Nonlinear elasticity in resonance experiments

NASA Astrophysics Data System (ADS)

Li, Xun; Sens-Schönfelder, Christoph; Snieder, Roel

2018-04-01

Resonant bar experiments have revealed that dynamic deformation induces nonlinearity in rocks. These experiments produce resonance curves that represent the response amplitude as a function of the driving frequency. We propose a model to reproduce the resonance curves with observed features that include (a) the log-time recovery of the resonant frequency after the deformation ends (slow dynamics), (b) the asymmetry in the direction of the driving frequency, (c) the difference between resonance curves with the driving frequency that is swept upward and downward, and (d) the presence of a "cliff" segment to the left of the resonant peak under the condition of strong nonlinearity. The model is based on a feedback cycle where the effect of softening (nonlinearity) feeds back to the deformation. This model provides a unified interpretation of both the nonlinearity and slow dynamics in resonance experiments. We further show that the asymmetry of the resonance curve is caused by the softening, which is documented by the decrease of the resonant frequency during the deformation; the cliff segment of the resonance curve is linked to a bifurcation that involves a steep change of the response amplitude when the driving frequency is changed. With weak nonlinearity, the difference between the upward- and downward-sweeping curves depends on slow dynamics; a sufficiently slow frequency sweep eliminates this up-down difference. With strong nonlinearity, the up-down difference results from both the slow dynamics and bifurcation; however, the presence of the bifurcation maintains the respective part of the up-down difference, regardless of the sweep rate.

Two types of expansion onsets in the Earth's two hemispheres

NASA Astrophysics Data System (ADS)

Foerster, M.; Mishin, V.; Mishin, V. M.; Kurikalova, M.; Karavaev, Y.; Lunyushkin, S.

2016-12-01

On the maps of distribution of field - aligned currents (FAC) of 15 investigated substorms we have found two main types of M-I feedback instability: 1) "summer" (type 1), and 2) "winter" (type 2). In equinox both types were observed, different in the two hemispheres. Each type of instability creates two simultaneous local expansion onsets, EOs: Type 1 - non-linear amplification of the downward FAC in one hemisphere and Type 2 - non-linear amplification of the upward FAC in the other hemisphere.

Climate change-driven treeline advances in the Urals alter soil microbial communities

NASA Astrophysics Data System (ADS)

Djukic, Ika; Moiseev, Pavel; Hagedorn, Frank

2016-04-01

Climatic warming may affect microbial communities and their functions either directly through increased temperatures or indirectly by changes in vegetation. Treelines are temperature-limited vegetation boundaries from tundra to forests. In unmanaged regions of the Ural mountains, there is evidence that the forest-tundra ecotone has shifted upward in response to climate warming during the 20th century. Little is known about the effects of the treeline advances on the microbial structure and function and hence they feedbacks on the belowground carbon and nitrogen cycling In our study, we aimed to estimate how ongoing upward shifts of the treeline ecotone might affect soil biodiversity and its function and hence soil carbon (C) and nitrogen (N) dynamics in the Southern and Polar Ural mountains. Along altitudinal gradients reaching from the tundra to forests, we determined the soil microbial community composition (using Phospholipid Fatty Acids method) and quantified the activity of several extracellular enzymes involved in the C and nutrient cycling. In addition, we measured C pools in biomass and soils and quantified C and N mineralization. The results for the top soils, both in South Urals and in the Polar Ural, indicate a close link between climate change driven vegetation changes and soil microbial communities. The observed changes in microbial structure are induced through the resulting more favorable conditions than due to a shift in litter quality. The activities of chitinase were significantly higher under trees than under herbaceous plants, while activities of cellulase and protease declined with altitude from the tundra to the closed forest. In contrast to enzymatic activities, soil carbon stocks did not change significantly with altitude very likely as a result of a balancing out of increased C inputs from vegetation by an enhanced C output through mineralization with forest expansion. The accelerated organic matter turnover in the forest than in the tundra leads to higher contents of mineral N and net nitrification rates. In turn, the increasing N availability may stimulate plant growth and hence, induce a positive feedback between treeline advances and soil nitrogen cycling through soil microbial communities.

Climate Warming and Seasonal Precipitation Change Interact to Limit Species Distribution Shifts across Western North America

PubMed Central

Harsch, Melanie A.; HilleRisLambers, Janneke

2016-01-01

Using an extensive network of occurrence records for 293 plant species collected over the past 40 years across a climatically diverse geographic section of western North America, we find that plant species distributions were just as likely to shift upwards (i.e., towards higher elevations) as downward (i.e., towards lower elevations)–despite consistent warming across the study area. Although there was no clear directional response to climate warming across the entire study area, there was significant region- to region- variation in responses (i.e. from as many as 73% to as few as 32% of species shifting upward). To understand the factors that might be controlling region-specific distributional shifts of plant species, we explored the relationship between the direction of change in distribution limits and the nature of recent climate change. We found that the direction that distribution limits shifted was explained by an interaction between the rate of change in local summer temperatures and seasonal precipitation. Specifically, species were more likely to shift upward at their upper elevational limit when minimum temperatures increased and snowfall was unchanging or declined at slower rates (<0.5 mm/year). This suggests that both low temperature and water availability limit upward shifts at upper elevation limits. By contrast, species were more likely to shift upwards at their lower elevation limit when maximum temperatures increased, but also shifted upwards under conditions of cooling temperatures when precipitation decreased. This suggests increased water stress may drive upward shifts at lower elevation limits. Our results suggest that species’ elevational distribution shifts are not predictable by climate warming alone but depend on the interaction between seasonal temperature and precipitation change. PMID:27447834

The Glass Floor: Education, Downward Mobility, and Opportunity Hoarding

ERIC Educational Resources Information Center

Reeves, Richard V.; Howard, Kimberly

2013-01-01

From an intergenerational perspective, the U.S. income distribution is sticky at both ends. Affluence and poverty are both partially inherited. Policy and research has focused on upward mobility, especially from the bottom. But relative intergenerational upward mobility is only possible with equivalent rates of downward mobility, where much less…

Observed and Simulated Radiative and Microphysical Properties of Tropical Convective Storms

NASA Technical Reports Server (NTRS)

DelGenio, Anthony D.; Hansen, James E. (Technical Monitor)

2001-01-01

Increases in the ice content, albedo and cloud cover of tropical convective storms in a warmer climate produce a large negative contribution to cloud feedback in the GISS GCM. Unfortunately, the physics of convective upward water transport, detrainment, and ice sedimentation, and the relationship of microphysical to radiative properties, are all quite uncertain. We apply a clustering algorithm to TRMM satellite microwave rainfall retrievals to identify contiguous deep precipitating storms throughout the tropics. Each storm is characterized according to its size, albedo, OLR, rain rate, microphysical structure, and presence/absence of lightning. A similar analysis is applied to ISCCP data during the TOGA/COARE experiment to identify optically thick deep cloud systems and relate them to large-scale environmental conditions just before storm onset. We examine the statistics of these storms to understand the relative climatic roles of small and large storms and the factors that regulate convective storm size and albedo. The results are compared to GISS GCM simulated statistics of tropical convective storms to identify areas of agreement and disagreement.

Simulations of the effect of a warmer climate on atmospheric humidity

NASA Technical Reports Server (NTRS)

Del Genio, Anthony D.; Lacis, Andrew A.; Ruedy, Reto A.

1991-01-01

Increases in the concentration of water vapor constitute the single largest positive feedback in models of global climate warming caused by greenhouse gases. It has been suggested that sinking air in the regions surrounding deep cumulus clouds will dry the upper troposphere and eliminate or reverse the direction of water vapor feedback. This hypothesis has been tested by performing an idealized simulation of climate change with two different versions of a climate model which both incorporate drying due to subsidence of clear air but differ in their parameterization of moist convection and stratiform clouds. Despite increased drying of the upper troposphere by cumulus clouds, upper-level humidity increases in the warmer climate because of enhanced upward moisture transport by the general circulation and increased accumulation of water vapor and ice at cumulus cloud tops.

Constraints on Upward Migration of Hydraulic Fracturing Fluid and Brine

PubMed Central

Flewelling, Samuel A; Sharma, Manu

2014-01-01

Recent increases in the use of hydraulic fracturing (HF) to aid extraction of oil and gas from black shales have raised concerns regarding potential environmental effects associated with predictions of upward migration of HF fluid and brine. Some recent studies have suggested that such upward migration can be large and that timescales for migration can be as short as a few years. In this article, we discuss the physical constraints on upward fluid migration from black shales (e.g., the Marcellus, Bakken, and Eagle Ford) to shallow aquifers, taking into account the potential changes to the subsurface brought about by HF. Our review of the literature indicates that HF affects a very limited portion of the entire thickness of the overlying bedrock and therefore, is unable to create direct hydraulic communication between black shales and shallow aquifers via induced fractures. As a result, upward migration of HF fluid and brine is controlled by preexisting hydraulic gradients and bedrock permeability. We show that in cases where there is an upward gradient, permeability is low, upward flow rates are low, and mean travel times are long (often >106 years). Consequently, the recently proposed rapid upward migration of brine and HF fluid, predicted to occur as a result of increased HF activity, does not appear to be physically plausible. Unrealistically high estimates of upward flow are the result of invalid assumptions about HF and the hydrogeology of sedimentary basins. PMID:23895673

Plant root and shoot dynamics during subsurface obstacle interaction

NASA Astrophysics Data System (ADS)

Conn, Nathaniel; Aguilar, Jeffrey; Benfey, Philip; Goldman, Daniel

As roots grow, they must navigate complex underground environments to anchor and retrieve water and nutrients. From gravity sensing at the root tip to pressure sensing along the tip and elongation zone, the complex mechanosensory feedback system of the root allows it to bend towards greater depths and avoid obstacles of high impedance by asymmetrically suppressing cell elongation. Here we investigate the mechanical and physiological responses of roots to rigid obstacles. We grow Maize, Zea mays, plants in quasi-2D glass containers (22cm x 17cm x 1.4cm) filled with photoelastic gel and observe that, regardless of obstacle interaction, smaller roots branch off the primary root when the upward growing shoot (which contains the first leaf) reaches an average length of 40 mm, coinciding with when the first leaf emerges. However, prior to branching, contacts with obstacles result in reduced root growth rates. The growth rate of the root relative to the shoot is sensitive to the angle of the obstacle surface, whereby the relative root growth is greatest for horizontally oriented surfaces. We posit that root growth is prioritized when horizontal obstacles are encountered to ensure anchoring and access to nutrients during later stages of development. NSF Physics of Living Systems.

Error-dependent modulation of speech-induced auditory suppression for pitch-shifted voice feedback.

PubMed

Behroozmand, Roozbeh; Larson, Charles R

2011-06-06

The motor-driven predictions about expected sensory feedback (efference copies) have been proposed to play an important role in recognition of sensory consequences of self-produced motor actions. In the auditory system, this effect was suggested to result in suppression of sensory neural responses to self-produced voices that are predicted by the efference copies during vocal production in comparison with passive listening to the playback of the identical self-vocalizations. In the present study, event-related potentials (ERPs) were recorded in response to upward pitch shift stimuli (PSS) with five different magnitudes (0, +50, +100, +200 and +400 cents) at voice onset during active vocal production and passive listening to the playback. Results indicated that the suppression of the N1 component during vocal production was largest for unaltered voice feedback (PSS: 0 cents), became smaller as the magnitude of PSS increased to 200 cents, and was almost completely eliminated in response to 400 cents stimuli. Findings of the present study suggest that the brain utilizes the motor predictions (efference copies) to determine the source of incoming stimuli and maximally suppresses the auditory responses to unaltered feedback of self-vocalizations. The reduction of suppression for 50, 100 and 200 cents and its elimination for 400 cents pitch-shifted voice auditory feedback support the idea that motor-driven suppression of voice feedback leads to distinctly different sensory neural processing of self vs. non-self vocalizations. This characteristic may enable the audio-vocal system to more effectively detect and correct for unexpected errors in the feedback of self-produced voice pitch compared with externally-generated sounds.

Treeline advances and associated shifts in the ground vegetation alter fine root dynamics and mycelia production in the South and Polar Urals.

PubMed

Solly, Emily F; Djukic, Ika; Moiseev, Pavel A; Andreyashkina, Nelly I; Devi, Nadezhda M; Göransson, Hans; Mazepa, Valeriy S; Shiyatov, Stepan G; Trubina, Marina R; Schweingruber, Fritz H; Wilmking, Martin; Hagedorn, Frank

2017-02-01

Climate warming is shifting the elevational boundary between forests and tundra upwards, but the related belowground responses are poorly understood. In the pristine South and Polar Urals with shifts of the treeline ecotone documented by historical photographs, we investigated fine root dynamics and production of extramatrical mycorrhizal mycelia (EMM) along four elevational transects reaching from the closed forest to the treeless tundra. In addition, we analysed elevational differences in climate and vegetation structure, and excavated trees to estimate related changes in the partitioning between below- and aboveground biomass. Fine root biomass of trees (<2 mm) increased by 13-79% with elevation, paralleled by a 35-72% increase in ground vegetation fine roots from the closed forest to the tundra. During the first year of decomposition, mass loss of fine root litter from different vegetation types was greater at lower elevations in the forest-tundra ecotone. The ratio between fine roots of trees and stem biomass largely increased with elevation in both regions, but these increases were not accompanied by a distinct production of EMM. Production of EMM, however, increased with the presence of ectomycorrhizal trees at the transition from the tundra to the forest. Our results imply that the recorded upward expansion of forest into former tundra in the Ural Mountains by 4-8 m per decade is decreasing the partitioning of plant biomass to fine roots. They further suggest that climate-driven forest advances will alter EMM production rates with potential feedbacks on soil carbon and nutrient cycling in these ecosystems.

Trends in Hospitalization and Mortality Rates Due to Acute Cardiovascular Disease in Castile and León, 2001 to 2015.

PubMed

López-Messa, Juan B; Andrés-de Llano, Jesús M; López-Fernández, Laura; García-Cruces, Jesús; García-Crespo, Julio; Prieto González, Miryam

2018-02-01

To analyze hospitalization and mortality rates due to acute cardiovascular disease (ACVD). We conducted a cross-sectional study of the hospital discharge database of Castile and León from 2001 to 2015, selecting patients with a principal discharge diagnosis of acute myocardial infarction (AMI), unstable angina, heart failure, or acute ischemic stroke (AIS). Trends in the rates of hospitalization/100 000 inhabitants/y and hospital mortality/1000 hospitalizations/y, overall and by sex, were studied by joinpoint regression analysis. A total of 239 586 ACVD cases (AMI 55 004; unstable angina 15 406; heart failure 111 647; AIS 57 529) were studied. The following statistically significant trends were observed: hospitalization: ACVD, upward from 2001 to 2007 (5.14; 95%CI, 3.5-6.8; P < .005), downward from 2011 to 2015 (3.7; 95%CI, 1.0-6.4; P < .05); unstable angina, downward from 2001 to 2010 (-12.73; 95%CI, -14.8 to -10.6; P < .05); AMI, upward from 2001 to 2003 (15.6; 95%CI, 3.8-28.9; P < .05), downward from 2003 to 2015 (-1.20; 95%CI, -1.8 to -0.6; P < .05); heart failure, upward from 2001 to 2007 (10.70; 95%CI, 8.7-12.8; P < .05), upward from 2007 to 2015 (1.10; 95%CI, 0.1-2.1; P < .05); AIS, upward from 2001 to 2007 (4.44; 95%CI, 2.9-6.0; P < .05). Mortality rates: downward from 2001 to 2015 in ACVD (-1.16; 95%CI, -2.1 to -0.2; P < .05), AMI (-3.37, 95%CI, -4.4 to -2, 3, P < .05), heart failure (-1.25; 95%CI, -2.3 to -0.1; P < .05) and AIS (-1.78; 95%CI, -2.9 to -0.6; P < .05); unstable angina, upward from 2001 to 2007 (24.73; 95%CI, 14.2-36.2; P < .05). The ACVD analyzed showed a rising trend in hospitalization rates from 2001 to 2015, which was especially marked for heart failure, and a decreasing trend in hospital mortality rates, which were similar in men and women. These data point to a stabilization and a decline in hospital mortality, attributable to established prevention measures. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Upward-Directed Persuasive Communication and Attribution of Success and Failure toward an Understanding of the Role of Gender.

ERIC Educational Resources Information Center

Andrews, Patricia Hayes

A study was conducted to examine the impact of gender on upward communication (subordinates to superiors) in organizations. It was hypothesized that women would (1) report less self-confidence when approaching a communicative performance situation, (2) rate themselves less successfully following persuasive presentations, and (3) be more likely to…

Physical mechanism and numerical simulation of the inception of the lightning upward leader

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Qingmin; Lu Xinchang; Shi Wei

2012-12-15

The upward leader is a key physical process of the leader progression model of lightning shielding. The inception mechanism and criterion of the upward leader need further understanding and clarification. Based on leader discharge theory, this paper proposes the critical electric field intensity of the stable upward leader (CEFISUL) and characterizes it by the valve electric field intensity on the conductor surface, E{sub L}, which is the basis of a new inception criterion for the upward leader. Through numerical simulation under various physical conditions, we verified that E{sub L} is mainly related to the conductor radius, and data fitting yieldsmore » the mathematical expression of E{sub L}. We further establish a computational model for lightning shielding performance of the transmission lines based on the proposed CEFISUL criterion, which reproduces the shielding failure rate of typical UHV transmission lines. The model-based calculation results agree well with the statistical data from on-site operations, which show the effectiveness and validity of the CEFISUL criterion.« less

Rapid control and feedback rates enhance neuroprosthetic control

PubMed Central

Shanechi, Maryam M.; Orsborn, Amy L.; Moorman, Helene G.; Gowda, Suraj; Dangi, Siddharth; Carmena, Jose M.

2017-01-01

Brain-machine interfaces (BMI) create novel sensorimotor pathways for action. Much as the sensorimotor apparatus shapes natural motor control, the BMI pathway characteristics may also influence neuroprosthetic control. Here, we explore the influence of control and feedback rates, where control rate indicates how often motor commands are sent from the brain to the prosthetic, and feedback rate indicates how often visual feedback of the prosthetic is provided to the subject. We developed a new BMI that allows arbitrarily fast control and feedback rates, and used it to dissociate the effects of each rate in two monkeys. Increasing the control rate significantly improved control even when feedback rate was unchanged. Increasing the feedback rate further facilitated control. We also show that our high-rate BMI significantly outperformed state-of-the-art methods due to higher control and feedback rates, combined with a different point process mathematical encoding model. Our BMI paradigm can dissect the contribution of different elements in the sensorimotor pathway, providing a unique tool for studying neuroprosthetic control mechanisms. PMID:28059065

Rapid control and feedback rates enhance neuroprosthetic control

NASA Astrophysics Data System (ADS)

Shanechi, Maryam M.; Orsborn, Amy L.; Moorman, Helene G.; Gowda, Suraj; Dangi, Siddharth; Carmena, Jose M.

2017-01-01

Brain-machine interfaces (BMI) create novel sensorimotor pathways for action. Much as the sensorimotor apparatus shapes natural motor control, the BMI pathway characteristics may also influence neuroprosthetic control. Here, we explore the influence of control and feedback rates, where control rate indicates how often motor commands are sent from the brain to the prosthetic, and feedback rate indicates how often visual feedback of the prosthetic is provided to the subject. We developed a new BMI that allows arbitrarily fast control and feedback rates, and used it to dissociate the effects of each rate in two monkeys. Increasing the control rate significantly improved control even when feedback rate was unchanged. Increasing the feedback rate further facilitated control. We also show that our high-rate BMI significantly outperformed state-of-the-art methods due to higher control and feedback rates, combined with a different point process mathematical encoding model. Our BMI paradigm can dissect the contribution of different elements in the sensorimotor pathway, providing a unique tool for studying neuroprosthetic control mechanisms.

Mining review

USGS Publications Warehouse

McCartan, L.; Morse, D.E.; Plunkert, P.A.; Sibley, S.F.

2004-01-01

The average annual growth rate of real gross domestic product (GDP) from the third quarter of 2001 through the second quarter of 2003 in the United States was about 2.6 percent. GDP growth rates in the third and fourth quarters of 2003 were about 8 percent and 4 percent, respectively. The upward trends in many sectors of the U.S. economy in 2003, however, were shared by few of the mineral materials industries. Annual output declined in most nonfuel mining and mineral processing industries, although there was an upward turn toward yearend as prices began to increase.

Geochronological and mineralogical constraints on depth of emplacement and ascencion rates of epidote-bearing magmas from northeastern Brazil

NASA Astrophysics Data System (ADS)

Sial, Alcides N.; Vasconcelos, Paulo M.; Ferreira, Valderez P.; Pessoa, Ricardo R.; Brasilino, Roberta G.; Morais Neto, João M.

2008-10-01

Calc-alkalic to high-K calc-alkalic granitoid plutons in the Borborema province, northeastern Brazil, have been studied to constrain depth of emplacement by mineralogical and geological methods and to estimate upward magma transport rate based on partial dissolution of magmatic epidote. Laser-probe incremental heating 40Ar/ 39Ar dating of biotite and hornblende single crystals from the Neoproterozoic Tavares and Brejinho high-K calc-alkalic magmatic epidote (mEp)-bearing plutons reveals age differences of around 60 M.y. between these two minerals in each of these two intrusions. These data suggest solidification at relatively great depth followed by prolonged cooling interval between the closure temperatures of biotite and hornblende. Al-in-hornblende barometry indicates that hornblende in several mEp-bearing plutons in the Transversal Domain of the Borborema province solidified at 5 to 7 kbar, whereas in the Seridó and Macururé terranes, solidification pressures range from 3 to 4 kbar. Partial dissolution of epidote indicates very rapid upward transport. Partial corrosion occurred during 15-35 years (Cachoerinha-Salgueiro terrane), 10-30 years (Alto Pajeú), 15 years (Seridó), and 10 years (Macururé) corresponding to upward transport rates of 450-1300, 650-1050, 1200, and 1800 m/year respectively in these four terranes. Rapid upward magma migration in most cases was probably facilitated by diking simultaneous with regional shearing.

Time-lapse analysis of gravitropism in Ceratodon protonemata

NASA Technical Reports Server (NTRS)

Young, J. C.; Sack, F. D.

1992-01-01

The tip cell of the protonema of the moss Ceratodon purpureus (Hedw.) Brid. is negatively gravitropic when grown in the dark on supplemented agar. Gravitropism, plastid distribution, and plastid movement were studied in living cells using time-lapse video microscopy and infrared light. A wrong-way (downward) curvature preceded upward curvature and was detected as early as 2 minutes after reorientation. Upward curvature began 30-45 minutes after reorientation to the horizontal. Cell division temporarily reversed upward curvature, but did not inhibit wrong-way curvature. Since significant amyloplast sedimentation always occurred before the start of upward curvature, it is possible that these amyloplasts function as statoliths for upward curvature. However, no significant amyloplast sedimentation occurred before wrong-way curvature. Thus, this early phase of gravitropism cannot require plastid sedimentation for gravity sensing. Most plastids moved within and between zones, and plastid zonation was highly dynamic. Plastids moved toward the apex and toward the base of the cell at rates much slower than cytoplasmic streaming. Despite the dynamic nature of plastid movement and zonation, during upward curvature the distance between sedimented plastids and the apex stayed constant. Time-lapse analysis has revealed intriguing events not readily seen previously using destructive sampling.

Error-dependent modulation of speech-induced auditory suppression for pitch-shifted voice feedback

PubMed Central

2011-01-01

Background The motor-driven predictions about expected sensory feedback (efference copies) have been proposed to play an important role in recognition of sensory consequences of self-produced motor actions. In the auditory system, this effect was suggested to result in suppression of sensory neural responses to self-produced voices that are predicted by the efference copies during vocal production in comparison with passive listening to the playback of the identical self-vocalizations. In the present study, event-related potentials (ERPs) were recorded in response to upward pitch shift stimuli (PSS) with five different magnitudes (0, +50, +100, +200 and +400 cents) at voice onset during active vocal production and passive listening to the playback. Results Results indicated that the suppression of the N1 component during vocal production was largest for unaltered voice feedback (PSS: 0 cents), became smaller as the magnitude of PSS increased to 200 cents, and was almost completely eliminated in response to 400 cents stimuli. Conclusions Findings of the present study suggest that the brain utilizes the motor predictions (efference copies) to determine the source of incoming stimuli and maximally suppresses the auditory responses to unaltered feedback of self-vocalizations. The reduction of suppression for 50, 100 and 200 cents and its elimination for 400 cents pitch-shifted voice auditory feedback support the idea that motor-driven suppression of voice feedback leads to distinctly different sensory neural processing of self vs. non-self vocalizations. This characteristic may enable the audio-vocal system to more effectively detect and correct for unexpected errors in the feedback of self-produced voice pitch compared with externally-generated sounds. PMID:21645406

Labor Market Structure, Intragenerational Mobility, and Discrimination: Black Male Advancement out of Low-Paying Occupations, 1962-1973

ERIC Educational Resources Information Center

Power, Marshall I.

1986-01-01

Comparison of intragenerational mobility of black and white men shows the following: (1) black upward mobility is less frequent and more restricted; (2) blacks within the public sector have substantial rates of upward mobility to nonmanagerial positions; and (3) discrimination against blacks in the labor market has not disappeared. (Author/PS)

The relativistic feedback discharge model of terrestrial gamma ray flashes

NASA Astrophysics Data System (ADS)

Dwyer, Joseph R.

2012-02-01

As thunderclouds charge, the large-scale fields may approach the relativistic feedback threshold, above which the production of relativistic runaway electron avalanches becomes self-sustaining through the generation of backward propagating runaway positrons and backscattered X-rays. Positive intracloud (IC) lightning may force the large-scale electric fields inside thunderclouds above the relativistic feedback threshold, causing the number of runaway electrons, and the resulting X-ray and gamma ray emission, to grow exponentially, producing very large fluxes of energetic radiation. As the flux of runaway electrons increases, ionization eventually causes the electric field to discharge, bringing the field below the relativistic feedback threshold again and reducing the flux of runaway electrons. These processes are investigated with a new model that includes the production, propagation, diffusion, and avalanche multiplication of runaway electrons; the production and propagation of X-rays and gamma rays; and the production, propagation, and annihilation of runaway positrons. In this model, referred to as the relativistic feedback discharge model, the large-scale electric fields are calculated self-consistently from the charge motion of the drifting low-energy electrons and ions, produced from the ionization of air by the runaway electrons, including two- and three-body attachment and recombination. Simulation results show that when relativistic feedback is considered, bright gamma ray flashes are a natural consequence of upward +IC lightning propagating in large-scale thundercloud fields. Furthermore, these flashes have the same time structures, including both single and multiple pulses, intensities, angular distributions, current moments, and energy spectra as terrestrial gamma ray flashes, and produce large current moments that should be observable in radio waves.

Buoyant Effects on the Flammability of Silicone Samples Planned for the Spacecraft Fire Experiment (Saffire)

NASA Technical Reports Server (NTRS)

Niehaus, Justin; Ferkul, Paul V.; Gokoglu, Suleyman; Ruff, Gary

2015-01-01

Flammability experiments on silicone samples were conducted in anticipation of the Spacecraft Fire Experiment (Saffire). The sample geometry was chosen to match the NASA 6001 Test 1 specification, namely 5 cm wide by 30 cm tall. Four thicknesses of silicone (0.25, 0.36, 0.61 and 1.00 mm) were examined. Tests included traditional upward buoyant flame spread using Test 1 procedures, downward opposed flow flame spread, horizontal and angled flame spread, forced flow upward and downward flame spread. In addition to these configurations, upward and downward tests were also conducted in a chamber with varying oxygen concentrations. In the upward buoyant flame spread tests, the flame generally did not burn the entire sample. As thickness was increased, the flame spread distance decreased before flame extinguishment. For the thickest sample, ignition could not be achieved. In the downward tests, the two thinnest samples permitted the flame to burn the entire sample, but the spread rate was lower compared to the corresponding upward values. The other two thicknesses could not be ignited in the downward configuration. The increased flammability for downward spreading flames relative to upward ones is uncommon. The two thinnest samples also burned completely in the horizontal configuration, as well as at angles up to 75 degrees from the horizontal. The upward and downward flammability behavior was compared in atmospheres of varying oxygen concentration to determine a maximum oxygen concentration for each configuration. Upward tests in air with an added forced flow were more flammable. Complementary analyses using SEM and TGA techniques suggest the importance of the silica layer formed on the burned sample surface. As silicone burns upward, silica deposits downstream •If the silicone is ignited in the downward configuration, it burns the entire length of the sample •Burning upward at an angle increases the burn length in some cases possibly due to less silica deposition •Forced flow in the upward burning case increases flammability, likely due to an increase in convective flow preventing silica from depositing •Samples in upward configuration burning under forced flow self extinguish after forced flow is removed

In situ pediatric trauma simulation: assessing the impact and feasibility of an interdisciplinary pediatric in situ trauma care quality improvement simulation program.

PubMed

Auerbach, Marc; Roney, Linda; Aysseh, April; Gawel, Marcie; Koziel, Jeannette; Barre, Kimberly; Caty, Michael G; Santucci, Karen

2014-12-01

This study aimed to evaluate the feasibility and measure the impact of an in situ interdisciplinary pediatric trauma quality improvement simulation program. Twenty-two monthly simulations were conducted in a tertiary care pediatric emergency department with the aim of improving the quality of pediatric trauma (February 2010 to November 2012). Each session included 20 minutes of simulated patient care, followed by 30 minutes of debriefing that focused on teamwork, communication, and the identification of gaps in care. A single rater scored the performance of the team in real time using a validated assessment instrument for 6 subcomponents of care (teamwork, airway, intubation, breathing, circulation, and disability). Participants completed a survey and written feedback forms. A trend analysis of the 22 simulations found statistically significant positive trends for overall performance, teamwork, and intubation subcomponents; the strength of the upward trend was the strongest for the teamwork (τ = 0.512), followed by overall performance (τ = 0.488) and intubation (τ = 0.433). Two hundred fifty-one of 398 participants completed the participant feedback form (response rate, 63%), reporting that debriefing was the most valuable aspect of the simulation. An in situ interdisciplinary pediatric trauma simulation quality improvement program resulted in improved validated trauma simulation assessment scores for overall performance, teamwork, and intubation. Participants reported high levels of satisfaction with the program, and debriefing was reported as the most valuable component of the program.

The Seasonal and Interannual Variability of the Budgets of N2O and CCl3F

NASA Technical Reports Server (NTRS)

Wong, Sun; Prather, Michael J.; Rind, David H.

1999-01-01

The 6-year wind archives from the Goddard Institute for Space Studies/Global Climate-Middle Atmosphere Model (GISS/GCMAM) were in- put to the GISS/Harvard/Irvine Chemical Transport Model (G/H/I CTM) to study the seasonal and interannual variability of the budgets and distributions of nitrous oxide (N2O) and trichlorofluoromethane (CCl3F), with the corresponding chemical loss frequencies recycled and boundary conditions kept unchanged from year to year. The effects of ozone feedback and quasi-biennial oscillation (QBO) were not included. However, the role of circulation variation in driving the lifetime variability is investigated. It was found that the global loss rates of these tracers are related to the extratropical planetary wave activity, which drives the tropical upward mass flux. For N2O, a semiannual signal in the loss rate variation is associated with the interhemispheric asymmetry in the upper stratospheric wave activity. For CCl3F, the semiannual signal is weaker, associated with the comparatively uniform wave episodes in the lower stratosphere. The loss rates lag behind the wave activity by about 1-2 months. The interannual variation of the GCM generated winds drives the interannual variation of the annually averaged lifetime. The year-to-year variations of the annually averaged lifetimes can be about 3% for N2O and 4% for CCl3F.

Intensity of Upward Muon Flux Due to Cosmic-Ray Neutrinos Produced in the Atmosphere

DOE R&D Accomplishments Database

Lee, T. D.; Robinson, H.; Schwartz, M.; Cool, R.

1963-06-01

Calculations were performed to determine the upward going muon flux leaving the earth's surface after production by cosmic-ray neutrinos in the crust. Only neutrinos produced in the earth's atmosphere are considered. Rates of the order of one per 100 sq m/day might be expected if an intermediate boson exists and has a mass less than 2 Bev. (auth)

A "La Niña-like" state occurring in the second year after large tropical volcanic eruptions during the past 1500 years

NASA Astrophysics Data System (ADS)

Sun, Weiyi; Liu, Jian; Wang, Bin; Chen, Deliang; Liu, Fei; Wang, Zhiyuan; Ning, Liang; Chen, Mingcheng

2018-04-01

Using an ensemble of nine El Niño/Southern Oscillation (ENSO) reconstructed proxies and volcano eruption proxies for the past 1500 years, this study shows that a significant La Niña state emerges in the second year (year (2) hereafter) after large tropical volcanic eruptions. The reasons for the development of La Niña are investigated using the Community Earth System Model (CESM). In the volcanic eruption experiment (Vol), a robust La Niña signal occurs in year (2), resembling the proxy records. The eastward positioning of the western North Pacific anomalous anticyclone (WNPAC) in Vol plays a critical role in the advanced decay of year (2) warming and the strong intensification of cooling in the equatorial eastern Pacific. The enhanced easterlies located on the southern edge of the WNPAC can stimulate consecutive oceanic upwelling Kelvin waves, shallowing the thermocline in the eastern Pacific, thereby resulting in a greater cooling rate by the enhanced thermocline feedback and cold zonal advection. Over the equatorial eastern Pacific, the reduced shortwave radiation contributes to the advanced decay of warming, while the upward latent heat flux augments the strong intensification of the cooling. Essentially, the eastward positioning of the WNPAC is a result of the volcanic forcing. The volcanic effect cools the maritime continent more than its adjacent oceans, thus pushing convective anomalies eastward during year (1). This induces vertical thermal advection and upward surface latent heat flux, thereby suppressing the development of warm Sea Surface Temperature over the central-western Pacific and causing the eastward positioning of the WNPAC in Vol.

What Is Being Done to Control Motion Sickness?

NASA Technical Reports Server (NTRS)

Hall, Y. D.

1985-01-01

AFT (Autogenic Feedback Training) involves practicing a series of mental exercises to speed up or slow down the control of autonomic activity. This produces a reduced tendency for autonomic activity levels to diverge from baseline (at rest) under stressful motion-sickness-inducing conditions. Subjects conditions. Subjects engaged in applying AFT exercises are required to closely monitor their own bodily sensations during motion-sickness-eliciting tests. These tests include the Coriolis Sickness Susceptibility Index (CSSI), which consists of sitting a subject into a rotating chair that moves at various speeds while a visual background turns at differing speeds and directions, and the Vertical Acceleration Rotation Device (VARD) test, which involves the placing of a subject in a drum that moves in an upward and downward motion until he or she is sick, while simultaneously monitoring the subject's vital signs. These tests provide investigators with evidence of slight changes in autonomic activities such as increases in heart rate, skin temperature, and sweat. All of these symptoms occur in subjects that experience bodily weakness or discomfort with the onset of motion sickness.

Buoyant Effects on the Flammability of Silicone Samples Planned for the Spacecraft Fire Experiment (Saffire)

NASA Technical Reports Server (NTRS)

Niehaus, Justin E.; Ferkul, Paul V.; Gokoglu, Suleyman A.; Ruff, Gary A.

2015-01-01

Flammability experiments on silicone samples were conducted in anticipation of the Spacecraft Fire Experiment (Saffire). The sample geometry was chosen to match the NASA 6001 Test 1 specification, namely 5 cm wide by 30 cm tall. Four thicknesses of silicone (0.25, 0.36, 0.61 and 1.00 mm) were examined. Tests included traditional upward buoyant flame spread using Test 1 procedures, downward opposed-flow flame spread, horizontal and angled flame spread, and forced-flow upward and downward flame spread. In addition to these configurations, upward and downward tests were conducted in a chamber with varying oxygen concentrations. In the upward buoyant flame spread tests, the flame generally did not burn the entire sample. As thickness was increased, the flame spread distance decreased before flame extinguishment. For the thickest sample, ignition could not be achieved. In the downward tests, the two thinnest samples permitted the flame to burn the entire sample, but the spread rate was lower compared to the corresponding upward values. The other two thicknesses could not be ignited in the downward configuration. The increased flammability for downward spreading flames relative to upward ones is uncommon. The two thinnest samples also burned completely in the horizontal configuration, as well as at angles up to 75 degrees from the horizontal. Upward tests in air with an added forced flow were more flammable. The upward and downward flammability behavior was compared in atmospheres of varying oxygen concentration to determine a maximum oxygen concentration for each configuration. Complementary analyses using EDS, TGA, and SEM techniques suggest the importance of the silica layer deposited downstream onto the unburned sample surface.

Television Image of a Large Upward Electrical Discharge Above a Thunderstorm System

NASA Astrophysics Data System (ADS)

Franz, R. C.; Nemzek, R. J.; Winckler, J. R.

1990-07-01

An image of an unusual luminous electrical discharge over a thunderstorm 250 kilometers from the observing site has been obtained with a low-light-level television camera. The discharge began at the cloud tops at 14 kilometers and extended into the clear air 20 kilometers higher. The image, which had a duration of less than 30 milliseconds, resembled two jets or fountains and was probably caused by two localized electric charge concentrations at the cloud tops. Large upward discharges may create a hazard for aircraft and rocket launches and, by penetrating into the ionosphere, may initiate whistler waves and other effects on a magnetospheric scale. Such upward electrical discharges may account for unexplained photometric observations of distant lightning events that showed a low rise rate of the luminous pulse and no electromagnetic sferic pulse of the type that accompanies cloud-to-earth lightning strokes. An unusually high rate of such photometric events was recorded during the night of 22 to 23 September 1989 during a storm associated with hurricane Hugo.

Television image of a large upward electrical discharge above a thunderstorm system.

PubMed

Franz, R C; Nemzek, R J; Winckler, J R

1990-07-06

An image of an unusual luminous electrical discharge over a thunderstorm 250 kilometers from the observing site has been obtained with a low-light-level television camera. The discharge began at the cloud tops at 14 kilometers and extended into the clear air 20 kilometers higher. The image, which had a duration of less than 30 milliseconds,resembled two jets or fountains and was probably caused by two localizd electric charge concentrations at the cloud tops. Large upward discharges may create a hazard for aircraft and rocket launches and, by penetrating into the ionosphere, may initiate whistler waves and other effects on a magnetospheric scale. Such upward electrical discharges may account for unexplained photometric observations of distant lightning events that showed a low rise rate of the luminous pulse and no electromagnetic sferic pulse of the type that accompanies cloud-to-earth lightning strokes. An unusually high rate of such photometric events was recorded during the night of 22 to 23 September 1989 during a storm associated with hurricane Hugo.

Liquid jet pumped by rising gas bubbles

NASA Technical Reports Server (NTRS)

Hussain, N. A.; Siegel, R.

1975-01-01

A two-phase mathematical model is proposed for calculating the induced turbulent vertical liquid flow. Bubbles provide a large buoyancy force and the associated drag on the liquid moves the liquid upward. The liquid pumped upward consists of the bubble wakes and the liquid brought into the jet region by turbulent entrainment. The expansion of the gas bubbles as they rise through the liquid is taken into account. The continuity and momentum equations are solved numerically for an axisymmetric air jet submerged in water. Water pumping rates are obtained as a function of air flow rate and depth of submergence. Comparisons are made with limited experimental information in the literature.

Iron availability limits the ocean nitrogen inventory stabilizing feedbacks between marine denitrification and nitrogen fixation

NASA Astrophysics Data System (ADS)

Moore, J. Keith; Doney, Scott C.

2007-06-01

Recent upward revisions in key sink/source terms for fixed nitrogen (N) in the oceans imply a short residence time and strong negative feedbacks involving denitrification and N fixation to prevent large swings in the ocean N inventory over timescales of a few centuries. We tested the strength of these feedbacks in a global biogeochemical elemental cycling (BEC) ocean model that includes water column denitrification and an explicit N fixing phytoplankton group. In the northern Indian Ocean and over longer timescales in the tropical Atlantic, we find strong stabilizing feedbacks that minimize changes in marine N inventory over timescales of ˜30-200 years. In these regions high atmospheric dust/iron inputs lead to phosphorus limitation of diazotrophs, and thus a tight link between N fixation and surface water N/P ratios. Maintenance of the oxygen minimum zones in these basins depends on N fixation driven export. The stabilizing feedbacks in other regions are significant but weaker owing to iron limitation of the diazotrophs. Thus Fe limitation appears to restrict the ability of N fixation to compensate for changes in denitrification in the current climate, perhaps leading the oceans to lose fixed N. We suggest that iron is the ultimate limiting nutrient leading to nitrogen being the proximate limiting nutrient over wide regions today. Iron stress was at least partially alleviated during more dusty, glacial times, leading to a higher marine N inventory, increased export production, and perhaps widespread phosphorus limitation of the phytoplankton community. The increased efficiency of the biological pump would have contributed to the glacial drawdown in atmospheric CO2.

Effects of feedback accountability and self-rating information on employee appraisals: a replication and extension.

PubMed

Shore, Ted H; Tashchian, Armen

2007-06-01

The influence of feedback accountability and self-rating information on employee performance appraisals was examined. Undergraduate business student participants assumed the role of "supervisor" and evaluated a fictitious "subordinate" whose performance on a clerical task was either moderately poor or very good. Participants were either given fictitious self-rating information, or no self-rating information, and were told they were expected to provide performance feedback to their ratee, or there was no feedback expectation. As expected, in Study 1 both self-rating information and expected feedback-sharing independently resulted in lenient ratings for poor performance, and the combined effects resulted in the highest ratings. By contrast, results for good performance (Study 2) were not significant. Implications of the findings for human resource management practice and research were discussed.

A Proposed Conceptual Framework and Investigation of Upward Feedback Receptivity in Medical Education.

PubMed

Kost, Amanda; Combs, Heidi; Smith, Sherilyn; Klein, Eileen; Kritek, Patricia; Robins, Lynne; Cianciolo, Anna T; Butani, Lavjay; Gigante, Joseph; Ramani, Subha

2015-01-01

WGEA 2015 CONFERENCE ABSTRACT (EDITED). Faculty Perceptions of Receiving Feedback From Third-Year Clerkship Students. Amanda Kost, Heidi Combs, Sherilyn Smith, Eileen Klein, Patricia Kritek, and Lynne Robins. PHENOMENON: In addition to giving feedback to 3rd-year clerkship students, some clerkship instructors receive feedback, requested or spontaneous, from students prior to the clerkship's end. The concept of bidirectional feedback is appealing as a means of fostering a culture of respectful communication and improvement. However, little is known about how teachers perceive this feedback in practice or how it impacts the learning environment. We performed 24 semistructured 30-minute interviews with 3 to 7 attending physician faculty members each in Pediatrics, Internal Medicine, Family Medicine, Surgery, Psychiatry, and Obstetrics and Gynecology who taught in 3rd-year required clerkships during the 2012-2013 academic year. Questions probed teachers' experience with and attitudes toward receiving student feedback. Prompts were used to elicit stories and obtain participant demographics. Interviews were audio-recorded, transcribed, and entered into Dedoose for qualitative analysis. Researchers read transcripts holistically for meaning, designed a coding template, and then independently coded each transcript. A constant comparative approach and regular meetings were used to ensure consistent coding between research team members. Participants ranged in age from 37 to 74, with 5 to 35 years of teaching experience. Seventy-one percent were male, and 83% identified as White. In our preliminary analysis, our informants reported a range of experience in receiving student feedback prior to the end of a clerkship, varying from no experience to having developed mechanisms to regularly request specific feedback about their programs. Most expressed openness to actively soliciting and receiving student feedback on their teaching during the clerkship although many questioned whether this process was feasible. Actual responses to receiving student feedback were mixed. Some reported having received feedback that motivated change, and others rejected the feedback they received on the grounds that it lacked validity or was inappropriate. Others expressed uncertainty about how they would react to student feedback. Faculty expressed a preference for receiving feedback about behaviors and items that were within their control. INSIGHTS: These findings suggest there is opportunity to pilot implementation of a structured student feedback mechanism, separate from teacher evaluations, in selected 3rd-year clerkships. Materials should developed to help faculty solicit, understand, and respond to student feedback and to help students frame and provide the kinds of feedback to teachers that will lead to suggested improvements. Both these endeavors have the potential to improve the clinical learning environment during 3rd-year clerkships through the cultivation of respectful communication and the encouragement of improvement in teaching efforts.

Social mobility and health in European countries: Does welfare regime type matter?

PubMed

Campos-Matos, Inês; Kawachi, Ichiro

2015-10-01

Health inequalities pose an important public health challenge in European countries, for which increased social mobility has been suggested as a cause. We sought to describe how the relationship between health inequalities and social mobility varies among welfare regime types in the European region. Data from six rounds of the European Social Survey was analyzed using multilevel statistical techniques, stratified by welfare regime type, including 237,535 individuals from 136 countries. Social mobility among individuals was defined according to the discrepancy between parental and offspring educational attainment. For each welfare regime type, the association between social mobility and self-rated health was examined using odds ratios and risk differences, controlling for parental education. Upwardly mobile individuals had between 23 and 44% lower odds of reporting bad or very bad self-rated health when compared to those who remained stable. On an absolute scale, former USSR countries showed the biggest and only significant differences for upward movement, while Scandinavian countries showed the smallest. Downward social mobility tended to be associated with worse health, but the results were less consistent. Upward social mobility is associated with worse health in all European welfare regime types. However, in Scandinavian countries the association of upward mobility was smaller, suggesting that the Nordic model is more effective in mitigating the impact of social mobility on health and/or of health on mobility. Copyright © 2015 Elsevier Ltd. All rights reserved.

Combined Student Ratings and Self-Assessment Provide Useful Feedback for Clinical Teachers

ERIC Educational Resources Information Center

Stalmeijer, Renee E.; Dolmans, Diana H. J. M.; Wolfhagen, Ineke H. A. P.; Peters, Wim G.; van Coppenolle, Lieve; Scherpbier, Albert J. J. A.

2010-01-01

Many evaluation instruments have been developed to provide feedback to physicians on their clinical teaching but written feedback alone is not always effective. We explored whether feedback effectiveness improved when teachers' self-assessment was added to written feedback based on student ratings. 37 physicians (10 residents, 27 attending…

Getting on the same page: The effect of normative feedback interventions on structured interview ratings.

PubMed

Hartwell, Christopher J; Campion, Michael A

2016-06-01

This study explores normative feedback as a way to reduce rating errors and increase the reliability and validity of structured interview ratings. Based in control theory and social comparison theory, we propose a model of normative feedback interventions (NFIs) in the context of structured interviews and test our model using data from over 20,000 interviews conducted by more than 100 interviewers over a period of more than 4 years. Results indicate that lenient and severe interviewers reduced discrepancies between their ratings and the overall normative mean rating after receipt of normative feedback, though changes were greater for lenient interviewers. When various waves of feedback were presented in later NFIs, the combined normative mean rating over multiple time periods was more predictive of subsequent rating changes than the normative mean rating from the most recent time period. Mean within-interviewer rating variance, along with interrater agreement and interrater reliability, increased after the initial NFI, but results from later NFIs were more complex and revealed that feedback interventions may lose effectiveness over time. A second study using simulated data indicated that leniency and severity errors did not impact rating validity, but did affect which applicants were hired. We conclude that giving normative feedback to interviewers will aid in minimizing interviewer rating differences and enhance the reliability of structured interview ratings. We suggest that interviewer feedback might be considered as a potential new component of interview structure, though future research is needed before a definitive conclusion can be drawn. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Video-augmented feedback for procedural performance.

PubMed

Wittler, Mary; Hartman, Nicholas; Manthey, David; Hiestand, Brian; Askew, Kim

2016-06-01

Resident programs must assess residents' achievement of core competencies for clinical and procedural skills. Video-augmented feedback may facilitate procedural skill acquisition and promote more accurate self-assessment. A randomized controlled study to investigate whether video-augmented verbal feedback leads to increased procedural skill and improved accuracy of self-assessment compared to verbal only feedback. Participants were evaluated during procedural training for ultrasound guided internal jugular central venous catheter (US IJ CVC) placement. All participants received feedback based on a validated 30-point checklist for US IJ CVC placement and validated 6-point procedural global rating scale. Scores in both groups improved by a mean of 9.6 points (95% CI: 7.8-11.4) on the 30-point checklist, with no difference between groups in mean score improvement on the global rating scale. In regards to self-assessment, participant self-rating diverged from faculty scoring, increasingly so after receiving feedback. Residents rated highly by faculty underestimated their skill, while those rated more poorly demonstrated increasing overestimation. Accuracy of self-assessment was not improved by addition of video. While feedback advanced the skill of the resident, video-augmented feedback did not enhance skill acquisition or improve accuracy of resident self-assessment compared to standard feedback.

Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

NASA Astrophysics Data System (ADS)

Meng, Yiqing; Lucas, Gary P.

2017-05-01

This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas-water and oil-gas-water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the water, which occurred preferentially at the pipe centre. For upward inclined multiphase flows RT#1 was found to give rise to water velocity profiles which are more consistent with results in the previous literature than was the case for RT#2—which leads to the tentative conclusion that the upward inclined multiphase flows investigated in the present study did not contain significant axisymmetric velocity components.

The mechanics of gravitaxis in Paramecium.

PubMed

Roberts, A M

2010-12-15

An analysis of swimming patterns in the ciliate Paramecium shows that the ability to swim preferentially upwards (negative gravitaxis) is primarily the result of upwardly curving trajectories. The trajectory characteristics are consistent with those produced by mechanical orientation. Cell profile measurements from microscope images suggest that the characteristic front-rear body asymmetry accounts for the observed orientation rates. Gravikinesis may result from interactions between the propelling cilia and the sedimentary flow around the cell, and it seems unlikely that an internal physiological gravity receptor exists in Paramecium.

High gradient magnetic beneficiation of dry pulverized coal via upwardly directed recirculating fluidization

DOEpatents

Eissenberg, David M.; Liu, Yin-An

1980-01-01

This invention relates to an improved device and method for the high gradient magnetic beneficiation of dry pulverized coal, for the purpose of removing sulfur and ash from the coal whereby the product is a dry environmentally acceptable, low-sulfur fuel. The process involves upwardly directed recirculating air fluidization of selectively sized powdered coal in a separator having sections of increasing diameters in the direction of air flow, with magnetic field and flow rates chosen for optimum separations depending upon particulate size.

Relaxation rates of gene expression kinetics reveal the feedback signs of autoregulatory gene networks

NASA Astrophysics Data System (ADS)

Jia, Chen; Qian, Hong; Chen, Min; Zhang, Michael Q.

2018-03-01

The transient response to a stimulus and subsequent recovery to a steady state are the fundamental characteristics of a living organism. Here we study the relaxation kinetics of autoregulatory gene networks based on the chemical master equation model of single-cell stochastic gene expression with nonlinear feedback regulation. We report a novel relation between the rate of relaxation, characterized by the spectral gap of the Markov model, and the feedback sign of the underlying gene circuit. When a network has no feedback, the relaxation rate is exactly the decaying rate of the protein. We further show that positive feedback always slows down the relaxation kinetics while negative feedback always speeds it up. Numerical simulations demonstrate that this relation provides a possible method to infer the feedback topology of autoregulatory gene networks by using time-series data of gene expression.

Controls on subsurface methane fluxes and shallow gas formation in Baltic Sea sediment (Aarhus Bay, Denmark)

NASA Astrophysics Data System (ADS)

Flury, Sabine; Røy, Hans; Dale, Andrew W.; Fossing, Henrik; Tóth, Zsuzsanna; Spiess, Volkhard; Jensen, Jørn Bo; Jørgensen, Bo Barker

2016-09-01

Shallow gas accumulates in coastal marine sediments when the burial rate of reactive organic matter beneath the sulfate zone is sufficiently high and the methanogenic zone is sufficiently deep. We investigated the controls on methane production and free methane gas accumulation along a 400 m seismo-acoustic transect across a sharp transition from gas-free into gas-bearing sediment in Aarhus Bay (Denmark). Twelve gravity cores were taken, in which the pore water was analyzed for inorganic solutes while rates of organic carbon mineralization were measured experimentally by 35SO42- radiotracer method. The thickness of organic-rich Holocene mud increased from 5 to 10 m along the transect concomitant with a shallowing of the depth of the sulfate-methane transition from >4 m to 2.5 m. In spite of drastic differences in the distribution of methane and sulfate in the sediment along the transect, there were only small differences in total mineralization, and methanogenesis was only equivalent to about 1% of sulfate reduction. Shallow gas appeared where the mud thickness exceeded 8-9 m. Rates of methanogenesis increased along the transect as did the upward diffusive flux of methane. Interestingly, the increase in the sedimentation rate and Holocene mud thickness had only a modest direct effect on methanogenesis rates in deep sediments. This increase in methane flux, however, triggered a shallowing of the sulfate-methane transition which resulted in a large increase in methanogenesis at the top of the methanogenic zone. Thus, our results demonstrate a positive feedback mechanism that causes a strong enhancement of methanogenesis and explains the apparently abrupt appearance of gas when a threshold thickness of organic-rich mud is exceeded.

Feedback on prescribing errors to junior doctors: exploring views, problems and preferred methods.

PubMed

Bertels, Jeroen; Almoudaris, Alex M; Cortoos, Pieter-Jan; Jacklin, Ann; Franklin, Bryony Dean

2013-06-01

Prescribing errors are common in hospital inpatients. However, the literature suggests that doctors are often unaware of their errors as they are not always informed of them. It has been suggested that providing more feedback to prescribers may reduce subsequent error rates. Only few studies have investigated the views of prescribers towards receiving such feedback, or the views of hospital pharmacists as potential feedback providers. Our aim was to explore the views of junior doctors and hospital pharmacists regarding feedback on individual doctors' prescribing errors. Objectives were to determine how feedback was currently provided and any associated problems, to explore views on other approaches to feedback, and to make recommendations for designing suitable feedback systems. A large London NHS hospital trust. To explore views on current and possible feedback mechanisms, self-administered questionnaires were given to all junior doctors and pharmacists, combining both 5-point Likert scale statements and open-ended questions. Agreement scores for statements regarding perceived prescribing error rates, opinions on feedback, barriers to feedback, and preferences for future practice. Response rates were 49% (37/75) for junior doctors and 57% (57/100) for pharmacists. In general, doctors did not feel threatened by feedback on their prescribing errors. They felt that feedback currently provided was constructive but often irregular and insufficient. Most pharmacists provided feedback in various ways; however some did not or were inconsistent. They were willing to provide more feedback, but did not feel it was always effective or feasible due to barriers such as communication problems and time constraints. Both professional groups preferred individual feedback with additional regular generic feedback on common or serious errors. Feedback on prescribing errors was valued and acceptable to both professional groups. From the results, several suggested methods of providing feedback on prescribing errors emerged. Addressing barriers such as the identification of individual prescribers would facilitate feedback in practice. Research investigating whether or not feedback reduces the subsequent error rate is now needed.

Effect of feedback mode and task difficulty on quality of timing decisions in a zero-sum game.

PubMed

Tikuisis, Peter; Vartanian, Oshin; Mandel, David R

2014-09-01

The objective was to investigate the interaction between the mode of performance outcome feedback and task difficulty on timing decisions (i.e., when to act). Feedback is widely acknowledged to affect task performance. However, the extent to which feedback display mode and its impact on timing decisions is moderated by task difficulty remains largely unknown. Participants repeatedly engaged a zero-sum game involving silent duels with a computerized opponent and were given visual performance feedback after each engagement. They were sequentially tested on three different levels of task difficulty (low, intermediate, and high) in counterbalanced order. Half received relatively simple "inside view" binary outcome feedback, and the other half received complex "outside view" hit rate probability feedback. The key dependent variables were response time (i.e., time taken to make a decision) and survival outcome. When task difficulty was low to moderate, participants were more likely to learn and perform better from hit rate probability feedback than binary outcome feedback. However, better performance with hit rate feedback exacted a higher cognitive cost manifested by higher decision response time. The beneficial effect of hit rate probability feedback on timing decisions is partially moderated by task difficulty. Performance feedback mode should be judiciously chosen in relation to task difficulty for optimal performance in tasks involving timing decisions.

Randomised crossover trial of rate feedback and force during chest compressions for paediatric cardiopulmonary resuscitation.

PubMed

Gregson, Rachael Kathleen; Cole, Tim James; Skellett, Sophie; Bagkeris, Emmanouil; Welsby, Denise; Peters, Mark John

2017-05-01

To determine the effect of visual feedback on rate of chest compressions, secondarily relating the forces used. Randomised crossover trial. Tertiary teaching hospital. Fifty trained hospital staff. A thin sensor-mat placed over the manikin's chest measured rate and force. Rescuers applied compressions to the same paediatric manikin for two sessions. During one session they received visual feedback comparing their real-time rate with published guidelines. Primary: compression rate. Secondary: compression and residual forces. Rate of chest compressions (compressions per minute (compressions per minute; cpm)) varied widely (mean (SD) 111 (13), range 89-168), with a fourfold difference in variation during session 1 between those receiving and not receiving feedback (108 (5) vs 120 (20)). The interaction of session by feedback order was highly significant, indicating that this difference in mean rate between sessions was 14 cpm less (95% CI -22 to -5, p=0.002) in those given feedback first compared with those given it second. Compression force (N) varied widely (mean (SD) 306 (94); range 142-769). Those receiving feedback second (as opposed to first) used significantly lower force (adjusted mean difference -80 (95% CI -128 to -32), p=0.002). Mean residual force (18 N, SD 12, range 0-49) was unaffected by the intervention. While visual feedback restricted excessive compression rates to within the prescribed range, applied force remained widely variable. The forces required may differ with growth, but such variation treating one manikin is alarming. Feedback technologies additionally measuring force (effort) could help to standardise and define effective treatments throughout childhood. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Impact of infection control interventions on rates of Staphylococcus aureus bacteraemia in National Health Service acute hospitals, East Midlands, UK, using interrupted time-series analysis.

PubMed

Newitt, S; Myles, P R; Birkin, J A; Maskell, V; Slack, R C B; Nguyen-Van-Tam, J S; Szatkowski, L

2015-05-01

Reducing healthcare-associated infection (HCAI) is a UK national priority. Multiple national and regional interventions aimed at reduction have been implemented in National Health Service acute hospitals, but assessment of their effectiveness is methodologically challenging. To assess the effectiveness of national and regional interventions undertaken between 2004 and 2008 on rates of meticillin-resistant Staphylococcus aureus (MRSA) and meticillin-sensitive Staphylococcus aureus (MSSA) bacteraemia within acute hospitals in the East Midlands, using interrupted time-series analysis. We used segmented regression to compare rates of MRSA and MSSA bacteraemia in the pre-intervention, implementation, and post-intervention phases for combined intervention packages in eight acute hospitals. Most of the change in MSSA and MRSA rates occurred during the implementation phase. During this phase, there were significant downward trends in MRSA rates for seven of eight acute hospital groups; in four, this was a steeper quarter-on-quarter decline compared with the pre-intervention phase, and, in one, an upward trend in the pre-intervention phase was reversed. Regarding MSSA, there was a significant positive effect in four hospital groups: one upward trend during the pre-intervention phase was reversed, two upward trends plateaued, and in one hospital group an indeterminate trend decreased significantly. However, there were significant increasing trends in quarterly MSSA rates in four hospital groups during the implementation or post-intervention periods. The impact of interventions varied by hospital group but the overall results suggest that national and regional campaigns had a beneficial impact on MRSA and MSSA bacteraemia within the East Midlands. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Frequency, predictors, and economic impact of upward dose adjustment of infliximab in managed care patients with rheumatoid arthritis.

PubMed

Ollendorf, Daniel A; Massarotti, Elena; Birbara, Charles; Burgess, Somali Misra

2005-06-01

To examine dosing patterns and costs among rheumatoid arthritis (RA) patients newly treated with infliximab in a large national health care claims database. Using data from a proprietary database of pharmacy and medical claims for 75 U.S. health plans, RA patients newly treated with infliximab between June 2000 and June 2002 were selected and assigned an .index date. based on the first infusion. A pretreatment period of 6 months was created; patients were also followed for a minimum of 6 months after the initial infusion. Follow-up was allowed to vary beyond this minimum 6 months in order to preserve all available patient data. A maintenance number of infliximab vials was determined as of the second infusion; patients with 1 subsequent increase in vials used or 2 intervals between infusions of <49 days were considered to have had an upward dose adjustment. Differences (i.e., between those with upward dose adjustment and those with no upward dose) in patient characteristics were examined using descriptive statistics. In addition, time to upward dose adjustment and factors influencing its likelihood were analyzed using Kaplan-Meier and Cox proportional hazards techniques. Finally, differences in RA-related and unrelated costs (medication, outpatient, inpatient, and total, expressed in 2003 dollars) were examined using Wilcoxon rank-sum tests and were also stratified by a number of patient characteristics found to differ between the 2 groups. A total of 1,236 patients met all study entry criteria and were included in these analyses. One or more upward dose adjustments were experienced by 61.7% (N=762) of patients during an average of 15 months of follow-up (median =13 months, range=6 to 31 months). The majority (63.3%) of upward dose adjustments were due to increases in the number of billed vials. Median time to upward dose adjustment was 254 days and declined steadily based on year of initiation (from 330 days in 2000 to 224 days in 2002). Factors significantly influencing upward dose adjustment included pretreatment use of leflunomide, comorbid Crohn.s disease, and pretreatment liver function testing. During followup, patients in the upward dose adjustment group used a mean (SD) of 30.28 (20.90) vials of infliximab, compared with 15.90 (14.28) among those not adjusting dose (P<0.001). Annualized (i.e., standardized to a 365-day rate) RA-related costs were higher by more than 50% among patients with upward dose adjustment (SD $22,283 [$20,517] versus $14,425 [$10,828] for those without upward dose adjustment; P<0.001); differences were driven almost entirely by the costs of infliximab itself ($16,336 [$9,490] versus $9,573 [$6,790], P<0.001). In a cohort of managed care members with RA, upward dose adjustment with infliximab was frequent and appeared to occur earlier in the drug therapy in 2002 compared with 2000. Upward dose adjustment was associated with significant increases in drug treatment costs; therefore, payers and providers should consider the impact of current dosing trends when monitoring the use of biologics for autoimmune diseases.

Micromachined force-balance feedback accelerometer with optical displacement detection

DOEpatents

Nielson, Gregory N.; Langlois, Eric; Baker, Michael; Okandan, Murat; Anderson, Robert

2014-07-22

An accelerometer includes a proof mass and a frame that are formed in a handle layer of a silicon-on-an-insulator (SOI). The proof mass is separated from the frame by a back-side trench that defines a boundary of the proof mass. The accelerometer also includes a reflector coupled to a top surface of the proof mass. An optical detector is located above the reflector at the device side. The accelerometer further includes at least one suspension spring. The suspension spring has a handle anchor that extends downwards from the device side to the handle layer to mechanically support upward and downward movement of the proof mass relative to a top surface of the proof mass.

Surviving annual performance reviews.

PubMed

Lazarus, Arthur

2008-01-01

Physicians who work in organizational settings can expect to be evaluated at least twice a year. Yet physicians are accustomed to functioning autonomously, and they may resist having their performance measured or become anxious at the thought of it. Several recommendations are made to help physicians survive the ordeal: (1) establish measurable goals and objectives for the year; (2) perform at your very best at all times; (3) obtain feedback about your performance from your colleagues; (4) ask for a mentor if you lack experience; (5) learn to manage upward; (6) let your boss know when other people have praised your work; (7) insist on face-to-face evaluations; and (8) sign your annual performance review and indicate agreement or disagreement.

Radiative effects of ozone waves on the Northern Hemisphere polar vortex and its modulation by the QBO

NASA Astrophysics Data System (ADS)

Silverman, Vered; Harnik, Nili; Matthes, Katja; Lubis, Sandro W.; Wahl, Sebastian

2018-05-01

The radiative effects induced by the zonally asymmetric part of the ozone field have been shown to significantly change the temperature of the NH winter polar cap, and correspondingly the strength of the polar vortex. In this paper, we aim to understand the physical processes behind these effects using the National Center for Atmospheric Research (NCAR)'s Whole Atmosphere Community Climate Model, run with 1960s ozone-depleting substances and greenhouse gases. We find a mid-winter polar vortex influence only when considering the quasi-biennial oscillation (QBO) phases separately, since ozone waves affect the vortex in an opposite manner. Specifically, the emergence of a midlatitude QBO signal is delayed by 1-2 months when radiative ozone-wave effects are removed. The influence of ozone waves on the winter polar vortex, via their modulation of shortwave heating, is not obvious, given that shortwave heating is largest during fall, when planetary stratospheric waves are weakest. Using a novel diagnostic of wave 1 temperature amplitude tendencies and a synoptic analysis of upward planetary wave pulses, we are able to show the chain of events that lead from a direct radiative effect on weak early fall upward-propagating planetary waves to a winter polar vortex modulation. We show that an important stage of this amplification is the modulation of individual wave life cycles, which accumulate during fall and early winter, before being amplified by wave-mean flow feedbacks. We find that the evolution of these early winter upward planetary wave pulses and their induced stratospheric zonal mean flow deceleration is qualitatively different between QBO phases, providing a new mechanistic view of the extratropical QBO signal. We further show how these differences result in opposite radiative ozone-wave effects between east and west QBOs.

Engaging Underserved and Underrepresented Students in the Earth Sciences through a Summer Outreach Program

NASA Astrophysics Data System (ADS)

Güereque, M.; Olgin, J. G.; Pennington, D. D.

2016-12-01

The EarthTech outreach program at the University of Texas at El Paso (UTEP) seeks to expand the inclusion of underserved and under-represented high-school students into the geoscience pipeline. A successful partnership with the federally funded, year round college preparatory program for high school students Upward Bound (UB) program at UTEP was decisive for the success and execution of the program. Program activities aimed to engage students and expand their knowledge of the Earth Sciences through participation in STEM hands-on activities, incorporating technology and field experiences. For its second year, the program chose to address the intersection of science and societal issues by selecting an overall topic for the weeklong program that students could relate and understand from personal experiences, facilitating participation. The exposure to outdoor on-site learning experiences via field trips proved a critical component based on student feedback, by allowing the students to engage with their surroundings and relate to basic Earth Science knowledge and principles. Qualitative feedback and discussion of the program and its activities are presented here.

Non-linear feedbacks drive strain partitioning within an active orogen, southern Alaska

NASA Astrophysics Data System (ADS)

Hooks, B.; Koons, P. O.; Upton, P.

2011-12-01

Temperature plays a very important role in the partitioning of deformation within an active orogen. Local variations in the thermal structure of actively uplifting areas can reinforce focused partitioning of strain locally, whereas regional variations can alter deformation patterns on a much broader scale resulting in the re-organization of an entire orogen. Within southern Alaska, the Yakutat micro-terrane has been subducting beneath North America over the previous ~10 Ma. Early deformation related to this event drove uplift of the Alaska Range, as evidenced by stratigraphic and thermochronologic datasets. This was followed by a southerly discontinuous spatial jump in the deformation front to the coastal St. Elias Range. Here we present 3D numerical models that simulate deformation of Earth materials given assigned applied velocity boundary conditions and mechanical and thermal constitutive relationships on a macro- (plate boundary) and meso-scale (<50-km). The goal is to reproduce first-order strain and uplift patterns within this evolving orogen. The macro-scale model undergoes a spatial and temporal reorganization of deformation as strain is progressively shifted to a trench-ward orogenic wedge, the inlet orogen. Subduction related cooling of the fore-arc (i.e. tectonic refrigeration) provides control on the location of the inlet orogen. This control is based upon the creation of a thin sliver of cold, strong material along the mega-thrust interface. The stronger mega-thrust facilitates more efficient transfer of strain, driving the formation of the inlet orogen and determining the location of its frontal toe. This toe is further stabilized by upward displacement of the upper crust over the refrigerated section. This upward motion causes thermal weakening of the upper crust as a tectonic aneurysm with the location controlled by the thermally strengthened lower crust. The net result is an ever weakening upper crust that focuses strain creating dramatic topography, extreme rates of erosion and uplift, and fast exhumation.

Sensory-Motor Networks Involved in Speech Production and Motor Control: An fMRI Study

PubMed Central

Behroozmand, Roozbeh; Shebek, Rachel; Hansen, Daniel R.; Oya, Hiroyuki; Robin, Donald A.; Howard, Matthew A.; Greenlee, Jeremy D.W.

2015-01-01

Speaking is one of the most complex motor behaviors developed to facilitate human communication. The underlying neural mechanisms of speech involve sensory-motor interactions that incorporate feedback information for online monitoring and control of produced speech sounds. In the present study, we adopted an auditory feedback pitch perturbation paradigm and combined it with functional magnetic resonance imaging (fMRI) recordings in order to identify brain areas involved in speech production and motor control. Subjects underwent fMRI scanning while they produced a steady vowel sound /a/ (speaking) or listened to the playback of their own vowel production (playback). During each condition, the auditory feedback from vowel production was either normal (no perturbation) or perturbed by an upward (+600 cents) pitch shift stimulus randomly. Analysis of BOLD responses during speaking (with and without shift) vs. rest revealed activation of a complex network including bilateral superior temporal gyrus (STG), Heschl's gyrus, precentral gyrus, supplementary motor area (SMA), Rolandic operculum, postcentral gyrus and right inferior frontal gyrus (IFG). Performance correlation analysis showed that the subjects produced compensatory vocal responses that significantly correlated with BOLD response increases in bilateral STG and left precentral gyrus. However, during playback, the activation network was limited to cortical auditory areas including bilateral STG and Heschl's gyrus. Moreover, the contrast between speaking vs. playback highlighted a distinct functional network that included bilateral precentral gyrus, SMA, IFG, postcentral gyrus and insula. These findings suggest that speech motor control involves feedback error detection in sensory (e.g. auditory) cortices that subsequently activate motor-related areas for the adjustment of speech parameters during speaking. PMID:25623499

Audit and Feedback: A Quality Improvement Study to Increase Pneumococcal Vaccination Rates.

PubMed

Clark, Rebecca Culver; Carter, Kimberly Ferren; Jackson, Julie; Hodges, Deborah

The purpose of this quality improvement study was to explore the impact of audit and feedback on the pneumococcal immunization rate for at-risk adults in ambulatory settings. Study findings support the hypothesis that timely, individualized audit and feedback can have a positive impact on immunization rate; generalized feedback that did not provide actionable information did not have the same impact. The difference between the interventions was significant, χ (1, N = 1993) = 124.7, P <.001.

High Upward Fluxes of Formic Acid from a Boreal Forest Canopy

NASA Technical Reports Server (NTRS)

Schobesberger, Siegfried; Lopez-Hilifiker, Felipe D.; Taipale, Ditte; Millet, Dylan B.; D'Ambro, Emma L.; Rantala, Pekka; Mammarella, Ivan; Zhou, Putian; Wolfe, Glenn M.; Lee, Ben H.;

Upward swimming of a sperm cell in shear flow.

PubMed

Omori, Toshihiro; Ishikawa, Takuji

2016-03-01

Mammalian sperm cells are required to swim over long distances, typically around 1000-fold their own length. They must orient themselves and maintain a swimming motion to reach the ovum, or egg cell. Although the mechanism of long-distance navigation is still unclear, one possible mechanism, rheotaxis, was reported recently. This work investigates the mechanism of the rheotaxis in detail by simulating the motions of a sperm cell in shear flow adjacent to a flat surface. A phase diagram was developed to show the sperm's swimming motion under different shear rates, and for varying flagellum waveform conditions. The results showed that, under shear flow, the sperm is able to hydrodynamically change its swimming direction, allowing it to swim upwards against the flow, which suggests that the upward swimming of sperm cells can be explained using fluid mechanics, and this can then be used to further understand physiology of sperm cell navigation.

Social deviance activates the brain's error-monitoring system.

PubMed

Kim, Bo-Rin; Liss, Alison; Rao, Monica; Singer, Zachary; Compton, Rebecca J

2012-03-01

Social psychologists have long noted the tendency for human behavior to conform to social group norms. This study examined whether feedback indicating that participants had deviated from group norms would elicit a neural signal previously shown to be elicited by errors and monetary losses. While electroencephalograms were recorded, participants (N = 30) rated the attractiveness of 120 faces and received feedback giving the purported average rating made by a group of peers. The feedback was manipulated so that group ratings either were the same as a participant's rating or deviated by 1, 2, or 3 points. Feedback indicating deviance from the group norm elicited a feedback-related negativity, a brainwave signal known to be elicited by objective performance errors and losses. The results imply that the brain treats deviance from social norms as an error.

Skill in Precipitation Forecasting in the National Weather Service.

NASA Astrophysics Data System (ADS)

Charba, Jerome P.; Klein, William H.

1980-12-01

All known long-term records of forecasting performance for different types of precipitation forecasts in the National Weather Service were examined for relative skill and secular trends in skill. The largest upward trends were achieved by local probability of precipitation (PoP) forecasts for the periods 24-36 h and 36-48 h after 0000 and 1200 GMT. Over the last 13 years, the skill of these forecasts has improved at an average rate of 7.2% per 10-year interval. Over the same period, improvement has been smaller in local PoP skill in the 12-24 h range (2.0% per 10 years) and in the accuracy of "Yea/No" forecasts of measurable precipitation. The overall trend in accuracy of centralized quantitative precipitation forecasts of 0.5 in and 1.0 in has been slightly upward at the 0-24 h range and strongly upward at the 24-48 h range. Most of the improvement in these forecasts has been achieved from the early 1970s to the present. Strong upward accuracy trends in all types of precipitation forecasts within the past eight years are attributed primarily to improvements in numerical and statistical centralized guidance forecasts.The skill and accuracy of both measurable and quantitative precipitation forecasts is 35-55% greater during the cool season than during the warm season. Also, the secular rate of improvement of the cool season precipitation forecasts is 50-110% greater than that of the warm season. This seasonal difference in performance reflects the relative difficulty of forecasting predominantly stratiform precipitation of the cool season and convective precipitation of the warm season.

Random bit generation at tunable rates using a chaotic semiconductor laser under distributed feedback.

PubMed

Li, Xiao-Zhou; Li, Song-Sui; Zhuang, Jun-Ping; Chan, Sze-Chun

2015-09-01

A semiconductor laser with distributed feedback from a fiber Bragg grating (FBG) is investigated for random bit generation (RBG). The feedback perturbs the laser to emit chaotically with the intensity being sampled periodically. The samples are then converted into random bits by a simple postprocessing of self-differencing and selecting bits. Unlike a conventional mirror that provides localized feedback, the FBG provides distributed feedback which effectively suppresses the information of the round-trip feedback delay time. Randomness is ensured even when the sampling period is commensurate with the feedback delay between the laser and the grating. Consequently, in RBG, the FBG feedback enables continuous tuning of the output bit rate, reduces the minimum sampling period, and increases the number of bits selected per sample. RBG is experimentally investigated at a sampling period continuously tunable from over 16 ns down to 50 ps, while the feedback delay is fixed at 7.7 ns. By selecting 5 least-significant bits per sample, output bit rates from 0.3 to 100 Gbps are achieved with randomness examined by the National Institute of Standards and Technology test suite.

Census Undercount and the Undercount of the Black Population.

ERIC Educational Resources Information Center

Nguyen, Phung

1996-01-01

Argues that blacks have been disproportionately undercounted in the census and this undercount has resulted in such biased statistics as proportions of black female-headed households, victimization rates of black males, or crude death rates of blacks. Further, these statistics are biased upward and downward, and together they generate distorted…

Developmental Change in Feedback Processing as Reflected by Phasic Heart Rate Changes

ERIC Educational Resources Information Center

Crone, Eveline A.; Jennings, J. Richard; Van der Molen, Maurits W.

2004-01-01

Heart rate was recorded from 3 age groups (8-10, 12, and 20-26 years) while they performed a probabilistic learning task. Stimuli had to be sorted by pressing a left versus right key, followed by positive or negative feedback. Adult heart rate slowed following negative feedback when stimuli were consistently mapped onto the left or right key…

Spatiotemporal changes of freezing/thawing indices and their response to recent climate change on the Qinghai-Tibet Plateau from 1980 to 2013

NASA Astrophysics Data System (ADS)

Wu, Tonghua; Qin, Yanhui; Wu, Xiaodong; Li, Ren; Zou, Defu; Xie, Changwei

2018-05-01

The spatial and temporal changes of the ground surface freezing indices (GFIs), ground surface thawing indices (GTIs), air freezing indices (AFIs), and air thawing indices (ATIs) in permafrost and seasonally frozen ground regions of the Qinghai-Tibet Plateau (QTP) were analyzed based on the daily ground surface and air temperatures from 69 meteorological stations using the Mann-Kendall test and Sen's slope estimate. The spatial patterns of the freezing indices (FIs) and thawing indices (TIs) are nearly negatively correlated. On the annual scale, the GFI and GTI are greater than the AFI and ATI in both permafrost and seasonally frozen ground regions. The marked upward and downward trends have been observed for the time series of TI and FI, respectively, since 1998 on the QTP. Moreover, GFI and AFI decrease more significantly in permafrost regions than in seasonally frozen ground regions; the increasing rate of GTI and ATI in the seasonally frozen ground regions is greater than that in the permafrost regions. In permafrost regions, the downward trend of FI is greater than the upward trend of TI. However, the upward trend of TI shows a more drastic change than the FI in the seasonally frozen ground regions. The results indicate that the warming in the permafrost regions is more pronounced in winter than in the other seasons. The summer warming is more pronounced than the other seasons in the seasonally frozen ground regions. The decreasing rate of AFI and GFI increases as the altitude rises, while they decrease with increasing ATI. The average decreasing rate of GFI is greater than that of the AFI in different altitudinal zones. The greatest decrease of FI occurs in permafrost regions in the hinterland of the QTP, which indicates the dominant winter warming in this region. The downward trend of FI and upward trend of TI are responsible for the reported permafrost degradation on the QTP.

Quantifying morphological changes of cape-related shoals

NASA Astrophysics Data System (ADS)

Paniagua-Arroyave, J. F.; Adams, P. N.; Parra, S. M.; Valle-Levinson, A.

2017-12-01

The rising demand for marine resources has motivated the study of inner shelf transport processes, especially in locations with highly-developed coastlines, endangered-species habitats, and valuable economic resources. These characteristics are found at Cape Canaveral shoals, on the Florida Atlantic coast, where transport dynamics and morphological evolution are not well understood. To study morphological changes at these shoals, two sets of paired upward- and downward-pointing acoustic Doppler current profilers (ADCPs) were deployed in winter 2015-2016. One set was deployed at the inner swale of Shoal E, 20 km southeast of the cape tip in 13 m depth, while the other set was located at the edge of Southeast shoal in 5 m deep. Upward-pointing velocity profiles and suspended particle concentrations were implemented in the Exner equation to quantify instantaneous rates of change in bed elevation. This computation includes changes in sediment concentration and the advection of suspended particles, but does not account for spatial gradients in bed-load fluxes and water velocities. The results of the computation were then compared to bed change rates measured directly by the downward-pointing ADCPs. At the easternmost ridge, quantified bed elevation change rates ranged from -7×10-7 to 4×10-7 m/s, and those at the inner swale ranged from -4×10-7 to 8×10-7 m/s. These values were two orders of magnitude smaller than rates measured by downward-pointing ADCPs. Moreover, the cumulative changes were two orders of magnitude larger at the ridge (-0.33 m, downward, and -0.13, m upward) than at the inner swale (cf. -6×10-3 m, downward, and 3×10-3 m, upward). These values suggest that bedform migration may be occurring at the ridge, that suspended sediments account for up to 30% of total bed changes, and that gradients in bed-load fluxes exert control on morphological change over the shoals. Despite uncertainties related to the ADCP-derived sediment concentrations, these findings provide preliminary evidence about the spatial variability in morphological changes over cape-related shoals.

Experimental investigation of wood combustion in a fixed bed with hot air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Markovic, Miladin, E-mail: m.markovic@utwente.nl; Bramer, Eddy A.; Brem, Gerrit

Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignitionmore » occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of the primary air speed, fuel moisture and inert content on the combustion characteristics (ignition rate, combustion rate, ignition front speed and temperature of the reaction zone) is evaluated. The upward combustion concept decouples the drying, devolatilization and burnout phase. In this way the moisture and inert content of the waste have almost no influence on the combustion process. In this paper an experimental comparison between conventional and reversed combustion is presented.« less

The effect of real-time vibrotactile feedback delivered through an augmented fork on eating rate, satiation, and food intake.

PubMed

Hermans, Roel C J; Hermsen, Sander; Robinson, Eric; Higgs, Suzanne; Mars, Monica; Frost, Jeana H

2017-06-01

Eating rate is a basic determinant of appetite regulation, as people who eat more slowly feel sated earlier and eat less. Without assistance, eating rate is difficult to modify due to its automatic nature. In the current study, participants used an augmented fork that aimed to decelerate their rate of eating. A total of 114 participants were randomly assigned to the Feedback Condition (FC), in which they received vibrotactile feedback from their fork when eating too fast (i.e., taking more than one bite per 10 s), or a Non-Feedback Condition (NFC). Participants in the FC took fewer bites per minute than did those in the NFC. Participants in the FC also had a higher success ratio, indicating that they had significantly more bites outside the designated time interval of 10 s than did participants in the NFC. A slower eating rate, however, did not lead to a significant reduction in the amount of food consumed or level of satiation. These findings indicate that real-time vibrotactile feedback delivered through an augmented fork is capable of reducing eating rate, but there is no evidence from this study that this reduction in eating rate is translated into an increase in satiation or reduction in food consumption. Overall, this study shows that real-time vibrotactile feedback may be a viable tool in interventions that aim to reduce eating rate. The long-term effectiveness of this form of feedback on satiation and food consumption, however, awaits further investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

In situ quantification of spatial and temporal variability of hyporheic exchange in static and mobile gravel-bed rivers

USGS Publications Warehouse

Rosenberry, Donald O.; Klos, P. Zion; Neal, Andrew

2012-01-01

Seepage meters modified for use in flowing water were used to directly measure rates of exchange between surface and subsurface water in a gravel- and cobble bed river in western Pennsylvania, USA (Allegheny River, Q mean = 190 m 3/s) and a sand- and gravel-bed river in Colorado, USA (South Platte River, Q mean = 9??7 m 3/s). Study reaches at the Allegheny River were located downstream from a dam. The bed was stable with moss, algae, and river grass present in many locations. Median seepage was + 0??28 m/d and seepage was highly variable among measurement locations. Upward and downward seepage greatly exceeded the median seepage rate, ranging from + 2??26 (upward) to - 3??76 (downward) m/d. At the South Platte River site, substantial local-scale bed topography as well as mobile bedforms resulted in spatial and temporal variability in seepage greatly in exceedence of the median groundwater discharge rate of 0??24 m/d. Both upward and downward seepage were recorded along every transect across the river with rates ranging from + 2??37 to - 3??40 m/d. Despite a stable bed, which commonly facilitates clogging by fine-grained or organic sediments, seepage rates at the Allegheny River were not reduced relative to those at the South Platte River. Seepage rate and direction depended primarily on measurement position relative to local- and meso-scale bed topography at both rivers. Hydraulic gradients were small at nearly all seepage-measurement locations and commonly were not a good indicator of seepage rate or direction. Therefore, measuring hydraulic gradient and hydraulic conductivity at in-stream piezometers may be misleading if used to determine seepage flux across the sediment-water interface. Such a method assumes that flow between the well screen and sediment-water interface is vertical, which appears to be a poor assumption in coarse-grained hyporheic settings.

Understanding Material Property Impacts on Co-Current Flame Spread: Improving Understanding Crucial for Fire Safety

NASA Technical Reports Server (NTRS)

Ruff, Gary (Technical Monitor); Rangwala, Ali S.; Buckley, Steven G.; Torero, Jose L.

2004-01-01

The prospect of long-term manned space flight brings fresh urgency to the development of an integrated and fundamental approach to the study of material flammability. Currently, NASA uses two tests, the upward flame propagation test and heat and visible smoke release rate test, to assess the flammability properties of materials to be used in space under microgravity conditions. The upward flame propagation test can be considered in the context of the 2-D analysis of Emmons. This solution incorporates material properties by a "mass transfer number", B in the boundary conditions.

Mass Conservation and Inference of Metabolic Networks from High-Throughput Mass Spectrometry Data

PubMed Central

Bandaru, Pradeep; Bansal, Mukesh

2011-01-01

Abstract We present a step towards the metabolome-wide computational inference of cellular metabolic reaction networks from metabolic profiling data, such as mass spectrometry. The reconstruction is based on identification of irreducible statistical interactions among the metabolite activities using the ARACNE reverse-engineering algorithm and on constraining possible metabolic transformations to satisfy the conservation of mass. The resulting algorithms are validated on synthetic data from an abridged computational model of Escherichia coli metabolism. Precision rates upwards of 50% are routinely observed for identification of full metabolic reactions, and recalls upwards of 20% are also seen. PMID:21314454

Analysis of vertical flow during ambient and pumped conditions in four monitoring wells at the Pantex Plant, Carson County, Texas, July-September 2008

USGS Publications Warehouse

Stanton, Gregory P.; Thomas, Jonathan V.; Stoval, Jeffery

2009-01-01

Logs collected in monitoring well PTX06–1068 during ambient conditions indicate a static environment with no flow. During pumping there was upward vertical flow at rates ranging from 0.4 to 4.8 gallons per minute. During pumping, a gradual trend of more positive flowmeter values (upward flow) with distance up the well was observed. Estimated total transmissivity for four production zones identified from Flow–B numerical model results taken together was calculated to be about 200 feet squared per day.

78 FR 18326 - Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

...; Comment Request; Upward Bound and Upward Bound Math Science Annual Performance Report AGENCY: The Office... considered public records. Title of Collection: Upward Bound and Upward Bound Math Science Annual Performance...) and Upward Bound Math and Science (UBMS) Programs. The Department is requesting a new APR because of...

Hydrodynamic implications of textural trends in sand deposits of the 2004 tsunami in Sri Lanka

USGS Publications Warehouse

Morton, R.A.; Goff, J.R.; Nichol, S.L.

2008-01-01

Field observations and sediment samples at a coastal-plain setting in southeastern Sri Lanka were used to document the erosional and depositional impacts of the 2004 Indian Ocean tsunami and to interpret the hydrodynamic processes that produced an extensive sand-sheet deposit. Tsunami deposit thicknesses ranged from 6 to 22??cm with thickness being controlled partly by antecedent topography. The deposit was composed of coarse to medium sand organized into plane-parallel laminae and a few laminasets. Vertical textural trends showed an overall but non-systematic upward fining and upward thinning of depositional units with an upward increase in heavy-mineral laminations at some locations. Repeated patterns in the vertical textural trends (upward fining, upward coarsening, uniform) were used to subdivide and correlate the deposit into five hydro-textural stratigraphic units. The depositional units were linked to hydrodynamic processes and upcurrent conditions, such as rates of sediment supply and composition of the sediment sources. Vertical changes in grain-size distributions recorded the depositional phases associated with flow acceleration, initial unsteady pulsating flow, relatively stable and uniform flow, flow deceleration, slack water, and return flow or flow redirection. Study results suggest that vertical textural trends from multiple cross-shore sections can be used to interpret complex tsunami flow histories, but at the location examined, interpretation of the lateral textural trends did not provide a basis for identifying the correct sediment transport pathways because flow near the landward boundary was multidirectional.

Implementing a Measurement Feedback System: A Tale of Two Sites

PubMed Central

Douglas, Susan R.; Vides De Andrade, Ana Regina; Tomlinson, Michele; Gleacher, Alissa; Olin, Serene; Hoagwood, Kimberly

2015-01-01

A randomized experiment was conducted in two outpatient clinics evaluating a measurement feedback system called contextualized feedback systems. The clinicians of 257 Youth 11–18 received feedback on progress in mental health symptoms and functioning either every 6 months or as soon as the youth’s, clinician’s or caregiver’s data were entered into the system. The ITT analysis showed that only one of the two participating clinics (Clinic R) had an enhanced outcome because of feedback, and only for the clinicians’ ratings of youth symptom severity on the SFSS. A dose–response effect was found only for Clinic R for both the client and clinician ratings. Implementation analyses showed that Clinic R had better implementation of the feedback intervention. Clinicians’ questionnaire completion rate and feedback viewing at Clinic R were 50 % higher than clinicians at Clinic U. The discussion focused on the differences in implementation at each site and how these differences may have contributed to the different outcomes of the experiment. PMID:25876736

Improving Principal Leadership through Feedback and Coaching

ERIC Educational Resources Information Center

Bickman, Leonard; Goldring, Ellen; De Andrade, Ana Regina; Breda, Carolyn; Goff, Peter

2012-01-01

The purpose of this study is to evaluate the efficacy of a feedback and coaching intervention designed to improve the quality of principal leadership. Principals received feedback from teachers on their instructional leadership, and their teachers' trust of them. Principals also provided self-ratings and they compared their teachers' ratings to…

CPR performance in the presence of audiovisual feedback or football shoulder pads.

PubMed

Tanaka, Shota; Rodrigues, Wayne; Sotir, Susan; Sagisaka, Ryo; Tanaka, Hideharu

2017-01-01

The initiation of cardiopulmonary resuscitation (CPR) can be complicated by the use of protective equipment in contact sports, and the rate of success in resuscitating the patient depends on the time from incident to start of CPR. The aim of our study was to see if (1) previous training, (2) the presence of audiovisual feedback and (3) the presence of football shoulder pads (FSP) affected the quality of chest compressions. Six basic life support certified athletic training students (BLS-ATS), six basic life support certified emergency medical service personnel (BLS-EMS) and six advanced cardiac life support certified emergency medical service personnel (ACLS-EMS) participated in a crossover manikin study. A quasi-experimental repeated measures design was used to measure the chest compression depth (cm), rate (cpm), depth accuracy (%) and rate accuracy (%) on four different conditions by using feedback and/or FSP. Real CPR Help manufactured by ZOLL (Chelmsford, Massachusetts, USA) was used for the audiovisual feedback. Three participants from each group performed 2 min of chest compressions at baseline first, followed by compressions with FSP, with feedback and with both FSP and feedback (FSP+feedback). The other three participants from each group performed compressions at baseline first, followed by compressions with FSP+feedback, feedback and FSP. CPR performance did not differ between the groups at baseline (median (IQR), BLS-ATS: 5.0 (4.4-6.1) cm, 114(96-131) cpm; BLS-EMS: 5.4 (4.1-6.4) cm, 112(99-131) cpm; ACLS-EMS: 6.4 (5.7-6.7) cm, 138(113-140) cpm; depth p=0.10, rate p=0.37). A statistically significant difference in the percentage of depth accuracy was found with feedback (median (IQR), 13.8 (0.9-49.2)% vs 69.6 (32.3-85.8)%; p=0.0002). The rate accuracy was changed from 17.1 (0-80.7)% without feedback to 59.2 (17.3-74.3)% with feedback (p=0.50). The use of feedback was effective for depth accuracy, especially in the BLS-ATS group, regardless of the presence of FSP (median (IQR), 22.0 (7.3-36.2)% vs 71.3 (35.4-86.5)%; p=0.0002). The use of audiovisual feedback positively affects the quality of the depth of CPR. Both feedback and FSP do not alter the rate measurements. Medically trained personnel are able to deliver the desired depth regardless of the presence of FSP even though shallower chest compressions depth can be seen in CPR with FSP. A feedback device must be introduced into the athletic training settings.

CPR performance in the presence of audiovisual feedback or football shoulder pads

PubMed Central

Tanaka, Shota; Rodrigues, Wayne; Sotir, Susan; Sagisaka, Ryo; Tanaka, Hideharu

2017-01-01

Objective The initiation of cardiopulmonary resuscitation (CPR) can be complicated by the use of protective equipment in contact sports, and the rate of success in resuscitating the patient depends on the time from incident to start of CPR. The aim of our study was to see if (1) previous training, (2) the presence of audiovisual feedback and (3) the presence of football shoulder pads (FSP) affected the quality of chest compressions. Methods Six basic life support certified athletic training students (BLS-ATS), six basic life support certified emergency medical service personnel (BLS-EMS) and six advanced cardiac life support certified emergency medical service personnel (ACLS-EMS) participated in a crossover manikin study. A quasi-experimental repeated measures design was used to measure the chest compression depth (cm), rate (cpm), depth accuracy (%) and rate accuracy (%) on four different conditions by using feedback and/or FSP. Real CPR Help manufactured by ZOLL (Chelmsford, Massachusetts, USA) was used for the audiovisual feedback. Three participants from each group performed 2 min of chest compressions at baseline first, followed by compressions with FSP, with feedback and with both FSP and feedback (FSP+feedback). The other three participants from each group performed compressions at baseline first, followed by compressions with FSP+feedback, feedback and FSP. Results CPR performance did not differ between the groups at baseline (median (IQR), BLS-ATS: 5.0 (4.4–6.1) cm, 114(96–131) cpm; BLS-EMS: 5.4 (4.1–6.4) cm, 112(99–131) cpm; ACLS-EMS: 6.4 (5.7–6.7) cm, 138(113–140) cpm; depth p=0.10, rate p=0.37). A statistically significant difference in the percentage of depth accuracy was found with feedback (median (IQR), 13.8 (0.9–49.2)% vs 69.6 (32.3–85.8)%; p=0.0002). The rate accuracy was changed from 17.1 (0–80.7)% without feedback to 59.2 (17.3–74.3)% with feedback (p=0.50). The use of feedback was effective for depth accuracy, especially in the BLS-ATS group, regardless of the presence of FSP (median (IQR), 22.0 (7.3–36.2)% vs 71.3 (35.4–86.5)%; p=0.0002). Conclusions The use of audiovisual feedback positively affects the quality of the depth of CPR. Both feedback and FSP do not alter the rate measurements. Medically trained personnel are able to deliver the desired depth regardless of the presence of FSP even though shallower chest compressions depth can be seen in CPR with FSP. A feedback device must be introduced into the athletic training settings. PMID:28761704

Effect of delayed auditory feedback on normal speakers at two speech rates

NASA Astrophysics Data System (ADS)

Stuart, Andrew; Kalinowski, Joseph; Rastatter, Michael P.; Lynch, Kerry

2002-05-01

This study investigated the effect of short and long auditory feedback delays at two speech rates with normal speakers. Seventeen participants spoke under delayed auditory feedback (DAF) at 0, 25, 50, and 200 ms at normal and fast rates of speech. Significantly two to three times more dysfluencies were displayed at 200 ms (p<0.05) relative to no delay or the shorter delays. There were significantly more dysfluencies observed at the fast rate of speech (p=0.028). These findings implicate the peripheral feedback system(s) of fluent speakers for the disruptive effects of DAF on normal speech production at long auditory feedback delays. Considering the contrast in fluency/dysfluency exhibited between normal speakers and those who stutter at short and long delays, it appears that speech disruption of normal speakers under DAF is a poor analog of stuttering.

Screening for inter-hospital differences in cesarean section rates in low-risk deliveries using administrative data: an initiative to improve the quality of care.

PubMed

Aelvoet, Willem; Windey, Francis; Molenberghs, Geert; Verstraelen, Hans; Van Reempts, Patrick; Foidart, Jean-Michel

2008-01-04

Rising national cesarean section rates (CSRs) and unexplained inter-hospital differences in CSRs, led national and international bodies to select CSR as a quality indicator. Using hospital discharge abstracts, we aimed to document in Belgium (1) inter-hospital differences in CSRs among low risk deliveries, (2) a national upward CSR trend, (3) lack of better neonatal outcomes in hospitals with high CSRs, and (4) possible under-use of CS. We defined a population of low risk deliveries (singleton, vertex, full-term, live born, <4500 g, >2499 g). Using multivariable logistic regression techniques, we provided degrees of evidence regarding the observed departure ([relative risk-1]*100) of each hospital (N = 107) from the national CSR and its trend. To determine a benchmark, we defined three CSR groups (high, average and low) and compared them regarding 1 minute Apgar scores and other neonatal endpoints. An anonymous feedback is provided to the hospitals, the College of Physicians (with voluntary disclosure of the outlying hospitals for quality improvement purposes) and to the policy makers. Compared with available information, the completeness and accuracy of the data, regarding the variables selected to determine our study population, showed adequate. Important inter-hospital differences were found. Departures ranged from -65% up to +75%, and 9 "high CSR" and 13 "low CSR" outlying hospitals were identified. We observed a national increasing trend of 1.019 (95%CI [1.015; 1.022]) per semester, adjusted for age groups. In the "high CSR" group 1 minute Apgar scores <4 were over-represented in the subgroup of vaginal deliveries, suggesting CSs not carried out for medical reasons. Under-use of CS was also observed. Given their questionable completeness, except Apgar scores, our neonatal results, showing a significant association of CS with adverse neonatal endpoints, are to be cautiously interpreted. Taking the available evidence into account, the "Average CSR" group seemed to be the best benchmark candidate. Rather than firm statements about quality of care, our results are to be considered a useful screening. The inter-hospital differences in CSR, the national CS upward trend, the indications of over-use and under-use, the geographically different obstetric patterns and the admission day-related concentration of deliveries, whether or not by CS, may trigger initiatives aiming at improving quality of care.

Flammability testing conducted in support of Apollo 13

NASA Technical Reports Server (NTRS)

Leger, L. J.; Bricker, R. W.

1971-01-01

In support of the Apollo 13 investigation of the oxygen tank failure, flame propagation rates were determined for Teflon insulation in cryogenic and ambient temperature oxygen for upward, downward, and zero g burns. The propagation rates depended heavily on configuration and varied from 4.8 to 10.9 cm/sec for upward one g burns to 0.48 cm/sec for zero g burns. In addition to the flame propagation rates, tests were conducted to determine if Teflon burning in cryogenic oxygen could ignite metals (promoted ignition) with which it came in contact. Tests conducted on various metal alloys used in the oxygen tank indicated that most of the alloys could be ignited by burning Teflon in certain configurations. After the propagation rates and promoted metal ignitions had been evaluated, a test was conducted on a quantity gauge and wire harness used in the oxygen tank to determine if flame propagation to the tank wall was possible. Propagation of the wire bundle after ignition resulted in a catastrophic failure of the test vessel in the area of the quantity gauge.

The impact of feedback and the hot halo on the rates of gas accretion onto galaxies

NASA Astrophysics Data System (ADS)

Correa, Camila A.; Schaye, Joop; van de Voort, Freeke; Duffy, Alan R.; Wyithe, J. Stuart B.

2018-04-01

We investigate the physics that drives the gas accretion rates onto galaxies at the centers of dark matter haloes using the EAGLE suite of hydrodynamical cosmological simulations. We find that at redshifts z ≤ 2 the accretion rate onto the galaxy increases with halo mass in the halo mass range 1010 - 1011.7 M⊙, flattens between the halo masses 1011.7 - 1012.7 M⊙, and increases again for higher-mass haloes. However, the galaxy gas accretion does not flatten at intermediate halo masses when AGN feedback is switched off. To better understand these trends, we develop a physically motivated semi-analytic model of galaxy gas accretion. We show that the flattening is produced by the rate of gas cooling from the hot halo. The ratio of the cooling radius and the virial radius does not decrease continuously with increasing halo mass as generally thought. While it decreases up to ˜1013 M⊙ haloes, it increases for higher halo masses, causing an upturn in the galaxy gas accretion rate. This may indicate that in high-mass haloes AGN feedback is not sufficiently efficient. When there is no AGN feedback, the density of the hot halo is higher, the ratio of the cooling and virial radii does not decrease as much and the cooling rate is higher. Changes in the efficiency of stellar feedback can also increase or decrease the accretion rates onto galaxies. The trends can plausibly be explained by the re-accretion of gas ejected by progenitor galaxies and by the suppression of black hole growth, and hence AGN feedback, by stellar feedback.

Three nested randomized controlled trials of peer-only or multiple stakeholder group feedback within Delphi surveys during core outcome and information set development.

PubMed

Brookes, Sara T; Macefield, Rhiannon C; Williamson, Paula R; McNair, Angus G; Potter, Shelley; Blencowe, Natalie S; Strong, Sean; Blazeby, Jane M

2016-08-17

Methods for developing a core outcome or information set require involvement of key stakeholders to prioritise many items and achieve agreement as to the core set. The Delphi technique requires participants to rate the importance of items in sequential questionnaires (or rounds) with feedback provided in each subsequent round such that participants are able to consider the views of others. This study examines the impact of receiving feedback from different stakeholder groups, on the subsequent rating of items and the level of agreement between stakeholders. Randomized controlled trials were nested within the development of three core sets each including a Delphi process with two rounds of questionnaires, completed by patients and health professionals. Participants rated items from 1 (not essential) to 9 (absolutely essential). For round 2, participants were randomized to receive feedback from their peer stakeholder group only (peer) or both stakeholder groups separately (multiple). Decisions as to which items to retain following each round were determined by pre-specified criteria. Whilst type of feedback did not impact on the percentage of items for which a participant subsequently changed their rating, or the magnitude of change, it did impact on items retained at the end of round 2. Each core set contained discordant items retained by one feedback group but not the other (3-22 % discordant items). Consensus between patients and professionals in items to retain was greater amongst those receiving multiple group feedback in each core set (65-82 % agreement for peer-only feedback versus 74-94 % for multiple feedback). In addition, differences in round 2 scores were smaller between stakeholder groups receiving multiple feedback than between those receiving peer group feedback only. Variability in item scores across stakeholders was reduced following any feedback but this reduction was consistently greater amongst the multiple feedback group. In the development of a core outcome or information set, providing feedback within Delphi questionnaires from all stakeholder groups separately may influence the final core set and improve consensus between the groups. Further work is needed to better understand how participants rate and re-rate items within a Delphi process. The three randomized controlled trials reported here were each nested within the development of a core information or outcome set to investigate processes in core outcome and information set development. Outcomes were not health-related and therefore trial registration was not applicable.

The Nature of Feedback: How Peer Feedback Features Affect Students' Implementation Rate and Quality of Revisions

ERIC Educational Resources Information Center

Patchan, Melissa M.; Schunn, Christian D.; Correnti, Richard J.

2016-01-01

Although feedback is often seen as a critical component of the learning process, many open questions about how specific feedback features contribute to the effectiveness of feedback remain--especially in regards to peer feedback of writing. Nelson and Schunn (2009) identified several important features of peer feedback in their nature of feedback…

Experimental Bedrock Channel Incision: Scaling, Sculpture and Sediment Transport

NASA Astrophysics Data System (ADS)

Johnson, J. P.; Whipple, K. X.

2004-12-01

Abrasion by sediment in turbulent flows often sculpts bedrock channels into dramatic forms; quantifying the feedbacks between fluid flow, sediment impacts, and channel morphology is needed to refine models of fluvial incision into bedrock. We present data from laboratory flume experiments funded by the National Center for Earth-Surface Dynamics and conducted at St. Anthony Falls Laboratory, University of Minnesota that show how the spatial and temporal distribution of erosion is strongly coupled to the evolving topography of the bed. These experiments focus on the high Froude number and tool-starved end of parameter space, where bed cover tends to be negligible. Independent variables include flume slope, water flux and sediment flux and size distribution. Sediment moves energetically as bedload, suspended load, or locally transitional between transport modes. Quantitative measurements of the evolving bed topography show that the synthetic brittle "bedrock" in the flume (cured sand-cement mixture) eroded to form narrow incised channels with tight scoops and potholes. The experimental erosional forms are similar in morphology, and sometimes in scale, to those observed in natural bedrock rivers in southeast Utah and other field settings. The experiments demonstrate that both the mean and distribution of measured erosion rates change as the bed topography evolves, even with constant water and sediment discharges. Even starting with a plane bed geometry, erosion and sediment transport very quickly become localized in interconnected topographic lows. Positive feedback develops between the evolving topography and the fluid velocity and sediment transport fields, resulting in the incision of an inner channel. Once formed, the erosion rate in the axis of the inner channel decreases as local bed shear stresses and fluid velocities are reduced by increasing wall drag, and sediment fluxes through the channel but causes less incision (no deposition). Decreasing the sediment flux (all else held equal) causes renewed incision, but of an even narrower inner channel; increasing the sediment flux leads to inner channel deposition. Where erosion is most vigorous, sediment generally moving as saltating bedload becomes locally suspended by upward-directed mean flow. For example, swirling clouds of "bedload" particles are continuously suspended by vortices developed within potholes such that the upward flux of particles out of the potholes balance the total sediment flux through the flume. Potholes spontaneously form where average bed slope and fluid velocities were highest, dramatically accelerating the local erosion rate. Our experimental potholes are smaller in scale but morphologically strikingly similar to many observed in the field, and include features such as corkscrew grooves down the outside walls and a protruding horn at the pothole center. More generally, abrasion becomes focused in places where the flow is spatially accelerated, such as in scoops and bends with high curvature. The knife-edge margins and spatial distribution of erosional forms indicate abrupt transitions in erosional efficiency that are tightly coupled to near-bed fluid flow patterns, which in turn are strongly influenced by the erosional forms themselves. Our experiments suggest that, in highly sculpted bedrock channels, naturally developed bed roughness presents a physical length scale that is important to controlling the interaction between sediment impacts and the bed, rather than a length scale based explicitly on sediment transport and average flow conditions such as the saltation hop length.

Feedback Functions, Optimization, and the Relation of Response Rate to Reinforcer Rate

ERIC Educational Resources Information Center

Soto, Paul L.; McDowell, Jack J.; Dallery, Jesse

2006-01-01

The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate…

Sensory-motor networks involved in speech production and motor control: an fMRI study.

PubMed

Behroozmand, Roozbeh; Shebek, Rachel; Hansen, Daniel R; Oya, Hiroyuki; Robin, Donald A; Howard, Matthew A; Greenlee, Jeremy D W

2015-04-01

Speaking is one of the most complex motor behaviors developed to facilitate human communication. The underlying neural mechanisms of speech involve sensory-motor interactions that incorporate feedback information for online monitoring and control of produced speech sounds. In the present study, we adopted an auditory feedback pitch perturbation paradigm and combined it with functional magnetic resonance imaging (fMRI) recordings in order to identify brain areas involved in speech production and motor control. Subjects underwent fMRI scanning while they produced a steady vowel sound /a/ (speaking) or listened to the playback of their own vowel production (playback). During each condition, the auditory feedback from vowel production was either normal (no perturbation) or perturbed by an upward (+600 cents) pitch-shift stimulus randomly. Analysis of BOLD responses during speaking (with and without shift) vs. rest revealed activation of a complex network including bilateral superior temporal gyrus (STG), Heschl's gyrus, precentral gyrus, supplementary motor area (SMA), Rolandic operculum, postcentral gyrus and right inferior frontal gyrus (IFG). Performance correlation analysis showed that the subjects produced compensatory vocal responses that significantly correlated with BOLD response increases in bilateral STG and left precentral gyrus. However, during playback, the activation network was limited to cortical auditory areas including bilateral STG and Heschl's gyrus. Moreover, the contrast between speaking vs. playback highlighted a distinct functional network that included bilateral precentral gyrus, SMA, IFG, postcentral gyrus and insula. These findings suggest that speech motor control involves feedback error detection in sensory (e.g. auditory) cortices that subsequently activate motor-related areas for the adjustment of speech parameters during speaking. Copyright © 2015 Elsevier Inc. All rights reserved.

Exploring Patients' Views Toward Giving Web-Based Feedback and Ratings to General Practitioners in England: A Qualitative Descriptive Study.

PubMed

Patel, Salma; Cain, Rebecca; Neailey, Kevin; Hooberman, Lucy

2016-08-05

Patient feedback websites or doctor rating websites are increasingly being used by patients to give feedback about their health care experiences. There is little known about why patients in England may give Web-based feedback and what may motivate or dissuade them from giving Web-based feedback. The aim of this study was to explore patients' views toward giving Web-based feedback and ratings to general practitioners (GPs), within the context of other feedback methods available in primary care in England, and in particular, paper-based feedback cards. A descriptive exploratory qualitative approach using face-to-face semistructured interviews was used in this study. Purposive sampling was used to recruit 18 participants from different age groups in London and Coventry. Interviews were transcribed verbatim and analyzed using applied thematic analysis. Half of the participants in this study were not aware of the opportunity to leave feedback for GPs, and there was limited awareness about the methods available to leave feedback for a GP. The majority of participants were not convinced that formal patient feedback was needed by GPs or would be used by GPs for improvement, regardless of whether they gave it via a website or on paper. Some participants said or suggested that they may leave feedback on a website rather than on a paper-based feedback card for several reasons: because of the ability and ease of giving it remotely; because it would be shared with the public; and because it would be taken more seriously by GPs. Others, however, suggested that they would not use a website to leave feedback for the opposite reasons: because of accessibility issues; privacy and security concerns; and because they felt feedback left on a website may be ignored. Patient feedback and rating websites as they currently are will not replace other mechanisms for patients in England to leave feedback for a GP. Rather, they may motivate a small number of patients who have more altruistic motives or wish to place collective pressure on a GP to give Web-based feedback. If the National Health Service or GP practices want more patients to leave Web-based feedback, we suggest they first make patients aware that they can leave anonymous feedback securely on a website for a GP. They can then convince them that their feedback is needed and wanted by GPs for improvement, and that the reviews they leave on the website will be of benefit to other patients to decide which GP to see or which GP practice to join.

Anthropocene Survival of Southern New England's Salt ...

EPA Pesticide Factsheets

In southern New England, salt marshes are exceptionally vulnerable to the impacts of accelerated sea level rise. Regional rates of sea level rise have been as much as 50 % greater than the global average over past decades, a more than fourfold increase over late Holocene background values. In addition, coastal development blocks many potential marsh migration routes, and compensatory mechanisms relying on positive feedbacks between inundation and sediment deposition are insufficient to counter inundation increases in extreme low-turbidity tidal waters. Accordingly, multiple lines of evidence suggest that marsh submergence is occurring in southern New England. A combination of monitoring data, field re-surveys, radiometric dating, and analysis of peat composition have established that, beginning in the early and mid-twentieth century, the dominant low-marsh plant, Spartina alterniflora, has encroached upward in tidal marshes, and typical high-marsh plants, including Juncus gerardii and Spartina patens, have declined, providing strong evidence that vegetation changes are being driven, at least in part, by higher water levels. Additionally, aerial and satellite imagery show shoreline retreat, widening and headward extension of channels, and new and expanded interior depressions. Papers in this special section highlight changes in marsh-building processes, patterns of vegetation loss, and shifts in species composition. The final papers turn to strategies for minimiz

Tuition Edges upward at Private Colleges.

ERIC Educational Resources Information Center

Brownstein, Andrew

2001-01-01

Discusses how many private colleges plan to raise tuition for next year by more than the rate of inflation, and more than the increases of recent years. Explores several institutions' reasoning on setting tuition levels. (EV)

Self-Other Agreement in Multisource Feedback: The Influence of Doctor and Rater Group Characteristics

ERIC Educational Resources Information Center

Roberts, Martin J.; Campbell, John L.; Richards, Suzanne H.; Wright, Christine

2013-01-01

Introduction: Multisource feedback (MSF) ratings provided by patients and colleagues are often poorly correlated with doctors' self-assessments. Doctors' reactions to feedback depend on its agreement with their own perceptions, but factors influencing self-other agreement in doctors' MSF ratings have received little attention. We aimed to identify…

“Booster” training: Evaluation of instructor-led bedside cardiopulmonary resuscitation skill training and automated corrective feedback to improve cardiopulmonary resuscitation compliance of Pediatric Basic Life Support providers during simulated cardiac arrest

PubMed Central

Sutton, Robert M.; Niles, Dana; Meaney, Peter A.; Aplenc, Richard; French, Benjamin; Abella, Benjamin S.; Lengetti, Evelyn L.; Berg, Robert A.; Helfaer, Mark A.; Nadkarni, Vinay

2013-01-01

Objective To investigate the effectiveness of brief bedside “booster” cardiopulmonary resuscitation (CPR) training to improve CPR guideline compliance of hospital-based pediatric providers. Design Prospective, randomized trial. Setting General pediatric wards at Children’s Hospital of Philadelphia. Subjects Sixty-nine Basic Life Support–certified hospital-based providers. Intervention CPR recording/feedback defibrillators were used to evaluate CPR quality during simulated pediatric arrest. After a 60-sec pretraining CPR evaluation, subjects were randomly assigned to one of three instructional/feedback methods to be used during CPR booster training sessions. All sessions (training/CPR manikin practice) were of equal duration (2 mins) and differed only in the method of corrective feedback given to participants during the session. The study arms were as follows: 1) instructor-only training; 2) automated defibrillator feedback only; and 3) instructor training combined with automated feedback. Measurements and Main Results Before instruction, 57% of the care providers performed compressions within guideline rate recommendations (rate >90 min−1 and <120 min−1); 71% met minimum depth targets (depth, >38 mm); and 36% met overall CPR compliance (rate and depth within targets). After instruction, guideline compliance improved (instructor-only training: rate 52% to 87% [p .01], and overall CPR compliance, 43% to 78% [p < .02]; automated feedback only: rate, 70% to 96% [p = .02], depth, 61% to 100% [p < .01], and overall CPR compliance, 35% to 96% [p < .01]; and instructor training combined with automated feedback: rate 48% to 100% [p < .01], depth, 78% to 100% [p < .02], and overall CPR compliance, 30% to 100% [p < .01]). Conclusions Before booster CPR instruction, most certified Pediatric Basic Life Support providers did not perform guideline-compliant CPR. After a brief bedside training, CPR quality improved irrespective of training content (instructor vs. automated feedback). Future studies should investigate bedside training to improve CPR quality during actual pediatric cardiac arrests. PMID:20625336

"Booster" training: evaluation of instructor-led bedside cardiopulmonary resuscitation skill training and automated corrective feedback to improve cardiopulmonary resuscitation compliance of Pediatric Basic Life Support providers during simulated cardiac arrest.

PubMed

Sutton, Robert M; Niles, Dana; Meaney, Peter A; Aplenc, Richard; French, Benjamin; Abella, Benjamin S; Lengetti, Evelyn L; Berg, Robert A; Helfaer, Mark A; Nadkarni, Vinay

2011-05-01

To investigate the effectiveness of brief bedside "booster" cardiopulmonary resuscitation (CPR) training to improve CPR guideline compliance of hospital-based pediatric providers. Prospective, randomized trial. General pediatric wards at Children's Hospital of Philadelphia. Sixty-nine Basic Life Support-certified hospital-based providers. CPR recording/feedback defibrillators were used to evaluate CPR quality during simulated pediatric arrest. After a 60-sec pretraining CPR evaluation, subjects were randomly assigned to one of three instructional/feedback methods to be used during CPR booster training sessions. All sessions (training/CPR manikin practice) were of equal duration (2 mins) and differed only in the method of corrective feedback given to participants during the session. The study arms were as follows: 1) instructor-only training; 2) automated defibrillator feedback only; and 3) instructor training combined with automated feedback. Before instruction, 57% of the care providers performed compressions within guideline rate recommendations (rate >90 min(-1) and <120 min(-1)); 71% met minimum depth targets (depth, >38 mm); and 36% met overall CPR compliance (rate and depth within targets). After instruction, guideline compliance improved (instructor-only training: rate 52% to 87% [p .01], and overall CPR compliance, 43% to 78% [p < .02]; automated feedback only: rate, 70% to 96% [p = .02], depth, 61% to 100% [p < .01], and overall CPR compliance, 35% to 96% [p < .01]; and instructor training combined with automated feedback: rate 48% to 100% [p < .01], depth, 78% to 100% [p < .02], and overall CPR compliance, 30% to 100% [p < .01]). Before booster CPR instruction, most certified Pediatric Basic Life Support providers did not perform guideline-compliant CPR. After a brief bedside training, CPR quality improved irrespective of training content (instructor vs. automated feedback). Future studies should investigate bedside training to improve CPR quality during actual pediatric cardiac arrests.

Understanding Surgical Resident and Fellow Perspectives on Their Operative Performance Feedback Needs: A Qualitative Study.

PubMed

Bello, Ricardo J; Sarmiento, Samuel; Meyer, Meredith L; Rosson, Gedge D; Cooney, Damon S; Lifchez, Scott D; Cooney, Carisa M

2018-04-20

Operative performance feedback is essential for surgical training. We aimed to understand surgical trainees' views on their operative performance feedback needs and to characterize feedback to elucidate factors affecting its value from the resident perspective. Using a qualitative research approach, 2 research fellows conducted semistructured, one-on-one interviews with surgical trainees. We analyzed recurring themes generated during interviews related to feedback characteristics, as well as the extent to which performance rating tools can help meet trainees' operative feedback needs. Departments or divisions of general or plastic surgery at 9 US academic institutions. Surgical residents and clinical fellows in general or plastic surgery. We conducted 30 interviews with 9 junior residents, 14 senior residents, and 7 clinical fellows. Eighteen (60%) participants were in plastic and 12 (40%) were in general surgery. Twenty-four participants (80%) reported feedback as very or extremely important during surgical training. All trainees stated that verbal, face-to-face feedback is the most valuable, especially if occurring during (92%) or immediately after (65%) cases. Of those trainees using performance rating tools (74%), most (57%) expressed positive views about them but wanted the tools to complement and not replace verbal feedback in surgical education. Trainees value feedback more if received within 1 week or the case. Verbal, face-to-face feedback is very or extremely important to surgical trainees. Residents and fellows prefer to receive feedback during or immediately after a case and continue to value feedback if received within 1 week of the event. Performance rating tools can be useful for providing formative feedback and documentation but should not replace verbal, face-to-face feedback. Considering trainee views on feedback may help reduce perceived gaps in feedback demand-versus-supply in surgical training, which may be essential to overcoming current challenges in surgical education. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Brain activation upon ideal-body media exposure and peer feedback in late adolescent girls.

PubMed

van der Meulen, Mara; Veldhuis, Jolanda; Braams, Barbara R; Peters, Sabine; Konijn, Elly A; Crone, Eveline A

2017-08-01

Media's prevailing thin-body ideal plays a vital role in adolescent girls' body image development, but the co-occurring impact of peer feedback is understudied. The present study used functional magnetic resonance imaging (fMRI) to test media imagery and peer feedback combinations on neural activity related to thin-body ideals. Twenty-four healthy female late adolescents rated precategorized body sizes of bikini models (too thin or normal), directly followed by ostensible peer feedback (too thin or normal). Consistent with prior studies on social feedback processing, results showed increased brain activity in the dorsal medial prefrontal cortex (dmPFC)/anterior cingulate cortex (ACC) and bilateral insula in incongruent situations: when participants rated media models' body size as normal while peer feedback indicated the models as too thin (or vice versa). This effect was stronger for girls with lower self-esteem. A subsequent behavioral study (N = 34 female late adolescents, separate sample) demonstrated that participants changed behavior in the direction of the peer feedback: precategorized normal sized models were rated as too thin more often after receiving too thin peer feedback. This suggests that the neural responses upon peer feedback may influence subsequent choice. Our results show that media-by-peer interactions have pronounced effects on girls' body ideals.

High upward fluxes of formic acid from a boreal forest canopy

DOE PAGES

Schobesberger, Siegfried; Lopez-Hilfiker, Felipe D.; Taipale, Ditte; ...

2016-08-14

Eddy covariance fluxes of formic acid, HCOOH, were measured over a boreal forest canopy in spring/summer 2014. The HCOOH fluxes were bidirectional but mostly upward during daytime, in contrast to studies elsewhere that reported mostly downward fluxes. Downward flux episodes were explained well by modeled dry deposition rates. The sum of net observed flux and modeled dry deposition yields an upward “gross flux” of HCOOH, which could not be quantitatively explained by literature estimates of direct vegetative/soil emissions nor by efficient chemical production from other volatile organic compounds, suggesting missing or greatly underestimated HCOOH sources in the boreal ecosystem. Here,more » we implemented a vegetative HCOOH source into the GEOS-Chem chemical transport model to match our derived gross flux and evaluated the updated model against airborne and spaceborne observations. Model biases in the boundary layer were substantially reduced based on this revised treatment, but biases in the free troposphere remain unexplained.« less

Influence of Hydraulic Fracturing on Overlying Aquifers in the Presence of Leaky Abandoned Wells.

PubMed

Brownlow, Joshua W; James, Scott C; Yelderman, Joe C

2016-11-01

The association between hydrocarbon-rich reservoirs and organic-rich source rocks means unconventional oil and gas plays usually occur in mature sedimentary basins-where large-scale conventional development has already taken place. Abandoned wells in proximity to hydraulic fracturing could be affected by increased fluid pressures and corresponding newly generated fractures that directly connect (frac hit) to an abandoned well or to existing fractures intersecting an abandoned well. If contaminants migrate to a pathway hydraulically connected to an abandoned well, upward leakage may occur. Potential effects of hydraulic fracturing on upward flow through a particular type of leaky abandoned well-abandoned oil and gas wells converted into water wells were investigated using numerical modeling. Several factors that affect flow to leaky wells were considered including proximity of a leaky well to hydraulic fracturing, flowback, production, and leaky well abandonment methods. The numerical model used historical records and available industry data for the Eagle Ford Shale play in south Texas. Numerical simulations indicate that upward contaminant migration could occur through leaky converted wells if certain spatial and hydraulic conditions exist. Upward flow through leaky converted wells increased with proximity to hydraulic fracturing, but decreased when flowback and production occurred. Volumetric flow rates ranged between 0 and 0.086 m 3 /d for hydraulic-fracturing scenarios. Potential groundwater impacts should be paired with plausible transport mechanisms, and upward flow through leaky abandoned wells could be unrelated to hydraulic fracturing. The results also underscore the need to evaluate historical activities. © 2016, National Ground Water Association.

Modelling terrestrial nitrous oxide emissions and implications for climate feedback.

PubMed

Xu-Ri; Prentice, I Colin; Spahni, Renato; Niu, Hai Shan

2012-10-01

Ecosystem nitrous oxide (N2O) emissions respond to changes in climate and CO2 concentration as well as anthropogenic nitrogen (N) enhancements. Here, we aimed to quantify the responses of natural ecosystem N2O emissions to multiple environmental drivers using a process-based global vegetation model (DyN-LPJ). We checked that modelled annual N2O emissions from nonagricultural ecosystems could reproduce field measurements worldwide, and experimentally observed responses to step changes in environmental factors. We then simulated global N2O emissions throughout the 20th century and analysed the effects of environmental changes. The model reproduced well the global pattern of N2O emissions and the observed responses of N cycle components to changes in environmental factors. Simulated 20th century global decadal-average soil emissions were c. 8.2-9.5 Tg N yr(-1) (or 8.3-10.3 Tg N yr(-1) with N deposition). Warming and N deposition contributed 0.85±0.41 and 0.80±0.14 Tg N yr(-1), respectively, to an overall upward trend. Rising CO2 also contributed, in part, through a positive interaction with warming. The modelled temperature dependence of N2O emission (c. 1 Tg N yr(-1) K(-1)) implies a positive climate feedback which, over the lifetime of N2O (114 yr), could become as important as the climate-carbon cycle feedback caused by soil CO2 release. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Designing Summer Outreach Programs as an Engagement tool to connect Underserved and Underrepresented HS Students with Climate Science Topics

NASA Astrophysics Data System (ADS)

Olgin, J. G.; Güereque, M.; Pennington, D. D.; Ricketts, J.; Salas, K.

2017-12-01

The EarthTech outreach program at the University of Texas at El Paso (UTEP) seeks to expand the inclusion of underserved and under-represented high-school students into the geoscience pipeline. A successful partnership with the federally funded, year-round college preparatory program for high school students Upward Bound (UB) program at UTEP was decisive for the success and execution of the program. Program activities aimed to engage students and expand their knowledge of the Earth Sciences through participation in STEM hands-on activities, incorporating technology and field experiences. For its third year, the program chose to address the intersection of climate science and societal issues by selecting an overall topic for the week-long program that students could relate and understand from personal experiences, facilitating participation. The exposure to outdoor on-site learning experiences via field trips, coupled with introducing data analysis projects using NASA's GLOBE program, proved to be critical learning components based on student feedback; allowing students to engage with their surroundings and relate to basic Earth Science knowledge and principles. Qualitative feedback and discussion of the program and its activities are presented here.

The impact of feedback and the hot halo on the rates of gas accretion on to galaxies

NASA Astrophysics Data System (ADS)

Correa, Camila A.; Schaye, Joop; van de Voort, Freeke; Duffy, Alan R.; Wyithe, J. Stuart B.

2018-07-01

We investigate the physics that drives the gas accretion rates on to galaxies at the centres of dark matter haloes using the EAGLE suite of hydrodynamical cosmological simulations. We find that at redshifts z ≤ 2, the accretion rate on to the galaxy increases with halo mass in the halo mass range 1010-1011.7 M⊙, flattens between the halo masses 1011.7 and 1012.7 M⊙, and increases again for higher mass haloes. However, the galaxy gas accretion does not flatten at intermediate halo masses when active galactic nucleus (AGN) feedback is switched off. To better understand these trends, we develop a physically motivated semi-analytic model of galaxy gas accretion. We show that the flattening is produced by the rate of gas cooling from the hot halo. The ratio of the cooling radius and the virial radius does not decrease continuously with increasing halo mass as generally thought. While it decreases up to ˜1013 M⊙ haloes, it increases for higher halo masses, causing an upturn in the galaxy gas accretion rate. This may indicate that in high-mass haloes, AGN feedback is not sufficiently efficient. When there is no AGN feedback, the density of the hot halo is higher, the ratio of the cooling and virial radii does not decrease as much, and the cooling rate is higher. Changes in the efficiency of stellar feedback can also increase or decrease the accretion rates on to galaxies. The trends can plausibly be explained by the re-accretion of gas ejected by progenitor galaxies and by the suppression of black hole growth, and hence AGN feedback, by stellar feedback.

Category Rating Is Based on Prototypes and Not Instances: Evidence from Feedback-Dependent Context Effects

ERIC Educational Resources Information Center

Petrov, Alexander A.

2011-01-01

Context effects in category rating on a 7-point scale are shown to reverse direction depending on feedback. Context (skewed stimulus frequencies) was manipulated between and feedback within subjects in two experiments. The diverging predictions of prototype- and exemplar-based scaling theories were tested using two representative models: ANCHOR…

34 CFR 645.12 - What services may regular Upward Bound and Upward Bound Math-Science projects provide?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 3 2014-07-01 2014-07-01 false What services may regular Upward Bound and Upward Bound Math-Science projects provide? 645.12 Section 645.12 Education Regulations of the Offices of the... services may regular Upward Bound and Upward Bound Math-Science projects provide? Any project assisted...

34 CFR 645.12 - What services may regular Upward Bound and Upward Bound Math-Science projects provide?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 3 2011-07-01 2011-07-01 false What services may regular Upward Bound and Upward Bound Math-Science projects provide? 645.12 Section 645.12 Education Regulations of the Offices of the... services may regular Upward Bound and Upward Bound Math-Science projects provide? Any project assisted...

34 CFR 645.12 - What services may regular Upward Bound and Upward Bound Math-Science projects provide?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 34 Education 3 2013-07-01 2013-07-01 false What services may regular Upward Bound and Upward Bound Math-Science projects provide? 645.12 Section 645.12 Education Regulations of the Offices of the... services may regular Upward Bound and Upward Bound Math-Science projects provide? Any project assisted...

34 CFR 645.12 - What services may regular Upward Bound and Upward Bound Math-Science projects provide?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 34 Education 3 2012-07-01 2012-07-01 false What services may regular Upward Bound and Upward Bound Math-Science projects provide? 645.12 Section 645.12 Education Regulations of the Offices of the... services may regular Upward Bound and Upward Bound Math-Science projects provide? Any project assisted...

Free-space optics mode-wavelength division multiplexing system using LG modes based on decision feedback equalization

NASA Astrophysics Data System (ADS)

Amphawan, Angela; Ghazi, Alaan; Al-dawoodi, Aras

2017-11-01

A free-space optics mode-wavelength division multiplexing (MWDM) system using Laguerre-Gaussian (LG) modes is designed using decision feedback equalization for controlling mode coupling and combating inter symbol interference so as to increase channel diversity. In this paper, a data rate of 24 Gbps is achieved for a FSO MWDM channel of 2.6 km in length using feedback equalization. Simulation results show significant improvement in eye diagrams and bit-error rates before and after decision feedback equalization.

21 CFR 137.200 - Whole wheat flour.

Code of Federal Regulations, 2012 CFR

2012-04-01

... upward stroke, at the rate of about 150 times per minute. Turn the sieves about one-sixth of a revolution each time in the same direction, after each 25 strokes. Continue shaking for 2 minutes. Weigh the...

21 CFR 137.200 - Whole wheat flour.

Code of Federal Regulations, 2013 CFR

2013-04-01

... upward stroke, at the rate of about 150 times per minute. Turn the sieves about one-sixth of a revolution each time in the same direction, after each 25 strokes. Continue shaking for 2 minutes. Weigh the...

21 CFR 137.200 - Whole wheat flour.

Code of Federal Regulations, 2014 CFR

2014-04-01

... upward stroke, at the rate of about 150 times per minute. Turn the sieves about one-sixth of a revolution each time in the same direction, after each 25 strokes. Continue shaking for 2 minutes. Weigh the...

Method of shielding a liquid-metal-cooled reactor

DOEpatents

Sayre, Robert K.

1978-01-01

The primary heat transport system of a nuclear reactor -- particularly for a liquid-metal-cooled fast-breeder reactor -- is shielded and protected from leakage by establishing and maintaining a bed of a powdered oxide closely and completely surrounding all components thereof by passing a gas upwardly therethrough at such a rate as to slightly expand the bed to the extent that the components of the system are able to expand without damage and yet the particles of the bed remain close enough so that the bed acts as a guard vessel for the system. Preferably the gas contains 1 to 10% oxygen and the gas is passed upwardly through the bed at such a rate that the lower portion of the bed is a fixed bed while the upper portion is a fluidized bed, the line of demarcation therebetween being high enough that the fixed bed portion of the bed serves as guard vessel for the system.

Responses to two-way selection on growth in mass-spawned F1 progeny of Argopecten irradians concentricus (Say)

NASA Astrophysics Data System (ADS)

Wang, Hui; Liu, Jin; Li, Yanhong; Zhu, Xiaowen; Liu, Zhigang

2014-03-01

In the present study, the effect of one-generation divergent selection on the growth and survival of the bay scallop ( Argopecten irradians concentricus) was examined to evaluate the efficacy of a selection program currently being carried out in Beibu Bay in the South China Sea. A total of 146 adult scallops were randomly selected from the same cultured population of A. i. concentricus, and divided into two groups in shell length (anterior-posterior measurement): large (4.91-6.02 cm, n=74) and small (3.31-4.18 cm, n=72). At the same time, a control group was also randomly sampled (4.21-4.88 cm, n =80). Mass-spawned F 1 progenies from the three size groups were obtained and reared under identical conditions at all growth phases. The effects of two-way (or upward-downward) selection on fertilization rate, hatching rate, survival rate, daily growth in shell length and body weight were assessed in the three size groups. Results show that significant differences ( P<0.01) were found in hatching rate, survival rate and daily growth of F1 progenies, but not in fertilization rate ( P>0.05), among the three groups. The hatching rate, survival rate and daily growth of the progeny of large-sized parents were greater than those of the control group ( P<0.05), which in turn were larger than those of small-sized group ( P<0.05). Responses to selection by shell length and body weight were 0.32 ± 0.04 cm and 2.18 ± 0.05 g, respectively, for the upward selection, and -0.14 ± 0.03 cm and -2.77 ± 0.06 g, respectively, for the downward selection. The realized heritability estimates of shell length and body weight were 0.38 ± 0.06 cm and 0.22 ± 0.07 g for the upward selection, and 0.24 ± 0.06 cm and 0.37 ± 0.09 g for the downward selection, respectively. The change in growth by bidirectional selection suggests that high genetic variation may be present in the cultured bay scallop population in China.

Impact of a feedback device on chest compression quality during extended manikin CPR: a randomized crossover study.

PubMed

Buléon, Clément; Delaunay, Julie; Parienti, Jean-Jacques; Halbout, Laurent; Arrot, Xavier; Gérard, Jean-Louis; Hanouz, Jean-Luc

2016-09-01

Chest compressions require physical effort leading to increased fatigue and rapid degradation in the quality of cardiopulmonary resuscitation overtime. Despite harmful effect of interrupting chest compressions, current guidelines recommend that rescuers switch every 2 minutes. The impact on the quality of chest compressions during extended cardiopulmonary resuscitation has yet to be assessed. We conducted randomized crossover study on manikin (ResusciAnne; Laerdal). After randomization, 60 professional emergency rescuers performed 2 × 10 minutes of continuous chest compressions with and without a feedback device (CPRmeter). Efficient compression rate (primary outcome) was defined as the frequency target reached along with depth and leaning at the same time (recorded continuously). The 10-minute mean efficient compression rate was significantly better in the feedback group: 42% vs 21% (P< .001). There was no significant difference between the first (43%) and the tenth minute (36%; P= .068) with feedback. Conversely, a significant difference was evident from the second minute without feedback (35% initially vs 27%; P< .001). The efficient compression rate difference with and without feedback was significant every minute, from the second minute onwards. CPRmeter feedback significantly improved chest compression depth from the first minute, leaning from the second minute and rate from the third minute. A real-time feedback device delivers longer effective, steadier chest compressions over time. An extrapolation of these results from simulation may allow rescuer switches to be carried out beyond the currently recommended 2 minutes when a feedback device is used. Copyright © 2016 Elsevier Inc. All rights reserved.

Exploring Patients’ Views Toward Giving Web-Based Feedback and Ratings to General Practitioners in England: A Qualitative Descriptive Study

PubMed Central

Cain, Rebecca; Neailey, Kevin; Hooberman, Lucy

2016-01-01

Background Patient feedback websites or doctor rating websites are increasingly being used by patients to give feedback about their health care experiences. There is little known about why patients in England may give Web-based feedback and what may motivate or dissuade them from giving Web-based feedback. Objective The aim of this study was to explore patients’ views toward giving Web-based feedback and ratings to general practitioners (GPs), within the context of other feedback methods available in primary care in England, and in particular, paper-based feedback cards. Methods A descriptive exploratory qualitative approach using face-to-face semistructured interviews was used in this study. Purposive sampling was used to recruit 18 participants from different age groups in London and Coventry. Interviews were transcribed verbatim and analyzed using applied thematic analysis. Results Half of the participants in this study were not aware of the opportunity to leave feedback for GPs, and there was limited awareness about the methods available to leave feedback for a GP. The majority of participants were not convinced that formal patient feedback was needed by GPs or would be used by GPs for improvement, regardless of whether they gave it via a website or on paper. Some participants said or suggested that they may leave feedback on a website rather than on a paper-based feedback card for several reasons: because of the ability and ease of giving it remotely; because it would be shared with the public; and because it would be taken more seriously by GPs. Others, however, suggested that they would not use a website to leave feedback for the opposite reasons: because of accessibility issues; privacy and security concerns; and because they felt feedback left on a website may be ignored. Conclusions Patient feedback and rating websites as they currently are will not replace other mechanisms for patients in England to leave feedback for a GP. Rather, they may motivate a small number of patients who have more altruistic motives or wish to place collective pressure on a GP to give Web-based feedback. If the National Health Service or GP practices want more patients to leave Web-based feedback, we suggest they first make patients aware that they can leave anonymous feedback securely on a website for a GP. They can then convince them that their feedback is needed and wanted by GPs for improvement, and that the reviews they leave on the website will be of benefit to other patients to decide which GP to see or which GP practice to join. PMID:27496366

Rating leniency and halo in multisource feedback ratings: testing cultural assumptions of power distance and individualism-collectivism.

PubMed

Ng, Kok-Yee; Koh, Christine; Ang, Soon; Kennedy, Jeffrey C; Chan, Kim-Yin

2011-09-01

This study extends multisource feedback research by assessing the effects of rater source and raters' cultural value orientations on rating bias (leniency and halo). Using a motivational perspective of performance appraisal, the authors posit that subordinate raters followed by peers will exhibit more rating bias than superiors. More important, given that multisource feedback systems were premised on low power distance and individualistic cultural assumptions, the authors expect raters' power distance and individualism-collectivism orientations to moderate the effects of rater source on rating bias. Hierarchical linear modeling on data collected from 1,447 superiors, peers, and subordinates who provided developmental feedback to 172 military officers show that (a) subordinates exhibit the most rating leniency, followed by peers and superiors; (b) subordinates demonstrate more halo than superiors and peers, whereas superiors and peers do not differ; (c) the effects of power distance on leniency and halo are strongest for subordinates than for peers and superiors; (d) the effects of collectivism on leniency were stronger for subordinates and peers than for superiors; effects on halo were stronger for subordinates than superiors, but these effects did not differ for subordinates and peers. The present findings highlight the role of raters' cultural values in multisource feedback ratings. PsycINFO Database Record (c) 2011 APA, all rights reserved

A Heart Rate Analysis of Developmental Change in Feedback Processing and Rule Shifting from Childhood to Early Adulthood

ERIC Educational Resources Information Center

Crone, Eveline A.; Somsen, Riek J. M.; Zanolie, Kiki; Van der Molen, Maurits W.

2006-01-01

Over the course of development, the ability to switch between different tasks on the basis of feedback cues increases profoundly, but the role of performance monitoring remains unclear. Heart rate indexes can provide critical information about how individuals monitor feedback cues indicating that performance should be adjusted. In this study,…

Are All Competencies Equal in the Eyes of Residents? A Multicenter Study of Emergency Medicine Residents' Interest in Feedback.

PubMed

Bentley, Suzanne; Hu, Kevin; Messman, Anne; Moadel, Tiffany; Khandelwal, Sorabh; Streich, Heather; Noelker, Joan

2017-01-01

Feedback, particularly real-time feedback, is critical to resident education. The emergency medicine (EM) milestones were developed in 2012 to enhance resident assessment, and many programs use them to provide focused resident feedback. The purpose of this study was to evaluate EM residents' level of interest in receiving real-time feedback on each of the 23 competencies/sub-competencies. This was a multicenter cross-sectional study of EM residents. We surveyed participants on their level of interest in receiving real-time on-shift feedback on each of the 23 competencies/sub-competencies. Anonymous paper or computerized surveys were distributed to residents at three four-year training programs and three three-year training programs with a total of 223 resident respondents. Residents rated their level of interest in each milestone on a six-point Likert-type response scale. We calculated average level of interest for each of the 23 sub-competencies, for all 223 respondents and separately by postgraduate year (PGY) levels of training. One-way analyses of variance were performed to determine if there were differences in ratings by level of training. The overall survey response rate across all institutions was 82%. Emergency stabilization had the highest mean rating (5.47/6), while technology had the lowest rating (3.24/6). However, we observed no differences between levels of training on any of the 23 competencies/sub-competencies. Residents seem to ascribe much more value in receiving feedback on domains involving high-risk, challenging procedural skills as compared to low-risk technical and communication skills. Further studies are necessary to determine whether residents' perceived importance of competencies/sub-competencies needs to be considered when developing an assessment or feedback program based on these 23 EM competencies/sub-competencies.

Reduction of characteristic RL time for fast, efficient magnetic levitation

NASA Astrophysics Data System (ADS)

Li, Yuqing; Feng, Guosheng; Wang, Xiaofeng; Wu, Jizhou; Ma, Jie; Xiao, Liantuan; Jia, Suotang

2017-09-01

We demonstrate the reduction of characteristic time in resistor-inductor (RL) circuit for fast, efficient magnetic levitation according to Kirchhoff's circuit laws. The loading time is reduced by a factor of ˜4 when a high-power resistor is added in series with the coils. By using the controllable output voltage of power supply and voltage of feedback circuit, the loading time is further reduced by ˜ 3 times. The overshoot loading in advance of the scheduled magnetic field gradient is equivalent to continuously adding a resistor without heating. The magnetic field gradient with the reduced loading time is used to form the upward magnetic force against to the gravity of the cooled Cs atoms, and we obtain an effectively levitated loading of the Cs atoms to a crossed optical dipole trap.

Enhanced mobility of non aqueous phase liquid (NAPL) during drying of wet sand

NASA Astrophysics Data System (ADS)

Govindarajan, Dhivakar; Deshpande, Abhijit P.; Raghunathan, Ravikrishna

2018-02-01

Enhanced upward mobility of a non aqueous phase liquid (NAPL) present in wet sand during natural drying, and in the absence of any external pressure gradients, is reported for the first time. This mobility was significantly higher than that expected from capillary rise. Experiments were performed in a glass column with a small layer of NAPL-saturated sand trapped between two layers of water-saturated sand. Drying of the wet sand was induced by flow of air across the top surface of the wet sand. The upward movement of the NAPL, in the direction of water transport, commenced when the drying effect reached the location of the NAPL and continued as long as there was significant water evaporation in the vicinity of NAPL, indicating a clear correlation between the NAPL rise and water evaporation. The magnitude and the rate of NAPL rise was measured at different water evaporation rates, different initial locations of the NAPL, different grain size of the sand and the type of NAPL (on the basis of different NAPL-glass contact angle, viscosity and density). A positive correlation was observed between average rate of NAPL rise and the water evaporation while a negative correlation was obtained between the average NAPL rise rate and the NAPL properties of contact angle, viscosity and density. There was no significant correlation of average NAPL rise rate with variation of sand grain size between 0.1 to 0.5 mm. Based on these observations and on previous studies reported in the literature, two possible mechanisms are hypothesized -a) the effect of the spreading coefficient resulting in the wetting of NAPL on the water films created and b) a moving water film due to evaporation that "drags" the NAPL upwards. The NAPL rise reported in this paper has implications in fate and transport of chemicals in NAPL contaminated porous media such as soils and exposed dredged sediment material, which are subjected to varying water saturation levels due to drying and rewetting.

Improving the efficiency of cognitive-behavioural therapy by using formal client feedback.

PubMed

Janse, Pauline D; De Jong, Kim; Van Dijk, Maarten K; Hutschemaekers, Giel J M; Verbraak, Marc J P M

2017-09-01

Feedback from clients on their view of progress and the therapeutic relationship can improve effectiveness and efficiency of psychological treatments in general. However, what the added value is of client feedback specifically within cognitive-behavioural therapy (CBT), is not known. Therefore, the extent to which the outcome of CBT can be improved is investigated by providing feedback from clients to therapists using the Outcome Rating Scale (ORS) and Session Rating Scale (SRS). Outpatients (n = 1006) of a Dutch mental health organization either participated in the "treatment as usual" (TAU) condition, or in Feedback condition of the study. Clients were invited to fill in the ORS and SRS and in the Feedback condition therapists were asked to frequently discuss client feedback. Outcome on the SCL-90 was only improved specifically with mood disorders in the Feedback condition. Also, in the Feedback condition, in terms of process, the total number of required treatment sessions was on average two sessions fewer. Frequently asking feedback from clients using the ORS/SRS does not necessarily result in a better treatment outcome in CBT. However, for an equal treatment outcome significantly fewer sessions are needed within the Feedback condition, thus improving efficiency of CBT.

Unipedal balance in healthy adults: effect of visual environments yielding decreased lateral velocity feedback.

PubMed

Deyer, T W; Ashton-Miller, J A

1999-09-01

To test the (null) hypotheses that the reliability of unipedal balance is unaffected by the attenuation of visual velocity feedback and that, relative to baseline performance, deterioration of balance success rates from attenuated visual velocity feedback will not differ between groups of young men and older women, and the presence (or absence) of a vertical foreground object will not affect balance success rates. Single blind, single case study. University research laboratory. Two volunteer samples: 26 healthy young men (mean age, 20.0yrs; SD, 1.6); 23 healthy older women (mean age, 64.9 yrs; SD, 7.8). Normalized success rates in unipedal balance task. Subjects were asked to transfer to and maintain unipedal stance for 5 seconds in a task near the limit of their balance capabilities. Subjects completed 64 trials: 54 trials of three experimental visual scenes in blocked randomized sequences of 18 trials and 10 trials in a normal visual environment. The experimental scenes included two that provided strong velocity/weak position feedback, one of which had a vertical foreground object (SVWP+) and one without (SVWP-), and one scene providing weak velocity/strong position (WVSP) feedback. Subjects' success rates in the experimental environments were normalized by the success rate in the normal environment in order to allow comparisons between subjects using a mixed model repeated measures analysis of variance. The normalized success rate was significantly greater in SVWP+ than in WVSP (p = .0001) and SVWP- (p = .013). Visual feedback significantly affected the normalized unipedal balance success rates (p = .001); neither the group effect nor the group X visual environment interaction was significant (p = .9362 and p = .5634, respectively). Normalized success rates did not differ significantly between the young men and older women in any visual environment. Near the limit of the young men's or older women's balance capability, the reliability of transfer to unipedal balance was adversely affected by visual environments offering attenuated visual velocity feedback cues and those devoid of vertical foreground objects.

The impact of expert- and peer feedback on communication skills of undergraduate dental students - a single-blinded, randomized, controlled clinical trial.

PubMed

Krause, Felix; Schmalz, Gerhard; Haak, Rainer; Rockenbauch, Katrin

2017-12-01

To evaluate the effect of peer- and expert feedback on communication skills of undergraduate dental students. All students of the first clinical treatment course (n=46) were randomly assigned into two groups. For three times a medical-dental interview/consultation of each student with a real patient was videotaped. After every consultation the videos were assessed either by a person experienced in communication (expert group) or by a fellow student (peer group), giving the students feedback regarding their chairside performed communication skills. Before and after the feedback-interventions all students conducted an interview with simulated patients, which was rated using a validated global rating and analyzed statistically. Global ratings mean scores after feedback-intervention were significantly improved (p<0.05). Thereby, no significant differences in the overall assessment could be observed between expert and peer feedback (p>0.05). During this study students improved their communication skills in dentist-patient interactions. The communication experience of the feedback provider seems not to have any impact on the communication skills in undergraduate dental students. The clinical courses in dentistry offer the opportunity to implement peer-feedback interventions in real treatment situation as part of communication training to longitudinally improve communication skills. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling Paragenesis: Erosion Opposite to Gravity in Cave Channels

NASA Astrophysics Data System (ADS)

Cooper, M. P.; Covington, M. D.

2017-12-01

Sediment plays an important role in bedrock channels, providing both tools and cover that influence patterns of bed erosion. It has also been shown that sediment load influences bedrock channel width, with increased sediment leading to wider channels. A variety of models have been developed to explore these effects. In caves, it is hypothesized that sediments covering the floors of fully flooded channels that are forming beneath the water table (phreatic zone) can force dissolution upwards towards the water table, leading to upward erosion balanced by gradual deposition of sediment within the channel bottom. This strange process is termed paragenesis, and while there are conceptual and experimental models of the process, no prior mathematical models of cave passage evolution has captured these effects. Consequently, there is little quantitative understanding of the processes that drive paragenesis and how they link to the morphology of the cave channels that develop. We adapt a previously developed algorithm for estimating boundary shear stress within channels with free-surface flows to enable calculation of boundary shear stress in pipe-full conditions. This model successfully duplicates scaling relationships in surface channels, and geometries of caves formed in the phreatic zone such as phreatic tubes. Once sediment flux is incorporated the model successfully duplicates the hypothesized processes of paragenetic gallery formation: the cover effect prevents dissolution in the direction of gravity; passages are enlarged upwards reducing the sediment transport capacity; sediment is deposited and the process drives a continuing feedback loop. Simulations reveal that equilibrium paragenetic channel widths scale with both sediment flux and discharge. Unlike in open channel settings, increased sediment load actually narrows paragenetic channels. The cross section evolution model also reveals that the existence of equilibrium widths in such galleries requires erosion to scale with shear stress, suggesting a role of either mechanical erosion or transport limited dissolution. These types of erosion contrast with current numerical models of speleogenesis, where chemically limited dissolution, a process independent of shear stress, is predicted to occur in most turbulent flow settings.

A mathematical analysis of rebound in a target-mediated drug disposition model: II. With feedback.

PubMed

Aston, Philip J; Derks, Gianne; Agoram, Balaji M; van der Graaf, Piet H

2017-07-01

We consider the possibility of free receptor (antigen/cytokine) levels rebounding to higher than the baseline level after the application of an antibody drug using a target-mediated drug disposition model. It is assumed that the receptor synthesis rate experiences homeostatic feedback from the receptor levels. It is shown for a very fast feedback response, that the occurrence of rebound is determined by the ratio of the elimination rates, in a very similar way as for no feedback. However, for a slow feedback response, there will always be rebound. This result is illustrated with an example involving the drug efalizumab for patients with psoriasis. It is shown that slow feedback can be a plausible explanation for the observed rebound in this example.

Long-term temperature monitoring at the biological community site on the Nankai accretionary prism off Kii Peninsula

NASA Astrophysics Data System (ADS)

Goto, S.; Hamamoto, H.; Yamano, M.; Kinoshita, M.; Ashi, J.

2008-12-01

Nankai subduction zone off Kii Peninsula is one of the most intensively surveyed areas for studies on the seismogenic zone. Multichannel seismic reflection surveys carried out in this area revealed the existence of splay faults that branched from the subduction zone plate boundary [Park et al., 2002]. Along the splay faults, reversal of reflection polarity was observed, indicating elevated pore fluid pressure along the faults. Cold seepages with biological communities were discovered along a seafloor outcrop of one of the splay faults through submersible observations. Long-term temperature monitoring at a biological community site along the outcrop revealed high heat flow carried by upward fluid flow (>180 mW/m2) [Goto et al., 2003]. Toki et al. [2004] estimated upward fluid flow rates of 40-200 cm/yr from chloride distribution of interstitial water extracted from sediments in and around biological community sites along the outcrop. These observation results suggest upward fluid flow along the splay fault. In order to investigate hydrological nature of the splay fault, we conducted long-term temperature monitoring again in the same cold seepage site where Goto et al. [2003] carried out long-term temperature monitoring. In this presentation, we present results of the temperature monitoring and estimate heat flow carried by upward fluid flow from the temperature records. In this long-term temperature monitoring, we used stand-alone heat flow meter (SAHF), a probe-type sediment temperature recorder. Two SAHFs (SAHF-3 and SAHF-4) were used in this study. SAHF-4 was inserted into a bacterial mat, within several meters of which the previous long-term temperature monitoring was conducted. SAHF-3 was penetrated into ordinary sediment near the bacterial mat. The sub-bottom temperature records were obtained for 8 months. The subsurface temperatures oscillated reflecting bottom- water temperature variation (BTV). For sub-bottom temperatures measured with SAHF-3 (outside of the bacterial mat), we found that the effects of the BTV propagated into sediment by conduction only. By correcting the effect of the BTV, conductive heat flow estimated is higher than 100 mW/m2. Sub-bottom temperatures measured within bacterial mat (SAHF-4) except for the topmost sensor could be explained by a conduction model. The heat flow estimated based on the conduction model is similar to that measured with SAHF-3. The temperature of the topmost sensor is slightly higher than that expected from the conduction model. To explain the high temperature, upward fluid flow at a rate of 10-7 m/s order is needed. Heat flow carried by the upward fluid flow is higher than that estimated by Goto et al. [2003]. Heat flow value expected from the distribution of heat flow around this area is 70-80 mW/m2. The high heat flow values inside and outside the bacterial mat estimated in the present and previous studies may reflect upward fluid flow along the splay fault.

34 CFR 645.1 - What is the Upward Bound Program?

Code of Federal Regulations, 2013 CFR

2013-07-01

... the following three types of projects: (1) Regular Upward Bound projects. (2) Upward Bound Math and Science Centers. (3) Veterans Upward Bound projects. (Authority: 20 U.S.C. 1070a-11 and 1070a-13) ...) The Upward Bound Program provides Federal grants to projects designed to generate in program...

34 CFR 645.1 - What is the Upward Bound Program?

Code of Federal Regulations, 2014 CFR

2014-07-01

... the following three types of projects: (1) Regular Upward Bound projects. (2) Upward Bound Math and Science Centers. (3) Veterans Upward Bound projects. (Authority: 20 U.S.C. 1070a-11 and 1070a-13) ...) The Upward Bound Program provides Federal grants to projects designed to generate in program...

34 CFR 645.42 - What are Upward Bound stipends?

Code of Federal Regulations, 2012 CFR

2012-07-01

... grantee is permitted to provide: (1) For Regular Upward Bound projects and Upward Bound Math and Science... What are Upward Bound stipends? (a) An Upward Bound project may provide stipends for all participants... evidence of satisfactory participation in activities of the project including— (1) Regular attendance; and...

34 CFR 645.42 - What are Upward Bound stipends?

Code of Federal Regulations, 2013 CFR

2013-07-01

... grantee is permitted to provide: (1) For Regular Upward Bound projects and Upward Bound Math and Science... What are Upward Bound stipends? (a) An Upward Bound project may provide stipends for all participants... evidence of satisfactory participation in activities of the project including— (1) Regular attendance; and...

34 CFR 645.42 - What are Upward Bound stipends?

Code of Federal Regulations, 2014 CFR

2014-07-01

... grantee is permitted to provide: (1) For Regular Upward Bound projects and Upward Bound Math and Science... What are Upward Bound stipends? (a) An Upward Bound project may provide stipends for all participants... evidence of satisfactory participation in activities of the project including— (1) Regular attendance; and...

34 CFR 645.1 - What is the Upward Bound Program?

Code of Federal Regulations, 2012 CFR

2012-07-01

... the following three types of projects: (1) Regular Upward Bound projects. (2) Upward Bound Math and Science Centers. (3) Veterans Upward Bound projects. (Authority: 20 U.S.C. 1070a-11 and 1070a-13) ...) The Upward Bound Program provides Federal grants to projects designed to generate in program...

34 CFR 645.1 - What is the Upward Bound Program?

Code of Federal Regulations, 2011 CFR

2011-07-01

... the following three types of projects: (1) Regular Upward Bound projects. (2) Upward Bound Math and Science Centers. (3) Veterans Upward Bound projects. (Authority: 20 U.S.C. 1070a-11 and 1070a-13) ...) The Upward Bound Program provides Federal grants to projects designed to generate in program...

Improving Diabetes-Related Parent-Adolescent Communication With Individualized Feedback.

PubMed

May, Dana K K; Ellis, Deborah A; Cano, Annmarie; Dekelbab, Bassem

2017-11-01

To pilot a brief individualized feedback intervention to improve the communication skills of parents with an adolescent with type 1 diabetes. Parent-adolescent dyads (N = 79) discussed a diabetes-related problem, while an interventionist rated the parent's communication skills to give feedback to the parents. Parents were then randomized to a brief feedback session to target person-centered communication skills or an educational session. Dyads discussed another diabetes care problem to assess for change in communication skills. Independent raters coded parent communication skills from video recordings to rate behaviors in the service of examining possible changes in communication skills. Dyads completed ratings of perceived closeness and empathy after each conversation. Controlling for overall positive communication at baseline, parents who received feedback showed more improvement in specific person-centered communication skills than parents in the control group. Adolescents in the feedback group reported greater increases in parental empathy and intimacy from pre- to postmanipulation than the control. The feedback intervention showed preliminary efficacy for increasing person-centered communication skills and perceived empathy and intimacy. © The Author 2017. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Digital Phase-Locked Loop With Phase And Frequency Feedback

NASA Technical Reports Server (NTRS)

Thomas, J. Brooks

1991-01-01

Advanced design for digital phase-lock loop (DPLL) allows loop gains higher than those used in other designs. Divided into two major components: counterrotation processor and tracking processor. Notable features include use of both phase and rate-of-change-of-phase feedback instead of frequency feedback alone, normalized sine phase extractor, improved method for extracting measured phase, and improved method for "compressing" output rate.

Adaptation effects in static postural control by providing simultaneous visual feedback of center of pressure and center of gravity.

PubMed

Takeda, Kenta; Mani, Hiroki; Hasegawa, Naoya; Sato, Yuki; Tanaka, Shintaro; Maejima, Hiroshi; Asaka, Tadayoshi

2017-07-19

The benefit of visual feedback of the center of pressure (COP) on quiet standing is still debatable. This study aimed to investigate the adaptation effects of visual feedback training using both the COP and center of gravity (COG) during quiet standing. Thirty-four healthy young adults were divided into three groups randomly (COP + COG, COP, and control groups). A force plate was used to calculate the coordinates of the COP in the anteroposterior (COP AP ) and mediolateral (COP ML ) directions. A motion analysis system was used to calculate the coordinates of the center of mass (COM) in both directions (COM AP and COM ML ). The coordinates of the COG in the AP direction (COG AP ) were obtained from the force plate signals. Augmented visual feedback was presented on a screen in the form of fluctuation circles in the vertical direction that moved upward as the COP AP and/or COG AP moved forward and vice versa. The COP + COG group received the real-time COP AP and COG AP feedback simultaneously, whereas the COP group received the real-time COP AP feedback only. The control group received no visual feedback. In the training session, the COP + COG group was required to maintain an even distance between the COP AP and COG AP and reduce the COG AP fluctuation, whereas the COP group was required to reduce the COP AP fluctuation while standing on a foam pad. In test sessions, participants were instructed to keep their standing posture as quiet as possible on the foam pad before (pre-session) and after (post-session) the training sessions. In the post-session, the velocity and root mean square of COM AP in the COP + COG group were lower than those in the control group. In addition, the absolute value of the sum of the COP - COM distances in the COP + COG group was lower than that in the COP group. Furthermore, positive correlations were found between the COM AP velocity and COP - COM parameters. The results suggest that the novel visual feedback training that incorporates the COP AP -COG AP interaction reduces postural sway better than the training using the COP AP alone during quiet standing. That is, even COP AP fluctuation around the COG AP would be effective in reducing the COM AP velocity.

Dryout-type critical heat flux in vertical upward annular flow: effects of entrainment rate, initial entrained fraction and diameter

NASA Astrophysics Data System (ADS)

Wu, Zan; Wadekar, Vishwas; Wang, Chenglong; Sunden, Bengt

2018-01-01

This study aims to reveal the effects of liquid entrainment, initial entrained fraction and tube diameter on liquid film dryout in vertical upward annular flow for flow boiling. Entrainment and deposition rates of droplets were included in mass conservation equations to estimate the local liquid film mass flux in annular flow, and the critical vapor quality at dryout conditions. Different entrainment rate correlations were evaluated using flow boiling data of water and organic liquids including n-pentane, iso-octane and R134a. Effect of the initial entrained fraction (IEF) at the churn-to-annular flow transition was also investigated. A transitional Boiling number was proposed to separate the IEF-sensitive region at high Boiling numbers and the IEF-insensitive region at low Boiling numbers. Besides, the diameter effect on dryout vapor quality was studied. The dryout vapor quality increases with decreasing tube diameter. It needs to be pointed out that the dryout characteristics of submillimeter channels might be different because of different mechanisms of dryout, i.e., drying of liquid film underneath long vapor slugs and flow boiling instabilities.

The Humble Leader: Association of Discrepancies in Leader and Follower Ratings of Implementation Leadership With Organizational Climate in Mental Health.

PubMed

Aarons, Gregory A; Ehrhart, Mark G; Torres, Elisa M; Finn, Natalie K; Beidas, Rinad S

2017-02-01

Discrepancies, or perceptual distance, between leaders' self-ratings and followers' ratings of the leader are common but usually go unrecognized. Research on discrepancies is limited, but there is evidence that discrepancies are associated with organizational context. This study examined the association of leader-follower discrepancies in Implementation Leadership Scale (ILS) ratings of mental health clinic leaders and the association of those discrepancies with organizational climate for involvement and performance feedback. Both involvement and performance feedback are important for evidence-based practice (EBP) implementation in mental health. A total of 593 individuals-supervisors (leaders, N=80) and clinical service providers (followers, N=513)-completed surveys that included ratings of implementation leadership and organizational climate. Polynomial regression and response surface analyses were conducted to examine the associations of discrepancies in leader-follower ILS ratings with organizational involvement climate and performance feedback climate, aspects of climate likely to support EBP implementation. Both involvement climate and performance feedback climate were highest where leaders rated themselves low on the ILS and their followers rated those leaders high on the ILS ("humble leaders"). Teams with "humble leaders" showed more positive organizational climate for involvement and for performance feedback, contextual factors important during EBP implementation and sustainment. Discrepancy in leader and follower ratings of implementation leadership should be a consideration in understanding and improving leadership and organizational climate for mental health services and for EBP implementation and sustainment in mental health and other allied health settings.

Fractional-order leaky integrate-and-fire model with long-term memory and power law dynamics.

PubMed

Teka, Wondimu W; Upadhyay, Ranjit Kumar; Mondal, Argha

2017-09-01

Pyramidal neurons produce different spiking patterns to process information, communicate with each other and transform information. These spiking patterns have complex and multiple time scale dynamics that have been described with the fractional-order leaky integrate-and-Fire (FLIF) model. Models with fractional (non-integer) order differentiation that generalize power law dynamics can be used to describe complex temporal voltage dynamics. The main characteristic of FLIF model is that it depends on all past values of the voltage that causes long-term memory. The model produces spikes with high interspike interval variability and displays several spiking properties such as upward spike-frequency adaptation and long spike latency in response to a constant stimulus. We show that the subthreshold voltage and the firing rate of the fractional-order model make transitions from exponential to power law dynamics when the fractional order α decreases from 1 to smaller values. The firing rate displays different types of spike timing adaptation caused by changes on initial values. We also show that the voltage-memory trace and fractional coefficient are the causes of these different types of spiking properties. The voltage-memory trace that represents the long-term memory has a feedback regulatory mechanism and affects spiking activity. The results suggest that fractional-order models might be appropriate for understanding multiple time scale neuronal dynamics. Overall, a neuron with fractional dynamics displays history dependent activities that might be very useful and powerful for effective information processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Up-down Asymmetries in Speed Perception

NASA Technical Reports Server (NTRS)

Thompson, Peter; Stone, Leland S.

1997-01-01

We compared speed matches for pairs of stimuli that moved in opposite directions (upward and downward). Stimuli were elliptical patches (2 deg horizontally by 1 deg vertically) of horizontal sinusoidal gratings of spatial. frequency 2 cycles/deg. Two sequential 380 msec reveal presentations were compared. One of each pair of gratings (the standard) moved at 4 Hz (2 deg/sec), the other (the test) moved at a rate determined by a simple up-down staircase. The point of subjectively equal speed was calculated from the average of the last eight reversals. The task was to fixate a central point and to determine which one of the pair appeared to move faster. Eight of 10 observers perceived the upward drifting grating as moving faster than a grating moving downward but otherwise identical. on average (N = 10), when the standard moved downward, it was matched by a test moving upward at 94.7+/-1.7(SE)% of the standard speed, and when the standard moved upward it was matched by a test moving downward at 105.1+/-2.3(SE)% of the standard speed. Extending this paradigm over a range of spatial (1.5 to 13.5 c/d) and temporal (1.5 to 13.5 Hz) frequencies, preliminary results (N = 4) suggest that, under the conditions of our experiment, upward matter is seen as faster than downward for speeds greater than approx.1 deg/sec, but the effect appears to reverse at speeds below approx.1 deg/sec with downward motion perceived as faster. Given that an up-down asymmetry has been observed for the optokinetic response, both perceptual and oculomotor contributions to this phenomenon deserve exploration.

Warming-induced upward migration of the alpine treeline in the Changbai Mountains, northeast China.

PubMed

Du, Haibo; Liu, Jie; Li, Mai-He; Büntgen, Ulf; Yang, Yue; Wang, Lei; Wu, Zhengfang; He, Hong S

2018-03-01

Treeline responses to environmental changes describe an important phenomenon in global change research. Often conflicting results and generally too short observations are, however, still challenging our understanding of climate-induced treeline dynamics. Here, we use a state-of-the-art dendroecological approach to reconstruct long-term changes in the position of the alpine treeline in relation to air temperature at two sides in the Changbai Mountains in northeast China. Over the past 160 years, the treeline increased by around 80 m, a process that can be divided into three phases of different rates and drives. The first phase was mainly influenced by vegetation recovery after an eruption of the Tianchi volcano in 1702. The slowly upward shift in the second phase was consistent with the slowly increasing temperature. The last phase coincided with rapid warming since 1985, and shows with 33 m per 1°C, the most intense upward shift. The spatial distribution and age structure of trees beyond the current treeline confirm the latest, warming-induced upward shift. Our results suggest that the alpine treeline will continue to rise, and that the alpine tundra may disappear if temperatures will increase further. This study not only enhances mechanistic understanding of long-term treeline dynamics, but also highlights the effects of rising temperatures on high-elevation vegetation dynamics. © 2017 John Wiley & Sons Ltd.

Quantification of natural vapor fluxes of trichloroethene in the unsaturated zone at Picatinny Arsenal, New Jersey

USGS Publications Warehouse

Smith, James A.; Tisdale, Amy K.; Cho, H. Jean

1996-01-01

The upward flux of trichloroethene (TCE) vapor through the unsaturated zone above a contaminated, water-table aquifer at Picatinny Arsenal, New Jersey, has been studied under natural conditions over a 12-month period. Vertical gas-phase diffusion fluxes were estimated indirectly by measuring the TCE vapor concentration gradient in the unsaturated zone and using Fick's law to calculate the flux. The total gas-phase flux (e.g., the sum of diffusion and advection fluxes) was measured directly with a vertical flux chamber (VFC). In many cases, the upward TCE vapor flux was several orders of magnitude greater than the upward TCE diffusion flux, suggesting that mechanisms other than steady-state vapor diffusion are contributing to the vertical transport of TCE vapors through the unsaturated zone. The measured total flux of TCE vapor from the subsurface to the atmosphere is approximately 50 kg/yr and is comparable in magnitude to the removal rate of TCE from the aquifer by an existing pump-and-treat system and by discharge into a nearby stream. The net upward flux of TCE is reduced significantly during a storm event, presumably due to the mass transfer of TCE from the soil gas to the infiltrating rainwater and its subsequent downward advection. Several potential problems associated with the measurement of total gas-phase fluxes are discussed.

Physical examination skills training: Faculty staff vs. patient instructor feedback-A controlled trial.

PubMed

Krautter, Markus; Diefenbacher, Katja; Schultz, Jobst-Hendrik; Maatouk, Imad; Herrmann-Werner, Anne; Koehl-Hackert, Nadja; Herzog, Wolfgang; Nikendei, Christoph

2017-01-01

Standardized patients are widely used in training of medical students, both in teaching and assessment. They also frequently lead complete training sessions delivering physical examination skills without the aid of faculty teaching staff-acting as "patient instructors" (PIs). An important part of this training is their ability to provide detailed structured feedback to students which has a strong impact on their learning success. Yet, to date no study has assessed the quality of physical examination related feedback by PIs. Therefore, we conducted a randomized controlled study comparing feedback of PIs and faculty staff following a physical examination assessed by students and video assessors. 14 PIs and 14 different faculty staff physicians both delivered feedback to 40 medical students that had performed a physical examination on the respective PI while the physicians observed the performance. The physical examination was rated by two independent video assessors to provide an objective performance standard (gold standard). Feedback of PI and physicians was content analyzed by two different independent video assessors based on a provided checklist and compared to the performance standard. Feedback of PIs and physicians was also rated by medical students and video assessors using a questionnaire consisting of 12 items. There was no statistical significant difference concerning overall matching of physician or PI feedback with gold standard ratings by video assessment (p = .219). There was also no statistical difference when focusing only on items that were classified as major key steps (p = .802), mistakes or parts that were left out during physical examination (p = .219) or mistakes in communication items (p = .517). The feedback of physicians was significantly better rated than PI feedback both by students (p = .043) as well as by video assessors (p = .034). In summary, our study demonstrates that trained PIs are able to provide feedback of equal quantitative value to that of faculty staff physicians with regard to a physical examination performed on them. However, both the students and the video raters judged the quality of the feedback given by the physicians to be significantly better than that of the PIs.

Useful but Different: Resident Physician Perceptions of Interprofessional Feedback.

PubMed

Vesel, Travis P; O'Brien, Bridget C; Henry, Duncan M; van Schaik, Sandrijn M

2016-01-01

Phenomenon: Based on recently formulated interprofessional core competencies, physicians are expected to incorporate feedback from other healthcare professionals. Based on social identity theory, physicians likely differentiate between feedback from members of their own profession and others. The current study examined residents' experiences with, and perceptions of, interprofessional feedback. In 2013, Anesthesia, Obstetrics-Gynecology, Pediatrics, and Psychiatry residents completed a survey including questions about frequency of feedback from different professionals and its perceived value (5-point scale). The authors performed an analysis of variance to examine interactions between residency program and profession of feedback provider. They conducted follow-up interviews with a subset of residents to explore reasons for residents' survey ratings. Fifty-two percent (131/254) of residents completed the survey, and 15 participated in interviews. Eighty percent of residents reported receiving written feedback from physicians, 26% from nurses, and less than 10% from other professions. There was a significant interaction between residency program and feedback provider profession, F(21, 847) = 3.82, p < .001, and a significant main effect of feedback provider profession, F(7, 847) = 73.7, p < .001. On post hoc analyses, residents from all programs valued feedback from attending physicians higher than feedback from others, and anesthesia residents rated feedback from other professionals significantly lower than other residents. Ten major themes arose from qualitative data analysis, which revealed an overall positive attitude toward interprofessional feedback and clarified reasons behind residents' perceptions and identified barriers. Insights: Residents in our study reported limited exposure to interprofessional feedback and valued such feedback less than intraprofessional feedback. However, our data suggest opportunities exist for effective utilization of interprofessional feedback.

Integrating 360° behavior-orientated feedback in communication skills training for medical undergraduates: concept, acceptance and students' self-ratings of communication competence.

PubMed

Engerer, Cosima; Berberat, Pascal O; Dinkel, Andreas; Rudolph, Baerbel; Sattel, Heribert; Wuensch, Alexander

2016-10-18

Feedback is considered a key didactic element in medical education, especially for teaching of communication skills. This study investigates the impact of a best evidence-based practice feedback concept within the context of communication skills training (CST). We evaluate this concept for acceptance and changes in students self-ratings of communication competence. Our CST integrating feedback process comprises a short theoretical introduction presenting standards for good communication and a constructive 360° feedback from three perspectives: feedback from peers, from standardized patients (SPs), and from a trainer. Feed-forward process was facilitated for documenting suggestions for improvements based on observable behaviors to maximize learning benefits. Our CST was applied to four groups of eight or nine students. We assessed the data on students' acceptance using a 6-point scale ranging from very good (1) to poor (6), applied a forced choice question to rank didactic items, and assessed changes in student' self-ratings of their communication competence on a 10-cm visual analogue scale (VAS). Thirty-four medical undergraduates (82 % female, 18 % male) in their first clinical year, with an average age of 21.4 years (SD = 1.0), participated in the new training. The concept achieved high acceptance from good to very good: overall impression (M = 1.56), sufficient interaction for discussion (M = 1.15), and constructive learning atmosphere (M = 1.18). Specific elements, such as practical training with SPs (M = 1.18) and feedback by SPs (M = 1.12), showed highest acceptance. The forced choice ranking placed all feedback elements at the top of the list (feedback (FB) by SPs, rank 2; FB by trainer, rank 3; FB by colleagues, rank 4), whereas theoretical elements were at the bottom (theoretical introduction, rank 7; memory card, rank 9). Overall, student self-ratings of communication competence significantly improved in nine of the ten communication items assessed by VAS and showed a pre-post effect size of ES = 0.74 on a global rating. This study demonstrates that the training concept based on 360° behavioral feedback was well accepted and generated significant changes in student self-ratings of their communication competence. Further research is needed to determine the effects on objective communication performance.

Rigid Body Rate Inference from Attitude Variation

NASA Technical Reports Server (NTRS)

Bar-Itzhack, I. Y.; Harman, Richard R.; Thienel, Julie K.

2006-01-01

In this paper we research the extraction of the angular rate vector from attitude information without differentiation, in particular from quaternion measurements. We show that instead of using a Kalman filter of some kind, it is possible to obtain good rate estimates, suitable for spacecraft attitude control loop damping, using simple feedback loops, thereby eliminating the need for recurrent covariance computation performed when a Kalman filter is used. This considerably simplifies the computations required for rate estimation in gyro-less spacecraft. Some interesting qualities of the Kalman filter gain are explored, proven and utilized. We examine two kinds of feedback loops, one with varying gain that is proportional to the well known Q matrix, which is computed using the measured quaternion, and the other type of feedback loop is one with constant coefficients. The latter type includes two kinds; namely, a proportional feedback loop, and a proportional-integral feedback loop. The various schemes are examined through simulations and their performance is compared. It is shown that all schemes are adequate for extracting the angular velocity at an accuracy suitable for control loop damping.

Comparative effectiveness of audit-feedback versus additional physician communication training to improve cancer screening for patients with limited health literacy.

PubMed

Price-Haywood, Eboni G; Harden-Barrios, Jewel; Cooper, Lisa A

2014-08-01

We designed a continuing medical education (CME) program to teach primary care physicians (PCP) how to engage in cancer risk communication and shared decision making with patients who have limited health literacy (HL). We evaluated whether training PCPs, in addition to audit-feedback, improves their communication behaviors and increases cancer screening among patients with limited HL to a greater extent than only providing clinical performance feedback. Four-year cluster randomized controlled trial. Eighteen PCPs and 168 patients with limited HL who were overdue for colorectal/breast/cervical cancer screening. Communication intervention PCPs received skills training that included standardized patient (SP) feedback on counseling behaviors. All PCPs underwent chart audits of patients' screening status semiannually up to 24 months and received two annual performance feedback reports. PCPs experienced three unannounced SP encounters during which SPs rated PCP communication behaviors. We examined between-group differences in changes in SP ratings and patient knowledge of cancer screening guidelines over 12 months; and changes in patient cancer screening rates over 24 months. There were no group differences in SP ratings of physician communication at baseline. At follow-up, communication intervention PCPs were rated higher in general communication about cancer risks and shared decision making related to colorectal cancer screening compared to PCPs who only received performance feedback. Screening rates increased among patients of PCPs in both groups; however, there were no between-group differences in screening rates except for mammography. The communication intervention did not improve patient cancer screening knowledge. Compared to audit and feedback alone, including PCP communication training increases PCP patient-centered counseling behaviors, but not cancer screening among patients with limited HL. Larger studies must be conducted to determine whether lack of changes in cancer screening were due to clinic/patient sample size versus ineffectiveness of communication training to change outcomes.

Auditory Masking Effects on Speech Fluency in Apraxia of Speech and Aphasia: Comparison to Altered Auditory Feedback

PubMed Central

Haley, Katarina L.

2015-01-01

Purpose To study the effects of masked auditory feedback (MAF) on speech fluency in adults with aphasia and/or apraxia of speech (APH/AOS). We hypothesized that adults with AOS would increase speech fluency when speaking with noise. Altered auditory feedback (AAF; i.e., delayed/frequency-shifted feedback) was included as a control condition not expected to improve speech fluency. Method Ten participants with APH/AOS and 10 neurologically healthy (NH) participants were studied under both feedback conditions. To allow examination of individual responses, we used an ABACA design. Effects were examined on syllable rate, disfluency duration, and vocal intensity. Results Seven of 10 APH/AOS participants increased fluency with masking by increasing rate, decreasing disfluency duration, or both. In contrast, none of the NH participants increased speaking rate with MAF. In the AAF condition, only 1 APH/AOS participant increased fluency. Four APH/AOS participants and 8 NH participants slowed their rate with AAF. Conclusions Speaking with MAF appears to increase fluency in a subset of individuals with APH/AOS, indicating that overreliance on auditory feedback monitoring may contribute to their disorder presentation. The distinction between responders and nonresponders was not linked to AOS diagnosis, so additional work is needed to develop hypotheses for candidacy and underlying control mechanisms. PMID:26363508

Validity evidence and reliability of a simulated patient feedback instrument.

PubMed

Schlegel, Claudia; Woermann, Ulrich; Rethans, Jan-Joost; van der Vleuten, Cees

2012-01-27

In the training of healthcare professionals, one of the advantages of communication training with simulated patients (SPs) is the SP's ability to provide direct feedback to students after a simulated clinical encounter. The quality of SP feedback must be monitored, especially because it is well known that feedback can have a profound effect on student performance. Due to the current lack of valid and reliable instruments to assess the quality of SP feedback, our study examined the validity and reliability of one potential instrument, the 'modified Quality of Simulated Patient Feedback Form' (mQSF). Content validity of the mQSF was assessed by inviting experts in the area of simulated clinical encounters to rate the importance of the mQSF items. Moreover, generalizability theory was used to examine the reliability of the mQSF. Our data came from videotapes of clinical encounters between six simulated patients and six students and the ensuing feedback from the SPs to the students. Ten faculty members judged the SP feedback according to the items on the mQSF. Three weeks later, this procedure was repeated with the same faculty members and recordings. All but two items of the mQSF received importance ratings of > 2.5 on a four-point rating scale. A generalizability coefficient of 0.77 was established with two judges observing one encounter. The findings for content validity and reliability with two judges suggest that the mQSF is a valid and reliable instrument to assess the quality of feedback provided by simulated patients.

Stratigraphic architecture of a fluvial-lacustrine basin-fill succession at Desolation Canyon, Uinta Basin, Utah: Reference to Walthers’ Law and implications for the petroleum industry

USGS Publications Warehouse

Ford, Grace L.; David R. Pyles,; Dechesne, Marieke

2016-01-01

Two large-scale (member-scale) upward patterns are noted: Waltherian, and non-Waltherian. The upward successions in Waltherian progressions record progradation or retrogradation of a linked fluvial-lacustrine system across the area; whereas the upward successions in non-Waltherian progressions record large-scale changes in the depositional system that are not related to progradation or retrogradation of the ancient lacustrine shoreline. Four Waltherian progressions are noted: 1) the Flagstaff Limestone to lower Wasatch Formation member records the upward transition from lacustrine to fluvial—or shallowing-upward succession; 2) the upper Wasatch to Uteland Butte records the upward transition from fluvial to lacustrine—or a deepening upward succession; 3) the Uteland Butte to Renegade Tongue records the upward transition from lacustrine to fluvial—a shallowing-upward succession; and 4) the Renegade Tongue to Mahogany oil shale interval records the upward transition from fluvial to lacustrine—a deepening upward succession. The two non-Waltherian progressions in the study area are: 1) the lower to middle Wasatch, which records the abrupt shift from low to high net-sand content fluvial system, and 2) the middle to upper Wasatch, which records the abrupt shift from high to intermediate net-sand content fluvial system.

Responses to false physiological feedback in individuals with panic attacks and elevated anxiety sensitivity.

PubMed

Story, Tyler J; Craske, Michelle G

2008-09-01

Participants with elevated anxiety sensitivity and a history of panic attacks were compared to a low anxiety comparison group with respect to physiological and subjective reactivity to false heart-rate feedback and reactivity to a priming procedure. Whereas accurate heart-rate feedback elicited minimal responses, participants across groups showed significant physiological and subjective responses to false feedback. High risk and low risk participants did not differ in heart-rate responses to false feedback, though panic attack frequency did predict physiological and subjective reactions to false feedback in the high risk group. Self-reported nonspecific anxiety was significantly higher in high risk female participants than in low risk female participants, while males did not different in general subjective anxiety. However, high risk participants reported more panic-specific symptoms during the false feedback task than low risk participants, regardless of the sex of the participant. Therefore, although the experimental paradigm appeared to trigger nonspecific anxiety in high risk female participants, panic attack symptoms in reaction to the task were specific to risk group, not sex, and consistent with hypotheses. Surprisingly, the priming procedure did not influence physiological or subjective responses to false feedback in either group. These results raise additional questions regarding the process and impact of interception in individuals with panic attacks, and suggest that false perception of internal changes may contribute to risk for panic disorder when exposed to believable cues.

Emergence of resonant mode-locking via delayed feedback in quantum dot semiconductor lasers.

PubMed

Tykalewicz, B; Goulding, D; Hegarty, S P; Huyet, G; Erneux, T; Kelleher, B; Viktorov, E A

2016-02-22

With conventional semiconductor lasers undergoing external optical feedback, a chaotic output is typically observed even for moderate levels of the feedback strength. In this paper we examine single mode quantum dot lasers under strong optical feedback conditions and show that an entirely new dynamical regime is found consisting of spontaneous mode-locking via a resonance between the relaxation oscillation frequency and the external cavity repetition rate. Experimental observations are supported by detailed numerical simulations of rate equations appropriate for this laser type. The phenomenon constitutes an entirely new mode-locking mechanism in semiconductor lasers.

Geothermal state and fluid flow within ODP Hole 843B: results from wireline logging

NASA Astrophysics Data System (ADS)

Wiggins, Sean M.; Hildebrand, John A.; Gieskes, Joris M.

2002-02-01

Borehole fluid temperatures were measured with a wireline re-entry system in Ocean Drilling Program Hole 843B, the site of the Ocean Seismic Network Pilot Experiment. These temperature data, recorded more than 7 years after drilling, are compared to temperature data logged during Leg 136, approximately 1 day after drilling had ceased. Qualitative interpretations of the temperature data suggest that fluid flowed slowly downward in the borehole immediately following drilling, and flowed slowly upward 7 years after drilling. Quantitative analysis suggests that the upward fluid flow rate in the borehole is approximately 1 m/h. Slow fluid flow interpreted from temperature data only, however, requires estimates of other unmeasured physical properties. If fluid flows upward in Hole 843B, it may have led to undesirable noise for the borehole seismometer emplaced in this hole as part of the Ocean Seismic Network Pilot Experiment. Estimates of conductive heat flow from ODP Hole 843B are 51 mW/m 2 for the sediment and the basalt. These values are lower than the most recent Hawaiian Arch seafloor heat flow studies.

Enhancing Feedback on Professionalism and Communication Skills in Anesthesia Residency Programs.

PubMed

Mitchell, John D; Ku, Cindy; Diachun, Carol Ann B; DiLorenzo, Amy; Lee, Daniel E; Karan, Suzanne; Wong, Vanessa; Schell, Randall M; Brzezinski, Marek; Jones, Stephanie B

2017-08-01

Despite its importance, training faculty to provide feedback to residents remains challenging. We hypothesized that, overall, at 4 institutions, a faculty development program on providing feedback on professionalism and communication skills would lead to (1) an improvement in the quantity, quality, and utility of feedback and (2) an increase in feedback containing negative/constructive feedback and pertaining to professionalism/communication. As secondary analyses, we explored these outcomes at the individual institutions. In this prospective cohort study (October 2013 to July 2014), we implemented a video-based educational program on feedback at 4 institutions. Feedback records from 3 months before to 3 months after the intervention were rated for quality (0-5), utility (0-5), and whether they had negative/constructive feedback and/or were related to professionalism/communication. Feedback records during the preintervention, intervention, and postintervention periods were compared using the Kruskal-Wallis and χ tests. Data are reported as median (interquartile range) or proportion/percentage. A total of 1926 feedback records were rated. The institutions overall did not have a significant difference in feedback quantity (preintervention: 855/3046 [28.1%]; postintervention: 896/3327 [26.9%]; odds ratio: 1.06; 95% confidence interval, 0.95-1.18; P = .31), feedback quality (preintervention: 2 [1-4]; intervention: 2 [1-4]; postintervention: 2 [1-4]; P = .90), feedback utility (preintervention: 1 [1-3]; intervention: 2 [1-3]; postintervention: 1 [1-2]; P = .61), or percentage of feedback records containing negative/constructive feedback (preintervention: 27%; intervention: 32%; postintervention: 25%; P = .12) or related to professionalism/communication (preintervention: 23%; intervention: 33%; postintervention: 24%; P = .03). Institution 1 had a significant difference in feedback quality (preintervention: 2 [1-3]; intervention: 3 [2-4]; postintervention: 3 [2-4]; P = .001) and utility (preintervention: 1 [1-3]; intervention: 2 [1-3]; postintervention: 2 [1-4]; P = .008). Institution 3 had a significant difference in the percentage of feedback records containing negative/constructive feedback (preintervention: 16%; intervention: 28%; postintervention: 17%; P = .02). Institution 2 had a significant difference in the percentage of feedback records related to professionalism/communication (preintervention: 26%; intervention: 57%; postintervention: 31%; P < .001). We detected no overall changes but did detect different changes at each institution despite the identical intervention. The intervention may be more effective with new faculty and/or smaller discussion sessions. Future steps include refining the rating system, exploring ways to sustain changes, and investigating other factors contributing to feedback quality and utility.

The role of feedback mechanisms in historic channel changes of the lower Rio Grande in the Big Bend region

NASA Astrophysics Data System (ADS)

Dean, David J.; Schmidt, John C.

2011-03-01

Over the last century, large-scale water development of the upper Rio Grande in the U.S. and Mexico, and of the Rio Conchos in Mexico, has resulted in progressive channel narrowing of the lower Rio Grande in the Big Bend region. We used methods operating at multiple spatial and temporal scales to analyze the rate, magnitude, and processes responsible for channel narrowing. These methods included: hydrologic analysis of historic stream gage data, analysis of notes of measured discharges, historic oblique and aerial photograph analysis, and stratigraphic and dendrogeomorphic analysis of inset floodplain deposits. Our analyses indicate that frequent large floods between 1900 and the mid-1940s acted as a negative feedback mechanism and maintained a wide, sandy, multi-threaded river. Declines in mean and peak flow in the mid-1940s resulted in progressive channel narrowing. Channel narrowing has been temporarily interrupted by occasional large floods that widened the channel, however, channel narrowing has always resumed. After large floods in 1990 and 1991, the active channel width of the lower Rio Grande has narrowed by 36-52%. Narrowing has occurred by the vertical accretion of fine-grained deposits on top of sand and gravel bars, inset within natural levees. Channel narrowing by vertical accretion occurred simultaneously with a rapid invasion of non-native riparian vegetation ( Tamarix spp., Arundo donax) which created a positive feedback and exacerbated the processes of channel narrowing and vertical accretion. In two floodplain trenches, we measured 2.75 and 3.5 m of vertical accretion between 1993 and 2008. In some localities, nearly 90% of bare, active channel bars were converted to vegetated floodplain during the same period. Upward shifts of stage-discharge relations occurred resulting in over-bank flooding at lower discharges, and continued vertical accretion despite a progressive reduction in stream flow. Thus, although the magnitude of the average annual flood was reduced between 40 and 50%, over-bank flooding continued. These changes reflect a shift in the geomorphic nature of the Rio Grande from a wide, laterally unstable, multi-thread river, to a laterally stable, single-thread channel with cohesive, vertical banks, and few active in-channel bars.

A Review of Literature on Formative Evaluation of Teachers through Mid-Term Student Feedback and How the Reiser and Dick Instructional Planning Model Can Enhance This Feedback.

ERIC Educational Resources Information Center

Hampton, Scott E.

Research has shown that student mid-term feedback has significantly increased subsequent ratings of teacher effectiveness, student achievement, and student attitudes when the feedback results were accompanied by expert consultation. A gap in the literature is an instrument intended to provide specific feedback on systematic planning and delivery…

Changing healthcare capital-to-labor ratios: evidence and implications for bending the cost curve in Canada and beyond.

PubMed

Nauenberg, Eric

2014-12-01

Healthcare capital-to-labor ratios are examined for the 10 provincial single-payer health care plans across Canada. The data show an increasing trend-particularly during the period 1997-2009 during which the ratio as much as doubled from 3 to 6 %. Multivariate analyses indicate that every percentage point uptick in the rate of increase in this ratio is associated with an uptick in the rate of increase of real per capita provincial government healthcare expenditures by approximately $31 ([Formula: see text] 0.01). While the magnitude of this relationship is not large, it is still substantial enough to warrant notice: every percentage point decrease in the upward trend of the capital-to-labor ratio might be associated with a one percentage point decrease in the upward trend of per capita government healthcare expenditures. An uptick since 1997 in the rate of increase in per capita prescription drug expenditures is also associated with a decline in the trend of increasing per capita healthcare costs. While there has been some recent evidence of a slowing in the rate of health care expenditure increase, it is still unclear whether this reflects just a pause, after which the rate of increase will return to its baseline level, or a long-term shift; therefore, it is important to continue to explore various policy avenues to affect the rate of change going forward.

Regional Exploratory Analysis Between Atomospheric Aerosols and Precipitable Water in the Lower Troposhere via Inferential Statistics

NASA Astrophysics Data System (ADS)

Martinez, B. S.; Ye, H.; Levy, R. C.; Fetzer, E. J.; Remer, L.

2017-12-01

Atmospheric aerosols expose high levels of uncertainty in regard to Earth's changing atmospheric energy budget. Continued exploration and analysis is necessary to obtain more complete understanding in which, and to what degree, aerosols contribute within climate feedbacks and global climate change. With the advent of global satellite retrievals, along with specific aerosol optical depth (AOD) Dark Target and Deep Blue algorithms, aerosols can now be better measured and analyzed. Aerosol effect on climate depends primarily on altitude, the reflectance albedo of the underlying surface, along with the presence of clouds and the dynamics thereof. As currently known, the majority of aerosol distribution and mixing occur in the lower troposphere from the surface upwards to around 2km. Additionally, being a primary greenhouse gas contributor, water vapor is significant to climate feedbacks and Earth's radiation budget. Feedbacks are generally reported from the top of atmosphere (TOA). Therefore, little is known of the relationship between water vapor and aerosols; specifically, in regional areas of the globe known for aerosol loading such as anthropogenic biomass burning in South America and naturally occurring dust blowing off the deserts in the African and Arabian peninsulas. Statistical regression and timeseries analysis are used in determining significant probabilities suggesting trends of both regional precipitable water (PW) and AOD increase and decrease over a 13-year time period from 2003-2015. Regions with statistically significant positive or negative trends of AOD and PW are analyzed in determining correlations, or lack thereof. This initial examination helps to deduce and better understand how aerosols contribute to the radiation budget and assessing climate change.

WES feedback and the Atlantic Meridional Mode: observations and CMIP5 comparisons

NASA Astrophysics Data System (ADS)

Amaya, Dillon J.; DeFlorio, Michael J.; Miller, Arthur J.; Xie, Shang-Ping

2017-09-01

The Atlantic Meridional Mode (AMM) is the dominant mode of tropical SST/wind coupled variability. Modeling studies have implicated wind-evaporation-SST (WES) feedback as the primary driver of the AMM's evolution across the Atlantic basin; however, a robust coupling of the SST and winds has not been shown in observations. This study examines observed AMM growth, propagation, and decay as a result of WES interactions. Investigation of an extended maximum covariance analysis shows that boreal wintertime atmospheric forcing generates positive SST anomalies (SSTA) through a reduction of surface evaporative cooling. When the AMM peaks in magnitude during spring and summer, upward latent heat flux anomalies occur over the warmest SSTs and act to dampen the initial forcing. In contrast, on the southwestern edge of the SSTA, SST-forced cross-equatorial flow reduces the strength of the climatological trade winds and provides an anomalous latent heat flux into the ocean, which causes southwestward propagation of the initial atmosphere-forced SSTA through WES dynamics. Additionally, the lead-lag relationship of the ocean and atmosphere indicates a transition from an atmosphere-forcing-ocean regime in the northern subtropics to a highly coupled regime in the northern tropics that is not observed in the southern hemisphere. CMIP5 models poorly simulate the latitudinal transition from a one-way interaction to a two-way feedback, which may explain why they also struggle to reproduce spatially coherent interactions between tropical Atlantic SST and winds. This analysis provides valuable insight on how meridional modes act as links between extratropical and tropical variability and focuses future research aimed at improving climate model simulations.

Microstructural indicators of convection: insights from the Little Minch Sill Complex, Scotland

NASA Astrophysics Data System (ADS)

Nicoli, Gautier; Holness, Marian; Neufeld, Jerome; Farr, Robert

2017-04-01

The fluid dynamic behaviour of crystal-bearing magmas is a key parameter to understand the formation of magmatic bodies. There are two opposite views on the subject: Some argue that solidification in intrusive bodies is affected by convection whereas others claim solidification happens in a static environment. A consensus on the question may be reached by carefully studying the grain size distribution in the settled accumulations of cargo crystals. In the absence of significant crystal growth or particle coarsening by agglomeration, settling of a polydisperse crystal load will always result in a fining-upwards sequence in static magmas as well as in convecting environments. If we assume the particle concentration is always sufficiently low to prevent hindered settling, gravitational settling in a static magma leads to the settling of individual crystals at a constant rate determined by their Stokes' velocity. Each size class is deposited at a constant rate, until all the grains of that size class have fallen out of suspension, leading to a well-stratified sequence and the complete disappearance of progressively smaller size classes upwards in the accumulation. In contrast, in a vigorously convecting magma crystals settle when they enter the stagnant basal boundary layer. In a system containing a polydisperse crystal population most of the bigger particles are removed rapidly from the bulk magma, leading to the creation of a fining-upwards sequence on the floor. However, in detail the structure of this fining-upwards sequence is critically different from that created by settling from a stagnant magma, with the gradual phasing out of each size class instead of the abrupt termination of size classes seen in static systems. This provides us with the opportunity to distinguish between settling from static or convecting magma using the spatial variation of grain size in settled accumulations. We focus on the Little Minch Sill Complex in Scotland, which formed from olivine-phyric magma and is characterised by both composite and single-injection bodies with significant accumulation of olivine on their lower margins. Comparison of the fining-upwards sequences in the picrodolerite/crinanite unit of the composite Shiant Isles Main Sill,and related single-injection sills on the Trotternish Peninsula, Skye, illustrate the ability of this method to distinguish between convecting and non-convecting magma bodies.

The Humble Leader: Association of Discrepancies in Leader and Follower Ratings of Implementation Leadership with Organizational Climate in Mental Health

PubMed Central

Aarons, Gregory A.; Ehrhart, Mark G.; Torres, Elisa M.; Finn, Natalie K.; Beidas, Rinad

2017-01-01

Objectives Discrepancies between leaders' self-ratings and follower ratings of the leader are common but usually go unrecognized. Research on discrepancies is limited but there is evidence that discrepancies are associated with organizational context. This study examined the association of leader-follower discrepancies in Implementation Leadership Scale (ILS) ratings of mental health clinic leaders, and the association of those discrepancies with organizational climate for involvement and performance feedback. Both involvement and performance feedback may be important for evidence-based practice implementation in mental health. Methods A total of 593 supervisors (i.e., leaders, n=80) and clinical service providers (i.e., followers, n=513) completed surveys including ratings of implementation leadership and organizational climate. Polynomial regression and response surface analyses were conducted to examine the associations of discrepancies in leader-follower ILS ratings with organizational involvement climate and performance feedback climate, aspects of climate likely to support EBP implementation. Results Both involvement climate and performance feedback climate were highest where leaders rated themselves low on the ILS and their followers rated those leaders high on the ILS (i.e., “humble leaders”). Conclusions Teams with “humble leaders” showed more positive organizational climate for involvement and for performance feedback, contextual factors important during EBP implementation and sustainment. Discrepancy in leader and follower ratings of implementation leadership should be a consideration in understanding and improving leadership and organizational climate for mental health services and for evidence-based practice implementation and sustainment in mental health and other allied health settings. PMID:27691380

Physical examination skills training: Faculty staff vs. patient instructor feedback—A controlled trial

PubMed Central

Diefenbacher, Katja; Schultz, Jobst-Hendrik; Maatouk, Imad; Herrmann-Werner, Anne; Koehl-Hackert, Nadja; Herzog, Wolfgang; Nikendei, Christoph

2017-01-01

Background Standardized patients are widely used in training of medical students, both in teaching and assessment. They also frequently lead complete training sessions delivering physical examination skills without the aid of faculty teaching staff–acting as “patient instructors” (PIs). An important part of this training is their ability to provide detailed structured feedback to students which has a strong impact on their learning success. Yet, to date no study has assessed the quality of physical examination related feedback by PIs. Therefore, we conducted a randomized controlled study comparing feedback of PIs and faculty staff following a physical examination assessed by students and video assessors. Methods 14 PIs and 14 different faculty staff physicians both delivered feedback to 40 medical students that had performed a physical examination on the respective PI while the physicians observed the performance. The physical examination was rated by two independent video assessors to provide an objective performance standard (gold standard). Feedback of PI and physicians was content analyzed by two different independent video assessors based on a provided checklist and compared to the performance standard. Feedback of PIs and physicians was also rated by medical students and video assessors using a questionnaire consisting of 12 items. Results There was no statistical significant difference concerning overall matching of physician or PI feedback with gold standard ratings by video assessment (p = .219). There was also no statistical difference when focusing only on items that were classified as major key steps (p = .802), mistakes or parts that were left out during physical examination (p = .219) or mistakes in communication items (p = .517). The feedback of physicians was significantly better rated than PI feedback both by students (p = .043) as well as by video assessors (p = .034). Conclusions In summary, our study demonstrates that trained PIs are able to provide feedback of equal quantitative value to that of faculty staff physicians with regard to a physical examination performed on them. However, both the students and the video raters judged the quality of the feedback given by the physicians to be significantly better than that of the PIs. PMID:28692703

34 CFR 645.32 - How does the Secretary evaluate prior experience?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Upward Bound and Upward Bound Math and Science Centers PE criteria in paragraph (e)(1)(ii) of this...) Regular Upward Bound and Upward Bound Math and Science Centers. (i) (3 points) Number of participants...

34 CFR 645.32 - How does the Secretary evaluate prior experience?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Upward Bound and Upward Bound Math and Science Centers PE criteria in paragraph (e)(1)(ii) of this...) Regular Upward Bound and Upward Bound Math and Science Centers. (i) (3 points) Number of participants...

34 CFR 645.32 - How does the Secretary evaluate prior experience?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Upward Bound and Upward Bound Math and Science Centers PE criteria in paragraph (e)(1)(ii) of this...) Regular Upward Bound and Upward Bound Math and Science Centers. (i) (3 points) Number of participants...

34 CFR 645.32 - How does the Secretary evaluate prior experience?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Upward Bound and Upward Bound Math and Science Centers PE criteria in paragraph (e)(1)(ii) of this...) Regular Upward Bound and Upward Bound Math and Science Centers. (i) (3 points) Number of participants...

Are All Competencies Equal in the Eyes of Residents? A Multicenter Study of Emergency Medicine Residents’ Interest in Feedback

PubMed Central

Bentley, Suzanne; Hu, Kevin; Messman, Anne; Moadel, Tiffany; Khandelwal, Sorabh; Streich, Heather; Noelker, Joan

2017-01-01

Introduction Feedback, particularly real-time feedback, is critical to resident education. The emergency medicine (EM) milestones were developed in 2012 to enhance resident assessment, and many programs use them to provide focused resident feedback. The purpose of this study was to evaluate EM residents’ level of interest in receiving real-time feedback on each of the 23 competencies/sub-competencies. Methods This was a multicenter cross-sectional study of EM residents. We surveyed participants on their level of interest in receiving real-time on-shift feedback on each of the 23 competencies/sub-competencies. Anonymous paper or computerized surveys were distributed to residents at three four-year training programs and three three-year training programs with a total of 223 resident respondents. Residents rated their level of interest in each milestone on a six-point Likert-type response scale. We calculated average level of interest for each of the 23 sub-competencies, for all 223 respondents and separately by postgraduate year (PGY) levels of training. One-way analyses of variance were performed to determine if there were differences in ratings by level of training. Results The overall survey response rate across all institutions was 82%. Emergency stabilization had the highest mean rating (5.47/6), while technology had the lowest rating (3.24/6). However, we observed no differences between levels of training on any of the 23 competencies/sub-competencies. Conclusion Residents seem to ascribe much more value in receiving feedback on domains involving high-risk, challenging procedural skills as compared to low-risk technical and communication skills. Further studies are necessary to determine whether residents’ perceived importance of competencies/sub-competencies needs to be considered when developing an assessment or feedback program based on these 23 EM competencies/sub-competencies. PMID:28116012

Continental Growth and Mantle Hydration as Earth System Feedback Cycles and possible Effects of the Biosphere

NASA Astrophysics Data System (ADS)

Höning, D.; Spohn, T.

2016-12-01

The evolution of Earth is charcterized by intertwined feedback cycles. We focus on two feedback cycles that include the mantle water budget and the continental crust and study possible effects of the Earth's biosphere. The first feedback loop includes cycling of water into the mantle at subduction zones and outgassing at volcanic chains and mid-ocean ridges. Water will reduce the viscosity of mantle rock, and therefore the speed of mantle convection and plate subduction will increase with the mantle water concentration, eventually enhancing the rates of mantle water regassing and outgassing. A second feedback loop includes the production and erosion of continental crust. Continents grow by volcanism above subduction zones, whose total length is determined by the total area of the continents. Furthermore, the erosion rate of the continents is proportional to the total surface area of continental crust. The rate of sediment subduction affects the rate of transport of water to the mantle and the production rate of new continental crust. We present a model that includes both cycles and show how the system develops stable and unstable fixed points in a plane defined by mantle water concentration and surface are of continents. The stable points represent either an Earth mostly covered by continents and a wet mantle or an Earth mostly covered by oceans with a dry mantle. The presently observed Earth is inbetween these extreme states but the state is intrinsically unstable. We couple the feedback model to a parameterized thermal evolution model. We show how Earth evolved towards its present unstable state. We argue that other feedback cycles such as the carbonate silicate cycle may act to stabilize the present state, however. By enhancing continental weathering and erosion, and eventually the sediment transport into subduction zones, the biosphere impacts both feedback cycles and might play a crucial role in regulating Earth's system and keep continental crust coverage and mantle water budget at its present day state.

Adaptive limited feedback for interference alignment in MIMO interference channels.

PubMed

Zhang, Yang; Zhao, Chenglin; Meng, Juan; Li, Shibao; Li, Li

2016-01-01

It is very important that the radar sensor network has autonomous capabilities such as self-managing, etc. Quite often, MIMO interference channels are applied to radar sensor networks, and for self-managing purpose, interference management in MIMO interference channels is critical. Interference alignment (IA) has the potential to dramatically improve system throughput by effectively mitigating interference in multi-user networks at high signal-to-noise (SNR). However, the implementation of IA predominantly relays on perfect and global channel state information (CSI) at all transceivers. A large amount of CSI has to be fed back to all transmitters, resulting in a proliferation of feedback bits. Thus, IA with limited feedback has been introduced to reduce the sum feedback overhead. In this paper, by exploiting the advantage of heterogeneous path loss, we first investigate the throughput of IA with limited feedback in interference channels while each user transmits multi-streams simultaneously, then we get the upper bound of sum rate in terms of the transmit power and feedback bits. Moreover, we propose a dynamic feedback scheme via bit allocation to reduce the throughput loss due to limited feedback. Simulation results demonstrate that the dynamic feedback scheme achieves better performance in terms of sum rate.

Identification of neural structures involved in stuttering using vibrotactile feedback.

PubMed

Cheadle, Oliver; Sorger, Clarissa; Howell, Peter

Feedback delivered over auditory and vibratory afferent pathways has different effects on the fluency of people who stutter (PWS). These features were exploited to investigate the neural structures involved in stuttering. The speech signal vibrated locations on the body (vibrotactile feedback, VTF). Eleven PWS read passages under VTF and control (no-VTF) conditions. All combinations of vibration amplitude, synchronous or delayed VTF and vibrator position (hand, sternum or forehead) were presented. Control conditions were performed at the beginning, middle and end of test sessions. Stuttering rate, but not speaking rate, differed between the control and VTF conditions. Notably, speaking rate did not change between when VTF was delayed versus when it was synchronous in contrast with what happens with auditory feedback. This showed that cerebellar mechanisms, which are affected when auditory feedback is delayed, were not implicated in the fluency-enhancing effects of VTF, suggesting that there is a second fluency-enhancing mechanism. Copyright © 2018 Elsevier Inc. All rights reserved.

Audit feedback on reading performance of screening mammograms: An international comparison.

PubMed

Hofvind, S; Bennett, R L; Brisson, J; Lee, W; Pelletier, E; Flugelman, A; Geller, B

2016-09-01

Providing feedback to mammography radiologists and facilities may improve interpretive performance. We conducted a web-based survey to investigate how and why such feedback is undertaken and used in mammographic screening programmes. The survey was sent to representatives in 30 International Cancer Screening Network member countries where mammographic screening is offered. Seventeen programmes in 14 countries responded to the survey. Audit feedback was aimed at readers in 14 programmes, and facilities in 12 programmes. Monitoring quality assurance was the most common purpose of audit feedback. Screening volume, recall rate, and rate of screen-detected cancers were typically reported performance measures. Audit reports were commonly provided annually, but more frequently when target guidelines were not reached. The purpose, target audience, performance measures included, form and frequency of the audit feedback varied amongst mammographic screening programmes. These variations may provide a basis for those developing and improving such programmes. © The Author(s) 2016.

Method and apparatus for large motor control

DOEpatents

Rose, Chris R [Santa Fe, NM; Nelson, Ronald O [White Rock, NM

2003-08-12

Apparatus and method for providing digital signal processing method for controlling the speed and phase of a motor involves inputting a reference signal having a frequency and relative phase indicative of a time based signal; modifying the reference signal to introduce a slew-rate limited portion of each cycle of the reference signal; inputting a feedback signal having a frequency and relative phase indicative of the operation of said motor; modifying the feedback signal to introduce a slew-rate limited portion of each cycle of the feedback signal; analyzing the modified reference signal and the modified feedback signal to determine the frequency of the modified reference signal and of the modified feedback signal and said relative phase between said modified reference signal and said modified feedback signal; and outputting control signals to the motor for adjusting said speed and phase of the motor based on the frequency determination and determination of the relative phase.

Attention to emotion and non-Western faces: revisiting the facial feedback hypothesis.

PubMed

Dzokoto, Vivian; Wallace, David S; Peters, Laura; Bentsi-Enchill, Esi

2014-01-01

In a modified replication of Strack, Martin, and Stepper's demonstration of the Facial Feedback Hypothesis (1988), we investigated the effect of attention to emotion on the facial feedback process in a non-western cultural setting. Participants, recruited from two universities in Ghana, West Africa, gave self-reports of their perceived levels of attention to emotion, and then completed cartoon-rating tasks while randomly assigned to smiling, frowning, or neutral conditions. While participants with low Attention to Emotion scores displayed the usual facial feedback effect (rating cartoons as funnier when in the smiling compared to the frowning condition), the effect was not present in individuals with high Attention to Emotion. The findings indicate that (1) the facial feedback process can occur in contexts beyond those in which the phenomenon has previously been studied, and (2) aspects of emotion regulation, such as Attention to Emotion can interfere with the facial feedback process.

Modeling and Simulation of Hydropower Station Diversion System's characteristic line method by introducing water head to flow feedback

NASA Astrophysics Data System (ADS)

Guangwen, Xu; Xi, Li; Ze, Yao

2018-06-01

To solve the damping problem of water hammer wave in the modeling method of water diversion system of hydropower station, this paper introduces the feedback regulation technology from head to flow, that is: A fixed water head is taken out for flow feedback, and the following conclusions are obtained through modeling and simulation. Adjusting the feedback coefficient F of the water head to the flow rate can change the damping characteristic of the system, which can simulate the attenuation process of the water shock wave in the true water diversion pipeline. Even if a small feedback coefficient is introduced, the damping effect of the system is very obvious, but it has little effect on the amplitude of the first water shock wave after the transition process. Therefore, it is feasible and reasonable to introduce water head to flow rate feedback coefficient F in hydraulic turbine diversion system.

29 CFR 37.4 - What definitions apply to this part?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (TDDs/TTYs), videotext displays, or other effective means of making aurally delivered materials..., brailled materials, large print materials, or other effective means of making visually delivered materials... employment-related training; (5) Participation in upward mobility programs; (6) Deciding rates of pay or...

29 CFR 37.4 - What definitions apply to this part?

Code of Federal Regulations, 2012 CFR

2012-07-01

... (TDDs/TTYs), videotext displays, or other effective means of making aurally delivered materials..., brailled materials, large print materials, or other effective means of making visually delivered materials... employment-related training; (5) Participation in upward mobility programs; (6) Deciding rates of pay or...

29 CFR 37.4 - What definitions apply to this part?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (TDDs/TTYs), videotext displays, or other effective means of making aurally delivered materials..., brailled materials, large print materials, or other effective means of making visually delivered materials... employment-related training; (5) Participation in upward mobility programs; (6) Deciding rates of pay or...

29 CFR 37.4 - What definitions apply to this part?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (TDDs/TTYs), videotext displays, or other effective means of making aurally delivered materials..., brailled materials, large print materials, or other effective means of making visually delivered materials... employment-related training; (5) Participation in upward mobility programs; (6) Deciding rates of pay or...

A new lattice hydrodynamic model based on control method considering the flux change rate and delay feedback signal

NASA Astrophysics Data System (ADS)

Qin, Shunda; Ge, Hongxia; Cheng, Rongjun

2018-02-01

In this paper, a new lattice hydrodynamic model is proposed by taking delay feedback and flux change rate effect into account in a single lane. The linear stability condition of the new model is derived by control theory. By using the nonlinear analysis method, the mKDV equation near the critical point is deduced to describe the traffic congestion. Numerical simulations are carried out to demonstrate the advantage of the new model in suppressing traffic jam with the consideration of flux change rate effect in delay feedback model.

EFFECT OF DELAYED AUDITORY FEEDBACK, SPEECH RATE, AND SEX ON SPEECH PRODUCTION.

PubMed

Stuart, Andrew; Kalinowski, Joseph

2015-06-01

Perturbations in Delayed Auditory Feedback (DAF) and speech rate were examined as sources of disruptions in speech between men and women. Fluent adult men (n = 16) and women (n = 16) spoke at a normal and an imposed fast rate of speech with 0, 25, 50, 100, and 200 msec. DAF. The syllable rate significantly increased when participants were instructed to speak at a fast rate, and the syllable rate decreased with increasing DAF delays. Men's speech rate was significantly faster during the fast speech rate condition with a 200 msec. DAF. Disfluencies increased with increasing DAF delay. Significantly more disfluency occurred at delays of 25 and 50 msec. at the fast rate condition, while more disfluency occurred at 100 and 200 msec. in normal rate conditions. Men and women did not display differences in the number of disfluencies. These findings demonstrate sex differences in susceptibility to perturbations in DAF and speech rate suggesting feedforward/feedback subsystems that monitor vocalizations may be different between sexes.

Upward flow of supercritical CO2 with transition to gaseous conditions: Simulations for design of large-scale CO2 flow experiments at LUCI

NASA Astrophysics Data System (ADS)

Oldenburg, C. M.; Peters, C. A.; Dobson, P. F.; Doughty, C.

2010-12-01

Understanding the processes involved in large-scale upward flow of CO2 related to Geologic Carbon Sequestration (GCS) is critical to evaluating trapping mechanisms and potential impacts of CO2 leakage over long distances. The Laboratory for Underground CO2 Investigations (LUCI) is being planned to be built at DUSEL to host large-scale vertical CO2 and brine flow experiments. As conceived, LUCI would consist of a 500 m-long vertical raisebore approximately 3 m in diameter which will contain three suspended long-column pressure vessels. The long-column pressure vessels are planned to be 1 m in diameter with thermal control on the outer walls with a centralized inner fiberglass well for accommodating monitoring tools for determining phase saturation, porosity, temperature, and other properties of the flow region. The outer wall of the inner fiberglass well and the inner wall of the main vessel comprise the lateral boundaries of the long vertical annular regions that will be filled with porous media in which experiments investigating flow and transport, geochemical alterations of well cement, and biological processes involving injected CO2 will be performed. The large vertical extent of the column is needed to span the full range of CO2 conditions from supercritical (scCO2, P > 7.4 MPa, T > 31 °C) to gaseous CO2 that is believed to be significant as CO2 flows upwards. Here we consider the CO2-brine flow experiments in which the annular region will be pressurized at the top and bottom and contain brine-filled porous media through which scCO2 introduced at the bottom will flow upward. We are carrying out two-phase flow simulations of the buoyancy- and pressure-driven flow of CO2 and brine upward in the annular porous media region to further design the flow columns, e.g., to determine critical length and diameter requirements, as well as to plan the experiments to be performed. The simulations are carried out using TOUGH2/ECO2N, which models two-phase non-isothermal flow and transport of water, CO2, and NaCl in porous media. To treat important issues of drainage and imbibition at the leading and trailing edges of the CO2 slug, we employ hysteretic relative permeability functions. Simulation results will be presented showing flow rate, saturation, and temperature dependence on permeability, relative permeability parameters, size of initial CO2 slug, imposed upward flow rate, and different side boundary conditions (e.g., fully insulated and temperature equal to a constant geothermal gradient).

Auditory feedback improves heart rate moderation during moderate-intensity exercise.

PubMed

Shaykevich, Alex; Grove, J Robert; Jackson, Ben; Landers, Grant J; Dimmock, James

2015-05-01

The objective of this study is to determine whether exposure to automated HR feedback can produce improvements in the ability to regulate HR during moderate-intensity exercise and to evaluate the persistence of these improvements after feedback is removed. Twenty healthy adults performed 10 indoor exercise sessions on cycle ergometers over 5 wk after a twice-weekly schedule. During these sessions (FB), participants received auditory feedback designed to maintain HR within a personalized, moderate-intensity training zone between 70% and 80% of estimated maximum HR. All feedback was delivered via a custom mobile software application. Participants underwent an initial assessment (PREFB) to measure their ability to maintain exercise intensity defined by the training zone without use of feedback. After completing the feedback training, participants performed three additional assessments identical to PREFB at 1 wk (POST1), 2 wk (POST2), and 4 wk (POST3) after their last feedback session. Time in zone (TIZ), defined as the ratio of the time spent within the training zone divided by the overall time of exercise, rate of perceived exertion, instrumental attitudes, and affective attitudes were then evaluated to assess results using two-way, mixed-model ANOVA with sessions and gender as factors. Training with feedback significantly improved TIZ (P < 0.01) compared with PREFB. An absence of significant differences in TIZ between FB, POST1, POST2, and POST3 (P ≥ 0.35) indicated that these improvements were maintained after feedback was removed. No significant differences in rate of perceived exertion (P ≥ 0.40) or attitude measures (P ≥ 0.30) were observed. Auditory biofeedback is an effective mechanism for entraining HR regulation during moderate-intensity exercise in healthy adults.

The Effect on Teenage Risky Driving of Feedback From a Safety Monitoring System: A Randomized Controlled Trial

PubMed Central

Bingham, C. Raymond; Ouimet, Marie Claude; Pradhan, Anuj; Chen, Rusan; Barretto, Andrea; Shope, Jean

2012-01-01

Purpose Teenage risky driving may be due to teenagers not knowing what is risky, preferring risk, or the lack of consequences. Elevated gravitational-force (g-force) events, caused mainly by hard braking and sharp turns, provide a valid measure of risky driving and are the target of interventions using in-vehicle data recording and feedback devices. The effect of two forms of feedback about risky driving events to teenagers only or to teenagers and their parents was tested in a randomized controlled trial. Methods Ninety parent-teen dyads were randomized to one of two groups: (1) immediate feedback to teens (Lights Only); or (2) immediate feedback to teens plus family access to event videos and ranking of the teen relative to other teenage drivers (Lights Plus). Participants’ vehicles were instrumented with data recording devices and events exceeding 0.5 g were assessed for two weeks of baseline and 13 weeks of feedback. Results Growth analysis with random slopes yielded a significant decrease in event rates for the Lights Plus group (slope = −.11, p < 0.01), but no change for the Lights Only group (slope = 0.05, p = 0.67) across the 15 weeks. A large effect size of 1.67 favored the Lights Plus group. Conclusions Provision of feedback with possible consequences associated with parents being informed reduced risky driving, while immediate feedback only to teenagers did not. Implications and Contribution Reducing elevated g-force events due to hard stops and sharp turns could reduce crash rates among novice teenage drivers. Using materials from the DriveCam For Families Program we found that feedback to both teens and parents significantly reduced rates, while feedback only to teens did not. PMID:23375825

34 CFR 645.20 - How many applications for an Upward Bound award may an eligible applicant submit?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Upward Bound project, an Upward Bound Math and Science Center, or a Veterans Upward Bound project... additional application describes a project that serves a different participant population. (b) Each...

Temporal Lobe Epilepsy Alters Auditory-motor Integration For Voice Control

PubMed Central

Li, Weifeng; Chen, Ziyi; Yan, Nan; Jones, Jeffery A.; Guo, Zhiqiang; Huang, Xiyan; Chen, Shaozhen; Liu, Peng; Liu, Hanjun

2016-01-01

Temporal lobe epilepsy (TLE) is the most common drug-refractory focal epilepsy in adults. Previous research has shown that patients with TLE exhibit decreased performance in listening to speech sounds and deficits in the cortical processing of auditory information. Whether TLE compromises auditory-motor integration for voice control, however, remains largely unknown. To address this question, event-related potentials (ERPs) and vocal responses to vocal pitch errors (1/2 or 2 semitones upward) heard in auditory feedback were compared across 28 patients with TLE and 28 healthy controls. Patients with TLE produced significantly larger vocal responses but smaller P2 responses than healthy controls. Moreover, patients with TLE exhibited a positive correlation between vocal response magnitude and baseline voice variability and a negative correlation between P2 amplitude and disease duration. Graphical network analyses revealed a disrupted neuronal network for patients with TLE with a significant increase of clustering coefficients and path lengths as compared to healthy controls. These findings provide strong evidence that TLE is associated with an atypical integration of the auditory and motor systems for vocal pitch regulation, and that the functional networks that support the auditory-motor processing of pitch feedback errors differ between patients with TLE and healthy controls. PMID:27356768

Validity evidence and reliability of a simulated patient feedback instrument

PubMed Central

2012-01-01

Background In the training of healthcare professionals, one of the advantages of communication training with simulated patients (SPs) is the SP's ability to provide direct feedback to students after a simulated clinical encounter. The quality of SP feedback must be monitored, especially because it is well known that feedback can have a profound effect on student performance. Due to the current lack of valid and reliable instruments to assess the quality of SP feedback, our study examined the validity and reliability of one potential instrument, the 'modified Quality of Simulated Patient Feedback Form' (mQSF). Methods Content validity of the mQSF was assessed by inviting experts in the area of simulated clinical encounters to rate the importance of the mQSF items. Moreover, generalizability theory was used to examine the reliability of the mQSF. Our data came from videotapes of clinical encounters between six simulated patients and six students and the ensuing feedback from the SPs to the students. Ten faculty members judged the SP feedback according to the items on the mQSF. Three weeks later, this procedure was repeated with the same faculty members and recordings. Results All but two items of the mQSF received importance ratings of > 2.5 on a four-point rating scale. A generalizability coefficient of 0.77 was established with two judges observing one encounter. Conclusions The findings for content validity and reliability with two judges suggest that the mQSF is a valid and reliable instrument to assess the quality of feedback provided by simulated patients. PMID:22284898

Network feedback regulates motor output across a range of modulatory neuron activity

PubMed Central

Spencer, Robert M.

2016-01-01

Modulatory projection neurons alter network neuron synaptic and intrinsic properties to elicit multiple different outputs. Sensory and other inputs elicit a range of modulatory neuron activity that is further shaped by network feedback, yet little is known regarding how the impact of network feedback on modulatory neurons regulates network output across a physiological range of modulatory neuron activity. Identified network neurons, a fully described connectome, and a well-characterized, identified modulatory projection neuron enabled us to address this issue in the crab (Cancer borealis) stomatogastric nervous system. The modulatory neuron modulatory commissural neuron 1 (MCN1) activates and modulates two networks that generate rhythms via different cellular mechanisms and at distinct frequencies. MCN1 is activated at rates of 5–35 Hz in vivo and in vitro. Additionally, network feedback elicits MCN1 activity time-locked to motor activity. We asked how network activation, rhythm speed, and neuron activity levels are regulated by the presence or absence of network feedback across a physiological range of MCN1 activity rates. There were both similarities and differences in responses of the two networks to MCN1 activity. Many parameters in both networks were sensitive to network feedback effects on MCN1 activity. However, for most parameters, MCN1 activity rate did not determine the extent to which network output was altered by the addition of network feedback. These data demonstrate that the influence of network feedback on modulatory neuron activity is an important determinant of network output and feedback can be effective in shaping network output regardless of the extent of network modulation. PMID:27030739

The effect of performance feedback on drivers' hazard perception ability and self-ratings.

PubMed

Horswill, Mark S; Garth, Megan; Hill, Andrew; Watson, Marcus O

2017-04-01

Drivers' hazard perception ability has been found to predict crash risk, and novice drivers appear to be particularly poor at this skill. This competency appears to develop only slowly with experience, and this could partially be a result of poor quality performance feedback. We report an experiment in which we provided high-quality artificial feedback on individual drivers' performance in a validated video-based hazard perception test via either: (1) a graph-based comparison of hazard perception response times between the test-taker, the average driver, and an expert driver; (2) a video-based comparison between the same groups; or (3) both. All three types of feedback resulted in both an improvement in hazard perception performance and a reduction in self-rated hazard perception skill, compared with a no-feedback control group. Video-based and graph-based feedback combined resulted in a greater improvement in hazard perception performance than either of the individual components, which did not differ from one another. All three types of feedback eliminated participants' self-enhancement bias for hazard perception skill. Participants judged both interventions involving video feedback to be significantly more likely to improve their real-world driving than the no feedback control group. While all three forms of feedback had some value, the combined video and graph feedback intervention appeared to be the most effective across all outcome measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

In Sync: The Effect of Physiology Feedback on the Match between Heart Rate and Self-Reported Stress.

PubMed

van Dijk, Elisabeth T; Westerink, Joyce H D M; Beute, Femke; IJsselsteijn, Wijnand A

2015-01-01

Over the past years self-tracking of physiological parameters has become increasingly common: more and more people are keeping track of aspects of their physiological state (e.g., heart rate, blood sugar, and blood pressure). To shed light on the possible effects of self-tracking of physiology, a study was conducted to test whether physiology feedback has acute effects on self-reported stress and the extent to which self-reported stress corresponds to physiological stress. In this study, participants executed several short tasks, while they were either shown visual feedback about their heart rate or not. Results show that self-reported stress is more in sync with heart rate for participants who received physiology feedback. Interactions between two personality factors (neuroticism and anxiety sensitivity) and feedback on the level of self-reported stress were found, indicating that while physiology feedback may be beneficial for individuals high in neuroticism, it may be detrimental for those high in anxiety sensitivity. Additional work is needed to establish how the results of this study may extend beyond immediate effects in a controlled lab setting, but our results do provide a first indication of how self-tracking of physiology may lead to better body awareness and how personality characteristics can help us predict which individuals are most likely to benefit from self-tracking of physiology.

In Sync: The Effect of Physiology Feedback on the Match between Heart Rate and Self-Reported Stress

PubMed Central

van Dijk, Elisabeth T.; Westerink, Joyce H. D. M.; Beute, Femke; IJsselsteijn, Wijnand A.

2015-01-01

Over the past years self-tracking of physiological parameters has become increasingly common: more and more people are keeping track of aspects of their physiological state (e.g., heart rate, blood sugar, and blood pressure). To shed light on the possible effects of self-tracking of physiology, a study was conducted to test whether physiology feedback has acute effects on self-reported stress and the extent to which self-reported stress corresponds to physiological stress. In this study, participants executed several short tasks, while they were either shown visual feedback about their heart rate or not. Results show that self-reported stress is more in sync with heart rate for participants who received physiology feedback. Interactions between two personality factors (neuroticism and anxiety sensitivity) and feedback on the level of self-reported stress were found, indicating that while physiology feedback may be beneficial for individuals high in neuroticism, it may be detrimental for those high in anxiety sensitivity. Additional work is needed to establish how the results of this study may extend beyond immediate effects in a controlled lab setting, but our results do provide a first indication of how self-tracking of physiology may lead to better body awareness and how personality characteristics can help us predict which individuals are most likely to benefit from self-tracking of physiology. PMID:26146611

Do volunteer community-based preceptors value students' feedback?

PubMed

Dent, M Marie; Boltri, John; Okosun, Ike S

2004-11-01

A key component of educational practice is to provide feedback and evaluation to teachers and learners to improve the teaching and learning process. The purpose of this study was to determine whether volunteer community preceptors value evaluation and feedback by students as much as they value other resources or rewards. In Fall 1999, a questionnaire concerning the resources and rewards of preceptorship was mailed to 236 community preceptors affiliated with the Mercer University School of Medicine, Macon, Georgia. Preceptors were asked to rate 20 factors on a five-point Likert scale (5 = very important to 1 = not very important). The mean values were compared using t-tests. One hundred sixty-eight preceptors (71%) completed questionnaires. Preceptors rated evaluation and feedback from students significantly higher (p < .001) than all other factors (mean = 4.02, standard deviation [SD] = .87). Continuing medical education for teaching was the next most highly valued factor (mean = 3.67, SD = 1.14). Preceptors rated financial compensation the lowest (mean = 2.01, SD = 1.19) of all factors. The high rank of feedback and evaluation from students persisted across gender, specialty, length of time as a preceptor, practice location, and years practicing medicine. This study demonstrates that feedback and evaluation from students is highly valued. The knowledge that community-based preceptors highly value feedback and evaluation from students should stimulate medical school programs to provide feedback and evaluation to preceptors that will enhance the educational outcomes for both faculty and learners.

A satellite technique for quantitatively mapping rainfall rates over the oceans

NASA Technical Reports Server (NTRS)

Wilheit, T. T.; Roa, M. S. V.; Chang, T. C.; Rodgers, E. B.; Theon, J. S.

1975-01-01

A theoretical model for calculating microwave radiative transfer in raining atmospheres is developed. These calculations are compared with microwave brightness temperatures at a wavelength of 1.55 cm measured on the Nimbus-5 satellite and rain rates derived from WSR-57 meteorological radar measurements. A specially designed ground based verification experiment was also performed wherein upward viewing microwave brightness temperature measurements at wavelengths of 1.55 cm and 0.81 cm were compared with directly measured rain rates.

Context-specific adaptation of the gain of the vestibulo-ocular reflex in humans.

PubMed

Shelhamer, M; Robinson, D A; Tan, H S

1992-01-01

Previous experiments show that altered visual feedback can change VOR gain. Such changes also presumably occur when eyeglasses are donned and doffed, or when bifocals are worn. In these cases, a nonvisual cue accompanies the required gain adjustment (frames on/off for eyeglasses, looking up/down for bifocals). We set out to show that a subject can establish two VOR gains, and to determine if one of the associated nonvisual cues alone is sufficient to subsequently determine which gain to employ. Each of three subjects sat in a rotating chair inside an OKN drum during 2 hours of sinusoidal rotation at 0.2 Hz, 30 degrees/s peak. For 10 minutes the chair and drum counterrotated , driving VOR gain toward 1.7, while subjects looked up 20 degrees. Chair and drum were then coupled for 10 minutes, driving gain toward zero, during which subjects looked down 20 degrees. This sequence was repeated for 2 hours. Immediately thereafter, VOR gains were measured while subjects looked alternately up and down, using 20 degrees to 40 degrees step rotations. A fixation target, presented before and after each step, provided accurate gain determination by measuring the size of the re-fixation saccade. Results show a consistent reduced VOR gain looking downward (average 6%) and increased gain looking upward (average 6%) and increased gain looking upward (average 8%). We conclude that humans can adjust their VOR gain dependent on a situational context; we speculate that this context can take many forms.

The wire-mesh sensor as a two-phase flow meter

NASA Astrophysics Data System (ADS)

Shaban, H.; Tavoularis, S.

2015-01-01

A novel gas and liquid flow rate measurement method is proposed for use in vertical upward and downward gas-liquid pipe flows. This method is based on the analysis of the time history of area-averaged void fraction that is measured using a conductivity wire-mesh sensor (WMS). WMS measurements were collected in vertical upward and downward air-water flows in a pipe with an internal diameter of 32.5 mm at nearly atmospheric pressure. The relative frequencies and the power spectral density of area-averaged void fraction were calculated and used as representative properties. Independent features, extracted from these properties using Principal Component Analysis and Independent Component Analysis, were used as inputs to artificial neural networks, which were trained to give the gas and liquid flow rates as outputs. The present method was shown to be accurate for all four encountered flow regimes and for a wide range of flow conditions. Besides providing accurate predictions for steady flows, the method was also tested successfully in three flows with transient liquid flow rates. The method was augmented by the use of the cross-correlation function of area-averaged void fraction determined from the output of a dual WMS unit as an additional representative property, which was found to improve the accuracy of flow rate prediction.

The Impact of NCAA Reclassification on Academic Success Rates

ERIC Educational Resources Information Center

Chandler, Jason I.

2014-01-01

Higher education institutions choose to invest in upward reclassification for their athletics program with anticipation of generating increased revenue and exposure for their school; however, this could have a detrimental effect on their student-athletes' academic progress. This study examined the relationship between four classifications of…

Sources of Intermodel Spread in the Lapse Rate and Water Vapor Feedbacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Po-Chedley, Stephen; Armour, Kyle C.; Bitz, Cecilia M.

Sources of intermodel differences in the global lapse rate (LR) and water vapor (WV) feedbacks are assessed using CO 2 forcing simulations from 28 general circulation models. Tropical surface warming leads to significant warming and moistening in the tropical and extratropical upper troposphere, signifying a nonlocal, tropical influence on extratropical radiation and feedbacks. Model spread in the locally defined LR and WV feedbacks is pronounced in the Southern Ocean because of large-scale ocean upwelling, which reduces surface warming and decouples the surface from the tropospheric response. The magnitude of local extratropical feedbacks across models and over time is well characterizedmore » using the ratio of tropical to extratropical surface warming. It is shown that model differences in locally defined LR and WV feedbacks, particularly over the southern extratropics, drive model variability in the global feedbacks. The cross-model correlation between the global LR and WV feedbacks therefore does not arise from their covariation in the tropics, but rather from the pattern of warming exerting a common control on extratropical feedback responses. Because local feedbacks over the Southern Hemisphere are an important contributor to the global feedback, the partitioning of surface warming between the tropics and the southern extratropics is a key determinant of the spread in the global LR and WV feedbacks. It is also shown that model Antarctic sea ice climatology influences sea ice area changes and southern extratropical surface warming. In conclusion, as a result, model discrepancies in climatological Antarctic sea ice area have a significant impact on the intermodel spread of the global LR and WV feedbacks.« less

Sources of Intermodel Spread in the Lapse Rate and Water Vapor Feedbacks

DOE PAGES

Po-Chedley, Stephen; Armour, Kyle C.; Bitz, Cecilia M.; ...

2018-03-23

Sources of intermodel differences in the global lapse rate (LR) and water vapor (WV) feedbacks are assessed using CO 2 forcing simulations from 28 general circulation models. Tropical surface warming leads to significant warming and moistening in the tropical and extratropical upper troposphere, signifying a nonlocal, tropical influence on extratropical radiation and feedbacks. Model spread in the locally defined LR and WV feedbacks is pronounced in the Southern Ocean because of large-scale ocean upwelling, which reduces surface warming and decouples the surface from the tropospheric response. The magnitude of local extratropical feedbacks across models and over time is well characterizedmore » using the ratio of tropical to extratropical surface warming. It is shown that model differences in locally defined LR and WV feedbacks, particularly over the southern extratropics, drive model variability in the global feedbacks. The cross-model correlation between the global LR and WV feedbacks therefore does not arise from their covariation in the tropics, but rather from the pattern of warming exerting a common control on extratropical feedback responses. Because local feedbacks over the Southern Hemisphere are an important contributor to the global feedback, the partitioning of surface warming between the tropics and the southern extratropics is a key determinant of the spread in the global LR and WV feedbacks. It is also shown that model Antarctic sea ice climatology influences sea ice area changes and southern extratropical surface warming. In conclusion, as a result, model discrepancies in climatological Antarctic sea ice area have a significant impact on the intermodel spread of the global LR and WV feedbacks.« less

Developmental remodeling of corticocortical feedback circuits in ferret visual cortex

PubMed Central

Khalil, Reem; Levitt, Jonathan B.

2014-01-01

Visual cortical areas in the mammalian brain are linked through a system of interareal feedforward and feedback connections, which presumably underlie different visual functions. We characterized the refinement of feedback projections to primary visual cortex (V1) from multiple sources in juvenile ferrets ranging in age from four to ten weeks postnatal. We studied whether the refinement of different aspects of feedback circuitry from multiple visual cortical areas proceeds at a similar rate in all areas. We injected the neuronal tracer cholera toxin B (CTb) into V1, and mapped the areal and laminar distribution of retrogradely labeled cells in extrastriate cortex. Around the time of eye opening at four weeks postnatal, the retinotopic arrangement of feedback appears essentially adultlike; however, Suprasylvian cortex supplies the greatest proportion of feedback, whereas area 18 supplies the greatest proportion in the adult. The density of feedback cells and the ratio of supragranular/infragranular feedback contribution declined in this period at a similar rate in all cortical areas. We also find significant feedback to V1 from layer IV of all extrastriate areas. The regularity of cell spacing, the proportion of feedback arising from layer IV, and the tangential extent of feedback in each area all remained essentially unchanged during this period, except for the infragranular feedback source in area 18 which expanded. Thus, while much of the basic pattern of cortical feedback to V1 is present before eye opening, there is major synchronous reorganization after eye opening, suggesting a crucial role for visual experience in this remodeling process. PMID:24665018

Developmental remodeling of corticocortical feedback circuits in ferret visual cortex.

PubMed

Khalil, Reem; Levitt, Jonathan B

2014-10-01

Visual cortical areas in the mammalian brain are linked through a system of interareal feedforward and feedback connections, which presumably underlie different visual functions. We characterized the refinement of feedback projections to primary visual cortex (V1) from multiple sources in juvenile ferrets ranging in age from 4-10 weeks postnatal. We studied whether the refinement of different aspects of feedback circuitry from multiple visual cortical areas proceeds at a similar rate in all areas. We injected the neuronal tracer cholera toxin B (CTb) into V1 and mapped the areal and laminar distribution of retrogradely labeled cells in extrastriate cortex. Around the time of eye opening at 4 weeks postnatal, the retinotopic arrangement of feedback appears essentially adult-like; however, suprasylvian cortex supplies the greatest proportion of feedback, whereas area 18 supplies the greatest proportion in the adult. The density of feedback cells and the ratio of supragranular/infragranular feedback contribution declined in this period at a similar rate in all cortical areas. We also found significant feedback to V1 from layer IV of all extrastriate areas. The regularity of cell spacing, the proportion of feedback arising from layer IV, and the tangential extent of feedback in each area all remained essentially unchanged during this period, except for the infragranular feedback source in area 18, which expanded. Thus, while much of the basic pattern of cortical feedback to V1 is present before eye opening, there is major synchronous reorganization after eye opening, suggesting a crucial role for visual experience in this remodeling process. © 2014 Wiley Periodicals, Inc.

MASS TRANSPORT AND TURBULENCE IN GRAVITATIONALLY UNSTABLE DISK GALAXIES. II. THE EFFECTS OF STAR FORMATION FEEDBACK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldbaum, Nathan J.; Krumholz, Mark R.; Forbes, John C., E-mail: ngoldbau@illinois.edu

2016-08-10

Self-gravity and stellar feedback are capable of driving turbulence and transporting mass and angular momentum in disk galaxies, but the balance between them is not well understood. In the previous paper in this series, we showed that gravity alone can drive turbulence in galactic disks, regulate their Toomre Q parameters to ∼1, and transport mass inwards at a rate sufficient to fuel star formation in the centers of present-day galaxies. In this paper we extend our models to include the effects of star formation feedback. We show that feedback suppresses galaxies’ star formation rates by a factor of ∼5 andmore » leads to the formation of a multi-phase atomic and molecular interstellar medium. Both the star formation rate and the phase balance produced in our simulations agree well with observations of nearby spirals. After our galaxies reach steady state, we find that the inclusion of feedback actually lowers the gas velocity dispersion slightly compared to the case of pure self-gravity, and also slightly reduces the rate of inward mass transport. Nevertheless, we find that, even with feedback included, our galactic disks self-regulate to Q ∼ 1, and transport mass inwards at a rate sufficient to supply a substantial fraction of the inner disk star formation. We argue that gravitational instability is therefore likely to be the dominant source of turbulence and transport in galactic disks, and that it is responsible for fueling star formation in the inner parts of galactic disks over cosmological times.« less

Process-based modeling of silicate mineral weathering responses to increasing atmospheric CO2 and climate change

NASA Astrophysics Data System (ADS)

Banwart, Steven A.; Berg, Astrid; Beerling, David J.

2009-12-01

A mathematical model describes silicate mineral weathering processes in modern soils located in the boreal coniferous region of northern Europe. The process model results demonstrate a stabilizing biological feedback mechanism between atmospheric CO2 levels and silicate weathering rates as is generally postulated for atmospheric evolution. The process model feedback response agrees within a factor of 2 of that calculated by a weathering feedback function of the type generally employed in global geochemical carbon cycle models of the Earth's Phanerozoic CO2 history. Sensitivity analysis of parameter values in the process model provides insight into the key mechanisms that influence the strength of the biological feedback to weathering. First, the process model accounts for the alkalinity released by weathering, whereby its acceleration stabilizes pH at values that are higher than expected. Although the process model yields faster weathering with increasing temperature, because of activation energy effects on mineral dissolution kinetics at warmer temperature, the mineral dissolution rate laws utilized in the process model also result in lower dissolution rates at higher pH values. Hence, as dissolution rates increase under warmer conditions, more alkalinity is released by the weathering reaction, helping maintain higher pH values thus stabilizing the weathering rate. Second, the process model yields a relatively low sensitivity of soil pH to increasing plant productivity. This is due to more rapid decomposition of dissolved organic carbon (DOC) under warmer conditions. Because DOC fluxes strongly influence the soil water proton balance and pH, this increased decomposition rate dampens the feedback between productivity and weathering. The process model is most sensitive to parameters reflecting soil structure; depth, porosity, and water content. This suggests that the role of biota to influence these characteristics of the weathering profile is as important, if not more important, than the role of biota to influence mineral dissolution rates through changes in soil water chemistry. This process-modeling approach to quantify the biological weathering feedback to atmospheric CO2 demonstrates the potential for a far more mechanistic description of weathering feedback in simulations of the global geochemical carbon cycle.

Highly ordered molecular rotor matrix on a nanopatterned template: titanyl phthalocyanine molecules on FeO/Pt(111).

PubMed

Lu, Shuangzan; Huang, Min; Qin, Zhihui; Yu, Yinghui; Guo, Qinmin; Cao, Gengyu

2018-08-03

Molecular rotors, motors and gears play important roles in artificial molecular machines, in which rotor and motor matrices are highly desirable for large-scale bottom-up fabrication of molecular machines. Here we demonstrate the fabrication of a highly ordered molecular rotor matrix by depositing nonplanar dipolar titanyl phthalocyanine (TiOPc, C 32 H 16 N 8 OTi) molecules on a Moiré patterned dipolar FeO/Pt(111) substrate. TiOPc molecules with O atoms pointing outwards from the substrate (upward) or towards the substrate (downward) are alternatively adsorbed on the fcc sites by strong lateral confinement. The adsorbed molecules, i.e. two kinds of molecular rotors, show different scanning tunneling microscopy images, thermal stabilities and rotational characteristics. Density functional theory calculations clarify that TiOPc molecules anchoring upwards with high adsorption energies correspond to low-rotational-rate rotors, while those anchoring downwards with low adsorption energies correspond to high-rotational-rate rotors. A robust rotor matrix fully occupied by low-rate rotors is fabricated by depositing molecules on the substrate at elevated temperature. Such a paradigm opens up a promising route to fabricate functional molecular rotor matrices, driven motor matrices and even gear groups on solid substrates.

Direct Observation of Clinical Skills Feedback Scale: Development and Validity Evidence.

PubMed

Halman, Samantha; Dudek, Nancy; Wood, Timothy; Pugh, Debra; Touchie, Claire; McAleer, Sean; Humphrey-Murto, Susan

2016-01-01

Construct: This article describes the development and validity evidence behind a new rating scale to assess feedback quality in the clinical workplace. Competency-based medical education has mandated a shift to learner-centeredness, authentic observation, and frequent formative assessments with a focus on the delivery of effective feedback. Because feedback has been shown to be of variable quality and effectiveness, an assessment of feedback quality in the workplace is important to ensure we are providing trainees with optimal learning opportunities. The purposes of this project were to develop a rating scale for the quality of verbal feedback in the workplace (the Direct Observation of Clinical Skills Feedback Scale [DOCS-FBS]) and to gather validity evidence for its use. Two panels of experts (local and national) took part in a nominal group technique to identify features of high-quality feedback. Through multiple iterations and review, 9 features were developed into the DOCS-FBS. Four rater types (residents n = 21, medical students n = 8, faculty n = 12, and educators n = 12) used the DOCS-FBS to rate videotaped feedback encounters of variable quality. The psychometric properties of the scale were determined using a generalizability analysis. Participants also completed a survey to gather data on a 5-point Likert scale to inform the ease of use, clarity, knowledge acquisition, and acceptability of the scale. Mean video ratings ranged from 1.38 to 2.96 out of 3 and followed the intended pattern suggesting that the tool allowed raters to distinguish between examples of higher and lower quality feedback. There were no significant differences between rater type (range = 2.36-2.49), suggesting that all groups of raters used the tool in the same way. The generalizability coefficients for the scale ranged from 0.97 to 0.99. Item-total correlations were all above 0.80, suggesting some redundancy in items. Participants found the scale easy to use (M = 4.31/5) and clear (M = 4.23/5), and most would recommend its use (M = 4.15/5). Use of DOCS-FBS was acceptable to both trainees (M = 4.34/5) and supervisors (M = 4.22/5). The DOCS-FBS can reliably differentiate between feedback encounters of higher and lower quality. The scale has been shown to have excellent internal consistency. We foresee the DOCS-FBS being used as a means to provide objective evidence that faculty development efforts aimed at improving feedback skills can yield results through formal assessment of feedback quality.

Theoretical Limits of Damping Attainable by Smart Beams with Rate Feedback

NASA Technical Reports Server (NTRS)

Balakrishnan, A. V.

1997-01-01

Using a generally accepted model we present a comprehensive analysis (within the page limitation) of an Euler- Bernoulli beam with PZT sensor-actuator and pure rate feedback. The emphasis is on the root locus - the dependence of the attainable damping on the feedback gain. There is a critical value of the gain beyond which the damping decreases to zero. We construct the time-domain response using semigroup theory, and show that the eigenfunctions form a Riesz basis, leading to a 'modal' expansion.

Performance Appraisal Interview: A Review of Research.

DTIC Science & Technology

1987-01-01

and valued outcomes than did supervisory feedback. Ivancevich and McMahon (1982) * . found that self-generated feedback on goal accomplishment was... Ivancevich (1980) found that engineers rated with behavior expectation scales perceived their interviews as providing more clarity, more meaningful feedback...accurate than evaluative, emotionally-tone feedback. In addition, the previously-discussed studies by Ivancevich (1980) and Hom et al. (1982) suggest

Effect of inhibitory feedback on correlated firing of spiking neural network.

PubMed

Xie, Jinli; Wang, Zhijie

2013-08-01

Understanding the properties and mechanisms that generate different forms of correlation is critical for determining their role in cortical processing. Researches on retina, visual cortex, sensory cortex, and computational model have suggested that fast correlation with high temporal precision appears consistent with common input, and correlation on a slow time scale likely involves feedback. Based on feedback spiking neural network model, we investigate the role of inhibitory feedback in shaping correlations on a time scale of 100 ms. Notably, the relationship between the correlation coefficient and inhibitory feedback strength is non-monotonic. Further, computational simulations show how firing rate and oscillatory activity form the basis of the mechanisms underlying this relationship. When the mean firing rate holds unvaried, the correlation coefficient increases monotonically with inhibitory feedback, but the correlation coefficient keeps decreasing when the network has no oscillatory activity. Our findings reveal that two opposing effects of the inhibitory feedback on the firing activity of the network contribute to the non-monotonic relationship between the correlation coefficient and the strength of the inhibitory feedback. The inhibitory feedback affects the correlated firing activity by modulating the intensity and regularity of the spike trains. Finally, the non-monotonic relationship is replicated with varying transmission delay and different spatial network structure, demonstrating the universality of the results.

Variable force and visual feedback effects on teleoperator man/machine performance

NASA Technical Reports Server (NTRS)

Massimino, Michael J.; Sheridan, Thomas B.

1989-01-01

An experimental study was conducted to determine the effects of various forms of visual and force feedback on human performance for several telemanipulation tasks. Experiments were conducted with varying frame rates and subtended visual angles, with and without force feedback.

Sources of Instructional Feedback, Job Satisfaction, and Basic Psychological Needs

ERIC Educational Resources Information Center

Wininger, Steven R.; Birkholz, Paige M.

2013-01-01

This study examined college instructors' utilization and perceived value of sources of instructional feedback (institutional student ratings, consultation with an instructional specialist, soliciting feedback from students, self-assessment, self-observation, peer/administrator observation, and peer coaching). We examined relationships between the…

Trends in precipitation, streamflow, reservoir pool elevations, and reservoir releases in Arkansas and selected sites in Louisiana, Missouri, and Oklahoma, 1951–2011

USGS Publications Warehouse

Wagner, Daniel M.; Krieger, Joshua D.; Merriman, Katherine R.

2014-01-01

The U.S. Geological Survey (USGS) and the U.S. Army Corps of Engineers (USACE) conducted a statistical analysis of trends in precipitation, streamflow, reservoir pool elevations, and reservoir releases in Arkansas and selected sites in Louisiana, Missouri, and Oklahoma for the period 1951–2011. The Mann-Kendall test was used to test for trends in annual and seasonal precipitation, annual and seasonal streamflows of 42 continuous-record USGS streamflow-gaging stations, annual pool elevations and releases from 16 USACE reservoirs, and annual releases from 11 dams on the Arkansas River. A statistically significant (p≤0.10) upward trend was observed in annual precipitation for the State, with a Sen slope of approximately 0.10 inch per year. Autumn and winter were the only seasons that had statistically significant trends in precipitation. Five of six physiographic sections and six of seven 4-digit hydrologic unit code (HUC) regions in Arkansas had statistically significant upward trends in autumn precipitation, with Sen slopes of approximately 0.06 to 0.10 inch per year. Sixteen sites had statistically significant upward trends in the annual mean daily streamflow and were located on streams that drained regions with statistically significant upward trends in annual precipitation. Expected annual rates of change corresponding to statistically significant trends in annual mean daily streamflows, which ranged from 0.32 to 0.88 percent, were greater than those corresponding to regions with statistically significant upward trends in annual precipitation, which ranged from 0.19 to 0.28 percent, suggesting that the observed trends in regional annual precipitation do not fully account for the observed trends in annual mean daily streamflows. Trends in annual maximum daily streamflows were similar to trends in the annual mean daily streamflows but were only statistically significant at seven sites. There were more statistically significant trends (28 of 42 sites) in the annual minimum daily streamflows than in the annual means or maximums. Statistically significant trends in the annual minimum daily streamflows were upward at 18 sites and downward at 10 sites. Despite autumn being the only season that had statistically significant upward trends in seasonal precipitation, statistically significant upward trends in seasonal mean streamflows occurred in every season but spring. Trends in the annual mean, maximum, and minimum daily pool elevations of USACE reservoirs were consistent between metrics for reservoirs in the White, Arkansas, and Ouachita River watersheds, while trends varied between metrics at DeQueen Lake, Millwood Lake, and Lake Chicot. Most of the statistically significant trends in pool elevation metrics were upward and gradual—Sen slopes were less than 0.37 foot per year—and were likely the result of changes in reservoir regulation plans. Trends in the annual mean and maximum daily releases from USACE reservoirs were generally upward in all HUC regions. There were few statistically significant trends in the annual mean daily releases because the reservoirs are operated to maintain a regulation stage at a downstream site according to guidelines set forth in the regulation plans of the reservoirs. The annual number of low-flow days was both increasing and decreasing for reservoirs in northern Arkansas and southern Missouri and generally increasing for reservoirs in southern Arkansas.

Using Quality Management Tools to Enhance Feedback from Student Evaluations

ERIC Educational Resources Information Center

Jensen, John B.; Artz, Nancy

2005-01-01

Statistical tools found in the service quality assessment literature--the "T"[superscript 2] statistic combined with factor analysis--can enhance the feedback instructors receive from student ratings. "T"[superscript 2] examines variability across multiple sets of ratings to isolate individual respondents with aberrant response…

Reducing failures of working memory with performance feedback.

PubMed

Adam, Kirsten C S; Vogel, Edward K

2016-10-01

Fluctuations in attentional control can lead to failures of working memory (WM), in which the subject is no better than chance at reporting items from a recent display. In three experiments, we used a whole-report measure of visual WM to examine the impact of feedback on the rate of failures. In each experiment, subjects remembered an array of colored items across a blank delay, and then reported the identity of items using a whole-report procedure. In Experiment 1, we gave subjects simple feedback about the number of items they correctly identified at the end of each trial. In Experiment 2, we gave subjects additional information about the cumulative number of items correctly identified within each block. Finally, in Experiment 3, we gave subjects weighted feedback in which poor trials resulted in lost points and consistent successful performance received "streak" points. Surprisingly, simple feedback (Exp. 1) was ineffective at improving average performance or decreasing the rate of poor-performance trials. Simple cumulative feedback (Exp. 2) modestly decreased poor-performance trials (by 7 %). Weighted feedback produced the greatest benefits, decreasing the frequency of poor-performance trials by 28 % relative to baseline performance. This set of results demonstrates the usefulness of whole-report WM measures for investigating the effects of feedback on WM performance. Further, we showed that only a feedback structure that specifically discouraged lapses using negative feedback led to large reductions in WM failures.

Providing rapid feedback to residents on their teaching skills: an educational strategy for contemporary trainees.

PubMed

Katz-Sidlow, Rachel J; Baer, Tamar G; Gershel, Jeffrey C

2016-03-20

The objective of this study was to assess the attitudes of contemporary residents toward receiving rapid feedback on their teaching skills from their medical student learners. Participants consisted of 20 residents in their second post-graduate training year. These residents facilitated 44 teaching sessions with medical students within our Resident-as-Teacher program. Structured, written feedback from students was returned to the resident within 3 days following each session. Residents completed a short survey about the utility of the feedback, whether they would make a change to future teaching sessions based on the feedback, and what specifically they might change. The survey utilized a 4-point scale ("Not helpful/likely=1" to "Very helpful/likely=4"), and allowed for one free-text response. Free-text responses were hand-coded and underwent qualitative analysis to identify themes. There were 182 student feedback encounters resulting from 44 teaching sessions. The survey response rate was 73% (32/44). Ninety-four percent of residents rated the rapid feedback as "very helpful," and 91% would "very likely" make a change to subsequent sessions based on student feedback. Residents' proposed changes included modifications to session content and/or their personal teaching style. Residents found that rapid feedback received from medical student learners was highly valuable to them in their roles as teachers. A rapid feedback strategy may facilitate an optimal educational environment for contemporary trainees.

Network feedback regulates motor output across a range of modulatory neuron activity.

PubMed

Spencer, Robert M; Blitz, Dawn M

2016-06-01

Modulatory projection neurons alter network neuron synaptic and intrinsic properties to elicit multiple different outputs. Sensory and other inputs elicit a range of modulatory neuron activity that is further shaped by network feedback, yet little is known regarding how the impact of network feedback on modulatory neurons regulates network output across a physiological range of modulatory neuron activity. Identified network neurons, a fully described connectome, and a well-characterized, identified modulatory projection neuron enabled us to address this issue in the crab (Cancer borealis) stomatogastric nervous system. The modulatory neuron modulatory commissural neuron 1 (MCN1) activates and modulates two networks that generate rhythms via different cellular mechanisms and at distinct frequencies. MCN1 is activated at rates of 5-35 Hz in vivo and in vitro. Additionally, network feedback elicits MCN1 activity time-locked to motor activity. We asked how network activation, rhythm speed, and neuron activity levels are regulated by the presence or absence of network feedback across a physiological range of MCN1 activity rates. There were both similarities and differences in responses of the two networks to MCN1 activity. Many parameters in both networks were sensitive to network feedback effects on MCN1 activity. However, for most parameters, MCN1 activity rate did not determine the extent to which network output was altered by the addition of network feedback. These data demonstrate that the influence of network feedback on modulatory neuron activity is an important determinant of network output and feedback can be effective in shaping network output regardless of the extent of network modulation. Copyright © 2016 the American Physiological Society.

Peer video review and feedback improve performance in basic surgical skills.

PubMed

Vaughn, Carolyn J; Kim, Edward; O'Sullivan, Patricia; Huang, Emily; Lin, Matthew Y C; Wyles, Susannah; Palmer, Barnard J A; Pierce, Jonathan L; Chern, Hueylan

2016-02-01

Incorporation of home-video assessments allows flexibility in feedback but requires faculty time. Peer feedback (PF) may provide additional benefits while avoiding these constraints. Twenty-four surgical interns completed a 12-week skills curriculum with home-video assignments focused on knot tying and suturing. Interns were randomized into 2 groups: PF or faculty feedback (FF). Peers and faculty provided feedback on home videos with checklists, global rating, and comments. Learners' skills were assessed at baseline, during, and at the conclusion of the curriculum. Performance of the 2 groups as rated by experts was compared. FF and PF were compared. Both groups improved from baseline, and the highest rated scores were seen on their home-video assessments. The PF group performed better at the final assessment than the FF group (effect size, .84). When using a checklist, there was no significant difference between scores given by peers and faculty. The PF group performed better at the final assessment, suggesting reviewing and analyzing another's performance may improve one's own performance. With checklists as guidance, peers can serve as raters comparable to faculty. Copyright © 2016 Elsevier Inc. All rights reserved.

On the Extraction of Angular Velocity from Attitude Measurements

NASA Technical Reports Server (NTRS)

Bar-Itzhack, I. Y.; Harman, Richard R.; Thienel, Julie K.

2006-01-01

In this paper we research the extraction of the angular rate vector from attitude information without differentiation, in particular from quaternion measurements. We show that instead of using a Kalman filter of some kind, it is possible to obtain good rate estimates, suitable for spacecraft attitude control loop damping, using simple feedback loops, thereby eliminating the need for recurrent covariance computation performed when a Kalman filter is used. This considerably simplifies the computations required for rate estimation in gyro-less spacecraft. Some interesting qualities of the Kalman filter gain are explored, proven and utilized. We examine two kinds of feedback loops, one with varying gain that is proportional to the well known Q matrix, which is computed using the measured quaternion, and the other type of feedback loop is one with constant coefficients. The latter type includes two kinds; namely, a proportional feedback loop, and a proportional-integral feedback loop. The various schemes are examined through simulations and their performance is compared. It is shown that all schemes are adequate for extracting the angular velocity at an accuracy suitable for control loop damping.

A Physics-Based Vibrotactile Feedback Library for Collision Events.

PubMed

Park, Gunhyuk; Choi, Seungmoon

2017-01-01

We present PhysVib: a software solution on the mobile platform extending an open-source physics engine in a multi-rate rendering architecture for automatic vibrotactile feedback upon collision events. PhysVib runs concurrently with a physics engine at a low update rate and generates vibrotactile feedback commands at a high update rate based on the simulation results of the physics engine using an exponentially-decaying sinusoidal model. We demonstrate through a user study that this vibration model is more appropriate to our purpose in terms of perceptual quality than more complex models based on sound synthesis. We also evaluated the perceptual performance of PhysVib by comparing eight vibrotactile rendering methods. Experimental results suggested that PhysVib enables more realistic vibrotactile feedback than the other methods as to perceived similarity to the visual events. PhysVib is an effective solution for providing physically plausible vibrotactile responses while reducing application development time to great extent.

[The relationship between unemployment rates and lost work time due to sickness absence in an economic recession].

PubMed

López López, J C; Ballesteros Polo, M; Sampere Valero, M; Sacristán Nieto, R; Alguacil García, S; Ruiz Julian, A; Santos Avila, E; García Rubia, S; López Costa, B; Martínez Martínez, J M

Different countries have shown an inverse relationship between unemployment rates (UR) and indicators of sickness absence during periods of economic recession. To evaluate the relationship between indicators of sickness absence and unemployment in Spain during 2009-2015. We obtained incidence and absenteeism rates of non-work related sickness absence (NWSA) from Social Security data, and UR from the National Institute of Statistics. The relationship between indicators of NWSA and UR in the period 2009 to 2015 was graphically described using time trend plots. Scatter plots of NWSA indicators were also made against UR. Finally, we fitted linear regression models. Incidence (IR) and absenteeism rates (AR) of NWSA showed downward trends in 2009-2013 (IR 2009=28.07%, IR 2013=20.41%; AR 2009=2.53% and AR 2013=1.86%), changing to an upward trend up to 2015 (IR 2015=22.52%, AR 2015=2.12%). Unemployment rates trended upward in 2009-2013 (UR 2009=17.86%, UR 2013=26.10%), and then changed to a downward trend through 2015 (UR 2015=22.06%). There was an inverse relationship between UR and NWSA indicators. As in previous international studies, we found an inverse relationship between unemployment rates and indicators of sickness absence in Spain. More detailed studies are needed to evaluate explanatory hypotheses, such as those associated with the effects of discipline, selection and/or changes in the workforce. Copyright belongs to the Societat Catalana de Salut Laboral.

Towards a theory of ecotone resilience: coastal vegetation on a salinity gradient.

PubMed

Jiang, Jiang; Gao, Daozhou; DeAngelis, Donald L

2012-08-01

Ecotones represent locations where vegetation change is likely to occur as a result of climate and other environmental changes. Using a model of an ecotone vulnerable to such future changes, we estimated the resilience of the ecotone to disturbances. The specific ecotone is that between two different vegetation types, salinity-tolerant and salinity-intolerant, along a gradient in groundwater salinity. In the case studied, each vegetation type, through soil feedback loops, promoted local soil salinity levels that favor itself in competition with the other type. Bifurcation analysis was used to study the system of equations for the two vegetation types and soil salinity. Alternative stable equilibria, one for salinity-tolerant and one for salinity intolerant vegetation, were shown to exist over a region of the groundwater salinity gradient, bounded by two bifurcation points. This region was shown to depend sensitively on parameters such as the rate of upward infiltration of salinity from groundwater into the soil due to evaporation. We showed also that increasing diffusion rates of vegetation can lead to shrinkage of the range between the two bifurcation points. Sharp ecotones are typical of salt-tolerant vegetation (mangroves) near the coastline and salt-intolerant vegetation inland, even though the underlying elevation and groundwater salinity change very gradually. A disturbance such as an input of salinity to the soil from a storm surge could upset this stable boundary, leading to a regime shift of salinity-tolerant vegetation inland. We showed, however, that, for our model as least, a simple pulse disturbance would not be sufficient; the salinity would have to be held at a high level, as a 'press', for some time. The approach used here should be generalizable to study the resilience of a variety of ecotones to disturbances. Published by Elsevier Inc.

Towards a theory of ecotone resilience: coastal vegetation on a salinity gradient

USGS Publications Warehouse

Jiang, Jiang; Gao, Daozhou; DeAngelis, Donald L.

2012-01-01

Ecotones represent locations where vegetation change is likely to occur as a result of climate and other environmental changes. Using a model of an ecotone vulnerable to such future changes, we estimated the resilience of the ecotone to disturbances. The specific ecotone is that between two different vegetation types, salinity-tolerant and salinity-intolerant, along a gradient in groundwater salinity. In the case studied, each vegetation type, through soil feedback loops, promoted local soil salinity levels that favor itself in competition with the other type. Bifurcation analysis was used to study the system of equations for the two vegetation types and soil salinity. Alternative stable equilibria, one for salinity-tolerant and one for salinity intolerant vegetation, were shown to exist over a region of the groundwater salinity gradient, bounded by two bifurcation points. This region was shown to depend sensitively on parameters such as the rate of upward infiltration of salinity from groundwater into the soil due to evaporation. We showed also that increasing diffusion rates of vegetation can lead to shrinkage of the range between the two bifurcation points. Sharp ecotones are typical of salt-tolerant vegetation (mangroves) near the coastline and salt-intolerant vegetation inland, even though the underlying elevation and groundwater salinity change very gradually. A disturbance such as an input of salinity to the soil from a storm surge could upset this stable boundary, leading to a regime shift of salinity-tolerant vegetation inland. We showed, however, that, for our model as least, a simple pulse disturbance would not be sufficient; the salinity would have to be held at a high level, as a 'press', for some time. The approach used here should be generalizable to study the resilience of a variety of ecotones to disturbances.

Quality of closed chest compression on a manikin in ambulance vehicles and flying helicopters with a real time automated feedback.

PubMed

Havel, Christof; Schreiber, Wolfgang; Trimmel, Helmut; Malzer, Reinhard; Haugk, Moritz; Richling, Nina; Riedmüller, Eva; Sterz, Fritz; Herkner, Harald

2010-01-01

Automated verbal and visual feedback improves quality of resuscitation in out-of-hospital cardiac arrest and was proven to increase short-term survival. Quality of resuscitation may be hampered in more difficult situations like emergency transportation. Currently there is no evidence if feedback devices can improve resuscitation quality during different modes of transportation. To assess the effect of real time automated feedback on the quality of resuscitation in an emergency transportation setting. Randomised cross-over trial. Medical University of Vienna, Vienna Municipal Ambulance Service and Helicopter Emergency Medical Service Unit (Christophorus Flugrettungsverein) in September 2007. European Resuscitation Council (ERC) certified health care professionals performing CPR in a flying helicopter and in a moving ambulance vehicle on a manikin with human-like chest properties. CPR sessions, with real time automated feedback as the intervention and standard CPR without feedback as control. Quality of chest compression during resuscitation. Feedback resulted in less deviation from ideal compression rate 100 min(-1) (9+/-9 min(-1), p<0.0001) with this effect becoming steadily larger over time. Applied work was less in the feedback group compared to controls (373+/-448 cm x compression; p<0.001). Feedback did not influence ideal compression depth significantly. There was some indication of a learning effect of the feedback device. Real time automated feedback improves certain aspects of CPR quality in flying helicopters and moving ambulance vehicles. The effect of feedback guidance was most pronounced for chest compression rate. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

78 FR 54459 - Agency Information Collection Activities; Submission to the Office of Management and Budget for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-04

... Upward Bound Math Science Annual Performance Report AGENCY: Office of Postsecondary Education (OPE... Upward Bound Math Science Annual Performance Report. OMB Control Number: 1840-NEW. Type of Review: New... Upward Bound (UB) and Upward Bound Math and Science (UBMS) Programs. The Department is requesting a new...

Privacy Impact Assessment for the TRIO Programs Annual Performance Report (APR) System

ERIC Educational Resources Information Center

US Department of Education, 2008

2008-01-01

The TRIO Programs Annual Performance Report (APR) System collects individual student records on individuals served by the following Federal TRIO Programs: Upward Bound (which includes regular Upward Bound (UB), Upward Bound Math-Science (UBMS), and Veterans Upward Bound (VUB)); Student Support Services (SSS); and the Ronald E. McNair Post…

How Upward Moral Comparison Influences Prosocial Behavioral Intention: Examining the Mediating Role of Guilt and the Moderating Role of Moral Identity.

PubMed

Zhang, Heyun; Chen, Sisi; Wang, Rong; Jiang, Jiang; Xu, Yan; Zhao, Huanhuan

2017-01-01

Although it has been shown that exceptional good deeds exert influences on people's prosocial behavior and intention, we have known little about how common moral actions in our daily life. The present study aimed to examine how upward moral comparison influenced prosocial behavioral intention as well as to explore the mediating role of guilt and the moderating role of moral identity in the focal relationship. An experimental study was conducted with 162 Chinese undergraduates (103 women, 59 men) randomly assigned to an upward moral comparison condition, an upward competence comparison condition or a control condition. Results indicated that participants in the upward moral comparison condition experienced higher levels of guilt and exhibited stronger motivation to act prosocially, relative to participants in the other two conditions. That is to say, upward moral comparison induces guilty experience, and then increases people's prosocial behavioral intention. Moreover, we have found that moral identity internalization moderates the upward moral comparison-guilt relationship, and the indirect effect of upward moral comparison on prosocial behavioral intention via guilt. The implications of these findings were discussed.

CPR feedback/prompt device improves the quality of hands-only CPR performed in manikin by laypersons following the 2015 AHA guidelines.

PubMed

Liu, Yuanshan; Huang, Zitong; Li, Heng; Zheng, Guanghui; Ling, Qin; Tang, Wanchun; Yang, Zhengfei

2018-03-06

We investigated the effects of a cardiopulmonary resuscitation (CPR) feedback/prompt device on the quality of chest compression (CC) during hands-only CPR following the 2015 AHA guidelines. A total of 124 laypersons were randomly assigned into three groups. The first (n=42) followed the 2010 guidelines, the second (n=42) followed the 2015 guidelines with no feedback/prompt device, the third (n=40) followed the 2015 guidelines with a feedback/prompt device (2015F). Participants underwent manual CPR training and took a written basic life support examination, then required to perform 2min of hands-only CPR monitored by a CPR feedback/prompt device. The quality of CPR was quantified as the percentage of correct CCs (mean CC depth and rate, complete recoil and chest compression fraction (CCF)) per 20s, as recorded by the CPR feedback/prompt device. Significantly higher correct ratios of CC, CC depth, and rate were achieved in the 2010 group in each minute vs the 2015 group. The greater mean CC depth and rate were observed in the 2015F group vs the 2015 group. The correct ratio of CC was significantly higher in the 2015F group vs the 2015 group. CCF was also significantly higher in the 2015F group vs the 2015 group in the last 20s of CPR. It is difficult for a large percentage of laypersons to achieve the targets of CC depth and rate following the 2015 AHA guidelines. CPR feedback/prompt devices significantly improve the quality of hands-only CPR performance by laypersons following the standards of the 2015 AHA guidelines. Copyright © 2017. Published by Elsevier Inc.

Motion detection technology as a tool for cardiopulmonary resuscitation (CPR) quality training: a randomised crossover mannequin pilot study.

PubMed

Semeraro, Federico; Frisoli, Antonio; Loconsole, Claudio; Bannò, Filippo; Tammaro, Gaetano; Imbriaco, Guglielmo; Marchetti, Luca; Cerchiari, Erga L

2013-04-01

Outcome after cardiac arrest is dependent on the quality of chest compressions (CC). A great number of devices have been developed to provide guidance during CPR. The present study evaluates a new CPR feedback system (Mini-VREM: Mini-Virtual Reality Enhanced Mannequin) designed to improve CC during training. Mini-VREM system consists of a Kinect(®) (Microsoft, Redmond, WA, USA) motion sensing device and specifically developed software to provide audio-visual feedback. Mini-VREM was connected to a commercially available mannequin (Laerdal Medical, Stavanger, Norway). Eighty trainees (healthcare professionals and lay people) volunteered in this randomised crossover pilot study. All subjects performed a 2 min CC trial, 1h pause and a second 2 min CC trial. The first group (FB/NFB, n=40) performed CC with Mini-VREM feedback (FB) followed by CC without feedback (NFB). The second group (NFB/FB, n=40) performed vice versa. Primary endpoints: adequate compression (compression rate between 100 and 120 min(-1) and compression depth between 50 and 60mm); compressions rate within 100-120 min(-1); compressions depth within 50-60mm. When compared to the performance without feedback, with Mini-VREM feedback compressions were more adequate (FB 35.78% vs. NFB 7.27%, p<0.001) and more compressions achieved target rate (FB 72.04% vs. 31.42%, p<0.001) and target depth (FB 47.34% vs. 24.87%, p=0.002). The participants perceived the system to be easy to use with effective feedback. The Mini-VREM system was able to improve significantly the CC performance by healthcare professionals and by lay people in a simulated CA scenario, in terms of compression rate and depth. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Dual-Polarization Radar Observations of Upward Lightning-Producing Storms

NASA Astrophysics Data System (ADS)

Lueck, R.; Helsdon, J. H.; Warner, T.

2013-12-01

The Upward Lightning Triggering Study (UPLIGHTS) seeks to determine how upward lightning, which originates from the tips of tall objects, is triggered by nearby flash activity. As a component of this study we analyze standard and dual-polarization weather radar data. The Correlation Coefficient (CC) in particular can be used to identify and quantify the melting layer associated with storms that produce upward lightning. It has been proposed that positive charge generation due to aggregate shedding at the melting layer results in a positive charge region just above the cloud base. This positive charge region may serve as a positive potential well favorable for negative leader propagation, which initiate upward positive leaders from tall objects. We characterize the horizontal coverage, thickness and height of the melting layer in addition to cloud base heights when upward lightning occurs to determine trends and possible threshold criteria relating to upward lightning production. Furthermore, we characterize storm type and morphology using relevant schemes as well as precipitation type using the Hydrometer Classification Algorithm (HCA) for upward lightning-producing storms. Ice-phase hydrometeors have been shown to be a significant factor in thunderstorm electrification. Only a small fraction of storms produce upward lightning, so null cases will be examined and compared as well.

Performance of cardiopulmonary resuscitation feedback systems in a long-distance train with distributed traction.

PubMed

González-Otero, Digna M; de Gauna, Sofía Ruiz; Ruiz, Jesus; Rivero, Raquel; Gutierrez, J J; Saiz, Purificación; Russell, James K

2018-04-20

Out-of-hospital cardiac arrest is common in public locations, including public transportation sites. Feedback devices are increasingly being used to improve chest-compression quality. However, their performance during public transportation has not been studied yet. To test two CPR feedback devices representative of the current technologies (accelerometer and electromag- netic-field) in a long-distance train. Volunteers applied compressions on a manikin during the train route using both feedback devices. Depth and rate measurements computed by the devices were compared to the gold-standard values. Sixty-four 4-min records were acquired. The accelerometer-based device provided visual help in all experiments. Median absolute errors in depth and rate were 2.4 mm and 1.3 compressions per minute (cpm) during conventional speed, and 2.5 mm and 1.2 cpm during high speed. The electromagnetic-field-based device never provided CPR feedback; alert messages were shown instead. However, measurements were stored in its internal memory. Absolute errors for depth and rate were 2.6 mm and 0.7 cpm during conventional speed, and 2.6 mm and 0.7 cpm during high speed. Both devices were accurate despite the accelerations and the electromagnetic interferences induced by the train. However, the electromagnetic-field-based device would require modifications to avoid excessive alerts impeding feedback.

Innovative curriculum for second-year Harvard-MIT medical students: practicing communication skills with volunteer patients giving immediate feedback

PubMed Central

Ali, Nadaa B; Pelletier, Stephen R; Shields, Helen M

2017-01-01

Purpose Medical students are expected to develop excellent communication skills. The purpose of our study was to create an innovative communication skills exercise using real volunteer patients and physician co-teachers for students to practice communication skills while receiving immediate feedback. Method This is a mixed methods study where second-year medical students participated in the communication skills exercise with real patients and physician co-teachers giving immediate feedback. Clinical scenarios reflected the patients’ actual experiences. Students acted out roles as physicians. Physicians co-taught with the patients and gave immediate feedback to students. Students completed an anonymous written survey at the end of the exercise. Qualitative and quantitative responses were recorded. Student feedback from the 2014 surveys was used to modify the teaching designs to increase active role play opportunities by having only two students in each group and doubling the number of stations with real patients. Results Students rated the overall exercise and the utility of patient volunteers in learning how to communicate on a Likert scale of 1–5, where in this medical school traditionally 1 is excellent and 5 is poor. In 2014, the exercises were rated with a mean score of 1.47 (SD 0.621). In 2015, the exercises were rated with a mean score of 1.03 (SD 0.62). In 2016, the exercises were rated with a mean score of 1.27 (SD 0.52). ANOVA analysis (p=0.002) and Bonferroni corrections indicate a statistically significant difference between combined mean scores of the exercise in 2014 and 2015 (p=0.001). No difference was shown between 2014 and 2016 or 2015 and 2016. Conclusions Medical students rated practicing communication skills with real patient volunteers and physician co-teachers giving immediate feedback in their preclinical years very highly. Student feedback indicated that they preferred active roles and increased opportunities to practice their communication skills. PMID:28579871

Innovative curriculum for second-year Harvard-MIT medical students: practicing communication skills with volunteer patients giving immediate feedback.

PubMed

Ali, Nadaa B; Pelletier, Stephen R; Shields, Helen M

2017-01-01

Medical students are expected to develop excellent communication skills. The purpose of our study was to create an innovative communication skills exercise using real volunteer patients and physician co-teachers for students to practice communication skills while receiving immediate feedback. This is a mixed methods study where second-year medical students participated in the communication skills exercise with real patients and physician co-teachers giving immediate feedback. Clinical scenarios reflected the patients' actual experiences. Students acted out roles as physicians. Physicians co-taught with the patients and gave immediate feedback to students. Students completed an anonymous written survey at the end of the exercise. Qualitative and quantitative responses were recorded. Student feedback from the 2014 surveys was used to modify the teaching designs to increase active role play opportunities by having only two students in each group and doubling the number of stations with real patients. Students rated the overall exercise and the utility of patient volunteers in learning how to communicate on a Likert scale of 1-5, where in this medical school traditionally 1 is excellent and 5 is poor. In 2014, the exercises were rated with a mean score of 1.47 (SD 0.621). In 2015, the exercises were rated with a mean score of 1.03 (SD 0.62). In 2016, the exercises were rated with a mean score of 1.27 (SD 0.52). ANOVA analysis ( p =0.002) and Bonferroni corrections indicate a statistically significant difference between combined mean scores of the exercise in 2014 and 2015 ( p =0.001). No difference was shown between 2014 and 2016 or 2015 and 2016. Medical students rated practicing communication skills with real patient volunteers and physician co-teachers giving immediate feedback in their preclinical years very highly. Student feedback indicated that they preferred active roles and increased opportunities to practice their communication skills.

CGILS: Results from the First Phase of an International Project to Understand the Physical Mechanisms of Low Cloud Feedbacks in Single Column Models

NASA Technical Reports Server (NTRS)

Zhang, Minghua; Bretherton, Christopher S.; Blossey, Peter N.; Austin, Phillip H.; Bacmeister, Julio T.; Bony, Sandrine; Brient, Florent; Cheedela, Suvarchal K.; Cheng, Anning; DelGenio, Anthony;

The Quality of Written Feedback by Attendings of Internal Medicine Residents.

PubMed

Jackson, Jeffrey L; Kay, Cynthia; Jackson, Wilkins C; Frank, Michael

2015-07-01

Attending evaluations are commonly used to evaluate residents. Evaluate the quality of written feedback of internal medicine residents. Retrospective. Internal medicine residents and faculty at the Medical College of Wisconsin from 2004 to 2012. From monthly evaluations of residents by attendings, a randomly selected sample of 500 written comments by attendings were qualitatively coded and rated as high-, moderate-, or low-quality feedback by two independent coders with good inter-rater reliability (kappa: 0.94). Small group exercises with residents and attendings also coded the utterances as high, moderate, or low quality and developed criteria for this categorization. In-service examination scores were correlated with written feedback. There were 228 internal medicine residents who had 6,603 evaluations by 334 attendings. Among 500 randomly selected written comments, there were 2,056 unique utterances: 29% were coded as nonspecific statements, 20% were comments about resident personality, 16% about patient care, 14% interpersonal communication, 7% medical knowledge, 6% professionalism, and 4% each on practice-based learning and systems-based practice. Based on criteria developed by group exercises, the majority of written comments were rated as moderate quality (65%); 22% were rated as high quality and 13% as low quality. Attendings who provided high-quality feedback rated residents significantly lower in all six of the Accreditation Council for Graduate Medical Education (ACGME) competencies (p <0.0005 for all), and had a greater range of scores. Negative comments on medical knowledge were associated with lower in-service examination scores. Most attending written evaluation was of moderate or low quality. Attendings who provided high-quality feedback appeared to be more discriminating, providing significantly lower ratings of residents in all six ACGME core competencies, and across a greater range. Attendings' negative written comments on medical knowledge correlated with lower in-service training scores.

Cloud and circulation feedbacks in a near-global aquaplanet cloud-resolving model

DOE PAGES

Narenpitak, Pornampai; Bretherton, Christopher S.; Khairoutdinov, Marat F.

2017-05-08

A near-global aquaplanet cloud-resolving model (NGAqua) with fixed meridionally varying sea-surface temperature (SST) is used to investigate cloud feedbacks due to three climate perturbations: a uniform 4 K SST increase, a quadrupled-CO2 concentration, and both combined. NGAqua has a horizontal resolution of 4 km with no cumulus parameterization. Its domain is a zonally periodic 20,480 km-long tropical channel, spanning 46°S–N. It produces plausible mean distributions of clouds, rainfall, and winds. After spin-up, 80 days are analyzed for the control and increased-SST simulations, and 40 days for those with quadrupled CO 2. The Intertropical Convergence Zone width and tropical cloud covermore » are not strongly affected by SST warming or CO 2 increase, except for the expected upward shift in high clouds with warming, but both perturbations weaken the Hadley circulation. Increased SST induces a statistically significant increase in subtropical low cloud fraction and in-cloud liquid water content but decreases midlatitude cloud, yielding slightly positive domain-mean shortwave cloud feedbacks. CO 2 quadrupling causes a slight shallowing and a statistically insignificant reduction of subtropical low cloud fraction. Warming-induced low cloud changes are strongly correlated with changes in estimated inversion strength, which increases modestly in the subtropics but decreases in the midlatitudes. Enhanced clear-sky boundary layer radiative cooling in the warmer climate accompanies the robust subtropical low cloud increase. The probability distribution of column relative humidity across the tropics and subtropics is compared between the control and increased-SST simulations. It shows no evidence of bimodality or increased convective aggregation in a warmer climate.« less

Cloud and circulation feedbacks in a near-global aquaplanet cloud-resolving model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narenpitak, Pornampai; Bretherton, Christopher S.; Khairoutdinov, Marat F.

A near-global aquaplanet cloud-resolving model (NGAqua) with fixed meridionally varying sea-surface temperature (SST) is used to investigate cloud feedbacks due to three climate perturbations: a uniform 4 K SST increase, a quadrupled-CO2 concentration, and both combined. NGAqua has a horizontal resolution of 4 km with no cumulus parameterization. Its domain is a zonally periodic 20,480 km-long tropical channel, spanning 46°S–N. It produces plausible mean distributions of clouds, rainfall, and winds. After spin-up, 80 days are analyzed for the control and increased-SST simulations, and 40 days for those with quadrupled CO 2. The Intertropical Convergence Zone width and tropical cloud covermore » are not strongly affected by SST warming or CO 2 increase, except for the expected upward shift in high clouds with warming, but both perturbations weaken the Hadley circulation. Increased SST induces a statistically significant increase in subtropical low cloud fraction and in-cloud liquid water content but decreases midlatitude cloud, yielding slightly positive domain-mean shortwave cloud feedbacks. CO 2 quadrupling causes a slight shallowing and a statistically insignificant reduction of subtropical low cloud fraction. Warming-induced low cloud changes are strongly correlated with changes in estimated inversion strength, which increases modestly in the subtropics but decreases in the midlatitudes. Enhanced clear-sky boundary layer radiative cooling in the warmer climate accompanies the robust subtropical low cloud increase. The probability distribution of column relative humidity across the tropics and subtropics is compared between the control and increased-SST simulations. It shows no evidence of bimodality or increased convective aggregation in a warmer climate.« less

Electron-positron pair production by gamma-rays in an anisotropic flux of soft photons, and application to pulsar polar caps

NASA Astrophysics Data System (ADS)

Voisin, Guillaume; Mottez, Fabrice; Bonazzola, Silvano

2018-02-01

Electron-positron pair production by collision of photons is investigated in view of application to pulsar physics. We compute the absorption rate of individual gamma-ray photons by an arbitrary anisotropic distribution of softer photons, and the energy and angular spectrum of the outgoing leptons. We work analytically within the approximation that 1 ≫ mc2/E > ɛ/E, with E and ɛ the gamma-ray and soft-photon maximum energy and mc2 the electron mass energy. We give results at leading order in these small parameters. For practical purposes, we provide expressions in the form of Laurent series which give correct reaction rates in the isotropic case within an average error of ˜ 7 per cent. We apply this formalism to gamma-rays flying downward or upward from a hot neutron star thermally radiating at a uniform temperature of 106 K. Other temperatures can be easily deduced using the relevant scaling laws. We find differences in absorption between these two extreme directions of almost two orders of magnitude, much larger than our error estimate. The magnetosphere appears completely opaque to downward gamma-rays while there are up to ˜ 10 per cent chances of absorbing an upward gamma-ray. We provide energy and angular spectra for both upward and downward gamma-rays. Energy spectra show a typical double peak, with larger separation at larger gamma-ray energies. Angular spectra are very narrow, with an opening angle ranging from 10-3 to 10-7 radians with increasing gamma-ray energies.

Force-dependent switch in protein unfolding pathways and transition-state movements

PubMed Central

Zhuravlev, Pavel I.; Hinczewski, Michael; Chakrabarti, Shaon; Marqusee, Susan; Thirumalai, D.

2016-01-01

Although it is known that single-domain proteins fold and unfold by parallel pathways, demonstration of this expectation has been difficult to establish in experiments. Unfolding rate, ku(f), as a function of force f, obtained in single-molecule pulling experiments on src SH3 domain, exhibits upward curvature on a log⁡ku(f) plot. Similar observations were reported for other proteins for the unfolding rate ku([C]). These findings imply unfolding in these single-domain proteins involves a switch in the pathway as f or [C] is increased from a low to a high value. We provide a unified theory demonstrating that if log⁡ku as a function of a perturbation (f or [C]) exhibits upward curvature then the underlying energy landscape must be strongly multidimensional. Using molecular simulations we provide a structural basis for the switch in the pathways and dramatic shifts in the transition-state ensemble (TSE) in src SH3 domain as f is increased. We show that a single-point mutation shifts the upward curvature in log⁡ku(f) to a lower force, thus establishing the malleability of the underlying folding landscape. Our theory, applicable to any perturbation that affects the free energy of the protein linearly, readily explains movement in the TSE in a β-sandwich (I27) protein and single-chain monellin as the denaturant concentration is varied. We predict that in the force range accessible in laser optical tweezer experiments there should be a switch in the unfolding pathways in I27 or its mutants. PMID:26818842

Force-dependent switch in protein unfolding pathways and transition-state movements.

PubMed

Zhuravlev, Pavel I; Hinczewski, Michael; Chakrabarti, Shaon; Marqusee, Susan; Thirumalai, D

2016-02-09

Although it is known that single-domain proteins fold and unfold by parallel pathways, demonstration of this expectation has been difficult to establish in experiments. Unfolding rate, [Formula: see text], as a function of force f, obtained in single-molecule pulling experiments on src SH3 domain, exhibits upward curvature on a [Formula: see text] plot. Similar observations were reported for other proteins for the unfolding rate [Formula: see text]. These findings imply unfolding in these single-domain proteins involves a switch in the pathway as f or [Formula: see text] is increased from a low to a high value. We provide a unified theory demonstrating that if [Formula: see text] as a function of a perturbation (f or [Formula: see text]) exhibits upward curvature then the underlying energy landscape must be strongly multidimensional. Using molecular simulations we provide a structural basis for the switch in the pathways and dramatic shifts in the transition-state ensemble (TSE) in src SH3 domain as f is increased. We show that a single-point mutation shifts the upward curvature in [Formula: see text] to a lower force, thus establishing the malleability of the underlying folding landscape. Our theory, applicable to any perturbation that affects the free energy of the protein linearly, readily explains movement in the TSE in a β-sandwich (I27) protein and single-chain monellin as the denaturant concentration is varied. We predict that in the force range accessible in laser optical tweezer experiments there should be a switch in the unfolding pathways in I27 or its mutants.

A movable-mass attitude stabilization system for cable-connected artificial-g space stations

NASA Technical Reports Server (NTRS)

Childs, D. W.; Hardison, T. L.

1974-01-01

The development of an active, momentum-exchange system to be used for attitude stabilization of a class of cable-connected artificial-g space stations is studied. A system which employs a single movable control mass is examined for the control of a space station which has the physical appearance of two cylinders connected axially by cables. The dynamic model for the space station includes its aggregate rigid body rotation and relative torsional rotation between the bodies. A zero torsional stiffness design (one cable) and a maximum torsional stiffness design (eight cables) are examined in various stages of deployment, for selected spin velocities ranging from 4 rpm upwards. A linear, time-invariant, feed-back control system is employed, with gains calculated via a root-specification procedure. The movable mass controller provides critical wobble-damping capability for the crew quarters for all configurations and spin velocity.

Engines-only flight control system

NASA Technical Reports Server (NTRS)

Burcham, Frank W. (Inventor); Gilyard, Glenn B (Inventor); Conley, Joseph L. (Inventor); Stewart, James F. (Inventor); Fullerton, Charles G. (Inventor)

1994-01-01

A backup flight control system for controlling the flightpath of a multi-engine airplane using the main drive engines is introduced. The backup flight control system comprises an input device for generating a control command indicative of a desired flightpath, a feedback sensor for generating a feedback signal indicative of at least one of pitch rate, pitch attitude, roll rate and roll attitude, and a control device for changing the output power of at least one of the main drive engines on each side of the airplane in response to the control command and the feedback signal.

Cirrus and Water Vapor Transport in the Tropical Tropopause Layer

NASA Astrophysics Data System (ADS)

Dinh, Tra Phuong

Simulations of tropical-tropopause-layer (TTL) cirrus under the influence of a large-scale equatorial Kelvin wave have been performed in two dimensions. These simulations show that, even under the influence of the large-scale wave, radiatively induced dynamics in TTL cirrus plays an important role in the transport of water vapor in the vertical direction. In a typical TTL cirrus, the heating that results from absorption of radiation by ice crystals induces a mesoscale circulation. Advection of ice and water vapor by the radiatively induced circulation leads to the persistence of the cloud and upward advection of the cloudy air. Upward advection of the cloudy air is equivalent to upward transport of water vapor when the air above the cloud is drier than the cloudy air, and downward transport otherwise. In TTL cirrus, microphysical processes also contribute to transport of water vapor in the vertical direction. Ice nucleation and growth, followed by sedimentation and sublimation, always lead to downward transport of water vapor. The magnitude of the downward transport by microphysical processes increases with the relative humidity of the air surrounding the cloud. Moisture in the surrounding environment is important because there is continuous interactions between the cloudy and environmental air throughout the cloud boundary. In our simulations, when the air surrounding the cloud is subsaturated, hence drier than the cloudy air, the magnitude of the downward transport due to microphysical processes is smaller than that of the upward transport due to the radiatively induced advection of water vapor. The net result is upward transport of water vapor, and equivalently hydration of the lower stratosphere. On the other hand, when the surrounding air is supersaturated, hence moister than the cloudy air, microphysical and radiatively induced dynamical processes work in concert to induce downward transport of water vapor, that is dehydration of the lower stratosphere. TTL cirrus processes also depend sensitively on the deposition coefficient of water vapor on ice crystals. The deposition coefficient determines the depositional growth rate of ice crystals, hence microphysical and radiative properties of the cloud. In our simulations, larger values of the deposition coefficient correspond to less ice crystals nucleated during homogeneous freezing, larger ice crystal sizes, faster ice sedimentation, smaller radiative heating rate and weaker dynamics. These results indicate that detailed observations of the relative humidity in the vicinity of TTL cirrus and accurate laboratory measurements of the deposition coefficient are necessary to quantify the impact of TTL cirrus in the dehydration of the stratosphere. This research highlights the complex role of microphysical, radiative and dynamical processes in the transport of water vapor within TTL cirrus. It shows that under certain realistic conditions, TTL cirrus may lead to upward transport of water vapor, which results in moistening of the lower stratosphere. Thus it is not accurate to always associate TTL cirrus with stratospheric dehydration.

Strength of German accent under altered auditory feedback

PubMed Central

HOWELL, PETER; DWORZYNSKI, KATHARINA

2007-01-01

Borden’s (1979, 1980) hypothesis that speakers with vulnerable speech systems rely more heavily on feedback monitoring than do speakers with less vulnerable systems was investigated. The second language (L2) of a speaker is vulnerable, in comparison with the native language, so alteration to feedback should have a detrimental effect on it, according to this hypothesis. Here, we specifically examined whether altered auditory feedback has an effect on accent strength when speakers speak L2. There were three stages in the experiment. First, 6 German speakers who were fluent in English (their L2) were recorded under six conditions—normal listening, amplified voice level, voice shifted in frequency, delayed auditory feedback, and slowed and accelerated speech rate conditions. Second, judges were trained to rate accent strength. Training was assessed by whether it was successful in separating German speakers speaking English from native English speakers, also speaking English. In the final stage, the judges ranked recordings of each speaker from the first stage as to increasing strength of German accent. The results show that accents were more pronounced under frequency-shifted and delayed auditory feedback conditions than under normal or amplified feedback conditions. Control tests were done to ensure that listeners were judging accent, rather than fluency changes caused by altered auditory feedback. The findings are discussed in terms of Borden’s hypothesis and other accounts about why altered auditory feedback disrupts speech control. PMID:11414137

How does the architecture of a fault system controls magma upward migration through the crust?

NASA Astrophysics Data System (ADS)

Iturrieta, P. C.; Cembrano, J. M.; Stanton-Yonge, A.; Hurtado, D.

2017-12-01

The orientation and relative disposition of adjacent faults locally disrupt the regional stress field, thus enhancing magma flow through previous or newly created favorable conduits. Moreover, the brittle-plastic transition (BPT), due to its stronger rheology, governs the average state of stress of shallower portions of the fault system. Furthermore, the BPT may coincide with the location of transient magma reservoirs, from which dikes can propagate upwards into the upper crust, shaping the inner structure of the volcanic arc. In this work, we examine the stress distribution in strike-slip duplexes with variable geometry, along with the critical fluid overpressure ratio (CFOP), which is the minimum value required for individual faults to fracture in tension. We also determine the stress state disruption of the fault system when a dike is emplaced, to answer open questions such as: what is the nature of favorable pathways for magma to migrate? what is the architecture influence on the feedback between fault system kinematics and magma injection? To this end, we present a 3D coupled hydro-mechanical finite element model of the continental lithosphere, where faults are represented as continuum volumes with an elastic-plastic rheology. Magma flow upon fracturing is modeled through non-linear Stoke's flow, coupling solid and fluid equilibrium. A non-linear sensitivity analysis is performed in function of tectonic, rheology and geometry inputs, to assess which are the first-order factors that governs the nature of dike emplacement. Results show that the CFOP is heterogeneously distributed in the fault system, and within individual fault segments. Minimum values are displayed near fault intersections, where local kinematics superimpose on regional tectonic loading. Furthermore, when magma is transported through a fault segment, the CFOP is now minimized in faults with non-favorable orientations. This suggests that these faults act as transient pathways for magma to continue migrating upwards, which may explain the heterogeneity of seismicity patterns in volcano-tectonic seismic swarms. Likewise, once magma is injected, the consequent disruption of the stress field enhances the slip of faults which are not favorably oriented to the regional tectonic loading.

Providing rapid feedback to residents on their teaching skills: an educational strategy for contemporary trainees

PubMed Central

Baer, Tamar G.; Gershel, Jeffrey C.

2016-01-01

Objectives The objective of this study was to assess the attitudes of contemporary residents toward receiving rapid feedback on their teaching skills from their medical student learners. Methods Participants consisted of 20 residents in their second post-graduate training year. These residents facilitated 44 teaching sessions with medical students within our Resident-as-Teacher program. Structured, written feedback from students was returned to the resident within 3 days following each session. Residents completed a short survey about the utility of the feedback, whether they would make a change to future teaching sessions based on the feedback, and what specifically they might change. The survey utilized a 4-point scale (“Not helpful/likely=1” to “Very helpful/likely=4”), and allowed for one free-text response. Free-text responses were hand-coded and underwent qualitative analysis to identify themes.   Results There were 182 student feedback encounters resulting from 44 teaching sessions. The survey response rate was 73% (32/44). Ninety-four percent of residents rated the rapid feedback as “very helpful,” and 91% would “very likely” make a change to subsequent sessions based on student feedback. Residents’ proposed changes included modifications to session content and/or their personal teaching style.    Conclusions Residents found that rapid feedback received from medical student learners was highly valuable to them in their roles as teachers. A rapid feedback strategy may facilitate an optimal educational environment for contemporary trainees. PMID:26995390

Evaluation of a multi-methods approach to the collection and dissemination of feedback on OSCE performance in dental education.

PubMed

Wardman, M J; Yorke, V C; Hallam, J L

2018-05-01

Feedback is an essential part of the learning process, and students expect their feedback to be personalised, meaningful and timely. Objective Structured Clinical Examination (OSCE) assessments allow examiners to observe students carefully over the course of a number of varied station types, across a number of clinical knowledge and skill domains. They therefore present an ideal opportunity to record detailed feedback which allows students to reflect on and improve their performance. This article outlines two methods by which OSCE feedback was collected and then disseminated to undergraduate dental students across 2-year groups in a UK dental school: (i) Individual written feedback comments made by examiners during the examination, (ii) General audio feedback recorded by groups of examiners immediately following the examination. Evaluation of the feedback was sought from students and staff examiners. A multi-methods approach utilising Likert questionnaire items (quantitative) and open-ended feedback questions (qualitative) was used. Data analysis explored student and staff perceptions of the audio and written feedback. A total of 131 students (response rate 68%) and 52 staff examiners (response rate 83%) completed questionnaires. Quantitative data analysis showed that the written and audio formats were reported as a meaningful source of feedback for learning by both students (93% written, 89% audio) and staff (96% written, 92% audio). Qualitative data revealed the complementary nature of both types of feedback. Written feedback gives specific, individual information whilst audio shares general observations and allows students to learn from others. The advantages, limitations and challenges of the feedback methods are discussed, leading to the development of an informed set of implementation guidelines. Written and audio feedback methods are valued by students and staff. It is proposed that these may be very easily applied to OSCEs running in other dental schools. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A real-time phoneme counting algorithm and application for speech rate monitoring.

PubMed

Aharonson, Vered; Aharonson, Eran; Raichlin-Levi, Katia; Sotzianu, Aviv; Amir, Ofer; Ovadia-Blechman, Zehava

2017-03-01

Adults who stutter can learn to control and improve their speech fluency by modifying their speaking rate. Existing speech therapy technologies can assist this practice by monitoring speaking rate and providing feedback to the patient, but cannot provide an accurate, quantitative measurement of speaking rate. Moreover, most technologies are too complex and costly to be used for home practice. We developed an algorithm and a smartphone application that monitor a patient's speaking rate in real time and provide user-friendly feedback to both patient and therapist. Our speaking rate computation is performed by a phoneme counting algorithm which implements spectral transition measure extraction to estimate phoneme boundaries. The algorithm is implemented in real time in a mobile application that presents its results in a user-friendly interface. The application incorporates two modes: one provides the patient with visual feedback of his/her speech rate for self-practice and another provides the speech therapist with recordings, speech rate analysis and tools to manage the patient's practice. The algorithm's phoneme counting accuracy was validated on ten healthy subjects who read a paragraph at slow, normal and fast paces, and was compared to manual counting of speech experts. Test-retest and intra-counter reliability were assessed. Preliminary results indicate differences of -4% to 11% between automatic and human phoneme counting. Differences were largest for slow speech. The application can thus provide reliable, user-friendly, real-time feedback for speaking rate control practice. Copyright © 2017 Elsevier Inc. All rights reserved.

Design Of Combined Stochastic Feedforward/Feedback Control

NASA Technical Reports Server (NTRS)

Halyo, Nesim

1989-01-01

Methodology accommodates variety of control structures and design techniques. In methodology for combined stochastic feedforward/feedback control, main objectives of feedforward and feedback control laws seen clearly. Inclusion of error-integral feedback, dynamic compensation, rate-command control structure, and like integral element of methodology. Another advantage of methodology flexibility to develop variety of techniques for design of feedback control with arbitrary structures to obtain feedback controller: includes stochastic output feedback, multiconfiguration control, decentralized control, or frequency and classical control methods. Control modes of system include capture and tracking of localizer and glideslope, crab, decrab, and flare. By use of recommended incremental implementation, control laws simulated on digital computer and connected with nonlinear digital simulation of aircraft and its systems.

How Upward Moral Comparison Influences Prosocial Behavioral Intention: Examining the Mediating Role of Guilt and the Moderating Role of Moral Identity

PubMed Central

Zhang, Heyun; Chen, Sisi; Wang, Rong; Jiang, Jiang; Xu, Yan; Zhao, Huanhuan

2017-01-01

Although it has been shown that exceptional good deeds exert influences on people's prosocial behavior and intention, we have known little about how common moral actions in our daily life. The present study aimed to examine how upward moral comparison influenced prosocial behavioral intention as well as to explore the mediating role of guilt and the moderating role of moral identity in the focal relationship. An experimental study was conducted with 162 Chinese undergraduates (103 women, 59 men) randomly assigned to an upward moral comparison condition, an upward competence comparison condition or a control condition. Results indicated that participants in the upward moral comparison condition experienced higher levels of guilt and exhibited stronger motivation to act prosocially, relative to participants in the other two conditions. That is to say, upward moral comparison induces guilty experience, and then increases people's prosocial behavioral intention. Moreover, we have found that moral identity internalization moderates the upward moral comparison-guilt relationship, and the indirect effect of upward moral comparison on prosocial behavioral intention via guilt. The implications of these findings were discussed. PMID:28959221

The Military Procurement System--Can It Be Improved?

DTIC Science & Technology

1983-05-03

reprice the outyears of the budget. Repricing upwards, however, tends to be a self -fulfilling prophecy so we must be very careful about adding costs...Congress must be more economically resposible . A- Up to now, we haven’t been very good in this regard. Our economic asump- tions: GNP, inflation rates

Measurement Reactivity and Fatigue Effects in Daily Diary Research with Families

ERIC Educational Resources Information Center

Reynolds, Bridget M.; Robles, Theodore F.; Repetti, Rena L.

2016-01-01

Methodological challenges associated with measurement reactivity and fatigue were addressed using diary data collected from mothers (n = 47), fathers (n = 39), and children (n = 47; 8-13 years) across 56 consecutive days. Demonstrating the feasibility of extended diary studies with families, on-time compliance rates were upward of 90% for all…

Gravity settling

DOEpatents

Davis, Hyman R.; Long, R. H.; Simone, A. A.

1979-01-01

Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

An Investigation of Double Bass Vibrato Characteristics

ERIC Educational Resources Information Center

Mick, James

2015-01-01

The purpose of this study was to investigate and describe various vibrato characteristics of university double bass students. The primary objectives were: (1) to describe vibrato rate and width for commonly used fingers in first, fourth, and thumb positions; (2) to investigate whether students initiate vibrato in an upward or downward direction;…

Aesthetic judgment of triangular shape: compactness and not the golden ratio determines perceived attractiveness

PubMed Central

Friedenberg, Jay

2012-01-01

Many studies over a period of more than a century have investigated the influence of the golden ratio on perceived geometric beauty. Surprisingly, very few of these studies used triangular shapes. In Experiment 1, we presented right triangles that differed in regard to their elongation determined by increasing the length of one side relative to another. Attractiveness ratings did not peak at the golden ratio, but there was a very strong influence of axis ratio overall. Participant ratings were a negative decreasing function of ratio. Triangles that pointed upward were judged as significantly more attractive than those that pointed down. We interpret these results according to a compactness hypothesis: triangles that are more compact are less likely to move or break and are thus considered more pleasing. Orientation also affects aesthetics. Upward-pointing triangles with a base parallel to the ground, regardless of their compactness, are also considered more perceptually stable and attractive. These findings were replicated across stimulus type in a second experiment with isosceles triangles and across testing procedure in a third experiment using a paired comparison technique. PMID:23145277

Self-handicapping, excuse making, and counterfactual thinking: consequences for self-esteem and future motivation.

PubMed

McCrea, Sean M

2008-08-01

Researchers interested in counterfactual thinking have often found that upward counterfactual thoughts lead to increased motivation to improve in the future, although at the cost of increased negative affect. The present studies suggest that because upward counterfactual thoughts indicate reasons for a poor performance, they can also serve as excuses. In this case, upward counterfactual thoughts should result in more positive self-esteem and reduced future motivation. Five studies demonstrated these effects in the context of self-handicapping. First, upward counterfactual thinking was increased in the presence of a self-handicap. Second, upward counterfactual thoughts indicating the presence of a self-handicap protected self-esteem following failure. Finally, upward counterfactual thoughts that protect self-esteem reduced preparation for a subsequent performance as well as performance itself. These findings suggest that the consequences of upward counterfactuals for affect and motivation are moderated by the goals of the individual as well as the content of the thoughts. (c) 2008 APA, all rights reserved

Interfacial heat transfer in multiphase molten pools with gas injection

NASA Astrophysics Data System (ADS)

Bilbao Y Leon, Rosa Marina

1998-12-01

In the very unlikely event of a severe reactor accident involving core meltdown and pressure vessel failure, it is vital to identify the circumstances that would allow the molten core material to cool down and resolidify, bringing core debris to a safe and stable state. In this type of accident, the molten material which escapes from the reactor pressure vessel will accumulate as a molten pool in the reactor cavity below. To achieve coolability of the corium in this configuration it has been proposed to flood the cavity with water from above forming a layered structure where upward heat loss from the molten pool to the water will cause the core material to quench and solidify. The effectiveness of this procedure depends largely on the rate of upward heat loss as well as on the formation and stability of an upper crust. In this situation the molten pool becomes a three phase mixture: the solid and liquid slurry formed by the molten pool cooled to a temperature below the temperature of liquidus, agitated by the gases formed in the concrete ablation process. The present work quantifies the partition of the heat losses upward and downward considering the influence of the solid fraction in the pool and the viscosity effects, and the rate of heat loss through a solid layer. To complete this task a intermediate scale experimental test section has been designed and built at the University of Wisconsin - Madison, in which simulant materials are used to model the process of heat and mass transfer which involves the molten pool, the solid layer atop and the coolant layer above. The design includes volumetric heating, gas injection from the bottom and solids within the pool. New experimental results showing the heat transfer behavior for pools with different viscosities and various solid fractions are presented. The current results indicate a power split which favors heat transfer upward to the coolant simulant above by a 2:1 or 3:1 ratio. In addition, the power split is unaffected by the viscosity of the pool, the solid fractions in the pool and the superficial velocity.

Hybrid Therapy in Patients with Complex Peripheral Multifocal Steno-obstructive Vascular Disease: Two-Year Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cotroneo, Antonio Raffaele; Iezzi, Roberto; Marano, Giuseppe

2007-06-15

Purpose. To report the 2-year results after hybrid (combined surgical-endovascular) therapy in patients with complex peripheral multifocal steno-obstructive vascular disease. Methods. From September 2001 through April 2003, 47 combined surgical-endovascular procedures were performed in a single session in 44 patients with peripheral occlusive artery disease. Although the common femoral artery is usually treated with open surgery, endoluminal procedures were performed upward in 23 patients (group A), distally in 18 patients (group B), and both upward and downward of the area treated with open surgery in 3 patients (group C). Patients underwent clinical assessment and color duplex ultrasonography examination at 1,more » 3, 6, 12, 18, and 24 months after the procedure. Results. The technical success rate was 100%. Two patients died, at 2 and 19 months after treatment, respectively, both from myocardial infarction. Primary and primary-assisted patency rates were 86.2% and 90.8% at 6 months and 79.1% and 86.1% at 24 months, respectively. Thirty-three patients remained free of symptoms, without any secondary interventions, which corresponded to a primary patency rate of 78.6% (33 of 42). Conclusion. Combined therapy simplifies and allows the one-step treatment of patients with complex peripheral multifocal steno-obstructive vascular disease that has indications for revascularization, and it provides excellent long-term patency rates.« less

Audit and feedback using the Robson classification to reduce caesarean section rates: a systematic review.

PubMed

Boatin, A A; Cullinane, F; Torloni, M R; Betrán, A P

2018-01-01

In most regions worldwide, caesarean section (CS) rates are increasing. In these settings, new strategies are needed to reduce CS rates. To identify, critically appraise and synthesise studies using the Robson classification as a system to categorise and analyse data in clinical audit cycles to reduce CS rates. Medline, Embase, CINAHL and LILACS were searched from 2001 to 2016. Studies reporting use of the Robson classification to categorise and analyse data in clinical audit cycles to reduce CS rates. Data on study design, interventions used, CS rates, and perinatal outcomes were extracted. Of 385 citations, 30 were assessed for full text review and six studies, conducted in Brazil, Chile, Italy and Sweden, were included. All studies measured initial CS rates, provided feedback and monitored performance using the Robson classification. In two studies, the audit cycle consisted exclusively of feedback using the Robson classification; the other four used audit and feedback as part of a multifaceted intervention. Baseline CS rates ranged from 20 to 36.8%; after the intervention, CS rates ranged from 3.1 to 21.2%. No studies were randomised or controlled and all had a high risk of bias. We identified six studies using the Robson classification within clinical audit cycles to reduce CS rates. All six report reductions in CS rates; however, results should be interpreted with caution because of limited methodological quality. Future trials are needed to evaluate the role of the Robson classification within audit cycles aimed at reducing CS rates. Use of the Robson classification in clinical audit cycles to reduce caesarean rates. © 2017 The Authors. BJOG An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.

34 CFR 645.13 - What additional services do Upward Bound Math and Science Centers provide and how are they...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false What additional services do Upward Bound Math and... Program? § 645.13 What additional services do Upward Bound Math and Science Centers provide and how are... provided under § 645.11(b), an Upward Bound Math and Science Center must provide— (1) Intensive instruction...

34 CFR 645.14 - What additional services do Upward Bound Math and Science Centers provide and how are they...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 3 2011-07-01 2011-07-01 false What additional services do Upward Bound Math and... Program? § 645.14 What additional services do Upward Bound Math and Science Centers provide and how are... provided under § 645.11(b), an Upward Bound Math and Science Center must provide— (1) Intensive instruction...

34 CFR 645.14 - What additional services do Upward Bound Math and Science Centers provide and how are they...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 3 2014-07-01 2014-07-01 false What additional services do Upward Bound Math and... Program? § 645.14 What additional services do Upward Bound Math and Science Centers provide and how are... provided under § 645.11(b), an Upward Bound Math and Science Center must provide— (1) Intensive instruction...

34 CFR 645.14 - What additional services do Upward Bound Math and Science Centers provide and how are they...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 34 Education 3 2012-07-01 2012-07-01 false What additional services do Upward Bound Math and... Program? § 645.14 What additional services do Upward Bound Math and Science Centers provide and how are... provided under § 645.11(b), an Upward Bound Math and Science Center must provide— (1) Intensive instruction...

34 CFR 645.14 - What additional services do Upward Bound Math and Science Centers provide and how are they...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 34 Education 3 2013-07-01 2013-07-01 false What additional services do Upward Bound Math and... Program? § 645.14 What additional services do Upward Bound Math and Science Centers provide and how are... provided under § 645.11(b), an Upward Bound Math and Science Center must provide— (1) Intensive instruction...

Experimenter Prestige and Feedback Related to Acceptance of Genuine Personality Interpretations and Self-Attitude

ERIC Educational Resources Information Center

Bradley, Gifford W.; Bradley, Laurence A.

1977-01-01

It was found that (a) subjects in all conditions rated the interpretations as being fairly accurate descriptions of their personalities; (b) the acceptance of the feedback did not vary as a function of experimenter prestige; and (c) receiving personality feedback had no effects on subjects' self-attitudes. (Author/MV)

Is Positive Feedback a Forgotten Classroom Practice? Findings and Implications for At-Risk Students

ERIC Educational Resources Information Center

Sprouls, Katie; Mathur, Sarup R.; Upreti, Gita

2015-01-01

Although using higher rates of positive to negative feedback is one best practice often recommended to teachers, particularly when it comes to students experiencing behavioral problems in classroom settings, research on the use of positive feedback in classroom teaching practice has revealed inconsistent results. Research has documented…

A case study of lightning attachment to flat ground showing multiple unconnected upward leaders

NASA Astrophysics Data System (ADS)

Cummins, Kenneth L.; Krider, E. Philip; Olbinski, Mike; Holle, Ronald L.

2018-04-01

On 10 July 2015, a cloud-to-ground (CG) lightning flash that produced two ground terminations was photographed from inside the safety of a truck in southern New Mexico. An analysis of archived NLDN data verified that this was a two-stroke flash, and a close-up view of the first stroke shows that it also initiated at least 12 unconnected, upward leaders (or "streamers") near the ground termination. No unconnected upward leaders were seen near the second ground attachment. After combining an analysis of the photograph with information provided by the NLDN, we infer that the first stroke was of negative (normal) polarity, had modest peak current, and struck about 460 m (± 24%) from the camera. Attachment occurred when an upward-propagating positive leader reached an inferred height of about 21 m above local ground. The second stroke struck ground about 740 m from the camera, and the height of its attachment leader is estimated to be 15 m. The estimated lengths of the unconnected upward leaders in the two-dimensional (2-D) plane of the first stroke range from 2 to 8 m, and all appear to be located within 15 m (2-D) of the main ground termination, with 24% uncertainty. Many of the unconnected upward leaders (inferred to be positive) exhibit multiple upward branches, and most of those branches have upward-directed forks or splits at their ends. This is the first report showing such extensive branching for positive upward leaders in natural lightning strikes to ground. None of the upward leaders can be seen to emanate from the tops of tall, isolated, or pointed objects on the ground, but they likely begin on small plants and rocks, or flat ground. In terms of lightning safety, this photo demonstrates that numerous upward leaders can be produced near a lightning strike point and have the potential to damage or cause injury at more than one specific point on the ground.

Investigation and Development of Control Laws for the NASA Langley Research Center Cockpit Motion Facility

NASA Technical Reports Server (NTRS)

Coon, Craig R.; Cardullo, Frank M.; Zaychik, Kirill B.

2014-01-01

The ability to develop highly advanced simulators is a critical need that has the ability to significantly impact the aerospace industry. The aerospace industry is advancing at an ever increasing pace and flight simulators must match this development with ever increasing urgency. In order to address both current problems and potential advancements with flight simulator techniques, several aspects of current control law technology of the National Aeronautics and Space Administration (NASA) Langley Research Center's Cockpit Motion Facility (CMF) motion base simulator were examined. Preliminary investigation of linear models based upon hardware data were examined to ensure that the most accurate models are used. This research identified both system improvements in the bandwidth and more reliable linear models. Advancements in the compensator design were developed and verified through multiple techniques. The position error rate feedback, the acceleration feedback and the force feedback were all analyzed in the heave direction using the nonlinear model of the hardware. Improvements were made using the position error rate feedback technique. The acceleration feedback compensator also provided noteworthy improvement, while attempts at implementing a force feedback compensator proved unsuccessful.

Nonlinear Bayesian cue integration explains the dynamics of vocal learning

NASA Astrophysics Data System (ADS)

Zhou, Baohua; Sober, Samuel; Nemenman, Ilya

The acoustics of vocal production in songbirds is tightly regulated during both development and adulthood as birds progressively refine their song using sensory feedback to match an acoustic target. Here, we perturb this sensory feedback using headphones to shift the pitch (fundamental frequency) of song. When the pitch is shifted upwards (downwards), birds eventually learn to compensate and sing lower (higher), bringing the experienced pitch closer to the target. Paradoxically, the speed and amplitude of this motor learning decrease with increases in the introduced error size, so that birds respond rapidly to a small sensory perturbation, while seemingly never correcting a much bigger one. Similar results are observed broadly across the animal kingdom, and they do not derive from a limited plasticity of the adult brain since birds can compensate for a large error as long as the error is imposed gradually. We develop a mathematical model based on nonlinear Bayesian integration of two sensory modalities (one perturbed and the other not) that quantitatively explains all of these observations. The model makes predictions about the structure of the probability distribution of the pitches sung by birds during the pitch shift experiments, which we confirm using experimental data. This work was supported in part by James S. McDonnell Foundation Grant # 220020321, NSF Grant # IOS/1208126, NSF Grant # IOS/1456912 and NIH Grants # R01NS084844.

The execution trap. Drawing a line between strategy and execution almost guarantees failure.

PubMed

Martin, Roger L

2010-01-01

The realization of a strategy depends on countless employees. So it's no surprise that when a strategy fails, the reason cited is usually poor execution. But this view of strategy and execution relies on a false metaphor in which senior management is a choosing brain while those in the rest of the company are choiceless arms and legs that merely carry out the brain's bidding. The approach does damage to the corporation because it alienates the people working for it. A better metaphor for strategy is a white-water river, in which choices cascade from its source in the mountains (the corporation) to its mouth (the rest of the organization). Executives at the top make the broader choices involving long-term investments while empowering employees toward the bottom to make more concrete, day-to-day decisions that directly influence customer service and satisfaction. For the cascade to flow properly, a choice maker upstream can set the context for those downstream by doing four things: explaining what the choice is and why it's been made, clearly identifying the next downstream choice, offering help with making choices as needed, and committing to revisit and adjust the choice based on feedback. When downstream choices are valued and feedback is encouraged, employees send information upward, improving the knowledge base of decision makers higher up and helping everyone in the organization make better choices.

[Traceability of labile blood products in Morocco: experience of the Ibn-Sina hospital of Rabat between 1999 and 2010].

PubMed

Ouadghiri, S; Atouf, O; Brick, C; Benseffaj, N; Essakalli, M

2012-02-01

The blood transfusion and haemovigilance service of the Ibn-Sina hospital in Rabat (Morocco) was created 1997. This unit manages the pretransfusional tests, distribution of blood products, traceability and haemovigilance. The objective of this study was to analyze, over a period of 12years, the traceability of blood products delivered in our hospital and the measures used to improve feedback information. This is a retrospective study conducted between 1999 and 2010. Traceability rate was calculated from the feedback of traceability forms supplied with blood products (number of blood products noted on traceability forms on the total number of delivered product). To improve traceability rate, several actions were undertaken: one-time training, awareness campaigns and call phones asking for feedback information. Between 1999 and 2010, the service has delivered 173,858 blood products. The average rate of traceability during this period was 13.4 %. Traceability rate varies widely over time (5.2 % in 1999, 15.5 % in 2010) and shows a maximum value of 27.2 % in 2005. Feedback information is lower in emergency departments than in medical and surgical services. Feedback information about traceability in Ibn-Sina hospital remains very poor despite the measures used. Other actions, such as continuous education courses, low enforcement and informatisation should be considered. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Individual Variability in Delayed Auditory Feedback Effects on Speech Fluency and Rate in Normally Fluent Adults

ERIC Educational Resources Information Center

Chon, HeeCheong; Kraft, Shelly Jo; Zhang, Jingfei; Loucks, Torrey; Ambrose, Nicoline G.

2013-01-01

Purpose: Delayed auditory feedback (DAF) is known to induce stuttering-like disfluencies (SLDs) and cause speech rate reductions in normally fluent adults, but the reason for speech disruptions is not fully known, and individual variation has not been well characterized. Studying individual variation in susceptibility to DAF may identify factors…

Digital phase-lock loop

NASA Technical Reports Server (NTRS)

Thomas, Jr., Jess B. (Inventor)

1991-01-01

An improved digital phase lock loop incorporates several distinctive features that attain better performance at high loop gain and better phase accuracy. These features include: phase feedback to a number-controlled oscillator in addition to phase rate; analytical tracking of phase (both integer and fractional cycles); an amplitude-insensitive phase extractor; a more accurate method for extracting measured phase; a method for changing loop gain during a track without loss of lock; and a method for avoiding loss of sampled data during computation delay, while maintaining excellent tracking performance. The advantages of using phase and phase-rate feedback are demonstrated by comparing performance with that of rate-only feedback. Extraction of phase by the method of modeling provides accurate phase measurements even when the number-controlled oscillator phase is discontinuously updated.

Time trends for prostate cancer mortality in Brazil and its geographic regions: An age-period-cohort analysis.

PubMed

Braga, Sonia Faria Mendes; de Souza, Mirian Carvalho; Cherchiglia, Mariangela Leal

2017-10-01

In the 1980s, an increase in mortality rates for prostate cancer was observed in North America and developed European countries. In the 1990s, however, mortality rates decreased for these countries, an outcome related to early detection of the disease. Conversely, an upward trend in mortality rates was observed in Brazil. This study describe the trends in mortality for prostate cancer in Brazil and geographic regions (North, Northeast, South, Southeast, and Central-West) between 1980 until 2014 and analyze the influence of age, period, and cohort effects on mortality rates. This time-series study used data from the Mortality Information System (SIM) and population data from Brazilian Institute for Geography and Statistics (IBGE). The effects on mortality rates were examined using age-period-cohort (APC) models. Crude and standardized mortality rates showed an upward trend for Brazil and its regions more than 2-fold the last 30 years. Age effects showed an increased risk of death in all regions. Period effects showed a higher risk of death in the finals periods for the North and Northeast. Cohort effects showed risk of death was higher for younger than older generations in Brazil and regions, mainly Northeast (RR Adjusted =3.12, 95% CI 1.29-1.41; RR Adjusted =0.28, 95% CI 0.26-0.30, respectively). The increase in prostate cancer mortality rates in Brazil and its regions was mainly due to population aging. The differences in mortality rates and APC effects between regions are related to demographic differences and access of health services across the country. Copyright © 2017 Elsevier Ltd. All rights reserved.

Landsat-based Analysis of Mountain Forest-tundra Ecotone Response to Climate Trends in Sayan Mountains

NASA Technical Reports Server (NTRS)

Kharuk, Viatcheslav I.; Im, Sergey T.; Ranson, K. Jon

2007-01-01

observations of temperatures Siberia has shown a several degree warming over the past 30 years. It is expected that forest will respond to warming at high latitudes through increased tree growth and northward or upward slope migration. migration. Tree response to climate trends is most likely observable in the forest-tundra ecotone, where temperature mainly limits tree growth. Making repeated satellite observations over several decades provides an opportunity to track vegetation response to climate change. Based on Landsat data of the Sayan Mountains, Siberia, there was an increase in forest stand crown closure and an upward tree-line shift in the of the forest-tundra ecotone during the last quarter of the 2oth century,. On-ground observations, supporting these results, also showed regeneration of Siberian pine in the alpine tundra, and the transformation of prostrate Siberian pine and fir into arboreal (upright) forms. During this time period sparse stands transformed into closed stands, with existing closed stands increasing in area at a rate of approx. 1 %/yr, and advancing their upper border at a vertical rate of approx. 1.0 m/yr. In addition, the vertical rate of regeneration propagation is approx. 5 m/yr. It was also found that these changes correlated positively with temperature trends

Field Effects of Buoyancy on a Premixed Turbulent Flame Studied by Particle Image Velocimetry

NASA Technical Reports Server (NTRS)

Cheng, Robert K.

2003-01-01

Typical laboratory flames for the scientific investigation of flame/turbulence interactions are prone to buoyancy effects. Buoyancy acts on these open flame systems and provides upstream feedbacks that control the global flame properties as well as local turbulence/flame interactions. Consequently the flame structures, stabilization limits, and turbulent reaction rates are directly or indirectly coupled with buoyancy. The objective of this study is to characterize the differences between premixed turbulent flames pointing upwards (1g), pointing downwards (-1g), and in microgravity (mg). The configuration is an inverted conical flame stabilized by a small cone-shaped bluff body that we call CLEAN Flames (Cone-Stabilized Lean Flames). We use two laser diagnostics to capture the velocity and scalar fields. Particle image velocimetry (PIV) measures the mean and root mean square velocities and planar imaging by the flame fronts method outlines the flame wrinkle topology. The results were obtained under typical conditions of small domestic heating systems such as water heaters, ovens, and furnaces. Significant differences between the 1g and -1g flames point to the need for including buoyancy contributions in theoretical and numerical calculations. In Earth gravity, there is a complex coupling of buoyancy with the turbulent flow and heat release in the flame. An investigation of buoyancy-free flames in microgravity will provide the key to discern gravity contributions. Data obtained in microgravity flames will provide the benchmark for interpreting and analyzing 1g and -1g flame results.

Does feedback matter? Practice-based learning for medical students after a multi-institutional clinical performance examination.

PubMed

Srinivasan, Malathi; Hauer, Karen E; Der-Martirosian, Claudia; Wilkes, Michael; Gesundheit, Neil

2007-09-01

Achieving competence in 'practice-based learning' implies that doctors can accurately self- assess their clinical skills to identify behaviours that need improvement. This study examines the impact of receiving feedback via performance benchmarks on medical students' self-assessment after a clinical performance examination (CPX). The authors developed a practice-based learning exercise at 3 institutions following a required 8-station CPX for medical students at the end of Year 3. Standardised patients (SPs) scored students after each station using checklists developed by experts. Students assessed their own performance immediately after the CPX (Phase 1). One month later, students watched their videotaped performance and reassessed (Phase 2). Some students received performance benchmarks (their scores, plus normative class data) before the video review. Pearson's correlations between self-ratings and SP ratings were calculated for overall performance and specific skill areas (history taking, physical examination, doctor-patient communication) for Phase 1 and Phase 2. The 2 correlations were then compared for each student group (i.e. those who received and those who did not receive feedback). A total of 280 students completed both study phases. Mean CPX scores ranged from 51% to 71% of items correct overall and for each skill area. Phase 1 self-assessment correlated weakly with SP ratings of student performance (r = 0.01-0.16). Without feedback, Phase 2 correlations remained weak (r = 0.13-0.18; n = 109). With feedback, Phase 2 correlations improved significantly (r = 0.26-0.47; n = 171). Low-performing students showed the greatest improvement after receiving feedback. The accuracy of student self-assessment was poor after a CPX, but improved significantly with performance feedback (scores and benchmarks). Videotape review alone (without feedback) did not improve self-assessment accuracy. Practice-based learning exercises that incorporate feedback to medical students hold promise to improve self-assessment skills.

Solute transport with time-variable flow paths during upward and downward flux in a heterogeneous unsaturated porous medium

NASA Astrophysics Data System (ADS)

Cremer, Clemens; Neuweiler, Insa; Bechtold, Michel; Vanderborght, Jan

2014-05-01

To acquire knowledge of solute transport through the unsaturated zone in the shallow subsurface is decisive to assess groundwater quality, nutrient cycling or to plan remediation strategies. The shallow subsurface is characterized by structural heterogeneity and strongly influenced by atmospheric conditions. This leads to changing flow directions, strong temporal changes in saturation and heterogeneous water fluxes during infiltration and evaporation events. Recent studies (e.g. Lehmann and Or, 2009; Bechtold et al.,2011) demonstrated the importance of lateral flow and solute transport during evaporation conditions (upward flux). The heterogeneous structure in these studies was constructed using two types of sand with strong material contrasts and arranged in parallel with a vertical orientation. Lateral transport and redistribution of solute from coarse to fine media was observed deeper in the soil column and from fine to coarse close to the soil surface. However, if boundary conditions are reversed due to precipitation, the flow field is not necessarily reversed in the same manner, resulting in entirely different transport patterns for downward and upward flow. Therefore, considering net-flow rates alone is misleading when describing transport under those conditions. In this contribution we analyze transport of a solute in the shallow subsurface to assess effects resulting from the temporal change of heterogeneous soil structures due to dynamic flow conditions. Two-dimensional numerical simulations of unsaturated flow and transport are conducted using a coupled finite volume and random walk particle tracking algorithm to quantify solute transport and leaching rates. Following previous studies (Lehmann and Or, 2009; Bechtold et al., 2011), the chosen domain is composed of two materials, coarse and fine sand, arranged in parallel with a vertical orientation. Hence, one sharp interface of strong material heterogeneity is induced. During evaporation both sands are assumed to stay under liquid-flow dominated evaporation conditions ("stage 1"). Simulations considering dynamic (infiltration-evaporation) and steady (solely infiltration) boundary conditions are carried out. The influence of dynamic boundary conditions (intensity and duration of precipitation and evaporation events) is examined in a multitude of simulations. If flow rates smaller than the saturated hydraulic conductivity of both materials are chosen to be applied as boundary condition, simulation results indicate that the flow field within the domain is exactly reversed. However, if applied flow rates exceed the saturated hydraulic conductivity of one material, the flow field is not just reversed, but different flow paths during downward and upward flow are observed. Results show the tendency of faster solute leaching under dynamic boundary conditions compared to steady infiltration conditions with the same net-infiltration rate. We use a double domain transport method as an upscaled model to reproduce vertically averaged concentration profiles with net flux only and compare the model parameters for information about flow dynamics and soil heterogeneity.

Rise in sexually transmitted diseases during democratization and economic crisis in Mongolia.

PubMed

Purevdawa, E; Moon, T D; Baigalmaa, C; Davaajav, K; Smith, M L; Vermund, S H

1997-06-01

In 1990, democratic changes and loss of Soviet economic subsidies led to enormous social upheaval in Mongolia. The objective of this study is to map sexually transmitted disease (STD) trends in Mongolia from 1983-1995 and review human immunodeficiency virus (HIV) surveillance data since 1987. Data for syphilis show a decreasing trend from 1983-1993 with a decline in cases from 70 to 18/100,000 population, followed by a rise in cases to 32/100,000 population in 1995. Data suggest a 1.5-3.0 fold higher rate of syphilis for ages 15-24 than for any other group. Data for gonorrhoea show an upward trend in the rate of cases, from 51/100,000 population in 1983 to 142/100,000 in 1995. The majority of cases are aged 15-44. Trichomonas rates also show an upward trend in the number of cases, from 47/100,000 population in 1983 to 155/100,000 cases in 1995. Like gonorrhoea the majority of cases are in the 15-44 year age range. For children aged 0-14, the 1983-1993 rate remained below 4.5/100,000; however, in 1994 and 1995 the rate increased reaching 53 and 48/100,000 respectively. Since 1987, more than 176,000 HIV tests have been done with only one confirmed positive result. Rises in STD rates coincide with deterioration in STD services and reduced active surveillance, suggesting that these data reflect a minimum estimation of the problem. Changes in business and social circumstances may have resulted in increasing HIV and STD risk behaviour.

Towards a Theory of Tropical/Midlatitude Mass Exchange from the Earth's Surface through the Stratosphere

NASA Technical Reports Server (NTRS)

Hartley, Dana

1998-01-01

The main findings of this research project have been the following: (1) there is a significant feedback from the stratosphere on tropospheric dynamics, and (2) a detailed analysis of the interaction between tropical and polar wave breaking in controlling stratospheric mixing. Two papers are were written and are included. The first paper is titled, "A New Perspective on the Dynamical Link Between the Stratosphere and Troposphere." Atmospheric processes of tropospheric origin can perturb the stratosphere, but direct feedback in the opposite direction is usually assumed to be negligible, despite the troposphere's sensitivity to changes in the release of wave activity into the stratosphere. Here, however, we present evidence that such a feedback exists and can be significant. We find that if the wintertime Arctic polar stratospheric vortex is distorted, either by waves propagating upward from the troposphere or by eastward-travelling stratospheric waves, then there is a concomitant redistribution of stratospheric potential vorticity that induces perturbations in key meteorological fields in the upper troposphere. The feedback is large despite the much greater mass of the troposphere: it can account for up to half of the geopotential height anomaly at the tropopause. Although the relative strength of the feedback is partly due to a cancellation between contributions to these anomalies from lower altitudes, our results imply that stratospheric dynamics and its feedback on the troposphere are more significant for climate modelling and data assimilation than was previously assumed. The second article is titled "Diagnosing the Polar Excitation of Subtropical Waves in the Stratosphere". The poleward migration of planetary scale tongues of subtropical air has often been associated with intense polar vortex disturbances in the stratosphere. This question of vortex influence is reexamined from a potential vorticity (PV) perspective. Anomalous geopotential height and wind fields associated solely with vortex PV anomalies are derived and their impact on the stratospheric subtropical circulation is evaluated. Combined PV inversion and Contour Advection (CA) calculations indicate that transient large scale disturbances of the polar vortex do have a far reaching impact that extends beyond the midlatitude surf zone all the way to the subtropics. This vortex influence is clearly non-local so that even simple wave 2 distortions that leave the vortex well confined within the midlatitudes are observed to excite subtropical waves. Treating subtropical PV as active tracers also showed that upon entrainment, these large scale tongues of low PV air also influenced the dynamics of their own poleward migration.

A Comparison of Climate Feedback Strength between CO2 Doubling and LGM Experiments

NASA Astrophysics Data System (ADS)

Yoshimori, M.; Yokohata, T.; Abe-Ouchi, A.

2008-12-01

Studies of past climate potentially provide a constraint on the uncertainty of climate sensitivity, but previous studies warn against a simple scaling to the future. The climate sensitivity is determined by various feedback processes and they may vary with climate states and forcings. In this study, we investigate similarities and differences of feedbacks for a CO2 doubling, a last glacial maximum (LGM), and LGM greenhouse gas (GHG) forcing experiments, using an atmospheric general circulation model coupled to a slab ocean model. After computing the radiative forcing, the individual feedback strengths: water vapor, lapse rate, albedo, and cloud feedbacks, are evaluated explicitly. For this particular model, the difference in the climate sensitivity among experiments is attributed to the shortwave cloud feedback in which there is a tendency that it becomes weaker or even negative in the cooling experiments. No significant difference is found in the water vapor feedback between warming and cooling experiments by GHGs despite the nonlinear dependence of the Clausius-Clapeyron relation on temperature. The weaker water vapor feedback in the LGM experiment due to a relatively weaker tropical forcing is compensated by the stronger lapse rate feedback due to a relatively stronger extratropical forcing. A hypothesis is proposed which explains the asymmetric cloud response between warming and cooling experiments associated with a displacement of the region of mixed- phase clouds. The difference in the total feedback strength between experiments is, however, relatively small compared to the current intermodel spread, and does not necessarily preclude the use of LGM climate as a future constraint.

Observational estimation of radiative feedback to surface air temperature over Northern High Latitudes

NASA Astrophysics Data System (ADS)

Hwang, Jiwon; Choi, Yong-Sang; Kim, WonMoo; Su, Hui; Jiang, Jonathan H.

2018-01-01

The high-latitude climate system contains complicated, but largely veiled physical feedback processes. Climate predictions remain uncertain, especially for the Northern High Latitudes (NHL; north of 60°N), and observational constraint on climate modeling is vital. This study estimates local radiative feedbacks for NHL based on the CERES/Terra satellite observations during March 2000-November 2014. The local shortwave (SW) and longwave (LW) radiative feedback parameters are calculated from linear regression of radiative fluxes at the top of the atmosphere on surface air temperatures. These parameters are estimated by the de-seasonalization and 12-month moving average of the radiative fluxes over NHL. The estimated magnitudes of the SW and the LW radiative feedbacks in NHL are 1.88 ± 0.73 and 2.38 ± 0.59 W m-2 K-1, respectively. The parameters are further decomposed into individual feedback components associated with surface albedo, water vapor, lapse rate, and clouds, as a product of the change in climate variables from ERA-Interim reanalysis estimates and their pre-calculated radiative kernels. The results reveal the significant role of clouds in reducing the surface albedo feedback (1.13 ± 0.44 W m-2 K-1 in the cloud-free condition, and 0.49 ± 0.30 W m-2 K-1 in the all-sky condition), while the lapse rate feedback is predominant in LW radiation (1.33 ± 0.18 W m-2 K-1). However, a large portion of the local SW and LW radiative feedbacks were not simply explained by the sum of these individual feedbacks.

The impact of post-resuscitation feedback for paramedics on the quality of cardiopulmonary resuscitation.

PubMed

Bleijenberg, Eduard; Koster, Rudolph W; de Vries, Hendrik; Beesems, Stefanie G

2017-01-01

The Guidelines place emphasis on high-quality cardiopulmonary resuscitation (CPR). This study aims to measure the impact of post-resuscitation feedback on the quality of CPR as performed by ambulance personnel. Two ambulances are dispatched for suspected cardiac arrest. The crew (driver and paramedic) of the first arriving ambulance is responsible for the quality of CPR. The crew of the second ambulance establishes an intravenous access and supports the first crew. All resuscitation attempts led by the ambulance crew of the study region were reviewed by two research paramedics and structured feedback was given based on defibrillator recording with impedance signal. A 12-months period before introduction of post-resuscitation feedback was compared with a 19-months period after introduction of feedback, excluding a six months run-in interval. Quality parameters were chest compression fraction (CCF), chest compression rate, longest peri-shock pause and longest non-shock pause. In the pre-feedback period 55 cases were analyzed and 69 cases in the feedback period. Median CCF improved significantly in the feedback period (79% vs 86%, p<0.001). The mean chest compression rate was within the recommended range of 100-120/min in 87% of the cases in the pre-feedback period and in 90% of the cases in the feedback period (p=0.65). The duration of longest non-shock pause decreased significantly (40s vs 19s, p<0.001), the duration of the longest peri-shock pause did not change significantly (16s vs 13s, p=0.27). Post-resuscitation feedback improves the quality of resuscitation, significantly increasing CCF and decreasing the duration of longest non-shock pauses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Cultural influences on social feedback processing of character traits

PubMed Central

Korn, Christoph W.; Fan, Yan; Zhang, Kai; Wang, Chenbo; Han, Shihui; Heekeren, Hauke R.

2014-01-01

Cultural differences are generally explained by how people see themselves in relation to social interaction partners. While Western culture emphasizes independence, East Asian culture emphasizes interdependence. Despite this focus on social interactions, it remains elusive how people from different cultures process feedback on their own (and on others') character traits. Here, participants of either German or Chinese origin engaged in a face-to-face interaction. Consequently, they updated their self- and other-ratings of 80 character traits (e.g., polite, pedantic) after receiving feedback from their interaction partners. To exclude potential confounds, we obtained data from German and Chinese participants in Berlin [functional magnetic resonance imaging (fMRI)] and in Beijing (behavior). We tested cultural influences on social conformity, positivity biases, and self-related neural activity. First, Chinese conformed more to social feedback than Germans (i.e., Chinese updated their trait ratings more). Second, regardless of culture, participants processed self- and other-related feedback in a positively biased way (i.e., they updated more toward desirable than toward undesirable feedback). Third, changes in self-related medial prefrontal cortex activity were greater in Germans than in Chinese during feedback processing. By investigating conformity, positivity biases, and self-related activity in relation to feedback obtained in a real-life interaction, we provide an essential step toward a unifying framework for understanding the diversity of human culture. PMID:24772075

Cultural influences on social feedback processing of character traits.

PubMed

Korn, Christoph W; Fan, Yan; Zhang, Kai; Wang, Chenbo; Han, Shihui; Heekeren, Hauke R

2014-01-01

Cultural differences are generally explained by how people see themselves in relation to social interaction partners. While Western culture emphasizes independence, East Asian culture emphasizes interdependence. Despite this focus on social interactions, it remains elusive how people from different cultures process feedback on their own (and on others') character traits. Here, participants of either German or Chinese origin engaged in a face-to-face interaction. Consequently, they updated their self- and other-ratings of 80 character traits (e.g., polite, pedantic) after receiving feedback from their interaction partners. To exclude potential confounds, we obtained data from German and Chinese participants in Berlin [functional magnetic resonance imaging (fMRI)] and in Beijing (behavior). We tested cultural influences on social conformity, positivity biases, and self-related neural activity. First, Chinese conformed more to social feedback than Germans (i.e., Chinese updated their trait ratings more). Second, regardless of culture, participants processed self- and other-related feedback in a positively biased way (i.e., they updated more toward desirable than toward undesirable feedback). Third, changes in self-related medial prefrontal cortex activity were greater in Germans than in Chinese during feedback processing. By investigating conformity, positivity biases, and self-related activity in relation to feedback obtained in a real-life interaction, we provide an essential step toward a unifying framework for understanding the diversity of human culture.

What You Don't Know: Improving Family Health History Knowledge among Multigenerational Families of Mexican Origin.

PubMed

Goergen, Andrea F; Ashida, Sato; Skapinsky, Kaley; de Heer, Hendrik D; Wilkinson, Anna V; Koehly, Laura M

2016-01-01

This study investigated diabetes and heart disease family health history (FHH) knowledge and changes after providing personalized disease risk feedback. A total of 497 adults from 162 families of Mexican origin were randomized by household to conditions based on feedback recipient and content. Each provided personal and relatives' diabetes and heart disease diagnoses and received feedback materials following baseline assessment. Multivariate models were fitted to identify factors associated with the rate of 'don't know' FHH responses. At baseline, US nativity was associated with a higher 'don't know' response rate (p = 0.002). Though confounded by country of birth, younger age showed a trend toward higher 'don't know' response rates. Overall, average 'don't know' response rates dropped from 20 to 15% following receipt of feedback (p < 0.001). An intervention effect was noted, as 'don't know' response rates decreased more in households where one family member (vs. all) received supplementary risk assessments (without behavioral recommendations; p = 0.011). Limited FHH knowledge was noted among those born in the US and younger participants, representing a key population to reach with intervention efforts. The intervention effect suggests that 'less is more', indicating the potential for too much information to limit health education program effectiveness. © 2016 S. Karger AG, Basel.

Chest compression rate feedback based on transthoracic impedance.

PubMed

González-Otero, Digna M; Ruiz de Gauna, Sofía; Ruiz, Jesus; Daya, Mohamud R; Wik, Lars; Russell, James K; Kramer-Johansen, Jo; Eftestøl, Trygve; Alonso, Erik; Ayala, Unai

2015-08-01

Quality of cardiopulmonary resuscitation (CPR) is an important determinant of survival from cardiac arrest. The use of feedback devices is encouraged by current resuscitation guidelines as it helps rescuers to improve quality of CPR performance. To determine the feasibility of a generic algorithm for feedback related to chest compression (CC) rate using the transthoracic impedance (TTI) signal recorded through the defibrillation pads. We analysed 180 episodes collected equally from three different emergency services, each one using a unique defibrillator model. The new algorithm computed the CC-rate every 2s by analysing the TTI signal in the frequency domain. The obtained CC-rate values were compared with the gold standard, computed using the compression force or the ECG and TTI signals when the force was not recorded. The accuracy of the CC-rate, the proportion of alarms of inadequate CC-rate, chest compression fraction (CCF) and the mean CC-rate per episode were calculated. Intervals with CCs were detected with a mean sensitivity and a mean positive predictive value per episode of 96.3% and 97.0%, respectively. Estimated CC-rate had an error below 10% in 95.8% of the time. Mean percentage of accurate alarms per episode was 98.2%. No statistical differences were found between the gold standard and the estimated values for any of the computed metrics. We developed an accurate algorithm to calculate and provide feedback on CC-rate using the TTI signal. This could be integrated into automated external defibrillators and help improve the quality of CPR in basic-life-support settings. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Relatively slow stochastic gene-state switching in the presence of positive feedback significantly broadens the region of bimodality through stabilizing the uninduced phenotypic state.

PubMed

Ge, Hao; Wu, Pingping; Qian, Hong; Xie, Xiaoliang Sunney

2018-03-01

Within an isogenic population, even in the same extracellular environment, individual cells can exhibit various phenotypic states. The exact role of stochastic gene-state switching regulating the transition among these phenotypic states in a single cell is not fully understood, especially in the presence of positive feedback. Recent high-precision single-cell measurements showed that, at least in bacteria, switching in gene states is slow relative to the typical rates of active transcription and translation. Hence using the lac operon as an archetype, in such a region of operon-state switching, we present a fluctuating-rate model for this classical gene regulation module, incorporating the more realistic operon-state switching mechanism that was recently elucidated. We found that the positive feedback mechanism induces bistability (referred to as deterministic bistability), and that the parameter range for its occurrence is significantly broadened by stochastic operon-state switching. We further show that in the absence of positive feedback, operon-state switching must be extremely slow to trigger bistability by itself. However, in the presence of positive feedback, which stabilizes the induced state, the relatively slow operon-state switching kinetics within the physiological region are sufficient to stabilize the uninduced state, together generating a broadened parameter region of bistability (referred to as stochastic bistability). We illustrate the opposite phenotype-transition rate dependence upon the operon-state switching rates in the two types of bistability, with the aid of a recently proposed rate formula for fluctuating-rate models. The rate formula also predicts a maximal transition rate in the intermediate region of operon-state switching, which is validated by numerical simulations in our model. Overall, our findings suggest a biological function of transcriptional "variations" among genetically identical cells, for the emergence of bistability and transition between phenotypic states.

A cognitive stressor for event-related potential studies: the Portland arithmetic stress task.

PubMed

Atchley, Rachel; Ellingson, Roger; Klee, Daniel; Memmott, Tabatha; Oken, Barry

2017-05-01

In this experiment, we developed and evaluated the Portland Arithmetic Stress Task (PAST) as a cognitive stressor to evaluate acute and sustained stress reactivity for event-related potential (ERP) studies. The PAST is a titrated arithmetic task adapted from the Montreal Imaging Stress Task (MIST), with added experimental control over presentation parameters, improved and synchronized acoustic feedback and generation of timing markers needed for physiological analyzes of real-time brain activity. Thirty-one older adults (M = 60 years) completed the PAST. EEG was recorded to assess feedback-related negativity (FRN) and the magnitude of the stress response through autonomic nervous system activity and salivary cortisol. Physiological measures other than EEG included heart rate, respiration rate, heart rate variability, blood pressure and salivary cortisol. These measures were collected at several time points throughout the task. Feedback-related negativity evoked-potential responses were elicited and they significantly differed depending on whether positive or negative feedback was received. The PAST also increased systolic blood pressure, heart rate variability and respiration rates compared to a control condition attentional task. These preliminary results suggest that the PAST is an effective cognitive stressor. Successful measurement of the feedback-related negativity suggests that the PAST is conducive to EEG and time-sensitive ERP experiments. Moreover, the physiological findings support the PAST as a potent method for inducing stress in older adult participants. Further research is needed to confirm these results, but the PAST shows promise as a tool for cognitive stress induction for time-locked event-related potential experiments.

The Role of Aspirational Experiences and Behaviors in Cultivating Momentum for Transfer Access in STEM: Variations across Gender and Race

ERIC Educational Resources Information Center

Wang, Xueli; Lee, Seo Young; Prevost, Amy

2017-01-01

Objective: Although upward transfer in science, technology, engineering, and mathematics (STEM) fields represents a prominent national policy concern, community college students' aspirations for transfer in STEM are often impeded, resulting in lower transfer rates. This study investigated four aspects of community college STEM students'…

Motor Controller System For Large Dynamic Range of Motor Operation

NASA Technical Reports Server (NTRS)

Howard, David E. (Inventor); Alhorn, Dean C. (Inventor); Smith, Dennis A. (Inventor); Dutton, Kenneth R. (Inventor); Paulson, Mitchell Scott (Inventor)

2006-01-01

A motor controller system uses a rotary sensor with a plurality of signal conditioning units, coupled to the rotary sensor. Each of these units, which is associated with a particular range of motor output shaft rotation rates, generate a feedback signal indicative of the position of the motor s output shaft. A controller (i) converts a selected motor output shaft rotation rate to a corresponding incremental amount of rotational movement for a selected fixed time period, (ii) selects, at periodic completions of the selected fixed time period, the feedback signal from one of the signal conditioning units for which the particular range of motor output shaft rotation rates associated therewith encompasses the selected motor output shaft rotation rate, and (iii) generates a motor drive signal based on a difference between the incremental amount of rotational movement and the feedback signal from the selected one of the signal conditioning Units.

Tuberculosis screening in patients with HIV: use of audit and feedback to improve quality of care in Ghana

PubMed Central

Bjerrum, Stephanie; Bonsu, Frank; Hanson-Nortey, Nii Nortey; Kenu, Ernest; Johansen, Isik Somuncu; Andersen, Aase Bengaard; Bjerrum, Lars; Jarbøl, Dorte; Munck, Anders

2016-01-01

Background Tuberculosis screening of people living with HIV (PLHIV) can contribute to early tuberculosis diagnosis and improved patient outcomes. Evidence-based guidelines for tuberculosis screening are available, but literature assessing their implementation and the quality of clinical practice is scarce. Objectives To assess tuberculosis screening practices and the effectiveness of audit and performance feedback to improve quality of tuberculosis screening at HIV care clinics in Ghana. Design Healthcare providers at 10 large HIV care clinics prospectively registered patient consultations during May and October 2014, before and after a performance feedback intervention in August 2014. The outcomes of interest were overall tuberculosis suspicion rate during consultations and provider adherence to the International Standards for Tuberculosis Care and the World Health Organizations’ guidelines for symptom-based tuberculosis screening among PLHIV. Results Twenty-one healthcare providers registered a total of 2,666 consultations; 1,368 consultations before and 1,298 consultations after the feedback intervention. Tuberculosis suspicion rate during consultation increased from 12.6 to 20.9% after feedback (odds ratio, OR 1.83; 95% confidence interval, CI: 1.09–3.09). Before feedback, sputum smear microscopy was requested for 58.7% of patients with suspected tuberculosis, for 47.2% of patients with cough ≥2 weeks, and for 27.5% of patients with a positive World Health Organization (WHO) symptom screen (any of current cough, fever, weight loss or night sweats). After feedback, patients with a positive WHO symptom screen were more likely to be suspected of tuberculosis (OR 2.21; 95% CI: 1.19–4.09) and referred for microscopy (OR 2.71; 95% CI: 1.25–5.86). Conclusions A simple prospective audit tool identified flaws in clinical practices for tuberculosis screening of PLHIV. There was no systematic identification of people with suspected active tuberculosis. We found low initial tuberculosis suspicion rate compounded by low referral rates of relevant patients for sputum smear microscopy. Adherence to recommended standards and guidelines for tuberculosis screening improved after performance feedback. PMID:27569593

Upward Flame Spread Over Thin Solids in Partial Gravity

NASA Technical Reports Server (NTRS)

Feier, I. I.; Shih, H. Y.; Sacksteder, K. R.; Tien, J. S.

2001-01-01

The effects of partial-gravity, reduced pressure, and sample width on upward flame spread over a thin cellulose fuel were studied experimentally and the results were compared to a numerical flame spread simulation. Fuel samples 1-cm, 2-cm, and 4-cm wide were burned in air at reduced pressures of 0.2 to 0.4 atmospheres in simulated gravity environments of 0.1-G, 0.16-G (Lunar), and 0.38-G (Martian) onboard the NASA KC-135 aircraft and in normal-gravity tests. Observed steady flame propagation speeds and pyrolysis lengths were approximately proportional to the gravity level. Flames spread more quickly and were longer with the wider samples and the variations with gravity and pressure increased with sample width. A numerical simulation of upward flame spread was developed including three-dimensional Navier-Stokes equations, one-step Arrhenius kinetics for the gas phase flame and for the solid surface decomposition, and a fuel-surface radiative loss. The model provides detailed structure of flame temperatures, the flow field interactions with the flame, and the solid fuel mass disappearance. The simulation agrees with experimental flame spread rates and their dependence on gravity level but predicts a wider flammable region than found by experiment. Some unique three-dimensional flame features are demonstrated in the model results.

Early Detection of Online Auction Opportunistic Sellers through the Use of Negative-Positive Feedback

ERIC Educational Resources Information Center

Reinert, Gregory J.

2010-01-01

Apparently fraud is a growth industry. The monetary losses from Internet fraud have increased every year since first officially reported by the Internet Crime Complaint Center (IC3) in 2000. Prior research studies and third-party reports of fraud show rates substantially higher than eBay's reported negative feedback rate of less than 1%. The…

Kiloparsec-scale Simulations of Star Formation in Disk Galaxies. IV. Regulation of Galactic Star Formation Rates by Stellar Feedback

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, Michael J.; Tan, Jonathan C.; Teyssier, Romain

2017-06-01

Star formation from the interstellar medium of galactic disks is a basic process controlling the evolution of galaxies. Understanding the star formation rate (SFR) in a local patch of a disk with a given gas mass is thus an important challenge for theoretical models. Here we simulate a kiloparsec region of a disk, following the evolution of self-gravitating molecular clouds down to subparsec scales, as they form stars that then inject feedback energy by dissociating and ionizing UV photons and supernova explosions. We assess the relative importance of each feedback mechanism. We find that H{sub 2}-dissociating feedback results in themore » largest absolute reduction in star formation compared to the run with no feedback. Subsequently adding photoionization feedback produces a more modest reduction. Our fiducial models that combine all three feedback mechanisms yield, without fine-tuning, SFRs that are in excellent agreement with observations, with H{sub 2}-dissociating photons playing a crucial role. Models that only include supernova feedback—a common method in galaxy evolution simulations—settle to similar SFRs, but with very different temperatures and chemical states of the gas, and with very different spatial distributions of young stars.« less

Modulation of Emotional Appraisal by False Physiological Feedback during fMRI

PubMed Central

Gray, Marcus A.; Harrison, Neil A.; Wiens, Stefan; Critchley, Hugo D.

2007-01-01

Background James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories of emotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions. Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover, anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiological arousal. However, the neural underpinnings of these phenomena previously have not been examined. Methodology/Principal Findings We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and second-order levels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12 participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of true and false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faces was enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behavioural interaction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anterior insula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change in perceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLD activity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at both a group and an individual level. Conclusions/Significance Our findings identify the neural substrates supporting behavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states, including the importance of the right anterior insula in guiding second-order “cognitive” representations of bodily arousal state. PMID:17579718

Interactions of forest disturbance-recovery dynamics with a changing climate

NASA Astrophysics Data System (ADS)

Anderson-Teixeira, K. J.; Miller, A. D.; Tepley, A. J.; Bennett, A. C.; Wang, M.

2015-12-01

As the climate changes, altered disturbance-recovery dynamics in forests worldwide are likely to result in significant biogeochemical and biophysical feedbacks to the climate system. Climate shapes forest disturbance events including tree mortality and fire, with consequent climate feedbacks. For instance, in forests globally, drought increases tree mortality rates, having a stronger impact on larger trees and resulting in greater feedbacks to climate change than would occur if drought sensitivities were equal across tree size classes. Forest regeneration and associated biogeochemical and biophysical feedbacks are also shaped by climate: across the tropics the rate of biomass accumulation is faster in everwet than in seasonally dry climates, and in the Klamath region (N California / S Oregon), post-fire vegetation dynamics and microclimate are shaped by aridity. Forest recovery dynamics will be affected by elevated CO2 and climate change; for instance, models predict that forest regeneration rate, successional dynamics, and climate feedbacks will all be altered under elevated CO2. In combination, climatic impacts on disturbance and recovery can result in dramatic shifts in forest cover on the landscape level. For instance, in fire-prone forested landscapes, forest cover decreases with increasing frequency of high-severity fire and decreasing forest recovery rate, both of which could be altered by climate change, producing rapid loss of forest on the landscape level. Such effects may be amplified by the existence of alternative stable states, which can cause systems to experience non-reversible changes in cover type. Critical transitions in landscape-level forest cover would have significant biogeochemical and biophysical feedbacks. Thus, altered disturbance-recovery dynamics under a changing climate may have sudden and dramatic impacts on forest-climate interactions.

Influence of feedback characteristics on perceived learning value of feedback in clerkships: does culture matter?

PubMed

Suhoyo, Yoyo; Van Hell, Elisabeth A; Kerdijk, Wouter; Emilia, Ova; Schönrock-Adema, Johanna; Kuks, Jan B M; Cohen-Schotanus, Janke

2017-04-05

Various feedback characteristics have been suggested to positively influence student learning. It is not clear how these feedback characteristics contribute to students' perceived learning value of feedback in cultures classified low on the cultural dimension of individualism and high on power distance. This study was conducted to validate the influence of five feedback characteristics on students' perceived learning value of feedback in an Indonesian clerkship context. We asked clerks in Neurology (n = 169) and Internal Medicine (n = 132) to assess on a 5-point Likert scale the learning value of the feedback they received. We asked them to record whether the feedback provider (1) informed the student what went well, (2) mentioned which aspects of performance needed improvement, (3) compared the student's performance to a standard, (4) further explained or demonstrated the correct performance, and (5) prepared an action plan with the student to improve performance. Data were analyzed using multilevel regression. A total of 250 students participated in this study, 131 from Internal Medicine (response rate 99%) and 119 from Neurology (response rate 70%). Of these participants, 225 respondents (44% males, 56% females) completed the form and reported 889 feedback moments. Students perceived feedback as more valuable when the feedback provider mentioned their weaknesses (β = 0.153, p < 0.01), compared their performance to a standard (β = 0.159, p < 0.01), explained or demonstrated the correct performance (β = 0.324, p < 0.001) and prepared an action plan with the student (β =0.496, p < 0.001). Appraisal of good performance did not influence the perceived learning value of feedback. No gender differences were found for perceived learning value. In Indonesia, we could validate four out of the five characteristics for effective feedback. We argue that our findings relate to culture, in particular to the levels of individualism and power distance. The recognized characteristics of what constitutes effective feedback should be validated across cultures.

A comparative study of AGN feedback algorithms

NASA Astrophysics Data System (ADS)

Wurster, J.; Thacker, R. J.

2013-05-01

Modelling active galactic nuclei (AGN) feedback in numerical simulations is both technically and theoretically challenging, with numerous approaches having been published in the literature. We present a study of five distinct approaches to modelling AGN feedback within gravitohydrodynamic simulations of major mergers of Milky Way-sized galaxies. To constrain differences to only be between AGN feedback models, all simulations start from the same initial conditions and use the same star formation algorithm. Most AGN feedback algorithms have five key aspects: the black hole accretion rate, energy feedback rate and method, particle accretion algorithm, black hole advection algorithm and black hole merger algorithm. All models follow different accretion histories, and in some cases, accretion rates differ by up to three orders of magnitude at any given time. We consider models with either thermal or kinetic feedback, with the associated energy deposited locally around the black hole. Each feedback algorithm modifies the region around the black hole to different extents, yielding gas densities and temperatures within r ˜ 200 pc that differ by up to six orders of magnitude at any given time. The particle accretion algorithms usually maintain good agreement between the total mass accreted by dot{M} dt and the total mass of gas particles removed from the simulation, although not all algorithms guarantee this to be true. The black hole advection algorithms dampen inappropriate dragging of the black holes by two-body interactions. Advecting the black hole a limited distance based upon local mass distributions has many desirably properties, such as avoiding large artificial jumps and allowing the possibility of the black hole remaining in a gas void. Lastly, two black holes instantly merge when given criteria are met, and we find a range of merger times for different criteria. This is important since the AGN feedback rate changes across the merger in a way that is dependent on the specific accretion algorithm used. Using the MBH-σ relation as a diagnostic of the remnants yields three models that lie within the one-sigma scatter of the observed relation and two that fall below the expected relation. The wide variation in accretion behaviours of the models reinforces the fact that there remains much to be learnt about the evolution of galactic nuclei.

Control of Adventitious Root Architecture in Rice by Darkness, Light, and Gravity1[OPEN

PubMed Central

2018-01-01

Rice (Oryza sativa) is a semiaquatic plant that is well adapted to partial flooding. Rice stems develop adventitious root (AR) primordia at each node that slowly mature but emerge only when the plant gets flooded, leading to the formation of a whole new secondary root system upon flooding. AR growth is induced by ethylene that accumulates in submerged plant tissues due to its lowered diffusion rate in water. Here, we report that the architecture of the secondary root system in flooded rice plants is controlled not only by altered gas diffusion but also by gravity and light. While ethylene promotes the emergence and growth of ARs, gravity and light determine their gravitropic setpoint angle (i.e. the deviation of growth direction relative to vertical). ARs grow upward at about 120° in the dark and downward at 54° in the light. The upward growth direction is conserved in indica and japonica rice varieties, suggestive of a conserved trait in rice. Experiments with a klinostat and with inverted stem orientation revealed that gravity promotes upward growth by about 10°. Red, far-red, and blue light lead to negative phototropism in a dose-dependent manner, with blue light being most effective, indicating that phytochrome and blue light signaling control AR system architecture. The cpt1 (coleoptile phototropism1) mutant, which lacks one of the phototropin-interacting CPT proteins, shows reduced sensitivity to blue light. Hence, the gravitropic setpoint angle of rice ARs is controlled by genetic and environmental factors that likely balance the need for oxygen supply (upward growth) with avoidance of root desiccation (downward growth). PMID:29242375

Control of Adventitious Root Architecture in Rice by Darkness, Light, and Gravity.

PubMed

Lin, Chen; Sauter, Margret

2018-02-01

Rice ( Oryza sativa ) is a semiaquatic plant that is well adapted to partial flooding. Rice stems develop adventitious root (AR) primordia at each node that slowly mature but emerge only when the plant gets flooded, leading to the formation of a whole new secondary root system upon flooding. AR growth is induced by ethylene that accumulates in submerged plant tissues due to its lowered diffusion rate in water. Here, we report that the architecture of the secondary root system in flooded rice plants is controlled not only by altered gas diffusion but also by gravity and light. While ethylene promotes the emergence and growth of ARs, gravity and light determine their gravitropic setpoint angle (i.e. the deviation of growth direction relative to vertical). ARs grow upward at about 120° in the dark and downward at 54° in the light. The upward growth direction is conserved in indica and japonica rice varieties, suggestive of a conserved trait in rice. Experiments with a klinostat and with inverted stem orientation revealed that gravity promotes upward growth by about 10°. Red, far-red, and blue light lead to negative phototropism in a dose-dependent manner, with blue light being most effective, indicating that phytochrome and blue light signaling control AR system architecture. The cpt1 ( coleoptile phototropism1 ) mutant, which lacks one of the phototropin-interacting CPT proteins, shows reduced sensitivity to blue light. Hence, the gravitropic setpoint angle of rice ARs is controlled by genetic and environmental factors that likely balance the need for oxygen supply (upward growth) with avoidance of root desiccation (downward growth). © 2018 American Society of Plant Biologists. All Rights Reserved.

Global Changes of the Water Cycle Intensity

NASA Technical Reports Server (NTRS)

Bosilovich, Michael G.; Schubert, Siegfried D.; Walker, Gregory K.

2003-01-01

In this study, we evaluate numerical simulations of the twentieth century climate, focusing on the changes in the intensity of the global water cycle. A new diagnostic of atmospheric water vapor cycling rate is developed and employed, that relies on constituent tracers predicted at the model time step. This diagnostic is compared to a simplified traditional calculation of cycling rate, based on monthly averages of precipitation and total water content. The mean sensitivity of both diagnostics to variations in climate forcing is comparable. However, the new diagnostic produces systematically larger values and more variability than the traditional average approach. Climate simulations were performed using SSTs of the early (1902-1921) and late (1979- 1998) twentieth century along with the appropriate C02 forcing. In general, the increase of global precipitation with the increases in SST that occurred between the early and late twentieth century is small. However, an increase of atmospheric temperature leads to a systematic increase in total precipitable water. As a result, the residence time of water in the atmosphere increased, indicating a reduction of the global cycling rate. This result was explored further using a number of 50-year climate simulations from different models forced with observed SST. The anomalies and trends in the cycling rate and hydrologic variables of different GCMs are remarkably similar. The global annual anomalies of precipitation show a significant upward trend related to the upward trend of surface temperature, during the latter half of the twentieth century. While this implies an increase in the hydrologic cycle intensity, a concomitant increase of total precipitable water again leads to a decrease in the calculated global cycling rate. An analysis of the land/sea differences shows that the simulated precipitation over land has a decreasing trend while the oceanic precipitation has an upward trend consistent with previous studies and the available observations. The decreasing continental trend in precipitation is located primarily over tropical land regions, with some other regions, such as North America experiencing an increasing trend. Precipitation trends are diagnosed further using the water tracers to delineate the precipitation that occurs because of continental evaporation, as opposed to oceanic evaporation. These diagnostics show that over global land areas, the recycling of continental moisture is decreasing in time. However, the recycling changes are not spatially uniform so that some regions, most notably over the United States, experience continental recycling of water that increases in time.

Opportunity for information search and the effect of false heart rate feedback.

PubMed

Barefoot, John C; Straub, Ronald B

2005-01-01

The role of information search in the attribution of physiological states was investigated by manipulating the subject's opportunity for information search following the presentation of false information about his heart-rate reactions to photographs of female nudes. Consistent with the self-persuasion hypothesis proposed by Valins, the rated attractiveness of the slides was not affected by the false heart-rate feedback for those subjects who were prevented from visually searching the slides. Those subjects who had ample opportunity to view the slides rated those slides accompanied by false information of a heart-rate change as more attractive than those slides which were not paired with a change in heart rate.

Evaluation of intrinsic and extrinsic motivation interventions with a self-help smoking cessation program.

PubMed

Curry, S J; Wagner, E H; Grothaus, L C

1991-04-01

Personalized feedback and a financial incentive, developed from an intrinsic/extrinsic motivation framework, were evaluated as adjuncts to self-help materials for smoking cessation. Ss (N = 1,217) were randomized to 4 treatment groups and were followed up at 3 and 12 months. Consistent with hypotheses derived from the motivation framework, the financial incentive increased the use of self-help materials, did not increase cessation rates among program users, and was associated with higher relapse rates among those who did manage to quit. The personalized feedback increased both smoking cessation and use of the materials 3 months after distribution of the materials. Continuous abstinence (abstinence at 3 and 12 months) in the group that received the personalized feedback alone was twice the rate of the other groups.

Feedbacks stablizing wetland geometry on a pattened landscape

NASA Astrophysics Data System (ADS)

Dong, X.; Heffernan, J. B.; Murray, A. B.

2017-12-01

Karst morphology is highly varied across different climatic and geologic regions of the world. Big Cypress National Preserve in SW Florida, features regularly distributed wetland depressions, located on exposed limestone bedrock. In this study, we explored the development of wetland depressions over the past 10kyrs of landscape formation. Specifically, we are interested in (1) whether the wetland depressions on the landscape have reached equilibrium size, and (2) if so, what are feedback mechanisms that contributed to stabilizing these depressions. We hypothesized three stabilizing feedback mechanisms. HYP1: increased size of depressions reduces landscape hydrological connectivity, which resulted in reduced landscape capacity to export dissolution products, hence lower weathering rate. HYP2: expansion of depression area increases tree biomass within the depression, which increased average evapotranspiration (ET) within the dome. The greater difference of ET rate between depression and upland leads to a lower water table in the depression. As a result, more subsurface water, carrying dissolved calcium, flows from catchment to depression. With lower export capacity and more calcium moving into the depression zones, rate of calcite precipitation increases, which lowers net weathering rate. HYP3: increasingly thicker sediment cover in the wetland depression over time decreases chemical transport capacity. This lowers both transport of CO2 from shallower soil to bedrock and transport of dissolution products from bedrock to surface. Both of these processes reduce bedrock-weathering rate. We built a 3-D numerical simulation model that partitioned the relative importance of different mechanisms. Preliminary results show that (1) there is an equilibrium size for wetland depressions for both radius and depth dimension; (2) current depressions are formed by coalescence of several nearby small depressions during development; (3) the soil cover feedback (HYP3) is the major feedback stabilizing depth of depressions, while reduced landscape connectivity (HYP1) and increased local exchange of dissolved calcium caused by differential ET between catchment and depression (HYP2) is the major radius stabilizing feedback.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darghouth, Naïm R.; Wiser, Ryan; Barbose, Galen

The substantial increase in deployment of customer-sited solar photovoltaics (PV) in the United States has been driven by a combination of steeply declining costs, financing innovations, and supportive policies. Among those supportive policies is net metering, which in most states effectively allows customers to receive compensation for distributed PV generation at the full retail electricity price. The current design of retail electricity rates and the presence of net metering have elicited concerns that the possible under-recovery of fixed utility costs from PV system owners may lead to a feedback loop of increasing retail prices that accelerate PV adoption and furthermore » rate increases. However, a separate and opposing feedback loop could offset this effect: increased PV deployment may lead to a shift in the timing of peak-period electricity prices that could reduce the bill savings received under net metering where time-varying retail electricity rates are used, thereby dampening further PV adoption. In this paper, we examine the impacts of these two competing feedback dynamics on U.S. distributed PV deployment through 2050 for both residential and commercial customers, across states. Our results indicate that, at the aggregate national level, the two feedback effects nearly offset one another and therefore produce a modest net effect, although their magnitude and direction vary by customer segment and by state. We also model aggregate PV deployment trends under various rate designs and net-metering rules, accounting for feedback dynamics. Our results demonstrate that future adoption of distributed PV is highly sensitive to retail rate structures. Whereas flat, time-invariant rates with net metering lead to higher aggregate national deployment levels than the current mix of rate structures (+5% in 2050), rate structures with higher monthly fixed customer charges or PV compensation at levels lower than the full retail rate can dramatically erode aggregate customer adoption of PV (from -14% to -61%, depending on the design). Moving towards time-varying rates, on the other hand, may accelerate near- and medium-term deployment (through 2030), but is found to slow adoption in the longer term (-22% in 2050).« less

Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres

NASA Technical Reports Server (NTRS)

Stoltzfus, Joel M.; Jeffers, Nathan; Gallus, Timothy D.

2012-01-01

The flammability in oxygen-enriched atmospheres of commercially pure (CP) titanium rods as a function of diameter and test gas pressure was determined. Test samples of varying diameters were ignited at the bottom and burned upward in 70% O2/balance N2 and in 99.5+% O2 at various pressures. The burning rate of each ignited sample was determined by observing the apparent regression rate of the melting interface (RRMI) of the burning samples. The burning rate or RRMI increased with decreasing test sample diameter and with increasing test gas pressure and oxygen concentration

Integrated optical sensor

DOEpatents

Watkins, Arthur D.; Smartt, Herschel B.; Taylor, Paul L.

1994-01-01

An integrated optical sensor for arc welding having multifunction feedback control. The sensor, comprising generally a CCD camera and diode laser, is positioned behind the arc torch for measuring weld pool position and width, standoff distance, and post-weld centerline cooling rate. Computer process information from this sensor is passed to a controlling computer for use in feedback control loops to aid in the control of the welding process. Weld pool position and width are used in a feedback loop, by the weld controller, to track the weld pool relative to the weld joint. Sensor standoff distance is used in a feedback loop to control the contact tip to base metal distance during the welding process. Cooling rate information is used to determine the final metallurgical state of the weld bead and heat affected zone, thereby controlling post-weld mechanical properties.

Integrated optical sensor

DOEpatents

Watkins, A.D.; Smartt, H.B.; Taylor, P.L.

1994-01-04

An integrated optical sensor for arc welding having multifunction feedback control is described. The sensor, comprising generally a CCD camera and diode laser, is positioned behind the arc torch for measuring weld pool position and width, standoff distance, and post-weld centerline cooling rate. Computer process information from this sensor is passed to a controlling computer for use in feedback control loops to aid in the control of the welding process. Weld pool position and width are used in a feedback loop, by the weld controller, to track the weld pool relative to the weld joint. Sensor standoff distance is used in a feedback loop to control the contact tip to base metal distance during the welding process. Cooling rate information is used to determine the final metallurgical state of the weld bead and heat affected zone, thereby controlling post-weld mechanical properties. 6 figures.

Return of spontaneous circulation and long-term survival according to feedback provided by automated external defibrillators.

PubMed

Agerskov, M; Hansen, M B; Nielsen, A M; Møller, T P; Wissenberg, M; Rasmussen, L S

2017-11-01

We aimed to investigate the effect of automated external defibrillator (AED) feedback mechanisms on survival in out-of-hospital cardiac arrest (OHCA) victims. In addition, we investigated converting rates in patients with shockable rhythms according to AED shock waveforms and energy levels. We collected data on OHCA occurring between 2011 and 2014 in the Capital Region of Denmark where an AED was applied prior to ambulance arrival. Patient data were obtained from the Danish Cardiac Arrest Registry and medical records. AED data were retrieved from the Emergency Medical Dispatch Centre (EMDC) and information on feedback mechanisms, energy waveform and energy level was downloaded from the applied AEDs. A total of 196 OHCAs had an AED applied prior to ambulance arrival; 62 of these (32%) provided audio visual (AV) feedback while no feedback was provided in 134 (68%). We found no difference in return of spontaneous circulation (ROSC) at hospital arrival according to AV-feedback; 34 (55%, 95% confidence interval (CI) [13-67]) vs. 72 (54%, 95% CI [45-62]), P = 1 (odds ratio (OR) 1.1, 95% CI [0.6-1.9]) or 30-day survival; 24 (39%, 95% CI [28-51]) vs. 53 (40%, 95% CI [32-49]), P = 0.88 (OR 1.1 (95% CI [0.6-2.0])). Moreover, we found no difference in converting rates among patients with initial shockable rhythm receiving one or more shocks according to AED energy waveform and energy level. No difference in survival after OHCA according to AED feedback mechanisms, nor any difference in converting rates according to AED waveform or energy levels was detected. © 2017 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.

Sound-Intensity Feedback During Running Reduces Loading Rates and Impact Peak.

PubMed

Tate, Jeremiah J; Milner, Clare E

2017-08-01

Study Design Controlled laboratory study, within-session design. Background Gait retraining has been proposed as an effective intervention to reduce impact loading in runners at risk of stress fractures. Interventions that can be easily implemented in the clinic are needed. Objective To assess the immediate effects of sound-intensity feedback related to impact during running on vertical impact peak, peak vertical instantaneous loading rate, and vertical average loading rate. Methods Fourteen healthy, college-aged runners who ran at least 9.7 km/wk participated (4 male, 10 female; mean ± SD age, 23.7 ± 2.0 years; height, 1.67 ± 0.08 m; mass, 60.9 ± 8.7 kg). A decibel meter provided real-time sound-intensity feedback of treadmill running via an iPad application. Participants were asked to reduce the sound intensity of running while receiving continuous feedback for 15 minutes, while running at their self-selected preferred speed. Baseline and follow-up ground reaction force data were collected during overground running at participants' self-selected preferred running speed. Results Dependent t tests indicated a statistically significant reduction in vertical impact peak (1.56 BW to 1.13 BW, P≤.001), vertical instantaneous loading rate (95.48 BW/s to 62.79 BW/s, P = .001), and vertical average loading rate (69.09 BW/s to 43.91 BW/s, P≤.001) after gait retraining, compared to baseline. Conclusion The results of the current study support the use of sound-intensity feedback during treadmill running to immediately reduce loading rate and impact force. The transfer of within-session reductions in impact peak and loading rates to overground running was demonstrated. Decreases in loading were of comparable magnitude to those observed in other gait retraining methods. J Orthop Sports Phys Ther 2017;47(8):565-569. Epub 6 Jul 2017. doi:10.2519/jospt.2017.7275.

Feedback Seeking in Early Adolescence: Self-Enhancement or Self-Verification?

PubMed

Rosen, Lisa H; Principe, Connor P; Langlois, Judith H

2013-02-13

The authors examined whether early adolescents ( N = 90) solicit self-enhancing feedback (i.e., positive feedback) or self-verifying feedback (i.e., feedback congruent with self-views, even when these views are negative). Sixth, seventh, and eighth graders first completed a self-perception measure and then selected whether to receive positive or negative feedback from an unknown peer in different domains of self. Results were consistent with self-verification theory; adolescents who perceived themselves as having both strengths and weaknesses were more likely to seek negative feedback regarding a self-perceived weakness compared to a self-perceived strength. The authors found similar support for self-verification processes when they considered the entire sample regardless of perceived strengths and weaknesses; hierarchical linear modeling (HLM) examined the predictive power of ratings of self-perceived ability, certainty, and importance on feedback seeking for all participants and provided additional evidence of self-verification strivings in adolescence.

Feedback Seeking in Early Adolescence: Self-Enhancement or Self-Verification?

PubMed Central

Rosen, Lisa H.; Principe, Connor P.; Langlois, Judith H.

2012-01-01

The authors examined whether early adolescents (N = 90) solicit self-enhancing feedback (i.e., positive feedback) or self-verifying feedback (i.e., feedback congruent with self-views, even when these views are negative). Sixth, seventh, and eighth graders first completed a self-perception measure and then selected whether to receive positive or negative feedback from an unknown peer in different domains of self. Results were consistent with self-verification theory; adolescents who perceived themselves as having both strengths and weaknesses were more likely to seek negative feedback regarding a self-perceived weakness compared to a self-perceived strength. The authors found similar support for self-verification processes when they considered the entire sample regardless of perceived strengths and weaknesses; hierarchical linear modeling (HLM) examined the predictive power of ratings of self-perceived ability, certainty, and importance on feedback seeking for all participants and provided additional evidence of self-verification strivings in adolescence. PMID:23543746

360 Degrees feedback for emergency physicians in Singapore.

PubMed

Tham, Kum-Ying

2007-08-01

To determine if emergency physicians (EPs) are ready to accept 360 degrees feedback, and agreement between self and colleagues' assessment in a 360 degrees feedback for EPs. Self-administered questionnaire to determine acceptability of 360 degrees feedback (n = 43). Each EP completed the Physician Achievement Review self-assessment and approached five colleagues to complete an assessment for him/her. Thirty-one responded: 77.4% preferred to select their appraisers, 90.3% wanted feedback to be confidential, 58.1% would share feedback with supervisors, but only 35.5% would link feedback to remuneration. Colleagues rated EPs' holistic management, humanistic aspects and patient communication, and professional relationship with colleagues as weak domains, weaknesses which EPs were only partially aware. EPs would accept 360 degrees feedback provided that they selected their appraisers and results were confidential. Colleagues reported that EPs were weak in "soft" and system skills.

360° feedback for emergency physicians in Singapore

PubMed Central

Tham, Kum‐Ying

2007-01-01

Objectives To determine if emergency physicians (EPs) are ready to accept 360° feedback, and agreement between self and colleagues' assessment in a 360° feedback for EPs. Methods Self‐administered questionnaire to determine acceptability of 360° feedback (n = 43). Each EP completed the Physician Achievement Review self‐assessment and approached five colleagues to complete an assessment for him/her. Results Thirty‐one responded: 77.4% preferred to select their appraisers, 90.3% wanted feedback to be confidential, 58.1% would share feedback with supervisors, but only 35.5% would link feedback to remuneration. Colleagues rated EPs' holistic management, humanistic aspects and patient communication, and professional relationship with colleagues as weak domains, weaknesses which EPs were only partially aware. Conclusions EPs would accept 360° feedback provided that they selected their appraisers and results were confidential. Colleagues reported that EPs were weak in “soft” and system skills. PMID:17652683

An Extension to the Constructivist Coding Hypothesis as a Learning Model for Selective Feedback when the Base Rate Is High

ERIC Educational Resources Information Center

Ghaffarzadegan, Navid; Stewart, Thomas R.

2011-01-01

Elwin, Juslin, Olsson, and Enkvist (2007) and Henriksson, Elwin, and Juslin (2010) offered the constructivist coding hypothesis to describe how people code the outcomes of their decisions when availability of feedback is conditional on the decision. They provided empirical evidence only for the 0.5 base rate condition. This commentary argues that…

Testing Quick Response (QR) Codes as an Innovation to Improve Feedback Among Geographically-Separated Clerkship Sites.

PubMed

Snyder, Matthew J; Nguyen, Dana R; Womack, Jasmyne J; Bunt, Christopher W; Westerfield, Katie L; Bell, Adriane E; Ledford, Christy J W

2018-03-01

Collection of feedback regarding medical student clinical experiences for formative or summative purposes remains a challenge across clinical settings. The purpose of this study was to determine whether the use of a quick response (QR) code-linked online feedback form improves the frequency and efficiency of rater feedback. In 2016, we compared paper-based feedback forms, an online feedback form, and a QR code-linked online feedback form at 15 family medicine clerkship sites across the United States. Outcome measures included usability, number of feedback submissions per student, number of unique raters providing feedback, and timeliness of feedback provided to the clerkship director. The feedback method was significantly associated with usability, with QR code scoring the highest, and paper second. Accessing feedback via QR code was associated with the shortest time to prepare feedback. Across four rotations, separate repeated measures analyses of variance showed no effect of feedback system on the number of submissions per student or the number of unique raters. The results of this study demonstrate that preceptors in the family medicine clerkship rate QR code-linked feedback as a high usability platform. Additionally, this platform resulted in faster form completion than paper or online forms. An overarching finding of this study is that feedback forms must be portable and easily accessible. Potential implementation barriers and the social norm for providing feedback in this manner need to be considered.

Real-time feedback can improve infant manikin cardiopulmonary resuscitation by up to 79%--a randomised controlled trial.

PubMed

Martin, Philip; Theobald, Peter; Kemp, Alison; Maguire, Sabine; Maconochie, Ian; Jones, Michael

2013-08-01

European and Advanced Paediatric Life Support training courses. Sixty-nine certified CPR providers. CPR providers were randomly allocated to a 'no-feedback' or 'feedback' group, performing two-thumb and two-finger chest compressions on a "physiological", instrumented resuscitation manikin. Baseline data was recorded without feedback, before chest compressions were repeated with one group receiving feedback. Indices were calculated that defined chest compression quality, based upon comparison of the chest wall displacement to the targets of four, internationally recommended parameters: chest compression depth, release force, chest compression rate and compression duty cycle. Baseline data were consistent with other studies, with <1% of chest compressions performed by providers simultaneously achieving the target of the four internationally recommended parameters. During the 'experimental' phase, 34 CPR providers benefitted from the provision of 'real-time' feedback which, on analysis, coincided with a statistical improvement in compression rate, depth and duty cycle quality across both compression techniques (all measures: p<0.001). Feedback enabled providers to simultaneously achieve the four targets in 75% (two-finger) and 80% (two-thumb) of chest compressions. Real-time feedback produced a dramatic increase in the quality of chest compression (i.e. from <1% to 75-80%). If these results transfer to a clinical scenario this technology could, for the first time, support providers in consistently performing accurate chest compressions during infant CPR and thus potentially improving clinical outcomes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Genesis and shape of natural solution cavities within salt deposits

NASA Astrophysics Data System (ADS)

Gechter, Daniel; Huggenberger, Peter; Ackerer, Philippe; Waber, H. Niklaus

2008-11-01

Since the genesis and shape of natural deep-seated cavities within a salt body are insufficiently understood, the current study tries to shed some light on this topic. To this end, freshwater was pumped slowly through a horizontal borehole in rock salt cores. Owing to fast halite dissolution kinetics, high solubility, and slow inflow rate, halite dissolution took place only in the inflow of the rock salt cylinder. The shape of the created cavities is an approximately symmetrical half cone with a horizontal base facing upward. A conceptual model is presented that is inspired by the experimental results and based on theoretical hydraulic-geochemical considerations, as well as on field observations. It proposes that triangular prism or conically shaped cavities develop within salt under confined conditions, where aggressive water flows upward along a fracture/conduit from an insoluble aquifer into the soluble stratum. Such cavity enlargements may cause land subsidence and structure collapse.

Evidence for ion heat flux in the light ion polar wind

NASA Technical Reports Server (NTRS)

Biddle, A. P.; Moore, T. E.; Chappell, C. R.

1985-01-01

Cold flowing hydrogen and helium ions have been observed using the retarding ion mass spectrometer on board the Dynamics Explorer 1 spacecraft in the dayside magnetosphere at subauroral latitudes. The ions show a marked flux asymmetry with respect to the relative wind direction. The observed data are fitted by a model of drifting Maxwellian distributions perturbed by a first order-Spritzer-Haerm heat flux distribution function. It is shown that both ion species are supersonic just equatorward of the auroral zone at L = 14, and the shape of asymmetry and direction of the asymmetry are consistent with the presence of an upward heat flux. At L = 6, both species evolve smoothly into warmer subsonic upward flows with downward heat fluxes. In the case of subsonic flows the downward heat flux implies a significant heat source at higher altitudes. Spin curves of the spectrometer count rate versus the spin phase angle are provided.

Laminar Premixed and Diffusion Flames (Ground-Based Study)

NASA Technical Reports Server (NTRS)

Dai, Z.; El-Leathy, A. M.; Lin, K.-C.; Sunderland, P. B.; Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

2000-01-01

Ground-based studies of soot processes in laminar flames proceeded in two phases, considering laminar premixed flames and laminar diffusion flames, in turn. The test arrangement for laminar premixed flames involved round flat flame burners directed vertically upward at atmospheric pressure. The test arrangement for laminar jet diffusion flames involved a round fuel port directed vertically upward with various hydrocarbon fuels burning at atmospheric pressure in air. In both cases, coflow was used to prevent flame oscillations and measurements were limited to the flame axes. The measurements were sufficient to resolve soot nucleation, growth and oxidation rates, as well as the properties of the environment needed to evaluate mechanisms of these processes. The experimental methods used were also designed to maintain capabilities for experimental methods used in corresponding space-based experiments. This section of the report will be limited to consideration of flame structure for both premixed and diffusion flames.

An experimental study of the transient regime to fluidized chimney in a granular medium

NASA Astrophysics Data System (ADS)

Philippe, Pierre; Mena, Sarah; Brunier-Coulin, Florian; Curtis, Jennifer

2017-06-01

Localized fluidization within a granular packing along an almost cylindrical chimney is observed when an upward fluid-flow, injected through a small port diameter, exceeds a critical flow-rate. Once this threshold reached, a fluidized area is first initiated in the close vicinity of the injection hole before gradually growing upward to the top surface of the granular layer. In this work, we present an experimental investigation specifically dedicated to the kinetics of chimney fluidization in an immersed granular bed. Two different transient regimes are identified depending on wether the expansion of the fluidized area is rather fast and regular, reaching the final chimney state typically in less than 10 seconds, or, on the contrary, slow and very progressively accelerated, giving rise to transient duration up to 1 hour or even more. Some systematic investigations allow to propose several empirical scaling relations for the kinetics of chimney fluidization in the fast regular regime.

34 CFR 645.13 - How are regular Upward Bound projects organized?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Regular Upward Bound projects— (1) Must provide participants with a summer instructional component that is...) May provide a summer bridge component to those Upward Bound participants who have graduated from... summer bridge component provides participants with services and activities, including college courses...

34 CFR 645.13 - How are regular Upward Bound projects organized?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Regular Upward Bound projects— (1) Must provide participants with a summer instructional component that is...) May provide a summer bridge component to those Upward Bound participants who have graduated from... summer bridge component provides participants with services and activities, including college courses...

Provider Communication, Prompts, and Feedback to Improve HPV Vaccination Rates in Resident Clinics.

PubMed

Rand, Cynthia M; Schaffer, Stanley J; Dhepyasuwan, Nui; Blumkin, Aaron; Albertin, Christina; Serwint, Janet R; Darden, Paul M; Humiston, Sharon G; Mann, Keith J; Stratbucker, William; Szilagyi, Peter G

2018-04-01

Human papillomavirus (HPV) vaccination rates lag behind vaccination rates for other adolescent vaccines; a bundled intervention may improve HPV vaccination rates. Our objective is to evaluate the impact of quality improvement (QI) training plus a bundled practice-based intervention (provider prompts plus communication skills training plus performance feedback) on improving HPV vaccinations in pediatric resident continuity clinics. Staff and providers in 8 resident clinics participated in a 12-month QI study. The intervention included training to strengthen provider communication about the HPV vaccine. Clinics also implemented provider prompts, received monthly performance feedback, and participated in learning collaborative calls. The primary outcome measure was eligible visits with vaccination divided by vaccine-eligible visits (captured HPV vaccination opportunities). Practices performed chart audits that were fed into monthly performance feedback on captured HPV vaccination opportunities. We used conditional logistic regression (conditioning on practice) to assess captured vaccination opportunities, with the time period of the study (before and after the QI intervention) as the independent variable. Overall, captured opportunities for HPV vaccination increased by 16.4 percentage points, from 46.9% to 63.3%. Special cause was demonstrated by centerline shift, with 8 consecutive points above the preintervention mean. On adjusted analyses, patients were more likely to receive a vaccine during, versus before, the intervention (odds ratio: 1.87; 95% confidence interval: 1.54-2.28). Captured HPV vaccination rates improved at both well-child and other visits (by 11.7 and 13.0 percentage points, respectively). A bundled intervention of provider prompts and training in communication skills plus performance feedback increased captured opportunities for HPV vaccination. Copyright © 2018 by the American Academy of Pediatrics.

What you don’t know…: Improving family health history knowledge among multigenerational Mexican origin families

PubMed Central

Goergen, Andrea F.; Ashida, Sato; Skapinsky, Kaley; de Heer, Hendrik D.; Wilkinson, Anna V.; Koehly, Laura M.

2016-01-01

Background This study investigated diabetes (DB) and heart disease (HD) family health history (FHH) knowledge and changes following provision of personalized disease risk feedback. Methods 497 adults from 162 Mexican-origin families were randomized by household to conditions based on feedback recipient and content. Each provided personal and relatives’ DB and HD diagnoses and received feedback materials following baseline assessment. Multivariate models were fitted to identify factors associated with the rate of “don’t know” FHH responses. Results At baseline U.S. nativity was associated with a higher “don’t know” response rate (p=0.002). Though confounded by country of birth, younger age showed a trend toward higher “don’t know” response rates. Overall, average “don’t know” response rates dropped from 20% to 15% following receipt of feedback (p<0.001). An intervention effect was noted, as “don’t know” response rates decreased more in households where one family member (vs all) received supplementary risk assessments (without behavioral recommendations) (p=0.011). Conclusions Limited FHH knowledge was noted among those born in the US and younger participants, representing a key population to reach with intervention efforts. The intervention effect suggests that “less is more” indicating the potential for too much information to limit health education program effectiveness. PMID:26854931

A Rating System for the Concrete in Navigation Lock Monoliths. Repair, Evaluation, Maintenance, and Rehabilitation Research Program

DTIC Science & Technology

1989-05-01

surface of concrete, shaped like an icicle. A.2.14. Stalagmite : As stalactite , but upward formation. ITU A.2.15. Dusting: The development of a pow...area: Area of concrete suir- 4 face which gives off a hollow sound when struck. A.2.13. Stalactite : A downward pointing for- mation, hanging from the

Evidence for Magnetic Reconnection in Three Homologous Solar Flares Observed by RHESSI

NASA Technical Reports Server (NTRS)

Sui, Lin-Hui; Holman, Gordon D.; Dennis, Brian R.

2004-01-01

We present RHESSI observF5oss of three homologous flares, which occurred between April 14 and 16, 2002. We find that the RHESSI images of all three flares at energies between 6 and 25 keV had some common features: (1) A. separate coronal source up to approx. 30 deg. above the flare loop appeared in the early impulsive phase and stayed stationary for several minutes. (2) Before the flare loop moved upward; previously reported by others, the flare loop-top centroid moved downward for 2-4 minutes during the early impulsive phase of the Ears: falling by 13 - 30% of its initial height with a speed between 8 and 23 km/s. We conclude that these features are associated with the formation and development of a current sheet between the loop-top and the coronal source. In the April 14-15 flare, we find that the hard X-ray flux (greater than 25 keV) is correlated with the rate at which the flare loop moves upward, indicating that the faster the loop grows, the faster the reconnection rate, and therefore, the greater the flux of accelerated electrons. Subject headings: Sun: L'iaies-Sun: X-1-ay-s -

The Role of Counterfactual Thinking on Attitudes Toward ADHD Medication Use.

PubMed

Ramos, Ashley M; Becker, Brittney; Biemer, Julie A; Clark, Lindsay; Fields, Sherecce; Smallman, Rachel

2016-01-01

Despite serious health risks, attitudes toward Attention-Deficit Hyperactivity Disorder (ADHD) medication use in college students remain favorable. Given the robust link between attitudes and behavior (e.g., the Theory of Planned Behavior), it is important to understand how these attitudes are developed and maintained. The current study examined the role of counterfactual, or "what if'" thinking as a mechanism for the development of attitudes toward ADHD medications. All participants (n = 190) were asked to read either a positive or negative scenario regarding ADHD medication misuse and rate their attitudes toward the behavior; half of the participants were also asked to generate counterfactuals prior to rating their attitudes. Results suggest that scenario valence influenced the direction of counterfactual statements. Further, through the generation of upward counterfactuals, the negative scenario elicited more positive attitudes toward ADHD medication misuse. Based on limited prior research, it is suggested that upward counterfactuals may allow individuals to explain away the misuse of ADHD medication and avoid negative emotions such as guilt and shame related to current or prior ADHD medication misuse. In sum, additional research is needed to confirm preliminary findings that suggest counterfactual thinking could be a precursor to ADHD medication misuse.

Changes in age patterns of suicide in Australia, the United States, Japan and Hong Kong.

PubMed

Snowdon, John; Phillips, Julie; Zhong, Baoliang; Yamauchi, Takashi; Chiu, Helen F K; Conwell, Yeates

2017-03-15

The patterns of association between age and suicide rate vary by country, subpopulation and gender, and over time. To shed light on factors associated with these differences, we analysed suicide data from four populations, two 'Western' (Australia, the United States [US]) and two Asian (Japan and Hong Kong). We computed suicide rates in five-year age-groups (between 10 and 14 years and 85+ years) for men and women separately, and present graphical representations of the age patterns during selected five-year periods. Rates and age patterns differed markedly, as did gender patterns except in Hong Kong. In 1964-8, male suicide rates in Australia and US were represented by upward-sloping graphs, whereas in Japan the pattern was bimodal. By 1979-83, male patterns in Australia and US were bimodal, but Japan's was trimodal, including a middle-age peak reached in 1994-98. In contrast, female age patterns in the Western countries were shallowly convex or uniform, while in Hong Kong and Japan the upward-sloping graphs became, over time, less steep; by 2009-13, the pattern in Japan was uniform (flat). In recent decades, suicide rates of older men in Australia, US and Japan, and older women in Japan and Hong Kong, have fallen considerably. Suicide rates of men aged 45-64 in Australia and US also fell, though by 2009-13 the US rate had risen again. The suicide rate of Australian men in their twenties halved between 1994-98 and 2009-13, while rates for younger men and women in Japan have risen since 1994-98. In Hong Kong, suicide rates of young men have increased. Age patterns of suicide likely reflect period and cohort effects shaped by socioeconomic stressors, availability of health and welfare services, access to lethal methods of suicide, and other factors. Greater understanding of their impact on age patterns of suicide can result in potential preventive solutions. Copyright © 2017 Elsevier B.V. All rights reserved.

Mass flow rate measurements in gas-liquid flows by means of a venturi or orifice plate coupled to a void fraction sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira, Jorge Luiz Goes; Passos, Julio Cesar; Verschaeren, Ruud

Two-phase flow measurements were carried out using a resistive void fraction meter coupled to a venturi or orifice plate. The measurement system used to estimate the liquid and gas mass flow rates was evaluated using an air-water experimental facility. Experiments included upward vertical and horizontal flow, annular, bubbly, churn and slug patterns, void fraction ranging from 2% to 85%, water flow rate up to 4000 kg/h, air flow rate up to 50 kg/h, and quality up to almost 10%. The fractional root mean square (RMS) deviation of the two-phase mass flow rate in upward vertical flow through a venturi platemore » is 6.8% using the correlation of Chisholm (D. Chisholm, Pressure gradients during the flow of incompressible two-phase mixtures through pipes, venturis and orifice plates, British Chemical Engineering 12 (9) (1967) 454-457). For the orifice plate, the RMS deviation of the vertical flow is 5.5% using the correlation of Zhang et al. (H.J. Zhang, W.T. Yue, Z.Y. Huang, Investigation of oil-air two-phase mass flow rate measurement using venturi and void fraction sensor, Journal of Zhejiang University Science 6A (6) (2005) 601-606). The results show that the flow direction has no significant influence on the meters in relation to the pressure drop in the experimental operation range. Quality and slip ratio analyses were also performed. The results show a mean slip ratio lower than 1.1, when bubbly and slug flow patterns are encountered for mean void fractions lower than 70%. (author)« less

Mortality from idiopathic pulmonary fibrosis: a temporal trend analysis in Brazil, 1979-2014

PubMed Central

Algranti, Eduardo; Saito, Cézar Akiyoshi; Silva, Diego Rodrigues Mendonça e; Carneiro, Ana Paula Scalia; Bussacos, Marco Antonio

2017-01-01

ABSTRACT Objective: To analyze mortality from idiopathic pulmonary fibrosis (IPF) in Brazil over the period 1979-2014. Methods: Microdata were extracted from the Brazilian National Ministry of Health Mortality Database. Only deaths for which the underlying cause was coded as International Classification of Diseases version 9 (ICD-9) 515 or 516.3 (until 1995) or as ICD version 10 (ICD-10) J84.1 (from 1996 onward) were included in our analysis. Standardized mortality rates were calculated for the 2010 Brazilian population. The annual trend in mortality rates was analyzed by joinpoint regression. We calculated risk ratios (RRs) by age group, time period of death, and gender, using a person-years denominator. Results: A total of 32,092 deaths were recorded in the study period. Standardized mortality rates trended upward, rising from 0.24/100,000 population in 1979 to 1.10/100,000 population in 2014. The annual upward trend in mortality rates had two inflection points, in 1992 and 2008, separating three distinct time segments with an annual growth of 2.2%, 6.8%, and 2.4%, respectively. The comparison of RRs for the age groups, using the 50- to 54-year age group as a reference, and for the study period, using 1979-1984 as a reference, were 16.14 (14.44-16.36) and 6.71 (6.34-7.12), respectively. Men compared with women had higher standardized mortality rates (per 100,000 person-years) in all age groups. Conclusion: Brazilian IPF mortality rates are lower than those of other countries, suggesting underdiagnosis or underreporting. The temporal trend is similar to those reported in the literature and is not explained solely by population aging. PMID:29340493

Upward trend in vehicle-miles resumed during 2009 : a time series analysis

DOT National Transportation Integrated Search

2010-04-01

After a 2-year interruption to a long-term upward trend, the : number of vehicle-miles traveled (VMT) on the Nations highways : appears to have resumed a pattern of upward growth in : 2009. While VMT rises and falls seasonally, the years 2007 : an...

A Randomized Control Trial of Cardiopulmonary Feedback Devices and Their Impact on Infant Chest Compression Quality: A Simulation Study.

PubMed

Austin, Andrea L; Spalding, Carmen N; Landa, Katrina N; Myer, Brian R; Donald, Cure; Smith, Jason E; Platt, Gerald; King, Heather C

2017-10-27

In effort to improve chest compression quality among health care providers, numerous feedback devices have been developed. Few studies, however, have focused on the use of cardiopulmonary resuscitation feedback devices for infants and children. This study evaluated the quality of chest compressions with standard team-leader coaching, a metronome (MetroTimer by ONYX Apps), and visual feedback (SkillGuide Cardiopulmonary Feedback Device) during simulated infant cardiopulmonary resuscitation. Seventy voluntary health care providers who had recently completed Pediatric Advanced Life Support or Basic Life Support courses were randomized to perform simulated infant cardiopulmonary resuscitation into 1 of 3 groups: team-leader coaching alone (control), coaching plus metronome, or coaching plus SkillGuide for 2 minutes continuously. Rate, depth, and frequency of complete recoil during cardiopulmonary resuscitation were recorded by the Laerdal SimPad device for each participant. American Heart Association-approved compression techniques were randomized to either 2-finger or encircling thumbs. The metronome was associated with more ideal compression rate than visual feedback or coaching alone (104/min vs 112/min and 113/min; P = 0.003, 0.019). Visual feedback was associated with more ideal depth than auditory (41 mm vs 38.9; P = 0.03). There were no significant differences in complete recoil between groups. Secondary outcomes of compression technique revealed a difference of 1 mm. Subgroup analysis of male versus female showed no difference in mean number of compressions (221.76 vs 219.79; P = 0.72), mean compression depth (40.47 vs 39.25; P = 0.09), or rate of complete release (70.27% vs 64.96%; P = 0.54). In the adult literature, feedback devices often show an increase in quality of chest compressions. Although more studies are needed, this study did not demonstrate a clinically significant improvement in chest compressions with the addition of a metronome or visual feedback device, no clinically significant difference in Pediatric Advanced Life Support-approved compression technique, and no difference between compression quality between genders.

The effect of feedback-assisted reduction in heart rate reactivity on videogame performance.

PubMed

Larkin, K T; Manuck, S B; Kasprowicz, A L

1990-12-01

In 67 male volunteers, we examined the reduction of cardiovascular responsivity to a psychomotor challenge (videogame) achieved by use of heart rate (HR) feedback and effects of these procedures on concomitant behavioral performance. Each subject participated in a pretraining assessment of his cardiovascular responses to the videogame, a training condition, and a posttraining assessment identical to the initial evaluation. During training, subjects were assigned to one of four conditions: (a) a habituation control group receiving no instructions to alter HR (HC); (b) an instructions-only control group receiving instructions to maintain a low or unchanged HR during videogame presentations (IC); (c) a feedback group receiving instructions to reduce HR using ongoing HR feedback (FB-); or (d) a feedback group receiving instructions to lower HR and given HR feedback plus a score contingency in which total game score was jointly determined by subjects' game performance and success at HR control (FB+). Subjects receiving feedback (FB+, FB-) exhibited greater reductions in HR response to the videogame in the posttraining assessment than control (HC, IC) subjects; FB+ subjects showed greater HR reductions than subjects in any other group. FB+ and FB- subjects showed a lower SBP at posttraining relative to the two control groups, but no reduction in task-induced blood pressure reactivity. There were no group differences in videogame performance, either before or following training.

Simulated effect of calcification feedback on atmospheric CO2 and ocean acidification

PubMed Central

Zhang, Han; Cao, Long

2016-01-01

Ocean uptake of anthropogenic CO2 reduces pH and saturation state of calcium carbonate materials of seawater, which could reduce the calcification rate of some marine organisms, triggering a negative feedback on the growth of atmospheric CO2. We quantify the effect of this CO2-calcification feedback by conducting a series of Earth system model simulations that incorporate different parameterization schemes describing the dependence of calcification rate on saturation state of CaCO3. In a scenario with SRES A2 CO2 emission until 2100 and zero emission afterwards, by year 3500, in the simulation without CO2-calcification feedback, model projects an accumulated ocean CO2 uptake of 1462 PgC, atmospheric CO2 of 612 ppm, and surface pH of 7.9. Inclusion of CO2-calcification feedback increases ocean CO2 uptake by 9 to 285 PgC, reduces atmospheric CO2 by 4 to 70 ppm, and mitigates the reduction in surface pH by 0.003 to 0.06, depending on the form of parameterization scheme used. It is also found that the effect of CO2-calcification feedback on ocean carbon uptake is comparable and could be much larger than the effect from CO2-induced warming. Our results highlight the potentially important role CO2-calcification feedback plays in ocean carbon cycle and projections of future atmospheric CO2 concentrations. PMID:26838480

Adaptive NN control for discrete-time pure-feedback systems with unknown control direction under amplitude and rate actuator constraints.

PubMed

Chen, Weisheng

2009-07-01

This paper focuses on the problem of adaptive neural network tracking control for a class of discrete-time pure-feedback systems with unknown control direction under amplitude and rate actuator constraints. Two novel state-feedback and output-feedback dynamic control laws are established where the function tanh(.) is employed to solve the saturation constraint problem. Implicit function theorem and mean value theorem are exploited to deal with non-affine variables that are used as actual control. Radial basis function neural networks are used to approximate the desired input function. Discrete Nussbaum gain is used to estimate the unknown sign of control gain. The uniform boundedness of all closed-loop signals is guaranteed. The tracking error is proved to converge to a small residual set around the origin. A simulation example is provided to illustrate the effectiveness of control schemes proposed in this paper.

Robust consensus control with guaranteed rate of convergence using second-order Hurwitz polynomials

NASA Astrophysics Data System (ADS)

Fruhnert, Michael; Corless, Martin

2017-10-01

This paper considers homogeneous networks of general, linear time-invariant, second-order systems. We consider linear feedback controllers and require that the directed graph associated with the network contains a spanning tree and systems are stabilisable. We show that consensus with a guaranteed rate of convergence can always be achieved using linear state feedback. To achieve this, we provide a new and simple derivation of the conditions for a second-order polynomial with complex coefficients to be Hurwitz. We apply this result to obtain necessary and sufficient conditions to achieve consensus with networks whose graph Laplacian matrix may have complex eigenvalues. Based on the conditions found, methods to compute feedback gains are proposed. We show that gains can be chosen such that consensus is achieved robustly over a variety of communication structures and system dynamics. We also consider the use of static output feedback.

Can corrective feedback improve recognition memory?

PubMed

Kantner, Justin; Lindsay, D Stephen

2010-06-01

An understanding of the effects of corrective feedback on recognition memory can inform both recognition theory and memory training programs, but few published studies have investigated the issue. Although the evidence to date suggests that feedback does not improve recognition accuracy, few studies have directly examined its effect on sensitivity, and fewer have created conditions that facilitate a feedback advantage by encouraging controlled processing at test. In Experiment 1, null effects of feedback were observed following both deep and shallow encoding of categorized study lists. In Experiment 2, feedback robustly influenced response bias by allowing participants to discern highly uneven base rates of old and new items, but sensitivity remained unaffected. In Experiment 3, a false-memory procedure, feedback failed to attenuate false recognition of critical lures. In Experiment 4, participants were unable to use feedback to learn a simple category rule separating old items from new items, despite the fact that feedback was of substantial benefit in a nearly identical categorization task. The recognition system, despite a documented ability to utilize controlled strategic or inferential decision-making processes, appears largely impenetrable to a benefit of corrective feedback.

Remote video auditing with real-time feedback in an academic surgical suite improves safety and efficiency metrics: a cluster randomised study.

PubMed

Overdyk, Frank J; Dowling, Oonagh; Newman, Sheldon; Glatt, David; Chester, Michelle; Armellino, Donna; Cole, Brandon; Landis, Gregg S; Schoenfeld, David; DiCapua, John F

2016-12-01

Compliance with the surgical safety checklist during operative procedures has been shown to reduce inhospital mortality and complications but proper execution by the surgical team remains elusive. We evaluated the impact of remote video auditing with real-time provider feedback on checklist compliance during sign-in, time-out and sign-out and case turnover times. Prospective, cluster randomised study in a 23-operating room (OR) suite. Surgeons, anaesthesia providers, nurses and support staff. ORs were randomised to receive, or not receive, real-time feedback on safety checklist compliance and efficiency metrics via display boards and text messages, followed by a period during which all ORs received feedback. Checklist compliance (Pass/Fail) during sign-in, time-out and sign-out demonstrated by (1) use of checklist, (2) team attentiveness, (3) required duration, (4) proper sequence and duration of case turnover times. Sign-in, time-out and sign-out PASS rates increased from 25%, 16% and 32% during baseline phase (n=1886) to 64%, 84% and 68% for feedback ORs versus 40%, 77% and 51% for no-feedback ORs (p<0.004) during the intervention phase (n=2693). Pass rates were 91%, 95% and 84% during the all-feedback phase (n=2001). For scheduled cases (n=1406, 71%), feedback reduced mean turnover times by 14% (41.4 min vs 48.1 min, p<0.004), and the improvement was sustained during the all-feedback period. Feedback had no effect on turnover time for unscheduled cases (n=587, 29%). Our data indicate that remote video auditing with feedback improves surgical safety checklist compliance for all cases, and turnover time for scheduled cases, but not for unscheduled cases. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Remote video auditing with real-time feedback in an academic surgical suite improves safety and efficiency metrics: a cluster randomised study

PubMed Central

Overdyk, Frank J; Dowling, Oonagh; Newman, Sheldon; Glatt, David; Chester, Michelle; Armellino, Donna; Cole, Brandon; Landis, Gregg S; Schoenfeld, David; DiCapua, John F

2016-01-01

Importance Compliance with the surgical safety checklist during operative procedures has been shown to reduce inhospital mortality and complications but proper execution by the surgical team remains elusive. Objective We evaluated the impact of remote video auditing with real-time provider feedback on checklist compliance during sign-in, time-out and sign-out and case turnover times. Design, setting Prospective, cluster randomised study in a 23-operating room (OR) suite. Participants Surgeons, anaesthesia providers, nurses and support staff. Exposure ORs were randomised to receive, or not receive, real-time feedback on safety checklist compliance and efficiency metrics via display boards and text messages, followed by a period during which all ORs received feedback. Main outcome(s) and measure(s) Checklist compliance (Pass/Fail) during sign-in, time-out and sign-out demonstrated by (1) use of checklist, (2) team attentiveness, (3) required duration, (4) proper sequence and duration of case turnover times. Results Sign-in, time-out and sign-out PASS rates increased from 25%, 16% and 32% during baseline phase (n=1886) to 64%, 84% and 68% for feedback ORs versus 40%, 77% and 51% for no-feedback ORs (p<0.004) during the intervention phase (n=2693). Pass rates were 91%, 95% and 84% during the all-feedback phase (n=2001). For scheduled cases (n=1406, 71%), feedback reduced mean turnover times by 14% (41.4 min vs 48.1 min, p<0.004), and the improvement was sustained during the all-feedback period. Feedback had no effect on turnover time for unscheduled cases (n=587, 29%). Conclusions and relevance Our data indicate that remote video auditing with feedback improves surgical safety checklist compliance for all cases, and turnover time for scheduled cases, but not for unscheduled cases. PMID:26658775

Performance Feedback Processing Is Positively Biased As Predicted by Attribution Theory.

PubMed

Korn, Christoph W; Rosenblau, Gabriela; Rodriguez Buritica, Julia M; Heekeren, Hauke R

2016-01-01

A considerable literature on attribution theory has shown that healthy individuals exhibit a positivity bias when inferring the causes of evaluative feedback on their performance. They tend to attribute positive feedback internally (e.g., to their own abilities) but negative feedback externally (e.g., to environmental factors). However, all empirical demonstrations of this bias suffer from at least one of the three following drawbacks: First, participants directly judge explicit causes for their performance. Second, participants have to imagine events instead of experiencing them. Third, participants assess their performance only after receiving feedback and thus differences in baseline assessments cannot be excluded. It is therefore unclear whether the classically reported positivity bias generalizes to setups without these drawbacks. Here, we aimed at establishing the relevance of attributions for decision-making by showing an attribution-related positivity bias in a decision-making task. We developed a novel task, which allowed us to test how participants changed their evaluations in response to positive and negative feedback about performance. Specifically, we used videos of actors expressing different facial emotional expressions. Participants were first asked to evaluate the actors' credibility in expressing a particular emotion. After this initial rating, participants performed an emotion recognition task and did--or did not--receive feedback on their veridical performance. Finally, participants re-rated the actors' credibility, which provided a measure of how they changed their evaluations after feedback. Attribution theory predicts that participants change their evaluations of the actors' credibility toward the positive after receiving positive performance feedback and toward the negative after negative performance feedback. Our results were in line with this prediction. A control condition without feedback showed that correct or incorrect performance alone could not explain the observed positivity bias. Furthermore, participants' behavior in our task was linked to the most widely used measure of attribution style. In sum, our findings suggest that positive and negative performance feedback influences the evaluation of task-related stimuli, as predicted by attribution theory. Therefore, our study points to the relevance of attribution theory for feedback processing in decision-making and provides a novel outlook for decision-making biases.

Performance Feedback Processing Is Positively Biased As Predicted by Attribution Theory

PubMed Central

Rodriguez Buritica, Julia M.; Heekeren, Hauke R.

2016-01-01

A considerable literature on attribution theory has shown that healthy individuals exhibit a positivity bias when inferring the causes of evaluative feedback on their performance. They tend to attribute positive feedback internally (e.g., to their own abilities) but negative feedback externally (e.g., to environmental factors). However, all empirical demonstrations of this bias suffer from at least one of the three following drawbacks: First, participants directly judge explicit causes for their performance. Second, participants have to imagine events instead of experiencing them. Third, participants assess their performance only after receiving feedback and thus differences in baseline assessments cannot be excluded. It is therefore unclear whether the classically reported positivity bias generalizes to setups without these drawbacks. Here, we aimed at establishing the relevance of attributions for decision-making by showing an attribution-related positivity bias in a decision-making task. We developed a novel task, which allowed us to test how participants changed their evaluations in response to positive and negative feedback about performance. Specifically, we used videos of actors expressing different facial emotional expressions. Participants were first asked to evaluate the actors’ credibility in expressing a particular emotion. After this initial rating, participants performed an emotion recognition task and did—or did not—receive feedback on their veridical performance. Finally, participants re-rated the actors’ credibility, which provided a measure of how they changed their evaluations after feedback. Attribution theory predicts that participants change their evaluations of the actors’ credibility toward the positive after receiving positive performance feedback and toward the negative after negative performance feedback. Our results were in line with this prediction. A control condition without feedback showed that correct or incorrect performance alone could not explain the observed positivity bias. Furthermore, participants’ behavior in our task was linked to the most widely used measure of attribution style. In sum, our findings suggest that positive and negative performance feedback influences the evaluation of task-related stimuli, as predicted by attribution theory. Therefore, our study points to the relevance of attribution theory for feedback processing in decision-making and provides a novel outlook for decision-making biases. PMID:26849646

34 CFR 645.1 - What is the Upward Bound Program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... participants the skills and motivation necessary to complete a program of secondary education and to enter and... the following three types of projects: (1) Regular Upward Bound projects. (2) Upward Bound Math and... Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY...

76 FR 43575 - Amendment of Class E Airspace; Staunton, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-21

... airspace extending upward from 700 feet above the surface at Shenandoah Valley Regional Airport, Staunton... airspace extending upward from 700 feet above the surface to support new SIAPs developed at Shenandoah... E airspace areas extending upward from 700 feet or more above the surface of the earth...

Evaluating TRIO Programs: A Case Study of Upward Bound Directors and Staff

ERIC Educational Resources Information Center

Carr, Yolanda Regina

2013-01-01

For over four decades, Upward Bound programs have influenced students' aspirations and goals toward attending college, college enrollment, and overall educational achievement, providing a standard for successful college preparation for historically marginalized students. Although Upward Bound has helped many Americans prepare for and earn their…

A Theoretical Concept of Educational Upward Mobility

ERIC Educational Resources Information Center

Kupfer, Antonia

2012-01-01

This paper's topic is the educational upward mobility of members of the working class. It seeks to find out what makes educational success possible and aims to build a theory of educational upward mobility. Data have been collected through biographical-narrative interviews of Austrian graduates from working-class backgrounds. Their narratives have…

Achieving optimal growth: lessons from simple metabolic modules

NASA Astrophysics Data System (ADS)

Goyal, Sidhartha; Chen, Thomas; Wingreen, Ned

2009-03-01

Metabolism is a universal property of living organisms. While the metabolic network itself has been well characterized, the logic of its regulation remains largely mysterious. Recent work has shown that growth rates of microorganisms, including the bacterium Escherichia coli, correlate well with optimal growth rates predicted by flux-balance analysis (FBA), a constraint-based computational method. How difficult is it for cells to achieve optimal growth? Our analysis of representative metabolic modules drawn from real metabolism shows that, in all cases, simple feedback inhibition allows nearly optimal growth. Indeed, product-feedback inhibition is found in every biosynthetic pathway and constitutes about 80% of metabolic regulation. However, we find that product-feedback systems designed to approach optimal growth necessarily produce large pool sizes of metabolites, with potentially detrimental effects on cells via toxicity and osmotic imbalance. Interestingly, the sizes of metabolite pools can be strongly restricted if the feedback inhibition is ultrasensitive (i.e. with high Hill coefficient). The need for ultrasensitive mechanisms to limit pool sizes may therefore explain some of the ubiquitous, puzzling complexity found in metabolic feedback regulation at both the transcriptional and post-transcriptional levels.

PROTOSTELLAR OUTFLOWS AND RADIATIVE FEEDBACK FROM MASSIVE STARS. II. FEEDBACK, STAR-FORMATION EFFICIENCY, AND OUTFLOW BROADENING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuiper, Rolf; Turner, Neal J.; Yorke, Harold W., E-mail: rolf.kuiper@uni-tuebingen.de, E-mail: Neal.J.Turner@jpl.nasa.gov, E-mail: Harold.W.Yorke@jpl.nasa.gov

2016-11-20

We perform two-dimensional axially symmetric radiation hydrodynamic simulations to assess the impact of outflows and radiative force feedback from massive protostars by varying when the protostellar outflow starts, and to determine the ratio of ejection to accretion rates and the strength of the wide-angle disk wind component. The star-formation efficiency, i.e., the ratio of final stellar mass to initial core mass, is dominated by radiative forces and the ratio of outflow to accretion rates. Increasing this ratio has three effects. First, the protostar grows slower with a lower luminosity at any given time, lowering radiative feedback. Second, bipolar cavities clearedmore » by the outflow become larger, further diminishing radiative feedback on disk and core scales. Third, the higher momentum outflow sweeps up more material from the collapsing envelope, decreasing the protostar's potential mass reservoir via entrainment. The star-formation efficiency varies with the ratio of ejection to accretion rates from 50% in the case of very weak outflows to as low as 20% for very strong outflows. At latitudes between the low-density bipolar cavity and the high-density accretion disk, wide-angle disk winds remove some of the gas, which otherwise would be part of the accretion flow onto the disk; varying the strength of these wide-angle disk winds, however, alters the final star-formation efficiency by only ±6%. For all cases, the opening angle of the bipolar outflow cavity remains below 20° during early protostellar accretion phases, increasing rapidly up to 65° at the onset of radiation pressure feedback.« less

Memory-guided force control in healthy younger and older adults.

PubMed

Neely, Kristina A; Samimy, Shaadee; Blouch, Samantha L; Wang, Peiyuan; Chennavasin, Amanda; Diaz, Michele T; Dennis, Nancy A

2017-08-01

Successful performance of a memory-guided motor task requires participants to store and then recall an accurate representation of the motor goal. Further, participants must monitor motor output to make adjustments in the absence of visual feedback. The goal of this study was to examine memory-guided grip force in healthy younger and older adults and compare it to performance on behavioral tasks of working memory. Previous work demonstrates that healthy adults decrease force output as a function of time when visual feedback is not available. We hypothesized that older adults would decrease force output at a faster rate than younger adults, due to age-related deficits in working memory. Two groups of participants, younger adults (YA: N = 32, mean age 21.5 years) and older adults (OA: N = 33, mean age 69.3 years), completed four 20-s trials of isometric force with their index finger and thumb, equal to 25% of their maximum voluntary contraction. In the full-vision condition, visual feedback was available for the duration of the trial. In the no vision condition, visual feedback was removed for the last 12 s of each trial. Participants were asked to maintain constant force output in the absence of visual feedback. Participants also completed tasks of word recall and recognition and visuospatial working memory. Counter to our predictions, when visual feedback was removed, younger adults decreased force at a faster rate compared to older adults and the rate of decay was not associated with behavioral performance on tests of working memory.

Complete analog control of the carrier-envelope-phase of a high-power laser amplifier.

PubMed

Feng, C; Hergott, J-F; Paul, P-M; Chen, X; Tcherbakoff, O; Comte, M; Gobert, O; Reduzzi, M; Calegari, F; Manzoni, C; Nisoli, M; Sansone, G

2013-10-21

In this work we demonstrate the development of a complete analog feedback loop for the control of the carrier-envelope phase (CEP) of a high-average power (20 W) laser operating at 10 kHz repetition rate. The proposed method combines a detection scheme working on a single-shot basis at the full-repetition-rate of the laser system with a fast actuator based either on an acousto-optic or on an electro-optic crystal. The feedback loop is used to correct the CEP fluctuations introduced by the amplification process demonstrating a CEP residual noise of 320 mrad measured on a single-shot basis. The comparison with a feedback loop operating at a lower sampling rate indicates an improvement up to 45% in the residual noise. The measurement of the CEP drift for different integration times clearly evidences the importance of the single-shot characterization of the residual CEP drift. The demonstrated scheme could be efficiently applied for systems approaching the 100 kHz repetition rate regime.

Chemical transport models: the combined non-local diffusion and mixing schemes, and calculation of in-canopy resistance for dry deposition fluxes.

PubMed

Mihailovic, Dragutin T; Alapaty, Kiran; Podrascanin, Zorica

2009-03-01

Improving the parameterization of processes in the atmospheric boundary layer (ABL) and surface layer, in air quality and chemical transport models. To do so, an asymmetrical, convective, non-local scheme, with varying upward mixing rates is combined with the non-local, turbulent, kinetic energy scheme for vertical diffusion (COM). For designing it, a function depending on the dimensionless height to the power four in the ABL is suggested, which is empirically derived. Also, we suggested a new method for calculating the in-canopy resistance for dry deposition over a vegetated surface. The upward mixing rate forming the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. The vertical eddy diffusivity is parameterized using the mean turbulent velocity scale that is obtained by the vertical integration within the ABL. In-canopy resistance is calculated by integration of inverse turbulent transfer coefficient inside the canopy from the effective ground roughness length to the canopy source height and, further, from its the canopy height. This combination of schemes provides a less rapid mass transport out of surface layer into other layers, during convective and non-convective periods, than other local and non-local schemes parameterizing mixing processes in the ABL. The suggested method for calculating the in-canopy resistance for calculating the dry deposition over a vegetated surface differs remarkably from the commonly used one, particularly over forest vegetation. In this paper, we studied the performance of a non-local, turbulent, kinetic energy scheme for vertical diffusion combined with a non-local, convective mixing scheme with varying upward mixing in the atmospheric boundary layer (COM) and its impact on the concentration of pollutants calculated with chemical and air-quality models. In addition, this scheme was also compared with a commonly used, local, eddy-diffusivity scheme. Simulated concentrations of NO2 by the COM scheme and new parameterization of the in-canopy resistance are closer to the observations when compared to those obtained from using the local eddy-diffusivity scheme. Concentrations calculated with the COM scheme and new parameterization of in-canopy resistance, are in general higher and closer to the observations than those obtained by the local, eddy-diffusivity scheme (on the order of 15-22%). To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO2) were compared for the years 1999 and 2002. The comparison was made for the entire domain used in simulations performed by the chemical European Monitoring and Evaluation Program Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.

General, database-driven fast-feedback system for the Stanford Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rouse, F.; Allison, S.; Castillo, S.

A new feedback system has been developed for stabilizing the SLC beams at many locations. The feedback loops are designed to sample and correct at the 60 Hz repetition rate of the accelerator. Each loop can be distributed across several of the standard 80386 microprocessors which control the SLC hardware. A new communications system, KISNet, has been implemented to pass signals between the microprocessors at this rate. The software is written in a general fashion using the state space formalism of digital control theory. This allows a new loop to be implemented by just setting up the online database andmore » perhaps installing a communications link. 3 refs., 4 figs.« less

A systematic review: the influence of real time feedback on wheelchair propulsion biomechanics.

PubMed

Symonds, Andrew; Barbareschi, Giulia; Taylor, Stephen; Holloway, Catherine

2018-01-01

Clinical guidelines recommend that, in order to minimize upper limb injury risk, wheelchair users adopt a semi-circular pattern with a slow cadence and a large push arc. To examine whether real time feedback can be used to influence manual wheelchair propulsion biomechanics. Clinical trials and case series comparing the use of real time feedback against no feedback were included. A general review was performed and methodological quality assessed by two independent practitioners using the Downs and Black checklist. The review was completed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Six papers met the inclusion criteria. Selected studies involved 123 participants and analysed the effect of visual and, in one case, haptic feedback. Across the studies it was shown that participants were able to achieve significant changes in propulsion biomechanics, when provided with real time feedback. However, the effect of targeting a single propulsion variable might lead to unwanted alterations in other parameters. Methodological assessment identified weaknesses in external validity. Visual feedback could be used to consistently increase push arc and decrease push rate, and may be the best focus for feedback training. Further investigation is required to assess such intervention during outdoor propulsion. Implications for Rehabilitation Upper limb pain and injuries are common secondary disorders that negatively affect wheelchair users' physical activity and quality of life. Clinical guidelines suggest that manual wheelchair users should aim to propel with a semi-circular pattern with low a push rate and large push arc in the range in order to minimise upper limbs' loading. Real time visual and haptic feedback are effective tools for improving propulsion biomechanics in both complete novices and experienced manual wheelchair users.

Simulation of a dynamical ecotourism system with low carbon activity: A case from western China.

PubMed

He, Yuan; Huang, Ping; Xu, Hong

2018-01-15

Currently, sustainable tourism is becoming more and more important in developing ecological economies. To achieve low-carbon development, some industries, such as logistics and municipal solid waste, have already taken action, but tourism has not attached sufficient importance to this issue. This paper designs an ecotourism system including tourism, carbon waste (solid waste and sewage), and ecology (water supply and green areas) to simulate low-carbon ecotourism through a quantitative approach. This paper explores the tourism system as well as some interactive factors and studies their quantitative relationship based on historical data. A feedback-loop dynamical system model is designed to simulate tourism, waste carbon, and ecology simultaneously. Finally, a case study applying the feedback-loop dynamical system model to Leshan City, a typical travel destination with colorful natural resources in western China, is conducted to indicate the development of ecotourism in an environmentally friendly economy, which verifies the positive effects of the model. Results show a coordinating upward tendency of tourism, solid waste carbon, and ecology from the dynamical model. When tourism increases, solid waste accumulation increases; however, the amount of sewage dumped directly into nature decreases sharply. After analysis of investment policy scenarios, the research indicates that more funds for sewage treatment will attract more tourists. To maintain the equilibrium of carbon waste, more funds shall be invested in solid waste treatment in the long term. Some discussions about local policy are included. Copyright © 2017 Elsevier Ltd. All rights reserved.

Origin and dynamics of depositionary subduction margins

USGS Publications Warehouse

Vannucchi, Paola; Morgan, Jason P.; Silver, Eli; Kluesner, Jared W.

2016-01-01

Here we propose a new framework for forearc evolution that focuses on the potential feedbacks between subduction tectonics, sedimentation, and geomorphology that take place during an extreme event of subduction erosion. These feedbacks can lead to the creation of a “depositionary forearc,” a forearc structure that extends the traditional division of forearcs into accretionary or erosive subduction margins by demonstrating a mode of rapid basin accretion during an erosive event at a subduction margin. A depositionary mode of forearc evolution occurs when terrigenous sediments are deposited directly on the forearc while it is being removed from below by subduction erosion. In the most extreme case, an entire forearc can be removed by a single subduction erosion event followed by depositionary replacement without involving transfer of sediments from the incoming plate. We need to further recognize that subduction forearcs are often shaped by interactions between slow, long-term processes, and sudden extreme events reflecting the sudden influences of large-scale morphological variations in the incoming plate. Both types of processes contribute to the large-scale architecture of the forearc, with extreme events associated with a replacive depositionary mode that rapidly creates sections of a typical forearc margin. The persistent upward diversion of the megathrust is likely to affect its geometry, frictional nature, and hydrogeology. Therefore, the stresses along the fault and individual earthquake rupture characteristics are also expected to be more variable in these erosive systems than in systems with long-lived megathrust surfaces.

Stellar feedback in galaxies and the origin of galaxy-scale winds

NASA Astrophysics Data System (ADS)

Hopkins, Philip F.; Quataert, Eliot; Murray, Norman

2012-04-01

Feedback from massive stars is believed to play a critical role in driving galactic super-winds that enrich the intergalactic medium and shape the galaxy mass function, mass-metallicity relation and other global galaxy properties. In previous papers, we have introduced new numerical methods for implementing stellar feedback on sub-giant molecular cloud (sub-GMC) through galactic scales in numerical simulations of galaxies; the key physical processes include radiation pressure in the ultraviolet through infrared, supernovae (Type I and Type II), stellar winds ('fast' O star through 'slow' asymptotic giant branch winds), and H II photoionization. Here, we show that these feedback mechanisms drive galactic winds with outflow rates as high as ˜10-20 times the galaxy star formation rate. The mass-loading efficiency (wind mass-loss rate divided by the star formation rate) scales roughly as ? (where Vc is the galaxy circular velocity), consistent with simple momentum-conservation expectations. We use our suite of simulations to study the relative contribution of each feedback mechanism to the generation of galactic winds in a range of galaxy models, from Small Magellanic Cloud like dwarfs and Milky Way (MW) analogues to z˜ 2 clumpy discs. In massive, gas-rich systems (local starbursts and high-z galaxies), radiation pressure dominates the wind generation. By contrast, for MW-like spirals and dwarf galaxies the gas densities are much lower and sources of shock-heated gas such as supernovae and stellar winds dominate the production of large-scale outflows. In all of our models, however, the winds have a complex multiphase structure that depends on the interaction between multiple feedback mechanisms operating on different spatial scales and time-scales: any single feedback mechanism fails to reproduce the winds observed. We use our simulations to provide fitting functions to the wind mass loading and velocities as a function of galaxy properties, for use in cosmological simulations and semi-analytic models. These differ from typically adopted formulae with an explicit dependence on the gas surface density that can be very important in both low-density dwarf galaxies and high-density gas-rich galaxies.

Modifying a shrug exercise can facilitate the upward rotator muscles of the scapula.

PubMed

Pizzari, Tania; Wickham, James; Balster, Simon; Ganderton, Charlotte; Watson, Lyn

2014-02-01

Scapular dyskinesis, characterised by drooping scapulae and reduced upward rotation, has been implicated in the presentation of a number of shoulder disorders. Traditionally, in shoulder rehabilitation programmes, the shrug exercise has been prescribed to facilitate upward rotation of the scapula by strengthening the upper trapezius muscle. The aim of this research was to compare muscle activation levels during the standard shrug and the upward rotation shrug in a normal and pathological population. Surface electrodes recorded electromyographical activity from upper trapezius, middle trapezius, lower trapezius and serratus anterior muscles in 23 normal participants and 14 participants with multi-directional shoulder instability. Participants completed 10 trials of the standard shrug exercise at 0° of shoulder abduction and the upward rotation shrug exercise at 30° of shoulder abduction in the coronal plane. Muscle activity was expressed as a percentage of maximum voluntary isometric contraction. The four muscles tested performed at a higher intensity during the modified shrug than the standard shrug. Upper trapezius and lower trapezius activity was significantly greater (P < 0.05) in both populations. Though for middle trapezius and serratus anterior muscles, the modified shrug was statistically significant only in the normal population, P = 0.031 and P = <0.001 respectively. The upward rotation shrug is a more effective exercise for eliciting muscle activity of the upper and lower trapezius than the standard shrug in a normal and multi-directional instability population. Clinically, the upward rotation shrug might be useful to address scapular dyskinesis involving drooping shoulders and reduced scapula upward rotation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mixed Convection Blowoff Limits as a Function of Oxygen Concentration and Upward Forced Stretch Rate for Burning Pmma Rods of Various Sizes

NASA Technical Reports Server (NTRS)

Marcum, Jeremy W.; Ferkul, Paul V.; Olson, Sandra L.

2017-01-01

Normal gravity flame blowoff limits in an axisymmetric pmma rod geometry in upward axial stagnation flow are compared with microgravity Burning and Suppression of Solids II (BASS-II) results recently obtained aboard the International Space Station. This testing utilized the same BASS-II concurrent rod geometry, but with the addition of normal gravity buoyant flow. Cast polymethylmethacrylate (pmma) rods of diameters ranging from 0.635 cm to 3.81 cm were burned at oxygen concentrations ranging from 14 to 18 by volume. The forced flow velocity where blowoff occurred was determined for each rod size and oxygen concentration. These blowoff limits compare favorably with the BASS-II results when the buoyant stretch is included and the flow is corrected by considering the blockage factor of the fuel. From these results, the normal gravity blowoff boundary for this axisymmetric rod geometry is determined to be linear, with oxygen concentration directly proportional to flow speed. We describe a new normal gravity upward flame spread test method which extrapolates the linear blowoff boundary to the zero stretch limit to resolve microgravity flammability limits, something current methods cannot do. This new test method can improve spacecraft fire safety for future exploration missions by providing a tractable way to obtain good estimates of material flammability in low gravity.

Effect of temperature and temperature fluctuation on thermophilic anaerobic digestion of cattle manure.

PubMed

El-Mashad, Hamed M; Zeeman, Grietje; van Loon, Wilko K P; Bot, Gerard P A; Lettinga, Gatze

2004-11-01

The influence of temperature, 50 and 60 degrees C, at hydraulic retention times (HRTs) of 20 and 10 days, on the performance of anaerobic digestion of cow manure has been investigated in completely stirred tank reactors (CSTRs). Furthermore, the effect of both daily downward and daily upward temperature fluctuations has been studied. In the daily downward temperature fluctuation regime the temperatures of each reactor was reduced by 10 degrees C for 10 h while in the daily upward fluctuation regime the temperature of each reactor was increased 10 degrees C for 5 h. The results show that the methane production rate at 60 degrees C is lower than that at 50 degrees C at all experimental conditions of imposed HRT except when downward temperature fluctuations were applied at an HRT of 10 days. It also was found that the free ammonia concentration not only affects the acetate-utilising bacteria but also the hydrolysis and acidification process. The upward temperature fluctuation affects the maximum specific methanogenesis activity more severely as compared to imposed downward temperature fluctuations. The results clearly reveal the possibility of using available solar energy at daytime to heat up the reactor(s) without the need of heat storage during nights, especially at an operational temperature of 50 degrees C and at a 20 days HRT, and without the jeopardising of the overheating.

Dynamic analysis and assessment for sustainable development.

PubMed

Shi, Xiao-qing

2002-01-01

The assessment of sustainable development is crucial for constituting sustainable development strategies. Assessment methods that exist so far usually only use an indicator system for making sustainable judgement. These indicators rarely reflect dynamic characteristics. However, sustainable development is influenced by changes in the social-economic system and in the eco-environmental system at different times. Besides the spatial character, sustainable development has a temporal character that can not be neglected; therefore the research system should also be dynamic. This paper focuses on this dynamic trait, so that the assessment results obtained provide more information for judgements in decision-making processes. Firstly the dynamic characteristics of sustainable development are analyzed, which point to a track of sustainable development that is an upward undulating curve. According to the dynamic character and the development rules of a social, economic and ecological system, a flexible assessment approach that is based on tendency analysis, restrictive conditions and a feedback system is then proposed for sustainable development.

Intrinsic dynamics and total energy-shaping control of the ballbot system

NASA Astrophysics Data System (ADS)

Satici, A. C.; Donaire, A.; Siciliano, B.

2017-12-01

Research on bipedal locomotion has shown that a dynamic walking gait is energetically more efficient than a statically stable one. Analogously, even though statically stable multi-wheeled robots are easier to control, they are energetically less efficient and have low accelerations to avoid tipping over. In contrast, the ballbot is an underactuated, nonholonomically constrained mobile robot, whose upward equilibrium point has to be stabilised by active control. In this work, we derive coordinate-invariant, reduced, Euler-Poincaré equations of motion for the ballbot. By means of partial feedback linearisation, we obtain two independent passive outputs with corresponding storage functions and utilise these to come up with energy-shaping control laws which move the system along the trajectories of a new Lagrangian system whose desired equilibrium point is asymptotically stable by construction. The basin of attraction of this controller is shown to be almost global under certain conditions on the design of the mechanism which are reflected directly in the mass matrix of the unforced equations of motion.

Data-driven magnetohydrodynamic modelling of a flux-emerging active region leading to solar eruption

PubMed Central

Jiang, Chaowei; Wu, S. T.; Feng, Xuesheng; Hu, Qiang

2016-01-01

Solar eruptions are well-recognized as major drivers of space weather but what causes them remains an open question. Here we show how an eruption is initiated in a non-potential magnetic flux-emerging region using magnetohydrodynamic modelling driven directly by solar magnetograms. Our model simulates the coronal magnetic field following a long-duration quasi-static evolution to its fast eruption. The field morphology resembles a set of extreme ultraviolet images for the whole process. Study of the magnetic field suggests that in this event, the key transition from the pre-eruptive to eruptive state is due to the establishment of a positive feedback between the upward expansion of internal stressed magnetic arcades of new emergence and an external magnetic reconnection which triggers the eruption. Such a nearly realistic simulation of a solar eruption from origin to onset can provide important insight into its cause, and also has the potential for improving space weather modelling. PMID:27181846

The roles of dry convection, cloud-radiation feedback processes and the influence of recent improvements in the parameterization of convection in the GLA GCM

NASA Technical Reports Server (NTRS)

Sud, Y.; Molod, A.

1988-01-01

The Goddard Laboratory for Atmospheres GCM is used to study the sensitivity of the simulated July circulation to modifications in the parameterization of dry and moist convection, evaporation from falling raindrops, and cloud-radiation interaction. It is shown that the Arakawa-Schubert (1974) cumulus parameterization and a more realistic dry convective mixing calculation yielded a better intertropical convergence zone over North Africa than the previous convection scheme. It is found that the physical mechanism for the improvement was the upward mixing of PBL moisture by vigorous dry convective mixing. A modified rain-evaporation parameterization which accounts for raindrop size distribution, the atmospheric relative humidity, and a typical spatial rainfall intensity distribution for convective rain was developed and implemented. This scheme led to major improvements in the monthly mean vertical profiles of relative humidity and temperature, convective and large-scale cloudiness, rainfall distributions, and mean relative humidity in the PBL.

A better understanding of ambulance personnel's attitude towards real-time resuscitation feedback.

PubMed

Brinkrolf, Peter; Lukas, Roman; Harding, Ulf; Thies, Sebastian; Gerss, Joachim; Van Aken, Hugo; Lemke, Hans; Schniedermeier, Udo; Bohn, Andreas

2018-03-01

High-quality chest compressions during cardiopulmonary resuscitation (CPR) play a significant role in surviving cardiac arrest. Chest-compression quality can be measured and corrected by real-time CPR feedback devices, which are not yet commonly used. This article looks at the acceptance of such systems in comparison of equipped and unequipped personnel. Two groups of emergency medical services' (EMS) personnel were interviewed using standardized questionnaires. The survey was conducted in the German cities Dortmund and Münster. Overall, 205 persons participated in the survey: 103 paramedics and emergency physicians from the Dortmund fire service and 102 personnel from the Münster service. The staff of the Dortmund service were not equipped with real-time feedback systems. The test group of equipped personnel of the ambulance service of Münster Fire brigade uses real-time feedback systems since 2007. What is the acceptance level of real-time feedback systems? Are there differences between equipped and unequipped personnel? The total sample is receptive towards real-time feedback systems. More than 80% deem the system useful. However, this study revealed concerns and prejudices by unequipped personnel. Negative ratings are significantly lower at the Münster site that is experienced with the use of the real-time feedback system in contrast to the Dortmund site where no such experience exists-the system's use in daily routine results in better evaluation than the expectations of unequipped personnel. Real-time feedback systems receive overall positive ratings. Prejudices and concerns seem to decrease with continued use of the system.

Active Galactic Nucleus Feedback in an Isolated Elliptical Galaxy: The Effect of Strong Radiative Feedback in the Kinetic Mode

NASA Astrophysics Data System (ADS)

Gan, Zhaoming; Yuan, Feng; Ostriker, Jeremiah P.; Ciotti, Luca; Novak, Gregory S.

2014-07-01

Based on two-dimensional high-resolution hydrodynamic numerical simulation, we study the mechanical and radiative feedback effects from the central active galactic nucleus (AGN) on the cosmological evolution of an isolated elliptical galaxy. The inner boundary of the simulation domain is carefully chosen so that the fiducial Bondi radius is resolved and the accretion rate of the black hole is determined self-consistently. It is well known that when the accretion rates are high and low, the central AGNs will be in cold and hot accretion modes, which correspond to the radiative and kinetic feedback modes, respectively. The emitted spectrum from the hot accretion flows is harder than that from the cold accretion flows, which could result in a higher Compton temperature accompanied by a more efficient radiative heating, according to previous theoretical works. Such a difference of the Compton temperature between the two feedback modes, the focus of this study, has been neglected in previous works. Significant differences in the kinetic feedback mode are found as a result of the stronger Compton heating. More importantly, if we constrain models to correctly predict black hole growth and AGN duty cycle after cosmological evolution, we find that the favored model parameters are constrained: mechanical feedback efficiency diminishes with decreasing luminosity (the maximum efficiency being ~= 10-3.5), and X-ray Compton temperature increases with decreasing luminosity, although models with fixed mechanical efficiency and Compton temperature can be found that are satisfactory as well. We conclude that radiative feedback in the kinetic mode is much more important than previously thought.

From Rags to "Rich as Rockefeller": Portrayals of Class Mobility in Newbery Titles

ERIC Educational Resources Information Center

Forest, Danielle E.

2014-01-01

Several scholars have noted the prevalence of the discourse of upward class mobility in the United States, particularly within K-12 education settings. "Rags-to-riches" stories, an extreme form of upward mobility discourse, have been embedded in American culture for generations. However, the prevalence of upward mobility discourse in…

77 FR 40834 - Proposed Amendment of Class E Airspace; Dillon, MT

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-11

... further expand the previous proposed amendment of Class E airspace extending upward from 700 feet above... an amendment of Class E airspace extending upward from 700 feet above the surface. DATES: Comments... published a NPRM to modify Class E airspace, extending upward from 700 feet or more above the surface, at...

Upward Bound Math-Science: Program Description and Interim Impact Estimates

ERIC Educational Resources Information Center

Olsen, Robert; Seftor, Neil; Silva, Tim; Myers, David; DesRoches, David; Young, Julie

2007-01-01

To help address continuing disparities in academic achievement and under-representation of disadvantaged groups in math and science majors and careers, the U.S. Department of Education (ED) established a math and science initiative in 1990 within Upward Bound, a federal grant program known as Upward Bound Math-Science (UBMS) designed to provide…

34 CFR 645.43 - What other requirements must a grantee meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... period, Regular Upward Bound projects shall serve between 50 and 150 participants and Upward Bound Math and Science projects shall serve between 50 and 75 participants. (2) Veterans Upward Bound projects... requirements of paragraphs (a)(1) and (a)(2) of this section if the applicant can demonstrate that the project...

34 CFR 645.42 - What are Upward Bound stipends?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 3 2011-07-01 2011-07-01 false What are Upward Bound stipends? 645.42 Section 645.42 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION UPWARD BOUND PROGRAM What Conditions Must Be Met by a Grantee? § 645.42...

34 CFR 645.12 - How are regular Upward Bound projects organized?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false How are regular Upward Bound projects organized? 645.12 Section 645.12 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION UPWARD BOUND PROGRAM What Kinds of Projects and Services Does...

Social comparison processes and catastrophising in fibromyalgia: A path analysis.

PubMed

Cabrera-Perona, V; Buunk, A P; Terol-Cantero, M C; Quiles-Marcos, Y; Martín-Aragón, M

2017-06-01

In addition to coping strategies, social comparison may play a role in illness adjustment. However, little is known about the role of contrast and identification in social comparison in adaptation to fibromyalgia. To evaluate through a path analysis in a sample of fibromyalgia patients, the association between identification and contrast in social comparison, catastrophising and specific health outcomes (fibromyalgia illness impact and psychological distress). 131 Spanish fibromyalgia outpatients (mean age: 50.15, SD = 11.1) filled out a questionnaire. We present a model that explained 33% of the variance in catastrophising by direct effects of more use of upward contrast and downward identification. In addition, 35% of fibromyalgia illness impact variance was explained by less upward identification, more upward contrast and more catastrophising and 42% of the variance in psychological distress by a direct effect of more use of upward contrast together with higher fibromyalgia illness impact. We suggest that intervention programmes with chronic pain and fibromyalgia patients should focus on enhancing the use of upward identification in social comparison, and on minimising the use of upward contrast and downward identification in social comparison.

The Mediating Roles of Upward Social Comparison and Self-esteem and the Moderating Role of Social Comparison Orientation in the Association between Social Networking Site Usage and Subjective Well-Being.

PubMed

Wang, Jin-Liang; Wang, Hai-Zhen; Gaskin, James; Hawk, Skyler

2017-01-01

The increased pervasiveness of social media use has raised questions about potential effects on users' subjective well-being, with studies reaching contrasting conclusions. To reconcile these discrepancies and shed new light on this phenomenon, the current study examined: (1) whether upward social comparison and self-esteem mediate the association between social networking site (SNS) usage and users' subjective well-being, and (2) whether the association between SNS usage and upward social comparison is moderated by users' social comparison orientation. Data from 696 participants were collected. Structural equation modeling revealed that upward social comparison and self-esteem mediated the relationship between SNS usage and users' subjective well-being. We found that social comparison orientation moderated the association between passive SNS usage and users' upward social comparison. Specifically, social comparison orientation strengthened the association between passive SNS usage and upward social comparison. The results might suggest a process through which passive SNS usage is related to subjective well-being, and identify a context under which these associations may differ.

The Mediating Roles of Upward Social Comparison and Self-esteem and the Moderating Role of Social Comparison Orientation in the Association between Social Networking Site Usage and Subjective Well-Being

PubMed Central

Wang, Jin-Liang; Wang, Hai-Zhen; Gaskin, James; Hawk, Skyler

2017-01-01

The increased pervasiveness of social media use has raised questions about potential effects on users’ subjective well-being, with studies reaching contrasting conclusions. To reconcile these discrepancies and shed new light on this phenomenon, the current study examined: (1) whether upward social comparison and self-esteem mediate the association between social networking site (SNS) usage and users’ subjective well-being, and (2) whether the association between SNS usage and upward social comparison is moderated by users’ social comparison orientation. Data from 696 participants were collected. Structural equation modeling revealed that upward social comparison and self-esteem mediated the relationship between SNS usage and users’ subjective well-being. We found that social comparison orientation moderated the association between passive SNS usage and users’ upward social comparison. Specifically, social comparison orientation strengthened the association between passive SNS usage and upward social comparison. The results might suggest a process through which passive SNS usage is related to subjective well-being, and identify a context under which these associations may differ. PMID:28553256

Pioneer spacecraft operation at low and high spin rates

NASA Technical Reports Server (NTRS)

1973-01-01

The feasibility of executing major changes upward or downward from the nominal spin rate for which the Pioneer F&G spacecraft was designed was investigated along with the extent of system and subsystem modifications required to implement these mode changes in future spacecraft evolving from the baseline Pioneer F and G. Results of a previous study are re-examined and updated for an extended range of spin rate variations for missions that include outer planet orbiters, outer planet flyby and outer planet probe delivery. However, in the interest of design simplicity and cost economy, major modifications of the baseline Pioneer system and subsystem concept were avoided.

When compliments don't hit but critiques do: an fMRI study into self-esteem and self-knowledge in processing social feedback.

PubMed

van Schie, C C; Chiu, C D; Rombouts, S A R B; Heiser, W J; Elzinga, B M

2018-02-27

The way we view ourselves may play an important role in our responses to interpersonal interactions. In this study, we investigate how feedback valence, consistency of feedback with self-knowledge and global self-esteem influence affective and neural responses to social feedback. Participants (N = 46) with a high range of self-esteem levels performed the social feedback task in an MRI scanner. Negative, intermediate and positive feedback was provided, supposedly by another person based on a personal interview. Participants rated their mood and applicability of feedback to the self. Analyses on trial basis on neural and affective responses are used to incorporate applicability of individual feedback words. Lower self-esteem related to low mood especially after receiving non-applicable negative feedback. Higher self-esteem related to increased PCC and precuneus activation (i.e., self-referential processing) for applicable negative feedback. Lower self-esteem related to decreased mPFC, insula, ACC and PCC activation (i.e, self-referential processing) during positive feedback and decreased TPJ activation (i.e., other referential processing) for applicable positive feedback. Self-esteem and consistency of feedback with self-knowledge appear to guide our affective and neural responses to social feedback. This may be highly relevant for the interpersonal problems that individuals face with low self-esteem and negative self-views.

Efficient Processing of Acoustic Signals for High Rate Information Transmission over Sparse Underwater Channels

DTIC Science & Technology

2016-09-02

the fractionally-spaced channel estimators and the short feedforward equalizer filters . Receiver algorithm is applied to real data transmitted at 10...multichannel decision-feedback equalizer (DFE)[1]. This receiver consists of a bank of adaptive feedforwad filters , one per array element, followed by a...decision-feedback filter . It has been implemented in the prototype high-rate acoustic modem developed at the Woods Hole Oceanographic Institution, and

Meteor burst communications for LPI applications

NASA Astrophysics Data System (ADS)

Schilling, D. L.; Apelewicz, T.; Lomp, G. R.; Lundberg, L. A.

A technique that enhances the performance of meteor-burst communications is described. The technique, the feedback adaptive variable rate (FAVR) system, maintains a feedback channel that allows the transmitted bit rate to mimic the time behavior of the received power so that a constant bit energy is maintained. This results in a constant probability of bit error in each transmitted bit. Experimentally determined meteor-burst channel characteristics and FAVR system simulation results are presented.

Iterative Frequency Domain Decision Feedback Equalization and Decoding for Underwater Acoustic Communications

NASA Astrophysics Data System (ADS)

Zhao, Liang; Ge, Jian-Hua

2012-12-01

Single-carrier (SC) transmission with frequency-domain equalization (FDE) is today recognized as an attractive alternative to orthogonal frequency-division multiplexing (OFDM) for communication application with the inter-symbol interference (ISI) caused by multi-path propagation, especially in shallow water channel. In this paper, we investigate an iterative receiver based on minimum mean square error (MMSE) decision feedback equalizer (DFE) with symbol rate and fractional rate samplings in the frequency domain (FD) and serially concatenated trellis coded modulation (SCTCM) decoder. Based on sound speed profiles (SSP) measured in the lake and finite-element ray tracking (Bellhop) method, the shallow water channel is constructed to evaluate the performance of the proposed iterative receiver. Performance results show that the proposed iterative receiver can significantly improve the performance and obtain better data transmission than FD linear and adaptive decision feedback equalizers, especially in adopting fractional rate sampling.

Upward electron beams measured by DE-1 - A primary source of dayside region-1 Birkeland currents

NASA Technical Reports Server (NTRS)

Burch, J. L.; Reiff, P. H.; Sugiura, M.

1983-01-01

Measurements made by the High Altitude Plasma Instrument on DE-1 have shown that intense upward electron beams with energies from about 20 eV to about 200 eV are a common feature of the region just equatorward of the morning-side polar cusp. Computations of the currents carried by these beams and by the precipitating cusp electrons show excellent agreement with the simultaneous DE-1 magnetometer measurements for both upward and downward Birkeland currents. The data indicate that cold ionospheric electrons, which carry the downward region-1 Birkeland currents on the morning side, are accelerated upward by potential drops of a few tens of eV at altitudes of several thousand kilometers. This acceleration process allows spacecraft above those altitudes to measure routinely the charge carriers of both downward and upward current systems.

Who wants feedback? An investigation of the variables influencing residents' feedback-seeking behavior in relation to night shifts.

PubMed

Teunissen, Pim W; Stapel, Diederik A; van der Vleuten, Cees; Scherpbier, Albert; Boor, Klarke; Scheele, Fedde

2009-07-01

The literature on feedback in clinical medical education has predominantly treated trainees as passive recipients. Past research has focused on how clinical supervisors can use feedback to improve a trainee's performance. On the basis of research in social and organizational psychology, the authors reconceptualized residents as active seekers of feedback. They investigated what individual and situational variables influence residents' feedback-seeking behavior on night shifts. Early in 2008, the authors sent obstetrics-gynecology residents in the Netherlands--both those in their first two years of graduate training and those gaining experience between undergraduate and graduate training--a questionnaire that assessed four predictor variables (learning and performance goal orientation, and instrumental and supportive leadership), two mediator variables (perceived feedback benefits and costs), and two outcome variables (frequency of feedback inquiry and monitoring). They used structural equation modeling software to test a hypothesized model of relationships between variables. The response rate was 76.5%. Results showed that residents who perceive more feedback benefits report a higher frequency of feedback inquiry and monitoring. More perceived feedback costs result mainly in more feedback monitoring. Residents with a higher learning goal orientation perceive more feedback benefits and fewer costs. Residents with a higher performance goal orientation perceive more feedback costs. Supportive physicians lead residents to perceive more feedback benefits and fewer costs. This study showed that some residents actively seek feedback. Residents' feedback-seeking behavior partially depends on attending physicians' supervisory style. Residents' goal orientations influence their perceptions of the benefits and costs of feedback-seeking.

College Enrollment and Work Activity of 2006 High School Graduate. Bureau of Labor Statistics News. USDL 07-0604

ERIC Educational Resources Information Center

Bureau of Labor Statistics, 2007

2007-01-01

In October 2006, 65.8 percent of high school graduates from the class of 2006 were enrolled in colleges or universities, according to data released by the U.S. Department of Labor's Bureau of Labor Statistics. Since 2001, the college enrollment rate for recent high school graduates has been trending upward. Information on school enrollment and…

Pressure regulator

DOEpatents

Ebeling, Jr., Robert W.; Weaver, Robert B.

1979-01-01

The pressure within a pressurized flow reactor operated under harsh environmental conditions is controlled by establishing and maintaining a fluidized bed of uniformly sized granular material of selected density by passing the gas from the reactor upwardly therethrough at a rate sufficient to fluidize the bed and varying the height of the bed by adding granular material thereto or removing granular material therefrom to adjust the backpressure on the flow reactor.

Modeling Fluid Flow and Microbial Reactions in the Peru Accretionary Complex

NASA Astrophysics Data System (ADS)

Bekins, B. A.; Matmon, D.

2002-12-01

Accretionary complexes are sites where sediment compaction and deeper reactions drive large-scale flow systems that can affect global solute budgets. Extensive modeling and drilling studies have elucidated the origin of the fluids, pore pressures, duration of flow, and major flow paths in these settings. An important research goal is to quantify the effect of these flow systems on global chemical budgets of reactive solutes such as carbon. The Peru margin represents an end member setting that can serve as a basis to extend the results to other margins. The sediments are relatively high in organic carbon with an average value of 2.6%. The subduction rate at ~9 cm/yr and taper angle at 14-17° are among the largest in the world. Recent microbial studies on Ocean Drilling Program Leg 201 at the Peru accretionary margin provide many key elements needed to quantify the processes affecting organic carbon in an accretionary complex. Pore water chemistry data from Site 1230 located in the Peru accretionary prism indicate that sulfate reduction is important in the top 8 mbsf. Below this depth, methanogenesis is the dominant process and methane concentrations are among the highest measured at any site on Leg 201. The presence of high methane concentrations at shallow depths suggests that methane is transported upward in the prism by fluid flow. Measurements of in-situ pore pressures and temperatures also support the presence of upward fluid flow. A single in-situ pressure measurement at ~100 mbsf indicated an overpressure of 0.14 MPa. For a reasonable formation permeability of ~ 10-16 m2, the measured overpressure is adequate to produce flow at a rate of ~5 mm/yr. This rate is comparable to previous model estimates for flow rates in the Peru accretionary prism. In addition, curvature in the downhole temperature profile can best be explained by upward fluid flow of 1-10 mm/yr. These data are used to constrain a two-dimensional coupled fluid flow and reactive transport model focusing on the fate of organic carbon entering in the Peru accretionary complex. The proposed work is the first attempt at a quantitative estimate of the processes affecting the fate of organic carbon entering a subduction zone.

Can providing feedback on driving behavior and training on parental vigilant care affect male teen drivers and their parents?

PubMed

Farah, Haneen; Musicant, Oren; Shimshoni, Yaara; Toledo, Tomer; Grimberg, Einat; Omer, Haim; Lotan, Tsippy

2014-08-01

This study focuses on investigating the driving behavior of young novice male drivers during the first year of driving (three months of accompanied driving and the following nine months of solo driving). The study's objective is to examine the potential of various feedback forms on driving to affect young drivers' behavior and to mitigate the transition from accompanied to solo driving. The study examines also the utility of providing parents with guidance on how to exercise vigilant care regarding their teens' driving. Driving behavior was evaluated using data collected by In-Vehicle Data Recorders (IVDR), which document events of extreme g-forces measured in the vehicles. IVDR systems were installed in 242 cars of the families of young male drivers, however, only 217 families of young drivers aged 17-22 (M=17.5; SD=0.8) completed the one year period. The families were randomly allocated into 4 groups: (1) Family feedback: In which all the members of the family were exposed to feedback on their own driving and on that of the other family members; (2) Parental training: in which in addition to the family feedback, parents received personal guidance on ways to enhance vigilant care regarding their sons' driving; (3) Individual feedback: In which family members received feedback only on their own driving behavior (and were not exposed to the data on other family members); (4) CONTROL: Group that received no feedback at all. The feedback was provided to the different groups starting from the solo period, thus, the feedback was not provided during the supervised period. The data collected by the IVDRs was first analyzed using analysis of variance in order to compare the groups with respect to their monthly event rates. Events' rates are defined as the number of events in a trip divided by its duration. This was followed by the development and estimation of random effect negative binomial models that explain the monthly event rates of young drivers and their parents. The study showed that: (1) the Parental training group recorded significantly lower events rates (-29%) compared to the CONTROL group during the solo period; (2) although directed mainly at the novice drivers, the intervention positively affected also the behavior of parents, with both fathers and mothers in the Parental training group improving their driving (by -23% for both fathers and mothers) and mothers improving it also in the Family feedback group (by -30%). Thus, the intervention has broader impact effect beside the targeted population. It can be concluded that providing feedback on driving behavior and parental training in vigilant care significantly improves the driving behavior of young novice male drivers. Future research directions could include applying the intervention to a broader population, with larger diversity with respect to their driving records, culture, and behaviors. The challenge is to reach wide dissemination of IVDR for young drivers accompanied by parents' involvement, and to find the suitable incentives for its sustainability. Copyright © 2013 Elsevier Ltd. All rights reserved.

A dynamical stabilizer in the climate system: a mechanism suggested by a simple model

NASA Astrophysics Data System (ADS)

Bates, J. R.

1999-05-01

A simple zonally averaged hemispheric model of the climate system is constructed, based on energy equations for two ocean basins separated at 30° latitude with the surface fluxes calculated explicitly. A combination of empirical input and theoretical calculation is used to determine an annual mean equilibrium climate for the model and to study its stability with respect to small perturbations. The insolation, the mean albedos and the equilibrium temperatures for the two model zones are prescribed from observation. The principal agent of interaction between the zones is the vertically integrated poleward transport of atmospheric angular momentum across their common boundary. This is parameterized using an empirical formula derived from a multiyear atmospheric data set. The surface winds are derived from the angular momentum transport assuming the atmosphere to be in a state of dynamic balance on the climatic timescales of interest. A further assumption that the air sea temperature difference and low level relative humidity remain fixed at their mean observed values then allows the surface fluxes of latent and sensible heat to be calculated. Results from a radiative model, which show a positive lower tropospheric water vapour/infrared radiative feedback on SST perturbations in both zones, are used to calculate the net upward infrared radiative fluxes at the surface. In the model's equilibrium climate, the principal processes balancing the solar radiation absorbed at the surface are evaporation in the tropical zone and net infrared radiation in the extratropical zone. The stability of small perturbations about the equilibrium is studied using a linearized form of the ocean energy equations. Ice-albedo and cloud feedbacks are omitted and attention is focussed on the competing effects of the water vapour/infrared radiative feedback and the turbulent surface flux and oceanic heat transport feedbacks associated with the angular momentum cycle. The perturbation equations involve inter-zone coupling and have coefficients dependent on the values of the equilibrium fluxes and the sensitivity of the angular momentum transport. Analytical solutions for the perturbations are obtained. These provide criteria for the stability of the equilibrium climate. If the evaporative feedback on SST perturbations is omitted, the equilibrium climate is unstable due to the influence of the water vapour/infrared radiative feedback, which dominates over the effects of the sensible heat and ocean heat transport feedbacks. The inclusion of evaporation gives a negative feedback which is of sufficient strength to stabilize the system. The stabilizing mechanism involves wind and humidity factors in the evaporative fluxes that are of comparable magnitude. Both factors involve the angular momentum transport. In including angular momentum and calculating the surface fluxes explicitly, the model presented here differs from the many simple climate models based on the Budyko Sellers formulation. In that formulation, an atmospheric energy balance equation is used to eliminate surface fluxes in favour of top-of-the-atmosphere radiative fluxes and meridional atmospheric energy transports. In the resulting models, infrared radiation appears as a stabilizing influence on SST perturbations and the dynamical stabilizing mechanism found here cannot be identified.

Development and Evaluation of a Novel Survey Tool Assessing Inpatient Consult Service Performance.

PubMed

Miloslavsky, Eli M; Chang, Yuchiao

2017-12-01

Subspecialty consultation in inpatient medicine is increasing, and enhancing performance of consultation services may have a broad-reaching impact. Multisource feedback is an important tool in assessing competence and improving performance. A mechanism for primary team resident feedback on performance of consult services has not been described. We developed and evaluated an instrument designed to assess internal medicine (IM) subspecialty inpatient consult service performance. We hypothesized that the instrument would be feasible to administer and provide important information to fellowship directors. The instrument was administered in 2015 and 2016 at a single academic center. All IM residents were invited to evaluate 10 IM subspecialty consult services on 4 items and an overall satisfaction rating. The instrument allowed for free-text feedback to fellows. Program directors completed another survey assessing the impact of the consult service evaluation. A total of 113 residents responded (47 in 2015 and 66 in 2016, for a combined response rate of 35%). Each of the 4 items measured (communication, professionalism, teaching, and pushback) correlated significantly with the overall satisfaction rating in univariate and multivariate analyses. There were no differences in ratings across postgraduate year or year of administration. There was considerable variation in ratings among the services evaluated. The 7 program directors who provided feedback found the survey useful and made programmatic changes following evaluation implementation. A primary team resident evaluation of inpatient medicine subspecialty consult services is feasible, provides valuable information, and is associated with changes in consult service structure and curricula.

Potential effects of fat mass and fat-free mass on energy intake in different states of energy balance.

PubMed

Stubbs, R James; Hopkins, M; Finlayson, G S; Duarte, C; Gibbons, C; Blundell, J E

2018-05-01

Recently models have attempted to integrate the functional relationships of fat mass (FM) and fat-free mass (FFM) with the control of human energy intake (EI). Cross-sectional evidence suggests that at or close to EB, FFM is positively related to hunger and EI, whereas FM either shows a weak negative or no association with ad libitum EI. Further analysis suggests that the effects of FFM and FM on EI may be mediated by resting metabolic rate (RMR). These studies suggest that energy turnover is associated with EI and the largest determinant of energy requirements in most humans is FFM. During chronic positive EBs both FM and FFM expand (but disproportionately so), increasing energy demands. There is little evidence that an expanding FM exerts strong negative feedback on longer term EI. However, during chronic negative EBs FM, FFM and RMR all decrease but appetite increases. Some studies suggest that proportionate loss of FFM during weight loss predicts subsequent weight regain. Taken together these lines of evidence suggest that changes in the size and functional integrity of FFM may influence appetite and EI. Increases in FFM associated with either weight gain or high levels of exercise may 'pull' EI upwards but energy deficits that decrease FFM may exert a distinct drive on appetite. The current paper discusses how FM and FFM relationships influence appetite regulation, and how size, structure and functional integrity of FFM may drive EI in humans (i) at EB (ii) during positive EB and (iii) during negative EB.

Lack of transfer of skills after virtual reality simulator training with haptic feedback.

PubMed

Våpenstad, Cecilie; Hofstad, Erlend Fagertun; Bø, Lars Eirik; Kuhry, Esther; Johnsen, Gjermund; Mårvik, Ronald; Langø, Thomas; Hernes, Toril Nagelhus

2017-12-01

Virtual reality (VR) simulators enrich surgical training and offer training possibilities outside of the operating room (OR). In this study, we created a criterion-based training program on a VR simulator with haptic feedback and tested it by comparing the performances of a simulator group against a control group. Medical students with no experience in laparoscopy were randomly assigned to a simulator group or a control group. In the simulator group, the candidates trained until they reached predefined criteria on the LapSim ® VR simulator (Surgical Science AB, Göteborg, Sweden) with haptic feedback (Xitact TM IHP, Mentice AB, Göteborg, Sweden). All candidates performed a cholecystectomy on a porcine organ model in a box trainer (the clinical setting). The performances were video rated by two surgeons blinded to subject training status. In total, 30 students performed the cholecystectomy and had their videos rated (N = 16 simulator group, N = 14 control group). The control group achieved better video rating scores than the simulator group (p < .05). The criterion-based training program did not transfer skills to the clinical setting. Poor mechanical performance of the simulated haptic feedback is believed to have resulted in a negative training effect.

Upward Mobility Programs in the Service Sector for Disadvantaged and Dislocated Workers. Volume I: Final Report.

ERIC Educational Resources Information Center

Tao, Fumiyo; And Others

Upward mobility programs in the service sector for low-skilled, economically disadvantaged, and dislocated or displaced workers promote employment security, career development, and productivity. Two basic types of upward mobility programs are basic and job-specific skills training. Although 60-80 percent of all employer-sponsored formal training…

77 FR 21089 - Notice of Submission for OMB Review; Application for Grants Under the Upward Bound Math and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-09

... Upward Bound Math and Science Program AGENCY: Office of Postsecondary Education, Department of Education. SUMMARY: The Upward Bound Math and Science (UBMS) program provides grants to institutions of higher... for success in a program of postsecondary education that lead to careers in math and science. DATES...

34 CFR 645.31 - What selection criteria does the Secretary use?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Upward Bound project, the Secretary reviews each type of project (Regular, Math and Science, or Veterans... need for an Upward Bound Math and Science Center in the proposed target area on the basis of— (i) The... careers in mathematics and science, and who could benefit from an Upward Bound Math and Science program...

34 CFR 645.31 - What selection criteria does the Secretary use?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Upward Bound project, the Secretary reviews each type of project (Regular, Math and Science, or Veterans... need for an Upward Bound Math and Science Center in the proposed target area on the basis of— (i) The... careers in mathematics and science, and who could benefit from an Upward Bound Math and Science program...

34 CFR 645.31 - What selection criteria does the Secretary use?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Upward Bound project, the Secretary reviews each type of project (Regular, Math and Science, or Veterans... need for an Upward Bound Math and Science Center in the proposed target area on the basis of— (i) The... careers in mathematics and science, and who could benefit from an Upward Bound Math and Science program...

34 CFR 645.31 - What selection criteria does the Secretary use?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Upward Bound project, the Secretary reviews each type of project (Regular, Math and Science, or Veterans... need for an Upward Bound Math and Science Center in the proposed target area on the basis of— (i) The... careers in mathematics and science, and who could benefit from an Upward Bound Math and Science program...

34 CFR 645.31 - What selection criteria does the Secretary use?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Upward Bound project, the Secretary reviews each type of project (Regular, Math and Science, or Veterans... need for an Upward Bound Math and Science Center in the proposed target area on the basis of— (i) The... careers in mathematics and science, and who could benefit from an Upward Bound Math and Science program...

Upwardly Mobile Working-Class Adolescents: A Biographical Approach on Habitus Dislocation

ERIC Educational Resources Information Center

Christodoulou, Michael; Spyridakis, Manos

2017-01-01

Habitus dislocation is a much debatable term. By presenting life-histories of working-class adolescents, this article argues (i) that not all upwardly mobile working-class adolescents experience habitus dislocation and, (ii) that habitus dislocation has its roots in the self-initiated ruptures that face some of those who want to be upwardly mobile…

34 CFR 645.3 - Who is eligible to participate in an Upward Bound project?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Who is eligible to participate in an Upward Bound project? An individual is eligible to participate in a Regular, Veterans, or a Math and Science Upward Bound project if the individual meets all of the... project? 645.3 Section 645.3 Education Regulations of the Offices of the Department of Education...

Social anxiety and the ironic effects of positive interviewer feedback.

PubMed

Budnick, Christopher J; Kowal, Marta; Santuzzi, Alecia M

2015-01-01

Positive interviewer feedback should encourage positive experiences and outcomes for interviewees. Yet, positive feedback is inconsistent with socially anxious interviewees' negative self-views. Socially anxious interviewees might experience increased self-focus while attempting to reconcile the inconsistency between their self-perceptions and that feedback. This could interfere with successful interview performance. This study used a 3 (feedback: positive, negative, no) × 2 (social anxiety: high, low) between-subjects design. Undergraduate students (N = 88) completed a measure of dispositional social anxiety. They then engaged in a simulated interview with a White confederate trained to adhere to a standardized script. Interviewees received positive, negative, or no interviewer feedback. Each interview was video recorded to code anxiety displays, impression management tactics, and interview success. Following positive feedback, socially anxious interviewees displayed more anxiety, less assertiveness, and received lower success ratings. Among anxious interviewees, increased self-focus provided an indirect path between positive feedback and lower success. Consistent with self-verification theory, anxious interviewees had poorer interview performance following positive feedback that contradicted their negative self-views. Thus, socially anxious interviewees might be at a disadvantage when interviewing, especially following positive feedback. Implications for interviewees and interviewers are discussed.

Some effects of horizontal discretization on linear baroclinic and symmetric instabilities

NASA Astrophysics Data System (ADS)

Barham, William; Bachman, Scott; Grooms, Ian

2018-05-01

The effects of horizontal discretization on linear baroclinic and symmetric instabilities are investigated by analyzing the behavior of the hydrostatic Eady problem in ocean models on the B and C grids. On the C grid a spurious baroclinic instability appears at small wavelengths. This instability does not disappear as the grid scale decreases; instead, it simply moves to smaller horizontal scales. The peak growth rate of the spurious instability is independent of the grid scale as the latter decreases. It is equal to cf /√{Ri} where Ri is the balanced Richardson number, f is the Coriolis parameter, and c is a nondimensional constant that depends on the Richardson number. As the Richardson number increases c increases towards an upper bound of approximately 1/2; for large Richardson numbers the spurious instability is faster than the Eady instability. To suppress the spurious instability it is recommended to use fourth-order centered tracer advection along with biharmonic viscosity and diffusion with coefficients (Δx) 4 f /(32√{Ri}) or larger where Δx is the grid scale. On the B grid, the growth rates of baroclinic and symmetric instabilities are too small, and converge upwards towards the correct values as the grid scale decreases; no spurious instabilities are observed. In B grid models at eddy-permitting resolution, the reduced growth rate of baroclinic instability may contribute to partially-resolved eddies being too weak. On the C grid the growth rate of symmetric instability is better (larger) than on the B grid, and converges upwards towards the correct value as the grid scale decreases.

Relationships between CO 2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

DOE PAGES

Winnick, Matthew J.; Maher, Kate

2018-01-27

Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO 2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO 2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. Here, we test this theoretical scaling relationship against reactive transport simulations of chemical weathering profilesmore » under open-and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO 2(y =kx n)where nis dependent on reaction stoichiometry and kis dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO 2 at low values and approach open-system scaling at high pCO 2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO 2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence of equilibrium solute concentrations on pCO 2 may represent a direct weathering feedback largely independent of climate and modulated by belowground organic carbon respiration.« less

Self-regulation of the anterior insula: Reinforcement learning using real-time fMRI neurofeedback.

PubMed

Lawrence, Emma J; Su, Li; Barker, Gareth J; Medford, Nick; Dalton, Jeffrey; Williams, Steve C R; Birbaumer, Niels; Veit, Ralf; Ranganatha, Sitaram; Bodurka, Jerzy; Brammer, Michael; Giampietro, Vincent; David, Anthony S

2014-03-01

The anterior insula (AI) plays a key role in affective processing, and insular dysfunction has been noted in several clinical conditions. Real-time functional MRI neurofeedback (rtfMRI-NF) provides a means of helping people learn to self-regulate activation in this brain region. Using the Blood Oxygenated Level Dependant (BOLD) signal from the right AI (RAI) as neurofeedback, we trained participants to increase RAI activation. In contrast, another group of participants was shown 'control' feedback from another brain area. Pre- and post-training affective probes were shown, with subjective ratings and skin conductance response (SCR) measured. We also investigated a reward-related reinforcement learning model of rtfMRI-NF. In contrast to the controls, we hypothesised a positive linear increase in RAI activation in participants shown feedback from this region, alongside increases in valence ratings and SCR to affective probes. Hypothesis-driven analyses showed a significant interaction between the RAI/control neurofeedback groups and the effect of self-regulation. Whole-brain analyses revealed a significant linear increase in RAI activation across four training runs in the group who received feedback from RAI. Increased activation was also observed in the caudate body and thalamus, likely representing feedback-related learning. No positive linear trend was observed in the RAI in the group receiving control feedback, suggesting that these data are not a general effect of cognitive strategy or control feedback. The control group did, however, show diffuse activation across the putamen, caudate and posterior insula which may indicate the representation of false feedback. No significant training-related behavioural differences were observed for valence ratings, or SCR. In addition, correlational analyses based on a reinforcement learning model showed that the dorsal anterior cingulate cortex underpinned learning in both groups. In summary, these data demonstrate that it is possible to regulate the RAI using rtfMRI-NF within one scanning session, and that such reward-related learning is mediated by the dorsal anterior cingulate. Copyright © 2013 Elsevier Inc. All rights reserved.

Relationships between CO 2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winnick, Matthew J.; Maher, Kate

Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO 2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO 2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. Here, we test this theoretical scaling relationship against reactive transport simulations of chemical weathering profilesmore » under open-and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO 2(y =kx n)where nis dependent on reaction stoichiometry and kis dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO 2 at low values and approach open-system scaling at high pCO 2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO 2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence of equilibrium solute concentrations on pCO 2 may represent a direct weathering feedback largely independent of climate and modulated by belowground organic carbon respiration.« less

Relationships between CO2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

NASA Astrophysics Data System (ADS)

Winnick, Matthew J.; Maher, Kate

2018-03-01

Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. We test this theoretical scaling relationship against reactive transport simulations of chemical weathering profiles under open- and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO2 (y = kxn) where n is dependent on reaction stoichiometry and k is dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO2 at low values and approach open-system scaling at high pCO2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence of equilibrium solute concentrations on pCO2 may represent a direct weathering feedback largely independent of climate and modulated by belowground organic carbon respiration.

Quantitative impact of direct, personal feedback on hand hygiene technique.

PubMed

Lehotsky, Á; Szilágyi, L; Ferenci, T; Kovács, L; Pethes, R; Wéber, G; Haidegger, T

2015-09-01

This study investigated the effectiveness of targeting hand hygiene technique using a new training device that provides objective, personal and quantitative feedback. One hundred and thirty-six healthcare workers in three Hungarian hospitals participated in a repetitive hand hygiene technique assessment study. Ultraviolet (UV)-labelled hand rub was used at each event, and digital images of the hands were subsequently taken under UV light. Immediate objective visual feedback was given to participants, showing missed areas on their hands. The rate of inadequate hand rubbing reduced from 50% to 15% (P < 0.001). However, maintenance of this reduced rate is likely to require continuous use of the electronic equipment. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Use of temperature profiles beneath streams to determine rates of vertical ground-water flow and vertical hydraulic conductivity

USGS Publications Warehouse

Lapham, Wayne W.

1989-01-01

The use of temperature profiles beneath streams to determine rates of vertical ground-water flow and effective vertical hydraulic conductivity of sediments was evaluated at three field sites by use of a model that numerically solves the partial differential equation governing simultaneous vertical flow of fluid and heat in the Earth. The field sites are located in Hardwick and New Braintree, Mass., and in Dover, N.J. In New England, stream temperature varies from about 0 to 25 ?C (degrees Celsius) during the year. This stream-temperature fluctuation causes ground-water temperatures beneath streams to fluctuate by more than 0.1 ?C during a year to a depth of about 35 ft (feet) in fine-grained sediments and to a depth of about 50 ft in coarse-grained sediments, if ground-water velocity is 0 ft/d (foot per day). Upward flow decreases the depth affected by stream-temperature fluctuation, and downward flow increases the depth. At the site in Hardwick, Mass., ground-water flow was upward at a rate of less than 0.01 ft/d. The maximum effective vertical hydraulic conductivity of the sediments underlying this site is 0.1 ft/d. Ground-water velocities determined at three locations at the site in New Braintree, Mass., where ground water discharges naturally from the underlying aquifer to the Ware River, ranged from 0.10 to 0.20 ft/d upward. The effective vertical hydraulic conductivity of the sediments underlying this site ranged from 2.4 to 17.1 ft/d. Ground-water velocities determined at three locations at the Dover, N.J., site, where infiltration from the Rockaway River into the underlying sediments occurs because of pumping, were 1.5 ft/d downward. The effective vertical hydraulic conductivity of the sediments underlying this site ranged from 2.2 to 2.5 ft/d. Independent estimates of velocity at two of the three sites are in general agreement with the velocities determined using temperature profiles. The estimates of velocities and conductivities derived from the temperature measurements generally fall within the ranges of expected rates of flow in, and conductivities of, the sediments encountered at the test sites. Application of the method at the three test sites demonstrates the feasibility of using the method to determine the rate of ground-water flow between a stream and underlying sediments and the effective vertical hydraulic conductivity of the sediments.

Modeling heart rate variability by stochastic feedback

NASA Technical Reports Server (NTRS)

Amaral, L. A.; Goldberger, A. L.; Stanley, H. E.

1999-01-01

We consider the question of how the cardiac rhythm spontaneously self-regulates and propose a new mechanism as a possible answer. We model the neuroautonomic regulation of the heart rate as a stochastic feedback system and find that the model successfully accounts for key characteristics of cardiac variability, including the 1/f power spectrum, the functional form and scaling of the distribution of variations of the interbeat intervals, and the correlations in the Fourier phases which indicate nonlinear dynamics.

The speech naturalness of people who stutter speaking under delayed auditory feedback as perceived by different groups of listeners.

PubMed

Van Borsel, John; Eeckhout, Hannelore

2008-09-01

This study investigated listeners' perception of the speech naturalness of people who stutter (PWS) speaking under delayed auditory feedback (DAF) with particular attention for possible listener differences. Three panels of judges consisting of 14 stuttering individuals, 14 speech language pathologists, and 14 naive listeners rated the naturalness of speech samples of stuttering and non-stuttering individuals using a 9-point interval scale. Results clearly indicate that these three groups evaluate naturalness differently. Naive listeners appear to be more severe in their judgements than speech language pathologists and stuttering listeners, and speech language pathologists are apparently more severe than PWS. The three listener groups showed similar trends with respect to the relationship between speech naturalness and speech rate. Results of all three indicated that for PWS, the slower a speaker's rate was, the less natural speech was judged to sound. The three listener groups also showed similar trends with regard to naturalness of the stuttering versus the non-stuttering individuals. All three panels considered the speech of the non-stuttering participants more natural. The reader will be able to: (1) discuss the speech naturalness of people who stutter speaking under delayed auditory feedback, (2) discuss listener differences about the naturalness of people who stutter speaking under delayed auditory feedback, and (3) discuss the importance of speech rate for the naturalness of speech.

A lattice hydrodynamic model based on delayed feedback control considering the effect of flow rate difference

NASA Astrophysics Data System (ADS)

Wang, Yunong; Cheng, Rongjun; Ge, Hongxia

2017-08-01

In this paper, a lattice hydrodynamic model is derived considering not only the effect of flow rate difference but also the delayed feedback control signal which including more comprehensive information. The control method is used to analyze the stability of the model. Furthermore, the critical condition for the linear steady traffic flow is deduced and the numerical simulation is carried out to investigate the advantage of the proposed model with and without the effect of flow rate difference and the control signal. The results are consistent with the theoretical analysis correspondingly.

THE EFFECT OF FEEDBACK ON THE ACCURACY OF CHECKLIST COMPLETION DURING INSTRUMENT FLIGHT TRAINING

PubMed Central

Rantz, William G; Dickinson, Alyce M; Sinclair, Gilbert A; Van Houten, Ron

2009-01-01

This study examined whether pilots completed airplane checklists more accurately when they receive postflight graphic and verbal feedback. Participants were 8 college students who are pilots with an instrument rating. The task consisted of flying a designated flight pattern using a personal computer aviation training device (PCATD). The dependent variables were the number of checklist items completed correctly. A multiple baseline design across pairs of participants with withdrawal of treatment was employed in this study. During baseline, participants were given postflight technical feedback. During intervention, participants were given postflight graphic feedback on checklist use and praise for improvements along with technical feedback. The intervention produced near perfect checklist performance, which was maintained following a return to the baseline conditions. PMID:20190914

Do 360-degree feedback survey results relate to patient satisfaction measures?

PubMed

Hageman, Michiel G J S; Ring, David C; Gregory, Paul J; Rubash, Harry E; Harmon, Larry

2015-05-01

There is evidence that feedback from 360-degree surveys-combined with coaching-can improve physician team performance and quality of patient care. The Physicians Universal Leadership-Teamwork Skills Education (PULSE) 360 is one such survey tool that is used to assess work colleagues' and coworkers' perceptions of a physician's leadership, teamwork, and clinical practice style. The Clinician & Group-Consumer Assessment of Healthcare Providers and System (CG-CAHPS), developed by the US Department of Health and Human Services to serve as the benchmark for quality health care, is a survey tool for patients to provide feedback that is based on their recent experiences with staff and clinicians and soon will be tied to Medicare-based compensation of participating physicians. Prior research has indicated that patients and coworkers often agree in their assessment of physicians' behavioral patterns. The goal of the current study was to determine whether 360-degree, also called multisource, feedback provided by coworkers could predict patient satisfaction/experience ratings. A significant relationship between these two forms of feedback could enable physicians to take a more proactive approach to reinforce their strengths and identify any improvement opportunities in their patient interactions by reviewing feedback from team members. An automated 360-degree software process may be a faster, simpler, and less resource-intensive approach than telephoning and interviewing patients for survey responses, and it potentially could facilitate a more rapid credentialing or quality improvement process leading to greater fiscal and professional development gains for physicians. Our primary research question was to determine if PULSE 360 coworkers' ratings correlate with CG-CAHPS patients' ratings of overall satisfaction, recommendation of the physician, surgeon respect, and clarity of the surgeon's explanation. Our secondary research questions were to determine whether CG-CAHPS scores correlate with additional composite scores from the Quality PULSE 360 (eg, insight impact score, focus concerns score, leadership-teamwork index score, etc). We retrospectively analyzed existing quality improvement data from CG-CAHPS patient surveys as well as from a department quality improvement initiative using 360-degree survey feedback questionnaires (Quality PULSE 360 with coworkers). Bivariate analyses were conducted to identify significant relationships for inclusion of research variables in multivariate linear analyses (eg, stepwise regression to determine the best fitting predictive model for CG-CAHPS ratings). In all higher order analyses, CG-CAHPS ratings were treated as the dependent variables, whereas PULSE 360 scores served as independent variables. This approach led to the identification of the most predictive linear model for each CG-CAHPS' performance rating (eg, [1] overall satisfaction; [2] recommendation of the physician; [3] surgeon respect; and [4] clarity of the surgeon's explanation) regressed on all PULSE scores with which there was a significant bivariate relationship. Backward stepwise regression was then used to remove unnecessary predictors from the linear model based on changes in the variance explained by the model with or without inclusion of the predictor. The Quality PULSE 360 insight impact score correlated with patient satisfaction (0.50, p = 0.01), patient recommendation (0.58, p = 0.002), patient rating of surgeon respect (0.74, p < 0.001), and patient impression of clarity of the physician explanation (0.69, p < 0.001). Additionally, leadership-teamwork index also correlated with patient rating of surgeon respect (0.46, p = 0.019) and patient impression of clarity of the surgeon's explanation (0.39, p = 0.05). Multivariate analyses supported retention of insight impact as a predictor of patient overall satisfaction, patient recommendation of the surgeon, and patient rating of surgeon respect. Both insight impact and leadership-teamwork index were retained as predictors of patient impression of explanation. Several other PULSE 360 variables were correlated with CG-CAHPS ratings, but none were retained in the linear models post stepwise regression. The relationship between Quality PULSE 360 feedback scores and measures of patient satisfaction reaffirm that feedback from work team members may provide helpful information into how patients may be perceiving their physicians' behavior and vice versa. Furthermore, the findings provide tentative support for the use of team-based feedback to improve the quality of relationships with both coworkers and patients. The 360-degree survey process may offer an effective tool for physicians to obtain feedback about behavior that could directly impact practice reimbursement and reputation or potentially be used for bonuses to incentivize better team professionalism and patient satisfaction, ie, "pay-for-professionalism." Further research is needed to expand on this line of inquiry, determine which interventions can improve 360-degree and patient satisfaction scores, and explain the shared variance in physician performance that is captured in the perceptions of patients and coworkers.

The mechanics of granitoid systems and maximum entropy production rates.

PubMed

Hobbs, Bruce E; Ord, Alison

2010-01-13

A model for the formation of granitoid systems is developed involving melt production spatially below a rising isotherm that defines melt initiation. Production of the melt volumes necessary to form granitoid complexes within 10(4)-10(7) years demands control of the isotherm velocity by melt advection. This velocity is one control on the melt flux generated spatially just above the melt isotherm, which is the control valve for the behaviour of the complete granitoid system. Melt transport occurs in conduits initiated as sheets or tubes comprising melt inclusions arising from Gurson-Tvergaard constitutive behaviour. Such conduits appear as leucosomes parallel to lineations and foliations, and ductile and brittle dykes. The melt flux generated at the melt isotherm controls the position of the melt solidus isotherm and hence the physical height of the Transport/Emplacement Zone. A conduit width-selection process, driven by changes in melt viscosity and constitutive behaviour, operates within the Transport Zone to progressively increase the width of apertures upwards. Melt can also be driven horizontally by gradients in topography; these horizontal fluxes can be similar in magnitude to vertical fluxes. Fluxes induced by deformation can compete with both buoyancy and topographic-driven flow over all length scales and results locally in transient 'ponds' of melt. Pluton emplacement is controlled by the transition in constitutive behaviour of the melt/magma from elastic-viscous at high temperatures to elastic-plastic-viscous approaching the melt solidus enabling finite thickness plutons to develop. The system involves coupled feedback processes that grow at the expense of heat supplied to the system and compete with melt advection. The result is that limits are placed on the size and time scale of the system. Optimal characteristics of the system coincide with a state of maximum entropy production rate. This journal is © 2010 The Royal Society

When compliments do not hit but critiques do: an fMRI study into self-esteem and self-knowledge in processing social feedback

PubMed Central

van Schie, Charlotte C; Chiu, Chui-De; Rombouts, Serge A R B; Heiser, Willem J; Elzinga, Bernet M

2018-01-01

Abstract The way we view ourselves may play an important role in our responses to interpersonal interactions. In this study, we investigate how feedback valence, consistency of feedback with self-knowledge and global self-esteem influence affective and neural responses to social feedback. Participants (N = 46) with a high range of self-esteem levels performed the social feedback task in an MRI scanner. Negative, intermediate and positive feedback was provided, supposedly by another person based on a personal interview. Participants rated their mood and applicability of feedback to the self. Analyses on trial basis on neural and affective responses are used to incorporate applicability of individual feedback words. Lower self-esteem related to low mood especially after receiving non-applicable negative feedback. Higher self-esteem related to increased posterior cingulate cortex and precuneus activation (i.e. self-referential processing) for applicable negative feedback. Lower self-esteem related to decreased medial prefrontal cortex, insula, anterior cingulate cortex and posterior cingulate cortex activation (i.e. self-referential processing) during positive feedback and decreased temporoparietal junction activation (i.e. other referential processing) for applicable positive feedback. Self-esteem and consistency of feedback with self-knowledge appear to guide our affective and neural responses to social feedback. This may be highly relevant for the interpersonal problems that individuals face with low self-esteem and negative self-views. PMID:29490088

Upward gaze and head deviation with frontal eye field stimulation.

PubMed

Kaiboriboon, Kitti; Lüders, Hans O; Miller, Jonathan P; Leigh, R John

2012-03-01

Using electrical stimulation to the deep, most caudal part of the right frontal eye field (FEF), we demonstrate a novel pattern of vertical (upward) eye movement that was previously only thought possible by stimulating both frontal eye fields simultaneously. If stimulation was started when the subject looked laterally, the initial eye movement was back to the midline, followed by upward deviation. Our finding challenges current view of topological organisation in the human FEF and may have general implications for concepts of topological organisation of the motor cortex, since sustained stimulation also induced upward head movements as a component of the vertical gaze shift. [Published with video sequences].

Hand hygiene compliance rates in the United States--a one-year multicenter collaboration using product/volume usage measurement and feedback.

PubMed

McGuckin, Maryanne; Waterman, Richard; Govednik, John

2009-01-01

Hand hygiene (HH) is the single most important factor in the prevention of health care-acquired infections. The 3 most frequently reported methods of measuring HH compliance are: (1) direct observation, (2) self-reporting by health care workers (HCWs), and (3) indirect calculation based on HH product usage. This article presents the results of a 12-month multicenter collaboration assessing HH compliance rates at US health care facilities by measuring product usage and providing feedback about HH compliance. Our results show that HH compliance at baseline was 26% for intensive care units (ICUs) and 36% for non-ICUs. After 12 months of measuring product usage and providing feedback, compliance increased to 37% for ICUs and 51% for non-ICUs. (ICU, P = .0119; non-ICU, P < .001). HH compliance in the United States can increase when monitoring is combined with feedback. However, HH still occurs at or below 50% compli- ance for both ICUs and non-ICUs.

Self-organization of pulsing and bursting in a CO{sub 2} laser with opto-electronic feedback

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freire, Joana G.; Instituto de Altos Estudos da Paraíba, Rua Infante Dom Henrique 100-1801, 58039-150 João Pessoa; CELC, Departamento de Matemática, Universidade de Lisboa, 1649-003 Lisboa

We report a detailed investigation of the stability of a CO{sub 2} laser with feedback as described by a six-dimensional rate-equations model which provides satisfactory agreement between numerical and experimental results. We focus on experimentally accessible parameters, like bias voltage, feedback gain, and the bandwidth of the feedback loop. The impact of decay rates and parameters controlling cavity losses are also investigated as well as control planes which imply changes of the laser physical medium. For several parameter combinations, we report stability diagrams detailing how laser spiking and bursting is organized over extended intervals. Laser pulsations are shown to emergemore » organized in several hitherto unseen regular and irregular phases and to exhibit a much richer and complex range of behaviors than described thus far. A significant observation is that qualitatively similar organization of laser spiking and bursting can be obtained by tuning rather distinct control parameters, suggesting the existence of unexpected symmetries in the laser control space.« less

The experience of agency in sequence production with altered auditory feedback.

PubMed

Couchman, Justin J; Beasley, Robertson; Pfordresher, Peter Q

2012-03-01

When speaking or producing music, people rely in part on auditory feedback - the sounds associated with the performed action. Three experiments investigated the degree to which alterations of auditory feedback (AAF) during music performances influence the experience of agency (i.e., the sense that your actions led to auditory events) and the possible link between agency and the disruptive effect of AAF on production. Participants performed short novel melodies from memory on a keyboard. Auditory feedback during performances was manipulated with respect to its pitch contents and/or its synchrony with actions. Participants rated their experience of agency after each trial. In all experiments, AAF reduced judgments of agency across conditions. Performance was most disrupted (measured by error rates and slowing) when AAF led to an ambiguous experience of agency, suggesting that there may be some causal relationship between agency and disruption. However, analyses revealed that these two effects were probably independent. A control experiment verified that performers can make veridical judgments of agency. Published by Elsevier Inc.

Firing-rate based network modeling of the dLGN circuit: Effects of cortical feedback on spatiotemporal response properties of relay cells.

PubMed

Mobarhan, Milad Hobbi; Halnes, Geir; Martínez-Cañada, Pablo; Hafting, Torkel; Fyhn, Marianne; Einevoll, Gaute T

2018-05-01

Visually evoked signals in the retina pass through the dorsal geniculate nucleus (dLGN) on the way to the visual cortex. This is however not a simple feedforward flow of information: there is a significant feedback from cortical cells back to both relay cells and interneurons in the dLGN. Despite four decades of experimental and theoretical studies, the functional role of this feedback is still debated. Here we use a firing-rate model, the extended difference-of-Gaussians (eDOG) model, to explore cortical feedback effects on visual responses of dLGN relay cells. For this model the responses are found by direct evaluation of two- or three-dimensional integrals allowing for fast and comprehensive studies of putative effects of different candidate organizations of the cortical feedback. Our analysis identifies a special mixed configuration of excitatory and inhibitory cortical feedback which seems to best account for available experimental data. This configuration consists of (i) a slow (long-delay) and spatially widespread inhibitory feedback, combined with (ii) a fast (short-delayed) and spatially narrow excitatory feedback, where (iii) the excitatory/inhibitory ON-ON connections are accompanied respectively by inhibitory/excitatory OFF-ON connections, i.e. following a phase-reversed arrangement. The recent development of optogenetic and pharmacogenetic methods has provided new tools for more precise manipulation and investigation of the thalamocortical circuit, in particular for mice. Such data will expectedly allow the eDOG model to be better constrained by data from specific animal model systems than has been possible until now for cat. We have therefore made the Python tool pyLGN which allows for easy adaptation of the eDOG model to new situations.

Effects and limitations of an AED with audiovisual feedback for cardiopulmonary resuscitation: a randomized manikin study.

PubMed

Fischer, Henrik; Gruber, Julia; Neuhold, Stephanie; Frantal, Sophie; Hochbrugger, Eva; Herkner, Harald; Schöchl, Herbert; Steinlechner, Barbara; Greif, Robert

2011-07-01

Correctly performed basic life support (BLS) and early defibrillation are the most effective measures to treat sudden cardiac arrest. Audiovisual feedback improves BLS. Automated external defibrillators (AED) with feedback technology may play an important role in improving CPR quality. The aim of this simulation study was to investigate if an AED with audiovisual feedback improves CPR parameters during standard BLS performed by trained laypersons. With ethics committee approval and informed consent, 68 teams (2 flight attendants each) performed 12 min of standard CPR with the AED's audiovisual feedback mechanism enabled or disabled. We recorded CPR quality parameters during resuscitation on a manikin in this open, prospective, randomized controlled trial. Between the feedback and control-group we measured differences in compression depth and rate as main outcome parameters and effective compressions, correct hand position, and incomplete decompression as secondary outcome parameters. An effective compression was defined as a compression with correct depth, hand position, and decompression. The feedback-group delivered compression rates closest to the recommended guidelines (101 ± 9 vs. 109 ± 15/min, p=0.009), more effective compressions (20 ± 18 vs. 5 ± 6%, p<0.001), more compressions with correct hand position (96 ± 13 vs. 88 ± 16%, p<0.001), and less leaning (21 ± 31 vs. 77 ± 33%, p<0.001). However, only the control-group adhered to the recommended compression depth (44 ± 7 mm vs. 39 ± 6, p=0.003). Use of an AED's audiovisual feedback system improved some CPR-quality parameters, thus confirming findings of earlier studies with the notable exception of decreased compression depth, which is a key parameter that might be linked to reduced cardiac output. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Active galactic nucleus feedback in an isolated elliptical galaxy: The effect of strong radiative feedback in the kinetic mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gan, Zhaoming; Yuan, Feng; Ostriker, Jeremiah P.

2014-07-10

Based on two-dimensional high-resolution hydrodynamic numerical simulation, we study the mechanical and radiative feedback effects from the central active galactic nucleus (AGN) on the cosmological evolution of an isolated elliptical galaxy. The inner boundary of the simulation domain is carefully chosen so that the fiducial Bondi radius is resolved and the accretion rate of the black hole is determined self-consistently. It is well known that when the accretion rates are high and low, the central AGNs will be in cold and hot accretion modes, which correspond to the radiative and kinetic feedback modes, respectively. The emitted spectrum from the hotmore » accretion flows is harder than that from the cold accretion flows, which could result in a higher Compton temperature accompanied by a more efficient radiative heating, according to previous theoretical works. Such a difference of the Compton temperature between the two feedback modes, the focus of this study, has been neglected in previous works. Significant differences in the kinetic feedback mode are found as a result of the stronger Compton heating. More importantly, if we constrain models to correctly predict black hole growth and AGN duty cycle after cosmological evolution, we find that the favored model parameters are constrained: mechanical feedback efficiency diminishes with decreasing luminosity (the maximum efficiency being ≅ 10{sup –3.5}), and X-ray Compton temperature increases with decreasing luminosity, although models with fixed mechanical efficiency and Compton temperature can be found that are satisfactory as well. We conclude that radiative feedback in the kinetic mode is much more important than previously thought.« less

A mathematical model of the mevalonate cholesterol biosynthesis pathway.

PubMed

Pool, Frances; Currie, Richard; Sweby, Peter K; Salazar, José Domingo; Tindall, Marcus J

2018-04-14

We formulate, parameterise and analyse a mathematical model of the mevalonate pathway, a key pathway in the synthesis of cholesterol. Of high clinical importance, the pathway incorporates rate limiting enzymatic reactions with multiple negative feedbacks. In this work we investigate the pathway dynamics and demonstrate that rate limiting steps and negative feedbacks within it act in concert to tightly regulate intracellular cholesterol levels. Formulated using the theory of nonlinear ordinary differential equations and parameterised in the context of a hepatocyte, the governing equations are analysed numerically and analytically. Sensitivity and mathematical analysis demonstrate the importance of the two rate limiting enzymes 3-hydroxy-3-methylglutaryl-CoA reductase and squalene synthase in controlling the concentration of substrates within the pathway as well as that of cholesterol. The role of individual feedbacks, both global (between that of cholesterol and sterol regulatory element-binding protein 2; SREBP-2) and local internal (between substrates in the pathway) are investigated. We find that whilst the cholesterol SREBP-2 feedback regulates the overall system dynamics, local feedbacks activate within the pathway to tightly regulate the overall cellular cholesterol concentration. The network stability is analysed by constructing a reduced model of the full pathway and is shown to exhibit one real, stable steady-state. We close by addressing the biological question as to how farnesyl-PP levels are affected by CYP51 inhibition, and demonstrate that the regulatory mechanisms within the network work in unison to ensure they remain bounded. Copyright © 2018 Elsevier Ltd. All rights reserved.

Supermassive black holes and their feedback effects in the IllustrisTNG simulation

NASA Astrophysics Data System (ADS)

Weinberger, Rainer; Springel, Volker; Pakmor, Rüdiger; Nelson, Dylan; Genel, Shy; Pillepich, Annalisa; Vogelsberger, Mark; Marinacci, Federico; Naiman, Jill; Torrey, Paul; Hernquist, Lars

2018-06-01

We study the population of supermassive black holes (SMBHs) and their effects on massive central galaxies in the IllustrisTNG cosmological hydrodynamical simulations of galaxy formation. The employed model for SMBH growth and feedback assumes a two-mode scenario in which the feedback from active galactic nuclei occurs through a kinetic, comparatively efficient mode at low accretion rates relative to the Eddington limit, and in the form of a thermal, less efficient mode at high accretion rates. We show that the quenching of massive central galaxies happens coincidently with kinetic-mode feedback, consistent with the notion that active supermassive black cause the low specific star formation rates observed in massive galaxies. However, major galaxy mergers are not responsible for initiating most of the quenching events in our model. Up to black hole masses of about 108.5 M⊙, the dominant growth channel for SMBHs is in the thermal mode. Higher mass black holes stay mainly in the kinetic mode and gas accretion is self-regulated via their feedback, which causes their Eddington ratios to drop, with SMBH mergers becoming the main channel for residual mass growth. As a consequence, the quasar luminosity function is dominated by rapidly accreting, moderately massive black holes in the thermal mode. We show that the associated growth history of SMBHs produces a low-redshift quasar luminosity function and a redshift zero black hole mass - stellar bulge mass relation in good agreement with observations, whereas the simulation tends to over-predict the high-redshift quasar luminosity function.

Psycho-physiological assessment of a prosthetic hand sensory feedback system based on an auditory display: a preliminary study.

PubMed

Gonzalez, Jose; Soma, Hirokazu; Sekine, Masashi; Yu, Wenwei

2012-06-09

Prosthetic hand users have to rely extensively on visual feedback, which seems to lead to a high conscious burden for the users, in order to manipulate their prosthetic devices. Indirect methods (electro-cutaneous, vibrotactile, auditory cues) have been used to convey information from the artificial limb to the amputee, but the usability and advantages of these feedback methods were explored mainly by looking at the performance results, not taking into account measurements of the user's mental effort, attention, and emotions. The main objective of this study was to explore the feasibility of using psycho-physiological measurements to assess cognitive effort when manipulating a robot hand with and without the usage of a sensory substitution system based on auditory feedback, and how these psycho-physiological recordings relate to temporal and grasping performance in a static setting. 10 male subjects (26+/-years old), participated in this study and were asked to come for 2 consecutive days. On the first day the experiment objective, tasks, and experiment setting was explained. Then, they completed a 30 minutes guided training. On the second day each subject was tested in 3 different modalities: Auditory Feedback only control (AF), Visual Feedback only control (VF), and Audiovisual Feedback control (AVF). For each modality they were asked to perform 10 trials. At the end of each test, the subject had to answer the NASA TLX questionnaire. Also, during the test the subject's EEG, ECG, electro-dermal activity (EDA), and respiration rate were measured. The results show that a higher mental effort is needed when the subjects rely only on their vision, and that this effort seems to be reduced when auditory feedback is added to the human-machine interaction (multimodal feedback). Furthermore, better temporal performance and better grasping performance was obtained in the audiovisual modality. The performance improvements when using auditory cues, along with vision (multimodal feedback), can be attributed to a reduced attentional demand during the task, which can be attributed to a visual "pop-out" or enhance effect. Also, the NASA TLX, the EEG's Alpha and Beta band, and the Heart Rate could be used to further evaluate sensory feedback systems in prosthetic applications.

Feedback-controlled robotics-assisted treadmill exercise to assess and influence aerobic capacity early after stroke: a proof-of-concept study.

PubMed

Stoller, Oliver; Schindelholz, Matthias; Bichsel, Lukas; Schuster, Corina; de Bie, Rob A; de Bruin, Eling D; Hunt, Kenneth J

2014-07-01

The majority of post-stroke individuals suffer from low exercise capacity as a secondary reaction to immobility. The aim of this study was to prove the concept of feedback-controlled robotics-assisted treadmill exercise (RATE) to assess aerobic capacity and guide cardiovascular exercise in severely impaired individuals early after stroke. Subjects underwent constant load and incremental exercise testing using a human-in-the-loop feedback system within a robotics-assisted exoskeleton (Lokomat, Hocoma AG, CH). Inclusion criteria were: stroke onset ≤8 weeks, stable medical condition, non-ambulatory status, moderate motor control of the lower limbs and appropriate cognitive function. Outcome measures included oxygen uptake kinetics, peak oxygen uptake (VO2peak), gas exchange threshold (GET), peak heart rate (HRpeak), peak work rate (Ppeak) and accuracy of reaching target work rate (P-RMSE). Three subjects (18-42 d post-stroke) were included. Oxygen uptake kinetics during constant load ranged from 42.0 to 60.2 s. Incremental exercise testing showed: VO2peak range 19.7-28.8 ml/min/kg, GET range 11.6-12.7 ml/min/kg, and HRpeak range 115-161 bpm. Ppeak range was 55.2-110.9 W and P-RMSE range was 3.8-7.5 W. The concept of feedback-controlled RATE for assessment of aerobic capacity and guidance of cardiovascular exercise is feasible. Further research is warranted to validate the method on a larger scale. Aerobic capacity is seriously reduced in post-stroke individuals as a secondary reaction to immobility. Robotics-assisted walking devices may have substantial clinical relevance regarding assessment and improvement of aerobic capacity early after stroke. Feedback-controlled robotics-assisted treadmill exercise represents a new concept for cardiovascular assessment and intervention protocols for severely impaired individuals.

Interactive content-based image retrieval (CBIR) computer-aided diagnosis (CADx) system for ultrasound breast masses using relevance feedback

NASA Astrophysics Data System (ADS)

Cho, Hyun-chong; Hadjiiski, Lubomir; Sahiner, Berkman; Chan, Heang-Ping; Paramagul, Chintana; Helvie, Mark; Nees, Alexis V.

2012-03-01

We designed a Content-Based Image Retrieval (CBIR) Computer-Aided Diagnosis (CADx) system to assist radiologists in characterizing masses on ultrasound images. The CADx system retrieves masses that are similar to a query mass from a reference library based on computer-extracted features that describe texture, width-to-height ratio, and posterior shadowing of a mass. Retrieval is performed with k nearest neighbor (k-NN) method using Euclidean distance similarity measure and Rocchio relevance feedback algorithm (RRF). In this study, we evaluated the similarity between the query and the retrieved masses with relevance feedback using our interactive CBIR CADx system. The similarity assessment and feedback were provided by experienced radiologists' visual judgment. For training the RRF parameters, similarities of 1891 image pairs obtained from 62 masses were rated by 3 MQSA radiologists using a 9-point scale (9=most similar). A leave-one-out method was used in training. For each query mass, 5 most similar masses were retrieved from the reference library using radiologists' similarity ratings, which were then used by RRF to retrieve another 5 masses for the same query. The best RRF parameters were chosen based on three simulated observer experiments, each of which used one of the radiologists' ratings for retrieval and relevance feedback. For testing, 100 independent query masses on 100 images and 121 reference masses on 230 images were collected. Three radiologists rated the similarity between the query and the computer-retrieved masses. Average similarity ratings without and with RRF were 5.39 and 5.64 on the training set and 5.78 and 6.02 on the test set, respectively. The average Az values without and with RRF were 0.86+/-0.03 and 0.87+/-0.03 on the training set and 0.91+/-0.03 and 0.90+/-0.03 on the test set, respectively. This study demonstrated that RRF improved the similarity of the retrieved masses.

Upward Shift and Steepening of the Blood Pressure Response to Exercise in Hypertensive Subjects at High Altitude.

PubMed

Caravita, Sergio; Faini, Andrea; Baratto, Claudia; Bilo, Grzegorz; Macarlupu, Josè Luis; Lang, Morin; Revera, Miriam; Lombardi, Carolina; Villafuerte, Francisco C; Agostoni, Piergiuseppe; Parati, Gianfranco

2018-06-09

Acute exposure to high-altitude hypobaric hypoxia induces a blood pressure rise in hypertensive humans, both at rest and during exercise. It is unclear whether this phenomenon reflects specific blood pressure hyperreactivity or rather an upward shift of blood pressure levels. We aimed at evaluating the extent and rate of blood pressure rise during exercise in hypertensive subjects acutely exposed to high altitude, and how these alterations can be counterbalanced by antihypertensive treatment. Fifty-five subjects with mild hypertension, double-blindly randomized to placebo or to a fixed-dose combination of an angiotensin-receptor blocker (telmisartan 80 mg) and a calcium-channel blocker (nifedipine slow release 30 mg), performed a cardiopulmonary exercise test at sea level and after the first night's stay at 3260 m altitude. High-altitude exposure caused both an 8 mm Hg upward shift ( P <0.01) and a 0.4 mm Hg/mL/kg per minute steepening ( P <0.05) of the systolic blood pressure/oxygen consumption relationship during exercise, independent of treatment. Telmisartan/nifedipine did not modify blood pressure reactivity to exercise (blood pressure/oxygen consumption slope), but downward shifted ( P <0.001) the relationship between systolic blood pressure and oxygen consumption by 26 mm Hg, both at sea level and at altitude. Muscle oxygen delivery was not influenced by altitude exposure but was higher on telmisartan/nifedipine than on placebo ( P <0.01). In hypertensive subjects exposed to high altitude, we observed a hypoxia-driven upward shift and steepening of the blood pressure response to exercise. The effect of the combination of telmisartan/nifedipine slow release outweighed these changes and was associated with better muscle oxygen delivery. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01830530. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Trends in a life threatening condition: morbid obesity in dutch, Turkish and Moroccan children in The Netherlands.

PubMed

van Dommelen, Paula; Schönbeck, Yvonne; van Buuren, Stef; HiraSing, Remy A

2014-01-01

Morbid obesity can be a life threatening condition. The aim of our study is to assess the trend in morbid obesity in The Netherlands among children of Dutch origin since 1980, and among children of Turkish and Moroccan origin since 1997. Cross-sectional height and weight data of children of Dutch, Turkish and Moroccan origin aged 2-18 years were selected from three national Dutch Growth Studies performed in 1980, 1997 and 2009 (n = 54,814). Extended international (IOTF) cut-offs in childhood were used to define morbid obesity (obesity class II and III combined). The morbidity index for overweight was calculated as the prevalence of morbid obesity divided by the prevalence of overweight. Our study showed that the prevalence of morbid obesity in children of Dutch origin was 0.59% in boys and 0.53% in girls in 2009. Significant upward trends occurred since 1980 and 1997. The prevalence was three to four fold higher in Turkish children compared to Dutch children. The Turkish children also had an upward trend since 1997, but this was only statistically significant in boys. The prevalence of morbid obesity in Moroccan children was two to three fold higher than in Dutch children, but it remained almost stable between 1997 and 2009. The Dutch and Turkish children showed an upward trend in morbidity index for overweight since respectively 1980 and 1997, while the Moroccan children showed a downward trend since 1997. In 2009, children of low educated parents had the highest prevalence rates of morbid obesity; 1.06% in Dutch, 2.11% in Turkish and 1.41% in Moroccan children. An upward trend of morbid obesity in Dutch and Turkish children in The Netherlands occurred. Monitoring and reducing the prevalence of childhood morbid obesity is of high importance for these children, health care and the community.

Observations of Upward Propagating Waves in the Transition Region and Corona above Sunspots

NASA Astrophysics Data System (ADS)

Hou, Zhenyong; Huang, Zhenghua; Xia, Lidong; Li, Bo; Fu, Hui

2018-03-01

We present observations of persistent oscillations of some bright features in the upper-chromosphere/transition region above sunspots taken by IRIS SJ 1400 Å and upward propagating quasi-periodic disturbances along coronal loops rooted in the same region taken by the AIA 171 Å passband. The oscillations of the features are cyclic oscillatory motions without any obvious damping. The amplitudes of the spatial displacements of the oscillations are about 1″. The apparent velocities of the oscillations are comparable to the sound speed in the chromosphere, but the upward motions are slightly larger than that of the downward. The intensity variations can take 24%–53% of the background, suggesting nonlinearity of the oscillations. The FFT power spectra of the oscillations show a dominant peak at a period of about 3 minutes, which is consistent with the omnipresent 3 minute oscillations in sunspots. The amplitudes of the intensity variations of the upward propagating coronal disturbances are 10%–15% of the background. The coronal disturbances have a period of about 3 minutes, and propagate upward along the coronal loops with apparent velocities in a range of 30 ∼ 80 km s‑1. We propose a scenario in which the observed transition region oscillations are powered continuously by upward propagating shocks, and the upward propagating coronal disturbances can be the recurrent plasma flows driven by shocks or responses of degenerated shocks that become slow magnetic-acoustic waves after heating the plasma in the coronal loops at their transition-region bases.

Separation of Lift-Generated Vortex Wakes Into Two Diverging Parts

NASA Technical Reports Server (NTRS)

Rossow, Vernon J.; Brown, Anthony P.

2010-01-01

As part of an ongoing study of the spreading rate of lift-generated vortex wakes, the present investigation considers possible reasons as to why segments of lift-generated wakes sometimes depart from the main part of the wake to move rapidly in either an upward or downward direction. It is assumed that deficiencies or enhancements of the lift carry over across the fuselage-shrouded wing are the driving mechanism for departures of wake-segments. The computations presented first indicate that upwardly departing wake segments that were observed and photographed could have been produced by a deficiency in lift carryover across the fuselage-shrouded part of the wing. Computations made of idealized vortex wakes indicate that upward departure of a wake segment requires a centerline reduction in the span loading of 70% or more, whether the engines are at idle or robust thrust. Similarly, it was found that downward departure of wake segments is produced when the lift over the center part of the wing is enhanced. However, it was also found that downward departures do not occur without the presence of robust engine-exhaust streams (i.e., engines must NOT be at idle). In those cases, downward departures of a wake segment occurs when the centerline value of the loading is enhanced by any amount between about 10% to 100%. Observations of condensation trails indicate that downward departure of wake segments is rare. Upward departures of wake segments appears to be more common but still rare. A study to determine the part of the aircraft that causes wake departures has not been carried out. However, even though departures of wake segments rarely occur, some aircraft do regularly shed these wake structures. If aircraft safety is to be assured to a high degree of reliability, and a solution for eliminating them is not implemented, existing guidelines for the avoidance of vortex wakes [1,3] may need to be broadened to include possible increases in wake sizes caused by vertical departures of wake segments. Further study may indicate that it is not possible to modify existing aircraft enough to prevent wake departures. Wake-avoidance guidelines must then be adjusted to provide the desired degree of safety. It appears that steps to avoid upwardly moving wake segments have already been incorporated into the avoidance procedures used for aircraft on approach to runways at the Frankfurt Airport [6,7]. The uncertainty in the prospects for compromises in flight safety caused by rapidly upwardly or downwardly moving wake segments suggest that it be specified that aircraft do not fly above or below each other during operations in the airport vicinity where aircraft are likely to be closely spaced [20].

Registered Replication Report: Strack, Martin, & Stepper (1988).

PubMed

Acosta, Alberto; Adams, Reginald B; Albohn, Daniel N; Allard, Eric S; Beek, Titia; Benning, Stephen D; Blouin- Hudon, Eve-Marie; Bulnes, Luis Carlo; Caldwell, Tracy L; Calin-Jageman, Robert J; Capaldi, Colin A; Carfagno, Nicholas S; Chasten, Kelsie T; Cleeremans, Axel; Connell, Louise; DeCicco, Jennifer M.; Dijkhoff, Laura; Dijkstra, Katinka; Fischer, Agneta H; Foroni, Francesco; Gronau, Quentin F; Hess, Ursula; Holmes, Kevin J; Jones, Jacob L H; Klein, Olivier; Koch, Christopher; Korb, Sebastian; Lewinski, Peter; Liao, Julia D; Lund, Sophie; Lupiáñez, Juan; Lynott, Dermot; Nance, Christin N; Oosterwijk, Suzanne; Özdog˘ru, Asil Ali; Pacheco-Unguetti, Antonia Pilar; Pearson, Bethany; Powis, Christina; Riding, Sarah; Roberts, Tomi-Ann; Rumiati, Raffaella I; Senden, Morgane; Shea-Shumsky, Noah B; Sobocko, Karin; Soto, Jose A; Steiner, Troy G; Talarico, Jennifer M; vanAllen, Zack M; Wagenmakers, E-J; Vandekerckhove, Marie; Wainwright, Bethany; Wayand, Joseph F; Zeelenberg, Rene; Zetzer, Emily E; Zwaan, Rolf A

2016-11-01

According to the facial feedback hypothesis, people's affective responses can be influenced by their own facial expression (e.g., smiling, pouting), even when their expression did not result from their emotional experiences. For example, Strack, Martin, and Stepper (1988) instructed participants to rate the funniness of cartoons using a pen that they held in their mouth. In line with the facial feedback hypothesis, when participants held the pen with their teeth (inducing a "smile"), they rated the cartoons as funnier than when they held the pen with their lips (inducing a "pout"). This seminal study of the facial feedback hypothesis has not been replicated directly. This Registered Replication Report describes the results of 17 independent direct replications of Study 1 from Strack et al. (1988), all of which followed the same vetted protocol. A meta-analysis of these studies examined the difference in funniness ratings between the "smile" and "pout" conditions. The original Strack et al. (1988) study reported a rating difference of 0.82 units on a 10-point Likert scale. Our meta-analysis revealed a rating difference of 0.03 units with a 95% confidence interval ranging from -0.11 to 0.16. © The Author(s) 2016.

Semiconductor ring lasers subject to both on-chip filtered optical feedback and external conventional optical feedback

NASA Astrophysics Data System (ADS)

Khoder, Mulham; Van der Sande, Guy; Danckaert, Jan; Verschaffelt, Guy

2016-05-01

It is well known that the performance of semiconductor lasers is very sensitive to external optical feedback. This feedback can lead to changes in lasing characteristics and a variety of dynamical effects including chaos and coherence collapse. One way to avoid this external feedback is by using optical isolation, but these isolators and their packaging will increase the cost of the total system. Semiconductor ring lasers nowadays are promising sources in photonic integrated circuits because they do not require cleaved facets or mirrors to form a laser cavity. Recently, some of us proposed to combine semiconductor ring lasers with on chip filtered optical feedback to achieve tunable lasers. The feedback is realized by employing two arrayed waveguide gratings to split/recombine light into different wavelength channels. Semiconductor optical amplifier gates are used to control the feedback strength. In this work, we investigate how such lasers with filtered feedback are influenced by an external conventional optical feedback. The experimental results show intensity fluctuations in the time traces in both the clockwise and counterclockwise directions due to the conventional feedback. We quantify the strength of the conventional feedback induced dynamics be extracting the standard deviation of the intensity fluctuations in the time traces. By using filtered feedback, we can shift the onset of the conventional feedback induced dynamics to larger values of the feedback rate [ Khoder et al, IEEE Photon. Technol. Lett. DOI: 10.1109/LPT.2016.2522184]. The on-chip filtered optical feedback thus makes the semiconductor ring laser less senstive to the effect of (long) conventional optical feedback. We think these conclusions can be extended to other types of lasers.

Chloride Transport in Heterogeneous Formation

NASA Astrophysics Data System (ADS)

Mukherjee, A.; Holt, R. M.

2017-12-01

The chloride mass balance (CMB) is a commonly-used method for estimating groundwater recharge. Observations of the vertical distribution of pore-water chloride are related to the groundwater infiltration rates (i.e. recharge rates). In CMB method, the chloride distribution is attributed mainly to the assumption of one dimensional piston flow. In many places, however, the vertical distribution of chloride will be influenced by heterogeneity, leading to horizontal movement of infiltrating waters. The impact of heterogeneity will be particularly important when recharge is locally focused. When recharge is focused in an area, horizontal movement of chloride-bearing waters, coupled with upward movement driven by evapotranspiration, may lead to chloride bulges that could be misinterpreted if the CMB method is used to estimate recharge. We numerically simulate chloride transport and evaluate the validity of the CMB method in highly heterogeneous systems. This simulation is conducted for the unsaturated zone of Ogallala, Antlers, and Gatuna (OAG) formations in Andrews County, Texas. A two dimensional finite element model will show the movement of chloride through heterogeneous systems. We expect to see chloride bulges not only close to the surface but also at depths characterized by horizontal or upward movement. A comparative study of focused recharge estimates in this study with available recharge data will be presented.

Quantifying the Sources of Intermodel Spread in Equilibrium Climate Sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caldwell, Peter M.; Zelinka, Mark D.; Taylor, Karl E.

This paper clarifies the causes of intermodel differences in the global-average temperature response to doubled CO 2, commonly known as equilibrium climate sensitivity (ECS). The authors begin by noting several issues with the standard approach for decomposing ECS into a sum of forcing and feedback terms. This leads to a derivation of an alternative method based on linearizing the effect of the net feedback. Consistent with previous studies, the new method identifies shortwave cloud feedback as the dominant source of intermodel spread in ECS. This new approach also reveals that covariances between cloud feedback and forcing, between lapse rate andmore » longwave cloud feedbacks, and between albedo and shortwave cloud feedbacks play an important and previously underappreciated role in determining model differences in ECS. Finally, defining feedbacks based on fixed relative rather than specific humidity (as suggested by Held and Shell) reduces the covariances between processes and leads to more straightforward interpretations of results.« less

Quantifying the Sources of Intermodel Spread in Equilibrium Climate Sensitivity

DOE PAGES

Caldwell, Peter M.; Zelinka, Mark D.; Taylor, Karl E.; ...

2016-01-07

This paper clarifies the causes of intermodel differences in the global-average temperature response to doubled CO 2, commonly known as equilibrium climate sensitivity (ECS). The authors begin by noting several issues with the standard approach for decomposing ECS into a sum of forcing and feedback terms. This leads to a derivation of an alternative method based on linearizing the effect of the net feedback. Consistent with previous studies, the new method identifies shortwave cloud feedback as the dominant source of intermodel spread in ECS. This new approach also reveals that covariances between cloud feedback and forcing, between lapse rate andmore » longwave cloud feedbacks, and between albedo and shortwave cloud feedbacks play an important and previously underappreciated role in determining model differences in ECS. Finally, defining feedbacks based on fixed relative rather than specific humidity (as suggested by Held and Shell) reduces the covariances between processes and leads to more straightforward interpretations of results.« less

Electrotactile Feedback Improves Performance and Facilitates Learning in the Routine Grasping Task.

PubMed

Isaković, Milica; Belić, Minja; Štrbac, Matija; Popović, Igor; Došen, Strahinja; Farina, Dario; Keller, Thierry

2016-06-13

Aim of this study was to investigate the feasibility of electrotactile feedback in closed loop training of force control during the routine grasping task. The feedback was provided using an array electrode and a simple six-level spatial coding, and the experiment was conducted in three amputee subjects. The psychometric tests confirmed that the subjects could perceive and interpret the electrotactile feedback with a high success rate. The subjects performed the routine grasping task comprising 4 blocks of 60 grasping trials. In each trial, the subjects employed feedforward control to close the hand and produce the desired grasping force (four levels). First (baseline) and the last (validation) session were performed in open loop, while the second and the third session (training) included electrotactile feedback. The obtained results confirmed that using the feedback improved the accuracy and precision of the force control. In addition, the subjects performed significantly better in the validation vs. baseline session, therefore suggesting that electrotactile feedback can be used for learning and training of myoelectric control.

The relationship between professional behaviour grades and tutor performance ratings in problem-based learning.

PubMed

Dolmans, Diana Hjm; Luijk, Scheltus J; Wolfhagen, Ineke Hap; Scherpbier, Albert Jja

2006-02-01

We investigated the influence of harsh grading by tutors on tutor performance rating by students. A total of 187 tutors assessed students' professional behaviour in tutorial groups. Students rated tutor performance after receiving their grades for professional behaviour. In addition, students were asked to indicate whether they perceived their professional behaviour grades as too positive, adequate or too negative. This was considered to reflect tutors' harshness of grading. Students also rated the quality of the feedback they received from tutors with respect to their grades. Professional behaviour grades that students perceived as too negative, adequate or too positive were associated with tutor performance ratings of 7.4 (SD = 0.9, scale 1-10, n = 33), 7.7 (SD = 0.9, scale 1-10, n = 95) and 7.5 (SD = 0.8, scale 1-10, n = 59), respectively. Harshness of grading did not influence tutor performance ratings significantly. Tutor ratings were predicted more effectively by the quality of the feedback tutors provided on grades than by the harshness of grading. Tutor performance ratings were not related significantly to harshness of grading. Two explanations can be given: (1) tutor performance ratings were based on rating by groups of students and (2) the percentage of tutors who rated students' professional behaviour as unsatisfactory was low. The strong relationship between tutor performance ratings and the adequacy of the feedback given by tutors suggests that the tutor performance ratings collected in this study are a valid measure of the quality of their teaching, although, for a full picture of teaching quality, more measures will be needed.

Double-diffusive translation of Earth's inner core

NASA Astrophysics Data System (ADS)

Deguen, R.; Alboussiére, T.; Labrosse, S.

2018-03-01

The hemispherical asymmetry of the inner core has been interpreted as resulting form a high-viscosity mode of inner core convection, consisting in a translation of the inner core. A thermally driven translation, as originally proposed, is unlikely if the currently favoured high values of the thermal conductivity of iron at core conditions are correct. We consider here the possibility that inner core translation results from an unstable compositional gradient, which would develop either because the light elements present in the core become increasingly incompatible as the inner core grows, or because of a possibly positive feedback of the development of the F-layer on inner core convection. Though the magnitude of the destabilising effect of the compositional field is predicted to be similar to or smaller than the stabilising effect of the thermal field, the huge difference between thermal and chemical diffusivities implies that double-diffusive instabilities can still arise even if the net buoyancy increases upward. Using linear stability analysis and numerical simulations, we demonstrate that a translation mode can indeed exist if the compositional field is destabilising, even if the temperature profile is subadiabatic, and irrespectively of the relative magnitudes of the composition and potential temperature gradients. The existence of this double diffusive mode of translation requires that the following conditions are met: (i) the compositional profile within the inner core is destabilising, and remains so for a duration longer than the destabilisation timescale (on the order of 200 My, but strongly dependent on the magnitude of the initial perturbation); and (ii) the inner core viscosity is sufficiently large, the required value being a strongly increasing function of the inner core size (e.g. 1017 Pa.s when the inner core was 200 km in radius, and ≃ 3 × 1021 Pa.s at the current inner core size). If these conditions are met, the predicted inner core translation rate is found to be similar to the inner core growth rate, which is more consistent with inferences from the geomagnetic field morphology and secular variation than the higher translation rate predicted for a thermally driven translation.

The Effects of Non-Contingent Feedback on the Incidence of Plateau at V̇O2max

PubMed Central

Gordon, Dan; Gernigon, Marie; Baker, James; Merzbach, Viviane; Scruton, Adrian

2017-01-01

The purpose of this study was to examine the effects of non-contingent feedback in the form of heart rate (HR) on the incidence of plateau at V̇O2max. Ten physically active males (age 24.8 yrs ± 4.2; mass 81.4 ± 9.0 kg; stature 1.80 ± 0.11 m, V̇O2max 53.2 ± 5.8 ml·kg-1.min-1) who were V̇O2max testing naïve but were cognisant as to the heart rate responses to exercise completed four incremental tests to volitional exhaustion, separated by ~72 h for the determination of V̇O2max and gas exchange threshold. The first trial served as a familiarisation with the remaining three being experimental conditions where HR was presented in a screen projection as either the actual response (HR-A) or 10 b·min-1 higher than recorded (HR-H) or 10 b·min-1 lower (HR-L). Throughout all trials V̇O2 was recorded on a breath-by-breath basis with plateau criteria of ≤ 50 ml·min-1. RESULTS: A significant difference was observed for Δ V̇O2 over the final two consecutive 30s sampling periods between HR-A, both HR-L and HR-H (p = 0.049) and for the incidence of plateau response between condition (p = 0.021). An additional significant difference was observed for sub-maximal Δ V̇O2 responses between HR-A and HR-H (p = 0.049) and HR-A and HR-L (p = 0.006). Non-significant differences were observed for all other criteria. These data indicate that when presented with non-contingent feedback in the form of HR, that the perceptually orientated pacing schema becomes disrupted promoting a sparing of the finite anaerobic capacity to compensate for the imbalance between the afferent signal and perception of effort. Key points The manifestation of the plateau at V̇O2max is disrupted (lower incidence rates) when participants are exposed to non-contingent feedback in the form of heart rate. Non-contingent feedback in the form of heart rate does not affect the V̇O2max score or associated cardio-respiratory parameters. Given the association between the V̇O2-plateau and the finite anaerobic capacity it is proposed that non-contingent feedback creates a sparing of this resource due to an imbalance between the perception of effort and the bio-feedback. PMID:28344458

Effects of altered auditory feedback across effector systems: production of melodies by keyboard and singing.

PubMed

Pfordresher, Peter Q; Mantell, James T

2012-01-01

We report an experiment that tested whether effects of altered auditory feedback (AAF) during piano performance differ from its effects during singing. These effector systems differ with respect to the mapping between motor gestures and pitch content of auditory feedback. Whereas this action-effect mapping is highly reliable during phonation in any vocal motor task (singing or speaking), mapping between finger movements and pitch occurs only in limited situations, such as piano playing. Effects of AAF in both tasks replicated results previously found for keyboard performance (Pfordresher, 2003), in that asynchronous (delayed) feedback slowed timing whereas alterations to feedback pitch increased error rates, and the effect of asynchronous feedback was similar in magnitude across tasks. However, manipulations of feedback pitch had larger effects on singing than on keyboard production, suggesting effector-specific differences in sensitivity to action-effect mapping with respect to feedback content. These results support the view that disruption from AAF is based on abstract, effector independent, response-effect associations but that the strength of associations differs across effector systems. Copyright © 2011. Published by Elsevier B.V.

A comparison of video review and feedback device measurement of chest compressions quality during pediatric cardiopulmonary resuscitation.

PubMed

Hsieh, Ting-Chang; Wolfe, Heather; Sutton, Robert; Myers, Sage; Nadkarni, Vinay; Donoghue, Aaron

2015-08-01

To describe chest compression (CC) rate, depth, and leaning during pediatric cardiopulmonary resuscitation (CPR) as measured by two simultaneous methods, and to assess the accuracy and reliability of video review in measuring CC quality. Resuscitations in a pediatric emergency department are videorecorded for quality improvement. Patients aged 8-18 years receiving CPR under videorecording were eligible for inclusion. CPR was recorded by a pressure/accelerometer feedback device and tabulated in 30-s epochs of uninterrupted CC. Investigators reviewed videorecorded CPR and measured rate, depth, and release by observation. Raters categorized epochs as 'meeting criteria' if 80% of CCs in an epoch were done with appropriate depth (>45 mm) and/or release (<2.5 kg leaning). Comparison between device measurement and video was made by Spearman's ρ for rate and by κ statistic for depth and release. Interrater reliability for depth and release was measured by κ statistic. Five patients underwent videorecorded CPR using the feedback device. 97 30-s epochs of CCs were analyzed. CCs met criteria for rate in 74/97 (76%) of epochs; depth in 38/97 (39%); release in 82/97 (84%). Agreement between video and feedback device for rate was good (ρ = 0.77); agreement was poor for depth and release (κ 0.04-0.41). Interrater reliability for depth and release measured by video was poor (κ 0.04-0.49). Video review measured CC rate accurately; depth and release were not reliably or accurately assessed by video. Future research should focus on the optimal combination of methods for measuring CPR quality. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

77 FR 70780 - Agency Forms Undergoing Paperwork Reduction Act Review

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-27

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2011-03-31

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Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-08

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Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-30

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Interrogative pressure in simulated forensic interviews: the effects of negative feedback.

PubMed

McGroarty, Allan; Baxter, James S

2007-08-01

Much experimental research on interrogative pressure has concentrated on the effects of leading questions, and the role of feedback in influencing responses in the absence of leading questions has been neglected by comparison. This study assessed the effect of negative feedback and the presence of a second interviewer on interviewee responding in simulated forensic interviews. Participants viewed a videotape of a crime, answered questions about the clip and were requestioned after receiving feedback. Compared with neutral feedback, negative feedback resulted in more response changes, higher reported state anxiety and higher ratings of interview difficulty. These results are consistent with Gudjonsson and Clark's (1986) model of interrogative suggestibility. The presence and involvement of a second interviewer did not significantly affect interviewee responding, although trait anxiety scores were elevated when a second interviewer was present. The theoretical and applied implications of these findings are considered.

Servo control booster system for minimizing following error

DOEpatents

Wise, William L.

1985-01-01

A closed-loop feedback-controlled servo system is disclosed which reduces command-to-response error to the system's position feedback resolution least increment, .DELTA.S.sub.R, on a continuous real-time basis for all operating speeds. The servo system employs a second position feedback control loop on a by exception basis, when the command-to-response error .gtoreq..DELTA.S.sub.R, to produce precise position correction signals. When the command-to-response error is less than .DELTA.S.sub.R, control automatically reverts to conventional control means as the second position feedback control loop is disconnected, becoming transparent to conventional servo control means. By operating the second unique position feedback control loop used herein at the appropriate clocking rate, command-to-response error may be reduced to the position feedback resolution least increment. The present system may be utilized in combination with a tachometer loop for increased stability.

The Impacts of Regular Upward Bound on Postsecondary Outcomes Seven to Nine Years after Scheduled High School Graduation. Final Report

ERIC Educational Resources Information Center

Seftor, Neil S.; Mamun, Arif; Schirm, Allen

2009-01-01

This last report from Mathematica's evaluation of Upward Bound analyzes data from the final round of survey and transcript data collection as well as administrative records from the National Student Clearinghouse and the federal Student Financial Aid files. It provides the first estimates of the effects of Upward Bound on postsecondary completion.…

The Impacts of Upward Bound Math-Science on Postsecondary Outcomes 7-9 Years after Scheduled High School Graduation: Final Report

ERIC Educational Resources Information Center

Seftor, Neil S.; Calcagno, Juan Carlos

2010-01-01

This final report updates the report "Upward Bound Math-Science: Program Description and Interim Impact Estimates" published in 2007 (Olsen et al. 2007). The 2007 interim report contained descriptive findings from a survey of Upward Bound Math-Science (UBMS) grantees from the late 1990s at the time of the study's initiation and impact estimates…

Experimental study on heat transfer to supercritical water flowing through tubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, M.; Gu, H.; Cheng, X.

2012-07-01

A test facility named SWAMUP (Supercritical Water Multi-Purpose Loop) has been constructed in Shanghai Jiao Tong Univ. to investigate heat transfer and pressure drop through tubes and rod bundles. SWAMUP is a closed loop with operating pressure up to 30 MPa, outlet-water temperature up to 550 deg. C, and mass flow rate up to 5 t/h. In this paper, experimental study has been carried out on heat transfer of supercritical water flowing vertically through tubes (ID=7.6 and 10 mm). A large number of test points in tubes has been obtained with a wide range of heat flux (200-1500 kw/m{sup 2})more » and mass flux (450-2000 kg/m{sup 2}s). Test results showed that heat transfer deterioration (HTD) caused by buoyancy effect only appears in upward flow and HTD caused by acceleration effect appears both in upward flow and downward flow. The heat transfer coefficients (HTC) produced in tube tests were compared with existing heat transfer correlations. (authors)« less

Neutrino-oscillation search with cosmic-ray neutrinos

NASA Astrophysics Data System (ADS)

Ayres, D. S.; Cortez, B.; Gaisser, T. K.; Mann, A. K.; Shrock, R. E.; Sulak, L. R.

1984-03-01

A sensitive search for neutrino oscillations involving νe, νμ, and ντ may be provided by measurements of the ratio of the total interaction rates of upward- and downward-going cosmic-ray neutrinos within a massive (~10 kton) detector. Assuming mixing between all pairs of νe, νμ, and ντ, the experiment is capable of observing time-averaged probabilities t and t of magnitude set by mixing strengths corresponding to, e.g., the d- to s-quark mixing strength, and of reaching the limit Δm2ij≡|mi2-mj2|~10-4 eV2, where mi, and mj are neutrino mass eigenstates, and Peτ and Pμτ are the probabilities for νe and νμ, respectively, to oscillate into ντ after traversing a distance L~ diameter of the Earth. Possible ambiguities may be resolved through comparison of the ratios NeNμ for the upward- and downward-going neutrinos.

Look who's judging-Feedback source modulates brain activation to performance feedback in social anxiety.

PubMed

Peterburs, Jutta; Sandrock, Carolin; Miltner, Wolfgang H R; Straube, Thomas

2016-06-01

It is as yet unknown if behavioral and neural correlates of performance monitoring in socially anxious individuals are affected by whether feedback is provided by a person or a computer. This fMRI study investigated modulation of feedback processing by feedback source (person vs. computer) in participants with high (HSA) (N=16) and low social anxiety (LSA) (N=16). Subjects performed a choice task in which they were informed that they would receive positive or negative feedback from a person or the computer. Subjective ratings indicated increased arousal and anxiety in HSA versus LSA, most pronounced for social and negative feedback. FMRI analyses yielded hyperactivation in ventral medial prefrontal cortex (vmPFC)/anterior cingulate cortex (ACC) and insula for social relative to computer feedback, and in mPFC/ventral ACC for positive relative to negative feedback in HSA as compared to LSA. These activation patterns are consistent with increased interoception and self-referential processing in social anxiety, especially during processing of positive feedback. Increased ACC activation in HSA to positive feedback may link to unexpectedness of (social) praise as posited in social anxiety disorder (SAD) psychopathology. Activation in rostral ACC showed a reversed pattern, with decreased activation to positive feedback in HSA, possibly indicating altered action values depending on feedback source and valence. The present findings corroborate a crucial role of mPFC for performance monitoring in social anxiety. Copyright © 2016 Elsevier Inc. All rights reserved.

Comprehensive feedback on trainee surgeons’ non-technical skills

PubMed Central

Dieckmann, Peter; Beier-Holgersen, Randi; Rosenberg, Jacob; Oestergaard, Doris

2015-01-01

Objectives This study aimed to explore the content of conversations, feedback style, and perceived usefulness of feedback to trainee surgeons when conversations were stimulated by a tool for assessing surgeons’ non-technical skills. Methods Trainee surgeons and their supervisors used the Non-Technical Skills for Surgeons in Denmark tool to stimulate feedback conversations. Audio recordings of post-operation feedback conversations were collected. Trainees and supervisors provided questionnaire responses on the usefulness and comprehensiveness of the feedback. The feedback conversations were qualitatively analyzed for content and feedback style. Usefulness was investigated using a scale from 1 to 5 and written comments were qualitatively analyzed. Results Six trainees and six supervisors participated in eight feedback conversations. Eighty questionnaires (response rate 83 percent) were collected from 13 trainees and 12 supervisors. Conversations lasted median eight (2-15) minutes. Supervisors used the elements and categories in the tool to structure the content of the conversations. Supervisors tended to talk about the trainees’ actions and their own frames rather than attempting to understand the trainees’ perceptions. Supervisors and trainees welcomed the feedback opportunity and agreed that the conversations were useful and comprehensive. Conclusions The content of the feedback conversations reflected the contents of the tool and the feedback was considered useful and comprehensive. However, supervisors talked primarily about their own frames, so in order for the feedback to reach its full potential, supervisors may benefit from training techniques to stimulate a deeper reflection among trainees. PMID:25602262

Simulated star formation rate functions at z ˜ 4-7, and the role of feedback in high-z galaxies

NASA Astrophysics Data System (ADS)

Tescari, E.; Katsianis, A.; Wyithe, J. S. B.; Dolag, K.; Tornatore, L.; Barai, P.; Viel, M.; Borgani, S.

2014-03-01

We study the role of feedback from supernovae (SN) and black holes in the evolution of the star formation rate function (SFRF) of z ˜ 4-7 galaxies. We use a new set of cosmological hydrodynamic simulations, ANGUS (AustraliaN GADGET-3 early Universe Simulations), run with a modified and improved version of the parallel TreePM-smoothed particle hydrodynamics code GADGET-3 called P-GADGET3(XXL), that includes a self-consistent implementation of stellar evolution and metal enrichment. In our simulations both SN-driven galactic winds and active galactic nuclei (AGN) act simultaneously in a complex interplay. The SFRF is insensitive to feedback prescription at z > 5, meaning that it cannot be used to discriminate between feedback models during reionization. However, the SFRF is sensitive to the details of feedback prescription at lower redshift. By exploring different SN-driven wind velocities and regimes for the AGN feedback, we find that the key factor for reproducing the observed SFRFs is a combination of `strong' SN winds and early AGN feedback in low-mass galaxies. Conversely, we show that the choice of initial mass function and inclusion of metal cooling have less impact on the evolution of the SFRF. When variable winds are considered, we find that a non-aggressive wind scaling is needed to reproduce the SFRFs at z ≳ 4. Otherwise, the amount of objects with low SFRs is greatly suppressed and at the same time winds are not effective enough in the most massive systems.

Reducing wait time in a hospital pharmacy to promote customer service.

PubMed

Slowiak, Julie M; Huitema, Bradley E; Dickinson, Alyce M

2008-01-01

The purpose of this study was to compare the effects of 2 different interventions on wait times at a hospital outpatient pharmacy: (1) giving feedback to employees about customer satisfaction with wait times and (2) giving a combined intervention package that included giving more specific feedback about actual wait times and goal setting for wait time reduction in addition to the customer satisfaction feedback. The relationship between customer satisfaction ratings and wait times was examined to determine whether wait times affected customer service satisfaction. Participants were 10 employees (4 pharmacists and 6 technicians) of an outpatient pharmacy. Wait times and customer satisfaction ratings were collected for "waiting customers." An ABCBA' within-subjects design was used to assess the effects of the interventions on both wait time and customer satisfaction, where A was the baseline (no feedback and no goal setting); B was the customer satisfaction feedback; C was the customer satisfaction feedback, the wait time feedback, and the goal setting for wait time reduction; and A' was a follow-up condition that was similar to the original baseline condition. Wait times were reduced by approximately 20%, and there was concomitant increased shift in levels of customer satisfaction, as indicated by the correlation between these variables (r = -0.57 and P < .05). Given the current prescription-filling process, we do not expect that major, additional reductions in wait times could be produced. Many variables may account for the variability in any individual customer's wait time. Data from this study may provide useful preliminary benchmarking data for standard pharmacy wait times.

Feedback from the heart: Emotional learning and memory is controlled by cardiac cycle, interoceptive accuracy and personality.

PubMed

Pfeifer, Gaby; Garfinkel, Sarah N; Gould van Praag, Cassandra D; Sahota, Kuljit; Betka, Sophie; Critchley, Hugo D

2017-05-01

Feedback processing is critical to trial-and-error learning. Here, we examined whether interoceptive signals concerning the state of cardiovascular arousal influence the processing of reinforcing feedback during the learning of 'emotional' face-name pairs, with subsequent effects on retrieval. Participants (N=29) engaged in a learning task of face-name pairs (fearful, neutral, happy faces). Correct and incorrect learning decisions were reinforced by auditory feedback, which was delivered either at cardiac systole (on the heartbeat, when baroreceptors signal the contraction of the heart to the brain), or at diastole (between heartbeats during baroreceptor quiescence). We discovered a cardiac influence on feedback processing that enhanced the learning of fearful faces in people with heightened interoceptive ability. Individuals with enhanced accuracy on a heartbeat counting task learned fearful face-name pairs better when feedback was given at systole than at diastole. This effect was not present for neutral and happy faces. At retrieval, we also observed related effects of personality: First, individuals scoring higher for extraversion showed poorer retrieval accuracy. These individuals additionally manifested lower resting heart rate and lower state anxiety, suggesting that attenuated levels of cardiovascular arousal in extraverts underlies poorer performance. Second, higher extraversion scores predicted higher emotional intensity ratings of fearful faces reinforced at systole. Third, individuals scoring higher for neuroticism showed higher retrieval confidence for fearful faces reinforced at diastole. Our results show that cardiac signals shape feedback processing to influence learning of fearful faces, an effect underpinned by personality differences linked to psychophysiological arousal. Copyright © 2017 Elsevier B.V. All rights reserved.

Decorrelation of Neural-Network Activity by Inhibitory Feedback

PubMed Central

Einevoll, Gaute T.; Diesmann, Markus

2012-01-01

Correlations in spike-train ensembles can seriously impair the encoding of information by their spatio-temporal structure. An inevitable source of correlation in finite neural networks is common presynaptic input to pairs of neurons. Recent studies demonstrate that spike correlations in recurrent neural networks are considerably smaller than expected based on the amount of shared presynaptic input. Here, we explain this observation by means of a linear network model and simulations of networks of leaky integrate-and-fire neurons. We show that inhibitory feedback efficiently suppresses pairwise correlations and, hence, population-rate fluctuations, thereby assigning inhibitory neurons the new role of active decorrelation. We quantify this decorrelation by comparing the responses of the intact recurrent network (feedback system) and systems where the statistics of the feedback channel is perturbed (feedforward system). Manipulations of the feedback statistics can lead to a significant increase in the power and coherence of the population response. In particular, neglecting correlations within the ensemble of feedback channels or between the external stimulus and the feedback amplifies population-rate fluctuations by orders of magnitude. The fluctuation suppression in homogeneous inhibitory networks is explained by a negative feedback loop in the one-dimensional dynamics of the compound activity. Similarly, a change of coordinates exposes an effective negative feedback loop in the compound dynamics of stable excitatory-inhibitory networks. The suppression of input correlations in finite networks is explained by the population averaged correlations in the linear network model: In purely inhibitory networks, shared-input correlations are canceled by negative spike-train correlations. In excitatory-inhibitory networks, spike-train correlations are typically positive. Here, the suppression of input correlations is not a result of the mere existence of correlations between excitatory (E) and inhibitory (I) neurons, but a consequence of a particular structure of correlations among the three possible pairings (EE, EI, II). PMID:23133368

Rapid change in articulatory lip movement induced by preceding auditory feedback during production of bilabial plosives.

PubMed

Mochida, Takemi; Gomi, Hiroaki; Kashino, Makio

2010-11-08

There has been plentiful evidence of kinesthetically induced rapid compensation for unanticipated perturbation in speech articulatory movements. However, the role of auditory information in stabilizing articulation has been little studied except for the control of voice fundamental frequency, voice amplitude and vowel formant frequencies. Although the influence of auditory information on the articulatory control process is evident in unintended speech errors caused by delayed auditory feedback, the direct and immediate effect of auditory alteration on the movements of articulators has not been clarified. This work examined whether temporal changes in the auditory feedback of bilabial plosives immediately affects the subsequent lip movement. We conducted experiments with an auditory feedback alteration system that enabled us to replace or block speech sounds in real time. Participants were asked to produce the syllable /pa/ repeatedly at a constant rate. During the repetition, normal auditory feedback was interrupted, and one of three pre-recorded syllables /pa/, /Φa/, or /pi/, spoken by the same participant, was presented once at a different timing from the anticipated production onset, while no feedback was presented for subsequent repetitions. Comparisons of the labial distance trajectories under altered and normal feedback conditions indicated that the movement quickened during the short period immediately after the alteration onset, when /pa/ was presented 50 ms before the expected timing. Such change was not significant under other feedback conditions we tested. The earlier articulation rapidly induced by the progressive auditory input suggests that a compensatory mechanism helps to maintain a constant speech rate by detecting errors between the internally predicted and actually provided auditory information associated with self movement. The timing- and context-dependent effects of feedback alteration suggest that the sensory error detection works in a temporally asymmetric window where acoustic features of the syllable to be produced may be coded.

Tailoring a video-feedback intervention for sensitive discipline to parents with intellectual disabilities: a process evaluation.

PubMed

Hodes, Marja W; Meppelder, H Marieke; Schuengel, Carlo; Kef, Sabina

2014-01-01

Parenting support programs for the general population may not be effective for parents with intellectual disabilities (ID). A videobased intervention program based on attachment and coercion theory (Video-feedback Intervention to promote Positive Parenting with additional focus on Sensitive Discipline; VIPP-SD) was tailored to parents with ID and the implementation of the adapted program was evaluated by the home visitors conducting the program. Home visitors (N = 17) of 36 families rated the intervention process during each session. Home visitors' evaluations showed a significant increase in positive ratings of parents' easiness to work with, amenability to influence, and openness. Cooperation remained stable. A case example illustrated this process, showing how feedback using video facilitated changes in the perceptions and attributions of a mother with mild ID.

Delayed excitatory and inhibitory feedback shape neural information transmission

NASA Astrophysics Data System (ADS)

Chacron, Maurice J.; Longtin, André; Maler, Leonard

2005-11-01

Feedback circuitry with conduction and synaptic delays is ubiquitous in the nervous system. Yet the effects of delayed feedback on sensory processing of natural signals are poorly understood. This study explores the consequences of delayed excitatory and inhibitory feedback inputs on the processing of sensory information. We show, through numerical simulations and theory, that excitatory and inhibitory feedback can alter the firing frequency response of stochastic neurons in opposite ways by creating dynamical resonances, which in turn lead to information resonances (i.e., increased information transfer for specific ranges of input frequencies). The resonances are created at the expense of decreased information transfer in other frequency ranges. Using linear response theory for stochastically firing neurons, we explain how feedback signals shape the neural transfer function for a single neuron as a function of network size. We also find that balanced excitatory and inhibitory feedback can further enhance information tuning while maintaining a constant mean firing rate. Finally, we apply this theory to in vivo experimental data from weakly electric fish in which the feedback loop can be opened. We show that it qualitatively predicts the observed effects of inhibitory feedback. Our study of feedback excitation and inhibition reveals a possible mechanism by which optimal processing may be achieved over selected frequency ranges.

Water-quality trends in the Scituate reservoir drainage area, Rhode Island, 1983-2012

USGS Publications Warehouse

Smith, Kirk P.

2015-01-01

Upward trends in pH were identified for nearly half of the monitoring stations for WYs 1983-2012 and may reflect regional reductions in acid precipitation. Many upward trends in alkalinity also were identified for both the WYs 1983-2012 and for WYs 2003-12 periods and are likely related to the natural weathering of structures containing concrete or, in some cases, the application of lime or fertilizers on agriculture lands. Significant trends in chloride concentrations at most stations during WYs 1983-2012 were upward; however, results for WYs 2003-12 substantiate few significant upward trends and, in a few cases, downward trends were identified in several tributary drainage areas.

Time-delay signature of chaos in 1550 nm VCSELs with variable-polarization FBG feedback.

PubMed

Li, Yan; Wu, Zheng-Mao; Zhong, Zhu-Qiang; Yang, Xian-Jie; Mao, Song; Xia, Guang-Qiong

2014-08-11

Based on the framework of spin-flip model (SFM), the output characteristics of a 1550 nm vertical-cavity surface-emitting laser (VCSEL) subject to variable-polarization fiber Bragg grating (FBG) feedback (VPFBGF) have been investigated. With the aid of the self-correlation function (SF) and the permutation entropy (PE) function, the time-delay signature (TDS) of chaos in the VPFBGF-VCSEL is evaluated, and then the influences of the operation parameters on the TDS of chaos are analyzed. The results show that the TDS of chaos can be suppressed efficiently through selecting suitable coupling coefficient and feedback rate of the FBG, and is weaker than that of chaos generated by traditional variable-polarization mirror feedback VCSELs (VPMF-VCSELs) or polarization-preserved FBG feedback VCSELs (PPFBGF-VCSELs).

[Effect of biochar addition on soil evaporation.

PubMed

Xu, Jian; Niu, Wen Quan; Zhang, Ming Zhi; Li, Yuan; Lyu, Wang; Li, Kang-Yong; Zou, Xiao-Yang; Liang, Bo-Hui

2016-11-18

In order to determine the rational amount of biochar application and its effect on soil hydrological processes in arid area, soil column experiments were conducted in the laboratory using three biochar additions (5%, 10% and 15%) and four different biochar types (d<0.25 mm bamboo charcoal, 0.25 mm

Benefit of pulsation in soft corals

PubMed Central

Kremien, Maya; Shavit, Uri; Mass, Tali; Genin, Amatzia

2013-01-01

Soft corals of the family Xeniidae exhibit a unique, rhythmic pulsation of their tentacles (Movie S1), first noted by Lamarck nearly 200 y ago. However, the adaptive benefit of this perpetual, energetically costly motion is poorly understood. Using in situ underwater particle image velocimetry, we found that the pulsation motions thrust water upward and enhance mixing across the coral–water boundary layer. The induced upward motion effectively prevents refiltration of water by neighboring polyps, while the intensification of mixing, together with the upward flow, greatly enhances the coral’s photosynthesis. A series of controlled laboratory experiments with the common xeniid coral Heteroxenia fuscescens showed that the net photosynthesis rate during pulsation was up to an order of magnitude higher than during the coral’s resting, nonpulsating state. This enhancement diminished when the concentration of oxygen in the ambient water was artificially raised, indicating that the enhancement of photosynthesis was due to a greater efflux of oxygen from the coral tissues. By lowering the internal oxygen concentration, pulsation alleviates the problem of reduced affinity of ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO) to CO2 under conditions of high oxygen concentrations. The photosynthesis–respiration ratio of the pulsating H. fuscescens was markedly higher than the ratios reported for nonpulsating soft and stony corals. Although pulsation is commonly used for locomotion and filtration in marine mobile animals, its occurrence in sessile (bottom-attached) species is limited to members of the ancient phylum Cnidaria, where it is used to accelerate water and enhance physiological processes. PMID:23610420

Benefit of pulsation in soft corals.

PubMed

Kremien, Maya; Shavit, Uri; Mass, Tali; Genin, Amatzia

2013-05-28

Soft corals of the family Xeniidae exhibit a unique, rhythmic pulsation of their tentacles (Movie S1), first noted by Lamarck nearly 200 y ago. However, the adaptive benefit of this perpetual, energetically costly motion is poorly understood. Using in situ underwater particle image velocimetry, we found that the pulsation motions thrust water upward and enhance mixing across the coral-water boundary layer. The induced upward motion effectively prevents refiltration of water by neighboring polyps, while the intensification of mixing, together with the upward flow, greatly enhances the coral's photosynthesis. A series of controlled laboratory experiments with the common xeniid coral Heteroxenia fuscescens showed that the net photosynthesis rate during pulsation was up to an order of magnitude higher than during the coral's resting, nonpulsating state. This enhancement diminished when the concentration of oxygen in the ambient water was artificially raised, indicating that the enhancement of photosynthesis was due to a greater efflux of oxygen from the coral tissues. By lowering the internal oxygen concentration, pulsation alleviates the problem of reduced affinity of ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO) to CO2 under conditions of high oxygen concentrations. The photosynthesis-respiration ratio of the pulsating H. fuscescens was markedly higher than the ratios reported for nonpulsating soft and stony corals. Although pulsation is commonly used for locomotion and filtration in marine mobile animals, its occurrence in sessile (bottom-attached) species is limited to members of the ancient phylum Cnidaria, where it is used to accelerate water and enhance physiological processes.

Ion Escape from the Ionosphere of Titan

NASA Technical Reports Server (NTRS)

Hartle, R.; Sittler, E.; Lipatov, A.

2008-01-01

Ions have been observed to flow away from Titan along its induced magnetic tail by the Plasma Science Instrument (PLS) on Voyager 1 and the Cassini Plasma Spectrometer (CAPS) on Cassini. In both cases, the ions have been inferred to be of ionospheric origin. Recent plasma measurements made at another unmagnetized body, Venus, have also observed similar flow in its magnetic tail. Much earlier, the possibility of such flow was inferred when ionospheric measurements made from the Pioneer Venus Orbiter (PVO) were used to derive upward flow and acceleration of H(+), D(+) and O(+) within the nightside ionosphere of Venus. The measurements revealed that the polarization electric field in the ionosphere produced the principal upward force on these light ions. The resulting vertical flow of H(+) and D(+) was found to be the dominant escape mechanism of hydrogen and deuterium, corresponding to loss rates consistent with large oceans in early Venus. Other electrodynamic forces were unimportant because the plasma beta in the nightside ionosphere of Venus is much greater than one. Although the plasma beta is also greater than one on Titan, ion acceleration is expected to be more complex, especially because the subsolar point and the subflow points can be 180 degrees apart. Following what we learned at Venus, upward acceleration of light ions by the polarization electric field opposing gravity in the ionosphere of Titan will be described. Additional electrodynamic forces resulting from the interaction of Saturn's magnetosphere with Titan's ionosphere will be examined using a recent hybrid model.

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Age vs. experience : evaluation of a video feedback intervention for newly licensed teen drivers.

DOT National Transportation Integrated Search

2013-02-06

This project examines the effects of age, experience, and video-based feedback on the rate and type of safety-relevant events captured on video event : recorders in the vehicles of three groups of newly licensed young drivers: : 1. 14.5- to 15.5-year...