1,058 research outputs found

    Global prevalence of developmental disabilities in children and adolescents: a systematic umbrella review

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    Aim: The provisions of the United Nation's Sustainable Development Goals (SDGs) for disability-inclusive education have stimulated a growing interest in ascertaining the prevalence of children with developmental disabilities globally. We aimed to systematically summarize the prevalence estimates of developmental disabilities in children and adolescents reported in systematic reviews and meta-analyses. Methods: For this umbrella review we searched PubMed, Scopus, Embase, PsycINFO, and Cochrane Library for systematic reviews published in English between September 2015 and August 2022. Two reviewers independently assessed study eligibility, extracted the data, and assessed risk of bias. We reported the proportion of the global prevalence estimates attributed to country income levels for specific developmental disabilities. Prevalence estimates for the selected disabilities were compared with those reported in the Global Burden of Disease (GBD) Study 2019. Results: Based on our inclusion criteria, 10 systematic reviews reporting prevalence estimates for attention-deficit/hyperactivity disorder, autism spectrum disorder, cerebral palsy, developmental intellectual disability, epilepsy, hearing loss, vision loss and developmental dyslexia were selected from 3,456 identified articles. Global prevalence estimates were derived from cohorts in high-income countries in all cases except epilepsy and were calculated from nine to 56 countries. Sensory impairments were the most prevalent disabilities (approximately 13%) and cerebral palsy was the least prevalent disability (approximately 0.2–0.3%) based on the eligible reviews. Pooled estimates for geographical regions were available for vision loss and developmental dyslexia. All studies had a moderate to high risk of bias. GBD prevalence estimates were lower for all disabilities except cerebral palsy and intellectual disability. Conclusion: Available estimates from systematic reviews and meta-analyses do not provide representative evidence on the global and regional prevalence of developmental disabilities among children and adolescents due to limited geographical coverage and substantial heterogeneity in methodology across studies. Population-based data for all regions using other approaches such as reported in the GBD Study are warranted to inform global health policy and intervention

    The Crustacean Fauna (Branchiopoda, Copepoda) of Shallow Freshwater Bodies in Iceland

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    A survey of shallow freshwaters of Iceland was conducted in June and July 1996. The 34 stations prospected were rainpools, ditches, wetlands. The composition of their crustacean communities, investigated by qualitative net samples, is discussed in relation to water characteristics. One notostracan, Lepidurus arcticus (Pallas, 1793), 17 cladoceran species (5 Daphniidae, 10 Chydoridae, 1 Macrothricidae, 1 Polyphemidae), and 12 copepods (2 Diaptomidae, 7 Cyclopidae, 3 Canthocamptidae) were identified. Two species are reported for the first time from Iceland: the diaptomid Diaptomus (Chaetodiaptomus) rostripes Herbst, 1955 and the chydorid Alona rustica Scott, 1895. Taxonomical comments about different species are added, and their ecological pecularities are given. The species richness as well as the biogeographical features of the freshwater zooplankton of Iceland are discussed in relation to neighbouring Greenland and Northern Europe.Обследование мелких пресных водоемов Исландии проведено в июне-июле 1996 г. Материал собирался в дождевых и талых лужах, канавах, болотах. Среди 30 обнаруженных видов отмечены 1 вид щитней Lepidurus arcticus (Pallas, 1793), 17 видов ветвистоусых ракообразных (5 представителей сем. Daphnidae, 10 Chydoridae, 1 Macrothricidae, 1 Polyphemidae), 12 видов веслоногих ракобразных (2 вида сем. Diaptomidae, 7 Cyclopidae, 3 Canthocamptidae). Два вида указаны впервые для фауны Исландии: Diaptomus (Chaetodiatomus) rostripes Herbst, 1955 и Alona rustica Scott, 1895. Состав ракообразных в водоемах обсуждается в связи с экологической характеристикой последних. Для отдельных видов представлены краткие таксономические и экологические замечания. Обсуждаются видовое разнообразие и биогеографические особенности Исландии в связи с фаунистическими контактами с Гренландией и северной Европой

    Impacto do exercício sobre o metabolismo dos lipídeos e da dislipidemia

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    The chronic practice of exercise induces a series of cellular and organismal adaptations that modify the way the human body metabolizes all macronutrients, including lipids. Endurance exercise and resistance exercise elicit different responses that result in differential effects on lipid and lipoprotein metabolism. These effects are quantitatively and qualitatively different and mediated by distinct signaling pathways. In this review, we summarize relevant evidence on the impact of exercise on lipid and lipoprotein metabolism, and finalize with some practical recommendations on exercise practice for patients with dyslipidemia in the primary care settingLa práctica crónica del ejercicio induce una serie de adaptaciones celulares y orgánicas que modifican la forma en que el cuerpo humano metaboliza todos los macronutrientes, incluidos los lípidos. El ejercicio de duración y el ejercicio de resistencia provocan diferentes respuestas que resultan en efectos diferenciales sobre el metabolismo de los lípidos y las lipoproteínas. Estos efectos son cuantitativa y cualitativamente diferentes y mediados por distintas vías de  señalización. Esta revisión, resume la evidencia pertinente sobre la repercusión del ejercicio en el metabolismo de los lípidos y las lipoproteínas, y finaliza con algunas recomendaciones sobre la práctica del ejercicio para los pacientes con dislipidemia en el ámbito de la atención primariaA prática crônica de exercício induz uma série de adaptações celulares e orgânicas que modificam a maneira pela qual o corpo humano metaboliza todos os macronutrientes, incluindo os lipídios. O exercício de duração e o exercício de resistência provocam diversas respostas que resultam em efeitos diferenciais no metabolismo de lipídios e lipoproteínas. Estes efeitos são quantitativa e qualitativamente distintos e mediados por diferentes vias de sinalização. Nesta revisão, se resume as evidências relevantes sobre o impacto do exercício no metabolismo de lipídios e das lipoproteínas e conclui, com algumas recomendações sobre a prática de exercícios para pacientes com dislipidemia no campo da atenção primári

    Levy flights from a continuous-time process

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    The Levy-flight dynamics can stem from simple random walks in a system whose operational time (number of steps n) typically grows superlinearly with physical time t. Thus, this processes is a kind of continuous-time random walks (CTRW), dual to usual Scher-Montroll model, in which nn grows sublinearly with t. The models in which Levy-flights emerge due to a temporal subordination let easily discuss the response of a random walker to a weak outer force, which is shown to be nonlinear. On the other hand, the relaxation of en ensemble of such walkers in a harmonic potential follows a simple exponential pattern and leads to a normal Boltzmann distribution. The mixed models, describing normal CTRW in superlinear operational time and Levy-flights under the operational time of subdiffusive CTRW lead to paradoxical diffusive behavior, similar to the one found in transport on polymer chains. The relaxation to the Boltzmann distribution in such models is slow and asymptotically follows a power-law

    Combined aerobic and resistance training: are there additional benefits for older hypertensive adults?

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    OBJECTIVES: The objective of this study was to compare the effects of a combination of aerobic and resistance training to those of isolated aerobic training on blood pressure, body composition, and insulin sensitivity in hypertensive older adults. METHOD: Forty-four patients were randomly assigned to the aerobic group, resistance and aerobic group, and control group. Before and after 10 weeks, the following data were obtained: 24-hour ambulatory blood pressure data, abdominal circumference, waist circumference, body mass index, lean mass, fat mass, and insulin sensitivity. The study was conducted with 3 training sessions per week. RESULTS: Comparison revealed significant reductions in the body mass index, abdominal and waist circumferences, and ambulatory blood pressure (24-hour, wakefulness and sleep systolic/diastolic blood pressures) in both the aerobic group and the resistance and aerobic (combined) group. The fat mass only changed in the combined group. There was no difference in the insulin sensitivity in any group. CONCLUSIONS: The combined treatment and aerobic treatment alone were equally effective in reducing the blood pressure, body mass index, and abdominal and waist circumferences, although the addition of the resistance component also helped reduce the fat mass

    The Apollo Lunar Orbit Rendezvous Architecture Decision Revisited

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    This conference features the work of authors from: Georgia Tech’s Space Systems Design Lab, Aerospace Systems Design Lab, School of Aerospace Engineering, Georgia Tech Research Institute; NASA’s Jet Propulsion Laboratory, Marshall Space Flight Center, Goddard Space Flight Center, Langley Research Center; and other aerospace industry and academic institutionsThe 1962 Apollo architecture mode decision process was revisited with modern analysis and systems engineer tools to determine driving selection criteria and technology/operational mode design decisions that may be used for NASA’s current Space Exploration program. Results of the study agreed with the Apollo selection of the Lunar Orbit Rendezvous mode based on the technology maturity and politics in 1962. Using today’s greater emphasis on human safety and improvements in technology and design maturity, a slight edge may be given to the direct lunar mode over lunar orbit rendezvous. Also, the NOVA direct mode and Earth orbit rendezvous mode are not competitive based any selection criteria. Finally, reliability and development, operations, and production costs are major drivers in today’s decision process.AIAA Space Systems Technical Committee ; AIAA Space Transportation Systems Technical Committee ; Space Technology Advanced Research Cente

    Implications of reflectance measurements on the mechanism for superconductivity in MgB2_2

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    Recent optical studies in c-axis oriented superconducting MgB2_2 films indicate that the electron-phonon coupling is weak [tu01]. We reinforce this conclusion by examining the raw reflectance data; its frequency dependence is incompatible with strong electron-phonon scattering. This is further strengthened by analysis of the real part of the conductivity, and by the temperature dependence of the effective Drude scattering rate. Using a realistic electron-phonon spectral shape [kong01], we find λtr0.15\lambda_{\rm tr} \approx 0.15, in agreement with Tu et al. [tu01]. To the extent that λtrλ\lambda_{\rm tr} \approx \lambda, this disagrees sharply with model calculations [kong01,kortus01,an01], and is far too low to provide the means for Tc=39T_c = 39 K. A simple model is constructed with coupling to a high frequency excitation, which is consistent with both the low frequency optical data and the high TcT_c.Comment: 4 pages, 4 figure

    Localized and Delocalized Charge Transport in Single-Wall Carbon-Nanotube Mats

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    We measured the complex dielectric constant in mats of single-wall carbon-nanotubes between 2.7 K and 300 K up to 0.5 THz. The data are well understood in a Drude approach with a negligible temperature dependence of the plasma frequency (omega_p) and scattering time (tau) with an additional contribution of localized charges. The dielectric properties resemble those of the best ''metallic'' polypyrroles and polyanilines. The absence of metallic islands makes the mats a relevant piece in the puzzle of the interpretation of tau and omega_p in these polymers.Comment: 4 pages including 4 figure

    Global prevalence of developmental disabilities in children and adolescents: A systematic umbrella review.

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    AIM: The provisions of the United Nation's Sustainable Development Goals (SDGs) for disability-inclusive education have stimulated a growing interest in ascertaining the prevalence of children with developmental disabilities globally. We aimed to systematically summarize the prevalence estimates of developmental disabilities in children and adolescents reported in systematic reviews and meta-analyses. METHODS: For this umbrella review we searched PubMed, Scopus, Embase, PsycINFO, and Cochrane Library for systematic reviews published in English between September 2015 and August 2022. Two reviewers independently assessed study eligibility, extracted the data, and assessed risk of bias. We reported the proportion of the global prevalence estimates attributed to country income levels for specific developmental disabilities. Prevalence estimates for the selected disabilities were compared with those reported in the Global Burden of Disease (GBD) Study 2019. RESULTS: Based on our inclusion criteria, 10 systematic reviews reporting prevalence estimates for attention-deficit/hyperactivity disorder, autism spectrum disorder, cerebral palsy, developmental intellectual disability, epilepsy, hearing loss, vision loss and developmental dyslexia were selected from 3,456 identified articles. Global prevalence estimates were derived from cohorts in high-income countries in all cases except epilepsy and were calculated from nine to 56 countries. Sensory impairments were the most prevalent disabilities (approximately 13%) and cerebral palsy was the least prevalent disability (approximately 0.2-0.3%) based on the eligible reviews. Pooled estimates for geographical regions were available for vision loss and developmental dyslexia. All studies had a moderate to high risk of bias. GBD prevalence estimates were lower for all disabilities except cerebral palsy and intellectual disability. CONCLUSION: Available estimates from systematic reviews and meta-analyses do not provide representative evidence on the global and regional prevalence of developmental disabilities among children and adolescents due to limited geographical coverage and substantial heterogeneity in methodology across studies. Population-based data for all regions using other approaches such as reported in the GBD Study are warranted to inform global health policy and intervention
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