102 research outputs found

    Aquisições públicas em Cabo Verde: desafios e potencialidades para promover o desenvolvimento rural

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    Este trabalho tem por objectivo verificar os desafios e oportunidades existentes na ligação entre o Programa de Alimentação Escolar e produção local em Cabo Verde. Entrevistas semi-estruturadas, observação in loco e dados secundários foram utilizados para coleta de dados. Constatou-se a necessidade de mudanças estruturais do Programa, descentralizando as compras públicas, introduzindo produtos locais no menu e melhorando as condições físicas das cozinhas e armazéns. Relativamente à produção, é possível afirmar que há quantidade suficiente para abastecimento, mas deficiências no processamento, escoamento e comercialização, com necessidade de investimentos em extensão rural, organização dos agricultores e crédito rural. Considera-se que a descentralização das compras poderia desonerar o Estado em relação aos custos com a logística e facilitar as aquisições dos produtores locais, tornando o Programa sustentável e vector de desenvolvimento.This work aims at studying the challenges and opportunities in this connection between School Feeding Program and local agriculture in Cape Verde. Semi-structured interviews, observation and secondary data were used for data collection. It was noted the need for structural changes of Program, decentralizing public procurement by introducing local products on the menu and improving the physical condition of kitchens and warehouses. On the side of the production, there is sufficient quantity to supply, but deficiencies in the processing, distribution and marketing, requiring investments in agricultural extension, organization of farmers and rural credit. It is considered that the decentralization of food procurement would relieve the State in relation to the cost of logistics, the Program would becoming sustainable and a vector of development

    Fruits, Frugivores, and the Evolution of Phytochemical Diversity

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    Plants produce an enormous diversity of secondary metabolites, but the evolutionary mechanisms that maintain this diversity are still unclear. The interaction diversity hypothesis suggests that complex chemical phenotypes are maintained because different metabolites benefit plants in different pairwise interactions with a diversity of other organisms. In this synthesis, we extend the interaction diversity hypothesis to consider that fruits, as potential hotspots of interactions with both antagonists and mutualists, are likely important incubators of phytochemical diversity. We provide a case study focused on the Neotropical shrub Piper reticulatum that demonstrates: 1) secondary metabolites in fruits have complex and cascading effects for shaping the outcome of both mutualistic and antagonistic fruit–frugivore interactions, and; 2) fruits can harbor substantially higher levels of phytochemical diversity than leaves, even though leaves have been the primary focus of plant chemical ecology research for decades. We then suggest a number of research priorities for integrating chemical ecology with fruit–frugivore interaction research and make specific, testable predictions for patterns that should emerge if fruit interaction diversity has helped shape phytochemical diversity. Testing these predictions in a range of systems will provide new insight into the mechanisms driving frugivory and seed dispersal and shape an improved, whole-plant perspective on plant chemical trait evolution

    Les Pédo-paysages des plaines centrales de Midi-Pyrénées

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    Les sols des zones de plaines de la région Midi-Pyrénées montrent une grande diversité liée, notamment, au carrefour des influences climatiques passées et actuelles : glaciaire, méditerranéenne et atlantique. Le présent article illustre la distribution des principales Unités Typologiques de Sols parmi les Unités pédo-paysagères dans les zones de plaines depuis le nord du Lot jusqu'au piémont ariégeois. La couverture pédologique y est très marquée par la nature des grands ensembles sédimentaires, depuis les contreforts du Massif central, jusqu'à la Molasse argilo-calcaire très largement étendue dans le bassin toulousain

    Conditions of emergence of the Sooty Bark Disease and aerobiology of Cryptostroma corticale in Europe

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    The sooty bark disease (SBD) is an emerging disease affecting sycamore maple trees (Acer pseudoplatanus) in Europe. Cryptostroma corticale, the causal agent, putatively native to eastern North America, can be also pathogenic for humans causing pneumonitis. It was first detected in 1945 in Europe, with markedly increasing reports since 2000. Pathogen development appears to be linked to heat waves and drought episodes. Here, we analyse the conditions of the SBD emergence in Europe based on a three-decadal time -series data set. We also assess the suitability of aerobiological samples using a species-specific quantitative PCR assay to inform the epidemiology of C. corticale, through a regional study in France comparing two-year aerobiological and epidemiological data, and a continental study including 12 air samplers from six countries (Czechia, France, Italy, Portugal, Sweden and Switzerland). We found that an accumulated water deficit in spring and summer lower than-132 mm correlates with SBD outbreaks. Our results suggest that C. corticale is an efficient airborne pathogen which can dis-perse its conidia as far as 310 km from the site of the closest disease outbreak. Aerobiology of C. corticale followed the SBD distribution in Europe. Pathogen detection was high in countries within the host native area and with longer disease presence, such as France, Switzerland and Czech Republic, and sporadic in Italy, where the pathogen was reported just once. The pathogen was absent in samples from Portugal and Sweden, where the disease has not been reported yet. We conclude that aerobiological surveillance can inform the spatial distribution of the SBD, and contribute to early detection in pathogen-free countries

    Conditions of emergence of the Sooty Bark Disease and aerobiology of Cryptostroma corticale in Europe

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    The sooty bark disease (SBD) is an emerging disease affecting sycamore maple trees (Acer pseudoplatanus) in Europe. Cryptostroma corticale, the causal agent, putatively native to eastern North America, can be also pathogenic for humans causing pneumonitis. It was first detected in 1945 in Europe, with markedly increasing reports since 2000. Pathogen development appears to be linked to heat waves and drought episodes. Here, we analyse the conditions of the SBD emergence in Europe based on a three-decadal time- series data set. We also assess the suitability of aerobiological samples using a species-specific quantitative PCR assay to inform the epidemiology of C. corticale, through a regional study in France comparing two- year aerobiological and epidemiological data, and a continental study including 12 air samplers from six countries (Czechia, France, Italy, Portugal, Sweden and Switzerland). We found that an accumulated water deficit in spring and summer lower than -132 mm correlates with SBD outbreaks. Our results suggest that C. corticale is an efficient airborne pathogen which can dis- perse its conidia as far as 310 km from the site of the closest disease outbreak. Aerobiology of C. corticale followed the SBD distribution in Europe. Pathogen detection was high in countries within the host native area and with longer disease presence, such as France, Switzerland and Czech Republic, and sporadic in Italy, where the pathogen was reported just once. The pathogen was absent in samples from Portugal and Sweden, where the disease has not been reported yet. We conclude that aerobiological surveillance can inform the spatial distribution of the SBD, and contribute to early detection in pathogen-free countriesinfo:eu-repo/semantics/publishedVersio

    The gp38 Adhesins of the T4 Superfamily: A Complex Modular Determinant of the Phage’s Host Specificity

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    The tail fiber adhesins are the primary determinants of host range in the T4-type bacteriophages. Among the indispensable virion components, the sequences of the long tail fiber genes and their associated adhesins are among the most variable. The predominant form of the adhesin in the T4-type phages is not even the version of the gene encoded by T4, the archetype of the superfamily, but rather a small unrelated protein (gp38) encoded by closely related phages such as T2 and T6. This gp38 adhesin has a modular design: its N-terminal attachment domain binds at the tip of the tail fiber, whereas the C-terminal specificity domain determines its host receptor affinity. This specificity domain has a series of four hypervariable segments (HVSs) that are separated by a set of highly conserved glycine-rich motifs (GRMs) that apparently form the domain’s conserved structural core. The role of gp38’s various components was examined by a comparative analysis of a large series of gp38 adhesins from T-even superfamily phages with differing host specificities. A deletion analysis revealed that the individual HVSs and GRMs are essential to the T6 adhesin’s function and suggests that these different components all act in synergy to mediate adsorption. The evolutionary advantages of the modular design of the adhesin involving both conserved structural elements and multiple independent and easily interchanged specificity determinants are discussed

    Exploring marine ecosystems with elementary school Portuguese children: inquiry-based project activities focused on ‘real-life’ contexts

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    The purpose of the study was to investigate how young students engage in an inquirybased project driven by real-life contexts. Elementary school children were engaged in a small inquiry project centred on marine biodiversity and species adaptations. All activities included the exploration of an out-of-school setting as a learning context. A total of 49 students and 2 teachers were involved in the activities. The research methods included observation, document analysis and content analysis of the answers to a questionnaire and an interview. The results revealed that most of the students acquired scientific knowledge related to biological diversity and adaptations to habitat. Moreover, students progressively demonstrate greater autonomy, argumentative ability and decision-making. One implication of the present study is that elementary science curriculum could be better managed with inquiry projectbased activities that explore different types of resources and out-of-school settings.info:eu-repo/semantics/publishedVersio
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