3,162 research outputs found

    Parallel Deterministic and Stochastic Global Minimization of Functions with Very Many Minima

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    The optimization of three problems with high dimensionality and many local minima are investigated under five different optimization algorithms: DIRECT, simulated annealing, Spall’s SPSA algorithm, the KNITRO package, and QNSTOP, a new algorithm developed at Indiana University

    On the relationships between the caudal intralaminar nuclei of the thalamus and the basal ganglia : implications for the pathophysiology of Parkinson’s disease

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    Besides corticostriatal projections, the thalamic intralaminar nuclei are a major source of glutamatergic afferents reaching the basal ganglia input nuclei. Although the thalamostriatal system is already well characterized from the anatomical point of view, the role to be played by this pathway within basal ganglia function (both in normal and pathological conditions) remains poorly understood. On one hand, neurode- generation phenomena restricted to the caudal intralaminar nuclei have been described in several neurodegenerative disorders such as Parkinson’s disease, progressive supranuclear palsy and Huntington’s disease. On the other hand, after unilateral dopaminergic depletion in rodents the caudal intralaminar nuclei are highly hyperactive. Indeed, the chemical ablation of the caudal intralaminar nuclei prevents the increase of the activity observed in both the basal ganglia output nuclei and the subthalamic nucleus (STN) after unilateral dopaminergic depletion. These findings suggest that the caudal intralaminar nuclei might be responsible (at least partially) for the changes in activity of the STN and basal ganglia output nuclei typically seen under circumstances of dopamine removal. These results paved the way for the implementation of pioneer clinical experiences focused on targeting the caudal intralaminar nuclei with a deep brain stimulation electrode in patients suffering from advanced Parkinson’s disease. This approach resulted in the alleviation of cardinal symptoms of the disease such as resting tremor, druginduced dyskinesias and chronic pain.peer-reviewe

    Prevalence and Predictors of Household Food Insecurity among Adult/Youth Dyads at the Initiation of the iCook 4-H Two-Year Obesity Prevention Study

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    Objective: Determine food insecurity prevalence and predictors among adult/youth dyads enrolled in a childhood obesity prevention study (iCook 4-H).Methods: The iCook 4-H intervention was designed for youth (9-10 years old) and their adult main meals preparer to cook, eat, and play together. Although not an inclusion criteria, diverse, low income, and/or rural families were the target during recruitment. At baseline, adults completed surveys on food insecurity, socioeconomic and demographic characteristics and youth anthropometrics were collected with body mass index (BMI) calculated. Descriptive statistics were computed and chi-square analysis was conducted to test differences between potential predictors and food insecurity. Binomial logistic regression was used to assess the relationship between food insecurity and its predictors.Results: Thirty-four percent of households (n=71 of 206) were food insecure. Youth were primarily white (69.9%) and normal weight (58.3%). Adults were also primarily white (74.8%), overweight or obese (67.9%), married (68.9%), not participating in government assistance programs (57.8%), and held no college degree (55.3%). Based on the logistic regression model, households with a non-white youth (OR=13.53; 95% CI=3.33, 55.05), an adult without a college degree (OR=5.62; 95% CI=2.01, 15.73), and government assistance program participation (OR=5.63; 95% CI=2.63, 12.07) were significantly associated with household food insecurity. However, there was no significant association with BMI found (youth p=0.167; adult p=0.179).Conclusion: Consistent with previous findings, household food insecurity status was associated with youth race, adult education, and government assistance program participation. In contrast, no relationship between BMI and food insecurity status was observed in this study, which warrants further investigation

    Effect of Sparse-Build Internal Structure on Performance of Fused Deposition Modeling Tools under Pressure

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    Two different approaches to design a sparse-build tool for fabrication by the fused deposition modeling (FDM) process are compared. One approach uses a 2D lattice structure and the other approach is inspired by topology optimization. Ultem 9085 is used as the material, and the amount of material used to build the tool is kept constant to ensure a fair comparison. A solid tool is also included in the comparison. The performance of the tool under uniform pressure is simulated using finite element analysis (FEA) and the accuracy of the FEA results is verified by comparing them with experimentally measured data for a similar tool. The build material, support material, build time, maximum displacement, and maximum von Mises stress are compared for the three build approaches, with an emphasis on the pros and cons of each sparsebuild tool with regards to performance under uniform pressure and fabrication by FDM

    The Effect of iCook 4-H, a Childhood Obesity Prevention Program, on Blood Pressure and Quality of Life in Youth and Adults: A Randomized Control Trial

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    Objective: Obesity increases the risk of developing hypertension and from population-based samples with estimations that of 2-4% of the U.S. pediatric population has hypertension, which may affect quality of life. This study examined the effects of an obesity prevention program on blood pressure and quality of life in youth and adult participants. Methods: A multi-state research team recruited treatment dyads (youth and their adult meal preparer) to participate in a 12-week randomized control trial and follow-up through 24 months. The treatment group received a cooking and physical activity intervention, followed by booster sessions and mailed newsletters over the remaining two-year period. The control group received no intervention. Resting blood pressure and health related quality of life (HRQOL) surveys were administered at 0,4,12 and 24 months. Results: 228 dyads were recruited (n=77 control and n=151 for treatment). Youth and adult systolic blood pressure (SBP) increased over the 24 months (p=0.003 and p=0.03, respectively) with no differences between groups. From baseline to 24 months both control and treatment youths’ physical and psychological HRQOL increased (p=0.01 and p=0.002, respectively). At 0 and 4 months, youth and adult SBP was positively correlated (r=0.24, p=0.003 and r=0.33, p\u3c0.001, respectively). In the treatment group, there was an inverse association between adult SBP and youth psychological HRQOL at 4 months (r=-0.20, p=0.04), and a similar trend in adult SBP and youth physical HRQOL at 4 months in the treatment group (r=-0.19, p=0.05). Conclusion: A youth-adult dyad obesity prevention program consisting of culinary, mealtime and physical activity education, elicited improvements in HRQOL in youth participants

    High yielding biomass ideotypes of willow (Salix spp.) show differences in below ground biomass allocation.

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    Willows (Salix spp.) grown as short rotation coppice (SRC) are viewed as a sustainable source of biomass with a positive greenhouse gas (GHG) balance due to their potential to fix and accumulate carbon (C) below ground. However, exploiting this potential has been limited by the paucity of data available on below ground biomass allocation and the extent to which it varies between genotypes. Furthermore, it is likely that allocation can be altered considerably by environment. To investigate the role of genotype and environment on allocation, four willow genotypes were grown at two replicated field sites in southeast England and west Wales, UK. Above and below ground biomass was intensively measured over two two-year rotations. Significant genotypic differences in biomass allocation were identified, with below ground allocation differing by up to 10% between genotypes. Importantly, the genotype with the highest below ground biomass also had the highest above ground yield. Furthermore, leaf area was found to be a good predictor of below ground biomass. Growth environment significantly impacted allocation; the willow genotypes grown in west Wales had up to 94% more biomass below ground by the end of the second rotation. A single investigation into fine roots showed the same pattern with double the volume of fine roots present. This greater below ground allocation may be attributed primarily to higher wind speeds, plus differences in humidity and soil characteristics. These results demonstrate that the capacity exists to breed plants with both high yields and high potential for C accumulation

    Mineralogy of Vera Rubin Ridge in Gale Crater from the Mars Science Laboratory CheMin instrument

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    Gale crater was selected as the landing site for the Mars Science Laboratory Curiosity rover because of orbital evidence for a variety of secondary minerals in the lower slopes of Aeolis Mons (aka Mount Sharp) that indicate changes in aqueous conditions over time. Distinct units demonstrate orbital spectral signatures of hematite, phyllosilicate (smectite), and sulfate minerals, which suggest that ancient aqueous environments in Gale crater varied in oxidation potential, pH, and water activity. Vera Rubin ridge (VRR) is the first of these units identified from orbit to have been studied by Curiosity. Orbital near-infrared data from VRR show a strong band at 860 nm indicative of hematite. Before Curiosity arrived at VRR, the hypotheses to explain the formation of hematite included (1) precipitation at a redox interface where aqueous Fe2+ was oxidized to Fe3+, and (2) acidic alteration of olivine in oxic fluids. Studying the composition and sedimentology of the rocks on VRR allow us to test and refine these hypotheses and flesh out the depositional and diagenetic history of the ridge. Here, we focus on the mineralogical results of four rock powders drilled from and immediately below VRR as determined by CheMin

    Quality of Life Associated with Physical Activity but not Sedentary Time in Youth

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    Purpose: It has been reported that youth who engaged in more screen time had lower quality of life scores compared to those that were more physically active. Furthermore, increased sedentary behavior increases health risks particularly the risk for obesity. A cross-sectional analysis was completed to examine the relationship between healthrelated quality-of-life (HRQOL) and accelerometer-measured sedentary time (ST) and physical activity (PA) in 9-10-yearold youth who were recruited for the family-based, childhood obesity intervention, iCook 4-H. It was hypothesized that objectively measured ST would be negatively correlated and PA would be positively correlated with HRQOL.Methods: A subset of participants (n=118) wore Actigraph GT3X+ accelerometers for 7 days and completed the Pediatric Quality of Life survey (PedsQLTM, version 4.0) to assess HRQOL. Mean daily minutes of accelerometermeasured ST (547 ± 60) and PA including light-intensity (LPA=240 ± 49), moderate-intensity (MPA=35 ± 11), vigorous-intensity (VPA=17 ± 9), and moderate-to vigorousintensity (MVPA=52 ± 19) were evaluated during waking hours. Multiple linear regressions were used to assess relationship between ST and PA intensities with HRQOL. Statistical significance was set at p ≀ 0.05.Results: There were no significant associations between ST or LPA with HRQOL. MPA, VPA and MVPA were positively associated with multiple HRQOL domains.Conclusion: The lack of relationship between objectively measured ST and LPA with the total HRQOL score and subscales merits further investigation. The findings of the current study support the need for lifestyle interventions that engage families in behavior that increases MVPA
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