Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 105
Filtrar
1.
Biol Lett ; 20(7): 20240216, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39046287

RESUMO

Most described species have not been explicitly included in phylogenetic trees-a problem named the Darwinian shortfall-owing to a lack of molecular and/or morphological data, thus hampering the explicit incorporation of evolution into large-scale biodiversity analyses. We investigate potential drivers of the Darwinian shortfall in tetrapods, a group in which at least one-third of described species still lack phylogenetic data, thus necessitating the imputation of their evolutionary relationships in fully sampled phylogenies. We show that the number of preserved specimens in scientific collections is the main driver of phylogenetic knowledge accumulation, highlighting the major role of biological collections in unveiling novel biodiversity data and the importance of continued sampling efforts to reduce knowledge gaps. Additionally, large-bodied and wide-ranged species, as well as terrestrial and aquatic amphibians and reptiles, are phylogenetically better known. Future efforts should prioritize phylogenetic research on organisms that are narrow-ranged, small-bodied and underrepresented in scientific collections, such as fossorial species. Addressing the Darwinian shortfall will be imperative for advancing our understanding of evolutionary drivers shaping biodiversity patterns and implementing comprehensive conservation strategies.


Assuntos
Biodiversidade , Evolução Biológica , Filogenia , Vertebrados , Animais , Vertebrados/genética , Vertebrados/classificação , Anfíbios/genética , Anfíbios/classificação , Répteis/classificação , Répteis/genética
3.
PLOS Glob Public Health ; 3(12): e0002679, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38091336

RESUMO

Brazil was one of the countries most affected during the first year of the COVID-19 pandemic, in a pre-vaccine era, and mathematical and statistical models were used in decision-making and public policies to mitigate and suppress SARS-CoV-2 dispersion. In this article, we intend to overview the modeling for COVID-19 in Brazil, focusing on the first 18 months of the pandemic. We conducted a scoping review and searched for studies on infectious disease modeling methods in peer-reviewed journals and gray literature, published between January 01, 2020, and June 2, 2021, reporting real-world or scenario-based COVID-19 modeling for Brazil. We included 81 studies, most corresponding to published articles produced in Brazilian institutions. The models were dynamic and deterministic in the majority. The predominant model type was compartmental, but other models were also found. The main modeling objectives were to analyze epidemiological scenarios (testing interventions' effectiveness) and to project short and long-term predictions, while few articles performed economic impact analysis. Estimations of the R0 and transmission rates or projections regarding the course of the epidemic figured as major, especially at the beginning of the crisis. However, several other outputs were forecasted, such as the isolation/quarantine effect on transmission, hospital facilities required, secondary cases caused by infected children, and the economic effects of the pandemic. This study reveals numerous articles with shared objectives and similar methods and data sources. We observed a deficiency in addressing social inequities in the Brazilian context within the utilized models, which may also be expected in several low- and middle-income countries with significant social disparities. We conclude that the models were of great relevance in the pandemic scenario of COVID-19. Nevertheless, efforts could be better planned and executed with improved institutional organization, dialogue among research groups, increased interaction between modelers and epidemiologists, and establishment of a sustainable cooperation network.

4.
Nature ; 622(7983): 537-544, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37758942

RESUMO

Climate's effect on global biodiversity is typically viewed through the lens of temperature, humidity and resulting ecosystem productivity1-6. However, it is not known whether biodiversity depends solely on these climate conditions, or whether the size and fragmentation of these climates are also crucial. Here we shift the common perspective in global biodiversity studies, transitioning from geographic space to a climate-defined multidimensional space. Our findings suggest that larger and more isolated climate conditions tend to harbour higher diversity and species turnover among terrestrial tetrapods, encompassing more than 30,000 species. By considering both the characteristics of climate itself and its geographic attributes, we can explain almost 90% of the variation in global species richness. Half of the explanatory power (45%) may be attributed either to climate itself or to the geography of climate, suggesting a nuanced interplay between them. Our work evolves the conventional idea that larger climate regions, such as the tropics, host more species primarily because of their size7,8. Instead, we underscore the integral roles of both the geographic extent and degree of isolation of climates. This refined understanding presents a more intricate picture of biodiversity distribution, which can guide our approach to biodiversity conservation in an ever-changing world.


Assuntos
Biodiversidade , Clima , Geografia , Animais , Conservação dos Recursos Naturais/métodos , Mapeamento Geográfico , Umidade , Temperatura , Clima Tropical
5.
An Acad Bras Cienc ; 95(1): e20220515, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36995886

RESUMO

Several factors influence the citation impact. This paper constructed paths from funding to citation impact on a country basis. Country data came from Incites® (2011-2020). The (2013 to 2018) UNESCO database was used to define investments in Research and Development (R&D). An overall analysis and analyses by clusters formed by investments in R&D were carried out. Countries that invest relatively less in R&D tend to have less investment by businesses and publish fewer documents. Some differences exist in this pattern. For example, countries in the lowest investment group show higher international collaboration and publications in Open Access Journals. This leads to a higher impact but below countries with the highest investments in R&D. The paths from funding to high impact differed by cluster. While international collaboration appeared in several clusters, the % of papers in Q1 (Top) journal quartile, based on citations, was in almost all clusters. More investments in R&D and open access publishing do not necessarily lead to high impact.


Assuntos
Publicação de Acesso Aberto , Editoração
7.
Lancet Reg Health Am ; 17: 100396, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36437904

RESUMO

Background: Developing countries have experienced significant COVID-19 disease burden. With the emergence of new variants, particularly omicron, the disease burden in children has increased. When the first COVID-19 vaccine was approved for use in children aged 5-11 years of age, very few countries recommended vaccination due to limited risk-benefit evidence for vaccination of this population. In Brazil, ranking second in the global COVID-19 death toll, the childhood COVID-19 disease burden increased significantly in early 2022. This prompted a risk-benefit assessment of the introduction and scaling-up of COVID-19 vaccination of children. Methods: To estimate the potential impact of vaccinating children aged 5-11 years with mRNA-based COVID-19 vaccine in the context of omicron dominance, we developed a discrete-time SEIR-like model stratified in age groups, considering a three-month time horizon. We considered three scenarios: No vaccination, slow, and maximum vaccination paces. In each scenario, we estimated the potential reduction in total COVID-19 cases, hospitalizations, deaths, hospitalization costs, and potential years of life lost, considering the absence of vaccination as the base-case scenario. Findings: We estimated that vaccinating at a maximum pace could prevent, between mid-January and April 2022, about 26,000 COVID-19 hospitalizations, and 4200 deaths in all age groups; of which 5400 hospitalizations and 410 deaths in children aged 5-11 years. Continuing vaccination at a slow/current pace would prevent 1450 deaths and 9700 COVID-19 hospitalizations in all age groups in this same time period; of which 180 deaths and 2390 hospitalizations in children only. Interpretation: Maximum vaccination of children results in a significant reduction of COVID-19 hospitalizations and deaths and should be enforced in developing countries with significant disease incidence in children. Funding: This manuscript was funded by the Brazilian Council for Scientific and Technology Development (CNPq - Process # 402834/2020-8).

8.
Glob Epidemiol ; 4: 100094, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36404949

RESUMO

We simulate the impact of school reopening during the COVID-19 pandemic in three major urban centers in Brazil to identify the epidemiological indicators and the best timing for the return of in-school activities and the effect of contact tracing as a mitigation measure. Our goal is to offer guidelines for evidence-based policymaking. We implement an extended SEIR model stratified by age and considering contact networks in different settings - school, home, work, and community, in which the infection transmission rate is affected by various intervention measures. After fitting epidemiological and demographic data, we simulate scenarios with increasing school transmission due to school reopening, and also estimate the number of hospitalization and deaths averted by the implementation of contact tracing. Reopening schools results in a non-linear increase in reported COVID-19 cases and deaths, which is highly dependent on infection and disease incidence at the time of reopening. When contact tracing and quarantining are restricted to school and home settings, a large number of daily tests is required to produce significant effects in reducing the total number of hospitalizations and deaths. Policymakers should carefully consider the epidemiological context and timing regarding the implementation of school closure and return of in-person school activities. While contact tracing strategies prevent new infections within school environments, they alone are not sufficient to avoid significant impacts on community transmission.

9.
Vaccine ; 40(46): 6616-6624, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-36210250

RESUMO

INTRODUCTION: Brazil experienced moments of collapse in its health system throughout 2021, driven by the emergence of variants of concern (VOC) combined with an inefficient initial vaccination strategy against Covid-19. OBJECTIVES: To support decision-makers in formulating COVID-19 immunization policy in the context of limited vaccine availability and evolving variants over time, we evaluate optimal strategies for Covid-19 vaccination in Brazil in 2021, when vaccination was rolled out during Gamma variant predominance. METHODS: Using a discrete-time epidemic model we estimate Covid-19 deaths averted, considering the currently Covid-19 vaccine products and doses available in Brazil; vaccine coverage by target population; and vaccine effectiveness estimates. We evaluated a 5-month time horizon, from early August to the end of December 2021. Optimal vaccination strategies compared the outcomes in terms of averted deaths when varying dose intervals from 8 to 12 weeks, and choosing the minimum coverage levels per age group required prior to expanding vaccination to younger target populations. We also estimated dose availability required over time to allow the implementation of optimal strategies. RESULTS: To maximize the number of averted deaths, vaccine coverage of at least 80 % should be reached in older age groups before starting vaccination into subsequent younger age groups. When evaluating varying dose intervals for AZD1222, reducing the dose interval from 12 to 8 weeks for the primary schedule would result in fewer COVID-19 deaths, but this can only be implemented if accompanied by an increase in vaccine supply of at least 50 % over the coming six-months in Brazil. CONCLUSION: Covid-19 immunization strategies should be tailored to local vaccine product availability and supply over time, circulating variants of concern, and vaccine coverage in target population groups. Modelling can provide valuable and timely evidence to support the implementation of vaccination strategies considering the local context, yet following international and regional technical evidence-based guidance.


Assuntos
COVID-19 , Vacinas , Humanos , Idoso , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , SARS-CoV-2 , Brasil/epidemiologia , ChAdOx1 nCoV-19 , Vacinação
10.
Environ Microbiol ; 24(10): 4714-4724, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35859337

RESUMO

We investigated whether a set of phylogeographical tracked emergent events of Orthocoronavirinae were related to developed, urban and polluted environments worldwide. We explored coronavirus records in response to climate (rainfall parameters), population density, CO2 emission, Human Developmental Index (HDI) and deforestation. We contrasted environmental characteristics from regions with spillovers or encounters of wild Orthocoronavirinae against adjacent areas having best-preserved conditions. We used all complete sequenced CoVs genomes deposited in NCBI and GISAID databases until January 2021. Except for Deltacoronavirus, concentrated in Hong Kong and in birds, the other three genera were scattered all over the planet, beyond the original distribution of the subfamily, and found in humans, mammals, fishes and birds, wild or domestic. Spillovers and presence in wild animals were only reported in developed/densely populated places. We found significantly more occurrences reported in places with higher HDI, CO2 emission, or population density, along with more rainfall and more accentuated seasonality. Orthocoronavirinae occurred in areas with significantly higher human populations, CO2 emissions and deforestation rates than in adjacent locations. Intermediately disturbed ecosystems seemed more vulnerable for Orthocoronavirinae emergence than forested regions in frontiers of deforestation. Sadly, people experiencing poverty in an intensely consumerist society are the most vulnerable.


Assuntos
Infecções por Coronavirus , Coronavirus , Animais , Dióxido de Carbono , Conservação dos Recursos Naturais , Ecossistema , Humanos , Mamíferos
12.
Nat Ecol Evol ; 6(5): 502-503, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35379936
13.
Proc Natl Acad Sci U S A ; 119(15): e2103745119, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35377801

RESUMO

Body size and shape fundamentally determine organismal energy requirements by modulating heat and mass exchange with the environment and the costs of locomotion, thermoregulation, and maintenance. Ecologists have long used the physical linkage between morphology and energy balance to explain why the body size and shape of many organisms vary across climatic gradients, e.g., why larger endotherms are more common in colder regions. However, few modeling exercises have aimed at investigating this link from first principles. Body size evolution in bats contrasts with the patterns observed in other endotherms, probably because physical constraints on flight limit morphological adaptations. Here, we develop a biophysical model based on heat transfer and aerodynamic principles to investigate energy constraints on morphological evolution in bats. Our biophysical model predicts that the energy costs of thermoregulation and flight, respectively, impose upper and lower limits on the relationship of wing surface area to body mass (S-MR), giving rise to an optimal S-MR at which both energy costs are minimized. A comparative analysis of 278 species of bats supports the model's prediction that S-MR evolves toward an optimal shape and that the strength of selection is higher among species experiencing greater energy demands for thermoregulation in cold climates. Our study suggests that energy costs modulate the mode of morphological evolution in bats­hence shedding light on a long-standing debate over bats' conformity to ecogeographical patterns observed in other mammals­and offers a procedure for investigating complex macroecological patterns from first principles.


Assuntos
Regulação da Temperatura Corporal , Quirópteros , Voo Animal , Asas de Animais , Animais , Fenômenos Biofísicos , Tamanho Corporal , Quirópteros/anatomia & histologia , Quirópteros/fisiologia , Clima , Voo Animal/fisiologia , Asas de Animais/anatomia & histologia , Asas de Animais/fisiologia
15.
An Acad Bras Cienc ; 93(4): e29290261, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495201

RESUMO

Public universities, and science in general, in Brazil, are under attack from key persons of the government in interviews and articles published in non-scientific journals. Here we look at bibliography data from international science metric platforms (Scival® and Incites®) and official Brazilian agencies such as CAPES and CNPq to reach some conclusions based on scientific analysis. Brazilian Science has shown a steady improvement in quantity and quality over the last 20 years but has recently suffered (since 2015) under severe financial restrictions. An increase in international collaboration also increased citation impact, reaching almost five times the world average. While the medical and natural sciences show the highest impact and prominence, social sciences and the humanities also have spotlight areas with international excellence. Different research institutions and universities offer a variety of production profiles and impacts. This diagnosis shows the need for universities and research institutes in Brazil and funding agencies to undergo strategic planning for definition of mission/vision, goals to be reached, and areas for priority development. Continued support of public universities by the government is necessary for Brazilian autonomy in science and technology and its full integration in the world scientific community.


Assuntos
Publicações , Universidades , Brasil
16.
Ecol Lett ; 24(11): 2521-2523, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34510685

RESUMO

Biddick & Burns (2021) proposed a null/neutral model that reproduces the island rule as a product of random drift. We agree that it is unnecessary to assume adaptive processes driving island dwarfing or gigantism, but several flaws make their approach unrealistic and thus unsuitable as a stochastic model for evolutionary size changes.


Assuntos
Evolução Biológica , Deriva Genética
17.
Environ Manage ; 68(4): 445-452, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34341867

RESUMO

The Tocantins-Araguaia Basin is one of the largest river systems in South America, located entirely within Brazilian territory. In the last decades, capital-concentrating activities such as agribusiness, mining, and hydropower promoted extensive changes in land cover, hydrology, and environmental conditions. These changes are jeopardizing the basin's biodiversity and ecosystem services. Threats are escalating as poor environmental policies continue to be formulated, such as environmentally unsustainable hydropower plants, large-scale agriculture for commodity production, and aquaculture with non-native fish. If the current model persists, it will deepen the environmental crisis in the basin, compromising broad conservation goals and social development in the long term. Better policies will require thought and planning to minimize growing threats and ensure the basin's sustainability for future generations.


Assuntos
Ecossistema , Rios , Animais , Biodiversidade , Conservação dos Recursos Naturais , Política Ambiental
18.
Genet Mol Biol ; 43(2): e20190161, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614355

RESUMO

Caryocar brasiliense (Caryocaraceae) is a Neotropical tree species widely distributed in Brazilian Savannas. This species is very popular in central Brazil mainly by the use of its fruits in the local cuisine, and indeed it is one of the candidates, among Brazilian native plants, for fast track incorporation into cropping systems. Here we sequenced the complete chloroplast genome of C. brasiliense and used the data to access its genomic resources using high-throughput sequencing. The chloroplast exhibits a genome length of 165,793 bp and the typical angiosperm quadripartite structure with two copies of an inverted repeat sequence (IRa and IRb) of 34,902 bp each, separating a small single copy (SSC) region of 11,852 bp and a large single copy (LSC) region of 84,137 bp. The annotation analysis identified 136 genes being 87 protein-coding, eight rRNA and 37 tRNA genes. We identified 49 repetitive DNA elements and 85 microsatellites. A bayesian phylogenetic analysis helped to understand previously unresolved relationships in Malpighiales, placing Caryocaraceae as a separated group in the order, with high supported nodes. This study synthetizes valuable information for further studies allowing a better understanding of evolutionary patterns in the group and providing resources for future breeding programs.

19.
Genet Mol Biol ; 43(2): e20180291, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353100

RESUMO

Phylogenetic niche conservatism can be investigated at multiple scales on an explicit geographical context. Haplotype-based comparative analyses of lineages occupying the same region, and thus subjected to similar environmental factors, allow decoupling shared evolutionary and ecological patterns, as well as multiple dimensions of adaptive diversification. Here we aimed to assess the role of environmental drivers on diversification of subtropical grassland, based on haplotypic diversity of two plant genera. We sampled two closely related and co-distributed grassland plant genera, Petunia and Calibrachoa, across their entire distribution area. Eigenvectors extracted from pairwise distances based on chloroplast DNA haplotypes were used to fit Phylogenetic Signal-Representation (PSR) curves to estimate evolutionary patterns in 19 bioclimatic variables and altitude. The PSR curves showed that altitude, precipitation, and temperature variables changed at different rates with haplotype differentiation. Altitude and temperature traits evolved under conditions closer to a neutral dynamics, whereas precipitation traits differentiated following more complex models. Our results indicated that the diversification in the two genera was more limited by precipitation conditions. Based on these novel findings, we suggest that future studies should test the possible impact of precipitation variables on the process of ecological differentiation in these genera.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...