191 research outputs found
Intellectual abilities, language comprehension, speech, and motor function in children with spinal muscular atrophy type 1
Background: Spinal muscular atrophy (SMA) is a chronic, neuromuscular disease characterized by degeneration of
spinal cord motor neurons, resulting in progressive muscular atrophy and weakness. SMA1 is the most severe form
characterized by significant bulbar, respiratory, and motor dysfunction. SMA1 prevents children from speaking a clearly
understandable and fluent language, with their communication being mainly characterized by eye movements,
guttural sounds, and anarthria (type 1a); severe dysarthria (type 1b); and nasal voice and dyslalia (type 1c).
The aim of this study was to analyze for the first time cognitive functions, language comprehension, and speech in
natural history SMA1 children according to age and subtypes, to develop cognitive and language benchmarks that
provide outcomes for the clinical medication trials that are changing SMA1 course/trajectory.
Methods: This is a retrospective study including 22 children with SMA1 (10 affected by subtype 1a-1b: AB and 12 by
1c: C) aged 3â11 years in clinical stable condition with a coded way to communicate âyesâ and ânoâ. Data from the
following assessments have been retrieved from patient charts: one-dimensional Raven test (RCPM), to evaluate
cognitive development (IQ); ALS Severity Score (ALSSS) to evaluate speech disturbances; Brown Bellugy modified for
Italian standards (TCGB) to evaluate language comprehension; and Childrenâs Hospital of Philadelphia Infant Test of
Neuromuscular Disorders (CHOP-INTEND) to assess motor functioning.
Results: SMA 1AB and 1C children were similar in age, with the former characterized by lower CHOP-INTEND scores
compared to the latter. All 22 children had collaborated to RCPM and their median IQ was 120 with no difference (p =
0.945) between AB and C. Global median score of the speech domain of the ALSSS was 5; however, it was 2 in AB
children, being significantly lower than C (6.5, p < 0.001).
TCGB test had been completed by 13 children, with morphosyntactic comprehension being in the normal range (50).
Although ALSSS did not correlate with both IQ and TCGB, it had a strong (p < 0.001) correlation with CHOP-INTEND described by an exponential rise to maximum.
Conclusions: Although speech and motor function were severely compromised, children with SMA1 showed general
intelligence and language comprehension in the normal range. Speech impairment was strictly related to global motor
impairment
Rain-induced turbulence and air-sea gas transfer
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): C07009, doi:10.1029/2008JC005008.Results from a rain and gas exchange experiment (Bio2 RainX III) at the Biosphere 2 Center demonstrate that turbulence controls the enhancement of the air-sea gas transfer rate (or velocity) k during rainfall, even though profiles of the turbulent dissipation rate É are strongly influenced by near-surface stratification. The gas transfer rate scales with É inline equation for a range of rain rates with broad drop size distributions. The hydrodynamic measurements elucidate the mechanisms responsible for the rain-enhanced k results using SF6 tracer evasion and active controlled flux technique. High-resolution k and turbulence results highlight the causal relationship between rainfall, turbulence, stratification, and air-sea gas exchange. Profiles of É beneath the air-sea interface during rainfall, measured for the first time during a gas exchange experiment, yielded discrete values as high as 10â2 W kgâ1. Stratification modifies and traps the turbulence near the surface, affecting the enhancement of the transfer velocity and also diminishing the vertical mixing of mass transported to the air-water interface. Although the kinetic energy flux is an integral measure of the turbulent input to the system during rain events, É is the most robust response to all the modifications and transformations to the turbulent state that follows. The Craig-Banner turbulence model, modified for rain instead of breaking wave turbulence, successfully predicts the near-surface dissipation profile at the onset of the rain event before stratification plays a dominant role. This result is important for predictive modeling of k as it allows inferring the surface value of É fundamental to gas transfer.This work was funded by a generous grant from the
David and Lucile Packard Foundation and the Lamont-Doherty Earth
Observatory Climate Center. Additional funding was provided by the
National Science Foundation (OCE-05-26677) and the Office of Naval
Research Young Investigator Program (N00014-04-1-0621)
Faecal occult blood screening and reduction of colorectal cancer mortality: a case-control study
To estimate the efficacy of screening on colorectal cancer mortality, a population-based caseâcontrol study was conducted in well-defined areas of Burgundy (France). Screening by faecal occult blood test prior to diagnosis in cases born between 1914 and 1943 and who died of colorectal cancer diagnosed in 1988â94 was compared with screening in controls matched with the case for age, sex and place of residence. Cases were less likely to have been screened than controls, with an odds ratio (OR) of 0.67 [95% confidence interval (CI) 0.48â0.94]. The negative overall association did not differ by gender or by anatomical location. The odds ratio of death from colorectal cancer was 0.64 (95% CI 0.46â0.91) for those screened within 3 years of case diagnosis compared with those not screened. It was 1.14 (95% CI 0.50â2.63) for those screened more than 3 years before case diagnosis. There was a negative association between the risk of death from colorectal cancer and the number of participations in the screening campaigns. The inverse association between screening for faecal occult blood and fatal colorectal cancer suggests that screening can reduce colorectal cancer mortality. This report further supports recommendations for population-based mass screening with faecal occult blood test. © 1999 Cancer Research Campaig
Weighted external difference families and R-optimal AMD codes
In this paper, we provide a mathematical framework for characterizing AMD codes that are R-optimal. We introduce a new combinatorial object, the reciprocally-weighted external difference family (RWEDF), which corresponds precisely to an R-optimal weak AMD code. This definition subsumes known examples of existing optimal codes, and also encompasses combinatorial objects not covered by previous definitions in the literature. By developing structural group-theoretic characterizations, we exhibit infinite families of new RWEDFs, and new construction methods for known objects such as near-complete EDFs. Examples of RWEDFs in non-abelian groups are also discussed
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Model uncertainties in climate change impacts on Sahel precipitation in ensembles of CMIP5 and CMIP6 simulations
The impact of climate change on Sahel precipitation suffers from large uncertainties and is strongly model-dependent. In this study, we analyse sources of inter-model spread in Sahel precipitation change by decomposing precipitation into its dynamic and thermodynamic terms, using a large set of climate model simulations. Results highlight that model uncertainty is mostly related to the response of the atmospheric circulation to climate change (dynamic changes), while thermodynamic changes are less uncertain among climate models. Uncertainties arise mainly because the models simulate different shifts in atmospheric circulation over West Africa in a warmer climate. We linked the changes in atmospheric circulation to the changes in Sea Surface Temperature, emphasising that the Northern hemispheric temperature gradient is primary to explain uncertainties in Sahel precipitation change. Sources of Sahel precipitation uncertainties are shown to be the same in the new generation of climate models (CMIP6) as in the previous generation of models (CMIP5)
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Challenges and opportunities for improved understanding of regional climate dynamics
Dynamical processes in the atmosphere and ocean are central to determining the large-scale drivers of regional climate change, yet their predictive understanding is poor. Here, we identify three frontline challenges in climate dynamics where significant progress can be made to inform adaptation: response of storms, blocks and jet streams to external forcing; basin-to-basin and tropicalâextratropical teleconnections; and the development of non-linear predictive theory. We highlight opportunities and techniques for making immediate progress in these areas, which critically involve the development of high-resolution coupled model simulations, partial coupling or pacemaker experiments, as well as the development and use of dynamical metrics and exploitation of hierarchies of models
Beyond forcing scenarios: predicting climate change through response operators in a coupled general circulation model
Global Climate Models are key tools for predicting the future response of the climate system to a variety of natural and anthropogenic forcings. Here we show how to use statistical mechanics to construct operators able to flexibly predict climate change for a variety of climatic variables of interest. We perform our study on a fully coupled model - MPI-ESM v.1.2 - and for the first time we prove the effectiveness of response theory in predicting future climate response to CO2 increase on a vast range of temporal scales, from inter-annual to centennial, and for very diverse climatic quantities. We investigate within a unified perspective the transient climate response and the equilibrium climate sensitivity and assess the role of fast and slow processes. The prediction of the ocean heat uptake highlights the very slow relaxation to a newly established steady state. The change in the Atlantic Meridional Overturning Circulation (AMOC) and of the Antarctic Circumpolar Current (ACC) is accurately predicted. The AMOC strength is initially reduced and then undergoes a slow and only partial recovery. The ACC strength initially increases as a result of changes in the wind stress, then undergoes a slowdown, followed by a recovery leading to a overshoot with respect to the initial value. Finally, we are able to predict accurately the temperature change in the Northern Atlantic
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