403 research outputs found
Bounds on quark mixing, and mixing angle from flavor changing neutral processes in a 3-3-1 model
Meson and antimeson mixing constitutes an important source of constraint on
models that give tree level contributions to flavor violating neutral
processes. In electroweak models, where anomaly
cancellation requires that one family of quarks transforms differently from the
other ones, processes involving flavor changing neutral currents gain tree
level contributions mediated by gauge and scalar fields. Here, we firstly
investigate the contributions to the , , and
mixings from the standard Higgs and confront our predictions
with experiments. We argue that the results shed light in the quark mixing
matrices . We, next, evaluate the contributions of and
to mixing. As a result, we obtain a severe bound on and .Comment: 14 pages, 1 figur
Flavor Changing Neutral Current processes and family discrimination in 3-3-1 models
In 3-3-1 models anomaly cancellation requires that one of the three families
of quarks transforms as triplet by with the other two
transforming necessarily as anti-triplet. This is an important feature of the
model because with it we explain family replication. Thus it is mandatory to
discriminate which of the families will transform as triplet by
because the main consequence of anomaly cancellation in
3-3-1 models is the arising of processes violating flavor at tree level by
means of neutral currents mediated by gauge and scalar fields and each case
leads to different results. In this work we consider the 3-3-1 model with
right-handed neutrinos. Among the spectrum of 3-3-1 particles that contributes
to the flavor changing neutral processes, there is a pseudoscalar that may be
the lightest of the 3-3-1 particles and then should give the main contribution
to such processes. We then calculate its contribution to the
mixing transition and confront it with the current experimental results. We do
this for the three cases in which one of the family of quarks transforms as a
triplet by . According to our findings each case leads
to different constraints on the mass of the pseudoscalar and the case in which
the third family of quarks transforms as triplet seems to be the favoured one.
We also obtain the most stringent bounds on the mass of the pseudoscalar of the
model.Comment: Typos fixed, references added, conclusions unchanged, 17 pages, 1
figures. Matches published versio
Ocorrência da infecção pelo vírus da artrite encefalite Caprina em Patos de Minas, Minas Gerais, Brasil.
Com o objetivo de investigar a ocorrência da artrite encefalite caprina (CAE) em um capril leiteiro no município de Patos de Minas (MG), colheram-se amostras de sangue de 57 caprinos de idades variadas, ambos os sexos e sem raça definida. Realizou-se um questionário epidemiológico abordando os dados da propriedade, como os tipos de intalações e os manejos sanitário, alimentar e reprodutivo. As amostras foram encaminhadas para o Laboratório de Virologia da Embrapa Caprinos e Ovinos, Sobral (CE), onde se realizou o teste de imunodifusão em gel de ágar (IDGA) para a detecção de anticorpos anti-CAEV. A freqüência de anticorpos anti-CAEV em uma propriedade no município de Patos de Minas (MG) foi de 22,80% (13/57). O manejo incorreto favoreceu a ocorrência da CAE nesta propriedade. A presença de anticorpos anti-CAEV é um alerta para a necessidade de adoção de medidas preventivas, evitando a sua disseminação para outras propriedades e regiões
Bacillus Calmette-Guérin immunotherapy induces an efficient antitumor response to control murine melanoma depending on MyD88 signaling
Bacillus Calmette-Guérin (BCG) is the first line treatment for bladder cancer and it is also proposed for melanoma immunotherapy. BCG modulates the tumor microenvironment (TME) inducing an antitumor effective response, but the immune mechanisms involved still poorly understood. The immune profile of B16-F10 murine melanoma cells was assessed by infecting these cells with BCG or stimulating them with agonists for different innate immune pathways such as TLRs, inflammasome, cGAS-STING and type I IFN. B16-F10 did not respond to any of those stimuli, except for type I IFN agonists, contrasting with bone marrow-derived macrophages (BMDMs) that showed high production of proinflammatory cytokines. Additionally, we confirmed that BCG is able to infect B16-F10, which in turn can activate macrophages and spleen cells from mice in co-culture experiments. Furthermore, we established a subcutaneous B16-F10 melanoma model for intratumoral BCG treatment and compared wild type mice to TLR2-/-, TLR3-/-, TLR4-/-, TLR7-/-, TLR3/7/9-/-, caspase 1-/-, caspase 11-/-, IL-1R-/-, cGAS-/-, STING-/-, IFNAR-/-, MyD88-/-deficient animals. These results in vivo demonstrate that MyD88 signaling is important for BCG immunotherapy to control melanoma in mice. Also, BCG fails to induce cytokine production in the co-culture experiments using B16-F10 and BMDMs or spleen cells derived from MyD88-/- compared to wild-type (WT) animals. Immunotherapy with BCG was not able to induce the recruitment of inflammatory cells in the TME from MyD88-/- mice, impairing tumor control and IFN-γ production by T cells. In conclusion, MyD88 impacts on both innate and adaptive responses to BCG leading to an efficient antitumor response against melanoma
T-independent B-cell effect of agents associated with swine grower-finisher diarrhea
Swine dysentery, spirochetal colitis, and salmonellosis are production-limiting enteric diseases of global importance to the swine industry. Despite decades of efforts, mitigation of these diseases still relies on antibiotic therapy. A common knowledge gap among the 3 agents is the early B-cell response to infection in pigs. Thus, this study aimed to characterize the porcine B-cell response to Brachyspira hyodysenteriae, Brachyspira hampsonii (virulent and avirulent strains), Brachyspira pilosicoli, and Salmonella Typhimurium, the agents of the syndromes mentioned above. Immortalized porcine B-cell line derived from a crossbred pig with lymphoma were co-incubated for 8 h with each pathogen, as well as E. coli lipopolysaccharide (LPS) and a sham-inoculum (n = 3/treatment). B-cell viability following treatments was evaluated using trypan blue, and the expression levels of B-cell activation-related genes was profiled using reverse transcription quantitative PCR. Only S. Typhimurium and LPS led to increased B-cell mortality. B. pilosicoli downregulated B-lymphocyte antigen (CD19), spleen associated tyrosine Kinase (syk), tyrosine-protein kinase (lyn), and Tumour Necrosis Factor alpha (TNF-α), and elicited no change in immunoglobulin-associated beta (CD79b) and swine leukocyte antigen class II (SLA-DRA) expression levels, when compared to the sham-inoculated group. In contrast, all other treatments significantly upregulated CD79b and stimulated responses in other B-cell downstream genes. These findings suggest that B. pilosicoli does not elicit an immediate T-independent B-cell response, nor does it trigger antigen-presenting mechanisms. All other agents activated at least one trigger within the T-independent pathways, as well as peptide antigen presenting mechanisms. Future research is warranted to verify these findings in vivo
A highly accurate level set approach for segmenting green microalgae images
We present a method for segmenting 2D microscopy images of freshwater green microalgae. Our approach is based on a specialized level set method, leading to efficient and highly accurate algae segmentation. The level set formulation of our problem allows us to generate an algae’s boundary curve as the result of an evolving level curve, based on computed background and algae regions in a given image. By characterizing the distributions of image intensity values in local regions, we are able to automatically classify image regions into background and algae regions. We present results obtained with our method. These results are very promising as they document that we can achieve highly accurate algae segmentations when comparing ours against manually segmented images (segmented by an expert biologist) and with results derived by other approaches covered in the literature.State of Sao Paulo Research Funding Agency (FAPESP) (procs. 2011/22749-8, 2012/00269-7, 2013/26647-0)Brazilian Federal Funding Agency (CNPq) (proc. 305696/2013-0
Herpetofauna of an urban environmental protection area in an Amazon forest remnant of Amapá state, northern Brazil
The herpetofauna of Amazonia biome is one of the richest in the world. However, there is a lack of information on its richness and distribution. Here we provide a list of the herpetofauna from the Environmental Protection Area of Lagoa dos Índios, state of Amapá, Brazil, in the northern Amazon Forest. Sampling effort was conducted by active search in three distinct transects from January to May 2018 (rainy season) and August to December 2019 (drought season). We recorded 46 species composing the local herpetofauna, being 18 amphibians and 28 reptiles. Scinax ruber, Gonatodes humeralis and Helicops angulatus were the most abundant species. Regarding the conservation status, two species are categorized as Date Data deficient, (Lysapsus bolivianus and Eunectes deschauenseei), and one as Vulnerable (Podocnemis unifilis) in the Red List of the International Union for Conservation of Nature. Podocnemis unifilis is also considered Near Threatened in the Brazilian Red List of Endangered Species. Our results suggest that local biodiversity is still underestimated and, if expanded, could increase the species richness in the area. This study represents preliminary trends and raise further questions concerning the herpetofauna assemblage of Eastern Brazilian Amazonia.El bioma de la herpetofauna de la Amazonia es uno de los más ricos del mundo. Sin embargo, falta información sobre su riqueza y distribución. Aquí proporcionamos una lista de la herpetofauna del Área de Protección Ambiental de Lagoa dos Índios, estado de Amapá, Brasil, en el norte de la Selva Amazónica. El esfuerzo de muestreo se realizó mediante búsqueda activa en tres transectos distintos de enero a mayo de 2018 (temporada de lluvias) y de agosto a diciembre de 2019 (temporada de sequía). Registramos 46 especies que componen la herpetofauna local, siendo 18 anfibios y 28 reptiles. Scinax ruber, Gonatodes humeralis y Helicops angulatus fueron las especies más abundantes. En cuanto al estado de conservación, dos especies están categorizadas como Datos deficientes en fecha, (Lysapsus bolivianus y Eunectes deschauenseei), y una como Vulnerable (Podocnemis unifilis) en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza. Podocnemis unifilis también se considera Casi Amenazada en la Lista Roja Brasileña de Especies Amenazadas. Nuestros resultados sugieren que la biodiversidad local todavía se subestima y, si se amplía, podría aumentar la riqueza de especies en el área. Este estudio representa tendencias preliminares y plantea más preguntas sobre el conjunto de herpetofauna de la Amazonia brasileña oriental.Asociación Herpetológica Argentin
The BLue Amazon Brain (BLAB): A Modular Architecture of Services about the Brazilian Maritime Territory
We describe the first steps in the development of an artificial agent focused
on the Brazilian maritime territory, a large region within the South Atlantic
also known as the Blue Amazon. The "BLue Amazon Brain" (BLAB) integrates a
number of services aimed at disseminating information about this region and its
importance, functioning as a tool for environmental awareness. The main service
provided by BLAB is a conversational facility that deals with complex questions
about the Blue Amazon, called BLAB-Chat; its central component is a controller
that manages several task-oriented natural language processing modules (e.g.,
question answering and summarizer systems). These modules have access to an
internal data lake as well as to third-party databases. A news reporter
(BLAB-Reporter) and a purposely-developed wiki (BLAB-Wiki) are also part of the
BLAB service architecture. In this paper, we describe our current version of
BLAB's architecture (interface, backend, web services, NLP modules, and
resources) and comment on the challenges we have faced so far, such as the lack
of training data and the scattered state of domain information. Solving these
issues presents a considerable challenge in the development of artificial
intelligence for technical domains
A proposal for the evaluation of the bioeconomic efficiency of beef cattle production systems
ABSTRACT The objective of this study was to identify types of production system and their main indicators on bioeconomic efficiency, using qualitative and quantitative methods to evaluate beef cattle farms in the western region of the state of Rio Grande do Sul. A survey was carried out with 43 farmers operating in the western region of that state. All farms operated with complete cycle production systems in areas larger or equal to 900 ha. A qualitative questionnaire with binary answers and a quantitative questionnaire with numerical answers were applied. Technology and Management drivers were used for the calculation of the efficiency index of farmers obtained by both questionnaires. Farmers were divided into three clusters: low-efficiency level (LEL), intermediate-efficiency level (IEM), or high-efficiency level (HEL), as a result of the comparison of the scores obtained for the analyzed parameters. Subfactors resulting from each comparison (LEL × IEL; LEL × HEL, and IEL × HEL) were different as a function of the comparison and of the methods applied. Low-efficiency level farmers need to improve essential production processes, such as technology and management, as well as health management practices together with the financial management of the production system. Intermediate-efficiency level farmers need to improve their routine animal management, pasture management, and calculation of financial indicators to become highly efficient. The quantitative method allowed to identify underestimation (39.3%) or overestimation (24.2%) when farmers were are classified in clusters. Different methods may be used, but those based on quantitative information have stronger discrimination power to identify different types of farmers
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