"MEN I MESS WITH DON'T HAVE ANYTHING TO DO WITH AIDS":

Pivotal in HIV/STD intervention and prevention is how individuals perceive risk. This article discusses how ethnotheory can be used to understand the underpinnings of risk perception from the subject's perspective. Ethnotheory's theoretical and methodological character extends present models used to explain sex-related HIV behaviors and provides insights into risk perception useful for the development of effective intervention strategies. Four detailed ethnographic excerpts from low-income African American and Mexican American men and women illustrate how people form perceptions of risk and how information gained through ethnotheory is useful in the design of culturally relevant interventions.     

The choice of migration destination: Dominican and Cuban immigrants to the mainland United States and Puerto Rico

"Puerto Rico provides an alternative destination for immigrants from the Spanish-speaking Caribbean because the culture is similar to that in the source country. In this study, we use the 1980 [U.S.] Census of Population to examine the importance of relative earnings and culture in the choice of destination. The main finding is the similar pattern of choice of location for immigrants from the Dominican Republic and Cuba. The more educated and more professional immigrants are found in either Puerto Rico or outside the enclave on the [U.S.] mainland. Within this group, those with less time remaining in the labor market and lower English ability are found in Puerto Rico. We find that not all differences in location decision are attributable to differences in reward structure by location."     

Children's computer usage: are they at risk of developing repetitive strain injury?

The purpose of this study was to determine the average time school children spend on computers and electronic games, the positions they assume, and any associated discomfort related to their use. A twenty three-point questionnaire was distributed to 476 children in first to eighth grade from three parochial schools in one of the New York City boroughs. The findings of this study suggest that children use the computer and electronic games differently than adults and that more boys than girls engage in electronic game playing. Results clearly indicated that children are experiencing discomfort from the use of computers or electronic games, and that the discomfort is largely concentrated in the neck region. Occupational therapy could be instrumental in terms of educating the children, their parents/guardians, and their teachers on proper body mechanics, applications of ergonomically suited workstations, and the use of rest/stretch breaks while engaged in computing and electronic game playing.     

A Methodology for Risk Analysis Based on Hybrid Bayesian Networks: Application to the Regasification System of Liquefied Natural Gas Onboard a Floating Storage and Regasification Unit

This article presents an iterative six‐step risk analysis methodology based on hybrid Bayesian networks (BNs). In typical risk analysis, systems are usually modeled as discrete and Boolean variables with constant failure rates via fault trees. Nevertheless, in many cases, it is not possible to perform an efficient analysis using only discrete and Boolean variables. The approach put forward by the proposed methodology makes use of BNs and incorporates recent developments that facilitate the use of continuous variables whose values may have any probability distributions. Thus, this approach makes the methodology particularly useful in cases where the available data for quantification of hazardous events probabilities are scarce or nonexistent, there is dependence among events, or when nonbinary events are involved. The methodology is applied to the risk analysis of a regasification system of liquefied natural gas (LNG) on board an FSRU (floating, storage, and regasification unit). LNG is becoming an important energy source option and the world's capacity to produce LNG is surging. Large reserves of natural gas exist worldwide, particularly in areas where the resources exceed the demand. Thus, this natural gas is liquefied for shipping and the storage and regasification process usually occurs at onshore plants. However, a new option for LNG storage and regasification has been proposed: the FSRU. As very few FSRUs have been put into operation, relevant failure data on FSRU systems are scarce. The results show the usefulness of the proposed methodology for cases where the risk analysis must be performed under considerable uncertainty.     

Firm-level social returns to education

Do workers benefit from the education of their co-workers? We examine this question first by introducing a model of learning, which argues that educated workers may transfer part of their general skills to uneducated workers, and then by examining detailed matched employer–employee panel data from Portugal. We find evidence of large firm-level social returns (between 14% and 23%), much larger than standard estimates of private returns, and of significant returns accruing to less educated workers but not to their more educated colleagues.     

Laplace approximation and natural gradient for Gaussian process regression with heteroscedastic student-t model

Statistics and Computing - We propose the Laplace method to derive approximate inference for Gaussian process (GP) regression in the location and scale parameters of the student- $$ {t}$$...     

The inverse weighted Lindley distribution: Properties,estimation and an application on a failure time data

In this paper a new distribution is proposed. This new model provides more flexibility to modeling data with upside-down bathtub hazard rate function. A significant account of mathematical properties of the new distribution is presented. The maximum likelihood estimators for the parameters in the presence of complete and censored data are presented. Two corrective approaches are considered to derive modified estimators that are bias-free to second order. A numerical simulation is carried out to examine the efficiency of the bias correction. Finally, an application using a real data set is presented in order to illustrate our proposed distribution.     

The evolutionary diversity of urban forests depends on their land-use history

Urban Ecosystems - Urbanization leads to strong modifications of landscape structure and ecosystem functioning, and urban areas are spreading rapidly. The aim of this study was to investigate how...     

The economic effects of common agricultural policy on Mediterranean montado/dehesa ecosystem

The decoupling of CAP payments leads production decisions and resources allocation to be more dependent on market prices and competitive advantages. The objective of this paper is to assess the effects of CAP trends on the montado/dehesa traditional ecosystem of Mediterranean regions in terms of farm income, land, labour and capital. A positive mathematical supply model disaggregated by the montado agro-forestry production systems of the Alentejo region in southern Portugal is developed. The results show that decoupling payments of CAP have negative economic effects on agricultural activities and resource use. Agricultural income increases with single farm payments but the foreseen increases in prices do not compensate the loss of the Agenda 2000 area payments in terms of competitiveness. These results reinforce the need to promote alternative agricultural and non-agricultural activities and policies in Mediterranean rural European areas and regions.     

Multivariate models for correlated count data

In this study, we deal with the problem of overdispersion beyond extra zeros for a collection of counts that can be correlated. Poisson, negative binomial, zero-inflated Poisson and zero-inflated negative binomial distributions have been considered. First, we propose a multivariate count model in which all counts follow the same distribution and are correlated. Then we extend this model in a sense that correlated counts may follow different distributions. To accommodate correlation among counts, we have considered correlated random effects for each individual in the mean structure, thus inducing dependency among common observations to an individual. The method is applied to real data to investigate variation in food resources use in a species of marsupial in a locality of the Brazilian Cerrado biome.