Nonparametric Test for Volatility in Clustered Multiple Time Series.

Contagion arising from clustering of multiple time series like those in the stock market indicators can further complicate the nature of volatility, rendering a parametric test (relying on asymptotic distribution) to suffer from issues on size and power. We propose a test on volatility based on the bootstrap method for multiple time series, intended to account for possible presence of contagion effect. While the test is fairly robust to distributional assumptions, it depends on the nature of volatility. The test is correctly sized even in cases where the time series are almost nonstationary (i.e., autocorrelation coefficient ≈1). The test is also powerful specially when the time series are stationary in mean and that volatility are contained only in fewer clusters. We illustrate the method in global stock prices data.

Corrigendum to "Effects of Canned Pineapple Consumption on Nutritional Status, Immunomodulation, and Physical Health of Selected School Children".

[This corrects the article DOI: 10.1155/2014/861659.].

Effects of Nutrient-Fortified Milk-Based Formula on the Nutritional Status and Psychomotor Skills of Preschool Children.

This randomized, single-masked, controlled trial examined the effects of nutrient-fortified milk-based formula supplementation on nutritional status, nutrient intake, and psychomotor skills of selected preschool children with mean age of 4.10 ± 0.14 years. The study participants were divided equally into three major groups, normal, underweight, and severely underweight based on WHO-Child Growth Standards, and were further divided into two groups: fortified milk group who was given two glasses of fortified milk (50 g of powdered milk/serving) a day for twelve weeks in addition to their usual diet and the nonintervention group who was not given fortified milk and thus maintained their usual intake. Anthropometric measurements, dietary intake, and psychomotor developmental score were analyzed. Results showed that consumption of two servings of fortified milk a day for twelve weeks significantly increased the height of preschool children by 1.40 cm, weight by 1.35 kg, body mass index by 0.96 kg/m2, mid-upper arm circumference by 0.66 cm, and psychomotor scores by 13.74% more than those children who did not consume fortified milk (p < 0.0001). Hence, fortified milk-based supplement in the diet of preschool children improved overall nutritional status, nutrient intake, and performance in psychomotor scale. This study is registered in Philippine Health Research Registry: PHRR140923-000234.

Effects of canned pineapple consumption on nutritional status, immunomodulation, and physical health of selected school children.

This randomized, controlled trial examined the effects of canned pineapple consumption on immunomodulation, nutritional status, and physical health of ninety-eight (98) school children with mean age of 8.44 ± 0.20. The study participants were divided into three groups: Group A (33) includes subjects who were not given canned pineapple, Group B (33) includes those who were given 140 g, and Group C (32) includes those given 280 g of canned pineapple for nine weeks. Each major group was further divided into two groups: normal (N) and underweight (U) based on 2007 WHO Growth Reference Standards. Sociodemographic, anthropometric, physical examination, dietary intake, hemoglobin level, and immunological data were analyzed. Results showed a decrease in incidence of viral and bacterial infections for both Group B and Group C (normal and underweight) after canned pineapple consumption. Granulocyte production increased by 0.77-26.61% for normal weight subjects and 14.95-34.55% for underweight. CD16+56 count augmented by 20.44-22.13% for normal weight and 3.57-15.89% for underweight subjects. Thus, intake of both one can (140 g) and two cans (280 g) of canned pineapple may shorten the duration and incidence of infection and may increase the production of granulocytes and CD16+56, but intake of two cans (280 g) demonstrated higher granulocyte and CD16+56 production. This trial is registered with Philippine Health Research Registry: PHRR140826-000225.

Glycaemic response to quality protein maize grits.

Background. Carbohydrates have varied rates of digestion and absorption that induces different hormonal and metabolic responses in the body. Given the abundance of carbohydrate sources in the Philippines, the determination of the glycaemic index (GI) of local foods may prove beneficial in promoting health and decreasing the risk of diabetes in the country. Methods. The GI of Quality Protein Maize (QPM) grits, milled rice, and the mixture of these two food items were determined in ten female subjects. Using a randomized crossover design, the control bread and three test foods were given on separate occasions after an overnight fast. Blood samples were collected through finger prick at time intervals of 0, 15, 30, 45, 60, 90, and 120 min and analyzed for glucose concentrations. Results. The computed incremental area under the glucose response curve (IAUC) varies significantly across test foods (P < .0379) with the pure QPM grits yielding the lowest IAUC relative to the control by 46.38. Resulting GI values of the test foods (bootstrapped) were 80.36 (SEM 14.24), 119.78 (SEM 18.81), and 93.17 (SEM 27.27) for pure QPM grits, milled rice, and rice-QPM grits mixture, respectively. Conclusion. Pure QPM corn grits has a lower glycaemic response compared to milled rice and the rice-corn grits mixture, which may be related in part to differences in their dietary fibre composition and physicochemical characteristics. Pure QPM corn grits may be a more health beneficial food for diabetic and hyperlipidemic individuals.

Effect of iodine status and other nutritional factors on psychomotor and cognitive performance of Filipino schoolchildren.

BACKGROUND: Until 1998, iodine deficiency was a public health problem in the Philippines. A law entitled "An Act Promoting Salt Iodization Nationwide" (ASIN) has been passed and implemented by the government to eliminate iodine deficiency. The contribution of salt iodization, as well as dietary, health, and environmental factors, to improving the intellectual performance of Filipino schoolchildren remains to be determined. OBJECTIVE: The objectives of the study were to determine the relationship between iodine status and levels of psychomotor and cognitive performance in first-grade children aged 6 to 10 years, and to examine the extent to which dietary, biochemical, health, and environmental factors contribute to children's mental performance. METHODS: Two hundred ninety children in six classroom sections from a public school in Manila were examined by measurement of urinary iodine excretion (UIE) and thyroid palpation. The median UIE level for each section was determined. Sixty-five children classified as iodine deficient (UIE < 90 microg/L with grade 1 goiter, n = 34) and non-iodine deficient (UIE > 100 microg/L without goiter, n = 31) were given psychomotor and cognitive function tests (Bender-Gestalt and Raven's Colored Progressive Matrices). Scores from the two tests were used to determine each child's general ability percentile rank. Other variables examined were dietary intake (% RDA of nutrients ingested based on two nonconsecutive 24-hour recalls); deficiencies in iron, vitamin A, and selenium; parasitic infection; coliform contamination of drinking water; household use of iodized salt; illness in the past 2 weeks; and wasting and stunting. RESULTS: Children whose general ability scores were at or above the 50th percentile had higher UIE levels, but the relationship was not significant. Children from sections with higher median UIE levels had higher percentile ranks for general ability (p = .002). Backward logistic regression showed that the variance in deficient and adequate mental performance was explained by dietary intakes that met > or = 80% of the RDA for energy, protein, thiamin, and riboflavin; the use of iodized salt; child's iodine status; and stunting (R2 = .520, p = .0016). Higher class median UIE was associated with better psychomotor and cognitive performance in children who were tested. Factors that contributed to better performance include higher intakes of energy, protein, thiamin, and riboflavin; household use of iodized salt; normal iodine status; and absence of stunting or chronic malnutrition. CONCLUSIONS: Salt iodization, accompanied by adequate intakes of energy, protein, and foods rich in thiamin and riboflavin, can contribute to improved mental performance in Filipino schoolchildren. Longer-term factors that can contribute to improved performance are achievement of normal iodine status and elimination of protein-energy malnutrition.