1,125 research outputs found
Acute Myocardial Infarction in the Puerperium
Os autores descrevem um caso clĂnico de
paciente de 42 anos, com enfarte agudo do
miocĂĄrdio (EAM) ao 3Âș dia de puerpĂ©rio, tendo
efectuado angioplastia directa.
A propĂłsito deste caso fez-se uma revisĂŁo das
principais alteraçÔes fisiológicas
cardiovasculares e da hemostase na gravidez,
habitualmente bem toleradas pelas gestantes,
mas que em mulheres com factores de risco ou
com doença cardĂaca prĂ©via aumentam a
probabilidade de eventos cardiovasculares.
O volume sanguĂneo e o dĂ©bito cardĂaco
aumentam em média 50% durante a gestação,
a concentração de hemoglobina diminui e a
menor resistĂȘncia vascular perifĂ©rica
condiciona uma queda da pressĂŁo arterial na
primeira metade da gravidez. No pĂłs parto
imediato verifica-se um incremento na pressĂŁo
de enchimento ventricular, volume sistĂłlico e
dĂ©bito cardĂaco e Ă© no perĂodo peri-parto que o risco cardiovascular se encontra mais elevado.
A incidĂȘncia de EAM na gravidez e puerpĂ©rio
Ă© baixa, no entanto a tendĂȘncia Ă© de aumento,
tendo em conta o nĂșmero crescente de
gestaçÔes nos extremos da idade reprodutiva
Transversal crack and delamination of laminates using XFEM
This paper offers a new insight into the computational modelling of crack and delamination of carbon fiber composite. Both transversal cracks (intralaminar) and delamination (interlaminar) are modelled with Extended Finite Element Method (XFEM). Constitutive and fracture laws are integrated to model the initiation of crack or delamination, and their subsequent evolution. The study includes the size effect assessment of composite due to the increment of composite thickness. The results are in close agreement between the experimental and analytical data of each specimen modelled based on the size of the carbon fiber composite volume
Balanço e anålise da sustentabilidade energética na produção orgùnica de hortaliças.
Os insumos e serviços utilizados na produção vegetal representam custo energĂ©tico. Dependendo desses fatores e das produtividades obtidas, a conversĂŁo da produção em energia determinarĂĄ a eficiĂȘncia energĂ©tica do sistema. A agricultura orgĂąnica somente atingirĂĄ a missĂŁo de preservação ambiental se tiver comprovada sustentabilidade energĂ©tica. Neste trabalho, objetivou-se caracterizar os balanços energĂ©ticos dos cultivos orgĂąnicos e analisar sua sustentabilidade, em comparação aos sistemas convencionais. Monitoraram-se campos de produção de dez culturas, de 1991 a 2000 em Domingos Martins-ES. Os dados do sistema convencional foram obtidos pelas mĂ©dias dos coeficientes tĂ©cnicos da regiĂŁo. Quantificaram-se os coeficientes tĂ©cnicos, convertendo suas grandezas fĂsicas em equivalentes energĂ©ticos, expressos em kcal. O sistema orgĂąnico gastou 4.571.159 kcal ha-1 e apresentou 12.696.712 kcal ha-1 de energia inserida na colheita, mostrando balanço mĂ©dio de 2,78. Esse valor foi similar ao obtido no sistema convencional (1,93). As participaçÔes dos componentes nos gastos do sistema orgĂąnico foram embalagem (35,8%), composto orgĂąnico (17,2%), irrigação (12,6%), sementes/mudas (12,4%) e mĂŁo-de-obra (11,0%), serviços mecĂąnicos (5,0%) e frete (4,5%). Se os custos com embalagens fossem eliminados, os gastos do sistema orgĂąnico seriam reduzidos para 2.930.113 kcal ha-1, aumentando sua eficiĂȘncia. A maioria dos cultivos orgĂąnicos pode ser considerada sustentĂĄvel em transformação de energia, com balanços superiores a 1,00 e produção mĂ©dia diĂĄria de 80.421 kcal ha-1 por dia, superior Ă necessidade mĂnima de 58.064 kcal ha-1
To respond or not to respond - a personal perspective of intestinal tolerance
For many years, the intestine was one of the poor relations of the immunology world, being a realm inhabited mostly by specialists and those interested in unusual phenomena. However, this has changed dramatically in recent years with the realization of how important the microbiota is in shaping immune function throughout the body, and almost every major immunology institution now includes the intestine as an area of interest. One of the most important aspects of the intestinal immune system is how it discriminates carefully between harmless and harmful antigens, in particular, its ability to generate active tolerance to materials such as commensal bacteria and food proteins. This phenomenon has been recognized for more than 100 years, and it is essential for preventing inflammatory disease in the intestine, but its basis remains enigmatic. Here, I discuss the progress that has been made in understanding oral tolerance during my 40 years in the field and highlight the topics that will be the focus of future research
Phenotypic redshifts with self-organizing maps: A novel method to characterize redshift distributions of source galaxies for weak lensing
Wide-field imaging surveys such as the Dark Energy Survey (DES) rely on
coarse measurements of spectral energy distributions in a few filters to
estimate the redshift distribution of source galaxies. In this regime, sample
variance, shot noise, and selection effects limit the attainable accuracy of
redshift calibration and thus of cosmological constraints. We present a new
method to combine wide-field, few-filter measurements with catalogs from deep
fields with additional filters and sufficiently low photometric noise to break
degeneracies in photometric redshifts. The multi-band deep field is used as an
intermediary between wide-field observations and accurate redshifts, greatly
reducing sample variance, shot noise, and selection effects. Our implementation
of the method uses self-organizing maps to group galaxies into phenotypes based
on their observed fluxes, and is tested using a mock DES catalog created from
N-body simulations. It yields a typical uncertainty on the mean redshift in
each of five tomographic bins for an idealized simulation of the DES Year 3
weak-lensing tomographic analysis of , which is a
60% improvement compared to the Year 1 analysis. Although the implementation of
the method is tailored to DES, its formalism can be applied to other large
photometric surveys with a similar observing strategy.Comment: 24 pages, 11 figures; matches version accepted to MNRA
Population genomics provide insights into the global genetic structure of Colletotrichum graminicola, the causal agent of maize anthracnose
Understanding the genetic diversity and mechanisms underlying genetic variation in pathogen populations is crucial to the development of effective control strategies. We investigated the genetic diversity and reproductive biology of Colletotrichum graminicola isolates which infect maize by sequencing the genomes of 108 isolates collected from 14 countries using restriction site-associated DNA sequencing (RAD-seq) and whole-genome sequencing (WGS). Clustering analyses based on single-nucleotide polymorphisms revealed three genetic groups delimited by continental origin, compatible with short-dispersal of the pathogen and geographic subdivision. Intra- and intercontinental migration was observed between Europe and South America, likely associated with the movement of contaminated germplasm. Low clonality, evidence of genetic recombination, and high phenotypic diversity were detected. We show evidence that, although it is rare (possibly due to losses of sexual reproduction- and meiosis-associated genes) C. graminicola can undergo sexual recombination. Our results support the hypotheses that intra- and intercontinental pathogen migration and genetic recombination have great impacts on the C. graminicola population structure
Can animal manure be used to increase soil organic carbon stocks in the Mediterranean as a mitigation climate change strategy?
Soil organic carbon (SOC) plays an important role on improving soil
conditions and soil functions. Increasing land use changes have induced an
important decline of SOC content at global scale. Increasing SOC in
agricultural soils has been proposed as a strategy to mitigate climate change.
Animal manure has the characteristic of enriching SOC, when applied to crop
fields, while, in parallel, it could constitute a natural fertilizer for the
crops. In this paper, a simulation is performed using the area of Catalonia,
Spain as a case study for the characteristic low SOC in the Mediterranean, to
examine whether animal manure can improve substantially the SOC of agricultural
fields, when applied as organic fertilizers. Our results show that the policy
goals of the 4x1000 strategy can be achieved only partially by using manure
transported to the fields. This implies that the proposed approach needs to be
combined with other strategies.Comment: Proc. of EnviroInfo 2020, Nicosia, Cyprus, September 2020. arXiv
admin note: text overlap with arXiv:2006.0912
Seeing the woods for the trees: the problem of information inefficiency and information overload on operator performance
One of the recurring questions in designing dynamic control environments is whether providing more information leads to better operational decisions. The idea of having every piece of information is increasingly tempting (and in safety critical domains often mandatory) but has become a potential obstacle for designers and operators. The present research study examined this challenge of appropriate information design and usability within a railway control setting. A laboratory study was conducted to investigate the presentation of different levels of information (taken from data processing framework, Dadashi et al., 2014) and the association with, and potential prediction of, the performance of a human operator when completing a cognitively demanding problem solving scenario within railways. Results indicated that presenting users only with information corresponding to their cognitive task, and in the absence of other, non task-relevant information, improves the performance of their problem solving/alarm handling. Knowing the key features of interest to various agents (machine or human) and using the data processing framework to guide the optimal level of information required by each of these agents could potentially lead to safer and more usable designs
Differential Effects of Vpr on Single-cycle and Spreading HIV-1 Infections in CD4+ T-cells and Dendritic Cells
The Vpr protein of human immunodeficiency virus type 1 (HIV-1) contributes to viral replication in non-dividing cells, specifically those of the myeloid lineage. However, the effects of Vpr in enhancing HIV-1 infection in dendritic cells have not been extensively investigated. Here, we evaluated the role of Vpr during infection of highly permissive peripheral blood mononuclear cells (PBMCs) and CD4+ T-cells and compared it to that of monocyte-derived dendritic cells (MDDCs), which are less susceptible to HIV-1 infection. Infections of dividing PBMCs and non-dividing MDDCs were carried out with single-cycle and replication-competent HIV-1 encoding intact Vpr or Vpr-defective mutants. In contrast to previous findings, we observed that single-cycle HIV-1 infection of both PBMCs and MDDCs was significantly enhanced in the presence of Vpr when the viral stocks were carefully characterized and titrated. HIV-1 DNA quantification revealed that Vpr only enhanced the reverse transcription and nuclear import processes in single-cycle HIV-1 infected MDDCs, but not in CD4+ T-cells. However, a significant enhancement in HIV-1 gag mRNA expression was observed in both CD4+ T-cells and MDDCs in the presence of Vpr. Furthermore, Vpr complementation into HIV-1 virions did not affect single-cycle viral infection of MDDCs, suggesting that newly synthesized Vpr plays a significant role to facilitate single-cycle HIV-1 infection. Over the course of a spreading infection, Vpr significantly enhanced replication-competent HIV-1 infection in MDDCs, while it modestly promoted viral infection in activated PBMCs. Quantification of viral DNA in replication-competent HIV-1 infected PBMCs and MDDCs revealed similar levels of reverse transcription products, but increased nuclear import in the presence of Vpr independent of the cell types. Taken together, our results suggest that Vpr has differential effects on single-cycle and spreading HIV-1 infections, which are dependent on the permissiveness of the target cell
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