmental Determinants of Diabetes in the Young planned biomarker discovery studies on longitudinal samples for persistent confirmed islet cell autoantibodies and type 1 diabetes using dietary biomarkers, metabolomics, microbiome/viral metagenomics and gene expression. This article describes the details of planning The Environmental Determinants of Diabetes in the Young biomarker discovery studies using a nested case-control design that was chosen as an alternative to the full cohort analysis. In the frame of a nested case-control design, it guides the choice of matching factors, selection of controls, preparation of external quality control samples and reduction of batch effects along with proper sample allocation. Our design is to reduce potential bias and retain study power while reducing the costs by limiting the numbers of samples requiring laboratory analyses. It also covers two primary end points (the occurrence of diabetes-related autoantibodies and the diagnosis of type 1 diabetes). The resulting list of case-control matched samples for each laboratory was augmented with external quality control samples. Copyright © 2013 John Wiley & Sons, Ltd.

Cohort Study of Severe Bronchiolitis during Infancy and Risk of Asthma by Age 5 Years.

PubMed

Balekian, Diana S; Linnemann, Rachel W; Hasegawa, Kohei; Thadhani, Ravi; Camargo, Carlos A

Severe bronchiolitis (ie, bronchiolitis requiring hospital admission) is thought to markedly increase asthma risk, with 30%-50% developing asthma by age 5 years. To date, studies of this association are small, and most are from outside the United States. The objective of this study was to investigate the association between severe bronchiolitis and risk of asthma in a US birth cohort. We studied a cohort nested within the Massachusetts General Hospital Obstetric Maternal Study (MOMS), a prospective cohort of pregnant women enrolled during 1998-2006. Children of mothers enrolled in MOMS were included in the analysis if they received care within our health system (n = 3653). Diagnoses and medications were extracted from the children's electronic health records; we also examined pregnancy and perinatal risk factors collected for the underlying pregnancy study. The birth cohort was 52% male, 49% white, and 105 infants (2.9%) had severe bronchiolitis. Overall, 421 children (11.5%) developed asthma by age 5 years. Among the children with severe bronchiolitis, 27.6% developed asthma by age 5 years. In multivariable logistic regression adjusting for 12 risk factors, severe bronchiolitis remained a strong risk factor for developing asthma by age 5 years (odds ratio 2.57; 95% confidence interval 1.61-4.09). In a large Boston birth cohort, the frequency of severe bronchiolitis and childhood asthma was similar to published data. Among children with severe bronchiolitis, the risk of developing asthma was lower than prior studies but still high (27.6%). This difference may be due to different study designs, populations, and outcome definitions studied. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Autism Spectrum Disorder and Particulate Matter Air Pollution before, during, and after Pregnancy: A Nested Case–Control Analysis within the Nurses’ Health Study II Cohort

PubMed Central

Roberts, Andrea L.; Lyall, Kristen; Hart, Jaime E.; Just, Allan C.; Laden, Francine; Weisskopf, Marc G.

2014-01-01

Background Autism spectrum disorder (ASD) is a developmental disorder with increasing prevalence worldwide, yet has unclear etiology. Objective We explored the association between maternal exposure to particulate matter (PM) air pollution and odds of ASD in her child. Methods We conducted a nested case–control study of participants in the Nurses’ Health Study II (NHS II), a prospective cohort of 116,430 U.S. female nurses recruited in 1989, followed by biennial mailed questionnaires. Subjects were NHS II participants’ children born 1990–2002 with ASD (n = 245), and children without ASD (n = 1,522) randomly selected using frequency matching for birth years. Diagnosis of ASD was based on maternal report, which was validated against the Autism Diagnostic Interview-Revised in a subset. Monthly averages of PM with diameters ≤ 2.5 μm (PM2.5) and 2.5–10 μm (PM10–2.5) were predicted from a spatiotemporal model for the continental United States and linked to residential addresses. Results PM2.5 exposure during pregnancy was associated with increased odds of ASD, with an adjusted odds ratio (OR) for ASD per interquartile range (IQR) higher PM2.5 (4.42 μg/m3) of 1.57 (95% CI: 1.22, 2.03) among women with the same address before and after pregnancy (160 cases, 986 controls). Associations with PM2.5 exposure 9 months before or after the pregnancy were weaker in independent models and null when all three time periods were included, whereas the association with the 9 months of pregnancy remained (OR = 1.63; 95% CI: 1.08, 2.47). The association between ASD and PM2.5 was stronger for exposure during the third trimester (OR = 1.42 per IQR increase in PM2.5; 95% CI: 1.09, 1.86) than during the first two trimesters (ORs = 1.06 and 1.00) when mutually adjusted. There was little association between PM10–2.5 and ASD. Conclusions Higher maternal exposure to PM2.5 during pregnancy, particularly the third trimester, was associated with greater odds of a child having ASD. Citation Raz R, Roberts AL, Lyall K, Hart JE, Just AC, Laden F, Weisskopf MG. 2015. Autism spectrum disorder and particulate matter air pollution before, during, and after pregnancy: a nested case–control analysis within the Nurses’ Health Study II cohort. Environ Health Perspect 123:264–270; http://dx.doi.org/10.1289/ehp.1408133 PMID:25522338

The decline of an adaptation in the absence of a presumed selection pressure

USGS Publications Warehouse

Cruz, A.; Wiley, J.W.

1989-01-01

The colonial nesting Village Weaver (Ploceus cucullatus) lays eggs that vary in ground color and pattern, but individual females lay similar eggs each time. Tests on captive African stocks have shown that females reject eggs of other cohorts if such eggs are sufficiently different.

Occupational Exposure to Magnetic Fields and Breast Cancer Among Women Textile Workers in Shanghai, China

PubMed Central

Li, Wenjin; Ray, Roberta M.; Thomas, David B.; Yost, Michael; Davis, Scott; Breslow, Norman; Gao, Dao Li; Fitzgibbons, E. Dawn; Camp, Janice E.; Wong, Eva; Wernli, Karen J.; Checkoway, Harvey

2013-01-01

Exposure to magnetic fields (MFs) is hypothesized to increase the risk of breast cancer by reducing production of melatonin by the pineal gland. A nested case-cohort study was conducted to investigate the association between occupational exposure to MFs and the risk of breast cancer within a cohort of 267,400 female textile workers in Shanghai, China. The study included 1,687 incident breast cancer cases diagnosed from 1989 to 2000 and 4,702 noncases selected from the cohort. Subjects’ complete work histories were linked to a job–exposure matrix developed specifically for the present study to estimate cumulative MF exposure. Hazard ratios and 95% confidence intervals were calculated using Cox proportional hazards modeling that was adapted for the case-cohort design. Hazard ratios were estimated in relation to cumulative exposure during a woman's entire working years. No association was observed between cumulative exposure to MFs and overall risk of breast cancer. The hazard ratio for the highest compared with the lowest quartile of cumulative exposure was 1.03 (95% confidence interval: 0.87, 1.21). Similar null findings were observed when exposures were lagged and stratified by age at breast cancer diagnosis. The findings do not support the hypothesis that MF exposure increases the risk of breast cancer. PMID:24043439

Oral health follow-up studies in the 1993 Pelotas (Brazil) birth cohort study: methodology and principal results

PubMed Central

Peres, Marco A.; Barros, Aluísio Jardim; Peres, Karen Glazer; Araújo, Cora Luiza; Menezes, Ana M. B.; Hallal, Pedro C.; Victora, Cesar G.

2013-01-01

The aim of this study was to describe oral health follow-up studies nested in a birth cohort. A population-based birth cohort was launched in 1993 in Pelotas, Rio Grande do Sul State, Brazil. Two oral health follow-up studies were conducted at six (n = 359) and 12 (n = 339) years of age. A high response rate was observed at 12 years of age; 94.4% of the children examined at six years of age were restudied in 2005. The mean DMF-T index at age 12 was 1.2 (SD = 1.6) for the entire sample, ranging from 0.6 (SD = 1.1) for children that were caries-free at age six, 1.3 (SD = 1.5) for those with 1-3 carious teeth at six years, and 1.8 (SD = 1.8) for those with 4-19 carious teeth at six years (p < 0.01). The number of individuals with severe malocclusions at 12 years was proportional to the number of malocclusions at six years. Oral health problems in early adolescence were more prevalent in individuals with dental problems at six years of age. PMID:20963297

Skew-t fits to mortality data--can a Gaussian-related distribution replace the Gompertz-Makeham as the basis for mortality studies?

PubMed

Clark, Jeremy S C; Kaczmarczyk, Mariusz; Mongiało, Zbigniew; Ignaczak, Paweł; Czajkowski, Andrzej A; Klęsk, Przemysław; Ciechanowicz, Andrzej

2013-08-01

Gompertz-related distributions have dominated mortality studies for 187 years. However, nonrelated distributions also fit well to mortality data. These compete with the Gompertz and Gompertz-Makeham data when applied to data with varying extents of truncation, with no consensus as to preference. In contrast, Gaussian-related distributions are rarely applied, despite the fact that Lexis in 1879 suggested that the normal distribution itself fits well to the right of the mode. Study aims were therefore to compare skew-t fits to Human Mortality Database data, with Gompertz-nested distributions, by implementing maximum likelihood estimation functions (mle2, R package bbmle; coding given). Results showed skew-t fits obtained lower Bayesian information criterion values than Gompertz-nested distributions, applied to low-mortality country data, including 1711 and 1810 cohorts. As Gaussian-related distributions have now been found to have almost universal application to error theory, one conclusion could be that a Gaussian-related distribution might replace Gompertz-related distributions as the basis for mortality studies.

Risk factors for hyperkalaemia in a cohort of patients with newly diagnosed heart failure: a nested case-control study in UK general practice.

PubMed

Michel, Alexander; Martín-Pérez, Mar; Ruigómez, Ana; García Rodríguez, Luis A

2015-02-01

The aim of this study was to identify risk factors for hyperkalaemia in a cohort of patients with newly diagnosed heart failure in the UK. A nested case-control study was conducted using data from The Health Improvement Network primary care database. A cohort of 19 194 patients aged 1-89 years between January 2000 and December 2005 with newly diagnosed heart failure was followed up and cases of hyperkalaemia identified. Cases were frequency matched to controls by age, sex, and calendar year, and information on demographics, co-morbidities, co-medications, and lifestyle factors was extracted from the database. Using unconditional logistic regression models, odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to identify potential risk factors. In total, 2176 hyperkalaemia cases were identified over a mean follow-up of 3.9 years. Significant risk factors for hyperkalaemia were: renal failure (OR 3.81; 95% CI 3.29-4.42), type II diabetes (OR 1.52; 95% CI 1.31-1.75), valvular heart disease (OR 1.28; 95% CI 1.06-1.54), and current use of potassium-sparing diuretics (OR 3.01; 95% CI 2.61-3.48), ACE inhibitors (OR 1.70; 95% CI 1.41-2.04), trimethoprim (OR 2.82; 95% CI 1.88-4.23), non-steroidal anti-inflammatory drugs (OR 1.41; 95% CI 1.11-1.79), and several drug combinations. The risk was highest within the first month of medication use and decreased thereafter. Our findings may help to better identify patients with heart failure most likely to benefit from careful monitoring of serum potassium levels. Particular vigilance is needed during the start of treatment with certain medications. © 2015 The Authors. European Journal of Heart Failure © 2015 European Society of Cardiology.

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

PubMed Central

Shen, Li-Jiuan; Wu, Fe-Lin Lin; Tsay, Woei; Hung, Chien-Ching; Lin, Shu-Wen

2016-01-01

Objective 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. Design A nationwide nested case-control study. Setting National Health Insurance Research database. Participants 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). Results 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 (<3 DDDs, aOR 1.62; 3–5 DDDs, aOR 1.78; and >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. Conclusions 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. PMID:27463687

Periodontal Disease and Incident Lung Cancer Risk: A Meta-Analysis of Cohort Studies.

PubMed

Zeng, Xian-Tao; Xia, Ling-Yun; Zhang, Yong-Gang; Li, Sheng; Leng, Wei-Dong; Kwong, Joey S W

2016-10-01

Periodontal disease is linked to a number of systemic diseases such as cardiovascular diseases and diabetes mellitus. Recent evidence has suggested periodontal disease might be associated with lung cancer. However, their precise relationship is yet to be explored. Hence, this study aims to investigate the association of periodontal disease and risk of incident lung cancer using a meta-analytic approach. PubMed, Scopus, and ScienceDirect were searched up to June 10, 2015. Cohort and nested case-control studies investigating risk of lung cancer in patients with periodontal disease were included. Hazard ratios (HRs) were calculated, as were their 95% confidence intervals (CIs) using a fixed-effect inverse-variance model. Statistical heterogeneity was explored using the Q test as well as the I(2) statistic. Publication bias was assessed by visual inspection of funnel plots symmetry and Egger's test. Five cohort studies were included, involving 321,420 participants in this meta-analysis. Summary estimates based on adjusted data showed that periodontal disease was associated with a significant risk of lung cancer (HR = 1.24, 95% CI = 1.13 to 1.36; I(2) = 30%). No publication bias was detected. Subgroup analysis indicated that the association of periodontal disease and lung cancer remained significant in the female population. Evidence from cohort studies suggests that patients with periodontal disease are at increased risk of developing lung cancer.

NO2, as a marker of air pollution, and recurrent wheezing in children: a nested case-control study within the BAMSE birth cohort.

PubMed

Emenius, G; Pershagen, G; Berglind, N; Kwon, H-J; Lewné, M; Nordvall, S L; Wickman, M

2003-11-01

To investigate the association between air pollution, including with NO2, and recurrent wheezing during the first two years of life. A birth cohort (BAMSE) comprised 4089 children, for whom information on exposures, symptoms, and diseases was available from parental questionnaires at ages 2 months, and 1 and 2 years. NO2 was measured during four weeks in and outside the dwellings of children with recurrent wheezing and two age matched controls, in a nested case-control study (540 children). Conditional logistic regression showed an OR of 1.60 (95% CI 0.78 to 3.26) among children in the highest quartile of outdoor NO2 exposure in relation to those in the lowest quartile, adjusted for potential confounders. The corresponding OR for indoor NO2 was 1.51 (95% CI 0.81 to 2.82). An interaction with environmental tobacco smoke (ETS) was indicated with an OR of 3.10 (95% CI 1.32 to 7.30) among children exposed to the highest quartile of indoor NO2 and ETS. The association between NO2 and recurrent wheezing appeared stronger in children who did not fulfil the criteria for recurrent wheezing until their second year. Although the odds of increased recurrent wheezing are not statistically significantly different from one, results suggest that exposure to air pollution including NO2, particularly in combination with exposure to ETS, increases the risk of recurrent wheezing in children.

Plasma 25-hydroxyvitamin D3 is associated with decreased risk of postmenopausal breast cancer in whites: a nested case-control study in the multiethnic cohort study.

PubMed

Kim, Yeonju; Franke, Adrian A; Shvetsov, Yurii B; Wilkens, Lynne R; Cooney, Robert V; Lurie, Galina; Maskarinec, Gertraud; Hernandez, Brenda Y; Le Marchand, Loïc; Henderson, Brian E; Kolonel, Laurence N; Goodman, Marc T

2014-01-17

Higher sunlight exposure is correlated with lower incidence of breast cancer in ecological studies, but findings from prospective studies regarding the association of circulating levels of vitamin D with the risk of breast cancer have been null. The objective of this study was to examine the relation between plasma levels of vitamin D and the risk of postmenopausal breast cancer. We conducted a nested case-control study within the Multiethnic Cohort Study of five race/ethnic groups (white, African-American, Native Hawaiian, Japanese, and Latino) from Hawaii and Los Angeles between 2001 and 2006. Pre-diagnostic plasma levels of 25-hydroxyvitamin D2 [25(OH)D2], 25-hydroxyvitamin D3 [25(OH)D3] and 25(OH)D (sum of 25(OH)D2 and 25(OH)D3) were examined among 707 postmenopausal breast cancer cases and matched controls. Using conditional logistic regression models, 20 ng/mL increases of plasma 25(OH)D3 (odds ratio (OR) 0.28; 95% confidence interval (CI) 0.14-0.56) and 25(OH)D (OR 0.43; 95% CI 0.23-0.80) were inversely associated with breast cancer risk among white women, but not among women in other race/ethnic groups. Using two-segmented, piecewise-linear logistic regression models, the change-points of the ORs, either for 25(OH)D3 or for 25(OH)D, were detected as 20 ng/mL among whites. Circulating 25(OH)D3 and 25(OH)D were associated with a reduced risk of postmenopausal breast cancer among whites, but not in other ethnic groups, who reside in low latitude regions.

Adversity and Syndemic Production Among Men Participating in the Multicenter AIDS Cohort Study: A Life-Course Approach

PubMed Central

Lim, Sin How; Plankey, Michael W.; Chmiel, Joan S.; Guadamuz, Thomas T.; Kao, Uyen; Shoptaw, Steven; Carrico, Adam; Ostrow, David; Stall, Ron

2013-01-01

Objectives. We tested a theory of syndemic production among men who have sex with men (MSM) using data from a large cohort study. Methods. Participants were 1551 men from the Multicenter AIDS Cohort Study enrolled at 4 study sites: Baltimore, Maryland–Washington, DC; Chicago, Illinois; Los Angeles, California; and Pittsburgh, Pennsylvania. Participants who attended semiannual visits from April 1, 2008, to March 31, 2009, completed an additional survey that captured data about events throughout their life course thought to be related to syndemic production. Results. Using multivariate analysis, we found that the majority of life-course predictor variables (e.g., victimization, internalized homophobia) were significantly associated with both the syndemic condition and the component psychosocial health outcomes (depressive symptoms, stress, stimulant use, sexual compulsivity, intimate partner violence). A nested negative binomial analysis showed that the overall life course significantly explained variability in the syndemic outcomes (χ2 = 247.94; P < .001; df = 22). Conclusions. We identified life-course events and conditions related to syndemic production that may help to inform innovative interventions that will effectively disentangle interconnecting health problems and promote health among MSM. PMID:23153154

Effect of telehealth on quality of life and psychological outcomes over 12 months (Whole Systems Demonstrator telehealth questionnaire study): nested study of patient reported outcomes in a pragmatic, cluster randomised controlled trial.

PubMed

Cartwright, Martin; Hirani, Shashivadan P; Rixon, Lorna; Beynon, Michelle; Doll, Helen; Bower, Peter; Bardsley, Martin; Steventon, Adam; Knapp, Martin; Henderson, Catherine; Rogers, Anne; Sanders, Caroline; Fitzpatrick, Ray; Barlow, James; Newman, Stanton P

2013-02-26

To assess the effect of second generation, home based telehealth on health related quality of life, anxiety, and depressive symptoms over 12 months in patients with long term conditions. A study of patient reported outcomes (the Whole Systems Demonstrator telehealth questionnaire study; baseline n=1573) was nested in a pragmatic, cluster randomised trial of telehealth (the Whole Systems Demonstrator telehealth trial, n=3230). General practice was the unit of randomisation, and telehealth was compared with usual care. Data were collected at baseline, four months (short term), and 12 months (long term). Primary intention to treat analyses tested treatment effectiveness; multilevel models controlled for clustering by general practice and a range of covariates. Analyses were conducted for 759 participants who completed questionnaire measures at all three time points (complete case cohort) and 1201 who completed the baseline assessment plus at least one other assessment (available case cohort). Secondary per protocol analyses tested treatment efficacy and included 633 and 1108 participants in the complete case and available case cohorts, respectively. Provision of primary and secondary care via general practices, specialist nurses, and hospital clinics in three diverse regions of England (Cornwall, Kent, and Newham), with established integrated health and social care systems. Patients with chronic obstructive pulmonary disease (COPD), diabetes, or heart failure recruited between May 2008 and December 2009. Generic, health related quality of life (assessed by physical and mental health component scores of the SF-12, and the EQ-5D), anxiety (assessed by the six item Brief State-Trait Anxiety Inventory), and depressive symptoms (assessed by the 10 item Centre for Epidemiological Studies Depression Scale). In the intention to treat analyses, differences between treatment groups were small and non-significant for all outcomes in the complete case (0.480 ≤ P ≤ 0.904) or available case (0.181 ≤ P ≤ 0.905) cohorts. The magnitude of differences between trial arms did not reach the trial defined, minimal clinically important difference (0.3 standardised mean difference) for any outcome in either cohort at four or 12 months. Per protocol analyses replicated the primary analyses; the main effect of trial arm (telehealth v usual care) was non-significant for any outcome (complete case cohort 0.273 ≤ P ≤ 0.761; available case cohort 0.145 ≤ P ≤ 0.696). Second generation, home based telehealth as implemented in the Whole Systems Demonstrator Evaluation was not effective or efficacious compared with usual care only. Telehealth did not improve quality of life or psychological outcomes for patients with chronic obstructive pulmonary disease, diabetes, or heart failure over 12 months. The findings suggest that concerns about potentially deleterious effect of telehealth are unfounded for most patients. ISRCTN43002091.

Long-term health experience of jet engine manufacturing workers: VI: incidence of malignant central nervous system neoplasms in relation to estimated workplace exposures.

PubMed

Marsh, Gary M; Youk, Ada O; Buchanich, Jeanine M; Xu, Hui; Downing, Sarah; Kennedy, Kathleen J; Esmen, Nurtan A; Hancock, Roger P; Lacey, Steven E; Fleissner, Mary Lou

2013-06-01

To determine whether glioblastoma (GB) incidence rates among jet engine manufacturing workers were associated with specific chemical or physical exposures. Subjects were 210,784 workers employed from 1952 to 2001. We conducted a cohort incidence study and two nested case-control studies with focus on the North Haven facility where we previously observed a not statistically significant overall elevation in GB rates. We estimated individual-level exposure metrics for 11 agents. In the total cohort, none of the agent metrics considered was associated with increased GB risk. The GB incidence rates in North Haven were also not related to workplace exposures, including the "blue haze" exposure unique to North Haven. If not due to chance alone, GB rates in North Haven may reflect external occupational factors, nonoccupational factors, or workplace factors unique to North Haven unmeasured in the current evaluation.

Fumonisin B1 and Risk of Hepatocellular Carcinoma in Two Chinese Cohorts

PubMed Central

Persson, E. Christina; Sewram, Vikash; Evans, Alison A.; London, W. Thomas; Volkwyn, Yvette; Shen, Yen-Ju; Van Zyl, Jacobus A.; Chen, Gang; Lin, Wenyao; Shephard, Gordon S.; Taylor, Philip R.; Fan, Jin-Hu; Dawsey, Sanford M.; Qiao, You-Lin; McGlynn, Katherine A.; Abnet, Christian C.

2011-01-01

Fumonisin B1 (FB1), a mycotoxin that contaminates corn in certain climates, has been demonstrated to cause hepatocellular cancer (HCC) in animal models. Whether a relationship between FB1 and HCC exists in humans is not known. To examine the hypothesis, we conducted case-control studies nested within two large cohorts in China; the Haimen City Cohort and the General Population Study of the Nutritional Intervention Trials cohort in Linxian. In the Haimen City Cohort, nail FB1 levels were determined in 271 HCC cases and 280 controls. In the General Population Nutritional Intervention Trial, nail FB1 levels were determined in 72 HCC cases and 147 controls. In each population, odds ratios and 95% confidence intervals (95%CI) from logistic regression models estimated the association between measurable FB1 and HCC, adjusting for hepatitis B virus infection and other factors. A meta-analysis that included both populations was also conducted. The analysis revealed no statistically significant association between FB1 and HCC in either Haimen City (OR=1.10, 95%CI=0.64–1.89) or in Linxian (OR=1.47, 95%CI=0.70–3.07). Similarly, the pooled meta-analysis showed no statistically significant association between FB1 exposure and HCC (OR=1.22, 95%CI=0.79–1.89). These findings, although somewhat preliminary, do not support an associated between FB1 and HCC. PMID:22142693

Exposure to sennoside-digoxin interaction and risk of digoxin toxicity: a population-based nested case-control study.

PubMed

Wang, Meng-Ting; Li, I-Hsun; Lee, Wan-Ju; Huang, Tien-Yu; Leu, Hsin-Bang; Chan, Agnes L F

2011-11-01

Digoxin is an important medication for heart failure (HF) patients and sennosides are widely used to treat constipation. Recently, safety concerns have been raised about a possible interaction between sennosides and digoxin, an issue that has not been studied empirically. This study therefore aimed to evaluate whether exposure to sennoside-digoxin interaction is associated with an increased risk of digoxin toxicity. This was a population-based nested case-control study that analysed data obtained from the Taiwan National Health Insurance Research Database between 1 January 2001 and 31 December 2004. All HF patients treated with digoxin for the first time were included as the study cohort. Of these, cases were identified as subjects hospitalized for digoxin toxicity (International Classification of Diseases, Ninth Revision, Clinical Modification, ICD-9-CM 972.1), and matched to randomly selected controls. Use of sennosides was compared between the two groups. Odds ratios (ORs) were employed to quantify the risk associated with exposure to sennoside-digoxin interaction by conditional logistic regression. The study cohort comprised 222,527 HF patients, of whom 524 were identified as cases and 2,502 as matched controls. Use of sennosides during the 14 days preceding the index date was found to be associated with a 1.61-fold increased risk of digoxin toxicity [95% confidence interval (CI) = 1.15, 2.25]. Additionally, a greater risk was observed for sennosides prescribed at an average daily dose ≥ 24 mg (adjusted OR = 1.93; 95% CI = 1.27, 2.94). The combined use of sennosides and digoxin was found to be associated with a modest increased risk of digoxin toxicity in HF patients.

Use of acid-suppressive drugs and risk of fracture: a meta-analysis of observational studies.

PubMed

Eom, Chun-Sick; Park, Sang Min; Myung, Seung-Kwon; Yun, Jae Moon; Ahn, Jeong-Soo

2011-01-01

Previous studies have reported inconsistent findings regarding the association between the use of acid-suppressive drugs such as proton pump inhibitors (PPIs) and histamine 2 receptor antagonists (H(2)RAs) and fracture risk. We investigated this association using meta-analysis. We searched MEDLINE (PubMed), EMBASE, and the Cochrane Library from inception through December 2010 using common key words. We included case-control, nested case-control, and cohort studies. Two evaluators independently reviewed and selected articles. We determined pooled effect estimates by using random-effects meta-analysis, because of heterogeneity. Of 1,809 articles meeting our initial inclusion criteria, 5 case-control studies, 3 nested case-control studies, and 3 cohort studies were included in the final analyses. The pooled odds ratio (OR) for fracture was 1.29 (95% confidence interval [CI], 1.18-1.41) with use of PPIs and 1.10 (95% CI, 0.99-1.23) with use of H(2)RAs when compared with nonuse of the respective medications. Long-term use of PPIs increased the risk of any fracture (adjusted OR = 1.30; 95% CI, 1.15-1.48) and hip fracture risk (adjusted OR = 1.34; 95% CI, 1.09-1.66), whereas long-term H(2)RA use was not significantly associated with fracture risk. We found possible evidence linking PPI use to an increased risk of fracture, but no association between H(2)RA use and fracture risk. Widespread use of PPIs with the potential risk of fracture is of great importance to public health. Clinicians should carefully consider their decision to prescribe PPIs for patients already having an elevated risk of fracture because of age or other factors.

ExplorinG frailty and mild cognitive impairmEnt in kidney tRansplantation to predict biomedicAl, psychosocial and health cost outcomeS (GERAS): protocol of a nationwide prospective cohort study.

PubMed

Mauthner, Oliver; Claes, Veerle; Walston, Jeremy; Engberg, Sandra; Binet, Isabelle; Dickenmann, Michael; Golshayan, Déla; Hadaya, Karine; Huynh-Do, Uyen; Calciolari, Stefano; De Geest, Sabina

2017-03-01

To present the rationale, design and methodology of the GERAS project, which examines whether assessment of frailty and mild cognitive impairment could enhance risk prediction for biomedical, psychosocial outcomes and foster efficient resource allocation in kidney transplantation. For the burgeoning cohort of older patients considered for kidney transplantation, evidence gaps regarding frailty and mild cognitive impairment limit clinical decision-making and medical management. As known risk factors for 'hard' clinical outcomes in chronic illness, both require further study in transplantation. Integrating these and other bio-psychosocial factors into a comprehensive pre-transplant patient assessment will provide insights regarding economic implications and may improve risk prediction. A nation-wide multi-centre prospective cohort study nested in the Swiss Transplant Cohort Study. Our nationally representative convenience sample includes 250 adult kidney transplant recipients. Data sources include the Swiss Transplant Cohort Study and primary data collected at time of transplantation, 6 months, 1 and 2 years post-transplant via established measures (the Montreal Cognitive Assessment, Psychosocial Questionnaire, Fried Frailty Instrument and a blood analysis), investigator-developed instruments and datasets compiled by hospitals' management control units, sickness funds, the Swiss Federal Statistical Office and the European Renal Association. Descriptive, competing risk survival and mixed effects analyses will be performed. Research Ethics Committee approval was obtained in January 2016. This pioneering project jointly examines frailty and mild cognitive impairment from bio-psychosocial and health economic perspectives. Results may significantly inform risk prediction, care tailoring and resource optimization to improve health outcomes in the ageing kidney transplant cohort. © 2016 John Wiley & Sons Ltd.

RISK FACTORS FOR SLOW GAIT SPEED: A NESTED CASE-CONTROL SECONDARY ANALYSIS OF THE MEXICAN HEALTH AND AGING STUDY

PubMed Central

Pérez-Zepeda, M.U.; González-Chavero, J.G.; Salinas-Martinez, R.; Gutiérrez-Robledo, L.M.

2016-01-01

Background Physical performance tests play a major role in the geriatric assessment. In particular, gait speed has shown to be useful for predicting adverse outcomes. However, risk factors for slow gait speed (slowness) are not clearly described. Objectives To determine risk factors associated with slowness in Mexican older adults. Design A two-step process was adopted for exploring the antecedent risk factors of slow gait speed. First, the cut-off values for gait speed were determined in a representative sample of Mexican older adults. Then, antecedent risk factors of slow gait speed (defined using the identified cut-points) were explored in a nested, cohort case-control study. Setting, participants One representative sample of a cross-sectional survey for the first step and the Mexican Health and Aging Study (a cohort characterized by a 10-year follow-up). Measurements A 4-meter usual gait speed test was conducted. Lowest gender and height-stratified groups were considered as defining slow gait speed. Sociodemographic characteristics, comorbidities, psychological and health-care related variables were explored to find those associated with the subsequent development of slow gait speed. Unadjusted and adjusted logistic regression models were performed. Results In the final model, age, diabetes, hypertension, and history of fractures were associated with the development of slow gait speed. Conclusions Early identification of subjects at risk of developing slow gait speed may halt the path to disability due to the robust association of this physical performance test with functional decline. PMID:26889463

Serum carotenoid and tocopherol concentrations and risk of asthma in childhood: a nested case-control study.

PubMed

Hämäläinen, N; Nwaru, B I; Erlund, I; Takkinen, H-M; Ahonen, S; Toppari, J; Ilonen, J; Veijola, R; Knip, M; Kaila, M; Virtanen, S M

2017-03-01

The antioxidant hypothesis regarding the risk of asthma in childhood has resulted in inconsistent findings. Some data indicate that the role of antioxidants in childhood asthma risk may have a critical time window of effect, but only a well-designed longitudinal cohort study can clarify this hypothesis. To study the longitudinal associations between serum carotenoid and tocopherol concentrations during the first 4 years of life and asthma risk by the age of 5 years. Based on a case-control design nested within a Finnish birth cohort, 146 asthma cases were matched to 270 controls on birth time, sex, genetic risk, and birth place. Non-fasting blood samples were collected at the ages of 1, 1.5, 2, 3, and 4 years and serum carotenoids and tocopherols were analysed. Parents reported the presence and age at start of persistent doctor-diagnosed asthma in the child at the age of 5 years. Data analyses were conducted using generalized estimating equations. We did not find strong associations between serum carotenoids and tocopherols and the risk of asthma based on age-specific and longitudinal analyses. Both lower and higher quarters of α-carotene and γ-tocopherol increased the risk of asthma. The current findings do not support the suggestion that the increased prevalence of asthma may be a consequence of decreased intake of antioxidant nutrients. Moreover, we did not confirm any critical time window of impact of antioxidants on asthma risk. Replication of these findings in similar longitudinal settings will strengthen this evidence base. © 2017 John Wiley & Sons Ltd.

Diet and alcohol as risk factors for rheumatoid arthritis: a nested case-control study.

PubMed

Sundström, B; Johansson, I; Rantapää-Dahlqvist, S

2015-03-01

The aim of this study was to investigate whether alcohol and diet, assessed as both macronutrients and dietary patterns, increased the risk of development of rheumatoid arthritis (RA) through a nested case-control design in the Västerbotten Intervention Program (VIP) cohort. Individuals in the VIP who had developed RA after the dietary survey were identified from medical records at the department of rheumatology at the University Hospital, Umeå (n = 386), and matched to 1,886 controls from the same database. Diet was assessed as food groups, as macronutrients and as scores of dietary patterns, namely the carbohydrate-restricted diet score, the Mediterranean diet score and the healthy diet indicator score. When analysing the dietary patterns, consumption of food groups and different macronutrients, a significant association was found in the highest tertile of carbohydrate-restricted diet among the cases with a subsequent anti-CCP-positive disease 1.40 (1.02-1.92), as well as in the highest tertile of protein consumption among smokers (OR = 1.80, 95% CI 1.09-2.95). However, after additional adjustment for sodium intake, these associations were no longer statistically significant. No association was observed between alcohol consumption and the risk of RA. To summarize, there were no significant associations between diet, or alcohol consumption, and the risk of development of RA within this cohort. The lack of any significant associations of alcohol consumption may be explained by a low consumption in the studied population overall or alternatively by methodological issues raised recently.

Attention Deficit/Hyperactivity Disorder and Childhood Autism in Association with Prenatal Exposure to Perfluoroalkyl Substances: A Nested Case–Control Study in the Danish National Birth Cohort

PubMed Central

Liew, Zeyan; Ritz, Beate; von Ehrenstein, Ondine S.; Bech, Bodil Hammer; Nohr, Ellen Aagaard; Fei, Chunyuan; Bossi, Rossana; Henriksen, Tine Brink; Bonefeld-Jørgensen, Eva Cecilie

2014-01-01

Background: Perfluoroalkyl substances (PFASs) are persistent pollutants found to be endocrine disruptive and neurotoxic in animals. Positive correlations between PFASs and neurobehavioral problems in children were reported in cross-sectional data, but findings from prospective studies are limited. Objectives: We investigated whether prenatal exposure to PFASs is associated with attention deficit/hyperactivity disorder (ADHD) or childhood autism in children. Methods: Among 83,389 mother–child pairs enrolled in the Danish National Birth Cohort during 1996–2002, we identified 890 ADHD cases and 301 childhood autism cases from the Danish National Hospital Registry and the Danish Psychiatric Central Registry. From this cohort, we randomly selected 220 cases each of ADHD and autism, and we also randomly selected 550 controls frequency matched by child’s sex. Sixteen PFASs were measured in maternal plasma collected in early or mid-pregnancy. We calculated risk ratios (RRs) using generalized linear models, taking into account sampling weights. Results: Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were detected in all samples; four other PFASs were quantified in ≥ 90% of the samples. We did not find consistent evidence of associations between mother’s PFAS plasma levels and ADHD [per natural log nanograms per milliliter increase: PFOS RR = 0.87 (95% CI: 0.74, 1.02); PFOA RR = 0.98 (95% CI: 0.82, 1.16)] or autism [per natural log nanograms per milliliter increase: PFOS RR = 0.92 (95% CI: 0.69, 1.22); PFOA RR = 0.98 (95% CI: 0.73, 1.31)]. We found positive as well as negative associations between higher PFAS quartiles and ADHD in models that simultaneously adjusted for all PFASs, but these estimates were imprecise. Conclusions: In this study we found no consistent evidence to suggest that prenatal PFAS exposure increases the risk of ADHD or childhood autism in children. Citation: Liew Z, Ritz B, von Ehrenstein OS, Bech BH, Nohr EA, Fei CY, Bossi R, Henriksen TB, Bonefeld-Jørgensen EC, Olsen J. 2015. Attention deficit/hyperactivity disorder and childhood autism in association with prenatal exposure to perfluoroalkyl substances: a nested case–control study in the Danish National Birth Cohort. Environ Health Perspect 123:367–373; http://dx.doi.org/10.1289/ehp.1408412 PMID:25616253

Chemical exposures and respiratory cancer among Finnish woodworkers.

PubMed Central

Kauppinen, T P; Partanen, T J; Hernberg, S G; Nickels, J I; Luukkonen, R A; Hakulinen, T R; Pukkala, E I

1993-01-01

A case-control study of respiratory cancer, nested within a cohort of male woodworkers, was updated in Finland. The update extended the initial follow up of 3805 workers from 19 plants to 7307 workers from 35 plants. Each case of respiratory cancer (n = 136) diagnosed between 1957 and 1982 within the cohort was matched by year of birth with three controls (n = 408) from the cohort. Chemical exposures were assessed for the cases and the controls by a plant and period specific job exposure matrix. An excess of respiratory cancer was associated with phenol. Concomitant exposures to several other agents occurred as well, however, and no exposure-response relation for phenol was seen. An excess risk and an increasing exposure-response relation were found for engine exhaust from petrol and diesel driven factory trucks. The excess risk associated with pesticides was lower than in our previous study, an indication of qualitative and quantitative differences in exposure between the initial and augmented cohorts. Slightly increased risks were found for terpenes and mould spores, which may be due to chance although the contribution of occupational exposure cannot be ruled out. Exposure to wood dust, mainly from pine, spruce and birch, at a level of about 1 mg/m3, was not associated with lung cancer, upper respiratory cancer, or adenocarcinoma of the lung. PMID:8435346

Immunodeficiency and the risk of cervical intraepithelial neoplasia 2/3 and cervical cancer: A nested case-control study in the Swiss HIV cohort study.

PubMed

Clifford, Gary M; Franceschi, Silvia; Keiser, Olivia; Schöni-Affolter, Franziska; Lise, Mauro; Dehler, Silvia; Levi, Fabio; Mousavi, Mohsen; Bouchardy, Christine; Wolfensberger, Aline; Darling, Katharine E; Staehelin, Cornelia; Bertisch, Barbara; Kuenzli, Esther; Bernasconi, Enos; Pawlita, Michael; Egger, Matthias

2016-04-01

HIV-infected women are at increased risk of cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (ICC), but it has been difficult to disentangle the influences of heavy exposure to HPV infection, inadequate screening and immunodeficiency. A case-control study including 364 CIN2/3 and 20 ICC cases matched to 1,147 controls was nested in the Swiss HIV Cohort Study (1985-2013). CIN2/3 risk was significantly associated with low CD4+ cell counts, whether measured as nadir [odds ratio (OR) per 100-cell/μL decrease = 1.15, 95% CI: 1.08, 1.22], or at CIN2/3 diagnosis (1.10, 95% CI: 1.04, 1.16). An association was evident even for nadir CD4+ 200-349 versus ≥350 cells/μL (OR = 1.57, 95% CI: 1.09, 2.25). After adjustment for nadir CD4+, a protective effect of >2-year cART use was seen against CIN2/3 (OR versus never cART use = 0.64, 95% CI: 0.42, 0.98). Despite low study power, similar associations were seen for ICC, notably with nadir CD4+ (OR for 50 vs. >350 cells/μL= 11.10, 95% CI: 1.24, 100). HPV16-L1 antibodies were significantly associated with CIN2/3, but HPV16-E6 antibodies were nearly exclusively detected in ICC. In conclusion, worsening immunodeficiency, even at only moderately decreased CD4+ cell counts, is a significant risk factor for CIN2/3 and cervical cancer. © 2015 UICC.

Exploring APOE genotype effects on Alzheimer's disease risk and amyloid β burden in individuals with subjective cognitive decline: The FundacioACE Healthy Brain Initiative (FACEHBI) study baseline results.

PubMed

Moreno-Grau, Sonia; Rodríguez-Gómez, Octavio; Sanabria, Ángela; Pérez-Cordón, Alba; Sánchez-Ruiz, Domingo; Abdelnour, Carla; Valero, Sergi; Hernández, Isabel; Rosende-Roca, Maitée; Mauleón, Ana; Vargas, Liliana; Lafuente, Asunción; Gil, Silvia; Santos-Santos, Miguel Ángel; Alegret, Montserrat; Espinosa, Ana; Ortega, Gemma; Guitart, Marina; Gailhajanet, Anna; de Rojas, Itziar; Sotolongo-Grau, Óscar; Ruiz, Susana; Aguilera, Nuria; Papasey, Judith; Martín, Elvira; Peleja, Esther; Lomeña, Francisco; Campos, Francisco; Vivas, Assumpta; Gómez-Chiari, Marta; Tejero, Miguel Ángel; Giménez, Joan; Serrano-Ríos, Manuel; Orellana, Adelina; Tárraga, Lluís; Ruiz, Agustín; Boada, Mercè

2018-05-01

Subjective cognitive decline (SCD) has been proposed as a potential preclinical stage of Alzheimer's disease (AD). Nevertheless, the genetic and biomarker profiles of SCD individuals remain mostly unexplored. We evaluated apolipoprotein E (APOE) ε4's effect in the risk of presenting SCD, using the Fundacio ACE Healthy Brain Initiative (FACEHBI) SCD cohort and Spanish controls, and performed a meta-analysis addressing the same question. We assessed the relationship between APOE dosage and brain amyloid burden in the FACEHBI SCD and Alzheimer's Disease Neuroimaging Initiative cohorts. Analysis of the FACEHBI cohort and the meta-analysis demonstrated SCD individuals presented higher allelic frequencies of APOE ε4 with respect to controls. APOE dosage explained 9% (FACEHBI cohort) and 11% (FACEHBI and Alzheimer's Disease Neuroimaging Initiative cohorts) of the variance of cerebral amyloid levels. The FACEHBI sample presents APOE ε4 enrichment, suggesting that a pool of AD patients is nested in our sample. Cerebral amyloid levels are partially explained by the APOE allele dosage, suggesting that other genetic or epigenetic factors are involved in this AD endophenotype. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Does comedy kill? A retrospective, longitudinal cohort, nested case-control study of humour and longevity in 53 British comedians.

PubMed

Stewart, Simon; Thompson, David R

2015-02-01

This work aims to test the hypothesis that the funniest comedians are most at risk of a premature death and reduced longevity compared to their relatively less funny counterparts. A retrospective longitudinal cohort study with a nested case-control analysis of longevity of 53 male British comedians born between 1900 and 1954 was conducted. All comedians were given a subjective score from 1 (relatively funny) to 10 (hilariously funny) by the study investigators. The survival profile of all comedians was then examined adjusting for decade of birth, whether they worked in a comedy team and their comedy score. A nested case-control analysis examined the longevity of those comedians working in teams according to their pre-specified status within the team (straight/less funny versus funny team member). On an adjusted basis, there was no correlation between the decade of birth (HR 0.94, 95% 0.65 to 1.38 per incremental decade; p=0.763) and comedy team status (HR 1.13, 95% 0.51 to 2.48 versus independent comedian; p=0.761) with longevity. However, an increasingly funny comedy score was associated with increased mortality (HR 1.24, 95% CI 1.06 to 1.44 per unit funny score; p=0.006). Of the 23 comedians adjudged to be very funny (score 8-10), 18 (78%) had died versus 12 (40%) of the rest; mean age at death 63.3±12.2 versus 72.3±14.7 (p=0.079). Within comedy teams, those identified as the funnier member(s) of the partnership were, on an adjusted basis, more than three times more likely to die prematurely when compared to their more serious comedy partners (HR 3.52, 95% CI 1.22, 10.1; p=0.020). These data suggest that elite comedians are at increased risk of premature death compared to their less funny counterparts. Mental health issues and personality characteristics that help shape their comedic talent and success may well explain their reduced longevity and raises serious issues for identifying and mitigating their risk of a premature death. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Associations between ambient air pollution and daily mortality in a cohort of congestive heart failure: Case-crossover and nested case-control analyses using a distributed lag nonlinear model.

PubMed

Buteau, Stephane; Goldberg, Mark S; Burnett, Richard T; Gasparrini, Antonio; Valois, Marie-France; Brophy, James M; Crouse, Dan L; Hatzopoulou, Marianne

2018-04-01

Persons with congestive heart failure may be at higher risk of the acute effects related to daily fluctuations in ambient air pollution. To meet some of the limitations of previous studies using grouped-analysis, we developed a cohort study of persons with congestive heart failure to estimate whether daily non-accidental mortality were associated with spatially-resolved, daily exposures to ambient nitrogen dioxide (NO 2 ) and ozone (O 3 ), and whether these associations were modified according to a series of indicators potentially reflecting complications or worsening of health. We constructed the cohort from the linkage of administrative health databases. Daily exposure was assigned from different methods we developed previously to predict spatially-resolved, time-dependent concentrations of ambient NO 2 (all year) and O 3 (warm season) at participants' residences. We performed two distinct types of analyses: a case-crossover that contrasts the same person at different times, and a nested case-control that contrasts different persons at similar times. We modelled the effects of air pollution and weather (case-crossover only) on mortality using distributed lag nonlinear models over lags 0 to 3 days. We developed from administrative health data a series of indicators that may reflect the underlying construct of "declining health", and used interactions between these indicators and the cross-basis function for air pollutant to assess potential effect modification. The magnitude of the cumulative as well as the lag-specific estimates of association differed in many instances according to the metric of exposure. Using the back-extrapolation method, which is our preferred exposure model, we found for the case-crossover design a cumulative mean percentage changes (MPC) in daily mortality per interquartile increment in NO 2 (8.8 ppb) of 3.0% (95% CI: -0.9, 6.9%) and for O 3 (16.5 ppb) 3.5% (95% CI: -4.5, 12.1). For O 3 there was strong confounding by weather (unadjusted MPC = 7.1%; 95% CI: 1.7, 12.7%). For the nested case-control approach the cumulative MPC for NO 2 in daily mortality was 2.9% (95% CI: -0.9, 6.9%) and for O 3 7.3% (95% CI: 3.0, 11.9%). We found evidence of effect modification between daily mortality and cumulative NO 2 and O 3 according to the prescribed dose of furosemide in the nested case-control analysis, but not in the case-crossover analysis. Mortality in congestive heart failure was associated with exposure to daily ambient NO 2 and O 3 predicted from a back-extrapolation method using a land use regression model from dense sampling surveys. The methods used to assess exposure can have considerable influence on the estimated acute health effects of the two air pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Factors associated with mother-to-child transmission of HIV-1 despite a maternal viral load <500 copies/ml at delivery: a case-control study nested in the French perinatal cohort (EPF-ANRS CO1).

PubMed

Tubiana, Roland; Le Chenadec, Jerome; Rouzioux, Christine; Mandelbrot, Laurent; Hamrene, Karima; Dollfus, Catherine; Faye, Albert; Delaugerre, Constance; Blanche, Stephane; Warszawski, Josiane

2010-02-15

The rate of mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) type 1 is as low as 0.5% in non-breast-feeding mothers who delivered at term while receiving antiretroviral therapy with a plasma viral load <500 copies/mL. This situation accounted for 20% of the infected children born during the period 1997-2006 in the French Perinatal Cohort. We aimed to identify factors associated with such residual transmission risk. We performed a case-control study nested in the aforementioned subpopulation of the French Perinatal Cohort. Nineteen case patients (transmitters) and 60 control subjects (nontransmitters) were included. Case patients and control subjects did not differ by geographical origin, gestational age at HIV diagnosis, type of antiretroviral therapy received, or elective Cesarean delivery. Case patients were less often receiving treatment at the time that they conceived pregnancy than control subjects (16% vs 45%; P=.017). A lower proportion of case patients had a viral load <500 copies/mL, compared with control subjects, at 14 weeks (0% vs 38.1%; P=.02), 28 weeks (7.7% vs 62.1%; P=.005), and 32 weeks: (21.4% vs 71.1%; P=.004). The difference remained significant when we restricted analysis to the 10 of 16 intrapartum transmission cases. In a multivariate analysis at 30+/-4 weeks adjusted for viral load, CD4(+) T cell count, and time at antiretroviral therapy initiation, viral load was the only factor independently associated with MTCT of HIV (adjusted odds ratio, 23.2; 95% confidence interval, 3.5-553; P<.001). Early and sustained control of viral load is associated with a decreasing residual risk of MTCT of HIV-1. Guidelines should take into account not only CD4(+) T cell count and risk of preterm delivery, but also baseline HIV-1 load for deciding when to start antiretroviral therapy during pregnancy.

Dietary and stored iron as predictors of breast cancer risk: A nested case-control study in Shanghai.

PubMed

Moore, Amber B; Shannon, Jackilen; Chen, Chu; Lampe, Johanna W; Ray, Roberta M; Lewis, Sharon K; Lin, Minggang; Stalsberg, Helge; Thomas, David B

2009-09-01

Increases in risk of breast cancer in successive generations of migrants to the United States from China and rapid temporal changes in incidence rates in China following social and economic changes clearly implicate environmental factors in the etiology of this disease. Case-control and cohort studies have provided evidence that at least some of these factors may be dietary. Iron, an essential element necessary for cell function, has also been demonstrated to have potential carcinogenic and co-carcinogenic activities. Iron overload, which was previously uncommon, has become more common in the United States than iron deficiency and may be increasing in China concurrently with dramatic increases in meat consumption. A case-control study nested in a cohort of women in Shanghai, China, was conducted to evaluate possible associations between risk of proliferative and nonproliferative fibrocystic changes as well as breast cancer and dietary iron intake and plasma ferritin levels. Plasma ferritin levels and reported dietary iron intake were compared in 346 women with fibrocystic changes, 248 breast cancer cases and 1,040 controls. Increasing ferritin levels were significantly associated with increasing risk of nonproliferative fibrocystic changes (OR: 2.51, 95% CI: 1.16-5.45, p trend = 0.04). Similar, but weaker, trends were observed for proliferative changes and for breast cancer. Risk of breast cancer relative to the risk of fibrocystic changes was associated with dietary iron intake in women with nonproliferative fibrocystic changes (OR: 2.63, 95% CI: 1.04-6.68, p = 0.02). In conclusion, this study finds significant associations between iron (stored and dietary) and fibrocystic disease and breast cancer. 2009 UICC.

Factors associated with Clostridium difficile infection: A nested case-control study in a three year prospective cohort.

PubMed

Khanafer, Nagham; Vanhems, Philippe; Barbut, Frédéric; Luxemburger, Christine

2017-04-01

Clostridium difficile infection (CDI) is a serious medical condition that is associated with substantial morbidity and mortality. Identification of risk factors associated with CDI and prompt recognition of patients at risk is key to successfully preventing CDI. A 3-year prospective, observational, cohort study was conducted in a French university hospital and a nested case-control study was performed to identify risk factors for CDI. Inpatients aged 18 years or older, suffering from diarrhea suspected to be related to CDI, were asked to participate. A total of 945 patients were included, of which 233 cases had a confirmed CDI. CDI infection was more common in men (58.4%) (P = 0.04) compared with patients with diarrhea not related to C. difficile. Previous hospitalization (P < 0.001), prior treatment with antibiotics (P = 0.001) or antiperistaltics (P = 0.002), liver disease (P = 0.003), malnutrition (P < 0.001), and previous CDI (P < 0.001) were significantly more common in patients with CDI. Multivariate logistic regression analysis showed that exposure to antibiotics in the last 60 days (especially third generation cephalosporins and penicillins with β-lactamase inhibitor), chronic renal or liver disease, malnutrition or previous CDI, were associated with an independent high risk of CDI. Age was not related with CDI. This study showed that antibiotics and some comorbid conditions were predictors of CDI. Patients at high risk of acquiring CDI at the time of admission may benefit from careful monitoring of antibiotic prescriptions and early attention to infection control issues. In future, these "high-risk" patients may benefit from novel agents being developed to prevent CDI. Copyright © 2017 Elsevier Ltd. All rights reserved.

Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study.

PubMed

Huang, Jiaqi; Zagai, Ulrika; Hallmans, Göran; Nyrén, Olof; Engstrand, Lars; Stolzenberg-Solomon, Rachael; Duell, Eric J; Overvad, Kim; Katzke, Verena A; Kaaks, Rudolf; Jenab, Mazda; Park, Jin Young; Murillo, Raul; Trichopoulou, Antonia; Lagiou, Pagona; Bamia, Christina; Bradbury, Kathryn E; Riboli, Elio; Aune, Dagfinn; Tsilidis, Konstantinos K; Capellá, Gabriel; Agudo, Antonio; Krogh, Vittorio; Palli, Domenico; Panico, Salvatore; Weiderpass, Elisabete; Tjønneland, Anne; Olsen, Anja; Martínez, Begoña; Redondo-Sanchez, Daniel; Chirlaque, Maria-Dolores; Hm Peeters, Petra; Regnér, Sara; Lindkvist, Björn; Naccarati, Alessio; Ardanaz, Eva; Larrañaga, Nerea; Boutron-Ruault, Marie-Christine; Rebours, Vinciane; Barré, Amélie; Bueno-de-Mesquita, H B As; Ye, Weimin

2017-04-15

The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case-control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non-significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction < 0.01). Our findings provided evidence supporting the null association between H. pylori infection and pancreatic cancer risk in western European populations. However, the suggested association between chronic corpus atrophic gastritis and pancreatic cancer risk warrants independent verification in future studies, and, if confirmed, further studies on the underlying mechanisms. © 2016 UICC.

Arsenic Exposure in Relation to Ischemic Stroke: The Reasons for Geographic and Racial Differences in Stroke Study.

PubMed

Tsinovoi, Cari L; Xun, Pengcheng; McClure, Leslie A; Carioni, Vivian M O; Brockman, John D; Cai, Jianwen; Guallar, Eliseo; Cushman, Mary; Unverzagt, Frederick W; Howard, Virginia J; He, Ka

2018-01-01

The purpose of this case-cohort study was to examine urinary arsenic levels in relation to incident ischemic stroke in the United States. We performed a case-cohort study nested within the REGARDS (REasons for Geographic and Racial Differences in Stroke) cohort. A subcohort (n=2486) of controls was randomly sampled within region-race-sex strata while all incident ischemic stroke cases from the full REGARDS cohort (n=671) were included. Baseline urinary arsenic was measured by inductively coupled plasma-mass spectrometry. Arsenic species, including urinary inorganic arsenic and its metabolites monomethylarsonic acid and dimethylarsinic acid, were measured in a random subset (n=199). Weighted Cox's proportional hazards models were used to calculate hazard ratios and 95% confidence intervals of ischemic stroke by arsenic and its species. The average follow-up was 6.7 years. Although incident ischemic stroke showed no association with total arsenic or total inorganic arsenic, for each unit higher level of urinary monomethylarsonic acid on a log-scale, after adjustment for potential confounders, ischemic stroke risk increased ≈2-fold (hazard ratio=1.98; 95% confidence interval: 1.12-3.50). Effect modification by age, race, sex, or geographic region was not evident. A metabolite of arsenic was positively associated with incident ischemic stroke in this case-cohort study of the US general population, a low-to-moderate exposure area. Overall, these findings suggest a potential role for arsenic methylation in the pathogenesis of stroke, having important implications for future cerebrovascular research. © 2017 American Heart Association, Inc.

Ambient Air Pollution and Adverse Pregnancy Outcomes in Wuhan, China.

PubMed

Qian, Zhengmin; Zhang, Bin; Liang, Shengwen; Wang, Jing; Yang, Shaoping; Hu, Ke; Trevathan, Edwin; Yang, Rong; Li, Qijie; Flick, Louise H; Hu, Ronghua; Huang, Zhen; Zhang, Yimin; Hu, Shixiang; Wang, Jing; Shen, Longjiao; Lu, Yuan; Peng, Hui; Yu, Yuzhen; Yang, Li; Chen, Wei; Liu, Wenjin; Zhang, Wei

2016-09-01

Several recent studies have suggested that maternal exposures to air pollution and temperature extremes might contribute to low birth weight (LBW), preterm birth (PTB), and other outcomes that can adversely affect infant health. At the time the current study began, most other studies had been conducted in the United States or Europe. Dr. Zhengmin Qian proposed to extend work he had done on ambient particulate air pollution and daily mortality in Wuhan, China (Qian et al. 2010), as part of the HEIsponsored Public Health and Air Pollution in Asia program, to study adverse birth outcomes. Wuhan is the capital city of Hubei province, has a large population of about 6.4 million within the urban study area, experiences temperature extremes, and generally has higher air pollution levels than those observed in the United States and Europe, thus providing a good opportunity to explore questions about air pollution and health. Qian and colleagues planned a cohort and nested case–control design with four specific aims, examining whether increased exposures to air pollutants (PM2.5, PM10, SO2, NO2, O3, and CO) during vulnerable pregnancy periods were associated with increased rates of PTB, LBW (<2500 g), or intrauterine growth retardation (IUGR, defined as having a birth weight below the 10th percentile of singleton live births in Wuhan) after adjusting for major risk factors and whether the associations were confounded by copollutant exposures, affected by residual confounding, or modified by temperature extremes, socioeconomic status (SES), or secondhand smoke (SHS) exposure. The cohort study included 95,911 births that occurred from June 10, 2011, to June 9, 2013, and met typical prespecified inclusion criteria used in other birth outcome studies. The case–control study included 3146 cases (PTB, LBW, or both, but not IUGR) and 4263 controls (matched to the cases by birth month) for whom investigators were able to complete home visits and questionnaires. The investigators obtained air pollution and daily weather data for August 2010 to June 2013 from nine monitoring stations representing background air pollution sites in seven Wuhan inner-city districts. Only two of these stations provided PM2.5 data. For the cohort study, the investigators assigned exposures to mothers according to the daily mean concentrations from the monitor nearest the residential community in which the mother lived at the time of the birth. For the case–control study, they assigned exposures based on the inverse distance weighted average of daily mean concentrations from the three nearest monitors, for all but PM2.5 for which the method was not specified. They also collected data on various factors that might confound or modify the impact of the pollutants on the adverse outcomes, including data collected in the cohort from mothers at the time of delivery and, in the case–control study, from questionnaires administered to mothers. In the case–control study, covariates representing SES (as indicated by the mother’s educational attainment and household income) and SHS exposures were of particular interest. The primary statistical analyses of the pollutant associations with PTB, LBW, and IUGR were conducted using logistic regression models. In the cohort study, exposures during the pregnancy period of interest (full term, trimesters, and selected months) were included as continuous variables. In the case–control study, the exposures were modeled as binary variables (i.e., above or below the median pollutant concentrations). Numerous sensitivity analyses were conducted. Although originally planning a nested case–control study, the investigators encountered challenges that led them to analyze the cohort and case–control studies using different ways of assigning exposures and characterizing them in their statistical models. These decisions precluded direct comparisons between the sets of results, making it difficult to answer the questions about residual confounding that nested case–control studies are designed to answer. The odds ratios from the two study designs using different exposures also have different interpretations. Still, one can ask whether the sets of findings were qualitatively consistent with each other or with those of similar studies. There were some similarities. Both studies suggested that increased PM(2.5), PM(10), CO, and O(3) exposures over the full pregnancy were associated with small increases in the odds of PTB (the case–control study also showed an association with NO2) and that increased PM(2.5) exposures were associated with significantly increased odds of LBW. However, most of the other pollutants had no effect on LBW, except CO in the cohort study and O(3) in the case–control study, both of which increased the odds of LBW. The exposures over the entire pregnancy were generally associated with decreased odds of IUGR. Adjustments for potential confounders were greatest for the delivery covariates. The investigators found no systematic association of any of these outcomes with particular trimesters or months, another result that differed from those of some other studies. They found little evidence that their main results were confounded or modified by the presence of copollutants, although with the exception of O3, most of the pollutants were highly correlated, making it difficult to disentangle the effects of individual pollutants. Could the two sets of data be analyzed in a more comparable way, as in a standard nested case–control study? At the Committee’s request, the investigators reanalyzed the case–control data using the same exposures and models as in the cohort study. The results were strikingly different from those using the inverse distance weighted exposures, modeled as binary variables — the pollutants had either no effect or an apparent beneficial effect on PTB and LBW. The Committee was not convinced by the explanations offered for these differences, leaving the reasons for them unresolved. This study set out to answer important questions about the effects of air pollution exposure on three measures of adverse birth outcomes — LBW, PTB, and IUGR — in a large cohort of mothers and newborns in Wuhan, China. Given the cohort size, high pollution levels and temperatures, and detailed covariate data, the investigators were well poised to address these questions. They sought to pattern their work on other studies of birth outcomes, were very responsive to Committee questions, and provided many additional analyses and explanations. In the Committee’s view, however, the study was unable to address with confidence several of its specific aims. Most important, the differences in results when the case–control data were analyzed with different exposure metrics remain unexplained, raising concerns about the ability to draw conclusions from subsequent analyses assessing residual confounding and effect modification by temperature extremes, SES, and SHS exposure. Consequently, any individual findings from the cohort and case–control studies should be considered suggestive rather than conclusive, and should be interpreted carefully together.

Hierarchical Bayesian modeling of heterogeneous variances in average daily weight gain of commercial feedlot cattle.

PubMed

Cernicchiaro, N; Renter, D G; Xiang, S; White, B J; Bello, N M

2013-06-01

Variability in ADG of feedlot cattle can affect profits, thus making overall returns more unstable. Hence, knowledge of the factors that contribute to heterogeneity of variances in animal performance can help feedlot managers evaluate risks and minimize profit volatility when making managerial and economic decisions in commercial feedlots. The objectives of the present study were to evaluate heteroskedasticity, defined as heterogeneity of variances, in ADG of cohorts of commercial feedlot cattle, and to identify cattle demographic factors at feedlot arrival as potential sources of variance heterogeneity, accounting for cohort- and feedlot-level information in the data structure. An operational dataset compiled from 24,050 cohorts from 25 U. S. commercial feedlots in 2005 and 2006 was used for this study. Inference was based on a hierarchical Bayesian model implemented with Markov chain Monte Carlo, whereby cohorts were modeled at the residual level and feedlot-year clusters were modeled as random effects. Forward model selection based on deviance information criteria was used to screen potentially important explanatory variables for heteroskedasticity at cohort- and feedlot-year levels. The Bayesian modeling framework was preferred as it naturally accommodates the inherently hierarchical structure of feedlot data whereby cohorts are nested within feedlot-year clusters. Evidence for heterogeneity of variance components of ADG was substantial and primarily concentrated at the cohort level. Feedlot-year specific effects were, by far, the greatest contributors to ADG heteroskedasticity among cohorts, with an estimated ∼12-fold change in dispersion between most and least extreme feedlot-year clusters. In addition, identifiable demographic factors associated with greater heterogeneity of cohort-level variance included smaller cohort sizes, fewer days on feed, and greater arrival BW, as well as feedlot arrival during summer months. These results support that heterogeneity of variances in ADG is prevalent in feedlot performance and indicate potential sources of heteroskedasticity. Further investigation of factors associated with heteroskedasticity in feedlot performance is warranted to increase consistency and uniformity in commercial beef cattle production and subsequent profitability.

Exacerbations in patients with chronic obstructive pulmonary disease receiving physical therapy: a cohort-nested randomised controlled trial

PubMed Central

2014-01-01

Background Physical exercise training aims at reducing disease-specific impairments and improving quality of life in patients with chronic obstructive pulmonary disease (COPD). COPD exacerbations in particular negatively impact COPD progression. Physical therapy intervention seems indicated to influence exacerbations and their consequences. However, information on the effect of physical therapy on exacerbation occurrence is scarce. This study aims to investigate the potential of a protocol-directed physical therapy programme as a means to prevent or postpone exacerbations, to shorten the duration or to decrease the severity of exacerbations in patients with COPD who have recently experienced an exacerbation. Besides, this study focuses on the effect of protocol-directed physical therapy on health status and quality of life and on cost-effectiveness and cost-utility in patients with COPD who have recently experienced an exacerbation. Methods/Design A prospective cohort of 300 COPD patients in all GOLD stages will be constructed. Patients will receive usual multidisciplinary COPD care including guideline-directed physical therapy. Patients in this cohort who have GOLD stage 2 to 4 (post-bronchodilator FEV1/FVC < 0.7 and FEV1 < 80% of predicted), who receive reimbursement by health insurance companies for physical therapy (post-bronchodilator Tiffeneau-index < 0.6) and who experience a COPD exacerbation will be asked within 56 days to participate in a cohort-nested prospective randomised controlled trial (RCT). In this RCT, the intervention group will receive a strict physical therapy programme for patients with COPD. This protocol-directed physical therapy (pdPT) will be compared to a control group that will receive sham-treatment, meaning no or very low-intensity exercise training (ST). An economic evaluation will be embedded in the RCT. Anthropometric measurements, comorbidities, smoking, functional exercise capacity, peripheral muscle strength, physical activity level, health related quality of life, patients’ perceived benefit, physical therapy compliance, motivation level, level of effective mucus clearance, exacerbation symptoms and health care contacts due to COPD will be recorded. Follow-up measurements are scheduled at 3 and 6 weeks, 3, 6, 12 and 24 months after inclusion. Discussion Ways to minimise potential problems regarding the execution of this study will be discussed. Trial registration The Netherlands National Trial Register NTR1972. PMID:24767519

Employment history indicators and mortality in a nested case-control study from the Spanish WORKing life social security (WORKss) cohort

PubMed Central

2017-01-01

Employment has transitioned from stable to more flexible schemes. Little is known about the effects of dynamic working lives and mortality. We examined the association of employment, unemployment and inactivity on mortality among workers born in 1926–1988, in a nested case-control study of workers from the Spanish WORKss cohort. Cases were all deaths that occurred during 2004–2013 and controls were living persons, matched for sex and age at the time the case occurred. We had information on employment from 1981 to 2013. Logistic regression was used to measure the associations between the 3 employment history indicators separately by sex. There were 53,989 cases and an equal number of controls (n = 107,978). More than 16 years employed showed a protective effect against mortality in women (OR = 0.88, 95%CI: 0.81, 0.94) and men (OR = 0.76, 95%CI: 0.70, 0.79). The number of spells and time in unemployment and inactivity were significantly related to mortality in men, but not women. Sensitivity analyses by labor relationship showed stronger associations of unemployment (OR = 1.42, 95%CI: 1.13, 1.78) and inactivity (OR = 1.34; 95%CI: 1.09, 1.65) for temporary workers. Employment gaps are detrimental to health and have worse effects if the gaps occur without unemployment benefits or after temporary contracts. These results may drive improvement of labor and social policies that protect workers against the potential negative effects of dynamic work lives. PMID:28570614

NO2, as a marker of air pollution, and recurrent wheezing in children: a nested case-control study within the BAMSE birth cohort

PubMed Central

Emenius, G; Pershagen, G; Berglind, N; Kwon, H; Lewne, M; Nordvall, S; Wickman, M

2003-01-01

Aims: To investigate the association between air pollution, including with NO2, and recurrent wheezing during the first two years of life. Methods: A birth cohort (BAMSE) comprised 4089 children, for whom information on exposures, symptoms, and diseases was available from parental questionnaires at ages 2 months, and 1 and 2 years. NO2 was measured during four weeks in and outside the dwellings of children with recurrent wheezing and two age matched controls, in a nested case-control study (540 children). Results: Conditional logistic regression showed an OR of 1.60 (95% CI 0.78 to 3.26) among children in the highest quartile of outdoor NO2 exposure in relation to those in the lowest quartile, adjusted for potential confounders. The corresponding OR for indoor NO2 was 1.51 (95% CI 0.81 to 2.82). An interaction with environmental tobacco smoke (ETS) was indicated with an OR of 3.10 (95% CI 1.32 to 7.30) among children exposed to the highest quartile of indoor NO2 and ETS. The association between NO2 and recurrent wheezing appeared stronger in children who did not fulfil the criteria for recurrent wheezing until their second year. Conclusions: Although the odds of increased recurrent wheezing are not statistically significantly different from one, results suggest that exposure to air pollution including NO2, particularly in combination with exposure to ETS, increases the risk of recurrent wheezing in children. PMID:14573719

The Influence of Hormonal Factors on the Risk of Developing Cervical Cancer and Pre-Cancer: Results from the EPIC Cohort

PubMed Central

Roura, Esther; Travier, Noémie; Waterboer, Tim; de Sanjosé, Silvia; Bosch, F. Xavier; Pawlita, Michael; Pala, Valeria; Weiderpass, Elisabete; Margall, Núria; Dillner, Joakim; Gram, Inger T.; Tjønneland, Anne; Munk, Christian; Palli, Domenico; Khaw, Kay-Tee; Overvad, Kim; Clavel-Chapelon, Françoise; Mesrine, Sylvie; Fournier, Agnès; Fortner, Renée T.; Ose, Jennifer; Steffen, Annika; Trichopoulou, Antonia; Lagiou, Pagona; Orfanos, Philippos; Masala, Giovanna; Tumino, Rosario; Sacerdote, Carlotta; Polidoro, Silvia; Mattiello, Amalia; Lund, Eiliv; Peeters, Petra H.; Bueno-de-Mesquita, H. B(as).; Quirós, J. Ramón; Sánchez, María-José; Navarro, Carmen; Barricarte, Aurelio; Larrañaga, Nerea; Ekström, Johanna; Lindquist, David; Idahl, Annika; Travis, Ruth C.; Merritt, Melissa A.; Gunter, Marc J.; Rinaldi, Sabina; Tommasino, Massimo; Franceschi, Silvia; Riboli, Elio; Castellsagué, Xavier

2016-01-01

Background In addition to HPV, high parity and hormonal contraceptives have been associated with cervical cancer (CC). However, most of the evidence comes from retrospective case-control studies. The aim of this study is to prospectively evaluate associations between hormonal factors and risk of developing cervical intraepithelial neoplasia grade 3 (CIN3)/carcinoma in situ (CIS) and invasive cervical cancer (ICC). Methods and Findings We followed a cohort of 308,036 women recruited in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study. At enrollment, participants completed a questionnaire and provided serum. After a 9-year median follow-up, 261 ICC and 804 CIN3/CIS cases were reported. In a nested case-control study, the sera from 609 cases and 1,218 matched controls were tested for L1 antibodies against HPV types 11,16,18,31,33,35,45,52,58, and antibodies against Chlamydia trachomatis and Human herpesvirus 2. Multivariate analyses were performed to estimate hazard ratios (HR), odds ratios (OR) and corresponding 95% confidence intervals (CI). The cohort analysis showed that number of full-term pregnancies was positively associated with CIN3/CIS risk (p-trend = 0.03). Duration of oral contraceptives use was associated with a significantly increased risk of both CIN3/CIS and ICC (HR = 1.6 and HR = 1.8 respectively for ≥15 years versus never use). Ever use of menopausal hormone therapy was associated with a reduced risk of ICC (HR = 0.5, 95%CI: 0.4–0.8). A non-significant reduced risk of ICC with ever use of intrauterine devices (IUD) was found in the nested case-control analysis (OR = 0.6). Analyses restricted to all cases and HPV seropositive controls yielded similar results, revealing a significant inverse association with IUD for combined CIN3/CIS and ICC (OR = 0.7). Conclusions Even though HPV is the necessary cause of CC, our results suggest that several hormonal factors are risk factors for cervical carcinogenesis. Adherence to current cervical cancer screening guidelines should minimize the increased risk of CC associated with these hormonal risk factors. PMID:26808155

Elevated maternal C-reactive protein and increased risk of schizophrenia in a national birth cohort.

PubMed

Canetta, Sarah; Sourander, Andre; Surcel, Heljä-Marja; Hinkka-Yli-Salomäki, Susanna; Leiviskä, Jaana; Kellendonk, Christoph; McKeague, Ian W; Brown, Alan S

2014-09-01

The objective of the present study was to investigate an association between early gestational C-reactive protein, an established inflammatory biomarker, prospectively assayed in maternal sera, and schizophrenia in a large, national birth cohort with an extensive serum biobank. A nested case-control design from the Finnish Prenatal Study of Schizophrenia cohort was utilized. A total of 777 schizophrenia cases (schizophrenia, N=630; schizoaffective disorder, N=147) with maternal sera available for C-reactive protein testing were identified and matched to 777 control subjects in the analysis. Maternal C-reactive protein levels were assessed using a latex immunoassay from archived maternal serum specimens. Increasing maternal C-reactive protein levels, classified as a continuous variable, were significantly associated with schizophrenia in offspring (adjusted odds ratio=1.31, 95% confidence interval=1.10-1.56). This finding remained significant after adjusting for potential confounders, including maternal and parental history of psychiatric disorders, twin/singleton birth, urbanicity, province of birth, and maternal socioeconomic status. This finding provides the most robust evidence to date that maternal inflammation may play a significant role in schizophrenia, with possible implications for identifying preventive strategies and pathogenic mechanisms in schizophrenia and other neurodevelopmental disorders.

Heart Disease, Hypertension, Gestational Diabetes Mellitus, and Preeclampsia/Eclampsia in Mothers With Juvenile Arthritis: A Nested Case-Control Study.

PubMed

Feldman, Debbie E; Vinet, Évelyne; Bérard, Anick; Duffy, Ciarán; Hazel, Beth; Meshefedjian, Garbis; Sylvestre, Marie-Pierre; Bernatsky, Sasha

2017-02-01

To determine whether women with a history of juvenile arthritis are at higher risk for heart disease and hypertension and for developing adverse maternal outcomes: gestational diabetes mellitus, maternal hypertension, and preeclampsia/eclampsia. We designed a nested case-control study from a cohort of first-time mothers with prior physician billing codes suggesting juvenile arthritis, and a matched comparison group without juvenile arthritis. For the nested case-control design, we selected 3 controls for each case for the outcomes of heart disease (n = 403), prepregnancy hypertension (n = 66), gestational diabetes mellitus (n = 285), maternal hypertension (n = 561), and preeclampsia/eclampsia (n = 236). We used conditional logistic regression, adjusting for maternal age and education. Having juvenile arthritis was associated with heart disease (odds ratio [OR] 2.44 [95% confidence interval (95% CI) 1.15-5.15]) but not with gestational hypertension, diabetes mellitus, or preeclampsia/eclampsia. All 66 cases of prepregnancy hypertension had juvenile arthritis. Having prepregnancy hypertension was strongly associated with preeclampsia/eclampsia (OR 8.05 [95% CI 2.69-24.07]). Women with a history of juvenile arthritis had a higher risk of heart disease. This risk signals the potential importance of cardiac prevention strategies in juvenile arthritis. As this was a retrospective study, it was not possible to correct for some relevant potential confounders. Further studies should assess the impact of medications, disease severity, and other factors (e.g., obesity) on cardiac outcomes in juvenile arthritis. © 2016, American College of Rheumatology.

Case–control and prospective studies of dietary α-linolenic acid intake and prostate cancer risk: a meta-analysis

PubMed Central

Carleton, Amanda J; Sievenpiper, John L; de Souza, Russell; McKeown-Eyssen, Gail; Jenkins, David J A

2013-01-01

Objective α-Linolenic acid (ALA) is considered to be a cardioprotective nutrient; however, some epidemiological studies have suggested that dietary ALA intake increases the risk of prostate cancer. The main objective was to conduct a systematic review and meta-analysis of case–control and prospective studies investigating the association between dietary ALA intake and prostate cancer risk. Design A systematic review and meta-analysis were conducted by searching MEDLINE and EMBASE for relevant prospective and case–control studies. Included studies We included all prospective cohort, case–control, nested case-cohort and nested case–control studies that investigated the effect of dietary ALA intake on the incidence (or diagnosis) of prostate cancer and provided relative risk (RR), HR or OR estimates. Primary outcome measure Data were pooled using the generic inverse variance method with a random effects model from studies that compared the highest ALA quantile with the lowest ALA quantile. Risk estimates were expressed as RR with 95% CIs. Heterogeneity was assessed by χ2 and quantified by I2. Results Data from five prospective and seven case–control studies were pooled. The overall RR estimate showed ALA intake to be positively but non-significantly associated with prostate cancer risk (1.08 (0.90 to 1.29), p=0.40; I2=85%), but the interpretation was complicated by evidence of heterogeneity not explained by study design. A weak, non-significant protective effect of ALA intake on prostate cancer risk in the prospective studies became significant (0.91 (0.83 to 0.99), p=0.02) without evidence of heterogeneity (I2=8%, p=0.35) on removal of one study during sensitivity analyses. Conclusions This analysis failed to confirm an association between dietary ALA intake and prostate cancer risk. Larger and longer observational and interventional studies are needed to define the role of ALA and prostate cancer. PMID:23674441

The effects of aminosalicylates or thiopurines on the risk of colorectal cancer in inflammatory bowel disease.

PubMed

Carrat, F; Seksik, P; Colombel, J-F; Peyrin-Biroulet, L; Beaugerie, L

2017-02-01

Whether aminosalicylates or thiopurines reduce the risk of colorectal cancer (CRC) in inflammatory bowel (IBD) disease is controversial. To assess simultaneously the chemopreventive effect of aminosalicylates or thiopurines in a case-control study nested in the CESAME observational cohort that enrolled consecutive patients with IBD between May 2004 and June 2005. Patients were followed up to December 2007. Study population comprised 144 case patients who developed CRC from the diagnosis of IBD (65 and 79 cases diagnosed, respectively, before and from 2004, starting year of the prospective observational period of CESAME) and 286 controls matched for gender, age, IBD subtype and year of diagnosis, and cumulative extent of colitis. Exposure to aminosalicylates or thiopurines was defined by an exposure to the treatment during the year of the diagnosis of cancer. The propensity of receiving 5-ASA and thiopurines was quantified by a composite score taking into account patient and IBD characteristics. The role of aminosalicylates or thiopurines was assessed by multivariate analysis. Propensity scores and the history of primary sclerosing cholangitis were entered into the multivariate model for adjustment. By multivariate analysis adjusted for propensity, a significant protective effect of exposure to drugs during the year of cancer was found for aminosalicylates (OR = 0.587, 95% CI: 0.367-0.937, P = 0.0257), but not for thiopurines (OR = 0.762, 95% CI: 0.432-1.343, P = 0.3468). In a case-control study nested in the CESAME cohort, a significant decrease in the risk of colorectal cancer in IBD was associated with exposure to aminosalicylates, not to thiopurines. © 2016 John Wiley & Sons Ltd.

Does physical activity moderate the relationship between depression symptomatology and low back pain? Cohort and co-twin control analyses nested in the longitudinal study of aging Danish twins (LSADT).

PubMed

Hübscher, Markus; Hartvigsen, Jan; Fernandez, Matthew; Christensen, Kaare; Ferreira, Paulo

2016-04-01

To investigate whether depression symptomatology is associated with low back pain (LBP) in twins aged 70+ and whether this effect depends on a person's physical activity (PA) status. This prospective cohort and nested case-control study used a nationally representative sample of twins. Data on depression symptomatology (modified Cambridge Mental Disorders Examination) and self-reported PA were obtained from the Longitudinal Study of Aging Danish Twins using twins without LBP at baseline. Associations between depression symptomatology (highest quartile) at baseline and LBP two years later were investigated using logistic regression analyses adjusted for sex. To examine the moderating effect of PA, we tested its interaction with depression. Associations were analysed using the complete sample of 2446 twins and a matched case-control analysis of 97 twin pairs discordant for LBP at follow-up. Odds ratios (OR) with 95% confidence intervals (CI) were calculated. Using the whole sample, high depression scores were associated with an increased probability of LBP (OR 1.56, 95% CI 1.22-1.99, P ≤ 0.01). There was no statistically significant interaction of light PA and depression symptomatology (OR 0.78, 95% CI 0.46-1.35, P = 0.39) and strenuous PA and depression symptomatology (0.84, 95% CI 0.50-1.41, P = 0.51). The case-control analysis showed similar ORs, although statistically insignificant. High depression symptomatology predicted incident LBP. This effect is supposedly not attributable to genetic or shared environmental factors. Physical activity did not moderate the effect of depression symptomatology on LBP.

Registered Nurse to Bachelor of Science in Nursing: nesting a fast-track to traditional generic program, teachings from nursing education in Burkina Faso.

PubMed

Beogo, Idrissa; Liu, Chieh-Yu; Dlamini, Colile P; Gagnon, Marie-Pierre

2015-01-01

Nursing education has evolved over time to fit societies' increasing care needs. Innovations in nursing education draw thorny debates on potential jeopardy in the quality, safety, and efficacy of nurse graduates. Accelerated nursing education programs have been among landmark strategic changes to address the persistent bedside nurse shortage. Despite the dearth of empirical studies in sub-Saharan Africa (SSA), the National School of Public Health of Burkina Faso has developed a State Diploma Nursing (SDN) fast-track program. With innovative features, the program is nested into the traditional SDN program. This study investigates preliminary outcomes of the implemented policy using the initial cohort that went through the program. Comparison of the traditional generic program and the fast-track one is drawn to inform nursing education policy. The study was conducted in the three campuses delivering the SDN program. Data collected from a representative sample included 255 students from the 2006-2009 cohort, after concluding the program. Surveyed students were assessed according to the program entry status. Outcomes were measured using students' academic performance. Besides descriptive analysis, bivariate t-test, F-test, and multivariate ordinary least square regression (OLSR) were employed to determine the comparative pattern between the traditional generic and the newly nested fast-track program. Students' varied statuses (private pre-registration, state pre-registration, private post-registration, and state post-registration) were kept to better outline the findings trend. A fifth (19.6 %) of surveyed students were enrolled in the fast-track stream from which, one third (33.7 %) consisted of post-registered students. Fast-track students comparatively achieved the best academic performance (mean: 73.68/100, SD: 5.52). Multivariate OLSR confirmed that fast-track students performed better (β: 5.559, p < 0.001), and further informed differences between campuses. Students entry status also displayed significant differences, yet the academic performance of post-registered students from traditional generic versus fast-track was similar (p = 0.409). Findings suggest that fast-track program students performed better than the ones from the traditional generic program. The uniqueness and success of this mixed nursing program experience sheds light for nursing educators engaged in policy making. The study results can serve as a crucial foundation for policymakers to alleviate the nurse shortage in SSA.

A nested case-control study of leukemia mortality and ionizing radiation at the Portsmouth Naval Shipyard.

PubMed

Kubale, Travis L; Daniels, Robert D; Yiin, James H; Couch, James; Schubauer-Berigan, Mary K; Kinnes, Gregory M; Silver, Sharon R; Nowlin, Susan J; Chen, Pi-Hsueh

2005-12-01

A nested case-control study using conditional logistic regression was conducted to evaluate the exposure-response relationship between external ionizing radiation exposure and leukemia mortality among civilian workers at the Portsmouth Naval Shipyard (PNS), Kittery, Maine. The PNS civilian workers received occupational radiation exposure while performing construction, overhaul, repair and refueling activities on nuclear-powered submarines. The study age-matched 115 leukemia deaths with 460 controls selected from a cohort of 37,853 civilian workers employed at PNS between 1952 and 1992. In addition to radiation doses received in the workplace, a secondary analysis incorporating doses from work-related medical X rays and other occupational radiation exposures was conducted. A significant positive association was found between leukemia mortality and external radiation exposure, adjusting for gender, radiation worker status, and solvent exposure duration (OR = 1.08 at 10 mSv of exposure; 95% CI = 1.01, 1.16). Solvent exposure (including benzene and carbon tetrachloride) was also significantly associated with leukemia mortality adjusting for radiation dose, radiation worker status, and gender. Incorporating doses from work-related medical X rays did not change the estimated leukemia risk per unit of dose.

Impact of human cytomegalovirus infection UL55-nested polymerase chain reaction method in hematopoietic stem cell transplant donors and recipients.

PubMed

Banan, A A; Yaghobi, R; Ramzi, M; Mehrabani, D

2009-09-01

Human cytomegalovirus (HCMV) is one of the most important and critical viral causes of graft rejection among hematopoietic stem cell transplant (HSCT) recipients. Monitoring of this viral infection has a critical role in the management of HSCT clinical complications. In this retrospective cohort, blood (plasma and buffy coat) and urine samples were collected from 110 HSCT patients and 95 donors pretransplantation and weekly for 100 days posttransplantation. An HCMV-optimized UL55-nested polymerase chain reaction (PCR) method was used to detect HCMV infection. Genotyping of the HCMV UL55 gene was performed for all UL55-nested, PCR-positive samples. HSCT donor and recipient laboratory and clinical data were statistically analyzed using SPSS version 15 software. UL55-nested, PCR-positive results were obtained in 3540/4950 (71.5%), 3634/4950 (73.4%), and 3292/4950 (66.5%) of these plasma, buffy coat, and urine samples, respectively. Twenty-five percent of transplant donors were infected with HCMV. An increase in HCMV infection was observed from pre- to post-HSCT conditions. Detection of the gB2 UL55 genotype in most transplant patient samples suggested the need to examine the possible impact of HCMV UL55 genotypes and HCMV infections among stem cell transplant recipients.

Inpatient hospital admission rates for nonmalignant respiratory disease among workers exposed to metal removal fluids at a U.S. automobile manufacturer.

PubMed

Reeve, Gordon R; Stout, Allen W; Hands, David; Curry, Emmanuel

2003-11-01

This study was undertaken to determine the impact of exposure to metal removal fluids (MRFs) on the respiratory health of exposed workers. The outcome measure selected was the rate of hospital admissions for nonmalignant respiratory disease episodes as determined from healthcare insurance claims data. A cohort of MRF-exposed employees was assembled from 11 manufacturing facilities where MRFs were extensively used in the manufacture of automotive engines, transmissions, and other machined parts. The MRF-exposed cohort included 20,434 employees of such facilities who worked at any time from 1993 through 1997. A non-MRF-exposed cohort was assembled from other employees of the same company during the same time period, but working in warehouse operations and other manufacturing facilities that did not use MRFs or any known respiratory sensitizing agents. The non-exposed cohort included 8681 employees. The crude hospital admission rate for the MRF-exposed cohort was 44 percent higher than that of the non-exposed cohort over the 5-year study period (6.67 vs. 4.62 per 1000 person years at risk, p < 0.05). With age adjustment, the MRF population's rate was still 35 percent higher, and still statistically significant. A nested case-control study was also conducted to determine whether the risk of hospital admission increased with the level of MRF exposure in the population working in MRF plants. The industrial hygiene reconstruction found the levels of exposures of both cases and controls to be very low, with the vast majority of study subjects (more than 90%) having exposures of less than 0.5 mg/m(3). The case-control study did not find any association between increased levels of MRF exposure and risk of hospitalization. The study did document an elevated risk of hospitalization among a sizable population employed in manufacturing operations where MRFs are used.

Recurrence of tuberculosis among patients following treatment completion in eight provinces of Vietnam: a nested case-control study.

PubMed

Bestrashniy, Jessica Rutledge Bruce Musselman; Nguyen, Viet Nhung; Nguyen, Thi Loi; Pham, Thi Lieu; Nguyen, Thu Anh; Pham, Duc Cuong; Nghiem, Le Phuong Hoa; Le, Thi Ngoc Anh; Nguyen, Binh Hoa; Nguyen, Kim Cuong; Nguyen, Huy Dung; Buu, Tran Ngoc; Le, Thi Nhung; Nguyen, Viet Hung; Dinh, Ngoc Sy; Britton, Warwick John; Marks, Guy Barrington; Fox, Greg James

2018-06-23

Patients completing treatment for tuberculosis (TB) in high-prevalence settings face a risk of developing recurrent disease. This has important consequences for public health, given its association with drug resistance and a poor prognosis. Previous research has implicated individual factors such as smoking, alcohol use, HIV, poor treatment adherence, and drug resistant disease as risk factors for recurrence. However, little is known about how these factors co-act to produce recurrent disease. Furthermore, perhaps factors related to the index disease means higher burden/low resource settings may be more prone to recurrent disease that could be preventable. We conducted a case-control study nested within a cohort of consecutively enrolled adults who were being treated for smear positive pulmonary TB in 70 randomly selected district clinics in Vietnam. Cases were patients with recurrent TB, identified by follow-up from the parent cohort study. Controls were selected from the cohort by random sampling. Information on demographic, clinical and disease-related characteristics was obtained by interview. information was extracted from clinic registries. Logistic regression, with stepwise selection, was used to develop a fully adjusted model for the odds of recurrence of TB. We recruited 10,964 patients between October 2010 and July 2013. Median follow-up was 988 days. At the end of follow-up, 505 patients (4.7%) with recurrence were identified as cases and 630 other patients were randomly selected as controls. Predictors of recurrence included multidrug-resistant (MDR)-TB (adjusted odds ratio 79.6; 95% CI: 25.1-252.0), self-reported prior TB therapy (aOR=2.5; 95% CI: 1.7-3.5), and incomplete adherence (aOR=1.9; 95% CI 1.1-3.1). Index disease treatment history is a leading determinant of relapse among patients with TB in Vietnam. Further research is required to identify interventions that will reduce the risk of recurrent disease and enhance its early detection within high-risk populations. Copyright © 2018. Published by Elsevier Ltd.

Elevated Maternal C-Reactive Protein is Associated with Increased Risk of Schizophrenia in a National Birth Cohort

PubMed Central

Canetta, Sarah; Sourander, Andre; Surcel, Helja-Marja; Hinkka-Yli-Salomäki, Susanna; Leiviskä, Jaana; Kellendonk, Christoph; McKeague, Ian W.; Brown, Alan S.

2014-01-01

Objective The goal of the present study was to investigate an association between early gestational C-reactive protein (CRP), an established inflammatory biomarker, prospectively assayed in maternal sera, and schizophrenia in a large national birth cohort with an extensive serum biobank. Methods This study utilized a nested case-control design from the Finnish Prenatal Study of Schizophrenia cohort. 777 schizophrenia cases (630 with schizophrenia, 147 with schizoaffective disorder) that had maternal sera available for CRP testing were identified and matched to 777 controls in the analysis. Maternal CRP levels were assessed using a latex immunoassay from archived maternal serum specimens. Results Increasing maternal CRP levels, classified as a continuous variable, were significantly associated with schizophrenia in offspring (adjusted odds ratio (OR)=1.31, 95% confidence interval (CI)=1.10-1.56, p=0.003). This finding remained significant after adjusting for potential confounders including maternal and parental history of psychiatric disorders, twin/singleton birth, urbanicity, province of birth, and maternal socioeconomic status. Conclusion This finding provides the most robust evidence to date that maternal inflammation may play a significant role in schizophrenia, with possible implications for identifying preventive strategies and pathogenic mechanisms in schizophrenia and other neurodevelopmental disorders. PMID:24969261

Insulin use increases risk of asthma but metformin use reduces the risk in patients with diabetes in a Taiwanese population cohort.

PubMed

Chen, Chiung-Zuei; Hsu, Chih-Hui; Li, Chung-Yi; Hsiue, Tzuen-Ren

2017-12-01

Recent reports have suggested that insulin promotes airway smooth muscle contraction and enhances airway hyperresponsiveness, which are cardinal features of asthma. In contrast, metformin can reduce both airway inflammatory and remodeling properties. However, these results are all from in vitro and animal studies. This study investigated whether diabetes and various antidiabetic agents associate with the risk of asthma. We used a retrospective population-based cohort study using Taiwan's National Health Insurance claim database from 2000 to 2010 and a Cox proportional hazards regression model to compare the incidence of asthma between patients with diabetes (n = 19,428) and a matched non-diabetic group (n = 38,856). We also used a case-control study nested from the above cohort including 1,982 incident cases of asthma and 1,982 age- and sex-matched controls. A time density sampling technique was used to assess the effects of various antidiabetic agents on the risk of asthma. The incidence of asthma was significantly higher in the diabetic cohort than that in the non-diabetic cohort after adjustment for age, sex, and obesity, with a hazard ratio of 1.30 (95% confidence interval [CI]: 1.24-1.38). Insulin was found to increase the risk of asthma among diabetic patients (odds ratio [OR] 2.23; 95% CI: 1.52-3.58). In contrast, the use of metformin correlated with a decreased risk of asthma (OR 0.75; 95% CI: 0.60-0.95). Individuals with diabetes are at an increased risk of asthma. Insulin may further increase the risk of asthma, but the risk could possibly be reduced by using metformin.

Lung cancer among glass fibre production workers: a case-control study.

PubMed Central

Gardner, M J; Magnani, C; Pannett, B; Fletcher, A C; Winter, P D

1988-01-01

A cohort study among 4734 employees at an English glass fibre plant previously reported no excess of lung cancer mortality either overall or when examined in broad occupational groups. To investigate occupation in more detail, and to test the hypothesis that processes producing or using finer (respirable) fibres may be related to a higher risk of lung cancer, a nested case-control study has now been carried out. Included are 73 cases of lung cancer and 506 matched controls, for whom jobs held and processes worked on have been blindly recorded in more detail than for the cohort study. Workers known to have been employed on processes containing respirable fibres had a relative risk of lung cancer of 1.2 (95% confidence interval 0.7-2.0) compared with other workers. There was no evidence of a relationship of lung cancer to fibre diameter, duration of exposure, or time since first exposure. The results by broad occupational group were similar to those of the cohort study, and although some of the many detailed occupational categories examined had significantly raised relative risks, these did not appear to be related to exposure to respirable glass fibre. Although the study has not indicated a differential risk of lung cancer among workers exposed to finer diameter glass fibres, the exposure levels were low and the number of cases small. PMID:3179236

Human oral microbiome and prospective risk for pancreatic cancer: a population-based nested case-control study.

PubMed

Fan, Xiaozhou; Alekseyenko, Alexander V; Wu, Jing; Peters, Brandilyn A; Jacobs, Eric J; Gapstur, Susan M; Purdue, Mark P; Abnet, Christian C; Stolzenberg-Solomon, Rachael; Miller, George; Ravel, Jacques; Hayes, Richard B; Ahn, Jiyoung

2018-01-01

A history of periodontal disease and the presence of circulating antibodies to selected oral pathogens have been associated with increased risk of pancreatic cancer; however, direct relationships of oral microbes with pancreatic cancer have not been evaluated in prospective studies. We examine the relationship of oral microbiota with subsequent risk of pancreatic cancer in a large nested case-control study. We selected 361 incident adenocarcinoma of pancreas and 371 matched controls from two prospective cohort studies, the American Cancer Society Cancer Prevention Study II and the National Cancer Institute Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. From pre-diagnostic oral wash samples, we characterised the composition of the oral microbiota using bacterial 16S ribosomal RNA (16S rRNA) gene sequencing. The associations between oral microbiota and risk of pancreatic cancer, controlling for the random effect of cohorts and other covariates, were examined using traditional and L1-penalised least absolute shrinkage and selection operator logistic regression. Carriage of oral pathogens, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans , were associated with higher risk of pancreatic cancer (adjusted OR for presence vs absence=1.60 and 95% CI 1.15 to 2.22; OR=2.20 and 95% CI 1.16 to 4.18, respectively). Phylum Fusobacteria and its genus Leptotrichia were associated with decreased pancreatic cancer risk (OR per per cent increase of relative abundance=0.94 and 95% CI 0.89 to 0.99; OR=0.87 and 95% CI 0.79 to 0.95, respectively). Risks related to these phylotypes remained after exclusion of cases that developed within 2 years of sample collection, reducing the likelihood of reverse causation in this prospective study. This study provides supportive evidence that oral microbiota may play a role in the aetiology of pancreatic cancer. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Prevalence of non-organ-specific autoantibodies and chronic liver disease in the general population: a nested case-control study of the Dionysos cohort

PubMed Central

Lenzi, M; Bellentani, S; Saccoccio, G; Muratori, P; Masutti, F; Muratori, L; Cassani, F; Bianchi, F; Tiribelli, C

1999-01-01

BACKGROUND—Several retrospective and prospective studies report an increased prevalence of non-organ-specific autoantibodies (NOSAs) in patients with hepatitis C virus (HCV) related chronic liver disease (CLD). Some of the data so far available are controversial and the true prevalence of NOSAs in the general population is still not known.
AIM—To explore the prevalence of NOSAs, their relation to different HCV genotypes, and the presence and severity of CLD in the general population of Northern Italy.
PATIENTS—All 226 anti-HCV positive and 87 hepatitis B surface antigen (HBsAg) positive patients of the Dionysos cohort study were analysed and compared with sex and age matched cases (226) negative for both anti-HCV antibody and HBsAg selected from the same cohort.
METHODS—Sera tested for the presence of NOSAs (anti-nuclear antibody (ANA), anti-smooth muscle antibody (SMA), and anti-liver/kidney microsomes type 1 antibody (LKM1)) were screened by indirect immunofluorescence at a 1:40 serum dilution. HCV RNA and HCV genotypes were also determined by nested polymerase chain reaction (PCR) of the 5' non-coding region and by PCR amplification of the core region with type specific primers.
RESULTS—The overall prevalence of NOSA reactivity was significantly higher in anti-HCV positive subjects than in both normal and pathological controls (25% v 6% and 7% respectively, p<0.05). ANA, SMA, and LKM1 occurred in 16, 10, and 1.3% of cases respectively. No specific association between NOSAs and a specific HCV genotype was found. NOSAs were found more often associated with more than one genotype (35.7%) and with untypable genotypes (34.6%), although the association was not statistically significant. NOSAs were associated with HCV RNA and CLD but not with the presence of cirrhosis and/or hepatocellular carcinoma. On univariate analysis, NOSA reactivity was independently associated with abnormal alanine aminotransferase (p<0.01) and γ-glutamyltranspeptidase levels (p<0.05). The risk for the presence of NOSAs was 5.1 times higher in anti-HCV subjects than in controls.
CONCLUSIONS—In the general population the prevalence of NOSAs is higher in anti-HCV positive subjects than in normal or disease controls. Moreover NOSAs are associated with CLD and with a more active disease in terms of alanine aminotransferase activity.


Keywords: non-organ-specific autoantibodies; hepatitis C virus genotypes; chronic liver disease; cohort study; prevalence PMID:10446115

Comparison of HIV incidence estimated in clinical trial and observational cohort settings in a high risk fishing population in Uganda: Implications for sample size estimates.

PubMed

Abaasa, Andrew; Asiki, Gershim; Price, Matthew A; Ruzagira, Eugene; Kibengo, Freddie; Bahemuka, Ubaldo; Fast, Patricia E; Kamali, Anatoli

2016-04-04

Clinical trial participants may differ from the source population due to the demands of trial participation and self-selection, inadvertent selection of a lower-risk group, or both. We investigated the HIV risk status of volunteers in a Simulated Vaccine Efficacy Trial (SiVET) nested within a prospective observational cohort of fisher folks in South Western Uganda. Volunteers aged 18-49 years, at high risk for HIV from fishing communities in Masaka district were recruited into an observational cohort and followed quarterly. High risk was defined as a self-report, of at least one of the following in the past three months; sexually transmitted infections, unprotected sex with >1 partner or a new sexual partner, use of recreational drugs, weekly alcohol use, and/or frequent travel. Volunteers who had at least three months of follow-up in the observational cohort were consecutively enrolled in SiVET, administered Hepatitis B vaccine at months (0, 1, 6) and followed-up three days post vaccinations to mimic a vaccine trial schedule. HIV incidence over the next 12 months was compared between SiVET and the observational cohort studies. Between January 2012 and February 2013, 575 individuals were enrolled in the observational cohort, of whom 282 were enrolled in SiVET between July 2012 and February 2013. Despite similar pattern of reported risk behaviour in both studies, HIV incidence was higher in observational cohort, 11.4 cases/100 PYO [95% CI: 7.4-17.7] compared to 3.8 [95% CI: 2.0-7.0] in SiVET (p<0.01). SiVET volunteers tended to be men, having some education and longer-term residents, all factors that are also associated with lower HIV risk. We observed a lower HIV incidence in SiVET than in the observational cohort. The two populations differed significantly in demographics but not in reported risk. HIV incidence estimates from observational cohorts must be used with caution to estimate the trial study size. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Genetic monogamy and biparental care in an externally fertilizing fish, the largemouth bass (Micropterus salmoides).

PubMed

DeWoody, J A; Fletcher, D E; Wilkins, S D; Nelson, W S; Avise, J C

2000-12-07

Breeding, male North American sunfish (Centrarchidae), are often brightly coloured and promiscuous. However, the largemouth bass (Micropterus salmoides) is sexually monomorphic in appearance and socially monogamous. Unlike some other nest-tending centrarchids in the genus Lepomis, largemouth bass have also been reported to provide biparental care to eggs and fry. Here we use microsatellite markers in order to test whether social monogamy predicts genetic monogamy in the largemouth bass. Offspring were collected from 26 nests each usually guarded by a pair of adults, many of which were also captured. Twenty-three of these progeny cohorts (88%) proved to be composed almost exclusively of full-sibs and were thus the product of monogamous matings. Cuckoldry by males was rare. The genetic data also revealed that some nests contain juveniles that were not the progeny of the guardian female, a finding that can be thought of as low-level 'female cuckoldry'. Overall, however, the data provide what may be the first genetic documentation of near-monogamy and biparental care in a vertebrate with external fertilization.

Genetic monogamy and biparental care in an externally fertilizing fish, the largemouth bass (Micropterus salmoides).

PubMed Central

DeWoody, J A; Fletcher, D E; Wilkins, S D; Nelson, W S; Avise, J C

2000-01-01

Breeding, male North American sunfish (Centrarchidae), are often brightly coloured and promiscuous. However, the largemouth bass (Micropterus salmoides) is sexually monomorphic in appearance and socially monogamous. Unlike some other nest-tending centrarchids in the genus Lepomis, largemouth bass have also been reported to provide biparental care to eggs and fry. Here we use microsatellite markers in order to test whether social monogamy predicts genetic monogamy in the largemouth bass. Offspring were collected from 26 nests each usually guarded by a pair of adults, many of which were also captured. Twenty-three of these progeny cohorts (88%) proved to be composed almost exclusively of full-sibs and were thus the product of monogamous matings. Cuckoldry by males was rare. The genetic data also revealed that some nests contain juveniles that were not the progeny of the guardian female, a finding that can be thought of as low-level 'female cuckoldry'. Overall, however, the data provide what may be the first genetic documentation of near-monogamy and biparental care in a vertebrate with external fertilization. PMID:11133034

Associated factors for treatment delay in pulmonary tuberculosis in HIV-infected individuals: a nested case-control study.

PubMed

Coimbra, Isabella; Maruza, Magda; Militão-Albuquerque, Maria de Fátima Pessoa; Moura, Líbia Vilela; Diniz, George Tadeu Nunes; Miranda-Filho, Demócrito de Barros; Lacerda, Heloísa Ramos; Rodrigues, Laura Cunha; Ximenes, Ricardo Arraes de Alencar

2012-09-07

The delay in initiating treatment for tuberculosis (TB) in HIV-infected individuals may lead to the development of a more severe form of the disease, with higher rates of morbidity, mortality and transmissibility. The aim of the present study was to estimate the time interval between the onset of symptoms and initiating treatment for TB in HIV-infected individuals, and to identify the factors associated to this delay. A nested case-control study was undertaken within a cohort of HIV-infected individuals, attended at two HIV referral centers, in the state of Pernambuco, Brazil. Delay in initiating treatment for TB was defined as the period of time, in days, which was greater than the median value between the onset of cough and initiating treatment for TB. The study analyzed biological, clinical, socioeconomic, and lifestyle factors as well as those related to HIV and TB infection, potentially associated to delay. The odds ratios were estimated with the respective confidence intervals and p-values. From a cohort of 2365 HIV-infected adults, 274 presented pulmonary TB and of these, 242 participated in the study. Patients were already attending 2 health services at the time they developed a cough (period range: 1 - 552 days), with a median value of 41 days. Factors associated to delay were: systemic symptoms asthenia, chest pain, use of illicit drugs and sputum smear-negative. The present study indirectly showed the difficulty of diagnosing TB in HIV-infected individuals and indicated the need for a better assessment of asthenia and chest pain as factors that may be present in co-infected patients. It is also necessary to discuss the role played by negative sputum smear results in diagnosing TB/HIV co-infection as well as the need to assess the best approach for drug users with TB/HIV.

Nested case-control study of night shift work and breast cancer risk among women in the Danish military.

PubMed

Hansen, Johnni; Lassen, Christina F

2012-08-01

Growing but limited evidence suggests that night shift work is associated with breast cancer. The authors conducted a nationwide case-control study nested within a cohort of 18,551 female military employees born in 1929-1968 to investigate the risk for breast cancer after night shift work and to explore the role of leisure time sun exposure and diurnal preference. The authors documented 218 cases of breast cancer (1990-2003) and selected 899 age-matched controls from the cohort by incidence density sampling. Information on shift work, sun exposure habits, diurnal preference and other potential confounders was obtained from a structured questionnaire. ORs were estimated by multivariate conditional logistic regression. Overall, the authors observed an adjusted OR of 1.4 (95% CI 0.9 to 2.1) among women with ever compared with never night shifts. The RR for breast cancer tended to increase with increasing number of years of night shift work (p=0.03) and with cumulative number of shifts (p=0.02),with a neutral risk for fewer than three night shifts per week. The OR for the group with the highest tertile of cumulative exposure was 2.3 (95% CI 1.2 to 4.6). The most pronounced effect of night shift work on breast cancer risk was observed in women with morning chronotype preference and intense night shifts (OR=3.9, 95% CI 1.6 to 9.5). Night shift workers tended to sunbathe more frequently than day workers. The results indicate that frequent night shift work increases the risk for breast cancer and suggest a higher risk with longer duration of intense night shifts. Women with morning preference who worked on night shifts tended to have a higher risk than those with evening preference.

Hypothyroxinemia During Gestation and Offspring Schizophrenia in a National Birth Cohort

PubMed Central

Gyllenberg, David; Sourander, Andre; Surcel, Heljä-Marja; Hinkka-Yli-Salomäki, Susanna; McKeague, Ian W.; Brown, Alan S.

2015-01-01

Background Evidence from animal and human studies indicates that thyroid hormone deficiency during early gestation alters brain development. As schizophrenia is associated with prenatal brain insults and premorbid cognitive deficits, we tested the a priori hypothesis that serologically defined maternal thyroid deficiency during early to mid-gestation is associated with offspring schizophrenia. Methods The investigation is based on the Finnish Prenatal Study of Schizophrenia (FiPS-S), a nested case-control study that included archived maternal sera from virtually all pregnancies since 1983 (total N over 1 million). We identified all offspring in the cohort diagnosed with schizophrenia based on the national inpatient and outpatient register and matched them to comparison subjects (1:1) from the cohort on sex, date of birth, and residence in Finland at time of onset of the case. Maternal sera on 1010 case-control pairs were assessed for free thyroxine (fT4) and 948 for thyroid stimulating hormone (TSH). Results Maternal hypothyroxinemia (fT4≤10th percentile, normal TSH) was associated with an increased odds of schizophrenia (OR=1.75, 95% CI=1.22 – 2.50; p=0.002). When adjusted for maternal psychiatric history, province of birth and maternal smoking during pregnancy, the association remained significant (OR=1.70, 95%CI 1.13 – 2.55; p=0.010). Conclusions In a large, national birth cohort, prospectively documented early to mid-gestational hypothyroxinemia was associated with increased odds of schizophrenia in offspring. This can inform translational studies of maternal hypothyroxinemia examining molecular and cellular deviations relevant to schizophrenia. PMID:26194598

Healthy Worker Survivor Bias in the Colorado Plateau Uranium Miners Cohort

PubMed Central

Keil, Alexander P.; Richardson, David B.; Troester, Melissa A.

2015-01-01

Cohort mortality studies of underground miners have been used to estimate the number of lung cancer deaths attributable to radon exposure. However, previous studies of the radon–lung cancer association among underground miners may have been subject to healthy worker survivor bias, a type of time-varying confounding by employment status. We examined radon-mortality associations in a study of 4,124 male uranium miners from the Colorado Plateau who were followed from 1950 through 2005. We estimated the time ratio (relative change in median survival time) per 100 working level months (radon exposure averaging 130,000 mega-electron volts of potential α energy per liter of air, per working month) using G-estimation of structural nested models. After controlling for healthy worker survivor bias, the time ratio for lung cancer per 100 working level months was 1.168 (95% confidence interval: 1.152, 1.174). In an unadjusted model, the estimate was 1.102 (95% confidence interval: 1.099, 1.112)—39% lower. Controlling for this bias, we estimated that among 617 lung cancer deaths, 6,071 person-years of life were lost due to occupational radon exposure during follow-up. Our analysis suggests that healthy worker survivor bias in miner cohort studies can be substantial, warranting reexamination of current estimates of radon's estimated impact on lung cancer mortality. PMID:25837305

Sun Exposure, Vitamin D Receptor Genetic Variants, and Risk of Breast Cancer in the Agricultural Health Study

PubMed Central

Satagopan, Jaya; Sima, Camelia S.; Orlow, Irene; Mujumdar, Urvi; Coble, Joseph; Roy, Pampa; Yoo, Sarah; Sandler, Dale P.; Alavanja, Michael C.

2013-01-01

Background: Epidemiologic evidence suggests a negative relation between sunlight exposure and breast cancer risk. The hypothesized mechanism is sunlight-induced cutaneous synthesis of vitamin D. Objectives: Our goal was to examine sun exposure and its interaction with vitamin D receptor (VDR) gene variants on breast cancer risk. Methods: We examined sun exposure and breast cancer incidence among 31,021 private pesticide applicators’ wives, including 578 cases, enrolled in the prospective Agricultural Health Study cohort and followed 8.6 years on average. We estimated interactions between sun exposure, VDR variants, and breast cancer in a nested case–control study comprising 293 cases and 586 matched controls. Information on sun exposure was obtained by questionnaire at cohort enrollment. Relative risks were estimated using Cox proportional hazards regression for the cohort data and conditional logistic regression for the nested case–control data. Results: We observed a small decrease in breast cancer risk in association with usual sun exposure of ≥ 1 hr/day (versus < 1 hr/day) 10 years before the start of follow-up among all participants [hazard ratio (HR) = 0.8; 95% CI: 0.6, 1.0]. The association appeared to be slightly stronger in relation to estrogen receptor–positive tumors (HR = 0.7; 95% CI: 0.5, 0.9) than estrogen receptor–negative tumors (HR = 1.1; 95% CI: 0.6, 2.1). The HR for joint exposure ≥ 1 hr/day of sunlight and one VDR haplotype was less than expected given negative HRs for each individual exposure (interaction p-value = 0.07). Conclusion: Our results suggest that sun exposure may be associated with reduced risk of breast cancer, but we did not find clear evidence of modification by VDR variants. Larger studies are warranted, particularly among populations in whom low levels of usual sun exposure can be more precisely characterized. Citation: Engel LS, Satagopan J, Sima CS, Orlow I, Mujumdar U, Coble J, Roy P, Yoo S, Sandler DP, Alavanja MC. 2014. Sun exposure, vitamin D receptor genetic variants, and risk of breast cancer in the Agricultural Health Study. Environ Health Perspect 122:165–171; http://dx.doi.org/10.1289/ehp.1206274 PMID:24252436

Prospective study of blood metabolites associated with colorectal cancer risk.

PubMed

Shu, Xiang; Xiang, Yong-Bing; Rothman, Nathaniel; Yu, Danxia; Li, Hong-Lan; Yang, Gong; Cai, Hui; Ma, Xiao; Lan, Qing; Gao, Yu-Tang; Jia, Wei; Shu, Xiao-Ou; Zheng, Wei

2018-02-26

Few prospective studies, and none in Asians, have systematically evaluated the relationship between blood metabolites and colorectal cancer risk. We conducted a nested case-control study to search for risk-associated metabolite biomarkers for colorectal cancer in an Asian population using blood samples collected prior to cancer diagnosis. Conditional logistic regression was performed to assess associations of metabolites with cancer risk. In this study, we included 250 incident cases with colorectal cancer and individually matched controls nested within two prospective Shanghai cohorts. We found 35 metabolites associated with risk of colorectal cancer after adjusting for multiple comparisons. Among them, 12 metabolites were glycerophospholipids including nine associated with reduced risk of colorectal cancer and three with increased risk [odds ratios per standard deviation increase of transformed metabolites: 0.31-1.98; p values: 0.002-1.25 × 10 -10 ]. The other 23 metabolites associated with colorectal cancer risk included nine lipids other than glycerophospholipid, seven aromatic compounds, five organic acids and four other organic compounds. After mutual adjustment, nine metabolites remained statistically significant for colorectal cancer. Together, these independently associated metabolites can separate cancer cases from controls with an area under the curve of 0.76 for colorectal cancer. We have identified that dysregulation of glycerophospholipids may contribute to risk of colorectal cancer. © 2018 UICC.

Coastal leatherback turtles reveal conservation hotspot

PubMed Central

Robinson, Nathan J.; Morreale, Stephen J.; Nel, Ronel; Paladino, Frank V.

2016-01-01

Previous studies have shown that the world’s largest reptile – the leatherback turtle Dermochelys coriacea – conducts flexible foraging migrations that can cover thousands of kilometres between nesting sites and distant foraging areas. The vast distances that may be travelled by migrating leatherback turtles have greatly complicated conservation efforts for this species worldwide. However, we demonstrate, using a combination of satellite telemetry and stable isotope analysis, that approximately half of the nesting leatherbacks from an important rookery in South Africa do not migrate to distant foraging areas, but rather, forage in the coastal waters of the nearby Mozambique Channel. Moreover, this coastal cohort appears to remain resident year-round in shallow waters (<50 m depth) in a relatively fixed area. Stable isotope analyses further indicate that the Mozambique Channel also hosts large numbers of loggerhead turtles Caretta caretta. The rare presence of a resident coastal aggregation of leatherback turtles not only presents a unique opportunity for conservation, but alongside the presence of loggerhead turtles and other endangered marine megafauna in the Mozambique Channel, highlights the importance of this area as a marine biodiversity hotspot. PMID:27886262

Observer visitation frequency and success of mourning dove nests: A field experiment

USGS Publications Warehouse

Nichols, J.D.; Percival, H.F.; Coon, R.A.; Conroy, M.J.; Hensler, G.L.; Hines, J.E.

1984-01-01

Field studies of nesting success generally require visits by the investigator to the nests under study. Such visits may themselves influence nesting success, however, and this possibility has been discussed and investigated by a number of workers with a variety of bird species. Livezey (1980) reviewed the relevant literature for duck nests and noted that most studies failed to demonstrate differences in nesting success between visited nests and those not visited. Livezey (1980) found in his own work that nest abandonment may have occurred as a result of disturbance by observers but that nest predation was not related to time spent by observers at nests or number of observers approaching nests. Various components of nesting and breeding success in seabirds are thought to be adversely affected by human disturbance and nest visitation (Gillett et al. 1975, Robert and Ralph 1975, Ollason and Dunnet 1980). Upland, ground-nesting species have also been studied (e.g. Stoddard 1931, Evans and Wolfe 1967, Henry 1969, Roseberry and Klimstra 1970, Klimstra and Roseberry 1975), and, although conclusions have varied, a number of these workers found no effect of observers on nest-predation rates.

Consumption of fish and meats and risk of hepatocellular carcinoma: the European Prospective Investigation into Cancer and Nutrition (EPIC)

PubMed Central

Fedirko, V.; Trichopolou, A.; Bamia, C.; Duarte-Salles, T.; Trepo, E.; Aleksandrova, K.; Nöthlings, U.; Lukanova, A.; Lagiou, P.; Boffetta, P.; Trichopoulos, D.; Katzke, V. A.; Overvad, K.; Tjønneland, A.; Hansen, L.; Boutron-Ruault, M. C.; Fagherazzi, G.; Bastide, N.; Panico, S.; Grioni, S.; Vineis, P.; Palli, D.; Tumino, R.; Bueno-de-Mesquita, H. B.; Peeters, P. H.; Skeie, G.; Engeset, D.; Parr, C. L.; Jakszyn, P.; Sánchez, M. J.; Barricarte, A.; Amiano, P.; Chirlaque, M.; Quirós, J. R.; Sund, M.; Werner, M.; Sonestedt, E.; Ericson, U.; Key, T. J.; Khaw, K. T.; Ferrari, P.; Romieu, I.; Riboli, E.; Jenab, M.

2013-01-01

Background While higher intake of fish and lower consumption of red/processed meats have been suggested to play a protective role in the etiology of several cancers, prospective evidence for hepatocellular carcinoma (HCC) is limited, particularly in Western European populations. Methods The associations of fish and meats with HCC risk were analyzed in the EPIC cohort. Between 1992 and 2010, 191 incident HCC were identified among 477 206 participants. Baseline diet was assessed using validated dietary questionnaires. A single 24-h diet recall from a cohort subsample was used for calibration. Multivariable proportional hazard regression was utilized to estimate hazard ratios (HR) and 95% confidence intervals (CI). In a nested case–control subset (HCC = 122), HBV/HCV status and liver function biomarkers were measured. Results HCC risk was inversely associated with intake of total fish (per 20 g/day increase, HR = 0.83, 95% CI 0.74–0.95 and HR = 0.80, 95% CI 0.69–0.97 before and after calibration, respectively). This inverse association was also suggested after adjusting for HBV/HCV status and liver function score (per 20-g/day increase, RR = 0.86, 95% CI 0.66–1.11 and RR = 0.74, 95% CI 0.50–1.09, respectively) in a nested case–control subset. Intakes of total meats or subgroups of red/processed meats, and poultry were not associated with HCC risk. Conclusions In this large European cohort, total fish intake is associated with lower HCC risk. PMID:23670094

The metabolic cost of nesting: body condition and blood parameters of Caiman crocodilus and Melanosuchus niger in Central Amazonia.

PubMed

Barão-Nóbrega, José António Lemos; Marioni, Boris; Botero-Arias, Robinson; Nogueira, António José Arsénia; Lima, Emerson Silva; Magnusson, William Ernest; Da Silveira, Ronis; Marcon, Jaydione Luiz

2018-01-01

Although nesting ecology is well studied in several crocodilian species, it is not known how nest attendance influences physiology and body condition of nesting females. In this study, we describe body condition and serum biochemical values of nesting female, non-nesting female and male spectacled caiman (Caiman crocodilus) and black caiman (Melanosuchus niger) in two areas of Central Amazonia. We also evaluated the effect of nest age and nest distance to water on body condition and blood parameters of nesting females. Body condition and plasmatic concentrations of glucose, triglycerides, lactate and uric acid of nesting females were significantly different from those of non-nesting females and males in C. crocodilus, but not in M. niger. Our study also demonstrated that nest age and distance to water had a negative effect on female body condition in C. crocodilus, but not in M. niger. Female C. crocodilus attending older nests or nests built further away from permanent water bodies tended to have lower body condition. Our results demonstrate that the nesting strategy of C. crocodilus has a metabolic cost associated with nest attendance for nesting females, which appear to depend on accumulated energetic reserves during nest attendance. In contrast, nest attendance had little effect on the physiology of female M. niger.

Correction to: The metabolic cost of nesting: body condition and blood parameters of Caiman crocodilus and Melanosuchus niger in Central Amazonia.

PubMed

Barão-Nóbrega, José António Lemos; Marioni, Boris; Botero-Arias, Robinson; Nogueira, António José Arsénia; Lima, Emerson Silva; Magnusson, William Ernest; Da Silveira, Ronis; Marcon, Jaydione Luiz

2017-11-13

Although nesting ecology is well studied in several crocodilian species, it is not known how nest attendance influences physiology and body condition of nesting females. In this study, we describe body condition and serum biochemical values of nesting female, non-nesting female and male spectacled caiman (Caiman crocodilus) and black caiman (Melanosuchus niger) in two areas of Central Amazonia. We also evaluated the effect of nest age and nest distance to water on body condition and blood parameters of nesting females. Body condition and plasmatic concentrations of glucose, triglycerides, lactate and uric acid of nesting females were significantly different from those of non-nesting females and males in C. crocodilus, but not in M. niger. Our study also demonstrated that nest age and distance to water had a negative effect on female body condition in C. crocodilus, but not in M. niger. Female C. crocodilus attending older nests or nests built further away from permanent water bodies tended to have lower body condition. Our results demonstrate that the nesting strategy of C. crocodilus has a metabolic cost associated with nest attendance for nesting females, which appear to depend on accumulated energetic reserves during nest attendance. In contrast, nest attendance had little effect on the physiology of female M. niger.

Risk factors for breast cancer in a cohort of mammographic screening program: a nested case-control study within the FRiCaM study.

PubMed

Bravi, Francesca; Decarli, Adriano; Russo, Antonio Giampiero

2018-05-01

Breast cancer is the most common cancer diagnosis and the leading cause of cancer death among women in the world, and differences across populations indicate a role of hormonal, reproductive and lifestyle factors. This study is based on a cohort of 78,050 women invited to undergo a mammogram by Local Health Authority of Milan, between 2003 and 2007. We carried out a nested case-control study including all the 3303 incident breast cancer cases diagnosed up to 2015, and 9909 controls matched by age and year of enrollment. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using logistic regression models. The ORs were 0.88 (95% CI: 0.78-0.98) for an age at menarche ≥14 years and 1.39 (95% CI: 1.07-1.81) for an age of 30 years or older at first pregnancy. Body mass index (BMI) was positively associated with breast cancer risk in women older than 50 years (OR = 1.89, 95% CI: 1.54-2.31, for BMI≥30 vs. <20), while the association tended to be inverse in younger women. A high mammographic density increased breast cancer risk (OR = 2.61, 95% CI: 2.02-3.38 for density >75% vs. adipose tissue). The ORs were 1.67 (95% CI: 1.47-1.89) and 2.04 (95% CI: 1.38-3.00) for one first-degree relative and two or more relatives affected by breast cancer, respectively. Our study confirms the role of major recognized risk factors for breast cancer in our population and provides the basis for a stratification of the participants in the mammographic screening according to different levels of risk. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Anti-Müllerian hormone and risk of ovarian cancer in nine cohorts.

PubMed

Jung, Seungyoun; Allen, Naomi; Arslan, Alan A; Baglietto, Laura; Barricarte, Aurelio; Brinton, Louise A; Egleston, Brian L; Falk, Roni T; Fortner, Renée T; Helzlsouer, Kathy J; Gao, Yutang; Idahl, Annika; Kaaks, Rudolph; Krogh, Vittorio; Merritt, Melissa A; Lundin, Eva; Onland-Moret, N Charlotte; Rinaldi, Sabina; Schock, Helena; Shu, Xiao-Ou; Sluss, Patrick M; Staats, Paul N; Sacerdote, Carlotta; Travis, Ruth C; Tjønneland, Anne; Trichopoulou, Antonia; Tworoger, Shelley S; Visvanathan, Kala; Weiderpass, Elisabete; Zeleniuch-Jacquotte, Anne; Dorgan, Joanne F

2018-01-15

Animal and experimental data suggest that anti-Müllerian hormone (AMH) serves as a marker of ovarian reserve and inhibits the growth of ovarian tumors. However, few epidemiologic studies have examined the association between AMH and ovarian cancer risk. We conducted a nested case-control study of 302 ovarian cancer cases and 336 matched controls from nine cohorts. Prediagnostic blood samples of premenopausal women were assayed for AMH using a picoAMH enzyme-linked immunosorbent assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable-adjusted conditional logistic regression. AMH concentration was not associated with overall ovarian cancer risk. The multivariable-adjusted OR (95% CI), comparing the highest to the lowest quartile of AMH, was 0.99 (0.59-1.67) (P trend : 0.91). The association did not differ by age at blood draw or oral contraceptive use (all P heterogeneity : ≥0.26). There also was no evidence for heterogeneity of risk for tumors defined by histologic developmental pathway, stage, and grade, and by age at diagnosis and time between blood draw and diagnosis (all P heterogeneity : ≥0.39). In conclusion, this analysis of mostly late premenopausal women from nine cohorts does not support the hypothesized inverse association between prediagnostic circulating levels of AMH and risk of ovarian cancer. © 2017 UICC.

The impact of an online disease management program on medical costs among health plan members.

PubMed

Schwartz, Steven M; Day, Brian; Wildenhaus, Kevin; Silberman, Anna; Wang, Chun; Silberman, Jordan

2010-01-01

This study evaluated the economic impact of an online disease management program within a broader population health management strategy. A retrospective, quasi-experimental, cohort design evaluated program participants and a matched cohort of nonparticipants on 2003-2007 claims data in a mixed model. The study was conducted through Highmark Inc, Blue Cross Blue Shield, covering 4.8 million members in five regions of Pennsylvania. Overall, 413 online self-management program participants were compared with a matched cohort of 360 nonparticipants. The costs and claims data were measured per person per calendar year. Total payments were aggregated from inpatient, outpatient, professional services, and pharmacy payments. The costs of the online program were estimated on a per-participant basis. All dollars were adjusted to 2008 values. The online intervention, implemented in 2006, was a commercially available, tailored program for chronic condition self management, nested within the Blues on Call(SM) condition management strategy. General linear modeling (with covariate adjustment) was used. Data trends were also explored using second-order polynomial regressions. Health care costs per person per year were $757 less than predicted for participants relative to matched nonparticipants, yielding a return on investment of $9.89 for every dollar spent on the program. This online intervention showed a favorable and cost-effective impact on health care cost.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robertson, Janeen Denise

In a mortality study of white males who had worked at the Rocky Flats Nuclear Weapons Plant between 1952 and 1979, an increased number of deaths from benign and unspecified intracranial neoplasms was found. A case-control study nested within this cohort investigated the hypothesis that an association existed between brain tumor death and exposure to either internally deposited plutonium or external ionizing radiation. There was no statistically significant association found between estimated radiation exposure from internally deposited plutonium and the development of brain tumors. Exposure by job or work area showed no significant difference between the cohort and the controlmore » groups. An update of the study found elevated risk estimates for (1) all lymphopoietic neoplasms, and (2) all causes of death in employees with body burdens greater than or equal to two nanocuries of plutonium. There was an excess of brain tumors for the entire cohort. Similar cohort studies conducted on worker populations from other plutonium handling facilities have not yet shown any elevated risks for brain tumors. Historically, the Rocky Flats Nuclear Weapons Plant used large quantities of chemicals in their production operations. The use of solvents, particularly carbon tetrachloride, was unique to Rocky Flats. No investigation of the possible confounding effects of chemical exposures was done in the initial studies. The objectives of the present study are to (1) investigate the history of chemical use at the Rocky Flats facility; (2) locate and analyze chemical monitoring information in order to assess employee exposure to the chemicals that were used in the highest volume; and (3) determine the feasibility of establishing a chemical exposure assessment model that could be used in future epidemiology studies.« less

Haemolysis in G6PD Heterozygous Females Treated with Primaquine for Plasmodium vivax Malaria: A Nested Cohort in a Trial of Radical Curative Regimens.

PubMed

Chu, Cindy S; Bancone, Germana; Moore, Kerryn A; Win, Htun Htun; Thitipanawan, Niramon; Po, Christina; Chowwiwat, Nongnud; Raksapraidee, Rattanaporn; Wilairisak, Pornpimon; Phyo, Aung Pyae; Keereecharoen, Lily; Proux, Stéphane; Charunwatthana, Prakaykaew; Nosten, François; White, Nicholas J

2017-02-01

Radical cure of Plasmodium vivax malaria with 8-aminoquinolines (primaquine or tafenoquine) is complicated by haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD heterozygous females, because of individual variation in the pattern of X-chromosome inactivation (Lyonisation) in erythroid cells, may have low G6PD activity in the majority of their erythrocytes, yet are usually reported as G6PD "normal" by current phenotypic screening tests. Their haemolytic risk when treated with 8-aminoquinolines has not been well characterized. In a cohort study nested within a randomised clinical trial that compared different treatment regimens for P. vivax malaria, patients with a normal standard NADPH fluorescent spot test result (≳30%-40% of normal G6PD activity) were randomised to receive 3 d of chloroquine or dihydroartemisinin-piperaquine in combination with primaquine, either the standard high dose of 0.5 mg base/kg/day for 14 d or a higher dose of 1 mg base/kg/d for 7 d. Patterns of haemolysis were compared between G6PD wild-type and G6PD heterozygous female participants. Between 21 February 2012 and 04 July 2014, 241 female participants were enrolled, of whom 34 were heterozygous for the G6PD Mahidol variant. Haemolysis was substantially greater and a larger proportion of participants reached the threshold of clinically significant haemolysis (fractional haematocrit reduction >25%) in G6PD heterozygotes taking the higher (7 d) primaquine dose (9/17 [53%]) compared with G6PD heterozygotes taking the standard high (14 d) dose (2/16 [13%]; p = 0.022). In heterozygotes, the mean fractional haematocrit reductions were correspondingly greater with the higher primaquine dose (7-d regimen): -20.4% (95% CI -26.0% to -14.8%) (nadir on day 5) compared with the standard high (14 d) dose: -13.1% (95% CI -17.6% to -8.6%) (nadir day 6). Two heterozygotes taking the higher (7 d) primaquine dose required blood transfusion. In wild-type participants, mean haematocrit reductions were clinically insignificant and similar with both doses: -5.8 (95% CI -7.2% to -4.4%) (nadir day 3) compared with -5.5% (95% CI -7.4% to -3.7%) (nadir day 4), respectively. Limitations to this nested cohort study are that the primary objective of the trial was designed to measure efficacy and not haemolysis in relation to G6PD genotype and that the heterozygote groups were small. Higher daily doses of primaquine have the potential to cause clinically significant haemolysis in G6PD heterozygous females who are reported as phenotypically normal with current point of care tests. ClinicalTrials.gov NCT01640574.

Cancer complicating systemic lupus erythematosus--a dichotomy emerging from a nested case-control study.

PubMed

Dey, D; Kenu, E; Isenberg, D A

2013-08-01

We determined whether any individual cancers are increased or decreased in a cohort of 595 patients with systemic lupus erythematosus (SLE) followed for up to 32 years at the University College London Hospitals Lupus Clinic, looking for any associated clinical or serological factors and the prognosis after cancer diagnosis. We undertook a careful retrospective review of the medical records and identified all individuals diagnosed with cancer. For controls, we selected three other patients in the cohort who had not developed cancer, carefully matched for age, sex, ethnicity and disease duration, to determine if any obvious differences emerged in a nested case-control design. Thirty-three patients developed cancer after being diagnosed with SLE. There was a statistically insignificant small increase in overall cancer risk, standardized incidence ratios (SIRs) 1.05 (95% CI 0.52-1.58) and increased SIRs for cervical, prostate, anal and pancreatic cancers and reduction in breast cancer SIRs. Haematological and musculoskeletal manifestations, anticardiolipin and antithyroid globulin antibodies were found to be positively associated with cancer risk in multivariate analysis. There was no drug, dose or duration was associated with cancer risk. There was a reduction in survival with a cancer fatality rate of 84.2% (p < 0.0001). We found a very small but statistically insignificant increased cancer risk with reduction in survival. Whereas some cancers appear to be more common in SLE, notably prostate and cervical cancer, others, particularly breast cancer, are less frequent. Multiple clinical and serological factors are involved in the increased risk of malignancy in SLE. No drug dose or duration effect was identified.

Into the Red and Back to the Nest? Student Debt, College Completion, and Returning to the Parental Home among Young Adults

ERIC Educational Resources Information Center

Houle, Jason N.; Warner, Cody

2017-01-01

Rising student debt has sparked concerns about its impact on the transition to adulthood. In this paper, we examine the claim that student debt is leading to a rise in "boomeranging," or returning home, using data from the National Longitudinal Survey of Youth 1997 Cohort and discrete time-event history models. We have four findings.…

Circulating 25-hydroxyvitamin D and risk of pancreatic cancer: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers.

PubMed

Stolzenberg-Solomon, Rachael Z; Jacobs, Eric J; Arslan, Alan A; Qi, Dai; Patel, Alpa V; Helzlsouer, Kathy J; Weinstein, Stephanie J; McCullough, Marjorie L; Purdue, Mark P; Shu, Xiao-Ou; Snyder, Kirk; Virtamo, Jarmo; Wilkins, Lynn R; Yu, Kai; Zeleniuch-Jacquotte, Anne; Zheng, Wei; Albanes, Demetrius; Cai, Qiuyin; Harvey, Chinonye; Hayes, Richard; Clipp, Sandra; Horst, Ronald L; Irish, Lonn; Koenig, Karen; Le Marchand, Loic; Kolonel, Laurence N

2010-07-01

Results from epidemiologic studies examining pancreatic cancer risk and vitamin D intake or 25-hydroxyvitamin D (25(OH)D) concentrations (the best indicator of vitamin D derived from diet and sun) have been inconsistent. Therefore, the authors conducted a pooled nested case-control study of participants from 8 cohorts within the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP) (1974-2006) to evaluate whether prediagnostic circulating 25(OH)D concentrations were associated with the development of pancreatic cancer. In total, 952 incident pancreatic adenocarcinoma cases occurred among participants (median follow-up, 6.5 years). Controls (n = 1,333) were matched to each case by cohort, age, sex, race/ethnicity, date of blood draw, and follow-up time. Conditional logistic regression analysis was used to calculate smoking-, body mass index-, and diabetes-adjusted odds ratios and 95% confidence intervals for pancreatic cancer. Clinically relevant 25(OH)D cutpoints were compared with a referent category of 50-<75 nmol/L. No significant associations were observed for participants with lower 25(OH)D status. However, a high 25(OH)D concentration (> or =100 nmol/L) was associated with a statistically significant 2-fold increase in pancreatic cancer risk overall (odds ratio = 2.12, 95% confidence interval: 1.23, 3.64). Given this result, recommendations to increase vitamin D concentrations in healthy persons for the prevention of cancer should be carefully considered.

Association between aspirin and upper gastrointestinal complications: Systematic review of epidemiologic studies

PubMed Central

Rodríguez, Luis A García; Hernández-Díaz, Sonia; de Abajo, Francisco J

2001-01-01

Aims Because of the widespread use of aspirin for prevention of cardiovascular diseases, side-effects associated with thromboprophylactic doses are of interest. This study summarizes the relative risk (RR) for serious upper gastrointestinal complications (UGIC) associated with aspirin exposure in general and with specific aspirin doses and formulations in particular. Methods After a systematic review, 17 original epidemiologic studies published between 1990 and 2001 were selected according to predefined criteria. Heterogeneity of effects was explored. Pooled estimates were calculated according to different study characteristics and patterns of aspirin use. Results The overall relative risk of UGIC associated with aspirin use was 2.2 (95% confidence interval (CI): 2.1, 2.4) for cohort studies and nested case-control studies and 3.1 (95% CI: 2.8, 3.3) for non-nested case-control studies. Original studies found a dose–response relationship between UGIC and aspirin, although the risk was still elevated for doses lower or up to 300 mg day−1. The summary RR was 2.6 (95% CI: 2.3, 2.9) for plain, 5.3 (95% CI: 3.0, 9.2) for buffered, and 2.4 (95% CI: 1.9, 2.9) for enteric-coated aspirin formulations. Conclusions Aspirin was associated with UGIC even when used at low doses or in buffered or enteric-coated formulations. The latter findings may be partially explained by channeling of susceptible patients to these formulations. PMID:11736865

A cross-sectional examination of the profile of chiropractors recruited to the Australian Chiropractic Research Network (ACORN): a sustainable resource for future chiropractic research.

PubMed

Adams, Jon; Peng, Wenbo; Steel, Amie; Lauche, Romy; Moore, Craig; Amorin-Woods, Lyndon; Sibbritt, David

2017-09-29

The Australian Chiropractic Research Network (ACORN) practice-based research network (PBRN) cohort was established to provide sustainable infrastructure necessary to address lack of rigorous investigation and to bridge the research-practice gap focused on chiropractic care for future years. This paper presents the profile of chiropractors recruited to the ACORN PBRN, a nationally representative sample of chiropractors working in Australia. Cross-sectional analysis of baseline data from a cohort study of chiropractors in Australia. All registered chiropractors in Australia were invited to participate in the ACORN study and those who completed a practitioner questionnaire and consent form were included in the PBRN cohort. A total of 1680 chiropractors (36%) were recruited to the cohort database. The average age of the PBRN participants is 41.9 years and 63% are male. The vast majority of the PBRN participants hold a university degree. General practitioners were identified as the most popular referral source for chiropractic care and low back pain and neck pain were the most common conditions 'often' treated by the PBRN chiropractors. The chiropractors in this PBRN cohort rated high velocity, low amplitude adjustment/manipulation/mobilisation as the most commonly used technique/method and soft tissue therapy as the most frequently employed musculoskeletal intervention in their patient management. The ACORN PBRN cohort constitutes the largest coverage of any single healthcare profession via a national voluntary PBRN providing a sustainable resource for future follow-up. The ACORN cohort provides opportunities for further nested substudies related to chiropractic care, chiropractors, their patients and a vast range of broader healthcare issues with a view to helping build a diverse but coordinated research programme and further research capacity building around Australian chiropractic. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Variation in clutch size in relation to nest size in birds

PubMed Central

Møller, Anders P; Adriaensen, Frank; Artemyev, Alexandr; Bańbura, Jerzy; Barba, Emilio; Biard, Clotilde; Blondel, Jacques; Bouslama, Zihad; Bouvier, Jean-Charles; Camprodon, Jordi; Cecere, Francesco; Charmantier, Anne; Charter, Motti; Cichoń, Mariusz; Cusimano, Camillo; Czeszczewik, Dorota; Demeyrier, Virginie; Doligez, Blandine; Doutrelant, Claire; Dubiec, Anna; Eens, Marcel; Eeva, Tapio; Faivre, Bruno; Ferns, Peter N; Forsman, Jukka T; García-Del-Rey, Eduardo; Goldshtein, Aya; Goodenough, Anne E; Gosler, Andrew G; Góźdź, Iga; Grégoire, Arnaud; Gustafsson, Lars; Hartley, Ian R; Heeb, Philipp; Hinsley, Shelley A; Isenmann, Paul; Jacob, Staffan; Järvinen, Antero; Juškaitis, Rimvydas; Korpimäki, Erkki; Krams, Indrikis; Laaksonen, Toni; Leclercq, Bernard; Lehikoinen, Esa; Loukola, Olli; Lundberg, Arne; Mainwaring, Mark C; Mänd, Raivo; Massa, Bruno; Mazgajski, Tomasz D; Merino, Santiago; Mitrus, Cezary; Mönkkönen, Mikko; Morales-Fernaz, Judith; Morin, Xavier; Nager, Ruedi G; Nilsson, Jan-Åke; Nilsson, Sven G; Norte, Ana C; Orell, Markku; Perret, Philippe; Pimentel, Carla S; Pinxten, Rianne; Priedniece, Ilze; Quidoz, Marie-Claude; Remeš, Vladimir; Richner, Heinz; Robles, Hugo; Rytkönen, Seppo; Senar, Juan Carlos; Seppänen, Janne T; da Silva, Luís P; Slagsvold, Tore; Solonen, Tapio; Sorace, Alberto; Stenning, Martyn J; Török, János; Tryjanowski, Piotr; van Noordwijk, Arie J; von Numers, Mikael; Walankiewicz, Wiesław; Lambrechts, Marcel M

2014-01-01

Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited to small-scale studies performed over short time periods. Here, we quantified the relationship between clutch size and nest size, using an exhaustive database of 116 slope estimates based on 17,472 nests of 21 species of hole and non-hole-nesting birds. There was a significant, positive relationship between clutch size and the base area of the nest box or the nest, and this relationship did not differ significantly between open nesting and hole-nesting species. The slope of the relationship showed significant intraspecific and interspecific heterogeneity among four species of secondary hole-nesting species, but also among all 116 slope estimates. The estimated relationship between clutch size and nest box base area in study sites with more than a single size of nest box was not significantly different from the relationship using studies with only a single size of nest box. The slope of the relationship between clutch size and nest base area in different species of birds was significantly negatively related to minimum base area, and less so to maximum base area in a given study. These findings are consistent with the hypothesis that bird species have a general reaction norm reflecting the relationship between nest size and clutch size. Further, they suggest that scientists may influence the clutch size decisions of hole-nesting birds through the provisioning of nest boxes of varying sizes. PMID:25478150

Variation in clutch size in relation to nest size in birds.

PubMed

Møller, Anders P; Adriaensen, Frank; Artemyev, Alexandr; Bańbura, Jerzy; Barba, Emilio; Biard, Clotilde; Blondel, Jacques; Bouslama, Zihad; Bouvier, Jean-Charles; Camprodon, Jordi; Cecere, Francesco; Charmantier, Anne; Charter, Motti; Cichoń, Mariusz; Cusimano, Camillo; Czeszczewik, Dorota; Demeyrier, Virginie; Doligez, Blandine; Doutrelant, Claire; Dubiec, Anna; Eens, Marcel; Eeva, Tapio; Faivre, Bruno; Ferns, Peter N; Forsman, Jukka T; García-Del-Rey, Eduardo; Goldshtein, Aya; Goodenough, Anne E; Gosler, Andrew G; Góźdź, Iga; Grégoire, Arnaud; Gustafsson, Lars; Hartley, Ian R; Heeb, Philipp; Hinsley, Shelley A; Isenmann, Paul; Jacob, Staffan; Järvinen, Antero; Juškaitis, Rimvydas; Korpimäki, Erkki; Krams, Indrikis; Laaksonen, Toni; Leclercq, Bernard; Lehikoinen, Esa; Loukola, Olli; Lundberg, Arne; Mainwaring, Mark C; Mänd, Raivo; Massa, Bruno; Mazgajski, Tomasz D; Merino, Santiago; Mitrus, Cezary; Mönkkönen, Mikko; Morales-Fernaz, Judith; Morin, Xavier; Nager, Ruedi G; Nilsson, Jan-Åke; Nilsson, Sven G; Norte, Ana C; Orell, Markku; Perret, Philippe; Pimentel, Carla S; Pinxten, Rianne; Priedniece, Ilze; Quidoz, Marie-Claude; Remeš, Vladimir; Richner, Heinz; Robles, Hugo; Rytkönen, Seppo; Senar, Juan Carlos; Seppänen, Janne T; da Silva, Luís P; Slagsvold, Tore; Solonen, Tapio; Sorace, Alberto; Stenning, Martyn J; Török, János; Tryjanowski, Piotr; van Noordwijk, Arie J; von Numers, Mikael; Walankiewicz, Wiesław; Lambrechts, Marcel M

2014-09-01

Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited to small-scale studies performed over short time periods. Here, we quantified the relationship between clutch size and nest size, using an exhaustive database of 116 slope estimates based on 17,472 nests of 21 species of hole and non-hole-nesting birds. There was a significant, positive relationship between clutch size and the base area of the nest box or the nest, and this relationship did not differ significantly between open nesting and hole-nesting species. The slope of the relationship showed significant intraspecific and interspecific heterogeneity among four species of secondary hole-nesting species, but also among all 116 slope estimates. The estimated relationship between clutch size and nest box base area in study sites with more than a single size of nest box was not significantly different from the relationship using studies with only a single size of nest box. The slope of the relationship between clutch size and nest base area in different species of birds was significantly negatively related to minimum base area, and less so to maximum base area in a given study. These findings are consistent with the hypothesis that bird species have a general reaction norm reflecting the relationship between nest size and clutch size. Further, they suggest that scientists may influence the clutch size decisions of hole-nesting birds through the provisioning of nest boxes of varying sizes.

Plasma 25-hydroxyvitamin D concentration and subsequent risk of total and site specific cancers in Japanese population: large case-cohort study within Japan Public Health Center-based Prospective Study cohort

PubMed Central

Budhathoki, Sanjeev; Hidaka, Akihisa; Sawada, Norie; Tanaka-Mizuno, Sachiko; Kuchiba, Aya; Charvat, Hadrien; Goto, Atsushi; Kojima, Satoshi; Sudo, Natsuki; Shimazu, Taichi; Sasazuki, Shizuka; Inoue, Manami; Tsugane, Shoichiro; Iwasaki, Motoki

2018-01-01

Abstract Objective To evaluate the association between pre-diagnostic circulating vitamin D concentration and the subsequent risk of overall and site specific cancer in a large cohort study. Design Nested case-cohort study within the Japan Public Health Center-based Prospective Study cohort. Setting Nine public health centre areas across Japan. Participants 3301 incident cases of cancer and 4044 randomly selected subcohort participants. Exposure Plasma concentration of 25-hydroxyvitamin D measured by enzyme immunoassay. Participants were divided into quarters based on the sex and season specific distribution of 25-hydroxyvitamin D among subcohorts. Weighted Cox proportional hazard models were used to calculate the multivariable adjusted hazard ratios for overall and site specific cancer across categories of 25-hydroxyvitamin D concentration, with the lowest quarter as the reference. Main outcome measure Incidence of overall or site specific cancer. Results Plasma 25-hydroxyvitamin D concentration was inversely associated with the risk of total cancer, with multivariable adjusted hazard ratios for the second to fourth quarters compared with the lowest quarter of 0.81 (95% confidence interval 0.70 to 0.94), 0.75 (0.65 to 0.87), and 0.78 (0.67 to 0.91), respectively (P for trend=0.001). Among the findings for cancers at specific sites, an inverse association was found for liver cancer, with corresponding hazard ratios of 0.70 (0.44 to 1.13), 0.65 (0.40 to 1.06), and 0.45 (0.26 to 0.79) (P for trend=0.006). A sensitivity analysis showed that alternately removing cases of cancer at one specific site from total cancer cases did not substantially change the overall hazard ratios. Conclusions In this large prospective study, higher vitamin D concentration was associated with lower risk of total cancer. These findings support the hypothesis that vitamin D has protective effects against cancers at many sites. PMID:29514781

Factors associated with heavy alcohol consumption in the U.K. armed forces: data from a health survey of Gulf, Bosnia, and era veterans.

PubMed

Iversen, Amy; Waterdrinker, Astrid; Fear, Nicola; Greenberg, Neil; Barker, Christopher; Hotopf, Matthew; Hull, Lisa; Wessely, Simon

2007-09-01

Little is known about the patterns of alcohol use in the U.K. Armed Forces or the factors associated with heavy drinking. Analysis of existing data from the King's Military Cohort was conducted of a large, randomly selected cohort of service personnel. The original sample consisted of 8,195 service personnel who served in the U.K. Armed Forces in 1991: a third deployed to the Gulf (1990-1991), a third deployed to Bosnia (1992-1997), and the final third, an "Era" comparison group, in the Armed Forces in 1991 but not deployed. For the purposes of this study, female serving personnel were excluded. The study used a "case-control" study design nested within the above cohort; "heavy drinkers" (those who drank >30 units/week) were compared with "light drinkers" (those who drank <21 units a week). Heavy drinking was associated with current military service and being unmarried or separated/divorced. Heavy drinking was more common in younger personnel who had deployed to Bosnia. Those who drank heavily were also more likely to smoke; heavy drinking was associated with poorer subjective physical and mental health. Certain subgroups of the Armed Forces appear to be more at risk and it may be possible to target resources to such individuals to improve detection and allow prompt treatment.

Association between Use of Exogenous Testosterone Therapy and Risk of Venous Thrombotic Events among Exogenous Testosterone Treated and Untreated Men with Hypogonadism.

PubMed

Li, Hu; Benoit, Karin; Wang, Wei; Motsko, Stephen

2016-04-01

Limited information exists about whether exogenous testosterone therapy is associated with a risk of venous thrombotic events. We investigated via cohort and nested case-control analyses whether exogenous testosterone therapy is associated with the risk of venous thrombotic events in men with hypogonadism. Databases were reviewed to identify men prescribed exogenous testosterone therapy and/or men with a hypogonadism diagnosis. Propensity score 1:1 matching was used to select patients for cohort analysis. Cases (men with venous thrombotic events) were matched 1:4 with controls (men without venous thrombotic events) for the nested case-control analysis. Primary outcome was defined as incident idiopathic venous thrombotic events. Cox regression and conditional logistic regression were used to assess HRs and ORs, respectively. Sensitivity analyses were also performed. A total of 102,650 exogenous testosterone treated and 102,650 untreated patients were included in cohort analysis after matching, and 2,785 cases and 11,119 controls were included in case-control analysis. Cohort analysis revealed a HR of 1.08 for all testosterone treated patients (95% CI 0.91, 1.27, p = 0.378). Case-control analysis resulted in an OR of 1.02 (95% CI 0.92, 1.13, p = 0.702) for current exogenous testosterone therapy exposure and an OR of 0.92 (95% CI 0.82, 1.03, p = 0.145) for past exogenous testosterone therapy exposure. These results remained nonstatistically significant after stratifying by exogenous testosterone therapy administration route and age category. Most sensitivity analyses yielded consistent results. No significant association was found between exogenous testosterone therapy and incidents of idiopathic or overall venous thrombotic events in men with hypogonadism. However, some discrepant findings exist for the association between injectable formulations and the risk of overall venous thrombotic events. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Quantifying the dose-response relationship between circulating folate concentrations and colorectal cancer in cohort studies: a meta-analysis based on a flexible meta-regression model.

PubMed

Chuang, Shu-Chun; Rota, Matteo; Gunter, Marc J; Zeleniuch-Jacquotte, Anne; Eussen, Simone J P M; Vollset, Stein Emil; Ueland, Per Magne; Norat, Teresa; Ziegler, Regina G; Vineis, Paolo

2013-10-01

Most epidemiologic studies on folate intake suggest that folate may be protective against colorectal cancer, but the results on circulating (plasma or serum) folate are mostly inconclusive. We conducted a meta-analysis of case-control studies nested within prospective studies on circulating folate and colorectal cancer risk by using flexible meta-regression models to test the linear and nonlinear dose-response relationships. A total of 8 publications (10 cohorts, representing 3,477 cases and 7,039 controls) were included in the meta-analysis. The linear and nonlinear models corresponded to relative risks of 0.96 (95% confidence interval (CI): 0.91, 1.02) and 0.99 (95% CI: 0.96, 1.02), respectively, per 10 nmol/L of circulating folate in contrast to the reference value. The pooled relative risks when comparing the highest with the lowest category were 0.80 (95% CI: 0.61, 0.99) for radioimmunoassay and 1.03 (95% CI: 0.83, 1.22) for microbiological assay. Overall, our analyses suggest a null association between circulating folate and colorectal cancer risk. The stronger association for the radioimmunoassay-based studies could reflect differences in cohorts and study designs rather than assay performance. Further investigations need to integrate more accurate measurements and flexible modeling to explore the effects of folate in the presence of genetic, lifestyle, dietary, and hormone-related factors.

Nest design in a changing world: great tit Parus major nests from a Mediterranean city environment as a case study.

PubMed

Lambrechts, Marcel M; Charmantier, Anne; Demeyrier, Virginie; Lucas, Annick; Perret, Samuel; Abouladzé, Matthieu; Bonnet, Michel; Canonne, Coline; Faucon, Virginie; Grosset, Stéphanie; le Prado, Gaëlle; Lidon, Frédéric; Noell, Thierry; Pagano, Pascal; Perret, Vincent; Pouplard, Stéphane; Spitaliéry, Rémy; Bernard, Cyril; Perret, Philippe; Blondel, Jacques; Grégoire, Arnaud

2017-12-01

Investigations of urbanization effects on birds have focused mainly on breeding traits expressed after the nest-building stage (e.g. first-egg date, clutch size, breeding success, and offspring characteristics). Urban studies largely ignored how and why the aspects of nest building might be associated with the degree of urbanization. As urban environments are expected to present novel environmental changes relative to rural environments, it is important to evaluate how nest-building behavior is impacted by vegetation modifications associated with urbanization. To examine nest design in a Mediterranean city environment, we allowed urban great tits ( Parus major ) to breed in nest boxes in areas that differed in local vegetation cover. We found that different measures of nest size or mass were not associated with vegetation cover. In particular, nests located adjacent to streets with lower vegetation cover were not smaller or lighter than nests in parks with higher vegetation cover. Nests adjacent to streets contained more pine needles than nests in parks. In addition, in nests adjacent to streets, nests from boxes attached to pine trees contained more pine needles than nests from boxes attached to other trees. We suggest that urban-related alterations in vegetation cover do not directly impose physical limits on nest size in species that are opportunistic in the selection of nesting material. However, nest composition as reflected in the use of pine needles was clearly affected by habitat type and the planted tree species present, which implies that rapid habitat change impacts nest composition. We do not exclude that urbanization might impact other aspects of nest building behaviour not covered in our study (e.g. costs of searching for nest material), and that the strengths of the associations between urbanization and nest structures might differ among study populations or species.

User-only design to assess drug effectiveness in clinical practice: application to bisphosphonates and secondary prevention of fractures.

PubMed

Corrao, Giovanni; Ghirardi, Arianna; Segafredo, Giulia; Zambon, Antonella; Della Vedova, Gianluca; Lapi, Francesco; Cipriani, Francesco; Caputi, Achille; Vaccheri, Alberto; Gregori, Dario; Gesuita, Rosaria; Vestri, Annarita; Staniscia, Tommaso; Mazzaglia, Giampiero; Di Bari, Mauro

2014-08-01

Different strategies applicable to control for confounding by indication in observational studies were compared in a large population-based study regarding the effect of bisphosphonates (BPs) for secondary prevention of fractures. The cohort was drawn from healthcare utilization databases of 13 Italian territorial units. Patients aged 55 years or more who were hospitalized for fracture during 2003-2005 entered into the cohort. A nested case-control design was used to compare BPs use in cohort members who did (cases) and who did not experience (controls) a new fracture until 2007 (outcome). Three designs were employed: conventional-matching (D1 ), propensity score-matching (D2 ), and user-only (D3 ) designs. They differed for (i) cohort composition, restricted to patients who received BPs straight after cohort entry (D3 ); (ii) using propensity score for case-control matching (D2 ); and (iii) compared groups of BPs users versus no users (D1 and D2 ) and long-term versus short-term users (D3 ). Bisphosphonate users had odds ratios (95% confidence interval) of 1.20 (1.01 to 1.44) and 0.95 (0.74 to 1.24) by applying D1 and D2 designs, respectively. Statistical evidence that long-term BPs use protects the outcome onset with respect to short-term use was observed for user-only design (D3 ) being the corresponding odds ratio (95% confidence interval) 0.64 (0.44 to 0.93). User-only design yielded closer results to those seen in RCTs. This approach is one possible strategy to account for confounding by indication. Copyright © 2014 John Wiley & Sons, Ltd.

[Design requirements for clinical trials on re-evaluation of safety and efficacy of post-marketed Chinese herbs].

PubMed

Xie, Yanming; Wei, Xu

2011-10-01

Re-evaluation of post-marketed based on pharmacoepidemiology is to study and collect clinical medicine safety in large population under practical applications for a long time. It is necessary to conduct re-evaluation of clinical effectiveness because of particularity of traditional Chinese medicine (TCM). Right before carrying out clinical trials on re-evaluation of post-marketed TCM, we should determine the objective of the study and progress it in the assessment mode of combination of disease and syndrome. Specical population, involving children and seniors who were excluded in pre-marketed clinical trial, were brought into drug monitoring. Sample size needs to comply with statistical requirement. We commonly use cohort study, case-control study, nested case-control, pragmatic randomized controlled trials.

Altered Growth Trajectory of Head Circumference During Infancy and Schizophrenia in a National Birth Cohort

PubMed Central

Brown, Alan S.; Gyllenberg, David; Hinkka-Yli-Salomäki, Susanna; Sourander, Andre; McKeague, Ian W.

2016-01-01

Identification of abnormalities in the developmental trajectory during infancy of future schizophrenia cases offers the potential to reveal pathogenic mechanisms of this disorder. Previous studies of head circumference in pre-schizophrenia were limited to measures at birth. The use of growth acceleration of head circumference (defined as the rate of change in head circumference) provides a more informative representation of the maturational landscape of this measure compared to studies based on static head circumference measures. To date, however, no study has examined whether HC growth acceleration differs between pre-schizophrenia cases and controls. In the present study, we employed a nested case control design of a national birth cohort in Finland. Cases with schizophrenia or schizoaffective disorder (N=375) and controls (N=375) drawn from the birth cohort were matched 1:1 on date of birth (within 1 month), sex, and residence in Finland at case diagnosis. Longitudinal data were obtained on head circumference from birth through age 1. Data were analyzed using a new nonparametric Bayesian inversion method which allows for a detailed understanding of growth dynamics. Adjusting for growth velocity of height and weight, and gestational age, there was significantly accelerated growth of head circumference in females with schizophrenia from birth to 2 months; the findings remained significant following Bonferroni correction (p < 0.0125). This is the first study to report abnormal HC growth acceleration, a more sensitive measure of somatic developmental deviation of this measure, in schizophrenia. PMID:27818077

Testing common assumptions in studies of songbird nest success

USGS Publications Warehouse

Streby, Henry M.; Andersen, David

2013-01-01

We studied Ovenbird Seiurus aurocapilla and Golden-winged Warbler Vermivora chrysopterapopulations in northern Minnesota, USA, to test two common assumptions in studies of songbird nest success: (1) that the condition of an empty nest on or near its expected fledge date is an indicator of nest fate; and (2) that the presence of a fledgling or family group within a territory confirms a successful nest in that territory. We monitored the condition of nests and used radiotelemetry to monitor juveniles through the expected fledging date and early post-fledging period. Of nests that contained nestlings 1–2 days before the expected fledge date, fates were misidentified using nest condition alone for 9.5% of Ovenbird nests, but those misidentifications were made in both directions (succeeded or failed), yielding only a small bias in estimated nest success. However, 20% of Golden-winged Warbler nests were misidentified as successful using nest condition during the final visit interval, biasing the nest success estimate upward by 21–28% depending on the treatment of uncertain nest fates. Fledgling Ovenbirds from 58% of nests travelled beyond their natal territory within 24 h, rising to 98% after 5 days, and those fledglings travelled up to 390 m from nests within 10 days of fledging. Fledgling Golden-winged Warblers from 13% of nests travelled beyond their natal territory within 24 h, rising to 85% after 5 days, and those fledglings travelled up to 510 m from nests within 10 days of fledging. We conclude that nest condition and fledgling presence can be misleading indicators of nest fate, probably commonly biasing nest success estimates upward, and we recommend that these assumptions should be tested in additional species.

Site selection and nest survival of the Bar-Headed Goose (Anser indicus) on the Mongolian Plateau

USGS Publications Warehouse

Batbayar, Nyambayar; Takekawa, John Y.; Natsagdorj, Tseveenmyadag; Spragens, Kyle A.; Xiao, Xiamgming

2014-01-01

Waterbirds breeding on the Mongolian Plateau in Central Asia must find suitable wetland areas for nesting in a semiarid region characterized by highly variable water conditions. The first systematic nesting study of a waterbird dependent on this region for breeding was conducted on the Bar-headed Goose (Anser indicus). The purpose of this study was to document Bar-headed Goose nesting locations, characterize nests and nesting strategies, and estimate daily nest survival (n = 235 nests) from eight areas of west-central Mongolia across three summers (2009–2011) using a modified Mayfield estimator. Bar-headed Goose daily nest survival ranged from 0.94 to 0.98, with a 3-year average nest success of 42.6% during incubation. Bar-headed Geese were found to primarily nest on isolated pond and lake islands as previously reported, but were also documented regularly, though less frequently, along rocky cliffs in several regions of west-central Mongolia. Daily nest survival was higher for cliff nests than for island nests. Information-theoretic models indicated that nest survival decreased with nest age and varied annually with changing environmental conditions. Results of this study suggest that while Bar-headed Geese primarily rely on nesting island sites these sites may be more susceptible to anthropogenic disturbance and predation events influenced by seasonal variation in environmental conditions, and that higher daily nest survival values documented for the less frequent cliff nest strategy may provide an important alternative strategy during poor island nest success years. Thus, conservation efforts for this and other waterbird species in the semiarid region should be focused on conserving nesting islands and protecting them from disturbance in areas of high livestock densities experiencing a rapidly warming climate.

Factors influencing predation associated with visits to artificial goose nests

USGS Publications Warehouse

Vacca, M. Michele; Handel, Colleen M.

1988-01-01

Artificial goose nests were used to determine what factors might increase predation after visits to nests of Cackling Canada Geese (Branta canadensis minima). We tested whether leaving the nest uncovered, marking the nest location with a flag, or placing the nest on an island or peninsula would increase the rate of predation. Predators destroyed significantly more of the nests with eggs exposed to view (61%) than of the nests with eggs covered with goose down (35%) (P < 0.05). However, the rate of predation was only slightly higher among nests located on peninsulas than on islands and equal proportions of flagged and unflagged nests were destroyed. We also determined that investigators attracted predators to the study area and caused an increase in predation at uncovered nests immediately after the visit. Covering the eggs with down essentially negated the effect of attracting predators when visiting the nest. Among the 46 nests destroyed, 78% were destroyed by birds and 22% by mammals. Results of our study suggested that visibility of exposed eggs rather than nest markers provided important cues to avian predators and that islands probably provided some refuge from mammalian predators. Investigators can take steps to minimize their impact on nesting success and should incorporate a measure of that impact in their studies.

Low organisational justice and heavy drinking: a prospective cohort study.

PubMed

Kouvonen, Anne; Kivimäki, Mika; Elovainio, Marko; Väänänen, Ari; De Vogli, Roberto; Heponiemi, Tarja; Linna, Anne; Pentti, Jaana; Vahtera, Jussi

2008-01-01

To investigate whether low perceived organisational injustice predicts heavy drinking among employees. Data from a prospective occupational cohort study, the 10-Town Study, on 15 290 Finnish public sector local government employees nested in 2432 work units, were used. Non-drinkers were excluded. Procedural, interactional and total organisational justice, heavy drinking (>/=210 g of absolute alcohol per week) and other psychosocial factors were determined by means of questionnaire in 2000-2001 (phase 1) and 2004 (phase 2). Multilevel logistic regression analyses taking into account the hierarchical structure of the data were conducted and adjustments were made for sex, age, socio-economic status, marital status, baseline heavy drinking, psychological distress and other psychosocial risk factors such as job strain and effort/reward imbalance. After adjustments, participants who reported low procedural justice at phase 1 were approximately 1.2 times more likely to be heavy drinkers at phase 2 compared with their counterparts reporting high justice. Low perceived justice in interpersonal treatment and low perceived total organisational justice were associated with increased prevalence of heavy drinking only in the model adjusted for sociodemographics. This is the first longitudinal study to show that low procedural justice is weakly associated with an increased likelihood of heavy drinking.

Sharp-Tailed Grouse Nest Survival and Nest Predator Habitat Use in North Dakota's Bakken Oil Field.

PubMed

Burr, Paul C; Robinson, Aaron C; Larsen, Randy T; Newman, Robert A; Ellis-Felege, Susan N

2017-01-01

Recent advancements in extraction technologies have resulted in rapid increases of gas and oil development across the United States and specifically in western North Dakota. This expansion of energy development has unknown influences on local wildlife populations and the ecological interactions within and among species. Our objectives for this study were to evaluate nest success and nest predator dynamics of sharp-tailed grouse (Tympanuchus phasianellus) in two study sites that represented areas of high and low energy development intensities in North Dakota. During the summers of 2012 and 2013, we monitored 163 grouse nests using radio telemetry. Of these, 90 nests also were monitored using miniature cameras to accurately determine nest fates and identify nest predators. We simultaneously conducted predator surveys using camera scent stations and occupancy modeling to estimate nest predator occurrence at each site. American badgers (Taxidea taxus) and striped skunks (Mephitis mephitis) were the primary nest predators, accounting for 56.7% of all video recorded nest depredations. Nests in our high intensity gas and oil area were 1.95 times more likely to succeed compared to our minimal intensity area. Camera monitored nests were 2.03 times more likely to succeed than non-camera monitored nests. Occupancy of mammalian nest predators was 6.9 times more likely in our study area of minimal gas and oil intensity compared to the high intensity area. Although only a correlative study, our results suggest energy development may alter the predator community, thereby increasing nest success for sharp-tailed grouse in areas of intense development, while adjacent areas may have increased predator occurrence and reduced nest success. Our study illustrates the potential influences of energy development on the nest predator-prey dynamics of sharp-tailed grouse in western North Dakota and the complexity of evaluating such impacts on wildlife.

Nest-site preference of northern goshawks in southcentral Wyoming

Treesearch

John R. Squires; Leonard F. Ruggiero

1996-01-01

In 1992, we studied the nest-site preference of goshawks (Accipiter gentilis atricapillus) nesting in lodgepole pine (Pinus contorta) forests of the Medicine Bow National Forest, southcentral Wyoming. For 39 active pairs of goshawks, we described nesting habitat at 3 spatial scales: nest tree, nest-tree area (0.04 ha circle centered at nest tree), and nest stand (...

Influence of olfactory and visual cover on nest site selection and nest success for grassland-nesting birds.

PubMed

Fogarty, Dillon T; Elmore, R Dwayne; Fuhlendorf, Samuel D; Loss, Scott R

2017-08-01

Habitat selection by animals is influenced by and mitigates the effects of predation and environmental extremes. For birds, nest site selection is crucial to offspring production because nests are exposed to extreme weather and predation pressure. Predators that forage using olfaction often dominate nest predator communities; therefore, factors that influence olfactory detection (e.g., airflow and weather variables, including turbulence and moisture) should influence nest site selection and survival. However, few studies have assessed the importance of olfactory cover for habitat selection and survival. We assessed whether ground-nesting birds select nest sites based on visual and/or olfactory cover. Additionally, we assessed the importance of visual cover and airflow and weather variables associated with olfactory cover in influencing nest survival. In managed grasslands in Oklahoma, USA, we monitored nests of Northern Bobwhite ( Colinus virginianus ), Eastern Meadowlark ( Sturnella magna ), and Grasshopper Sparrow ( Ammodramus savannarum ) during 2015 and 2016. To assess nest site selection, we compared cover variables between nests and random points. To assess factors influencing nest survival, we used visual cover and olfactory-related measurements (i.e., airflow and weather variables) to model daily nest survival. For nest site selection, nest sites had greater overhead visual cover than random points, but no other significant differences were found. Weather variables hypothesized to influence olfactory detection, specifically precipitation and relative humidity, were the best predictors of and were positively related to daily nest survival. Selection for overhead cover likely contributed to mitigation of thermal extremes and possibly reduced detectability of nests. For daily nest survival, we hypothesize that major nest predators focused on prey other than the monitored species' nests during high moisture conditions, thus increasing nest survival on these days. Our study highlights how mechanistic approaches to studying cover informs which dimensions are perceived and selected by animals and which dimensions confer fitness-related benefits.

Free breakfasts in schools: design and conduct of a cluster randomised controlled trial of the Primary School Free Breakfast Initiative in Wales [ISRCTN18336527

PubMed Central

Moore, Laurence; Moore, Graham F; Tapper, Katy; Lynch, Rebecca; Desousa, Carol; Hale, Janine; Roberts, Chris; Murphy, Simon

2007-01-01

Background School-based breakfast provision is increasingly being seen as a means of improving educational performance and dietary behaviour amongst children. Furthermore, recognition is growing that breakfast provision offers potential as a means of addressing social inequalities in these outcomes. At present however, the evidence base on the effectiveness of breakfast provision in bringing about these improvements is limited. Methods/Design This paper describes the research design of a large scale evaluation of the effectiveness of the Welsh Assembly Government's Primary School Free Breakfast Initiative. A cluster randomised trial, with school as the unit of randomisation was used for the outcome evaluation, with a nested qualitative process evaluation. Quantitative outcome measures included dietary habits, attitudes, cognitive function, classroom behaviour, and school attendance. The study recruited 111 primary schools in Wales, of which 56 were randomly assigned to control condition and 55 to intervention. Participants were Year 5 and 6 students (aged 9–11 years) in these schools. Data were collected for all 111 schools at each of three time points: baseline, 4 month and 12 month follow-up. This was achieved through a repeated cross-sectional survey of approximately 4350 students on each of these occasions. Of those students in Year 5 at baseline, 1975 provided data at one or both of the follow-ups, forming a nested cohort. The evaluation also included a nested process evaluation, using questionnaires, semi-structured interviews and case studies with students, school staff, and local authority scheme coordinators as key informants. Discussion An overview of the methods used for the evaluation is presented, providing an example of the feasibility of conducting robust evaluations of policy initiatives using a randomised trial design with nested process evaluation. Details are provided of response rates and the flow of participants. Reflection is offered on methodological issues encountered at various stages through the course of the study, focusing upon issues associated with conducting a randomised trial of a government policy initiative, and with conducting research in school settings. Trial registration Current Controlled Trials ISRCTN18336527 PMID:17888158

Free breakfasts in schools: design and conduct of a cluster randomised controlled trial of the Primary School Free Breakfast Initiative in Wales [ISRCTN18336527].

PubMed

Moore, Laurence; Moore, Graham F; Tapper, Katy; Lynch, Rebecca; Desousa, Carol; Hale, Janine; Roberts, Chris; Murphy, Simon

2007-09-21

School-based breakfast provision is increasingly being seen as a means of improving educational performance and dietary behaviour amongst children. Furthermore, recognition is growing that breakfast provision offers potential as a means of addressing social inequalities in these outcomes. At present however, the evidence base on the effectiveness of breakfast provision in bringing about these improvements is limited. This paper describes the research design of a large scale evaluation of the effectiveness of the Welsh Assembly Government's Primary School Free Breakfast Initiative. A cluster randomised trial, with school as the unit of randomisation was used for the outcome evaluation, with a nested qualitative process evaluation. Quantitative outcome measures included dietary habits, attitudes, cognitive function, classroom behaviour, and school attendance. The study recruited 111 primary schools in Wales, of which 56 were randomly assigned to control condition and 55 to intervention. Participants were Year 5 and 6 students (aged 9-11 years) in these schools. Data were collected for all 111 schools at each of three time points: baseline, 4 month and 12 month follow-up. This was achieved through a repeated cross-sectional survey of approximately 4350 students on each of these occasions. Of those students in Year 5 at baseline, 1975 provided data at one or both of the follow-ups, forming a nested cohort. The evaluation also included a nested process evaluation, using questionnaires, semi-structured interviews and case studies with students, school staff, and local authority scheme coordinators as key informants. An overview of the methods used for the evaluation is presented, providing an example of the feasibility of conducting robust evaluations of policy initiatives using a randomised trial design with nested process evaluation. Details are provided of response rates and the flow of participants. Reflection is offered on methodological issues encountered at various stages through the course of the study, focusing upon issues associated with conducting a randomised trial of a government policy initiative, and with conducting research in school settings.

Crude incidence in two-phase designs in the presence of competing risks.

PubMed

Rebora, Paola; Antolini, Laura; Glidden, David V; Valsecchi, Maria Grazia

2016-01-11

In many studies, some information might not be available for the whole cohort, some covariates, or even the outcome, might be ascertained in selected subsamples. These studies are part of a broad category termed two-phase studies. Common examples include the nested case-control and the case-cohort designs. For two-phase studies, appropriate weighted survival estimates have been derived; however, no estimator of cumulative incidence accounting for competing events has been proposed. This is relevant in the presence of multiple types of events, where estimation of event type specific quantities are needed for evaluating outcome. We develop a non parametric estimator of the cumulative incidence function of events accounting for possible competing events. It handles a general sampling design by weights derived from the sampling probabilities. The variance is derived from the influence function of the subdistribution hazard. The proposed method shows good performance in simulations. It is applied to estimate the crude incidence of relapse in childhood acute lymphoblastic leukemia in groups defined by a genotype not available for everyone in a cohort of nearly 2000 patients, where death due to toxicity acted as a competing event. In a second example the aim was to estimate engagement in care of a cohort of HIV patients in resource limited setting, where for some patients the outcome itself was missing due to lost to follow-up. A sampling based approach was used to identify outcome in a subsample of lost patients and to obtain a valid estimate of connection to care. A valid estimator for cumulative incidence of events accounting for competing risks under a general sampling design from an infinite target population is derived.

Risk and mortality of traumatic brain injury in stroke patients: two nationwide cohort studies.

PubMed

Chou, Yi-Chun; Yeh, Chun-Chieh; Hu, Chaur-Jong; Meng, Nai-Hsin; Chiu, Wen-Ta; Chou, Wan-Hsin; Chen, Ta-Liang; Liao, Chien-Chang

2014-01-01

Patients with stroke had higher incidence of falls and hip fractures. However, the risk of traumatic brain injury (TBI) and post-TBI mortality in patients with stroke was not well defined. Our study is to investigate the risk of TBI and post-TBI mortality in patients with stroke. Using reimbursement claims from Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study of 7622 patients with stroke and 30 488 participants without stroke aged 20 years and older as reference group. Data were collected on newly developed TBI after stroke with 5 to 8 years' follow-up during 2000 to 2008. Another nested cohort study including 7034 hospitalized patients with TBI was also conducted to analyze the contribution of stroke to post-TBI in-hospital mortality. Compared with the nonstroke cohort, the adjusted hazard ratio of TBI risk among patients with stroke was 2.80 (95% confidence interval = 2.58-3.04) during the follow-up period. Patients with stroke had higher mortality after TBI than those without stroke (10.2% vs 3.2%, P < .0001) with an adjusted relative risk (RR) of 1.46 (95% confidence interval = 1.15-1.84). Recurrent stroke (RR = 1.60), hemorrhagic stroke (RR = 1.68), high medical expenditure for stroke (RR = 1.80), epilepsy (RR = 1.79), neurosurgery (RR = 1.94), and hip fracture (RR = 2.11) were all associated with significantly higher post-TBI mortality among patients with stroke. Patients with stroke have an increased risk of TBI and in-hospital mortality after TBI. Various characteristics of stroke severity were all associated with higher post-TBI mortality. Special attention is needed to prevent TBI among these populations.

Frequency of nest use by golden eagles in southwestern Idaho

USGS Publications Warehouse

Kochert, Michael N.; Steenhof, Karen

2012-01-01

We studied nest use by Golden Eagles (Aquila chrysaetos) from 1966 to 2011 to assess nest reuse within territories, ascertain the length of time that elapses between uses of nests, and test the hypotheses that reproductive success and adult turnover influence nest switching. Golden Eagles used 454 nests in 66 territories and used individual nests 1 to 26 times during 45 continuous years of observation. Time between reuse ranged from 1 to 39 yr. Distances between nearest adjacent alternative nests within territories ranged between 5 times. Two nests were unused for 21 and 27 yr after 1971 before being used every 1 to 3 yr thereafter. Eagles used 43% of the nests in series of consecutive years (range 3 to 20 consecutive nestings). Protecting unused nests for a proposed 10 yr after the last known use would not have protected 34% of all 300 nests that were reused during the study and 49% of 37 reused nests monitored consistently for 41 yr. The 102 nests that would not have received protection were in 56 of the 66 territories.

Canada goose nest survival at rural wetlands in north-central Iowa

USGS Publications Warehouse

Ness, Brenna N.; Klaver, Robert W.

2016-01-01

The last comprehensive nest survival study of the breeding giant Canada goose (Branta canadensis maxima) population in Iowa, USA, was conducted >30 years ago during a period of population recovery, during which available nesting habitat consisted primarily of artificial nest structures. Currently, Iowa's resident goose population is stable and nests in a variety of habitats. We analyzed the effects of available habitat on nest survival and how nest survival rates compared with those of the expanding goose population studied previously to better understand how to maintain a sustainable Canada goose population in Iowa. We documented Canada goose nest survival at rural wetland sites in north-central Iowa. We monitored 121 nests in 2013 and 149 nests in 2014 at 5 Wildlife Management Areas (WMAs) with various nesting habitats, including islands, muskrat (Ondatra zibethicus) houses, and elevated nest structures. We estimated daily nest-survival rate using the nest survival model in Program MARK. Survival was influenced by year, site, stage, presence of a camera, nest age, and an interaction between nest age and stage. Nest success rates for the 28-day incubation period by site and year combination ranged from 0.10 to 0.84. Nest survival was greatest at sites with nest structures (β = 17.34). Nest survival was negatively affected by lowered water levels at Rice Lake WMA (2013 β = −0.77, nest age β = −0.07). Timing of water-level drawdowns for shallow lake restorations may influence nest survival rates.

Psychiatric and substance use disorders in HIV/hepatitis C virus (HCV)-coinfected patients: does HCV clearance matter? [Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) HEPAVIH CO13 cohort].

PubMed

Michel, L; Lions, C; Winnock, M; Lang, J-P; Loko, M-A; Rosenthal, E; Marchou, B; Valantin, M-A; Morlat, P; Roux, P; Sogni, P; Spire, B; Poizot-Martin, I; Lacombe, K; Lascoux-Combe, C; Duvivier, C; Neau, D; Dabis, F; Salmon-Ceron, D; Carrieri, M P

2016-11-01

The objective of this nested study was to assess the prevalence of psychiatric disorders in a sample of HIV/hepatitis C virus (HCV)-coinfected patients according to their HCV status. The nested cross-sectional study, untitled HEPAVIH-Psy survey, was performed in a subset of HIV/HCV-coinfected patients enrolled in the French Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) CO13 HEPAVIH cohort. Psychiatric disorders were screened for using the Mini International Neuropsychiatric Interview (MINI 5.0.0). Among the 286 patients enrolled in the study, 68 (24%) had never received HCV treatment, 87 (30%) were treatment nonresponders, 44 (15%) were currently being treated and 87 (30%) had a sustained virological response (SVR). Of the 286 patients enrolled, 121 patients (42%) screened positive for a psychiatric disorder other than suicidality and alcohol/drug abuse/dependence, 40 (14%) screened positive for alcohol abuse/dependence, 50 (18%) screened positive for drug abuse/dependence, 50 (17.5%) were receiving an antidepressant treatment and 69 (24%) were receiving an anxiolytic. Patients with an SVR did not significantly differ from the other groups in terms of psychiatric disorders. Patients receiving HCV treatment screened positive less often for an anxiety disorder. The highest rate of drug dependence/abuse was among HCV treatment-naïve patients. Psychiatric disorders were frequent in HIV/HCV-coinfected patients and their rates were comparable between groups, even for patients achieving an SVR. Our results emphasize the need for continuous assessment and care of coinfected patients, even after HCV clearance. Drug addiction remains an obstacle to access to HCV treatment. Despite the recent advent and continued development of directly acting antiviral agents (DAAs), it is still crucial to offer screening and comprehensive care for psychiatric and addictive disorders. © 2016 British HIV Association.

Risk of bleeding and antibiotic use in patients receiving continuous phenprocoumon therapy. A case-control study nested in a large insurance- and population-based German cohort.

PubMed

Abbas, Sascha; Ihle, Peter; Harder, Sebastian; Schubert, Ingrid

2014-05-05

There is major concern about coumarins interacting with various drug classes and increasing the risk of overanticoagulation. The aim of the study was to assess bleeding risk in patients with concurrent use of antibiotics and phenprocoumon, the most widely prescribed coumarin in many European countries. We conducted a nested-case-control study within a cohort of 513,338 incident and continuous phenprocoumon users ≥ 18 years of age using claims data of the statutory health insurance company AOK, covering 30% of the German population. Bleeding risk associated with current use of antibiotics for systemic use (antibacterials/antimycotics) was calculated using conditional logistic regression in 13,785 cases with a bleeding event and 55,140 risk-set sampling-matched controls. Bleeding risk associated with any antibacterial use in phenprocoumon users was significantly increased [odds ratio (OR) 2.37, 95% confidence interval (CI) 2.20-2.56]. The association was stronger for gastrointestinal than for cerebral bleeding (OR 2.09, 95% CI 1.84-2.38 and OR 1.34, 95% CI 1.03-1.74, respectively) and highest for other/unspecified bleeding (OR 2.92, 95% CI 2.62-3.26). Specific antibiotic classes were strongly associated with bleeding risk, e.g. cotrimoxazole (OR 3.86, 95% CI 3.08-4.84) and fluorquinolones (OR 3.13, 95% CI 2.74-3.59), among those highest for ofloxacin (OR 5.00, 95% CI 3.01-8.32). Combined use of phenprocoumon and antimycotics was not significantly associated with bleeding risk. Risk was not significantly modified by age (pint=0.25) or sex (pint=0.96). The association was stronger the closer the antibiotic exposure was to the bleeding event. Among continuous phenprocoumon users, antibiotics - particularly quinolones and cotrimoxazole - should be prescribed after careful consideration due to an increased bleeding risk. Close monitoring of international normalised ratio levels after prescription is recommended.

Incidence, risk factors, management and outcomes of amniotic-fluid embolism: a population-based cohort and nested case-control study.

PubMed

Fitzpatrick, K E; Tuffnell, D; Kurinczuk, J J; Knight, M

2016-01-01

To describe the incidence, risk factors, management and outcomes of amniotic-fluid embolism (AFE) over time. A population-based cohort and nested case-control study using the UK Obstetric Surveillance System (UKOSS). All UK hospitals with obstetrician-led maternity units. All women diagnosed with AFE in the UK between February 2005 and January 2014 (n = 120) and 3839 control women. Prospective case and control identification through UKOSS monthly mailing. Amniotic-fluid embolism, maternal death or permanent neurological injury. The total and fatal incidence of AFE, estimated as 1.7 and 0.3 per 100 000, respectively, showed no significant temporal trend over the study period and there was no notable temporal change in risk factors for AFE. Twenty-three women died (case fatality 19%) and seven (7%) of the surviving women had permanent neurological injury. Women who died or had permanent neurological injury were more likely to present with cardiac arrest (83% versus 33%, P < 0.001), be from ethnic-minority groups (adjusted odds ratio [OR] 2.85, 95% confidence interval [95% CI] 1.02-8.00), have had a hysterectomy (unadjusted OR 2.49, 95% CI 1.02-6.06), had a shorter time interval between the AFE event and when the hysterectomy was performed (median interval 77 minutes versus 248 minutes, P = 0.0315), and were less likely to receive cryoprecipitate (unadjusted OR 0.30, 95% CI 0.11-0.80). There is no evidence of a temporal change in the incidence of or risk factors for AFE. Further investigation is needed to establish whether earlier treatments can reverse the cascade of deterioration leading to severe outcomes. © 2015 The Authors. BJOG An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.

Risk of acute coronary events associated with glyburide compared with gliclazide use in patients with type 2 diabetes: a nested case-control study.

PubMed

Abdelmoneim, A S; Eurich, D T; Gamble, J M; Johnson, J A; Seubert, J M; Qiu, W; Simpson, S H

2014-01-01

Sulfonylureas might increase the risk of adverse cardiovascular events; however, emerging evidence suggests there may be important differences amongst these drugs. Some, like glyburide, inhibit KATP channels in the heart and pancreas, while others, like gliclazide, are more likely to selectively inhibit KATP channels in the pancreas. We hypothesized that the risk of acute coronary syndrome (ACS) events would be higher in patients using glyburide compared with gliclazide. This nested case-control study used administrative health data from Alberta, Canada. New users of glyburide or gliclazide aged ≥66 years between 1998 and 2010 were included. Cases were individuals with an ACS-related hospitalization or death. Up to four controls were matched based on birth year, sex, cohort-entry year and follow-up time. Multivariable conditional logistic regression was used to estimate adjusted odds ratios (OR), controlling for baseline drug use and co-morbidities. Our cohort included 7441 gliclazide and 13 884 glyburide users; 51.4% men, mean (s.d.) age 75.5 (6.6) years and mean (s.d.) duration of follow-up 5.5 (4.0) years. A total of 4239 patients had an ACS-related hospitalization or death and were matched to 16 723 controls. Compared with gliclazide use, glyburide use was associated with a higher risk (adjusted OR 1.14; 95% CI 1.06-1.23) of ACS-related hospitalization or death over 5.5 years (number needed to harm: 50). In this observational study, glyburide use was associated with a 14% higher risk of ACS events compared with gliclazide use. Although the difference is small and probably to have implications at the population level rather than the individual patient or clinician, any causal inferences regarding sulfonylurea use and adverse cardiovascular risk should be tested in a large-scale randomized controlled trial. © 2013 John Wiley & Sons Ltd.

Protocol and baseline data for a multi-year cohort study of the effects of different mass drug treatment approaches on functional morbidities from schistosomiasis in four African countries.

PubMed

Shen, Ye; King, Charles H; Binder, Sue; Zhang, Feng; Whalen, Christopher C; Evan Secor, W; Montgomery, Susan P; Mwinzi, Pauline N M; Olsen, Annette; Magnussen, Pascal; Kinung'hi, Safari; Phillips, Anna E; Nalá, Rassul; Ferro, Josefo; Aurelio, H Osvaldo; Fleming, Fiona; Garba, Amadou; Hamidou, Amina; Fenwick, Alan; Campbell, Carl H; Colley, Daniel G

2017-09-29

The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) focus is on randomized trials of different approaches to mass drug administration (MDA) in endemic countries in Africa. Because their studies provided an opportunity to evaluate the effects of mass treatment on Schistosoma-associated morbidity, nested cohort studies were developed within SCORE's intervention trials to monitor changes in a suite of schistosomiasis disease outcomes. This paper describes the process SCORE used to select markers for prospective monitoring and the baseline prevalence of these morbidities in four parallel cohort studies. In July 2009, SCORE hosted a discussion of the potential impact of MDA on morbidities due to Schistosoma infection that might be measured in the context of multi-year control. Candidate markers were reviewed and selected for study implementation. Baseline data were then collected from cohorts of children in four country studies: two in high endemic S. mansoni sites (Kenya and Tanzania), and two in high endemic S. haematobium sites (Niger and Mozambique), these cohorts to be followed prospectively over 5 years. At baseline, 62% of children in the S. mansoni sites had detectable eggs in their stool, and 10% had heavy infections (≥ 400 eggs/g feces). Heavy S. mansoni infections were found to be associated with increased baseline risk of anemia, although children with moderate or heavy intensity infections had lower risk of physical wasting. Prevalence of egg-positive infection in the combined S. haematobium cohorts was 27%, with 5% of individuals having heavy infection (≥50 eggs/10 mL urine). At baseline, light intensity S. haematobium infection was associated with anemia and with lower scores in the social domain of health-related quality-of-life (HRQoL) assessed by Pediatric Quality of Life Inventory. Our consensus on practical markers of Schistosoma-associated morbidity indicated that height, weight, hemoglobin, exercise tolerance, HRQoL, and ultrasound abnormalities could be used as reference points for gauging treatment impact. Data collected over five years of program implementation will provide guidance for future evaluation of morbidity control in areas endemic for schistosomiasis. These cohort studies are registered and performed in conjunction with the International Standard Randomised Controlled Trial Registry trials ISRCTN16755535 , ISRCTN14117624 , ISRCTN95819193 , and ISRCTN32045736 .

EUropean prospective cohort study on Enterobacteriaceae showing REsistance to CArbapenems (EURECA): a protocol of a European multicentre observational study.

PubMed

Gutiérrez-Gutiérrez, Belén; Sojo-Dorado, Jesús; Bravo-Ferrer, José; Cuperus, Nienke; de Kraker, Marlieke; Kostyanev, Tomislav; Raka, Lul; Daikos, George; Feifel, Jan; Folgori, Laura; Pascual, Alvaro; Goossens, Herman; O'Brien, Seamus; Bonten, Marc J M; Rodríguez-Baño, Jesús

2017-04-03

The rapid worldwide spread of carbapenem-resistant Enterobacteriaceae (CRE) constitutes a major challenge. The aim of the EUropean prospective cohort study on Enterobacteriaceae showing REsistance to CArbapenems (EURECA), which is part of the Innovative Medicines Initiative Joint Undertaking (IMI JU) funded COMBACTE-CARE project, is to investigate risk factors for and outcome determinants of CRE infections to inform randomised clinical trial designs and to provide a historical cohort that could eventually be used for future comparisons with new drugs targeting CRE. A multicentre (50 sites), multinational (11 European countries), analytical observational project was designed, comprising 3 studies. The aims of study 1 (a prospective cohort study) include characterising the features, clinical management and outcomes of hospitalised patients with intra-abdominal infection, pneumonia, complicated urinary tract infections and bloodstream infections caused by CRE (202 patients in each group). The main outcomes will be 30-day all-cause mortality and clinical response. Study 2 (a nested case-control study) will identify the risk factors for target infections caused by CRE; 248 selected patients from study 1 will be matched with patients with carbapenem-susceptible Enterobacteriaceae (1:1) and with hospitalised patients (1:3) and will provide a historical cohort of patients with CRE infections. Study 3 (a matched cohort study) will follow patients in study 2 in order to assess mortality, length of stay and hospital costs associated with CRE. All patients will be followed for 30 days. Different, up-to-date statistical methods will be applied to come to unbiased estimates for all 3 studies. Before-study sites will be initiated, approval will be sought from appropriate regulatory agencies and local Ethics Committees of Research or Institutional Review Boards (IRBs) to conduct the study in accordance with regulatory requirements. This is an observational study and therefore no intervention in the diagnosis, management or treatment of the patients will be required on behalf of the investigation. Any formal presentation or publication of data collected from this study will be considered as a joint publication by the participating physician(s) and will follow the recommendations of the International Committee of Medical Journal Editors (ICMJE) for authorship. NCT02709408. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Circulating FABP4 is a prognostic biomarker in patients with acute coronary syndrome but not in asymptomatic individuals.

PubMed

Reiser, Hans; Klingenberg, Roland; Hof, Danielle; Cooksley-Decasper, Seraina; Fuchs, Nina; Akhmedov, Alexander; Zoller, Stefan; Marques-Vidal, Pedro; Marti Soler, Helena; Heg, Dik; Landmesser, Ulf; Rodondi, Nicolas; Mach, Francois; Windecker, Stephan; Vollenweider, Peter; Matter, Christian M; Lüscher, Thomas F; von Eckardstein, Arnold; Gawinecka, Joanna

2015-08-01

Blood-borne biomarkers reflecting atherosclerotic plaque burden have great potential to improve clinical management of atherosclerotic coronary artery disease and acute coronary syndrome (ACS). Using data integration from gene expression profiling of coronary thrombi versus peripheral blood mononuclear cells and proteomic analysis of atherosclerotic plaque-derived secretomes versus healthy tissue secretomes, we identified fatty acid-binding protein 4 (FABP4) as a biomarker candidate for coronary artery disease. Its diagnostic and prognostic performance was validated in 3 different clinical settings: (1) in a cross-sectional cohort of patients with stable coronary artery disease, ACS, and healthy individuals (n=820), (2) in a nested case-control cohort of patients with ACS with 30-day follow-up (n=200), and (3) in a population-based nested case-control cohort of asymptomatic individuals with 5-year follow-up (n=414). Circulating FABP4 was marginally higher in patients with ST-segment-elevation myocardial infarction (24.9 ng/mL) compared with controls (23.4 ng/mL; P=0.01). However, elevated FABP4 was associated with adverse secondary cerebrovascular or cardiovascular events during 30-day follow-up after index ACS, independent of age, sex, renal function, and body mass index (odds ratio, 1.7; 95% confidence interval, 1.1-2.5; P=0.02). Circulating FABP4 predicted adverse events with similar prognostic performance as the GRACE in-hospital risk score or N-terminal pro-brain natriuretic peptide. Finally, no significant difference between baseline FABP4 was found in asymptomatic individuals with or without coronary events during 5-year follow-up. Circulating FABP4 may prove useful as a prognostic biomarker in risk stratification of patients with ACS. © 2015 American Heart Association, Inc.

Prevalence of non-organ-specific autoantibodies and chronic liver disease in the general population: a nested case-control study of the Dionysos cohort.

PubMed

Lenzi, M; Bellentani, S; Saccoccio, G; Muratori, P; Masutti, F; Muratori, L; Cassani, F; Bianchi, F B; Tiribelli, C

1999-09-01

Several retrospective and prospective studies report an increased prevalence of non-organ-specific autoantibodies (NOSAs) in patients with hepatitis C virus (HCV) related chronic liver disease (CLD). Some of the data so far available are controversial and the true prevalence of NOSAs in the general population is still not known. To explore the prevalence of NOSAs, their relation to different HCV genotypes, and the presence and severity of CLD in the general population of Northern Italy. All 226 anti-HCV positive and 87 hepatitis B surface antigen (HBsAg) positive patients of the Dionysos cohort study were analysed and compared with sex and age matched cases (226) negative for both anti-HCV antibody and HBsAg selected from the same cohort. Sera tested for the presence of NOSAs (anti-nuclear antibody (ANA), anti-smooth muscle antibody (SMA), and anti-liver/kidney microsomes type 1 antibody (LKM1)) were screened by indirect immunofluorescence at a 1:40 serum dilution. HCV RNA and HCV genotypes were also determined by nested polymerase chain reaction (PCR) of the 5' non-coding region and by PCR amplification of the core region with type specific primers. The overall prevalence of NOSA reactivity was significantly higher in anti-HCV positive subjects than in both normal and pathological controls (25% v 6% and 7% respectively, p<0.05). ANA, SMA, and LKM1 occurred in 16, 10, and 1. 3% of cases respectively. No specific association between NOSAs and a specific HCV genotype was found. NOSAs were found more often associated with more than one genotype (35.7%) and with untypable genotypes (34.6%), although the association was not statistically significant. NOSAs were associated with HCV RNA and CLD but not with the presence of cirrhosis and/or hepatocellular carcinoma. On univariate analysis, NOSA reactivity was independently associated with abnormal alanine aminotransferase (p<0.01) and gamma-glutamyltranspeptidase levels (p<0.05). The risk for the presence of NOSAs was 5.1 times higher in anti-HCV subjects than in controls. In the general population the prevalence of NOSAs is higher in anti-HCV positive subjects than in normal or disease controls. Moreover NOSAs are associated with CLD and with a more active disease in terms of alanine aminotransferase activity.

Nickel Allergy Is a Risk Factor for Endometriosis: An 11-Year Population-Based Nested Case-Control Study.

PubMed

Yuk, Jin-Sung; Shin, Jong Seung; Shin, Ji-Yeon; Oh, Eunsuk; Kim, Hyunmee; Park, Won I

2015-01-01

A cross-sectional study has reported that nickel allergy is associated with endometriosis. However, causal studies of this association are limited. The objective of this study was to compare the prevalence of nickel allergy in women with and without endometriosis. We used a National Health Insurance Service (NHIS) sample cohort dataset that included approximately 1 million individuals from South Korea; the data were obtained between January 01, 2002, and December 31, 2013. We selected the endometriosis group according to diagnosis code (N80.X), surgery codes, and drug codes during the years 2009~2013. The controls were randomly matched to the endometriosis patients at a ratio of 4:1 by age and socioeconomic status. Patients with nickel allergy were defined in the cohort dataset as those with a simultaneous diagnosis code (L23.0) and patch test code during 2002~2008. In total, 4,985 women were selected from the NHIS cohort database and divided into an endometriosis group (997 women) and a control group (3,988 women). The number of patients with nickel allergy in the endometriosis group was eight (0.8%), and that in the control group was thirteen (0.3%). After adjustment for age and socioeconomic status, the rate of nickel allergy in was higher in the endometriosis group than in the control group [odds ratio: 2.474; 95% confidence interval: 1.023~5.988; p = 0.044]. We found that nickel allergy is a risk factor for endometriosis.

Red and processed meat consumption and risk of glioma in adults: A systematic review and meta-analysis of observational studies

PubMed Central

Saneei, Parvane; Willett, Walter; Esmaillzadeh, Ahmad

2015-01-01

Background: These findings from several observational studies, investigated the association between red meat consumption and gliomas, were inconsistent. We conducted a systematic review and meta-analysis of observational studies to summarize available date on the relation between meat intake and risk of glioma. Materials and Methods: A systematic literature search of relevant reports published until May 2014 of the PubMed/Medline, ISI Web of Knowledge, Excerpta Medica database, Ovid database, Google Scholar, and Scopus databases was conducted. From 723 articles yielded in the preliminary literature search, data from eighteen publications (14 case-control, three cohort, and one nested case-control study) on unprocessed red meat, processed meat, and/or total red meat consumption in relation to glioma in adults were included in the analysis. Quality assessment of studies was performed. Random effects model was used to conduct the meta-analysis. Results: We found a positive significant association between unprocessed red meat intake and risk of glioma (relative risk [RR] = 1.30; 95% confidence interval [CI]: 1.08-1.58) after excluding three studies with uncertain type of brain cancer. This analysis included only one cohort study which revealed no relation between unprocessed red meat intake and glioma (RR = 1.75; 95% CI: 0.35-8.77). Consumption of processed meats was not related to increased risk of glioma in population-based case-control studies (RR = 1.26; 95% CI: 1.05-1.51) and reduced risk in hospital-based case-controls (RR = 0.79; 95% CI: 0.65-0.97). No significant association was seen between processed red meat intake and risk of glioma in cohort studies (RR: 1.08; 95% CI: 0.84-1.37). Total red meat consumption was not associated with risk of adult glioma in case-control or cohort studies. Conclusion: In this meta-analysis of 18 observational studies, we found a modest positive association between unprocessed red meat intake and risk of gliomas based almost entirely on case-control studies. Processed red meat was overall not associated with risk of gliomas in case-control or cohort studies. PMID:26600837

Nesting ecology of Whimbrels in boreal Alaska

USGS Publications Warehouse

Harwood, Christopher M.; Gill, Robert E.; Powell, Abby

2016-01-01

Breeding ecology studies of boreal waders have been relatively scarce in North America. This paucity is due in part to boreal habitats being difficult to access, and boreal waders being widely dispersed and thus difficult to monitor. Between 2008 and 2014 we studied the nesting ecology of Whimbrels Numenius phaeopus hudsonicus in interior Alaska, a region characterized by an active wildfire regime. Our objectives were to (1) describe the nesting ecology of Whimbrels in tundra patches within the boreal forest, (2) assess the influence of habitat features at multiple scales on nest-site selection, and (3) characterize factors affecting nest survival. Whimbrels nested in the largest patches and exhibited a consistently compressed annual breeding schedule. We hypothesized that these Whimbrels would exhibit synchronous and clustered nesting, but observed synchronous nesting in only 2009 and 2011, and evidence of clustered nesting at just one study area in 2009, providing limited support for the hypothesis. Nests tended to be on hummocks and exhibited lateral concealment around the bowl, suggesting a trade-off between a greater view from the nest and concealment. However, our analysis failed to identify other important habitat features at scales from 1–400 m from the nest. Our best-supported nest survival model showed a strong difference between our two main study areas, but this difference remains largely unexplained. Given the increased frequency, severity, and extent of wildfires predicted under climate change scenarios, our study highlights the importance of monitoring the persistence of boreal tundra patches and the Whimbrels breeding therein.

Observational methods to assess the effectiveness of screening colonoscopy in reducing right colon cancer mortality risk: SCOLAR.

PubMed

Goodman, Michael; Fletcher, Robert H; Doria-Rose, V Paul; Jensen, Christopher D; Zebrowski, Alexis M; Becerra, Tracy A; Quinn, Virginia P; Zauber, Ann G; Corley, Douglas A; Doubeni, Chyke A

2015-11-01

Screening colonoscopy's effectiveness in reducing risk of death from right colon cancers remains unclear. Methodological challenges of existing observational studies addressing this issue motivated the design of 'Effectiveness of Screening for Colorectal Cancer in Average-Risk Adults (SCOLAR)'. SCOLAR is a nested case-control study based on two large integrated health systems. This affords access to a large, well-defined historical cohort linked to integrated data on cancer outcomes, patient eligibility, test indications and important confounders. We found electronic data adequate for excluding ineligible patients (except family history), but not the detailed information needed for test indication assignment. The lessons of SCOLAR's design and implementation may be useful for future studies seeking to evaluate the effectiveness of screening tests in community settings.

Cancer risk in nuclear workers occupationally exposed to uranium-emphasis on internal exposure.

PubMed

Canu, Irina Guseva; Ellis, Elizabeth Dupree; Tirmarche, Margot

2008-01-01

Workers involved in the nuclear fuel cycle have a potential for internal exposure to uranium. The present review of epidemiological studies of these workers aims to elucidate the relationship between occupational internal uranium exposure and cancer risk. Eighteen cohort and 5 nested case-control studies published since 1980 are reviewed. Workers occupationally exposed to uranium appear to be at increased risk of mortality from neoplasms of the lung, larynx, and lymphatic and haematopoietic tissue. Currently available evidence for a positive association between internal exposure to uranium and the risk of cancer is limited. The common weaknesses in reviewed studies include low statistical power and inaccurate assessment of internal exposure to uranium. Further investigations should focus on precise assessment of occupational exposure and address the issue of potential confounders.

Effects of grazing on nesting by upland sandpipers in southcentral North Dakota

USGS Publications Warehouse

Bowen, Bonnie S.; Kruse, Arnold D.

1993-01-01

Grazing by livestock is often used to reduce litter, improve plant vigor, and alter plant species composition, but additional information is needed on the effects of these management practices on upland-nesting birds. Thus, we conducted an experimental study of the effect of grazing on nest density and nest success of upland sandpipers (Bartramia longicauda) in southcentral North Dakota from 1981 to 1987. Our experimental design consisted of 4 treatments and 1 control, each applied to 1 field in each of 3 study areas. The treatments represented options available to grassland managers: spring grazing, autumn grazing, autumn-and-spring grazing, season-long grazing, and control (ungrazed during the study). Nests (n = 342) were found by searching study areas with a cable-chain drag. Nest density was lower (P = 0.006) for treatments where cattle were present (spring, autumn-and-spring, and season-long) than where cattle were not present (autumn and control) during the nesting season. We concluded that grazing during the nesting season reduced the nest density of upland sandpipers. Nest success varied among years (P = 0.01) and was low in the first year of grazing and higher at the end of the study period. We found little evidence that the grazing treatment influenced nest success. We recommend that public lands with breeding populations of upland sandpipers include a complex of fields under various management practices, including fields undisturbed during the nesting season.

The nest-concealment hypothesis: New insights from a comparative analysis

USGS Publications Warehouse

Borgmann, Kathi L.; Conway, Courtney J.

2015-01-01

Selection of a breeding site is critical for many animals, especially for birds whose offspring are stationary during development. Thus, birds are often assumed to prefer concealed nest sites. However, 74% of studies (n = 106) that have evaluated this relationship for open-cup nesting songbirds in North America failed to support the nest-concealment hypothesis. We conducted a comparative analysis to identify factors that contribute to variation in the ability of researchers to find support for the nest-concealment hypothesis. We found that some of the discrepancy among studies can be explained by interspecific differences in morphological and extrinsic factors that affect nest predation. Moreover, methods that investigators used to estimate concealment affected whether studies found support for the nest-concealment hypothesis; 33% of the studies that used quantitative estimates found support for the nest-concealment hypothesis whereas only 10% of the studies that used qualitative estimates found support. The timing of measurements also explained some of the ambiguity; studies that provided little information regarding the timing of their foliage density estimates were less likely to support the nest-concealment hypothesis. Species with more conspicuous male plumage were less likely to support the nest-concealment hypothesis when we analyzed studies that used visual estimates. Whereas species with more conspicuous female plumage were more likely to support the nest-concealment hypothesis when we analyzed studies that used quantitative measures. Our results demonstrate that support for the nest-concealment hypothesis has been equivocal, but that some of the ambiguity can be explained by morphological traits and methods used to measure concealment.

Do Predation Rates on Artificial Nests Accurately Reflect Predation Rates on Natural Bird Nests?

Treesearch

David I. King; Richard M. DeGraaf; Curtice R. Griffin; Thomas J. Maier

1999-01-01

Artificial nests are widely used in avian field studies. However, it is unclear how well predation rates on artificial nests reflect predation rates on natural nests. Therefore, we compared survival rates of artificial nests (unused natural nests baited with House Sparrow eggs) with survival rates of active bird nests in the same habitat at the same sites. Survival...

Cancer complicating systemic lupus erythematosus – a dichotomy emerging from a nested case-control study

PubMed Central

Kenu, E; Isenberg, DA

2013-01-01

Objectives We determined whether any individual cancers are increased or decreased in a cohort of 595 patients with systemic lupus erythematosus (SLE) followed for up to 32 years at the University College London Hospitals Lupus Clinic, looking for any associated clinical or serological factors and the prognosis after cancer diagnosis. Methods We undertook a careful retrospective review of the medical records and identified all individuals diagnosed with cancer. For controls, we selected three other patients in the cohort who had not developed cancer, carefully matched for age, sex, ethnicity and disease duration, to determine if any obvious differences emerged in a nested case-control design. Results Thirty-three patients developed cancer after being diagnosed with SLE. There was a statistically insignificant small increase in overall cancer risk, standardized incidence ratios (SIRs) 1.05 (95% CI 0.52–1.58) and increased SIRs for cervical, prostate, anal and pancreatic cancers and reduction in breast cancer SIRs. Haematological and musculoskeletal manifestations, anticardiolipin and antithyroid globulin antibodies were found to be positively associated with cancer risk in multivariate analysis. There was no drug, dose or duration was associated with cancer risk. There was a reduction in survival with a cancer fatality rate of 84.2% (p < 0.0001). Conclusion We found a very small but statistically insignificant increased cancer risk with reduction in survival. Whereas some cancers appear to be more common in SLE, notably prostate and cervical cancer, others, particularly breast cancer, are less frequent. Multiple clinical and serological factors are involved in the increased risk of malignancy in SLE. No drug dose or duration effect was identified. PMID:23857987

A novel public health threat - high lead solder in stainless steel rainwater tanks in Tasmania.

PubMed

Lodo, Kerryn; Dalgleish, Cameron; Patel, Mahomed; Veitch, Mark

2018-02-01

We identified two water tanks in Tasmania with water lead concentrations exceeding the Australian Drinking Water Guidelines (ADWG) limit; they had been constructed with stainless steel and high-lead solder from a single manufacturer. An investigation was initiated to identify all tanks constructed by this manufacturer and prevent further exposure to contaminated water. To identify water tanks we used sales accounts, blood and water lead results from laboratories, and media. We analysed blood and water lead concentration results from laboratories and conducted a nested cohort study of blood lead concentrations in children aged <18 years. We identifed 144 tanks constructed from stainless steel and high lead solder. Median water lead concentrations were significantly higher in the stainless steel tanks (121µg/L) than in the galvanised tanks (1µg/L). Blood lead concentrations ranged from 1 to 26µg/dL (median 5µg/dL); of these, 77% (n=50) were below the then-recommended health-related concentration of 10µg/dL. Concentrations in the 15 people (23%) above this limit ranged from 10-26µg/dL, with a median of 14µg/dL. The median blood lead concentration in the nested cohort of children was initially 8.5µg/dL, dropping to 4.5µg/dL after follow-up. Lead concentrations in the water tanks constructed from stainless steel and high-lead solder were up to 200 times above the recommended ADWG limits. Implications for public health: This investigation highlights the public health risk posed by use of non-compliant materials in constructing water tanks. © 2017 Department of Health and Human Services Tasmania.

Body Weight and Breast Cancer: Nested Case-Control Study in Southern Brazil.

PubMed

Kops, Natália Luiza; Bessel, Marina; Caleffi, Maira; Ribeiro, Rodrigo Antonini; Wendland, Eliana Marcia

2018-04-28

Current studies have shown that fast weight gain may be more important than body mass index on the incidence of breast cancer. The aim of this study was to evaluate the association between body weight and breast cancer. This was a case-control study nested in a cohort of a breast cancer mammography screening program in Southern Brazil. A trained investigator administered a standardized interview to collect sociodemographic and clinical data, and body weight history (weight at menarche, at marriage, at first and last pregnancy, and at menopause). Current anthropometric measurements were also made. Fifty-seven women with cancer (66.7% postmenopausal) and 159 controls were included. Current age (60.3 ± 10.4 vs. 55.8 ± 8.4 years, P < .01), marital status (49.1% vs. 64.8% with a partner, P = .03), and physical activity (48.2% vs. 32.3% sedentary, P = .01) were significantly different between cases and controls, respectively. Odds ratio showed that age and current waist circumference were associated with postmenopausal cancer. No difference was found in relation to body weight at different stages of life. Women with social vulnerability recruited at a mammography screening program in Southern Brazil showed a large weight gain during life, but no significant differences were found in body weight between women with or without breast cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

Nest Site Characteristics of Cavity Nesting Birds in Central Missouri

Treesearch

Jeffery D. Brawn; Bernice Tannenbaum; Keith E. Evans

1984-01-01

Two study sites in central Missouri oak-hickory forests were searched for nest sites of cavity nesting birds. Researchers located and measured 133 nests of 11 species. Cavity nesting bird habitat selection is affected by both snag characteristics and vegetation structure.

Circulating 25-Hydroxyvitamin D and Risk of Pancreatic Cancer

PubMed Central

Stolzenberg-Solomon, Rachael Z.; Jacobs, Eric J.; Arslan, Alan A.; Qi, Dai; Patel, Alpa V.; Helzlsouer, Kathy J.; Weinstein, Stephanie J.; McCullough, Marjorie L.; Purdue, Mark P.; Shu, Xiao-Ou; Snyder, Kirk; Virtamo, Jarmo; Wilkins, Lynn R.; Yu, Kai; Zeleniuch-Jacquotte, Anne; Zheng, Wei; Albanes, Demetrius; Cai, Qiuyin; Harvey, Chinonye; Hayes, Richard; Clipp, Sandra; Horst, Ronald L.; Irish, Lonn; Koenig, Karen; Le Marchand, Loic; Kolonel, Laurence N.

2010-01-01

Results from epidemiologic studies examining pancreatic cancer risk and vitamin D intake or 25-hydroxyvitamin D (25(OH)D) concentrations (the best indicator of vitamin D derived from diet and sun) have been inconsistent. Therefore, the authors conducted a pooled nested case-control study of participants from 8 cohorts within the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP) (1974–2006) to evaluate whether prediagnostic circulating 25(OH)D concentrations were associated with the development of pancreatic cancer. In total, 952 incident pancreatic adenocarcinoma cases occurred among participants (median follow-up, 6.5 years). Controls (n = 1,333) were matched to each case by cohort, age, sex, race/ethnicity, date of blood draw, and follow-up time. Conditional logistic regression analysis was used to calculate smoking-, body mass index-, and diabetes-adjusted odds ratios and 95% confidence intervals for pancreatic cancer. Clinically relevant 25(OH)D cutpoints were compared with a referent category of 50–<75 nmol/L. No significant associations were observed for participants with lower 25(OH)D status. However, a high 25(OH)D concentration (≥100 nmol/L) was associated with a statistically significant 2-fold increase in pancreatic cancer risk overall (odds ratio = 2.12, 95% confidence interval: 1.23, 3.64). Given this result, recommendations to increase vitamin D concentrations in healthy persons for the prevention of cancer should be carefully considered. PMID:20562185

Prevalence and early determinants of common mental disorders in the 1982 birth cohort, Pelotas, Southern Brazil

PubMed Central

Anselmi, Luciana; Barros, Fernando C; Minten, Gicele C; Gigante, Denise P; Horta, Bernardo L; Victora, Cesar G

2009-01-01

OBJECTIVE To estimate the prevalence of common mental disorders and assess its association with risk factors in a cohort of young adults. METHODS Cross-sectional study nested in a 1982 birth cohort study conducted in Pelotas, Southern Brazil. In 2004-5, 4,297 subjects were interviewed during home visits. Common mental disorders were assessed using the Self-Report Questionnaire. Risk factors included socioeconomic, demographic, perinatal, and environmental variables. The analysis was stratified by gender and crude and adjusted prevalence ratios were estimated by Poisson regression. RESULTS The overall prevalence of common mental disorders was 28.0%; 32.8% and 23.5% in women and men, respectively. Men and women who were poor in 2004-5, regardless of their poor status in 1982, had nearly 1.5-fold increased risk for common mental disorders (p≤0.001) when compared to those who have never been poor. Among women, being poor during childhood (p≤0.001) and black/mixed skin color (p=0.002) increased the risk for mental disorders. Low birth weight and duration of breastfeeding were not associated to the risk of these disorders. CONCLUSIONS Higher prevalence of common mental disorders among low-income groups and race-ethnic minorities suggests that social inequalities present at birth have a major impact on mental health, especially common mental disorders. PMID:19142342

Maternal Depression Increases Childhood Dental Caries: A Cohort Study in Brazil.

PubMed

Dos Santos Pinto, Gabriela; de Ávila Quevedo, Luciana; Britto Correa, Marcos; Sousa Azevedo, Marina; Leão Goettems, Marília; Tavares Pinheiro, Ricardo; Demarco, Flávio Fernando

2017-01-01

To investigate the relationship between maternal depression and childhood caries in a cohort of adolescent mothers. This cross-sectional study nested in a cohort evaluated a sample of 538 mother/child dyads. When the children were 24-36 months of age, data regarding oral health from children and mothers were collected by clinical dental examination. A mother's major depressive disorder was assessed by using the Mini International Neuropsychiatric Interview (MINI [Plus]), at the current moment. Independent variables were obtained by using questionnaires. The outcome on dental caries experience was dichotomized by using 2 cut points: dmfs ≥1 and dmfs ≥3. Poisson regression analysis, using a hierarchical approach, was applied to assess the association between major depressive disorder in mothers with and those without caries experience and the outcome. The prevalence of dental caries in children was 15.1% (n = 82). The mean dmfs index was 1.12 (SD = 3.72). The prevalence of major depressive disorder was 32.6% (n = 168). An interaction between caries status and depressive disorder was found, and after adjusted analysis, children from mothers with major depressive disorder with negative caries experience presented a higher caries prevalence (prevalence ratio 4.00, 95% confidence interval 1.29-12.41). Our findings suggest that maternal psychiatric disorders could have a negative impact on children's oral health. © 2016 S. Karger AG, Basel.

Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil.

PubMed

Matos, Sheila M A; Jesus, Sandra R; Saldiva, Silvia R D M; Prado, Matildes S; D'Innocenzo, Silvana; Assis, Ana M O; Rodrigues, Laura C; Alcantara-Neves, Neuza M; Cruz, Álvaro A; Simões, Silvia de Magalhães; Barreto, Maurício L

2011-07-01

To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005. Cross-sectional study nested in a cohort. The metropolitan region of Salvador, Bahia, Brazil. The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. Poisson's multivariate regression was adopted. Wheezing was found in 29·1% and asthma in 22·8% of children, both conditions being more common in those under 6 years of age and 34% more common in overweight children (prevalence ratio (PR) = 1·34; 95% CI 1·07, 1·67) following adjustment. The ratio between forced expiratory volume in 1s and forced vital capacity was associated with overweight (PR = 1·35; 95% CI 1·11, 1·61). No statistically significant association was found between overweight and allergen-specific IgE or with wheezing. These results are in agreement with the hypothesis that overweight is associated with asthma and pulmonary function, even following adjustment for intervening variables known to be associated with the pathogeny of asthma.

Impact of Trichiasis Surgery on Physical Functioning in Ethiopian Patients: STAR Trial

PubMed Central

Wolle, Meraf A.; Cassard, Sandra D.; Gower, Emily W.; Munoz, Beatriz E.; Wang, Jiangxia; Alemayehu, Wondu; West, Sheila K.

2010-01-01

Purpose To evaluate the physical functioning of Ethiopian trichiasis surgery patients before and six months after surgery. Design Nested Cohort Study Methods This study was nested within the Surgery for Trichiasis, Antibiotics to Prevent Recurrence (STAR) clinical trial conducted in Ethiopia. Demographic information, ocular examinations, and physical functioning assessments were collected before and 6 months after surgery. A single score for patients’ physical functioning was constructed using Rasch analysis. A multivariate linear regression model was used to determine if change in physical functioning was associated with change in visual acuity. Results Of the 438 participants, 411 (93.8%) had both baseline and follow-up questionnaires. Physical functioning scores at baseline ranged from −6.32 (great difficulty) to +6.01 (no difficulty). The percent of participants reporting no difficulty in physical functioning increased by 32.6%; the proportion of participants in the mild/no visual impairment category increased by 8.6%. A multivariate linear regression model showed that for every line of vision gained, physical functioning improves significantly (0.09 units; 95% CI: 0.02–0.16). Conclusions Surgery to correct trichiasis appears to improve patients’ physical functioning as measured at 6 months. More effort in promoting trichiasis surgery is essential, not only to prevent corneal blindness, but also to enable improved functioning in daily life. PMID:21333268

Incidence of hypoglycaemia associated with transient loss of consciousness. A retrospective cohort study.

PubMed

Lagi, A; Cencetti, S; Lagi, F

2014-08-01

To define the incidence of hypoglycaemia associated with transient loss of consciousness (TLoC). Retrospective cohort study using a nested case-control analysis. Presentations to the emergency departments (EDs) of four general metropolitan hospitals in Azienda Sanitaria 10, Florence, Italy during 2012. The cohort consisted of 133,285 patients extracted from the database of ED presentations. All patients with TLoC were identified by nurse triage, and their levels of glycaemia were recorded. Clinical investigations were undertaken using patients' charts and witness statements. Patients were matched with controls according to year of birth, year of cohort entry and gender. Of the 133,285 patients, 3964 (2.9%) presented with TLoC, and 39 (1%) of the patients with TLoC had transient hypoglycaemia. Mean glycaemia in these 39 patients was 52 mg/dl (a level of 112 mg/dl was in controls). Symptoms associated with TLoC during hypoglycaemia differed from those characteristic of syncope. TLoC during hypoglycaemia mainly occurred in elderly patients with diabetes, who had relatively long disease duration, were receiving treatment, often also had renal failure and were experiencing symptoms as a result of lack of food intake. Together, these factors make it easier to diagnose hypoglycaemia associated with TLoC, and our results may prompt modification in medical practice. Correct diagnosis of hypoglycaemia associated with TLoC has economic benefits if a protracted and costly series of clinical investigations can be avoided. A diagnosis of hypoglycaemia might also facilitate the resolution of patients' symptoms through lifestyle changes and adjustment of therapy. © 2014 John Wiley & Sons Ltd.

Circulating 25-Hydroxyvitamin D and Risk of Kidney Cancer

PubMed Central

Gallicchio, Lisa; Moore, Lee E.; Stevens, Victoria L.; Ahn, Jiyoung; Albanes, Demetrius; Hartmuller, Virginia; Setiawan, V. Wendy; Helzlsouer, Kathy J.; Yang, Gong; Xiang, Yong-Bing; Shu, Xiao-Ou; Snyder, Kirk; Weinstein, Stephanie J.; Yu, Kai; Zeleniuch-Jacquotte, Anne; Zheng, Wei; Cai, Qiuyin; Campbell, David S.; Chen, Yu; Chow, Wong-Ho; Horst, Ronald L.; Kolonel, Laurence N.; McCullough, Marjorie L.; Purdue, Mark P.; Koenig, Karen L.

2010-01-01

Although the kidney is a major organ for vitamin D metabolism, activity, and calcium-related homeostasis, little is known about whether this nutrient plays a role in the development or the inhibition of kidney cancer. To address this gap in knowledge, the authors examined the association between circulating 25-hydroxyvitamin D (25(OH)D) and kidney cancer within a large, nested case-control study developed as part of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. Concentrations of 25(OH)D were measured from 775 kidney cancer cases and 775 age-, sex-, race-, and season-matched controls from 8 prospective cohort studies. Overall, neither low nor high concentrations of circulating 25(OH)D were significantly associated with kidney cancer risk. Although the data showed a statistically significant decreased risk for females (odds ratio = 0.31, 95% confidence interval: 0.12, 0.85) with 25(OH)D concentrations of ≥75 nmol/L, the linear trend was not statistically significant and the number of cases in this category was small (n = 14). The findings from this consortium-based study do not support the hypothesis that vitamin D is inversely associated with the risk of kidney cancer overall or with renal cell carcinoma specifically. PMID:20562187

[Risk factors for students desertion from the UASLP School of Medicine, México].

PubMed

Hernández-Mata, José María; Hernández-Castro, Rodrigo; Nieto-Caraveo, Amado; Hernández-Sierra, Juan Francisco

2005-01-01

To obtain the profile of students that deserted from the Faculty of Medicine of the Autonomous University of San Luis Potosi, México. Cases and controls nested in a cohort. All students that voluntarily deserted between 1992 and 2002 were consulted. Each student was compared in an aleatory form with a regular student and a proper questionnaire was applied. The significantly associated factors to abandon the Faculty of Medicine were: high school of origin (OR=2.43), extra-ordinary exam (OR=3.13), and lack of vocation (OR=2.41). The subjacent factors for not deserting from the Faculty of Medicine were: study habits, capacity for sustained effort, and tolerance to frustration.

From neurons to nests: nest-building behaviour as a model in behavioural and comparative neuroscience.

PubMed

Hall, Zachary J; Meddle, Simone L; Healy, Susan D

Despite centuries of observing the nest building of most extant bird species, we know surprisingly little about how birds build nests and, specifically, how the avian brain controls nest building. Here, we argue that nest building in birds may be a useful model behaviour in which to study how the brain controls behaviour. Specifically, we argue that nest building as a behavioural model provides a unique opportunity to study not only the mechanisms through which the brain controls behaviour within individuals of a single species but also how evolution may have shaped the brain to produce interspecific variation in nest-building behaviour. In this review, we outline the questions in both behavioural and comparative neuroscience that nest building could be used to address, summarize recent findings regarding the neurobiology of nest building in lab-reared zebra finches and across species building different nest structures, and suggest some future directions for the neurobiology of nest building.

Nest habitat use of Rio Grande wild turkeys

USGS Publications Warehouse

Schmutz, Joel A.; Braun, Clait E.; Andelt, William F.

1989-01-01

Nest habitat use of Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) was studied along the South Platte River in northeast Colorado in 1986-87. Thirty-three of 35 nests were in riparian habitats. Nests were either in western snowberry (Symphoricarpos occidentalis) (67%) or mixed forbs and grasses (33%). Early season nests were more likely to be in snowberry than late season nests. Nest sites were characterized by greater overstory canopy cover, more shrubs, fewer grasses, and greater understory cover and height than surrounding areas. These areas had more shrubs, fewer large trees, and greater understory cover and height than riparian habitats throughout the study area. Phenology of understory vegetation and the effect of such vegetation on nest predation may influence temporal patterns of nest habitat use.

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

PubMed Central

Tomasek, Ladislav

2013-01-01

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. PMID:23470882

Aspergillus fumigatus and other thermophilic fungi in nests of wetland birds.

PubMed

Korniłłowicz-Kowalska, Teresa; Kitowski, Ignacy

2013-02-01

A study was performed on the numbers and species diversity of thermophilic fungi (growing at 45 °C in vitro) in 38 nests of 9 species of wetland birds, taking into account the physicochemical properties of the nests and the bird species. It was found that in nests with the maximum weight (nests of Mute Swan), the number and diversity of thermophilic fungi were significantly greater than in other nests, with lower weight. The diversity of the thermophilic biota was positively correlated with the individual mass of bird and with the level of phosphorus in the nests. The dominant species within the mycobiota under study was Aspergillus fumigatus which inhabited 95% of the nests under study, with average frequency of ca. 650 cfu g(-1) of dry mass of the nest material. In a majority of the nests studied (nests of 7 bird species), the share of A. fumigatus exceeded 50% of the total fungi growing at 45 °C. Significantly higher frequencies of the fungal species were characteristic of the nests of small and medium-sized piscivorous species, compared with the other bird species. The number of A. fumigatus increased with increase in the moisture level of the nests, whereas the frequency of occurrence of that opportunistic pathogen, opposite to the general frequency of thermophilic mycobiota, was negatively correlated with the level of phosphorus in the nest material, and with the body mass and length of the birds. The authors indicate the causes of varied growth of thermophilic fungi in nests of wetland birds and, in particular, present a discussion of the causes of accumulation of A. fumigatus, the related threats to the birds, and its role as a source of transmission in the epidemiological chain of aspergillosis.

Cerulean warbler reproduction, survival, and models of population decline

Treesearch

David A. Buehler; James J. Giocomo; Jason Jones; Paul B. Hamel; Christopher M. Rogers; Tiffany A. Beachy; Dustin W. Varble; Charles P. Nicholson; Kirk L. Roth; JEnnifer Barg; Raleigh J. Robertson; Joseph R. Robb; Kamal Islam

2008-01-01

We present and compare demographic data for cerulean warblers (Dendroica cerulea) from 5 study sites across the range of the species from 1992 to 2006. We conducted field studies to collect data on daily nest survival, nest success, and young fledged per successful nest, and we used data to estimate fecundity. Daily nest survival, nest success, young...

Air Pollution and Pulmonary Tuberculosis: A Nested Case–Control Study among Members of a Northern California Health Plan

PubMed Central

Smith, Geneé S.; Van Den Eeden, Stephen K.; Garcia, Cynthia; Shan, Jun; Baxter, Roger; Herring, Amy H.; Richardson, David B.; Van Rie, Annelies; Emch, Michael; Gammon, Marilie D.

2016-01-01

Background: Ecologic analyses, case–case comparisons, and animal experiments suggest positive associations between air pollution and tuberculosis. Objectives: We evaluated this hypothesis in a large sample, which yielded results that are applicable to the general population. Methods: We conducted a case–control study nested within a cohort of Kaiser Permanente of Northern California members. All active pulmonary tuberculosis (TB) cases newly diagnosed between 1996 and 2010 (n = 2,309) were matched to two controls (n = 4,604) by age, sex, and race/ethnicity on the index date corresponding with the case diagnosis date. Average individual-level concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) and 10 μm (PM10) for 2 years before diagnosis/entry into the study were estimated using measurements from the California Air Resources Board monitor closest to the participant’s residence. Results: In single-pollutant adjusted conditional logistic regression models, the pulmonary TB odds ratios (95% confidence intervals) for the highest quintile (vs. lowest) were 1.50 (95% CI: 1.15, 1.95) for CO and 1.42 (95% CI: 1.10, 1.84) for NO2. Corresponding estimates were higher among never [1.68 (95% CI: 1.26, 2.24)] than ever [1.19 (95% CI: 0.74, 1.92)] smokers for CO. In contrast, for NO2, estimates were higher among ever [1.81 (95% CI: 1.13, 2.91)] than never [1.29 (95% CI: 0.97, 1.71)] smokers. O3 was inversely associated for smokers [0.66 (95% CI: 0.43, 1.02)] and never smokers [0.65 (95% CI: 0.52, 0.81)]. No other consistent patterns were observed. Conclusions: In this first, to our knowledge, U.S. nested case–control study on air pollution and pulmonary TB, we observed positive associations with ambient CO and NO2, which require confirmation. Citation: Smith GS, Van Den Eeden SK, Garcia C, Shan J, Baxter R, Herring AH, Richardson DB, Van Rie A, Emch M, Gammon MD. 2016. Air pollution and pulmonary tuberculosis: a nested case-control study among members of a Northern California health plan. Environ Health Perspect 124:761–768; http://dx.doi.org/10.1289/ehp.1408166 PMID:26859438

Air Pollution and Pulmonary Tuberculosis: A Nested Case-Control Study among Members of a Northern California Health Plan.

PubMed

Smith, Geneé S; Van Den Eeden, Stephen K; Garcia, Cynthia; Shan, Jun; Baxter, Roger; Herring, Amy H; Richardson, David B; Van Rie, Annelies; Emch, Michael; Gammon, Marilie D

2016-06-01

Ecologic analyses, case-case comparisons, and animal experiments suggest positive associations between air pollution and tuberculosis. We evaluated this hypothesis in a large sample, which yielded results that are applicable to the general population. We conducted a case-control study nested within a cohort of Kaiser Permanente of Northern California members. All active pulmonary tuberculosis (TB) cases newly diagnosed between 1996 and 2010 (n = 2,309) were matched to two controls (n = 4,604) by age, sex, and race/ethnicity on the index date corresponding with the case diagnosis date. Average individual-level concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) and 10 μm (PM10) for 2 years before diagnosis/entry into the study were estimated using measurements from the California Air Resources Board monitor closest to the participant's residence. In single-pollutant adjusted conditional logistic regression models, the pulmonary TB odds ratios (95% confidence intervals) for the highest quintile (vs. lowest) were 1.50 (95% CI: 1.15, 1.95) for CO and 1.42 (95% CI: 1.10, 1.84) for NO2. Corresponding estimates were higher among never [1.68 (95% CI: 1.26, 2.24)] than ever [1.19 (95% CI: 0.74, 1.92)] smokers for CO. In contrast, for NO2, estimates were higher among ever [1.81 (95% CI: 1.13, 2.91)] than never [1.29 (95% CI: 0.97, 1.71)] smokers. O3 was inversely associated for smokers [0.66 (95% CI: 0.43, 1.02)] and never smokers [0.65 (95% CI: 0.52, 0.81)]. No other consistent patterns were observed. In this first, to our knowledge, U.S. nested case-control study on air pollution and pulmonary TB, we observed positive associations with ambient CO and NO2, which require confirmation. Smith GS, Van Den Eeden SK, Garcia C, Shan J, Baxter R, Herring AH, Richardson DB, Van Rie A, Emch M, Gammon MD. 2016. Air pollution and pulmonary tuberculosis: a nested case-control study among members of a Northern California health plan. Environ Health Perspect 124:761-768; http://dx.doi.org/10.1289/ehp.1408166.

Endogenous estrogens and breast cancer risk: the case for prospective cohort studies.

PubMed Central

Toniolo, P G

1997-01-01

It is generally agreed that estrogens, and possibly androgens, are important in the etiology of breast cancer, but no consensus exists as to the precise estrogenic or androgenic environment that characterizes risk, or the exogenous factors that influence the hormonal milieu. Nearly all the epidemiological studies conducted in the 1970s and 1980s were hospital-based case-control studies in which specimen sampling was performed well after the clinical appearance of the disease. Early prospective cohort studies also had limitations in their small sample sizes or short follow-up periods. However, more recent case-control studies nested within large cohorts, such as the New York University Women's Health Study and the Ormoni e Dieta nell'Eziologia dei Tumori study in Italy, are generating new data indicating that increased levels of estrone, estradiol and bioavailable estradiol, as well as their androgenic precursors, may be associated with a 4- to 6-fold increase in the risk of postmenopausal breast cancer. Further new evidence, which complements and expands the observations from the latter studies, shows that women with the thickest bone density, which may be a surrogate for cumulated exposure to hormones, experience severalfold increased risk of subsequent breast cancer as compared to women with thin bones. These data suggests that endogenous sex hormones are a key factor in the etiology of postmenopausal breast cancer. New prospective cohort studies should be conducted to examine the role of endogenous sex hormones in blood and urine samples obtained early in the natural history of breast cancer jointly with an assessment of bone density and of other important risk factors, such as mammographic density, physical activity, body weight, and markers of individual susceptibility, which may confer increased risk through an effect on the metabolism of endogenous hormones or through specific metabolic responses to Western lifestyle and diet. PMID:9168000

Influence of Nest Box Color and Release Sites on Osmia lignaria (Hymenoptera: Megachilidae) Reproductive Success in a Commercial Almond Orchard.

PubMed

Artz, Derek R; Allan, Matthew J; Wardell, Gordon I; Pitts-Singer, Theresa L

2014-12-01

Intensively managed, commercial orchards offer resources for managed solitary bees within agricultural landscapes and provide a means to study bee dispersal patterns, spatial movement, nest establishment, and reproduction. In 2012, we studied the impact of 1) the color of nest boxes covaried with four nest box density treatments and 2) the number of bee release sites covaried with two nest box density treatments on the reproductive success of Osmia lignaria Say in a California almond orchard pollinated by a mixture of O. lignaria and Apis mellifera L. Nest box color influenced the number of nests, total cells, and cells with male and female brood. More nests and cells were produced in light blue nest boxes than in orange or yellow nest boxes. The covariate nest box density also had a significant effect on brood production. The number of release sites did not affect O. lignaria nesting and reproduction, but the number of cavities in nest boxes influenced reproduction. Overall, the color of nest boxes and their distribution, but not the number of release sites, can greatly affect O. lignaria nest establishment and reproductive success in a commercial almond orchard. The ability to locate nesting sites in a homogenous, large orchard landscape may also be facilitated by the higher frequency of nest boxes with low numbers of cavities, and by the ability to detect certain nest box colors that best contrast with the blooming trees. © 2014 Entomological Society of America.

The effect of canopy closure on chimpanzee nest abundance in Lagoas de Cufada National Park, Guinea-Bissau.

PubMed

Sousa, Joana; Casanova, Catarina; Barata, André V; Sousa, Cláudia

2014-04-01

The present study aimed to gather baseline information about chimpanzee nesting and density in Lagoas de Cufada Natural Park (LCNP), in Guinea-Bissau. Old and narrow trails were followed to estimate chimpanzee density through marked-nest counts and to test the effect of canopy closure (woodland savannah, forest with a sparse canopy, and forest with a dense canopy) on nest distribution. Chimpanzee abundance was estimated at 0.79 nest builders/km(2), the lowest among the areas of Guinea-Bissau with currently studied chimpanzee populations. Our data suggest that sub-humid forest with a dense canopy accounts for significantly higher chimpanzee nest abundance (1.50 nests/km of trail) than sub-humid forest with a sparse canopy (0.49 nests/km of trail) or woodland savannah (0.30 nests/km of trail). Dense-canopy forests play an important role in chimpanzee nesting in the patchy and highly humanized landscape of LCNP. The tree species most frequently used for nesting are Dialium guineense (46%) and Elaeis guineensis (28%). E. guineensis contain nests built higher in the canopy, while D. guineense contain nests built at lower heights. Nests observed during baseline sampling and replications suggest seasonal variations in the tree species used for nest building.

Interaction in Balanced Cross Nested Designs

NASA Astrophysics Data System (ADS)

Ramos, Paulo; Mexia, João T.; Carvalho, Francisco; Covas, Ricardo

2011-09-01

Commutative Jordan Algebras, CJA, are used in the study of mixed models obtained, through crossing and nesting, from simpler ones. In the study of cross nested models the interaction between nested factors have been systematically discarded. However this can constitutes an artificial simplification of the models. We point out that, when two crossed factors interact, such interaction is symmetric, both factors playing in it equivalent roles, while when two nested factors interact, the interaction is determined by the nesting factor. These interactions will be called interactions with nesting. In this work we present a coherent formulation of the algebraic structure of models enabling the choice of families of interactions between cross and nested factors using binary operations on CJA.

Barrett's Esophagus Methylation Profiles — EDRN Public Portal

Cancer.gov

We propose a nested case-control study of biomarkers in the setting of BE. By bringing together research institutions with large populations of patients with BE, we will perform a multi-center study of FISH and hypermethylation markers as possible prognostic factors in BE. The centers will select from their cohorts who have progressed to HGD or to adenocarcinoma of the esophagus ("progressors"), and who also donated samples prior to the development of cancer, when their histology was felt to be benign. These subjects will be compared to individuals who have been under endoscopic surveillance, but who have not progressed to HGD or EAC ("non-progressors"). Using this approach, we hope to identify promising markers for risk stratification in BE. We expect to be able to make successful application for a prospective study of markers identified in this case-control study.

Avian nest success in midwestern forests fragmented by agriculture

USGS Publications Warehouse

Knutson, M.G.; Friberg, M.A.; Niemi, G.J.; Newton, W.E.

2004-01-01

Knutson et al. (2004) report the results of an avian nest success study conducted to investigate how forest-bird nest success varied by nest location and type as well as by landscape context from 1996 to 1998 in an agricultural region of southwestern Minnesota, and southwestern Wisconsin, and northeastern Iowa. The authors found an overall Mayfield adjusted nest success of 48%, 82% for cavity-nesting species, and 42% for cup-nesting species. Common species varied from 23% for American Redstart (Setophaga ruticilla) to 43% for the Eastern Wood-Pewee (Contopus virens). Nest success was lowest for open-cup nesters, species that reject Brown-headed Cowbird (Molothrus ater) eggs, species that next near forest edges, and Neotropical migrants. These tendencies were consistent across the years of the study. Assessments of nest success considering surrounding landscape metrics indicated that forest area may not be a strong indicator of nest success in landscapes where all the available forests are fragmented.

Survival and breeding advantages of larger Black Brant (Branta bernicla nigricans) goslings: Within- and among-cohort variation

USGS Publications Warehouse

Sedinger, J.S.; Chelgren, N.D.

2007-01-01

We examined the relationship between mass late in the first summer and survival and return to the natal breeding colony for 12 cohorts (1986-1997) of female Black Brant (Branta bernicla nigricans). We used Cormack-Jolly-Seber methods and the program MARK to analyze capture-recapture data. Models included two kinds of residuals from regressions of mass on days after peak of hatch when goslings were measured; one based on the entire sample (12 cohorts) and the other based only on individuals in the same cohort. Some models contained date of peak of hatch (a group covariate related to lateness of nesting in that year) and mean cohort residual mass. Finally, models allowed survival to vary among cohorts. The best model of encounter probability included an effect of residual mass on encounter probability and allowed encounter probability to vary among age classes and across years. All competitive models contained an effect of one of the estimates of residual mass; relatively larger goslings survived their first year at higher rates. Goslings in cohorts from later years in the analysis tended to have lower first-year survival, after controlling for residual mass, which reflected the generally smaller mean masses for these cohorts but was potentially also a result of population-density effects additional to those on growth. Variation among cohorts in mean mass accounted for 56% of variation among cohorts in first-year survival. Encounter probabilities, which were correlated with breeding probability, increased with relative mass, which suggests that larger goslings not only survived at higher rates but also bred at higher rates. Although our findings support the well-established linkage between gosling mass and fitness, they suggest that additional environmental factors also influence first-year survival.

Male Eastern Screech-owl (Otus asio) roosting behavior: possible effects from nesting stage and nest type

Treesearch

Thomas McK. Sproat

1997-01-01

This study examined the diurnal roosting behavior of male Eastern Screech-owls (Otus asio) and proposed some possible functions for this behavior. As part of a nest defense study, male diurnal roost locations were marked and, later, the distance to the corresponding nest was measured. Male screech-owls roosted significantly closer to their nests...

Effects of invasive woody plants on avian nest site selection and nesting success in shrublands

Treesearch

S. Schlossberg; D.I. King

2010-01-01

Exotic, invasive plants are a growing conservation problem. Birds frequently use invasive plants as nest substrates, but effects of invasives on avian nesting success have been equivocal in past studies. In 2004 and 2005, we assessed effects of invasive woody plants on avian nest-site selection and nesting success in western Massachusetts shrublands. At the nest scale...

Differential effects of coyotes and red foxes on duck nest success

USGS Publications Warehouse

Sovada, Marsha A.; Sargeant, A.; Grier, J.W.

1995-01-01

Low recruitment rates prevail among ducks in the Prairie Pothole Region of North America, primarily because of high nest depredation rates. The red fox (Vulpes vulpes) is a major predator of duck eggs, but fox abundance is depressed by coyotes (Canis latrans). We tested the hypothesis that nest success of upland-nesting ducks is higher in areas with coyotes than in areas with red foxes. We conducted the study during 1990-92 in uplands of 36 areas managed for nesting ducks in North Dakota and South Dakota. Overall nest success averaged 32% (95% CI = 25-40) on 17 study areas where coyotes were the principal canid and 17% (CI = 11-25) on 13 study areas where red foxes were the principal canid (P = 0.01). Both canids were common on 6 other areas, where nest success averaged 25% (CI = 13-47). Habitat composition, predator communities with the exception of canids, and species composition of duck nests in coyote and red fox areas were similar overall. Upon examining only nests with greater than or equal to 6 eggs on the last visit prior to hatch or depredation, we determined nests with evidence characteristic of fox predation accounted for 4% of depredated nests in coyote areas and 27% in fox areas (P = 0.001). An expanding coyote population is contributing to higher overall nest success. Management of coyotes may be an effective method for increasing duck nest success.

Nest size is predicted by female identity and the local environment in the blue tit (Cyanistes caeruleus), but is not related to the nest size of the genetic or foster mother

PubMed Central

Parker, Timothy H.; Griffith, Simon C.

2018-01-01

The potential for animals to respond to changing climates has sparked interest in intraspecific variation in avian nest structure since this may influence nest microclimate and protect eggs and offspring from inclement weather. However, there have been relatively few large-scale attempts to examine variation in nests or the determinates of individual variation in nest structure within populations. Using a set of mostly pre-registered analyses, we studied potential predictors of variation in the size of a large sample (803) of blue tit (Cyanistes caeruleus) nests across three breeding seasons at Wytham Woods, UK. While our pre-registered analyses found that individual females built very similar nests across years, there was no evidence in follow-up (post hoc) analyses that their nest size correlated to that of their genetic mother or, in a cross-fostering experiment, to the nest where they were reared. In further pre-registered analyses, spatial environmental variability explained nest size variability at relatively broad spatial scales, and especially strongly at the scale of individual nest boxes. Our study indicates that nest structure is a characteristic of individuals, but is not strongly heritable, indicating that it will not respond rapidly to selection. Explaining the within-individual and within-location repeatability we observed requires further study. PMID:29765658

Estimating raptor nesting success: old and new approaches

USGS Publications Warehouse

Brown, Jessi L.; Steenhof, Karen; Kochert, Michael N.; Bond, Laura

2013-01-01

Studies of nesting success can be valuable in assessing the status of raptor populations, but differing monitoring protocols can present unique challenges when comparing populations of different species across time or geographic areas. We used large datasets from long-term studies of 3 raptor species to compare estimates of apparent nest success (ANS, the ratio of successful to total number of nesting attempts), Mayfield nesting success, and the logistic-exposure model of nest survival. Golden eagles (Aquila chrysaetos), prairie falcons (Falco mexicanus), and American kestrels (F. sparverius) differ in their breeding biology and the methods often used to monitor their reproduction. Mayfield and logistic-exposure models generated similar estimates of nesting success with similar levels of precision. Apparent nest success overestimated nesting success and was particularly sensitive to inclusion of nesting attempts discovered late in the nesting season. Thus, the ANS estimator is inappropriate when exact point estimates are required, especially when most raptor pairs cannot be located before or soon after laying eggs. However, ANS may be sufficient to assess long-term trends of species in which nesting attempts are highly detectable.

Nest visits and capture events affect breeding success of Yellow-billed and Pacific loons

USGS Publications Warehouse

Uher-Koch, Brian D.; Schmutz, Joel A.; Wright, Kenneth G.

2015-01-01

Accurate estimates of breeding success are essential for understanding population dynamics and for managing populations. Unfortunately, research activities to collect these data can negatively impact the breeding success of the study species and bias estimates of breeding success. Despite the potential for negative impacts, few studies have documented the effect of capturing incubating adults on nest survival or compared nest survival following different capture methods. In this study we evaluate the impacts of investigator disturbance associated with captures and nest visits on nest survival of Yellow-billed Loons (Gavia adamsii) and Pacific Loons (Gavia pacifica) in the National Petroleum Reserve-Alaska (NPR-A), an area of conservation concern, in 2011–2013. In an effort to reduce capture-related nest failures, we developed a new suspended dive net technique to catch territorial aquatic birds while off their nests. We then compared nest survival following suspended dive net captures to bow-net trap captures of breeding adult loons. Daily nest survival following bow-net trap or suspended dive net capture was about 30% lower than when adults were not captured. The effect of captures on nest survival was similar between bow-net trap and suspended dive net capture methods. Nest visits without captures also negatively impacted nest survival, although less than captures. If not accounted for, nest visitation biased daily survival rates of nests downward 6%. Effects of investigator disturbance did not differ by species or between years. Our results suggest that any source of disturbance that displaces incubating adult loons could potentially reduce nest survival. To maximize breeding success, human disturbance factors should be limited near loon nests.

Uncertain Associations of Major Bleeding and Concurrent Use of Antiplatelet Agents and Chinese Medications: A Nested Case-Crossover Study

PubMed Central

Yam, Felix K.

2017-01-01

Despite the evidence that some commonly used Chinese medications (CMs) have antiplatelet/anticoagulant effects, many patients still used antiplatelets combined with CMs. We conducted a nested case-crossover study to examine the associations between the concomitant use of antiplatelets and CMs and major bleeding using population-based health database in Taiwan. Among the cohort of 79,463 outpatients prescribed antiplatelets (e.g., aspirin and clopidogrel) continuously, 1,209 patients hospitalized with new occurring bleeding in 2012 and 2013 were included. Those recruited patients served as their own controls to compare different times of exposure to prespecified CMs (e.g., Asian ginseng and dong quai) and antiplatelet agents. The periods of case, control 1, and control 2 were defined as 1–4 weeks, 6–9 weeks, and 13–16 weeks before hospitalization, respectively. Conditional logistic regression analyses found that concurrent use of antiplatelet drugs with any of the prespecified CMs in the case period might not significantly increase the risks of bleeding over that in the control periods (OR = 1.00, 95% CI 0.51 to 1.95 and OR = 1.13, 95% CI 0.65 to 1.97). The study showed no strong relationships between hospitalization for major bleeding events and concurrent use of antiplatelet drugs with the prespecified CMs. PMID:28831288

Risk of Extrapyramidal Adverse Events With Aripiprazole.

PubMed

Etminan, Mahyar; Procyshyn, Ric M; Samii, Ali; Carleton, Bruce C

2016-10-01

Aripiprazole is a unique atypical antipsychotic with partial agonist activity on the dopamine-2 (D2) receptor. This unique pharmacological profile of aripiprazole was thought to lead to a lower incidence of extrapyramidal symptoms (EPSs). However, recent case reports have alluded to an increase in the risk of EPS in aripiprazole users compared with nonusers of the drug. No epidemiologic studies to date have quantified this risk. We conducted a pharmacoepidemiologic study composed of a nested case-control study using a large health claims database (IMS Health) in the United States. In the nested case-control analysis, there were 5242 cases of EPS with 50,532 corresponding controls in the entire cohort. The odds ratio (OR) for EPS among those with any prescription of aripiprazole was 5.38 (95% confidence interval [CI], 3.03-9.57). The OR was lower among those taking 2 to 3 prescriptions (OR, 2.9; 95% CI, 1.07-7.85) but increased in those receiving greater than 4 prescriptions (OR, 8.64; 95% CI, 2.63-28.38). All risk periods were compared with those of subjects who had not used aripiprazole or other antipsychotics. For the secondary outcome of dyskinesia, the risk for aripiprazole was 8.50 (95% CI, 8.53-2.27-31.97) compared with that of nonusers. In conclusion, we found an increase in the risk of EPS and dyskinesias among users of aripiprazole.

Daily Intake of Milk Powder and Risk of Celiac Disease in Early Childhood: A Nested Case-Control Study.

PubMed

Hård Af Segerstad, Elin M; Lee, Hye-Seung; Andrén Aronsson, Carin; Yang, Jimin; Uusitalo, Ulla; Sjöholm, Ingegerd; Rayner, Marilyn; Kurppa, Kalle; Virtanen, Suvi M; Norris, Jill M; Agardh, Daniel

2018-04-28

Milk powder and gluten are common components in Swedish infants' diets. Whereas large intakes of gluten early in life increases the risk of celiac disease in genetically at-risk Swedish children, no study has yet evaluated if intake of milk powder by 2 years of age is associated with celiac disease. A 1-to-3 nested case-control study, comprised of 207 celiac disease children and 621 controls matched for sex, birth year, and HLA genotype, was performed on a birth cohort of HLA-DR3-DQ2 and/or DR4-DQ8-positive children. Subjects were screened annually for celiac disease using tissue transglutaminase autoantibodies (tTGA). Three-day food records estimated the mean intake of milk powder at ages 6 months, 9 months, 12 months, 18 months, and 24 months. Conditional logistic regression calculated odds ratios (OR) at last intake prior to seroconversion of tTGA positivity, and for each time-point respectively and adjusted for having a first-degree relative with celiac disease and gluten intake. Intake of milk powder prior to seroconversion of tTGA positivity was not associated with celiac disease (OR = 1.00; 95% CI = 0.99, 1.03; p = 0.763). In conclusion, intake of milk powder in early childhood is not associated with celiac disease in genetically susceptible children.

Pernicious anemia and colorectal cancer risk - A nested case-control study.

PubMed

Boursi, Ben; Mamtani, Ronac; Haynes, Kevin; Yang, Yu-Xiao

2016-11-01

Hypergastrinemia was shown to stimulate colonic epithelial cell proliferation. To evaluate the association between pernicious anemia (PA), a disease with hypergastrinemia, and colorectal cancer (CRC) risk. We conducted a nested case-control study within a large database from the UK. Cases were defined as all individuals in the cohort with at least one medical code for CRC. Controls were selected based on incidence-density sampling. For each case, up to four eligible controls were matched on age at diagnosis, sex, practice-site, and both duration and calendar time of follow-up. Exposure of interest was diagnosis of PA prior to CRC diagnosis date. The primary analysis was a multivariable conditional logistic regression. Our study included 22,098 CRC cases and 85,969 matched controls. We identified 154 (0.70%) cases and 563 (0.65%) controls with past history of PA. The adjusted OR for the association between PA and CRC risk was 1.02 (95% CI 0.85-1.22). There was no difference in the results after stratification according to sex. In a sensitivity analysis only among individuals without chronic use of proton pump inhibitors (PPIs) the adjusted OR was 1.14 (95% CI 0.90-1.45). There was no association between duration of PA and CRC risk. PA is not associated with higher CRC risk. Copyright © 2016. Published by Elsevier Ltd.

Variability in vegetation effects on density and nesting success of grassland birds

USGS Publications Warehouse

Winter, Maiken; Johnson, Douglas H.; Shaffer, Jill A.

2005-01-01

The structure of vegetation in grassland systems, unlike that in forest systems, varies dramatically among years on the same sites, and among regions with similar vegetation. The role of this variation in vegetation structure on bird density and nesting success of grassland birds is poorly understood, primarily because few studies have included sufficiently large temporal and spatial scales to capture the variation in vegetation structure, bird density, or nesting success. To date, no large-scale study on grassland birds has been conducted to investigate whether grassland bird density and nesting success respond similarly to changes in vegetation structure. However, reliable management recommendations require investigations into the distribution and nesting success of grassland birds over larger temporal and spatial scales. In addition, studies need to examine whether bird density and nesting success respond similarly to changing environmental conditions. We investigated the effect of vegetation structure on the density and nesting success of 3 grassland-nesting birds: clay-colored sparrow (Spizella pallida), Savannah sparrow (Passerculus sandwichensis), and bobolink (Dolichonyx oryzivorus) in 3 regions of the northern tallgrass prairie in 1998-2001. Few vegetation features influenced the densities of our study species, and each species responded differently to those vegetation variables. We could identify only 1 variable that clearly influenced nesting success of 1 species: clay-colored sparrow nesting success increased with increasing percentage of nest cover from the surrounding vegetation. Because responses of avian density and nesting success to vegetation measures varied among regions, years, and species, land managers at all times need to provide grasslands with different types of vegetation structure. Management guidelines developed from small-scale, short-term studies may lead to misrepresentations of the needs of grassland-nesting birds.

Altered growth trajectory of head circumference during infancy and schizophrenia in a National Birth Cohort.

PubMed

Brown, Alan S; Gyllenberg, David; Hinkka-Yli-Salomäki, Susanna; Sourander, Andre; McKeague, Ian W

2017-04-01

Identification of abnormalities in the developmental trajectory during infancy of future schizophrenia cases offers the potential to reveal pathogenic mechanisms of this disorder. Previous studies of head circumference in pre-schizophrenia were limited to measures at birth. The use of growth acceleration of head circumference (defined as the rate of change in head circumference) provides a more informative representation of the maturational landscape of this measure compared to studies based on static head circumference measures. To date, however, no study has examined whether HC growth acceleration differs between pre-schizophrenia cases and controls. In the present study, we employed a nested case control design of a national birth cohort in Finland. Cases with schizophrenia or schizoaffective disorder (N=375) and controls (N=375) drawn from the birth cohort were matched 1:1 on date of birth (within 1month), sex, and residence in Finland at case diagnosis. Longitudinal data were obtained on head circumference from birth through age 1. Data were analyzed using a new nonparametric Bayesian inversion method which allows for a detailed understanding of growth dynamics. Adjusting for growth velocity of height and weight, and gestational age, there was significantly accelerated growth of head circumference in females with schizophrenia from birth to 2months; the findings remained significant following Bonferroni correction (p<0.0125). This is the first study to report abnormal HC growth acceleration, a more sensitive measure of somatic developmental deviation of this measure, in schizophrenia. Copyright © 2016 Elsevier B.V. All rights reserved.

Prediagnostic serum calcium and albumin and ovarian cancer: A nested case-control study in the Norwegian Janus Serum Bank Cohort.

PubMed

Schwartz, Gary G; Tretli, Steinar; Vos, Linda; Robsahm, Trude E

2017-08-01

Women with higher serum calcium may be more likely to be diagnosed and die of ovarian cancer. We evaluated that finding in a large, prospective cohort. We conducted a nested case-control study using a population-based biobank from Norway. We compared 202 ovarian cancer cases and 202 controls, matched for age, date at blood draw, and county of residence, with respect to serum calcium and albumin, adjusted for anthropometric variables. We evaluated risks using the entire follow-up period as well as 2-15 years and 16-25 years ("early" and "late", respectively). For the entire follow-up, risk was significantly increased in the highest tertile of albumin and for high albumin and calcium jointly. Risks for ovarian cancer differed markedly by follow-up time. In early follow-up, women in the highest tertile of serum calcium had a 2.5-fold increased risk, adjusted for height and body mass index (OR=2.47, 95% C.I. 1.12-5.45) with a significant dose-response (p=0.024). Risk was not elevated in late follow-up (OR=0.62, 95% C.I. 0.27-1.36). Similarly, in early follow-up, women in the highest tertile of serum albumin had an increased risk (OR=2.55, 95% C.I.1.22-5.49) with a significant dose-response (p=0.009). Conversely, risk was not increased in late follow-up (OR=1.36, 95% C.I. 0.65-2.83). These data confirm a prospective association between higher serum calcium and ovarian cancer. An association in early, but not late, follow-up suggests that the higher calcium reflects the presence of existing cancer. A positive association with serum albumin is novel and should be interpreted cautiously. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Adaptive nest clustering and density-dependent nest survival in dabbling ducks

USGS Publications Warehouse

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.

Egg flotation estimates nest age for Pacific and Red-throated Loons

USGS Publications Warehouse

Rizzolo, Daniel; Schmutz, Joel A.

2007-01-01

We used Pacific Loon (Gavia pacifica) and Red-throated Loon (G. stellata) nests with known ages to gauge the efficacy of egg flotation for determining nest age in coastal Alaska. Egg flotation accurately estimated nest age for both species; the mean ± 1SD difference between known age and age determined with egg flotation was - 0.05 ± 2.00 d and -0.02 ± 1.63 d for Pacific and Red-throated Loons, respectively. Day of nest initiation did not influence the relationship between known nest age and nest age estimated with egg flotation, indicating incubation period was not shortened in nests initiated later in the season. Additionally, we found no difference in the ability of egg flotation to estimate nest age between two widely dispersed study sites for Pacific Loons, and only a small difference between two of three widely dispersed study sites for Red-throated Loons. Thus, our described relationships between egg flotation categories and nest age should be broadly applicable for these holarctic species. We conclude that for Pacific and Red-throated Loons, egg flotation is a useful technique for determining nest age in the field to better monitor nest fate, and to quantify nest age effects on nest daily survival rate.

Daily survival rate and habitat characteristics of nests of Wilson's Plover

USGS Publications Warehouse

Zinsser, Elizabeth; Sanders, Felicia J.; Gerard, Patrick D.; Jodice, Patrick G.R.

2017-01-01

We assessed habitat characteristics and measured daily survival rate of 72 nests of Charadrius wilsonia (Wilson's Plover) during 2012 and 2013 on South Island and Sand Island on the central coast of South Carolina. At both study areas, nest sites were located at slightly higher elevations (i.e., small platforms of sand) relative to randomly selected nearby unused sites, and nests at each study area also appeared to be situated to enhance crypsis and/or vigilance. Daily survival rate (DSR) of nests ranged from 0.969 to 0.988 among study sites and years, and the probability of nest survival ranged from 0.405 to 0.764. Flooding and predation were the most common causes of nest failure at both sites. At South Island, DSR was most strongly related to maximum tide height, which suggests that flooding and overwash may be common causes of nest loss for Wilson's Plovers at these study sites. The difference in model results between the 2 nearby study sites may be partially due to more-frequent flooding at Sand Island because of some underlying yet unmeasured physiographic feature. Remaining data gaps for the species include regional assessments of nest and chick survival and habitat requirements during chick rearing.

Contrasting nest survival patterns for ducks and songbirds in northern mixed-grass prairie

USGS Publications Warehouse

Grant, Todd; Shaffer, Terry L.; Madden, Elizabeth M.; Nenneman, Melvin P.

2017-01-01

Management actions intended to protect or improve habitat for ducks may benefit grassland-nesting passerines, but scant information is available to explore this assumption. During 1998–2003, we examined nest survival of ducks and songbirds to determine whether effects of prescribed fire and other habitat features (e.g., shrub cover and distance to habitat edges) were similar for ducks and passerines breeding in North Dakota. We used the logistic-exposure method to estimate survival of duck and songbird nests (n = 3,171). We used an information-theoretic approach to identify factors that most influenced nest survival. Patterns of nest survival were markedly different between taxonomic groups. For ducks, nest survival was greater during the first postfire nesting season (daily survival rate [DSR] = 0.957, 85% CI = 0.951–0.963), relative to later postfire nesting seasons (DSR = 0.946, 85% CI = 0.942–0.950). Furthermore duck nest survival and nest densities were inversely related. Duck nest survival also was greater as shrub cover decreased and as distance from cropland and wetland edges increased. Passerines had lower nest survival during the first postfire nesting season (DSR = 0.934, 85% CI = 0.924–0.944), when densities also were low compared to subsequent postfire nesting seasons (DSR = 0.947, 85% CI = 0.944–0.950). Parasitism by brown-headed cowbirds (Molothrus ater) reduced passerine nest survival and this effect was more pronounced during the first postfire nesting season compared to subsequent nesting seasons. Passerine nest survival was greater as shrub cover decreased and perhaps for more concealed nests. Duck and songbird nest survival rates were not correlated during this study and for associated studies that examined additional variables using the same dataset, suggesting that different mechanisms influenced their survival. Based on our results, ducks should not be considered direct surrogates for passerines when predicting effects of prescribed fire, shrub cover, and habitat edges on nest survival.

Variability in nest survival rates and implications to nesting studies

USGS Publications Warehouse

Klett, A.T.; Johnson, D.H.

1982-01-01

We used four reasonably large samples (83-213) of Mallard (Anas platyrhynchos) and Blue-winged Teal (A. discors) nests on an interstate highway right-of-way in southcentral North Dakota to evaluate potential biases in hatch-rate estimates. Twelve consecutive, weekly searches for nests were conducted with a cable-chain drag in 1976 and 1977. Nests were revisited at weekly intervals. Four methods were used to estimate hatch rates for the four data sets: the Traditional Method, the Mayfield Method, and two modifications of the Mayfield Method that are sometimes appropriate when daily mortality rates of nests are not constant. Hatch rates and the average age of nests at discovery declined as the interval between searches decreased, suggesting that mortality rates were not constant in our samples. An analysis of variance indicated that daily mortality rates varied with the age of nests in all four samples. Mortality was generally highest during the early laying period, moderately high during the late laying period, and lowest during incubation. We speculate that this relationship of mortality to nest age might be due to the presence of hens at nests or to differences in the vulnerability of nest sites to predation. A modification of the Mayfield Method that accounts for age-related variation in nest mortality was most appropriate for our samples. We suggest methods for conducting nesting studies and estimating nest success for species possessing similar nesting habits.

Upland duck nesting related to land use and predator reduction

USGS Publications Warehouse

Duebbert, H.F.; Kantrud, H.A.

1974-01-01

Duck nesting was studied during 1971 in north-central South Dakota under four conditions: in idle, five or six year old fields of domestic grass-legume mixtures in an area where predators including the red fox (Vulpes fulva), raccoon (Procyon lotor), striped skunk (Mephitis mephitis), and badger (Taxidea taxus) were (1) reduced and (2) not reduced. Nesting was also studied in tracts of active agricultural land (primarily croplands and pastures) where predators were (3) reduced, and (4) not reduced. Under condition (1), 260 nests were found on 0.87 km2 (299 nests/km2), eggs hatched in 92 percent of the nests and production was 22.0 ducklings/hectare. Under condition (2), 187 nests were found on 2.22 km2 (84 nests/km2), nest success was 68 percent and 4.7 ducklings/hectare were produced. On active agricultural land subject to predator reduction (condition 3), 64 nests were found on 5.14 km2 (12 nests/km2). Eggs in 85 percent of the nests hatched and production was 0.7 duckling/hectare. On active agricultural land not subject to predator reduction (condition 4), 58 nests were found on 4.01 km2 (14 nests/km2), nest success was 51 percent and 0.5 duckling/hectare was produced. Idle, 16 to 65-hectare (40 to 160-acre) stands of cool-season, introduced grasses in combination with legumes produced maximum numbers of upland nesting ducks.

Avian nest success in midwestern forests fragmented by agriculture

USGS Publications Warehouse

Knutson, M.G.; Niemi, G.J.; Newton, W.E.; Friberg, M.A.

2004-01-01

We studied how forest-bird nest success varied by landscape context from 1996 to 1998 in an agricultural region of southeastern Minnesota, southwestern Wisconsin, and northeastern Iowa. Nest success was 48% for all nests, 82% for cavity-nesting species, and 42% for cup-nesting species. Mayfield-adjusted nest success for five common species ranged from 23% for the American Redstart (Setophaga ruticilla) to 43% for the Eastern Wood-Pewee (Contopus virens). Nest success was lowest for open-cup nesters, species that reject Brown-headed Cowbird (Molothrus ater) eggs, species that nest near forest edges, and Neo-tropical migrants. The proportion of forest core area in a 5-km radius around the plot had a weakly negative relationship with daily survival rate of nests for all species pooled and for medium or high canopy nesters, species associated with interior and edge habitats, open-cup nesters, and nests located between 75 and 199 m from an edge. The proportion of forest core area was positively related to daily survival rate only for ground and low nesters. Our findings are in contrast to a number of studies from the eastern United States reporting strong positive associations between forest area and nesting success. Supported models of habitat associations changed with the spatial scale of analysis and included variables not often considered in studies of forest birds, including the proportion of water, shrubs, and grasslands in the landscape. Forest area may not be a strong indicator of nest success in landscapes where all the available forests are fragmented.

Study designs may influence results: the problems with questionnaire-based case-control studies on the epidemiology of glioma.

PubMed

Johansen, Christoffer; Schüz, Joachim; Andreasen, Anne-Marie Serena; Dalton, Susanne Oksbjerg

2017-03-28

Glioma is a rare brain tumour with a very poor prognosis and the search for modifiable factors is intense. We reviewed the literature concerning risk factors for glioma obtained in case-control designed epidemiological studies in order to discuss the influence of this methodology on the observed results. When reviewing the association between three exposures, medical radiation, exogenous hormone use and allergy, we critically appraised the evidence from both case-control and cohort studies. For medical radiation and hormone replacement therapy (HRT), questionnaire-based case-control studies appeared to show an inverse association, whereas nested case-control and cohort studies showed no association. For allergies, the inverse association was observed irrespective of study design. We recommend that the questionnaire-based case-control design be placed lower in the hierarchy of studies for establishing cause-and-effect for diseases such as glioma. We suggest that a state-of-the-art case-control study should, as a minimum, be accompanied by extensive validation of the exposure assessment methods and the representativeness of the study sample with regard to the exposures of interest. Otherwise, such studies cannot be regarded as 'hypothesis testing' but only 'hypothesis generating'. We consider that this holds true for all questionnaire-based case-control studies on cancer and other chronic diseases, although perhaps not to the same extent for each exposure-outcome combination.

Seroprevalence of neutralizing antibodies against dengue virus in two localities in the state of Morelos, Mexico.

PubMed

Amaya-Larios, Irma Y; Martínez-Vega, Ruth Aralí; Mayer, Sandra V; Galeana-Hernández, Marisol; Comas-García, Andreu; Sepúlveda-Salinas, Karla J; Falcón-Lezama, Jorge A; Vasilakis, Nikos; Ramos-Castañeda, José

2014-11-01

Humoral immune response against dengue virus (DENV) is an important component in dengue-endemic transmission. We conducted a cross-sectional nested cohort study to determine the seroprevalence and frequency of neutralizing antibodies against DENV serotypes in two endemic localities in the state of Morelos, Mexico. The cohort participants (N = 1,196) were screened to determine previous exposure to DENV. Overall seroprevalence was 76.6% (95% confidence interval [95% CI] = 73.6-79.2), and prevalence of neutralizing antibodies in the 5- to 9-year-old group was 82.5% (95% CI = 67.2-92.7), 45% (95% CI = 29.3-61.5), and 65% (95% CI = 48.3-79.4) for DENV-1, DENV-2, and DENV-3, respectively. For participants older than 10 years, the observed seroprevalence was above 60% for each serotype, except DENV-4 in the 10- to 25-year-old group (42.9%); 81% of humoral responses were multitypic. The outcomes of our study contribute to understanding the immune component of dengue transmission and provide focal information for the evaluation of vaccine candidates under development. © The American Society of Tropical Medicine and Hygiene.

Seroprevalence of Neutralizing Antibodies Against Dengue Virus in Two Localities in the State of Morelos, Mexico

PubMed Central

Amaya-Larios, Irma Y.; Martínez-Vega, Ruth Aralí; Mayer, Sandra V.; Galeana-Hernández, Marisol; Comas-García, Andreu; Sepúlveda-Salinas, Karla J.; Falcón-Lezama, Jorge A.; Vasilakis, Nikos; Ramos-Castañeda, José

2014-01-01

Humoral immune response against dengue virus (DENV) is an important component in dengue-endemic transmission. We conducted a cross-sectional nested cohort study to determine the seroprevalence and frequency of neutralizing antibodies against DENV serotypes in two endemic localities in the state of Morelos, Mexico. The cohort participants (N = 1,196) were screened to determine previous exposure to DENV. Overall seroprevalence was 76.6% (95% confidence interval [95% CI] = 73.6–79.2), and prevalence of neutralizing antibodies in the 5- to 9-year-old group was 82.5% (95% CI = 67.2–92.7), 45% (95% CI = 29.3–61.5), and 65% (95% CI = 48.3–79.4) for DENV-1, DENV-2, and DENV-3, respectively. For participants older than 10 years, the observed seroprevalence was above 60% for each serotype, except DENV-4 in the 10- to 25-year-old group (42.9%); 81% of humoral responses were multitypic. The outcomes of our study contribute to understanding the immune component of dengue transmission and provide focal information for the evaluation of vaccine candidates under development. PMID:25294613

Genetic variants in loci 1p13 and 9p21 and fatal coronary heart disease in a Norwegian case-cohort study.

PubMed

Jansen, Mona Dverdal; Knudsen, Gun Peggy; Myhre, Ronny; Høiseth, Gudrun; Mørland, Jørg; Næss, Øyvind; Tambs, Kristian; Magnus, Per

2014-05-01

Single nucleotide polymorphisms (SNPs) in loci 1p13 and 9p21 have previously been found to be associated with incident coronary heart disease (CHD). This study aimed to investigate whether these SNPs show associations with fatal CHD in a population-based cohort study after adjustment for socioeconomic- and lifestyle-related CHD risk factors not commonly included in genetic association studies. Using the population-based Cohort of Norway (CONOR), a nested case-cohort study was set up and DNA from 2,953 subjects (829 cases and 2,124 non-cases) were genotyped. The association with fatal CHD was estimated for four SNPs, three from locus 1p13 and one from locus 9p21. Multivariable Cox regression was used to estimate unstratified and gender-stratified hazard ratios while adjusting for major CHD risk factors. The associations between three SNPs from locus 1p13 and non-HDL cholesterol levels were also estimated. Men homozygous for the risk alleles on rs1333049 (9p21) and rs14000 (1p13) were found to have significantly increased hazard ratios in crude and adjusted models, and the hazard ratios remained statistically significant when both genders were analyzed together. Adjustment for additional socioeconomic- and lifestyle-related CHD risk factors influenced the association estimates only slightly. No significant associations were observed between the other two SNPs in loci 1p13 (rs599839 and rs646776) and CHD mortality in either gender. Both rs599839 and rs646776 showed significant, gradual increases in non-HDL cholesterol levels with increasing number of risk alleles. This study confirms the association between 9p21 (rs1333049) and fatal CHD in a Norwegian population-based cohort. The effect was not influenced by several socioeconomic- and lifestyle-related risk factors. Our results show that 1p13 (rs14000) may also be associated with fatal CHD. SNPs at 1p13 (rs599839 and rs646776) were associated with non-HDL cholesterol levels.

Plasma 25-hydroxyvitamin D concentration and subsequent risk of total and site specific cancers in Japanese population: large case-cohort study within Japan Public Health Center-based Prospective Study cohort.

PubMed

Budhathoki, Sanjeev; Hidaka, Akihisa; Yamaji, Taiki; Sawada, Norie; Tanaka-Mizuno, Sachiko; Kuchiba, Aya; Charvat, Hadrien; Goto, Atsushi; Kojima, Satoshi; Sudo, Natsuki; Shimazu, Taichi; Sasazuki, Shizuka; Inoue, Manami; Tsugane, Shoichiro; Iwasaki, Motoki

2018-03-07

To evaluate the association between pre-diagnostic circulating vitamin D concentration and the subsequent risk of overall and site specific cancer in a large cohort study. Nested case-cohort study within the Japan Public Health Center-based Prospective Study cohort. Nine public health centre areas across Japan. 3301 incident cases of cancer and 4044 randomly selected subcohort participants. Plasma concentration of 25-hydroxyvitamin D measured by enzyme immunoassay. Participants were divided into quarters based on the sex and season specific distribution of 25-hydroxyvitamin D among subcohorts. Weighted Cox proportional hazard models were used to calculate the multivariable adjusted hazard ratios for overall and site specific cancer across categories of 25-hydroxyvitamin D concentration, with the lowest quarter as the reference. Incidence of overall or site specific cancer. Plasma 25-hydroxyvitamin D concentration was inversely associated with the risk of total cancer, with multivariable adjusted hazard ratios for the second to fourth quarters compared with the lowest quarter of 0.81 (95% confidence interval 0.70 to 0.94), 0.75 (0.65 to 0.87), and 0.78 (0.67 to 0.91), respectively (P for trend=0.001). Among the findings for cancers at specific sites, an inverse association was found for liver cancer, with corresponding hazard ratios of 0.70 (0.44 to 1.13), 0.65 (0.40 to 1.06), and 0.45 (0.26 to 0.79) (P for trend=0.006). A sensitivity analysis showed that alternately removing cases of cancer at one specific site from total cancer cases did not substantially change the overall hazard ratios. In this large prospective study, higher vitamin D concentration was associated with lower risk of total cancer. These findings support the hypothesis that vitamin D has protective effects against cancers at many sites. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Neural correlates of nesting behavior in zebra finches (Taeniopygia guttata).

PubMed

Hall, Zachary J; Bertin, Marion; Bailey, Ida E; Meddle, Simone L; Healy, Susan D

2014-05-01

Nest building in birds involves a behavioral sequence (nest material collection and deposition in the nest) that offers a unique model for addressing how the brain sequences motor actions. In this study, we identified brain regions involved in nesting behavior in male and female zebra finches (Taeniopygia guttata). We used Fos immunohistochemistry to quantify production of the immediate early gene protein product Fos (a molecular indicator of neuronal activity) in the brain correlated this expression with the variation in nesting behavior. Using this technique, we found that neural circuitry involved in motor sequencing, social behavior, reward and motivation were active during nesting. Within pairs of nesting birds, the number of times a male picked up or deposited nesting material and the amount of time a female spent in the nest explained the variation in Fos expression in the anterior motor pathway, social behavior network, and reward neural circuits. Identification of the brain regions that are involved in nesting enables us to begin studying the roles of motor sequencing, context, and reward in construction behavior at the neural level. Copyright © 2014 Elsevier B.V. All rights reserved.

Neural correlates of nesting behavior in zebra finches (Taeniopygia guttata)

PubMed Central

Hall, Zachary J.; Bertin, Marion; Bailey, Ida E.; Meddle, Simone L.; Healy, Susan D.

2014-01-01

Nest building in birds involves a behavioral sequence (nest material collection and deposition in the nest) that offers a unique model for addressing how the brain sequences motor actions. In this study, we identified brain regions involved in nesting behavior in male and female zebra finches (Taeniopygia guttata). We used Fos immunohistochemistry to quantify production of the immediate early gene protein product Fos (a molecular indicator of neuronal activity) in the brain correlated this expression with the variation in nesting behavior. Using this technique, we found that neural circuitry involved in motor sequencing, social behavior, reward and motivation were active during nesting. Within pairs of nesting birds, the number of times a male picked up or deposited nesting material and the amount of time a female spent in the nest explained the variation in Fos expression in the anterior motor pathway, social behavior network, and reward neural circuits. Identification of the brain regions that are involved in nesting enables us to begin studying the roles of motor sequencing, context, and reward in construction behavior at the neural level. PMID:24508238

Nest-site habitat of cavity-nesting birds at the San Joaquin Experimental Range

Treesearch

Kathryn L. Purcell; Jared. Verner

2008-01-01

Detailed information about the nesting habitats of birds, including those needed for successful nesting, can provide a better understanding of the ecological factors that permit coexistence of different species and may aid in conservation efforts. From 1989 through 1994, we studied the nesting habitat of secondary cavity-nesting birds in oak woodlands at the San...

Nest mortality of sagebrush songbirds due to a severe hailstorm

USGS Publications Warehouse

Hightower, Jessica N.; Carlisle, Jason D.; Chalfoun, Anna D.

2018-01-01

Demographic assessments of nesting birds typically focus on failures due to nest predation or brood parasitism. Extreme weather events such as hailstorms, however, can also destroy eggs and injure or kill juvenile and adult birds at the nest. We documented the effects of a severe hailstorm on 3 species of sagebrush-associated songbirds: Sage Thrasher (Oreoscoptes montanus), Brewer's Sparrow (Spizella breweri), and Vesper Sparrow (Pooecetes gramineus), nesting at eight 24 ha study plots in central Wyoming, USA. Across all plots, 17% of 128 nests failed due to the hailstorm; however, all failed nests were located at a subset of study plots (n = 3) where the hailstorm was most intense, and 45% of all nests failures on those plots were due to hail. Mortality rates varied by species, nest architecture, and nest placement. Nests with more robust architecture and those sited more deeply under the shrub canopy were more likely to survive the hailstorm, suggesting that natural history traits may modulate mortality risk due to hailstorms. While sporadic in nature, hailstorms may represent a significant source of nest failure to songbirds in certain locations, especially with increasing storm frequency and severity forecasted in some regions with ongoing climate change.

Nesting ecology of Spectacled Eiders Somateria fischeri on the Indigirka River Delta, Russia

USGS Publications Warehouse

Pearce, John M.; Esler, Daniel N.; Degtyarev, Andrei G.

1998-01-01

In 1994 and 1995 we investigated breeding biology and nest site habitat of Spectacled Eiders on two study areas within the coastal fringe of the Indigirka River Delta, Russia (71°20' N, 150°20' E). Spectacled Eiders were first observed on 6 June in both years and nesting commenced by mid-June. Average clutch size declined with later nest initiation dates by 0.10 eggs per day; clutches were larger in 1994 than 1995 and were slightly larger on a coastal island study area compared to an interior area. Nesting success varied substantially between years, with estimates of 1.6% in 1994 and 27.6% in 1995. Total egg loss, through avian or mammalian predation, occurred more frequently than partial egg loss. Partial egg loss was detected in 16 nests and appeared unrelated to nest initiation date or clutch size. We found no difference among survival rates of nests visited weekly, biweekly, and those at which the hen was never flushed, suggesting that researcher presence did not adversely affect nesting success. A comparison of nine habitat variables within each study area revealed little difference between nest sites and a comparable number of randomly located sites, leading us to conclude that Spectacled Eiders nest randomly with respect to most small scale habitat features. We propose that large scale landscape features are more important indicators of nesting habitat as they may afford greater protection from land-based predators, such as the Arctic Fox. Demographic data collected during this study, along with recent conservation measures implemented by the Republic of Sakha (Yakutia), lead us to conclude that there are few threats to the Indigirka River Delta Spectacled Eider population. Presently, the Indigirka River Delta contains the largest concentration of nesting Spectacled Eiders and deserves continued monitoring and conservation.

Reengagement in PTSD psychotherapy: A case-control study.

PubMed

Buchholz, Katherine R; Bohnert, Kipling M; Pfeiffer, Paul N; Valenstein, Marcia; Ganoczy, Dara; Anderson, RaeAnn E; Sripada, Rebecca K

2017-09-01

This study sought to identify patient characteristics and care processes related to reengagement in VA psychotherapy. Using national VA data, a retrospective cohort was constructed (N=24,492) of veterans who received a new PTSD diagnosis in FY08/FY09 and attended only one to five PTSD psychotherapy sessions. A nested case-control study was conducted comparing veterans who reengaged in psychotherapy (n=9649) in a 1:5 ratio with those who did not reengage by the end of FY12. Conditional logistic regression models were run to examine differences in sociodemographic, mental health, and service utilization factors between cases and controls. Among veterans in the study cohort, 39.4% reengaged in psychotherapy. In adjusted analyses, all measured types of health system encounters (primary care [OR=1.61], primary care mental health [OR=1.61], non-PTSD psychotherapy [OR=1.76], other non-PTSD mental health care [OR=1.43], other non-psychotherapy PTSD care [OR=3.31], emergency room [OR=1.14], and psychiatric hospitalization [OR=1.56]) were related to greater odds of reengagement in PTSD psychotherapy. Veterans' receipt of a broad range of care services may play an important role in reengagement in PCT psychotherapy, suggesting providers across care settings should be knowledgeable in how to support a Veteran's return to psychotherapy for PTSD. Published by Elsevier Inc.

Nesting ecology of a population of Gopherus agassizii at a utility-scale wind energy facility in southern California

USGS Publications Warehouse

Ennen, Joshua R.; Lovich, Jeffrey E.; Meyer, Katherin P.; Bjurlin, Curtis; Arundel, Terence R.

2012-01-01

We investigated the annual nesting ecology of a population of Desert Tortoises (Gopherus agassizii) inhabiting a utility-scale renewable energy (USRE) facility in southern California and compared our results with populations inhabiting relatively undisturbed sites. In 2000, 15 radio-tracked females produced 29 clutches, and 24 nests were monitored to examine nest-site selection, nest predation, hatching success, date of emergence of hatchlings, and hatchling mass and carapace length. Overall, the nesting ecology of the population inhabiting the USRE facility was very similar to other populations of Desert Tortoises inhabiting relatively undisturbed habitats. Oviposition occurred from 12 May to 8 July, which was similar to other sites. Nest depths (11.1 cm), nest predation (12%), hatchling emergence date (7 August and 29 September), and hatchling morphometrics (i.e., MCL: 44.5 mm; mass: 23 g) were all within ranges reported in other populations. Unlike within other populations, we observed no relationship between hatchling size and either maternal body size or egg width. We found no evidence of females selecting for a particular burrow for oviposition of eggs based on environmental or anthropogenic variables. Most nests were located in or near burrows, and nest depth was greater for nests near the entrance than those deeper in the burrow. Although this study suggests that the nesting ecology of the Desert Tortoise population we studied was not adversely affected by the USRE facility, this relationship is only correlative because our study was not a before-after-control-impact (BACI) study, which would establish a cause and effect relationship. As pointed out in a recent review, BACI studies are critically needed to address the wildlife impacts of utility-scale renewable energy development.

The importance of illumination in nest site choice and nest characteristics of cavity nesting birds.

PubMed

Podkowa, Paweł; Surmacki, Adrian

2017-05-02

Light has a significant impact on many aspects of avian biology, physiology and behaviour. An increasing number of studies show that illumination may positively influences birds' offspring fitness by e.g. acceleration of embryo development, stimulation of skeleton growth or regulation of circadian rhythm. Because nest cavities have especially low illumination, suitable light levels may be especially important for species which nest there. We may therefore expect that birds breeding in relatively dim conditions should prefer brighter nest sites and/or evolve behavioral mechanisms to secure sufficient light levels in the nest. Using nest boxes with modified internal illumination, we experimentally tested whether light regime is a cue for nest site selection of secondary cavity-nesting species. Additionally, we investigated whether nest building strategies are tuned to internal illumination. Our results demonstrate that, nest boxes with elevated illumination were chosen twice as often as dark nest boxes. Moreover, birds built higher nests in dark nest boxes than birds in boxes with elevated illumination, which suggests a mechanism of compensating for low light conditions. Our results provide the first experimental support for the idea that nest site choice and nest building behaviour in cavity-nesting birds are influenced by ambient illumination.

Plasma carotenoids and breast cancer risk in the Cancer Prevention Study II Nutrition Cohort.

PubMed

Wang, Ying; Gapstur, Susan M; Gaudet, Mia M; Furtado, Jeremy D; Campos, Hannia; McCullough, Marjorie L

2015-09-01

Several circulating carotenoids have been inversely associated with postmenopausal breast cancer risk in large cohort studies and a pooled analysis. Whether associations differ by tumor or participant characteristics remains unclear. We investigated the associations of plasma carotenoids with postmenopausal breast cancer risk overall and by estrogen receptor (ER) status, tumor stage, smoking status, and body mass index, in a case-control study nested in the Cancer Prevention Study II Nutrition Cohort. A total of 496 invasive breast cancer cases diagnosed between blood draw in 1998-2001 and June 30, 2007 and matched 1:1 with controls on race, birth date, and blood draw date were included. Multivariable-adjusted conditional and unconditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Plasma α-carotene above the lowest quartile was associated with significant 40-43% lower risk of invasive breast cancer risk (fourth vs. first quartile OR 0.60, 95% CI 0.41-0.87, P-trend = 0.037) after adjustment for multiple covariates. This inverse association was strengthened after further adjustment for other plasma carotenoids and total fruit and vegetable intake (fourth vs. first quartile OR 0.50, 95% CI 0.29-0.85, P-trend = 0.041). Other plasma carotenoids or total carotenoids were not associated with breast cancer risk. The inverse association of α-carotene with breast cancer remained for ER+, but not for ER- tumors, although test for heterogeneity was not statistically significant (P-heterogeneity = 0.49). These results suggest that higher plasma α-carotene is associated with lower risk of invasive breast cancer.

Identification of novel loci for Alzheimer disease and replication of CLU, PICALM, and BIN1 in Caribbean Hispanic individuals.

PubMed

Lee, Joseph H; Cheng, Rong; Barral, Sandra; Reitz, Christiane; Medrano, Martin; Lantigua, Rafael; Jiménez-Velazquez, Ivonne Z; Rogaeva, Ekaterina; St George-Hyslop, Peter H; Mayeux, Richard

2011-03-01

To identify novel loci for late-onset Alzheimer disease (LOAD) in Caribbean Hispanic individuals and to replicate the findings in a publicly available data set from the National Institute on Aging Late-Onset Alzheimer's Disease Family Study. Nested case-control genome-wide association study. The Washington Heights-Inwood Columbia Aging Project and the Estudio Familiar de Influencia Genetica de Alzheimer study. Five hundred forty-nine affected and 544 unaffected individuals of Caribbean Hispanic ancestry. The Illumina HumanHap 650Y chip for genotyping. Clinical diagnosis or pathologically confirmed diagnosis of LOAD. The strongest support for allelic association was for rs9945493 on 18q23 (P=1.7×10(-7)), but 22 additional single-nucleotide polymorphisms (SNPs) had a P value less than 9×10(-6) under 3 different analyses: unadjusted and stratified by the presence or absence of the APOE ε4 allele. Of these SNPs, 5 SNPs (rs4669573 and rs10197851 on 2p25.1; rs11711889 on 3q25.2; rs1117750 on 7p21.1; and rs7908652 on 10q23.1) were associated with LOAD in an independent cohort from the National Institute on Aging Late-Onset Alzheimer's Disease Family Study. We also replicated genetic associations for CLU, PICALM, and BIN1. Our genome-wide search of Caribbean Hispanic individuals identified several novel genetic variants associated with LOAD and replicated these associations in a white cohort. We also replicated associations in CLU, PICALM, and BIN1 in the Caribbean Hispanic cohort.

Birth weight and gestational age characteristics of children with autism, including a comparison with other developmental disabilities.

PubMed

Schendel, Diana; Bhasin, Tanya Karapurkar

2008-06-01

The objectives of this study were to compare the birth weight and gestational age distributions and prevalence rates of autism with those of other developmental disabilities and to estimate the birth weight-and gestational age-specific risks for autism. For the first objective, a retrospective cohort of children born in Atlanta, Georgia, in 1981-1993 who survived to 3 years of age was identified through vital records. Children in the cohort who had developmental disabilities (autism, mental retardation, cerebral palsy, hearing loss, or vision impairment) and were still residing in metropolitan Atlanta at 3 to 10 years of age were identified through the Metropolitan Atlanta Developmental Disabilities Surveillance Program. A nested case-control sample from the cohort was used for the second objective; all cohort children identified with autism were case participants, and control participants were cohort children who were not identified as having developmental disabilities or receiving special education services. The prevalence of autism in low birth weight or preterm children was markedly lower than those of other developmental disabilities. In multivariate analyses, birth weight of <2500 g and preterm birth at <33 weeks' gestation were associated with an approximately twofold increased risk for autism, although the magnitude of risk from these factors varied according to gender (higher in girls) and autism subgroup (higher for autism accompanied by other developmental disabilities). For example, a significant fourfold increased risk was observed in low birth weight girls for autism accompanied by mental retardation, whereas there was no significantly increased risk observed in low birth weight boys for autism alone. Gender and autism subgroup differences in birth weight and gestational age, resulting in lower gender ratios with declining birth weight or gestational age across all autism subgroups, might be markers for etiologic heterogeneity in autism.

Carbapenem-resistant Enterobacteriaceae colonization and infection in critically ill patients: a retrospective matched cohort comparison with non-carriers.

PubMed

Dickstein, Y; Edelman, R; Dror, T; Hussein, K; Bar-Lavie, Y; Paul, M

2016-09-01

To examine whether carbapenem-resistant Enterobacteriaceae (CRE) carriage is associated with incidence of clinical infection as a means of assessing whether the morbidity and mortality associated with these bacteria are mediated by underlying conditions or intrinsic properties of CRE. This retrospective matched cohort study compared the incidence of invasive infections in CRE-colonized patients and matched non-carriers in the intensive care unit (ICU). The primary outcome was infection caused by CRE of the same species as the colonizing strain among CRE carriers, and infections caused by carbapenem-sensitive strains of the same organism in non-carriers. Hospital discharge and death were considered as competing events. Competing-risks hazard analysis was performed for the entire cohort and for a nested cohort matched by Acute Physiology and Chronic Health Evaluation (APACHE) II scores, stratified by matching. In total, 146 CRE carriers were compared with 292 non-carriers. Patients were well matched for most risk factors for Enterobacteriaceae infection, including age, renal failure, previous invasive infection, previous hospitalization, APACHE II score, length of mechanical ventilation, length of hospitalization and CRE carriage. On regression analysis, colonization with CRE was independently associated with Enterobacteriaceae infection {cause-specific hazard ratio (CSHR) 2.06 [95% confidence interval (CI) 1.03-4.09]}. On regression analysis of the APACHE-II-matched cohort (N=284), colonization with CRE remained significantly associated with Enterobacteriaceae infection [CSHR 3.32 (95% CI 1.31-8.43)]. Colonization with CRE was associated with at least a two-fold increased risk of infection by the colonizing strain amongst ICU patients. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Beach erosion and nest site selection by the leatherback sea turtle Dermochelys coriacea (Testudines: Dermochelyidae) and implications for management practices at Playa Gandoca, Costa Rica.

PubMed

Spanier, Matthew J

2010-12-01

Leatherback sea turtles (Dermochelys coriacea) nest on dynamic, erosion-prone beaches. Erosive processes and resulting nest loss have long been presumed to be a hindrance to clutch survival. In order to better understand how leatherbacks cope with unstable nesting beaches, I investigated the role of beach erosion in leatherback nest site selection at Playa Gandoca, Costa Rica. I also examined the potential effect of nest relocation, a conservation strategy in place at Playa Gandoca to prevent nest loss to erosion, on the temperature of incubating clutches. I monitored changes in beach structure as a result of erosion at natural nest sites during the time the nest was laid, as well as in subsequent weeks. To investigate slope as a cue for nest site selection, I measured the slope of the beach where turtles ascended from the sea to nest, as well as the slopes at other random locations on the beach for comparison. I examined temperature differences between natural and relocated nest sites with thermocouples placed in the sand at depths typical of leatherback nests. Nests were distributed non-randomly in a clumped distribution along the length of the beach and laid at locations that were not undergoing erosion. The slope at nest sites was significantly different than at randomly chosen locations on the beach. The sand temperature at nest depths was significantly warmer at natural nest sites than at locations of relocated nests. The findings of this study suggest leatherbacks actively select nest sites that are not undergoing erosive processes, with slope potentially being used as a cue for site selection. The relocation of nests appears to be inadvertently cooling the nest environment. Due to the fact that leatherback clutches undergo temperature-dependent sex determination, the relocation of nests may be producing an unnatural male biasing of hatchlings. The results of this study suggest that the necessity of relocation practices, largely in place to protect nests from erosion, should be reevaluated to ensure the proper conservation of this critically endangered species.

Advanced techniques for modeling avian nest survival

USGS Publications Warehouse

Dinsmore, S.J.; White, Gary C.; Knopf, F.L.

2002-01-01

Estimation of avian nest survival has traditionally involved simple measures of apparent nest survival or Mayfield constant-nest-survival models. However, these methods do not allow researchers to build models that rigorously assess the importance of a wide range of biological factors that affect nest survival. Models that incorporate greater detail, such as temporal variation in nest survival and covariates representative of individual nests represent a substantial improvement over traditional estimation methods. In an attempt to improve nest survival estimation procedures, we introduce the nest survival model now available in the program MARK and demonstrate its use on a nesting study of Mountain Plovers (Charadrius montanus Townsend) in Montana, USA. We modeled the daily survival of Mountain Plover nests as a function of the sex of the incubating adult, nest age, year, linear and quadratic time trends, and two weather covariates (maximum daily temperature and daily precipitation) during a six-year study (1995–2000). We found no evidence for yearly differences or an effect of maximum daily temperature on the daily nest survival of Mountain Plovers. Survival rates of nests tended by female and male plovers differed (female rate = 0.33; male rate = 0.49). The estimate of the additive effect for males on nest survival rate was 0.37 (95% confidence limits were 0.03, 0.71) on a logit scale. Daily survival rates of nests increased with nest age; the estimate of daily nest-age change in survival in the best model was 0.06 (95% confidence limits were 0.04, 0.09) on a logit scale. Daily precipitation decreased the probability that the nest would survive to the next day; the estimate of the additive effect of daily precipitation on the nest survival rate was −1.08 (95% confidence limits were −2.12, −0.13) on a logit scale. Our approach to modeling daily nest-survival rates allowed several biological factors of interest to be easily included in nest survival models and allowed us to generate more biologically meaningful estimates of nest survival.

The Role of Healthy Lifestyle in the Implementation of Regressing Suboptimal Health Status among College Students in China: A Nested Case-Control Study

PubMed Central

Chen, Jieyu; Xiang, Hongjie; Jiang, Pingping; Yu, Lin; Jing, Yuan; Li, Fei; Wu, Shengwei; Fu, Xiuqiong; Liu, Yanyan; Kwan, Hiuyee; Luo, Ren; Zhao, Xiaoshan; Sun, Xiaomin

2017-01-01

Background: Suboptimal health status (SHS) is the intermediate health state between health and disease, it is medically undiagnosed and is also termed functional somatic syndrome. Although its clinical manifestations are complicated and various, SHS has not reached the disease status. Unhealthy lifestyle is associated with many chronic diseases and mortality. In accordance with the impact of lifestyle on health, it is intriguing to determine the association between unhealthy lifestyle and SHS risk. Methods: We conducted a nested case-control study among healthy Chinese college students from March 2012 to September 2013, which was nested in a prospective cohort of 5676 students. We performed 1:1 incidence density sampling with matched controls for birth year, sex, grade, specialty and individual character. SHS was evaluated using the medical examination report and Sub-health Measurement Scale V1.0 (SHMS V1.0). Exposure was defined as an unhealthy lifestyle per the frequency of six behavioral dimensions from the Health-promoting Lifestyle Profile (HPLP-II). Results: We matched 543 cases of SHS (42.66%) in a cohort of 1273 students during the 1.5 years mean follow-up time with controls. A significant difference (t = 9.79, p < 0.001) and a reduction in HPLP-II total score was present at 1.5 years follow-up (135.93 ± 17.65) compared to baseline (144.48 ± 18.66). A level-response effect was recorded with an increase of the total HPLP-II (every dimension was correlated with a decreased SHS risk). Compared to respondents with the least exposure (excellent level), those reporting a general HPLP-II level were approximately 2.3 times more likely to develop SHS (odd ratio = 2.333, 95% CI = 1.471 to 3.700); and those with less HPLP-II level (good level) were approximately 1.6 times more likely (1.644, 1.119–2.414) to develop SHS (p < 0.05). Our data indicated that unhealthy lifestyle behavior with respect to behavioral dimensions significantly affected SHS likelihood. Further analyses revealed a marked increase (average increased 14.73 points) in lifestyle level among those SHS regression to health after 1.5 years, with respect to the HPLP-II behavioral dimensions, in addition to the total score (t = −15.34, p < 0.001). Conclusions: SHS is highly attributable to unhealthy lifestyles, and the mitigation of modifiable lifestyle risk factors may lead to SHS regression. Increased efforts to modify unhealthy lifestyles are necessary to prevent SHS. PMID:28264509

The Role of Healthy Lifestyle in the Implementation of Regressing Suboptimal Health Status among College Students in China: A Nested Case-Control Study.

PubMed

Chen, Jieyu; Xiang, Hongjie; Jiang, Pingping; Yu, Lin; Jing, Yuan; Li, Fei; Wu, Shengwei; Fu, Xiuqiong; Liu, Yanyan; Kwan, Hiuyee; Luo, Ren; Zhao, Xiaoshan; Sun, Xiaomin

2017-02-28

Suboptimal health status (SHS) is the intermediate health state between health and disease, it is medically undiagnosed and is also termed functional somatic syndrome. Although its clinical manifestations are complicated and various, SHS has not reached the disease status. Unhealthy lifestyle is associated with many chronic diseases and mortality. In accordance with the impact of lifestyle on health, it is intriguing to determine the association between unhealthy lifestyle and SHS risk. We conducted a nested case-control study among healthy Chinese college students from March 2012 to September 2013, which was nested in a prospective cohort of 5676 students. We performed 1:1 incidence density sampling with matched controls for birth year, sex, grade, specialty and individual character. SHS was evaluated using the medical examination report and Sub-health Measurement Scale V1.0 (SHMS V1.0). Exposure was defined as an unhealthy lifestyle per the frequency of six behavioral dimensions from the Health-promoting Lifestyle Profile (HPLP-II). We matched 543 cases of SHS (42.66%) in a cohort of 1273 students during the 1.5 years mean follow-up time with controls. A significant difference (t = 9.79, p < 0.001) and a reduction in HPLP-II total score was present at 1.5 years follow-up (135.93 ± 17.65) compared to baseline (144.48 ± 18.66). A level-response effect was recorded with an increase of the total HPLP-II (every dimension was correlated with a decreased SHS risk). Compared to respondents with the least exposure (excellent level), those reporting a general HPLP-II level were approximately 2.3 times more likely to develop SHS (odd ratio = 2.333, 95% CI = 1.471 to 3.700); and those with less HPLP-II level (good level) were approximately 1.6 times more likely (1.644, 1.119-2.414) to develop SHS (p < 0.05). Our data indicated that unhealthy lifestyle behavior with respect to behavioral dimensions significantly affected SHS likelihood. Further analyses revealed a marked increase (average increased 14.73 points) in lifestyle level among those SHS regression to health after 1.5 years, with respect to the HPLP-II behavioral dimensions, in addition to the total score (t = -15.34, p < 0.001). SHS is highly attributable to unhealthy lifestyles, and the Int. J. Environ. Res. Public Health 2017, 14, 240 2 of 17 mitigation of modifiable lifestyle risk factors may lead to SHS regression. Increased efforts to modify unhealthy lifestyles are necessary to prevent SHS.

Factor determining prochard nest predation along a wetland gradient

USGS Publications Warehouse

Albrecht, T.; Horak, D.; Kreisinger, J.; Weidinger, K.; Klvana, P.; Michot, T.C.

2006-01-01

Waterfowl management on breeding grounds focuses on improving nest success, but few studies have compared waterfowl nest success and factors affecting nest survival along a wetland gradient and simultaneously identified nest predators. We monitored nests (n = 195) of common pochards (Aythya ferina) in Trebon Basin Biosphere Reserve, Czech Republic, during 1999-2002. Daily nest survival rates (DSRs, logistic-exposure) declined from island (0.985, 95% confidence interval, 0.978-0.991) to overwater (0.962, 0.950-0.971) and terrestrial (0.844, 0.759-0.904) nests. The most parsimonious model for DSRs included habitat class (DSRs: island > overwater > terrestrial) and nest visibility. Nest survival was improved by reduced nest visibility, increased water depth, and increased distance from the nest to habitat edge in littoral habitats. On islands, nest success increased with advancing date and increased distance to open water. A model of constant nest survival best explained the data for terrestrial nests. There were no observer effects on DSRs in any habitat. In 2003, artificial nests (n = 180; 120 contained a wax-filled egg) were deployed on study plots. The model that best explained variation in DSRs for artificial nests included only 1 variable: habitat class (DSRs: island ??? overwater > terrestrial). Mammalian predation of artificial nests (by foxes [Vulpes vulpes] and martens [Martes spp.]) was more likely in terrestrial habitats than in littoral habitats or on islands. By contrast, corvids and marsh harriers (Circus aeruginosus) prevailed among predators of overwater and island nests. Our data indicate that artificial islands and wide strips of littoral vegetation may represent secure breeding habitats for waterfowl because those habitats allow nests to be placed in areas that are not accessible to, or that are avoided by, mammalian predators. Management actions should be aimed at preserving these habitats. This, along with creation of new artificial islands, could help to enhance breeding productivity of pochards and possibly other waterfowl species inhabiting man-made ponds.

Effect of nesting environment on incubation temperature and hatching success of Morelet's crocodile (Crocodylus moreletii) in an urban lake of Southeastern Mexico.

PubMed

López-Luna, Marco A; Hidalgo-Mihart, Mircea G; Aguirre-León, Gustavo; González-Ramón, Mariana Del C; Rangel-Mendoza, Judith A

2015-01-01

Incubation temperature is an important aspect in terms of biological performance among crocodiles, and several controlled experiments have demonstrated a significant relationship between incubation temperature, success in hatching and survival of hatchlings. However, a few studies have tested these relationships in the wild. The objective of this study was to determine the relationship of nest characteristics and environment (hatch year, nest basal area and height, clutch size, distance to shore line, and vegetation cover), to incubation temperature and hatching success among Morelet's crocodile (Crocodylus moreletii). The study was carried out during the nesting seasons of Morelet's crocodile, from 2007 to 2009 in the Laguna de Las Ilusiones, an urban lake located in Villahermosa, Tabasco, Mexico. We physically characterized 18 nests and inserted a temperature data logger in each nest chamber. At the end of the nesting season and prior to hatching, we recovered the crocodile eggs and data loggers and calculated hatching success, under laboratory conditions. We related the environmental variables of the nest with the mean and fluctuation (standard deviation) of nest temperature, using linear models. We also related the environmental variables affecting the nest, to mean nest temperature and fluctuation in incubation temperature and to hatching success, using linear models. Although we found differences in incubation temperature between nests, mean incubation temperature did not differ between years, but there were differences in nest thermal fluctuation between years. The mean incubation temperature for 11 nests (61.1%) was lower than the suggested Female-Male pivotal temperature (producing 50% of each sex) for this species, and all hatchlings obtained were males. There were no differences in clutch size between years, but hatching success varied. Our study indicates that hatching success depends on certain environmental variables and nest conditions to which the eggs are subjected, including season, nest size and clutch size. We also discuss the importance of the fluctuation of incubation temperature on hatching success and sex determination. Copyright © 2015 Elsevier Ltd. All rights reserved.

Factors influencing depredation of artificial duck nests

USGS Publications Warehouse

Esler, Daniel N.; Grand, James B.

1993-01-01

Because artificial nests can facilitate controlled experiments of nest success, we used them to assess whether human visitation, nest density, vegetation structure, and proximity to habitat edge could affect depredation of duck nests on Yukon Flats National Wildlife Refuge, Alaska. More (P < 0.01) nests in a plot visited daily (100%) were depredated than those in plots visited at intervals of 7 (40%), 14 (35%), or 28 days (45%). More (P < 0.01) nests were depredated in a plot with 10 nests/ha (95%) than nests in a plot of a lower density (2/ha; 40%). Vegetation height, vegetation density, distance to a wetland, distance to forest edge, or distance to the nearest ecotone did not differ (P > 0.05) between depredated and undisturbed nests. We suggest that daily visitation of duck nests increases depredation, but longer intervals, typical of most nest studies, do not. High nesting densities, which could occur when flooding limits nesting habitat, may result in higher depredation rates.

Cavity-nesting bird use of nest boxes in vineyards of central-coast California

Treesearch

Daniel P. Mummert; Laura Baines; William D. Tietje

2002-01-01

Oak woodland habitat is being degraded or replaced by vineyards in many areas of central-coastal California. Oak woodlands are home to many insectivorous, cavity-nesting birds that would be beneficial in and around vineyards. During March to June 2001, we used bluebird nest boxes to study nest box use and productivity of cavity-nesting birds in vineyards versus...

Effects of timber size-class on predation of artificial nests in extensive forest

Treesearch

Richard M. DeGraaf; Per Angelstam

1993-01-01

Depredation on artificial ground and cup nests in even-aged seedling/sapling, pole, and mature stands of continuous northern hardwood forest was studied in the White Mountain National Forest in New Hampshire, USA from May to June 1988. Track-board nests were used to identify predators of ground nests; plain ground nests and cup nests were used to investigate the...

Differences in predators of artificial and real songbirds nests: Evidence of bias in artificial nest studies

Treesearch

Frank R. Thompson; Dirk E. Burhans

2004-01-01

In the past two decades, many researchers have used artificial nest to measure relative rates of nest predation. Recent comparisons show that real and artificial nests may not be depredated at the same rate, but no one has examined the mechanisms underlying these patterns. We determined differences in predator-specific predation rates of real and artificial nests. we...

Major benefits of guarding behavior in subsocial bees: implications for social evolution.

PubMed

Mikát, Michael; Černá, Kateřina; Straka, Jakub

2016-10-01

Parental care is a behavior that increases the growth and survival of offspring, often at a cost to the parents' own survival and/or future reproduction. In this study, we focused on nest guarding, which is one of the most important types of extended parental care; we studied this behavior in two solitary bee species of the genus Ceratina with social ancestors. We performed the experiment of removing the laying female, who usually guards the nest after completing its provisioning, to test the effects of nest guarding on the offspring survival and nest fate. By dissecting natural nests, we found that Ceratina cucurbitina females always guarded their offspring until the offspring reached adulthood. In addition, the females of this species were able to crawl across the nest partitions and inspect the offspring in the brood cells. In contrast, several Ceratina chalybea females guarded their nests until the offspring reached adulthood, but others closed the nest entrance with a plug and deserted the nest. Nests with a low number of provisioned cells were more likely to be plugged and abandoned than nests with a higher number of cells. The female removal experiment had a significantly negative effect on offspring survival in both species. These nests frequently failed due to the attacks of natural enemies (e.g., ants, chalcidoid wasps, and other competing Ceratina bees). Increased offspring survival is the most important benefit of the guarding strategy. The abandonment of a potentially unsuccessful brood might constitute a benefit of the nest plugging behavior. The facultative nest desertion strategy is a derived behavior in the studied bees and constitutes an example of an evolutionary reduction in the extent of parental care.

Nest defense- Grassland bird responses to snakes

USGS Publications Warehouse

Ellison, Kevin S.; Ribic, Christine

2012-01-01

Predation is the primary source of nest mortality for most passerines; thus, behaviors to reduce the impacts of predation are frequently quantified to study learning, adaptation, and coevolution among predator and prey species. Video surveillance of nests has made it possible to examine real-time parental nest defense. During 1999-2009, we used video camera systems to monitor 518 nests of grassland birds. We reviewed video of 48 visits by snakes to 34 nests; 37 of these visits resulted in predation of active nests. When adult birds encountered snakes at the nest (n = 33 visits), 76% of the encounters resulted in a form of nest defense (nonaggressive or aggressive); in 47% of the encounters, birds physically struck snakes. When defending nests, most birds pecked at the snakes; Eastern Meadowlarks (Sturnella magna) and Bobolinks (Dolichonyx oryzivorus) pecked most frequently in anyone encounter. Also, two Eastern Meadowlarks ran around snakes, frequently with wings spread, and three Bobolinks struck at snakes from the air. Nest defense rarely appeared to alter snake behavior; the contents of seven nests defended aggressively and two nests defended nonaggressively were partially depredated, whereas the contents of six nests defended each way were consumed completely. One fledgling was produced at each of three nests that had been aggressively defended. During aggressive defense, one snake appeared to be driven away and one was wounded. Our findings should be a useful starting point for further research. For example, future researchers may be able to determine whether the behavioral variation we observed in nest defense reflects species differences, anatomic or phylogenetic constraints, or individual differences related to a bird's prior experience. There appears to be much potential for studying nest defense behavior using video recording of both real and simulated encounters. 

SHIFT WORK AND BREAST CANCER AMONG WOMEN TEXTILE WORKERS IN SHANGHAI, CHINA

PubMed Central

Li, Wenjin; Ray, Roberta M.; Thomas, David B.; Davis, Scott; Yost, Michael; Breslow, Norman; Gao, Dao Li; Fitzgibbons, E. Dawn; Camp, Janice E.; Wong, Eva; Wernli, Karen J.; Checkoway, Harvey

2014-01-01

PURPOSE Although night shift work has been associated with elevated risk of breast cancer in numerous epidemiologic studies, evidence is not consistent. We conducted a nested case-cohort study to investigate a possible association between shift work including a night shift and risk of breast cancer within a large cohort of women textile workers in Shanghai, China. METHODS The study included 1709 incident breast cancer cases and 4780 non-cases. Data on historical shift-work schedules were collected by categorized jobs from the factories where the study subjects had worked, and then were linked to the complete work histories of each subject. No jobs in the factories involved exclusively night shift work. Therefore, night shift was evaluated as part of a rotating shift work pattern. Hazard ratios and 95% confidence intervals were calculated using Cox proportional hazards modeling adapted for the case-cohort design for years of night-shift work and the total number of nights worked. Additionally, analyses were repeated with exposures lagged by 10 and 20 years. RESULTS We observed no associations with either years of night-shift work, or number of nights worked during the entire employment period, irrespective of lag intervals. Findings from the age-stratified analyses were very similar to those observed for the entire study population. CONCLUSIONS The findings from this study provide no evidence to support the hypothesis that shift work increases breast cancer risk. The positive association between shift work and breast cancer observed in Western populations, but not observed in this and other studies of the Chinese population, suggest that the effect of shift work on breast cancer risk may be different in Asian and Caucasian women. PMID:25421377

Shift work and breast cancer among women textile workers in Shanghai, China.

PubMed

Li, Wenjin; Ray, Roberta M; Thomas, David B; Davis, Scott; Yost, Michael; Breslow, Norman; Gao, Dao Li; Fitzgibbons, E Dawn; Camp, Janice E; Wong, Eva; Wernli, Karen J; Checkoway, Harvey

2015-01-01

Although night-shift work has been associated with elevated risk of breast cancer in numerous epidemiologic studies, evidence is not consistent. We conducted a nested case-cohort study to investigate a possible association between shift work including a night shift and risk of breast cancer within a large cohort of women textile workers in Shanghai, China. The study included 1,709 incident breast cancer cases and 4,780 non-cases. Data on historical shift work schedules were collected by categorized jobs from the factories, where the study subjects had worked, and then were linked to the complete work histories of each subject. No jobs in the factories involved exclusively night-shift work. Therefore, night shift was evaluated as part of a rotating shift work pattern. Hazard ratios and 95 % confidence intervals were calculated using Cox proportional hazards modeling adapted for the case-cohort design for years of night-shift work and the total number of nights worked. Additionally, analyses were repeated with exposures lagged by 10 and 20 years. We observed no associations with either years of night-shift work or number of nights worked during the entire employment period, irrespective of lag intervals. Findings from the age-stratified analyses were very similar to those observed for the entire study population. The findings from this study provide no evidence to support the hypothesis that shift work increases breast cancer risk. The positive association between shift work and breast cancer observed in Western populations, but not observed in this and other studies of the Chinese population, suggests that the effect of shift work on breast cancer risk may be different in Asian and Caucasian women.

Age and breeding success related to nest position in a White stork Ciconia ciconia colony

NASA Astrophysics Data System (ADS)

Vergara, Pablo; Aguirre, José I.

2006-11-01

Coloniality is a breeding system that may produce benefits in terms of breeding success, although these advantages could vary according to factors such as colony size or nest position. We studied breeder's age in relation to nest position (peripheral or central) within the colony. In addition, we studied the relationship between breeding success and nest position, controlling for breeder's age, a highly correlated factor, in a White Stork Ciconia ciconia colony over a 7-year period. Our results show that central nests are mainly occupied by adult birds and had lower failure rates. However, controlling for breeder's age, nest position per se did not explain breeding success. The scarce predation and the lack of human disturbance in the study colony could explain the absence of differences in breeding success between different nest positions within the colony.

Turnover and dispersal of prairie falcons in southwestern Idaho

USGS Publications Warehouse

Lehman, Robert N.; Steenhof, Karen; Carpenter, L.B.; Kochert, Michael N.

2000-01-01

We studied Prairie Falcon (Falco mexicanus) breeding dispersal, natal dispersal, and turnover at nesting areas in the Snake River Birds of Prey National Conservation Area (NCA) from 1971- 95. Of 61 nesting areas where falcons identified one year were known to be present or absent the following year, 57% had a different falcon. This turnover rate was 2-3 times higher than that reported elsewhere for large falcons, and may have been related to high nesting densities in the NCA. Turnover at nesting areas was independent of nesting success in the previous year, but was significantly higher for females nesting on large cliffs. Mean distance between natal and breeding locations for 26 falcons banded as nestlings and later encountered as nesting adults was 8.9 km. Natal dispersal distances were similar for males and females, but more than twice as many males marked as nestlings were later encountered nesting in the NCA. Fourteen adult falcons found on different nesting areas in successive years moved an average of 1.5 km between nesting areas; males dispersed significantly farther than females. Natal and breeding dispersal distances in the NCA were lower than those reported for Prairie Falcons in other study areas. Only four falcons banded as nestlings were found outside NCA boundaries during the breeding period, and only one of these birds was known to be occupying a nesting area. We encountered no falcons banded outside the NCA occupying nesting areas in the NCA during this study.

Importance of structural stability to success of mourning dove nests

USGS Publications Warehouse

Coon, R.A.; Nichols, J.D.; Percival, H.F.

1981-01-01

Studies of nest-site selection and nesting habitats often involve a "characterization" of nests and of habitats in which nests are found. Our objective in the present work is to identify nest-site characteristics that are associated with variation in components of Mourning Dove (Zenaida macroura) fitness (e.g. the probability of a nest succeeding), as opposed to simply "characterizing" dove nest sites. If certain nest- site characteristics affect the probability that a nest will succeed, then we suspect that these characteristics will be associated with either concealment (the probability of detection by certain predators) or structural stability (the probability of eggs or entire nests falling to the ground as a result of wind, rain storms, parental activity, etc.). Although other workers agree that structural stability is an important determinant of Mourning Dove nesting success (e.g. McClure 1944: 384; Woolfenden and Rohwer 1969: 59), we are aware of no actual tests of this hypothesis.

Can selection on nest size from nest predation explain the latitudinal gradient in clutch size?

PubMed

Biancucci, Luis; Martin, Thomas E

2010-09-01

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.

Can selection on nest size from nest predation explain the latitudinal gradient in clutch size?

USGS Publications Warehouse

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.

Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma: a nested case-control study.

PubMed

Fedirko, Veronika; Tran, Hao Quang; Gewirtz, Andrew T; Stepien, Magdalena; Trichopoulou, Antonia; Aleksandrova, Krasimira; Olsen, Anja; Tjønneland, Anne; Overvad, Kim; Carbonnel, Franck; Boutron-Ruault, Marie-Christine; Severi, Gianluca; Kühn, Tilman; Kaaks, Rudolf; Boeing, Heiner; Bamia, Christina; Lagiou, Pagona; Grioni, Sara; Panico, Salvatore; Palli, Domenico; Tumino, Rosario; Naccarati, Alessio; Peeters, Petra H; Bueno-de-Mesquita, H B; Weiderpass, Elisabete; Castaño, José María Huerta; Barricarte, Aurelio; Sánchez, María-José; Dorronsoro, Miren; Quirós, J Ramón; Agudo, Antonio; Sjöberg, Klas; Ohlsson, Bodil; Hemmingsson, Oskar; Werner, Mårten; Bradbury, Kathryn E; Khaw, Kay-Tee; Wareham, Nick; Tsilidis, Konstantinos K; Aune, Dagfinn; Scalbert, Augustin; Romieu, Isabelle; Riboli, Elio; Jenab, Mazda

2017-04-04

Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking. We used a case-control study design nested within a large prospective cohort to assess the association between circulating levels of anti-lipopolysaccharide (LPS) and anti-flagellin immunoglobulin A (IgA) and G (IgG) (reflecting long-term exposures to LPS and flagellin, respectively) and risk of hepatocellular carcinoma. A total of 139 men and women diagnosed with hepatocellular carcinoma between 1992 and 2010 were matched to 139 control subjects. Multivariable rate ratios (RRs), including adjustment for potential confounders, hepatitis B/C positivity, and degree of liver dysfunction, were calculated with conditional logistic regression. Antibody response to LPS and flagellin was associated with a statistically significant increase in the risk of hepatocellular carcinoma (highest vs. lowest quartile: RR = 11.76, 95% confidence interval = 1.70-81.40; P trend  = 0.021). This finding did not vary substantially by time from enrollment to diagnosis, and did not change after adjustment for chronic infection with hepatitis B and C viruses. These novel findings, based on exposures up to several years prior to diagnosis, support a role for gut-derived bacterial products in hepatocellular carcinoma development. Further study into the role of gut barrier failure and exposure to bacterial products in liver diseases is warranted.

Comprehensive Comparison between Empty Nest and Non-Empty Nest Elderly: A Cross-Sectional Study among Rural Populations in Northeast China

PubMed Central

Chang, Ye; Guo, Xiaofan; Guo, Liang; Li, Zhao; Yang, Hongmei; Yu, Shasha; Sun, Guozhe; Sun, Yingxian

2016-01-01

This study aimed to comprehensively compare the general characteristics, lifestyles, serum parameters, ultrasonic cardiogram (UCG) parameters, depression, quality of life, and various comorbidities between empty nest and non-empty nest elderly among rural populations in northeast China. This analysis was based on our previous study which was conducted from January 2012 to August 2013, using a multistage, stratified, random cluster sampling scheme. The final analyzed sample consisted of 3208 participants aged no less than 60 years, which was further classified into three groups: non-empty nest group, empty nest group (living as a couple), and empty nest group (living alone). More than half of the participants were empty nest elderly (60.5%). There were no significant statistical differences for serum parameters, UCG parameters, lifestyles, dietary pattern, and scores of Patient Health Questionnaire-9 (PHQ-9) and World Health Organization Quality of Life questionnaire, abbreviated version (WHOQOL-BREF) among the three groups. Empty nest elderly showed no more risk for comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, left atrial enlargement (LAE), and stroke. Our study indicated that empty nest elderly showed no more risk for depression, low quality of life and comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, LAE, and stroke among rural populations in northeast China. PMID:27618905

Comprehensive Comparison between Empty Nest and Non-Empty Nest Elderly: A Cross-Sectional Study among Rural Populations in Northeast China.

PubMed

Chang, Ye; Guo, Xiaofan; Guo, Liang; Li, Zhao; Yang, Hongmei; Yu, Shasha; Sun, Guozhe; Sun, Yingxian

2016-08-27

This study aimed to comprehensively compare the general characteristics, lifestyles, serum parameters, ultrasonic cardiogram (UCG) parameters, depression, quality of life, and various comorbidities between empty nest and non-empty nest elderly among rural populations in northeast China. This analysis was based on our previous study which was conducted from January 2012 to August 2013, using a multistage, stratified, random cluster sampling scheme. The final analyzed sample consisted of 3208 participants aged no less than 60 years, which was further classified into three groups: non-empty nest group, empty nest group (living as a couple), and empty nest group (living alone). More than half of the participants were empty nest elderly (60.5%). There were no significant statistical differences for serum parameters, UCG parameters, lifestyles, dietary pattern, and scores of Patient Health Questionnaire-9 (PHQ-9) and World Health Organization Quality of Life questionnaire, abbreviated version (WHOQOL-BREF) among the three groups. Empty nest elderly showed no more risk for comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, left atrial enlargement (LAE), and stroke. Our study indicated that empty nest elderly showed no more risk for depression, low quality of life and comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, LAE, and stroke among rural populations in northeast China.

Effects of parents and Brown-headed Cowbirds (Molothrus ater) on nest predation risk for a songbird

PubMed Central

Latif, Quresh S; Heath, Sacha K; Rotenberry, John T

2012-01-01

Nest predation limits avian fitness, so ornithologists study nest predation, but they often only document patterns of predation rates without substantively investigating underlying mechanisms. Parental behavior and predator ecology are two fundamental drivers of predation rates and patterns, but the role of parents is less certain, particularly for songbirds. Previous work reproduced microhabitat-predation patterns experienced by Yellow Warblers (Setophaga petechia) in the Mono Lake basin at experimental nests without parents, suggesting that these patterns were driven by predator ecology rather than predator interactions with parents. In this study, we further explored effects of post-initiation parental behavior (nest defense and attendance) on predation risk by comparing natural versus experimental patterns related to territory density, seasonal timing of nest initiation, and nest age. Rates of parasitism by Brown-headed Cowbirds (Molothrus ater) were high in this system (49% nests parasitized), so we also examined parasitism-predation relationships. Natural nest predation rates (NPR) correlated negatively with breeding territory density and nonlinearly (U-shaped relationship) with nest-initiation timing, but experimental nests recorded no such patterns. After adjusting natural-nest data to control for these differences from experimental nests other than the presence of parents (e.g., defining nest failure similarly and excluding nestling-period data), we obtained similar results. Thus, parents were necessary to produce observed patterns. Lower natural NPR compared with experimental NPR suggested that parents reduced predation rates via nest defense, so this parental behavior or its consequences were likely correlated with density or seasonal timing. In contrast, daily predation rates decreased with nest age for both nest types, indicating this pattern did not involve parents. Parasitized nests suffered higher rates of partial predation but lower rates of complete predation, suggesting direct predation by cowbirds. Explicit behavioral research on parents, predators (including cowbirds), and their interactions would further illuminate mechanisms underlying the density, seasonal, and nest age patterns we observed. PMID:23301174

Why Women Join the Military: Enlistment Decisions and Postdeployment Experiences of Service Members and Veterans.

PubMed

Mankowski, Mariann; Tower, Leslie E; Brandt, Cynthia A; Mattocks, Kristin

2015-10-01

Over the past three decades women's enlistment has continued to increase. In an effort to help social workers better meet the needs of female veterans, this study sought to learn women's enlistment motivations and postdeployment experiences. This qualitative study was nested within the Women Veterans Cohort Study. Using a semistructured interview guide, authors interviewed 18 enlisted female service members and veterans. The themes that emerged, based on grounded theory, included not only opportunity and calling, but also outcomes. Unexpectedly, enlistment resulted in a professional military career, with over half of the participants making the military their life's work. Further study on the motivation, retention, and the reintegration needs of women postmilitary is necessary, particularly with military recruitment targets of 20 percent women by the year 2020 and the increased awareness of the military as a potentially hostile work environment for women.

Density and Distribution of Xylocopa Nests (Hymenoptera: Apidae) in Caatinga Areas in the Surroundings of Passion Fruit Crops.

PubMed

Martins, C F; de Siqueira, K M M; Kiill, L H P; Sá, I I S; Aguiar, C M L

2014-08-01

Due to their importance as pollinators of many plant species, this study aimed to know the nest density, spatial distribution, and nesting substrates used by Xylocopa species in the Caatinga, a xerophilous vegetation of Northeastern Brazil. Three areas of Caatinga in the surroundings of passion fruit crops were sampled. The bee species found in these areas were Xylocopa grisescens Lepeletier and Xylocopa frontalis (Olivier). All nests were in Commiphora leptophloeos (Burseraceae) trees (n = 113). Phytosociological analysis showed that this tree species presented the highest absolute density (212.5 individuals/ha) and index of importance value (52.7). The distribution pattern of the C. leptophloeos was aggregated. The nests were located in dead and dried branches with an average diameter of 5.3 ± 2.0 cm (n = 43). The mean number of nests/tree was 3.1 ± 2.8 (n = 113). The less disturbed area showed 6.7 nests/ha and 4.2 nests/tree. In the disturbed areas, 0.9 nests/ha and 2.4 to 2.7 nests/tree were observed. The availability of substrate for nesting in the studied areas and its importance as a limiting factor for nesting are discussed.

The effect of predation on begging-call evolution in nestling wood warblers.

PubMed

Haskell

1999-04-01

I combined a comparative study of begging in ground- and tree-nesting wood warblers (Parulidae) with experimental measures of the predation costs of warbler begging calls. Throughout their development, ground-nesting warbler nestlings had significantly higher-frequency begging calls than did tree-nesting warblers. There was also a trend for ground-nesting birds to have less rapidly modulated calls. There were no consistent associations between nesting site and the amplitude of the calls. Using miniature walkie-talkies hidden inside artificial nests, I reciprocally transplanted the begging calls of 5- and 8-day-old black-throated blue warblers, Dendroica caerulescens (tree-nesting) and ovenbirds, Seiurus aurocapillus (ground-nesting) and measured the corresponding changes in rates of nest predation. For the begging calls of 8-day-old nestlings, but not those of 5-day-olds, the calls of the tree-nesting species coming from ground nests incurred greater costs than did the calls of ground nesters. The reciprocal transplant had little effect on the rate of predation. Tooth imprints on clay eggs placed in artificial nests indicated that eastern chipmunks, Tamias striatus, were responsible for the increased cost of begging for black-throated blue calls coming from the ground. These data suggest that nest predation may be responsible for maintaining some of the interspecific differences in the acoustic structure of begging calls. Copyright 1999 The Association for the Study of Animal Behaviour.

Nesting biology of Lesser Canada Geese, Branta canadensis parvipes, along the Tanana River, Alaska

USGS Publications Warehouse

Ely, Craig R.; Pearce, J.M.; Ruess, Roger W.

2008-01-01

Lesser Canada Geese (Branta canadensis parvipes) are widespread throughout interior regions of Alaska and Canada, yet there have been no published studies documenting basic aspects of their nesting biology. We conducted a study to determine reproductive parameters of Lesser Canada Geese nesting along the Tanana River near the city of Fairbanks, in interior Alaska. Fieldwork was conducted in May of 2003, and consisted of locating nests along the riparian corridor between Fairbanks and Northpole, Alaska. Nests were found on gravel islands and shore habitats along the Tanana River, and were most commonly observed among driftwood logs associated with patches of alder (Alnus spp.) and willow (Salix spp.). Peak of nest initiation was 3-8 May, with a range from 27 April to 20 May; renesting was likely. Clutches ranged in size from 2 to 7 eggs and averaged 4.6 eggs. There was a negative correlation between clutch size and date of nest initiation. Egg size (mean mass = 128 g) was similar to other medium-sized Canada Geese. A positive correlation between egg size and clutch size was likely related to female age. Nineteen of 28 nests (68%) were active when visited; nests located on islands with nesting Mew Gulls (Larus canus) were more likely to be active than nests located elsewhere. Evidence at nest sites implicated Bald Eagles (Haliaeetus leucocephalus) and Red Foxes (Vulpes vulpes) as nest predators.

Multivariate analysis of early and late nest sites of Abert's Towhees

Treesearch

Deborah M. Finch

1985-01-01

Seasonal variation in nest site selection by the Abert's towhee (Pipilo aberti) was studied in honey mesquite (Prosopis glandulosa) habitat along the lower Colorado River from March to July, 1981. Stepwise discriminant function analysis identified nest vegetation type, nest direction, and nest height as the three most important variables that characterized the...

Nesting success of Northern Pintails on the coastal Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Flint, Paul L.; Grand, James B.

1996-01-01

We studied nesting chronology and success of Northern Pintails (Anas acuta) on the coastal Yukon-Kuskokwim Delta, Alaska during the summers of 1991-1993. We found a total of 795 nests during three annual searches of a 27.4 km2 area. Minimum nest density averaged 9.67 nests per km2. Nesting success varied among years and ranged from 43.12% in 1991 to 10.74% in 1993 (average 23.95%). Most nest loss was the result of predation and tidal flooding. Daily nest survival probability declined with nest initiation date in all three years and also varied with nest age in 1992. Clutch size averaged 7.63 ± 0.067 (SE) eggs per nest and was larger than reported for other populations of Northern Pintails. Clutch size declined during the 44-47 day nesting interval at a greater rate than reported for other populations of Northern Pintails. We conclude that sub-arctic and prairie nesting Northern Pintails have similar reproductive potentials.

Savanna chimpanzee (Pan troglodytes verus) nesting ecology at Bagnomba (Kedougou, Senegal).

PubMed

Badji, L; Ndiaye, P I; Lindshield, S M; Ba, C T; Pruetz, J D

2018-05-01

We studied the nesting behavior of the critically endangered West African chimpanzee (Pan troglodytes verus). We assumed that the nesting data stemmed from a single, unhabituated community at the Bagnomba hill site in the savanna-woodlands of southeastern Senegal. The aim of this study was to examine chimpanzees' nesting habits in terms of the tree species utilized and sleeping nest heights. We recorded a total of 550 chimpanzee nests at Bagnomba between January 2015 and December 2015. The chimpanzees here made nests in particular tree species more often than others. The majority of nests (63%) were in two tree species: Diospyros mespiliformis and Pterocarpus erinaceus. The average height of nesting trees was 10.54 m (SD 3.91, range, 0.0-29.0 m) and average nest height was 7.90 m (SD 3.62, range, 0.0-25.0 m). The result of a linear regression analysis (r = 0.7874; n = 550; p < 0.05) is consistent with a preference for nesting at a particular height. Bagnomba chimpanzees rarely made ground nests (0.36% of nests), but the presence of any ground nesting was unexpected, given that at least one leopard (Panthera pardus) also occupied the hill. This knowledge will enable stakeholders involved in the protection of chimpanzees specifically and of biodiversity in general to better understand chimpanzee ecology and inform a conservation action plan in Senegal where the survival of this species is threatened.

Effect of nest design, passages, and hybrid on use of nest and production performance of layers in furnished cages.

PubMed

Wall, H; Tauson, R; Elwinger, K

2002-03-01

Production performance, including egg quality, and proportion of eggs laid in nests were studied in furnished experimental cages incorporating nests, litter baths, and perches. The study comprised a total of 972 hens of two genotypes: Lohmann Selected Leghorn (LSL) and Hy-Line White. The birds were studied from 20 to 80 wk of age, and conventional four-hen cages were included as a reference. In furnished cages for six hens, the effects of 30 or 50% vs. 100% nest bottom lining (Astro turf) were studied with LSL hens. Nest bottom lining had no significant effect on egg production or proportions of cracked or dirty eggs, but the use of nests was significantly higher in cages incorporating nests with 100% lining, compared with 50 or 30%. The two hybrids were compared when housed in large, group-furnished cages for 14 or 16 hens of two designs; with a rear partition with two pop holes or fully open, i.e., no rear partition. LSL birds produced significantly better and had a significantly lower proportion of cracked eggs. There was no difference between H- and O-cages, either in production or in egg quality. LSL birds laid a significantly lower proportion of eggs in the nests, especially in O-cages, implying a significant hybrid x cage interaction. When housed in conventional cages, the hybrids did not differ in proportion of cracked eggs but differed in production traits. It was concluded that with the present nest design, the proportion of nest bottom lining cannot be reduced without affecting birds' use of nests, but the proportion did not affect exterior egg quality. The effect of genotype should be considered in the further development of furnished cages.

Patch size and edge proximity are useful predictors of brood parasitism but not nest survival of grassland birds.

PubMed

Benson, Thomas J; Chiavacci, Scott J; Ward, Michael P

2013-06-01

Declines of migratory birds have led to increased focus on causative factors for these declines, including the potential adverse effects of habitat fragmentation on reproductive success. Although numerous studies have addressed how proximity to a habitat edge, patch size, or landscape context influence nest survival or brood parasitism, many have failed to find the purported effects. Furthermore, many have sought to generalize patterns across large geographic areas and habitats. Here, we examined evidence for effects of edge proximity, patch size, and landscape context on nest survival and brood parasitism of grassland birds, a group of conservation concern. The only consistent effect was a positive association between edge proximity and brood parasitism. We examined effects of patch size on nest survival (37 studies) and brood parasitism (30 studies) representing 170 and 97 different estimates, respectively, with a total sample size of > 14000 nests spanning eastern North America. Nest survival weakly increased with patch size in the Great Plains, but not in the Midwestern or Eastern United States, and brood parasitism was inversely related to patch size and consistently greater in the Great Plains. The consistency in brood parasitism relative to nest survival patterns is likely due to parasitism being caused by one species, while nest survival is driven by a diverse and variable suite of nest predators. Often, studies assume that predators responsible for nest predation, the main driver of nest success, either are the same or exhibit the same behaviors across large geographic areas. These results suggest that a better mechanistic understanding of nest predation is needed to provide meaningful conservation recommendations for improving grassland bird productivity, and that the use of general recommendations across large geographic areas should only be undertaken when sufficient data are available from all regions.

Predators of Greater Sage-Grouse nests identified by video monitoring

USGS Publications Warehouse

Coates, P.S.; Connelly, J.W.; Delehanty, D.J.

2008-01-01

Nest predation is the primary cause of nest failure for Greater Sage-Grouse (Centrocercus urophasianus), but the identity of their nest predators is often uncertain. Confirming the identity of these predators may be useful in enhancing management strategies designed to increase nest success. From 2002 to 2005, we monitored 87 Greater Sage-Grouse nests (camera, N = 55; no camera, N = 32) in northeastern Nevada and south-central Idaho and identified predators at 17 nests, with Common Ravens (Corvus corax) preying on eggs at 10 nests and American badgers (Taxidea taxis) at seven. Rodents were frequently observed at grouse nests, but did not prey on grouse eggs. Because sign left by ravens and badgers was often indistinguishable following nest predation, identifying nest predators based on egg removal, the presence of egg shells, or other sign was not possible. Most predation occurred when females were on nests. Active nest defense by grouse was rare and always unsuccessful. Continuous video monitoring of Sage-Grouse nests permitted unambiguous identification of nest predators. Additional monitoring studies could help improve our understanding of the causes of Sage-Grouse nest failure in the face of land-use changes in the Intermountain West. ?? 2008 Association of Field Ornithologists.

High-tech or field techs: Radio-telemetry is a cost-effective method for reducing bias in songbird nest searching

USGS Publications Warehouse

Peterson, Sean M.; Streby, Henry M.; Lehman, Justin A.; Kramer, Gunnar R.; Fish, Alexander C.; Andersen, David E.

2015-01-01

We compared the efficacy of standard nest-searching methods with finding nests via radio-tagged birds to assess how search technique influenced our determination of nest-site characteristics and nest success for Golden-winged Warblers (Vermivora chrysoptera). We also evaluated the cost-effectiveness of using radio-tagged birds to find nests. Using standard nest-searching techniques for 3 populations, we found 111 nests in locations with habitat characteristics similar to those described in previous studies: edges between forest and relatively open areas of early successional vegetation or shrubby wetlands, with 43% within 5 m of forest edge. The 83 nests found using telemetry were about half as likely (23%) to be within 5 m of forest edge. We spent little time searching >25 m into forest because published reports state that Golden-winged Warblers do not nest there. However, 14 nests found using telemetry (18%) were >25 m into forest. We modeled nest success using nest-searching method, nest age, and distance to forest edge as explanatory variables. Nest-searching method explained nest success better than nest age alone; we estimated that nests found using telemetry were 10% more likely to fledge young than nests found using standard nest-searching methods. Although radio-telemetry was more expensive than standard nest searching, the cost-effectiveness of both methods differed depending on searcher experience, amount of equipment owned, and bird population density. Our results demonstrate that telemetry can be an effective method for reducing bias in Golden-winged Warbler nest samples, can be cost competitive with standard nest-searching methods in some situations, and is likely to be a useful approach for finding nests of other forest-nesting songbirds.

Density-dependent nest predation in waterfowl: the relative importance of nest density versus nest dispersion

USGS Publications Warehouse

Ackerman, Joshua T.; Ringelman, Kevin M.; Eadie, J.M.

2012-01-01

When nest predation levels are very high or very low, the absolute range of observable nest success is constrained (a floor/ceiling effect), and it may be more difficult to detect density-dependent nest predation. Density-dependent nest predation may be more detectable in years with moderate predation rates, simply because there can be a greater absolute difference in nest success between sites. To test this, we replicated a predation experiment 10 years after the original study, using both natural and artificial nests, comparing a year when overall rates of nest predation were high (2000) to a year with moderate nest predation (2010). We found no evidence for density-dependent predation on artificial nests in either year, indicating that nest predation is not density-dependent at the spatial scale of our experimental replicates (1-ha patches). Using nearest-neighbor distances as a measure of nest dispersion, we also found little evidence for “dispersion-dependent” predation on artificial nests. However, when we tested for dispersion-dependent predation using natural nests, we found that nest survival increased with shorter nearest-neighbor distances, and that neighboring nests were more likely to share the same nest fate than non-adjacent nests. Thus, at small spatial scales, density-dependence appears to operate in the opposite direction as predicted: closer nearest neighbors are more likely to be successful. We suggest that local nest dispersion, rather than larger-scale measures of nest density per se, may play a more important role in density-dependent nest predation.

Nesting Ecology of Hawksbill Sea Turtles (Eretmochelys imbricata) on Utila, Honduras

NASA Astrophysics Data System (ADS)

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 preferentially nested along 80 m that differed from the remainder of the beach in having higher elevation and extensive forest cover. This is the first study from Honduras to report a regular nesting population of hawksbills as well as characterize a nesting beach for this species. It provides an important foundation for hawksbill research in Honduras, a region where we have insufficient knowledge to adequately protect this critically endangered species.

Influence of human development and predators on nest survival of tundra birds, Arctic Coastal Plain, Alaska.

PubMed

Liebezeit, J R; Kendall, S J; Brown, S; Johnson, C B; Martin, P; McDonald, T L; Payer, D C; Rea, C L; Streever, B; Wildman, A M; Zack, S

2009-09-01

Nest predation may influence population dynamics of birds on the Arctic Coastal Plain (ACP) of Alaska, USA. Anthropogenic development on the ACP is increasing, which may attract nest predators by providing artificial sources of food, perches, den sites, and nest sites. Enhanced populations or concentrations of human-subsidized predators may reduce nest survival for tundra-nesting birds. In this study, we tested the hypothesis that nest survival decreases in proximity to human infrastructure. We monitored 1257 nests of 13 shorebird species and 619 nests of four passerine species at seven sites on the ACP from 2002 to 2005. Study sites were chosen to represent a range of distances to infrastructure from 100 m to 80 km. We used Cox proportional hazards regression models to evaluate the effects of background (i.e., natural) factors and infrastructure on nest survival. We documented high spatial and temporal variability in nest survival, and site and year were both included in the best background model. We did not detect an effect of human infrastructure on nest survival for shorebirds as a group. In contrast, we found evidence that risk of predation for passerine nests increased within 5 km of infrastructure. This finding provides quantitative evidence of a relationship between infrastructure and nest survival for breeding passerines on the ACP. A posteriori finer-scale analyses (within oil field sites and individual species) suggested that Red and Red-necked Phalaropes combined (Phalaropus fulicarius, P. lobatus) had lower productivity closer to infrastructure and in areas with higher abundance of subsidized predators. However, we did not detect such a relationship between infrastructure and nest survival for Semipalmated and Pectoral Sandpipers (Calidris pusilla, C. melanotos), the two most abundant shorebirds. High variability in environmental conditions, nest survival, and predator numbers between sites and years may have contributed to these inconsistent results. We recommend targeted management actions to minimize anthropogenic effects and suggest new research needed on this issue as expanding development is planned for the ACP of Alaska. In particular, we recommend research on demography of key predators and their importance with respect to nest survival, and experimental studies that better address challenges posed by high natural variability.

Breast-feeding and maternal risk of type 2 diabetes: a prospective study and meta-analysis.

PubMed

Jäger, Susanne; Jacobs, Simone; Kröger, Janine; Fritsche, Andreas; Schienkiewitz, Anja; Rubin, Diana; Boeing, Heiner; Schulze, Matthias B

2014-07-01

We aimed to examine the association between breast-feeding and maternal risk of type 2 diabetes and to investigate whether this association is mediated by anthropometric and biochemical factors. A case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study between 1994 and 2005 including 1,262 childbearing women (1,059 in a random sub-cohort and 203 incident cases) mainly aged between 35 and 64 years at baseline was applied. Self-reported lifetime duration of breast-feeding was assessed by questionnaire. Blood samples were used for biomarker measurement (HDL-cholesterol, triacylglycerols, C-reactive protein, fetuin-A, γ-glutamyltransferase, adiponectin). A systematic literature search and meta-analysis was conducted of prospective cohort studies investigating breast-feeding and risk of type 2 diabetes. The HR for each additional 6 months of breast-feeding was 0.73 (95% CI 0.56, 0.94) in EPIC-Potsdam. Meta-analysis of three previous prospective studies and the current study revealed an inverse association between breast-feeding duration and risk of diabetes (pooled HR for lifetime breast-feeding duration of 6-11 months compared with no breast-feeding 0.89; 95% CI 0.82, 0.97). Adjustment for BMI and waist circumference attenuated the association (HR per six additional months in EPIC-Potsdam 0.80; 95% CI 0.61, 1.04). Further controlling for potentially mediating biomarkers largely explained this association (HR 0.89; 95% CI 0.68, 1.16). Longer duration of breast-feeding may be related to a lower risk of diabetes. This potentially protective effect seems to be reflected by a more favourable metabolic profile; however, the role of body weight as a mediator or confounder remains uncertain.

Can routine chest radiography be used to diagnose mild COPD? A nested case-control study.

PubMed

den Harder, A M; Snoek, A M; Leiner, T; Suyker, W J; de Heer, L M; Budde, R P J; Lammers, J W J; de Jong, P A; Gondrie, M J A

2017-07-01

To determine whether mild stage chronic obstructive pulmonary disease (COPD) can be detected on chest radiography without substantial overdiagnosis. A retrospective nested case-control study (case:control, 1:1) was performed in 783 patients scheduled for cardiothoracic surgery who underwent both spirometry and a chest radiograph preoperative. Diagnostic accuracy of chest radiography for diagnosing mild COPD was investigated using objective measurements and overall appearance specific for COPD on chest radiography. Inter-observer variability was investigated and variables with a kappa >0.40 as well as baseline characteristics were used to make a diagnostic model which was aimed at achieving a high positive predictive value (PPV). Twenty percent (155/783) had COPD. The PPV of overall appearance specific for COPD alone was low (37-55%). Factors in the diagnostic model were age, type of surgery, gender, distance of the right diaphragm apex to the first rib, retrosternal space, sternodiaphragmatic angle, maximum height right diaphragm (lateral view) and subjective impression of COPD (using both views). The model resulted in a PPV of 100%, negative predictive value (NPV) of 82%, sensitivity of 10% and specificity of 100% with an area under the curve of 0.811. Detection of mild COPD without substantial overdiagnosis was not feasible on chest radiographs in our cohort. Copyright © 2017 Elsevier B.V. All rights reserved.

Spatial Assessment of the Association between Long-Term Exposure to Environmental Factors and the Occurrence of Amyotrophic Lateral Sclerosis in Catalonia, Spain: A Population-Based Nested Case-Control Study.

PubMed

Povedano, Mònica; Saez, Marc; Martínez-Matos, Juan-Antonio; Barceló, Maria Antònia

2018-05-31

It is believed that an interaction between genetic and non-genetic factors may be involved in the development of amyotrophic lateral sclerosis (ALS). With the exception of exposure to agricultural chemicals like pesticides, evidence of an association between environmental risk factors and ALS is inconsistent. Our objective here was to investigate the association between long-term exposure to environmental factors and the occurrence of ALS in Catalonia, Spain, and to provide evidence that spatial clusters of ALS related to these environmental factors exist. We carried out a nested case-control study constructed from a retrospective population-based cohort, covering the entire region. Environmental variables were the explanatory variables of interest. We controlled for both observed and unobserved confounders. We have found some spatial clusters of ALS. The results from the multivariate model suggest that these clusters could be related to some of the environmental variables, in particular agricultural chemicals. In addition, in high-risk clusters, besides corresponding to agricultural areas, key road infrastructures with a high density of traffic are also located. Our results indicate that some environmental factors, in particular those associated with exposure to pesticides and air pollutants as a result of urban traffic, could be associated with the occurrence of ALS. © 2018 S. Karger AG, Basel.

Predictors and outcomes of superior mesenteric artery syndrome in patients with constipation: a prospective, nested case-control study.

PubMed

Xu, Lin; Yu, Wen-Kui; Lin, Zhi-Liang; Jiang, Jun; Feng, Xiao-Bo; Li, Ning

2014-10-01

Superior mesenteric artery (SMA) syndrome may occur in patients with constipation, whereas the association between these two distinct diseases has not been confirmed yet. We investigated the incidence, risk factors and treatment strategy associated with SMA syndrome in constipated patients. We conducted a prospective nested case-control study from a 9-year hospitalization cohort (n=973). Cases were matched to controls 1:4 on factors of age and gender. Cases developed SMA syndrome in long term follow-up (n=26) and controls did not (n=104). Independent risk factors were identified by using univariate analysis and conditional logistic regression analysis. Enteral nutritional support was applied in all cases and its curative effect was evaluated by retrospective analysis. The incidence of SMA syndrome was 2.67%. The risk factors under scrutiny were body mass index (BMI)≤18 (odds ratio (OR) 2.89, 95% CI 1.14 to 9.31) and abnormal colon transit time (OR 3.57, 95% CI 1.36 to 9.35). Twenty-two patients recovered after treatment of nutritional support, and the success rate of conservative treatment was 84.6%. BMI≤18 and prolonged colon transit time both were risk factors associated with SMA syndrome in constipated patients. Enteral nutritional support should be adopted as the first-line treatment for this condition.

Mourning Dove nesting habitat and nest success in Central Missouri

USGS Publications Warehouse

Drobney, R.D.; Schulz, J.H.; Sheriff, S.L.; Fuemmeler, W.J.

1998-01-01

Previous Mourning Dove (Zenaida macroura) nesting studies conducted in areas containing a mixture of edge and continuous habitats have focused on edge habitats. Consequently, little is known about the potential contribution of continuous habitats to dove production. In this study we evaluated the relative importance of these two extensive habitat types by monitoring the habitat use and nest success of 59 radio-marked doves during 1990-1991 in central Missouri. Of 83 nests initiated by our marked sample, most (81.9%) were located in edge habitats. Although continuous habitats were selected less as nest sites, the proportion of successful nests did not differ significantly from that in edge habitats. Our data indicate that continuous habitats should not be considered marginal nesting habitat. If the intensity of use and nest success that we observed are representative regionally or nationally, continuous habitats could contribute substantially to annual Mourning Dove production because of the high availability of these habitats throughout much of the Mourning Dove breeding range.

Decline in a population of spectacled eiders nesting on the Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Ely, Craig R.; Dau, Christian; Babcock, Christopher

1994-01-01

The number of spectacled eiders nesting on two study areas near the Kashunuk River, on the central Yukon-Kuskokwim (Y-K) Delta, Alaska, declined by over 75% in the last 20 years. Nesting densities have remained low, but have not significantly declined since 1985. There has been no decrease in the reproductive effort of individual females as indicated by average clutch sizes. There has been a significant decline in the proportion of nests located on islands on one of the two study areas. Nesting success declined significantly during the 1970's. Success was not monitored in recent years, but has likely been low, based on the poor nesting success and declining numbers of cackling Canada geese and black brant nesting on the area. Nest predation by arctic foxes severely limited the productivity of cackling Canada geese, and foxes were likely the major predators of eider nests. Persistent high predation rates may lead to local extirpation in highly philopatric species such as eiders.

Nest Records of Wreathed Hornbill (Rhyticeros undulates) in Gunung Gentong Station, Mount Ungaran Central Java

NASA Astrophysics Data System (ADS)

Rahayuningsih, M.; Kartijomo, NE; Retnaningsih, A.; Munir, M.; Dahlan, J.

2017-04-01

The remaining forest of Mount Ungaran, Central Javais the suitable habitat of Wreathed Hornbill (Rhyticeros undulatus), especially for a nesting site. The objective of the study was to analyse the nest record and characteristics of habitat around the nest, especially in Gunung Gentong station. The research was conducted from 2010-2016 using exploration method. The methodhabitat profile of the vertical structure tree canopy was taken by plot size 60 × 20 m. Measurements were taken to the standing of vegetation, canopy closure, the direction of the canopy, height canopy, a former branch of the vegetation height, and stem diameter. The Result of the study showed that Gunung Gentong is one of the research station that we have been recorded for nesting site on 2010-2015. Atotal of the nest record on Gunung Genting station was 10 nests. Estimate the elevation of nest location between 939-1240 AMSL. The tree species that used for nesting was Syzygium glabatrum, Syzygium antisepticum, Ceratoxylon formosum, and Ficus sp

Why wasp foundresses change nests: relatedness, dominance, and nest quality.

PubMed

Seppä, Perttu; 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 temporarily or permanently, or abandon nests. Females can become helpers or egglayers, effectively workers or queens. What they actually do can be predicted by a combination of ecological and relatedness factors. Advantages through increased lifetime success of individuals and nests drives foundresses of the social wasp Polistes from solitary to social nest founding. We studied reproductive options of spring foundresses of P. carolina by monitoring individually-marked wasps and assessing reproductive success of each foundress by using DNA microsatellites. We examined what behavioral decisions foundresses make after relaxing a strong ecological constraint, shortage of nesting sites. We also look at the reproductive consequences of different behaviors. As in other Polistes, the most successful strategy for a foundress was to initiate a nest as early as possible and then accept others as subordinates. A common feature for many P. carolina foundresses was, however, that they reassessed their reproductive options by actively monitoring other nests at the field site and sometimes moving permanently to new nests should that offer better (inclusive) fitness prospects compared to their original nests. A clear motivation for moving to new nests was high genetic relatedness; by the end of the foundress period all females were on nests with full sisters.

Ground-nesting by the chimpanzees of the Nimba Mountains, Guinea: environmentally or socially determined?

PubMed

Koops, Kathelijne; Humle, Tatyana; Sterck, Elisabeth H M; Matsuzawa, Tetsuro

2007-04-01

The chimpanzees (Pan troglodytes verus) of the Nimba Mountains, Guinea, West Africa, commonly make both elaborate ("night") and simple ("day") nests on the ground. In this study we investigated which factors might influence ground-nesting in this population, and tested two ecological hypotheses: 1) climatic conditions, such as high wind speeds at high altitudes, may deter chimpanzees from nesting in trees; and 2) a lack of appropriate arboreal nesting opportunities may drive the chimpanzees to nest on the ground. In addition to testing these two hypotheses, we explored whether ground-nesting is a sex-linked behavior. Data were collected monthly between August 2003 and May 2004 along transects and ad libitum. To identify the sex of ground-nesting individuals, we used DNA extracted from hair samples. The results showed that the occurrence and distribution of ground nests were not affected by climatic conditions or a lack of appropriate nest trees. Support was found for the notion that ground-nesting is a sex-linked behavior, as males were responsible for building all of the elaborate ground nests and most of the simple ground nests sampled. Elaborate ground nests occurred mostly in nest groups associated with tree nests, whereas simple ground nests usually occurred without tree nests in their vicinity. These results suggest that ground-nesting may be socially, rather than ecologically, determined.

Large increase in nest size linked to climate change: an indicator of life history, senescence and condition.

PubMed

Møller, Anders Pape; Nielsen, Jan Tøttrup

2015-11-01

Many animals build extravagant nests that exceed the size required for successful reproduction. Large nests may signal the parenting ability of nest builders suggesting that nests may have a signaling function. In particular, many raptors build very large nests for their body size. We studied nest size in the goshawk Accipiter gentilis, which is a top predator throughout most of the Nearctic. Both males and females build nests, and males provision their females and offspring with food. Nest volume in the goshawk is almost three-fold larger than predicted from their body size. Nest size in the goshawk is highly variable and may reach more than 600 kg for a bird that weighs ca. 1 kg. While 8.5% of nests fell down, smaller nests fell down more often than large nests. There was a hump-shaped relationship between nest volume and female age, with a decline in nest volume late in life, as expected for senescence. Clutch size increased with nest volume. Nest volume increased during 1977-2014 in an accelerating fashion, linked to increasing spring temperature during April, when goshawks build and start reproduction. These findings are consistent with nest size being a reliable signal of parental ability, with large nest size signaling superior parenting ability and senescence, and also indicating climate warming.

Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections.

PubMed

Cebey-López, Miriam; Herberg, Jethro; Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Nazareth; Salas, Antonio; Martinón-Sánchez, José María; Gormley, Stuart; Sumner, Edward; Fink, Colin; Martinón-Torres, Federico

2015-01-01

Molecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques. A nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1-4), rhinovirus, adenovirus (A-F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011-2013. The results were corroborated in an independent cohort collected in the UK. A total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12-24 months age group. The most frequently observed co-infection patterns were RSV-Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV-bocavirus / bocavirus-influenza (5 patients, 5.2%, UK cohort). The presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12-24 months of age. The clinical significance of these findings is unclear but should warrant further analysis.

Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections

PubMed Central

Cebey-López, Miriam; Herberg, Jethro; Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Nazareth; Salas, Antonio; Martinón-Sánchez, José María; Gormley, Stuart; Sumner, Edward; Fink, Colin; Martinón-Torres, Federico

2015-01-01

Background Molecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques. Methods A nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1–4), rhinovirus, adenovirus (A—F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011–2013. The results were corroborated in an independent cohort collected in the UK. Results A total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12–24 months age group. The most frequently observed co-infection patterns were RSV—Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV—bocavirus / bocavirus—influenza (5 patients, 5.2%, UK cohort). Conclusion The presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12–24 months of age. The clinical significance of these findings is unclear but should warrant further analysis. PMID:26332375

Nest site selection in native and exotic trees by Black-chinned Hummingbirds

Treesearch

Deborah M. Finch; Jeffrey Kelly

2002-01-01

We studied nest site selection and nesting success in Black-chinned Hummingbirds (Archilochus alexandri) along the middle Rio Grande, New Mexico. The study was conducted in association with an exotic woody plant removal program to determine whether the removal of exotic plants would affect wildlife populations and nesting success, either positively or negatively. Point...

Association between traditional systemic antipsoriatic drugs and tuberculosis risk in patients with psoriasis with or without psoriatic arthritis: results of a nationwide cohort study from Taiwan.

PubMed

Chen, Yi-Ju; Wu, Chun-Ying; Shen, Jui-Lung; Chen, Tzu-Ting; Chang, Yun-Ting

2013-07-01

Although the link between tuberculosis (TB) and biologics use is well established, the risk of TB among patients with psoriasis exposed to traditional systemic therapies remains elusive. The aim is to investigate the association between traditional systemic therapies and TB among patients with psoriasis. We conducted a retrospective cohort study on the risk of active TB among patients with psoriasis and psoriatic arthritis, using the National Health Insurance Research Database of Taiwan, 1996 through 2008. Standardized incidence ratios of TB were analyzed in comparison with age- and gender-matched general population. Logistic regression was used in a nested case-control analysis to estimate the odds ratios of TB related to exposure to traditional systemic agents during the year before TB development. Among the 81,266 patients in the psoriasis cohort, 497 new active TB cases were identified. The incidence rate of TB was 102 cases per 100,000 person-years among patients with psoriasis (standardized incidence ratio 1.22, 95% confidence interval 1.18-1.33). The risk of TB was higher in patients with severe disease (standardized incidence ratio 1.52, 95% confidence interval 1.46-1.74). To facilitate comparisons with the 497 active TB cases, a total of 1988 matched control subjects were selected for a nested case-control study. Patients taking systemic corticosteroids and nonsteroidal anti-inflammatory drugs were associated with higher incidence of TB, especially frequent users, after adjustment for multiple TB risk factors, drug exposures, hospital visits, and level of urbanization. Stratified analyses of current users and new users of these drugs revealed similar results. Finally, traditional systemic antipsoriatic treatment was not associated with TB on any of the analyses. The National Health Insurance Research Database did not contain information regarding severity of psoriasis, smoking status, alcohol use, diet, laboratory parameters, chest radiograph, or history of recent contact with an individual with TB. Misclassification of disease cannot be ruled out in a registry-based database. The accessibility of health care may be associated with the level of urbanization, which could confound the effect of drugs in multivariate analyses. Severe psoriasis may be associated with an elevated TB risk. Traditional systemic therapies do not seem to be strongly associated with TB occurrence. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Urinary Biomarkers of Catechins and Risk of Hepatocellular Carcinoma in the Shanghai Cohort Study

PubMed Central

Butler, Lesley M.; Huang, Joyce Yongxu; Wang, Renwei; Lee, Mao-Jun; Yang, Chung S.; Gao, Yu-Tang; Yuan, Jian-Min

2015-01-01

Dietary catechins are phytochemicals with both antioxidative and prooxidative stress properties. Green tea is a major source of catechins and may be associated with hepatocellular carcinoma (HCC) risk, but the catechin-HCC relationship has not been evaluated using a biomarker-based approach. A nested case-control study of HCC (211 cases and 1,067 matched controls) was conducted within the Shanghai Cohort Study, which enrolled 18,244 men between 1986 and 1989. Concentrations of specific catechins, including epicatechin, epigallocatechin (EGC), and 4′-O-methyl-epigallocatechin, were measured in urine specimens that had been collected prior to HCC diagnosis. None of the catechins measured were associated with HCC risk. In stratified analyses, there was a statistically significant trend for an association of higher urinary EGC with increased HCC risk among subjects with positive serology for hepatitis B surface antigen (P for trend = 0.02). This positive EGC-HCC association became stronger for hepatitis B surface antigen–positive persons who also had low serum retinol levels (for detectable levels vs. undetectable levels, odds ratio = 2.62, 95% confidence interval: 1.25, 5.51). There was no evidence supporting a protective role of catechins in the development of HCC. Instead, exposure to high levels of catechins may increase the risk of developing HCC for high-risk individuals. PMID:25713334

Should adrenaline be used in patients with hemodynamically stable anaphylaxis? Incident case control study nested within a retrospective cohort study.

PubMed

Ko, Byuk Sung; Kim, Ji Yeon; Seo, Dong-Woo; Kim, Won Young; Lee, Jae Ho; Sheikh, Aziz; Bates, David W

2016-02-03

Although adrenaline (epinephrine) is a cornerstone of initial anaphylaxis treatment, it is not often used. We sought to assess whether use of adrenaline in hemodynamically stable patients with anaphylaxis could prevent the development of hypotension. We conducted a retrospective cohort study of 761 adult patients with anaphylaxis presenting to the emergency department (ED) of a tertiary care hospital over a 10-year period. We divided the patients into two groups according to the occurrence of hypotension and compared demographic characteristics, clinical features, treatments and outcomes. Of the 340 patients with anaphylaxis who were normotensive at first presentation, 40 patients experienced hypotension during their ED stay. The ED stay of the hypotension group was significantly longer than that of patients who did not experience hypotension (496 min vs 253 min, P = 0.000). Adrenaline use in hemodynamically stable anaphylaxis patient was independently associated with a lower risk of developing in-hospital occurrence of hypotension: OR, 0.254 [95% CI, 0.091-0.706]. Adrenaline use in hemodynamically stable anaphylaxis patients was associated with a reduced risk of developing in-hospital occurrence of hypotension. Adverse events induced by adrenaline were rare when the intramuscular route was used.

Should adrenaline be used in patients with hemodynamically stable anaphylaxis? Incident case control study nested within a retrospective cohort study

PubMed Central

Ko, Byuk Sung; Kim, Ji Yeon; Seo, Dong-Woo; Kim, Won Young; Lee, Jae Ho; Sheikh, Aziz; Bates, David W.

2016-01-01

Although adrenaline (epinephrine) is a cornerstone of initial anaphylaxis treatment, it is not often used. We sought to assess whether use of adrenaline in hemodynamically stable patients with anaphylaxis could prevent the development of hypotension. We conducted a retrospective cohort study of 761 adult patients with anaphylaxis presenting to the emergency department (ED) of a tertiary care hospital over a 10-year period. We divided the patients into two groups according to the occurrence of hypotension and compared demographic characteristics, clinical features, treatments and outcomes. Of the 340 patients with anaphylaxis who were normotensive at first presentation, 40 patients experienced hypotension during their ED stay. The ED stay of the hypotension group was significantly longer than that of patients who did not experience hypotension (496 min vs 253 min, P = 0.000). Adrenaline use in hemodynamically stable anaphylaxis patient was independently associated with a lower risk of developing in-hospital occurrence of hypotension: OR, 0.254 [95% CI, 0.091–0.706]. Adrenaline use in hemodynamically stable anaphylaxis patients was associated with a reduced risk of developing in-hospital occurrence of hypotension. Adverse events induced by adrenaline were rare when the intramuscular route was used. PMID:26837822

Individual variation in nest size and nest site features of the Bornean orangutans (Pongo pygmaeus).

PubMed

Rayadin, Yaya; Saitoh, Takashi

2009-05-01

Nest construction is a daily habit of independent orangutans for sleeping or resting. Data on their nests have been used in various ecological studies (e.g., density estimation, ranging behavior, evolution of material culture) because they are the most observable field signs. We investigated nest size and nest site features of Bornean orangutans in the wild during 10 months' fieldwork at three sites in East Kalimantan, Indonesia: Kutai National Park, Birawa, and Meratus. To examine individual variation, we followed 31 individual orangutans and recorded the 92 nests they made for nest size (diameter) and nest site features (height of nest above ground, tree species used for the nest site, the diameter and height of the tree, whether the nest was new or reused, and nest location within the tree). Analyses taking age-sex classes of the focal individuals into consideration showed significant age-sex differences in nest size and location, but not in nest height or nest tree features (diameter, height of tree, and height of lowest branch). Mature orangutans (adult females, unflanged and flanged males) made larger nests than immatures (juveniles and adolescents). Flanged male orangutans with larger nests used stable locations for nesting sites and reused old nests more frequently than immatures. The overall proportion of nests in open (exposed) locations was higher than in closed (sheltered) locations. Flanged males and immatures frequently made open nests, whereas adult females with an infant preferred closed locations. The good correspondence between nest size and age-sex classes indicates that nest size variation may reflect body size and therefore age-sex variation in the population. (c) 2009 Wiley-Liss, Inc.

Therapeutic assessment of chloroquine-primaquine combined regimen in adult cohort of Plasmodium vivax malaria from a tertiary care hospital in southwestern India.

PubMed

Rishikesh, Kumar; Kamath, Asha; Hande, Manjunatha H; Vidyasagar, Sudha; Acharya, Raviraja V; Acharya, Vasudeva; Belle, Jayaprakash; Shastry, Ananthakrishna B; Saravu, Kavitha

2015-08-11

Of late there have been accounts of therapeutic failure and chloroquine resistance in Plasmodium vivax malaria especially from Southeast Asian regions. The present study was conducted to assess the therapeutic efficacy of chloroquine-primaquine (CQ-PQ) combined regimen in a cohort of uncomplicated P. vivax mono-infection. A tertiary care hospital-based prospective study was conducted among adult cohort with mono-infection P. vivax malaria as per the World Health Organization's protocol of in vivo assessment of anti-malarial therapeutic efficacy. Participants were treated with CQ 25 mg/kg body weight divided over 3 days and PQ 0.25 mg/kg body weight daily for 2 weeks. Of a total of 125 participants recruited, 122 (97.6%) completed day 28 follow up, three (2.4%) participants were lost to follow-up. Eight patients (6.4%) were ascertained to have mixed P. vivax and Plasmodium falciparum infection by nested polymerase chain reaction test. The majority of subjects (56.8%, 71/125) became aparasitaemic on day 2 followed by 35.2% (44/125) on day 3, and 8% (10/125) on day 7, and remained so thereafter. Overall only one therapeutic failure (0.8%, 1/125) occurred on day 3 due to persistence of fever and parasitaemia. CQ-PQ combined regimen remains outstandingly effective for uncomplicated P. vivax malaria and should be retained as treatment of choice in the study region. One case of treatment failure indicates possible resistance which warrants constant vigilance and periodic surveillance.

Nesting of Morelet's crocodile, Crocodylus moreletii (Dumeril and Bibron), in Los Tuxtlas, Mexico.

PubMed

Villegas, A; Mendoza, G D; Arcos-García, J L; Reynoso, V H

2017-11-01

We evaluated the nesting by Crocodylus moreletii in Lago de Catemaco, Veracruz, southeastern, Mexico. During the nesting and hatching seasons, we searched for nests along the northern margins of the lake and small associated streams. We investigated egg mortality by weekly monitoring each of the nests found, recording sign of predation (tracks and holes dug into the nest) and the effect of water level fluctuations. We not found differences to nest between inland or flooded zones. However, we found that egg size varied among nests. In nests built inland, predation was the major cause of egg mortality whereas flooding resulted in more deaths of eggs in the flooding zone. Flooding killed 25% of eggs monitored in this study. We suggest that to increase nest success in the Morelet's crocodile it is necessary to promote conservation of nesting areas around the lake, recently occupied by urban or tourist developments.

Is nest predation by Steller's jays (Cyanocitta stelleri) incidental or the resrult of a specialized search strategy?

Treesearch

Stacey M. Vigallon; John M. Marzluff

2005-01-01

Decreased nest success and elevated levels of nest predation have been linked to changes in landscape configuration and increased edge. Using radiotelemetry and artifical nests, we studied the ranging and nest-predation behavior of the Steller's jay (Cyanocitta stelleri) in the managed forests of western...

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

PubMed

Dalleau, Mayeul; Ciccione, Stéphane; Mortimer, Jeanne A; Garnier, Julie; Benhamou, Simon; Bourjea, Jérôme

2012-01-01

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.

Nesting Phenology of Marine Turtles: Insights from a Regional Comparative Analysis on Green Turtle (Chelonia mydas)

PubMed Central

Dalleau, Mayeul; Ciccione, Stéphane; Mortimer, Jeanne A.; Garnier, Julie; Benhamou, Simon; Bourjea, Jérôme

2012-01-01

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. PMID:23056527

Phytosterol plasma concentrations and coronary heart disease in the prospective Spanish EPIC cohort

PubMed Central

Escurriol, Verónica; Cofán, Montserrat; Moreno-Iribas, Concepción; Larrañaga, Nerea; Martínez, Carmen; Navarro, Carmen; Rodríguez, Laudina; González, Carlos A.; Corella, Dolores; Ros, Emilio

2010-01-01

Phytosterol intake with natural foods, a measure of healthy dietary choices, increases plasma levels, but increased plasma phytosterols are believed to be a coronary heart disease (CHD) risk factor. To address this paradox, we evaluated baseline risk factors, phytosterol intake, and plasma noncholesterol sterol levels in participants of a case control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) Spanish cohort who developed CHD (n = 299) and matched controls (n = 584) who remained free of CHD after a 10 year follow-up. Sitosterol-to-cholesterol ratios increased across tertiles of phytosterol intake (P = 0.026). HDL-cholesterol level increased, and adiposity measures, cholesterol/HDL ratios, and levels of glucose, triglycerides, and lathosterol, a cholesterol synthesis marker, decreased across plasma sitosterol tertiles (P < 0.02; all). Compared with controls, cases had nonsignificantly lower median levels of phytosterol intake and plasma sitosterol. The multivariable-adjusted odds ratio for CHD across the lowest to highest plasma sitosterol tertile was 0.59 (95% confidence interval, 0.36–0.97). Associations were weaker for plasma campesterol. The apolipoprotein E genotype was unrelated to CHD risk or plasma phytosterols. The data suggest that plasma sitosterol levels are associated with a lower CHD risk while being markers of a lower cardiometabolic risk in the EPIC-Spain cohort, a population with a high phytosterol intake. PMID:19786566

Effects of nest density, location, and timing on breeding success of Caspian Terns

USGS Publications Warehouse

Antolos, Michelle; Roby, D.D.; Lyons, Donald E.; Anderson, Scott K.; Collis, K.

2006-01-01

One of the proposed benefits of colonial nesting in birds is the protection afforded against avian predators. This advantage may be counter-balanced by the negative effects of intraspecific aggression on breeding success. Effects of nest density, nest location within the colony, and timing of nest initiation on productivity of Caspian Terns (Sterna caspia) were investigated on Crescent Island in the mid-Columbia River, Washington, USA. In the absence of intense nest predation at the Crescent Island tern colony, it was hypothesized that nest density would be negatively associated with productivity. A rangefinder was used to determine spatial distribution of Caspian Tern nests, and these data used to calculate nest characteristics (nest density, nearest neighbor distance, and distance to colony edge) for a randomly-selected subset of nests monitored for nest chronology and productivity. Productivity did not differ between nests in high- and low-density areas of the colony, and was positively associated with earlier nest initiation. Early nests were more productive, were located in areas of higher nest density, and were further from the colony edge than late nests. The strong effect of timing may have been attributable to seasonal declines in prey resources for terns at this site. Our results suggest that Caspian Terns nesting at the highest densities observed in this study did not incur immediate reproductive costs, despite increased potential for encounters between chicks and aggressive conspecific adults.

Intracranial haemorrhage and use of selective serotonin reuptake inhibitors

PubMed Central

de Abajo, Francisco J; Jick, Hershel; Derby, Laura; Jick, Susan; Schmitz, Stephen

2000-01-01

Aims In the past few years an increasing number of bleeding disorders have been reported in association with the use of selective serotonin reuptake inhibitors (SSRIs), including serious cases of intracranial haemorrhage, raising concerns about the safety of this class of drugs. The present study was performed to test the hypothesis of an increased risk of intracranial haemorrhage associated with the use of SSRIs. Methods We carried out a case-control study nested in a cohort of antidepressants users with the UK-based General Practice Research Database (GPRD) as the primary source of information. The study cohort encompassed subjects aged between 18 and 79 years who received a first-time prescription for any antidepressant from January, 1990 to October, 1997. Patients with presenting conditions or treatments that could be associated with an increased risk of intracranial haemorrhage were excluded from the cohort. Patients were followed-up until the occurrence of an idiopathic intracranial haemorrhage. Up to four controls per case, matched on age, sex, calendar time and practice were randomly selected from the study cohort. We estimated adjusted odds ratios and 95% confidence intervals of intracranial haemorrhage with current use of SSRIs and other antidepressants as compared with nonuse using conditional logistic regression. Results We identified 65 cases of idiopathic intracranial haemorrhage and 254 matched controls. Current exposure to SSRIs was ascertained in 7 cases (10.8%) and 24 controls (9.7%) resulting in an adjusted OR (95%CI) of 0.8 (0.3,2.3). The estimate for ‘other antidepressants’ was 0.7 (0.3,1.6). The effect measures were not modified by gender or age. No effect related to dose or treatment duration was detected. The risk estimates did not change according to the location of bleeding (intracerebral or subarachnoid). Conclusions Our results are not compatible with a major increased risk of intracranial haemorrhage among users of SSRIs or other antidepressants at large. However, smaller but still relevant increased risks cannot be ruled out. PMID:10886117

Reproductive rate and temporal spacing of nesting of red-winged blackbirds in upland habitat

USGS Publications Warehouse

Dolbeer, Richard A.

1976-01-01

The literature contains numerous studies on Red-winged Blackbird (Agelaius phoeniceus) reproduction. Francis (1971) summarized eight studies dealing with nesting success. These and other studies have also provided information on breeding chronology, clutch sizes, sex ratios, survival rates for eggs and nestlings, reproductive physiology, and other life history aspects of reproduction. With few exceptions, these studies have provided no data on the number of young fledged per female, per territorial male, or per unit area. This is especially true for upland nesting habitats where, at least in the midwestern United States, most Red-wings now nest (Graber and Graber 1963, Dyer et al. 1973). Also insufficient quantitative information is available on the extent and nature of renesting (i.e. nesting more than once in a nesting season) and on movements of adult females during the nesting season.A better understanding of these aspects of reproduction is critical for the development of an accurate population-dynamics model for the species. Such a model is sorely needed to evaluate the impact and effectiveness of proposed population management strategies in places where blackbirds are deemed a health or safety hazard, or cause damage to agricultural crops (Tosh et al. 1970, Solman 1971, Stone et al. 1972).This study had three objectives: (1) to determine the distribution, size, and number of Red-winged Blackbird territories for an old-field habitat; (2) to determine the number of nesting females, nesting success, extent of renesting, and number of young fledged for these territories; and (3) to examine movements of female Red-wings during the nesting season.

The nest architecture of the ant Odontomachus brunneus.

PubMed

Cerquera, Lina M; Tschinkel, Walter R

2010-01-01

The architecture of the subterranean nests of the ant Odontomachus brunneus (Patton) (Hymenoptera: Formicidae) was studied by means of casts with dental plaster or molten metal. The entombed ants were later recovered by dissolution of plaster casts in hot running water. O. brunneus excavates simple nests, each consisting of a single, vertical shaft connecting more or less horizontal, simple chambers. Nests contained between 11 and 177 workers, from 2 to 17 chambers, and 28 to 340 cm(2) of chamber floor space and reached a maximum depth of 18 to 184 cm. All components of nest size increased simultaneously during nest enlargement, number of chambers, mean chamber size, and nest depth, making the nest shape (proportions) relatively size-independent. Regardless of nest size, all nests had approximately 2 cm(2) of chamber floor space per worker. Chambers were closer together near the top and the bottom of the nest than in the middle, and total chamber area was greater near the bottom. Colonies occasionally incorporated cavities made by other animals into their nests.

Factors determining presence of passerines breeding within White Stork Ciconia ciconia nests

NASA Astrophysics Data System (ADS)

Zbyryt, Adam; Jakubas, Dariusz; Tobolka, Marcin

2017-10-01

Nests of White Stork Ciconia ciconia are commonly used by various passerines as nesting sites. In this study, we investigated factors determining presence and number of pairs of species breeding within White Stork nests in an extensive farmland in NE Poland. In 133 (57%) out of 233 White Stork nests, we found at least one breeding pair of passerine bird. These were from three species: House Sparrows Passer domesticus (68% of 133 nests with co-breeding), Tree Sparrows Passer montanus (65%), and Starlings Sturnus vulgaris (30%). The probability of breeding passerines within White Stork nests increased with increasing nest thickness, and was significantly higher in currently occupied nests. Sparrows were more likely to breed in White Stork nests located on electricity poles, situated closer to settlements and surrounded mainly by arable fields where meadows were not prevalent. In this paper, we show that White Stork nests are favorable nesting sites for passerines, as they are well insulated and provide an anti-predatory shield.

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

USGS Publications Warehouse

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.

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

PubMed

Newmark, William D; Stanley, Thomas R

2011-07-12

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.

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

PubMed Central

Newmark, William D.; Stanley, Thomas 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. PMID:21709237

Plasma homocysteine, dietary B vitamins, betaine, and choline and risk of peripheral artery disease

PubMed Central

Bertoia, Monica L.; Pai, Jennifer K.; Cooke, John P.; Joosten, Michel M.; Mittleman, Murray A.; Rimm, Eric B.; Mukamal, Kenneth J.

2014-01-01

Objective Few studies have examined the roles of homocysteine and related nutrients in the development of peripheral artery disease (PAD). We examined the associations between plasma homocysteine, dietary B vitamins, betaine, choline, and supplemental folic acid use and incidence of PAD. Methods We used two cohort studies of 72,348 women in the Nurses' Health Study (NHS, 1990-2010) and 44,504 men in the Health Professionals Follow-up Study (HPFS, 1986-2010). We measured plasma homocysteine in nested matched case-control studies of clinically recognized PAD within both cohorts, including 143 PAD cases and 424 controls within the NHS (1990-2010) and 143 PAD cases and 428 controls within the HPFS (1994-2008). We examined the association between diet and risk of incident PAD in the cohorts using a food frequency questionnaire and 790 cases of PAD over 3.1 million person-years of follow-up. Results Higher homocysteine levels were positively associated with risk of PAD in men (adjusted IRR 2.17; 95% CI, 1.08-4.38 for tertile 3 vs. 1). There was no evidence of an association in women (adjusted IRR 1.14; 95% CI, 0.61-2.12). Similarly, higher folate intake, including supplements, was inversely associated with risk of PAD in men (adjusted HR 0.90; 95% CI, 0.82-0.98 for each 250 μg increase) but not women (HR 1.01, 95% CI, 0.88-1.15). Intakes of the other B vitamins, betaine, and choline were not consistently associated with risk of PAD in men or women. Conclusion Homocysteine levels were positively associated and dietary folate intake was inversely associated with risk of PAD in men but not in women. PMID:24819748

Plasma homocysteine, dietary B vitamins, betaine, and choline and risk of peripheral artery disease.

PubMed

Bertoia, Monica L; Pai, Jennifer K; Cooke, John P; Joosten, Michel M; Mittleman, Murray A; Rimm, Eric B; Mukamal, Kenneth J

2014-07-01

Few studies have examined the roles of homocysteine and related nutrients in the development of peripheral artery disease (PAD). We examined the associations between plasma homocysteine, dietary B vitamins, betaine, choline, and supplemental folic acid use and incidence of PAD. We used two cohort studies of 72,348 women in the Nurses' Health Study (NHS, 1990-2010) and 44,504 men in the Health Professionals Follow-up Study (HPFS, 1986-2010). We measured plasma homocysteine in nested matched case-control studies of clinically recognized PAD within both cohorts, including 143 PAD cases and 424 controls within the NHS (1990-2010) and 143 PAD cases and 428 controls within the HPFS (1994-2008). We examined the association between diet and risk of incident PAD in the cohorts using a food frequency questionnaire and 790 cases of PAD over 3.1 million person-years of follow-up. Higher homocysteine levels were positively associated with risk of PAD in men (adjusted IRR 2.17; 95% CI, 1.08-4.38 for tertile 3 vs. 1). There was no evidence of an association in women (adjusted IRR 1.14; 95% CI, 0.61-2.12). Similarly, higher folate intake, including supplements, was inversely associated with risk of PAD in men (adjusted HR 0.90; 95% CI, 0.82-0.98 for each 250 μg increase) but not women (HR 1.01, 95% CI, 0.88-1.15). Intakes of the other B vitamins, betaine, and choline were not consistently associated with risk of PAD in men or women. Homocysteine levels were positively associated and dietary folate intake was inversely associated with risk of PAD in men but not in women. Copyright © 2014. Published by Elsevier Ireland Ltd.

Risk Factors Associated with HIV Infection among Male Homosexuals and Bisexuals Followed in an Open Cohort Study: Project Horizonte, Brazil (1994-2010)

PubMed Central

Silva, Ana Paula; Greco, Marília; Fausto, Maria Arlene; Greco, Dirceu B.; Carneiro, Mariângela

2014-01-01

Background There has recently been an increase in HIV infection rates among men who have sex with men (MSM). This study aimed at investigating risk factors associated with incident HIV infection in a MSM cohort–Project Horizonte, Belo Horizonte, Minas Gerais, Brazil. Methodology This is a nested case-control study in an ongoing open cohort of homosexual and bisexual men, carried out in 1994–2010, during which 1,085 volunteers were enrolled. Each HIV seroconverted volunteer (case) was compared with three randomly selected HIV negative controls, matched by admission date and age (±3 years). During follow-up, 93 volunteers seroconverted and were compared with 279 controls. Principal Findings The risk factors associated with HIV seroconversion were: contact with partner’s blood during sexual relations (OR 3.7; 95% CI 1.2–11.6), attendance at gay saunas in search for sexual partners (OR 2.6; 95% CI 1.3–5.4), occasional intake of alcohol when flirting and engaging in sexual activity (OR 2.5; 95% CI 1.3–5.1), inconsistent use of condoms in receptive anal sex (OR 2.4; 95% CI 1.1–5.4), little interest to look up information about AIDS (OR 2.6; 95% CI 1.0–6.7) particularly in newspapers (OR 3.4; 95% CI 1.4–8.1). Conclusions This study shows that MSM are still engaging in risk behavior, such as unprotected anal intercourse, despite taking part in a cohort study on various preventive measures. New preventive strategies in touch with the epidemic’s development and the specificities of this particular population are needed. PMID:25279670

Family history of cancer and risk of Pancreatic Cancer: A Pooled Analysis from the Pancreatic Cancer Cohort Consortium (PanScan)

PubMed Central

Jacobs, Eric J.; Chanock, Stephen J.; Fuchs, Charles S.; LaCroix, Andrea; McWilliams, Robert R.; Steplowski, Emily; Stolzenberg-Solomon, Rachael Z.; Arslan, Alan A.; Bueno-de-Mesquita, H. Bas; Gross, Myron; Helzlsouer, Kathy; Petersen, Gloria; Zheng, Wei; Agalliu, Ilir; Allen, Naomi E.; Amundadottir, Laufey; Boutron-Ruault, Marie-Christine; Buring, Julie E.; Canzian, Federico; Clipp, Sandra; Dorronsoro, Miren; Gaziano, J. Michael; Giovannucci, Edward L.; Hankinson, Susan E.; Hartge, Patricia; Hoover, Robert N.; Hunter, David J.; Jacobs, Kevin B.; Jenab, Mazda; Kraft, Peter; Kooperberg, Charles; Lynch, Shannon M.; Sund, Malin; Mendelsohn, Julie B.; Mouw, Tracy; Newton, Christina C.; Overvad, Kim; Palli, Domenico; Peeters, Petra H.M.; Rajkovic, Aleksandar; Shu, Xiao-Ou; Thomas, Gilles; Tobias, Geoffrey S.; Trichopoulos, Dimitrios; Virtamo, Jarmo; Wactawski-Wende, Jean; Wolpin, Brian M.; Yu, Kai; Zeleniuch-Jacquotte, Anne

2010-01-01

A family history of pancreatic cancer has consistently been associated with increased risk of pancreatic cancer. However, uncertainty remains about the strength of this association. Results from previous studies suggest a family history of select cancers (i.e. ovarian, breast, and colorectal) could also be associated, although not as strongly, with increased risk of pancreatic cancer. We examined the association between a family history of five types of cancer (pancreas, prostate, ovarian, breast, and colorectal) and risk of pancreatic cancer using data from a collaborative nested case-control study conducted by the Pancreatic Cancer Cohort Consortium. Cases and controls were from cohort studies from the United States, Europe, and China, and a case-control study from the Mayo Clinic. Analyses of family history of pancreatic cancer included 1,183 cases and 1,205 controls. A family history of pancreatic cancer in a parent, sibling, or child was associated with increased risk of pancreatic cancer (multivariate-adjusted OR = 1.76, 95% CI 1.19–2.61). A family history of prostate cancer was also associated with increased risk (OR = 1.45, 95% CI 1.12–1.89). There were no statistically significant associations with a family history of ovarian cancer (OR = 0.82, 95% CI 0.52–1.31), breast cancer (OR = 1.21, 95% CI 0.97–1.51), or colorectal cancer (OR = 1.17, 95% CI 0.93–1.47). Our results confirm a moderate sized association between a family history of pancreatic cancer and risk of pancreatic cancer and also provide evidence for an association with a family history of prostate cancer worth further study. PMID:20049842

Experimental shifts in egg-nest contrasts do not alter egg rejection responses in an avian host-brood parasite system.

PubMed

Hauber, Mark E; Aidala, Zachary; Igic, Branislav; Shawkey, Matthew D; Moskát, Csaba

2015-09-01

Obligate brood parasitic birds exploit their hosts to provide care for unrelated young in the nest. Potential hosts can reduce the cost of parasitism by rejecting foreign eggs from the nest. Observational, comparative, and experimental studies have concluded that most hosts use the coloration and patterning of eggshells to discriminate between own and foreign eggs in the nest. However, an alternative hypothesis is that birds use the colour contrasts between eggshells and the nest lining to identify parasitic eggs (egg-nest contrast hypothesis). In support of this hypothesis, we found that the avian perceivable chromatic contrasts between dyed eggs and unmanipulated nest linings significantly and negatively covaried with the rejection rates of different dyed eggs of the great reed warbler Acrocephalus arundinaceus, a frequently parasitized host of the common cuckoo Cuculus canorus. To experimentally test whether egg-nest contrasts influence rejection, we reciprocally dyed both eggs and the nest lining of this host species with one of two colours: orange and green. Contrary to the egg-nest contrast hypothesis, host rejection patterns in response to dyed eggs were not altered by dyeing nests, relative to unmanipulated control eggs and nests. In turn, experimental egg colour was the only significant predictor of egg rejection rate. Our results demonstrate that egg-nest contrast is a collateral, not a causal factor in egg rejection, and confirm the conclusions of previous studies that hosts can rely on the parasitic egg's appearance itself to recognize the foreign egg in the nest.

Thermal fluctuation within nests and predicted sex ratio of Morelet's Crocodile.

PubMed

Escobedo-Galván, Armando H; López-Luna, Marco A; Cupul-Magaña, Fabio G

2016-05-01

Understanding the interplay between thermal variations and sex ratio in reptiles with temperature-dependent sex determination is the first step for developing long-term conservation strategies. In case of crocodilians, the information is fragmentary and insufficient for establishing a general framework to consider how thermal fluctuation influence sex determination under natural conditions. The main goal of this study was to analyze thermal variation in nests of Crocodylus moreletii and to discuss the potential implications for predicting offspring sex ratio. The study was carried out at the Centro de Estudios Tecnológicos del Mar N° 2 and at the Sistemas Productivos Cocodrilo, Campeche, Mexico. Data was collected in the nesting season of Morelet's Crocodiles during three consecutive seasons (2007-2009). Thermal fluctuations for multiple areas of the nest chamber were registered by data loggers. We calculate the constant temperature equivalent based on thermal profiles among nests to assess whether there are differences between the nest temperature and its equivalent to constant temperature. We observed that mean nest temperature was only different among nests, while daily thermal fluctuations vary depending on the depth position within the nest chamber, years and nests. The constant temperature equivalent was different among and within nests, but not among survey years. We observed differences between constant temperature equivalent and mean nest temperature both at the top and in the middle of the nest cavities, but were not significantly different at the bottom of nest cavities. Our results enable examine and discuss the relevance of daily thermal fluctuations to predict sex ratio of the Morelet's Crocodile. Copyright © 2016 Elsevier Ltd. All rights reserved.

Grasshopper sparrow reproductive success and habitat use on reclaimed surface mines varies by age of reclamation

USGS Publications Warehouse

Wood, Petra; Ammer, Frank K.

2015-01-01

We studied 3 mountaintop mining–valley fill (MTMVF) complexes in southern West Virginia, USA to examine grasshopper sparrow (Ammodramus savannarum pratensis) demographic response to different age classes of mine land reclamation. For 71 nests monitored during the 2001–2002 breeding seasons, overall nest success (36%) was within the range of nest success rates previously reported for this species, but it was highest on more recently reclaimed sites (56%). Nest density and clutch size did not differ (P > 0.30) among reclamation age classes, whereas number of fledglings was greater (P = 0.01) on more recently reclaimed sites. We measured vegetation variables at 70 nest subplots and at 96 systematic subplots to compare nest vegetation with vegetation available on the plots. We found that nests occurred in areas with more bare ground near the nest, greater vegetation height–density surrounding the nest site, lower grass height, and fewer woody stems, similar to previous studies. As postreclamation age increased, vegetation height–density and maximum grass height increased, and sericea (Lespedeza cuneata) became more dominant. Nest success declined with increasing vegetation height–density at the nest. The grasslands available on these reclaimed mine complexes are of sufficient quality to support breeding populations of grasshopper sparrows, but nest success decreased on the older reclaimed areas. Without active management, grasslands on reclaimed MTMVF mines become less suitable for nesting grasshopper sparrows about 10 years after reclamation.

High, low, or familiar? Nest site preferences of experienced laying hens.

PubMed

Krause, E T; Schrader, L

2018-05-22

1. The aim of this study was to investigate which nest heights are preferred by laying hens in the absence of familiar nest locations and whether preferred nest heights are more attractive than a familiar location. In two experiments, a total of 108 hens of four different layer breeds, which were at least 50 weeks of age, were studied. 2. In the first experiment, hens were given individual free choice between nests for 1-week at four different heights (0 cm, 39 cm, 78 cm, and 117 cm above ground). Hens of the four breeds differed in their nest height preferences (P = 0.0013). However, hens of three breeds preferred ground level nests (P < 0.007) and the fourth line showed an equal preference for the ground level and level three, the latter level corresponding to the height of the nests in their home compartments. 4. In the second experiment, hens from the four breeds were given a choice between ground level nests and nests at a familiar location, i.e. at the same location as in their home compartment. Hens of all strains preferred the familiar nest location (P = 0.002) and preferences did not differ between strains (P = 0.77). 5. Laying hens seem to prefer nests at ground level in the absence of a familiar nest. However, if possible, experienced 50 week old hens continue to use a familiar nest location instead of a ground nest location. The results are discussed with respect to a potential primary preference that may be modifiable by experience and with respect to possible relevance in commercial housing.

Factors associated with duck nest success in the prairie pothole region of Canada

USGS Publications Warehouse

Greenwood, Raymond J.; Sargeant, Alan B.; Johnson, Douglas H.; Cowardin, Lewis M.; Shaffer, Terry L.

1995-01-01

Populations of some dabbling ducks have declined sharply in recent decades and information is needed to understand reasons for this. During 1982-85, we studied duck nesting for 1-4 years in 17 1.6 by 16.0-km, high-density duck areas in the Prairie Pothole Region (PPR) of Canada, 9 in parkland and 8 in prairie. We estimated nest-initiation dates, habitat preferences, nest success, and nest fates for mallards (Anas platyrhynchos), gadwalls (A. strepera), blue-winged teals (A. discors), northern shovelers (A. clypeata), and northern pintails (A. acuta). We also examined the relation of mallard production to geographic and temporal variation in wetlands, breeding populations, nesting effort, and hatch rate.Average periods of nest initiation were similar for mallards and northern pintails, and nearly twice as long as those of gadwalls, blue-winged teals, and northern shovelers. Median date of nest initiation was related to presence of wet wetlands (contained visible standing water), spring precipitation, and May temperature. Length of initiation period was related to presence of wet wetlands and precipitation in May, June temperature, and nest success; it was negatively related overall to drought that prevailed over much of Prairie Canada during the study, especially in 1984.Mallards, gadwalls, and northern pintails nested most often in brush in native grassland, blue-winged teals in road rights-of-way, and northern shovelers in hayfields and small (< 2 ha) untilled tracts of upland habitat (hereafter called Odd area). Among 8 habitat classes that composed all suitable nesting habitat of each study area, nest success estimates averaged 25% in Woodland, 19% in Brush, 18% in Hayland, 16% in Wetland, 15% in Grass, 11% in Odd area, 8% in Right-of-way, and 2% in Cropland. We detected no significant difference in nest success among species: mallard (11%), gadwall (14%), blue-winged teal (15%), northern shoveler (12%), and northern pintail (7%). Annual nest success (pooled by study area and averaged [unweighted] over all study areas) was 17% in 1982, 15% in 1983, 7% in 1984, and 14% in 1985.We estimated that predators destroyed 72% of mallard, gadwall, blue-winged teal, and northern shoveler nests and 65% of northern pintail nests. In prairie, average nest success decreased about 4 percentage points for every 10 percentage points increase in Cropland, suggesting that under conditions of 1982-85, local populations of these species probably were not stable when Cropland exceeded about 56% of available habitat. We found recent remains of 573 dead ducks during 1983-85; most were females (Anas spp.) apparently killed by predators. In some years, mallards and northern pintails were more numerous among dead ducks than we expected. More females than males were found dead among mallards and northern shovelers, suggesting higher vulnerability of females. Of factors we examined, nest-success rate appeared to be the most influential factor in determining mallard production. Nest success varied both geographically and annually.

Coping with shifting nest predation refuges by European reed Warblers Acrocephalus scirpaceus.

PubMed

Halupka, Lucyna; Halupka, Konrad; Klimczuk, Ewelina; Sztwiertnia, Hanna

2014-01-01

Predation, the most important source of nest mortality in altricial birds, has been a subject of numerous studies during past decades. However, the temporal dynamics between changing predation pressures and parental responses remain poorly understood. We analysed characteristics of 524 nests of European reed warblers monitored during six consecutive breeding seasons in the same area, and found some support for the shifting nest predation refuge hypothesis. Nest site characteristics were correlated with nest fate, but a nest with the same nest-site attributes could be relatively safe in one season and vulnerable to predation in another. Thus nest predation refuges were ephemeral and there was no between-season consistency in nest predation patterns. Reed warblers that lost their first nests in a given season did not disperse farther for the subsequent reproductive attempt, compared to successful individuals, but they introduced more changes to their second nest sites. In subsequent nests, predation risk remained constant for birds that changed nest-site characteristics, but increased for those that did not. At the between-season temporal scale, individual birds did not perform better with age in terms of reducing nest predation risk. We conclude that the experience acquired in previous years may not be useful, given that nest predation refuges are not stable.

Coping with Shifting Nest Predation Refuges by European Reed Warblers Acrocephalus scirpaceus

PubMed Central

Halupka, Lucyna; Halupka, Konrad; Klimczuk, Ewelina; Sztwiertnia, Hanna

2014-01-01

Predation, the most important source of nest mortality in altricial birds, has been a subject of numerous studies during past decades. However, the temporal dynamics between changing predation pressures and parental responses remain poorly understood. We analysed characteristics of 524 nests of European reed warblers monitored during six consecutive breeding seasons in the same area, and found some support for the shifting nest predation refuge hypothesis. Nest site characteristics were correlated with nest fate, but a nest with the same nest-site attributes could be relatively safe in one season and vulnerable to predation in another. Thus nest predation refuges were ephemeral and there was no between-season consistency in nest predation patterns. Reed warblers that lost their first nests in a given season did not disperse farther for the subsequent reproductive attempt, compared to successful individuals, but they introduced more changes to their second nest sites. In subsequent nests, predation risk remained constant for birds that changed nest-site characteristics, but increased for those that did not. At the between-season temporal scale, individual birds did not perform better with age in terms of reducing nest predation risk. We conclude that the experience acquired in previous years may not be useful, given that nest predation refuges are not stable. PMID:25522327

Arboreal nesting as anti-predator adaptation by savanna chimpanzees (Pan troglodytes verus) in southeastern Senegal.

PubMed

Pruetz, J D; Fulton, S J; Marchant, L F; McGrew, W C; Schiel, M; Waller, M

2008-04-01

Chimpanzees (Pan troglodytes) make nests for resting and sleeping, which is unusual for anthropoid primates but common to all great apes. Arboreal nesting has been linked to predation pressure, but few studies have tested the adaptive nature of this behavior. We collected data at two chimpanzee study sites in southeastern Senegal that differed in predator presence to test the hypothesis that elevated sleeping platforms are adaptations for predator defense. At Assirik in the Parc National du Niokolo-Koba, chimpanzees face four species of large carnivore, whereas at Fongoli, outside national park boundaries, humans have exterminated almost all natural predators. We quantified the availability of vegetation at the two sites to test the alternative hypothesis that differences in nesting reflect differences in habitat structure. We also examined possible sex differences in nesting behavior, community demographic differences, seasonality and nest age differences as variables also potentially affecting nest characteristics and nesting behavior between the two sites. Chimpanzees at Fongoli nested at lower heights and farther apart than did chimpanzees at Assirik and sometimes made nests on the ground. The absence of predators outside of the national park may account for the differences in nest characteristics at the two sites, given the similarities in habitat structure between Fongoli and Assirik. However, Fongoli chimpanzees regularly build arboreal nests for sleeping, even under minimal predation pressure, and this requires explanation.

Postfledging nest dependence period for bald eagles in Florida

USGS Publications Warehouse

Wood, P.B.; Collopy, Michael W.; Sekerak, C.M.

1998-01-01

We studied the postfledging dependency period in bald eagles (Haliaeetus leucocephalus), a little studied but important period in the life cycle of avian species. Bald eagles in Florida had a postfledging dependency period of 4-11 weeks (15-22 weeks old). The length of the dependency period did not vary by year of study, sex, number of fledgings, timing of fledging, or hatch order (P > 0.05). Mean distance fledglings ranged from the nest increased with age, but they were observed in the nest or nest tree throughout the postfledging dependency period. Distance from the nest did not vary by sex, number of fledglings, or timing of fledging (P > 0.05). Over 80% of the fledgling observations were within 229 m of the nest. The boundary of the primary protection zone specified in the bald eagle habitat management guidelines for the southeastern United States is 229 m. Restrictions on human disturbance around nest sites should remain in place during the postfledging dependency period because of the close association of fledglings with the nest site. Restrictions also should be flexible because of the varying length of the dependency period.

Sorting it out: bedding particle size and nesting material processing method affect nest complexity.

PubMed

Robinson-Junker, Amy; Morin, Amelia; Pritchett-Corning, Kathleen; Gaskill, Brianna N

2017-04-01

As part of routine husbandry, an increasing number of laboratory mice receive nesting material in addition to standard bedding material in their cages. Nesting material improves health outcomes and physiological performance in mice that receive it. Providing usable nesting material uniformly and efficiently to various strains of mice remains a challenge. The aim of this study was to determine how bedding particle size, method of nesting material delivery, and processing of the nesting material before delivery affected nest building in mice of strong (BALB/cAnNCrl) and weak (C3H/HeNCrl) gathering abilities. Our data suggest that processing nesting material through a grinder in conjunction with bedding material, although convenient for provision of bedding with nesting material 'built-in', negatively affects the integrity of the nesting material and subsequent nest-building outcomes. We also found that C3H mice, previously thought to be poor nest builders, built similarly scored nests to those of BALB/c mice when provided with unprocessed nesting material. This was true even when nesting material was mixed into the bedding substrate. We also observed that when nesting material was mixed into the bedding substrate, mice of both strains would sort their bedding by particle size more often than if it were not mixed in. Our findings support the utility of the practice of distributing nesting material mixed in with bedding substrate, but not that of processing the nesting material with the bedding in order to mix them.

Greater sage-grouse nest predators in the Virginia Mountains of northwestern Nevada

USGS Publications Warehouse

Lockyer, Zachary B.; Coates, Peter S.; Casazza, Michael L.; Espinosa, Shawn; Delehanty, David J.

2013-01-01

Greater sage-grouse Centrocercus urophasianus, hereafter sage-grouse, populations have declined across their range due to the loss, degradation, and fragmentation of habitat. Habitat alterations can lead not only to vegetative changes but also to shifts in animal behavior and predator composition that may influence population vital rates, such as nest success. For example, common ravens Corvus corax are sage-grouse nest predators, and common raven abundance is positively associated with human-caused habitat alterations. Because nest success is a central component to sage-grouse population persistence, research that identifies factors influencing nest success will better inform conservation efforts. We used videography to unequivocally identify sage-grouse nest predators within the Virginia Mountains of northwestern Nevada, USA, from 2009 to 2011 and used maximum likelihood to calculate daily probability of nest survival. In the Virginia Mountains, fires, energy exploration, and other anthropogenic activities have altered historic sage-grouse habitat. We monitored 71 sage-grouse nests during the study, placing video cameras at 39 nests. Cumulative nest survival for all nests was 22.4% (95% CI, 13.0–33.4%), a survival rate that was significantly lower than other published results for sage-grouse in the Great Basin. Depredation was the primary cause for nest failure in our study (82.5%), and common ravens were the most frequent sage-grouse nest predator, accounting for 46.7% of nest depredations. We also successfully documented a suite of mammalian and reptilian species depredating sage-grouse nests, including some predators never previously confirmed in the literature to be sage-grouse nest predators (i.e., bobcats Lynx rufus and long-tailed weasels Mephitis frenata). Within the high elevation, disturbed habitat of the Virginia Mountains, low sage-grouse nest success may be limiting sage-grouse population growth. These results suggest that management actions that restore habitat in the Virginia Mountains and decrease anthropogenic subsidies of ravens will benefit sage-grouse.

Human Exposure to Endocrine-Disrupting Chemicals and Prenatal Risk Factors for Cryptorchidism and Hypospadias: A Nested Case–Control Study

PubMed Central

Fernandez, Mariana F.; Olmos, Begoña; Granada, Alicia; López-Espinosa, Maria José; Molina-Molina, José-Manuel; Fernandez, Juan Manuel; Cruz, Milagros; Olea-Serrano, Fátima; Olea, Nicolás

2007-01-01

Background Exposure to xenoestrogens during pregnancy may disturb the development and function of male sexual organs. Objective In this study we aimed to determine whether the combined effect of environmental estrogens measured as total effective xenoestrogen burden (TEXB) is a risk factor for male urogenital malformations. Methods In a case–control study, nested in a mother–child cohort (n = 702) established at Granada University Hospital, we compared 50 newborns with diagnosis of cryptorchidism and/or hypospadias with 114 boys without malformations matched by gestational age, date of birth, and parity. Controls did not differ from the total cohort in confounding variables. TEXB and levels of 16 organochlorine pesticides were measured in placenta tissues. Characteristics of parents, pregnancy, and birth were gathered by questionnaire. We used conditional and unconditional regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results TEXB from organohalogenated compounds was detectable in 72% and 54% of case and control placentas, respectively. Compared with controls, cases had an OR for detectable versus non-detectable TEXB of 2.82 (95% CI, 1.10–7.24). More pesticides were detected in cases than in controls (9.34 ± 3.19 vs. 6.97 ± 3.93). ORs for cases with detectable levels of pesticides, after adjusting for potential confounders in the conditional regression analysis, were o,p′-DDT (OR = 2.25; 95% CI, 1.03–4.89), p,p′-DDT (OR = 2.63; 95% CI, 1.21–5.72), lindane (OR = 3.38; 95% CI, 1.36–8.38), mirex (OR = 2.85; 95% CI, 1.22–6.66), and endosulfan alpha (OR = 2.19; 95% CI, 0.99–4.82). Engagement of mothers in agriculture (OR = 3.47; 95% CI, 1.33–9.03), fathers’ occupational exposure to xenoestrogens (OR = 2.98; 95% CI, 1.11–8.01), and history of previous stillbirths (OR = 4.20; 95% CI, 1.11–16.66) were also associated with risk of malformations. Conclusions We found an increased risk for male urogenital malformations related to the combined effect of environmental estrogens in placenta. PMID:18174944

Lower omega-3 fatty acids are associated with the presence of anti-cyclic citrullinated peptide autoantibodies in a population at risk for future rheumatoid arthritis: a nested case-control study

PubMed Central

Gan, Ryan W.; Young, Kendra A.; Zerbe, Gary O.; Demoruelle, M. Kristen; Weisman, Michael H.; Buckner, Jane H.; Gregersen, Peter K.; Mikuls, Ted R.; O’Dell, James R.; Keating, Richard M.; Clare-Salzler, Michael J.; Deane, Kevin D.; Holers, V. Michael

2016-01-01

Objective. The aim of this study was to investigate omega-3 fatty acid (FA) supplement use and omega-3 FAs in erythrocyte membranes [omega-3 FA % in erythrocyte membranes (RBC)] and their association with anti-CCP autoantibodies in a population without RA, but who are at genetic risk for RA. Methods. The multicentre Studies of the Etiology of RA (SERA) cohort includes RA-free subjects who are first-degree relatives of RA probands or are enriched with the HLA-DR4 allele. In a nested case-control study, 30 SERA cases were identified who were anti-CCP2 antibody positive. We further identified 47 autoantibody negative controls, frequency matched to cases on age at study visit, sex, race and study site. Anti-CCP2 status, self-reported omega-3 FA supplement use and omega-3 FA % in RBCs were obtained from a single visit. Results. Anti-CCP2 positive cases were less likely than controls to report omega-3 FA supplement use (odds ratio: 0.14; 95% CI 0.03, 0.68). In addition, the likelihood of anti-CCP2 positivity was inversely associated with total omega-3 FA % in RBCs (odds ratio: 0.47; 95% CI 0.24, 0.92, for a s.d. increase). Conclusion. The inverse association between anti-CCP2 positivity and self-reported omega-3 FA supplement use and omega-3 FA % in RBCs suggests that omega-3 FAs may protect against the development of RA-related autoimmunity in pre-clinical RA. PMID:26370400

Methods and materials, for locating and studying spotted owls.

Treesearch

Eric D. Forsman

1983-01-01

Nocturnal calling surveys are the most effective and most frequently used technique for locating spotted owls. Roosts and general nest locations may be located during the day by calling in suspected roost or nest areas. Specific nest trees are located by: (1) baiting with a live mouse to induce owls to visit the nest, (2) calling in suspected nest areas to stimulate...

Inter-seasonal maintenance of individual nest site preferences in hawksbill sea turtles.

PubMed

Kamel, Stephanie J; Mrosovsky, N

2006-11-01

Within a single population of hawksbill sea turtles (Eretmochelys imbricata), we found a behavioral polymorphism for maternal nest site choice with respect to beach microhabitat characteristics. Some females preferred to nest in littoral forest and in places with overstory vegetation cover, and others preferred to nest in more open, deforested areas. Nest site choice was consistent within and between nesting seasons two years apart. This was not a result of females simply returning to the same location along the shoreline; beach sections used by individual turtles varied between seasons. Nest site choice was not influenced by changes in beach environment (e.g., beach width and foliage cover) or by changes in females' reproductive output (e.g., clutch size), suggesting that fidelity to particular microhabitats is a major determinant of the observed nesting patterns. Because hawksbills exhibit temperature-dependent sex determination, if the behavioral polymorphism in nest site choice has a genetic basis, as is plausible, then this would have implications for sex ratio evolution and offspring survival. By taking an individual-based approach to the study of maternal behavior we reveal previously overlooked individual variation and hope to provide some impetus for more detailed studies of nest site choice.

Aetiology of childhood pneumonia in a well vaccinated South African birth cohort: a nested case-control study of the Drakenstein Child Health Study.

PubMed

Zar, Heather J; Barnett, Whitney; Stadler, Attie; Gardner-Lubbe, Sugnet; Myer, Landon; Nicol, Mark P

2016-06-01

Pneumonia is a leading cause of mortality and morbidity in children globally. The cause of pneumonia after introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) has not been well studied in low-income and middle-income countries, and most data are from cross-sectional studies of children admitted to hospital. We aimed to longitudinally investigate the incidence and causes of childhood pneumonia in a South African birth cohort. We did a nested case-control study of children in the Drakenstein Child Health Study who developed pneumonia from May 29, 2012, to Dec 1, 2014. Children received immunisations including acellular pertussis vaccine and PCV13. A nested subgroup had nasopharyngeal swabs collected every 2 weeks throughout infancy. We identified pneumonia episodes and collected blood, nasopharyngeal swabs, and induced sputum specimens. We used multiplex real-time PCR to detect pathogens in nasopharyngeal swabs and induced sputum of pneumonia cases and in nasopharyngeal swabs of age-matched and site-matched controls. To show associations between organisms and pneumonia we used conditional logistic regression; results are presented as odds ratios (ORs) with 95% CIs. 314 pneumonia cases occurred (incidence of 0·27 episodes per child-year, 95% CI 0·24-0·31; median age 5 months [IQR 3-9]) in 967 children during 1145 child-years of follow-up. 60 (21%) cases of pneumonia were severe (incidence 0·05 episodes per child-year [95% CI 0·04-0·07]) with a case fatality ratio of 1% (three deaths). A median of five organisms (IQR 4-6) were detected in cases and controls with nasopharyngeal swabs, and a median of six organisms (4-7) recorded in induced sputum (p=0·48 compared with nasopharyngeal swabs). Bordetella pertussis (OR 11·08, 95% CI 1·33-92·54), respiratory syncytial virus (8·05, 4·21-15·38), or influenza virus (4·13, 2·06-8·26) were most strongly associated with pneumonia; bocavirus, adenovirus, parainfluenza virus, Haemophilus influenzae, and cytomegalovirus were also associated with pneumonia. In cases, testing of induced sputum in addition to nasopharyngeal swabs provided incremental yield for detection of B pertussis and several viruses. Pneumonia remains common in this highly vaccinated population. Respiratory syncytial virus was the most frequently detected pathogen associated with pneumonia; influenza virus and B pertussis were also strongly associated with pneumonia. Testing of induced sputum increases the yield for detection of several organisms. New vaccines and strategies are needed to address the burden of childhood pneumonia. Bill & Melinda Gates Foundation, Medical Research Council South Africa, National Research Foundation South Africa, National Institute of Health, and H3Africa. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of four molecular methods to detect Leishmania infection in dogs.

PubMed

Albuquerque, Andreia; Campino, Lenea; Cardoso, Luís; Cortes, Sofia

2017-03-13

Canine leishmaniasis, a zoonotic disease caused by Leishmania infantum vectored by phlebotomine sand flies, is considered a relevant veterinary and public health problem in various countries, namely in the Mediterranean basin and Brazil, where dogs are considered the main reservoir hosts. Not only diseased dogs but also those subclinically infected play a relevant role in the transmission of L. infantum to vectors; therefore, early diagnosis is essential, under both a clinical and an epidemiological perspective. Molecular tools can be a more accurate and sensitive approach for diagnosis, with a wide range of protocols currently in use. The aim of the present report was to compare four PCR based protocols for the diagnosis of canine Leishmania infection in a cohort of dogs from the Douro region, Portugal. A total of 229 bone marrow samples were collected from dogs living in the Douro region, an endemic region for leishmaniasis. Four PCR protocols were evaluated for Leishmania DNA detection in canine samples, three single (ITS1-PCR, MC-PCR and Uni21/Lmj4-PCR) and one nested (nested SSU rRNA-PCR). Two of the protocols were based on nuclear targets and the other two on kinetoplastid targets. The higher overall percentage of infected dogs was detected with the nested SSU rRNA-PCR (37.6%), which also was able to detect Leishmania DNA in a higher number of samples from apparently healthy dogs (25.3%). The ITS1-PCR presented the lowest level of Leishmania detection. Nested SSU rRNA-PCR is an appropriate method to detect Leishmania infection in dogs. Accurate and early diagnosis in clinically suspect as well as apparently healthy dogs is essential, in order to treat and protect animals and public health and contribute to the control and awareness of the disease.

Ecological consequences of colony structure in dynamic ant nest networks.

PubMed

Ellis, Samuel; Franks, Daniel W; Robinson, Elva J H

2017-02-01

Access to resources depends on an individual's position within the environment. This is particularly important to animals that invest heavily in nest construction, such as social insects. Many ant species have a polydomous nesting strategy: a single colony inhabits several spatially separated nests, often exchanging resources between the nests. Different nests in a polydomous colony potentially have differential access to resources, but the ecological consequences of this are unclear. In this study, we investigate how nest survival and budding in polydomous wood ant ( Formica lugubris ) colonies are affected by being part of a multi-nest system. Using field data and novel analytical approaches combining survival models with dynamic network analysis, we show that the survival and budding of nests within a polydomous colony are affected by their position in the nest network structure. Specifically, we find that the flow of resources through a nest, which is based on its position within the wider nest network, determines a nest's likelihood of surviving and of founding new nests. Our results highlight how apparently disparate entities in a biological system can be integrated into a functional ecological unit. We also demonstrate how position within a dynamic network structure can have important ecological consequences.

Mourning dove nesting: seasonal patterns and effects of September hunting

USGS Publications Warehouse

Geissler, Paul H.; Dolton, David D.; Field, Rebecca; Coon, Richard A.; Percival, H. Franklin; Hayne, Don W.; Soileau, Lawrence D.; George, Ronnie R.; Dunks, James H.; Bunnell, S. Dwight

1987-01-01

A nationwide State-Federal cooperative study was initiated in 1978 to examine effects of September hunting on nesting mourning doves (Zenaida macroura). This study was designed to (1) determine the proportion of the annual total of dove nesting activity and production that occurs in September and October, and (2) determine if survival rates of mourning dove eggs and nestlings are lower in zones where early September dove hunting is permitted than in zones where it is prohibited. During 1979 and 1980, 6,950 active nests were monitored to obtain data on nesting patterns. Nest initiation was estimated using two measurements, backdating from hatch dates and counting numbers of nests found for the first time. The nationwide percentage of the annual total of nests that were initiated in September and October was 1.0% based on backdating from hatch dates and 2.7% based on nests found for the first time. Nesting activity was measured by numbers of eggs and nestlings present in weekly counts. Nationally, 4.5% of the annual nesting activity occurred in September and October. The activity of 80% of the observed nests was within the period of 22 April to 4 September. The measure of production used in this study was numbers of young fledged. Nationally, 10.3% of all observed fledging occurred in September and October. Because a decline in nests found in the latter half of the nesting season preceded the 1 September start of hunting, we concluded that the reduction in nesting activity at the end of the season is a natural phenomenon and is not caused by hunting disturbance. In a separate part of this study, we estimated survival rates in adjacent hunted and nonhunted zones from data on 668 nests. The estimated daily survival rates for individual eggs and nestlings were 95.8% in the nonhunted and 95.0% in the hunted zones; the corresponding fledging rates were 33 and 26%, respectively. The fledging rates are lower because they are the daily survival rates operating over a 26-day nesting period. Neither differences in survival nor fledging rates between nonhunted and hunted zones were found to be statistically significant (P > 0.05). We determined that the statistical test was powerful enough to detect a reduction due to hunting from a hypothetical 96.0 to 94.2% in daily nestling survival rates (from 35 to 21 o/o in fledging rates) with 80% probability. An undetected reduction in fledging rate of that magnitude would probably reduce the overall fledging rate by less than 1 percentage point, because only a small proportion of the nesting doves are exposed to hunting for the full 26-day nesting cycle. In conclusion, we found that only a small proportion of total annual nesting attempts occurred after the start of hunting season. There was no statistically significant difference in survival rates in zones where hunting was permitted compared with zones where it was prohibited. We concluded from this study that dove hunting under current regulations has no substantial effect on recruitment of fledglings into the mourning dove population.

Mourning Dove Nesting: Seasonal Patterns and Effects of September Hunting

USGS Publications Warehouse

Geissler, P.H.; Dolton, D.D.; Coon, R.A.; Percival, H.F.; Field, R.; Hayne, D.W.; Soileau, L.D.; George, R.R.; Dunks, J.H.; Bunnell, S.D.

1982-01-01

A nationwide State/Federal cooperative study was initiated in 1978 to examine effects of September hunting on mourning dove (Zenaida macroura) nesting. This study was designed to (1) determine the proportion of the annual total of dove nesting activity and production that occurs in September and October, and (2) determine if survival rates of mourning dove eggs and nestlings are lower in areas where early September dove hunting is permitted compared to areas where it is prohibited. During 1979 and 1980, 6,950 active nests were followed to obtain data on nesting patterns. Nest initiation was estimated both by backdating from hatch dates and by the numbers of nests found for the first time. The nationwide percent of the annual total of nests that were initiated in September and October was 1.0% based on backdating hatch dates and 2.7% based on nests found for the first time. Nesting activity was measured by numbers of eggs and nestlings present in weekly counts. Nationally, 4.5% of the annual total of nesting activity occurred in September and October. The observed period when 80% of the nests were active, based on hatch dates, lasted from April 22 to September 4. The measure of production used in this study was numbers of young fledged. Nationally, 10.3% of all observed fledging occurred in September and October. A decline in nests found in the latter half of the nesting season preceded the September 1 start of hunting. From this we concluded that the reduction in nesting activity at the end of the season is a natural phenomenon and not caused by hunting disturbance. In a separate part of this study, we estimated survival rates in hunted and nonhunted sections from data on 668 nests. The estimated daily survival rates for individual eggs and nestlings were 95.8% in the nonhunted and 95.0% in the hunted sections; the corresponding fledging rates were 33% and 26%, respectively. The fledging rates are lower because they are the daily survival rates operating over a 26-day nesting period. Neither differences in survival nor fledging rates between nonhunted and hunted sections were found to be statistically significant (p> 0.05). We determined that the statistical test was powerful enough to detect a reduction due to hunting from a hypothetical 96.0% to 94.2% in daily nestling survival rates (from 35% to 21% fledging rates) with 80% probability. An undetected reduction in fledging rate of that magnitude would probably reduce the overall fledging rate by less than 1 percentage point, because only a small proportion of the nesting doves is exposed to hunting for the full 26 day nesting cycle. In conclusion, we found that only a small proportion of total annual nesting attempts was exposed to hunting. There was no statistically significant difference in survival rates in sections where hunting was permitted compared to sections where it was prohibited. We concluded from this study that dove hunting under current regulations has no substantial effect on recruitment of fledglings into the mourning dove population.

The effects of ant nests on soil fertility and plant performance: a meta-analysis.

PubMed

Farji-Brener, Alejandro G; Werenkraut, Victoria

2017-07-01

Ants are recognized as one of the major sources of soil disturbance world-wide. However, this view is largely based on isolated studies and qualitative reviews. Here, for the first time, we quantitatively determined whether ant nests affect soil fertility and plant performance, and identified the possible sources of variation of these effects. Using Bayesian mixed-models meta-analysis, we tested the hypotheses that ant effects on soil fertility and plant performance depend on the substrate sampled, ant feeding type, latitude, habitat and the plant response variable measured. Ant nests showed higher nutrient and cation content than adjacent non-nest soil samples, but similar pH. Nutrient content was higher in ant refuse materials than in nest soils. The fertilizer effect of ant nests was also higher in dry habitats than in grasslands or savannas. Cation content was higher in nests of plant-feeding ants than in nests of omnivorous species, and lower in nests from agro-ecosystems than in nests from any other habitat. Plants showed higher green/root biomass and fitness on ant nests soils than in adjacent, non-nest sites; but plant density and diversity were unaffected by the presence of ant nests. Root growth was particularly higher in refuse materials than in ant nest soils, in leaf-cutting ant nests and in deserts habitats. Our results confirm the major role of ant nests in influencing soil fertility and vegetation patterns and provide information about the factors that mediate these effects. First, ant nests improve soil fertility mainly through the accumulation of refuse materials. Thus, different refuse dump locations (external or in underground nest chambers) could benefit different vegetation life-forms. Second, ant nests could increase plant diversity at larger spatial scales only if the identity of favoured plants changes along environmental gradients (i.e. enhancing β-diversity). Third, ant species that feed on plants play a relevant role fertilizing soils, which may balance their known influence as primary consumers. Fourth, the effects of ant nests as fertility islands are larger in arid lands, possibly because fertility is intrinsically lower in these habitats. Overall, this study provide novel and quantitative evidence confirming that ant nests are key soil modifiers, emphasizing their role as ecological engineers. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Subtypes of Benign Breast Disease as a Risk Factor for Breast Cancer: A Systematic Review and Meta-Analysis Protocol

PubMed Central

Zendehdel, Manoosh; Niakan, Babak; Keshtkar, Abbasali; Rafiei, Elahe; Salamat, Fatemeh

2018-01-01

Breast cancer is a multifactorial disease. Benign breast disease (BBD) is one of the most important risk factors for breast cancer. The etiology of BBD is unknown. It is divided into nonproliferative and proliferative diseases. The selection of studies will be based on titles, abstract screening, inclusion and exclusion criteria, and quality assessment. Previous studies have shown that all types of BBD increase the risk of breast cancer, but the risk degree is different for each one. Accurate risk estimation of breast cancer in each category can be very important for proper clinical management. This systematic review and meta-analysis will be conducted on observational studies (traditional case control, nested case control, case cohort, and cohort) published in the Web of Science (ISI), PubMed (MEDLINE), Scopus, Google Scholar, and the key journals of this field such as Breast Cancer Research and Treatment and Cancer Research from January 2000 to June 2015. Reference lists and gray literature will be reviewed too. All the initial retrievals will be performed by 2 researchers independently. The data extraction form will consist of general information concerning the studies, study eligibility, method, risk of bias assessment, and results—including odds ratios, risk ratios, rate ratios, and hazard ratios. The PRISMA and MOOSE guidelines will be used to report our findings. Registration Details: PROSPERO-42016035243 PMID:29398746

Subtypes of Benign Breast Disease as a Risk Factor for Breast Cancer: A Systematic Review and Meta-Analysis Protocol.

PubMed

Zendehdel, Manoosh; Niakan, Babak; Keshtkar, Abbasali; Rafiei, Elahe; Salamat, Fatemeh

2018-01-01

Breast cancer is a multifactorial disease. Benign breast disease (BBD) is one of the most important risk factors for breast cancer. The etiology of BBD is unknown. It is divided into nonproliferative and proliferative diseases. The selection of studies will be based on titles, abstract screening, inclusion and exclusion criteria, and quality assessment. Previous studies have shown that all types of BBD increase the risk of breast cancer, but the risk degree is different for each one. Accurate risk estimation of breast cancer in each category can be very important for proper clinical management. This systematic review and meta-analysis will be conducted on observational studies (traditional case control, nested case control, case cohort, and cohort) published in the Web of Science (ISI), PubMed (MEDLINE), Scopus, Google Scholar, and the key journals of this field such as Breast Cancer Research and Treatment and Cancer Research from January 2000 to June 2015. Reference lists and gray literature will be reviewed too. All the initial retrievals will be performed by 2 researchers independently. The data extraction form will consist of general information concerning the studies, study eligibility, method, risk of bias assessment, and results-including odds ratios, risk ratios, rate ratios, and hazard ratios. The PRISMA and MOOSE guidelines will be used to report our findings. Registration Details: PROSPERO-42016035243.

Local individual preferences for nest materials in a passerine bird.

PubMed

Mennerat, Adèle; Perret, Philippe; Lambrechts, Marcel M

2009-01-01

Variation in the behavioural repertoire of animals is acquired by learning in a range of animal species. In nest-building birds, the assemblage of nest materials in an appropriate structure is often typical of a bird genus or species. Yet plasticity in the selection of nest materials may be beneficial because the nature and abundance of nest materials vary across habitats. Such plasticity can be learned, either individually or socially. In Corsican populations of blue tits Cyanistes caeruleus, females regularly add in their nests fragments of several species of aromatic plants during the whole breeding period. The selected plants represent a small fraction of the species present in the environment and have positive effects on nestlings. We investigated spatiotemporal variations of this behaviour to test whether the aromatic plant species composition in nests depends on 1) plant availability in territories, 2) female experience or 3) female identity. Our results indicate that territory plays a very marginal role in the aromatic plant species composition of nests. Female experience is not related to a change in nest plant composition. Actually, this composition clearly depends on female identity, i.e. results from individual preferences which, furthermore, are repeatable both within and across years. A puzzling fact is the strong difference in plant species composition of nests across distinct study plots. This study demonstrates that plant species composition of nests results from individual preferences that are homogeneous within study plots. We propose several hypotheses to interpret this pattern of spatial variation before discussing them in the light of preliminary results. As a conclusion, we cannot exclude the possibility of social transmission of individual preferences for aromatic plants. This is an exciting perspective for further work in birds, where nest construction behaviour has classically been considered as a stereotypic behaviour.

Nest trees of northern spotted owls (Strix occidentalis caurina) in Washington and Oregon, USA

PubMed Central

Lesmeister, Damon B.; Forsman, Eric D.

2018-01-01

The northern spotted owl (Strix occidentalis caurina) is a federally-threatened subspecies in the United States associated with late-successional forests. In mesic forests it nests primarily in tree cavities, but also uses various types of external platform nests in drier forests. We describe 1717 northern spotted owl nests in 16 different tree species in five study areas in Washington and Oregon in the Pacific Northwest, USA. The vast majority of nests (87%) were in Douglas-fir (Pseudotsuga menziesii) trees, except on the Olympic Peninsula, Washington, where nests were about equally abundant in Douglas-fir, western red cedar (Thuja plicata), and western hemlock (Tsuga heterophylla) trees. Distribution of nests was 57.9% in top cavities of trees with broken tops, 20.3% in side cavities of hollow tree trunks, and 21.8% on external platforms of trees. Platforms were most common in the two driest study areas in the Eastern Cascades Physiographic Province, Washington (89% of nests), and the Klamath Province, Oregon (32%). The vast majority (89%) of nests were in trees with intact or declining crowns. Nests in dead trees were most common on the Olympic Peninsula. Nest trees with top and side cavities were larger and much more prevalent in study areas where annual precipitation was highest (Olympic Peninsula, Oregon Coast Range). Large nest cavities and platforms used by northern spotted owls occur almost exclusively in old forest. Managing for the retention of such forests and for their replacement is a significant challenge for land managers, especially in the face of climate change and an increasing human population, but will likely be required for the persistence of viable populations of northern spotted owls. PMID:29852017

Nest predation risk influences a cavity-nesting passerine during the post-hatching care period

PubMed Central

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

Nest predation risk influences a cavity-nesting passerine during the post-hatching care period.

PubMed

Yoon, Jongmin; Kim, Byung-Su; Joo, Eun-Jin; Park, Shi-Ryong

2016-08-24

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.

Predicting nest success from habitat features in aspen forests of the central Rocky Mountains

Treesearch

Heather M. Struempf; Deborah M. Finch; Gregory Hayward; Stanley Anderson

2001-01-01

We collected nesting data on bird use of aspen stands in the Routt and Medicine Bow National Forests between 1987 and 1989. We found active nest sites of 28 species of small nongame birds on nine study plots in undisturbed aspen forests. We compared logistic regression models predicting nest success (at least one nestling) from nest-site or stand-level habitat...

Nest-site selection by cavity-nesting birds in relation to postfire salvage logging

Treesearch

Victoria A. Saab; Robin E. Russell; Jonathan G. Dudley

2009-01-01

Large wildfire events in coniferous forests of the western United States are often followed by postfire timber harvest. The long-term impacts of postfire timber harvest on fire-associated cavity-nesting bird species are not well documented. We studied nest-site selection by cavity-nesting birds over a 10-year period (1994-2003), representing 1-11 years after fire, on...

Facultative nest patch shifts in response to nest predation risk in the Brewer's sparrow: a "win-stay, lose-switch" strategy?

Treesearch

Anna D. Chalfoun; Thomas E. Martin

2010-01-01

Facultative shifts in nesting habitat selection in response to perceived predation risk may allow animals to increase the survival probability of sessile offspring. Previous studies on this behavioral strategy have primarily focused on single attributes, such as the distance moved or changes in nesting substrate. However, nest site choice often encompasses multiple...

A red-cockaded woodpecker group with two simultaneous nest trees

Treesearch

Richard N. Conner; James M. McCormick; Richard R. Schaefer; Daniel Saenz; D. Craig Rudolph

2001-01-01

During a study of red cockaded woodpecker (P icoides borealis) nesting in eastern Texas, we discovered a single breeding pair of woodpeckers with two simultaneous nests in nest trees that were 24 m apart. Incubation of eggs in each nest tree was at least 13 d and may have been as long as 16 d. The breeding male incubated and fed a nestling in one...

Use of Hardwood Tree Species by Birds Nesting in Ponderosa Pine Forests

Treesearch

Kathryn L. Purcell; Douglas A. Drynan

2008-01-01

We examined the use of hardwood tree species for nesting by bird species breeding in ponderosa pine (Pinus ponderosa) forests in the Sierra National Forest, California. From 1995 through 2002, we located 668 nests of 36 bird species nesting in trees and snags on four 60-ha study sites. Two-thirds of all species nesting in trees or snags used...

Nesting Ecology of Wood Thrush (Turdidae: Passeriformes) in Hardwood Forests of South Carolina

Treesearch

Robert A. Sargent; John C. Kilgo; Brian R. Chapman; Karl V. Miller

2003-01-01

We studied nesting success of the Wood Thrush (Hylocichla mustelina) in bottomland and upland hardwood forests in South Carolina. Twenty-one of 26 nests (80.8%) were located in bottomland sites, and 76.2% of these nests were in narrow (

Nesting fidelity and molecular evidence for natal homing in the freshwater turtle, Graptemys kohnii

PubMed Central

Freedberg, Steven; Ewert, Michael A; Ridenhour, Benjamin J; Neiman, Maurine; Nelson, Craig E

2005-01-01

Numerous studies of sea turtle nesting ecology have revealed that females exhibit natal homing, whereby they imprint on the nesting area from which they hatch and subsequently return there to nest as adults. Because freshwater turtles comprise the majority of reptiles known to display environmental sex determination (ESD), the study of natal homing in this group may shed light on recent evolutionary models of sex allocation that are predicated on natal homing in reptiles with ESD. We examined natal homing in Graptemys kohnii, a freshwater turtle with ESD, using mitochondrial sequencing, microsatellite genotyping and mark and recapture of 290 nesting females. Females showed high fidelity to nesting areas, even after being transplanted several kilometres away. A Mantel test revealed significant genetic isolation by distance with respect to nesting locations (r=0.147; p<0.05), suggesting that related females nest in close proximity to one another. The patterns of fidelity and genotype distributions are consistent with homing at a scale that may affect population sex ratios. PMID:16006324

Nest Mosquito Trap quantifies contact rates between nesting birds and mosquitoes.

PubMed

Caillouët, Kevin A; Riggan, Anna E; Rider, Mark; Bulluck, Lesley P

2012-06-01

Accurate estimates of host-vector contact rates are required for precise determination of arbovirus transmission intensity. We designed and tested a novel mosquito collection device, the Nest Mosquito Trap (NMT), to collect mosquitoes as they attempt to feed on unrestrained nesting birds in artificial nest boxes. In the laboratory, the NMT collected nearly one-third of the mosquitoes introduced to the nest boxes. We then used these laboratory data to estimate our capture efficiency of field-collected bird-seeking mosquitoes collected over 66 trap nights. We estimated that 7.5 mosquitoes per trap night attempted to feed on nesting birds in artificial nest boxes. Presence of the NMT did not have a negative effect on avian nest success when compared to occupied nest boxes that were not sampled with the trap. Future studies using the NMT may elucidate the role of nestlings in arbovirus transmission and further refine estimates of nesting bird and vector contact rates. © 2012 The Society for Vector Ecology.

Nest Mosquito Trap quantifies contact rates between nesting birds and mosquitoes

PubMed Central

Caillouët, Kevin A.; Riggan, Anna E.; Rider, Mark; Bulluck, Lesley P.

2012-01-01

Accurate estimates of host-vector contact rates are required for precise determination of arbovirus transmission intensity. We designed and tested a novel mosquito collection device, the Nest Mosquito Trap (NMT), to collect mosquitoes as they attempt to feed on unrestrained nesting birds in artificial nest boxes. In the laboratory, the NMT collected nearly one-third of the mosquitoes introduced to the nest boxes. We then used these laboratory data to estimate our capture efficiency of field-collected bird-seeking mosquitoes collected over 66 trap nights. We estimated that 7.5 mosquitoes per trap night attempted to feed on nesting birds in artificial nest boxes. Presence of the NMT did not have a negative effect on avian nest success when compared to occupied nest boxes that were not sampled with the trap. Future studies using the NMT may elucidate the role of nestlings in arbovirus transmission and further refine estimates of nesting bird and vector contact rates. PMID:22548555

Who are the important predators of sea turtle nests at Wreck Rock beach?

PubMed Central

Booth, David T.

2017-01-01

Excessive sea turtle nest predation is a problem for conservation management of sea turtle populations. This study assessed predation on nests of the endangered loggerhead sea turtle (Caretta caretta) at Wreck Rock beach adjacent to Deepwater National Park in Southeast Queensland, Australia after a control program for feral foxes was instigated. The presence of predators on the nesting dune was evaluated by tracking plots (2 × 1 m) every 100 m along the dune front. There were 21 (2014–2015) and 41 (2015–2016) plots established along the dune, and these were monitored for predator tracks daily over three consecutive months in both nesting seasons. Predator activities at nests were also recorded by the presence of tracks on top of nests until hatchlings emerged. In addition, camera traps were set to record the predator activity around selected nests. The tracks of the fox (Vulpes vulpes) and goanna (Varanus spp) were found on tracking plots. Tracking plots, nest tracks and camera traps indicated goanna abundance varied strongly between years. Goannas were widely distributed along the beach and had a Passive Activity Index (PAI) (0.31 in 2014–2015 and 0.16 in 2015–2016) approximately seven times higher than that of foxes (PAI 0.04 in 2014–2015 and 0.02 in 2015–2016). Five hundred and twenty goanna nest visitation events were recorded by tracks but no fox tracks were found at turtle nests. Camera trap data indicated that yellow-spotted goannas (Varanus panoptes) appeared at loggerhead turtle nests more frequently than lace monitors (V. varius) did, and further that lace monitors only predated nests previously opened by yellow-spotted goannas. No foxes were recorded at nests with camera traps. This study suggests that large male yellow-spotted goannas are the major predator of sea turtle nests at the Wreck Rock beach nesting aggregation and that goanna activity varies between years. PMID:28674666

Linking snake behavior to nest predation in a Midwestern bird community.

PubMed

Weatherhead, Patrick J; Carfagno, Gerardo L F; Sperry, Jinelle H; Brawn, Jeffrey D; Robinson, Scott K

2010-01-01

Nest predators can adversely affect the viability of songbird populations, and their impact is exacerbated in fragmented habitats. Despite substantial research on this predator-prey interaction, however, almost all of the focus has been on the birds rather than their nest predators, thereby limiting our understanding of the factors that bring predators and nests into contact. We used radiotelemetry to document the activity of two snake species (rat snakes, Elaphe obsoleta; racers, Coluber constrictor) known to prey on nests in Midwestern bird communities and simultaneously monitored 300 songbird nests and tested the hypothesis that predation risk should increase for nests when snakes were more active and in edge habitat preferred by both snake species. Predation risk increased when rat snakes were more active, for all nests combined and for two of the six bird species for which we had sufficient nests to allow separate analyses. This result is consistent with rat snakes being more important nest predators than racers. We found no evidence, however, that nests closer to forest edges were at greater risk. These results are generally consistent with the one previous study that investigated rat snakes and nest predation simultaneously. The seemingly paradoxical failure to find higher predation risk in the snakes' preferred habitat (i.e., edge) might be explained by the snakes using edges at least in part for non-foraging activities. We propose that higher nest predation in fragmented habitats (at least that attributable to snakes) results indirectly from edges promoting larger snake populations, rather than from edges directly increasing the risk of nest predation by snakes. If so, the notion of edges per se functioning as ecological "traps" merits further study.

Ducks and passerines nesting in northern mixed-grass prairie treated with fire

USGS Publications Warehouse

Grant, Todd A.; Shaffer, Terry L.; Madden, Elizabeth M.; Berkey, Gordon B.

2011-01-01

Prescribed fire is an important, ecology-driven tool for restoration of grassland systems. However, prescribed fire remains controversial for some grassland managers because of reported reductions in bird use of recently burned grasslands. Few studies have evaluated effects of fire on grassland bird populations in the northern mixed-grass prairie region. Fewer studies yet have examined the influence of fire on nest density or survival. In our review, we found no studies that simultaneously examined effects of fire on duck and passerine nesting. During 1998—2003, we examined effects of prescribed fire on the density of upland-nesting ducks and passerines nesting in north-central North Dakota, USA. Apparent nest densities of gadwall (Anas strepera), mallard (A. platyrhynchos), and all duck species combined, were influenced by fire history of study units, although the degree of influence was not compelling. Fire history was not related to nest densities of blue-winged teal (A. discors), northern shoveler (A. clypeata), or northern pintail (A. acuta); however, apparent nest densities in relation to the number of postfire growing seasons exhibited a strikingly similar pattern among all duck species. When compared to ducks, fire history strongly influenced apparent nest densities of clay-colored sparrow (Spizella pallida), Savannah sparrow (Passerculus sandwichensis), and bobolink (Dolichonyx oryzivorus). For most species examined, apparent nest densities were lowest in recently burned units, increased during the second postfire growing season, and stabilized or, in some cases, decreased thereafter. Prescribed fire is critical for restoring the ecology of northern mixed-grass prairies and our findings indicate that reductions in nest densities are limited mostly to the first growing season after fire. Our results support the premise that upland-nesting ducks and several grassland passerine species are adapted to periodic fires occurring at a frequency similar to that of pre-Euro-American settlement of the region.

What constitutes a nesting attempt? Variation in criteria causes bias and hinders comparisons across studies

USGS Publications Warehouse

Garcia, V.; Conway, C.J.

2009-01-01

Because reliable estimates of nesting success are very important to avian studies, the defnition of a “successful nest” and the use of different analytical methods to estimate success have received much attention. By contrast, variation in the criteria used to determine whether an occupied site that did not produce offspring contained a nesting attempt is a source of bias that has been largely ignored. This problem is especially severe in studies that deal with species whose nest contents are relatively inaccessible because observers cannot determine whether or not an egg was laid for a large proportion of occupied sites. Burrowing Owls (Athene cunicularia) often lay their eggs ≥3 m below ground, so past Burrowing Owl studies have used a variety of criteria to determine whether a nesting attempt was initiated. We searched the literature to document the extent of that variation and examined how that variation influenced estimates of daily nest survival. We found 13 different sets of criteria used by previous authors and applied each criterion to our data set of 1,300 occupied burrows. We found significant variation in estimates of daily nest survival depending on the criteria used. Moreover, differences in daily nest survival among populations were apparent using some sets of criteria but not others. These inconsistencies may lead to incorrect conclusions and invalidate comparisons of the productivity and relative site quality among populations. We encourage future authors working on cavity-, canopy-, or burrow-nesting birds to provide specific details on the criteria they used to identify a nesting attempt.

Real-world antidiabetic drug use and fracture risk in 12,277 patients with type 2 diabetes mellitus: a nested case-control study.

PubMed

Losada, E; Soldevila, B; Ali, M S; Martínez-Laguna, D; Nogués, X; Puig-Domingo, M; Díez-Pérez, A; Mauricio, D; Prieto-Alhambra, D

2018-06-02

We conducted a nested case-control study to study the association between antidiabetic treatments (alone or in combination) use and fracture risk among incident type 2 Diabetes mellitus patients. We found an increased risk of bone fracture with insulin therapy compared to metformin monotherapy. Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fragility fractures, to which antidiabetic therapies may contribute. We aimed to characterize the risk of fracture associated with different antidiabetic treatments as usually prescribed to T2DM patients in actual practice conditions. A case-control study was nested within a cohort of incident T2DM patients registered in 2006-2012 in the Information System for Research Development in Primary Care (Catalan acronym, SIDIAP), a database which includes records for > 5.5 million patients in Catalonia (Spain). Each case (incident major osteoporotic fracture) was risk-set matched with up to five same-sex controls by calendar year of T2DM diagnosis and year of birth (± 10 years). Study exposure included previous use of all antidiabetic medications (alone or in combination), as dispensed in the 6 months before the index date, with metformin (MTF) monotherapy, the most commonly used drug, as a reference group (active comparator). Data on 12,277 T2DM patients (2049 cases and 10,228 controls) were analyzed. Insulin use was associated with increased fracture risk (adjusted OR 1.63 (95% CI 1.30-2.04)), as was the combination of MTF and sulfonylurea (SU) (adjusted OR 1.29 (1.07-1.56)), compared with MTF monotherapy. Sensitivity analyses suggest possible causality for insulin therapy but not for the MTF + SU combination association. No significant association was found with any other antidiabetic medications. Insulin monotherapy was associated with an increased fracture risk compared to MTF monotherapy in T2DM patients. Fracture risk should be taken into account when starting a glucose-lowering drug as part of T2DM treatment.

Risk for attempted suicide in children and youths after contact with somatic hospitals: a Danish register based nested case-control study.

PubMed

Christiansen, E; Stenager, E

2012-03-01

A range of studies have found an association between some somatic diseases and increased risk of suicide and attempted suicide. These studies are mostly analyses of adult populations and illnesses related to adulthood. To study the risk of attempted suicide in children and youths with a somatic diagnosis, and to assess a possible association from a somatic perspective. From a cohort of 403 431 individuals (born 1983-89), 3465 children and youths who had attempted suicide were identified. Each case was matched with 20 population controls. 72 765 children and youths constituted the case-control population. All data were obtained from national population registers and analysed in a nested case-control design. Contact of children and youths with a somatic hospital is correlated with increased risk of attempted suicide; the risk peaks in the time immediately after contact. Risk factors were treatment for injury caused by violence, epilepsy, asthma and malformation for males; and spontaneous and medical abortions, treatment for injury caused by violence, epilepsy, asthma, insulin dependent diabetes mellitus and malformation for females. Not all the mentioned diagnoses were significant in the adjusted model. Based on the results of the study a strategy to minimise the risk of attempted suicide among children and youths must be implemented. The strategy should mainly focus on children at high risk-that is, children from families with low socioeconomic status, and children with a psychiatric history, a history of previous suicide attempts and with an unstable somatic disease subsequently causing many admissions.

Validity of the diagnosis of pre-eclampsia in the Medical Birth Registry of Norway.

PubMed

Thomsen, Liv C V; Klungsøyr, Kari; Roten, Linda T; Tappert, Christian; Araya, Elisabeth; Baerheim, Gunhild; Tollaksen, Kjersti; Fenstad, Mona H; Macsali, Ferenc; Austgulen, Rigmor; Bjørge, Line

2013-08-01

Evaluating the validity of pre-eclampsia registration in the Medical Birth Registry of Norway (MBRN) according to both broader and restricted disease definitions. Retrospective nested cohort study. Multicenter study. In this study, two cohorts of women with pre-eclamptic pregnancies registered in the MBRN were selected. Study group 1 contained 966 pregnancies from 1967 to 2002. Concomitant participation in the Nord-Trøndelag Health Study 2 was required. Study group 2 comprised 1138 pregnancies recorded in 1967-2005, examined as a pre-eclampsia biobank was established. Diagnostic criteria vary. The broader criteria for pre-eclampsia, used by the MBRN, are one measurement of hypertension and proteinuria (Criterion A). Criteria used internationally today require two measurements of hypertension and proteinuria (Criterion B). The diagnostic validities in Study groups 1 and 2 were judged against medical records according to Criterion A and B, respectively. Positive predictive value (PPV) and trend analyses. The diagnosis was confirmed in 88.3% of pregnancies in Study group 1, and in 63.6% in Study group 2. PPV was high for Study group 1 throughout the period. For Study group 2, results improved significantly after 1986. This study ascertains high PPV of pre-eclampsia in the MBRN using broader traditional criteria, although the PPV decreases through assessment using restricted modern criteria. This illustrates how inclusion of direct measurements may improve registration of complex disorders defined by changing diagnostic criteria. © 2013 Nordic Federation of Societies of Obstetrics and Gynecology.

Ischaemic cardiac events and use of strontium ranelate in postmenopausal osteoporosis: a nested case-control study in the CPRD.

PubMed

Cooper, C; Fox, K M; Borer, J S

2014-02-01

We explored the cardiac safety of the osteoporosis treatment strontium ranelate in the UK Clinical Practice Research Datalink. While known cardiovascular risk factors like obesity and smoking were associated with increased cardiac risk, use of strontium ranelate was not associated with any increase in myocardial infarction or cardiovascular death. It has been suggested that strontium ranelate may increase risk for cardiac events in postmenopausal osteoporosis. We set out to explore the cardiac safety of strontium ranelate in the Clinical Practice Research Datalink (CPRD) and linked datasets. We performed a nested case-control study. Primary outcomes were first definite myocardial infarction, hospitalisation with myocardial infarction, and cardiovascular death. Cases and matched controls were nested in a cohort of women treated for osteoporosis. The association with exposure to strontium ranelate was analysed by multivariate conditional logistic regression. Of the 112,445 women with treated postmenopausal osteoporosis, 6,487 received strontium ranelate. Annual incidence rates for first definite myocardial infarction (1,352 cases), myocardial infarction with hospitalisation (1,465 cases), and cardiovascular death (3,619 cases) were 3.24, 6.13, and 14.66 per 1,000 patient-years, respectively. Obesity, smoking, and cardiovascular treatments were associated with significant increases in risk for cardiac events. Current or past use of strontium ranelate was not associated with increased risk for first definite myocardial infarction (odds ratio [OR] 1.05, 95 % confidence interval [CI] 0.68-1.61 and OR 1.12, 95 % CI 0.79-1.58, respectively), hospitalisation with myocardial infarction (OR 0.84, 95 % CI 0.54-1.30 and OR 1.17, 95 % CI 0.83-1.66), or cardiovascular death (OR 0.96, 95 % CI 0.76-1.21 and OR 1.16, 95 % CI 0.94-1.43) versus patients who had never used strontium ranelate. Analysis in the CPRD did not find evidence for a higher risk for cardiac events associated with the use of strontium ranelate in postmenopausal osteoporosis.

Development and validation of the Neonatal Mortality Score-9 Mexico to predict mortality in critically ill neonates.

PubMed

Márquez-González, Horacio; Jiménez-Báez, María Valeria; Muñoz-Ramírez, C Mireya; Yáñez-Gutiérrez, Lucelli; Huelgas-Plaza, Ana C; Almeida-Gutiérrez, Eduardo; Villa-Romero, Antonio Rafael

2015-06-01

Prognostic scales or scores are useful for physicians who work in neonatal intensive care units. There are several validated neonatal scores but they are mostly applicable to low birth weight infants. The aim of this study was to develop and validate a mortality prognostic score in newborn infants, that would include new prognostic outcome measures. The study was conducted in a mother and child hospital in the city of Mexico, part of the Instituto Mexicano del Seguro Social (Mexican Institute of Social Security). In the first phase of the study, a nested case-control study was designed (newborn infants admitted on the basis of severity criteria during the first day of life), in which a scale was identified and developed with gradual parameters of cumulative score consisting of nine independent outcome measures to predict death, as follows: weight, metabolic acidemia, lactate, PaO2/FiO2, p(A-a) O2, A/a, platelets and serum glucose.Validation was performed in a matched prospective cohort, using 7-day mortality as an endpoint. The initial cohort consisted of 424 newborn infants. Twenty-two cases and 132 controls were selected; and 9 outcome measures were identified, making up the scale named neonatal mortality score-9 Mexico. The validation cohort consisted of 227 newborn infants. Forty-four (19%) deaths were recorded, with an area under the curve (AUC) of 0.92. With a score between 16 and 18, an 85 (11-102) hazard ratio, 99% specificity, 71% positive predictive value and 90% negative predictive value were reported. Conclusions .The proposed scale is a reliable tool to predict severity in newborn infants.

Nest site attributes and temporal patterns of northern flicker nest loss: effects of predation and competition.

PubMed

Fisher, Ryan J; Wiebe, Karen L

2006-04-01

To date, most studies of nest site selection have failed to take into account more than one source of nest loss (or have combined all sources in one analysis) when examining nest site characteristics, leaving us with an incomplete understanding of the potential trade-offs that individuals may face when selecting a nest site. Our objectives were to determine whether northern flickers (Colaptes auratus) may experience a trade-off in nest site selection in response to mammalian nest predation and nest loss to a cavity nest competitor (European starling, Sturnus vulgaris). We also document within-season temporal patterns of these two sources of nest loss with the hypothesis that flickers may also be constrained in the timing of reproduction under both predatory and competitive influence. Mammalian predators frequently depredated flicker nests that were: lower to the ground, less concealed by vegetation around the cavity entrance and at the base of the nest tree, closer to coniferous forest edges and in forest clumps with a high percentage of conifer content. Proximity to coniferous edges or coniferous trees increased the probability of nest predation, but nests near conifers were less likely to be lost to starlings. Flickers may thus face a trade-off in nest site selection with respect to safety from predators or competitors. Models suggested that peaks of nest predation and nest loss to eviction occurred at the same time, although a competing model suggested that the peak of nest loss to starlings occurred 5 days earlier than the peak of mammalian predation. Differences in peaks of mammalian predation and loss to starlings may constrain any adjustment in clutch initiation date by flickers to avoid one source of nest loss.

The role of moisture in the nest thermoregulation of social wasps.

PubMed

Klingner, R; Richter, K; Schmolz, E; Keller, B

2005-09-01

Paper nests of social wasps are intriguing constructions for both, biologists and engineers. We demonstrate that moisture and latent heat significantly influence the thermal performance of the nest construction. Two colonies of the hornet Vespa crabro were investigated in order to clarify the relation of the temperature and the moisture regime inside the nest. Next to fairly stable nest temperatures the hornets maintain a high relative humidity inside the nest. We found that in consequence a partial vapor-pressure gradient between nest and ambient drives a constant vapor flux through the envelope. The vapor flux is limited by the diffusion resistance of the envelope. The driving force of vapor flux is heat, which is consumed through evaporation inside the nest. The colony has to compensate this loss with metabolic heat production in order to maintain a stable nest temperature. However, humidity fluctuations inside the nest induce circadian adsorption and desorption cycles, which stabilize the nest temperature and thus contribute significantly to temperature homeostasis. Our study demonstrates that both mechanisms influence nest thermoregulation and need to be considered to understand the thermodynamic behavior of nests of wasps and social insects in general.

Is courtship intensity a signal of male parental care in Red-winged Blackbirds (Agelaius phoeniceus)?

USGS Publications Warehouse

Yasukawa, Ken; Knight, Richard L.; Skagen, Susan Knight

1987-01-01

We studied Red-winged Blackbird (Agelaius phoeniceus) behavior in marsh and prairie habitats to determine whether courting males provide cues of their nest defense, whether females prefer males that defend nests vigorously, and whether male nest defense affects nest success. We found no evidence that courtship behavior provides cues of male nest defense, or that females prefer males that court intensely. We found evidence that females nesting in marshes prefer males that defend nests intensely, but no evidence that intensely defending males in the prairie habitat achieve high nest success. We found differences, however, between marsh and prairie habitats that suggest a coarse-grained relationship between male parental quality and female choice of mate in this species.

Vegetation used for nesting by the red-winged blackbird in Florida

USGS Publications Warehouse

Stowers, J.F.; Harke, D.T.; Stickley, A.R.

1968-01-01

During the breeding season of 1966, as an adjunct to a taxonomic study of Red-winged Blackbirds in Florida, 177 Redwin g nests were found. The general habitat types were noted, and the plant species harboring nests were listed.....Redwing nests were found in 30 genera of plants. Buttonbush was the primary choice; it was used to support 50 of the 177 nests. Silverling and willow were the next most often used plants. Nests also were found in other shrubs and trees, in assorted herbs and grasses, and in fields of sweet corn and sugarcane. The great degree of nesting adaptability of the Red-winged Blackbird is attested by the diversity of nesting site selections in several habitats.

Ecology and behavior of the zenaida dove

USGS Publications Warehouse

Wiley, J.W.

1991-01-01

Data are summarized from a 10 year study of the Zenaida Dove (Zenaida aurita) in Puerto Rico and its offshore islands. The dove displays sexual size dimorphism, with males generally larger than females: Most activities (feeding, courtship, fighting) occurred in mornings and afternoons, whereas loafing and maintenance activities were more prevalent at mid-day. I recorded 77 plant species used as food by Zenaida Doves in Puerto Rico. Major food species uncluded Scleria lithosperma, Argemone mexicana, Croton rigidus, Phyllanthus amarus, Cordia angustifolia, Zanthoxylum martinicense, Euphorbia heterophylla, and several species of legumes. Zenaida Doves have two major vocalizations: the 'Coo', or Advertisement Call, given in assertive and sexual contexts, and the Nest Call, primarily used at or near the nest. Doves nested in a wide variety of habitats, including forest edge, mangrove forest, dry scrub, and mixed agriculture-urban areas. Nests were generally placed in trees, but doves nested on the ground where certain terrestrial predators were absent. Nests were found in all months of the year, although a breeding peak occurred from March through Mayor July. Doves replaced clutches when nests were destroyed, and recycled up to four times in a season. Males selected nest sites and initiated building. Eggs (2) were laid on alternate days, beginning about two days after the nest was completed. Incubation and nestling stages averaged 13.9 :t 0.5 [SE] and 14.3 :t 0.6 days. The male attended the nest from mid-morning (X = 08:59 hr) through mid-afternoon (x = 16:53), then the female took over incubation and brooding duties for the night. Nests were continuously covered from the laying of the first egg through day seven of the nestling stage. Thereafter, adult attendance dropped steadily until day 14, when they carne to the nest only for chick feedings. Chicks (days 0-15) showed a mean daily weight gain of 18.3% and attained a fledging weight of about 120g (81% of adult weight). The mean daily growth (culmen, tarsometatarsus, ulna) was 6.8% (range = 4.0-9.8% daily). Dove productivity varied among and within study areas over the 10 years. Mean number of chicks hatched per nest that held eggs ranged from 0.3 to 1.6 for 3 study areas. Mean number fledged per nest ranged from 0.3 to 1.4. Productivity was lowest in the dry southwestern Puerto Rico study area (Susua and Guanica forests; x = 0.7 chicks fledged per nest) and was highest for the lower montane mixed agriculture/urban area (Cidra; 1.2). Populations nesting in scrub and mangrove forests (Roosevelt Roads Naval Station) fledged an average of 0.9 chicks/nest. Nest success followed a similar geographic pattern: southwestern Puerto Rico -40.9% of nests with eggs were successful, Cidra -62.6%, and Roosevelt Roads -52.0%. The most important sources of dove egg and chick loss were Pearly-eyed Thrashers (Margarops fuscatus -49% of losses) and roof rats (Rattus rattus -16%).

Bone Turnover Does Not Reflect Skeletal Aging in Older Hispanic Men with Type 2 Diabetes

NASA Technical Reports Server (NTRS)

Rianon, N.; McCormick, J.; Ambrose, C.; Smith, S. M.; Fisher-Hoch, S.

2016-01-01

The paradox of fragility fracture in the presence of non-osteoporotic bone mineral density in older patients with type 2 diabetes mellitus (DM2) makes it difficult to clinically predict fracture in this vulnerable group. Serum osteocalcin (OC), a marker of bone turnover, increases with normal skeletal aging indicating risk of fracture. However, OC has been reported to be lower in patients with DM2. An inverse association between higher glycated hemoglobin levels (HbA1c) and lower serum OC in older DM2 patients triggered discussions encouraging further investigation. A key question to be answered is whether changes in glucose metabolism is responsible for bone metabolic changes, ultimately leading to increased risk of fragility fractures in DM2 patients. While these studies were conducted among Caucasian and Asian populations, this has not been studied in Hispanic populations who suffer from a higher prevalence of DM2. The Cameron County Hispanic Cohort (CCHC) in Texas is a homogeneous Hispanic cohort known to have high prevalence of DM2 (30%). Our preliminary data from this cohort reported OC levels lower than the suggested threshold for fragility fracture in post-menopausal women. We further investigated whether bone turnover in older CCHC adults with DM2 show a normal pattern of skeletal aging. Samples and data were obtained from a nested cohort of 68 (21 men and 47 women) Hispanic older adults (=50 years) who had a diagnosis of DM2. Given high prevalence of uncontrolled DM2 in this cohort, we divided population into two groups: i) poor DM2 control with HbA1c level =8 (48% men and 38% women) and ii) good DM2 control with HbA1c level <8). A crosssectional analysis documented associations between serum OC and age adjusted HbA1c levels. There was no direct association between age and OC concentrations in our study. Higher HbA1c was associated with lower serum OC in men (odds ratio -6.5, 95% confidence interval -12.7 to - 0.3, p < 0.04). No significant associations were identified in women. Bone turnover in older Hispanic men with DM2 in our study does not reflect normal pattern of skeletal aging. It is unclear why similar results were not identified in women. We will continue to follow this cohort to investigate longitudinal trend of changes of bone turnover and its relationship with HbA1c in both men and women of this cohort.

Sunrise nest attendance and aggression by least Bell's vireos fail to deter cowbird parasitism

USGS Publications Warehouse

Sharp, Bryan L.; Kus, Barbara E.

2004-01-01

We video-recorded three, natural, brood-parasitism events by Brown-headed Cowbirds (Molothrus ater) at nests of Least Bell's Vireos (Vireo bellii pusillus). All instances occurred near dawn, during both egg-laying and incubation stages of the nesting cycle. In each case, an adult vireo was on the nest when the female cowbird arrived. Both members of each parasitized pair vigorously attacked the intruding cowbird, but in no encounter did a pair of vireos successfully defend its nest from parasitism. Thus, Least Bell's Vireos in our study were unable to prevent a female cowbird from parasitizing their nests once the cowbird had reached the nest.

Genetic Relatedness of Low Solitary Nests of Apis dorsata from Marang, Terengganu, Malaysia

PubMed Central

Ali, Abdul Manaf; Tan, Soon Guan; Adam, Nur Azura; Lau, Wei Hong

2012-01-01

Knowledge on the population of genetic structure and ecological behaviour of Apis dorsata from Peninsular Malaysia is needed for effective management and conservation of this species since unsustainable whole solitary low nest cutting for product harvesting is the current common practice here. The analysis of 15 single locus DNA microsatellite markers on samples from 20 solitary nests of A. dorsata showed that while these markers were polymorphic, high intracolonial relatedness existed. Furthermore, in general, slightly negative values of intercolony relatedness (R) among the nests of A. dorsata were found. However, positive values of mean intercolony relatedness were observed between 54 pairs of nests out of 190 possible combinations. The R values among nest pairs 3–4 and 3–5 was higher than 0.50 showing that their queens were half siblings, whereas nest pair 19–20 showed relatedness of 0.95 indicating that the same queen was sampled. The results that we obtained could not conclusively support the hypothesis of this study that the honey hunters in Marang district of Malaysia repeatedly harvest the same nest located at a different site and at a different time during the same honey harvesting season. However, our finding of an appreciable level of intercolonial relatedness between several pairs of nests in this pioneer study indicated that a comprehensive study with a larger sample size of solitary nests found throughout the region would be necessary to provide concrete proof for this novel idea. PMID:22911733

Nesting tree characteristics of heronry birds of urban ecosystems in peninsular India: implications for habitat management

PubMed Central

Sinu, Palatty Allesh

2017-01-01

Abstract Wetland ecosystems, particularly the mangrove forest, are the primary wild habitat of heronry birds. However, urban ecosystems have become a favorite breeding habitat of these birds. To provide inputs into the habitat management for conservation of these birds, we investigated the quantitative and qualitative characteristics of nesting trees of heronry birds in the urban environment of the North Kerala region of peninsular India. Census on nesting trees was done in 3 major microhabitats of the urban ecosystem: avenues of national highways and towns, nonresidential plots, and residential areas apart from the mangrove islets in the peri-urban locality. The study found that 174 trees of 22 species hosted 1,928 heronry bird nests in the urban habitats; mangrove forests, although plentiful in the study area, hosted only about 20% of the total nests encountered in the study. Rain trees Samanea saman (43.7%) were the most available nesting tree. The greatest number of nests and nesting trees were encountered on the roads of urban areas, followed by nonresidential areas and residential areas. The differences in the observed frequencies of nesting trees in 3 microhabitats and in 3 types of roads (national highways > state highways > small pocket road) were significant. Canopy spread, girth size, and quality of the trees predicted the tree selection of the heronry birds in urban environments. Therefore, we recommend proper management and notification of the identified nesting trees as protected sites for the conservation of herorny birds. PMID:29492020

Nesting tree characteristics of heronry birds of urban ecosystems in peninsular India: implications for habitat management.

PubMed

Roshnath, Ramesh; Sinu, Palatty Allesh

2017-12-01

Wetland ecosystems, particularly the mangrove forest, are the primary wild habitat of heronry birds. However, urban ecosystems have become a favorite breeding habitat of these birds. To provide inputs into the habitat management for conservation of these birds, we investigated the quantitative and qualitative characteristics of nesting trees of heronry birds in the urban environment of the North Kerala region of peninsular India. Census on nesting trees was done in 3 major microhabitats of the urban ecosystem: avenues of national highways and towns, nonresidential plots, and residential areas apart from the mangrove islets in the peri-urban locality. The study found that 174 trees of 22 species hosted 1,928 heronry bird nests in the urban habitats; mangrove forests, although plentiful in the study area, hosted only about 20% of the total nests encountered in the study. Rain trees Samanea saman (43.7%) were the most available nesting tree. The greatest number of nests and nesting trees were encountered on the roads of urban areas, followed by nonresidential areas and residential areas. The differences in the observed frequencies of nesting trees in 3 microhabitats and in 3 types of roads (national highways > state highways > small pocket road) were significant. Canopy spread, girth size, and quality of the trees predicted the tree selection of the heronry birds in urban environments. Therefore, we recommend proper management and notification of the identified nesting trees as protected sites for the conservation of herorny birds.

Detection of low plasma estradiol concentrations in nesting green turtles (Chelonia mydas) by HPLC/Ms-Ms.

PubMed

Mahmoud, I Y; Alkindi, A Y; Khan, T; Al-Bahry, S N

2011-03-01

In previous studies on nesting green turtles under natural conditions from different geographical regions, 17-β-estradiol (E(2) ) was either undetectable or detected at very low levels. RIA and other related techniques were not sensitive enough to measure low E(2) values in the green turtles. In this study, a sensitive method was used in detecting low hormone concentrations: high performance liquid chromatography with tandem quadruple mass spectrometry (HPLC-MS/MS). Using this technique, estradiol for the first time was detected in nesting green turtles during the peak season (June-October) at Ras Al-Hadd Reserve, Oman. The E(2) values recorded from this study were the highest ever recorded from nesting green turtles in any geographical region, but the levels did not vary significantly throughout different phases of nesting. The presence of E(2) during nesting presumably plays a role in the physiology and behavior of this species. Ras Al-Hadd hosts one of the largest nesting populations of green turtles in the world, and an understanding of their nesting patterns may be of value in conservation and management programs for this endangered species. Copyright © 2011 Wiley-Liss, Inc., A Wiley Company.

A review of the nest protection hypothesis: does inclusion of fresh green plant material in birds' nests reduce parasite infestation?

PubMed

Scott-Baumann, James F; Morgan, Eric R

2015-07-01

The use of aromatic plants and their essential oils for ectoparasite treatment is a field of growing interest. Several species of birds regularly introduce aromatic herbs into their nests putatively to reduce parasites. The behaviour is most often seen in cavity nesting birds and after nest building has finished. The plants are included in a non-structural manner and are often strongly aromatic. Various different hypotheses have been proposed regarding the function of this behaviour; from the plants altering some non-living factor in the nest (crypsis, water loss and insulation hypotheses) to them being involved in mate selection (mate hypothesis) or even having a beneficial effect, direct or indirect, on chicks (drug or nest protection hypothesis, NPH). Many studies have been carried out over the years observing and experimentally testing these hypotheses. This review focuses on studies involving the most popular of these hypotheses, the NPH: that plants decrease nest parasites or pathogens, thereby conveying positive effects to the chicks, allowing the behaviour to evolve. Studies providing observational evidence towards this hypothesis and those experimentally testing it are discussed.

Stabilities of ant nests and their adjacent soils

NASA Astrophysics Data System (ADS)

Echezona, B. C.; Igwe, C. A.

2012-10-01

Nests habour ants and termites and protect them from harsh environmental conditions. The structural stabilities of nests were studied to ascertain their relative vulnerability to environmental stresses. Arboreal-ant nests were pried from different trees, while epigeous-termite nests were excavated from soil surface within the sample area. Soils without any visible sign of ant or termite activity were also sampled 6 m away from the nests as control. Laboratory analysis result showed that irrespective of the tree hosts, the aggregate stabilities of the ant nests were lower than those of the ground termite, with nests formed on Cola nitida significantly showing lower aggregate stability (19.7%) than other antnest structures. Clay dispersion ratio, moisture content, water stable aggregate class <0.25mm and sand mass were each negatively correlated with aggregate stability, while water stable aggregate class1.00-0.50 mm gave a positive correlation. Nest structures were dominated more by water stable aggregate class >2.00 mm but path analysis demonstrated that water stable aggregate class <0.25 mm contributed most to the higher aggregate stability of the termite nest than the other nest. Nest aggregates had greater structural stability compared to the control soil. The higher structural stability of termite nests over other nest and soil was considered a better adaptive mechanism against body desiccation.

Characteristics of nest trees and nest sites of California spotted owls in coniferous forests of the southern Sierra Nevada

Treesearch

George N. Steger; Thomas E. Munton; Kenneth D. Johnson; Gary E. Eberlein

1997-01-01

We described 86 nest sites of California spotted owl (Sh-ix occidentalis occrdentalzs) and tested for differences in vegetation structure at nest locations rn conifer-dominated stands in 2 study areas, the Sierra National Forest (SNF) and Sequoia and Kings Canyon National Parks (SNP), California. All nests were between 1061 and 2414 m in elevation, 52 were side-cavity...

Automated chart review utilizing natural language processing algorithm for asthma predictive index.

PubMed

Kaur, Harsheen; Sohn, Sunghwan; Wi, Chung-Il; Ryu, Euijung; Park, Miguel A; Bachman, Kay; Kita, Hirohito; Croghan, Ivana; Castro-Rodriguez, Jose A; Voge, Gretchen A; Liu, Hongfang; Juhn, Young J

2018-02-13

Thus far, no algorithms have been developed to automatically extract patients who meet Asthma Predictive Index (API) criteria from the Electronic health records (EHR) yet. Our objective is to develop and validate a natural language processing (NLP) algorithm to identify patients that meet API criteria. This is a cross-sectional study nested in a birth cohort study in Olmsted County, MN. Asthma status ascertained by manual chart review based on API criteria served as gold standard. NLP-API was developed on a training cohort (n = 87) and validated on a test cohort (n = 427). Criterion validity was measured by sensitivity, specificity, positive predictive value and negative predictive value of the NLP algorithm against manual chart review for asthma status. Construct validity was determined by associations of asthma status defined by NLP-API with known risk factors for asthma. Among the eligible 427 subjects of the test cohort, 48% were males and 74% were White. Median age was 5.3 years (interquartile range 3.6-6.8). 35 (8%) had a history of asthma by NLP-API vs. 36 (8%) by abstractor with 31 by both approaches. NLP-API predicted asthma status with sensitivity 86%, specificity 98%, positive predictive value 88%, negative predictive value 98%. Asthma status by both NLP and manual chart review were significantly associated with the known asthma risk factors, such as history of allergic rhinitis, eczema, family history of asthma, and maternal history of smoking during pregnancy (p value < 0.05). Maternal smoking [odds ratio: 4.4, 95% confidence interval 1.8-10.7] was associated with asthma status determined by NLP-API and abstractor, and the effect sizes were similar between the reviews with 4.4 vs 4.2 respectively. NLP-API was able to ascertain asthma status in children mining from EHR and has a potential to enhance asthma care and research through population management and large-scale studies when identifying children who meet API criteria.

Nesting habits of Centris (Hemisiella) dichrootricha (Hymenoptera: Apidae) in the Northern Cerrado of Brazil.

PubMed

Carvalho, Gracy C A; Carreira, Léa M M; Rêgo, Márcia M C; Albuquerque, Patricia M C

2016-09-01

The Neotropical bee Centris (Hemisiella) dichrootricha is a solitary bee that nests in pre-existing cavities that occur in the rain forest. This study describes the nesting biology of C. dichrootricha and its preference for nesting in Cerrado and gallery forest habitats. The study was conducted from January 2012 and December 2013, in Mirador State Park in the municipality of Formosa da Serra Negra, Maranhão State, Brazil. For this, wooden trap-nests of 6, 8, 10, 12, 14 and 16 mm in diameter were used; a total of 300 trap-nests were placed in the gallery forest and Cerrado areas, respectively. Traps were monitored monthly and all completed nests were collected and replaced with empty ones. The nests were then taken to the laboratory to analyze bee development and emergence, nests characteristics and parasites presence. The species used 29 of the trap-nests, which had diameters of 8, 10, 12 and 14 mm. A total of 87 C. dichrootricha specimens emerged. The nests were parasitized by two bee species, Mesocheira bicolor (Apinae) and Coelioxys sp. (Megachilinae), and one fly species, Antrax sp. (Diptera). The highest nesting incidence of 72.4 % was observed in the gallery forest, whereas only 27.6 % in the Cerrado; this difference in habitat use was significant (χ² = 5.56; p < 0.05; DF = 1). For the nests that were built in the gallery forest, 80.9% of the soil originated from the Cerrado. The females were significantly larger than the males (F1, 76 = 595.19; p < 0.001). There were 11 pollen types that belonged to six families. Pollen of the family Malpighiaceae was most frequently used, with four species represented (Byrsonima crassifolia, B. rotunda, B. spicata and Heteropterys sp.). C. dichrootricha showed a preference for nesting in cavities of various diameters in gallery forest sites. The present study provides a novel description of the nesting habits and biology of C. dichrootricha in habitats of Central/Southern Maranhão. C. dichrootricha primarily used resources from the Cerrado, including soil to build their nests, pollen and floral oils; we concluded that gallery forest and Cerrado areas are intrinsically related to the maintenance of local populations of this species.

Using Artificial Nests to Study Nest Predation in Birds

ERIC Educational Resources Information Center

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.

Landscape and regional context differentially affect nest parasitism and nest predation for Wood Thrush in central Virginia, USA (Presentation)

EPA Science Inventory

Many empirical studies have shown that forest-breeding songbirds suffer greater rates of nest predation and nest parasitism in smaller forest patches and in fragmented landscapes. To compare the performance of different metrics of spatial habitat configuration resulting from defo...

Lesser prairie-chicken nest site selection, microclimate, and nest survival in association with vegetation response to a grassland restoration program

USGS Publications Warehouse

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 captured at individual leks, and then for all leks pooled. There was no clear pattern of selection for treatment type for nest placement among hens associated with individual leks; however, when hens from all leks were pooled, we found nesting lesser prairie-chickens selected control plots for nesting over plots that were grazed, treated with tebuthiuron, or were both grazed and treated with tebuthiuron. Overall, the probability of a nest surviving the incubation period was 0.57 for this study and did not vary significantly among treatment types. In contrast to nesting preference for untreated habitats, lek use exhibited no noticeable selection of treatment type. Over the 10 years of the habitat management study, there was 91 percent less sand shinnery oak (Quercus havardii) in treated areas than untreated areas. The removal of sand shinnery oak made environmental soil moisture more available for grasses and forbs to germinate and grow. Grasses increased by 149 percent and forbs increased by 257 percent in treated areas as compared to untreated areas throughout the study period. Our combined results, including our habitat selection analysis at the individual lek level, indicated that reduced rates of herbicide and short-duration grazing treatments were not detrimental to nesting lesser prairie-chickens and that populations of lesser prairie-chickens in shrub-dominated ecosystems may benefit from reduced rates of herbicide application and short duration of grazing that results in increased habitat heterogeneity.

Is it safe to nest near conspicuous neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nests

PubMed Central

Trottier-Paquet, Myriam; Bêty, Joël; Lamarre, Vincent; Lecomte, Nicolas

2016-01-01

Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, selecting nest sites protected from predators, and nesting in association with protective species. American Golden-Plovers (Pluvialis dominica) defend their territory by using various warning and distraction behaviours displayed at varying levels of intensity (hereafter “conspicuous behaviour”), as well as more aggressive behaviours such as aerial attacks, but only in some populations. Such antipredator behaviour has the potential to repel predators and thus benefit the neighbouring nests by decreasing their predation risk. Yet, conspicuous behaviour could also attract predators by signalling the presence of a nest. To test for the existence of a protective effect associated with the conspicuous antipredator behaviour of American Golden-Plovers, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests would decrease with proximity to and density of plover nests. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200, and 500 m from seven of those plover nests. We found that the predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represents a key step to better understand the importance of these species of conservation concern in tundra food webs. PMID:27602257

Is it safe to nest near conspicuous neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nests.

PubMed

Giroux, Marie-Andrée; Trottier-Paquet, Myriam; Bêty, Joël; Lamarre, Vincent; Lecomte, Nicolas

2016-01-01

Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, selecting nest sites protected from predators, and nesting in association with protective species. American Golden-Plovers (Pluvialis dominica) defend their territory by using various warning and distraction behaviours displayed at varying levels of intensity (hereafter "conspicuous behaviour"), as well as more aggressive behaviours such as aerial attacks, but only in some populations. Such antipredator behaviour has the potential to repel predators and thus benefit the neighbouring nests by decreasing their predation risk. Yet, conspicuous behaviour could also attract predators by signalling the presence of a nest. To test for the existence of a protective effect associated with the conspicuous antipredator behaviour of American Golden-Plovers, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests would decrease with proximity to and density of plover nests. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200, and 500 m from seven of those plover nests. We found that the predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represents a key step to better understand the importance of these species of conservation concern in tundra food webs.

Different bees, different needs: how nest-site requirements have shaped the decision-making processes in homeless honeybees (Apis spp.).

PubMed

Beekman, Madeleine; Oldroyd, Benjamin P

2018-05-19

During reproductive swarming, a honeybee swarm needs to decide on a new nest site and then move to the chosen site collectively. Most studies of swarming and nest-site selection are based on one species, Apis mellifera Natural colonies of A. mellifera live in tree cavities. The quality of the cavity is critical to the survival of a swarm. Other honeybee species nest in the open, and have less strict nest-site requirements, such as the open-nesting dwarf honeybee Apis florea Apis florea builds a nest comprised of a single comb suspended from a twig. For a cavity-nesting species, there is only a limited number of potential nest sites that can be located by a swarm, because suitable sites are scarce. By contrast, for an open-nesting species, there is an abundance of equally suitable twigs. While the decision-making process of cavity-nesting bees is geared towards selecting the best site possible, open-nesting species need to coordinate collective movement towards areas with potential nest sites. Here, we argue that the nest-site selection processes of A. florea and A. mellifera have been shaped by each species' specific nest-site requirements. Both species use the same behavioural algorithm, tuned to allow each species to solve their species-specific problem.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Author(s).

Night shift work and lung cancer risk among female textile workers in Shanghai, China.

PubMed

Kwon, Paul; Lundin, Jessica; Li, Wenjin; Ray, Roberta; Littell, Christopher; Gao, Daoli; Thomas, David B; Checkoway, Harvey

2015-01-01

In 2007, the International Agency for Research on Cancer classified shift work that involves circadian disruption as a probable human carcinogen. Suppression of the anti-neoplastic hormone, melatonin, is a presumed mechanism of action. We conducted a case-cohort study nested within a cohort of 267,400 female textile workers in Shanghai, China. Newly diagnosed lung cancer cases (n = 1451) identified during the study period (1989-2006) were compared with an age-stratified subcohort (n = 3040). Adjusting for age, smoking, parity, and endotoxin exposure, relative risks [hazard ratios (HRs)] were estimated by Cox regression modeling to assess associations with cumulative years and nights of rotating shift work. Results did not consistently reveal any increased risk of lung cancer among rotating shift work or statistically significant trends for both cumulative years (HR 0.82, 95% CI 0.66 to 1.02; P(trend) = 0.294) and nights (HR 0.81, 95% CI 0.65 to 1.00; P(trend) = 0.415). Further analyses imposing 10- and 20-year lag times for disease latency also revealed similar results. Contrary to the initial hypothesis, rotating nighttime shift work appears to be associated with a relatively reduced lung cancer risk although the magnitude of the effect was modest and not statistically significant.

Are IQ and educational outcomes in teenagers related to their cannabis use? A prospective cohort study

PubMed Central

Mokrysz, C; Landy, R; Gage, SH; Munafò, MR; Roiser, JP; Curran, HV

2016-01-01

There is much debate about the impact of adolescent cannabis use on intellectual and educational outcomes. We investigated associations between adolescent cannabis use and IQ and educational attainment in a sample of 2235 teenagers from the Avon Longitudinal Study of Parents and Children. By the age of 15, 24% reported having tried cannabis at least once. A series of nested linear regressions was employed, adjusted hierarchically by pre-exposure ability and potential confounds (e.g. cigarette and alcohol use, childhood mental-health symptoms and behavioural problems), to test the relationships between cumulative cannabis use and IQ at the age of 15 and educational performance at the age of 16. After full adjustment, those who had used cannabis ⩾50 times did not differ from never-users on either IQ or educational performance. Adjusting for group differences in cigarette smoking dramatically attenuated the associations between cannabis use and both outcomes, and further analyses demonstrated robust associations between cigarette use and educational outcomes, even with cannabis users excluded. These findings suggest that adolescent cannabis use is not associated with IQ or educational performance once adjustment is made for potential confounds, in particular adolescent cigarette use. Modest cannabis use in teenagers may have less cognitive impact than epidemiological surveys of older cohorts have previously suggested. PMID:26739345

The History of Stuttering by 7 Years of Age: Follow-Up of a Prospective Community Cohort.

PubMed

Kefalianos, Elaina; Onslow, Mark; Packman, Ann; Vogel, Adam; Pezic, Angela; Mensah, Fiona; Conway, Laura; Bavin, Edith; Block, Susan; Reilly, Sheena

2017-10-17

For a community cohort of children confirmed to have stuttered by the age of 4 years, we report (a) the recovery rate from stuttering, (b) predictors of recovery, and (c) comorbidities at the age of 7 years. This study was nested in the Early Language in Victoria Study. Predictors of stuttering recovery included child, family, and environmental measures and first-degree relative history of stuttering. Comorbidities examined at 7 years included temperament, language, nonverbal cognition, and health-related quality of life. The recovery rate by the age of 7 years was 65%. Girls with stronger communication skills at the age of 2 years had higher odds of recovery (adjusted OR = 7.1, 95% CI [1.3, 37.9], p = .02), but similar effects were not evident for boys (adjusted OR = 0.5, 95% CI [0.3, 1.1], p = .10). At the age of 7 years, children who had recovered from stuttering were more likely to have stronger language skills than children whose stuttering persisted (p = .05). No evident differences were identified on other outcomes including nonverbal cognition, temperament, and parent-reported quality of life. Overall, findings suggested that there may be associations between language ability and recovery from stuttering. Subsequent research is needed to explore the directionality of this relationship.

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

PubMed

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. © 2014 Wiley Periodicals, Inc.

Nest survival of clay-colored and vesper sparrows in relation to woodland edge in mixed-grass prairies

USGS Publications Warehouse

Grant, T.A.; Madden, E.M.; Shaffer, T.L.; Pietz, P.J.; Berkey, G.B.; Kadrmas, N.J.

2006-01-01

The quantity and quality of northern mixed-grass prairie continues to decline because of conversion to agriculture, invasion of woody and exotic plants, and disruption of important ecological processes that shape grasslands. Declines in grassland bird populations in North Dakota, USA, have coincided with these largely anthropogenic alterations to prairie habitat. In grasslands of north-central and northwestern North Dakota, woody plants have increased due primarily to fire suppression, extirpation of bison (Bos bison), and widescale planting of tree shelter belts. In northern grasslands, effects of woody vegetation on survival of grassland birds are poorly understood, and conclusions are based mainly on studies conducted outside the region. We examined nest survival of clay-colored sparrows (Spizella pallida) and vesper sparrows (Pooecetes gramineus) relative to the distance nests were located from aspen (Populus tremuloides,) woodland edges and relative to other habitat features near the nest. Clay-colored and vesper sparrow nest survival was higher for nests located near woodland edges, nests with greater cover of Kentucky bluegrass (Poa pratensis), and nests more concealed by vegetation. Vesper sparrow nest survival increased as the percent cover of tall shrubs near the nest increased. Based on video-camera data, the 13-lined ground squirrel (Spermophilus tridecemlineatus,) was the most common predator of sparrow eggs and young. Thirteen-lined ground squirrels were more common far from woodland edges than near, and this pattern may, in part, explain clay-colored and vesper sparrow nest survival in relation to woodland edges. In contrast to our results, studies conducted in other grassland systems generally report lower nest survival for grassland birds nesting near trees and shrubs. This disparity in results demonstrates the need to identify specific nest predators and their distributions with respect to important habitat features because these data can be important in explaining-and perhaps predicting-patterns of nest predation.

The common redstart as a suitable model to study cuckoo-host coevolution in a unique ecological context.

PubMed

Samaš, Peter; Rutila, Jarkko; Grim, Tomáš

2016-11-25

Co-evolutionary arms-races result in spatio-temporally dynamic relationships between interacting species, e.g., brood parasites and their avian hosts. However, majority of avian co-evolutionary studies are limited to "snap-shots" of a single breeding season in an open-nesting host. In a long-term study (11 breeding seasons), we explored a unique system between the brood parasitic common cuckoo (Cuculus canorus) and its host, the common redstart (Phoenicurus phoenicurus) which is exceptional among all cuckoo hosts due to being a cavity nester. Conditions in cavities are different from open nests, e.g., lower risks of predation, more favourable microclimate, increased risks of unsuccessful eviction of host offspring by the cuckoo nestling. Different conditions in cavities thus can be expected to shape parasite-host coevolution differently from what is typically studied in open nesting hosts. In our highly parasitised nest-box population (32.5%, n = 569 nests) only 35.7% of cuckoo eggs were laid into the nest cup and incubated by redstarts. Host nests shifted availability to later into the breeding season from 2006 to 2016 and cuckoos followed this trend by also shifting their timing of parasitism. Although previous studies revealed that redstarts selectively eject experimental non-mimetic eggs (desertion was not a specific response to foreign eggs), the hosts never ejected naturally-laid cuckoo eggs or cuckoo eggs cross-fostered into naturally non-parasitised nests. We solve the long-standing debate about the origin of cuckoo eggs found on the nest rim: we gained the first direct video-recording evidence that eggs found on the nest rim were mislaid by parasites and not ejected by hosts. Naturally-parasitised nests were deserted more often (18.6%) than control non-parasitized nests (5.6%) or nests artificially parasitised by us (1.4%). This suggests that the sight of the laying cuckoo female is the primary cue that triggers egg rejection (by desertion) in this host. Review of data from this and other study sites (10 populations, n = 853 experiments) demonstrates high variability in rejection rates and shows that populations facing higher parasitism rates reject parasitic eggs with higher frequencies. Surprisingly, cuckoo chicks either growing solitarily or with redstart chicks did not differ in their fledging success. We suggest that the redstart is an ideal model system to study the flexibility and limits of brood parasite-host co-evolution in an extreme ecological setting.

Effects of industrial and investigator disturbance on Arctic-nesting geese

USGS Publications Warehouse

Meixell, Brandt W.; Flint, Paul L.

2017-01-01

Oil and gas development on the Arctic Coastal Plain (ACP) of Alaska, USA may have effects on Arctic-nesting birds. To estimate effects of industrial activity and investigator disturbance on avian productivity, we monitored nests of greater white-fronted geese (Anser albifrons) with digital cameras and periodic nest visits during 2013–2014 at 2 sites on the ACP. A disturbed site was adjacent to human-made infrastructure and industrial clean-up activities initiated at the onset of the study and a control site was >2 km from sources of industrial disturbance. We assessed variation in estimates of incubation constancy, nest survival, and predator behavior relative to site, year, and distance from industrial activity using nest photographs obtained at 1-minute intervals. We compared analysis of hourly nest survival informed by intensive monitoring with cameras to analysis of daily nest survival informed by traditional nest visit data obtained at intervals of 5–7 days to assess how method and time scale of sampling affect ecological inference. Geese in both sites exhibited high levels of nest attendance and initiated incubation breaks less than once per day. Observer-caused incubation breaks associated with nest visits ( = 37.8 min) were longer than other types of incubation breaks ( = 8.7 min), demonstrating a differential response by nesting geese to direct human encroachment versus indirect vehicular and aircraft traffic. During both years, geese were absent from nests more frequently in the disturbed ( = 0.9 breaks/day) than control ( = 0.6 breaks/day) site, and this break frequency was slightly higher for nests closer to industrial activity. In the year with high rates of depredation, nest survival was positively related to distance from industrial activity and abandoned infrastructure, consistent with predictions of industry-caused effects. This relationship, however, was not evident in the year with reduced predation pressure, likely because of annual variation in arctic fox (Vulpes lagopus) behavior. Analysis of nest survival probability informed by camera data allowed for detection of detailed patterns of variation that were not supported when using only visit data for the same nests. Observer visits were responsible for reductions of 7–35% in nest survival probability, highlighting the importance of minimizing, and controlling for, observer effects in studies of avian productivity. Indirect vehicular and aircraft disturbance posed less risk to nest survival than direct encroachment by observers at nest sites. Therefore, effects of industrial activities on avian productivity in the Arctic can be minimized through practices that limit direct encounters with nests. 

Enclosed nests may provide greater thermal than nest predation benefits compared with open nests across latitudes

USGS Publications Warehouse

Martin, Thomas E.; Boyce, Andy J.; Fierro-Calderon, Karolina; Mitchell, Adam E.; Armstad, Connor E.; Mouton, James C.; Bin Soudi, Evertius E.

2017-01-01

Nest structure is thought to provide benefits that have fitness consequences for several taxa. Traditionally, reduced nest predation has been considered the primary benefit underlying evolution of nest structure, whereas thermal benefits have been considered a secondary or even non-existent factor. Yet, the relative roles of these factors on nest structures remain largely unexplored.Enclosed nests have a constructed or natural roof connected to sides that allow a restricted opening or tube entrance that provides cover in all directions except the entrance, whereas open nests are cups or platforms that are open above. We show that construction of enclosed nests is more common among songbirds (Passeriformes) in tropical and southern hemisphere regions than in north temperate regions. This geographic pattern may reflect selection from predation risk, under long-standing assumptions that nest predation rates are higher in southern regions and that enclosed nests reduce predation risk compared with open cup nests. We therefore compared nest predation rates between enclosed vs. open nests in 114 songbird species that do not nest in tree holes among five communities of coexisting birds, and for 205 non-hole-nesting species from the literature, across northern temperate, tropical, and southern hemisphere regions.Among coexisting species, enclosed nests had lower nest predation rates than open nests in two south temperate sites, but not in either of two tropical sites or a north temperate site. Nest predation did not differ between nest types at any latitude based on literature data. Among 319 species from both our field studies and the literature, enclosed nests did not show consistent benefits of reduced predation and, in fact, predation was not consistently higher in the tropics, contrary to long-standing perspectives.Thermal benefits of enclosed nests were indicated based on three indirect results. First, species that built enclosed nests were smaller than species using open nests both among coexisting species and among species from the literature. Smaller species lose heat fastest and thereby may gain important thermal benefits from reduced convective cooling. Second, eggs were warmed by parents for less time in species with enclosed nests, as can be expected if egg cooling rates are slower. Finally, species using enclosed nests exhibited enhanced growth of mass and wings compared with species using open nests, suggesting reduced thermoregulatory costs allowed increased energy for growth.Enclosed nests may therefore provide more consistent thermal than nest predation benefits, counter to long-standing perspectives.

Temporal variation in black-caiman-nest predation in varzea of central Brazilian amazonia

PubMed Central

2017-01-01

On the Amazon floodplain, the main predators of black caiman (Melanosuchus niger) eggs are jaguars (Panthera onca), tegu lizards (Tupinambis teguixim), capuchin monkeys (Sapajus macrocephalus) and humans (Homo sapiens). In this study, we investigated the relationship between predator attacks on nests and incubation period, and evaluated the influence of initial predation on subsequent predation in the Mamirauá Sustainable Development Reserve. We also evaluated the influence of presence of females near the nests and manipulation of nests on the occurrence of attacks. We compared results from data obtained with camera traps and vestiges left by predators on estimates of rates of predation by different predators. Egg predation was recorded in 32% of the 658 black caiman nests monitored during two years. Our results suggest that the probability of predation on black caiman eggs is relatively constant throughout the incubation period and that predation on eggs was lower when adults, presumably females, were present. Careful opening of nests and handling of eggs did not increase the number of attacks on black caiman nests. Nest opening by a predator appeared to increase the chances of a subsequent attack because most of the attacks on nests occurred soon after a predator first opened the nest. However, attacks by another species of predator do not appear to be necessary to initiate attacks by any other species of predator. Results based on camera traps and vestiges differed, but use of vestiges was adequate for identifying the principal predators on eggs in black caiman nests and, in many circumstances, the vestiges may be better for estimating predation by humans. In this study, opening nests and handling eggs did not increase the number of attacks on black caiman nests. PMID:28854258

Temporal variation in black-caiman-nest predation in varzea of central Brazilian amazonia.

PubMed

Torralvo, Kelly; Botero-Arias, Robinson; Magnusson, William E

2017-01-01

On the Amazon floodplain, the main predators of black caiman (Melanosuchus niger) eggs are jaguars (Panthera onca), tegu lizards (Tupinambis teguixim), capuchin monkeys (Sapajus macrocephalus) and humans (Homo sapiens). In this study, we investigated the relationship between predator attacks on nests and incubation period, and evaluated the influence of initial predation on subsequent predation in the Mamirauá Sustainable Development Reserve. We also evaluated the influence of presence of females near the nests and manipulation of nests on the occurrence of attacks. We compared results from data obtained with camera traps and vestiges left by predators on estimates of rates of predation by different predators. Egg predation was recorded in 32% of the 658 black caiman nests monitored during two years. Our results suggest that the probability of predation on black caiman eggs is relatively constant throughout the incubation period and that predation on eggs was lower when adults, presumably females, were present. Careful opening of nests and handling of eggs did not increase the number of attacks on black caiman nests. Nest opening by a predator appeared to increase the chances of a subsequent attack because most of the attacks on nests occurred soon after a predator first opened the nest. However, attacks by another species of predator do not appear to be necessary to initiate attacks by any other species of predator. Results based on camera traps and vestiges differed, but use of vestiges was adequate for identifying the principal predators on eggs in black caiman nests and, in many circumstances, the vestiges may be better for estimating predation by humans. In this study, opening nests and handling eggs did not increase the number of attacks on black caiman nests.

Ovarian Brenner tumors and Walthard nests: a histologic and immunohistochemical study.

PubMed

Roma, Andres A; Masand, Ramya P

2014-12-01

Brenner tumors are composed of urothelial/transitional-type epithelium and, hence, are morphologically similar to Walthard nests and tubal/mesothelial transitional metaplasia. In this study, we analyzed immunohistochemical markers on Brenner tumors to explore Müllerian as well as Wolffian and germ cell derivation. We also attempted to explore their possible association with tubal/paratubal Walthard nests/transitional metaplasia, using the same immunostains. Thirty-two consecutive cases of Brenner tumors were identified. Thirteen (43%) of the patients had Walthard nests in the tubal/periovarian soft tissue. All Brenner tumors were diffusely positive for GATA3 (strongly positive in 30/32 and weakly positive in the remaining 2) and negative for PAX8, PAX2, and SALL4. Similarly, all Walthard nests were positive for GATA3, whereas only 3 (23%) of 13 showed occasional PAX8 expression; all were negative for PAX2 and SALL4. In our study, more than 40% of Brenner tumors had associated Walthard nests. The similar morphology and immunoprofile of Brenner tumors and Walthard nests suggest a probable link between Brenner tumors and Walthard nests. Two additional cases presented highlight small transitional lesions involving the ovary: a possible precursor lesion or the initial steps of Brenner tumor formation. Brenner tumors and most Walthard nests lacked staining for Müllerian (PAX8 and PAX2) and germ cell tumor markers (SALL4). Copyright © 2014 Elsevier Inc. All rights reserved.

Impact of pest control strategies on the arthropodofauna living in bird nests built in nestboxes in pear and apple orchards.

PubMed

Roy, Lise; Bouvier, Jean-Charles; Lavigne, Claire; Galès, Mathieu; Buronfosse, Thierry

2013-08-01

Pesticide applications have a strong impact on biodiversity in agroecosystems. The present study aimed to assess the impact of pest control strategies on the arthropodofauna of Parus major nests built within nestboxes installed in orchards. Unlike many studied groups, these arthropod communities are not in direct contact with pesticide sprays (on account of their being sheltered by nestboxes) and are also unable to move away from the treated area. In this pilot study, we estimated the prevalence and the taxonomic and ecological diversities of arthropodofauna sampled in the nests and assessed the extent to which the whole and nest-specific arthropodofauna were affected by pest control strategies. Sixteen different insect and arachnid Primary Taxonomic Groups (PTGs, order level or below) were found in nests. The best represented PTGs (≥10% occurrence in years 2007 and 2008) were Psocoptera (Insecta, detritivorous/saprophagous), detritivorous/saprophagous Astigmata (Acari) and hematophagous Mesostigmata (Acari). Pest control strategies had a large impact on the prevalence of arthropods in nests, with higher proportions of nests hosting arthropods in organic orchards than in conventional orchards and with intermediate proportions in nests in Integrated Pest Management orchards. In contrast, pest control strategies had no significant effect on the composition of the arthropod communities when only nests hosting nidicolous arthropods were considered.

Nest-niche differentiation in two sympatric columbid species from a Mediterranean Tetraclinis woodland: Considerations for forest management

NASA Astrophysics Data System (ADS)

Hanane, Saâd; Yassin, Mohamed

2017-01-01

Studies of niche partitioning among Columbid species have mainly addressed food habits and foraging activities, while partitioning in relation to nest-niche differentiation has been little studied. Here we investigate whether two sympatric columbid species-Woodpigeon (Columba palumbus) and Turtle dove (Streptopelia turtur)-occupy similar niches. A total of 74 nests were monitored: 37 nests for each species. The study, conducted in June 2016, attempted to determine the factors that may play a role in nest-niche differentiation among the two sympatric columbid species in a Moroccan Thuya (Tetraclinis articulata) forest. We used Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) to test the relevance of nest placement, proximity of food resources, forest edge and human presence variables in the nest distribution of the two species. The results show substantial niche segregation in the T. articulata nest-trees selected by Woodpigeons and Turtle doves, with selection depending primarily on the tree size and nest height. Observed nest-niche partitioning may diminish the potential for competition between these species and enhance opportunities for their coexistence. Management policies and practices aimed at ensuring the presence of mixed-sized class of Thuya trees must be prioritized. We recommend additional studies designed to: (1) reproduce the same experimental approach on other Mediterranean Thuya forests to improve our understanding of the effects of different levels of anthropogenic disturbance on the breeding behaviour of these two game species; (2) better understand the spatio-temporal dynamics of Woodpigeon and Turtle dove coexistence in the region; and (3) better identify the spatio-temporal extent of the effect of forest management on Woodpigeon and Turtle dove site occupancy.

Nest site characteristics, nesting movements, and lack of long-term nest site fidelity in Agassiz's desert tortoises at a wind energy facility in southern California

USGS Publications Warehouse

Lovich, Jeffrey E.; Agha, Mickey; Yackulic, Charles B.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Ennen, Joshua R.; Arundel, Terry R.; Austin, Meaghan

2014-01-01

Nest site selection has important consequences for maternal and offspring survival and fitness. Females of some species return to the same nesting areas year after year. We studied nest site characteristics, fidelity, and daily pre-nesting movements in a population of Agassiz’s desert tortoises (Gopherus agassizii) at a wind energy facility in southern California during two field seasons separated by over a decade. No females returned to the same exact nest site within or between years but several nested in the same general area. However, distances between first and second clutches within a year (2000) were not significantly different from distances between nests among years (2000 and 2011) for a small sample of females, suggesting some degree of fidelity within their normal activity areas. Environmental attributes of nest sites did not differ significantly among females but did among years due largely to changes in perennial plant structure as a result of multiple fires. Daily pre-nesting distances moved by females decreased consistently from the time shelled eggs were first visible in X-radiographs until oviposition, again suggesting some degree of nest site selection. Tortoises appear to select nest sites that are within their long-term activity areas, inside the climate-moderated confines of one of their self-constructed burrows, and specifically, at a depth in the burrow that minimizes exposure of eggs and embryos to lethal incubation temperatures. Nesting in “climate-controlled” burrows and nest guarding by females relaxes some of the constraints that drive nest site selection in other oviparous species.

Assessing nest-building behavior of mice using a 3D depth camera.

PubMed

Okayama, Tsuyoshi; Goto, Tatsuhiko; Toyoda, Atsushi

2015-08-15

We developed a novel method to evaluate the nest-building behavior of mice using an inexpensive depth camera. The depth camera clearly captured nest-building behavior. Using three-dimensional information from the depth camera, we obtained objective features for assessing nest-building behavior, including "volume," "radius," and "mean height". The "volume" represents the change in volume of the nesting material, a pressed cotton square that a mouse shreds and untangles in order to build its nest. During the nest-building process, the total volume of cotton fragments is increased. The "radius" refers to the radius of the circle enclosing the fragments of cotton. It describes the extent of nesting material dispersion. The "radius" averaged approximately 60mm when a nest was built. The "mean height" represents the change in the mean height of objects. If the nest walls were high, the "mean height" was also high. These features provided us with useful information for assessment of nest-building behavior, similar to conventional methods for the assessment of nest building. However, using the novel method, we found that JF1 mice built nests with higher walls than B6 mice, and B6 mice built nests faster than JF1 mice. Thus, our novel method can evaluate the differences in nest-building behavior that cannot be detected or quantified by conventional methods. In future studies, we will evaluate nest-building behaviors of genetically modified, as well as several inbred, strains of mice, with several nesting materials. Copyright © 2015 Elsevier B.V. All rights reserved.

Bee species-specific nesting material attracts a generalist parasitoid: implications for co-occurring bees in nest box enhancements.

PubMed

Macivor, J Scott; Salehi, Baharak

2014-08-01

Artificial nests (e.g., nest boxes) for bees are increasingly being used to contribute to nesting habitat enhancement for bees that use preexisting cavities to provision brood. They usually incorporate additional nesting materials that vary by species. Cavity-nesting bees are susceptible to brood parasitoids that recognize their host(s) using visual and chemical cues. Understanding the range of cues that attract parasitoids to bee nests, including human-made analogues, is important if we wish to control parasitism and increase the potential value of artificial nests as habitat-enhancement strategies. In this study, we investigated the cues associated with the orientation of the generalist brood parasitoid Monodontomerus obscurus Westwood (Hymenoptera: Torymidae) to the nests of a common cavity-nesting resin bee Megachile campanulae (Robertson) (Megachilidae). The parasitoids were reared from previously infested M. campanulae brood cells and placed into choice trials where they were presented with pairs of different nest material cues. Among different materials tested, we found that Mo. obscurus was most attracted to fresh resin collected directly from Pinus strobus trees followed by previously used resin collected from the bee nest. The parasitoid also attacked other bee species in the same nest boxes, including those that do not use resin for nesting. Our findings suggest that M. campanulae could act as a magnet, drawing parasites away from other bee hosts co-occurring in nest boxes, or, as an attractant of Mo. obscurus to nest boxes, increasing attacks on co-occurring host bee species, potentially undermining bee diversity enhancement initiatives.

Prostate cancer incidence in relation to time windows of exposure to metalworking fluids in the auto industry.

PubMed

Agalliu, Ilir; Kriebel, David; Quinn, Margaret M; Wegman, David H; Eisen, Ellen A

2005-09-01

Exposure to metalworking fluids has been previously associated with prostate cancer mortality in a cohort of autoworkers. Our objective was to further explore this finding in a study of prostate cancer incidence in the same cohort, with reduced misclassification of outcome. We conducted a nested case-control study in the General Motors cohort of autoworkers. Incident cases of prostate cancer (n = 872) were identified via the Michigan Cancer Registry from 1985 through 2000. Controls were selected using incidence-density sampling with 5:1 ratio. Using cumulative exposure (mg/m-years) as the dose metric, we first examined varying lengths of lags (0-25 years). Then, we evaluated consecutive windows of exposure: 25 or more years before risk age, and fewer than 25 years. We used penalized splines to model the relative risk as a smooth function of exposure, and adjusted for race and calendar year of diagnosis in a Cox model. Risk of prostate cancer increased with exposure to soluble and straight fluids 25 years or more before risk age but not with exposure in the last 25 years. The relationship with soluble fluids was piecewise linear, with a small increase in risk at lower exposures followed by a steeper rise. By contrast, the relationship with straight fluids was linear, with a relative risk of 1.12 per 10mg/m-years of exposure (95% confidence interval = 1.04-1.20). Exposure to oil-based fluids, soluble and straight, is modestly associated with prostate cancer risk among autoworkers, with a latency period of at least 25 years.

Time-specific patterns of nest survival for ducks and passerines breeding in North Dakota

USGS Publications Warehouse

Shaffer, Terry L.; Grant, Todd A.

2012-01-01

In many bird species, survival can vary with the age of the nest, with the date a nest was initiated, or among years within the same nesting area. A literature review showed that patterns of survival vary in relation to nest age and date and are often contradictory. Inconsistencies could be a result of temporal variation in the environment or life-history differences among species. We examined patterns of nest survival in relation to nest age, date, and year for several duck and passerine species nesting at a single location in North Dakota during 1998–2003. We predicted that if environment shaped nest survival patterns, then temporal patterns in survival might be similar among three species of upland nesting ducks, and also among three species of grassland passerines nesting at the same site. We expected that survival patterns would differ between ducks and passerines because of relatively disparate life histories and differences in predators that prey on their nests. Nest survival was rarely constant among years, seasonally, or with age of the nest for species that we studied. As predicted, the pattern of survival was similar among duck species, driven mainly by differences in nest survival associated with nest initiation date. The pattern of survival also was similar among passerine species, but nest survival was more influenced by nest age than by date. Our findings suggest that some but not all variation in temporal patterns of nest survival in grassland birds reported in the literature can be explained on the basis of temporal environmental variation. Because patterns of survival were dissimilar among ducks and passerines, it is likely that mechanisms such as predation or brood parasitism have variable influences on productivity of ducks and passerines nesting in the same area. Our results indicate that biologists and managers should not assume that temporal environmental variations, especially factors that affect nest survival, act similarly on all grassland birds.

Lifespan Analyses of Forest Raptor Nests: Patterns of Creation, Persistence and Reuse

PubMed Central

Jiménez-Franco, María V.; Martínez, José E.; Calvo, José F.

2014-01-01

Structural elements for breeding such as nests are key resources for the conservation of bird populations. This is especially true when structural elements require a specific and restricted habitat, or if the construction of nests is costly in time and energy. The availability of nesting-platforms is influenced by nest creation and persistence. In a Mediterranean forest in southeastern Spain, nesting-platforms are the only structural element for three forest-dwelling raptor species: booted eagle Aquila pennata, common buzzard Buteo buteo and northern goshawk Accipiter gentilis. From 1998 to 2013, we tracked the fate of 157 nesting-platforms built and reused by these species with the aim of determining the rates of creation and destruction of nesting-platforms, estimating nest persistence by applying two survival analyses, describing the pattern of nest reuse and testing the effects of nest use on breeding success. Nest creation and destruction rates were low (0.14 and 0.05, respectively). Using Kaplan Meier survival estimates and Cox proportional-hazards regression models we found that median nest longevity was 12 years and that this was not significantly affected by nest characteristics, nest-tree dimensions, nest-builder species, or frequency of use of the platform. We also estimated a transition matrix, considering the different stages of nest occupation (vacant or occupied by one of the focal species), to obtain the fundamental matrix and the average life expectancies of nests, which varied from 17.9 to 19.7 years. Eighty six percent of nests were used in at least one breeding attempt, 67.5% were reused and 17.8% were successively occupied by at least two of the study species. The frequency of nest use had no significant effects on the breeding success of any species. We conclude that nesting-platforms constitute an important resource for forest raptors and that their longevity is sufficiently high to allow their reuse in multiple breeding attempts. PMID:24717935

Lifespan analyses of forest raptor nests: patterns of creation, persistence and reuse.

PubMed

Jiménez-Franco, María V; Martínez, José E; Calvo, José F

2014-01-01

Structural elements for breeding such as nests are key resources for the conservation of bird populations. This is especially true when structural elements require a specific and restricted habitat, or if the construction of nests is costly in time and energy. The availability of nesting-platforms is influenced by nest creation and persistence. In a Mediterranean forest in southeastern Spain, nesting-platforms are the only structural element for three forest-dwelling raptor species: booted eagle Aquila pennata, common buzzard Buteo buteo and northern goshawk Accipiter gentilis. From 1998 to 2013, we tracked the fate of 157 nesting-platforms built and reused by these species with the aim of determining the rates of creation and destruction of nesting-platforms, estimating nest persistence by applying two survival analyses, describing the pattern of nest reuse and testing the effects of nest use on breeding success. Nest creation and destruction rates were low (0.14 and 0.05, respectively). Using Kaplan Meier survival estimates and Cox proportional-hazards regression models we found that median nest longevity was 12 years and that this was not significantly affected by nest characteristics, nest-tree dimensions, nest-builder species, or frequency of use of the platform. We also estimated a transition matrix, considering the different stages of nest occupation (vacant or occupied by one of the focal species), to obtain the fundamental matrix and the average life expectancies of nests, which varied from 17.9 to 19.7 years. Eighty six percent of nests were used in at least one breeding attempt, 67.5% were reused and 17.8% were successively occupied by at least two of the study species. The frequency of nest use had no significant effects on the breeding success of any species. We conclude that nesting-platforms constitute an important resource for forest raptors and that their longevity is sufficiently high to allow their reuse in multiple breeding attempts.

Microhabitat characteristics of Lapland Longspur, Calcarius lapponicus, nests at Cape Churchill, Manitoba

USGS Publications Warehouse

Boal, C.W.; Andersen, D.E.

2005-01-01

We examined microsite characteristics at 21 Lapland Longspur (Calcarius lapponicus) nests and land cover types in which they occurred in Wapusk National Park, Cape Churchill, Manitoba. Nests were located in four of six physiographic-vegetation land-cover types. Regardless of land-cover type, all but one nest was built on a pressure ridge or mound. Nests were built midway between the bottom and top of ridges or mounds with steeper slopes than was randomly available. Longspur nests had a distinctive southwest orientation (P < 0.001). Longspurs selected nest sites that consisted of comparatively greater amounts of shrub species and lesser amounts of moss than were randomly available. Nests were generally well concealed by vegetation (mean = 67.0%) and concealment was negatively associated with amount of graminoid species at the nest (P = 0.0005). Our nesting habitat data may facilitate a better understanding of breeding Lapland Longspur habitat requirements, and potential impacts of habitat degradation by increasing Snow Goose (Chen caerulescens) populations in the study area.

Oral bisphosphonates do not increase the risk of severe upper gastrointestinal complications: a nested case–control study

PubMed Central

2014-01-01

Background Data on the effect of oral bisphosphonates (BPs) on risk of upper gastrointestinal complications (UGIC) are conflicting. We conducted a large population-based study from a network of Italian healthcare utilization databases aimed to assess the UGIC risk associated with use of BPs in the setting of secondary prevention of osteoporotic fractures. Methods A nested case–control study was carried out within a cohort of 68,970 patients aged 45 years or older, who have been hospitalized for osteoporotic fracture from 2003 until 2005. Cases were the 804 patients who experienced hospitalization for UGIC until 2007. Up to 20 controls were randomly selected for each case. Conditional logistic regression model was used to estimate odds ratio (OR) associated with current and past use of BPs (i.e. for drug dispensation within 30 days and over 31 days prior the outcome onset, respectively) after adjusting for several covariates. Results Compared with patients who did not use BPs, current and past users had OR (and 95% confidence interval) of 0.86 (0.60 to 1.22) and 1.07 (0.80 to 1.44) respectively. There was no difference in the ORs estimated according with BPs type (alendronate or risedronate) and regimen (daily or weekly), nor with co-therapies and comorbidities. Conclusions Further evidence that BPs dispensed for secondary prevention of osteoporotic fractures are not associated with increased risk of severe gastrointestinal complications is supplied from this study. Further research is required to clarify the role BPs and other drugs of co-medication in inducing UGIC. PMID:24397769

Olive Ridley Sea Turtle Hatching Success as a Function of the Microbial Abundance in Nest Sand at Ostional, Costa Rica

PubMed Central

Bézy, Vanessa S.; Valverde, Roldán A.; Plante, Craig J.

2015-01-01

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. PMID:25714355

Evaluation of ecological risk to populations of a threatened plant from an invasive biocontrol insect

USGS Publications Warehouse

Louda, S.M.; Rand, T.A.; Arnett, A.E.; McClay, A.S.; McEachern, A.K.

2005-01-01

This study was conducted to determine the influence of residues of organochlorine pollutants on reproductive success in the brown pelican. A sample egg was taken from each of 93 marked nests in the nesting colony in South Carolina. Periodic visits were made to determine the fate of marked nests. Each sample egg was analysed for residues of organochlorine pollutants. Nest success in the brown pelican was related to residues of DDE and dieldrin in sample eggs. DDE seemed primarily responsible for nest failure; however, deleterious effects of this pollutant on nest success were not satisfactorily separated from those induced by dieldrin. Significant intercorrelation of all five organochlorine residues identified in the eggs complicated the relationship of residues to nest success. Maximum DDE residues in an egg from a successful nest were 2.37 ?g/g and 8.48 ?g/g in an egg from an unsuccessful nest. Comparable maximum residues for dieldrin in sample eggs were 0.54 ?g/g (successful) and 0.99 ?g/g (unsuccessful). Nineteen of the 26 eggs from unsuccessful nests contained DDE residues that exceeded 2.37 ?g/g, and 14 of these 26 eggs contained dieldrin residues that exceeded O.54 ?g/g. Residues of DDD, DDT or PCBs in sample eggs were not significantly related to nest success. Reproductive success in the brown pelican colony was subnormal in the years of study--1971 and 1972--but reproductive success was normal in those nests in which the sample egg contained either <2,5 ?g/g of DDE or 0.54 ?g/g of dieldrin.

Development of camera technology for monitoring nests. Chapter 15

Treesearch

W. Andrew Cox; M. Shane Pruett; Thomas J. Benson; Scott J. Chiavacci; Frank R., III Thompson

2012-01-01

Photo and video technology has become increasingly useful in the study of avian nesting ecology. However, researchers interested in using camera systems are often faced with insufficient information on the types and relative advantages of available technologies. We reviewed the literature for studies of nests that used cameras and summarized them based on study...

Estimating stage-specific daily survival probabilities of nests when nest age is unknown

USGS Publications Warehouse

Stanley, T.R.

2004-01-01

Estimation of daily survival probabilities of nests is common in studies of avian populations. Since the introduction of Mayfield's (1961, 1975) estimator, numerous models have been developed to relax Mayfield's assumptions and account for biologically important sources of variation. Stanley (2000) presented a model for estimating stage-specific (e.g. incubation stage, nestling stage) daily survival probabilities of nests that conditions on “nest type” and requires that nests be aged when they are found. Because aging nests typically requires handling the eggs, there may be situations where nests can not or should not be aged and the Stanley (2000) model will be inapplicable. Here, I present a model for estimating stage-specific daily survival probabilities that conditions on nest stage for active nests, thereby obviating the need to age nests when they are found. Specifically, I derive the maximum likelihood function for the model, evaluate the model's performance using Monte Carlo simulations, and provide software for estimating parameters (along with an example). For sample sizes as low as 50 nests, bias was small and confidence interval coverage was close to the nominal rate, especially when a reduced-parameter model was used for estimation.

Construction patterns of birds' nests provide insight into nest-building behaviours.

PubMed

Biddle, Lucia; Goodman, Adrian M; Deeming, D Charles

2017-01-01

Previous studies have suggested that birds and mammals select materials needed for nest building based on their thermal or structural properties, although the amounts or properties of the materials used have been recorded for only a very small number of species. Some of the behaviours underlying the construction of nests can be indirectly determined by careful deconstruction of the structure and measurement of the biomechanical properties of the materials used. Here we examined this idea in an investigation of Bullfinch ( Pyrrhula pyrrhula ) nests as a model for open-nesting songbird species that construct a "twig" nest, and tested the hypothesis that materials in different parts of nests serve different functions. The quantities of materials present in the nest base, sides and cup were recorded before structural analysis. Structural analysis showed that the base of the outer nests were composed of significantly thicker, stronger and more rigid materials compared to the side walls, which in turn were significantly thicker, stronger and more rigid than materials used in the cup. These results suggest that the placement of particular materials in nests may not be random, but further work is required to determine if the final structure of a nest accurately reflects the construction process.

Spawning chronology, nest site selection and nest success of smallmouth bass during benign streamflow conditions

USGS Publications Warehouse

Dauwalter, D.C.; Fisher, W.L.

2007-01-01

We documented the nesting chronology, nest site selection and nest success of smallmouth bass Micropterus dolomieu in an upstream (4th order) and downstream (5th order) reach of Baron Fork Creek, Oklahoma. Males started nesting in mid-Apr. when water temperatures increased to 16.9 C upstream, and in late-Apr. when temperatures increased to 16.2 C downstream. Streamflows were low (77% upstream to 82% downstream of mean Apr. streamflow, and 12 and 18% of meanjun. streamflow; 47 and 55 y of record), and decreased throughout the spawning period. Larger males nested first upstream, as has been observed in other populations, but not downstream. Upstream, progeny in 62 of 153 nests developed to swim-up stage. Downstream, progeny in 31 of 73 nests developed to swim-up. Nesting densities upstream (147/km) and downstream (100/km) were both higher than any densities previously reported. Males selected nest sites with intermediate water depths, low water velocity and near cover, behavior that is typical of smallmouth bass. Documented nest failures resulted from human disturbance, angling, and longear sunfish predation. Logistic exposure models showed that water velocity at the nest was negatively related and length of the guarding male was positively related to nest success upstream. Male length and number of degree days were both positively related to nest success downstream. Our results, and those of other studies, suggest that biological factors account for most nest failures during benign (stable, low flow) streamflow conditions, whereas nest failures attributed to substrate mobility or nest abandonment dominate when harsh streamflow conditions (spring floods) coincide with the spawning season.

When social behaviour is moulded in clay: on growth and form of social insect nests.

PubMed

Perna, Andrea; Theraulaz, Guy

2017-01-01

The nests built by social insects are among the most complex structures produced by animal groups. They reveal the social behaviour of a colony and as such they potentially allow comparative studies. However, for a long time, research on nest architecture was hindered by the lack of technical tools allowing the visualisation of their complex 3D structures and the quantification of their properties. Several techniques, developed over the years, now make it possible to study the organisation of these nests and how they are built. Here, we review present knowledge of the mechanisms of nest construction, and how nest structure affects the behaviour of individual insects and the organisation of activities within a colony. © 2017. Published by The Company of Biologists Ltd.

Landscaping pebbles attract nesting by the native ground-nesting bee Halictus rubicundus (Hymenoptera: Halictidae)

USDA-ARS?s Scientific Manuscript database

Most species of bees nest underground. Recent interest in pollinator-friendly gardens and landscaping focuses on planting suitable flowering species for bees, but we know little about providing for the ground-nesting needs of bees other than leaving them bare dirt surfaces. In this study, a surfac...

The Correlation of Tree Phenology with nest number of Orang Utan Sumatera (Pongo abelii) on Primary Forest, Resort Sei Betung, Gunung Leuser National Park

NASA Astrophysics Data System (ADS)

Hartini, K. S.; Patana, P.; Oktaviani, M.

2017-03-01

Food availability affect the orangutan activities, including activities to make nests. This study was conducted to determine the correlation between the phenology of trees with the number of nests made by orangutans in primary forest Resort Sei Betung, Gunung Leuser National Park. Multi linear regression was used in this study to determine the relation and correlation between phenology and the presence of orangutan nests on a track that has been created. It took over 6 months (March - August 2015). There were 15 orangutan nests found on the track during the study. The equation model was : = 27,649 -0,011X1-0,104X2-0,056X3, and there was no significant differences (sig >0,05). The value of R2 was 70,3%. It means that all predictors simultaneously explain 70,3% of the presence of orangutan’s nest, and there is an expected predictors that may be the most affect on nest presence. The season or the intensity of rain may consider as an expected predictor.

Effects of grazing on nesting of the Oriental pratincole (Glareola maldivarum) in Bueng Boraphet Wetland, Thailand.

PubMed

Chaiyarat, Rattanawat; Eiam-Ampai, Kairat

2014-02-01

Livestock grazing may negatively impact bird nesting in wetland habitats. This study evaluated the effect of grazing on the nests of the Oriental pratincole (Glareola maldivarum) along the grassland of a wetland at six study sites with different densities of grazing cattle and buffalo. Species richness, density, cover, and height of vegetation in the study areas were different (P < 0.05). The density of cattle and buffalo at the various sites affected vegetation composition and amount, which in turn influenced bird nest density. The estimated trampling rates, number of fledglings, and number of trampled eggs were different among study sites (P < 0.05). The density of cattle and buffalo has an influence on nest failure rates. The factors that influenced the mortality rates of the Oriental pratincole were trampling and unhatched eggs. Only 48.5% of the nests were successful at sites where cattle and buffalo continuously grazed in the grasslands at high densities. Thus, increases in the density of cattle and buffalo will reduce the number of nests of the Oriental pratincole, which may result in a reduction of the overall population in the future.

[Common mental disorders and self-esteem in pregnancy: prevalence and associated factors].

PubMed

Silva, Ricardo Azevedo da; Ores, Liliane da Costa; Mondin, Thaíse Campos; Rizzo, Raquel Nolasco; Moraes, Inácia Gomes da Silva; Jansen, Karen; Pinheiro, Ricardo Tavares

2010-09-01

The aim of this study was to assess the prevalence of common mental disorders and the association with self-esteem and other factors in pregnant women. A nested cross-sectional study was performed in a cohort of pregnant women treated in the public health system in Pelotas, Rio Grande do Sul State, Brazil. The Self-Reporting Questionnaire (SRQ-20) was used to screen for common mental disorders and the Rosenberg's Self-Esteem Scale for self-esteem. The sample consisted of 1,267 pregnant women with a mean age of 25 years (SD = 6.53). Mean self-esteem was 9.3 points (SD = 4.76), and prevalence of common mental disorders was 41.4%. Lower self-esteem was associated with higher odds of common mental disorders (p < 0.001). There was a significant association between higher prevalence of common mental disorders and low self-esteem.

Vitamin A serostatus and heterosexual transmission of HIV: case-control study in Tanzania and review of the evidence.

PubMed

Villamor, Eduardo; Kapiga, Saidi H; Fawzi, Wafaie W

2006-03-01

Results from a randomized clinical trial suggested that vitamin A/beta-carotene supplementation to HIV-1-infected women during pregnancy and lactation may increase the risk of vertical transmission. Limited information is available on the potential role of vitamin A on heterosexual HIV transmission. This is a relevant question in many resource-limited settings where both vitamin A deficiency and HIV infection are highly prevalent. We conducted a case-control study (34 cases and 38 controls) nested within a cohort of HIV-negative women attending family planning clinics in Tanzania, to examine whether low serum concentrations at baseline were associated with the risk of seroconversion. There was not a significant association (OR = 2.14, 95% C I = 0.54, 8.45). In light of these and previous results, we conclude that there is not enough evidence yet to suggest a causal association between vitamin A and heterosexual transmission.

Double-Crested Cormorant ( Phalacrocorax auritus) Nesting Effects on Understory Composition and Diversity on Island Ecosystems in Lake Erie

NASA Astrophysics Data System (ADS)

McGrath, Darby M.; Murphy, Stephen D.

2012-08-01

The context for this study is the management concerns over the severity and extent of the impact of cormorants on island flora in the recent past on Lake Erie islands. Accordingly, this study sought to quantify the nesting colonies' influence on coarse woody litter and how nest densities and litter depth may influence the herbaceous layer, the seed bank composition and viability across the extent of three Lake Erie islands. The data for this study were collected from 2004 to 2008 on East Sister Island and Middle Island using two main strategies. First, herbaceous layer surveys, cormorant nest counts, soil seed bank cores, and litter depth measurements were executed using a plotless-point quarter method to test island-wide impacts from nesting activities (data were also collected on a third island, West Sister Island as a reference for the other two islands). Secondly, a sub-sample of the entire plot set was examined in particularly high nesting density areas for two islands (Middle Island and East Sister Island). Kruskal-Wallis tests indicated that there are subtle changes in the herbaceous diversity (total, native and exotic) and seed bank composition across the islands. The sub sample set of the plots demonstrated that Phalacrocorax auritus nest density does influence litter depth, herbaceous species abundance and diversity. Cormorant nesting pressures are restricted to areas of high nesting pressures and competition. However, there remains a risk to the interior herbaceous layer of the island if the effects of nesting pressures at the edges advance inward from this perimeter.

Adrenocortical responses to offspring-directed threats in two open-nesting birds.

PubMed

Butler, Luke K; Bisson, Isabelle-Anne; Hayden, Timothy J; Wikelski, Martin; Romero, L Michael

2009-07-01

Dependent young are often easy targets for predators, so for many parent vertebrates, responding to offspring-directed threats is a fundamental part of reproduction. We tested the parental adrenocortical response of the endangered black-capped vireo (Vireo atricapilla) and the common white-eyed vireo (V. griseus) to acute and chronic threats to their offspring. Like many open-nesting birds, our study species experience high offspring mortality. Parents responded behaviorally to a predator decoy or human 1-2m from their nests, but, in contrast to similar studies of cavity-nesting birds, neither these acute threats nor chronic offspring-directed threats altered plasma corticosterone concentrations of parents. Although parents in this study showed no corticosterone response to offspring-directed threats, they always increased corticosterone concentrations in response to capture. To explain these results, we propose that parents perceive their risk of nest-associated death differently depending on nest type, with cavity-nesting adults perceiving greater risk to themselves than open-nesters that can readily detect and escape from offspring-directed threats. Our results agree with previous studies suggesting that the hypothalamic-pituitary-adrenal axis, a major physiological mechanism for coping with threats to survival, probably plays no role in coping with threats to offspring when risks to parents and offspring are not correlated. We extend that paradigm by demonstrating that nest style may influence how adults perceive the correlation between offspring-directed and self-directed threats.

Selection indicates preference in diverse habitats: A Ground-Nesting bird (charadrius melodus) using reservoir shoreline

USGS Publications Warehouse

Anteau, M.J.; Sherfy, M.H.; Wiltermuth, M.T.

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006-2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m 2) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

Selection indicates preference in diverse habitats: A ground-nesting bird (Charadrius melodus) using reservoir shoreline

USGS Publications Warehouse

Anteau, Michael J.; Sherfy, Mark H.; Wiltermuth, Mark T.

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006–2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m2) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

Local Individual Preferences for Nest Materials in a Passerine Bird

PubMed Central

Mennerat, Adèle; Perret, Philippe; Lambrechts, Marcel M.

2009-01-01

Background Variation in the behavioural repertoire of animals is acquired by learning in a range of animal species. In nest-building birds, the assemblage of nest materials in an appropriate structure is often typical of a bird genus or species. Yet plasticity in the selection of nest materials may be beneficial because the nature and abundance of nest materials vary across habitats. Such plasticity can be learned, either individually or socially. In Corsican populations of blue tits Cyanistes caeruleus, females regularly add in their nests fragments of several species of aromatic plants during the whole breeding period. The selected plants represent a small fraction of the species present in the environment and have positive effects on nestlings. Methodology/Principal Findings We investigated spatiotemporal variations of this behaviour to test whether the aromatic plant species composition in nests depends on 1) plant availability in territories, 2) female experience or 3) female identity. Our results indicate that territory plays a very marginal role in the aromatic plant species composition of nests. Female experience is not related to a change in nest plant composition. Actually, this composition clearly depends on female identity, i.e. results from individual preferences which, furthermore, are repeatable both within and across years. A puzzling fact is the strong difference in plant species composition of nests across distinct study plots. Conclusions/Significance This study demonstrates that plant species composition of nests results from individual preferences that are homogeneous within study plots. We propose several hypotheses to interpret this pattern of spatial variation before discussing them in the light of preliminary results. As a conclusion, we cannot exclude the possibility of social transmission of individual preferences for aromatic plants. This is an exciting perspective for further work in birds, where nest construction behaviour has classically been considered as a stereotypic behaviour. PMID:19337365

Nest suitability, fine-scale population structure and male-mediated dispersal of a solitary ground nesting bee in an urban landscape.

PubMed

López-Uribe, Margarita M; Morreale, Stephen J; Santiago, Christine K; Danforth, Bryan N

2015-01-01

Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei's GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing bee population abundance and connectivity in human dominated habitats and highlights the critical contribution of landscape genetic studies for enhanced conservation and management of native pollinators.

Nest Suitability, Fine-Scale Population Structure and Male-Mediated Dispersal of a Solitary Ground Nesting Bee in an Urban Landscape

PubMed Central

López-Uribe, Margarita M.; Morreale, Stephen J.; Santiago, Christine K.; Danforth, Bryan N.

2015-01-01

Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei’s GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing bee population abundance and connectivity in human dominated habitats and highlights the critical contribution of landscape genetic studies for enhanced conservation and management of native pollinators. PMID:25950429

Selection indicates preference in diverse habitats: a ground-nesting bird (Charadrius melodus) using reservoir shoreline.

PubMed

Anteau, Michael J; Sherfy, Mark H; Wiltermuth, Mark T

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006-2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m(2)) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

Selection Indicates Preference in Diverse Habitats: A Ground-Nesting Bird (Charadrius melodus) Using Reservoir Shoreline

PubMed Central

Anteau, Michael J.; Sherfy, Mark H.; Wiltermuth, Mark T.

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006–2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m2) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies. PMID:22299037

Timing of nest vegetation measurement may obscure adaptive significance of nest-site characteristics: A simulation study.

PubMed

McConnell, Mark D; Monroe, Adrian P; Burger, Loren Wes; Martin, James A

2017-02-01

Advances in understanding avian nesting ecology are hindered by a prevalent lack of agreement between nest-site characteristics and fitness metrics such as nest success. We posit this is a result of inconsistent and improper timing of nest-site vegetation measurements. Therefore, we evaluated how the timing of nest vegetation measurement influences the estimated effects of vegetation structure on nest survival. We simulated phenological changes in nest-site vegetation growth over a typical nesting season and modeled how the timing of measuring that vegetation, relative to nest fate, creates bias in conclusions regarding its influence on nest survival. We modeled the bias associated with four methods of measuring nest-site vegetation: Method 1-measuring at nest initiation, Method 2-measuring at nest termination regardless of fate, Method 3-measuring at nest termination for successful nests and at estimated completion for unsuccessful nests, and Method 4-measuring at nest termination regardless of fate while also accounting for initiation date. We quantified and compared bias for each method for varying simulated effects, ranked models for each method using AIC, and calculated the proportion of simulations in which each model (measurement method) was selected as the best model. Our results indicate that the risk of drawing an erroneous or spurious conclusion was present in all methods but greater with Method 2 which is the most common method reported in the literature. Methods 1 and 3 were similarly less biased. Method 4 provided no additional value as bias was similar to Method 2 for all scenarios. While Method 1 is seldom practical to collect in the field, Method 3 is logistically practical and minimizes inherent bias. Implementation of Method 3 will facilitate estimating the effect of nest-site vegetation on survival, in the least biased way, and allow reliable conclusions to be drawn.

Evidence of territoriality and species interactions from spatial point-pattern analyses of subarctic-nesting geese

USGS Publications Warehouse

Reiter, Matthew E.; Andersen, David E.

2013-01-01

Quantifying spatial patterns of bird nests and nest fate provides insights into processes influencing a species’ distribution. At Cape Churchill, Manitoba, Canada, recent declines in breeding Eastern Prairie Population Canada geese (Branta canadensis interior) has coincided with increasing populations of nesting lesser snow geese (Chen caerulescens caerulescens) and Ross’s geese (Chen rossii). We conducted a spatial analysis of point patterns using Canada goose nest locations and nest fate, and lesser snow goose nest locations at two study areas in northern Manitoba with different densities and temporal durations of sympatric nesting Canada and lesser snow geese. Specifically, we assessed (1) whether Canada geese exhibited territoriality and at what scale and nest density; and (2) whether spatial patterns of Canada goose nest fate were associated with the density of nesting lesser snow geese as predicted by the protective-association hypothesis. Between 2001 and 2007, our data suggest that Canada geese were territorial at the scale of nearest neighbors, but were aggregated when considering overall density of conspecifics at slightly broader spatial scales. The spatial distribution of nest fates indicated that lesser snow goose nest proximity and density likely influence Canada goose nest fate. Our analyses of spatial point patterns suggested that continued changes in the distribution and abundance of breeding lesser snow geese on the Hudson Bay Lowlands may have impacts on the reproductive performance of Canada geese, and subsequently the spatial distribution of Canada goose nests.

Nesting ecology of tundra swans on the coastal Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Babcock, C.A.; Fowler, A.C.; Ely, Craig R.

2002-01-01

Nesting ecology of Tundra Swans (Cygnus columbianus columbianus) was studies the Kashunuk River near Old Chevak (61A?26a??N, 165A?27a??W), on the Yukon-Kuskokwim Delta of western Alaska from 1988-2000. Annual variation in snow-melt chronology, nesting phenology, nesting density, clutch size and nest success was examined. The same area (approximately 23 kmA?) was searched each year and nests were found as early as possible in the laying period. Laying initiation dates ranged from 1-27 May and hatch dates from 12 June a?? 4 July among pairs and years of study. The peak arrival of Tundra Swans and the phenology of nest initiation and hatch were highly correlated with the progression of ice and snow melt in spring. Nest density averaged 0.71 kmA? and 89% of nesting pairs hatched at least one egg. Incubation period ranged from 26 to 33 days with a median of 30 days. Clutch size varied significantly among years, driven by a low mean value of 3.4 eggs in 1999. Clutch sizes were generally larger than found in previous investigations on the Yukon-Kuskokwim Delta, and nearly one egg larger than reported for clutches from Alaskaa??s North Slope (=70A?N). There was no indication of reduced clutch size in years of late spring snow melt, although nesting density tended to be lower.

Nest materials as a source of genetic data for avian ecological studies

USGS Publications Warehouse

Pearce, J.M.; Fields, R.L.; Scribner, K.T.

1997-01-01

We examined the utility of feathers and egg shell membranes, deposited in the nests of Spectacled Eiders (Somateria fischeri), as a source of DNA for genetic studies at both the population and individual level. The potential for feather DNA contamination as a result of female behavioral interactions (e.g. nest parasitism), reuse of nest sites from previous years, or other unknown occurrences was acknowledged and specifically tested. DNA was successfully extracted from both feathers and egg shell membranes and waterfowl microsatellite loci were used to construct individual genotypes. We found no difference in the genotypes obtained from nest feathers or blood of the incubating female. Detection of nest feather contamination was possible with as little as one feather when samples from multiple females were intentionally mixed. Triplicate DNA extractions from 33 nests provided a means of detecting contamination in 3 nests. Egg membranes proved a viable source of offspring DNA and can contribute valuable data to investigations of parentage when assayed jointly with maternal feather DNA. Nest materials provide an efficient, non-invasive method of genetic sampling that can be readily incorporated into field research. However, the natural history traits and mating strategies of a species must be considered during sample collection to identify the possible sources of nest materials (e.g., paternal, maternal, parasite, etc.). Specific experiments should also be designed to test sampling assumptions.

Nesting ecology of roseate spoonbills at Nueces Bay, Texas

USGS Publications Warehouse

White, D.H.; Mitchell, C.A.

1982-01-01

We conducted a 3-year study in 1978-80 of thenesting ecology of Roseate Spoonbills (Ajaia ajaja) at Nueces Bay, Texas. Reproductive success, as well as nesting chronology, nest composition and placement, growth and development of young, egg measurements, and pollutant residues in eggs were determined. For 154 marked nests, the average clutch size was 3.0 eggs; 73% of the eggs hatched, and 87% of the nests were successful (fledged at least one young). Nest success (total fledglings: total eggs) averaged 50% during the study, or 1.5 fledglings per nest. Incubation began the day after the first egg was laid, and the incubation period for each egg was 22 days. Eggs hatched in the order that they were laid; the first and second egg hatched on consecutive days, and the second, third, and fourth egg hatched every other day. Nest composition and size were highly consistent, as was distance between nests within clusters, but nest placement varied considerably and was dependent on the vegetative configuration of the dredged-material islands. Growth rate of nestlings conformed to a 'standard' growth curve where body weight equaled that of adults at fledging. There was no difference in weight gain among siblings based on actual age. Nestlings fledged at about siz weeks of age when feather development was complete. At fledging, the bills of juveniles had almost reached adult width, but bill length was only 67% that of adults.

Identifying Kittlitz's Murrelet nesting habitat in North America at the landscape scale

USGS Publications Warehouse

Felis, Jonathan J.; Kissling, Michelle L.; Kaler, Robb S.A.; Kenney, Leah A.; Lawonn, Matthew J.

2016-01-01

The Kittlitz's Murrelet (Brachyramphus brevirostris) is a small, non-colonial seabird endemic to marine waters of Alaska and eastern Russia that may have experienced significant population decline in recent decades, in part because of low reproductive success and terrestrial threats. Although recent studies have shed new light on Kittlitz's Murrelet nesting habitat in a few discrete areas, the location and extent of suitable nesting habitat throughout most of its range remains unclear. Here, we have compiled all existing nest records and locations to identify landscape-scale parameters (distance to coast, elevation, slope, and land cover) that provide potential nesting habitat in four regions: northern Alaska, Aleutian Islands, Alaska Peninsula Mountains and Kodiak Island, and Pacific Coastal Mountains (including nearshore interior Canada). We produced a final map classifying 12% (70,411 km2) of the lands assessed as potential Kittlitz's Murrelet nesting habitat, with dense but distinct patches in northern Alaska and a more uninterrupted, narrow band extending across the Pacific Coastal Mountains, Alaska Peninsula Mountains, and Aleutian Islands. The extent of habitat-capable parameter values varied regionally, indicating that the Kittlitz's Murrelet may be able to use a variety of habitats for nesting, depending on availability. Future nesting habitat studies could employ spatially random sampling designs to allow for quantitatively robust modeling of nesting habitat and predictive extrapolation to areas where nests have not been located but likely exist.

Landscape distribution of food and nesting sites affect larval diet and nest size, but not abundance of Osmia bicornis.

PubMed

Coudrain, Valérie; Rittiner, Sarah; Herzog, Felix; Tinner, Willy; Entling, Martin H

2016-10-01

Habitat fragmentation is a major threat for beneficial organisms and the ecosystem services they provide. Multiple-habitat users such as wild bees depend on both nesting and foraging habitat. Thus, they may be affected by the fragmentation of at least two habitat types. We investigated the effects of landscape-scale amount of and patch isolation from both nesting habitat (woody plants) and foraging habitat (specific pollen sources) on the abundance and diet of Osmia bicornis L. Trap-nests of O. bicornis were studied in 30 agricultural landscapes of the Swiss Plateau. Nesting and foraging habitats were mapped in a radius of 500 m around the sites. Pollen composition of larval diet changed as isolation to the main pollen source, Ranunculus, increased, suggesting that O. bicornis adapted its foraging strategy in function of the nest proximity to main pollen sources. Abundance of O. bicornis was neither related to isolation or amount of nesting habitat nor to isolation or abundance of food plants. Surprisingly, nests of O. bicornis contained fewer larvae in sites at forest edge compared to isolated sites, possibly due to higher parasitism risk. This study indicates that O. bicornis can nest in a variety of situations by compensating scarcity of its main larval food by exploiting alternative food sources. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Relatedness and nesting dispersion within breeding populations of greater white-fronted geese

USGS Publications Warehouse

Fowler, A.C.; Eadie, J.M.; Ely, Craig R.

2004-01-01

We studied patterns of relatedness and nesting dispersion in female Pacific Greater White-fronted Geese (Anser albifrons frontalis) in Alaska. Female Greater White-fronted Geese are thought to be strongly philopatric and are often observed nesting in close association with other females. Analysis of the distribution of nests on the Yukon-Kuskokwim Delta in 1998 indicated that nests were significantly clumped. We tested the hypothesis that females in the same nest cluster would be closely related using estimates of genetic relatedness based on six microsatellite DNA loci. There was no difference in the mean relatedness of females in the same cluster compared to females found in different clusters. However, relatedness among females was negatively correlated with distance between their nests, and geese nesting within 50 m of one another tended to be more closely related than those nesting farther apart. Randomization tests revealed that pairs of related individuals (R > 0.45) were more likely to occur in the same cluster when analyzed at the scale of the entire study site. However, the pattern did not hold when restricted to pairs found within 500 m of each other. Our results indicate that nest clusters are not composed primarily of closely related females, but Greater White-fronted Geese appear to be sufficiently philopatric to promote nonrandom patterns of relatedness at a local scale.

After-effects reported by women having follow-up cervical cytology tests in primary care: a cohort study within the TOMBOLA trial.

PubMed

Cotton, Seonaidh; Sharp, Linda; Cochran, Claire; Gray, Nicola; Cruickshank, Maggie; Smart, Louise; Thornton, Alison; Little, Julian

2011-06-01

Although it is recognised that some women experience pain or bleeding during a cervical cytology test, few studies have quantified physical after-effects of these tests. To investigate the frequency, severity, and duration of after-effects in women undergoing follow-up cervical cytology tests, and to identify subgroups with higher frequencies in Grampian, Tayside, and Nottingham. Cohort study nested with a multi-centre individually randomised controlled trial. The cohort included 1120 women, aged 20-59 years, with low-grade abnormal cervical cytology who completed a baseline sociodemographic questionnaire and had a follow-up cervical cytology test in primary care 6 months later. Six weeks after this test, women completed a postal questionnaire on pain, bleeding, and discharge experienced after the test, including duration and severity. The adjusted prevalence of each after-effect was computed using logistic regression. A total of 884 women (79%) completed the after-effects questionnaire; 30% of women experienced one or more after-effect: 15% reported pain, 16% bleeding, and 7% discharge. The duration of discharge was ≤2 days for 66%, 3-6 days for 22%, and ≥7 days for 11% of women. Pain or bleeding lasted ≤2 days in more than 80% of women. Severe after-effects were reported by <1% of women. The prevalence of pain decreased with increasing age. Bleeding was more frequent among nulliparous women. Discharge was more common among oral contraceptive users. Pain, bleeding, and discharge are not uncommon in women having follow-up cervical cytology tests. Informing women about possible after-effects could better prepare them and provide reassurance, thereby minimising potential non-adherence with follow-up or non-participation with screening in the future.

Mortality study among workers producing ferroalloys and stainless steel in France.

PubMed Central

Moulin, J J; Portefaix, P; Wild, P; Mur, J M; Smagghe, G; Mantout, B

1990-01-01

A mortality study was carried out among the workers of a plant that had produced ferrochromium and stainless steel, and was still producing stainless steel, in order to determine whether exposure to chromium compounds, to nickel compounds, and to polycyclic aromatic hydrocarbons (PAH) could result in a risk of lung cancer for the exposed workers. The cohort comprised 2269 men whose vital status were recorded between 1 January 1952 and 31 December 1982. The smoking habits of 67% of the cohort members were known from medical records. The observed numbers of deaths were compared with the expected ones based on national rates with adjustment for age, sex, and calendar time. A low mortality, achieving statistical significance, was found from all causes (observed = 137, standardised mortality ratio (SMR) = 0.82) and from benign respiratory diseases (observed = one, SMR = 0.15). With regard to mortality from lung cancer, a non-significant excess appeared in the whole cohort (observed = 12, SMR = 1.40). Among the exposed workers, however, a significant lung cancer excess was found (observed = 11, SMR = 2.04) that contrasted with a low SMR (0.32) in the non-exposed group. This excess is unlikely to be explained by smoking, as the tobacco consumption of these two groups was similar. No trend was observed for mortality from lung cancer either according to time since first exposure, or according to duration of exposure. A nested case-control study clearly suggested that this excess of deaths from lung cancer was attributable to former PAH exposures in the ferrochromium production workshops rather than to exposures in the stainless steel manufacturing areas. PMID:2393634

Plasma Arginine/Asymmetric Dimethylarginine Ratio and Incidence of Cardiovascular Events: A Case-Cohort Study.

PubMed

Yu, Edward; Ruiz-Canela, Miguel; Hu, Frank B; Clish, Clary B; Corella, Dolores; Salas-Salvadó, Jordi; Hruby, Adela; Fitó, Montserrat; Liang, Liming; Toledo, Estefanía; Ros, Emilio; Estruch, Ramón; Gómez-Gracia, Enrique; Lapetra, José; Arós, Fernando; Romaguera, Dora; Serra-Majem, Lluís; Guasch-Ferré, Marta; Wang, Dong D; Martínez-González, Miguel A

2017-06-01

Arginine, its methylated metabolites, and other metabolites related to the urea cycle have been independently associated with cardiovascular risk, but the potential causal meaning of these associations (positive for some metabolites and negative for others) remains elusive due to a lack of studies measuring metabolite changes over time. To examine the association between baseline and 1-year concentrations of urea cycle metabolites and cardiovascular disease (CVD) in a case-cohort setting. A case-cohort study was nested within the Prevención con Dieta Mediterránea trial. We used liquid chromatography-tandem mass spectrometry to assess metabolite levels at baseline and after 1-year follow-up. The primary CVD outcome was a composite of myocardial infarction, stroke and cardiovascular death. We used weighted Cox regression models (Barlow weights) to estimate multivariable-adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs). Multicenter randomized trial in Spain. Participants were 984 participants accruing 231 events over 4.7 years' median follow-up. Incident CVD. Baseline arginine/asymmetric dimethylarginine ratio [HR per standard deviation (SD) = 0.80; 95% CI, 0.67 to 0.96] and global arginine availability [arginine / (ornithine + citrulline)] (HR per SD = 0.83; 95% CI, 0.69 to 1.00) were significantly associated with lower risk of CVD. We observed no significant association for 1-year changes in these ratios or any effect modification by the Mediterranean diet (MD) intervention. A higher baseline arginine/asymmetric dimethylarginine ratio was associated with lower CVD incidence in a high cardiovascular risk population. The intervention with the MD did not change 1-year levels of these metabolites. Copyright © 2017 Endocrine Society

Food insecurity and mental health: an analysis of routine primary care data of pregnant women in the Born in Bradford cohort.

PubMed

Power, Madeleine; Uphoff, Eleonora; Kelly, Brian; Pickett, Kate E

2017-04-01

Since 2008, use of food banks has risen sharply in the UK; however, evidence on the epidemiology of UK food insecurity is sparse. The aim of this study was to describe the trajectory of common mental disorder across the pre-pregnancy, pregnancy and postnatal period for food secure compared with food insecure women. Data from the Born in Bradford (BiB) cohort, the nested BiB1000 study and primary care records were linked based on National Health Service (NHS) numbers. Data linkage was completed for 1297, and primary care records were available from 18 months prior to 40 months after birth of the cohort child. Incidence rates of common mental disorders per 1000 patient years at risk were compared between food secure and insecure women, and for Pakistani compared with white British women, in 10 6-month periods around pregnancy. Poisson regression was used to calculate incidence rate ratios, adjusted for ethnicity and exposure. Food insecurity was significantly associated with an increased risk of common mental disorder before and during pregnancy (incidence rate ratio 1.9, 95% confidence interval 1.3 to 2.8, p=0.001) and after giving birth (incidence rate ratio 1.3, 95% confidence interval 1.0 to 1.7, p=0.029). Our study shows that food insecure women have worse mental health than food secure women, and that this difference is most pronounced for white British pregnant women. These findings provide evidence for concerns expressed by public health experts that food insecurity may become the next public health emergency. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Interleukin-1β gene variants are associated with QTc interval prolongation following cardiac surgery: a prospective observational study.

PubMed

Kertai, Miklos D; Ji, Yunqi; Li, Yi-Ju; Mathew, Joseph P; Daubert, James P; Podgoreanu, Mihai V

2016-04-01

We characterized cardiac surgery-induced dynamic changes of the corrected QT (QTc) interval and tested the hypothesis that genetic factors are associated with perioperative QTc prolongation independent of clinical and procedural factors. All study subjects were ascertained from a prospective study of patients who underwent elective cardiac surgery during August 1999 to April 2002. We defined a prolonged QTc interval as > 440 msec, measured from 24-hr pre- and postoperative 12-lead electrocardiograms. The association of 37 single nucleotide polymorphisms (SNPs) in 21 candidate genes -involved in modulating arrhythmia susceptibility pathways with postoperative QTc changes- was investigated in a two-stage design with a stage I cohort (n = 497) nested within a stage II cohort (n = 957). Empirical P values (Pemp) were obtained by permutation tests with 10,000 repeats. After adjusting for clinical and procedural risk factors, we selected four SNPs (P value range, 0.03-0.1) in stage I, which we then tested in the stage II cohort. Two functional SNPs in the pro-inflammatory cytokine interleukin-1β (IL1β), rs1143633 (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.53 to 0.95; Pemp = 0.02) and rs16944 (OR, 1.31; 95% CI, 1.01 to 1.70; Pemp = 0.04), remained independent predictors of postoperative QTc prolongation. The ability of a clinico-genetic model incorporating the two IL1B polymorphisms to classify patients at risk for developing prolonged postoperative QTc was superior to a clinical model alone, with a net reclassification improvement of 0.308 (P = 0.0003) and an integrated discrimination improvement of 0.02 (P = 0.000024). The results suggest a contribution of IL1β in modulating susceptibility to postoperative QTc prolongation after cardiac surgery.

Coffee intake and gastric cancer risk: The Singapore Chinese Health Study

PubMed Central

Ainslie-Waldman, Cheryl E.; Koh, Woon-Puay; Jin, Aizhen; Yeoh, Khay Guan; Zhu, Feng; Wang, Renwei; Yuan, Jian-Min; Butler, Lesley M.

2014-01-01

Background Despite experimental evidence showing chemopreventive effects of coffee-related compounds on gastric carcinogenesis, epidemiologic studies generally do not support coffee-gastric cancer associations. Observational data are lacking among high-risk populations with sufficient regular coffee consumption. Methods We examined the association between caffeinated coffee intake and gastric cancer risk in a population-based cohort that enrolled 63,257 Chinese men and women aged 45–74 years between 1993 and 1998 in Singapore. Incident gastric cancer cases (n=647) were identified after a mean follow-up of 14.7 years. Biomarkers of Helicobacter pylori (H. pylori) infection were measured in a subset of gastric cancer cases with blood collected prior to cancer diagnosis and their matched controls. Results In the total cohort, daily versus non-daily coffee intake was associated with a statistically non-significant decrease in gastric cancer risk [hazards ratio (HR) = 0.85; 95% confidence interval (CI): 0.69, 1.04). In women, the inverse association strengthened and reached statistical significance (HR=0.63; 95% CI: 0.46, 0.87). In analyses restricted to never smokers and nondrinkers of alcohol, inverse associations strengthened in the total cohort (HR=0.69; 95% CI: 0.52, 0.91) and in women (HR=0.52; 95% CI: 0.37, 0.74). There was no coffee-gastric cancer risk association among men, regardless of smoking status or alcohol consumption. Similar results were observed in the nested case-control study after adjustment for H. pylori infection. Conclusion Daily coffee consumption may reduce the risk of gastric cancer in high-risk populations, especially among women. Impact: Research aimed at identifying the compounds in coffee that may protect against gastric carcinogenesis is warranted. PMID:24608187

Coffee intake and gastric cancer risk: the Singapore Chinese health study.

PubMed

Ainslie-Waldman, Cheryl E; Koh, Woon-Puay; Jin, Aizhen; Yeoh, Khay Guan; Zhu, Feng; Wang, Renwei; Yuan, Jian-Min; Butler, Lesley M

2014-04-01

Despite experimental evidence showing chemopreventive effects of coffee-related compounds on gastric carcinogenesis, epidemiologic studies generally do not support coffee-gastric cancer associations. Observational data are lacking among high-risk populations with sufficient regular coffee consumption. We examined the association between caffeinated coffee intake and gastric cancer risk in a population-based cohort that enrolled 63,257 Chinese men and women ages 45 to 74 years between 1993 and 1998 in Singapore. Incident gastric cancer cases (n = 647) were identified after a mean follow-up of 14.7 years. Biomarkers of Helicobacter pylori (H. pylori) infection were measured in a subset of gastric cancer cases with blood collected before cancer diagnosis and their matched controls. In the total cohort, daily versus nondaily coffee intake was associated with a statistically nonsignificant decrease in gastric cancer risk [HR = 0.85; 95% confidence interval (CI), 0.69-1.04]. In women, the inverse association strengthened and reached statistical significance (HR = 0.63; 95% CI, 0.46-0.87). In analyses restricted to never smokers and nondrinkers of alcohol, inverse associations strengthened in the total cohort (HR = 0.69; 95% CI, 0.52-0.91) and in women (HR = 0.52; 95% CI, 0.37-0.74). There was no coffee-gastric cancer risk association among men, regardless of smoking status or alcohol consumption. Similar results were observed in the nested case-control study after adjustment for H. pylori infection. Daily coffee consumption may reduce the risk of gastric cancer in high-risk populations, especially among women. Research aimed at identifying the compounds in coffee that may protect against gastric carcinogenesis is warranted.

Major histocompatibility complex (MHC) class I and II alleles which confer susceptibility or protection in the Morphea in Adults and Children (MAC) cohort

PubMed Central

Jacobe, Heidi; Ahn, Chul; Arnett, Frank; Reveille, John D.

2014-01-01

Objective To determine human leukocyte antigen class I (HLA-class I) and II (HLA-class II) alleles associated with morphea (localized scleroderma) in the Morphea in Adults and Children (MAC) cohort by a nested case–control association study. Methods Morphea patients were included from MAC cohort and matched controls from the NIH/NIAMS Scleroderma Family Registry and DNA Repository and Division of Rheumatology at the University of Texas Health Science Center at Houston. HLA- Class II genotyping and SSCP typing was performed of HLA-A, -B, -C alleles. Associations between HLA-Class I and II alleles and morphea as well as its subphenotypes were determined. Results There were 211 cases available for HLA-class I typing with 726 matched controls and 158 cases available for HLA Class-II typing with 1108 matched controls. The strongest associations were found with DRB1*04:04 (OR 2.3, 95% CI 1.4–4.0 P=0.002) and HLA-B*37 conferred the highest OR among Class I alleles (3.3, 95% CI 1.6–6.9, P= 0.0016). Comparison with risk alleles in systemic sclerosis determined using the same methods and control population revealed one common allele (DRB*04:04). Conclusion Results of the present study demonstrate specific HLA Class I and II alleles are associated with morphea and likely generalized and linear subtypes. The associated morphea alleles are different than in scleroderma, implicating morphea is also immunogenetically distinct. Risk alleles in morphea are also associated with conditions such as rheumatoid arthritis (RA) and other autoimmune conditions. Population based studies indicate patients with RA have increased risk of morphea, implicating a common susceptibility allele. PMID:25223600

After-effects reported by women having follow-up cervical cytology tests in primary care: a cohort study within the TOMBOLA trial

PubMed Central

Cotton, Seonaidh; Sharp, Linda; Cochran, Claire; Gray, Nicola; Cruickshank, Maggie; Smart, Louise; Thornton, Alison; Little, Julian

2011-01-01

Background Although it is recognised that some women experience pain or bleeding during a cervical cytology test, few studies have quantified physical after-effects of these tests. Aim To investigate the frequency, severity, and duration of after-effects in women undergoing follow-up cervical cytology tests, and to identify subgroups with higher frequencies in Grampian, Tayside, and Nottingham. Design Cohort study nested with a multi-centre individually randomised controlled trial. Method The cohort included 1120 women, aged 20–59 years, with low-grade abnormal cervical cytology who completed a baseline sociodemographic questionnaire and had a follow-up cervical cytology test in primary care 6 months later. Six weeks after this test, women completed a postal questionnaire on pain, bleeding, and discharge experienced after the test, including duration and severity. The adjusted prevalence of each after-effect was computed using logistic regression. Results A total of 884 women (79%) completed the after-effects questionnaire; 30% of women experienced one or more after-effect: 15% reported pain, 16% bleeding, and 7% discharge. The duration of discharge was ≤2 days for 66%, 3–6 days for 22%, and ≥7 days for 11% of women. Pain or bleeding lasted ≤2 days in more than 80% of women. Severe after-effects were reported by <1% of women. The prevalence of pain decreased with increasing age. Bleeding was more frequent among nulliparous women. Discharge was more common among oral contraceptive users. Conclusion Pain, bleeding, and discharge are not uncommon in women having follow-up cervical cytology tests. Informing women about possible after-effects could better prepare them and provide reassurance, thereby minimising potential non-adherence with follow-up or non-participation with screening in the future. PMID:21801512

Direct medical costs of constipation from childhood to early adulthood: a population-based birth cohort study.

PubMed

Choung, Rok Seon; Shah, Nilay D; Chitkara, Denesh; Branda, Megan E; Van Tilburg, Miranda A; Whitehead, William E; Katusic, Slavica K; Locke, G Richard; Talley, Nicholas J

2011-01-01

Although direct medical costs for constipation-related medical visits are thought to be high, to date there have been no studies examining whether longitudinal resource use is persistently elevated in children with constipation. Our aim was to estimate the incremental direct medical costs and types of health care use associated with constipation from childhood to early adulthood. A nested case-control study was conducted to evaluate the incremental costs associated with constipation. The original sample consisted of 5718 children in a population-based birth cohort who were born during 1976 to 1982 in Rochester, MN. The cases included individuals who presented to medical facilities with constipation. The controls were matched and randomly selected among all noncases in the sample. Direct medical costs for cases and controls were collected from the time subjects were between 5 and 18 years of age or until the subject emigrated from the community. We identified 250 cases with a diagnosis of constipation in the birth cohort. Although the mean inpatient costs for cases were $9994 (95% Confidence interval [CI] 2538-37,201) compared with $2391 (95% CI 923-7452) for controls (P = 0.22) during the time period, the mean outpatient costs for cases were $13,927 (95% CI 11,325-16,525) compared with $3448 (95% CI 3771-4621) for controls (P < 0.001) during the same time period. The mean annual number of emergency department visits for cases was 0.66 (95% CI 0.62-0.70) compared with 0.34 (95% CI 0.32-0.35) for controls (P < 0.0001). Individuals with constipation have higher medical care use. Outpatient costs and emergency department use were significantly greater for individuals with constipation from childhood to early adulthood.

Near work, education, family history, and myopia in Greek conscripts.

PubMed

Konstantopoulos, A; Yadegarfar, G; Elgohary, M

2008-04-01

To investigate potential factors associated with the presence of myopia in a cohort of young adult men carrying out their military service in Greece. A nested case-control study of 200 conscripts (99 myopes and 101 non-myopes). The cohort consisted of approximately 1000 conscripts in compulsory national service. All cohort members had been screened for refractive errors by Snellen visual acuity measurement at presentation to military service; individuals not achieving visual activity 6/6 underwent noncycloplaegic refraction. The study sample consisted of the first 99 myopic and 101 nonmyopic conscripts who attended the study. In-person interviews of these 200 conscripts were conducted to obtain information on family history, occupation, level of education, near-work activities, and sleeping behaviour. chi(2) and Mann-Whitney tests were used as univariate analysis methods to identify the potential factors associated with the presence of myopia. Multiple logistic regression was used to estimate the adjusted relative risk of myopia. Univariate analysis showed that parental family history (P<0.001), older age (P<0.001), tertiary education (P<0.001), hours of reading per day (P<0.001), hours of computer use per day (P<0.001), and higher social classes (P<0.001) were associated with myopia. Sleeping in artificial or ambient light was not associated with myopia (P=0.75). Multiple logistic regression analysis showed that older age (OR=1.25, 95% CI 1.05-1.49), tertiary education (OR=12.67, 95% CI 3.57-44.88) and parental family history (OR=3.39, 95% CI 1.56-7.36) were independently associated with myopia. In young Greek conscripts, parental family history, older age, and education level are independently associated with myopia.

Member Perceptions of Informal Science Institution Graduate Certificate Program: Case Study of a Community of Practice

NASA Astrophysics Data System (ADS)

Ball, Lois A.

This research attempted to understand the experiences of a cohort of informal and formal science educators and informal science institution (ISI) community representatives during and after completion of a pilot graduate certificate program. Informal science educators (ISEs) find limited opportunities for professional development and support which influence their contributions to America's science literacy and school science education. This emergent design nested case study described how an innovative program provided professional development and enabled growth in participants' abilities to contribute to science literacy. Data were collected through interviews, participant observations, and class artifacts. The program by design and constituency was the overarching entity that accounted for members' experiences. Three principal aspects of the ISI certificate program and cohort which influenced perceptions and reported positive outcomes were (1) the cohort's composition and their collaborative activities which established a vigorous community of practice and fostered community building, mentoring, and networking, (2) long term program design and implementation which promoted experiential learning in a generative classroom, and (3) ability of some members who were able to be independent or autonomous learners to embrace science education reform strategies for greater self-efficacy and career advancement. This research extends the limited literature base for professional development of informal science educators and may benefit informal science institutions, informal and formal science educators, science education reform efforts, and public education and science-technology-society understanding. The study may raise awareness of the need to establish more professional development opportunities for ISEs and to fund professional development. Further, recognizing and appreciating informal science educators as a diverse committed community of professionals who positively influence science education for everyone is essential.

A nested case-control study of predictors for tuberculosis recurrence in a large UK Centre.

PubMed

Rosser, Andrew; Richardson, Matthew; Wiselka, Martin J; Free, Robert C; Woltmann, Gerrit; Mukamolova, Galina V; Pareek, Manish

2018-02-27

Tuberculosis (TB) recurrence represents a challenge to control programs. In low incidence countries, the prevailing risk factors leading to recurrence are poorly characterised. We conducted a nested case-control study using the Leicester TB service TBIT database. Cases were identified from database notifications between 1994 and 2014. Controls had one episode and were matched to cases on a ratio of two to one by the date of notification. Multiple imputation was used to account for missing data. Multivariate conditional logistic regression analysis was employed to identify clinical, sociodemographic and TB specific risk factors for recurrence. From a cohort of 4628 patients, 82 TB recurrences occurred (1.8%). Nineteen of 82 patients had paired isolates with MIRU-VNTR strain type profiles available, of which 84% were relapses and 16% reinfections. On multivariate analysis, smoking (OR 3.8; p = 0.04), grade 3/4 adverse drug reactions (OR 5.6; p = 0.02), ethnicity 'Indian subcontinent' (OR 8.5; p = <0.01), ethnicity 'other' (OR 31.2; p = 0.01) and receipt of immunosuppressants (OR 6.8; p = <0.01) were independent predictors of TB recurrence. Within this UK setting, the rate of TB recurrence was low, predominantly due to relapse. The identification of an elevated recurrence risk amongst the ethnic group contributing most cases to the national TB burden presents an opportunity to improve individual and population health.

Beach Geomorphology and Kemp's Ridley (Lepidochelys kempii) Nest Site Selection along Padre Island, Texas, USA

NASA Astrophysics Data System (ADS)

Culver, M.; Gibeaut, J. C.; Shaver, D. J.; Tissot, P.; Starek, M. J.

2017-12-01

The Kemp's ridley sea turtle (Lepidochelys kempii) is the most endangered sea turtle in the world, largely due to the limited geographic range of its nesting habitat. In the U.S., the majority of nesting occurs along Padre Island National Seashore (PAIS) in Texas. There has been limited research regarding the connection between beach geomorphology and Kemp's ridley nesting patterns, but studies concerning other sea turtle species suggest that certain beach geomorphology variables, such as beach slope and width, influence nest site selection. This research investigates terrestrial habitat variability of the Kemp's ridley sea turtle and quantifies the connection between beach geomorphology and Kemp's ridley nest site selection on PAIS and South Padre Island, Texas. Airborne topographic lidar data collected annually along the Texas coast from 2009 through 2012 was utilized to extract beach geomorphology characteristics, such as beach slope and width, dune height, and surface roughness, among others. The coordinates of observed Kemp's ridley nests from corresponding years were integrated with the aforementioned data in statistical models, which analyzed the influence of both general trends in geomorphology and individual morphologic variables on nest site selection. This research identified the terrestrial habitat variability of the Kemp's ridley and quantified the range of geomorphic characteristics of nesting beaches. Initial results indicate that dune width, beach width, and wind speed are significant variables in relation to nest presence, using an alpha of 0.1. Higher wind speeds and narrower beaches and foredunes favor nest presence. The average nest elevation is 1.13 m above mean sea level, which corresponds to the area directly below the potential vegetation line, and the majority of nesting occurs between the elevations of 0.68 m and 1.4 m above mean sea level. The results of this study include new information regarding Kemp's ridley beach habitat and its influence on nesting patterns that could be useful for the conservation and management of the species.

Hatching and fledging times from grassland passerine nests

USGS Publications Warehouse

Pietz, Pamela J.; Granfors, Diane A.; Grant, Todd A.; Ribic, Christine A.; Thompson, Frank R.; Pietz, Pamela J.

2012-01-01

1 day and was positively correlated with clutch size. Length of the fledging period for a brood was usually Accurate estimates of fledging age are needed in field studies to avoid inducing premature fledging or missing the fledging event. Both may lead to misinterpretation of nest fate. Correctly assessing nest fate and length of the nestling period can be critical for accurate calculation of nest survival rates. For researchers who mark nestlings, knowing the age at which their activities may cause young to leave nests prematurely could prevent introducing bias to their studies. We obtained estimates of fledging age using data from grassland bird nests monitored from hatching through fledging with video-surveillance systems in North Dakota and Minnesota during 1996–2001. We compared these values to those obtained from traditional nest visits and from available literature. Mean and modal fledging ages for video-monitored nests were generally similar to those for visited nests, although Clay-colored Sparrows (Spizella pallida) typically fledged 1 day earlier from visited nests. Average fledging ages from both video and nest visits occurred within ranges reported in the literature, but expanded by 1–2 days the upper age limit for Clay-colored Sparrows and the lower age limit for Bobolinks (Dolichonyx oryzivorus). Video showed that eggs hatched throughout the day whereas most young fledged in the morning (06:30–12:30 CDT). Length of the hatching period for a clutch was usually >1 day and was positively correlated with clutch size. Length of the fledging period for a brood was usually <1 day, and in nearly half the nests, fledging was completed within <2 hr. Video surveillance has proven to be a useful tool for providing new information and for corroborating published statements related to hatching and fledging chronology. Comparison of data collected from video and nest visits showed that carefully conducted nest visits generally can provide reliable data for deriving estimates of survival.

Nest temperature fluctuations in a cavity nester, the southern ground-hornbill.

PubMed

Combrink, L; Combrink, H J; Botha, A J; Downs, C T

2017-05-01

Southern ground-hornbills Bucorvus leadbeateri inhabit savanna and bushveld regions of South Africa. They nest in the austral summer, which coincides with the wet season and hottest daytime temperatures in the region. They are secondary cavity nesters and typically nest in large cavities in trees, cliffs and earth banks, but readily use artificial nest boxes. Southern ground-hornbills are listed as Endangered in South Africa, with reintroductions into suitable areas highlighted as a viable conservation intervention for the species. Nest microclimate, and the possible implications this may have for the breeding biology of southern ground-hornbills, have never been investigated. We used temperature dataloggers to record nest cavity temperature and ambient temperature for one artificial and 11 natural southern ground-hornbill tree cavity nests combined, spanning two breeding seasons. Mean hourly nest temperature, as well as mean minimum and mean maximum nest temperature, differed significantly between southern ground-hornbill nests in both breeding seasons. Mean nest temperature also differed significantly from mean ambient temperature for both seasons. Natural nest cavities provided a buffer against the ambient temperature fluctuations. The artificial nest provided little insulation against temperature extremes, being warmer and cooler than the maximum and minimum local ambient temperatures, respectively. Nest cavity temperature was not found to have an influence on the breeding success of the southern ground-hornbill groups investigated in this study. These results have potentially important implications for southern ground-hornbill conservation and artificial nest design, as they suggest that the birds can tolerate greater nest cavity temperature extremes than previously thought. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does Viral Co-Infection Influence the Severity of Acute Respiratory Infection in Children?

PubMed

Cebey-López, Miriam; Herberg, Jethro; Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Nazareth; Salas, Antonio; Martinón-Sánchez, José María; Justicia, Antonio; Rivero-Calle, Irene; Sumner, Edward; Fink, Colin; Martinón-Torres, Federico

2016-01-01

Multiple viruses are often detected in children with respiratory infection but the significance of co-infection in pathogenesis, severity and outcome is unclear. To correlate the presence of viral co-infection with clinical phenotype in children admitted with acute respiratory infections (ARI). We collected detailed clinical information on severity for children admitted with ARI as part of a Spanish prospective multicenter study (GENDRES network) between 2011-2013. A nested polymerase chain reaction (PCR) approach was used to detect respiratory viruses in respiratory secretions. Findings were compared to an independent cohort collected in the UK. 204 children were recruited in the main cohort and 97 in the replication cohort. The number of detected viruses did not correlate with any markers of severity. However, bacterial superinfection was associated with increased severity (OR: 4.356; P-value = 0.005), PICU admission (OR: 3.342; P-value = 0.006), higher clinical score (1.988; P-value = 0.002) respiratory support requirement (OR: 7.484; P-value < 0.001) and longer hospital length of stay (OR: 1.468; P-value < 0.001). In addition, pneumococcal vaccination was found to be a protective factor in terms of degree of respiratory distress (OR: 2.917; P-value = 0.035), PICU admission (OR: 0.301; P-value = 0.011), lower clinical score (-1.499; P-value = 0.021) respiratory support requirement (OR: 0.324; P-value = 0.016) and oxygen necessity (OR: 0.328; P-value = 0.001). All these findings were replicated in the UK cohort. The presence of more than one virus in hospitalized children with ARI is very frequent but it does not seem to have a major clinical impact in terms of severity. However bacterial superinfection increases the severity of the disease course. On the contrary, pneumococcal vaccination plays a protective role.

Lung cancer and diesel exhaust: an updated critical review of the occupational epidemiology literature.

PubMed

Gamble, John F; Nicolich, Mark J; Boffetta, Paolo

2012-08-01

A recent review concluded that the evidence from epidemiology studies was indeterminate and that additional studies were required to support the diesel exhaust-lung cancer hypothesis. This updated review includes seven recent studies. Two population-based studies concluded that significant exposure-response (E-R) trends between cumulative diesel exhaust and lung cancer were unlikely to be entirely explained by bias or confounding. Those studies have quality data on life-style risk factors, but do not allow definitive conclusions because of inconsistent E-R trends, qualitative exposure estimates and exposure misclassification (insufficient latency based on job title), and selection bias from low participation rates. Non-definitive results are consistent with the larger body of population studies. An NCI/NIOSH cohort mortality and nested case-control study of non-metal miners have some surrogate-based quantitative diesel exposure estimates (including highest exposure measured as respirable elemental carbon (REC) in the workplace) and smoking histories. The authors concluded that diesel exhaust may cause lung cancer. Nonetheless, the results are non-definitive because the conclusions are based on E-R patterns where high exposures were deleted to achieve significant results, where a posteriori adjustments were made to augment results, and where inappropriate adjustments were made for the "negative confounding" effects of smoking even though current smoking was not associated with diesel exposure and therefore could not be a confounder. Three cohort studies of bus drivers and truck drivers are in effect air pollution studies without estimates of diesel exhaust exposure and so are not sufficient for assessing the lung cancer-diesel exhaust hypothesis. Results from all occupational cohort studies with quantitative estimates of exposure have limitations, including weak and inconsistent E-R associations that could be explained by bias, confounding or chance, exposure misclassification, and often inadequate latency. In sum, the weight of evidence is considered inadequate to confirm the diesel-lung cancer hypothesis.

Lung cancer and diesel exhaust: an updated critical review of the occupational epidemiology literature

PubMed Central

Gamble, John F.; Nicolich, Mark J.; Boffetta, Paolo

2012-01-01

A recent review concluded that the evidence from epidemiology studies was indeterminate and that additional studies were required to support the diesel exhaust-lung cancer hypothesis. This updated review includes seven recent studies. Two population-based studies concluded that significant exposure-response (E-R) trends between cumulative diesel exhaust and lung cancer were unlikely to be entirely explained by bias or confounding. Those studies have quality data on life-style risk factors, but do not allow definitive conclusions because of inconsistent E-R trends, qualitative exposure estimates and exposure misclassification (insufficient latency based on job title), and selection bias from low participation rates. Non-definitive results are consistent with the larger body of population studies. An NCI/NIOSH cohort mortality and nested case-control study of non-metal miners have some surrogate-based quantitative diesel exposure estimates (including highest exposure measured as respirable elemental carbon (REC) in the workplace) and smoking histories. The authors concluded that diesel exhaust may cause lung cancer. Nonetheless, the results are non-definitive because the conclusions are based on E-R patterns where high exposures were deleted to achieve significant results, where a posteriori adjustments were made to augment results, and where inappropriate adjustments were made for the “negative confounding” effects of smoking even though current smoking was not associated with diesel exposure and therefore could not be a confounder. Three cohort studies of bus drivers and truck drivers are in effect air pollution studies without estimates of diesel exhaust exposure and so are not sufficient for assessing the lung cancer-diesel exhaust hypothesis. Results from all occupational cohort studies with quantitative estimates of exposure have limitations, including weak and inconsistent E-R associations that could be explained by bias, confounding or chance, exposure misclassification, and often inadequate latency. In sum, the weight of evidence is considered inadequate to confirm the diesel-lung cancer hypothesis. PMID:22656672

Clinical course, characteristics and prognostic indicators in patients presenting with back and leg pain in primary care. The ATLAS study protocol

PubMed Central

2012-01-01

Background Low-back related leg pain with or without nerve root involvement is associated with a poor prognosis compared to low back pain (LBP) alone. Compared to the literature investigating prognostic indicators of outcome for LBP, there is limited evidence on prognostic factors for low back-related leg pain including the group with nerve root pain. This 1 year prospective consultation-based observational cohort study will describe the clinical, imaging, demographic characteristics and health economic outcomes for the whole cohort, will investigate differences and identify prognostic indicators of outcome (i.e. change in disability at 12 months), for the whole cohort and, separately, for those classified with and without nerve root pain. In addition, nested qualitative studies will provide insights on the clinical consultation and the impact of diagnosis and treatment on patients' symptom management and illness trajectory. Methods Adults aged 18 years and over consulting their General Practitioner (GP) with LBP and radiating leg pain of any duration at (n = 500) GP practices in North Staffordshire and Stoke-on-Trent, UK will be invited to participate. All participants will receive a standardised assessment at the clinic by a study physiotherapist and will be classified according to the clinically determined presence or absence of nerve root pain/involvement. All will undergo a lumbar spine MRI scan. All participants will be managed according to their clinical need. The study outcomes will be measured at 4 and 12 months using postal self-complete questionnaires. Data will also be collected each month using brief postal questionnaires to enable detailed description of the course of low back and leg pain over time. Clinical observations and patient interviews will be used for the qualitative aspects of the study. Discussion This prospective clinical observational cohort will combine self-reported data, comprehensive clinical and MRI assessment, together with qualitative enquiries, to describe the course, health care usage, patients' experiences and prognostic indicators in an adult population presenting in primary care with LBP and leg pain with or without nerve root involvement. PMID:22264273

Microplastic at nesting grounds used by the northern Gulf of Mexico loggerhead recovery unit.

PubMed

Beckwith, Valencia K; Fuentes, Mariana M P B

2018-06-01

Microplastics can impact key habitats used by endangered species, such as marine turtles. They impact the environment by transporting toxicants and altering sediment properties affecting temperature and sediment permeability. Our study determined the exposure of the ten most important nesting sites for the Northern Gulf of Mexico Loggerhead Recovery Unit to microplastic. Sand samples were obtained at each nesting site during the 2017 nesting season and analyzed for abundance and characteristics of microplastic. Microplastic was found at all sites, with an average abundance of 61.08 ± 34.61 pieces/m 2 , and 59.9% located at the dunes, where turtles primarily nest. A gradual decrease in microplastics abundance was observed from the most western nesting ground to the east. The results from this study indicate that microplastic accumulation on nesting sites for the Northern Gulf of Mexico may be of great concern, and could negatively affect the incubating environment for marine turtles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Osprey distribution, abundance, and status in western North America: III. The Baja California and Gulf of California population

USGS Publications Warehouse

Henny, C.J.; Anderson, D.W.

1979-01-01

-An estimated 810 ? 55 pairs (minimum estimate) of ospreys (Pandion haliaetus) were nesting in the study area during our survey (24 March-l April 1977). Approximately 174 pairs nested along the Pacific side of Baja California, 255 pairs along the gulf side, 187 pairs on the Midriff Islands, and 194 pairs in coastal Sonora and Sinaloa. Most nested on cliffs adjacent to the sea (59%); some nested on cactus in flat terrain (26%). Seven per cent nested on the ground, three percent nested in mangroves and other trees in the southern portion of the study area,.and four percent nested on man-made structures. The extreme northwestern Baja California population that was extirpated early in this century has not recovered. However, several populations immediately to the south along the Pacific Coast now appear stationary. Pesticide residues in osprey eggs from Mexico were among the lowest reported for the species in North America.

Epidemiologic Profile of Patients Transplanted With Hematopoietic Stem Cells in a Reference Service in the State of Rio Grande do Norte, Brazil.

PubMed

Campos de Azevedo, I; Ferreira Júnior, M A; Pereira de Aquino, L A; de Oliveira, A A; Cruz, G K P; de Queiroz Cardoso, A I; Ivo, M L; Santos, V E P

2018-04-01

Hematopoietic stem cell transplantation (HSCT) consists of the intravenous infusion of healthy hematopoietic stem cells to restore the medullary and immunologic function of patients affected by a series of hematologic, oncologic, immunologic, malignant and nonmalignant inherited or acquired diseases, with the possibility of cure or increase of disease-free survival. To characterize the epidemiologic profile and the cases of death of patients who underwent HSCT. This is a cohort quantitative study, nested with a retrospective, descriptive, and analytical study of a hospital-based cohort that included the patients who underwent HSCT at a referral service in the state of Rio Grande do Norte, a region of northeastern Brazil. There was a slight male prevalence (52.94%), the age of the patients ranged from 2 to 73 years old, 18.38% were brown, 47.06% were married, 15.07% were students, 78.31% had a diagnosis of multiple myeloma, 93.38% developed gastrointestinal toxicities, all patients received chemotherapeutic treatment, 54.78% had allogeneic HSCT, and the cause of the most recorded deaths was septic shock (48.19%). This study showed relevant scientific evidence on the clinical and epidemiologic profile of patients who underwent HSCT. In general, sociodemographic data are similar to national and international research results. Copyright © 2018 Elsevier Inc. All rights reserved.

Edge, height and visibility effects on nest predation by birds and mammals in the Brazilian cerrado

NASA Astrophysics Data System (ADS)

Dodonov, Pavel; Paneczko, Ingrid Toledo; Telles, Marina

2017-08-01

Edge influence is one of the main impacts in fragmented landscapes; yet, most of studies on edge influence have focused on high-contrast edges, and the impacts of low-contrast edges and narrow linear openings are less understood. Edge influence often affects bird nest predation, but these effects are not ubiquitous and may depend on characteristics such as nest height and visibility. We performed an experiment on nest predation in a migratory passerine, Elaenia chiriquensis (Lesser Elaenia; Passeriformes: Tyrannidae), in a savanna vegetation of the Brazilian Cerrado biome in South-Eastern Brazil. We used 89 real E. chiriquensis nests, collected during previous reproductive seasons, with two plasticine eggs in each, and randomly distributed them at two locations (edge - up to 20 m from a firebreak edge and interior - approx. 150-350 m from the edge) and two heights (low - 60-175 cm and high - 190-315 cm above ground). We also measured leaf and branch density around each nest. We performed this study on two 15-days campaigns, checking the nests every 2-3 days and removing those with predation marks. We sorted the predation marks into those made by birds, mammals, or unidentified predators, and used generalized linear models to assess the effects of location, height and leaf density on survival time and predator type. Only four nests had not been predated during the experiment; 55 nests were predated by birds, 7 by mammals, and 23 by unidentified predators. Low nests in the interior tended to have larger survival times whereas high nests at the edge tended to be more predated by birds and less predated by mammals. Thus, even a low-contrast (firebreak) edge may significantly increase nest predation, which is also affected by the nest's height, mainly due to predation by birds. These effects may be due to predator movement along the edge as well as to edge-related changes in vegetation structure. We suggest that higher-contrast edges which may also be used as movement conduits, for example powerline openings, may have even stronger effects, demanding further studies.

Marine turtles are not fussy nesters: a novel test of small-scale nest site selection using structure from motion beach terrain information

PubMed Central

Leon, Javier X.; Gilby, Ben L.; Olds, Andrew D.; Schlacher, Thomas A.

2017-01-01

Background Nest selection is widely regarded as a key process determining the fitness of individuals and viability of animal populations. For marine turtles that nest on beaches, this is particularly pivotal as the nesting environment can significantly control reproductive success.The aim of this study was to identify the environmental attributes of beaches (i.e., morphology, vegetation, urbanisation) that may be associated with successful oviposition in green and loggerhead turtle nests. Methods We quantified the proximity of turtle nests (and surrounding beach locations) to urban areas, measured their exposure to artificial light, and used ultra-high resolution (cm-scale) digital surface models derived from Structure-from-Motion (SfM) algorithms, to characterise geomorphic and vegetation features of beaches on the Sunshine Coast, eastern Australia. Results At small spatial scales (i.e., <100 m), we found no evidence that turtles selected nest sites based on a particular suite of environmental attributes (i.e., the attributes of nest sites were not consistently different from those of surrounding beach locations). Nest sites were, however, typically characterised by occurring close to vegetation, on parts of the shore where the beach- and dune-face was concave and not highly rugged, and in areas with moderate exposure to artificial light. Conclusion This study used a novel empirical approach to identify the attributes of turtle nest sites from a broader ‘envelope’ of environmental nest traits, and is the first step towards optimizing conservation actions to mitigate, at the local scale, present and emerging human impacts on turtle nesting beaches. PMID:28070454

Determinants of mallard and gadwall nesting on constructed islands in North Dakota

USGS Publications Warehouse

Shaffer, Terry L.; Dahl, Ann L.; Reynolds, Ronald E.; Baer, Kathy L.; Johnson, Michael A.; Sargeant, Glen A.

2006-01-01

Constructed islands with adequate nesting cover provide secure nesting sites for ducks because islands restrict access by mammalian predators. These islands are costly to construct and should be placed in areas that ensure the greatest use by nesting ducks. We studied mallard (Anas platyrhynchos) and gadwall (A. strepera) nesting on constructed islands in North Dakota in 1996 (n = 20) and 1997 (n = 22) to evaluate factors—particularly amount of perennial grass cover in the surrounding landscape and density of breeding pairs—that possibly influence numbers of initiated nests. We also examined effects of island characteristics, such as island vegetation, on numbers of nests. Numbers of mallard and gadwall nests on islands were negatively related to amounts of perennial grass cover in the surrounding uplands. Numbers of mallard nests were positively related to percentages of tall dense cover on islands. We found no effects of breeding-pair density on numbers of nests initiated by either species, possibly because breeding pairs were abundant on all study sites. Percent shrub cover on islands was a better predictor of island use than was percent tall dense cover. Island use by these species increased with island age and distance from mainland shore. Amounts of perennial cover in landscapes should be primary considerations in determining where to build islands. Our data suggest that use of islands by nesting mallards and gadwalls is greatest in landscapes with little perennial grass cover (i.e., high amounts of cropland). Other researchers documented a positive relation between nest success in upland covers and amount of perennial grass cover in the landscape. Therefore, islands constructed in landscapes with little perennial cover should provide greater gains in duck recruitment rates than islands constructed in landscapes with greater amounts of perennial grass cover.

Habitat comparisons and productivity in nesting common terns on the mid-Atlantic coast

USGS Publications Warehouse

Erwin, R.M.; Smith, D.C.

1985-01-01

Nesting Common Terns (Sterna hirundo) were studied at a number of barrier beaches and small islands of tidal salt marsh in New Jersey and the Eastern Shore of Maryland-Virginina from 1980 through 1982. Data were collected on clutch sizes, nest spacing, and nesting success. The principal null hypothesis tested was that no difference in reproductive success exists between beach and marsh habitats. Nests were monitored from egg-laying in mid-May until mid-July when young fledged. Clutch sizes varied among colonies and across years but no systematic effect of year, habitat, or colony size on mean clutch size per colony was detected. Analyses of nest productivity (estimated using both the Mayfield method and using a colony average) failed to reveal significant effects of habitat or colony size but showed a stronger year effect. Storm tide flooding and egg chick disappearance (presumably predation by Herring Gulls Larus argentatus and Laughing Gulls L. atricilla nesting nearby) accounted for most nest failures. Losses due to both these mortality factors were unpredictable from year to year. Nest spacing in salt marsh colonies was much closer than it was on barrier beaches. In mixed-species colonies with Black Skimmers (Rynchops niger), distances between tern and skimmer nests were also much smaller in marsh colonies than they were on beaches. The limited amount of wrack (windrows of dead, matted vegetation) preferred by marsh-nesting terns probably explains these spacing differences. Several lines of evidence suggest that terns prefer beaches to marshes for nesting, however, the uncertainty of predation and flooding may often obscure any intrinsic differences in habitat quality. Long-term field studies are essential for testing hypotheses related to differential fitness of individuals among habitats.

Nesting success of birds in different silvicultural treatments in southeastern U.S. Pine Forests

USGS Publications Warehouse

Barber, D.R.; Martin, T.E.; Melchiors, M.A.; Thill, R.E.; Wigley, T.B.

2001-01-01

We examined nesting success and levels of nest predation and cowbird parasitism among five different silvicultural treatments: regenerating (3-6 years old), mid-rotation (12-15 years old), and thinned (17-23 years old) pine plantations, single-tree selection, and late-rotation pine-hardwood stands in the Ouachita Mountains of Arkansas from 1993 to 1995. We monitored 1674 nests. Differences in daily mortality and daily predation rate among two or more treatments were found for 4 and 3 of 12 species, respectively. These differences were lost following Bonferroni adjustments, but thinned stands had higher levels of predation than single-tree selection stands when predation levels were averaged across species. Daily predation rates were positively correlated with the relative abundance of birds, suggesting that nest predators respond to prey availability (i.e., nests) in a density-dependent manner. The relative abundance of cowbirds differed among treatments, with the highest densities in regenerating, thinned, and single-tree selection stands. Field Sparrows (Spizella pusilla) and Yellow-breasted Chats (Icteria virens) experienced higher levels of parasitism in thinned than regenerating plantations, whereas White-eyed Vireos (Vireo griseus) experienced higher parasitism in regenerating plantations than in mid-rotation or thinned plantations. Several shrub-nesting and 1 ground-nesting species had lower nesting success in thinned and regenerating plantations than has been reported in previously published studies. Thus, some seral stages of even-aged management may provide low-quality nesting habitat for several early-successional bird species. In contrast, many species nesting in mid-rotation and single-tree selection stands had nesting success similar to or greater than that found in previous studies, suggesting that some silvicultural treatments, when embedded in a largely forested landscape, may provide suitable habitat for forest land birds without affecting their reproductive success.

Risk Factors of Clinical and Immunological Failure in South Indian Cohort on Generic Antiretroviral Therapy.

PubMed

Sadashiv, Mucheli Shravan; Rupali, Priscilla; Manesh, Abi; Kannangai, Rajesh; Abraham, Ooriapadickal Cherian; Pulimood, Susanne A; Karthik, Rajiv; Rajkumar, S; Thomas, Kurien

2017-12-01

Since the time of NACO Antiretroviral (ART) roll-out, generic ART has been the mainstay of therapy. There are many studies documenting the efficacy of generic ART but with the passage of time, failure of therapy is on the rise. As institution of second line ART has significant financial implications both for a program and for an individual it is imperative that we determine factors which contribute towards treatment failure in a cohort of patients on generic antiretroviral therapy. This was a nested matched case-control study assessing the predictors for treatment failure in our cohort who had been on Anti-retroviral therapy for at least a year. We identified 42 patients (Cases) with documented treatment failure out of our cohort of 823 patients and 42 sex, age and duration of therapy-matched controls. Using a structured proforma, we collected information from the out-patient and in-patient charts of the Infectious Diseases clinic Cohort in CMC, Vellore. A set of predetermined variables were studied as potential risk factors for treatment failure on ART. Univariate analysis showed significant association with 1) Self-reported nonadherence<95% [OR 12.81 (95%CI 1.54-281.45)]. 2) Treatment interruptions in adherent cases (OR 9.56 (95% CI 1.11-213.35)]. 3) Past inappropriate therapies [OR 9.65 (95% CI 1.12-215.94)]. 4) Diarrhoea [OR 16.40 (95% CI 2.02-3.55.960]. 5) GI opportunistic infections (OR 11.06 (95% CI 1.31 -244.27)] and 6) Drug Toxicity [OR 3.69 (95% CI 1.15-12.35).In multiple logistic regression analysis, we found independent risk factors of treatment failure to be: Self-reported non-adherence (<95%) with OR 15.46(95%CI 1.55 - 154.08), drug toxicity - OR 4.13(95%CI 1.095 - 15.534) and history of diarrhoea - OR 23.446(95%CI 2.572 - 213.70). This study reveals that besides adherence to therapy, presence of diarrhoea and occurrence of drug toxicity are significant risk factors associated with failure of anti-retroviral therapy. There is a need for further prospective studies to assess their role in development of treatment failure on ART and thus help development of targeted interventions.