692 research outputs found
Pollinators and climate change
El cambio climático está ampliamente reconocido como una de las principales amenazas para la biodiversidad y los polinizadores no son ajenos a
este impacto. En este trabajo, revisamos la literatura existente sobre los diferentes mecanismos mediante los cuales el cambio climático afecta a
los polinizadores: (1) desplazamientos en las áreas de distribución de las especies y el subsiguiente desajuste espacial con las plantas con las que
interactúan, (2) desajustes temporales entre la fenología de la floración de las plantas y la actividad de los polinizadores. Además, se consideran
otros efectos del cambio climático diferentes del aumento de temperaturas, así como las potenciales interacciones del cambio climático con otros
componentes de cambio global como la pérdida y fragmentación del hábitat y las invasiones biológicas. También exponemos un ejemplo sobre los
efectos del cambio climático en los patrones de distribución de una comunidad de abejorros (Bombus spp.) a lo largo de un gradiente altitudinal en
el norte de la península ibérica durante las últimas dos décadas. Se señalan así mismo algunas de las lagunas de conocimiento en esta área y se
indican necesidades de investigaciónClimate change is widely recognized as being a major threat to biodiversity, including pollinators. In the present paper, we review the existing knowledge
regarding how climate change impacts pollinators and its implication on their long-term survival. This includes: (1) spatial shifts in distribution
patterns and concomitant spatial mismatches with plant-food resources, (2) temporal shifts in activity patterns and concomitant temporal mismatches
with flowering plants. Furthermore, we consider other climatic effects besides global warming and potential interactions with other global change
pressures such as habitat loss and fragmentation and biological invasions. We also expose an example of the impact of climate change on the spatial
distribution patterns of bumblebees (Bombus spp.) along an elevation gradient in Northern Iberian Peninsula during the last two decades. Knowledge
gaps and future research needs are also highlightedPeer reviewe
Diagnóstico ecográfico de las alteraciones del músculo extensor digital lateral, tendón y vaina sinovial en caballos criollos colombianos con signos clínicos de hiperflexión del tarso
ABSTRACT: Tarsus hyperflexion alterslocomotion biomechanicsin horses. This alteration is of frequent
presentation in the Colombian creole horse (CCH). Objective: To determine the echographic alterations
of lateral digital extensor (LDE) muscle, tendon, and synovial sheath in CCH with clinical signs of tarsus
hyperflexion. Methods: Thirty horses were divided into two groups: 15 healthy horses with no history of
locomotion defects (Group 1; control), and 15 horses with clinical signs of tarsus hyperflexion (Group 2).
A cross-sectional and a longitudinal echocardiographic examination of the LDE muscle and tendon was
performed in all horses, and a histopathological study was performed only to Group 2. Results: 86.7% of
the horses showed echographic alterations, with 53.4% showing signs of adhesions in the LDE muscle and
tendon in the lateralsurface of the hock, where it crossesthe tarsus. 33.3% presented increased tendon synovial sheath fluid. 13.3% showed no echographic alterations and 53.3% presented histopathological alterations. Conclusion: These findings may be related to the presentation of tarsus hyperflexion that could characterize the classic stringhalt in CCH.RESUMEN: Antecedentes: la hiperflexin del tarso (corvej´´on) altera la biomecánica del desplazamiento en los caballos.
Esta alteración es de presentación frecuente en el caballo criollo colombiano (CCC). Objetivo: determinar
las alteraciones ecográficas del músculo extensor digital lateral (EDL), tendón y vaina sinovial en CCC con
signos clínicos de hiperflexión del corvejón. Métodos: treinta caballos fueron divididos en dos grupos: 15
equinos clínicamente sanos, sin historia de defectos de locomocion (Grupo 1; considerado como control),
y 15 equinos con signos clínicos de hiperflexión del corvejón (Grupo 2). Se realizó un examen ecográfico
transversal y longitudinal del músculo y tendón del EDL en todos los animales, y un estudio histopatológico
solo al Grupo 2. Resultados: el 86,7% de los caballos mostraron alteraciones ecográficas. El 53,4% mostró
signos de adherencias en el músculo y tendón del EDL, en donde la superficie lateral del corvejón se cruza
con el tarso. El 33,3% presentó un aumento en el líquido de la vaina sinovial del tendón. El 13,3% no presentó
ninguna alteración ecográfica, y el 53,3% mostró alteraciones histopatológicas. Conclusión: estos hallazgos
podrían estar relacionados con la presentación de hiperflexión del tarso que puede caracterizar el arpeo clásico en el CCC
Sectores Económicos: Análizar la Invesrión Extranjera Directa en Nicaragua, 2009-2013
La inversión extranjera directa (IED) desde los años 90 hasta nuestros días se ha constituido como un pilar importante para la generación de empleo en Nicaragua, en el último quinquenio esta ha sido estimulada por el gobierno a través de una serie de incentivos económicos tales como la suscripción de acuerdos con organismos internacionales para financiamiento de inversión en infraestructura, acuerdos comerciales, un marco legal fortalecido y estabilidad macroeconómica.
Lo que se busca con esta serie de incentivos económicos, es que la IED contribuya al desarrollo del país directa e indirectamente, aumentando la producción, el empleo, la cantidad de divisas, promoviendo el aprendizaje y la capacidad tecnológica
Propuesta de un programa para el control de la exposición ocupacional a calor en la recolección de "citrus cinensis" (naranja) en las Plantaciones de Ticofrut Agrícola S.A. del cantón fronterizo de Los Chiles
Proyecto de Graduación (Bachillerato en Ingeniería en Seguridad Laboral e Higiene Ambiental) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería en Seguridad Laboral e Higiene Ambiental, 2017.This project consists of applied descriptive research, with both quantitative and qualitative
approaches. It was developed during the harvesting citrus x cinensis plantations of TicoFrut
Agrícola S.A., located in the border region of Los Chiles, where approximately 2400 pickers,
mostly seasonal migrants, are involved in a labor relationship with poor root and piecework.
During the analysis of the current situation, it is concluded that people who participate in the
orange harvesting are in a condition of thermal stress, which generates affectation to their
health. The work involved requires a moderated metabolic load with respect to the reference
levels established in INTE / ISO 7243: 2016. The hydration practices used by the pickers
are not efficient. There is a high prevalence of possible dehydration signs. Acclimatization,
for the particular case of pickers, does not seem to be a process of relevance for its
implementation.
Administrative and integrated control alternatives are designed and proposed through an
occupational exposure control program, which defines planning, organization, management
and control of strategic activities, to prevent the health affectation of the people involved in
the orange picking work.Plantaciones de Ticofrut Agrícola S.A. del cantón fronterizo de Los Chile
La reforma laboral. Expedientes de regulación de empleo extintivos, estrategis empresariales y sentencias de la sala social de la Audiencia Nacional
Dada la situación del mercado laboral, y dentro del marco actual de las
Relaciones Laborales en España, para un Graduado en RRLL y RRHH es
necesario obtener los conocimientos necesarios para poder promover un
Expediente de Regulación de Empleo.
El presente trabajo trata de analizar los requisitos legales que tienen que
cumplir las empresas para poder promover un Expediente de Regulación de
Empleo Extintivo (ERE)
Para ello se analiza el artículo 51 del Estatuto de los Trabajadores, que señala
los supuestos legales que se han de cumplir, y se estudia detalladamente el
ERE presentado por LUMAC SA, debido a sus peculiaridades, sobre todo en la
decisión empresarial de demandar a los trabajadores ante la Audiencia
Nacional para que ésta declare el ERE ajustado a derecho, toda vez que los
trabajadores no han ejercido el derecho de impugnar el ERE legalmente en
plazo.Grado en Relaciones Laborales y Recursos Humano
Strategies to incorporate a fluorinated acrylate monomer into polymer particles: from particle morphology to film morphology and anticorrosion properties
[EN] Four strategies to incorporate a fluorinated monomer (perfluoro octyl acrylate, POA) into a waterborne polymeric dispersion are investigated. Due to the very low water solubility of the POA monomer, three of the strategies use miniemulsion droplets containing the whole POA monomer in the initial charge. The rest of the comonomers of the formulation (methyl methacrylate, MMA, and n-butyl acrylate, BA) are partially incorporated in the initial miniemulsion or fed to the reactor as a preemulsion. In the fourth strategy, a conventional seeded semibatch emulsion polymerization is carried out using cyclodextrin in the seed and feeding the POA/MMA/BA preemulsion to the reactor. Each process strategy led to a distinct particle morphology and hence a particular film morphology. We found that the strategy that produced core-shell particles with the core composed by pure polyPOA yielded the films that showed the best corrosion protection as measured in salt-spray test (1200 h standing without damage).Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature
Lab non destructive test to analyze the effect of corrosion on ground penetrating radar scans
Corrosion is a significant damage in many reinforced concrete structures, mainly in coastal areas. The oxidation of embedded iron or steel elements degrades rebar, producing a porous layer not adhered to the metallic surface. This process could completely destroy rebar. In addition, the concrete around the metallic targets is also damaged, and a dense grid of fissures appears around the oxidized elements. The evaluation of corrosion is difficult in early stages, because damage is usually hidden. Non-destructive testing measurements, based on non-destructive testing (NDT) electric and magnetic surveys, could detect damage as consequence of corrosion. The work presented in this paper is based in several laboratory tests, which are centered in defining the effect of different corrosion stage on ground penetrating radar (GPR) signals. The analysis focuses on the evaluation of the reflected wave amplitude and its behavior. The results indicated that an accurate analysis of amplitude decay and intensity could most likely reveal an approach to the state of degradation of the embedded metallic targets because GPR images exhibit characteristics that depend on the effects of the oxidized rebar and the damaged concrete. These characteristics could be detected and measured in some cases. One important feature is referred to as the reflected wave amplitude. In the case of corroded targets, this amplitude is lower than in the case of reflection on non-oxidized surfaces. Additionally, in some cases, a blurred image appears related to high corrosion. The results of the tests highlight the higher amplitude decay of the cases of specimens with corroded elements.Peer ReviewedPostprint (published version
Ground-penetrating radar evaluation of the ancient Mycenaean monument Tholos Acharnon tomb
The assessment of cultural heritage requires high-resolution and non-destructive methodologies. Ground-penetrating radar is widely applied in the inspection of historical buildings. However, some structures with curved surfaces make the radar data acquisition process difficult and consequently the following data interpretation. This paper describes a case study concerning a circular and buried Greek monument. This monument is a magnificent tomb buried with irregular stones. However, its structure and the internal stones arrangement are unknown. Therefore, a radar survey was carried out to achieve two main objectives: (i) identification of hidden elements and arrangement of the stones and (ii) detection of specific zones where further restoration and maintenance should be recommended. The methodology for the radar data acquisition involves the use of a laser scan in order to define accurately each radar line, covering all the internal surface of the tomb. Radar data processing was developed by converting Cartesian coordinates into polar coordinates. This procedure allows defining better the internal anomalies, improving the radar data interpretation. The main results of the survey were three: (i) the presence of a hidden target buried in the corridor access to the tomb; (ii) the description of the internal structure of the walls of the tomb, defining the stones arrangement and the position and depth to the keystone; and (iii) the existence of delimited zones where the signal is highly attenuated, probably due to a high salt content.Peer ReviewedPostprint (author's final draft
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