Persistence in surface overflow of Andean rivers

The temporal structure of both deficit (negative) and excess (positive) periods in surface overflow of Andean rivers were analyzed by studying the runs. In Southern areas (in the province of Neuquén and the Southern part of the province of Mendoza), positive and negative groups of anomalies have been found to diminish geometrically over the years. In the Northern areas (in the province of San Juan and Northern part of the province of Mendoza) persistence occurs in negative runs only. This behavior is produced by the influence of the basins located in an arid zone, because of the heterogeneity in the structure of the precipitation in this region.En este trabajo se analiza el comportamiento de la persistencia en el escurrimiento superficial de los ríos andinos, usando el método de rachas de eventos con anomalías positivas o negativas. Se ha encontrado que las rachas positivas o negativas tienen en la zona más austral (provincia de Neuquén y sur de Mendoza) un decaimiento de tipo geométrico con los años; en cambio, hacia la zona más septentrional (provincia de San Juan y norte de Mendoza) aparece la persistencia solamente en las rachas negativas o de sequías. Este comportamiento no se encuentra en la estructura de la precipitación que cae en la cuenca, por lo tanto, se infiere que el mismo sería debido a la regulación que ejercen las cuencas del norte, inmersas en una región de clima árido.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Precipitación y escurrimientos superficiales de ríos andinos

Se analizan las relaciones existentes entre la precipitación calda en diversas regiones de Chile con los escurrimientos superficiales de ríos andinos. Se muestra que la precipitación media regional ajusta mejor a los escurrimientos, y que la relación entre ambas variables es de tipo curvilínea. Posteriormente se Infiere la probable causa de esta respuesta y se comparan los diferentes comportamientos entre ellas.The relationship between the preclpltations observed in dlfferent sites in Chile and the river runoffs of the Andean rivers in Argentlne are anallzed. It is shown that the mean regional preclpitation flts well with the runoffs; it is also observed that the relationshlp between both variables is not linear. The problable cause is inferred and different behaviours are compared.Asociación Argentina de Geofísicos y Geodesta

Precipitación y escurrimientos superficiales de ríos andinos

Se analizan las relaciones existentes entre la precipitación calda en diversas regiones de Chile con los escurrimientos superficiales de ríos andinos. Se muestra que la precipitación media regional ajusta mejor a los escurrimientos, y que la relación entre ambas variables es de tipo curvilínea. Posteriormente se Infiere la probable causa de esta respuesta y se comparan los diferentes comportamientos entre ellas.The relationship between the preclpltations observed in dlfferent sites in Chile and the river runoffs of the Andean rivers in Argentlne are anallzed. It is shown that the mean regional preclpitation flts well with the runoffs; it is also observed that the relationshlp between both variables is not linear. The problable cause is inferred and different behaviours are compared.Asociación Argentina de Geofísicos y Geodesta

Persistence in surface overflow of Andean rivers

The temporal structure of both deficit (negative) and excess (positive) periods in surface overflow of Andean rivers were analyzed by studying the runs. In Southern areas (in the province of Neuquén and the Southern part of the province of Mendoza), positive and negative groups of anomalies have been found to diminish geometrically over the years. In the Northern areas (in the province of San Juan and Northern part of the province of Mendoza) persistence occurs in negative runs only. This behavior is produced by the influence of the basins located in an arid zone, because of the heterogeneity in the structure of the precipitation in this region.En este trabajo se analiza el comportamiento de la persistencia en el escurrimiento superficial de los ríos andinos, usando el método de rachas de eventos con anomalías positivas o negativas. Se ha encontrado que las rachas positivas o negativas tienen en la zona más austral (provincia de Neuquén y sur de Mendoza) un decaimiento de tipo geométrico con los años; en cambio, hacia la zona más septentrional (provincia de San Juan y norte de Mendoza) aparece la persistencia solamente en las rachas negativas o de sequías. Este comportamiento no se encuentra en la estructura de la precipitación que cae en la cuenca, por lo tanto, se infiere que el mismo sería debido a la regulación que ejercen las cuencas del norte, inmersas en una región de clima árido.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Aplicación del análisis factorial para discriminar espacialmente variables geograficas

This work aims to show the effectiveness of Factor Analysis in geographic research, explaining how to discriminate spatially to any geographic variable, which in this case; Is the precipitation in the Argentine Republic and Chile, taking into account its interannual variability, This task was carried out applying this multivariate methodology, given its recognized validity to find the underlyingstructures in a high number of variables.The spatial discrimination of a variable is important to analyze the processes involved, taking into account homogeneous areas from the point of view of its geographical distribution and its genesis, Understanding the behavior of such uniform areas, the geographer can perform an adequate planning of that scenario.The additional purpose of this investigation is to provide a contribution to the understanding of the regime of the interannual variability of rainfall in the Argentinean and Chilean territory analyzed from a sandy point of view. With the application of this methodology, eight domains with spatial uniformity were identified in the variability of the mean annual precipitation, from the same number of factors, which explain 61% of the variance. The criterion adopted in the definitive retention of these eight factors is that they follow a pattern of territorial homogeneity, since they condense with enough spatial discrimination the information contained in the ninety-five original variables.Este trabajo tiene el propósito de mostrar la eficacia del Análisis Factorial en la investigación geográfica, explicando cómo discriminar espacialmente a una variable geográfica cualquiera, que en este caso; es la precipitación anual en la República Argentina y Chile, teniendo en cuenta su variabilidad interanual. Esta tarea se realizó aplicando dicha metodología multivariante, dada su reconocida validez para encontrar las estructuras subyacentes en un elevado número devariables.La discriminación espacial de una variable, resulta importante para analizar los procesos en ella involucrados, teniendo en cuenta áreas homogéneas desde el punto de vista de su distribución geográfica y su génesis. Comprendido el comportamiento de dichas áreas uniformes, el geógrafo puede realizar una adecuada planificación de ese escenario.El propósito adicional de esta indagación es brindar un aporte para lacomprensión del régimen de la variabilidad interanual de las precipitaciones en el territorio argentino y chileno analizadas desde un punto de vista areal. Con la aplicación de esta metodología se identificaron ocho dominios con uniformidad espacial en la variabilidad de la precipitación media anual, a partir de igual número de factores, que llegan a explicar el 61% de la varianza. El criterio adoptado en la retención definitiva de esos ocho factores, es que siguen un patrón de homogeneidad territorial, puesto que condensan con bastante discriminación espacial la información contenida en las noventa y cinco variables originales

Análisis de autocorrelaciones en series hidrológicas andinas

Se ha realizado una evaluación de los procesos temporales contenidos en series hidrológicas de ríos andinos. Analizando los correlogramas de las series en estudio, se han encontrado en ellos dependencias importantes entre los escurrimientos de un ciclo hidrológico y su consecutivo, y otras de rezagos 7 y 11-12 años, particularmente los ríos Jáchal, San Juan, Mendoza y Tunuyán. El 33,4 % de las series muestran un comportamiento definidamente aleatorio, y ninguna de ellas parece responder a un proceso autorregresivo de tipo Markov. Las series de precipitación regional en Chile, entre latitudes de 32.5° y 35.5° S, muestran correlogramas semejantes a los de los ríos del Norte de la zona de Cuyo en los rezagos de 11-12 años.An evaluation of the hydrological processes involved in the time series of the andean rivers runoff is done. Series correlograras are analysed; iraportant dependences between one hydrological annual cycle runoff with its consecutive one are found. Other significant autocorrelation at lag 7 and 11-12 years, in particular for the Jáchal, San Juan, Mendoza and Tunuyán rivers, are also found. It has been observed that 33,l+ % of series are random and all of them do not behave as Autorregresive Processes like Markov processes. Regional rainfall series between 32.5° and 35.5° S in Chile and the North Cuyan runoff series are compared showing similar correlograms at lags 11-12 years.Asociación Argentina de Geofísicos y Geodesta

Phlebotominae (Diptera: Psycodidae) fauna in the Chaco region and Cutaneous Leishmaniasis transmission patterns in Argentina

In Argentina, the incidence of American Cutaneous Leishmaniasis (ACL) has shown a steady increase over the last few decades. In the Chaco biogeographical region, specifically, several outbreaks of ACL were recently reported in addition to the usual time-space scattering of ACL cases. However, little is known about the sandfly composition in the eastern, humid Chaco (HC) region or the western, dry Chaco (DC) region. Therefore, phlebotomine captures were performed throughout this region and an analysis of the distribution of reported ACL cases was conducted in order to assess the vector diversity in ACL endemic and epidemic scenarios in the Chaco region. The results support the hypothesis of two distinct patterns: (1) the DC, where Lutzomyia migonei was the most prevalent species, had isolated ACL cases and a zoonotic cycle; (2) the HC, where Lutzomyia neivai was the most prevalent species, had an increase in ACL incidence and outbreaks and an anthropozoonotic cycle. The epidemic risk in the Chaco region may be associated with the current climate trends, landscape modification, connection with other ACL foci, and Lu. neivai predominance and abundance. Therefore, changes in sandfly population diversity and density in the Chaco region are an indicator of emergent epidemic risk in sentinel capture sites

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

La respuesta del anticiclón del pacífico sur en la costa de Chile frente al cambio climático-impactos

Aprovechando la reconstrucción del índice de posición latitudinal del anticiclón del O.Pacífico Sur sobre la costa de Chile (L) durante el período 1901-2004, se analiza su comportamiento de largo plazo como variable anual o mensual en el período más precipitante del clima mediterráneo sudamericano. Existe una importante evidencia del traslado de L hacia latitudes altas desde mediados del Siglo XX al presente, que podría ser justificado con el actual proceso de calentamiento global, sin embargo esto no parece justificar el comportamiento opuesto observado en la primer mitad del Siglo XX. En términos mensuales la tendencia hacia latitudes altas es más evidente en L, pero el mes de Junio (opuesto) es el encargado de mostrar que fluctuaciones de media y alta frecuencia pueden torcer una tendencia larga, lo que no hace recomendable el análisis en esta escala. Esto también es válido para series de variables anuales de alrededor de medio siglo o menos. Otra variable importante para el análisis en esta ocasión fue la intensidad anual del flujo de los Oeste en latitudes altas, que sí parece tener un comportamiento tendencial acorde a los cambios del calentamiento global