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Rainfall variability in space and time, in relation to catchment characteristics and model complexity, plays an important role in explaining the sensitivity of hydrological response in urban areas. In this work we present a new approach to classify rainfall variability in space and time and we use this classification to investigate rainfall aggregation effects on urban hydrological response. Nine rainfall events, measured with a dual polarimetric X-Band radar instrument at the CAESAR site (Cabauw Experimental Site for Atmospheric Research, NL), were aggregated in time and space in order to obtain different resolution combinations. The aim of this work was to investigate the influence that rainfall and catchment scales have on hydrological response in urban areas. Three dimensionless scaling factors were introduced to investigate the interactions between rainfall and catchment scale and rainfall input resolution in relation to the performance of the model. Results showed that (1) rainfall classification based on cluster identification well represents the storm core, (2) aggregation effects are stronger for rainfall than flow, (3) model complexity does not have a strong influence compared to catchment and rainfall scales for this case study, and (4) scaling factors allow the adequate rainfall resolution to be selected to obtain a given level of accuracy in the calculation of hydrological response.

In urban areas, hydrological processes are characterized by high variability in space and time, making them sensitive to small-scale temporal and spatial rainfall variability. In the last decades new instruments, techniques, and methods have been developed to capture rainfall and hydrological processes at high resolution. Weather radars have been introduced to estimate high spatial and temporal rainfall variability. At the same time, new models have been proposed to reproduce hydrological response, based on small-scale representation of urban catchment spatial variability. Despite these efforts, interactions between rainfall variability, catchment heterogeneity, and hydrological response remain poorly understood. This paper presents a review of our current understanding of hydrological processes in urban environments as reported in the literature, focusing on their spatial and temporal variability aspects. We review recent findings on the effects of rainfall variability on hydrological response and identify gaps where knowledge needs to be further developed to improve our understanding of and capability to predict urban hydrological response.

Introduction: Previous studies showed gender-associated clinical and MRI differences in multiple sclerosis (MS) evolution. However, only few studies were done with nonconventional MRI techniques and no study was done in a South American MS population. The aim of this study was to investigate gender differences according to nonconventional MRI measures in patients with MS from Buenos Aires, Argentina. Methods: Relapsing-remitting MS patients (RRMS) with at least 6 years of follow up and an MRI at onset and at 6 years were included. Patients were assessed using nonconventional MRI measures: total brain volume (TBV), neocortical grey brain volume (GBV), white brain volume (WBV), lesion load (LL), % of brain volume change between onset and year 6 (% BVC) and regional brain volume change. Gender-related MRI differences were investigated using general linear model analysis. Results: The 45 patients were included (25 female). Mean follow up time was 7.3 ± 0.2 years. No differences in age, EDSS at onset, DMD treatment, TBV, GBV, WBV neither LL were found between gender at baseline. Six years later, males showed a decrease in TBV (P = .002) and GBV (P ≤ .001) and an increase in LL (P = .02) and % BVC (P

Introduction: Epidemiological studies on acute transverse myelitis (ATM) in South America are scarce. The aim of our study was to describe demographic, clinical and para-clinical features of patients with ATM in a health care organisation in Buenos Aires. A further objective was to determine the aetiologies of ATM. Methods: All patients diagnosed with ATM between June 1, 2002 and June 30, 2010 were retrospectively identified, using the Transverse Myelitis Consortium Working Group (TMCWG) criteria. Results: A total of 40 patients diagnosed with ATM (24 females, 60%) were included. The mean follow-up was 57 ± 8 months. The principal cause of myelitis found was ATM secondary to demyelinating disease (55%). Idiopathic ATM was diagnosed in 15 (37.5%) cases in the sample. The majority of patients had an extensive cord lesion (50%) detectable with spinal MRI. Conclusion: There are few epidemiological studies concerning ATM in Argentina, and we believe that it is important to be aware of the manner in which this condition manifests itself in this region. We would therefore be able to compare them with studies previously published in other countries. Resumen: Introducción: Existen escasos estudios epidemiológicos sobre mielitis transversa aguda (MTA) en Sudamérica. El objetivo de nuestro estudio fue describir las características clínicas, paraclínicas y demográficas de pacientes con MTA en un centro de salud de Buenos Aires, Argentina. Además, se determinaron las diferentes etiologías asociadas a MTA. Métodos: Todos los pacientes con diagnóstico de MTA entre el 1 de junio del 2002 y el 30 de junio del 2010 fueron identificados retrospectivamente, utilizando los criterios del The Transverse Myelitis Consortium Working Group. Resultados: Se incluyó a un total de 40 pacientes con diagnóstico de MTA, de los cuales el 60% (n = 24) fueron mujeres. El tiempo medio de seguimiento fue de 57 ± 8 meses. La principal causa de MTA fue la secundaria a enfermedad desmielinizante (55%). La MTA idiopática se presentó en el 37,5% de los pacientes. La mayor parte de los casos se presentaron con mielitis longitudinal extensa en la RM (50%). Conclusión: Consideramos que es necesario conocer la manera en la cual esta entidad neurológica se presenta en nuestra región y de esta manera poder comparar nuestros resultados con los previamente publicados en otros países. Además, debido a las implicaciones terapéuticas, consideramos que es de suma importancia realizar una exhaustiva evaluación etiológica para diferenciar las diferentes posibles enfermedades asociadas a la MTA. Keywords: Acute transverse myelitis, Demyelinating disease, Longitudinal extensive myelitis, Partial myelitis, Buenos Aires, Palabras clave: Buenos Aires, Enfermedad desmielinizante, Mielitis longitudinal extensa, Mielitis partial, Mielitis transversa aguda

Introduction: Previous reports have shown that brain atrophy appears early in the course of multiple sclerosis (MS). The aim of the present study was to evaluate whether brain atrophy already exists in clinically isolated syndrome (CIS) by comparing with a control sample. Methods: Patients with CIS were included prospectively from June 2008 to June 2009. A control group of healthy persons, matched by age and gender with CIS, was also included during the same period of time. An automated analysis tool, SIENAX, was used to obtain total brain volume (TBV), gray matter volume (GMV) and white matter volume (WMV). Mann-Whitney U test was used to analyze the data. Results: Twenty CIS patients and 30 healthy controls were included (8 vs. 17 females, p = 0.11). Mean age for CIS was 35 ± 6 years vs. 34.4 ± 5 in controls (p = 0.61). Mean EDSS in CIS was 1.1 ± 0.5. Eighteen patients with CIS (90%) had abnormal baseline MRI. The TBV in CIS was 1.6 μl ± 0.22 μl×106 vs.1.65 ± 0.15×106 in controls (p = 0.005), the GMV in CIS was 0.58 ± 0.05×106 vs. 0.67 ± 0.03×106 in controls (p = 0.001) and the WMV in CIS was 1 ± 0.1×106 vs. 1.12 ± 0.02×106 in controls (p = 0.03). Conclusions: This is the first study dealing with brain atrophy in a CIS sample from Latin America in which brain atrophy, mainly grey matter atrophy, was shown in early stages of the disease compared with healthy individuals. Resumen: Introducción: Estudios previos demostraron que la atrofia cerebral (AC) aparece precozmente en esclerosis múltiple. Es nuestro objetivo evaluar la AC en pacientes con síndrome desmielinizante aislado (SDA) respecto a un grupo control en una población argentina. Métodos: Se incluyó prospectivamente a pacientes con SDA durante el período junio de 2008 a junio de 2009. El grupo control estaba formado por sujetos sanos apareados por edad y sexo. Se utilizó el programa SIENAX para medir el volumen cerebral total (VCT), el volumen de sustancia gris (VSG) y de sustancia blanca (VSB) en cada grupo. Los datos se compararon con la prueba de Mann-Whitney. Se consideró significativo p

In this essay, we try to figure out, based on Wilson Gomes’s filmanalysis methodology and on the musical minimalistic theory, which are the cognitive, sensorial, and emotional elements that are composed in the effect production strategies in the experimental film Koyaanisqatsi (Godfrey Reggio, USA, 1982).