L'Association des Elèves de l'UniCampo (AAUC) : d'un réseau d'acteurs à une organisation de développement

The main objective of APPRI Workshop was to analyse conditions for implementing alternative action-research practices in partnership for development, taking into account the difficulties of "official" research and of the rural world, faced with the major challenges of sustainable development in the South. One originality of APPRI was to compare experiences from rural zones of Africa, with those of the UNICAMPO Peasants' University set up 10 years ago in the Brazilian Nordeste, a semi-arid region where small holders' farms exhibit some major similarities with those in Drylands Africa. The "Peasants' University" concept was unanimously chosen as a place to unify partnership initiatives bringing together research, rural development officers, farmer's organizations and rural communities. These Peasants' Universities will be places of learning where a common vision is shared for implementing development and environmental improvement activities. The APPRI group unanimously accepted that technical and institutional innovation in partnership is paramount. It needs to be co-constructed from local know-how and scientific and technical knowledge. Information and communication between all those involved in development needs to be revised and strengthened for ore interactivity and efficiency in order to contribute to cultural recognition and social economic transformation of rural communities. L'objectif de l'atelier APPRI était principalement d'analyser les conditions de mise en œuvre de pratiques alternatives de recherche-action en partenariat pour le développement, prenant en compte les difficultés de la recherche "officielle" et du monde rural face aux grands enjeux du développement durable au Sud. Une originalité d'APPRI était de confronter les expériences des zones rurales africaines à celles de l'Université Paysanne UNICAMPO mise en place depuis 10 ans dans le Nordeste brésilien, région semi-aride où les petites exploitations familiales présentent de grandes similitudes avec celles des zones sèches d'Afrique. Le concept d' "Université Paysanne" a été retenu à l'unanimité comme lieu de fédération d'initiatives en partenariat regroupant la recherche, les agents du développement rural, les organisations et groupements de producteurs et les communautés rurales. Ces universités paysannes seront des lieux d'apprentissage où se partage une vision commune pour la mise en œuvre d'actions de développement et de valorisation du milieu destinées. De façon unanime, le groupe APPRI2008 admet que l'innovation technique et institutionnelle en partenariat est centrale. Elle doit être co-construite à partir des savoirs locaux et de la connaissance scientifique et technique. L'information et la communication entre tous les acteurs du développement doivent être repensées et renforcées pour être plus interactives et plus efficaces afin de participer à la reconnaissance culturelle et la transformation sociale et économique des communautés rurales

Study of the magnetohydrodynamic flow of a Newtonian fluid using Laplace transform / Estudo do escoamento magnetohidrodinâmico de um fluido Newtoniano via transformada de Laplace

The present work studies the magnetohydrodynamic flow of a Newtonian fluid as a complementary case of the simple flow in a parallel plate channel. The effects of kinematic parameters and the influence of the transverse and uniform magnetic field on the fields of speed, flow and shear rate are analyzed. To solve the equations that govern movement, the Laplace Transform technique was used, and the Python programming language and wxMaxima program for the construction of graphs and convergence analysis, respectively. The results obtained were analyzed for different values of the Hartmann’s number and the limit case in which this parameter tends to zero compared to the simple flow in the absence of a field. The study showed the effect of the magnetic field on the velocity profile and other derived properties. And the limit case proved to be compatible with the case in which there is no magnetic field applied. In general, the work proved to be valid as a complementary study of the simple case, since the results obtained for the limit case clearly express its tendency towards the simple case presented by the literature

A list of land plants of Parque Nacional do Caparaó, Brazil, highlights the presence of sampling gaps within this protected area

Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of “Parque Nacional do Caparaó” (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states

Os fatores determinantes e as complicações oriundas do crescimento fetal restrito: Determining factors and complications arising from restricted fetal growth

O feto portador de restrição do crescimento fetal intra-uterino evolui sem alcançar o seu potencial genético de crescimento. Destacando, que o Crescimento Intra-Uterino Restrito (CIUR) condiz a um complexo heterogêneo, caracterizado pela maioria ser de fetos biologicamente pequenos, mas não se encaixam na condição patológica, a qual urge por monitoramento. Neste contexto, pode estar ou não relacionado a inúmeras doenças a qual necessitam ser diagnosticadas. O objetivo deste estudo foi analisar os fatores relacionados na etiologia e das complicações da restrição do crescimento intra-uterino. As informações existentes na literatura evidenciam a existência de vários desencadeantes nesta ocorrência, a qual abordam a associação de fatores maternos, placentários e fetais. Os distintos grupos possivelmente podem coexistir de modo simultâneo, sendo parte destes passíveis de prevenção

Local hydrological conditions influence tree diversity and composition across the Amazon basin

Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well-drained and potentially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of 443 1-ha non-flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1) tree alpha diversity, 2) the community-weighted wood density mean (CWM-wd) – a proxy for hydraulic resistance and 3) tree species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more evident in wetter forests, where diversity increases towards locations with well-drained soils. CWM-wd increased towards better drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients in Central-Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood density of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R$^{2}$ = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R$^{2}$ = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types