231 research outputs found
Silicon increased the growth, productivity, and nutraceutical quality of tomato (Solanum lycopersicum L.)
Tomato (Solanum lycopersicum L.) is considered one of the most important horticultural crops worldwide due to its nutritional and organoleptic properties. Instead of chemical fertilizers, recent research has shown in several plant species the importance of silicon fertilization. Hence, the present investigation aims to evaluate the effect of three different doses (low, medium, and high dose) of silicon on the growth (stem length and diameter, root length diameter, and stem, leaf and root biomass), productivity (polar and equatorial fruit diameter, number of fruits per bunch and plant, and yield), and nutraceutical quality (total soluble solids, titratable acids, and vitamin C) parameters of tomato. The Si treatment affected the evaluated parameters in a dose dependent way in almost all the parameters evaluated. Despite the tomato is classified as a non-Si accumulator, it has a significant response to Si treatment at a low dose of 0.15 g plant-1, medium dose of 0.25 g plant-1, and high dose of 0.35 g plant-1 after 120 d of transplantation in terms of plant growth, yield, and quality parameters. The effectiveness of Si nutrition is dependent on factors such as element source, plant species, and cultivar, and even, the absorption and bioaccumulation capacity of this element could be different between varieties
Intervenciones Psicosociales en las Inundaciones de Sierras Chicas
En el marco de las Prácticas Profesionales en Servicio de la Facultad de Psicología, UNC, en las localidades afectadas por las inundaciones de Sierras Chicas: Mendiolaza, Río Ceballos y Unquillo, se presentan las intervenciones desarrolladas durante el 2015. Se trabajó a partir de la perspectiva de gestión psicosocial de riesgo, realizando asistencia clínica y trabajo en comunidad. Acompañar a las comunidades en su proceso de rehabilitación psicosocial, en conjunto con los equipos de salud locales. Investigación Acción Participativa. Se logró acompañar y asistir a los damnificados de las inundaciones. Se promovió la articulación de redes entre las comunidades y entre las comunidades y las instituciones. Se reforzó el trabajo de los equipos locales de salud en la asistencia de los damnificados. Se promovió el fortalecimiento de la participación activa en la toma de decisiones y autogestión de los vecinos. Considerando la complejidad de trabajar con comunidades vulnerabilizadas por diversos factores sumado al fuerte impacto del evento y a la desestructuración-irrupción del tejido social, es importante discutir la construcción del rol del psicólogo en esta área emergente. En este sentido se entiende que uno de los aspectos fundamentales a tener en cuenta es el trabajo interdisciplinario y la articulación intersectorial. Finalmente se resalta la necesidad de la continuidad del equipo de trabajo para pensar y proponer nuevas estrategias y líneas de acción preventivas, de capacitación, y de promoción de la salud integral
Cellular Automata Applications in Shortest Path Problem
Cellular Automata (CAs) are computational models that can capture the
essential features of systems in which global behavior emerges from the
collective effect of simple components, which interact locally. During the last
decades, CAs have been extensively used for mimicking several natural processes
and systems to find fine solutions in many complex hard to solve computer
science and engineering problems. Among them, the shortest path problem is one
of the most pronounced and highly studied problems that scientists have been
trying to tackle by using a plethora of methodologies and even unconventional
approaches. The proposed solutions are mainly justified by their ability to
provide a correct solution in a better time complexity than the renowned
Dijkstra's algorithm. Although there is a wide variety regarding the
algorithmic complexity of the algorithms suggested, spanning from simplistic
graph traversal algorithms to complex nature inspired and bio-mimicking
algorithms, in this chapter we focus on the successful application of CAs to
shortest path problem as found in various diverse disciplines like computer
science, swarm robotics, computer networks, decision science and biomimicking
of biological organisms' behaviour. In particular, an introduction on the first
CA-based algorithm tackling the shortest path problem is provided in detail.
After the short presentation of shortest path algorithms arriving from the
relaxization of the CAs principles, the application of the CA-based shortest
path definition on the coordinated motion of swarm robotics is also introduced.
Moreover, the CA based application of shortest path finding in computer
networks is presented in brief. Finally, a CA that models exactly the behavior
of a biological organism, namely the Physarum's behavior, finding the
minimum-length path between two points in a labyrinth is given.Comment: To appear in the book: Adamatzky, A (Ed.) Shortest path solvers. From
software to wetware. Springer, 201
Using indirect methods to constrain symbiotic nitrogen fixation rates : a case study from an Amazonian rain forest
© The Authors 2009. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Biogeochemistry 99 (2010): 1-13, doi:10.1007/s10533-009-9392-y.Human activities have profoundly altered the global nitrogen (N) cycle. Increases in anthropogenic N have had multiple effects on the atmosphere, on terrestrial, freshwater and marine ecosystems, and even on human health. Unfortunately, methodological limitations challenge our ability to directly measure natural N inputs via biological N fixation (BNF)—the largest natural source of new N to ecosystems. This confounds efforts to quantify the extent of anthropogenic perturbation to the N cycle. To address this gap, we used a pair of indirect methods—analytical modeling and N balance—to generate independent estimates of BNF in a presumed hotspot of N fixation, a tropical rain forest site in central Rondônia in the Brazilian Amazon Basin. Our objectives were to attempt to constrain symbiotic N fixation rates in this site using indirect methods, and to assess strengths and weaknesses of this approach by looking for areas of convergence and disagreement between the estimates. This approach yielded two remarkably similar estimates of N fixation. However, when compared to a previously published bottom-up estimate, our analysis indicated much lower N inputs via symbiotic BNF in the Rondônia site than has been suggested for the tropics as a whole. This discrepancy may reflect errors associated with extrapolating bottom-up fluxes from plot-scale measures, those resulting from the indirect analyses, and/or the relatively low abundance of legumes at the Rondônia site. While indirect methods have some limitations, we suggest that until the technological challenges of directly measuring N fixation are overcome, integrated approaches that employ a combination of model-generated and empirically-derived data offer a promising way of constraining N inputs via BNF in natural ecosystems.We acknowledge and are grateful for financial support from the Andrew W. Mellon Foundation (C.C. and B.H.), the National Science Foundation (NSF DEB-0515744 to C.C. and A.T. and DEB-0315656 to C.N.), and the NASA LBA Program (NCC5-285 to C.N.)
Classification methods to identify lesions in skin starting from spectra of diffuse reflectance
Con el objetivo de discriminar lesiones benignas y malignas en la piel humana a partir de espectros de reflexión
difusa, se han analizado diferentes algoritmos de clasificación usando el software de aprendizaje automático y reconocimiento de
patrones WEKA. Además, dada la alta dimensionalidad de la señal espectral, fue empleada una técnica selección de atributos para
determinar las variables que aporten la mayor cantidad de información. Se probó la clasificación de la señal usando los algoritmos
de máquinas de vectores de soporte, redes neuronales y bosques aleatorios, el desempeño fue evaluado usando el promedio de la
k-fold cross-validation tomando en cuenta los porcentajes de instancias clasificadas correctamente, el índice kappa, el área bajo
la curva ROC, la sensibilidad, y la especifidad. Finalmente se demuestra que el algoritmo de redes neuronales con los parámetros
momentum y learning rate en 0,6 y 0,3 respectivamente, es el que mejor se adapta al problema de reconocimiento de patrones ya
que clasifica correctamente al 89,89% de los casos.In order to differentiate between benign and malignant lesions in the human skin using diffuse reflection spectra,
different classification algorithms were tested using the WEKA data mining software. In addition, due to the high dimensionality
of the spectral signal, an attribute selection technique was applied to determine the variables that contribute with more information.
The spectral signal classification was tested using support vector machines, neural networks and random forests, their performance
was measured using the k-fold cross-validation percentages of the Kappa statistic, area under the ROC curve, specificity and
sensitivity. Finally it is shown that the one layer neural network with 6 neurons and the parameters momentum and learning rate
in 0.6 and 0.3 respectively, is best suited to the problem of pattern recognition, achieving correctly classify 89.89% of the cases
Reproductive biology traits affecting productivity of sour cherry
The objective of this work was to evaluate variability in reproductive biology traits and the correlation between them in genotypes of 'Oblacinska' sour cherry (Prunus cerasus). High genetic diversity was found in the 41 evaluated genotypes, and significant differences were observed among them for all studied traits: flowering time, pollen germination, number of fruiting branches, production of flower and fruit, number of flowers per bud, fruit set, and limb yield efficiency. The number of fruiting branches significantly influenced the number of flower and fruit, fruit set, and yield efficiency. In addition to number of fruiting branches, yield efficiency was positively correlated with fruit set and production of flower and fruit. Results from principal component analysis suggested a reduction of the reproductive biology factors affecting yield to four main characters: number and structure of fruiting branches, flowering time, and pollen germination. Knowledge of the reproductive biology of the 'Oblacinska' genotypes can be used to select the appropriate ones to be grown or used as parents in breeding programs. In this sense, genotypes II/2, III/9, III/13, and III/14 have very good flower production and satisfactory pollen germination
Cloning whole bacterial genomes in yeast
Most microbes have not been cultured, and many of those that are cultivatable are difficult, dangerous or expensive to propagate or are genetically intractable. Routine cloning of large genome fractions or whole genomes from these organisms would significantly enhance their discovery and genetic and functional characterization. Here we report the cloning of whole bacterial genomes in the yeast Saccharomyces cerevisiae as single-DNA molecules. We cloned the genomes of Mycoplasma genitalium (0.6 Mb), M. pneumoniae (0.8 Mb) and M. mycoides subspecies capri (1.1 Mb) as yeast circular centromeric plasmids. These genomes appear to be stably maintained in a host that has efficient, well-established methods for DNA manipulation
Wnt5a Regulates Midbrain Dopaminergic Axon Growth and Guidance
During development, precise temporal and spatial gradients are responsible for
guiding axons to their appropriate targets. Within the developing ventral
midbrain (VM) the cues that guide dopaminergic (DA) axons to their forebrain
targets remain to be fully elucidated. Wnts are morphogens that have been
identified as axon guidance molecules. Several Wnts are expressed in the VM
where they regulate the birth of DA neurons. Here, we describe that a precise
temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal
projections by VM DA neurons. In mice at E11.5, Wnt5a is
expressed in the VM where it was found to promote DA neurite and axonal growth
in VM primary cultures. By E14.5, when DA axons are approaching their striatal
target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM
explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is
capable of repelling DA neurites. Antagonism experiments revealed that the
effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase,
Rac1 (a component of the non-canonical Wnt planar cell polarity pathway).
Moreover, the effects were specific as they could be blocked by Wnt5a antibody,
sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further
verified in Wnt5a−/− mice, where
fasciculation of the medial forebrain bundle (MFB) as well as the density of DA
neurites in the MFB and striatal terminals were disrupted. Thus, our results
identify a novel role of Wnt5a in DA axon growth and guidance
Smoking cessation opportunities in severe mental illness (tobacco intensive motivational and estimate risk — TIMER—): study protocol for a randomized controlled trial
There is an increased risk of premature death in people with severe mental illness (SMI). Respiratory
disorders and cardiovascular disease are leading causes of increased mortality rates in these patients, and tobacco
consumption remains the most preventable risk factor involved. Developing new tools to motivate patients
towards cessation of smoking is a high priority. Information on the motivational value of giving the lung age and
prevention opportunities is unknown in this high-risk population. In the context of community care, screening and early detection of lung damage could potentially
be used, together with mobile technology, in order to produce a prevention message, which may provide
patients with SMI with a better chance of quitting smoking.This study receives funding by the Spanish Ministry of Economy, Industry
and Competitiveness, Instituto Carlos III (FIS PI16/00802)
Measured and Simulated Nitrous Oxide Emissions from Ryegrass- and Ryegrass/White Clover-Based Grasslands in a Moist Temperate Climate
There is uncertainty about the potential reduction of soil nitrous oxide (N2O) emission when fertilizer nitrogen (FN) is partially or completely replaced by biological N fixation (BNF) in temperate grassland. The objectives of this study were to 1) investigate the changes in N2O emissions when BNF is used to replace FN in permanent grassland, and 2) evaluate the applicability of the process-based model DNDC to simulate N2O emissions from Irish grasslands. Three grazing treatments were: (i) ryegrass (Lolium perenne) grasslands receiving 226 kg FN ha−1 yr−1 (GG+FN), (ii) ryegrass/white clover (Trifolium repens) grasslands receiving 58 kg FN ha−1 yr−1 (GWC+FN) applied in spring, and (iii) ryegrass/white clover grasslands receiving no FN (GWC-FN). Two background treatments, un-grazed swards with ryegrass only (G–B) or ryegrass/white clover (WC–B), did not receive slurry or FN and the herbage was harvested by mowing. There was no significant difference in annual N2O emissions between G–B (2.38±0.12 kg N ha−1 yr−1 (mean±SE)) and WC-B (2.45±0.85 kg N ha−1 yr−1), indicating that N2O emission due to BNF itself and clover residual decomposition from permanent ryegrass/clover grassland was negligible. N2O emissions were 7.82±1.67, 6.35±1.14 and 6.54±1.70 kg N ha−1 yr−1, respectively, from GG+FN, GWC+FN and GWC-FN. N2O fluxes simulated by DNDC agreed well with the measured values with significant correlation between simulated and measured daily fluxes for the three grazing treatments, but the simulation did not agree very well for the background treatments. DNDC overestimated annual emission by 61% for GG+FN, and underestimated by 45% for GWC-FN, but simulated very well for GWC+FN. Both the measured and simulated results supported that there was a clear reduction of N2O emissions when FN was replaced by BNF
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