Global Rice Atlas: Disaggregated seasonal crop calendar and production

Purpose: Rice is an important staple crop cultivated in more than 163 million ha globally. Although information on the distribution of global rice production is available by country and, at times, at subnational level, information on its distribution within a year is often lacking in different rice growing regions. Knowing when and where rice is planted and harvested and the associated production is crucial to policy and decision making on food security. To examine seasonal and geographic variations in food supply, we developed a detailed rice crop calendar and linked it with disaggregated production data. Approach and methods used: We compiled from various sources detailed data on rice production, and planting and harvesting dates by growing season. To standardize the production data to the same period, we adjusted the production values so that the totals for each country will be the same as those of FAO for 2010-2012. We then linked data on rice production with the corresponding crop calendar information to estimate production at harvest time by month then we calculated totals for each country and region. Key results: The bulk of global annual harvests of rice is from September to November, corresponding with the harvest of the wet season rice in Asia and Africa. Total rough rice production during those peak months exceed 381 million tons, which account for about half of annual global rice output. Production is lowest in January with only 11 million tons in total. Regional production is lowest in Asia in January, Americas in December, Africa in July and rest of the world in May. Synthesis and Applications: A globally complete and spatially detailed rice crop calendar is important to crop growth simulation modelling and assessment of vulnerability of rice areas to biotic and abiotic stresses. Linked to production estimates, it can be used in analyzing spatial and seasonal production trends to better assess and predict price fluctuations , and to mitigate potential significant shortfalls in food production at certain times of the year

Temperature Dependence of the Dynamics of Portevin-Le Chatelier Effect in Al-2.5%Mg alloy

Tensile tests were carried out by deforming polycrystalline samples of Al-2.5%Mg alloy at four different temperatures in an intermediate strain rate regime of 2x10-4s-1 to 2x10-3s-1. The Portevin-Le Chatelier (PLC) effect was observed throughout the strain rate and temperature region. The mean cumulative stress drop magnitude and the mean reloading time exhibit an increasing trend with temperature which is attributed to the enhanced solute diffusion at higher temperature. The observed stress-time series data were analyzed using the nonlinear dynamical methods. From the analyses, we could establish the presence of deterministic chaos in the PLC effect throughout the temperature regime. The dynamics goes to higher dimension at a sufficiently high temperature of 425K but the complexity of the dynamics is not affected by the temperature.Comment: 18 pages, 8 figures; accepted in Met. Mater. Trans.

Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafauna

The Pakistan Margin is characterised by a strong mid-water oxygen minimum zone (OMZ) that intercepts the seabed at bathyal depths (150–1300 m). We investigated whether faunal abundance and diversity trends were similar among protists (foraminiferans and gromiids), metazoan macrofauna and megafauna along a transect (140–1850 m water depth) across the OMZ during the 2003 intermonsoon (March–May) and late/post-monsoon (August–October) seasons. All groups exhibited some drop in abundance in the OMZ core (250–500 m water depth; O2: 0.10–0.13 mL L−1=4.46–5.80 μM) but to differing degrees. Densities of foraminiferans >63 μm were slightly depressed at 300 m, peaked at 738 m, and were much lower at deeper stations. Foraminiferans >300 μm were the overwhelmingly dominant macrofaunal organisms in the OMZ core. Macrofaunal metazoans reached maximum densities at 140 m depth, with additional peaks at 850, 940 and 1850 m where foraminiferans were less abundant. The polychaete Linopherus sp. was responsible for a macrofaunal biomass peak at 950 m. Apart from large swimming animals (fish and natant decapods), metazoan megafauna were absent between 300 and 900 m (O2 0.2 mL L−1=8.92 μM). The progressively deeper abundance peaks for foraminiferans (>63 μm), Linopherus sp. and ophiuroids probably represent lower OMZ boundary edge effects and suggest a link between body size and tolerance of hypoxia. Macro- and megafaunal organisms collected between 800 and 1100 m were dominated by a succession of different taxa, indicating that the lower part of the OMZ is also a region of rapid faunal change. Species diversity was depressed in all groups in the OMZ core, but this was much more pronounced for macrofauna and megafauna than for foraminiferans. Oxygen levels strongly influenced the taxonomic composition of all faunal groups. Calcareous foraminiferans dominated the seasonally and permanently hypoxic sites (136–300 m); agglutinated foraminiferans were relatively more abundant at deeper stations where oxygen concentrations were >0.13 mL L−1(=5.80 μM). Polychaetes were the main macrofaunal taxon within the OMZ; calcareous macrofauna and megafauna (molluscs and echinoderms) were rare or absent where oxygen levels were lowest. The rarity of larger animals between 300 and 700 m on the Pakistan Margin, compared with the abundant macrofauna in the OMZ core off Oman, is the most notable contrast between the two sides of the Arabian Sea. This difference probably reflects the slightly higher oxygen levels and better food quality on the western side

Range-based people detection and tracking for socially enabled service robots

With a growing number of robots deployed in populated environments, the ability to detect and track humans, recognize their activities, attributes and social relations are key components for future service robots. In this article we will consider fundamentals towards these goals and present several results using 2D range data.We first propose a learning method to detect people in sensory data based on a set of boosted features. The method largely outperforms the state of the art that typically relies on hand-tuned classifiers. Then, we present a person tracking approach based on the detection and fusion of leg tracks. To deal with the frequent occlusion and self-occlusion of legs, we extend a Multi-Hypothesis Tracking (MHT) approach by the ability to explicitly reason about and deal with adaptive occlusion probabilities. Finally, we address the problem of tracking groups of people, a first step towards the recognition of social relations. We further extend the MHT approach by a multiple model hypothesis stage able to reflect split/merge events in group formation processes. The proposed extension is mathematically elegant, runs in real-time and further allows to accurately estimate the number of people in each group. The article concludes with prospects and suggestions for future research

Eficiência dos dialelos circulantes na escolha de genitores Efficiency of circulant diallels in parental choice

O objetivo foi avaliar, por simulação de dados, a eficiência de dialelos circulantes em relação aos completos, nas estimativas de capacidade geral de combinação (CGC) e capacidade específica de combinação (CEC). Foram simuladas 50 linhagens com 100 genes com distribuição independente, efeitos iguais, sem epistasia. Consideraram-se herdabilidades de 10%, 20%, 50% e 75%, em modelos com interação alélica aditiva e dominância completa. Utilizaram-se também dados de experimentos disponíveis na literatura, ambos comparados por meio de: correlação entre estimativas de CGC e CEC, e proporções de estimativas nos circulantes que ocorreram nos intervalos de confiança dos completos. Os resultados permitiram concluir que os dialelos circulantes são tão eficientes quanto os completos, tanto na classificação dos pais quanto à CGC e à CEC, como na magnitude desses parâmetros, e que o número de cruzamentos (s) afeta as estimativas de CGC e de CEC, embora com um valor pequeno de s seja possível obter boa concordância com as estimativas obtidas nos dialelos completos; com baixa herdabilidade, é vantajoso aumentar o número de cruzamentos de cada pai, embora com a metade do número de pais envolvidos já se consiga alta eficiência dos dialelos circulantes.<br>This paper aimed to evaluate the efficiency of circulant diallel in relation to the complete ones, with data simulation based on estimates of general combining ability (GCA) and specific combining ability (SCA). Fifty lines with 100 independent genes of same effects and without epistasy were simulated. Heritabilities of 10%, 20%, 50% and 75% were considered, in models with addictive and complete dominant allelic interaction. Real data experiments presented in literature were used. They were compared by means of correlation between estimates of GCA and SCA, and also by means of proportions of estimates in the circulant that occurred in the confidence intervals of the complete ones. It was concluded that the efficiency is the same in both diallels, considering the parents classification in relation to GCA and SCA, and the magnitude of those parameters; that the number of crossings (s) affects the estimates of GCA and SCA, although with a small value of s it is possible to obtain good agreement with the estimates of the complete diallel; and, that with low heritability it is advantageous to increase the number of each parent crossings, although with the half of the number of parents involved, high efficiency of the circulant diallels is reached