About identification of features that affect the estimation of citrus harvest

Accurate models for early harvest estimation in citrus production generally involve expensive variables. The goal of this research work was to develop a model to provide early and accurate estimations of harvest using low-cost features. Given the original data may derive from tree measurements, meteorological stations, or satellites, they have varied costs. The studied orchards included tangerines (Citrus reticulata x C. sinensis) and sweet oranges (C. sinensis) located in northeastern Argentina. Machine learning methods combined with different datasets were tested to obtain the most accurate harvest estimation. The final model is based on support vector machines with low-cost variables like species, age, irrigation, red and near-infrared reflectance in February and December, NDVI in December, rain during ripening, and humidity during fruit growth. Highlights: Red and near-infrared reflectance in February and December are helpful values to predict orange harvest. SVM is an efficient method to predict harvest. A ranking method to A ranking-based method has been developed to identify the variables that best predict orange production.  Accurate models for early harvest estimation in citrus production generally involve expensive variables. The goal of this research work was to develop a model to provide early and accurate estimations of harvest using low-cost features. Given the original data may derive from tree measurements, meteorological stations, or satellites, they have varied costs. The studied orchards included tangerines (Citrus reticulata x C. sinensis) and sweet oranges (C. sinensis) located in northeastern Argentina. Machine learning methods combined with different datasets were tested to obtain the most accurate harvest estimation. The final model is based on support vector machines with low-cost variables like species, age, irrigation, red and near-infrared reflectance in February and December, NDVI in December, rain during ripening, and humidity during fruit growth. Highlights: Red and near-infrared reflectance in February and December are helpful values to predict orange harvest. SVM is an efficient method to predict harvest. A ranking method to A ranking-based method has been developed to identify the variables that best predict orange production

The acute gravitational stress of parabolic flight affects red blood cell aggregation and functionality of circulating immune cells

Postprint (published version

Linear approach to the orbiting spacecraft thermal problem

We develop a linear method for solving the nonlinear differential equations of a lumped-parameter thermal model of a spacecraft moving in a closed orbit. Our method, based on perturbation theory, is compared with heuristic linearizations of the same equations. The essential feature of the linear approach is that it provides a decomposition in thermal modes, like the decomposition of mechanical vibrations in normal modes. The stationary periodic solution of the linear equations can be alternately expressed as an explicit integral or as a Fourier series. We apply our method to a minimal thermal model of a satellite with ten isothermal parts (nodes) and we compare the method with direct numerical integration of the nonlinear equations. We briefly study the computational complexity of our method for general thermal models of orbiting spacecraft and conclude that it is certainly useful for reduced models and conceptual design but it can also be more efficient than the direct integration of the equations for large models. The results of the Fourier series computations for the ten-node satellite model show that the periodic solution at the second perturbative order is sufficiently accurate.Comment: 20 pages, 11 figures, accepted in Journal of Thermophysics and Heat Transfe

Hydrological response of a dryland ephemeral river to southern African climatic variability during the last millennium

12 páginas, 6 figuras, 2 tablas.-- El PDF del artículo esta en su versión post print.A long-term flood record from the Buffels River, the largest ephemeral river of NW South Africa (9250 km2), was reconstructed based on interpretation of palaeoflood, documentary and instrumental rainfall data. Palaeoflood data were obtained at three study reaches, with preserved sedimentary evidence indicating at least 25 large floods during the last 700 yr. Geochronological control for the palaeoflood record was provided by radiocarbon and optically stimulated luminescence (OSL) dating. Annual resolution was obtained since the 19th century using the overlapping documentary and instrumental records. Large floods coincided in the past within three main hydroclimatic settings: (1) periods of regular large flood occurrence (1 large flood/~30 yr) under wetter and cooler prevailing climatic conditions (AD 1600–1800), (2) decreasing occurrence of large floods (1 large flood/~100 yr) during warmer conditions (e.g., AD 1425–1600 and after 1925), and (3) periods of high frequency of large floods (~ 4–5 large floods in 20–30 yr) coinciding with wetter conditions of decadal duration, namely at AD 1390–1425, 1800–1825 and 1915–1925. These decadal-scale periods of the highest flood frequency seem to correspond in time with changes in atmospheric circulation patterns, as inferred when comparing their onset and distribution with temperature proxies in southern Africa.The study was funded by the 6th Framework Programme of the European Commission through the project “FloodWater recharge of alluvial Aquifers in Dryland Environments”, WADE Project (contract no. GOCE-CT-2003-506680).Peer reviewe

Effects of rapid gravity load changes on immunophenotyping and leukocyte function of human peripheral blood after parabolic flight

One of the biological systems that suffers a physiological de-conditioning in space is the immune system. It is in charge of defending the body against pathogens and other aggressions. The aim of this work is to assess if there are any relevant changes in the aggregation of erythrocytes, cell count, immunophenotyping and functionality after parabolic flight. This effect has been assessed ex vivo using human peripheral blood, which was drawn from the radial vein (n=6 healthy volunteers) and anticoagulated with heparin and EDTA. Blood samples were split into two aliquots and maintained in two identical thermally isolated boxes; one stayed on the ground whereas the other one was subjected to parabolic flight. The parabolic flight consisted of 15 parabolas performed with a Mudry CAP-10B acrobatic aircraft. Each parabola consists of 8 seconds of hypogravity preceded and followed by 2 seconds of hypergravity. Any of the biological parameters measured showed no statistically significant differences. Altered gravity could increase aggregation of red blood cells, as demonstrated by a decrease in the number of single cells after parabolic flight exposure. No counting changes in haemoglobin concentration were observed when comparing the two different groups. Furthermore, potential functional alterations of monocytes and neutrophils cannot be rejected. Although these possible changes could be associated with hypogravity, other factors such as hypergravity and acceleration or deceleration cannot be ruled out. Our findings indicate that, under this specific experimental setup, there was no significant alteration in leukocyte immunophenotyping and functional capacity when using ex vivo blood samples and short exposure to altered gravity.Peer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarPostprint (published version

Endurance, Refuge, and Reemergence of Dengue Virus Type 2, Puerto Rico, 1986–2007

To study the evolution of dengue virus (DENV) serotype 2 in Puerto Rico, we examined the genetic composition and diversity of 160 DENV-2 genomes obtained through 22 consecutive years of sampling. A clade replacement took place in 1994–1997 during a period of high incidence of autochthonous DENV-2 and frequent, short-lived reintroductions of foreign DENV-2. This unique clade replacement was complete just before DENV-3 emerged. By temporally and geographically defining DENV-2 lineages, we describe a refuge of this virus through 4 years of low genome diversity. Our analyses may explain the long-term endurance of DENV-2 despite great epidemiologic changes in disease incidence and serotype distribution

Improved measurement of intersession latency in mfVEPs

Purpose: The purpose of the study is to present a method (Selfcorr) by which to measure intersession latency differences between multifocal VEP (mfVEP) signals. Methods: The authors compared the intersession latency difference obtained using a correlation method (Selfcorr) against that obtained using a Template method. While the Template method cross-correlates the subject’s signals with a reference database, the Selfcorr method cross-correlates traces across subsequent recordings taken from the same subject. Results: The variation in latency between intersession signals was 0.8 ± 13.6 and 0.5 ± 5.0 ms for the Template and Selfcorr methods, respectively, with a coefficient of variability C V_TEMPLATE = 15.83 and C V_SELFCORR = 5.68 (n = 18, p = 0.0002, Wilcoxon). The number of analyzable sectors with the Template and Selfcorr methods was 36.7 ± 8.5 and 45.3 ± 8.7, respectively (p = 0.0001, paired t test, two tailed). Conclusions: The Selfcorr method produces smaller intersession mfVEP delays and variability over time than the Template method.Ministerio de Ciencia e Innovació

Study protocol for the evaluation of the health effects of superblocks in barcelona : The "salut als carrers" (health in the streets) project

Superblocks are currently being introduced in Barcelona to respond to the city's scarcity of green spaces and high levels of air pollution, traffic injuries, and sedentariness. The aim is to calm the streets by reducing the number of square meters dedicated to private vehicles and to reclaim part of this public space for people. Salut als Carrers (Health in the Streets) is a project to evaluate the potential environmental and health effects of the superblock model with an equity perspective in Barcelona. This study aims to explain the various interventions implemented in different neighborhoods in Barcelona and the methods that will be used to evaluate them in a quasi-experimental and health impact assessment (HIA) approaches. Given the complexity of the intervention evaluated, the project employs mixed methodologies. Quantitative methods include: (a) a pre-post health survey of 1200 people randomly selected from the municipal register asked about self-perceived health and quality of life, social support, mental health, mobility, physical activity, neighborhood characteristics, and housing; (b) pre-post environmental measurements, mainly of nitrogen dioxide (NO), particulate matter of less than 10 µm (PM), and particulate matter of less than 2.5 µm (PM) and black carbon; (c) pre-post environmental walkability measures using the Microscale Audit of Pedestrian Streetscapes (MAPS) tool; (d) use of public space and physical activity levels using the System for Observing Play and Recreation in Communities (SOPARC), a validated observation tool; (e) pre-post traffic injury measures with a comparison group; and (f) the comparison and integration of pre-post assessment with previous HIAs and the improvement of future HIAs. Qualitative studies will be performed to analyze residents' perception of these effects by using: (a) various focus groups according to different participant characteristics who are more or less likely to use the superblocks; and (b) a guerrilla ethnography, which is a method that combines ethnographic observation and semi-structured interviews. This study, which evaluates the impact of an ambitious urban-renewal program on health, will help to assess the effectiveness of public policy in terms of health and health inequalities