Ecomorfologia e uso de recursos por quatro espécies sintópicas de peixes (Characidae) em igarapés amazônicos de terra firme, Amazonas, Brasil

tetras (Characidae) compose a group of fishes that share a generalized morphology and a superficial similarity that is apparently associated with a generalized diet based on the opportunistic consumption of a wide variety of food items. This morphological and functional similarity, coupled with the known occurrence of several species of tetras in the same aquatic environment, has raised the hypothesis that there would be a high ecological niche overlap between simpatric species of this family, especially relevant in environments where food resources are limited, as is the case of the oligotrophic upland forest streams of the Central Brazilian Amazon. To test this hypothesis, we analyzed the morphological characteristics, diet and hábitat use of four syntopic species of characins (Iguanodectes geisleri, Bryconops giacopinii, B. inpai, and Hyphessobrycon melazonatus) in streams of the Adolpho Ducke Forest Reserve, Manaus. We evaluated the degree of overlap in the use of food resources and space, and the morphological and behavioral characteristics that allow the coexistence of these four species (in different combinations) in the streams. Fish were collected by seine nets in 50-m stretches of eight streams, selected on the basis of previous records of occurrence of these species. The use of space in the streams, recorded by underwater observations, was compared between species, as well as the frequency of foraging events. We analyzed 18 ecomorphological attributes of 22 specimens of each species, which were compared by means of ordination techniques (PCA). The diet of the species was analyzed by means of the alimentary index (AI), and information about the relative volume of the food items consumed were used to assess the amplitude and degree of overlap of the food niche between them. The different combinations of co-occurrence of species of minnows in streams (without co-occurrence; with a co-occurrence (alone, with one additional species, or with two other species) were tested using niche breadth data calculated for the individuals of H. melazonatus and B. giacopinii. We detected a significant difference in the use of the horizontal space by the species, separating H. melazonatus (that predominantly occupyed the margins) from the other species (that inhabited mainly the stream channel). All species used predominantly the middle third of the water column, but I. geisleri exhibited a higher proportion of use of the lower third, near the stream bottom. The analysis of ecomorphological characteristics showed significant interspecific differences, especially in body shape, size and orientation of the mouth, despite the high overlap in the diet of the species. However, when analyzing the composition of the diet on co-occurrence with one or two syntopic H. melazonatus and B. giacopinii exhibited narrowing of trophic niche. In short, despite the minnows are considered phylogenetically related and morphologically similar, the integrated analysis of information on habitat use, behavior, diet, and ecomorphological characteristics found significant differences between these species, which can act as mediators of coexistence in Amazonian lowland forest streams , through the partition of available resources.As piabas ou lambaris constituem um grupo de peixes da família Characidae que apresentam características morfológicas generalizadas e superficialmente similares, aparentemente associadas à dieta generalista, baseada no consumo oportunista de ampla variedade de tipos de alimento. Essa similaridade morfológica e funcional, associada à conhecida ocorrência de várias espécies de piabas em um mesmo ambiente aquático, suscitou a hipótese de que haveria elevada sobreposição de nicho ecológico entre as espécies dessa família, especialmente em ambientes onde os recursos alimentares fossem limitados, como é o caso dos igarapés oligotróficos de terra firme da Amazônia Central brasileira. Para testar essa hipótese, foram analisadas as características morfológicas, a dieta e o uso do hábitat de quatro espécies sintópicas de piabas (Iguanodectes geisleri, Bryconops giacopinii, Bryconops inpai e Hyphessobrycon melazonatus) em igarapés na Reserva Florestal Adolpho Ducke, Manaus. Foram avaliados o grau de sobreposição no uso dos recursos tróficos e espaciais, e as características morfológicas e comportamentais que permitem a coexistência dessas quatro espécies nos igarapés. Os peixes foram coletados com rede de arrasto manual em trechos de 50 metros de oito igarapés, previamente selecionados com base em registros anteriores de ocorrência dessas espécies. O uso do espaço nos igarapés, registrado por meio de observações subaquáticas, foi comparado entre as espécies, bem como a frequência de eventos de forrageamento. Foram analisados 18 atributos ecomorfológicos de 22 exemplares de cada espécie, as quais foram comparadas por meio de técnicas de ordenação (PCA). A dieta das espécies foi analisada por meio do cálculo do Índice Alimentar (IAi), e informações sobre volume relativo dos itens alimentares foram utilizadas para avaliar a amplitude e sobreposição de nicho trófico entre elas. As diferentes situações de coocorrência das espécies de piabas nos igarapés (sem coocorrência; coocorrência com uma espécie adicional; ou com duas outras espécies) foram testadas com os dados de largura de nicho dos indivíduos para H. melazonatus e B. giacopinii. Foi detectada nítida segregação no uso horizontal, com H. melazonatus ocupando predominantemente as margens e as demais espécies habitando o canal. As espécies utilizaram predominantemente o terço médio da coluna d’água, mas I. geisleri exibiu maior proporção de uso do terço inferior. A análise das características ecomorfológicas demonstrou diferenças interespecíficas significativas, especialmente na forma do corpo, tamanho e orientação da boca, apesar da alta sobreposição na dieta das espécies. No entanto, quando analisada a composição da dieta em coocorrência com uma ou duas espécies sintópicas, H. melazonatus e B. giacopinii exibiram estreitamento de nicho trófico. Em suma, apesar das piabas serem filogeneticamente relacionadas e consideradas morfologicamente semelhantes, a análise integrada de informações sobre uso do hábitat, comportamento, dieta e características ecomorfológicas detectou diferenças significativas entre essas espécies, que podem atuar como mediadoras da coexistência nos igarapés amazônicos de terra firme, por meio da partição dos recursos disponíveis

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 understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

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 understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial

Background: COVID-19 is associated with a prothrombotic state leading to adverse clinical outcomes. Whether therapeutic anticoagulation improves outcomes in patients hospitalised with COVID-19 is unknown. We aimed to compare the efficacy and safety of therapeutic versus prophylactic anticoagulation in this population. Methods: We did a pragmatic, open-label (with blinded adjudication), multicentre, randomised, controlled trial, at 31 sites in Brazil. Patients (aged ≥18 years) hospitalised with COVID-19 and elevated D-dimer concentration, and who had COVID-19 symptoms for up to 14 days before randomisation, were randomly assigned (1:1) to receive either therapeutic or prophylactic anticoagulation. Therapeutic anticoagulation was in-hospital oral rivaroxaban (20 mg or 15 mg daily) for stable patients, or initial subcutaneous enoxaparin (1 mg/kg twice per day) or intravenous unfractionated heparin (to achieve a 0·3–0·7 IU/mL anti-Xa concentration) for clinically unstable patients, followed by rivaroxaban to day 30. Prophylactic anticoagulation was standard in-hospital enoxaparin or unfractionated heparin. The primary efficacy outcome was a hierarchical analysis of time to death, duration of hospitalisation, or duration of supplemental oxygen to day 30, analysed with the win ratio method (a ratio >1 reflects a better outcome in the therapeutic anticoagulation group) in the intention-to-treat population. The primary safety outcome was major or clinically relevant non-major bleeding through 30 days. This study is registered with ClinicalTrials.gov (NCT04394377) and is completed. Findings: From June 24, 2020, to Feb 26, 2021, 3331 patients were screened and 615 were randomly allocated (311 [50%] to the therapeutic anticoagulation group and 304 [50%] to the prophylactic anticoagulation group). 576 (94%) were clinically stable and 39 (6%) clinically unstable. One patient, in the therapeutic group, was lost to follow-up because of withdrawal of consent and was not included in the primary analysis. The primary efficacy outcome was not different between patients assigned therapeutic or prophylactic anticoagulation, with 28 899 (34·8%) wins in the therapeutic group and 34 288 (41·3%) in the prophylactic group (win ratio 0·86 [95% CI 0·59–1·22], p=0·40). Consistent results were seen in clinically stable and clinically unstable patients. The primary safety outcome of major or clinically relevant non-major bleeding occurred in 26 (8%) patients assigned therapeutic anticoagulation and seven (2%) assigned prophylactic anticoagulation (relative risk 3·64 [95% CI 1·61–8·27], p=0·0010). Allergic reaction to the study medication occurred in two (1%) patients in the therapeutic anticoagulation group and three (1%) in the prophylactic anticoagulation group. Interpretation: In patients hospitalised with COVID-19 and elevated D-dimer concentration, in-hospital therapeutic anticoagulation with rivaroxaban or enoxaparin followed by rivaroxaban to day 30 did not improve clinical outcomes and increased bleeding compared with prophylactic anticoagulation. Therefore, use of therapeutic-dose rivaroxaban, and other direct oral anticoagulants, should be avoided in these patients in the absence of an evidence-based indication for oral anticoagulation. Funding: Coalition COVID-19 Brazil, Bayer SA.Duke Clinical Research Institute Duke University Medical CenterBrazilian Clinical Research InstituteHCor Research InstituteHospital Samaritano PaulistaAcademic Research Organization Hospital Israelita Albert EinsteinInstituto do Coração Universidade de São PauloInstituto do Câncer do Estado de São Paulo Hospital das Clínicas da Faculdade de Medicina Universidade de São PauloScience Valley Research InstituteHemostasis & Thrombosis Research Laboratories at Loyola University Medical CenterHospital Estadual Dr Jayme Santos NevesHospital Cárdio PulmonarEscola Bahiana de MedicinaUniversidade Federal da BahiaHospital Vera CruzHospital Da BahiaHospital Naval Marcílio DiasHospital Santa PaulaSanta Casa de Misericórdia de VotuporangaHospital das Clínicas da Faculdade de Medicina de BotucatuBrazilian Research in Intensive Care NetworkBP—A Beneficência Portuguesa de São PauloHospital Universitário da Universidade Estadual de LondrinaHospital Felício RochoSanta Casa de Misericórdia da Bahia–Hospital Santa IzabelCentro Universitário Faculdade de Tecnologia e CiênciasHospital Moinhos de VentoInstituto Dante Pazzanese de CardiologiaHospital de Amor de Barretos (Pio XII)Hospital de Base de São José do Rio PretoAnesthesiology Pain and Intensive Care Department Federal University of São PauloInstituto Socrates GuanaesHospital Sírio Libanês Research and Education InstituteInternational Research Center Hospital Alemão Oswaldo CruzHospital das Clínicas da Faculdade de Medicina de Botucat

Neutrino Interaction Vertex Reconstruction in DUNE with Pandora Deep Learning

International audienceThe Pandora Software Development Kit and algorithm libraries perform reconstruction of neutrino interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at the Deep Underground Neutrino Experiment, which will operate four large-scale liquid argon time projection chambers at the far detector site in South Dakota, producing high-resolution images of charged particles emerging from neutrino interactions. While these high-resolution images provide excellent opportunities for physics, the complex topologies require sophisticated pattern recognition capabilities to interpret signals from the detectors as physically meaningful objects that form the inputs to physics analyses. A critical component is the identification of the neutrino interaction vertex. Subsequent reconstruction algorithms use this location to identify the individual primary particles and ensure they each result in a separate reconstructed particle. A new vertex-finding procedure described in this article integrates a U-ResNet neural network performing hit-level classification into the multi-algorithm approach used by Pandora to identify the neutrino interaction vertex. The machine learning solution is seamlessly integrated into a chain of pattern-recognition algorithms. The technique substantially outperforms the previous BDT-based solution, with a more than 20% increase in the efficiency of sub-1 cm vertex reconstruction across all neutrino flavours

DUNE Phase II: Scientific Opportunities, Detector Concepts, Technological Solutions

The international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy toward the implementation of this leading-edge, large-scale science project. The 2023 report of the US Particle Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly endorsed DUNE Phase I and Phase II, as did the European Strategy for Particle Physics. While the construction of the DUNE Phase I is well underway, this White Paper focuses on DUNE Phase II planning. DUNE Phase-II consists of a third and fourth far detector (FD) module, an upgraded near detector complex, and an enhanced 2.1 MW beam. The fourth FD module is conceived as a "Module of Opportunity", aimed at expanding the physics opportunities, in addition to supporting the core DUNE science program, with more advanced technologies. This document highlights the increased science opportunities offered by the DUNE Phase II near and far detectors, including long-baseline neutrino oscillation physics, neutrino astrophysics, and physics beyond the standard model. It describes the DUNE Phase II near and far detector technologies and detector design concepts that are currently under consideration. A summary of key R&D goals and prototyping phases needed to realize the Phase II detector technical designs is also provided. DUNE's Phase II detectors, along with the increased beam power, will complete the full scope of DUNE, enabling a multi-decadal program of groundbreaking science with neutrinos