Diabetes Insipidus: An Overview and a Case Report

Antidiuretic hormone (ADH, vasporessin) is an octapeptide produced in the nuclei of the anterior hypothalamus. The major source of this homrone is the supraoptic nuclei with minor production taking place in the paraventricular and filiform nuclei

Harmony Search Optimization and Damage Tolerance of Structural Systems

In this thesis, multiple structural systems are investigated by utilizing the Harmony Search optimization algorithm for least weight optimization. An analytical overview of structural optimization, matrix analysis, damage tolerance, steel connections and structural reliability analysis and methodology are presented. To support the methodology, three example problems have been provided. The first example demonstrates damage tolerant optimization of a simple truss structure. The second example focuses on the harmony search optimization of a more complex steel frame along with damage tolerant optimization. The third example provides a brief connection between damage tolerance and structural reliability. The findings show that the harmony search algorithm can be a powerful tool when optimizing structural systems. They also show the power of linking optimization, damage tolerance and structural reliability when considering the design of a structure

Bilingualism Is Associated with a Delayed Onset of Dementia but Not with a Lower Risk of Developing it: a Systematic Review with Meta-Analyses.

Some studies have linked bilingualism with a later onset of dementia, Alzheimer's disease (AD), and mild cognitive impairment (MCI). Not all studies have observed such relationships, however. Differences in study outcomes may be due to methodological limitations and the presence of confounding factors within studies such as immigration status and level of education. We conducted the first systematic review with meta-analysis combining cross-sectional studies to explore if bilingualism might delay symptom onset and diagnosis of dementia, AD, and MCI. Primary outcomes included the age of symptom onset, the age at diagnosis of MCI or dementia, and the risk of developing MCI or dementia. A secondary outcome included the degree of disease severity at dementia diagnosis. There was no difference in the age of MCI diagnosis between monolinguals and bilinguals [mean difference: 3.2; 95% confidence intervals (CI): -3.4, 9.7]. Bilinguals vs. monolinguals reported experiencing AD symptoms 4.7 years (95% CI: 3.3, 6.1) later. Bilinguals vs. monolinguals were diagnosed with dementia 3.3 years (95% CI: 1.7, 4.9) later. Here, 95% prediction intervals showed a large dispersion of effect sizes (-1.9 to 8.5). We investigated this dispersion with a subgroup meta-analysis comparing studies that had recruited participants with dementia to studies that had recruited participants with AD on the age of dementia and AD diagnosis between mono- and bilinguals. Results showed that bilinguals vs. monolinguals were 1.9 years (95% CI: -0.9, 4.7) and 4.2 (95% CI: 2.0, 6.4) older than monolinguals at the time of dementia and AD diagnosis, respectively. The mean difference between the two subgroups was not significant. There was no significant risk reduction (odds ratio: 0.89; 95% CI: 0.68-1.16) in developing dementia among bilinguals vs. monolinguals. Also, there was no significant difference (Hedges' g = 0.05; 95% CI: -0.13, 0.24) in disease severity at dementia diagnosis between bilinguals and monolinguals, despite bilinguals being significantly older. The majority of studies had adjusted for level of education suggesting that education might not have played a role in the observed delay in dementia among bilinguals vs. monolinguals. Although findings indicated that bilingualism was on average related to a delayed onset of dementia, the magnitude of this relationship varied across different settings. This variation may be due to unexplained heterogeneity and different sources of bias in the included studies. Registration: PROSPERO CRD42015019100

Intense physical activity is associated with cognitive performance in the elderly

Numerous studies have reported positive impacts of physical activity on cognitive function. However, the majority of these studies have utilised physical activity questionnaires or surveys, thus results may have been influenced by reporting biases. Through the objective measurement of routine levels of physical activity via actigraphy, we report a significant association between intensity, but not volume, of physical activity and cognitive functioning. A cohort of 217 participants (aged 60–89 years) wore an actigraphy unit for 7 consecutive days and underwent comprehensive neuropsychological assessment. The cohort was stratified into tertiles based on physical activity intensity. Compared with individuals in the lowest tertile of physical activity intensity, those in the highest tertile scored 9%, 9%, 6% and 21% higher on the digit span, digit symbol, Rey Complex Figure Test (RCFT) copy and Rey Figure Test 30-min recall test, respectively. Statistically, participants in the highest tertile of physical activity intensity performed significantly better on the following cognitive tasks: digit symbol, RCFT copy and verbal fluency test (all P<0.05). The results indicate that intensity rather than quantity of physical activity may be more important in the association between physical activity and cognitive function

Intrarater reliability and agreement of the physioflow bioimpedance cardiography device during rest, moderate and high-intensity exercise

The PhysioFlow bioimpedance cardiography device provides key measures of central systolic and diastolic and peripheral vascular function. Many of these variables have not been assessed for intrarater reliability and agreement during rest, submaximal exercise and high-intensity interval exercise. Twenty healthy adults (age: 26±4 years) completed two identical trials beginning with five minutes of rest followed by two 5-minute submaximal cycling bouts at 50% and 70% of peak power output. Subjects then completed ten 30-second cycling intervals at 90% of peak power output interspersed with 60 s of passive recovery. Bioimpedance cardiography (PhysioFlow; Manatec Biomedical, France) monitored heart rate, stroke volume, cardiac output, stroke volume index, cardiac index, ventricular ejection time, contractility index, ejection fraction, left cardiac work index, end diastolic volume, early diastolic filling ratio, systemic vascular resistance and systemic vascular resistance index continuously throughout both trials. Intraclass correlation coefficients (ICC), standard errors of measurement and minimal detectable differences were calculated for all variables. Heart rate, stroke volume, cardiac output, left cardiac work index and end diastolic volume demonstrated a good level of reliability (ICC>.75) at rest, during submaximal exercise and high-intensity interval exercise. All other variables demonstrated inconsistent reliability across activity types and intensities. When using the PhysioFlow device, heart rate, stroke volume, cardiac output, left cardiac work index and end diastolic volume were deemed acceptable for use regardless of exercise type (continuous vs. interval) or intensity (low, moderate, or high). However, other variables measured by this device appear less reliable

Brain weight differences associated with induced focal microgyria

BACKGROUND: Disrupting neural migration with bilateral focal freezing necrosis on postnatal day 1 (P1) results in the formation of 4-layered microgyria. This developmental injury triggers a pervasive neural reorganization, which is evident at the electrophysiological, behavioral, and anatomical levels. In this experiment, we investigated changes in brain weight as an index of global disruption of neural systems caused by focal damage to the developing cortical plate. RESULTS: We found a dramatic reduction in overall brain weight in microgyric subjects. This reduction in brain weight among animals with microgyria is reflected in decreased total brain volume, with a disproportionate decrease in neocortical volume. This effect is so robust that it is seen across varied environments, at variable ages, and across the sexes. CONCLUSIONS: This finding supports previous work suggesting that substantial reorganization of the brain is triggered by the induction of bilateral freezing damage. These results have critical implications for the profound re-organizational effects of relatively small focal injuries early in development to distributed systems throughout the brain, and particularly in the cerebral cortex

Effect of water immersion temperature on heart rate variability following exercise in the heat

This study compared the effect of passive rest (CON) and water immersion at 8.6±0.2°C (CWI9), 14.6±0.3°C (CWI15) and 35.0±0.4°C (thermoneutral water immersion [TWI]) on post-exercise heart rate variability (HRV) indices. In a climate chamber (32.8±0.4°C, 32±5% relative humidity), nine men completed 25 min of cycling at the first ventilatory threshold and repeated 30-second bouts at 90% of peak power followed by a 5-minute recovery treatment in a randomised crossover manner. All water immersion re-established the HRV indices (natural logarithm of the square root of the mean sum squared differences between RR intervals [ln rMSSD], low-frequency [lnLF] and high-frequency power densities [lnHF] and Poincaré plotderived measures [lnSD1 and lnSD2]) to the pre-exercise levels at 60 min post immersion; however, only CWI9 accelerated parasympathetic reactivation during immersion. CWI9 increased lnLF and lnSD2 during immersion when compared with CON (p0.80) on all HRV indices during immersion when compared with CON, between-conditions differences were observed only in lnLF and lnSD2 (p=.017-.023). CWI15 had a large positive ES on ln rMSSD and lnSD1 when compared with CON (both p=.064). Sympathovagal antagonism (i.e., SD ratio<0.15) did not occur during CWI9 and CWI15. Hence, both CWI treatments are effective means of enhancing post-exercise parasympathetic reactivation, but CWI9 is likely to be more effective at increasing post-exercise cardiac vagal tone

Effect of water immersion temperature on heart rate variability following exercise in the heat

This study compared the effect of passive rest (CON) and water immersion at 8.6±0.2°C (CWI9), 14.6±0.3°C (CWI15) and 35.0±0.4°C (thermoneutral water immersion [TWI]) on post-exercise heart rate variability (HRV) indices. In a climate chamber (32.8±0.4°C, 32±5% relative humidity), nine men completed 25 min of cycling at the first ventilatory threshold and repeated 30-second bouts at 90% of peak power followed by a 5-minute recovery treatment in a randomised crossover manner. All water immersion re-established the HRV indices (natural logarithm of the square root of the mean sum squared differences between RR intervals [ln rMSSD], low-frequency [lnLF] and high-frequency power densities [lnHF] and Poincaré plotderived measures [lnSD1 and lnSD2]) to the pre-exercise levels at 60 min post-immersion; however, only CWI9 accelerated parasympathetic reactivation during immersion. CWI9 increased lnLF and lnSD2 during immersion when compared with CON (p\u3c.05). Although CWI9 had a large positive effect size (ES\u3e0.80) on all HRV indices during immersion when compared with CON, between-conditions differences were observed only in lnLF and lnSD2 (p=.017-.023). CWI15 had a large positive ES on ln rMSSD and lnSD1 when compared with CON (both p=.064). Sympathovagal antagonism (i.e., SD ratio\u3c0.15) did not occur during CWI9 and CWI15. Hence, both CWI treatments are effective means of enhancing post-exercise parasympathetic reactivation, but CWI9 is likely to be more effective at increasing post-exercise cardiac vagal tone