535 research outputs found
An eco‐epidemiological modeling approach to investigate dilution effect in two different tick‐borne pathosystems
Disease (re)emergence appears to be driven by biodiversity decline and environmental change. As a result, it is increasingly important to study host-pathogen interactions within the context of their ecology and evolution. The dilution effect is the concept that higher biodiversity decreases pathogen transmission. It has been observed especially in zoonotic vector-borne pathosystems, yet evidence against it has been found. In particular, it is still debated how the community (dis)assembly assumptions and the degree of generalism of vectors and pathogens affect the direction of the biodiversity-pathogen transmission relationship. The aim of this study was to use empirical data and mechanistic models to investigate dilution mechanisms in two rodent-tick-pathogen systems differing in their vector degree of generalism. A community was assembled to include ecological interactions that expand from purely additive to purely substitutive. Such systems are excellent candidates to analyze the link between vector ecology, community (dis)assembly dynamics, and pathogen transmission. To base our mechanistic models on empirical data, rodent live-trapping, including tick sampling, was conducted in Wales across two seasons for three consecutive years. We have developed a deterministic single-vector, multi-host compartmental model that includes ecological relationships with non-host species, uniquely integrating theoretical and observational approaches. To describe pathogen transmission across a gradient of community diversity, the model was populated with parameters describing five different scenarios differing in ecological complexity; each based around one of the pathosystems: Ixodes ricinus (generalist tick) - Borrelia burgdorferi and I. trianguliceps (small mammals specialist tick) - Babesia microti. The results suggested that community composition and inter-specific dynamics affected pathogen transmission with different dilution outcomes depending on the vector degree of generalism. The model provides evidence that dilution and amplification effects are not mutually exclusive in the same community, but depend on vector ecology and the epidemiological output considered (i.e. the “risk” of interest). In our scenarios, more functionally diverse communities resulted in fewer infectious rodents, supporting the dilution effect. In the pathosystem with generalist vector we identified a hump shaped relationship between diversity and infections in hosts, while for that characterized by specialist tick, this relationship was more complex and more dependent upon specific parameter values
Community Science in Support of Ecosystem-Based Management: A Case Study from the Damariscotta River Estuary, Maine, USA
Coastal marine ecosystems are dynamic social-ecological systems (SESs) that support diverse ecosystem services and human activities. The complexity of SESs means that ecosystem-based approaches are increasingly used to support coastal marine ecosystem stewardship. We report how a community science program in Maine, USA offers a model of organizational innovation to expand capacities for shellfish research and management. Since 2019, we have collaborated with local students, shellfish harvesters, and others in data collection, interpretation, and application, contributing to local shellfish management and ecosystem sustainability. We demonstrate how community-based social and ecological research can build adaptive capacities by centering local knowledge; generating long-term and fine-scale datasets; supporting community-led management and civic engagement; and contributing to field methods that people with varied lived experiences and training can implement in a sustainable fashion. Our approach can be adapted to other contexts, particularly in data-limited SESs that are experiencing observable social and ecological change
Algumas dimensões ainda atuais da análise do comportamento aplicada
Vinte anos atrás, uma nota antropológica descreveu as dimensões vigentes da análise do comportamento aplicada como prescrita e praticada em 1968: ela era, ou deveria se tornar, aplicada, comportamental, analítica, tecnológica, conceitual, eficaz e capaz de resultados apropriadamente generalizados. Uma nota antropológica semelhante, hoje, ainda encontra as mesmas dimensões prescritivas e, em maior medida, descritivas. Várias estratégias novas tornaram-se conhecidas; algumas no domínio da análise conceitual, algumas relacionadas ao status sociológico da disciplina e algumas sobre sua compreensão da natureza sistêmica necessária para qualquer disciplina aplicada que operará no domínio de comportamentos humanos importantes.Palavras-chave: aplicação, disseminação, tecnologia, terminologia, história. Nota: referência do texto original, cuja permissão de tradução foi garantida pela editora Wiley: Baer, D. M., Wolf, M. M. & Risley, T. R. (1987). Some still-current dimensions of applied behavior analysis. Journal of Applied Behavior Analysis, 20(4), 313-327. https://doi.org/10.1901/jaba.1987.20-313. TradutoresJoão Eduardo Cattani Vilares eMarcos Spector Azoubel
Algumas dimensões atuais da análise do comportamento aplicada
A análise do comportamento individual tem sido sistematicamente estudada e praticada em vários contextos, ao longo de muitos anos. Essa análise resultou em descrições de princípios comportamentais que têm sido aplicados a problemas de comportamento socialmente relevantes nos últimos anos. As pesquisas de análise do comportamento aplicada – direcionadas a investigar as variáveis que podem ser efetivas para melhorar o comportamento sob estudo – possuem características que as distinguem das tradicionais pesquisas da análise do comportamento não aplicadas, conduzidas em laboratório. O estudo precisa ser aplicado, evidenciando a importância do comportamento alterado, comportamental, apresentando medidas diretas e quantitativas do comportamento alterado, e analítico, identificando com clareza o que foi responsável pela mudança. Além disso, o estudo deveria ser tecnológico, descrevendo precisamente todos os procedimentos que contribuíram para a mudança, conceitualmente sistemático, relacionando os procedimentos empregados e os resultados identificados com os processos comportamentais básicos, e efetivo, produzindo mudanças suficientemente relevantes, e deveria demonstrar alguma generalidade, planejando e avaliando a extensão dos efeitos da aplicação ao longo do tempo, para outras situações e para outros comportamentos.Palavras-chave: análise do comportamento aplicada, delineamentos experimentais, metodologia, pesquisa aplicada, tecnologia comportamental. Nota: Referência do texto original, cuja permissão de tradução foi garantida pela editora Wiley: Baer, D. M., Wolf, M. M. & Risley, T. R. (1968). Some current dimensions of applied behavior analysis. Journal of Applied Behavior Analysis, 1(1), 91-97. Resumo e abstract foram elaborados a partir dos principais aspectos do texto; a publicação original não incluía resumo. https://doi.org/10.1901/jaba.1968.1-91.TradutoresJoão Eduardo Cattani Vilares eMarcos Spector Azoubel
Protection From Influenza by Intramuscular Gene Vector Delivery of a Broadly Neutralizing Nanobody Does Not Depend on Antibody Dependent Cellular Cytotoxicity
Cross-subtype neutralizing single domain antibodies against influenza present new opportunities for immunoprophylaxis and pandemic preparedness. Their simple modular structure and single open reading frame format are highly amenable to gene therapy-mediated delivery. We have previously described R1a-B6, an alpaca-derived single domain antibody (nanobody), that is capable of potent cross-subtype neutralization in vitro of H1N1, H5N1, H2N2, and H9N2 influenza viruses, through binding to a highly conserved epitope in the influenza hemagglutinin stem region. To evaluate the potential of R1a-B6 for immunoprophylaxis, we have reformatted it as an Fc fusion for adeno-associated viral (AAV) vector delivery. Our findings demonstrate that a single intramuscular injection in mice of AAV encoding R1a-B6 fused to Fc fragments of different isotypes equipped either, with or without antibody dependent cellular cytotoxicity (ADCC) activity, was able to drive sustained high-level expression (0.5–1.1 mg/mL) in sera with no evidence of reduction for up to 6 months. R1a-B6-Fc fusions of both isotypes gave complete protection against lethal challenge with both pandemic A/California/07/2009 (H1N1)pdm09 and avian influenza A/Vietnam/1194/2004 (H5N1). This data suggests that R1a-B6 is capable of cross-subtype protection and ADCC was not essential for R1a-B6 efficacy. Our findings demonstrate AAV delivery of cross-subtype neutralizing nanobodies may be an effective strategy to prevent influenza infection and provide long-term protection independent of a host induced immune response
Dual role of immune cells in the testis: protective or pathogenic for germ cells?
The purpose of this review is to describe how the immune cells present in the testis interact with the germinal epithelium contributing to survival or apoptosis of germ cells (GCs). Physiologically, the immunosuppressor testicular microenvironment protects GCs from immune attack, whereas in inflammatory conditions, tolerance is disrupted and immune cells and their mediators respond to GC self antigens, inducing damage of the germinal epithelium. Considering that experimental models of autoimmune orchitis have clarified the local immune mechanisms by which protection of the testis is compromised, we described the following topics in the testis of normal and orchitic rats: (1) cell adhesion molecule expression of seminiferous tubule specialized junctions and modulation of blood-testis barrier permeability by cytokines (2) phenotypic and functional characteristics of testicular dendritic cells, macrophages, effector and regulatory T cells and mast cells and (3) effects of pro-inflammatory cytokines (TNF-α, IL-6 and FasL) and the nitric oxide-nitric oxide synthase system on GC apoptosis.Fil: Pérez, Cecilia Valeria. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Theas, Maria Susana. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Jacobo, Patricia Verónica. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Jarazo Dietrich, Sabrina Soledad. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Guazzone, Vanesa Anabella. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Lustig, Livia. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentin
A Complete Version of the Glauber Theory for Elementary Atom - Target Atom Scattering and Its Approximations
A general formalism of the Glauber theory for elementary atom (EA) - target
atom (TA) scattering is developed. A second-order approximation of its complete
version is considered in the framework of the optical-model perturbative
approach. A `potential' approximation of a second-order optical model is
formulated neglecting the excitation effects of the TA. Its accuracy is
evaluated within the second-order approximation for the complete version of the
Glauber EA-TA scattering theory.Comment: PDFLaTeX, 10 pages, no figures; an updated versio
Live Well, Eat Well, Be Active With Diabetes Curriculum Improves Type 2 Diabetes Management
Type 2 diabetes is a complex disease with several modifiable lifestyle factors. The Extension ‘Live well, Eat well, be Active with Diabetes’ curriculum provides four 90-minute lessons teaching individuals to live well, eat well, and be active with diabetes. Fourteen Extension educators implemented and evaluated the curriculum with 107 participants. Participants reported the program helped them feel better able to take care of their health. We observed significant differences in participants’ retrospective pre and post ‘Live well,’ ‘Eat well’ and ‘be Active’ total scores. Extension has a unique opportunity to educate individuals so they may better manage their diabetes
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