509,737 research outputs found
The application of predictive modelling for determining bio-environmental factors affecting the distribution of blackflies (Diptera: Simuliidae) in the Gilgel Gibe watershed in Southwest Ethiopia
Blackflies are important macroinvertebrate groups from a public health as well as ecological point of view. Determining the biological and environmental factors favouring or inhibiting the existence of blackflies could facilitate biomonitoring of rivers as well as control of disease vectors. The combined use of different predictive modelling techniques is known to improve identification of presence/absence and abundance of taxa in a given habitat. This approach enables better identification of the suitable habitat conditions or environmental constraints of a given taxon. Simuliidae larvae are important biological indicators as they are abundant in tropical aquatic ecosystems. Some of the blackfly groups are also important disease vectors in poor tropical countries. Our investigations aim to establish a combination of models able to identify the environmental factors and macroinvertebrate organisms that are favourable or inhibiting blackfly larvae existence in aquatic ecosystems. The models developed using macroinvertebrate predictors showed better performance than those based on environmental predictors. The identified environmental and macroinvertebrate parameters can be used to determine the distribution of blackflies, which in turn can help control river blindness in endemic tropical places. Through a combination of modelling techniques, a reliable method has been developed that explains environmental and biological relationships with the target organism, and, thus, can serve as a decision support tool for ecological management strategies
Sociological and Human Developmental Explanations of Crime: Conflict or Consensus
This paper examines multidisciplinary correlates of delinquency in an attempt to integrate sociological and environmental theories of crime with human developmental and biological explanations of crime. Structural equation models are applied to assess links among biological, psychological, and environmental variables collected prospectively from birth through age 17 on a sample of 800 black children at high risk for learning and behavioral disorders. Results show that for both males and females, aggression and disciplinary problems in school during adolescence are the strongest predictors of repeat offense behavior. Whereas school achievement and family income and stability are also significant predictors of delinquency for males, early physical development is the next strongest predictor for females. Results indicate that some effects on delinquency also vary during different ages. It is suggested that behavioral and learning disorders have both sociological and developmental correlates and that adequate educational resources are necessary to ensure channels of legitimate opportunities for high-risk youths
Sustainable Investing and the Cross-Section of Maximum Drawdown
We use supervised learning to identify factors that predict the cross-section
of maximum drawdown for stocks in the US equity market. Our data run from
January 1980 to June 2018 and our analysis includes ordinary least squares,
penalized linear regressions, tree-based models, and neural networks. We find
that the most important predictors tended to be consistent across models, and
that non-linear models had better predictive power than linear models.
Predictive power was higher in calm periods than stressed periods, and
environmental, social, and governance indicators augmented predictive power for
non-linear models
Place effects on environmental views
How people respond to questions involving the environment depends partly on individual characteristics. Characteristics such as age, gender, education, and ideology constitute the well-studied social bases of environmental concern, which have been explained in terms of cohort effects or of cognitive and cultural factors related to social position. It seems likely that people\u27s environmental views depend not only on personal characteristics but also on their social and physical environments. This hypothesis has been more difficult to test, however. Using data from surveys in 19 rural U.S. counties, we apply mixed-effects modeling to investigate simple place effects with respect to locally focused environmental views. We find evidence for two kinds of place effects. Net of individual characteristics, specific place characteristics have the expected effect on related environmental views. Local changes are related to attitudes about regulation and growth. For example, respondents more often perceive rapid development as a problem, and favor environmental rules that restrict development, in rural counties with growing populations. Moreover, they favor conserving resources for the future rather than using them now to create jobs in counties that have low unemployment. After we controlled for county growth, unemployment and jobs in resource based industries, and individual social-position and ideological factors, there remains significant place-to-place variation in mean levels of environmental concern. Even with both kinds of place effects in the models, the individual level predictors of environmental concern follow patterns expected from previous research. Concern increases with education among Democrats, whereas among Republicans, the relationship is attenuated or reversed. The interaction marks reframing of environmental questions as political wedge issues, through nominally scientific counterarguments aimed at educated, ideologically receptive audiences. © 2010, by the Rural Sociological Society
Why it is so hard to predict our partner's product preferences : the effect of target familiarity on prediction accuracy.
Many buying decisions require predictions of another person's product attitudes. Yet, consumers are often inaccurate predictors, even for familiar others. We provide strong evidence that target familiarity can even hurt accuracy in the presence of attitude feedback. Although overprojection and lack of product-specific attitude information have been identified as possible reasons for prediction in accuracy, our results suggest a retrieval explanation. When presented with product-specific attitude feedback, predictors adapted their level of projection and encoded the attitude information, but they did not use this information. Instead, they retrieved less diagnostic, pre-stored information about the familiar target stop redict their product attitudes.(pro-environmental) attitudes; Behavior; Self-perception theory; Ecological consumer; Ego depletion; Social marketing;
DETERMINANTS OF PARTICIPATION BEHAVIOR OF LIMITED RESOURCE FARMERS IN CONSERVATION RESERVE PROGRAM IN ALABAMA
This study investigated factors that affect participation behavior of limited resource farmers (LRF) in Conservation Reserve Program (CRP) in Alabama. A binary logit model was employed to analyze data obtained from 611 respondents. Results indicated that males, part-time occupation, total acres, participation in non-conservation related programs, direct method of receiving CRP information, and respondents' interest in receiving CRP information, were strong predictors of participation in the CRP. Key words: Limited resource, CRP, minorities, participation behaviorLimited resource, CRP, minorities, participation behavior, Environmental Economics and Policy,
Decomposing Cross-Country Gaps in Obesity and Overweight: Does the Social Environment Matter?
[cat] Una qüestió clau sobre la producció de salut relativament poc explorada es refereix a la influència dels factors socioeconòmics i mediambientals sobre el pes i l’obesitat. Aquesta problemàtica adquireix particular rellevància quan es comparen dos països Mediterranis com Itàlia i Espanya. És interessant adonar-se que l’obesitat a Espanya és 5 punts percentual més elevada al 2003 mentre que a l’any 1990 era aproximadament la mateixa en ambdós països. Aquesta article presenta una descomposició no lineal dels gaps o diferencials en taxes de sobrepès (índex de massa corporal – IMC- entre 25 i 29.9 9 kg/m2), obesitat classe 1 (IMC≥30 kg/m2) i classe 2 (IMC≥35 kg/m2) entre Espanya i Itàlia per gènere i grups d’edat. En explicar aquests gaps entre països aïllem les influències dels estils de vida, els efectes socioeconòmics i els mediambientals. Els nostres resultats indiquen que quan no es controla pels efectes mediambientals (efectes de grup o ‘peer effects’) els hàbits alimentaris i el nivell educatiu són els principals predictors del gaps totals entre països (36-52%), si bé aquests dos factors exerceixen un impacte diferenciat segons gènere i edat. Un tant paradoxalment, quan controlem pels efectes de grup aquests predictors perden la seva capacitat explicativa i els efectes de grup passen a explicar entre el 46-76% dels gaps en sobrepès i obesitat i mostren un patró creixent amb l’edat.[eng] A key question underpinning health production, and one that remains relatively unexplored, is the influence of socio-economic and environmental factors on weight gain and obesity. Such issues acquire particular relevance when data from two Mediterranean countries (Italy and Spain) are compared. Interestingly, the obesity rate was 5 percentage points higher in Spain in 2003 while in 1990 it had been roughly the same in the two countries. This paper reports a non-linear decomposition of gaps in overweight (body mass index – BMI - between 25 and 29.9 kg/m2), class 1 (BMI≥30 kg/m2) and class 2 obesity (BMI≥35 kg/m2) between Spain and Italy by both gender and age. We isolate the influence of lifestyles, socioeconomic and environmental effects in explaining cross-country gaps in the prevalence of obesity. Our findings suggest that when the social environment (peer effects) is not controlled for, eating habits and education are the main predictors of total cross-country gaps (36-52%), albeit that these two factors have a different impact depending on gender and age. Somewhat paradoxically, however, when we controlled for the social environment, these previous predictors lost their explanatory power and peer effects were found to explain between 46 and 76% of gaps and to exhibit an increasing age pattern
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Linking Aboveground Traits to Root Traits and Local Environment: Implications of the Plant Economics Spectrum.
The plant economics spectrum proposes that ecological traits are functionally coordinated and adapt along environmental gradients. However, empirical evidence is mixed about whether aboveground and root traits are consistently linked and which environmental factors drive functional responses. Here we measure the strength of relationships between aboveground and root traits, and examine whether community-weighted mean trait values are adapted along gradients of light and soil fertility, based on the seedling censuses of 57 species in a subtropical forest. We found that aboveground traits were good predictors of root traits; specific leaf area, dry matter, nitrogen and phosphorus content were strongly correlated with root tissue density and specific root length. Traits showed patterns of adaptation along the gradients of soil fertility and light; species with fast resource-acquisitive strategies were more strongly associated with high soil phosphorus, potassium, openness, and with low nitrogen, organic matter conditions. This demonstrates the potential to estimate belowground traits from known aboveground traits in seedling communities, and suggests that soil fertility is one of the main factors driving functional responses. Our results extend our understanding of how ecological strategies shape potential responses of plant communities to environmental change
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