ABSTRACT:The evaluation of the possible climate change influence on extreme precipitation is very interesting in the Mediterranean area due to the usual and characteristic high intensities of its rainfall pattern. This analysis is also very important in urban zones, especially those densely populated with complex sewer systems, generally vulnerable to torrential rainfall. In this work, a total of 114 simulated daily rainfall series, 84 for the period 2000-2099 and 30 for the control period 1951-1999, have been analysed. These series were obtained for six thermo-pluviometric stations located in the metropolitan area of Barcelona using the information provided by five general circulation models under four future climate scenarios of greenhouse gas emissions and applying statistical downscaling methods. The potential changes in the intensity-duration-frequency relationships due to climate change have been investigated. For the last third of the 21st century, under A1B, A2 and B2 climate scenarios, an increase of at least 4% has been found on the expected daily rainfall with return period longer than 20 years. Using a temporal downscaling based on scaling properties of rainfall, future hourly extreme rainfall has been estimated. For almost all the scenarios and periods considered, the increase on the expected hourly rainfall has resulted slightly higher than the corresponding daily rainfall. The greatest differences between the future hourly and daily rainfall estimated have been found in the second third of the century under scenarios A1B (8%) and A2 (9%).
ObjectiveSpinocerebellar ataxia type 2 (SCA2) is an autosomal dominantly inherited neurodegenerative disease mainly affecting the cerebellum and brainstem. In this Cuban‐German research collaboration, we aimed to characterize atrophy patterns and associations with clinical measures in preclinical and manifest SCA2.MethodsIn this study, 16 nonmanifest SCA2 mutation carriers, 26 manifest patients with SCA2, and 18 healthy control subjects underwent magnetic resonance imaging, as well as genetic and clinical characterization including assessment of ataxia (Scale for the Assessment and Rating of Ataxia) and saccade velocity in Cuba were enrolled. Semiautomated quantitative volumetry of the cerebellum and brainstem, subdivided into the medulla oblongata, the pontine brainstem, and mesencephalon was performed. Additionally, the anteroposterior diameter of the pontine brainstem was measured.ResultsAnalysis of volumetric data revealed degeneration of the cerebellum and brainstem, in particular of pontine volumes and the anteroposterior diameter of the pons, in both manifest SCA2 patients and individuals at risk for SCA2 compared to controls. Comparing patients with nonataxic preclinical SCA2 mutation carriers, we found more pronounced reductions of the pontine brainstem and cerebellum in manifest SCA2. Volumetric data further showed associations with CAG repeat length and predicted age of onset in preclinical SCA2 individuals, and by trend with ataxia signs in patients. Although saccade velocity was associated with reduction in the pontine brainstem in preclinical and manifest SCA2, reduced ability to suppress interfering stimuli measured by the Stroop task was related to cerebellar volume loss in patients.InterpretationPreclinical SCA2 mutation carriers exhibit brain abnormalities, which could be targeted as surrogate parameters for disease progression and in future preventive trials.
Background: Sleep disturbances are common features in spinocerebellar ataxias (SCAs). Nevertheless, sleep data on SCA2 come from scarce studies including few patients, limiting the evaluation of the prevalence and determinants of sleep disorders. Objective: To assess the frequency and possible determinants of sleep disorders in the large and homogeneous SCA2 Cuban population. Methods: Thirty-two SCA2 patients and their age- and sex-matched controls were studied by video-polysomnography and sleep interviews. Results: The most striking video-polysomnography features were rapid eye movement (REM) sleep pathology and periodic leg movements (PLMs). REM sleep abnormalities included a consistent reduction of the REM sleep percentage and REM density as well as an increase in REM sleep without atonia (RWA). REM sleep and REM density decreases were closely related to the increase in ataxia scores, whereas the RWA percentage was influenced by the cytosine-adenine-guanine (CAG) repeats. PLMs were observed in 37.5% of cases. The PLM index showed a significant association with the ataxia score and disease duration but not with CAG repeats. Conclusions: REM sleep pathology and PLMs are closely related to SCA2 severity, suggesting their usefulness as disease progression markers. The RWA percentage is influenced by the CAG repeats and might thus be a sensitive parameter for reflecting polyglutamine toxicity. Finally, as PLMs are sensible to drug treatment, they represents a new therapeutic target for the symptomatic treatment of SCA2.
ABSTRACT:The main objective of this study is to estimate the probable maximum precipitation (PMP) in Barcelona for durations ranging from 5 min to 30 h. To this end, rain records from the Jardí gauge of the Fabra Observatory located in Barcelona (1927Barcelona ( -1992) and the urban pluviometric network supported by Clavegueram de Barcelona, S.A. (CLABSA, 1994(CLABSA, -2007 were analysed. Two different techniques were used and compared: a physical method based on the maximization of actual storms, and the Hershfield' statistical method. The PMP values obtained using the two techniques are very similar. In both cases, the expected increasing behaviour of the PMP with duration was found, with the increase especially notable for the mesoscale durations 2-9 h, and not significant from 12 h on up. This result seems to be related to the scale of the meteorological situations producing high intense rainfall amounts over our territory.
A comprehensive 24-week rehabilitation program significantly improves the motor cerebellar symptoms of spinocerebellar ataxia type 2 patients as assessed by the ataxia rating score likely as result of the partial preservation of motor learning and neural plasticity mechanisms. These findings provide evidence in support of this therapeutic approach as palliative treatment in spinocerebellar ataxia type 2 suggesting its use in combination with other symptomatic or neuroprotective drugs and in prodromal stages. © 2018 International Parkinson and Movement Disorder Society.
Extreme storms registered by the urban rain gauge network installed and supported by CLABSA (Clavegueram de Barcelona S. A.) in Barcelona in the period 1994-2001 have been investigated. Eleven rain events presenting intensities for durations between 5 min and 24 h with return periods equal to or larger than 5 years for any of the network gauges have been found. A cluster analysis has yielded four main classes of extreme rainfall events in this area, related to the meteorological scales involved: local (18%), mesoscale (37%) and synoptic storms (27%), as well as more complex rain events originated by multiscale mechanisms acting together (18%). An intensity index to classify extreme rainfall events in order to their complexity and severity, taking into account the contribution of the different scales implied in the rainfall processes, has been calculated. The frequency distribution of the intensity index values obtained for the urban network has resulted very similar to that calculated for rain data recorded by the Jardí gauge of the Observatory
A brief overview of the different techniques used to estimate the probable maximum precipitation (PMP) is presented. As a particular case, the 1-day PMP over Catalonia has been calculated and mapped with a high spatial resolution. For this purpose, the annual maximum daily rainfall series from 145 pluviometric stations of the Instituto Nacional de Meteorología (Spanish Weather Service) in Catalonia have been analyzed. In order to obtain values of PMP, an enveloping frequency factor curve based on the actual rainfall data of stations in the region has been developed. This enveloping curve has been used to estimate 1-day PMP values of all the 145 stations. Applying the Cressman method, the spatial analysis of these values has been achieved. Monthly precipitation climatological data, obtained from the application of Geographic Information Systems techniques, have been used as the initial field for the analysis. The 1-day PMP at 1 km(2) spatial resolution over Catalonia has been objectively determined, varying from 200 to 550 mm. Structures with wavelength longer than approximately 35 km can be identified and, despite their general concordance, the obtained 1-day PMP spatial distribution shows remarkable differences compared to the annual mean precipitation arrangement over Catalonia.
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