781 research outputs found
Modeling the Distribution of Organic Coffee Supply Chain from JunÃn Region, Peru
This research uses Supply Chain (SC) data gathered during the distribution and transportation activities of organic coffee. The purpose of this research is to analyze different ways in which crop-chain solutions are adopted in the region of Junn, Peru. The disintegration of the SC is revealed, as each cooperative member works uncoordinatedly on his own leading to different results standards with high costs and low returns. The study focused on different entities from farmers to the port of Callao of an organic coffee supply chain where disintegration is constant. The paper describes a misaligned supply chain including poorly collaboration. All problems found will be an opportunity to develop a distribution model in the organic coffee supply chain of Junn region
Sistemas caóticos y su aplicación a la encriptación de señales
La sincronización y control de señales caóticas es una activa área de investigación por sus posibles aplicaciones en telecomunicaciones y transmisión de señales [1, 2, 3, 4]. En el presente trabajo se estudia un sistema de comunicación basado
en la sincronización de dos sistemas no lineales caóticos, cada uno modelado a partir de las ecuaciones de movimiento de un péndulo forzado amortiguado y que se encuentran en el mismo punto de operación del espacio de parámetros.
Synchronization and control of chaotic signals is an active research area because of its applications
in telecommunications and secure signal transmission [1,2,3,4]. In this work a communication system
based in the synchronization of two chaotic nonlinear systems, each one being modeled by the motion
equations of a driven damped pendulum and operated in the same parameter space region is shown. Two
communication channels were used: the first one for the synchronizing signal and the second one for the
sent message. By using two channels the initial conditions sensibility problem is solved. In the receiver
system a feedback loop as a proportional controller is used in order to drive quickly the error between the
decoder and encoder states to zero. The last two facts make the system to be robust to external pertubative
signals such as noise in the communication channels
Efecto de la carga sobre la productividad de diferentes clases de animales en la asociación andropogon gayanus, melinis minutiflora y stylosanthes capitata
En el Centro Carimagua (ICA-CIAT) se investigaron los efectos de la disponibilidad de forraje y de la carga en praderas mejoradas sobre la productividad de diferentes clases de animales representativos de los sistemas de producción ganadera del área. Así mismo, se evaluó un sistema de pastoreo continuo donde se relacionaron las tasas de crecimiento de novillos de destete con otras clases de animales, tales como novillas de destete adultos machos para ceba y vacas viejas de descarte. E I diseño experimental fue completamente al azar. Para las estaciones de lluvias las cargas fueron 1.38, 1.85 Y 2.32 animales/ha y de 0.64, 0.85 y 1.07 para la estación seca. En la estación de lluvia I (1983), se detectó interacción significativa (P and lt; 0.05) de carga por clase de animal, con una media general de ganancia de peso de 379 q/an/día. En la estación lluviosa II (1984), el análisis de varianza presentó efecto significativo de las cargas y de las clases de animales. Las ganancias de peso tendieron a aumentar al disminuír la carga. Los machos tuvieron las mayores ganancias de peso. En la estación seca no se presentaron diferencias significativas (P and gt;0.05) ni entre carga ni entre clases de animales. Y la media general de ganancia de peso fue de 137 g/an/día.Experiments were carried out at Carimagua with the aim of investigating the effects of forage availability and stocking rate on the productivity of different classes of animal with in representative improved pasture beef production systems. In addition, a continuos grazing system was evaluated in an attemp to relate steer calf growth rates to other animal classes, such as weaned heifers, adult steers for fattening and cull cows.The experimental desings was completely randomized. The stocking rates were 1.38, 1.85 and 2.32 animals per ha and 0_64, 0.85 and 1.07 animals/ha for the wet dry seasons respectively. F or the first, a significant interaction (P and lt; 0.05) was found between stocking rate an class of animal, with an overall average of 379 g/animal/día. During the second rainy season, the average gain was 513 g/animal/ day. A significant interaction between stocking rates and animal classes was founded. Weight gains tended to increase as stocking rate decreased. Steers exhibited the heighest weight gains. During the dry season no significant differences (P and gt; 0.05) were found either between stocking rates of between animal classes; average weight gain was 137 g/animal/día for this season
Postmortem diagnosis of acute myocardial infarction in patients with acute respiratory failure - demographics, etiologic and pulmonary histologic analysis
OBJECTIVES: Acute respiratory failure is present in 5% of patients with acute myocardial infarction and is responsible for 20% to 30% of the fatal post-acute myocardial infarction. The role of inflammation associated with pulmonary edema as a cause of acute respiratory failure post-acute myocardial infarction remains to be determined. We aimed to describe the demographics, etiologic data and histological pulmonary findings obtained through autopsies of patients who died during the period from 1990 to 2008 due to acute respiratory failure with no diagnosis of acute myocardial infarction during life. METHODS: This study considers 4,223 autopsies of patients who died of acute respiratory failure that was not preceded by any particular diagnosis while they were alive. The diagnosis of acute myocardial infarction was given in 218 (4.63%) patients. The age, sex and major associated diseases were recorded for each patient. Pulmonary histopathology was categorized as follows: diffuse alveolar damage, pulmonary edema, alveolar hemorrhage and lymphoplasmacytic interstitial pneumonia. The odds ratio of acute myocardial infarction associated with specific histopathology was determined by logistic regression. RESULTS: In total, 147 men were included in the study. The mean age at the time of death was 64 years. Pulmonary histopathology revealed pulmonary edema as well as the presence of diffuse alveolar damage in 72.9% of patients. Bacterial bronchopneumonia was present in 11.9% of patients, systemic arterial hypertension in 10.1% and dilated cardiomyopathy in 6.9%. A multivariate analysis demonstrated a significant positive association between acute myocardial infarction with diffuse alveolar damage and pulmonary edema. CONCLUSIONS: For the first time, we demonstrated that in autopsies of patients with acute respiratory failure as the cause of death, 5% were diagnosed with acute myocardial infarction. Pulmonary histology revealed a significant inflammatory response, which has not previously been reported
Solar Power Integration in Water (H2O) Distillation (SPIN-HD)
As the world faces a looming crisis of water scarcity and contamination, water use and safe consumption have been compromised worldwide. People depend on tap water whose contamination causes a wide range of diseases, which are often life-threatening. Given that water purifying methods are not commonly accessible in households, and solar stills are only efficient with sunlight, this study employed a creation of a solar-powered water distiller prototype that can be used in small settings. The study consisted of designing and building a battery-powered safety testing setup, safety testing, designing and building of the solarpowered water distiller prototype, prototype testing, and data collection. An integration of hardware materials, i.e., 2 stainless steel cylindrical containers, AWG 14, car glow plug heater, customized condensation sloping lid, and 12V4.5Ah battery, was done in building the safety testing setup. The safety testing was followed by the removal of the 12V4.5aH battery, and the consequent integration of the 50-watt solar panel, solar charge controller, and 12V30Ah battery. After five (5) experimental testings, the solar-powered water distiller prototype produced an average volume of 58.6mL in an average heating time of 112.2 minutes, making an average distillation rate of 31.3mL/hr. Such a distillation rate was obtained under an average ambient temperature of 31.2oC, average starting battery voltage of 12.3, and average end battery voltage of 4.1
Solution and Asymptotic Behavior for a Nonlocal Coupled System of Reaction-Diffusion
This paper concerns with existence, uniqueness and asymptotic behavior of the
solutions for a nonlocal coupled system of reaction-diffusion. We prove the
existence and uniqueness of weak solutions by the Faedo-Galerkin method and
exponential decay of solutions by the classic energy method. We improve the
results obtained by Chipot-Lovato and Menezes for coupled systems. A numerical
scheme is presented
ON the CONSERVATION of the VERTICAL ACTION in GALACTIC DISKS
We employ high-resolution N-body simulations of isolated spiral galaxy models, from low-amplitude, multi-armed galaxies to Milky Way-like disks, to estimate the vertical action of ensembles of stars in an axisymmetrical potential. In the multi-armed galaxy the low-amplitude arms represent tiny perturbations of the potential, hence the vertical action for a set of stars is conserved, although after several orbital periods of revolution the conservation degrades significantly. For a Milky Way-like galaxy with vigorous spiral activity and the formation of a bar, our results show that the potential is far from steady, implying that the action is not a constant of motion. Furthermore, because of the presence of high-amplitude arms and the bar, considerable in-plane and vertical heating occurs that forces stars to deviate from near-circular orbits, reducing the degree at which the actions are conserved for individual stars, in agreement with previous results, but also for ensembles of stars. If confirmed, this result has several implications, including the assertion that the thick disk of our Galaxy forms by radial migration of stars, under the assumption of the conservation of the action describing the vertical motion of stars. © 2016. The American Astronomical Society. All rights reserved
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Global ecological predictors of the soil priming effect.
Identifying the global drivers of soil priming is essential to understanding C cycling in terrestrial ecosystems. We conducted a survey of soils across 86 globally-distributed locations, spanning a wide range of climates, biotic communities, and soil conditions, and evaluated the apparent soil priming effect using 13C-glucose labeling. Here we show that the magnitude of the positive apparent priming effect (increase in CO2 release through accelerated microbial biomass turnover) was negatively associated with SOC content and microbial respiration rates. Our statistical modeling suggests that apparent priming effects tend to be negative in more mesic sites associated with higher SOC contents. In contrast, a single-input of labile C causes positive apparent priming effects in more arid locations with low SOC contents. Our results provide solid evidence that SOC content plays a critical role in regulating apparent priming effects, with important implications for the improvement of C cycling models under global change scenarios
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Identification of sequence changes in myosin II that adjust muscle contraction velocity.
The speed of muscle contraction is related to body size; muscles in larger species contract at slower rates. Since contraction speed is a property of the myosin isoform expressed in a muscle, we investigated how sequence changes in a range of muscle myosin II isoforms enable this slower rate of muscle contraction. We considered 798 sequences from 13 mammalian myosin II isoforms to identify any adaptation to increasing body mass. We identified a correlation between body mass and sequence divergence for the motor domain of the 4 major adult myosin II isoforms (β/Type I, IIa, IIb, and IIx), suggesting that these isoforms have adapted to increasing body mass. In contrast, the non-muscle and developmental isoforms show no correlation of sequence divergence with body mass. Analysis of the motor domain sequence of β-myosin (predominant myosin in Type I/slow and cardiac muscle) from 67 mammals from 2 distinct clades identifies 16 sites, out of 800, associated with body mass (padj 0.05). Both clades change the same small set of amino acids, in the same order from small to large mammals, suggesting a limited number of ways in which contraction velocity can be successfully manipulated. To test this relationship, the 9 sites that differ between human and rat were mutated in the human β-myosin to match the rat sequence. Biochemical analysis revealed that the rat-human β-myosin chimera functioned like the native rat myosin with a 2-fold increase in both motility and in the rate of ADP release from the actin-myosin crossbridge (the step that limits contraction velocity). Thus, these sequence changes indicate adaptation of β-myosin as species mass increased to enable a reduced contraction velocity and heart rate
Signatures of selection for bonamiosis resistance in European flat oyster (Ostrea edulis): New genomic tools for breeding programs and management of natural resources
The European flat oyster (Ostrea edulis) is a highly appreciated mollusk with an important aquaculture production throughout the 20th century, in addition to playing an important role on coastal ecosystems. Overexploitation of natural beds, habitat degradation, introduction of non‐native species, and epidemic outbreaks have severely affected this important resource, particularly, the protozoan parasite Bonamia ostreae, which is the main concern affecting its production and conservation. In order to identify genomic regions and markers potentially associated with bonamiosis resistance, six oyster beds distributed throughout the European Atlantic coast were sampled. Three of them have been exposed to this parasite since the early 1980s and showed some degree of innate resistance (long‐term affected group, LTA), while the other three were free of B. ostreae at least until sampling date (naïve group, NV). A total of 14,065 SNPs were analyzed, including 37 markers from candidate genes and 14,028 from a medium‐density SNP array. Gene diversity was similar between LTA and NV groups suggesting no genetic erosion due to long‐term exposure to the parasite, and three population clusters were detected using the whole dataset. Tests for divergent selection between NV and LTA groups detected the presence of a very consistent set of 22 markers, located within a putative single genomic region, which suggests the presence of a major quantitative trait locus associated with B. ostreae resistance. Moreover, 324 outlier loci associated with factors other than bonamiosis were identified allowing fully discrimination of all the oyster beds. A practical tool which included the 84 highest discriminative markers for tracing O. edulis populations was developed and tested with empirical data. Results reported herein could assist the production of stocks with improved resistance to bonamiosis and facilitate the management of oyster beds for recovery production and ecosystem services provided by this species.This work was funded by the OYSTERECOVER project (FP7‐SME‐2008‐2‐243583) from the European Community's Seventh Framework Programme, the European Regional Development's funds (FEDER), and Xunta de Galicia local government (GRC2014/010, R2014/046). The development and provision of the medium‐density SNP array for oysters was supported by Biotechnology and Biological Sciences Research Council (BBSRC), and National Environment Research Council (NERC) grants (BB/M026140/1, NE/P010695/1), in addition to BBSRC Institute Strategic Program Grants (BBS/E/D/20002172 and BBS/E/D/30002275)S
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