66 research outputs found
Solitonic lattice and Yukawa forces in the rare earth orthoferrite TbFeO3
The control of domains in ferroic devices lies at the heart of their
potential for technological applications. Multiferroic materials offer another
level of complexity as domains can be either or both of a ferroelectric and
magnetic nature. Here we report the discovery of a novel magnetic state in the
orthoferrite TbFeO3 using neutron diffraction under an applied magnetic field.
This state has a very long incommensurate period ranging from 340 Angstrom at
3K to 2700 Angstrom at the lowest temperatures and exhibits an anomalously
large number of higher-order harmonics, allowing us to identify it with the
periodic array of sharp domain walls of Tb spins separated by many lattice
constants. The Tb domain walls interact by exchanging spin waves propagating
through the Fe magnetic sublattice. The resulting Yukawa-like force, familiar
from particle physics, has a finite range that determines the period of the
incommensurate state.Comment: 11 pages 14 figure
Beyond the “resprout or not resprout” dichotomy: on the prevalence and evolutionary fingerprint of resprouting in tropical dry forest trees
Photobiomodulation reduces the cytokine storm syndrome associated with Covid-19 in the zebrafish model
Although the exact mechanism of the pathogenesis of COVID-19 is not fully understood, oxidative stress and the release of pro-inflammatory cytokines have been highlighted as playing a vital role in the pathogenesis of the disease. In this sense, alternative treatments are needed to reduce the inflammation caused by COVID-19. Therefore, this study aimed to investigate the potential effect of red PBM as an attractive therapy to downregulate the cytokine storm caused by COVID-19 from a zebrafish model. RT-PCR analyses and protein-protein interaction prediction among SARS-CoV-2 and Danio rerio proteins showed that rSpike was responsible for generating systemic inflammatory processes with significantly increased pro-inflammatory (il1b, il6, tnfa, and nfkbiab), oxidative stress (romo1) and energy metabolism (slc2a1a, coa1) mRNA markers, with a pattern like those observed in COVID-19 cases in humans. On the other hand, PBM treatment decreased the mRNA levels of these pro-inflammatory and oxidative stress markers compared with rSpike in various tissues, promoting an anti-inflammatory response. Conversely, PBM promotes cellular and tissue repair of injured tissues and significantly increases the survival rate of rSpike-inoculated individuals. Additionally, metabolomics analysis showed that the most impacted metabolic pathways between PBM and the rSpike-treated groups were related to steroid metabolism, immune system, and lipids metabolism. Together, our findings suggest that the inflammatory process is an incisive feature of COVID-19, and red PBM can be used as a novel therapeutic agent for COVID-19 by regulating the inflammatory response. Nevertheless, the need for more clinical trials remains, and there is a significant gap to overcome before clinical trials.publishedVersio
Data standardization of plant–pollinator interactions
Background: Animal pollination is an important ecosystem function and service, ensuring both the integrity of natural systems
and human well-being. Although many knowledge shortfalls remain, some high-quality data sets on biological interactions are now
available. The development and adoption of standards for biodiversity data and metadata has promoted great advances in biological
data sharing and aggregation, supporting large-scale studies and science-based public policies. However, these standards are currently
not suitable to fully support interaction data sharing.
Results: Here we present a vocabulary of terms and a data model for sharing plant–pollinator interactions data based on the Darwin
Core standard. The vocabulary introduces 48 new terms targeting several aspects of plant–pollinator interactions and can be used to
capture information from different approaches and scales. Additionally, we provide solutions for data serialization using RDF, XML,
and DwC-Archives and recommendations of existing controlled vocabularies for some of the terms. Our contribution supports open
access to standardized data on plant–pollinator interactions.
Conclusions: The adoption of the vocabulary would facilitate data sharing to support studies ranging from the spatial and temporal
distribution of interactions to the taxonomic, phenological, functional, and phylogenetic aspects of plant–pollinator interactions. We
expect to fill data and knowledge gaps, thus further enabling scientific research on the ecology and evolution of plant–pollinator
communities, biodiversity conservation, ecosystem services, and the development of public policies. The proposed data model is
flexible and can be adapted for sharing other types of interactions data by developing discipline-specific vocabularies of termsinfo:eu-repo/semantics/publishedVersio
Hematology and blood biochemistry in wild hybrid marmosets from the Atlantic Forest, Brazil
Simplified sewerage to prevent urban leptospirosis transmission: a cluster non-randomised controlled trial protocol in disadvantaged urban communities of Salvador, Brazil.
INTRODUCTION: Leptospirosis is a globally distributed zoonotic and environmentally mediated disease that has emerged as a major health problem in urban slums in developing countries. Its aetiological agent is bacteria of the genus Leptospira, which are mainly spread in the urine of infected rodents, especially in an environment where adequate sanitation facilities are lacking, and it is known that open sewers are key transmission sources of the disease. Therefore, we aim to evaluate the effectiveness of a simplified sewerage intervention in reducing the risk of exposure to contaminated environments and Leptospira infection and to characterise the transmission mechanisms involved. METHODS AND ANALYSIS: This matched quasi-experimental study design using non-randomised intervention and control clusters was designed to assess the effectiveness of an urban simplified sewerage intervention in the low-income communities of Salvador, Brazil. The intervention consists of household-level piped sewerage connections and community engagement and public involvement activities. A cohort of 1400 adult participants will be recruited and grouped into eight clusters consisting of four matched intervention-control pairs with approximately 175 individuals in each cluster in baseline. The primary outcome is the seroincidence of Leptospira infection assessed through five serological measurements: one preintervention (baseline) and four postintervention. As a secondary outcome, we will assess Leptospira load in soil, before and after the intervention. We will also assess Leptospira exposures before and after the intervention, through transmission modelling, accounting for residents' movement, contact with flooding, contaminated soil and water, and rat infestation, to examine whether and how routes of exposure for Leptospira change following the introduction of sanitation. ETHICS AND DISSEMINATION: This study protocol has been reviewed and approved by the ethics boards at the Federal University of Bahia and the Brazilian National Research Ethics Committee. Results will be disseminated through peer-reviewed publications and presentations to implementers, researchers and participating communities. TRIAL REGISTRATION NUMBER: Brazilian Clinical Trials Registry (RBR-8cjjpgm)
Produtividade do maracujazeiro amarelo sob diferentes níveis de irrigação e doses de potássio via fertirrigação
Catálogo de plantas e fungos do Brasil
"Parabenizo a todos os botânicos que contribuíram para completar o presente catálogo. O Brasil é o país que provavelmente possui a maior flora do mundo, portanto, a produção de uma lista completa dessa flora é uma extensa tarefa. Os coordenadores mobilizaram uma grande equipe de pessoas para compilar a lista, e é ótimo ver que este projeto, diferentemente do que se observa em outros países, foi coordenado no Brasil. Isto demonstra o alto nível e a capacidade da comunidade botânica brasileira que se desenvolveu rapidamente nas últimas décadas. Este catálogo, por ter sido preparado na sua maioria por especialistas dos grupos estudados, mostra quais espécies são correntemente aceitas pelos botânicos envolvidos. As espécies foram padronizadas por meio da citação de materiais-voucher, a maioria dos quais foi coletada por brasileiros e está alojada em herbários do Brasil. A informação a respeito da distribuição geográfica de cada espécie será extremamente útil para fins de conservação, e é interessante notar o número expressivo de espécies endêmicas do Brasil. Este catálogo certamente será utilizado por estudantes de diversas áreas envolvendo botânica, ecologia e outras, e tenho certeza de que a sua existência estimulará futuras pesquisas a respeito de plantas brasileiras e que a sua versão online o manterá atualizado. O desafio agora é conservar os muitos ecossistemas diferentes nos quais estas espécies ocorrem, para manter a diversidade botânica do país.
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