Universidade Estadual do Maranhão
UniversitySão Luís, Brazil
Research output, citation impact, and the most-cited recent papers from Universidade Estadual do Maranhão (Brazil). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Universidade Estadual do Maranhão
Abstract Most of the planet's diversity is concentrated in the tropics, which includes many regions undergoing rapid climate change. Yet, while climate‐induced biodiversity changes are widely documented elsewhere, few studies have addressed this issue for lowland tropical ecosystems. Here we investigate whether the floristic and functional composition of intact lowland Amazonian forests have been changing by evaluating records from 106 long‐term inventory plots spanning 30 years. We analyse three traits that have been hypothesized to respond to different environmental drivers (increase in moisture stress and atmospheric CO 2 concentrations): maximum tree size, biogeographic water‐deficit affiliation and wood density. Tree communities have become increasingly dominated by large‐statured taxa, but to date there has been no detectable change in mean wood density or water deficit affiliation at the community level, despite most forest plots having experienced an intensification of the dry season. However, among newly recruited trees, dry‐affiliated genera have become more abundant, while the mortality of wet‐affiliated genera has increased in those plots where the dry season has intensified most. Thus, a slow shift to a more dry‐affiliated Amazonia is underway, with changes in compositional dynamics (recruits and mortality) consistent with climate‐change drivers, but yet to significantly impact whole‐community composition. The Amazon observational record suggests that the increase in atmospheric CO 2 is driving a shift within tree communities to large‐statured species and that climate changes to date will impact forest composition, but long generation times of tropical trees mean that biodiversity change is lagging behind climate change.
Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, and biomass. We found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms. However, high species dissimilarity across tropical locations may cause diversity across the entirety of the tropics to be higher than elsewhere. Climate variables were found to be more important in shaping earthworm communities than soil properties or habitat cover. These findings suggest that climate change may have serious implications for earthworm communities and for the functions they provide.
's estimate (Reports, 5 July 2019, p. 76) that tree planting for climate change mitigation could sequester 205 gigatonnes of carbon is approximately five times too large. Their analysis inflated soil organic carbon gains, failed to safeguard against warming from trees at high latitudes and elevations, and considered afforestation of savannas, grasslands, and shrublands to be restoration.
Estudos sobre a climatologia das precipitações no Estado do Pará são essenciais para o planejamento das atividades agrícolas. A variação da precipitação anual e sazonal no Estado do Pará foi analisada com base em séries históricas de 23 anos (1976-1998) de dados diários de chuva. A análise foi realizada para 31 localidades do Estado do Pará, sendo os resultados representados em mapas com a utilização de técnicas de sistemas de informações geográficas (SIG). A variabilidade da precipitação anual e sazonal foi caracterizada com base no coeficiente de variação e no índice de variabilidade interanual relativo. A variação desses coeficientes para a precipitação anual no Estado do Pará foi de 15 a 30%. As características mensais da estação chuvosa, em termos de início, fim e duração, foram determinadas utilizando-se o critério proposto por KASSAM (1979). A variação entre as datas de plantio precoces e tardias corresponderam aos decêndios identificados pelos dias julianos 309319 e 353363, respectivamente.
Plant genotype selects the rhizosphere microbiome. The success of plant–microbe interactions is dependent on factors that directly or indirectly influence the plant rhizosphere microbial composition. We investigated the rhizosphere bacterial community composition of seven different sorghum cultivars in two different soil types (abandoned (CF) and agricultural (VD)). The rhizosphere bacterial community was evaluated at four different plant growth stages: emergence of the second (day 10) and third leaves (day 20), the transition between the vegetative and reproductive stages (day 35), and the emergence of the last visible leaf (day 50). At early stages (days 10 and 20), the sorghum rhizosphere bacterial community composition was mainly driven by soil type, whereas at late stages (days 35 and 50), the bacterial community composition was also affected by the sorghum genotype. Although this effect of sorghum genotype was small, different sorghum cultivars assembled significantly different bacterial community compositions. In CF soil, the striga-resistant cultivar had significantly higher relative abundances of Acidobacteria GP1, Burkholderia, Cupriavidus (Burkholderiaceae), Acidovorax and Albidiferax (Comamonadaceae) than the other six cultivars. This study is the first to simultaneously investigate the contributions of plant genotype, plant growth stage and soil type in shaping sorghum rhizosphere bacterial community composition.
Inorganic fertilization and mowing alter soil factors with subsequent effects-direct and indirect - on above- and below-ground communities. We explored direct and indirect effects of long-term fertilization (N, P, NPK, Liming) and twice yearly mowing on the plant, bacterial and fungal communities and soil factors. We analyzed co-variation using 16S and 18S rRNA genes surveys, and plant frequency and edaphic factors across treatments. The plant and fungal communities were distinct in the NPK and L treatments, while the bacterial communities and soil factors were distinct in the N and L treatments. Plant community diversity and evenness had low diversity in the NPK and high diversity in the liming treatment, while the diversity and evenness of the bacterial and fungal communities did not differ across treatments, except of higher diversity and evenness in the liming treatment for the bacteria. We found significant co-structures between communities based on plant and fungal comparisons but not between plant and bacterial nor bacterial and fungal comparisons. Our results suggested that the plant and fungal communities are more tightly linked than either community with the bacterial community in fertilized soils. We found co-varying plant, bacterial and fungal taxa in different treatments that may indicate ecological interactions.
BACKGROUND: Brazilian spotted fever (BSF), caused by the bacterium Rickettsia rickettsii, has been associated with the transmission by the tick Amblyomma sculptum, and one of its main hosts, the capybara (Hydrochoerus hydrochaeris). METHODS: During 2015-2019, we captured capybaras and ticks in seven highly anthropic areas of São Paulo state (three endemic and four nonendemic for BSF) and in two natural areas of the Pantanal biome, all with established populations of capybaras. RESULTS: The BSF-endemic areas were characterized by much higher tick burdens on both capybaras and in the environment, when compared to the BSF-nonendemic areas. Only two tick species (A. sculptum and Amblyomma dubitatum) were found in the anthropic areas; however, with a great predominance of A. sculptum (≈90% of all ticks) in the endemic areas, in contrast to a slight predominance of A. dubitatum (≈60%) in the nonendemic areas. Tick species richness was higher in the natural areas, where six species were found, albeit with a predominance of A. sculptum (≈95% of all ticks) and environmental tick burdens much lower than in the anthropic areas. The BSF-endemic areas were characterized by overgrowth populations of A. sculptum that were sustained chiefly by capybaras, and decreased populations of A. dubitatum. In contrast, the BSF-nonendemic areas with landscape similar to the endemic areas differed by having lower tick burdens and a slight predominance of A. dubitatum over A.sculptum, both sustained chiefly by capybaras. While multiple medium- to large-sized mammals have been incriminated as important hosts for A. sculptum in the natural areas, the capybara was the only important host for this tick in the anthropic areas. CONCLUSIONS: The uneven distribution of R. rickettsii infection among A. sculptum populations in highly anthropic areas of São Paulo state could be related to the tick population size and its proportion to sympatric A. dubitatum populations.
Selenium (Se) is an essential element for humans and animals that is required for key antioxidant reactions, but can be toxic at high concentrations. We have investigated the effect of Se in the form of selenite on coffee cell suspension cultures over a 12-day period. The antioxidant defence systems were induced in coffee cells grown in the presence of 0.05 and 0.5 mm sodium selenite (Na2SeO3). Lipid peroxidation and alterations in antioxidant enzymes were the main responses observed, including a severe reduction in ascorbate peroxidase activity, even at 0.05 mm sodium selenite. Ten superoxide dismutase (SOD) isoenzymes were detected and the two major Mn-SOD isoenzymes (bands V and VI) responded more to 0.05 mm selenite. SOD band V exhibited a general decrease in activity after 12 h of treatment with 0.05 mm selenite, whereas band VI exhibited the opposite behavior and increased in activity. An extra isoenzyme of glutathione reductase (GR) was induced in the presence of selenite, which confirmed our previous results obtained with Cd and Ni indicating that this GR isoenzyme may have the potential to be a marker for oxidative stress in coffee.
BACKGROUND: Childhood pneumonia is a major cause of childhood illness and the second leading cause of child death globally. Understanding the costs associated with the management of childhood pneumonia is essential for resource allocation and priority setting for child health. METHODS: We conducted a systematic review to identify studies reporting data on the cost of management of pneumonia in children younger than 5 years old. We collected unpublished cost data on non-severe, severe and very severe pneumonia through collaboration with an international working group. We extracted data on cost per episode, duration of hospital stay and unit cost of interventions for the management of pneumonia. The mean (95% confidence interval, CI) and median (interquartile range, IQR) treatment costs were estimated and reported where appropriate. RESULTS: We identified 24 published studies eligible for inclusion and supplemented these with data from 10 unpublished studies. The 34 studies included in the cost analysis contained data on more than 95 000 children with pneumonia from both low- and-middle income countries (LMIC) and high-income countries (HIC) covering all 6 WHO regions. The total cost (per episode) for management of severe pneumonia was US$ 4.3 (95% CI 1.5-8.7), US$ 51.7 (95% CI 17.4-91.0) and US$ 242.7 (95% CI 153.6-341.4)-559.4 (95% CI 268.9-886.3) in community, out-patient facilities and different levels of hospital in-patient settings in LMIC. Direct medical cost for severe pneumonia in hospital inpatient settings was estimated to be 26.6%-115.8% of patients' monthly household income in LMIC. The mean direct non-medical cost and indirect cost for severe pneumonia management accounted for 0.5-31% of weekly household income. The mean length of stay (LOS) in hospital for children with severe pneumonia was 5.8 (IQR 5.3-6.4) and 7.7 (IQR 5.5-9.9) days in LMIC and HIC respectively for these children. CONCLUSION: This is the most comprehensive review to date of cost data from studies on the management of childhood pneumonia and these data should be helpful for health services planning and priority setting by national programmes and international agencies.
OBJECTIVE: To analyze the applicability of the Braden Scale to individuals admitted to an Intensive Care Unit (ICU) with the nursing diagnosis Impaired Physical Mobility, in its prediction potential to develop pressure ulcer (PU). METHODS: A cross-sectional, quantitative study that evaluated all patients hospitalized in an ICU between November 2016 and February 2017, with the Braden Scale. RESULTS: The prevalence of PU was 35.8% (24/67), in male individuals 58.3% (14/24), diagnosed with ischemic CVA 51.9% (12/27), and with hemorrhagic CVA 7.4% (2/27). Among patients classified at severe risk of developing pressure ulcer, 83.3% (20/53) developed it, and 76.7% (33/53) did not develop it. CONCLUSION: The performance of the Braden Scale showed a balance between sensitivity and specificity, confirming it as a better predictive risk assessment instrument in this group of patients.
The restoration and reforestation of 12 million hectares of forests by 2030 are amongst the leading mitigation strategies for reducing carbon emissions within the Brazilian Nationally Determined Contribution targets assumed under the Paris Agreement. Understanding the dynamics of forest cover, which steeply decreased between 1985 and 2018 throughout Brazil, is essential for estimating the global carbon balance and quantifying the provision of ecosystem services. To know the long-term increment, extent, and age of secondary forests is crucial; however, these variables are yet poorly quantified. Here we developed a 30-m spatial resolution dataset of the annual increment, extent, and age of secondary forests for Brazil over the 1986-2018 period. Land-use and land-cover maps from MapBiomas Project (Collection 4.1) were used as input data for our algorithm, implemented in the Google Earth Engine platform. This dataset provides critical spatially explicit information for supporting carbon emissions reduction, biodiversity, and restoration policies, enabling environmental science applications, territorial planning, and subsidizing environmental law enforcement.
Abstract Aim Macroinvertebrates comprise a highly diverse set of taxa with great potential as indicators of soil quality. Communities were sampled at 3,694 sites distributed world‐wide. We aimed to analyse the patterns of abundance, composition and network characteristics and their relationships to latitude, mean annual temperature and rainfall, land cover, soil texture and agricultural practices. Location Sites are distributed in 41 countries, ranging from 55° S to 57° N latitude, from 0 to 4,000 m in elevation, with annual rainfall ranging from 500 to >3,000 mm and mean temperatures of 5–32°C. Time period 1980–2018. Major taxa studied All soil macroinvertebrates: Haplotaxida; Coleoptera; Formicidae; Arachnida; Chilopoda; Diplopoda; Diptera; Isoptera; Isopoda; Homoptera; Hemiptera; Gastropoda; Blattaria; Orthoptera; Lepidoptera; Dermaptera; and “others”. Methods Standard ISO 23611‐5 sampling protocol was applied at all sites. Data treatment used a set of multivariate analyses, principal components analysis (PCA) on macrofauna data transformed by Hellinger’s method, multiple correspondence analysis for environmental data (latitude, elevation, temperature and average annual rainfall, type of vegetation cover) transformed into discrete classes, coinertia analysis to compare these two data sets, and bias‐corrected and accelerated bootstrap tests to evaluate the part of the variance of the macrofauna data attributable to each of the environmental factors. Network analysis was performed. Each pairwise association of taxonomic units was tested against a null model considering local and regional scales, in order to avoid spurious correlations. Results Communities were separated into five clusters reflecting their densities and taxonomic richness. They were significantly influenced by climatic conditions, soil texture and vegetation cover. Abundance and diversity, highest in tropical forests (1,895 ± 234 individuals/m 2 ) and savannahs (1,796 ± 72 individuals/m 2 ), progressively decreased in tropical cropping systems (tree‐associated crops, 1,358 ± 120 individuals/m 2 ; pastures, 1,178 ± 154 individuals/m 2 ; and annual crops, 867 ± 62 individuals/m 2 ), temperate grasslands (529 ± 60 individuals/m 2 ), forests (232 ± 20 individuals/m 2 ) and annual crops (231 ± 24 individuals/m 2 ) and temperate dry forests and shrubs (195 ± 11 individuals/m 2 ). Agricultural management decreased overall abundance by ≤54% in tropical areas and 64% in temperate areas. Connectivity varied with taxa, with dominant positive connections in litter transformers and negative connections with ecosystem engineers and Arachnida. Connectivity and modularity were higher in communities with low abundance and taxonomic richness. Main conclusions Soil macroinvertebrate communities respond to climatic, soil and land‐cover conditions. All taxa, except termites, are found everywhere, and communities from the five clusters cover a wide range of geographical and environmental conditions. Agricultural practices significantly decrease abundance, although the presence of tree components alleviates this effect.
This study describes forest succession following slash-and-burn agriculture in central Amazonia, based on four chronosequences (22 sites) of 2- to 25-y-old secondary regrowth and mature forest. Biomass accumulated in the form of a saturation curve: 25 y of regrowth restored half of the mature-forest biomass, 75% would be restored after an estimated 175 y. Biomass accumulation was accompanied by a rapid decrease in woody plant density and an increase of the positive skew of plant size distribution. Liana biomass share declined from 5.0% in young to 1.9% in old regrowth, and 1.3% in mature forest, whereas the share of palms was low (0.5%) in young regrowth and high in old regrowth (1.8%) and mature forest (2.2%). 25-y-old regrowth was similar with mature forest in respect to woody plant density and growth-form composition, but both the plant size distribution and the number of stems per plant differed strongly from mature forest. A moderate increase in land use had only minor effects on biomass accumulation, but profoundly changed structural characteristics of regrowth, pointing to a high vulnerability to degradation. Thus, the sustainability of slash-and-burn in central Amazonia may be lower than the rapid initial biomass accumulation would make it seem.
In the middle of a political and fiscal crisis, the Brazilian government is applying successive budget cuts, including in science funding. Recent cuts radically affect research programs on biodiversity that are crucial components for the design and monitoring of public policies for nature conservation and sustainable development. We analyze the consequences of such cuts on the Research Program on Biodiversity (PPBio), the largest biodiversity research network in Brazil (626 researchers, nine networks in all Brazilian biomes). Brazil holds a substantial part of the world's biodiversity and of tropical forests that play a significant role for regional and global climate stability. If underfunding is maintained, the dismantling of the Brazilian PPBio will have consequences that go beyond biodiversity knowledge itself but affect society as a whole. Brazil will likely fail to reach the National Targets for Biodiversity 2011–2020, and it will be difficult to fulfill the restoration target of the Brazilian NDC and to advance with the sustainable development goals.
Abstract Aim Our aim was to investigate how the distance to water (flooding gradients) and riverine barriers (Tapajós and Jamanxim rivers) influence the distributional patterns of amphibian and squamate assemblages in the middle Tapajós River region, south‐eastern Amazonia. We also considered the planned hydroelectric dams on both rivers in reviewing the possible impacts of these factors on the amphibian and squamate assemblages. Location Middle Tapajós River system, south‐eastern Amazonia. Methods We conducted diurnal and nocturnal surveys combining pitfall traps and active searches along both banks of the Tapajós and Jamanxim rivers. We identified specimens using an integrative morphological, acoustic, ecological and molecular approach and evaluated the influence of riverine barriers and distance to water using uni‐ and multivariate ordinations, regressions and ANOVA . Results We found changes in species composition for both groups along the flooding gradient and differential riverine barrier effects. The rivers restricted the distribution of 33% of the amphibian species and 8% of the squamates. For amphibians, the main distributional barrier was the Tapajós River, while for squamates both rivers were of similar importance. The assemblages most affected by riverine barriers were non‐riparian amphibians and squamates, as well as riparian amphibians associated with small streams. The functional groups most affected were small, diurnal terrestrial amphibians and small–medium, diurnal partly tree‐dwelling squamates. Main conclusions The Tapajós River is a distributional boundary for lineages centred in western and eastern Amazonia. The fact that many taxa occur on both banks suggests that the Tapajós is a recent or semi‐permeable barrier, while the Jamanxim is an even more recent or weaker barrier. Anthropogenic activities that affect water level, flooding cycles and river flow may influence these natural patterns and cause changes to the equilibrium of the riverine barrier effect. Studies seeking to identify these influences should focus on the most affected functional groups.
Here, we report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. Data on shark fisheries are scarce in Brazil, although the northern and northeastern regions have the highest indices of shark bycatch. Harvest is made primarily with processed carcasses lacking head and fins, which hampers reliable species identification and law enforcement on illegal catches. We used partial sequences of two mitochondrial genes (COI and/or NADH2) to identify 17 shark species from 427 samples being harvested and marketed on the northern coast of Brazil. Nine species (53%) are listed under some extinction threat category according to Brazilian law and international authorities (IUCN - International Union for Conservation of Nature; CITES - Convention on International Trade of Endangered Species of Wild Fauna and Flora). The number increases to 13 (76%) if we also consider the Near Threatened category. Hammerhead sharks are under threat worldwide, and composed 18.7% of samples, with Sphyrna mokarran being the fourth most common species among samples. As illegal trade of threatened shark species is a worldwide conservation problem, molecular identification of processed meat or specimens lacking diagnostic body parts is a highly effective tool for species identification and law enforcement.
Despite growing recognition of the conservation value of grassy biomes, our understanding of how to restore biodiverse tropical and subtropical grassy biomes (grasslands and savannas; TGB) remains limited. Several tools have recently been identified for TGB restoration, including prescribed fires, appropriate management of livestock and wild herbivores, tree cutting and shrub removal, invasive species control, and the reintroduction of native grasses and forbs via seeding or transplants. However, additional research for improved TGB restoration is needed. This article aims to identify ecological research priorities for TGB restoration. The following points are crucial to scale up TGB restoration and meet the challenges of the UN Restoration Decade. Research should focus on: disentangling the reasons why TGB are often undervalued and misunderstood; mapping TGB restoration opportunities; identifying regions where TGB and other biomes naturally exist as alternative stable states; recognizing areas with natural regeneration potential to avoid unnecessary intervention; restoring soil conditions; disentangling factors driving low seed quality, determining germination requirements and developing vegetative propagation techniques for TGB species; disentangling the limiting factors and key ecological processes underlying seedling establishment and community assembly; improving and validating long‐term management to mimic natural disturbance regimes; setting the minimum attributes of desirable TGB in terms of structure, composition, functioning, and resilience; and improving monitoring of restoration outcomes. Such research has the potential to advance theory, policy, and practice in TGB restoration, ultimately resulting in long‐term benefits for people and nature in some of the more neglected ecosystems of our planet.
Abstract The science of agroforestry has progressed significantly during the past three decades. This article describes and documents various prominent traditional agroforestry systems. In‐depth research on interactive processes of some agrisilvicultural systems have been undertaken and quantified. It has been found that the presence of woody species can enhance nutrient cycling, and can improve soil productivity, soil conservation and soil biotic andfaunal activities. In simultaneous systems however, their presence can also cause competition with the associated food crops. Most agroforestry systems constitute ecologically and bio‐physically sustainable land use systems. Some are highly sustainable and economically viable, in particular the highly complex and specialized types, such as the damar and rubber agroforests in Indonesia. Agroforestry systems have potential uses in stabilization of sloping lands and buffer zones around forest reserves, for recovering degraded lands, and for improving the productivity of the bush fallow system. Despite rapid progress in biophysical research, field application of the science of agroforestry is still minimal. This article examines the possibilities of exploring the multiple contributions of trees to food security, rural income generation, diversity of products and ecosystem conservation within sustainable agroforestry contexts. Research efforts in the new millennium need to focus more on practical research and also on socio‐economic and policy factors that can enhance beneficial application of the science in the near future to smallholder farmers in the tropics.
Human activities are pushing earth beyond its natural limits, so recycling nutrients is mandatory. Microalgae are highly effective in nutrient recovery and have strong potential as a sustainable wastewater treatment technology. Here, nutrients from black water (toilet wastewater) were recovered as microalgal biomass, which was dried and assessed as a fertilizer in pot experiments compared with inorganic fertilizer. We deciphered the effects of microalgal biomass as a biofertilizer on plant growth and quality and the biological processes linked to greenhouse gas (GHG) emissions. In addition, we elucidated the assembly of the active microbiome in bulk soil and rhizosphere during barley development. Microalgal biomass application and inorganic fertilizer (NPK) resulted in similar plant productivity (16.6 g pot−1). Cumulative nitrous oxide (N2O) emissions were 4.6-fold higher in the treatment amended with microalgal fertilizer (3.1% of applied N) than that with inorganic fertilizer (0.5% of applied N). Nitrification by bacteria was likely the main pathway responsible for N2O emissions (R2 = 0.7, p ≤ 0.001). The application of nitrogen fertilizers affected the structures of both the active bacterial and protozoan communities, but these effects were less obvious than the strong plant effect, as the recruited microbiota varied among different plant developmental stages. Both treatments enriched similar bacterial and protozoan taxonomic orders but with different distributions through time across the plant developmental stages. Furthermore, the bacterial community showed a clear trend of resilience from the beginning of the experiment until harvest, which was not observed for protozoa. Our results indicate that the use of microalgal biomass as a fertilizer is a viable option for recycling nutrients from wastewater into plant production.
RESUMO O presente estudo teve como objetivo analisar o perfil epidemiológico e a distribuição espacial dos casos de sífilis gestacional e congênita. Trata-se de uma pesquisa descritiva, exploratória e retrospectiva, com abordagem quantitativa, realizada em Caxias (MA). Utilizaram-se os dados das fichas de investigação dos casos confirmados de sífilis gestacional e congênita do Sistema de Informação de Agravos de Notificação no período de 2013 a 2017. Com a tecnologia Global Positioning System (Sistema de Posicionamento Global), foram coletadas as coordenadas dos casos, e com o programa Quantum GIS, versão 1.7.0, os mapas foram construídos. Foram 149 casos de sífilis gestacional, apresentando crescimento de 73% no período. As maiores prevalências ocorreram em mulheres jovens, pardas, com baixa escolaridade e donas de casa. Evidenciou-se maior frequência do diagnóstico no terceiro trimestre gestacional, com maior prevalência de sífilis primária. Foram 18 casos de sífilis congênita, com redução de 33% na taxa de detecção e prevalência na idade entre 1 e 28 dias de vida. Na análise espacial, as zonas Oeste e Leste, periferia do município, concentraram o maior número de casos. Revelou-se frágil o manejo de investigação, tornando necessária a educação permanente para qualificar os profissionais, com o intuito de instituir a identificação precoce, o tratamento oportuno e o acompanhamento efetivo.