427 research outputs found

    Representation of tropical deep convection in atmospheric models - Part 1 : Meteorology and comparison with satellite observations

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    Published under Creative Commons Licence 3.0. Original article can be found at : http://www.atmospheric-chemistry-and-physics.net/ "The author's copyright for this publication is transferred to University of Hertfordshire".Fast convective transport in the tropics can efficiently redistribute water vapour and pollutants up to the upper troposphere. In this study we compare tropical convection characteristics for the year 2005 in a range of atmospheric models, including numerical weather prediction (NWP) models, chemistry transport models (CTMs), and chemistry-climate models (CCMs). The model runs have been performed within the framework of the SCOUT-O3 (Stratospheric-Climate Links with Emphasis on the Upper Troposphere and Lower Stratosphere) project. The characteristics of tropical convection, such as seasonal cycle, land/sea contrast and vertical extent, are analysed using satellite observations as a benchmark for model simulations. The observational datasets used in this work comprise precipitation rates, outgoing longwave radiation, cloud-top pressure, and water vapour from a number of independent sources, including ERA-Interim analyses. Most models are generally able to reproduce the seasonal cycle and strength of precipitation for continental regions but show larger discrepancies with observations for the Maritime Continent region. The frequency distribution of high clouds from models and observations is calculated using highly temporally-resolved (up to 3-hourly) cloud top data. The percentage of clouds above 15 km varies significantly between the models. Vertical profiles of water vapour in the upper troposphere-lower stratosphere (UTLS) show large differences between the models which can only be partly attributed to temperature differences. If a convective plume reaches above the level of zero net radiative heating, which is estimated to be ~15 km in the tropics, the air detrained from it can be transported upwards by radiative heating into the lower stratosphere. In this context, we discuss the role of tropical convection as a precursor for the transport of short-lived species into the lower stratosphere.Peer reviewe

    investigation of the agouti gene for the identification of useful markers for coat colour association studies in domestic rabbits

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    AbstractIn wild-type mice, it is well known that Agouti is expressed in skin where it controls the banded-hair Agouti phenotype. Molecular genetics and pharmacological studies show that mutually exclusive binding of the melanocortin 1 receptor (MC1R) by the Agouti protein or by -melanocyte-stimulating hormone (a-MSH) signals hair-bulb melanocytes to synthesise preferentially either pheomelanin (yellow-red pigment) or eumelanin (black-brown pigment), respectively. In mice as well as in other species, loss-of-function mutations of the Agouti gene determine only the production of eumelanin while gain-of-function mutations lead to pheomelanin production. A variety of coat colours appear as a result of these alterations that show also epistatic interactions with MC1R mutations. In rabbit, classical studies have suggested the presence of three alleles at the Agouti locus: A (wild type allele), at (black and tan) and a (non-agouti). We recently showed that mutations in the rabbit MC1R gene are associated with c..

    Discreteness of the spectrum of the compactified D=11 supermembrane with non-trivial winding

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    We analyze the Hamiltonian of the compactified D=11 supermembrane with non-trivial central charge in terms of the matrix model constructed recently by some of the authors. Our main result provides a rigorous proof that the quantum Hamiltonian of the supersymmetric model has compact resolvent and thus its spectrum consists of a discrete set of eigenvalues with finite multiplicity.Comment: 16 pages, final versio

    Ambiguous emotion recognition in temporal lobe epilepsy: The role of expression intensity

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    The lateralization of emotion processing is currently debated and may be further explored by examining facial expression recognition (FER) impairments in temporal lobe epilepsy (TLE). Furthermore, there is also debate in the literature whether FER deficits in individuals with TLE are more pronounced in the right than in the left hemisphere. Individuals with TLE were tested with an FER task designed to be more sensitive than those classically used to shed light on this issue. A total of 25 right- and 32 left-TLE patients, candidates for surgery, along with controls, underwent an FER task composed of stimuli shown not only at full-blown intensities (100 %), but also morphed to lower-intensity display levels (35 %, 50 %, and 75 %). The results showed that, as compared to controls, right-TLE patients showed deficits in the recognition of all emotional categories. Furthermore, when considering valence, right-TLE patients were impaired only in negative emotion recognition, but no deficits for positive emotions were highlighted in left-TLE patients. Finally, only the right-TLE patients’ impairment was found to be related to the age of epilepsy onset. Our work demonstrates that the FER deficits in TLE span multiple emotional categories and show manifestations dependent on the laterality of the epileptic focus. Taken together, our findings provide the strongest evidence for the right-hemisphere model, but they also partially support the valence model. We suggest that current models are not exhaustive at explaining emotional-processing cerebral control, and further that multistep models should be developed

    Peripartum Cardiomyopathy: Euro Observational Research Program

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    Peripartum cardiomyopathy is a rare but potentially life-threatening form of heart failure affecting women late in pregnancy or in the first months after delivery. Peripartum cardiomyopathy is difficult to diagnose and its onset and progression are variable between individuals. The pathophysiology remains poorly understood, hence treatment options are limited and possibly harmful to the foetus. Furthermore, geographical incidence varies greatly and little is known about the incidence in Western countries. To gain further understanding of the pathophysiology and incidence of peripartum cardiomyopathy, the European Society of Cardiology initiated a study group to implement a registry. This review provides an overview of current insights into peripartum cardiomyopathy, highlights the need for such a registry and provides information about this Euro Observational Research Program

    Complex rearrangement involving 9p deletion and duplication in a syndromic patient : Genotype/phenotype correlation and review of the literature

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    We describe a 7-year-old boy with a complex rearrangement involving the whole short arm of chromosome 9 defined by means of molecular cytogenetic techniques. The rearrangement is characterized by a 18.3Mb terminal deletion associated with the inverted duplication of the adjacent 21,5Mb region. The patient shows developmental delay, psychomotor retardation, hypotonia. Other typical features of 9p deletion (genital disorders, midface hypoplasia, long philtrum) and of the 9p duplication (brachycephaly, down slanting palpebral fissures and bulbous nasal tip) are present. Interestingly, he does not show trigonocephaly that is the most prominent dysmorphism associated with the deletion of the short arm of chromosome 9. Patient's phenotype and the underlying flanking opposite 9p imbalances are compared with that of reported patients and the proposed critical regions for 9p deletion and 9p duplication syndromes

    Medical care of adolescents and women with Rett syndrome : an Italian study

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    Rett syndrome (RTT) is a rare neurodevelopmental disorder, linked to MECP2 gene mutations in the majority of cases, which results in severe disability and is associated with several comorbidities. The clinical condition of RTT patients tends to stabilize over time, and prolonged survival has recently been demonstrated. However, limited information is available on the long-term course of older patients with RTT, especially among those in Southern Europe. The aim of our study is to evaluate the main clinical features and state of health of adult Italian patients with RTT and to present their evolution over time, identifying major clinical issues present at different ages. A total of 130 families of patients with RTT aged 6514 years were asked to complete a questionnaire, 84 of which were returned (65%). Among the clinical characteristics of RTT, stereotypies and poor hand function and feeding ability remained stable over time, while nonverbal communication tended to improve. With regard to the main pathologies, sleep, behavioral, and autonomic disorders persisted into adulthood, while epilepsy improved and musculoskeletal problems worsened. In our sample, older patients with R294X and R133C mutations and with C-terminal deletions showed lower levels of clinical severity. The development of guidelines for the clinical management of patients with RTT will assist health care providers in dealing with the complex RTT phenotype. More extensive data about the long-term course of the condition could help in the design of programs for secondary prevention of disabilities for younger females affected by the syndrome
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