51 research outputs found
Assessing the conservation of Miombo timber species through an integrated index of anthropogenic and climatic threats
Aim: Angolan Miombo woodlands, rich in timber species of the Leguminosae family, go through one of the highest rates of deforestation in sub-Saharan Africa. This study presents, on the basis of updated information of the distribution of Leguminosae timber species native to Angola, an integrated index framing the main threats for trees, which aims to support new conservation measures. Location: Sub-Saharan Africa, Republic of Angola. Methods: The current distribution areas of six Leguminosae timber species (i.e., Afzelia quanzensis, Brachystegia spiciformis, Guibourtia coleosperma, Isoberlinia angolensis, Julbernardia paniculata, and Pterocarpus angolensis) were predicted through ensemble modeling techniques. The level of threat to each species was analyzed, comparing the species potential distribution with a threat index map and with the protected areas. The threat index of anthropogenic and climatic factors encompasses the effects of population density, agriculture, proximity to roads, loss of tree cover, overexploitation, trends in wildfires, and predicted changes in temperature and precipitation.
Results: Our results revealed that about 0.5% of Angola's area is classified as of “Very high” threat, 23.9% as “High” threat, and 66.5% as “Moderate” threat. Three of the studied species require special conservation efforts, namely B. spiciformis and I. angolensis, which have a large fraction of predicted distribution in areas of high threat, and G. coleosperma since it has a restricted distribution area and is one of the most
valuable species in international markets. The priority areas for the conservation of Leguminosae timber species were found in Benguela and Huíla.Main conclusions: This study provides updated data that should be applied to inform policymakers, contributing to national conservation planning and protection of native
flora in Angola. Moreover, it presents a methodological approach for the predictions of species distribution and for the creation of a threat index map that can be applied in other poorly surveyed tropical regions.info:eu-repo/semantics/publishedVersio
Cabo Verde’s Poaceae Flora: A Reservoir of Crop Wild Relatives Diversity for Crop Improvement
Africa is home to important centers of origin and diversity of crop wild relatives (CWR), including many species adapted to adverse agroecological conditions, namely drought and poor soils. Plant genetic resources from Cabo Verde Islands have been poorly explored for their potential to supplement the genetic pool of cultivated species. In this paper we identify Cabo Verde's CWR from the Poaceae family and provide a checklist of priority CWR taxa, highlighting those of particular conservation concern and the areas which should be the focus of the most intensive conservation efforts in these islands. Our results revealed that Cabo Verde archipelago is an important center of CWR diversity of West African crop millets, namely fonio (e.g., white fonio, Digitaria exilis, and black fonio, Digitaria iburua) and other African millets [e.g., pearl millet (Cenchrus americanus = Pennisetum glaucum), teff millet (Eragrostis tef), finger millet (Eleusine coracana), barnyard millet (Echinochloa colona), proso millet (Panicum miliaceum), and foxtail millet (Setaria italica)], which represent a diverse group of cereal crops, and important components in agriculture and food security of this country. Also, hotspot areas of diversity for in situ conservation were identified in Cabo Verde, as well as several populations occurring under extreme habitats conditions that are well adapted to drylands and poor soils. The evaluation of their potential for new ecologically important adaptive characteristics associated with tolerance to abiotic stresses is discussed. The survey of international Germplasm Banks revealed that very few accessions from Cabo Verde are conserved, contributing to the loss of genetic diversity of plant genetic resources in this archipelago. Particularly, the diversity of millets and the associated indigenous knowledge are critical for the food security and cultural identity of many poor farmers in Cabo Verde.info:eu-repo/semantics/publishedVersio
Disease-Causing Agents in Cashew: A Review in a Tropical Cash Crop
Due to the high market value of cashew nut, cashew became a significantly important cash
crop in many countries. Originating from Brazil, the plant was introduced into Africa, India, and
Southeast Asia and is nowadays found across most of the tropical regions. However, the diseases
that threaten and compromise crop production have not yet been comprehensively documented.
The aim of this study was to examine the published scientific data on cashew diseases, to identify
current knowledge gaps, and to present a review of the most important diseases and pathogens
affecting cashew productivity. The most described diseases are caused by fungi genera—mainly
Colletotrichum, Lasiodiplodia, and Erysiphe (worldwide); Cryptosporiopsis (East Africa); and recently
Fusarium in Tanzania. Other fungal genera (e.g., Septoria, Pilgeriella, and Pestalotia) may correspond
to emerging local cashew diseases that have not yet expanded to other geographic regions or for
which records are lacking. Gummosis (Lasiodiplodia spp.), which is considered the most prevalent and
damaging disease of cashew, has a pantropical distribution. There is large discrepancy concerning the
causal agents of cashew diseases that might be explained by the lack of proper species identification
through morpho-cultural and molecular approaches. This, in turn, can easily lead to misdiagnoses
that have serious negative consequences for the implementation of specific control actions. It is
important to establish a standardized identification workflow that will allow a reliable identification
of the disease-causing agent and to determine the occurrence and/or expansion of a given pathogen
across cashew-producing regionsinfo:eu-repo/semantics/publishedVersio
Improving thermal stability of the metastable bacteriocin LCN972
Póster presentado en el 11th International Symposium on Lactic Acid Bacteria, celebrado en Países Bajos, del 31 de agosto al 4 de septiembre de 2014.Bacteriocins are ribosomally‐synthesized antimicrobial peptides produced by
bacteria. Most LAB bacteriocins are pore formers but some are also active as cell
wall inhibitors by targeting cell wall precursors. GOALS
Lcn972 is a bacteriocin that inhibits cell wall biosynthesis at the division septum by
binding to lipid II. It is active exclusively against other lactococci and lacks any
post‐translational modifications. These features make Lcn972 an attractive
molecule as template for developing new antibiotics as it may bear a new lipid II
binding domain. Unfortunately Lcn972 unfolds irreversible at room temperature
preventing its use to map the interactions with lipid II.Grant BIO2010‐17414 (Ministerio de Economía y Competitividad ‐Spain) and PEstOE/EQB/LA0004/2011,Contract REDE/1517/RMN/2005 and PTDC/QUI‐BIQ/114904/2009 (Fundação para a Ciência e a Tecnologia‐Portugal.Peer reviewe
Species Diversity and Endemicity in the Angolan Leguminosae Flora
Angola has a great diversity of species and ecosystems and a high level of endemism. However, knowledge of the native flora remains very incomplete and outdated. Leguminosae is the largest family in the country, including many species which are of local or more regional economic importance. Based on an extensive review of bibliographic sources, natural history collections, and online databases, the checklist of Angolan Leguminosae plants was updated, including data on their native distribution, conservation status, and principal uses. The endemic taxa were the subject of additional investigation, including the main habitat, the number of collections preserved in herbaria, and the locality of the first collection. We identified 953 Leguminosae taxa occurring in Angola, of which 165 are endemic to the country. Among the 180 genera found, Crotalaria (136) and Indigofera (96) have the highest number of taxa. Almost half of the studied species have important applications, mainly in traditional medicine (385), forage (267), timber (188), and food (120). Nevertheless, only 27.7% have been assessed according to the IUCN Red List and 10 species are classified as threatened. Thirty-three endemics are known only from the type specimen, revealing the lack of knowledge on these species and the need for further field research. More than 30 type specimens were collected in the Serra da Chela, which highlights the importance of this region for biodiversity conservation.info:eu-repo/semantics/publishedVersio
Bayesian methods to analyze historical collections in time and space: a case study using Cabo Verde endemic flora
Original ResearchBiological collections, including herbarium specimens, are unique sources of biodiversity
data presenting a window on the history of the development and accumulation of
knowledge of a specific geographical region. Understanding how the process of
discovery impacts that knowledge is particularly important for oceanic islands which
are often characterized by both high levels of endemic diversity and high proportions of
threatened taxa. The archipelagos of the Macaronesian region (i.e. Azores, Canaries,
Savages, Madeira, and Cabo Verde) have been the focus of attention for scientific
expeditions since the end of the 17th century. However, there is no integrated study
describing the historical process of collecting, discovery and description of its flora.
Using as a case study the Cabo Verde endemic angiosperm flora, we review the history
of collecting in the flora and apply a Bayesian approach to assess the accumulation of
species discovery, through time and space across the nine islands of the archipelago.
Our results highlight the central role not only of natural characteristics (e.g. area, age,
maximum altitude and average value of the terrain ruggedness index) but also historical
factors (i.e. the location of major harbors) for the development of knowledge of the
flora. The main factors that have determined the process of species description in
the archipelago and how this impact our understanding of diversity patterns across
archipelagos are discussedinfo:eu-repo/semantics/publishedVersio
Conservation and sustainable use of the medicinal Leguminosae plants from Angola
Leguminosae is an economically important family that contains a large number of medicinal plants, many of which are widely used in African traditional medicine. Angola holds a great socio-cultural diversity and is one of the richest floristic regions of the world, with over 900 native Leguminosae species. This study is the first to assess the medicinal uses of the legumes in Angola and provides new data to promote the conservation and the sustainable use of these unique resources. We document the ethnobotanical knowledge on Angola by reviewing the most important herbarium collections and literature, complemented by recent field surveys. Our results revealed that 127 native legume species have medicinal uses and 65% of them have other important uses by local populations. The species with most medicinal applications are Erythrina abyssinica, Bauhinia thonningii and Pterocarpus angolensis. The rich flora found in Angola suggests an enormous potential for discovery of new drugs with therapeutic value. However, the overexploitation and the indiscriminate collection of legumes for multiple uses such as forage, food, timber and medical uses, increases the threats upon the native vegetation. Efforts to assess the conservation status of these species are urgently needed, and future actions should promote the sustainable use of medicinal plants in Angola together with the implementation of conservation strategies
Diversity of Useful Plants in Cabo Verde Islands: A Biogeographic and Conservation Perspective
Cabo Verde’s biodiversity is threatened by activities that meet human needs. To counteract this, an integration of scientific and indigenous knowledge is required, but no comprehensive list of the useful local plants is available. Thus, in this work, we assess (1) their diversity and phytogeography; (2) the role of geophysical, historical, and socio-economic factors on species distribution and uses; and (3) potentially relevant species for sustainable development. Data were obtained from flora, scientific publications, historical documents, herbarium specimens and field work. Many species were introduced since the 15th century to support settlement and commercial interests. We identified 518 useful taxa, of which 145 are native, 38 endemic and 44 endangered. The number of useful taxa is correlated with altitude and agricultural area, as well as with rural population indicators, but not with total population or socio-economic indicators such as gross domestic product. Native taxa are mostly used for fuelwood, forage and utilitarian purposes. Agrobiodiversity and traditional practices seem crucial to cope with recurrent droughts and ensure food security. Most of the introduced species do not present conservation problems, contrasting with the overuse of some native taxa. The safeguarding of native populations will ensure the sustainable exploitation of these resources and benefit the local economy.info:eu-repo/semantics/publishedVersio
Spatial and temporal trends of burnt area in Angola: implications for natural vegetation and protected area management
Fire is a key driver of natural ecosystems in Africa. However, human activity and
climate change have altered fire frequency and severity, with negative consequences for biodiversity
conservation. Angola ranks among the countries with the highest fire activity in sub-Saharan Africa.
In this study, we investigated the spatial and temporal trends of the annual burnt area in Angola,
from 2001 to 2019, and their association with terrestrial ecoregions, land cover, and protected areas.
Based on satellite imagery, we analyzed the presence of significant trends in burnt area, applying the
contextual Mann–Kendall test and the Theil–Sen slope estimator. Data on burnt areas were obtained
from the moderate-resolution imaging spectroradiometer (MODIS) burnt area product and the
analyses were processed in TerrSet. Our results showed that ca. 30% of the country’s area burned
every year. The highest percentage of annual burnt area was found in northeast and southeast Angola,
which showed large clusters of decreasing trends of burnt area. The clusters of increasing trends
were found mainly in central Angola, associated with savannas and grasslands of Angolan Miombo
woodlands. The protected areas of Cameia, Luengue-Luiana, and Mavinga exhibited large areas
of decreasing trends of burnt area. Conversely, 23% of the Bicuar National Park was included in
clusters of increasing trends. Distinct patterns of land cover were found in areas of significant trends,
where the clusters of increasing trends showed a higher fraction of forest cover (80%) than the clusters
of decreasing trends (55%). The documentation of burnt area trends was very important in tropical
regions, since it helped define conservation priorities and management strategies, allowing more
effective management of forests and fires in countries with few human and financial resourcesinfo:eu-repo/semantics/publishedVersio
Aprendizaje en línea durante COVID-19 con estudiantes de ingeniería de zonas rurales marginadas en México
COVID-19 has affected education worldwide, in Mexico. In this study, the impact of the extraordinary online modality because of the pandemic on the accreditation of courses for engineering students was evaluated, of the 64 students officially registered in three courses of microbiology, only 90% registered on the Moodle platform to take the online course, 71% of the dynamics were delivered, 67% of the final project and 80% of the delivery of the team's activities were not reached, there was an approval of 54%. Some problems were that videoconferences were not attended and assignments were not turned in
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