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High Variance (high + variance)

Distribution by Scientific Domains

Medical Sciences	42%
Life Sciences	28%
Earth and Environmental Science	28%

Selected Abstracts

Job stress and depressive symptoms among Japanese fire fighters

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 6 2007
Yasuaki Saijo MD
Abstract Background Associations between job stresses, as assessed by theoretical job stress model and depressive symptoms among fire fighters have not been fully investigated. The purpose of this study is to clarify the factors of job stress that influence the depressive symptoms in Japanese fire fighters. Methods The subjects involved 1,672 fire fighters from a local government. The questionnaire comprised age, gender, job type, job class, martial status, smoking, and drinking habit, the Center for Epidemiologic Studies Depression Scale (CES-D), and The National Institute for Occupational Safety and Health (NIOSH) generic job questionnaire. Results A group showing depressive symptoms (CES-D,,,16) included 373 subjects (22.3%). In a multivariate logistic regression analysis, high variance in workload, high intergroup conflict, high role conflict, and low self-esteem had significantly higher odds ratio for depressive symptoms. Conclusions High variance in workload, high intergroup conflict, high role conflict, and low self-esteem were significantly related to depressive symptoms among Japanese fire fighters. Further prospective studies are needed to clarify the influence of these stress factors on other health outcomes, and to elucidate whether alleviation of these stress factors improve the mental health among fire fighters. Am. J. Ind. Med. 50:470,480, 2007. © 2007 Wiley-Liss, Inc. [source]

Relationship of Specific Electrogram Characteristics During Sinus Rhythm and Ventricular Pacing Determined by Adaptive Template Matching to the Location of Functional Reentrant Circuits that Cause Ventricular Tachycardia in the Infarcted Canine Heart

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2000
EDWARD J. CIACCIO Ph.D.
Localization of Reentrant Circuits. Introduction: It would be advantageous, for ablation therapy, to localize reentrant circuits causing ventricular tachycardia by quantifying electrograms obtained during sinus rhythm (SR) or ventricular pacing (VP). In this study, adaptive template matching (ATM) was used to localize reentrant circuits by measuring dynamic electrogram shape using SR and VP data. Methods and Results: Four days after coronary occlusion, reentrant ventricular tachycardia was induced in the epicardial border zone of canine hearts by programmed electrical stimulation. Activation maps of circuits were constructed using electrograms recorded from a multichannel array to ascertain block line location. Electrogram recordings obtained during SR/AP then were used for ATM analysis. A template electrogram was matched with electrograms on subsequent cycles by weighting amplitude, vertical shift, duration, and phase lag for optimal overlap. Sites of largest cycle-to-cycle variance in the optimal ATM weights were found to be adjacent to block lines bounding the central isthmus during reentry (mean 61.1% during SR; 63.9% during VP). The distance between the mean center of mass of the ten highest ATM variance peaks and the narrowest isthmus width was determined. For all VP data, the center of mass resided in the isthmus region ocurring during reentry. Conclusion: ATM high variance measured from SR/AP data localizes functional block lines forming during reentry. The center of mass of the high variance peaks localizes the narrowest width of the isthmus. Therefore, ATM methodology may guide ablation catheter position without resorting to reentry induction. [source]

Amphibolites with staurolite and other aluminous minerals: calculated mineral equilibria in NCFMASH

JOURNAL OF METAMORPHIC GEOLOGY, Issue 1 2000
Arnold
Amphibolite facies mafic rocks that consist mainly of hornblende, plagioclase and quartz may also contain combinations of chlorite, garnet, epidote, and, more unusually, staurolite, kyanite, sillimanite, cordierite and orthoamphiboles. Such assemblages can provide tighter constraints on the pressure and temperature evolution of metamorphic terranes than is usually possible from metabasites. Because of the high variance of most of the assemblages, the phase relationships in amphibolites depend on rock composition, in addition to pressure, temperature and fluid composition. The mineral equilibria in the Na2O,CaO,FeO,MgO,Al2O3,SiO2,H2O (NCFMASH) model system demonstrate that aluminium content is critical in controlling the occurrence of assemblages involving hornblende with aluminous minerals such as sillimanite, kyanite, staurolite and cordierite. Except in aluminous compositions, these assemblages are restricted to higher pressures. The iron to magnesium ratio (XFe), and to a lesser extent, sodium to calcium ratio, have important roles in determining which (if any) of the aluminous minerals occur under particular pressure,temperature conditions. Where aluminous minerals occur in amphibolites, the P,T,X dependence of their phase relationships is remarkably similar to that in metapelitic rocks. The mineral assemblages of Fe-rich amphibolites are typically dominated by garnet- and staurolite-bearing assemblages, whereas their more Mg-rich counterparts contain chlorite and cordierite. Assemblages involving staurolite,hornblende can occur over a wide range of pressures (4,10 kbar) at temperatures of 560,650 °C; however, except in the more aluminous, iron-rich compositions, they occupy a narrow pressure,temperature window. Thus, although their occurrence in ,typical' amphibolites may be indicative of relatively high pressure metamorphism, in more aluminous compositions their interpretation is less straightforward. [source]

Genetic effective size, Ne, tracks density in a small freshwater cyprinid, Pecos bluntnose shiner (Notropis simus pecosensis)

MOLECULAR ECOLOGY, Issue 14 2010
MEGAN J. OSBORNE
Abstract Genetic monitoring tracks changes in measures of diversity including allelic richness, heterozygosity and genetic effective size over time, and has emerged as an important tool for understanding evolutionary consequences of population management. One proposed application of genetic monitoring has been to estimate abundance and its trajectory through time. Here, genetic monitoring was conducted across five consecutive year for the Pecos bluntnose shiner, a federally threatened minnow. Temporal changes in allele frequencies at seven microsatellite DNA loci were used to estimate variance effective size (NeV) across adjacent years in the time series. Likewise, effective size was computed using the linkage disequilibrium method (NeD) for each sample. Estimates of Ne were then compared to estimates of adult fish density obtained from traditional demographic monitoring. For Pecos bluntnose shiner, density (catch-per-unit-effort), NeV and NeD were positively associated across this time series. Results for Pecos bluntnose shiner were compared to a related and ecologically similar species, the Rio Grande silvery minnow. In this species, density and NeV were negatively associated, which suggested decoupling of abundance and effective size trajectories. Conversely, density and NeD were positively associated. For Rio Grande silvery minnow, discrepancies among estimates of Ne and their relationships with adult fish density could be related to effects of high variance in reproductive success in the wild and/or effects of supplementation of the wild population with captive-bred and reared fish. The efficacy of Ne as a predictor of density and abundance may depend on intrinsic population dynamics of the species and how these dynamics are influenced by the landscape features, management protocols and other factors. [source]

Job stress and depressive symptoms among Japanese fire fighters

Milk composition varies in relation to the presence and abundance of Balantidium coli in the mother in captive rhesus macaques (Macaca mulatta)

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 6 2007
Katherine Hinde
Abstract Primate infants require extensive maternal investment, and lactation is the most expensive aspect of this investment. However, the relationship between maternal condition and milk composition has been largely uninvestigated in primates. To better understand this relationship, I collected mid-lactation milk samples from 46 captive multiparous rhesus macaques (Macaca mulatta) at the Caribbean Primate Research Center, Sabana Seca Field Station, Puerto Rico. The maternal variables assessed were age, weight, weight for crown,rump length (CRL), and presence of parasites. Additionally the analysis included infant age, weight, and sex. Protein concentration in milk showed little interindividual variation, whereas fat had a high variance. Mothers without the lower intestinal parasite Balantidium coli had a significantly higher fat concentration in milk than mothers with B. coli, but other parasite species (Trichuris trichiura and Strongyloides fulleborni) were not associated with milk fat concentration. Females with younger infants had a higher fat concentration in their milk than mothers with older infants; however, the association between B. coli and milk fat remained significant after controlling for infant age. These results, obtained from a well fed captive population, indicate that even small differences among mothers are associated with milk composition. Am. J. Primatol. 69:625,634, 2007. © 2007 Wiley Liss, Inc. [source]

The consequences of differential family survival rates and equalizing maternal contributions on the effective population size (Ne) of cultured silver-lipped pearl oysters, Pinctada maxima

AQUACULTURE RESEARCH, Issue 8 2010
Curtis E Lind
Abstract The effective population size (Ne) is a critical gauge of how efficiently an aquaculture operation is capturing or maintaining genetic diversity and can govern the long-term success of genetic selection programmes. In communally reared pearl oysters (Pinctada maxima), high variance in family sizes is a significant contributor towards low Ne and its severity may be compounded by differential survival rates of individual families. To determine the effect of variable survival on Ne in cultured P. maxima, families from two commercial populations were analysed using DNA parentage analyses to monitor survival and changes in relative contributions. Significant shifts in relative contributions were observed between 72 days and 18 months of age in both commercial cohorts (P<0.001). Survival rates were found to be highly variable among families (ranging from 2.5% to 49.5%) when reared in a common environment. Additionally, we investigated whether equalizing maternal family sizes before communal rearing will reduce family size variance, and increase Ne, compared with stocking at naturally produced proportions. Family equalization (E) significantly improved Ne (P=0.013) compared with rearing at natural (N) proportions (E: Ne=7.18±0.34; N: Ne=5.60±0.15); however, this practice may unintentionally magnify negative influences of poor performing families if survival is correlated with other commercially important traits. It is concluded that highly variable family survival will affect Ne in communally reared P. maxima, and the practice of equalizing family sizes in order to maximize Ne may only become consistently beneficial once further progress is made towards understanding, and then reducing variation in family survival rates. [source]