92 research outputs found
Parâmetros de crescimento do sorgo e do capim no consórcio Sorghum bicolor e Brachiaria brizantha cv. Marandu.
Objetivou-se determinar o efeito do consórcio Sorghum bicolor e Brachiaria brizantha sob os parâmetros de crescimento do sorgo e do capim. Os tratamentos utilizados foram: braquiária no plantio solteiro, sorgo no plantio solteiro, sorgo consorciado com capim na linha e entrelinhas de plantio, sorgo consorciado com capim nas entrelinhas de plantio, sorgo consorciado com capim na linha de plantio. Foi utilizado o delineamento em blocos ao acaso com cinco repetições por tratamento. O corte foi feito, aproximadamente, 108 a 110 dias após o plantio, manualmente no dia 13 de maio (111 dias após o plantio) em uma altura de 35 cm. Uma amostra de plantas de sorgo e capim braquiária foi cortada e pesada juntas para que se obtivesse o peso verde do material a ser ensilado, sendo o resultado utilizado para cálculo de produção de matéria verde por hectare. A altura das plantas foi determinada, no momento do corte, por meio da medida do nível do solo até a extremidade superior da panícula em 20% das plantas de cada parcela. Outra amostra de plantas da unidade experimental foi tomada, separadas as plantas de sorgo e capim, pesadas separadamente para obtenção do peso verde (PV) e levadas ao laboratório para secagem em estufa de circulação forçada à 65ºC para determinação do peso seco. Não houve diferença entre as médias (P>0,05), para as alturas das plantas de sorgo e de capim, mas essa diferença foi significativa para as variáveis, estande de sorgo, produção de matéria verde e seca
Pecuária leiteira de precisão: uso de sensores para monitoramento e detecção precoce de alterações na saúde de bovinos leiteiros.
O diagnóstico precoce e direcionado pode eliminar e/ou minimizar os efeitos das doenças, reduzindo as taxas de descarte de animais, favorecendo a recuperação da condição de saúde e gerando decréscimo nas perdas econômicas. Por esse motivo, a identificação precoce e individualizada de animais doentes pelo uso de tecnologias de precisão está se tornando uma realidade cada vez mais frequente no campo. O objetivo dessa série Documentos da Embrapa é descrever as possibilidades de utilização de sensores para o diagnóstico precoce de problemas de saúde em bovinos leiteiros.bitstream/item/179729/1/DOC-227-Pec-Leit-Prec-Sensores.pd
Using rumination and activity data for early detection of anaplasmosis disease in dairy heifer calves.
Bovine anaplasmosis causes considerable economic losses in dairy cattle production systems worldwide, ranging from 900 million annually. It is commonly detected through rectal temperature, blood smear microscopy, and packed cell volume (PCV). Such methodologies are laborious, costly, and difficult to systematically implement in large-scale operations. The objectives of this study were to evaluate (1) rumination and activity data collected by Hr-Tag sensors (SCR Engineers Ltd.) in heifer calves exposed to anaplasmosis; and (2) the predictive ability of recurrent neural networks in early identification of anaplasmosis. Additionally, we aimed to investigate the effect of time series length before disease diagnosis (5, 7, 10, or 12 consecutive days) on the predictive performance of recurrent neural networks, and how early anaplasmosis disease can be detected in dairy calves (5, 3, and 1 d in advance). Twenty-three heifer calves aged 119 ± 15 (mean ± SD) d and weighing 148 ± 20 kg of body weight were challenged with 2 × 107 erythrocytes infected with UFMG1 strain (GenBank no. EU676176) isolated from Anaplasma marginale. After inoculation, animals were monitored daily by assessing PCV. The lowest PCV value (14 ± 1.8%) and the finding of rickettsia on blood smears were used as a criterion to classify an animal as sick (d 0). Rumination and activity data were collected continuously and automatically at 2-h intervals, using SCR Heatime Hr-Tag collars. Two time series were built including last sequence of ?5, ?7, ?10, or ?12 d preceding d 0 or a sequence of 5, 7, 10, or 12 d randomly selected in a window from ?50 to ?15 d before d 0 to ensure a sequence of days in which PCV was considered normal (32 ± 2.4%). Long shortterm memory was used as a predictive approach, and a leave-one-animal-out cross-validation (LOAOCV) was used to assess prediction quality. Anaplasmosis disease reduced 34 and 11% of rumination and activity, respectively. The accuracy, sensitivity, and specificity of long short-term memory in detecting anaplasmosis ranged from 87 to 98%, 83 to 100%, and 83 to 100%, respectively, using rumination data. For activity data, the accuracy, sensitivity, and specificity varied from 70 to 98%, 61 to 100%, and 74 to 100%, respectively. Predictive performance did not improve when combining rumination and activity. The use of longer time-series did not improve the performance of models to predict anaplasmosis. The accuracy and sensitivity in predicting anaplasmosis up to 3 d before clinical diagnosis (d 0) were greater than 80%, confirming the possibility for early identification of Anaplasmosis disease. These findings indicate the great potential of wearable sensors in early identification of anaplasmosis diseases. This could positively affect the profitability of dairy farmers and animal welfare
Infectivity of Plasmodium falciparum in malaria-naive individuals is related to knob expression and cytoadherence of the parasite
Plasmodium falciparum is the most virulent human malaria parasite because of its ability to cytoadhere in the microvasculature. Nonhuman primate studies demonstrated relationships among knob expression, cytoadherence, and infectivity. This has not been examined in humans. Cultured clinical-grade P. falciparum parasites (NF54, 7G8, and 3D7B) and ex vivo-derived cell banks were characterized. Knob and knob-associated histidine-rich protein expression, CD36 adhesion, and antibody recognition of parasitized erythrocytes (PEs) were evaluated. Parasites from the cell banks were administered to malaria-naive human volunteers to explore infectivity. For the NF54 and 3D7B cell banks, blood was collected from the study participants for in vitro characterization. All parasites were infective in vivo. However, infectivity of NF54 was dramatically reduced. In vitro characterization revealed that unlike other cell bank parasites, NF54 PEs lacked knobs and did not cytoadhere. Recognition of NF54 PEs by immune sera was observed, suggesting P. falciparum erythrocyte membrane protein 1 expression. Subsequent recovery of knob expression and CD36-mediated adhesion were observed in PEs derived from participants infected with NF54. Knobless cell bank parasites have a dramatic reduction in infectivity and the ability to adhere to CD36. Subsequent infection of malaria-naive volunteers restored knob expression and CD36-mediated cytoadherence, thereby showing that the human environment can modulate virulence
A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles
In recent years, there has been a dramatic increase in the use of unmanned
aerial vehicles (UAVs), particularly for small UAVs, due to their affordable
prices, ease of availability, and ease of operability. Existing and future
applications of UAVs include remote surveillance and monitoring, relief
operations, package delivery, and communication backhaul infrastructure.
Additionally, UAVs are envisioned as an important component of 5G wireless
technology and beyond. The unique application scenarios for UAVs necessitate
accurate air-to-ground (AG) propagation channel models for designing and
evaluating UAV communication links for control/non-payload as well as payload
data transmissions. These AG propagation models have not been investigated in
detail when compared to terrestrial propagation models. In this paper, a
comprehensive survey is provided on available AG channel measurement campaigns,
large and small scale fading channel models, their limitations, and future
research directions for UAV communication scenarios
Glycosaminoglycan and Proteoglycan Biotherapeutics in Articular Cartilage Protection and Repair Strategies: Novel Approaches to Visco?supplementation in Orthobiologics
The aim of this study is to review developments in glycosaminoglycan and proteoglycan research relevant to cartilage repair biology and in particular the treatment of osteoarthritis (OA). Glycosaminoglycans decorate a diverse range of extracellular matrix and cell associated proteoglycans conveying structural organization and physico‐chemical properties to tissues. They play key roles mediating cellular interactions with bioactive growth factors, cytokines, and morphogenetic proteins, and structural fibrillar collagens, cell interactive and extracellular matrix proteoglycans, and glycoproteins which define tissue function. Proteoglycan degradation detrimentally affects tissue functional properties. Therapeutic strategies have been developed to counter these degenerative changes. Neo‐proteoglycans prepared from chondroitin sulfate or hyaluronan and hyaluronan or collagen‐binding peptides emulate the interactive, water imbibing, weight bearing, and surface lubricative properties of native proteoglycans. Many neo‐proteoglycans outperform native proteoglycans in terms of water imbibition, matrix stabilization, and resistance to proteolytic degradation. The biospecificity of recombinant proteoglycans however, provides precise attachment to native target molecules. Visco‐supplements augmented with growth factors/therapeutic cells, hyaluronan, and lubricin (orthobiologicals) have the capacity to lubricate and protect cartilage, control inflammation, and promote cartilage repair and regeneration of early cartilage lesions and may represent a more effective therapeutic approach to the treatment of mild to moderate OA and deserve further study
GENETIC DIVERGENCE AND MORPHO-AGRONOMIC PERFORMANCE OF JATROPHA CURCAS L. CLONES FOR SELECTION OF CLONAL VARIETIES
Cellular Phenotype-Dependent and -Independent Effects of Vitamin C on the Renewal and Gene Expression of Mouse Embryonic Fibroblasts
Vitamin C has been shown to delay the cellular senescence and was considered a candidate for chemoprevention and cancer therapy. To understand the reported contrasting roles of vitamin C: growth-promoting in the primary cells and growth-inhibiting in cancer cells, primary mouse embryonic fibroblasts (MEF) and their isogenic spontaneously immortalized fibroblasts with unlimited cell division potential were used as the model pair. We used microarray gene expression profiling to show that the immortalized MEF possess human cancer gene expression fingerprints including a pattern of up-regulation of inflammatory response-related genes. Using the MEF model, we found that a physiological treatment level of vitamin C (10−5 M), but not other unrelated antioxidants, enhanced cell growth. The growth-promoting effect was associated with a pattern of enhanced expression of cell cycle- and cell division-related genes in both primary and immortalized cells. In the immortalized MEF, physiological treatment levels of vitamin C also enhanced the expression of immortalization-associated genes including a down-regulation of genes in the extracellular matrix functional category. In contrast, confocal immunofluorescence imaging of the primary MEF suggested an increase in collagen IV protein upon vitamin C treatment. Similar to the cancer cells, the growth-inhibitory effect of the redox-active form of vitamin C was preferentially observed in immortalized MEF. All effects of vitamin C required its intracellular presence since the transporter-deficient SVCT2−/− MEF did not respond to vitamin C. SVCT2−/− MEF divided and became immortalized readily indicating little dependence on vitamin C for the cell division. Immortalized SVCT2−/− MEF required higher concentration of vitamin C for the growth inhibition compared to the immortalized wildtype MEF suggesting an intracellular vitamin C toxicity. The relevance of our observation in aging and human cancer prevention was discussed
Intelligence, educational attainment, and brain structure in those at familial high-risk for schizophrenia or bipolar disorder
First-degree relatives of patients diagnosed with schizophrenia (SZ-FDRs) show similar patterns of brain abnormalities and cognitive alterations to patients, albeit with smaller effect sizes. First-degree relatives of patients diagnosed with bipolar disorder (BD-FDRs) show divergent patterns; on average, intracranial volume is larger compared to controls, and findings on cognitive alterations in BD-FDRs are inconsistent. Here, we performed a meta-analysis of global and regional brain measures (cortical and subcortical), current IQ, and educational attainment in 5,795 individuals (1,103 SZ-FDRs, 867 BD-FDRs, 2,190 controls, 942 schizophrenia patients, 693 bipolar patients) from 36 schizophrenia and/or bipolar disorder family cohorts, with standardized methods. Compared to controls, SZ-FDRs showed a pattern of widespread thinner cortex, while BD-FDRs had widespread larger cortical surface area. IQ was lower in SZ-FDRs (d = −0.42, p = 3 × 10−5), with weak evidence of IQ reductions among BD-FDRs (d = −0.23, p =.045). Both relative groups had similar educational attainment compared to controls. When adjusting for IQ or educational attainment, the group-effects on brain measures changed, albeit modestly. Changes were in the expected direction, with less pronounced brain abnormalities in SZ-FDRs and more pronounced effects in BD-FDRs. To conclude, SZ-FDRs and BD-FDRs show a differential pattern of structural brain abnormalities. In contrast, both had lower IQ scores and similar school achievements compared to controls. Given that brain differences between SZ-FDRs and BD-FDRs remain after adjusting for IQ or educational attainment, we suggest that differential brain developmental processes underlying predisposition for schizophrenia or bipolar disorder are likely independent of general cognitive impairment
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