232 research outputs found
Single-Objective Front Optimization: Application to RF Circuit Design
This paper proposes a new algorithm which promotes well distributed non-dominated fronts in the parameters space when a single- objective function is optimized. This algorithm is based on ǫ-dominance concept and maxmin sorting scheme. Besides that, the paper also presents the results of the algorithm when it is used in the automated synthesis of optimum performance CMOS radiofrequency and microwave binary-weighted differential switched capacitor arrays (RFDSCAs). The genetic synthesis tool optimizes a fitness function which is based on the performance parameter of the RFDSCAs. To validate the proposed design methodology, a CMOS RFDSCA is synthesized, using a 0.25 μm BiCMOS technology.N/
Avaliação do rendimento de raízes de diferentes genótipos de mandioca brava (Manihot esculenta, Crantz).
O potencial de capacidade de produção máximo de mandioca é estimado em condições ótimas, através de modelos matemáticos de crescimento, preveem que bons genótipos possam produzir até 90 t/ha/ano de raízes ou 30 t/ha/ano de matéria seca. As cascas constituem cerca de 20-35% do peso do tubérculo, especialmente no caso da má descamação (Obadina, 2006). Os teores de matéria seca nas raízes são altamente correlacionados com os teores de amido ou fécula, dependendo da variedade do local onde se cultiva, sua idade e época de colheita. Assim, objetivou-se avaliar o rendimento de polpa fresca, de amido total, massa seca de amido e umidade de 15 genótipos de mandioca brava (Manihot esculenta, Crantz), pertencente ao banco ativo de germoplasma (BAG) da Embrapa Amazônia Oriental localizada em Belém do Pará. A média percentual dos genótipos de mandioca para polpa fresca variou de (62,39% a 83,95%), do amido total extraído variou de (8,80% a 33,17%) e da massa seca do amido foi de (66,83% a 91,20%). Portanto, as caracterizações de os materiais genéticos auxiliarão ao programa de melhoramento genético da Embrapa Amazônia Oriental
Aerosol optical depth retrievals in central Amazonia from a multi-filter rotating shadow-band radiometer calibrated on-site
Extraterrestrial spectral response calibration of a multi-filter rotating
shadow band radiometer (MFRSR) under pristine Amazonian Forest atmosphere
conditions was performed using the Langley plot method. The MFRSR is
installed in central Amazonia as part of a long-term monitoring site, which
was used in the context of the GoAmazon2014/5 experiment. It has been
operating continuously since 2011 without regular extraterrestrial
calibration, preventing its application to accurate monitoring of aerosol
particles. Once calibrated, the MFRSR measurements were applied to retrieve
aerosol particle columnar optical properties, specifically aerosol optical depth (AODλ) and
Ångström exponent (AE), which were evaluated against retrievals from
a collocated Cimel Sun photometer belonging to the AErosol RObotic NETwork
(AERONET). Results obtained revealed that pristine Amazonian conditions are
able to provide MFRSR extraterrestrial spectral response with relative
uncertainty lower than 1.0 % in visible channels. The worst estimate (air
mass =1) for absolute uncertainty in AODλ retrieval varied
from ≈0.02 to ≈0.03, depending on the assumption regarding
uncertainty for MFRSR direct normal irradiance measured at the surface. The
obtained root mean square error (RMSE ≈0.025) from the evaluation of
MFRSR retrievals against AERONET AODλ was, in general, lower than
estimated MFRSR AODλ uncertainty, and close to the uncertainty of
AERONET field Sun photometers (≈0.02).</p
Análise de vizinhança de castanheiras: existe relação entre produção de frutos e floresta do entorno?
Brazilian Guidelines for Hereditary Angioedema Management - 2017 Update Part 1: Definition, Classification and Diagnosis
Hereditary angioedema is an autosomal dominant disease characterized by recurrent angioedema attacks with the involvement of multiple organs. The disease is unknown to many health professionals and is therefore underdiagnosed. Patients who are not adequately diagnosed and treated have an estimated mortality rate ranging from 25% to 40% due to asphyxiation by laryngeal angioedema. Intestinal angioedema is another important and incapacitating presentation that may be the main or only manifestation during an attack. In this article, a group of experts from the “Associação Brasileira de Alergia e Imunologia (ASBAI)” and the “Grupo de Estudos Brasileiro em Angioedema Hereditário (GEBRAEH)” has updated the Brazilian guidelines for the diagnosis and treatment of hereditary angioedema
Modelling the radiative effects of biomass burning aerosols on carbon fluxes in the Amazon region
Every year, a dense smoke haze covers a large portion of South America originating from fires in the Amazon Basin and central parts of Brazil during the dry biomass burning season between August and October. Over a large portion of South America, the average aerosol optical depth at 550 nm exceeds 1.0 during the fire season, while the background value during the rainy season is below 0.2. Biomass burning aerosol particles increase scattering and absorption of the incident solar radiation. The regional-scale aerosol layer reduces the amount of solar energy reaching the surface, cools the near-surface air, and increases the diffuse radiation fraction over a large disturbed area of the Amazon rainforest. These factors affect the energy and CO2 fluxes at the surface. In this work, we applied a fully integrated atmospheric model to assess the impact of biomass burning aerosols in CO2 fluxes in the Amazon region during 2010. We address the effects of the attenuation of global solar radiation and the enhancement of the diffuse solar radiation flux inside the vegetation canopy. Our results indicate that biomass burning aerosols led to increases of about 27 % in the gross primary productivity of Amazonia and 10 % in plant respiration as well as a decline in soil respiration of 3 %. Consequently, in our model Amazonia became a net carbon sink; net ecosystem exchange during September 2010 dropped from +101 to −104 TgC when the aerosol effects are considered, mainly due to the aerosol diffuse radiation effect. For the forest biome, our results point to a dominance of the diffuse radiation effect on CO2 fluxes, reaching a balance of 50–50 % between the diffuse and direct aerosol effects for high aerosol loads. For C3 grasses and savanna (cerrado), as expected, the contribution of the diffuse radiation effect is much lower, tending to zero with the increase in aerosol load. Taking all biomes together, our model shows the Amazon during the dry season, in the presence of high biomass burning aerosol loads, changing from being a source to being a sink of CO2 to the atmosphere
Multiple Origins of Knockdown Resistance Mutations in the Afrotropical Mosquito Vector Anopheles gambiae
How often insecticide resistance mutations arise in natural insect populations is a fundamental question for understanding the evolution of resistance and also for modeling its spread. Moreover, the development of resistance is regarded as a favored model to study the molecular evolution of adaptive traits. In the malaria vector Anopheles gambiae two point mutations (L1014F and L1014S) in the voltage-gated sodium channel gene, that confer knockdown resistance (kdr) to DDT and pyrethroid insecticides, have been described. In order to determine whether resistance alleles result from single or multiple mutation events, genotyping of the kdr locus and partial sequencing of the upstream intron-1 was performed on a total of 288 A. gambiae S-form collected from 28 localities in 15 countries. Knockdown resistance alleles were found to be widespread in West Africa with co-occurrence of both 1014S and 1014F in West-Central localities. Differences in intron-1 haplotype composition suggest that kdr alleles may have arisen from at least four independent mutation events. Neutrality tests provided evidence for a selective sweep acting on this genomic region, particularly in West Africa. The frequency and distribution of these kdr haplotypes varied geographically, being influenced by an interplay between different mutational occurrences, gene flow and local selection. This has important practical implications for the management and sustainability of malaria vector control programs
- …