Design of Optimum Ducts Using an Efficient 3-D Viscous Computational Flow Analysis

Design of fluid dynamically efficient ducts is addressed through the combination of an optimization analysis with a three-dimensional viscous fluid dynamic analysis code. For efficiency, a parabolic fluid dynamic analysis was used. Since each function evaluation in an optimization analysis is a full three-dimensional viscous flow analysis requiring 200,000 grid points, it is important to use both an efficient fluid dynamic analysis and an efficient optimization technique. Three optimization techniques are evaluated on a series of test functions. The Quasi-Newton (BFGS, eta = .9) technique was selected as the preferred technique. A series of basic duct design problems are performed. On a two-parameter optimization problem, the BFGS technique is demonstrated to require half as many function evaluations as a steepest descent technique

Exploring Aerosols near Clouds with High-Spatial-Resolution Aircraft Remote Sensing During SEAC4RS

Since aerosols are important to our climate system, we seek to observe the variability of aerosol properties within cloud systems. When applied to the satelliteborne Moderateresolution Imaging Spectroradiometer (MODIS), the Dark Target retrieval algorithm provides global aerosol optical depth (AOD; at 0.55 m) in cloudfree scenes. Since MODIS' resolution (500m pixels, 3 or 10km product) is too coarse for studying nearcloud aerosol, we ported the Dark Target algorithm to the highresolution (~50m pixels) enhancedMODIS Airborne Simulator (eMAS), which flew on the highaltitude ER2 during the Studies of Emissions, Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys Airborne Science Campaign over the United States in 2013. We find that even with aggressive cloud screening, the ~0.5km eMAS retrievals show enhanced AOD, especially within 6 km of a detected cloud. To determine the cause of the enhanced AOD, we analyze additional eMAS products (cloud retrievals and degradedresolution AOD), coregistered Cloud Physics Lidar profiles, MODIS aerosol retrievals, and groundbased Aerosol Robotic Network observations. We also define spatial metrics to indicate local cloud distributions near each retrieval and then separate into nearcloud and farfromcloud environments. The comparisons show that low cloud masking is robust, and unscreened thin cirrus would have only a small impact on retrieved AOD. Some of the enhancement is consistent with clearcloud transition zone microphysics such as aerosol swelling. However, 3D radiation interaction between clouds and the surrounding clear air appears to be the primary cause of the high AOD near clouds

Tracking of TV and video gaming during childhood: Iowa Bone Development Study

<p>Abstract</p> <p>Background</p> <p>Tracking studies determine the stability and predictability of specific phenomena. This study examined tracking of TV viewing (TV) and video game use (VG) from middle childhood through early adolescence after adjusting for moderate and vigorous physical activity (MVPA), percentage of body fat (% BF), and maturity.</p> <p>Methods</p> <p>TV viewing and VG use were measured at ages 5, 8, 11, and 13 (n = 434) via parental- and self-report. MVPA was measured using the Actigraph, % BF using dual-energy x-ray absorptiometry, and maturity via Mirwald predictive equations. Generalized Estimating Equations (GEE) were used to assess stability and logistic regression was used to predict children "at risk" for maintaining sedentary behaviors. Additional models examined tracking only in overfat children (boys ≥ 25% BF; girls ≥ 32% BF). Data were collected from 1998 to 2007 and analyzed in 2010.</p> <p>Results</p> <p>The adjusted stability coefficients (GEE) for TV viewing were 0.35 (95% CI = 0.26, 0.44) for boys, 0.32 (0.23, 0.40) for girls, and 0.45 (0.27, 0.64) for overfat. For VG use, the adjusted stability coefficients were 0.14 (0.05, 0.24) for boys, 0.24 (0.10, 0.38) for girls, and 0.29 (0.08, 0.50) for overfat. The adjusted odds ratios (OR) for TV viewing were 3.2 (2.0, 5.2) for boys, 2.9 (1.9, 4.6) for girls, and 6.2 (2.2, 17.2) for overfat. For VG use, the OR were 1.8 (1.1, 3.1) for boys, 3.5 (2.1, 5.8) for girls, and 1.9 (0.6, 6.1) for overfat.</p> <p>Conclusions</p> <p>TV viewing and VG use are moderately stable throughout childhood and predictive of later behavior. TV viewing appears to be more stable in younger children than VG use and more predictive of later behavior. Since habitual patterns of sedentarism in young children tend to continue to adolescence, early intervention strategies, particularly to reduce TV viewing, are warranted.</p

Epidural Electrical Stimulation for Stroke Rehabilitation: Results of the Prospective, Multicenter, Randomized, Single-Blinded Everest Trial.

BackgroundThis prospective, single-blinded, multicenter study assessed the safety and efficacy of electrical epidural motor cortex stimulation (EECS) in improving upper limb motor function of ischemic stroke patients with moderate to moderately severe hemiparesis.MethodsPatients ≥ 4 months poststroke were randomized 2:1 to an investigational (n = 104) or control (n = 60) group, respectively. Investigational patients were implanted (n = 94) with an epidural 6-contact lead perpendicular to the primary motor cortex and a pulse generator. Both groups underwent 6 weeks of rehabilitation, but EECS was delivered to investigational patients during rehabilitation. The primary efficacy endpoint (PE) was defined as attaining a minimum improvement of 4.5 points in the upper extremity Fugl-Meyer (UEFM) scale as well as 0.21 points in the Arm Motor Ability Test (AMAT) 4 weeks postrehabilitation. Follow-up assessments were performed 1, 4, 12, and 24 weeks postrehabilitation. Safety was evaluated by monitoring adverse events (AEs) that occurred between enrollment and the end of rehabilitation.ResultsPrimary intent-to-treat analysis showed no group differences at 4 weeks, with PE being met by 32% and 29% of investigational and control patients, respectively (P = .36). Repeated-measures secondary analyses revealed no significant treatment group differences in mean UEFM or AMAT scores. However, post hoc comparisons showed that a greater proportion of investigational (39%) than control (15%) patients maintained or achieved PE (P = .003) at 24 weeks postrehabilitation. Investigational group mean AMAT scores also improved significantly (P &lt; .05) when compared to the control group at 24 weeks postrehabilitation. Post hoc analyses also showed that 69% (n = 9/13) of the investigational patients who elicited movement thresholds during stimulation testing met PE at 4 weeks, and mean UEFM and AMAT scores was also significantly higher (P &lt; .05) in this subgroup at the 4-, 12-, and 24-week assessments when compared to the control group. Headache (19%), pain (13%), swelling (7%), and infection (7%) were the most commonly observed implant procedure-related AEs. Overall, there were 11 serious AEs in 9 investigational group patients (7 procedure related, 4 anesthesia related).ConclusionsThe primary analysis pertaining to efficacy of EECS during upper limb motor rehabilitation in chronic stroke patients was negative at 4 weeks postrehabilitation. A better treatment response was observed in a subset of patients eliciting stimulation induced upper limb movements during motor threshold assessments performed prior to each rehabilitation session. Post hoc comparisons indicated treatment effect differences at 24 weeks, with the control group showing significant decline in the combined primary outcome measure relative to the investigational group. These results have the potential to inform future chronic stroke rehabilitation trial design

Timing of primary tooth emergence among U.S. racial and ethnic groups

ObjectivesTo compare timing of tooth emergence among groups of American Indian (AI), Black and White children in the United States at 12 months of age.MethodsData were from two sources – a longitudinal study of a Northern Plains tribal community and a study with sites in Indiana, Iowa and North Carolina. For the Northern Plains study, all children (n = 223) were American Indian, while for the multisite study, children (n = 320) were from diverse racial groups. Analyses were limited to data from examinations conducted within 30 days of the child’s first birthday.ResultsAI children had significantly more teeth present (Mean: 7.8, Median: 8.0) than did Whites (4.4, 4.0, P < 0.001) or Blacks (4.5, 4.0, P < 0.001). No significant differences were detected between Black and White children (P = 0.58). There was no significant sex difference overall or within any of the racial groups.ConclusionsTooth emergence occurs at a younger age for AI children than it does for contemporary White or Black children in the United States.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135387/1/jphd12154.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135387/2/jphd12154_am.pd

Predicting functional gains in a stroke trial.

A number of therapies in development for patients with central nervous system injury aim to reduce disability by improving function of surviving brain elements rather than by salvaging tissue. The current study tested the hypothesis that, after adjusting for a number of clinical assessments, a measure of brain function at baseline would improve prediction of behavioral gains after treatment.Twenty-four patients with chronic stroke underwent baseline clinical and functional MRI assessments, received 6 weeks of rehabilitation therapy with or without investigational motor cortex stimulation, and then had repeat assessments. Thirteen baseline clinical/radiological measures were evaluated for ability to predict subsequent trial-related gains.Across all patients, bivariate analyses found that greater trial-related functional gains were predicted by (1) smaller infarct volume, (2) greater baseline clinical status, and (3) lower degree of activation in stroke-affected motor cortex on baseline functional MRI. When these 3 variables were further assessed using multivariate linear regression modeling, only lower motor cortex activation and greater clinical status at baseline remained significant predictors. Note that lower baseline motor cortex activation was also associated with larger increases in motor cortex activation after treatment.Lower motor cortex activity at baseline predicted greater behavioral gains after therapy, even after controlling for a number of clinical assessments. The boosts in cortical activity that paralleled behavioral gains suggest that in some patients, low baseline cortical activity represents underuse of surviving cortical resources. A measure of brain function might be important for optimal clinical decision-making in the context of a restorative intervention

Aluminium‐Catalyzed C(sp)−H Borylation of Alkynes

Historically used in stoichiometric hydroalumination chemistry, recent advances have transformed aluminium hydrides into versatile catalysts for the hydroboration of unsaturated multiple bonds. This catalytic ability is founded on the defining reactivity of aluminium hydrides with alkynes and alkenes: 1,2‐hydroalumination of the unsaturated π‐system. This manuscript reports the aluminium hydride catalyzed dehydroborylation of terminal alkynes. A tethered intramolecular amine ligand controls reactivity at the aluminium hydride centre, switching off hydroalumination and instead enabling selective reactions at the alkyne C−H σ‐bond. Chemoselective C−H borylation was observed across a series of aryl‐ and alkyl‐substituted alkynes (21 examples). On the basis of kinetic and density functional theory studies, a mechanism in which C−H borylation proceeds by σ‐bond metathesis between pinacolborane (HBpin) and alkynyl aluminium intermediates is proposed