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This paper introduces a new statistical methodology for estimating Duncan dissimilarity indexes of occupational segregation by sex in administrative areas and time periods. Given that direct estimators of the proportion of men (or women) in the group of employed people for each occupational sector are not accurate enough in the considered estimation domains, we fit to them a three-fold Fay–Herriot model with random effects at three hierarchical levels. Based on the fitted area-level model, empirical best predictors of the cited proportions and Duncan segregation indexes are derived. A parametric bootstrap algorithm is implemented to estimate the mean squared error. Some simulation studies are included to show how the proposed predictors have a good balance between bias and mean squared error. Data from the Spanish Labour Force Survey are used to illustrate the performance of the new statistical methodology and to give some light about the current state of sex occupational segregation by province in Spain. Research claims that there is a sex gap that persists despite advances in the inclusion of women in the labour market in recent years and that is related to the unequal sharing of family responsabilities and the stigmas still present in modern societies. [ABSTRACT FROM AUTHOR]

This paper introduces a three-fold Fay–Herriot model with random effects at three hierarchical levels. Small area best linear unbiased predictors of linear indicators are derived from the new model and the corresponding mean squared errors are approximated and estimated analytically and by parametric bootstrap. The problem of influence analysis and model diagnostics is addressed by introducing measures adapted to small area estimation. Simulation experiments empirically investigate the behavior of the predictors and mean squared error estimators. The new statistical methodology is applied to Spanish living conditions survey of 2004–2008. The target is the estimation of proportions of women and men under the poverty line by province and year. [ABSTRACT FROM AUTHOR]

Evolutionary theory suggests two alternative ways in which competitive interactions could vary in response to different levels of food abundance. Competition theory suggests that aggression should be greater when resource availability is lower, as an evolutionary stable strategy to access food. Alternatively, energy allocated to aggressive interactions should increase when the available spectrum of food resources is wider, in turn allowing a greater selection. We tested these hypotheses on a group-living herbivore, the Apennine chamois, Rupicapra pyrenaica ornata. We compared social, aggressive and vigilance behaviour and relevant endocrine correlates across three areas: two 'poorer' areas, i.e. with a lower availability of nutritious pasture, and a 'richer' one. In the richer area, we observed: (1) the largest group size/greatest proportion of young individuals in groups; (2) the lowest rate/intensity of aggression between individuals, at feeding; (3) the lowest duration of vigilance and proportion of 'costly' vigilance, i.e. postures performed without chewing food; and (4) the lowest levels of testosterone and cortisol metabolites, suggesting a lower endogenous aggressiveness/stress response. Our findings agree with the competition theory, suggesting a role of food depletion in increasing aggression between foraging individuals, as an evolutionary stable strategy, with cascading effects on group phenology, vigilance and stress. [ABSTRACT FROM AUTHOR]

Large-scale remote sensing-based inventories of forest cover are usually carried out by combining unsupervised classifications of satellite pixels into forest/non forest classes (map data) with subsequent time-consuming visual on-screen imagery classification of a probabilistic sample of pixels taken as the ground truth (reference data). In this paper the estimation of forest change from a sample of reference data is approached by: (i) exploiting map data to construct strata in which changes are occurred, and then adopting the stratified sampling joined with the HT estimator with most sampling effort devoted to strata where changes are occurred irrespective of their size, as suggested in most remote sensing literature regarding land change assessments; (ii) adopting a spatial scheme ensuring spatially balanced samples, as suggested in most recent statistical literature regarding spatial surveys, and exploiting the map data in the difference estimator. The results of a comparison performed on an artificial population of reference data generated from a real population of map data recorded in Sardinia (Italy) discourage the use of unbalanced stratified samples that achieve the worst precision. The best results are obtained by means of spatially balanced samples or stratification with nearly proportional allocation to strata. [ABSTRACT FROM AUTHOR]

The Fay-Herriot area-level model for correlated response data is augmented with a between-groups-of-domains effect. Correlated-response parameters of small-area estimates no longer need the assumption of spatial contiguity. A simulation shows that area-level correlated-response observations increase the efficiency of the estimates, but do not reduce the biases. [ABSTRACT FROM AUTHOR]

In polygynous mating systems, reproductive skew depends on the ability of males to monopolize females, which in turn may promote the development of contrasting traits in the two sexes. Although dominant individuals normally enjoy a higher reproductive success (RS) than subordinates, the use of genetic markers has shown that behavioural observations of male mating success may not provide reliable clues of RS. We report the preliminary results of the first DNA-based paternity analysis on the Northern chamois ( Rupicapra rupicapra), a scarcely dimorphic mountain ungulate described as highly polygynous, in relation to mating tactic and age. Because of sampling difficulties, the success in parentage assignment was low, and the interpretation of results requires caution. Territorial males had a greater RS than nonterritorial ones but they were unable to monopolize mating events. Age had a weak effect on paternity outcome but only males ≥ 6 years showed siring success. Although future studies are needed to assess the opportunity for sexual selection in male chamois, the concurrence of limited sexual size dimorphism, compensatory growth, unbiased sex-specific survival, RS of alternative mating tactics and, possibly, long breeding tenure, may hint at the adoption of a conservative mating strategy in this species. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to compare some spatial strategies for sampling polygons onto a grid partitioning a study area. Most of the schemes considered in the paper are aimed at avoiding the selection of neighboring polygons. When one or more auxiliary variables are similar or well correlated with the values of the survey variable, the auxiliary information is adopted at estimation level by means of the difference or the regression estimators, or at design level, using the values of auxiliary variables to determine the inclusion probabilities. Applications to large-scale forest inventories, land use estimation, and forest cover estimation are discussed. A simulation study is performed to compare the adopted strategies in terms of bias (if present), accuracy, and accuracy estimation. The simulation is designed to mimic forest inventories and forest cover estimation, starting from some real situations. An application to plan future surveys for land use estimation in Italy is reported. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Intrinsic and environmental stressors, such as age and seasonality, may influence social behavior and endocrine levels in gregarious foragers, but little is known about how season and age affect both behavioral and physiological responses. We evaluated seasonal/age variation of aggression and vigilance, and seasonal/age variation of endocrine levels (fecal cortisol and testosterone metabolites), in a gregarious herbivore, the Apennine chamois Rupicapra pyrenaica ornata. We examined a period of decreasing resource abundance and maternal care from July to October, a key period for nursing, weaning, and early growth of offspring. Aggression rate, vigilance, and cortisol levels decreased throughout July-October, while aggression intensity showed the reverse. Aggression intensity peaked when chamois were on the most nutritious vegetation patches. Dominance increased with age, and prime-aged females (4-8 years old) showed higher cortisol and testosterone levels and were involved in aggressive interactions more often than subadult or older females. Our findings suggest that, in early summer, when nursing effort is the greatest, selection of nutritious food patches leads to frequent encounters between female chamois, enhancing aggression rate, vigilance, and endogenous stress response. The progressive decrease in food abundance throughout July-October triggers competition for scarce resources and increased intensity of aggression. Most likely, the energetic demands of lactation and offspring guarding were key determinants of behavioral and physiological stress of female chamois. Our results suggest a multi-factorial compromise between reproductive state and stress levels, in a group-living species.Significance statement: The cost of motherhood: in female chamois, aggression, vigilance, and stress peak during lactation, despite abundant food resources. In females, aggression and dominance increase with age. A multi-factorial compromise between reproductive stage and stress may be necessary in a group-living animal. We suggest that motherhood is a stressful event for female chamois. [ABSTRACT FROM AUTHOR]