Testing physiologically-based resource allocation rules in laboratory experiments with Daphnia magna Straus

The rules governing the allocation of available resources to varying physiological processes are evaluated in three physiologically-based models of individual Daphnia. In laboratory experiments using a single clone, subjected to varying regimes of food deprivation, growth was found to vary inversely with food level, ceasing in the absence of food, implying that growth allocation is derived directly from food. Reproductive investment was reduced under food deprivation, ceasing at low food levels. By exposing juvenile and adult daphnia to varying food deprivation regimens during different periods within their intermoult interval, it was shown that instar durations vary as a function of body size and food availability independent of the age of the animal. For the first time, the role of variable instar duration, which critically influences physiological processes such as growth, moulting and reproduction in adult females, that has been neglected by existing Daphnia models, is explicitly incorporated in a physiological allocation model. The consequent model provides a simplified framework for modelling the consequences of food deprivation in cladocerans which has important application in population modelling and environmental risk assessment.EC - STEP and Environment ProgrammesEV5V-CT91-0009EV5V-CT94-0422FCTPRAXIS programBritish Counci

Avaliação das sementes do nim (Azadirachta indica) no controle de nematódeos gastrintestinais de caprinos criados em sistema de base agroecológica: resultados preliminares.

O objetivo desse trabalho foi avaliar a eficácia das sementes do nim (Azadiracht indica A. Juss) no controle das verminoses gastrintestinais de caprinos criados no sistema de produção do Cabrito Ecológico da Embrapa Semi-Árido. O trabalho foi realizado durante a época chuvosa (fevereiro a março), utilizando 18 caprinos ser padrão racial definido, divididos em três grupos homogêneos de acordo com os seguintes tratamentos: T1 controle (água); T2 (1,0 glkg) e T3 (3,0 glkg). Foram realizadas três aplicações com intervalo de 13 dias. Para avaliar a eficácia dos tratamentos, foi realizada a contagem do número de ovos de nematódeos pc gramas de fezes (OPG) antes e sete dias após as dosificações. Foi observado aumento do OPG em quase todos os tratamentos. Nas condições desse trabalho, a sementes do nim não foram eficazes no controle de nematódeos gastrintestinais de caprinos

Avaliação de plantas medicinais no controle de nematódeos gastrintestinais de caprinos criados em sistema de base agroecológica.

Este trabalho objetivou avaliar a eficácia de plantas medicinais no controle de nematódeos gastrintestinais. Foram utilizados 36 caprinos distribuídos em seis grupos de seis animais, nos seguintes tratamentos: T1 água (50 mL/animal); T2 closantel (10 mg/kg); T3 Curcubita sp. (3 g/kg); T4 Operculina sp. (8 g/kg); T5 Azadirachta indica (1 g/kg) e T6 Azadirachta indica (3 g/kg). As dosagens foram administradas após 12 horas de jejum, sob a forma de suco, por via oral. A eficácia dos tratamentos foi obtida pela contagem do OPG antes e sete dias após os tratamentos. A média do número de OPG antes dos tratamentos em todas as avaliações foi de 2.500 ovos. Apesar da discreta redução do OPG causada pelo T3 (41,0%) e T4 (34,9%) após a primeira administração, o OPG ainda permaneceu bastante elevado. Nos tratamentos T1, T5 e T6 foi observado aumento do OPG. A eficiência do closantel (T2) foi de 75,9%. Portanto, as dosagens utilizadas não apresentaram eficácia na redução do OPG

Produção de geléia à base de frutos da carnaubeira.

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Attitudes towards same-sex marriage in Portugal: predictors and scale validation

The goal of the present research was to validate a Portuguese version of Pearl and Galupo's (2007) Attitudes toward Same-Sex Marriage Scale (ATSM). Participants were 1,402 heterosexual men and women that completed an on-line questionnaire. The final 15-item scale formed a single factor showing high internal consistency (alpha = .95). This one factor structure was backed-up by a confirmatory factorial analysis. In a general way, the results indicate a clearly positive attitude toward same-sex marriage (overall mean was 63.79, SD = 12.66, above the scale mid-point, t(1401) = 55.55, p < .001). Furthermore, analysis of the scale's predictors demonstrates how a left-wing orientation (beta = .22, p < .001) and the level of denial of deservingness for lesbian/gay discrimination (beta = .30, p < .001) prove to be the best predictors of attitudes towards same-sex marriage. On the whole, these results indicate that the Portuguese ATSM version is a reliable instrument for carrying out scientific research and measuring and monitoring public opinion on this subject.info:eu-repo/semantics/acceptedVersio

Does the Brazilian soybean production increase pose a threat on the Amazon rainforest?

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Portuguese Adaptation of Students Engagement in Schools International Scale (SESIS)

The importance of student’s engagement has been recently pointed out in research. However, there has been a lack of engagement assessment instrument, pertaining psychometric qualities. Objective: This paper presents the Portuguese adaptation of the “Student’s Engagement in School International Scale” (SESIS), drawn up from a12 countries international study (Lam et al., 2012; Lam et al., in press). Method: Psychometric properties of this scale were examined with data from 685 students from different grades (6th, 7th, 9th and 10th), from both sexes, and different regions of the country. Results: Factorial analysis of the results, with varimax rotation, lead to three different factors which explain 50.88% of the variance. The scale integrates the original 33 items, and cognitive, affective and behavioural dimensions. For the external validity study, the relationship between student’s engagement in school results and other school variables — academic performance, self-concept — was considered, and significant relations were observed, as expected. Conclusion: The data presented highlights the qualities of SESIS, as well as its usefulness for research purposes. Suggestion: It is suggested the investigation of the extension of SESIS’s three-dimensionality, in future studiesKeywords: Innovation, technology, research projects, etc. [Arial 10-point, justified alignment]

Deconfined quantum criticality driven by Dirac fermions in SU(2) antiferromagnets

Quantum electrodynamics in 2+1 dimensions is an effective gauge theory for the so called algebraic quantum liquids. A new type of such a liquid, the algebraic charge liquid, has been proposed recently in the context of deconfined quantum critical points [R. K. Kaul {\it et al.}, Nature Physics {\bf 4}, 28 (2008)]. In this context, we show by using the renormalization group in $d=4-\epsilon$ spacetime dimensions, that a deconfined quantum critical point occurs in a SU(2) system provided the number of Dirac fermion species $N_f\geq 4$. The calculations are done in a representation where the Dirac fermions are given by four-component spinors. The critical exponents are calculated for several values of $N_f$. In particular, for $N_f=4$ and $\epsilon=1$ ($d=2+1$) the anomalous dimension of the N\'eel field is given by $\eta_N=1/3$, with a correlation length exponent $\nu=1/2$. These values change considerably for $N_f>4$. For instance, for $N_f=6$ we find $\eta_N\approx 0.75191$ and $\nu\approx 0.66009$. We also investigate the effect of chiral symmetry breaking and analyze the scaling behavior of the chiral holon susceptibility, $G_\chi(x)\equiv$.Comment: 13 pages, 3 figures; published versio

Efeito da adubação no crescimento de mudas de Eugenia uniflora L.

Eugenia uniflora é uma planta frutífera muito cultivada em pomares domésticos e frequente em seu habitat natural das matas semidecíduas. O objetivo deste trabalho foi verificar qual o efeito da adubação no crescimento de mudas de E. uniflora. Após a coleta e beneficiamento dos frutos, as sementes foram germinadas entre vermiculita e repicadas para tubetes contendo substrato comercial à base de casca de pinus. A adubação foi realizada semanalmente, durante três meses. Foram realizadas quatro avaliações, sendo determinado a altura e o diâmetro do colo das mudas. Na última avaliação as mudas adubadas apresentaram 17,9 cm de altura e 2,3 mm de diâmetro do colo, enquanto que as mudas não adubadas apresentaram 14,7 cm de altura e 1,7 mm de diâmetro do colo, demonstrando que as mudas de pitanga possuem resposta boa à adubação, ao contrário do proposto para espécies secundárias tardias ou climax. Concluiu-se que as mudas de E. uniflora responderam à adubação a partir do segundo mês, apresentando incremento tanto em altura como em diâmetro do colo.Resumo expandido