115 research outputs found

    Bioavailability of heavy metals and their effects on the midgut cells of a phytopaghous insect inhabiting volcanic environments

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    © 2008 Elsevier B.V. All rights reserved.Organisms living in volcanic environments are chronically exposed to metals, either as particles or associated with gases, from volcanic emissions, being therefore potential sentinels of the effects derived from such exposure. Concentrations of Ca, Cd, Cu, Mg, Mn, Pb, Rb, and Zn were measured in soil, grass (Lolium perenne), and larvae of Pseudaletia uninpuncta captured in sites exposed and non-exposed to volcanic activity. The midgut epithelial cell morphometry and apoptosis of P. unipuncta larvae were also analyzed. Larvae from the site with volcanic activity showed higher levels of Cu, Mn, Rb and Zn. Metals such as Pb, Cd and Mg levels of P. unipuncta larvae were similar between sites. Apoptosis was higher in cells from digestive epithelium of larvae exposed to volcanic activity. Soils and grass not exposed to volcanic activity showed higher levels for most of the analyzed elements with the exception of Rb. Such result when compared with metal levels of larvae may reveal that bioavailability of elements differs between sites. The higher levels of Cd, Zn and Mg in soils and grass from the site with no volcanic activity are probably related to the severe artificial fertilization in the studied pastures. Such result, when compared with metal levels of larvae, suggest that the bioavailability of metals differs between sites.CIRN, Centro de Investigação de Recursos Naturais, Ponta Delgada

    Slurry preparation methods affect dental porcelain reliability

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    One-step and incremental mixing procedures are currently used to produce dental ceramic pastes. In the ceramic industry, high quality is obtained using one-step mixing, but in dentistry, the best method has not been yet determined. The purpose of this study is to evaluate the effects of 2 mixing techniques on the biaxial flexural strength and microstructure of dental porcelain. Feldspathic porcelain discs (2 × 15 mm in diameter) were produced and divided according to the ceramic paste preparation method, powder-liquid incremental mixing group (n=50) or one-step mixing, as a control group (n=50). Specimens were tested for biaxial flexural strength and characterized using porosimetry, relative humidity, SEM/EDS, XRD, and FT-IR analyses. Statistical analysis was conducted using Weibull statistics. The Weibull modulus, characteristic strength and relative humidity were compared between groups, using Student's t-test and Mann-Whitney U test (a=.05). The powder-liquid incremental mixing group showed significantly higher values (SD) of Weibull modulus (6.74 (0.70), P<.001) and characteristic strength (79.87 (2.01) MPa, P<.001) when compared to the one-step mixing group (4.94 (0.94) and 75.95 (2.61) MPa). Significantly lower mean (SD) relative humidity values (P=.009) were found for powder-liquid incremental mixing group (20% (0.5%)) compared to one-step mixing group (22% (1%)). XRD spectra showed that the one-step mixing group produced higher amounts of the amorphous phase. Specimens produced by the incremental mixing technique showed higher biaxial flexural strength than one-step mixing

    Aldicarb leaching in macrolysimeters of two Latosols

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    O objetivo deste trabalho foi avaliar a lixiviação do inseticida aldicarbe em macrolisímetros contendo material indeformado dos solos Latossolo Vermelho distroférrico (LVdf) e Latossolo Vermelho-Amarelo distrófico (LVAd), em condições de campo. Uma formulação granulada de aldicarbe foi aplicada na dose recomendada, a 5 cm de profundidade, em lisímetros de 1,0 m de diâmetro e 0,45 e 0,90 m de profundidade, no início do período chuvoso. Nos cinco meses seguintes, o volume de água percolada nos lisímetros foi medido e amostras de água foram analisadas por cromatografia gás-líquido para a determinação da concentração de resíduos do composto. Os resíduos de aldicarbe e de seus produtos de oxidação ativos, sulfóxido e sulfona de aldicarbe, foram conjuntamente determinados na forma de sulfona de aldicarbe. Houve alta mobilidade dos resíduos de aldicarbe nos solos, porém, a intensa degradação desses resíduos resultou em sua lixiviação em quantidades relativamente baixas, a profundidades abaixo de 0,45 m (4,9% e 5,9% no LVdf e LVAd, respectivamente); na água percolada nos lisímetros de 0,90 m foram detectados resíduos apenas no LVdf. O risco de contaminação do lençol freático nos solos estudados, caracterizados como muito profundos, é mínimo.The objective of this work was to evaluate the leaching of aldicarb in macrolysimeters containing undisturbed soil material of a distroferric Red Latosol and of a distrofic Red Yellow Latosol, under field conditions. A granular formulation of the aldicarb pesticide was applied at the recommended rate, at 5 cm depth, in soil columns of 1.0 m diameter by 0.45 and 0.90 m long, at the beginning of the rainy season. The volume of percolated water in each lysimeter was measured during the subsequent five months, and water samples were analysed by gas-liquid chromatography for the determination of the pesticide residues concentration. Residues of aldicarb and its toxic transformation products, aldicarb sulfoxide and aldicarb sulfone, were jointly determined as aldicarbe sulfone. There was high mobility of aldicarb residues in soils, although their fairly rapid degradation in the soil resulted in the leaching of relatively low amounts below the depth of 0.45 m (4.9% for the distroferric Red Latosol and 5.9% for the distrofic Red Yellow Latosol). In 0.90 m lysimeters, aldicarb residues were detected only in the percolated water of the distroferric Red Latosol. Groundwater contamination risk in these soils, pointed out as too deep, is remote

    Volto Já:um modelo de negócio na área do turismo social de intercâmbio sénior

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    Apresenta-se o modelo de negócio do PROJETO VOLTO JÁ, cujo objetivo geral consiste na operacionalização de um programa de intercâmbio social sénior, entre organizações de economia social, procurando promover experiências turísticas aos idosos. O modelo de negócio proposto baseia-se na partilha de recursos como forma de potenciar a proposta de valor acrescentado. O VOLTO JÁ desenvolve um conjunto de ações com impacto direto na mobilidade e inclusão social dos idosos, enquadrando-se nas abordagens conceptuais do turismo social e do turismo para todos. Esta investigação apresenta um processo de recolha de dados com duas fases. Na primeira fase, foi aplicado um questionário a uma amostra de 134 indivíduos seniores institucionalizados, de 8 instituições na região do Alentejo, para caraterizar o perfil dos idosos e os interesses associados à prática de turismo. Na segunda fase, realizaram-se dois focus groups junto de uma amostra de 6 diretores técnicos de Instituições Particulares de Solidariedade Social, de modo a perceber as condições e a disponibilidade de participação dos seniores. Os resultados serão utilizados para desenvolver uma plataforma web para disponibilizar/comercializar, a baixo custo, as ofertas ao nível de pacotes turísticos de turismo social, num trabalho concertado com os agentes da oferta turística.info:eu-repo/semantics/publishedVersio

    DISTRIBUIÇÃO DIAMÉTRICA DE Araucaria angustifolia (Bert.) O. Ktze. EM UM FRAGMENTO DE FLORESTA OMBRÓFILA MISTA

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    The objective of the present research was to evaluate the behavior of probabilistic density functions for fitting of Araucaria angustifolia diameter distribution taking in account 3 different class intervals. The data used for fitting the functions came from a complete enumeration forest inventory of a Mixed Ombrophylous Forest fragment with 15.24 ha, located at the Campus III of the Federal University of Paraná. The diameters of 341 araucárias trees were measured at 1.3 m (DBH). The following probabilistic density functions were fitted: Normal, Log-Normal, Gamma, Beta, Weibull 3P, Weibull 2P and Sb of Johnson. The diameter class intervals of 2 cm, 5 cm and 6.55 cm were tested. The results of the Kolmogorov-Smirnov test indicated that the most efficient function for class intervals with amplitude of 6.55 cm and 2 cm was the Normal and for amplitudes of 5 cm the Sb function was the best one. The Weibull 2P function was rejected by the Kolmogorov-Smirnov adherence test for all diameter class intervals adopted. This research also indicated that the Araucaria angustifolia diameter distribution is symmetric and platicurtic.O objetivo do presente estudo foi avaliar o comportamento de Funções de Densidade Probabilística no ajuste da distribuição diamétrica de Araucaria angustifolia levando em consideração diferentes intervalos de classe de diâmetro. Os dados utilizados para o ajuste das funções provieram do censo realizado no Capão da Engenharia Florestal, correspondente a um fragmento de Floresta Ombrófila Mista de 15,24 ha, localizado no Campus III da Universidade Federal do Paraná. Nesse censo foram medidos os diâmetros a 1,3 m de altura (DAP) de 341 araucárias. Para avaliar a distribuição diamétrica de Araucaria angustifolia nesse fragmento foram ajustadas as seguintes funções de densidade probabilística: Normal, Log-Normal, Gamma, Beta, Weibull 3P, Weibull 2P e Sb de Johnson. Foram definidos intervalos de classes com 2 cm, 5 cm e 6,55 cm. Os resultados do teste de Kolmogorov-Smirnov indicaram que, a função mais eficiente para intervalos de classes com amplitudes de 6,55 cm e 2 cm foi a Normal e para intervalos de classes de 5 cm a Sb de Johnson. A função Weibull 2P foi rejeitada pelo teste de aderência para todos os intervalos de classe adotados. O estudo também identificou que a distribuição diamétrica de Araucaria angustifolia nesse fragmento é simétrica e platicúrtica

    I'll be right back:senior exchange program

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    Modern society presents an unprecedented ageing process and an increasing number of elderly people. In tourism industry, the increase of active ageing practices, as well as the importance of improvement of the quality of life of elderly, increase their interest and readiness to participate in various touristic activities. It encourage, as well, one market segment–the senior tourism–that enhances the creation of employment and can help to fight the seasonal nature of the tourism sector.Considering the characteristics of this age group, some limitations relative to the autonomy, and alower purchasing power, touristic packages have to be adapted to take into account the specific profile of elderly. The public that this project addresses is the institutionalized elderly in the Sector of Social Economy organisations.Considering the characteristics of this age group, some limitations relative to the autonomy, and a lower purchasing power, touristic packages have to be adapted to take into account the specific profile of elderly. The public that this project addresses is the institutionalized elderly in the Sector of Social Economy organisations.In Portugal, this public has a lack of economic and financial resources, and is growing in number, as well as in economic and social difficulties. This project focuses in Social Tourism for low-income groups, particularly institutionalized seniors, who would not otherwise go on holiday. Special focus will be put on the elderly population motivations to experiment new cultural expressions and on the impact that this process may have on their cognitive abilities and culture.N/

    Treatment and prevention of epilepsy in onchocerciasis-endemic areas is urgently needed.

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    Background There is increasing epidemiological evidence supporting the association between onchocerciasis and seizures, reinforcing the concept of onchocerciasis-associated epilepsy (OAE). The aim of this paper is to provide an update on the new knowledge about OAE and to propose recommendations to the World Health Organization how to address this public health problem. Main text During the 2nd International Workshop on OAE held on 19-21 September, 2023, in Antwerp, Belgium, participants recognised OAE as a substantial yet neglected public health problem, particularly in areas of sub-Saharan Africa where onchocerciasis remains hyperendemic. Evidence from prospective population-based studies suggest that strengthening onchocerciasis elimination efforts leads to a significant reduction of OAE incidence. There is a need to validate an OAE case definition to estimate the burden of disease and identify onchocerciasis-endemic areas requiring intensification of onchocerciasis elimination programmes and integration of epilepsy care. It is expected that raising awareness about OAE will boost the population uptake of ivermectin. The implementation of a community-based epilepsy treatment programme offering free anti-seizure medications (ASMs) has shown high effectiveness in reducing the frequency of seizures and improving the overall quality of life of people with epilepsy. Conclusions To reduce OAE burden, enhanced collaboration between onchocerciasis and mental health programmes at community, national, and international levels is required. Urgent efforts are needed to ensure the uninterrupted provision of free ASMs in onchocerciasis-endemic areas. Furthermore, OAE should be included in the quantification of the onchocerciasis disease burden
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