Regional trends and controlling factors of fatal landslides in Latin America and the Caribbean

A new data set of landslides that caused loss of life in Latin America and the Caribbean in the 10-year period from 2004 and 2013 inclusive has been compiled, providing new insight into the impact of landslides in this key part of the world. This data set indicates that in the 10-year period a total of 11 631 people lost their lives across the region in 611 landslides. The geographical distribution of the landslides is highly heterogeneous, with areas of high incidence in parts of the Caribbean (most notably Haiti), Central America, Colombia, and southeast Brazil. There is significant interannual variation in the number of landslides, with the El Niño/La Niña cycle emerging as a key control. Our analysis suggests that on a continental scale the mapped factors that best explain the observed distribution are topography, annual precipitation and population density. On a national basis we have compared the occurrence of fatality-inducing landslide occurrence with the production of locally authored research articles, demonstrating that there is a landslide research deficit in Latin America and the Caribbean. Understanding better the mechanisms, distribution causes and triggers of landslides in Latin America and the Caribbean must be an essential first step towards managing the hazard

All-optical 3D atomic loops generated with Bessel light fields

The propagation invariance of Bessel beams as well as their transversal structure are used to perform a comparative analysis of their effect on cold atoms for four different configurations and combinations thereof. We show that, even at temperatures for which the classical description of the atom center of mass motion is valid, the interchange of momentum, energy and orbital angular momentum between light and atoms yields efficient tools for all-optical trapping, transporting and, in general, manipulating the state of motion of cold atoms.Comment: 13 pages, 9 figure

EEF en matemática con aplicaciones digitales del sector financiero

Economic and Financial Education (EEF) under guidance of the Ministry of National Education of Colombia (MEN) has purpose to empower the knowledge, skills and attitudes necessary for the informed decision making. This study has the aim of providing the mathematics teacher tools for the design of strategies that promote the development of EEF competences. It were studied different digital applications (Apps) that the financial sector presents to the common citizen to promote financial culture. As a result was found that the teacher could use the free Apps to develop and strengthen the skills in EEF. Concluding that the Apps of the financial sector are tools for the design of didactic strategies since it is possible to establish coherence with the guidelines of the MEN in order to develop competences in EEF in the students.La Educación Económica y Financiera (EEF) bajo orientaciones del Ministerio de Educación Nacional de Colombia(MEN) tiene la finalidad de potencializar conocimientos, habilidades y actitudes necesarias para la toma de decisiones informadas. Este artíıculo tiene como objetivo proporcionar al docente de matemáticas un banco de herramientas para la elaboración de estrategias que propendan por el desarrollo de competencias de EEF. Se estudiaron diferentes aplicaciones digitales (Apps) que presenta el sector financiero al ciudadano común para fomentar la cultura financiera. Como resultado se encuentra que el profesor podría usar estas Apps de uso libre en sus secuencias didácticas para desarrollar y fortalecer competencias en EEF. Concluyendo que las Apps del sector financiero constituyen herramientas didácticas en clase de matemáticas pues hay coherencia con los lineamientos del MEN para desarrollar competencias en EEF en cada uno de sus estudiantes

Operación cesárea

ResumenLa operación cesárea permite el nacimiento por vía abdominal. De origen no claro, su indicación es para condiciones extremas a indicaciones consideradas como relativas. Su incidencia ha aumentado significativamente en los últimos años con una gran variabilidad de tasas entre países e instituciones. Las causas de este aumento son diversas. Se han descrito múltiples técnicas quirúrgicas. En el presente artículo se describen los aspectos técnicos de su ejecución así como las indicaciones más frecuentes.SummaryCesarean section allows the birth by histeroromy performed through the abdomen. Of unclear origin, its original indications were very few. Its incidence has increased significantly in recent years with a large variability of rates between countries and institutions. The causes of this increase are varied. Multiple surgical techniques have been described. The technical aspects of its implementation as well as the most frequent indications are described

Compensador de tensão do tipo activo série controlado por computador pessoal

Os filtros activos do tipo série são equipamentos de electrónica de potência capazes de compensar alguns dos problemas de qualidade de energia dos sistemas eléctricos, nomeadamente: interrupções, sobretensões e subtensões momentâneas, distorção da tensão causada por harmónicos, desequilíbrio de tensões em sistemas trifásicos, flutuação de tensão (flicker), sobretensões e subtensões momentâneas, e podem também realizar a correcção dinámica do factor de potência. O objectivo principal deste trabalho consistiu no estudo, simulação, desenvolvimento, e teste de um filtro activo série com sistema de controlo implementado num computador pessoal (PC) munido de uma placa de aquisição de dados genérica para o barramento PCI. Esta opção justifica-se devido ao seu baixo custo, elevada capacidade de processamento e versatilidade. Neste artigo apresenta-se o esquema eléctrico do compensador activo série desenvolvido, o seu algoritmo de controlo e resultados experimentais obtidos

A single-phase power series compensator for voltage distortion

The purpose of this paper is to describe the work that is being done in the design and implementation of a single phase series power compensator for electrical power quality purposes. This system is able to compensate several voltage related problems in the power grid, namely: voltage distortion due to harmonics, voltage flicker (sub harmonics) and over or under voltages. The power circuit of the series compensator is described in this paper, and some experimental results are presented.Fundação para a Ciência e a Tecnologia (FCT), project funding POCTI/ESE/41170/2001

A series active power filter controlled by personal computer

This paper describes work that is being done in the design and implementation of a series active power filter for electrical power quality purposes. This type of filter is able to compensate for the following voltage related problems in the power grid: short blackouts for a few cycles, voltage distortion due to harmonics on a repetitive basis, voltage unbalance in three-phase systems, voltage flicker (subharmonics) and momentary over or under voltages. The main objective of the work described in the paper is to build a series active filter controlled by a personal computer with a standard multifunction data acquisition PCI bus card, because of its relative low cost and versatility. This PC based solution presents some difficulties since the control of a series active filter is a kind of application which requires a fast controller which that does not miss samples and where all real-time deadlines must be met each and every time, or the system will not operate properly. These characteristics imply that this application falls in the “hard real-time” control category. In the paper, some results are presented and some conclusions are taken using two different operating systems. Furthermore, a comparison with a microcontroller based implementation will be made.(undefined

P-q theory power components calculations

The “Generalized theory of the instantaneous reactive power in three-phase circuits", proposed by Akagi et al., and also known as the p-q theory, is an interesting tool to apply to the control of active power filters, or even to analyze three-phase power systems in order to detect problems related to harmonics, reactive power and unbalance. In this paper it will be shown that in three phase electrical systems the instantaneous power waveform presents symme-tries of 1/6, 1/3, 1/2 or 1 cycle of the power system fundamen-tal frequency, depending on the system being balanced or not, and having or not even harmonics (interharmonics and sub-harmonics are not considered in this analysis). These symme-tries can be exploited to accelerate the calculations for active filters controllers based on the p-q theory. In the case of the conventional reactive power or zero-sequence compensation, it is shown that the theoretical control system dynamic response delay is zero.Fundação para a Ciência e a Tecnologia (FCT) - POCTI/ESE/41170/2001

Genetic polymorphism in meat fatty acids in araucano creole sheeps

Meat is a source of proteins and minerals. However, red meats have high levels of saturated fatty acids (SFA) and a low proportion of monounsaturated fatty acids (MUFA), a combination which has been linked to cancer and cardiovascular diseases. In ruminants, there are several genes that regulate the proportions of MUFA in tissues, but the most important is SCD (Stearoyl-CoA desaturase). The polymorphism g.31C >A has been described in the promoter region of the SCD gene, which is associated with changes in the gene expression and MUFA levels in the meat. The aim of this study was to detect the presence of polymorphism g.31C >A in a population of Araucano creole sheep using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism). Genomic DNA was obtained from 157 Araucano creole sheep. The SCD promoter region was amplified using PCR and the amplicons were digested with restriction enzyme MnlI. The allelic frequency was 0.98 for the C allele and 0.02 for the A allele. The in silico analysis showed that the A allele could alter the expression of SCD. This is the first report of the presence of polymorphism g.31C >A in Chilean sheep, and its association with SCD expression levels and the proportion of MUFA in the meat will require further investigation

Milk consumption after exercise decreases electrolyte excretion.

La rehidratación es fundamental para la correcta recuperación posterior al ejercicio físico y el deporte. Las bebidas lácteas parecen ser una buena opción como bebidas rehidratantes después del ejercicio, pero aún los mecanismos no están completamente dilucidados. El presente estudio tiene por objetivo medir los efectos en la excreción de electrolitos en la orina al rehidratar con una bebida láctea baja en grasa o una bebida isotónica tras la realización de una sesión de ejercicio intermitente. 14 sujetos físicamente activos (23 ± 4 años), se dividieron en dos grupos: 1) rehidratación con bebida isotónica (ISO) y 2) rehidratación con bebida láctea baja en grasa (LBG). Se evaluó la gravedad específica de la orina (GEO), electrolitos (Na+ y K+) en orina y retención de fluidos, después del ejercicio y 4 horas posterior a la rehidratación. Se encontraron diferencias significativas en la GEO y en la excreción de K+ en el grupo LBG (p<0.005), ambos grupos muestran diferencias significativas en la excreción de Na+. Los resultados muestran que la rehidratación con bebida láctea mejora la GEO y disminuyen la excreción de K+ de forma más eficiente que la bebida isotónica posterior al ejercicioRehydration is essential for post-exercise and sport recovery. Milk seems to be a good option like sport drinks after exercise, yet the rehydration mechanisms are still not fully understood. The aim of this study was to measure the effect of drinking low-fat milk and an isotonic beverage after intermittent exercise on urine electrolytes. 14 physically active men (23 ± 4 y) were split into two groups: 1) rehydration with isotonic drink (ISO), and 2) rehydration with low-fat milk (LBG). Specific gravity (GEO) and electrolytes (Na+ and K+) were measured in urine before and after exercise with rehydration. Significant differences were found for the GEO and in K+ excretion in the LBG group (p <0.05). Both groups showed significant differences for Na+ excretion concentrations. We conclude that drinking low fat milk after exercise when compared to an isotonic drink, improves GEO and K excretio