Calcium supplementation for the prevention of pre-eclampsia: Challenging the evidence from meta-analyses.

OBJECTIVE: To investigate the validity of the conclusion from Cochrane reviews and meta-analyses that treatment with calcium supplementation during pregnancy reduces the risk for pre-eclampsia by 55%, which has been influential in international guidelines and future research. DESIGN: Sensitivity analysis of data from Cochrane reviews of trials evaluating high-dose calcium supplementation (of at least 1 g/day) for reduction of pre-eclampsia risk. SETTING: Systematic review and meta-analysis. POPULATION: The Cochrane reviews and meta-analyses included 13 trials enrolling a total of 15 730 women. Random-effects meta-analysis of these studies resulted in a mean risk ratio (RR, calcium/placebo) of 0.45 (95% confidence interval [CI] 0.31-0.65; p < 0.0001). METHODS: We carried out a sensitivity analysis of evidence from the relevant Cochrane review, to examine the impact of study size. MAIN OUTCOME MEASURES: pre-eclampsia. RESULTS: In the three largest studies, accounting for 13 815 (88%) of total recruitment, mean RR was 0.92 (95% CI 0.80-1.06) and there was no evidence of heterogeneity between studies (I2 = 0). With inclusion of the smaller studies, mean RR decreased to 0.45 and I2 increased to 70%. CONCLUSIONS: In assessment of the effect of calcium supplementation on pre-eclampsia risk, the naive focus on the mean of the random-effects meta-analysis in the presence of substantial heterogeneity is highly misleading.

Dietary Supplement Use in US Army Personnel: A Mixed-Methods, Survey and Focus-Group Study Examining Decision Making and Factors Associated With Use.

BACKGROUND: Dietary supplement (DS) use by Army personnel is high and is a safety and readiness issue. OBJECTIVE: Our aim was to examine factors motivating use of DSs among US Army personnel and preferred safety education strategies. DESIGN: This mixed-method study used a validated DS questionnaire and subsequent focus groups that were formed based on questionnaire-identified demographic characteristics. An embedded qualitative dominant design was used. PARTICIPANTS/SETTING: Data were collected from April to July 2015 from active duty soldiers at 3 military installations in the United States. MAIN OUTCOME MEASURES: A self-report questionnaire (n = 289) provided data on demographic characteristics, health, exercise, detailed use, and attitudes regarding DS safety and efficacy. Fourteen focus-group sessions (n = 129) examined factors motivating DS use, education strategies, and identified themes and DS-related behaviors. STATISTICAL ANALYSIS PERFORMED: Descriptive statistics and χ2 analyses were conducted. RESULTS: Of the soldiers who completed questionnaires, 83% were male, 60% were enlisted, and 40% were officers; mean age ± standard deviation was 27.6 ± 0.36 years and 75% used at least 1 type of DS per week: 52% used protein/amino acids, 47% used multivitamins/minerals, and 35% used a combination of products. Focus groups indicated reasons for use included physical appearance, fitness, peer endorsement, ease of access, limited availability of healthy food, occupational demands, and health. Participants requested education from an expert on safe use that was not focused on dangerous products. CONCLUSIONS: Soldiers are high DS users, especially products marked for purported performance enhancement. Motivating factors for DS use are fitness/appearance and occupational demands, but soldiers lack knowledge of DS regulatory requirements and safety/efficacy. Soldiers wished to receive education on DSs from trusted health care professionals, such as registered dietitian nutritionists, that was not focused on dangerous products. Study findings suggest guidance and education should occur before periods of high DS use, such as deployment.

Understanding stoichiometric mechanisms of nutrient retention in wetland macrophytes: stoichiometric homeostasis along a nutrient gradient in a subtropical wetland.

Nutrient homeostasis relates ambient stoichiometric conditions in an environment to the stoichiometry of living entities of that ecosystem. Plant nutrient sequestration in wetland ecosystems is a key process for downstream water quality. However, few studies have examined stoichiometric homeostasis of aquatic vegetation despite the importance of stoichiometry to plant nutrient uptake efficiency. This study investigated stoichiometric homeostasis of dominant emergent and submerged aquatic vegetation (EAV and SAV, respectively) within two treatment flow-ways of Everglades Stormwater Treatment Area 2 (STA-2). These flow-ways encompass a large gradient in plant nutrient availability. This study hypothesizes that wetland vegetation is homeostatic relative to ambient nutrients and consequently nutrient resorption does not vary along the nutrient gradient. We developed a framework to investigate how vegetation uptake and resorption of nutrients contribute separately to homeostasis. Overall, we determined that the wetland vegetation in this study was non-homeostatic with respect to differential uptake of nitrogen (N) versus phosphorus (P). In EAV, P resorption was relatively high and N resorption was moderate, and resorption efficiency did not vary significantly along the gradient. In separating the proportional contribution of resorption and uptake to the degree of homeostasis, resorption did not affect overall homeostatic status in EAV.

Estimating the Spatial Distribution of Soil Properties Using Environmental Variables at a Catchment Scale in the Loess Hilly Area, China.

A comprehensive understanding of the spatial distribution and dynamic changes of soil properties are the basis for sustainable land management. Topography and land use types are key factors affecting soil property variability. This study analyzed the effects of land use types and landscape locations on soil properties, based on data from 111 points of surface soil (0⁻20 cm) in the Zhujiagou catchment on the Loess Plateau of Northwest China. Soil properties include clay, silt, bulk density (BD), soil organic matter (SOM), total nitrogen (TN) and total phosphorus (TP). Land use types include slope farmland (SFL), terrace farmland (TFL), check-dam farmland (CDL), woodland (WL), shrub land (SL) and grassland (GL). Landscape locations include crest (CT), upper slope (US), middle slope (MS), lower slope (LS) and flat valley (FV). Topographical attributes were divided into primary and secondary (or compound) attributes. Correlation analyses were carried out between soil properties and terrain attribute, and multiple-linear regression models were established to estimate soil properties using land use types and topographic attributes as independents. Results indicated that significant differences in soil properties existed between six land use types, except for bulk density. Higher values of clay, silt, SOM and TN occurred in soils from check-dam farmland, but lower values in soils from shrub land. Significant differences among landscape positions were observed for clay, BD, SOM and TN. Clay, SOM and TN contents on flat valley (FV) positions were higher than those of other positions. Different correlations were found between soil properties and terrain attributes. The regression models explained 13% to 63% of the variability of the measured soil properties, and the model for Clay had the highest R² value, followed by TN, silt, BD, SOM and TP. Validation results of the regression models showed that the model was precise for soil bulk density, but the variation was large and a high smoothing effect existed for predicted values of other soil properties. For TP, the predicted result was poor. Further observations suggested that land use was the dominant factor affecting soil chemical properties. But for soil physical properties, especially for BD, topography was the dominant factor.

Personality Traits and Occupational Demands Are Linked to Dietary Supplement Use in Soldiers: A Cross-sectional Study of Sensation Seeking Behaviors.

INTRODUCTION: Military personnel use dietary supplements (DS) more frequently and in a higher quantity than the general population. Patterns of DS used and the motivation for use among the military population are different than those of the civilian population. Soldiers are much more likely to use potentially dangerous DS purported to enhance physical performance and/or promote weight loss in spite of limited evidence regarding the safety and efficacy of these products. Sensation seeking (SS) behaviors can be associated with risky lifestyle behaviors and may be associated with use of DS by Soldiers. This study assessed Soldiers' SS behaviors in relation to DS use and various demographic factors. MATERIALS AND METHODS: Demographic and behavioral questionnaires were administered to 289 Soldiers (mean ± SD, 28 ± 6 years, 27 ± 3 kg/m2 BMI, 83% male) at three U.S. military installations. The Brief SS Scale (four 10-point subscales) and Arnett Inventory of SS (two 40-point subscales) were used to assess SS behaviors. Independent sample t-tests determined the significant differences between SS subscale scores of DS users and non-users for each type of DS (i.e., protein, multivitamin, etc.). One-way analysis of variances and Tukey's post hoc comparisons assessed differences in SS scores across demographic categories. Tukey's post hoc analyses assessed SS scores between users and non-users within the DS categories. RESULTS: Overall, 75% of Soldiers used DS ≥1 time/week. The most frequently used DS were protein/amino acids (52%), multivitamins/multiminerals (47%), "other" supplements (43%), and combination products (35%). Overall, DS users scored higher in experience seeking (8.0 ± 1.7 vs 7.5 ± 2.0; p < 0.05) and novelty (28.4 ± 3.7 vs 26.8 ± 4.7; p < 0.05) than non-users. Protein/amino acid users scored higher than non-users for all six SS traits: experience seeking (p < 0.001), boredom susceptibility (p < 0.001), thrill seeking (p < 0.001), disinhibition (p < 0.01), novelty (p < 0.001), and intensity (p < 0.001). Users of bodybuilding DS scored higher than non-users in four of the six SS traits: boredom susceptibility (p < 0.05), thrill seeking (p < 0.001), disinhibition (p < 0.01), and intensity (p < 0.001). CONCLUSIONS: Soldiers who use DS that are frequently associated with health risks scored higher for sensation-seeking characteristics which are predictors of risky behaviors. Protein/AA and combination product DS users scored higher in sensation-seeking traits and this may be due to underestimation of risk, anticipation of positive outcomes, and/or high levels of confidence in these types of DS by high sensation seekers. Additional investigation into the association of sensation-seeking behaviors as predictors of harmful DS use is warranted.

Wading bird guano enrichment of soil nutrients in tree islands of the Florida Everglades.

Differential distribution of nutrients within an ecosystem can offer insight of ecological and physical processes that are otherwise unclear. This study was conducted to determine if enrichment of phosphorus (P) in tree island soils of the Florida Everglades can be explained by bird guano deposition. Concentrations of total carbon, nitrogen (N), and P, and N stable isotope ratio (δ(15)N) were determined on soil samples from 46 tree islands. Total elemental concentrations and δ(15)N were determined on wading bird guano. Sequential chemical extraction of P pools was also performed on guano. Guano contained between 53.1 and 123.7 g-N kg(-1) and 20.7 and 56.7 g-P kg(-1). Most of the P present in guano was extractable by HCl, which ranged from 82 to 97% of the total P. Total P of tree islands classified as having low or high P soils averaged 0.71 and 40.6 g kg(-1), respectively. Tree island soil with high total P concentration was found to have a similar δ(15)N signature and total P concentration as bird guano. Phosphorus concentrations and δ(15)N were positively correlated in tree island soils (r = 0.83, p< 0.0001). Potential input of guano with elevated concentrations of N and P, and (15)N enriched N, relative to other sources suggests that guano deposition in tree island soils is a mechanism contributing to this pattern.

Impact of a multi-nutrient diet on cognition, brain metabolism, hemodynamics, and plasticity in apoE4 carrier and apoE knockout mice.

Lipid metabolism and genetic background together strongly influence the development of both cardiovascular and neurodegenerative diseases like Alzheimer's disease (AD). A non-pharmacological way to prevent the genotype-induced occurrence of these pathologies is given by dietary behavior. In the present study, we tested the effects of long-term consumption of a specific multi-nutrient diet in two models for atherosclerosis and vascular risk factors in AD: the apolipoprotein ε4 (apoE4) and the apoE knockout (apoE ko) mice. This specific multi-nutrient diet was developed to support neuronal membrane synthesis and was expected to contribute to the maintenance of vascular health. At 12 months of age, both genotypes showed behavioral changes compared to control mice and we found increased neurogenesis in apoE ko mice. The specific multi-nutrient diet decreased anxiety-related behavior in the open field, influenced sterol composition in serum and brain tissue, and increased the concentration of omega-3 fatty acids in the brain. Furthermore, we found that wild-type and apoE ko mice fed with this multi-nutrient diet showed locally increased cerebral blood volume and decreased hippocampal glutamate levels. Taken together, these data suggest that a specific dietary intervention has beneficial effects on early pathological consequences of hypercholesterolemia and vascular risk factors for AD.

Compost impacts on dissolved organic carbon and available nitrogen and phosphorus in turfgrass soil.

Compost application to turfgrass soils may increase dissolved organic C (DOC) levels which affects nutrient dynamics in soil. The objectives of this study were to investigate the influence of compost source and application rate on soil organic C (SOC), DOC, NO(3), and available P during 29 months after a one-time application to St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] turf. Compost sources had variable composition, yet resulted in few differences in SOC, DOC, and NO(3) after applied to soil. Available NO(3) rapidly decreased after compost application and was unaffected by compost source and application rate. Available P increased after compost application and exhibited cyclical seasonal patterns related to DOC. Compost application decreased soil pH relative to unamended soil, but pH increased during the course of the study due to irrigation with sodic water. Increasing the compost application rate increased SOC by 3 months, and levels remained fairly stable to 29 months. In contrast, DOC continued to increase from 3 to 29 months after application, suggesting that compost mineralization and growth of St. Augustinegrass contributed to seasonal dynamics. Dissolved organic C was 75%, 78%, and 101% greater 29 months after application of 0, 80, and 160 Mg compostha(-1), respectively, than before application. Impacts of composts on soil properties indicated that most significant effects occurred within a few months of application. Seasonal variability of SOC, DOC, and available P was likely related to St. Augustinegrass growth stages as well as precipitation, as declines occurred after precipitation events.