Food security and agriculture productivity assessments in sub-Saharan Africa (SSA) require a better understanding of how climate and other drivers influence regional crop yields. In this paper, our objective was to identify the climate signal in the realized yields of maize, sorghum, and groundnut in SSA. We explored the relation between crop yields and scale-compatible climate data for the 1962-2014 period using Random Forest, a diagnostic machine learning technique. We found that improved agricultural technology and country fixed effects are three times more important than climate variables for explaining changes in crop yields in SSA. We also found that increasing temperatures reduced yields for all three crops in the temperature range observed in SSA, while precipitation increased yields up to a level roughly matching crop evapotranspiration. Crop yields exhibited both linear and nonlinear responses to temperature and precipitation, respectively. For maize, technology steadily increased yields by about 1% (13 kg/ha) per year while increasing temperatures decreased yields by 0.8% (10 kg/ha) per °C. This study demonstrates that although we should expect increases in future crop yields due to improving technology, the potential yields could be progressively reduced due to warmer and drier climates.
The test weight or hectoliter weight is an important parameter used to classify the quality of the grain. Globally, it is evaluated by using 250, 500 or 1000 ml devices. Despite its importance, there is no standard equipment to assess it in small samples from the research plots. This study aims to test a newly developed microchondrometer (15.30 ml) in the triticale and oats. A second microchondrometer (31.26 ml) was also designed to be tested in oats. The performance of the two microchondrometers, their comparison and relationship with 250 ml commercial chondrometer were analyzed using the t-test and Pearson's correlation coefficient. The results revealed no significant differences between two microchondrometers or their relationship with 250 ml chondrometer by t-test (p> 0.05). Based on two-year evaluations, the correlation between the 250 and 15.30 ml was highly significant (p <0.0001) for triticale (0.9873), and oats (0.9557 for 15.30 ml device and 0.9448 for 31.26 ml device). The correlation between 15.30 and 31.26 ml devices was also highly significant (p <0.0001) for oats (0.9399). These results suggest that in small samples, the 15.30 ml microchondrometer can be used successfully in triticale and oats to assess its test weight. Key words: Plant breeding, grain density, genotype screening.
Foram estudadas madeiras de híbridos de Eucalyptus grandis x Eucalyptus urophylla, em três idades diferentes, com o objetivo de avaliar o comportamento da madeira e do carvão vegetal produzido diante do aumento controlado de temperatura, bem como verificar a influência das características da madeira sobre o carvão vegetal. Foram realizadas análises químicas (extrativos totais, lignina, holocelulose, celulose, cinza e análise elementar) e térmicas (análise termogravimétrica - TG, análise térmica diferencial - DTA e calorimetria 1,67 ºC min-1 e temperatura final de 450 ºC. No carvão vegetal produzido, foram realizadas análise imediata, elementar e térmica. A densidade básica da madeira correlacionou-se positivamente com a relação carbono/ hidrogênio (C/H) e negativamente com os teores de cinza, nitrogênio, oxigênio, enxofre e relação siringil/ guaiacil (S/G). Os teores de cinza, nitrogênio, enxofre e S/G da madeira correlacionaram-se positivamente entre si e negativamente com a variável C/H da madeira. O teor de carbono fixo (TCF), o poder calorífico do carvão vegetal, o teor de carbono elementar e a relação C/H correlacionaram-se positivamente entre si e negativamente com o teor de materiais voláteis (TMV). O teor de lignina correlacionou-se positivamente com o rendimento gravimétrico em carvão (RGC) e negativamente com o TCF. Three different ages of . Eucalyptus grandis x . Eucalyptos urophylla wood hybrids were studied, with purpose of evaluating wood and charcoal behavior by temperature rising, and investigating the influence of wood characteristics on charcoal. Wood was analyzed chemically (total extractives, lignin, holocellulose, cellulose, ash and elementary composition) and thermally (thermogravimetry analysis - TG, differential thermal analysis - DTA and differential scanning calorimetry - DSC). Also, basic density and higher heating value were evaluated. Charcoal was produced in muffle furnace with constant heating rate of 1,67 ºC min-1 up to 450 ºC. In the produced charcoal, immediate analysis were conducted, elementary and thermal. The basic density of wood had positive correlation with C/H relation, and negative correlation with ash, nitrogen, oxygen, sulfur contents and S/G relation. The wood contents of ash, nitrogen, sulfur and S/G had positive correlation among each other, and negative correlation with C/H relation. In charcoal, the fixed carbon content, calorific value, elementary carbon content and C/H relation had positive correlation among each other, and negative correlation with volatiles content. The lignin had positive correlation with gravimetric yield in charcoal (RGC) and negative correlation with fixed carbon.
Publisher: Embrapa Secretaria de Pesquisa e Desenvolvimento
Abstract: The objective of this work was to evaluate a recirculating aquaculture system using biological aerated filters in tanks for tambaqui (Colossoma macropomum) fingerlings farming, with two initial stocking densities (1.4 and 2.5 kg m-3). The biofilters had similar materials (media) and the same granulometric standards, but inverted orders of the media (classic and inverted). The following were monitored for 90 days: water quality; zootechnical, parasitological, and hematological parameters; and hematimetric indices. Water temperature, oxygen levels, pH, electrical conductivity, and dissolved solids concentration were compatible with tambaqui farming and did not differ between the different biofilters and densities. The ammonia and nitrite value was associated with the stocking densities and not with biofilter. The zootechnical and hematological parameters and the hematimetric indices evaluated were not influenced either by the type of biofilter or by the stocking densities. Ichthyophthirius multifiliis, Anacanthorus spathulatus, Notozothecium janauachensis, and Mymarothecium boegeri were the parasites found. The aerated, classical, and inverted biological filters have similar efficiency in maintaining water quality parameters for tambaqui fingerling farming. Resumo: O objetivo deste trabalho foi avaliar um sistema de recirculação de água com uso de filtros biológicos aerados em tanques de criação de alevinos de tambaqui (Colossoma macropomum), com duas densidades de estocagem (1,4 e 2,5 kg m-3). Os biofiltros possuíam materiais semelhantes (meios) e os mesmos padrões granulométricos, mas com a ordem dos meios invertida (clássico e invertido). Foram monitorados durante 90 dias: a qualidade da água; os parâmetros zootécnicos, parasitológicos e hematológicos; e os índices hematimétricos. A temperatura da água, os níveis de oxigênio, o pH, a condutividade elétrica e a concentração de sólidos dissolvidos foram compatíveis com a produção de tambaqui e não diferiram entre os diferentes biofiltros e densidades. O valor de amônia e nitrito foi associado à densidade de estocagem e não ao biofiltro. Os parâmetros zootécnicos e hematológicos e os índices hematimétricos avaliados não foram influenciados nem pelo tipo de biofiltro nem pela densidade de estocagem. Ichthyophthirius multifiliis, Anacanthorus spathulatus, Notozothecium janauachensis e Mymarothecium boegeri foram os parasitas encontrados. Os filtros biológicos aerados, clássico e invertido têm similar eficiência na manutenção de parâmetros de qualidade de água para o cultivo de alevinos de tambaqui.
Abstract Crowd counting in specific places has recently been considered as a significant contribution in many applications in terms of security and economic values. Recently, the Kingdom of Saudi Arabia has considered new ways and methods to diversify sources of income, where many non-traditional establishments in several fields have been initiated and put in place. However, controlling the number of visitors and participants to events and exhibitions has always been a challenge, as it has always been considered as an important success factor to any event. Smart public places approach is one of the inevitable directions of development in Saudi Arabia, where security, comfort, and safety of crowds is to be controlled and managed using machine learning techniques, more specifically, IoT-based crowd counting techniques. Such a technology will not only help in resolving security and safety problems, but also will play a significant role in reducing waiting time for visitors, by giving indicators, projections and advices on crowded places. In this paper, a mobile-based model is proposed for counting people in high and low crowded public places in Saudi Arabia under various scene conditions with no prior knowledge. The proposed model is built based on pre-trained convolutional neural network (CNN) called VGG-16 with some modifications on the last layer of the CNN to increase the efficiency of the training model. In addition to the improvement of efficiency, the proposed method accepts images of arbitrary sizes/scales as inputs. The applicability of the proposed method has been evaluated by incorporating IoT architecture, where surveillance cameras to be connected to the Internet to capture live pictures of different public places. To achieve this goal, New and special Saudi people dataset as well as some other existing dataset, have been produced and used to train the network. The result shows a significant improvement to the efficiency of the DCNN over the existing counting networks.
Abstract To explore how humans can dexterously pick fruits of various sizes from a tomato plant from different positions and postures, some anthropometric dimensions related to the hand-harvesting of the fruits were determined within 261 volunteers, and their correlations were investigated using a bivariate correlation analysis method. The heights of the body (stature), shoulder tip, waist and knee of participants ranged from 111.2 to 193.6, 87.5 to 163.0, 62.1 to 117.3, and 31.0 to 56.0 cm, respectively; the ratios of the knee height, waist height, and shoulder tip height to the stature were 0.25–0.33, 0.52–0.65, and 0.76–0.87, respectively; the shoulder tip breadth, upper limb length and foot length of participants ranged from 26.0 to 48.5, 45.4 to 85.6, and 19.5 to 28.0 cm, respectively; and the length ratios of the hand, forearm, and upper arm to the upper limb were 0.23–0.31, 0.29–0.38, and 0.35–0.45, respectively. There were high linear correlations among the stature, waist height and knee height, between the forearm and hand lengths, and among the stature, hand length and arm length and moderate linear correlations between most hand dimensions. These human body dimensions determine the upper limb workspace, body balance, working comfort and lower limb movement frequency during picking, and this information will be useful for the bionic dimensional synthesis design of a harvesting robotic arm, walking mechanism and body. The results of multiple comparisons in ANOVA showed that there were significant differences between some of the finger dimensions and between some of the hand-scaling dimensions, which is one of the main features enabling the human hand to pick various sizes of fruits. This study can provide guidance and inspiration for the anthropomorphic design of robotic tomato-harvesting end-effectors.
The Energization and Radiation in Geospace (ERG) mission seeks to explore the dynamics of the radiation belts in theEarth’s inner magnetosphere with a space-borne probe (ERG satellite) in coordination with related ground observations and simulations/modeling studies. For this mission, the Science Center of the ERG project (ERG-SC) will provide a useful data analysisplatform based on the THEMIS Data Analysis software Suite (TDAS), which has been widely used by researchers in many conjunctionstudies of the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft and grounddata. To import SuperDARN data to this highly useful platform, ERG-SC, in close collaboration with SuperDARN groups, developedthe Common Data Format (CDF) design suitable for fitacf data and has prepared an open database of SuperDARN data archivedin CDF. ERG-SC has also been developing programs written in Interactive Data Language (IDL) to load fitacf CDF filesand to generate various kinds of plots.not only range-time-intensity-type plots but also two-dimensional map plots that can besuperposed with other data, such as all-sky images of THEMIS-GBO and orbital footprints of various satellites. The CDF-TDASscheme developed by ERG-SC will make it easier for researchers who are not familiar with SuperDARN data to access and analyzeSuperDARN data and thereby facilitate collaborative studies with satellite data, such as the inner magnetosphere data providedby the ERG (Japan).RBSP (USA).THEMIS (USA) fleet.
Social network analysis is increasingly used by geographers to better understand network phenomena. This article employs a promising analytic approach for the study of relational networks in human geography—dyadic regression analysis (DRA)—to examine labor sharing networks among peasant households. Data from a floodplain community in the Peruvian Amazon are incorporated into a relational data set that represents all reported cooperative labor flows for agriculture over one year. Matrices capturing both link and node (household) attributes are analyzed to explain the formation of cooperative labor links and the intensity (and direction) of labor flows. Results reveal that cooperative labor, which entails work predominantly done by males, is strongly shaped by relations among women, as well as by kin networks and household structure. Our findings suggest the utility of DRA for the study of other relational networks of interest to geographers.
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