64 research outputs found
Towards an understanding of the interactions of Trypanosoma cruzi and Trypanosoma rangeli within the reduviid insect host Rhodnius prolixus
Can the diet of the prey Tenebrio molitor (Coleoptera: Tenebrionidae) affect the development of the predator Podisus nigrispinus (Heteroptera: Pentatomidae)?
Inimigos naturais s?o importantes para o controle de pragas em culturas agr?colas e forestais. A cria??o de insetos predadores em biof?bricas deve ser de baixo custo para serem utilizados em programas de Manejo Integrado de Pragas (MIP). O objetivo deste trabalho foi avaliar o desenvolvimento de Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae), alimentado com larvas de Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae), criadas com as seguintes dietas: farelo de trigo, ra??o triturada ou peletizada para aves poedeiras e fub? de milho. Foram obtidos os par?metros de desenvolvimento e reprodu??o necess?rios para calcular a tabela de vida do predador. Os par?metros da tabela de vida revelaram crescimento populacional em todos os tratamentos. No entanto, a taxa l?quida de reprodu??o (Ro) de P. nigrispinus foi menor quando alimentados com larvas de T. molitor criadas com fub? de milho, mostrando ser a alimenta??o menos adequada para esse predador. Por proporcionar maior n?mero total de ovos, o farelo de trigo constituiu a melhor dieta para P. nigrispinus. Estudos sobre dietas de presas alternativas s?o importantes, pois podem favorecer a nutri??o de inimigos naturais e, consequentemente, melhorar o desempenho das cria??es massais em laborat?rio.Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Empresa de Pesquisa Agropecu?ria de Minas Gerais (EPAMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)Natural enemies are important for controlling pests in agricultural and forestry culture. The reproductions of predatory insects in biofactories should have low cost to be used in Integrated Pest Management Program (IPM). The objective of this study was to evaluate the development of Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae) fed with Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae). The larvae of T. molitor were created with the following diets: wheat bran, shredded or pelleted poultry feed layers and corn meal. Parameters for the development and reproduction of the P. nigrispinus were obtained. Parameters of the life table show population growth in all treatments. However, the net rate of reproduction (Ro) of P. nigrispinus was lower when they were fed with larvae of T. molitor created with corn meal, which proved to be the least adequate food for this predator. By providing a larger total number of eggs, wheat bran was the best diet for P. nigrispinus. Studies on alternative prey diets are important as they may favor the nutrition of natural enemies and, consequently, improve the performance in laboratory rearing
Sensor data classification for the indication of lameness in sheep
Lameness is a vital welfare issue in most sheep farming countries, including the UK. The pre-detection at the farm level could prevent the disease from becoming chronic. The development of wearable sensor technologies enables the idea of remotely monitoring the changes in animal movements which relate to lameness. In this study, 3D-acceleration, 3D-orientation, and 3D-linear acceleration sensor data were recorded at ten samples per second via the sensor attached to sheep neck collar. This research aimed to determine the best accuracy among various supervised machine learning techniques which can predict the early signs of lameness while the sheep are walking on a flat field. The most influencing predictors for lameness indication were also addressed here. The experimental results revealed that the Decision Tree classifier has the highest accuracy of 75.46%, and the orientation sensor data (angles) around the neck are the strongest predictors to differentiate among severely lame, mildly lame and sound classes of sheep
Associação entre o apoio social e o perfil de cuidadores familiares de pacientes com incapacidades e dependência
Critical defining characteristics for nursing diagnosis about ineffective breastfeeding
Sensor data classification for the indication of lameness in sheep
Lameness is a vital welfare issue in most sheep farming countries, including the UK. The pre-detection at the farm level could prevent the disease from becoming chronic. The development of wearable sensor technologies enables the idea of remotely monitoring the changes in animal movements which relate to lameness. In this study, 3D-acceleration, 3D-orientation, and 3D-linear acceleration sensor data were recorded at ten samples per second via the sensor attached to sheep neck collar. This research aimed to determine the best accuracy among various supervised machine learning techniques which can predict the early signs of lameness while the sheep are walking on a flat field. The most influencing predictors for lameness indication were also addressed here. The experimental results revealed that the Decision Tree classifier has the highest accuracy of 75.46%, and the orientation sensor data (angles) around the neck are the strongest predictors to differentiate among severely lame, mildly lame and sound classes of sheep
Acúmulo de massa seca e nutrientes pelo tomateiro 'SM-16' cultivado em solo com diferentes coberturas
A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction
Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acidinduced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5dihydroxybenzoic acid to a range of 2,5substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholineinduced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF2 and H2DCFDA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RTPCR and western blotting were utilized to measure Akt, eNOS, Nrf2, NQO1 and HO1 expression. Results: Ex vivo endotheliumdependent relaxation was significantly improved by the glycomimetics under palmitateinduced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitateinduced oxidative stress and enhanced NO production. We demonstrate that the protective effects of preincubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROSinduced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease
Kinetic and thermal decomposition of ettringite synthesized from aqueous solutions.
The kinetics of the thermal decomposition of a
synthetic ettringite sample was studied between 298 and
820 K in an inert atmosphere for the present work. The
ettringite and its thermal decomposition products were
characterized using X-ray diffraction, infrared spectroscopy,
and scanning electron microscopy. Four
endothermic events were observed with thermogravimetry
curves, the maxima of which occurred at 366, 397, 537,
and 641 K. All events were associated with the loss of
water molecules with different degrees of interaction
within the ettringite structure. Chemical equations for each
decomposition step were proposed based on the percentages
of mass loss observed. In addition, for the first time,
the activation energies of each ettringite decomposition
events were determined by the isoconversional methods of
Ozawa?Flynn?Wall, Friedman, and Kissinger?Akahira?
Sunose. The modeling revealed that the activation energy
varied from *50 kJ mol-1, characteristic of mass transfer
control steps, to *150 kJ mol-1, which is typical of
chemical control, as the temperature increased and the
ettringite structure lost water. A total of 32 mol of water
was released equivalent to 43.1 % of the initial sample
mass
Kinetics and mechanism of oxidation of a concentrate of spfalerite.
A oxida??o do concentrado de esfalerita (ZnS) por oxig?nio gasoso foi realizada por meio de an?lise termogravim?trica (TGA). Os produtos de oxida??o foram analisados por difratometria de raios X e microscopia eletr?nica de varredura (MEV/EDS) e a forma??o de sulfato de zinco foi detectada durante o processo de oxida??o. A pirita presente no concentrado foi aquecida a uma temperatura mais baixa do que a esfalerita e o mecanismo de oxida??o estava de acordo com o mecanismo proposto por Dunn J. G. et. al. (1989). A cin?tica da oxida??o da esfalerita foi avaliada por meio do m?todo de isoconvers?o de Linhas de Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) e n?o-linear (MNL) e os resultados sugerem que o processo de oxida??o segue um mecanismo complexo. Os valores de energia de ativa??o encontrados foram superiores a 40kJ/mol na gama completa de convers?o sugerindo que a etapa de controle ocorre por meio de rea??o qu?mica.The oxidation of sphalerite (ZnS) concentrate by gaseous oxygen was carried out by means of thermogravimetric analysis (TGA). The products of oxidation were analyzed by X-ray difractometry and microscopy electronic scanning (MEV/EDS) and the formation of zinc sulphate was detected during the oxidation process. The pyrite present on concentrate was roasted at lower temperature than sphalerite and the mechanism of oxidation was in agreement with the mechanism proposed by Dunn J. G. et. al. (1989). The kinetics of sphalerite oxidation was evaluated by mean of Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) and nonlinear (MNL) isoconversional method and the results suggest that the oxidation process follow a complex mechanism. The values of activation energy founded were higher than 40kJ/mol at full range of conversion and suggest that the controlling step takes place via chemical reaction
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