Predictive neural coding of reward preference involves dissociable responses in human ventral midbrain and ventral striatum.

Food preferences are acquired through experience and can exert strong influence on choice behavior. In order to choose which food to consume, it is necessary to maintain a predictive representation of the subjective value of the associated food stimulus. Here, we explore the neural mechanisms by which such predictive representations are learned through classical conditioning. Human subjects were scanned using fMRI while learning associations between arbitrary visual stimuli and subsequent delivery of one of five different food flavors. Using a temporal difference algorithm to model learning, we found predictive responses in the ventral midbrain and a part of ventral striatum (ventral putamen) that were related directly to subjects' actual behavioral preferences. These brain structures demonstrated divergent response profiles, with the ventral midbrain showing a linear response profile with preference, and the ventral striatum a bivalent response. These results provide insight into the neural mechanisms underlying human preference behavior.

Behavior of Montandoniola confusa Streito & Matocq (Hemiptera: Anthocoridae) preying upon gall-forming thrips Gynaikothrips ficorum Marchal (Thysanoptera: Phlaeothripidae)

The gall-forming thrips Gynaikothrips ficorum Marchal (Thysanoptera: Phlaeothripidae) is recorded in all regions where its host plant, Ficus microcarpa (Marchal) (Moraceae), has been cultivated as an urban and interior landscape plant species, including potted plants and bonsai. Similarly, the thrips predator Montandoniola confusa Streito & Matocq (Hemiptera: Anthocoridae) has generally followed the prey distribution. The gall induced by thrips degrades the plant foliage, and the thrips themselves can be annoying for people both outdoors and indoors. The galls, however, create a microcosm with all developmental stages of the thrips and its predator. In this study we present the first records of M. confusa in South America, document the species' widespread concomitant occurrence across Brazil, and report our studies of three aspects of M. confusa predation upon the eggs, larvae/prepupae, and adults of G. ficorum thrips: (i) functional response of the predator adult female as a function of different densities of thrips eggs, larvae/prepupae and adults separately: (ii) predation on eggs by adult M. confusa with adult thrips present in the gall; and (iii) adult M. confusa prey preferences when all thrips stages occurred simultaneously in the gall. For all three thrips life stages tested, the predator exhibited a type II functional response. Despite the availability of different life stages in the gall, M. confusa adults are capable of preying upon all life stages of G. ficorum, predation was preferentially on thrips eggs, with an estimated similar to 10-fold greater predation on eggs compared to larvae/prepupae and adult thrips. Egg predation was unaffected by the presence of defensive adult thrips in the gall under low densities (<30 eggs/gall) but when egg densities were greater than 30 eggs/gall, it was reduced when adult thrips were present. However, the relative number of thrips adults per gall did not statistically change the outcome. (C) 2013 Elsevier Inc. All rights reserved.

Demand for ecolabeled seafood in the Japanese market: A conjoint analysis of the impact of information and interaction with other labels

The use of seafood ecolabels is expanding in the world marketplace, but so are labels indicating other product attributes, such as country of origin and wild vs. farmed. The interactive effects of these labels and attributes in evaluating consumers' preferences for ecolabeled seafood are relatively unexplored. In this paper we investigate (1) the direct and interactive effects of seafood ecolabels with other common fish labels, and (2) how consumers' perceptions about the state of marine stocks and the valuation of ecolabels may be affected by different information. We find moderate interactive effects between ecolabels and country of origin labels, whereas the valuation for seafood ecolabels is fairly high. In terms of information, we find that consumers' perceptions about fish stock levels changed (negatively) after receiving information on declining stock levels, and more sensationalized information led to increased change. However, valuation for a seafood ecolabel increases only when the information was perceived positively (credible/interesting); whereas exaggerated information (which was also perceived less credible) had insignificant effects on WTP.

O conteúdo orgânico do sedimento influencia na distribuição intraespecífica de caranguejos-chama-maré

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Within plant distribution of Anthonomus grandis (Coleoptera: Curculionidae) feeding and oviposition damages in cotton cultivars

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preferência por substratos escuros no C. auratus: influência das condições de luz no alojamento

Pós-graduação em Psicologia do Desenvolvimento e Aprendizagem - FC

O conteúdo orgânico do sedimento influencia na distribuição intraespecífica de caranguejos-chama-maré

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Extractos cítricos como atrayentes para cebos hormiguicidas con sustancias naturales

La formulación de cebos para el control de hormigas cortadoras es conveniente por su mayor practicidad y economía. En el proceso de desarrollo de hormiguicidas con sustancias naturales, se probaron extractos de cítricos como atrayentes para cebos, sobre obreras de Acromyrmex lundi, en dos ensayos: en laboratorio y en campo. Con extractos de naranja dulce, pomelo rosado, mandarina y naranja amarga se impregnaron discos de papel de filtro. Se ofrecieron a las hormigas en un diseño de bloques al azar (DBA) con libre elección. En laboratorio, en hormiguero artificial, se presentaron grupos de 20 discos con los tratamientos. Se registró el número de discos remanentes y el tiempo transcurrido hasta la remoción del primer disco. En campo, el bloque correspondió a cada hormiguero y se dispusieron grupos de 10 discos en cada senda, registrándose los mismos parámetros. El extracto de mandarina resultó preferido en laboratorio según la prueba de Tukey. En campo, fue preferido el extracto de pomelo. Los extractos utilizados atrajeron a las obreras de A. lundi, podadoras en dicotiledóneas; se observó respuesta diferencial para las distintas especies pero el ordenamiento en la preferencia no fue consistente para los ensayos en condiciones artificiales y de campo.

Three essays on hospital efficiency

This dissertation analyzes hospital efficiency using various econometric techniques. The first essay provides additional and recent evidence to the presence of contract management behavior in the U.S. hospital industry. Unlike previous studies, which focus on either an input-demand equation or the cost function of the firm, this paper estimates the two jointly using a system of nonlinear equations. Moreover, it addresses the longitudinal problem of institutions adopting contract management in different years, by creating a matched control group of non-adopters with the same longitudinal distribution as the group under study. The estimation procedure then finds that labor, and not capital, is the preferred input in U.S. hospitals regardless of managerial contract status. With institutions that adopt contract management benefiting from lower labor inefficiencies than the simulated non-contract adopters. These results suggest that while there is a propensity for expense preference behavior towards the labor input, contract managed firms are able to introduce efficiencies over conventional, owner controlled, firms. Using data for the years 1998 through 2007, the second essay investigates the production technology and cost efficiency faced by Florida hospitals. A stochastic frontier multiproduct cost function is estimated in order to test for economies of scale, economies of scope, and relative cost efficiencies. The results suggest that small-sized hospitals experience economies of scale, while large and medium sized institutions do not. The empirical findings show that Florida hospitals enjoy significant scope economies, regardless of size. Lastly, the evidence suggests that there is a link between hospital size and relative cost efficiency. The results of the study imply that state policy makers should be focused on increasing hospital scale for smaller institutions while facilitating the expansion of multiproduct production for larger hospitals. The third and final essay employs a two staged approach in analyzing the efficiency of hospitals in the state of Florida. In the first stage, the Banker, Charnes, and Cooper model of Data Envelopment Analysis is employed in order to derive overall technical efficiency scores for each non-specialty hospital in the state. Additionally, input slacks are calculated and reported in order to identify the factors of production that each hospital may be over utilizing. In the second stage, we employ a Tobit regression model in order to analyze the effects a number of structural, managerial, and environmental factors may have on a hospital’s efficiency. The results indicated that most non-specialty hospitals in the state are operating away from the efficient production frontier. The results also indicate that the structural make up, managerial choices, and level of competition Florida hospitals face have an impact on their overall technical efficiency.

Assessment of eating rate and food intake in spoon versus fork users in a laboratory setting

Accumulating evidence show positive relationships between eating rate and body weight. Acute food intake is affected by eating rate, bite size, and palatability. The objective was to assess differences between participants who chose to use a spoon vs. fork in eating rate and food intake of four meals that differ in palatability (low vs. high salt) and in energy density (low vs. high fat). Forty-eight healthy adults (16 males, 18-54 y, BMI: 17.8-34.4 kg/m2) were recruited. Participants attended four lunch time sessions after a standardised breakfast. Meals were either (1) low-fat/low-salt, (2) low-fat/high-salt, (3) high-fat/low-salt, or (4) high-fat/high-salt. Nineteen participants (6 males) consistently used a fork and 21 (8 males) used a spoon, 8 participants were inconsistent in cutlery use and excluded from analyses. Spoon users had on average a higher BMI than fork users (p=0.006). Effects of cutlery use, BMI status (BMI<25 vs. BMI>25), salt, and fat, and their interactions were assessed in a General Linear Model. Spoon users consumed faster (fork: 53±2.8g/min; spoon: 62±2.1g/min, p=0.022) and tended to consume more (p=0.09), whereas the duration of the meals were similar (fork: 6.9±0.3min; spoon: 6:7±0.2min, p=0.55). BMI status affected both eating rate and food intake (p=0.005). There were no significant two-way or three-way interactions between salt, fat, and cutlery use on eating rate or food intake. In conclusion, participants who chose to consume with forks ate slower compared to spoon users.

Feeding behavior and food preference of Penaeus monodon Fabricius with scrap tilapia

The time of day during which P. monodon feeds at different depth levels in earthen ponds, and its preference for three types of tilapia feeds (dry, fresh and fermented) were determined. It was observed that P. monodon concentrated at the bottom beds during the day and along the periphery of dikes during night-time, with a slight tendency to swim and feed towards the surface as darkness increased. P. monodon showed special preference for dried tilapia compared to fresh and fermented tilapia. P. monodon also showed adaptability to the platform method of feeding, especially during night-time.

Physical activity and sedentary behavior: a population-based study of barriers, enjoyment, and preference

The associations of physical activity and sedentary behavior with barriers, enjoyment, and preferences were examined in a population-based mail survey of 1,332 adults. Respondents reporting high enjoyment and preference for physical activity were more likely to report high levels of activity. Those reporting cost, the weather, and personal barriers to physical activity were less likely to be physically active. Preference for sedentary behavior was associated with the decreased likelihood of being physically active, and the weather as a barrier to physical activity was associated with the increased likelihood of sedentary behavior. These constructs can be used to examine individual and environmental influences on physical activity and sedentary behavior in specific populations and could inform the development of targeted interventions.

Differences within and between travel preference, planned travel and choice behavior of Australians traveling to Asian and oversea destinations

This study seeks to examine differences in travel preference, travel intention and destination choice behavior of an aggregated set of Australian travelers. Additionally the study seeks to relate income, age, gender, life cycle and life style of Australians to the preference, planning and choice of Asian and overseas destinations. A large representative sample of 49,000 Australian respondents is utilized. Binomial regression is used to profile travelers to Asia and overseas in general. Specific significant variables and differences are highlighted. There are consistent relationships between travel preference, planning and choice and the set of independent variables of income, life cycle and life style. Age nor gender are not consistently related to travel planning or travel choice. It is apparent that a combination of demographics, e.g. age, income and life cycle, combined with life style will provide a more valuable basis for segmentation of Asian and overseas travel markets. The study aims to profile potential Australian tourists thereby making a contribution to tourism knowledge and market segmentation practice.

Preference mining techniques for customer behavior analysis

The thesis has studied a number of critical problems in data mining for customer behavior analysis and has proposed novel techniques for better modeling of the customers’ decision making process, more efficient analysis of their travel behavior, and more effective identification of their emerging preference.

Adult partner preference and sexual behavior of male rats exposed prenatally to betamethasone

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)