The Comportmental Learning Disabilities of Early Frontal Lobe Damage

Two adult patients are described who suffered bilateral prefrontal damage early in life and who subsequently came to psychiatric attention because of severely aberrant behaviour. A battery of developmental psychology paradigms (not previously used to assess neurologically impaired individuals) showed that social and moral development of these 2 patients was arrested at an immature stage. In comparison with other types of brain damage which disrupt cognitive development, frontal damage acquired early in life appears to provide the neurological substrate for a special type of learning disability in the realms of insight, foresight, social judgement, empathy, and complex reasoning

Hydrogen Motion in Magnesium Hydride by NMR

In coarse-grained MgH2, the diffusive motion of hydrogen remains too slow (<10^5 hops s^−1) to narrow the H NMR line up to 400 °C. Slow-motion dipolar relaxation time T1D measurements reveal the motion, with hopping rate ωH from 0.1 to 430 s^−1 over the range of 260 to 400 °C, the first direct measurement of H hopping in MgH2. The ωH data are described by an activation energy of 1.72 eV (166 kJ/mol) and attempt frequency of 2.5 × 10^15 s^−1. In ball-milled MgH2 with 0.5 mol % added Nb2O5 catalyst, line-narrowing is evident already at 50 °C. The line shape shows distinct broad and narrow components corresponding to immobile and mobile H, respectively. The fraction of mobile H grows continuously with temperature, reaching ∼30% at 400 °C. This demonstrates that this material’s superior reaction kinetics are due to an increased rate of H motion, in addition to the shorter diffusion paths from ball-milling. In ball-milled MgH2 without additives, the line-narrowed component is weaker and is due, at least in part, to trapped H2 gas. The spin−lattice relaxation rates T1^−1 of all materials are compared, with ball-milling markedly increasing T1^−1. The weak temperature dependence of T1^−1 suggests a mechanism with paramagnetic relaxation centers arising from the mechanical milling

Sleep abnormalities in the synaptopathies—SYNGAP1-related intellectual disability and Phelan–McDermid syndrome

Neurodevelopmental disorders are frequently associated with sleep disturbances. One class of neurodevelopmental disorders, the genetic synaptopathies, is caused by mutations in genes encoding proteins found at the synapse. Mutations in these genes cause derangement of synapse development and function. We utilized a validated sleep instrument, Children’s Sleep Habits Questionnaire (CSHQ) to examine the nature of sleep abnormalities occurring in individuals with two synaptopathies—Phelan–McDermid syndrome (PMD) (N = 47, male = 23, female = 24, age 1–46 years) and SYNGAP1-related intellectual disability (SYNGAP1-ID) (N = 64, male = 31, female = 33, age 1–64 years), when compared with unaffected siblings (N = 61, male = 25, female = 36, age 1–17 years). We found that both PMD and SYNGAP1-ID have significant sleep abnormalities with SYNGAP1-ID having greater severity of sleep disturbance than PMD. In addition, sleep disturbances were more severe for PMD in individuals 11 years and older compared with those less than 11 years old. Individuals with either disorder were more likely to use sleep aids than unaffected siblings. In conclusion, sleep disturbances are a significant phenotype in the synaptopathies PMD and SYNGAP1-ID. Improved sleep is a viable endpoint for future clinical trials for these neurodevelopmental disorders

NMR Studies of the Hydrogen Storage Compound NaMgH_3

Hydrogen and ^(23)Na NMR were performed to 400 °C on NaMgH3 powder produced by reactive ball-milling of NaH and MgH2. The H resonance shows narrowing already at 100 °C as a narrow line superimposed on the broad, rigid-lattice signal. With increasing temperature, the fraction of spins in the narrow component grows smoothly, approaching 100% near 275 °C. This heterogeneous narrowing suggests a wide distribution of H motion rates. After annealing at 400 °C, the narrow component intensity at temperatures below 200 °C was substantially reduced and both H and ^(23)Na relaxation rates 1/T_1 were decreased. Thus, it appears that the high rates of H motion, particularly on first heating, are due to regions with poorly organized crystal structure. If this disorder could be maintained, this might be an avenue toward improved reaction kinetics of this or other hydrides. In the annealed sample, the activation energy for H diffusion is approximately 95 kJ/mol

Evaluating drug treatments for Parkinson's disease: how good are the trials?

The prevalence of Parkinson's disease will increase as the population ages, making it important to identify reliably the most effective drug therapy Although many randomised controlled trials have evaluated the efficacy of different classes of drugs in both early and later Parkinson's disease, uncertainty about best treatment remains because of small numbers, inadequate follow up, and inappropriate end points Much larger trials are needed with long term follow up and end points of relevance to patients Large simple pragmatic trials have improved treatment of heart disease, stroke, and cancer and their methods should be applied to Parkinson's disease and other neurodegenerative disease

Sun, Moon, Stars, Rain, Vol. 7 No. 11

Official publication of the Sigma Tau Delta English Honor Society, Alpha Zet Chapter, Stephen F. Austin State University. Published one a year in the Fall Semester, in cooperation with the English Department of Stephen F. Austin State University.https://scholarworks.sfasu.edu/smsr/1000/thumbnail.jp

Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24&nbsp;months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500&nbsp;steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30&nbsp;minutes spent performing activities ≥500&nbsp;counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24&nbsp;months), both the number of steps per day (per 500&nbsp;steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500&nbsp;counts per minute (per 30&nbsp;minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score &gt;10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

Sun, Moon, Stars, Rain, Vol. 7 No. 11

Official publication of the Sigma Tau Delta English Honor Society, Alpha Zet Chapter, Stephen F. Austin State University. Published one a year in the Fall Semester, in cooperation with the English Department of Stephen F. Austin State University

Effects of Global Warming on Ancient Mammalian Communities and Their Environments

Current global warming affects the composition and dynamics of mammalian communities and can increase extinction risk; however, long-term effects of warming on mammals are less understood. Dietary reconstructions inferred from stable isotopes of fossil herbivorous mammalian tooth enamel document environmental and climatic changes in ancient ecosystems, including C(3)/C(4) transitions and relative seasonality.Here, we use stable carbon and oxygen isotopes preserved in fossil teeth to document the magnitude of mammalian dietary shifts and ancient floral change during geologically documented glacial and interglacial periods during the Pliocene (approximately 1.9 million years ago) and Pleistocene (approximately 1.3 million years ago) in Florida. Stable isotope data demonstrate increased aridity, increased C(4) grass consumption, inter-faunal dietary partitioning, increased isotopic niche breadth of mixed feeders, niche partitioning of phylogenetically similar taxa, and differences in relative seasonality with warming.Our data show that global warming resulted in dramatic vegetation and dietary changes even at lower latitudes (approximately 28 degrees N). Our results also question the use of models that predict the long term decline and extinction of species based on the assumption that niches are conserved over time. These findings have immediate relevance to clarifying possible biotic responses to current global warming in modern ecosystems