312 research outputs found
Hair Transplantation in Advanced Male Pattern Alopecia: The Role of Incisional Slit Grafting
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98796/1/j.1524-4725.1991.tb03654.x.pd
A flight evaluation of a trailing anemometer for low-speed calibrations of airspeed systems on research aircraft
Research airspeed systems on three low-speed general aviation airplanes were calibrated by the trailing anemometer method. Each airplane was fitted with an NASA pitot-static pressure tube mounted on either a nose or wing boom. The uncalibrated airspeed systems contained residual static-pressure position errors which were too large for high-accuracy flight research applications. The trailing anemometer calibration was in agreement with the tower flyby calibration for the one aircraft for which the comparison was made. The continuous deceleration technique for the trailing anemometer method offers reduced test time with no appreciable loss of accuracy for airspeed systems with pitot-static system lag characteristics similar to those described
A Randomized, Controlled Trial of Meditation for Work Stress, Anxiety and Depressed Mood in Full-Time Workers
Objective. To assess the effect of meditation on work stress, anxiety and mood in full-time workers. Methods. 178 adult workers participated in an 8-week, 3-arm randomized controlled trial comparing a “mental silence” approach to meditation (n = 59) to a “relaxation” active control (n = 56) and a wait-list control (n = 63). Participants were assessed before and after using Psychological Strain Questionnaire (PSQ), a subscale of the larger Occupational Stress Inventory (OSI), the State component of the State/Trait Anxiety Inventory for Adults (STAI), and the depression-dejection (DD) subscale of the Profile of Mood States (POMS).
Results. There was a significant improvement for the meditation group compared to both the relaxation control and the wait-list groups the PSQ (P = .026), and DD (P = .019). Conclusions. Mental silence-orientated meditation, in this case Sahaja Yoga meditation, is a safe and effective strategy for dealing with work stress and depressive feelings. The findings suggest that “thought reduction” or “mental silence” may have specific effects relevant to work stress and hence occupational health
Total Lightning Characteristics with Respect to Radar-Derived Mesocyclone Strength
Recent work investigating the microphysical and kinematic relationship between a storm's updraft, its total lightning production, and manifestations of severe weather has resulted in development of tools for improved nowcasting of storm intensity. The total lightning jump algorithm, which identifies rapid increases in total lightning flash rate that often precede severe events, has shown particular potential to benefit warning operations. Maximizing this capability of total lightning and its operational implementation via the lightning jump may best be done through its fusion with radar and radarderived intensity metrics. Identification of a mesocyclone, or quasisteady rotating updraft, in Doppler velocity is the predominant radarinferred early indicator of severe potential in a convective storm. Fused lightningradar tools that capitalize on the most robust intensity indicators would allow enhanced situational awareness for increased warning confidence. A foundational step toward such tools comes from a better understanding of the updraftcentric relationship between intensification of total lightning production and mesocyclone development and strength. The work presented here utilizes a sample of supercell case studies representing a spectrum of severity. These storms are analyzed with respect to total lightning flash rate and the lightning jump alongside mesocyclone strength derived objectively from the National Severe Storms Laboratory (NSSL) Mesocyclone Detection Algorithm (MDA) and maximum azimuthal shear through a layer. Early results indicate that temporal similarities exist in the trends between total lightning flash rate and low to midlevel rotation in supercells. Other characteristics such as polarimetric signatures of rotation, flash size, and cloudtoground flash ratio are explored for added insight into the significance of these trends with respect to the updraft and related processes of severe weather production
Age-related changes to the neural correlates of working memory which emerge after midlife
Previous research has indicated that the neural processes which underlie working memory change with age. Both age-related increases and decreases to cortical activity have been reported. This study investigated which stages of working memory are most vulnerable to age-related changes after midlife. To do this we examined age-differences in the 13 Hz steady state visually evoked potential (SSVEP) associated with a spatial working memory delayed response task. Participants were 130 healthy adults separated into a midlife (40-60 years) and an older group (61-82 years). Relative to the midlife group, older adults demonstrated greater bilateral frontal activity during encoding and this pattern of activity was related to better working memory performance. In contrast, evidence of age-related under activation was identified over left frontal regions during retrieval. Findings from this study suggest that after midlife, under-activation of frontal regions during retrieval contributes to age-related decline in working memory performance. © 2014 Macpherson, White, Ellis, Stough, Camfield, Silberstein and Pipingas
Flight investigation of stall, spin and recovery characteristics of a low-wing, single-engine, T-tail light airplane
Flight tests were performed to investigate the stall, spin, and recovery characteristics of a four-place, low-wing, single-engine, T-tail, general aviation research airplane at an aft center-of-gravity position. Most stalls resulted in roll-offs. Spins were oscillatory in roll and pitch at 43 deg angle of attack; the magnitude of the oscillations was determined by aileron position. Power, flap deflection, and landing gear position did not affect the angle of attack to the spin. Antispin rudder followed by forward wheel with ailerons neutral produced the fastest and most consistent recoveries but the initial application of recovery controls did not always stop a spin
Examining Brain-Cognition Effects of Ginkgo Biloba Extract: Brain Activation in the Left Temporal and Left Prefrontal Cortex in an Object Working Memory Task
Ginkgo Biloba extract (GBE) is increasingly used to alleviate symptoms of age related cognitive impairment, with preclinical evidence pointing to a pro-cholinergic effect. While a number of behavioral studies have reported improvements to working memory (WM) associated with GBE, electrophysiological studies of GBE have typically been limited to recordings during a resting state. The current study investigated the chronic effects of GBE on steady state visually evoked potential (SSVEP) topography in nineteen healthy middle-aged (50-61 year old) male participants whilst completing an object WM task. A randomized double-blind crossover design was employed in which participants were allocated to receive 14 days GBE and 14 days placebo in random order. For both groups, SSVEP was recorded from 64 scalp electrode sites during the completion of an object WM task both pre- and 14 days post-treatment. GBE was found to improve behavioural performance on the WM task. GBE was also found to increase the SSVEP amplitude at occipital and frontal sites and increase SSVEP latency at left temporal and left frontal sites during the hold component of the WM task. These SSVEP changes associated with GBE may represent more efficient processing during WM task completion
Separated flow
A brief overview of flow separation phenomena is provided. Langley has many active research programs in flow separation related areas. Three cases are presented which describe specific examples of flow separation research. In each example, a description of the fundamental fluid physics and the complexity of the flow field is presented along with a method of either reducing or controlling the extent of separation. The following examples are discussed: flow over a smooth surface with an adverse pressure gradient; flow over a surface with a geometric discontinuity; and flow with shock-boundary layer interactions. These results will show that improvements are being made in the understanding of flow separation and its control
‘Silence does not sound the same for everyone’: student teachers’ narratives:Student Teachers’ Narratives Around Behavior Management in Scottish Schools
Total Lightning as an Indicator of Mesocyclone Behavior
Apparent relationship between total lightning (in-cloud and cloud to ground) and severe weather suggests its operational utility. Goal of fusion of total lightning with proven tools (i.e., radar lightning algorithms. Preliminary work here investigates circulation from Weather Suveilance Radar- 1988 Doppler (WSR-88D) coupled with total lightning data from Lightning Mapping Arrays
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