A Suite of Prey Traits Determine Predator and Nutrient Enrichment Effects in a Tri-Trophic Food Chain

Predation, predation risk, and resource quality affect suites of prey traits that collectively impact individual fitness, population dynamics, and community structure. However, studies of multi-trophic level effects generally focus on a single prey trait, failing to capture trade-offs among suites of covarying traits that govern population responses and emergent community patterns. We used structural equation models (SEM) to summarize the non-lethal and lethal effects of crayfish, Procambarus fallax, and phosphorus (P) addition, which affected prey food quality (periphyton), on the interactive effects of behavioral, morphological, developmental, and reproductive traits of snails, Planorbella duryi. Univariate and multivariate analyses suggested trade-offs between production (growth, reproduction) and defense (foraging behavior, shell shape) traits of snails in response to non-lethal crayfish and P addition, but few lethal effects. SEM revealed that non-lethal crayfish effects indirectly limited per capita offspring standing stock by increasing refuge use, slowing individual growth, and inducing snails to produce thicker, compressed shells. The negative effects of non-lethal crayfish on snails were strongest with P addition; snails increased allocation to shell defense rather than growth or reproduction. However, compared to ambient conditions, P addition with non-lethal crayfish still yielded greater per capita offspring standing stock by speeding individual snail growth enabling them to produce more offspring that also grew faster. Increased refuge use in response to non-lethal crayfish led to a non-lethal trophic cascade that altered the spatial distribution of periphyton. Independent of crayfish effects, snails stimulated periphyton growth through nutrient regeneration. These findings illustrate the importance of studying suites of traits that reveal costs associated with inducing different traits and how expressing those traits impacts population and community level processes.

The role of individualism and collectivism as predictors of attributions for unethical work behavior : an empirical examination across two culturally diverse groups

This dissertation addresses how the cultural dimensions of individualism and collectivism affect the attributions people make for unethical behavior at work. The moderating effect of ethnicity is also examined by considering two culturally diverse groups: Hispanics and Anglos. The sample for this study is a group of business graduate students from two universities in the Southeast. A 20-minute survey was distributed to master's degree students at their classroom and later on returned to the researcher. Individualism and collectivism were operationalized as by a set of attitude items, while unethical work behavior was introduced in the form of hypothetical descriptions or scenarios. Data analysis employed multiple group confirmatory factor analysis for both independent and dependent variables, and subsequently multiple group LISREL models, in order to test predictions. Results confirmed the expected link between cultural variables and attribution responses, although the role of independent variables shifted, due to the moderating effect of ethnicity, and to the nuances of each particular situation.

Fabricação e estudo de um forno solar com dispositivo de transporte

It presents a solar oven manufactured from MDF boards intended for the baking of foods such as pizza, cakes, breads, hamburgers and the like. They will be given the manufacturing processes and assembly of such an oven which has features of low cost manufacturing. The main feature of the proposed furnace and can be transported to any locations because it is seated on a device for carrying case / backpack. Tests will be conducted for the baking of various foods and their results will be compared with the various types of existing solar ovens shown by the literature. They will analyze the thermal and economic feasibility of such an oven that can provide socialization of the use of solar energy for poor communities and can become a source of generation of employment and income. The proposed solar oven baking has capacity for two foods and can be manufactured to allow multiple simultaneous baking of food.

Downwelling spectral irradiance as measured in different depths, remote sensing reflectance and phytoplankton pigment concentration during POLARSTERN cruises ANT-XXIV/1, ANT-XXIV/4, ANT-XXVI/4 and Maria S. Merian cruise MSM18/3

The composition and abundance of algal pigments provide information on phytoplankton community characteristics such as photoacclimation, overall biomass and taxonomic composition. In particular, pigments play a major role in photoprotection and in the light-driven part of photosynthesis. Most phytoplankton pigments can be measured by high-performance liquid chromatography (HPLC) techniques applied to filtered water samples. This method, as well as other laboratory analyses, is time consuming and therefore limits the number of samples that can be processed in a given time. In order to receive information on phytoplankton pigment composition with a higher temporal and spatial resolution, we have developed a method to assess pigment concentrations from continuous optical measurements. The method applies an empirical orthogonal function (EOF) analysis to remote-sensing reflectance data derived from ship-based hyperspectral underwater radiometry and from multispectral satellite data (using the Medium Resolution Imaging Spectrometer - MERIS - Polymer product developed by Steinmetz et al., 2011, doi:10.1364/OE.19.009783) measured in the Atlantic Ocean. Subsequently we developed multiple linear regression models with measured (collocated) pigment concentrations as the response variable and EOF loadings as predictor variables. The model results show that surface concentrations of a suite of pigments and pigment groups can be well predicted from the ship-based reflectance measurements, even when only a multispectral resolution is chosen (i.e., eight bands, similar to those used by MERIS). Based on the MERIS reflectance data, concentrations of total and monovinyl chlorophyll a and the groups of photoprotective and photosynthetic carotenoids can be predicted with high quality. As a demonstration of the utility of the approach, the fitted model based on satellite reflectance data as input was applied to 1 month of MERIS Polymer data to predict the concentration of those pigment groups for the whole eastern tropical Atlantic area. Bootstrapping explorations of cross-validation error indicate that the method can produce reliable predictions with relatively small data sets (e.g., < 50 collocated values of reflectance and pigment concentration). The method allows for the derivation of time series from continuous reflectance data of various pigment groups at various regions, which can be used to study variability and change of phytoplankton composition and photophysiology.

Trajetórias e fatores associados a qualidade de vida de mães de recém-nascidos pré-termos de muito baixo peso até três anos após o parto

Preterm birth is a public health problem worldwide. It holds growing global incidence rates, high mortality rates and a risk of the long-term sequelae in the newborn. It is also poses burden on the family and society. Mothers of very low birth weight (VLBW) preterm infants may develop psychological disorders, and impaired quality of life (QoL). Factors related to mothers and children in the postpartum period may be negatively associated with the QoL of these mothers. The aim of this study was to assess factors possibly associated with the QoL of mothers of VLBW preterm newborns during the first three years after birth. Mothers of VLBW preterm answered the World Health Organization Quality of Life (WHOQOL)-bref and the Beck Depression Inventory (BDI) in five time points up to 36 months postpartum, totalizing 260 observations. The WHOQOL–bref scores were compared and correlated with sociodemographic and clinical variables of mothers and children at discharge (T0) and at six (T1), twelve (T2), 24 (T3) and 36 (T4) months after the delivery. We used the Kruskal Wallis test to compared scores across different time points and correlated WHOQOL-bref scores with the sociodemographic and clinical variables of mothers and preterm infants. Multiple linear regression models were used to evaluate the contribution of these variables for the QoL of mothers. The WHOQOL–bref scores at T1 and T2 were higher when compared to scores in T0 in the physical health dimension (p = 0.013). BDI scores were also higher at T1 and T2 than those at T0 (p = 0.027). Among the maternal variables that contributed most to the QoL of mothers, there were: at T0, stable marital union (b= 13.60; p= 0.000) on the social relationships dimension, gestational age (b= 2.38; p= 0.010) in the physical health dimension; post-hemorrhagic hydrocephalus (b= -10.05; p= 0.010; b= -12.18; p= 0.013, respectively) in the psychological dimension; at T1 and T2, Bronchopulmonary dysplasia (b= -7.41; p= 0.005) and female sex (b= 8,094; p= 0.011) in the physical health dimension and environment, respectively. At T3, family income (b= -12.75’ p= 0.001) in the environment dimension, the SNAPPE neonatal severity score (b= -0.23; p= 0.027) on the social relationships dimension; at the T4, evangelical religion (b= 8.11; p= 0.019) and post-hemorrhagic hydrocephalus (b: -18.84 p: 0.001) on the social relationships dimension. The BDI scores were negatively associated with WHOQOL scores in all dimensions and at all times points: (-1.42 ≤ b ≤ -0.36; T0, T1, T2, T3 and T4). We conclude that mothers of preterm infants VLBW tend to have a transient improvement in the physical well-being during the first postpartum year. Their quality of life seems to return to levels at discharge between two and three years after delivery. The presence of maternal depressive symptoms and diagnosis of post-hemorrhagic hydrocephalus or BDP are factors negatively associated with the QoL of mothers. Social, religious and economic variables are positively associated with the QoL of mothers of VLBW preterm.

To what extent does the Health Professions Admission Test-Ireland predict performance in early undergraduate tests of communication and clinical skills? – An observational cohort study

Background: Internationally, tests of general mental ability are used in the selection of medical students. Examples include the Medical College Admission Test, Undergraduate Medicine and Health Sciences Admission Test and the UK Clinical Aptitude Test. The most widely used measure of their efficacy is predictive validity.A new tool, the Health Professions Admission Test- Ireland (HPAT-Ireland), was introduced in 2009. Traditionally, selection to Irish undergraduate medical schools relied on academic achievement. Since 2009, Irish and EU applicants are selected on a combination of their secondary school academic record (measured predominately by the Leaving Certificate Examination) and HPAT-Ireland score. This is the first study to report on the predictive validity of the HPAT-Ireland for early undergraduate assessments of communication and clinical skills. Method. Students enrolled at two Irish medical schools in 2009 were followed up for two years. Data collected were gender, HPAT-Ireland total and subsection scores; Leaving Certificate Examination plus HPAT-Ireland combined score, Year 1 Objective Structured Clinical Examination (OSCE) scores (Total score, communication and clinical subtest scores), Year 1 Multiple Choice Questions and Year 2 OSCE and subset scores. We report descriptive statistics, Pearson correlation coefficients and Multiple linear regression models. Results: Data were available for 312 students. In Year 1 none of the selection criteria were significantly related to student OSCE performance. The Leaving Certificate Examination and Leaving Certificate plus HPAT-Ireland combined scores correlated with MCQ marks.In Year 2 a series of significant correlations emerged between the HPAT-Ireland and subsections thereof with OSCE Communication Z-scores; OSCE Clinical Z-scores; and Total OSCE Z-scores. However on multiple regression only the relationship between Total OSCE Score and the Total HPAT-Ireland score remained significant; albeit the predictive power was modest. Conclusion: We found that none of our selection criteria strongly predict clinical and communication skills. The HPAT- Ireland appears to measures ability in domains different to those assessed by the Leaving Certificate Examination. While some significant associations did emerge in Year 2 between HPAT Ireland and total OSCE scores further evaluation is required to establish if this pattern continues during the senior years of the medical course.

Climat motivationnel en éducation physique et besoins psychologiques : impact sur les buts d’accomplissement, les attitudes et les habitudes des élèves

Pour permettre de mieux comprendre la problématique du désengagement des adolescents en éducation physique et aussi à l’endroit de l’activité physique en général, la présente étude avait pour objectif d’examiner les liens entre, d’une part, le climat motivationnel en classe d’éducation physique (maîtrise et performance) et les besoins psychologiques des élèves des deux sexes (compétence, autonomie et appartenance) et, d’autre part, les buts d’accomplissement (maîtrise, performance-approche et performance-évitement) poursuivis en éducation physique. Elle visait aussi à examiner l’impact des buts d’accomplissement sur les attitudes et habitudes des adolescents à l’endroit de l’activité physique en général. Pour atteindre ces objectifs, 909 élèves (âge moyen = 13,87[0,94]) ont rempli des questionnaires à items auto-révélés à trois reprises pendant l’année scolaire. Des modèles d’équations structurelles (AMOS 22), des analyses d’invariance ainsi que l’approche sans contrainte ont servi à analyser les données. Les résultats indiquent que les buts d’accomplissement des élèves varient en fonction du climat motivationnel perçu et que le sentiment de compétence entretient une relation positive avec les trois buts d’accomplissement. Ces relations étaient invariantes selon le sexe des élèves. Par ailleurs, une seule interaction climat-besoin s’est avérée significative : l’interaction entre le climat de maîtrise et le sentiment d’autonomie prédit négativement l’adoption de buts de performance-évitement. Cela signifie que la perception d’un climat de maîtrise réduit l’adoption de buts de performance-évitement par les élèves, mais seulement lorsque ceux-ci affichent un fort sentiment d’autonomie. Finalement, l’adoption de buts de maîtrise et de buts de performance-approche en éducation physique exerce une influence positive sur les attitudes des élèves qui, à leur tour, influencent leurs habitudes en activité physique. Seule l’adoption de buts de performance-approche entretient une relation positive directe avec les habitudes des élèves. En conclusion, l’enseignant d’éducation physique peut agir sur la motivation et l’engagement des élèves en classe, mais aussi à l’extérieur des cours, en instaurant un climat motivationnel de maîtrise et en aidant les élèves à satisfaire leur besoin de compétence.

(MIS)PERCEIVED DRINKING NORMS AND HAZARDOUS DRINKING BEHAVIOURS IN UNIVERSITY FIRST-YEAR UNDERGRADUATE STUDENTS AND THE EFFECTS OF GENDER

Purpose: Across Canada, undergraduate university students are one of the highest alcohol-consuming populations. Many students engage in hazardous drinking and are at risk for negative health and social consequences. Social Norms Theory suggests that students’ overestimation of drinking norms can result in an increase in their drinking behaviour. As of yet, none of the literature addresses the possible link between drinking norm (mis)perception and hazardous drinking in a Canadian undergraduate context. This is the first Canadian study to examine this potential association in first-year undergraduate students across multiple universities using gender as an effect modifier. Methods: Using data collected by the Caring Campus Project, for 2347 first-year students from three Canadian universities, I evaluated the prevalence of drinking norm misperceptions by site and gender. Using multiple-logistic regression models, I analyzed the relationship between misperceived drinking norms and hazardous drinking behaviours (assessed via AUDIT-C). Results: The proportion of students who overestimated drinking and binge drinking frequency norms varied by site and gender. There was a positive relationship between overestimated drinking/ binge drinking frequency norms and hazardous drinking, modified by gender. Controlling for living arrangement and site, the odds of female students being hazardous drinkers increased by a factor of 2.27 (CI: 1.73-2.99) when the drinking frequency norm was overestimated. A non-significant association was found for male students. Among female students, when living arrangement and site were controlled, the odds of being a hazardous drinker were 1.83 (0.84-3.95) and 2.69 (1.24-5.83) times greater when the drinking frequency norm was perceived at “2-4 times per month” and “2 or more times per week”, respectively. Among male students, when living arrangement, previous residence and site were controlled, the odds of being a hazardous drinker were 4.03 (2.62-6.19) and 8.54 (5.41-13.49) times greater when the binge drinking frequency norm was perceived at “2-4 times per month” and “2 or more times per week”, respectively. Conclusion: This novel study enhances the understanding of the association between (mis)perceived drinking norms and drinking behaviours in Canadian undergraduate students. The demonstrated importance of gender and site provides a strong impetus for Canadian universities to develop targeted alcohol reduction interventions.

Service Loyalty: An Integrative Model and Examination across Service Contexts

Marketing academics and practitioners generally agree that customer loyalty is vital to business success. There is less agreement on the factors that determine customer loyalty, particularly in service contexts. Research on the determinants of service loyalty has taken three distinct paths: 1) quality/value/satisfaction; 2) relationship quality; and, 3) relational benefits. In this research, the authors coalesce these paths to derive a model that links dimensions of customer loyalty (cognitive, affective, intention, and behavioral) with a system of determinants. The model is tested with data from varied services (airlines, banks, beauty salons, hospitals, hotels, and mobile telephone) and 3,500 customers in China. Results are consistent across contexts and support a multidimensional view of customer loyalty. Key loyalty determinants are customer satisfaction, commitment, service fairness, service quality, trust, and a construct new to service loyalty models—commercial friendship. The research contributes to the literature by providing a more complete, integrated view of customer loyalty and its determinants in services contexts.

Random Access over Multi-Packet Reception Channels: A Mean-Field Approach

Thesis (Ph.D.)--University of Washington, 2016-06

Effects of Soil Organic Matter Properties and Microbial Community Composition on Enzyme Activities in Cryoturbated Arctic Soils

Enzyme-mediated decomposition of soil organic matter (SOM) is controlled, amongst other factors, by organic matter properties and by the microbial decomposer community present. Since microbial community composition and SOM properties are often interrelated and both change with soil depth, the drivers of enzymatic decomposition are hard to dissect. We investigated soils from three regions in the Siberian Arctic, where carbon rich topsoil material has been incorporated into the subsoil (cryoturbation). We took advantage of this subduction to test if SOM properties shape microbial community composition, and to identify controls of both on enzyme activities. We found that microbial community composition (estimated by phospholipid fatty acid analysis), was similar in cryoturbated material and in surrounding subsoil, although carbon and nitrogen contents were similar in cryoturbated material and topsoils. This suggests that the microbial community in cryoturbated material was not well adapted to SOM properties. We also measured three potential enzyme activities (cellobiohydrolase, leucine-amino-peptidase and phenoloxidase) and used structural equation models (SEMs) to identify direct and indirect drivers of the three enzyme activities. The models included microbial community composition, carbon and nitrogen contents, clay content, water content, and pH. Models for regular horizons, excluding cryoturbated material, showed that all enzyme activities were mainly controlled by carbon or nitrogen. Microbial community composition had no effect. In contrast, models for cryoturbated material showed that enzyme activities were also related to microbial community composition. The additional control of microbial community composition could have restrained enzyme activities and furthermore decomposition in general. The functional decoupling of SOM properties and microbial community composition might thus be one of the reasons for low decomposition rates and the persistence of 400 Gt carbon stored in cryoturbated material.

Waves, bumps, and patterns in neural field theories

Neural field models of firing rate activity have had a major impact in helping to develop an understanding of the dynamics seen in brain slice preparations. These models typically take the form of integro-differential equations. Their non-local nature has led to the development of a set of analytical and numerical tools for the study of waves, bumps and patterns, based around natural extensions of those used for local differential equation models. In this paper we present a review of such techniques and show how recent advances have opened the way for future studies of neural fields in both one and two dimensions that can incorporate realistic forms of axo-dendritic interactions and the slow intrinsic currents that underlie bursting behaviour in single neurons.

Children's mental representations of attachment: associations with attachment security and parent-child narrative quality

The goal of this study was to examine the antecedents and correlates of children’s mental representations of attachment at 5 years (Attachment Story Completion Task, Bretherton, Ridgeway, & Cassidy, 1990; MacArthur Story Stem Battery, Bretherton, Oppenheim, Buchsbaum, Emde, & the MacArthur Narrative Group, 1990). Predictors included children’s attachment security with mothers and fathers assessed via the Attachment Q-Set (AQS, Waters, 1987) at 3 years, and parent-child narrative quality regarding positive and negative events at 5 years. Participants included 71 children and their mothers and fathers. Structural equation models (SEM) indicated that children’s attachment security exerted a significant indirect effect on children’s mental representations through parent-child narrative quality. Specifically, children’s attachment security with fathers was related to their mental representations via father-child reminiscing about positive events, and children’s attachment security with mothers was related to their mental representations via mother-child reminiscing about negative events. Results are discussed in terms of the development and implications of attachment relationships within the family context.

INFLUÊNCIA DA POSIÇÃO SOCIAL NAS RELAÇÕES MORFOMÉTRICAS DE Araucaria angustifolia

The morphometric relations allow describing dimensions of trees without prior knowledge of the age, it help the forest planning and implementation of silvicultural treatments, especially when needs to make sustainable use of forests. For this purpose, the aim of this study was to model and comparising the morphometric relations araucaria trees in social position dominant, codominant and dominated in native forest remnant, located in Lages, SC. A total of 294 trees distributed in dbh classes were intentionally selected inside of forest. In each tree was measured dbh, total height, bole height, crown diameter by eight radius, as well as the classification of social position. Simple and multiple linear regression models were used to describe the relation h/d, the proportion of the crown and formal crown in function of diameter at breast height with simple transformation, quadratic, cubic, inverse and logarithmic form. The analysis of covariance with dummy variables were used to describe the social position and tested the parallelism and slope of regression indicating need or not of the use independent regressions. The results indicated that even with great variability in the shape and size of the crown due to growth and competition process, the morphometric relations of araucaria can be accurately estimated by regression models. The relation h/d, proportion of the crown and formal crown can be described by individual model for social position dominant, codominant and dominant, or alternatively a single model with the use of dummy variables that differentiate trees group dominated for the relation h/d and formal crown. The proportion of crown presented difference in dimensions of the trees, being necessary to use dummy variable for each social stratus or use the individual models.

Quantificação de açúcares com uma língua eletrónica: calibração multivariada com seleção de sensores

Este trabalho incide na análise dos açúcares majoritários nos alimentos (glucose, frutose e sacarose) com uma língua eletrónica potenciométrica através de calibração multivariada com seleção de sensores. A análise destes compostos permite contribuir para a avaliação do impacto dos açúcares na saúde e seu efeito fisiológico, além de permitir relacionar atributos sensoriais e atuar no controlo de qualidade e autenticidade dos alimentos. Embora existam diversas metodologias analíticas usadas rotineiramente na identificação e quantificação dos açúcares nos alimentos, em geral, estes métodos apresentam diversas desvantagens, tais como lentidão das análises, consumo elevado de reagentes químicos e necessidade de pré-tratamentos destrutivos das amostras. Por isso se decidiu aplicar uma língua eletrónica potenciométrica, construída com sensores poliméricos selecionados considerando as sensibilidades aos açucares obtidas em trabalhos anteriores, na análise dos açúcares nos alimentos, visando estabelecer uma metodologia analítica e procedimentos matemáticos para quantificação destes compostos. Para este propósito foram realizadas análises em soluções padrão de misturas ternárias dos açúcares em diferentes níveis de concentração e em soluções de dissoluções de amostras de mel, que foram previamente analisadas em HPLC para se determinar as concentrações de referência dos açúcares. Foi então feita uma análise exploratória dos dados visando-se remover sensores ou observações discordantes através da realização de uma análise de componentes principais. Em seguida, foram construídos modelos de regressão linear múltipla com seleção de variáveis usando o algoritmo stepwise e foi verificado que embora fosse possível estabelecer uma boa relação entre as respostas dos sensores e as concentrações dos açúcares, os modelos não apresentavam desempenho de previsão satisfatório em dados de grupo de teste. Dessa forma, visando contornar este problema, novas abordagens foram testadas através da construção e otimização dos parâmetros de um algoritmo genético para seleção de variáveis que pudesse ser aplicado às diversas ferramentas de regressão, entre elas a regressão pelo método dos mínimos quadrados parciais. Foram obtidos bons resultados de previsão para os modelos obtidos com o método dos mínimos quadrados parciais aliado ao algoritmo genético, tanto para as soluções padrão quanto para as soluções de mel, com R²ajustado acima de 0,99 e RMSE inferior a 0,5 obtidos da relação linear entre os valores previstos e experimentais usando dados dos grupos de teste. O sistema de multi-sensores construído se mostrou uma ferramenta adequada para a análise dos iii açúcares, quando presentes em concentrações maioritárias, e alternativa a métodos instrumentais de referência, como o HPLC, por reduzir o tempo da análise e o valor monetário da análise, bem como, ter um preparo mínimo das amostras e eliminar produtos finais poluentes.