Shrinking factors of hyperbranched polysaccharide from fungus

The branched structure properties of hyperbranched polysaccharides (TM3a and TM3b), extracted from sclerotia of Pleurotus tuber-regium, were studied by using laser light scattering and viscometry. The configurational shrinking factor (g) and viscometric shrinking factor (g′) of TM3a and TM3b were discussed, where curdlan and pullulan were taken as the linear references for derivation of g and g′. The dependences of g factor, g′ factor, and Flory factor (Φ_branched) on weight average molecular weight (M_w) were established to be g = 1.07 × 10²$M_{\text{w}}^{-0.48\pm 0.09}$, g′ = 3.63 × 10¹$M_{\text{w}}^{-0.43\pm 0.01}$, and Φ_branched = 7.08 × 10²⁰$M_{\text{w}}^{0.39\pm 0.1}$ for TM3a in 0.25 M LiCl/DMSO at 25 °C, when curdlan acted as the linear reference. A power law relationship g′ = 2.71 × 10^?1g^?0.61±0.1 for TM3a was found, and the exponent was approximately same to 0.60 established by Kurata et al. for polystyrene star molecules. The dependence of g factor on M_w for TM3b was found to be g = 1.99 × 10²$M_{\text{w}}^{-0.53\pm 0.02}$, when pullulan was used as the linear reference. On the basis of Zimm–Stockmayer equation for tetrafunctional units, molecular weight of branching unit (M₀) deduced from nonlinear curve fitting of g versus M_w was 8739 ± 564 g/mol and 3961 ± 1245 g/mol for TM3a and TM3b, respectively. The effect of different linear reference curves and polydispersity was discussed. This work gave valuable information on branched structure characterization and insights into the biosynthetic pathways of the hyperbranched polysaccharide from fungus.     

Factors influencing diurnal variation in height among adults

This study evaluates height loss during the day in light of variables assessable through participant self-report. Participants were 19 female and 15 male staff and students who met with us twice with a mean interval between measurement sessions of 6.96 h (SD = 0.86). Hypotheses were evaluated using two-stage least squares regression analysis (SYSTAT 10). Males and females lost similar amounts of height between sessions $(\text{male},\overline{x}=6.9\text{mm};\text{female},\overline{x}=7.4\text{mm})$. Among factors considered to impact overall height loss, sleep duration (Adj. R² = 0.181, p = 0.022) and height (Adj. R² = 0.121, p = 0.048) were useful in univariate analyses, though they were not significant in any models that included variables other than sex. Judging from log-transformed BMI variation, heavier males and females lost more height (F_{(2, 31)} = 4.59, Adj. R² = 0.179, p = 0.018). Among factors anticipated to reduce height loss by acting prior to morning measurements, only time spent walking was significantly associated (β = 2.6 ± 0.8 mm, t = 3.16, p = 0.004) when included as a predictor along with sex (p = 0.17) and log-BMI (p = 0.003). This model explained about 38% of height loss variance. None of the factors considered as potentially acting between measurement sessions showed statistically significant influences when included in the model just described, though predictor coefficients were in the anticipated direction. Results suggest that self-reported activities may be an important supplement to anthropometric studies, both for planning and later evaluation, particularly in large studies.     

Biological maturity at birth,the course of the subsequent ontogenetic stages and age at menarche

The main aim of the study was to assess the influence of biological maturity at birth on growth processes in the subsequent years and during puberty in girls. The material of this study comes from the outpatient clinic cards and cross-sectional research on girls from the province of Wielkopolska in Poland. It includes data of 527 girls. The influence of perinatal maturity on body weight in the later stages of ontogeny was determined with the use of the Kruskal–Wallis test and the Mann–Whitney U test. In order to determine the relationship between perinatal maturity and age at menarche, the survival analysis module was used.The results show a diverse influence of perinatal maturity on the values of body weight achieved in later years of life. The indicated predictive factors included both birth weight and gestational age. In the examined girls menarche occurred between the 10th year and the 17th year of life $(\overline{X}=12.87$, s = 1.26; Me = 13 years). The comparison showed a significant variation in age at menarche depending on the length of pregnancy (log-rank ${\chi }_2^2=27.068$, p < 0.0001) and birth weight (log-rank ${\chi }_2^2=23.241$, p < 0.0001). There was no variation in maturation of the examined girls conditioned by the occurrence of intra-uterine growth retardation (log-rank ${\chi }_2^2=2.046$, p > 0.05). Remote prognoses as to the postnatal development of preterm-born children and/or children with low birth weight indicate adverse influence of these variables on age at menarche. Perinatal biological maturity of a newborn conditions the course of postnatal development.     

The effect of ice-slushy consumption on plasma vasoactive intestinal peptide during prolonged exercise in the heat

The aim of this study was to determine the effect of exercise in the heat on thermoregulatory responses and plasma vasoactive intestinal peptide concentration (VIP) and whether it is modulated by ice-slushy consumption. Ten male participants cycled at 62% $\dot{V}{\mathrm{O}}_2$max for 90 min in 32 °C and 40% relative humidity. A thermoneutral (37 °C) or ice-slushy (−1 °C) sports drink was given at 3.5 ml kg⁻¹ body mass every 15 min during exercise. VIP and rectal temperature increased during exercise (mean±standard deviation: 4.6±4.4 pmol L⁻¹, P=0.005; and 1.3±0.4 °C, P<0.001 respectively) and were moderately associated (r=0.35, P=0.008). While rectal temperature and VIP were not different between trials, ice-slushy significantly reduced heat storage (P=0.010) and skin temperature (time×trial interaction P=0.038). It appears that VIP does not provide the signal linking cold beverage ingestion and lower skin temperature in the heat.