ALTERNATIVE CYCLING STRATEGIES FOR SHRIMP FARMING IN ARID ZONES OF MEXICO: DEALING WITH RISK AND UNCERTAINTY

Northwest Mexican coastal waters have large seasonal temperature variations, high salinity, and are subject to intense solar radiation. Shrimp farms in this region have been using two annual production strategies; six- to eight-month cycle with one complete harvest and several partial harvests, or two, three- to four-month cycles with complete harvests. The preferred strategy depends on two uncertain variables; shrimp growth, which varies across the region, and market price, which varies across the season. A bioeconomic model was used to compare the economic yield of the two cycling strategies for three zones across the region, under three alternative average annual temperatures states. Simple decision theory criteria are used to show that the two-cycle strategy dominates the one-cycle strategy in the Bahia de La Paz zone. Results for central and northern Sonora are conditional on temperature.Resource /Energy Economics and Policy,

Synthetic and structural studies of mixed sodium bis(trimethylsilyl)amide/sodium halide aggregates in the presence of η2-N,N-, η3-N,N,N/N,O,N-, and η4-N,N,N,N-donor ligands

When the important utility amide sodium bis(trimethylsilyl)amide is combined with hydrocarbon-soluble molecular forms of sodium halide salts, a complex structural chemistry is observed. Through utilization of several different multidentate donor molecules, it is possible to isolate a series of compounds that have structural motifs previously not observed in sodium chemistry

Reproductive Structures and Early Life History of the Gulf Toadfish, Opsanus beta, in the Tecolutla Estuary, Veracruz, Mexico

Although the Gulf toadfish, Opsanus beta, is an abundant member of the nearshore Gulf of Mexico ichthyofaunal assemblage, little information exists regarding the ecology of the species, especially for southern Gulf of Mexico populations. We added to the existing knowledge of this species by describing the reproductive structures and examining the early life history of this species in the Tecolutla estuary, Mexico. Macro- and microscopic examination of 7 males showed spermatogenesis to be similar to other teleost species except for the occurrence of biflagellate spermatozoa. Histological examination of the male accessory gland showed 3 tissue layers, but their functions are still undetermined. We found asynchronous development of oocytes in the ovaries of 16 females, which may indicate multiple spawning over the long spawning season noted in this study. Batch fecundity estimates among females ranged from 79 to 518 mature ova with a mean ovum diameter of 3.5 mm. The above-mentioned factors along with large size at hatching, attached larval forms, and paternal care may account, in part, for the abundance of this species in highly dynamic systems

Simulating the behavior of the human brain on GPUS

The simulation of the behavior of the Human Brain is one of the most important challenges in computing today. The main problem consists of finding efficient ways to manipulate and compute the huge volume of data that this kind of simulations need, using the current technology. In this sense, this work is focused on one of the main steps of such simulation, which consists of computing the Voltage on neurons’ morphology. This is carried out using the Hines Algorithm and, although this algorithm is the optimum method in terms of number of operations, it is in need of non-trivial modifications to be efficiently parallelized on GPUs. We proposed several optimizations to accelerate this algorithm on GPU-based architectures, exploring the limitations of both, method and architecture, to be able to solve efficiently a high number of Hines systems (neurons). Each of the optimizations are deeply analyzed and described. Two different approaches are studied, one for mono-morphology simulations (batch of neurons with the same shape) and one for multi-morphology simulations (batch of neurons where every neuron has a different shape). In mono-morphology simulations we obtain a good performance using just a single kernel to compute all the neurons. However this turns out to be inefficient on multi-morphology simulations. Unlike the previous scenario, in multi-morphology simulations a much more complex implementation is necessary to obtain a good performance. In this case, we must execute more than one single GPU kernel. In every execution (kernel call) one specific part of the batch of the neurons is solved. These parts can be seen as multiple and independent tridiagonal systems. Although the present paper is focused on the simulation of the behavior of the Human Brain, some of these techniques, in particular those related to the solving of tridiagonal systems, can be also used for multiple oil and gas simulations. Our studies have proven that the optimizations proposed in the present work can achieve high performance on those computations with a high number of neurons, being our GPU implementations about 4× and 8× faster than the OpenMP multicore implementation (16 cores), using one and two NVIDIA K80 GPUs respectively. Also, it is important to highlight that these optimizations can continue scaling, even when dealing with a very high number of neurons.This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 720270 (HBP SGA1), from the Spanish Ministry of Economy and Competitiveness under the project Computación de Altas Prestaciones VII (TIN2015-65316-P), the Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya, under project MPEXPAR: Models de Programació i Entorns d’Execució Parallels (2014-SGR-1051). We thank the support of NVIDIA through the BSC/UPC NVIDIA GPU Center of Excellence, and the European Union’s Horizon 2020 Research and Innovation Program under the Marie Sklodowska-Curie Grant Agreement No. 749516.Peer ReviewedPostprint (published version

Contamination des moules (Mytilus galloprovincialis) des côtes de la région de Dakar par les Hydrocarbures Aromatiques Polycycliques (HAPs)

Dans ce travail, nous avons etudie la contamination par les Hydrocarbures Aromatiques Polycycliques des moules recoltees au niveau des cotes de la region de Dakar. Les sites ont ete choisis en fonction des activites qui y sont developpees. Lfextraction des HAPs a ete faite au moyen dfun extracteur Soxhlet avec un melange hexane/acetone et la purification est realisee avec lfoxyde dfaluminium. Nous avons analyse lfextraitpar un chromatographe de gaz couple a un spectrographe de masse (GC/MS). Les resultats montrent que les teneurs en hydrocarbures evoluent de facon croissante en fonction du temps. Au port de Dakar, lesconcentrations passent de 5308,67 en 2007 a 17973,37 ƒÊg/kg de poids sec, en 2008. Lfevolution des hydrocarbures suit la meme tendance dans les differents sites. Ainsi, le Port concentre la plus forte teneur, ensuite suivent les sites de Mbao et de Hann. Au niveau du port, la contamination proviendrait des depots de stockages des hydrocarbures mais egalement des operations de transbordement du petrole. La zone de Mbao estpolluee par la presence de nombreuses usines dont une raffinerie qui a ces canaux directement ouvert sur la plage. Le site de Hann abrite un canal qui draine les eaux usees domestiques mais aussi les huiles de rejet des stations services. Ainsi, les moules deviennent un bon indicateur de la qualite des eaux mais egalement un danger pour la population, grande consommatrice de cette espece. Ces etudes qui constituent un etat de lieu doivent etre poursuivies afin de fournir des donnees scientifiques de base aux decideurs politiques pour la recherche de solutions durables a la pollution de notre environnement

Overview of neutrino-nucleus quasielastic scattering

A review of quasielastic neutrino-nucleus scattering will be presented, with emphasis on bringing together the knowledge (and language) of neutrino physics, electron scattering, and nuclear structure communities. Assumptions commonly made which simplify the theoretical calculations will be examined. Finally, an attempt will be made to identify places where improvement from either theoretical or experimental sides would be more significant.Dirección General de Investigación (DGI). España FPA2007-62216, FIS2008-04189 y FPA2006-13807-C02-01Spanish Consolider-Ingenio programme CPAN CSD2007-0004

Hybrid Silicon-Organic Heterojunction Structures for Photovoltaic Applications

The concept for inorganic-organic device is an attractive technology to develop devices with better characteristics and functionality due to the complementary advantages of inorganic and organic materials. This chapter provides an overview of the principal requirements for organic and inorganic semiconductor properties and their fabrication processes and focus on the compatibility between low temperature plasma enhanced chemical vapor deposition (PECVD) and polymer organic materials deposition. The concept for inorganic-organic device was validated with the fabrication of three hybrid thin film photovoltaic structures, based on hydrogenated silicon (Si:H), organic poly(3-hexythiophene): methano-fullerenephenyl-C61-butyric-acid-methyl-ester (P3HT:PCBM), and poly(3,4ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) films. Optoelectronic characteristics, performance characteristics, and interfaces of the different configurations aspects are discussed. Hybrid ITO/PEDOT:PSS/(i)Si:H/(n)Si:H structure results in a remarkably high short circuit current density as large as 17.74 mA/cm2, which is higher than the values in organic or inorganic reference samples. Although some hybrid structures demonstrated substantial improvement of performance, other hybrid structures showed poor performance, further R&D efforts seem to be promising, and should be focused on deeper study of organic materials and related interface properties