294 research outputs found

    Determination of the availability of payment for conservation and improvement activities of wetlands ecosystem of the Huaraz City, Peru

    Get PDF
    Universidad Nacional Agraria La Molina. Facultad de Economía y Planificación. Departamento Académico de Economía y PlanificaciónEl Método de Valoración Contingente (MVC) fue utilizado con el propósito de determinar la intención de pago (IDP) de los ciudadanos en la ciudad de Huaraz - Perú (Región Ancash) con el fin de estimar un financiamiento para subsidiar el diseño e implementación de las actividades de conservación y restauración de un ecosistema de humedales. Para estimar la IDP, se usó el modelo probabilístico LOGIT; el cual es base de las proposiciones teóricas de Bishop-Heberlein. Los resultados indicaron que las variables más influenciables en la (IDP), son una serie de variables de “apreciación” (de los ciudadanos) respecto a la importancia ecológica de los humedales en la región. Sin embargo, las variables socioeconómicas, como los ingresos, la edad, educación, etc., no fueron muy significativos en explicar la variación en la intención de pago. El mejor indicador estadístico para medir la IDP fue la media, que se estimó al 1.05USD/familia/mes,revelandoquelaRegioˊnAncash(Peruˊ)podrıˊaerigirseanualmenteporunestimadode1.05 USD/familia/mes, revelando que la Región Ancash (Perú) podría erigirse anualmente por un estimado de 312,266 USD. Una importante conclusión es que la valoración económica es la llave para diseñar e implementar actividades de conservación y mejoramiento de los humedales, este sería el comienzo de un proceso que terminaría exitosamente si son completados algunos escalones pendientes.Contingent Valuation Method (CVM) was used with the purpose of determining the willingness to pay (WTP) of the citizens of Huaraz city - Peru (Ancash Region) in order to estimate a financial to subsidize the design and implementation of conservation and restoration activities of the wetland ecosystem. To estimate the WTP, a LOGIT probabilistic model was use; which is base on the theoretical proposal of Bishop-Heberlein. Results indicate that the most influential variables in the WTP, are a set of variables of "appreciation" (of te citizen´s) regarding the ecological importance of the wetlands in their region. However, socioeconomic variables, such as income, age, education, etc., were not significant in explaining the WTP variation. The best statistical indicator for measuring the WTP was the median, which was estimated at 1.05USD/family/month,revealingthatinAncashregion(Peru)itcouldraiseannuallybyanestimatedof1.05 USD/family/month, revealing that in Ancash region (Peru) it could raise annually by an estimated of 312,266 USD. An important conclusion is that economic valuation is key to design and implement activities of conservation and improvement of the wetlands, this being the beginning of a process that will end successfully if some remaining steps are completed

    Efecto del ejercicio y la actividad física sobre las funciones ejecutivas en niños y en jóvenes. Una revisión sistemática

    Get PDF
    This qualitative systematic review tries to advance knowledge about the effect of physical activity on executive functions, paying special attention to healthy children, teenagers and youngsters.  Several articles have been identified, categorized and analyzed in electronic databases such as ISI Web of Knowledge, SCOPUS, PubMed, SPORTDiscus, PsyINFO, ERIC, Google Scholar and Dialnet. According to the inclusion/exclusion criteria, following the PRISMA statement to record and categorize the results and throughout the quality assessment tool "The Effective Public Health Practice Project”, 44 pieces of research, structured in acute and chronic episodes of physical activity under two approaches: qualitative and quantitative, were chosen. The results show a higher number of experiments with quantitative acute episodes (45,45%) against qualitative ones (18,18%), chronic quantitative (20,45%) and chronic qualitative episodes (15,92%). The analysis of these investigations has allowed identifying the benefits of different types of physical activity studied on executive components.En la presente revisión sistemática cualitativa se intenta avanzar en el conocimiento sobre la incidencia de la actividad física sobre las funciones ejecutivas, focalizada en poblaciones sanas infantiles, adolescentes y jóvenes. Se identificaron, categorizaron y analizaron artículos de bases de datos electrónicas como ISI Web of Knowledge, SCOPUS, PubMed, SPORTDiscus, PsyINFO, ERIC, Google Scholar y Dialnet. Atendiendo a los criterios de inclusión/exclusión, siguiendo la declaración PRISMA para registrar y categorizar los resultados, y mediante la herramienta de evaluación de calidad “The Effective Public Health Practice Project”, se seleccionaron finalmente 44 investigaciones experimentales, estructuradas en episodios agudos y crónicos de actividad física bajo dos enfoques: cuantitativos y cualitativos. Los resultados muestran una superior cantidad de experimentos con episodios agudos cuantitativos (45,45%), frente a los agudos cualitativos (18,18%), crónicos cuantitativos (20,45%) y crónicos cualitativos (15,92%). Los análisis de estas investigaciones han permitido identificar los beneficios de los diferentes tipos de actividad física estudiados sobre los componentes ejecutivos

    Síndrome de dermatitis y nefropatía porcino: una revisión sobre su epidemiología, patología y etiología

    Get PDF
    Porcine dermatitis and nephropathy syndrome (PDNS) is a disease that affects growing and finishing pigs characterized by a sporadic presentation, prevalence lower than 1 % and variable lethality. PDNS affected pigs shows acute multifocal red-to-purple skin lesions and enlarged tan kidneys with petechial hemorrhages. The hallmark microscopic lesions of PDNS are a generalized vasculitis and glomerulonephritis that suggest a type III hypersensitivity reaction. Although the etiology remains unknown, different works have showed the association between porcine circovirus type 2 (PCV-2) and PDNS based on epidemiological evidences, microscopic lesions and, the inconstant detection of PCV-2 antigen and / or nucleic acid in affected tissues. In this article the main characteristics of the disease from an epidemiological, pathological and etiological standpoint are described. Information about national situation is also included.El síndrome de dermatitis y nefropatía porcino (SDNP) es una entidad exclusiva de los cerdos que afecta, en general, a animales de desarrollo y engorde. Su presentación suele ser esporádica con una prevalencia en las granjas afectadas menor al 1% y una letalidad entre el 50 y 100% que varia según la edad. Se caracteriza por la aparición súbita de lesiones multifocales rojo-violáceas en piel y riñones pálidos que se cubren de hemorragias petequiales. La lesión microscópica típica consiste en una vasculitis generalizada y glomérulonefritis sugestivas de una reacción de hipersensibilidad tipo III, mediada por inmunocomplejos. Si bien su etiología no es conocida, distintos trabajos asocian al SDNP con la infección por circovirus porcino tipo 2 (PCV-2) basados en ciertas evidencias epidemiológicas, las características de algunas de las lesiones microscópicas y, aún cuando inconstante, la detección de antígeno y/o ácido nucleico de PCV-2 en tejidos de animales enfermos. En el presente trabajo se describen las principales características de la enfermedad desde el punto de vista de su epidemiología, patología y etiología, incluyendo datos sobre la situación en la Argentina

    Folding of the apolipoprotein A1 driven by the salt concentration as a possible mechanism to improve cholesterol trapping

    Full text link
    The folding of the cholesterol trapping apolipoprotein A1 in aqueous solution at increasing ionic strength is studied using atomically detailed molecular dynamics simulations. We calculate various structural properties to characterize the conformation of the protein, such as the radius of gyration, the radial distribution function and the end to end distance. Additionally we report information using tools specifically tailored for the characterization of proteins, such as the mean smallest distance matrix and the Ramachandran plot. We find that two qualitatively different configurations of this protein are preferred, one where the protein is extended, and one where it forms loops or closed structures. It is argued that the latter promote the association of the protein with cholesterol and other fatty acids.Comment: 14 pages, 6 figures. To appear in "Selected Topics of Computational and Experimental Fluid Mechanics", Springer, J. Klapp, G. Ru\'iz, A. Medina, A. L\'opez & L. Di G. Sigalotti (eds.), 201

    Evaluación funcional en ancianos intervenidos de fractura de cadera

    Get PDF
    Estudio observacional prospectivo en pacientes mayores de 65 años intervenidos de fractura de cadera. El objetivo fue conocer la evolución funcional de los pacientes a los tres meses del alta hospitalaria, identificar variables relacionadas con dicha recuperación funcional, describir la mortalidad e institucionalización asociadas al proceso. Se analizaron variables demográficas como edad, sexo, convivencia. Otros aspectos registrados fueron: comorbilidad, deterioro cognitivo, capacidad para caminar, nivel de dependencia según índice de Barthel, institucionalización y mortalidad. Se recogió la información al ingreso y a los 3 meses del alta. El 89,6% de la muestra, fueron mujeres, la edad media fue de 83,56 años. El 40% de los pacientes recuperaron la independencia previa registrándose una mortalidad del 16,7% así como una leve progresión hacia la institucionalización. La capacidad funcional y el deterioro cognitivo del paciente, previos a la fractura condicionan su recuperación funcional y dependencias posteriores

    The macroecology of phylogenetically structured hummingbird-plant networks

    Get PDF
    Aim To investigate the association between species richness, species' phylogenetic signal, insularity and historical and current climate with hummingbird-plant network structure. Location 54 communities along a c. 10,000 kilometer latitudinal gradient across the Americas (39ºN - 32ºS), ranging from sea level to c. 3700 m asl, located on the mainland and on islands, and covering a wide range of climate regimes. Methods We measured null-modeled corrected complementary specialization and bipartite modularity (compartmentalization) in networks of quantitative interactions between hummingbird and plant species. Using an ordinary least squares multi-model approach, we examined the influence of species richness, phylogenetic signal, insularity, and current and historical climate conditions on network structure. Results Phylogenetically-related species, especially plants, showed a tendency to interact with a similar array of partners. The spatial variation in network structure exhibited a constant association with species' phylogeny (R2=0.18-0.19). Species richness and environmental factors showed the strongest associations with network structure (R2=0.20-0.44; R2138 =0.32-0.45, respectively). Specifically, higher levels of complementary specialization and modularity were associated to species-rich communities and communities in which closely-related hummingbirds visited distinct sets of flowering species. On the mainland, warmer temperatures and higher historical temperature stability associated to higher levels of complementary specialization. Main conclusions Previous macroecological studies of interaction networks have highlighted the importance of environment and species richness in determining network structure. Here, for the first time, we report an association between species phylogenetic signal and network structure at macroecological scale. Specifically, null model corrected complementary specialization and modularity exhibited a positive association with species richness and a negative association with hummingbird phylogenetic signal, indicating that both high richness and high inter-specific competition among closely-related 150 hummingbirds exhibit important relationships with specialization in hummingbird-plant networks. Our results document how species richness, phylogenetic signal and climate associate with network structure in complex ways at macroecological scale

    Biology, Methodology or Chance? The Degree Distributions of Bipartite Ecological Networks

    Get PDF
    The distribution of the number of links per species, or degree distribution, is widely used as a summary of the topology of complex networks. Degree distributions have been studied in a range of ecological networks, including both mutualistic bipartite networks of plants and pollinators or seed dispersers and antagonistic bipartite networks of plants and their consumers. The shape of a degree distribution, for example whether it follows an exponential or power-law form, is typically taken to be indicative of the processes structuring the network. The skewed degree distributions of bipartite mutualistic and antagonistic networks are usually assumed to show that ecological or co-evolutionary processes constrain the relative numbers of specialists and generalists in the network. I show that a simple null model based on the principle of maximum entropy cannot be rejected as a model for the degree distributions in most of the 115 bipartite ecological networks tested here. The model requires knowledge of the number of nodes and links in the network, but needs no other ecological information. The model cannot be rejected for 159 (69%) of the 230 degree distributions of the 115 networks tested. It performed equally well on the plant and animal degree distributions, and cannot be rejected for 81 (70%) of the 115 plant distributions and 78 (68%) of the animal distributions. There are consistent differences between the degree distributions of mutualistic and antagonistic networks, suggesting that different processes are constraining these two classes of networks. Fit to the MaxEnt null model is consistently poor among the largest mutualistic networks. Potential ecological and methodological explanations for deviations from the model suggest that spatial and temporal heterogeneity are important drivers of the structure of these large networks

    Prognostic factors in left-sided endocarditis: results from the andalusian multicenter cohort

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Despite medical advances, mortality in infective endocarditis (IE) is still very high. Previous studies on prognosis in IE have observed conflicting results. The aim of this study was to identify predictors of in-hospital mortality in a large multicenter cohort of left-sided IE.</p> <p>Methods</p> <p>An observational multicenter study was conducted from January 1984 to December 2006 in seven hospitals in Andalusia, Spain. Seven hundred and five left-side IE patients were included. The main outcome measure was in-hospital mortality. Several prognostic factors were analysed by univariate tests and then by multilogistic regression model.</p> <p>Results</p> <p>The overall mortality was 29.5% (25.5% from 1984 to 1995 and 31.9% from 1996 to 2006; Odds Ratio 1.25; 95% Confidence Interval: 0.97-1.60; p = 0.07). In univariate analysis, age, comorbidity, especially chronic liver disease, prosthetic valve, virulent microorganism such as <it>Staphylococcus aureus</it>, <it>Streptococcus agalactiae </it>and fungi, and complications (septic shock, severe heart failure, renal insufficiency, neurologic manifestations and perivalvular extension) were related with higher mortality. Independent factors for mortality in multivariate analysis were: Charlson comorbidity score (OR: 1.2; 95% CI: 1.1-1.3), prosthetic endocarditis (OR: 1.9; CI: 1.2-3.1), <it>Staphylococcus aureus </it>aetiology (OR: 2.1; CI: 1.3-3.5), severe heart failure (OR: 5.4; CI: 3.3-8.8), neurologic manifestations (OR: 1.9; CI: 1.2-2.9), septic shock (OR: 4.2; CI: 2.3-7.7), perivalvular extension (OR: 2.4; CI: 1.3-4.5) and acute renal failure (OR: 1.69; CI: 1.0-2.6). Conversely, <it>Streptococcus viridans </it>group etiology (OR: 0.4; CI: 0.2-0.7) and surgical treatment (OR: 0.5; CI: 0.3-0.8) were protective factors.</p> <p>Conclusions</p> <p>Several characteristics of left-sided endocarditis enable selection of a patient group at higher risk of mortality. This group may benefit from more specialised attention in referral centers and should help to identify those patients who might benefit from more aggressive diagnostic and/or therapeutic procedures.</p
    corecore