195 research outputs found
Hierarchical Poly Tree Configurations for the Solution of Dynamically Refined Finte Element Models
This paper demonstrates how a multilevel substructuring technique, called the Hierarchical Poly Tree (HPT), can be used to integrate a localized mesh refinement into the original finite element model more efficiently. The optimal HPT configurations for solving isoparametrically square h-, p-, and hp-extensions on single and multiprocessor computers is derived. In addition, the reduced number of stiffness matrix elements that must be stored when employing this type of solution strategy is quantified. Moreover, the HPT inherently provides localize 'error-trapping' and a logical, efficient means with which to isolate physically anomalous and analytically singular behavior
Estimation of the Normal Boiling Points of Haloalkanes Using Molecular Similarity
A molecular similarity measure has been used to estimate the normal
boiling points of a set of 267 haloalkanes with 1-4 carbon atoms.
Molecular similarity/dissimilarity was quantified in terms of Euclidean distances of molecules in the eight dimensional principal component space derived from fifty-nine topological indices. Correlation coefficients between the experimental and estimated boiling points ranged from 0.854 to 0.943 in the K-nearest neighbor estimation of boiling points using a different number of nearest neighbors (K = 1-10, 15, 20, 25)
Interrelationship of Major Topological Indices Evidenced by Clustering
This study examines the mutual relatedness of 318 major topological indices (TIs) for three sets of molecules: (i) a set of 139 hydrocarbons, (ii) a diverse set of 1029 compounds and (iii) a diverse set of 2887 compounds. The TIs included in this study are those that have been frequently used in the characterization of structure and QSAR/ QSPR studies. After variable reduction based on the elimination of TIs for which all values were zero and those that were completely correlated with another TI, a variable clustering technique was used to cluster the TIs which resulted in 16, 37 and 56 clusters, respectively, for the three data sets mentioned above. Analysis of the correspondence among the clusters derived from the three groups of chemicals has been carried out in an effort to understand the dimensionality of the structure spaces derived for the three different sets of chemicals and the structural aspects characterized by the various TIs
Efficacy and tolerability of darunavir/r 600/100 mg bid in treatment-experienced patients: 48-week data from a German outpatient cohort
Depressive Symptoms and Weight Status Among Women Recently Immigrating to the US
Objectives Depressive symptoms have been associated with obesity. Little is known about this relationship among immigrants. We examined relationships between depressive symptoms and weight status in immigrant women from three ethnic groups.
Methods Participants were Brazilian, Haitian, and Latina women (n = 345) enrolled in Live Well, a community-based, randomized intervention designed to prevent weight gain in recent immigrants. Study data are from baseline when participants completed the Center for Epidemiological Studies Depression Scale (CES-D), Perceived Stress Scale, a physical activity questionnaire, and socio-demographic questions; BMI was calculated from measured height and weight.
Results Forty-four percent of participants (36 % of Brazilians, 66 % of Haitians, 30 % of Latinas) had high depressive symptoms (CES-D ≥ 16), and 38 % (26 % of Brazilians, 49 % of Haitians, 42 % of Latinas) were obese (BMI ≥ 30.0). Those reporting more depressive symptoms were more likely to be obese (Wald Chi square = 4.82, p \u3c .05). An interaction between depressive symptoms, ethnic group, and income was revealed (F(4,340) = 2.91, p \u3c .05), such that higher depressive symptoms were associated with higher BMI among Brazilians earning ≥30,000. The relationship between depressive symptoms and obesity did not differ by income among Haitians or Latinas.
Conclusions Depressive symptoms and obesity were highly prevalent among these recently-immigrated women. Positive relationships between these variables were consistent across ethnic and income groups, with the exception of lower-income Brazilians. While these findings suggest similar patterns and health needs across several groups of immigrants, cultural differences should be considered when addressing these health conditions
Use of Statistical and Neural Net Approaches in Predicting Toxicity of Chemicals
Hierarchical quantitative structure-activity relationships (H-QSAR) have been developed as a new approach in constructing models for estimating physicochemical, biomedicinal, and toxicological properties of interest. This approach uses increasingly more complex molecular descriptors in a graduated approach to model building. In this study, statistical and neural network methods have been applied to the development of H-QSAR models for estimating the acute aquatic toxicity (LC 50 ) of 69 benzene derivatives to Pimephales promelas (fathead minnow). Topostructural, topochemical, geometrical, and quantum chemical indices were used as the four levels of the hierarchical method. It is clear from both the statistical and neural network models that topostructural indices alone cannot adequately model this set of congeneric chemicals. Not surprisingly, topochemical indices greatly increase the predictive power of both statistical and neural network models. Quantum chemical indices also add significantly to the modeling of this set of acute aquatic toxicity data
The HERMES Back Drift Chambers
The tracking system of the HERMES spectrometer behind the bending magnet
consists of two pairs of large planar 6-plane drift chambers. The design and
performance of these chambers is described. This description comprises details
on the mechanical and electronical design, information about the gas mixture
used and its properties, results on alignment, calibration, resolution, and
efficiencies, and a discussion of the experience gained through the first three
years of operation.Comment: 21 pages, LaTex, 16 figures include
Low demanding parental feeding style is associated with low consumption of whole grains among children of recent immigrants
We explored the influence of immigrant mothers feeding style on their children\u27s fruit, vegetable and whole grain intake and how this relationship differed by mother\u27s time in the U.S. Baseline data were collected on mother-child (3–12 yrs) dyads enrolled in Live Well (n = 313), a community-based, participatory, randomized controlled lifestyle intervention (2008–2013). Socio-demographics, years of residence in the U.S., behavioral data, and responses to the Caregiver\u27s Feeding Styles Questionnaire (CFSQ) were obtained from the mother. Measured heights and weights were obtained for both mother and child. Child dietary intake was assessed using the Block Food Screener. Separate multiple linear regression models were run, adjusting for child and mother covariates. Interactions between feeding styles and years in the U.S. (\u3c5 and ≥ 5 years), ethnicity, and child age were tested. Sixty-nine percent of mothers were overweight or obese, 46% of the children were overweight or obese. For mothers in the U.S. for \u3c 5 years, having a low demanding/high responsive style was associated with lower child intake of whole grains in adjusted models vs. a high demanding/high responsive style (p \u3c 0.05). This was not seen for mothers in the U.S. for ≥ 5 years. Thus, the influence of feeding style on dietary intake may change with length of time in the U.S. These hypotheses-generating findings call for future research to understand how broader socio-cultural factors influence the feeding dynamic among immigrants
Feeding styles and child weight status among recent immigrant mother-child dyads
Background:
Research has shown that parental feeding styles may influence children’s food consumption, energy intake, and ultimately, weight status. We examine this relationship, among recent immigrants to the US. Given that immigrant parents and children are at greater risk for becoming overweight/obese with increased time in the US, identification of risk factors for weight gain is critical.
Methods:
Baseline data was collected on 383 mother-child dyads enrolled in Live Well, a community-based, participatory, randomized controlled lifestyle intervention to prevent weight gain in recent immigrant mothers. Socio-demographic information together with heights and weights were collected for both mother and child. Acculturation, behavioral data, and responses to the Caregiver’s Feeding Styles Questionnaire (CFSQ) were also obtained from the mother.
Results:
The children’s average age was 6.2 ± 2.7 years, 58% male. Mothers had been in the country for an average of 6.0 ± 3.3 years, and are Brazilian (36%), Haitian (34%) and Latino (30%). Seventy-two percent of the mothers were overweight/obese, while 43% of the children were overweight/obese. Fifteen percent of mothers reported their feeding style as being high demanding/high responsive; 32% as being high demanding/low responsive; 34% as being low demanding/high responsive and 18% as being low demanding/low responsive. In bivariate analyses, feeding styles significantly differed by child BMIz-score, ethnic group, and mother’s perceived stress. In multiple linear regression, a low demanding/high responsive feeding style was found to be positively associated (ß = 0.56) with a higher child weight as compared to high demanding/high responsive, controlling for known covariates (p = 0.01).
Conclusions:
Most mothers report having a low demanding/high responsive feeding style, which is associated with higher child weight status in this diverse immigrant population. This finding adds to the growing literature that suggests this type of feeding style may be a risk factor for childhood obesity. Further research is needed to help understand the larger socio-cultural context and its influence on feeding dynamics among immigrant families and families of lower incomes. How parents establish a certain feeding style in their home country compared to when they move to the US “obesogenic” environment, should also be explored
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