552 research outputs found

    Intellectual disabilitiy in developmental age

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    Intellectual disability (ID) is a neurodevelopmental dis- order characterized by deficits in intellectual and adap- tive functioning that present before 18 years of age [1]. ID is heterogeneous in etiology and encompasses a broad spectrum of functioning, disability, needs and strengths. Originally formulated in strictly psychometric terms as performance greater than 2.5 SDs below the mean on intelligence testing, the conceptualisation of ID has been extended to include defects in adaptive beha- viours [2]. The term-global developmental delay-(GDD) is usually used to describe children younger than 5-years of age who fail to meet expected developmental milestones in multiple areas of intellectual functioning [1]. In both conditions the symptoms must be present in the early developmental period, but they may not become fully manifest until social demands exceed patients’ capacities. ID affects 1.5 to 2% of the population in Western countries and represents an important health burden [3]. During the past decade, advances in genetic research have enabled genomewide discovery of chromosomal copy-number and single-nucleotide changes in patients with ID and autism as well as in those with other neu- rodevelopmental disorders. These technological advances-which include array comparative genomic hybridization (CGH), single nucleotide polymorphism genotyping arrays and massively parallel sequencing- have transformed the approach to the identification of etiologic genes and genomic rearrangements in the research laboratory and are now being applied in the clinical diagnostic arena [4]. In this view, the American Academy of Pediatrics recently released a guidance for the clinician in rendering Pediatric Care [5]. The sug- gested clinical approach to the patient should be con- ducted closely with a geneticist and includes the child’s medical history, the family history, the physical and neu- rologic examinations (emphasizing the dysmorphology examination) and the examination for neurologic or behavioral signs that might suggest a specific recogniz- able syndrome or diagnosis. After this clinical evalua- tion, focused use of genetic laboratory tests, imaging and other consultations are critical in establishing the right diagnosis, its pattern of inheritance and the subse- quent follow-up. Finally, this guidance highlights a renewed emphasis on array CGH, that is now considered the first-line diagnostic test for children who present with GDD/ID of unknown cause, and on the identification of-treatable-causes of GDD/ID with the recommendation to consider screening for inborn errors of metabolism [5]. The future use of whole-genome or next generation sequencing offers pro- mises and challenges needing to be yet addressed before their regular implementation in the clinic

    Drift Effects on the Galactic Cosmic Ray Modulation

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    Cosmic ray (CR) modulation is driven by both solar activity and drift effects in the heliosphere, although their role is only qualitatively understood as it is difficult to connect the CR variations to their sources. In order to address this problem, the Empirical Mode Decomposition technique has been applied to the CR intensity, recorded by three neutron monitors at different rigidities (Climax, Rome, and Huancayo-Haleakala (HH)), the sunspot area, as a proxy for solar activity, the heliospheric magnetic field magnitude, directly related to CR propagation, and the tilt angle (TA) of the heliospheric current sheet (HCS), which characterizes drift effects on CRs. A prominent periodicity at ~six years is detected in all the analyzed CR data sets and it is found to be highly correlated with changes in the HCS inclination at the same timescale. In addition, this variation is found to be responsible for the main features of the CR modulation during periods of low solar activity, such as the flat (peaked) maximum in even (odd) solar cycles. The contribution of the drift effects to the global Galactic CR modulation has been estimated to be between 30% and 35%, depending on the CR particle energy. Nevertheless, the importance of the drift contribution is generally reduced in periods nearing the sunspot maximum. Finally, threshold values of ~40°, ~45°, and >55° have been derived for the TA, critical for the CR modulation at the Climax, Rome, and HH rigidity thresholds, respectively

    Thermal behavior study of pristine and modified halloysite nanotubes: A modern kinetic study

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    Pristine halloysite nanotubes (HNTs) were studied by thermogravimetry (TG) up to 800 C. Etching of alumina from inside the tube (causing a significant increase in tube lumen) was realized by treating the material with an acidic H2SO4 solution at 50 C. Both materials were characterized by TG-FTIR techniques and their thermal behaviors were compared with that of kaolinite. The coupling of TG with FTIR enables to detect the gases evolved during the TG experiments, thus confirming that only pristine HNTs undergo dehydration with the loss of interlayer water molecules at around 245 C, while dehydroxylation occurs in all these materials in close temperature ranges around 500 C. TG runs at five different heating rates (2, 5, 10, 15 and 20 C min-1), was carried out in the same experimental conditions used for the thermal analysis study with the aim to investigate dehydration and dehydroxylation kinetics using some isoconversional methods recommended by the ICTAC kinetic committee, and thermogravimetric data under a modulated rising temperature program. Finally, the results of the kinetic analysis were discussed and explained in terms of the strengths of the hydrogen bonds broken during these processes

    Esophageal atresia and Beckwith–Wiedemann syndrome in one of the naturally conceived discordant newborn twins: first report

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    Recent studies report a high incidence of monozygotic twinning in Beckwith–Wiedemann syndrome. A phenotypical discordance in monozygotic twins israre. Twinning and Beckwith–Wiedemann syndrome show higher incidence inchildren born after assisted reproductive techniques. We report on the first observation of esophageal atresia and Beckwith–Wiedemann syndrome in one of the naturally conceived discordant monozygotic twins

    Agricultural biodiversity in Northwest Somalia—An assessment among selected Somali sorghum [Sorphum Lambrou

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    Abstract. The seed sector situation in Northwest Somalia is critical. The availability of food has decreased and many people are at risk of hunger. Food security can be restored by enhancing the local genetic resources and creating an efficient seed sector. Sorghum is important as a food and fodder crop in this region. It is close to Ethiopia, which is considered as the probable origin and domestication of Sorghum. Twelve morphological and productive characteristics were chosen to assess the phenotypic variability of 16 accessions of sorghum from Northwest Somalia. Univariate (analysis of variance and G test) and multivariate (discriminant and cluster analysis) methods were used to assess the morphological variation within the accession and to group the 16 accessions into clusters based upon quantitative and qualitative characters. Elmi Jama Cas, Masego Cas, Masego Cad and Carabi clearly represent distinct landraces with specific features suitable for different purpose, such as grain and/or forage production. Each landrace tested is able to grow under harsh environmental conditions, thus ensuring a low, but stable production for small poor resources farmers. Knowledge and conservation of local landraces will provide a broad base of genetic variability from which improved sorghum varieties can be developed, thus aiding in the stabilisation of a secure and sustainable food supply for farmers of Northwest Somalia

    Composite nafion-catio3-δ membranes as electrolyte component for pem fuel cells

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    Manufacturing new electrolytes with high ionic conductivity has been a crucial challenge in the development and large-scale distribution of fuel cell devices. In this work, we present two Nafion composite membranes containing a non-stoichiometric calcium titanate perovskite (CaTiO3−δ ) as a filler. These membranes are proposed as a proton exchange electrolyte for Polymer Electrolyte Membrane (PEM) fuel cell devices. More precisely, two different perovskite concentrations of 5 wt% and 10 wt%, with respect to Nafion, are considered. The structural, morphological, and chemical properties of the composite membranes are studied, revealing an inhomogeneous distribution of the filler within the polymer matrix. Direct methanol fuel cell (DMFC) tests, at 110◦ C and 2 M methanol concentration, were also performed. It was observed that the membrane containing 5 wt% of the additive allows the highest cell performance in comparison to the other samples, with a maximum power density of about 70 mW cm−2 at 200 mA cm−2 . Consequently, the ability of the perovskite structure to support proton carriers is here confirmed, suggesting an interesting strategy to obtain successful materials for electrochemical devices

    Identification of the different magnetic field contributions during a geomagnetic storm in magnetospheric and ground observations

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    Abstract. We used the empirical mode decomposition (EMD) to investigate the time variation of the magnetospheric and ground-based observations of the Earth's magnetic field during both quiet and disturbed periods. We found two timescale variations in magnetospheric data which are associated with different magnetospheric current systems and the characteristic diurnal orbital variation, respectively. On the ground we identified three timescale variations related to the solar-wind–magnetosphere high-frequency interactions, the ionospheric processes, and the internal dynamics of the magnetosphere. This approach is able to identify the different physical processes involved in solar-wind–magnetosphere–ionosphere coupling. In addition, the large-timescale contribution can be used as a local index for the identification of the intensity of a geomagnetic storm on the ground
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