Checking the concurrence among macrobenthic organism distribution patterns at different taxonomic scales in relation to environmental factors

The interaction of both natural conditions and anthropogenic environmental impacts can lead to different soft-bottom macrobenthic distribution patterns. Soft-bottom macrobenthic community was analysed at different taxonomic scales in order to evaluate whether diverse subset of organisms respond to the variability of the environmental pressures (natural and human induced) showing or not similar distribution patterns. Therefore, this long-term survey had been focused on a heterogeneous area, where both anthropogenic and natural stress may affect the community. Three perpendicular transects to the coast were established and stations at 4, 10 and 15 m depths were sampled at each transect twice a year (summer- winter) from 2004 to 2009. Non-parametric multivariate techniques were used to analyse soft-bottom macrobenthic community distribution and its relation to the environmental factors. Similar distribution patterns between investigated taxonomic levels were detected and they were mainly related to depth.

Delphi study for the design and validation of a questionnaire about digital competences in higher education

The study of digital competence remains an issue of interest for both the scientific community and the supranational political agenda. This study uses the Delphi method to validate the design of a questionnaire to determine the perceived importance of digital competence in higher education. The questionnaire was constructed from different framework documents in digital competence standards (NETS, ACLR, UNESCO). The triangulation of non-parametric techniques made it possible to consolidate the results obtained through the Delphi panel, the suitability of which was highlighted through the expert competence index (K). The resulting questionnaire emerges as a good tool for undertaking future national and international studies on digital competence in higher education.

O atendimento ao cliente como fator de diferenciação

A presente investigação pretende identificar os fatores que compõem a vantagem competitiva da cadeia de pronto-a-vestir Zara, contribuindo para a sua diferenciação do mercado. Pretende-se ainda perceber se esses fatores diferem de acordo com as caraterísticas sociodemográficas dos consumidores (idade, grau académico e rendimento), bem como se a frequência de realização de compras na loja influencia significativamente os fatores de diferenciação pela vantagem competitiva. Para tal, desenvolveu-se um estudo de caso, assente numa metodologia quantitativa, que contou com a aplicação de um questionário como método de recolha dos dados. O tratamento estatístico recorreu a técnicas descritivas e inferenciais como a análise fatorial e testes de comparação de médias. Os resultados demonstram haver quatro fatores que compõem a vantagem competitiva da Zara (atendimento, marca e produto, ambiente da loja e valor percebido), verificando-se uma influência maioritariamente do grau de escolaridade e da frequência de compras na loja.

O Risco Percebido e Coberto pelas Seguradoras

Os Portugueses desde imemoráveis tempos gostam de partir à descoberta de mundos novos, fazemo-lo pelas mais variadas razões, no entanto, neste trabalho iremos apenas analisar os riscos associados ao turismo de lazer. Os atentados de Nova Iorque em 11 Setembro 2001, Síndrome Respiratório Grave em HongKong em Fevereiro de 2003, o Tsunami no oceano Indico em Dezembro 2004, a erupção vulcânica na Islândia em Abril de 2010 ou os atentados de Paris em 13 de Novembro 2015, estas datas ficaram marcadas para sempre, lemos e relemos inúmeros depoimentos de pessoas que se encontravam de férias nestas cidades e pensamos e se fossemos nós? Os primeiros registos da atividade seguradora datam do ano 5.000 A.C. inicialmente seguravam transportes de mercadorias, hoje em dia podem cobrir “qualquer coisa”. Com a perceção dos riscos que hoje em dia podem ocorrer numa viagem, será que as Seguradoras estão preparadas para minimizar os mesmos? E qual a perceção dos riscos para quem viaja. Para o efeito realizou-se um estudo exploratório por suporte a uma amostra de conveniência que reuniu 152 observações. Análises descritivas e testes não paramétricos foram aplicados para definir quais os riscos mais percebidos e quais os que os turistas portugueses pretendem ver cobertos. Concluiu-se que as pessoas que dão maior importância aos Risco de Saúde e Financeiro são os que efetuam seguros de viagem, já as que dão maior importância aos Risco Equipamento, Risco Politico, Risco Psicológico e Risco de Satisfação são as que optam por não fazer seguro.

A Comparative Analysis of Two Slug Test Methods in Puget Lowland Glacio-Fluvial Sediments near Coupeville, WA

Two different slug test field methods are conducted in wells completed in a Puget Lowland aquifer and are examined for systematic error resulting from water column displacement techniques. Slug tests using the standard slug rod and the pneumatic method were repeated on the same wells and hydraulic conductivity estimates were calculated according to Bouwer & Rice and Hvorslev before using a non-parametric statistical test for analysis. Practical considerations of performing the tests in real life settings are also considered in the method comparison. Statistical analysis indicates that the slug rod method results in up to 90% larger hydraulic conductivity values than the pneumatic method, with at least a 95% certainty that the error is method related. This confirms the existence of a slug-rod bias in a real world scenario which has previously been demonstrated by others in synthetic aquifers. In addition to more accurate values, the pneumatic method requires less field labor, less decontamination, and provides the ability to control the magnitudes of the initial displacement, making it the superior slug test procedure.

Doxorubicin pharmacokinetics following a single-dose infusion to sulphur-crested cockatoos (Cacatua galerita)

Objective To determine the pharmacokinetics of doxorubicin in sulphur-crested cockatoos, so that its use in clinical studies in birds can be considered. Design A pharmacokinetic study of doxorubicin, following a single intravenous (IV) infusion over 20 min, was performed in four healthy sulphur-crested cockatoos (Cacatua galerita). Procedure Birds were anaesthetised and both jugular veins were cannulated, one for doxorubicin infusion and the other for blood collection. Doxorubicin hydrochloride (2 mg/kg) in normal saline was infused IV over 20 min at a constant rate. Serial blood samples were collected for 96 h after initiation of the infusion. Plasma doxorubicin concentrations were assayed using an HPLC method involving ethyl acetate extraction, reverse-phase chromatography and fluorescence detection. The limit of quantification was 20 ng/mL. Established non-parametric methods were used for the analysis of plasma doxorubicin data. Results During the infusion the mean +/- SD for the C-max of doxorubicin was 4037 +/- 2577 ng/mL. Plasma concentrations declined biexponentially immediately after the infusion was ceased. There was considerable intersubject variability in all pharmacokinetic variables. The terminal (beta-phase) half-life was 41.4 +/- 18.5 min, the systemic clearance (Cl) was 45.7 +/- 18.0 mL/min/kg, the mean residence time (MRT) was 4.8 +/- 1.4 min, and the volume of distribution at steady state (V-SS) was 238 131 mL/kg. The extrapolated area under the curve (AUC(0-infinity)) was 950 +/- 677 ng/mL.h. The reduced metabolite, doxorubicinol, was detected in the plasma of all four parrots but could be quantified in only one bird with the profile suggesting formation rate-limited pharmacokinetics of doxorubicinol. Conclusions and clinical relevance Doxorubicin infusion in sulphur-crested cockatoos produced mild, transient inappetence. The volume of distribution per kilogram and terminal half-life were considerably smaller, but the clearance per kilogram was similar to or larger than reported in the dog, rat and humans. Traces of doxorubicinol, a metabolite of doxorubicin, were detected in the plasma.

Spatial and temporal variability in somatic growth of green sea turtles (Chelonia mydas) resident in the Hawaiian Archipelago

The somatic growth dynamics of green turtles ( Chelonia mydas) resident in five separate foraging grounds within the Hawaiian Archipelago were assessed using a robust non-parametric regression modelling approach. The foraging grounds range from coral reef habitats at the north-western end of the archipelago, to coastal habitats around the main islands at the southeastern end of the archipelago. Pelagic juveniles recruit to these neritic foraging grounds from ca. 35 cm SCL or 5 kg ( similar to 6 years of age), but grow at foraging-ground-specific rates, which results in quite different size- and age-specific growth rate functions. Growth rates were estimated for the five populations as change in straight carapace length ( cm SCL year) 1) and, for two of the populations, also as change in body mass ( kg year) 1). Expected growth rates varied from ca. 0 - 2.5 cm SCL year) 1, depending on the foraging-ground population, which is indicative of slow growth and decades to sexual maturity, since expected size of first-time nesters is greater than or equal to 80 cm SCL. The expected size- specific growth rate functions for four populations sampled in the southeastern archipelago displayed a non-monotonic function, with an immature growth spurt at ca. 50 - 53 cm SCL ( similar to 18 - 23 kg) or ca. 13 - 19 years of age. The growth spurt for the Midway atoll population in the northwestern archipelago occurs at a much larger size ( ca. 65 cm SCL or 36 kg), because of slower immature growth rates that might be due to a limited food stock and cooler sea surface temperature. Expected age-at-maturity was estimated to be ca. 35 - 40 years for the four populations sampled at the south-eastern end of the archipelago, but it might well be > 50 years for the Midway population. The Hawaiian stock comprises mainly the same mtDNA haplotype, with no differences in mtDNA stock composition between foraging-ground populations, so that the geographic variability in somatic growth rates within the archipelago is more likely due to local environmental factors rather than genetic factors. Significant temporal variability was also evident, with expected growth rates declining over the last 10 - 20 years, while green turtle abundance within the archipelago has increased significantly since the mid-1970s. This inverse relationship between somatic growth rates and population abundance suggests a density-dependent effect on somatic growth dynamics that has also been reported recently for a Caribbean green turtle stock. The Hawaiian green turtle stock is characterised by slow growth rates displaying significant spatial and temporal variation and an immature growth spurt. This is consistent with similar findings for a Great Barrier Reef green turtle stock that also comprises many foraging-ground populations spanning a wide geographic range.

Canonical valuation of options in the presence of stochastic volatility

Proposed by M. Stutzer (1996), canonical valuation is a new method for valuing derivative securities under the risk-neutral framework. It is non-parametric, simple to apply, and, unlike many alternative approaches, does not require any option data. Although canonical valuation has great potential, its applicability in realistic scenarios has not yet been widely tested. This article documents the ability of canonical valuation to price derivatives in a number of settings. In a constant-volatility world, canonical estimates of option prices struggle to match a Black-Scholes estimate based on historical volatility. However, in a more realistic stochastic-volatility setting, canonical valuation outperforms the Black-Scholes model. As the volatility generating process becomes further removed from the constant-volatility world, the relative performance edge of canonical valuation is more evident. In general, the results are encouraging that canonical valuation is a useful technique for valuing derivatives. (C) 2005 Wiley Periodicals, Inc.

Caries experience in preschool children referred for specialist dental care in hospital

Background : Increasing numbers of preschool children are being referred for specialist dental management in a paediatric hospital. Most cases have severe early childhood caries and require comprehensive management under general anaesthesia. The present study investigated risk factors for disease presence at initial consultation. Methods : A convenience sample of 125 children under four years of age from the north Brisbane region were examined and caries experience recorded using dmft and dmfs indices. A self-administered questionnaire obtained information regarding social, demographic, birth, neonatal, infant feeding and dental health behaviour variables. The data were analysed using the chi-square and one-way analysis of variance procedures. Results : Ninety-four per cent of referred children had severe ECC with mean dmft of 10.5 ± 3.8 and mean dmfs of 27.1 ± 15.1. Prevalence of severe ECC was significantly higher in children allowed a sweetened liquid in the infant feeding bottle (99 per cent) and allowed to sip from an infant feeding bottle during the day (100 per cent). Mean dmfs was significantly higher in children allowed to sleep with a bottle (28.7) and sip from a bottle during the day (29.9), children from a non-Caucasian background (31.8), those children that commenced regular toothbrushing between 6 to 12 months of age (28.1), had no current parental supervision of daily tooth-brushing (34.2) and had not taken daily fluoride supplements (27.8), vitamin supplements (27.8) or prescription medicine previously (27.6). Conclusions : The behavioural determinants for severe early childhood caries presence in hospital-referred children were similar to those identified in the regional preschool population.

Validation of the Action Research Arm Test using item response theory in patients after stroke

Objective: To validate the unidimensionality of the Action Research Arm Test (ARAT) using Mokken analysis and to examine whether scores of the ARAT can be transformed into interval scores using Rasch analysis. Subjects and methods: A total of 351 patients with stroke were recruited from 5 rehabilitation departments located in 4 regions of Taiwan. The 19-item ARAT was administered to all the subjects by a physical therapist. The data were analysed using item response theory by non-parametric Mokken analysis followed by Rasch analysis. Results: The results supported a unidimensional scale of the 19-item ARAT by Mokken analysis, with the scalability coefficient H = 0.95. Except for the item pinch ball bearing 3rd finger and thumb'', the remaining 18 items have a consistently hierarchical order along the upper extremity function's continuum. In contrast, the Rasch analysis, with a stepwise deletion of misfit items, showed that only 4 items (grasp ball'', grasp block 5 cm(3)'', grasp block 2.5 cm(3)'', and grip tube 1 cm(3)'') fit the Rasch rating scale model's expectations. Conclusion: Our findings indicated that the 19-item ARAT constituted a unidimensional construct measuring upper extremity function in stroke patients. However, the results did not support the premise that the raw sum scores of the ARAT can be transformed into interval Rasch scores. Thus, the raw sum scores of the ARAT can provide information only about order of patients on their upper extremity functional abilities, but not represent each patient's exact functioning.

INFLUÊNCIA DO LASER DE BAIXA INTENSIDADE NA VELOCIDADE DA MOVIMENTAÇÃO ORTODÔNTICA

Este estudo investigou os efeitos do laser de baixa intensidade na velocidade da movimentação ortodôntica de caninos submetidos à retração inicial. A amostra constou de 26 caninos superiores e inferiores, submetidos à retração inicial realizada com mola Niti, com força de 150g. Um dos caninos foi irradiado com laser de diodo, seguindo o protocolo de aplicação: 780nm/20mW/5Jcm2/0,2J por ponto/Et=2J, nos dias 0, 3 e 7 pós-ativação, sendo que o contralateral foi considerado placebo. A retração durou em média 4 meses, num total de 9 aplicações de laser. Os modelos de cada mês foram escaneados com scanner 3D (3Shape) e as imagens tridimensionais foram analisadas por meio do Software Geomagic Studio 5, para a mensuração da quantidade de movimentação dos caninos retraídos. Foi empregada a Análise de Variância a três critérios, seguida pelo teste de Tukey (p<0,05). Para verificação da integridade tecidual, foram efetuadas radiografias periapicais iniciais e finais dos caninos retraídos e dos molares, nas quais foram avaliados uma possível reabsorção na crista alveolar, por meio da distância da crista óssea alveolar até a junção cemento-esmalte e os níveis de reabsorção radicular, por meio do índice de Levander e Malmgreen, sendo este último avaliado somente nos caninos retraídos. Para isto, foi empregado o teste não paramétrico de Wilcoxon (p<0,05). Os resultados indicaram que houve um aumento estatisticamente significante na velocidade da movimentação dos caninos irradiados comparados ao seu contralateral, em todos os tempos avaliados, como também a preservação da integridade tecidual. Com isso, concluiu-se que o laser de diodo pode acelerar a movimentação ortodôntica, podendo contribuir para a diminuição do tempo de tratamento.(AU)

A Treinabilidade da Atenção na Prática Esportiva: uma abordagem com goleiros de futebol de campo.

Alguma forma de atenção está continuamente presente na atividade consciente humana, trazendo implicações e interesses tanto de cunho clínico quanto para a Psicologia da Saúde. A atenção é entendida como um estado seletivo, intensivo e dirigido da percepção. Dentro do contexto esportivo a muito da atenção para ser explorada. O objetivo neste trabalho foi testar a atenção de goleiros de futebol de campo através de duas tarefas experimentais. Nossas hipóteses foram que prática esportiva, especificamente em goleiros, e em função do seu treinamento, melhora seu desempenho em tarefas dissociativas do contexto peculiar ao esporte. E ainda; havendo melhora no desempenho, se é devida a componente perceptivo de discriminação, ao alocamento temporal de atenção, ou à sustentação da mesma por períodos prolongados, isto é, uma maior capacidade de concentração ou menos fadigabilidade. Comparamos 27 goleiros de futebol de campo, com idades entre 15 e 27 anos; separados por tempo de treino. Utilizamos neste estudo um programa comercial de computador, configurado para a criação de testes de atenção (Stim, Neurosoft. Inc); que controla todos os aspectos da tarefa. Correlacionamos tempo de reação e porcentagem de acertos com duração do treinamento dos goleiros em meses (e com a idade). Dividimos o grupo de goleiros em dois subgrupos, pela mediana de tempo de treinamento. Apesar da alta correlação entre tempo de treinamento e idade, inevitavelmente em nossa amostra, não houve correlação significativa entre idade e desempenho em ambas as tarefas. A correlação entre desempenho e tempo de treinamento foi altamente significativa na tarefa I. Não verificamos a correlação entre desempenho e tempo de treinamento na tarefa II, apesar da correlação significativa entre desempenhos nas duas tarefas. Foram feitas análises de correlações entre tempo de treinamento e desempenho nas tarefas separadas por blocos. Na tarefa I, a correlação entre tempo de treino e desempenho em cada bloco foi sempre significativa; tanto em teste paramétrico quanto em teste não paramétrico. Já na tarefa II não houve correlação significativa em tempo de treinamento e desempenho em qualquer dos blocos. Na análise categórica, ou seja, dos grupos divididos em dois subgrupos pela mediana de tempo de treinamento; a diferença de desempenho entre os subgrupos foi significativa apenas na tarefa I, no total de acertos (T- test de amostras independentes; F=4.36, p=0.037) e em acertos nos últimos dois blocos (bloco 3 p=0.048; bloco 4 p=0.026). Com o tempo de treinamento, a melhora no que diferenciar e o aumento na condição da fadigabilidade, tende a refinar e a diminuir. A prática esportiva pode de fato melhorar a capacidade perceptiva e a sustentação da atenção, que é à base da disciplina humana para realização de qualquer tarefa. Conseqüentemente, uma melhora afetiva e somática, além disso, uma melhora cognitiva e intelectual traz consigo uma aplicabilidade real na qualidade de vida das pessoas

Regression with input-dependent noise: A Gaussian process treatment

Gaussian processes provide natural non-parametric prior distributions over regression functions. In this paper we consider regression problems where there is noise on the output, and the variance of the noise depends on the inputs. If we assume that the noise is a smooth function of the inputs, then it is natural to model the noise variance using a second Gaussian process, in addition to the Gaussian process governing the noise-free output value. We show that prior uncertainty about the parameters controlling both processes can be handled and that the posterior distribution of the noise rate can be sampled from using Markov chain Monte Carlo methods. Our results on a synthetic data set give a posterior noise variance that well-approximates the true variance.

Gaussian processes:iterative sparse approximations

In recent years there has been an increased interest in applying non-parametric methods to real-world problems. Significant research has been devoted to Gaussian processes (GPs) due to their increased flexibility when compared with parametric models. These methods use Bayesian learning, which generally leads to analytically intractable posteriors. This thesis proposes a two-step solution to construct a probabilistic approximation to the posterior. In the first step we adapt the Bayesian online learning to GPs: the final approximation to the posterior is the result of propagating the first and second moments of intermediate posteriors obtained by combining a new example with the previous approximation. The propagation of em functional forms is solved by showing the existence of a parametrisation to posterior moments that uses combinations of the kernel function at the training points, transforming the Bayesian online learning of functions into a parametric formulation. The drawback is the prohibitive quadratic scaling of the number of parameters with the size of the data, making the method inapplicable to large datasets. The second step solves the problem of the exploding parameter size and makes GPs applicable to arbitrarily large datasets. The approximation is based on a measure of distance between two GPs, the KL-divergence between GPs. This second approximation is with a constrained GP in which only a small subset of the whole training dataset is used to represent the GP. This subset is called the em Basis Vector, or BV set and the resulting GP is a sparse approximation to the true posterior. As this sparsity is based on the KL-minimisation, it is probabilistic and independent of the way the posterior approximation from the first step is obtained. We combine the sparse approximation with an extension to the Bayesian online algorithm that allows multiple iterations for each input and thus approximating a batch solution. The resulting sparse learning algorithm is a generic one: for different problems we only change the likelihood. The algorithm is applied to a variety of problems and we examine its performance both on more classical regression and classification tasks and to the data-assimilation and a simple density estimation problems.

A performance assessment method for hospitals:the case of municipal hospitals in Angola

Over 60% of the recurrent budget of the Ministry of Health (MoH) in Angola is spent on the operations of the fixed health care facilities (health centres plus hospitals). However, to date, no study has been attempted to investigate how efficiently those resources are used to produce health services. Therefore the objectives of this study were to assess the technical efficiency of public municipal hospitals in Angola; assess changes in productivity over time with a view to analyzing changes in efficiency and technology; and demonstrate how the results can be used in the pursuit of the public health objective of promoting efficiency in the use of health resources. The analysis was based on a 3-year panel data from all the 28 public municipal hospitals in Angola. Data Envelopment Analysis (DEA), a non-parametric linear programming approach, was employed to assess the technical and scale efficiency and productivity change over time using Malmquist index.The results show that on average, productivity of municipal hospitals in Angola increased by 4.5% over the period 2000-2002; that growth was due to improvements in efficiency rather than innovation. © 2008 Springer Science+Business Media, LLC.