ERIC Educational Resources Information Center
Vuolo, Mike; Uggen, Christopher; Lageson, Sarah
2016-01-01
Given their capacity to identify causal relationships, experimental audit studies have grown increasingly popular in the social sciences. Typically, investigators send fictitious auditors who differ by a key factor (e.g., race) to particular experimental units (e.g., employers) and then compare treatment and control groups on a dichotomous outcome…
David N. Cole
1995-01-01
1. Experimental trampling was conducted in 18 vegetation types in five separate mountain regions in the United States. Each type was trampled 0-500 times. Response to trampling was assessed by determining vegetation cover 2 weeks after trampling and 1 year after trampling.2. Response varied significantly with trampling intensity and vegetation type. Trampling...
The neurovascular unit, matrix proteases, and innate inflammation.
del Zoppo, Gregory J
2010-10-01
In the central nervous system, microvessel-neuron interactions appear highly coordinated. The rapid simultaneous responses of the microvasculature, neurons, and glia to focal ischemia in experimental ischemic stroke suggest that these responses could be viewed in a unitary fashion, rather than as individual components. The "neurovascular unit" consists of microvessels (endothelial cells-basal lamina matrix-astrocyte end-feet [and pericytes]), astrocytes, neurons and their axons, and other supporting cells that are likely to modulate the function of the "unit." Each cell component generates an inflammatory response to ischemia. Matrix metalloproteinase (MMP)-9 was first associated with hemorrhagic transformation following focal ischemia in an experimental model. A series of studies of ischemic stroke patients also suggests a relationship between MMP-9 levels and several consequences of ischemic injury, including hemorrhagic transformation. Recent experimental work suggests specific cell sources for MMP-9 generation and for matrix proteases from four distinct families that could impact neurovascular unit integrity. © 2010 New York Academy of Sciences.
Mechanics of additively manufactured porous biomaterials based on the rhombicuboctahedron unit cell.
Hedayati, R; Sadighi, M; Mohammadi-Aghdam, M; Zadpoor, A A
2016-01-01
Thanks to recent developments in additive manufacturing techniques, it is now possible to fabricate porous biomaterials with arbitrarily complex micro-architectures. Micro-architectures of such biomaterials determine their physical and biological properties, meaning that one could potentially improve the performance of such biomaterials through rational design of micro-architecture. The relationship between the micro-architecture of porous biomaterials and their physical and biological properties has therefore received increasing attention recently. In this paper, we studied the mechanical properties of porous biomaterials made from a relatively unexplored unit cell, namely rhombicuboctahedron. We derived analytical relationships that relate the micro-architecture of such porous biomaterials, i.e. the dimensions of the rhombicuboctahedron unit cell, to their elastic modulus, Poisson's ratio, and yield stress. Finite element models were also developed to validate the analytical solutions. Analytical and numerical results were compared with experimental data from one of our recent studies. It was found that analytical solutions and numerical results show a very good agreement particularly for smaller values of apparent density. The elastic moduli predicted by analytical and numerical models were in very good agreement with experimental observations too. While in excellent agreement with each other, analytical and numerical models somewhat over-predicted the yield stress of the porous structures as compared to experimental data. As the ratio of the vertical struts to the inclined struts, α, approaches zero and infinity, the rhombicuboctahedron unit cell respectively approaches the octahedron (or truncated cube) and cube unit cells. For those limits, the analytical solutions presented here were found to approach the analytic solutions obtained for the octahedron, truncated cube, and cube unit cells, meaning that the presented solutions are generalizations of the analytical solutions obtained for several other types of porous biomaterials. Copyright © 2015 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Ratkovich, Nicolas; Bentzen, Thomas R.; Rasmussen, Michael R.
2012-10-01
Two types of submerged membrane bioreactors (MBR): hollow fiber (HF) and hollow sheet (HS), have been studied and compared in terms of energy consumption and average shear stress over the membrane wall. The analysis of energy consumption was made using the correlation to determine the blower power and the blower power demand per unit of permeate volume. Results showed that for the system geometries considered, in terms the of the blower power, the HF MBR requires less power compared to HS MBR. However, in terms of blower power per unit of permeate volume, the HS MBR requires less energy. The analysis of shear stress over the membrane surface was made using computational fluid dynamics (CFD) modelling. Experimental measurements for the HF MBR were compared with the CFD model and an error less that 8% was obtained. For the HS MBR, experimental measurements of velocity profiles were made and an error of 11% was found. This work uses an empirical relationship to determine the shear stress based on the ratio of aeration blower power to tank volume. This relationship is used in bubble column reactors and it is extrapolate to determine shear stress on MBR systems. This relationship proved to be overestimated by 28% compared to experimental measurements and CFD results. Therefore, a corrective factor is included in the relationship in order to account for the membrane placed inside the bioreactor.
Ventilation-Perfusion Relationships Following Experimental Pulmonary Contusion
2007-06-14
696.7 6.1 to 565.0 24.3 Hounsfield units ), as did VOL (4.3 0.5 to 33.5 3.2%). Multivariate linear regression of MGSD, VOL, VD/VT, and QS vs. PaO2...parenchyma was separated into four regions based on the Hounsfield unit (HU) ranges reported by Gattinoni et al. (23) via a segmentation process executed...determined by repeated measures ANOVA. CT, computed tomography; MGSD, mean gray-scale density of the entire lung by CT scan; HU, Hounsfield units
Probing Kill Mechanisms and Tuning Energetic Biocides
2018-02-01
Satcher, J. H., Jr.; Poco, J. F. Nanostructured Energetic Materials Using Sol−Gel Methodologies . J. Non -Cryst. Solids 2001, 285, 338−345. (16) Seo, H...customary unit. 2" " Abstract This project focuses on developing a methodology to accurately assess the time- temperature-kill relationships for spores...Task 1: Develop experimental protocol Task 2: Characterize Time-Temperature killing relationship Task 3: Determine kill mechanisms Task 4: Expose
An experimental design for quantification of cardiovascular responses to music stimuli in humans.
Chang, S-H; Luo, C-H; Yeh, T-L
2004-01-01
There have been several researches on the relationship between music and human physiological or psychological responses. However, there are cardiovascular index factors that have not been explored quantitatively due to the qualitative nature of acoustic stimuli. This study proposes and demonstrates an experimental design for quantification of cardiovascular responses to music stimuli in humans. The system comprises two components: a unit for generating and monitoring quantitative acoustic stimuli and a portable autonomic nervous system (ANS) analysis unit for quantitative recording and analysis of the cardiovascular responses. The experimental results indicate that the proposed system can exactly achieve the goal of full control and measurement for the music stimuli, and also effectively support many quantitative indices of cardiovascular response in humans. In addition, the analysis results are discussed and predicted in the future clinical research.
1998-01-01
to their large unit size and to experimental difficulties in determining geometries of carbon-based complex materials because of the weak X - ray ...qualitative relationship between the calculated local density of states and the experimental X - ray pho- toelectron spectra (XPS) and the Bremsstrahlung...from interaction schemes and allows complete data sets from different sources (neutron or X - ray diffraction, chemical constraints) to be fitted. In
Effects of a Math Intervention Program on Math Academic Performance among African American Students
ERIC Educational Resources Information Center
Johnson, Willie F., Jr.
2013-01-01
In the United States, an academic achievement gap has prevented many African American students from advancement and educational empowerment. Guided by Bandura's theoretical belief, which posits a relationship between social factors and an individual's perception, this non-experimental, causal comparative, control treatment group design study…
Simulation, Gaming, and Conventional Instruction: An Experimental Comparison.
ERIC Educational Resources Information Center
Fennessey, Gail M.; And Others
An environmental problems unit was organized to be taught with three approaches. One approach contained two simulation exercises, one contained a simulation game and a simulation exercise, and one contained no simulations. These approaches were compared for their effectiveness for teaching facts and relationships and for producing favorable…
Atmosphere, Science (Experimental): 5343.08.
ERIC Educational Resources Information Center
Reese, Sandra Kay
This unit of instruction deals with a study of the general atmosphere by layers with an emphasis on physical characteristics. The formation of layers in the atmosphere and the energy relationships that exist between them are also discussed. No requisites for prior course work, experience, or courses to be taken concurrently are required for…
USDA-ARS?s Scientific Manuscript database
Purpose: To examine relationships among psychosocial constructs (PSC) of behavior change and post-intervention changes in physical activity (PA) and dietary outcomes. Design: Non-controlled, pre- post-experimental intervention. Setting: Midsized, southern United States city. Subjects: 269 prima...
NASA Astrophysics Data System (ADS)
Otto, Paul B.; Schuck, Robert F.
The use of questions in the classroom has been employed throughout the recorded history of teaching. One still hears the term Socratic method during discussions of questioning procedures. The use of teacher questions is presently viewed as a viable procedure for effective instruction. This study was conducted to investigate the feasibility of training teachers in the use of a questioning technique and the resultant effect upon student learning. The Post-Test Only Control Group Design was used in randomly assigning teachers and students to experimental and control groups. A group of teachers was trained in the use of a specific questioning technique. Follow-up periodic observations were made of questioning technique behavior while teaching science units to groups of students. Post-unit achievement tests were administered to the student groups to obtain evidence of a relationship between the implementation of specific types of teacher questions and student achievement and retention. Analysis of observation data indicated a higher use of managerial and rhetorical questions by the control group than the experimental group. The experimental group employed a greater number of recall and data gathering questions as well as higher order data processing and data verification type questions. The student posttest achievement scores for both units of instruction were greater for the experimental groups than for the control groups. The retention scores for both units were Beater for the experimental groups than for the control groups.
The Relationships of Intergroup Ideologies to Ethnic Prejudice: A Meta-Analysis.
Whitley, Bernard E; Webster, Gregory D
2018-04-01
This meta-analysis summarizes the results of research on the relationships of majority group members' endorsement of assimilation, colorblindness, multiculturalism, and the relative relationships of colorblindness and multiculturalism to ethnic prejudice. Random effects analyses found that assimilation was positively related to explicit prejudice ( g. = 0.80), multiculturalism was negatively related to both explicit ( g. = -0.26) and implicit prejudice ( g. = -0.19), and colorblindness was negatively related to explicit prejudice ( g. = -0.07). Multiculturalism was more closely associated with low prejudice than colorblindness ( g. = 0.15). Effect sizes varied as a function of methodology (experimental vs. correlational), country in which research was conducted (United States vs. other countries), and, in experimental studies of multiculturalism, type of prime used (abstract vs. concrete). Discussion points include methodological issues, groups used as targets of prejudice, national diversity norms, additional issues raised in the studies reviewed, and directions for future research.
Alkorta, Ibon; Popelier, Paul L A
2015-02-02
Remarkably simple yet effective linear free energy relationships were discovered between a single ab initio computed bond length in the gas phase and experimental pKa values in aqueous solution. The formation of these relationships is driven by chemical features such as functional groups, meta/para substitution and tautomerism. The high structural content of the ab initio bond length makes a given data set essentially divide itself into high correlation subsets (HCSs). Surprisingly, all molecules in a given high correlation subset share the same conformation in the gas phase. Here we show that accurate pKa values can be predicted from such HCSs. This is achieved within an accuracy of 0.2 pKa units for 5 drug molecules. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Mechanical behavior of regular open-cell porous biomaterials made of diamond lattice unit cells.
Ahmadi, S M; Campoli, G; Amin Yavari, S; Sajadi, B; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A
2014-06-01
Cellular structures with highly controlled micro-architectures are promising materials for orthopedic applications that require bone-substituting biomaterials or implants. The availability of additive manufacturing techniques has enabled manufacturing of biomaterials made of one or multiple types of unit cells. The diamond lattice unit cell is one of the relatively new types of unit cells that are used in manufacturing of regular porous biomaterials. As opposed to many other types of unit cells, there is currently no analytical solution that could be used for prediction of the mechanical properties of cellular structures made of the diamond lattice unit cells. In this paper, we present new analytical solutions and closed-form relationships for predicting the elastic modulus, Poisson׳s ratio, critical buckling load, and yield (plateau) stress of cellular structures made of the diamond lattice unit cell. The mechanical properties predicted using the analytical solutions are compared with those obtained using finite element models. A number of solid and porous titanium (Ti6Al4V) specimens were manufactured using selective laser melting. A series of experiments were then performed to determine the mechanical properties of the matrix material and cellular structures. The experimentally measured mechanical properties were compared with those obtained using analytical solutions and finite element (FE) models. It has been shown that, for small apparent density values, the mechanical properties obtained using analytical and numerical solutions are in agreement with each other and with experimental observations. The properties estimated using an analytical solution based on the Euler-Bernoulli theory markedly deviated from experimental results for large apparent density values. The mechanical properties estimated using FE models and another analytical solution based on the Timoshenko beam theory better matched the experimental observations. Copyright © 2014 Elsevier Ltd. All rights reserved.
Can forest watershed management mitigate climate change effects on water resources
James M. Vose; Chelcy R. Ford; Stephanie Laseter; Salli Dymond; Ge Sun; Mary Beth Adams; Stephen Sebestyen; John Campbell; Charlie Luce; Devendra Amatya; Kelly Elder; Tamara Heartsill Scalley
2012-01-01
Long-term hydrology and climate data from United States Forest Service Experimental Forests and Ranges (EFR) provide critical information on the interactions among climate, streamflow, and forest management practices. We examined the relationships among streamflow responses to climate variation and forest management using long-term data. Analysis of climate data from a...
Can forest watershed management mitigate climate change impacts on water resources?
James M. Vose; Chelcy R. Ford; Stephanie Laseter; Salli Dymond; GE Sun; Mary Beth Adams; Stephen Sebestyen; John Campbell; Charles Luce; Devendra Amatya; Kelly Elder; Tamara. Heartsill-Scalley
2012-01-01
Long-term hydrology and climate data from United States Forest Service Experimental Forests and Ranges (EFR) provide critical information on the interactions among climate, streamflow, and forest management practices. We examined the relationships among streamflow responses to climate variation and forest management using long-term data. Analysis of climate data from a...
Animal Structures and Functions, Science (Experimental): 5314.13.
ERIC Educational Resources Information Center
Silver, Barbara A.
This unit of instruction was designed to introduce the student to the relationship between structure and function in the animal kingdom, with emphasis given to: (1) the evolution of physiological systems in the major animal phyla, (2) the complementarity of structure and function, and (3) the concept of homeostasis. The booklet lists the relevant…
Kang, Jiyeon; Kim, Jeung Im; Yun, Seonyoung
2017-10-01
This research aimed to investigate the effects of a cognitive rehearsal program (CRP) on workplace bullying among nurses. A randomized controlled trial was performed. Participants were 40 nurses working in different university hospitals in B city, South Korea. The experimental group was provided with a 20-hour CRP comprising scenarios on bullying situations, standard communication, and role-playing. To evaluate effects of the CRP, we measured interpersonal relationships, workplace bullying, symptom experience, and turnover intention at preand post-intervention. Follow-up effect was measured in the experimental group only at 4 weeks after the intervention. After the intervention, there were significant differences in interpersonal relationships (F=6.21, p=.022) and turnover intention (F=5.55, p=.024) between experimental and wait-list groups. However, there was no significant difference in workplace bullying or symptom experience between the 2 groups. The beneficial effects on interpersonal relationships and turnover intention lasted at least up to 4 weeks after CRP. The CRP for workplace bullying improves interpersonal relationships and decreases turnover intention. So it can be utilized as one of the personal coping strategies to reduce the the turnover among nurses. Further studies on the effects of unit- or hospital-based CRP and on the long-term effects of CRP are necessary. © 2017 Korean Society of Nursing Science
John L. Campbell; Amey S. Bailey; Christopher Eagar; Mark B. Green; John J. Battles
2013-01-01
By the late 19th and early 20th century, extensive forest harvesting was occurring throughout the United States, often with little regard for natural resources. The effects of logging on the environment were relatively unknown, which contributed to rising environmental concerns. Relationships between forests and stream water yield were of particular interest, because...
ERIC Educational Resources Information Center
D'Costa, Aspen
2013-01-01
The purpose of this study was to discover the relationship between employee engagement with chosen engagement drivers (quality of life, company practices, total rewards, work, people, and opportunities) along with the consequence of intention to turnover and job satisfaction. An experimental survey was carefully designed to examine employee…
Comber, Mike H I; Walker, John D; Watts, Chris; Hermens, Joop
2003-08-01
The use of quantitative structure-activity relationships (QSARs) for deriving the predicted no-effect concentration of discrete organic chemicals for the purposes of conducting a regulatory risk assessment in Europe and the United States is described. In the United States, under the Toxic Substances Control Act (TSCA), the TSCA Interagency Testing Committee and the U.S. Environmental Protection Agency (U.S. EPA) use SARs to estimate the hazards of existing and new chemicals. Within the Existing Substances Regulation in Europe, QSARs may be used for data evaluation, test strategy indications, and the identification and filling of data gaps. To illustrate where and when QSARs may be useful and when their use is more problematic, an example, methyl tertiary-butyl ether (MTBE), is given and the predicted and experimental data are compared. Improvements needed for new QSARs and tools for developing and using QSARs are discussed.
Germolec, Dori R.; Luebke, Robert W.; Johnson, Victor J.
2016-01-01
This overview is an update of the unit originally published in 2004. While the basic tenants of immunotoxicity have not changed in the past 10 years, several publications have explored the application of immunotoxicological data to the risk assessment process. Therefore, the goal of this unit is still to highlight relationships between xenobiotic-induced immunosuppression and risk of clinical diseases progression. In immunotoxicology, this may require development of models to equate moderate changes in markers of immune functions to potential changes in incidence or severity of infectious diseases. For most xenobiotics, exposure levels and disease incidence data are rarely available and safe exposure levels must be estimated based on observations from experimental models or human biomarker studies. Thus, it is important to establish a scientifically sound framework that allows accurate and quantitative interpretation of experimental or biomarker data in the risk assessment process. PMID:26828330
DeWitt, Jamie C; Germolec, Dori R; Luebke, Robert W; Johnson, Victor J
2016-02-01
This overview is an update of the unit originally published in 2004. While the basic tenets of immunotoxicity have not changed in the past 10 years, several publications have explored the application of immunotoxicological data to the risk assessment process. Therefore, the goal of this unit is still to highlight relationships between xenobiotic-induced immunosuppression and risk of clinical diseases progression. In immunotoxicology, this may require development of models to equate moderate changes in markers of immune functions to potential changes in incidence or severity of infectious diseases. For most xenobiotics, exposure levels and disease incidence data are rarely available, and safe exposure levels must be estimated based on observations from experimental models or human biomarker studies. Thus, it is important to establish a scientifically sound framework that allows accurate and quantitative interpretation of experimental or biomarker data in the risk assessment process. Copyright © 2016 John Wiley & Sons, Inc.
Disturbance alters local-regional richness relationships in appalachian forests
Belote, R.T.; Sanders, N.J.; Jones, R.H.
2009-01-01
Whether biological diversity within communities is limited by local interactions or regional species pools remains an important question in ecology. In this paper, we investigate how an experimentally applied tree-harvesting disturbance gradient influenced local-regional richness relationships. Plant species richness was measured at three spatial scales (2 ha = regional; 576 m2 and 1 m2 = local) on three occasions (one year pre-disturbance, one year post-disturbance, and 10 years post-disturbance) across five disturbance treatments (uncut control through clearcut) replicated throughout the southern Appalachian Mountains, USA. We investigated whether species richness in 576-m2 plots and 1-m2 subplots depended on species richness in 2-ha experimental units and whether this relationship changed through time before and after canopy disturbance. We found that, before disturbance, the relationship between local and regional richness was weak or nonexistent. One year after disturbance local richness was a positive function of regional richness, because local sites were colonized from the regional species pool. Ten years after disturbance, the positive relationship persisted, but the slope had decreased by half. These results suggest that disturbance can set the stage for strong influences of regional species pools on local community assembly in temperate forests. However, as time since disturbance increases, local controls on community assembly decouple the relationships between regional and local diversity. ?? 2009 by the Ecological Society of America.
Schwenke, T.; Wimmer, M. A.
2013-01-01
Wear of polyethylene (UHMWPE) is dependent on cross-shear. The aim of the present study was: 1) to develop a theoretical description of cross-shear, 2) to experimentally determine the relationship between cross-shear motion and UHMWPE wear using a wheel-on-flat apparatus, and 3) to calculate the work it takes to remove a unit volume of wear for the use in advanced computational models of wear. The theoretical description of cross-shear has been based on the previously reported finding that cross-shear is maximal when movement occurs perpendicular to fibril orientation. Here, cross-shear is described with a double-sinusoidal function that uses the angle between fibril orientation and velocity vector as input, and maximum cross-shear occurs at 90° and 270°. In the experimental part of the study, friction and wear of polyethylene were plotted against increasing sliding velocity vector angles, i.e. increasing cross-shear. It was found that wear intensified with increasing cross-shear, and wear depth could be predicted well using the double-sinusoidal function for cross-shear (r2=0.983). The friction data were then used to calculate the work to remove a unit particle by integrating the frictional force over the directional sliding distance. Using the wear volumes, determined for both longitudinal and perpendicular motion directions, the work to remove a unit volume of material was qy= 8.473 × 108 J/mm3 and qx= 1.321 × 108 J/mm3, respectively. Hence, 6.4 times more work was necessary to remove a unit wear volume in the direction of principal motion (i.e. along the molecular fibril orientation) than 90° perpendicular to it. In the future, these findings will be implemented in computational models to assess wear. PMID:23794761
Stenzel, Angelika; Goss, Kai-Uwe; Endo, Satoshi
2013-02-05
Polyparameter linear free energy relationships (pp-LFERs) can predict partition coefficients for a multitude of environmental and biological phases with high accuracy. In this work, the pp-LFER substance descriptors of 40 established and alternative flame retardants (e.g., polybrominated diphenyl ethers, hexabromocyclododecane, bromobenzenes, trialkyl phosphates) were determined experimentally. In total, 251 data for gas-chromatographic (GC) retention times and liquid/liquid partition coefficients (K) were measured and used to calibrate the pp-LFER substance descriptors. Substance descriptors were validated through a comparison between predicted and experimental log K for the systems octanol/water (K(ow)), water/air (K(wa)), organic carbon/water (K(oc)) and liposome/water (K(lipw)), revealing a high reliability of pp-LFER predictions based on our descriptors. For instance, the difference between predicted and experimental log K(ow) was <0.3 log units for 17 out of 21 compounds for which experimental values were available. Moreover, we found an indication that the H-bond acceptor value (B) depends on the solvent for some compounds. Thus, for predicting environmentally relevant partition coefficients it is important to determine B values using measurements in aqueous systems. The pp-LFER descriptors calibrated in this study can be used to predict partition coefficients for which experimental data are unavailable, and the predicted values can serve as references for further experimental measurements.
The impact of retirement on health: quasi-experimental methods using administrative data.
Horner, Elizabeth Mokyr; Cullen, Mark R
2016-02-19
Is retirement good or bad for health? Disentangling causality is difficult. Much of the previous quasi-experimental research on the effect of health on retirement used self-reported health and relied upon discontinuities in public retirement incentives across Europe. The current study investigated the effect of retirement on health by exploiting discontinuities in private retirement incentives to test the effect of retirement on health using a quasi-experimental study design. Secondary data (1997-2009) on a cohort of male manufacturing workers in a United States setting. Health status was determined using claims data from private insurance and Medicare. Analyses used employer-based administrative and claims data and claim data from Medicare. Widely used selection on observables models overstate the negative impact of retirement due to the endogeneity of the decision to retire. In addition, health status as measured by administrative claims data provide some advantages over the more commonly used survey items. Using an instrument and administrative health records, we find null to positive effects from retirement on all fronts, with a possible exception of increased risk for diabetes. This study provides evidence that retirement is not detrimental and may be beneficial to health for a sample of manufacturing workers. In addition, it supports previous research indicating that quasi-experimental methodologies are necessary to evaluate the relationship between retirement and health, as any selection on observable model will overstate the negative relationship of retirement on health. Further, it provides a model for how such research could be implemented in countries like the United States that do not have a strong public pension program. Finally, it demonstrates that such research need-not rely upon survey data, which has certain shortcomings and is not always available for homogenous samples.
Perspectives for a new realization of the pascal by optical methods
NASA Astrophysics Data System (ADS)
Jousten, Karl; Hendricks, Jay; Barker, Daniel; Douglas, Kevin; Eckel, Steve; Egan, Patrick; Fedchak, James; Flügge, Jens; Gaiser, Christof; Olson, Douglas; Ricker, Jacob; Rubin, Tom; Sabuga, Wladimir; Scherschligt, Julia; Schödel, Rene; Sterr, Uwe; Stone, Jack; Strouse, Gregory
2017-12-01
Since the beginning of measurement of pressure in the 17th century, the unit of pressure has been defined by the relationship of force per unit area. The present state of optical technology now offers the possibility of using a thermodynamic definition—specifically the ideal gas law—for the realization of the pressure unit, in the vacuum regime and slightly above, with an accuracy comparable to or better than the traditional methods of force per area. The changes planned for the SI in 2018 support the application of this thermodynamic definition that is based on the ideal gas law with the necessary corrections for real-gas effects. The paper reviews the theoretical and experimental foundations of those optical methods that are considered to be most promising to realize the unit of pressure at the highest level of metrology.
What is the Relationship Between Altitude and Weight in a Model Rocket?
NASA Technical Reports Server (NTRS)
Betz, Jonathan
1993-01-01
This experiment was designed to find a function of payload weight for altitude. The same rocket was launched a repeated number of times with the same engine and varying amounts of weight. After performing experimentation, it was calculated that the altitude in meters could be predicted with the equation A = (2.8(W exp 2)) - (70.6W + 310.3), with weight expressed in the unit ounces.
Reserve Officer Commissioning Program (ROCP) Officer and Reserve Personnel Readiness
2017-04-07
Stata Journal 2 (4): 358- 377. [14] Starks, Helene, and Melissa Garrido. 2014. "Observational & Quasi - Experimental Research Methods." 8th Annual...have active-duty (AD) experience . We also found a positive relationship between the presence of lieutenants at SMCR units and the retention of nonobligor... experience , and continue to monitor ROCP officers’ career development as the program matures. 15. SUBJECT TERMS Reserve, Officer, Recruiting, Retention 16
2013-01-01
Background Sport as a mechanism to build relationships across cultural boundaries and to build positive interactions among young people has often been promoted in the literature. However, robust evaluation of sport-for-development program impacts is limited. This study reports on an impact evaluation of a sport-for-development program in Australia, Football United®. Methods A quasi-experimental mixed methods design was employed using treatment partitioning (different groups compared had different levels of exposure to Football United). A survey was undertaken with 142 young people (average age of 14.7 years with 22.5% of the sample comprising girls) in four Australian schools. These schools included two Football United and two Comparison schools where Football United was not operating. The survey instrument was composed of previously validated measures, including emotional symptoms, peer problems and relationships, prosocial behaviour, other-group orientation, feelings of social inclusion and belonging and resilience. Face to face interviews were undertaken with a purposeful sample (n = 79) of those who completed the survey. The participants in the interviews were selected to provide a diversity of age, gender and cultural backgrounds. Results Young people who participated in Football United showed significantly higher levels of other-group orientation than a Comparison Group (who did not participate in the program). The Football United boys had significantly lower scores on the peer problem scale and significantly higher scores on the prosocial scale than boys in the Comparison Group. Treatment partitioning analyses showed positive, linear associations between other-group orientation and total participation in the Football United program. A lower score on peer problems and higher scores on prosocial behaviour in the survey were associated with regularity of attendance at Football United. These quantitative results are supported by qualitative data analysed from interviews. Conclusions The study provides evidence of the effects of Football United on key domains of peer and prosocial relationships for boys and other-group orientation for young people in the program sites studied. The effects on girls, and the impacts of the program on the broader school environment and at the community level, require further investigation. PMID:23621898
Ye, Xin; Beck, Travis W; DeFreitas, Jason M; Wages, Nathan P
2015-04-01
The aim of this study was to compare the acute effects of concentric versus eccentric exercise on motor control strategies. Fifteen men performed six sets of 10 repetitions of maximal concentric exercises or eccentric isokinetic exercises with their dominant elbow flexors on separate experimental visits. Before and after the exercise, maximal strength testing and submaximal trapezoid isometric contractions (40% of the maximal force) were performed. Both exercise conditions caused significant strength loss in the elbow flexors, but the loss was greater following the eccentric exercise (t=2.401, P=.031). The surface electromyographic signals obtained from the submaximal trapezoid isometric contractions were decomposed into individual motor unit action potential trains. For each submaximal trapezoid isometric contraction, the relationship between the average motor unit firing rate and the recruitment threshold was examined using linear regression analysis. In contrast to the concentric exercise, which did not cause significant changes in the mean linear slope coefficient and y-intercept of the linear regression line, the eccentric exercise resulted in a lower mean linear slope and an increased mean y-intercept, thereby indicating that increasing the firing rates of low-threshold motor units may be more important than recruiting high-threshold motor units to compensate for eccentric exercise-induced strength loss. Copyright © 2014 Elsevier B.V. All rights reserved.
Predicting rainfall erosivity by momentum and kinetic energy in Mediterranean environment
NASA Astrophysics Data System (ADS)
Carollo, Francesco G.; Ferro, Vito; Serio, Maria A.
2018-05-01
Rainfall erosivity is an index that describes the power of rainfall to cause soil erosion and it is used around the world for assessing and predicting soil loss on agricultural lands. Erosivity can be represented in terms of both rainfall momentum and kinetic energy, both calculated per unit time and area. Contrasting results on the representativeness of these two variables are available: some authors stated that momentum and kinetic energy are practically interchangeable in soil loss estimation while other found that kinetic energy is the most suitable expression of rainfall erosivity. The direct and continuous measurements of momentum and kinetic energy by a disdrometer allow also to establish a relationship with rainfall intensity at the study site. At first in this paper a comparison between the momentum-rainfall intensity relationships measured at Palermo and El Teularet by an optical disdrometer is presented. For a fixed rainfall intensity the measurements showed that the rainfall momentum values measured at the two experimental sites are not coincident. However both datasets presented a threshold value of rainfall intensity over which the rainfall momentum assumes a quasi-constant value. Then the reliability of a theoretically deduced relationship, linking momentum, rainfall intensity and median volume diameter, is positively verified using measured raindrop size distributions. An analysis to assess which variable, momentum or kinetic energy per unit area and time, is the best predictor of erosivity in Italy and Spain was also carried out. This investigation highlighted that the rainfall kinetic energy per unit area and time can be substituted by rainfall momentum as index for estimating the rainfall erosivity, and this result does not depend on the site where precipitation occurs. Finally, rainfall intensity measurements and soil loss data collected from the bare plots equipped at Sparacia experimental area were used to verify the reliability of some rainfall erosivity indices and their ability to distinguish the type of involved soil erosion processes.
Moreno-Poyato, Antonio R; Delgado-Hito, Pilar; Suárez-Pérez, Raquel; Leyva-Moral, Juan M; Aceña-Domínguez, Rosa; Carreras-Salvador, Regina; Roldán-Merino, Juan F; Lluch-Canut, Teresa; Montesó-Curto, Pilar
2017-01-01
Psychiatric nurses are aware of the importance of the therapeutic relationship in psychiatric units. Nevertheless, a review of the scientific evidence indicates that theoretical knowledge alone is insufficient to establish an adequate therapeutic alliance. Therefore, strategies are required to promote changes to enhance the establishment of the working relationship. The aims of the study are to generate changes in how nurses establish the therapeutic relationship in acute psychiatric units, based on participative action research and to evaluate the effectiveness of the implementation of evidence through this method. The study will use a mixed method design. Qualitative methodology, through participative action research, will be employed to implement scientific evidence on the therapeutic relationship. A quasi-experimental, one-group, pre-test/post-test design will also be used to quantitatively measure the effectiveness of the implementation of the evidence. Participants will consist of nurses and patients from two psychiatric units in Barcelona. Nurses will be selected by theoretical sampling, and patients assigned to each nurses will be selected by consecutive sampling. Qualitative data will be gathered through discussion groups and field diaries. Quantitative data will be collected through the Working Alliance Inventory and the Interpersonal Reactivity Index. Qualitative data will be analysed through the technique of content analysis and quantitative data through descriptive and inferential statistics. This study will help to understand the process of change in a nursing team working in an inpatient psychiatric ward and will allow nurses to generate knowledge, identify difficulties, and establish strategies to implement change, as well as to assess whether the quality of the care they provide shows a qualitative improvement.
Coexistence of twitch potentiation and tetanic force decline in rat hindlimb muscle
NASA Technical Reports Server (NTRS)
Rankin, Lucinda L.; Enoka, Roger M.; Volz, Kathryn A.; Stuart, Douglas G.
1988-01-01
The effect of whole-muscle fatigue on the isometric twitch was investigated in various hindlimb muscles of anesthetized rats, using an experimental protocol designed to assess the levels of fatigability in motor units. The results of EMG and force measurements revealed the existence of a linear relationship between fatigability and the magnitude of the twitch force following the fatigue test in both soleus and extensor digitorum longus muscles.
A Computer Model of the Evaporator for the Development of an Automatic Control System
NASA Astrophysics Data System (ADS)
Kozin, K. A.; Efremov, E. V.; Kabrysheva, O. P.; Grachev, M. I.
2016-08-01
For the implementation of a closed nuclear fuel cycle it is necessary to carry out a series of experimental studies to justify the choice of technology. In addition, the operation of the radiochemical plant is impossible without high-quality automatic control systems. In the technologies of spent nuclear fuel reprocessing, the method of continuous evaporation is often used for a solution conditioning. Therefore, the effective continuous technological process will depend on the operation of the evaporation equipment. Its essential difference from similar devices is a small size. In this paper the method of mathematic simulation is applied for the investigation of one-effect evaporator with an external heating chamber. Detailed modelling is quite difficult because the phase equilibrium dynamics of the evaporation process is not described. Moreover, there is a relationship with the other process units. The results proved that the study subject is a MIMO plant, nonlinear over separate control channels and not selfbalancing. Adequacy was tested using the experimental data obtained at the laboratory evaporation unit.
Tao, Zhi-Fu; Han, Zhong-Ling; Yao, Meng
2011-01-01
Using the difference of dielectric constant between malignant tumor tissue and normal breast tissue, breast tumor microwave sensor system (BRATUMASS) determines the detected target of imaging electromagnetic trait by analyzing the properties of target tissue back wave obtained after near-field microwave radicalization (conelrad). The key of obtained target properties relationship and reconstructed detected space is to analyze the characteristics of the whole process from microwave transmission to back wave reception. Using traveling wave method, we derive spatial transmission properties and the relationship of the relation detected points distances, and valuate the properties of each unit by statistical valuation theory. This chapter gives the experimental data analysis results.
Rose, Anne C
2016-09-01
The British-born psychologist William McDougall (1871-1938) spent more than half of his academic career in the United States, holding successive positions after 1920 at Harvard and Duke universities. Scholarly studies uniformly characterize McDougall's relationship with his New World colleagues as contentious: in the standard view, McDougall's theory of innate drives clashed with the Americans' experimentation into learned habits. This essay argues instead that rising American curiosity about inborn appetites-an interest rooted in earlier pragmatic philosophy and empirically investigated by interwar scientists-explains McDougall's migration to the United States and his growing success there. A review of McDougall's intellectual and professional ties, evolving outside public controversy, highlights persistent American attention to natural agency and complicates arguments voiced by contemporaries in favor of nurture. © 2016 Wiley Periodicals, Inc.
Miller, Jonathan D; Herda, Trent J; Trevino, Michael A; Sterczala, Adam J; Ciccone, Anthony B
2017-08-01
What is the central question of this study? The influences of motor unit recruitment threshold and twitch force potentiation on the changes in firing rates during steady-force muscular contractions are not well understood. What is the main finding and its importance? The behaviour of motor units during steady force was influenced by recruitment threshold, such that firing rates decreased for lower-threshold motor units but increased for higher-threshold motor units. In addition, individuals with greater changes in firing rates possessed greater twitch force potentiation. There are contradictory reports regarding changes in motor unit firing rates during steady-force contractions. Inconsistencies are likely to be the result of previous studies disregarding motor unit recruitment thresholds and not examining firing rates on a subject-by-subject basis. It is hypothesized that firing rates are manipulated by twitch force potentiation during contractions. Therefore, in this study we examined time-related changes in firing rates at steady force in relationship to motor unit recruitment threshold in the first dorsal interosseous and the influence of twitch force potentiation on such changes in young versus aged individuals. Subjects performed a 12 s steady-force contraction at 50% maximal voluntary contraction, with evoked twitches before and after the contraction to quantify potentiation. Firing rates, in relationship to recruitment thresholds, were determined at the beginning, middle and end of the steady force. There were no firing rate changes for aged individuals. For the young, firing rates decreased slightly for lower-threshold motor units but increased for higher-threshold motor units. Twitch force potentiation was greater for young than aged subjects, and changes in firing rates were correlated with twitch force potentiation. Thus, individuals with greater increases in firing rates of higher-threshold motor units and decreases in lower-threshold motor units possessed greater twitch force potentiation. Overall, changes in firing rates during brief steady-force contractions are dependent on recruitment threshold and explained in part by twitch force potentiation. Given that firing rate changes were measured in relationship to recruitment threshold, this study illustrates a more complete view of firing rate changes during steady-force contractions. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.
Peper, John D.; McCartan, Lucy; Horton, J. Wright; Reddy, James E.
2001-01-01
This preliminary experimental lithogeochemical map shows the distribution of rock types in the Virginia and Maryland parts of the Chesapeake Bay watershed. The map was produced digitally by classifying geologic-map units according to composition, mineralogy, and texture; rather than by age and stratigraphic relationships as shown on traditional geologic maps. This map differs from most lithologic maps in that the lithogeochemical unit classification distinguishes those rock units having key water-reactive minerals that may induce acid neutralization, or reduction, of hosted water at the weathering interface. The validity of these rock units, however, is independent of water chemistry, because the rock units are derived from geologic maps and rock descriptions. Areas of high soil carbon content, and sulfide metal deposits are also shown. Water-reactive minerals and their weathering reactions yield five lithogeochemical unit classes: 1) carbonate rock and calcareous rocks and sediments, the most acid-neutralizing; 2)carbonaceous-sulfidic rocks and sediments, oxygen-depleting and reducing; 3) quartzofeldspathic rocks and siliciclastic sediments, relatively weakly reactive with water; 4) mafic silicate rocks/sediments, oxygen consuming and high solute-load delivering; and, 5) the rarer calcareous-sulfidic (carbonaceous) rocks, neutralizing and reducing. Earlier studies in some parts of the map area have related solute loads in ground and stream waters to some aspects of bedrock lithology. More recent preliminary tests of relationships between four of the classes of mapped lithogeochemical units and ground water chemistry, in the Mid-Atlantic area using this map, have focused on and verified the nitrate-reducing and acid-neutralizing properties of some bedrock and unconsolidated aquifer rock types. Sulfide mineral deposits and their mine-tailings effects on waters are beginning to be studied by others. Additional testing of relationships among the lithogeochemical units and aspects of ground and surface water chemistry could help to refine the lithogeochemical classification, and this map. The testing could also improve the usefulness of the map for assessing aquifer reactivity and the transport properties of reactive contaminants such as acid rain, and nitrate from agricultural sources, in the Chesapeake Bay watershed.
NASA Astrophysics Data System (ADS)
Mutch, E. J. F.; Blundy, J. D.; Tattitch, B. C.; Cooper, F. J.; Brooker, R. A.
2016-10-01
We report new experimental data on the composition of magmatic amphiboles synthesised from a variety of granite (sensu lato) bulk compositions at near-solidus temperatures and pressures of 0.8-10 kbar. The total aluminium content (Altot) of the synthetic calcic amphiboles varies systematically with pressure ( P), although the relationship is nonlinear at low pressures (<2.5 kbar). At higher pressures, the relationship resembles that of other experimental studies, which suggests of a general relationship between Altot and P that is relatively insensitive to bulk composition. We have developed a new Al-in-hornblende geobarometer that is applicable to granitic rocks with the low-variance mineral assemblage: amphibole + plagioclase (An15-80) + biotite + quartz + alkali feldspar + ilmenite/titanite + magnetite + apatite. Amphibole analyses should be taken from the rims of grains, in contact with plagioclase and in apparent textural equilibrium with the rest of the mineral assemblage at temperatures close to the haplogranite solidus (725 ± 75 °C), as determined from amphibole-plagioclase thermometry. Mean amphibole rim compositions that meet these criteria can then be used to calculate P (in kbar) from Altot (in atoms per formula unit, apfu) according to the expression: {it{P }}( {{kbar}} ) = 0.5 + 0.331( 8 ) × {{Al}}^{{tot}} + 0.995( 4 ) × ( {{{Al}}^{{tot}} } )2 This expression recovers equilibration pressures of our calibrant dataset, comprising both new and published experimental and natural data, to within ±16 % relative uncertainty. An uncertainty of 10 % relative for a typical Altot value of 1.5 apfu translates to an uncertainty in pressure estimate of 0.5 kbar, or 15 % relative. Thus the accuracy of the barometer expression is comparable to the precision with which near-solidus amphibole rim composition can be characterised.
1984-08-01
Requirements 63 3.3.1 Hypothesis 4: Relationship Between Unit Technology and Information Source Requirements..................64 3.3.2 Hypothesis 5... Relationship Between Environ- mental Uncertainty and Information Source Requirements..................65 3.3.3 Hypothesis 6: Relationship Between Inter-Unit...Sources. ............ 67 3.4.1 Hypothesis 1: Relationship Between Unit Structure and the Accessibility and Quality of Information Sources .. ........ 68
Correlating low-similarity peptide sequences and allergenic epitopes.
Kanduc, D
2008-01-01
Although a high number of allergenic peptide epitopes has been experimentally identified and defined, the molecular basis and the precise mechanisms underlying peptide allergenicity are unknown. This issue was analyzed exploring the relationship between peptide allergenicity and sequence similarity to the human proteome. The structured analysis of the data reported in literature put into evidence that the most part of IgE-binding epitopes are (or harbor) pentapeptide unit(s) with no/low similarity to the human proteome, this way suggesting that no or low sequence similarity to the host proteome might represent a minimum common denominator identifying allergenic peptides. The present literature analysis might be of relevance in devising and designing short amino acid modules to be used for blocking pathogenic IgE.
Nazione, Samantha; Pace, Kristin
2015-01-01
Medical malpractice lawsuits are a growing problem in the United States, and there is much controversy regarding how to best address this problem. The medical error disclosure framework suggests that apologizing, expressing empathy, engaging in corrective action, and offering compensation after a medical error may improve the provider-patient relationship and ultimately help reduce the number of medical malpractice lawsuits patients bring to medical providers. This study provides an experimental examination of the medical error disclosure framework and its effect on amount of money requested in a lawsuit, negative intentions, attitudes, and anger toward the provider after a medical error. Results suggest empathy may play a large role in providing positive outcomes after a medical error.
Cooperativity in Molecular Dynamics Structural Models and the Dielectric Spectra of 1,2-Ethanediol
NASA Astrophysics Data System (ADS)
Usacheva, T. M.
2018-05-01
Linear relationships are established between the experimental equilibrium correlation factor and the molecular dynamics (MD) mean
The fracture energy and some mechanical properties of a polyurethane elastomer.
NASA Technical Reports Server (NTRS)
Mueller, H. K.; Knauss, W. G.
1971-01-01
The energy required to form a unit of new surface in the fracture of a polyurethane elastomer is determined. The rate sensitivity of the material has been reduced by swelling it in toluene. This paper primarily describes the experimental work of measuring the lower limit of the fracture energy. With this value and the creep compliance as a basis, the rate dependence of fracture energy for the unswollen material has been determined. It is thus shown that the dependence of the fracture energy on the rate of crack propagation can be explained by energy dissipation around the tip of the crack. Good agreement between the theoretically and experimentally determined relationships for the rate-sensitive fracture energy is demonstrated.
Liang, Yuzhen; Kuo, Dave T F; Allen, Herbert E; Di Toro, Dominic M
2016-10-01
There is concern about the environmental fate and effects of munition constituents (MCs). Polyparameter linear free energy relationships (pp-LFERs) that employ Abraham solute parameters can aid in evaluating the risk of MCs to the environment. However, poor predictions using pp-LFERs and ABSOLV estimated Abraham solute parameters are found for some key physico-chemical properties. In this work, the Abraham solute parameters are determined using experimental partition coefficients in various solvent-water systems. The compounds investigated include hexahydro-1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX), hexahydro-1,3-dinitroso-5- nitro-1,3,5-triazine (DNX), 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), and 4-nitroanisole. The solvents in the solvent-water systems are hexane, dichloromethane, trichloromethane, octanol, and toluene. The only available reported solvent-water partition coefficients are for octanol-water for some of the investigated compounds and they are in good agreement with the experimental measurements from this study. Solvent-water partition coefficients fitted using experimentally derived solute parameters from this study have significantly smaller root mean square errors (RMSE = 0.38) than predictions using ABSOLV estimated solute parameters (RMSE = 3.56) for the investigated compounds. Additionally, the predictions for various physico-chemical properties using the experimentally derived solute parameters agree with available literature reported values with prediction errors within 0.79 log units except for water solubility of RDX and HMX with errors of 1.48 and 2.16 log units respectively. However, predictions using ABSOLV estimated solute parameters have larger prediction errors of up to 7.68 log units. This large discrepancy is probably due to the missing R2NNO2 and R2NNO2 functional groups in the ABSOLV fragment database. Copyright © 2016. Published by Elsevier Ltd.
Ashab, A.S.M. Ayman; Ruan, Dong; Lu, Guoxing; Bhuiyan, Arafat A.
2016-01-01
The mechanical behavior of aluminum hexagonal honeycombs subjected to out-of-plane dynamic indentation and compression loads has been investigated numerically using ANSYS/LS-DYNA in this paper. The finite element (FE) models have been verified by previous experimental results in terms of deformation pattern, stress-strain curve, and energy dissipation. The verified FE models have then been used in comprehensive numerical analysis of different aluminum honeycombs. Plateau stress, σpl, and dissipated energy (EI for indentation and EC for compression) have been calculated at different strain rates ranging from 102 to 104 s−1. The effects of strain rate and t/l ratio on the plateau stress, dissipated energy, and tearing energy have been discussed. An empirical formula is proposed to describe the relationship between the tearing energy per unit fracture area, relative density, and strain rate for honeycombs. Moreover, it has been found that a generic formula can be used to describe the relationship between tearing energy per unit fracture area and relative density for both aluminum honeycombs and foams. PMID:28773288
Martin, Richard L; Simon, Cory M; Smit, Berend; Haranczyk, Maciej
2014-04-02
Porous polymer networks (PPNs) are a class of advanced porous materials that combine the advantages of cheap and stable polymers with the high surface areas and tunable chemistry of metal-organic frameworks. They are of particular interest for gas separation or storage applications, for instance, as methane adsorbents for a vehicular natural gas tank or other portable applications. PPNs are self-assembled from distinct building units; here, we utilize commercially available chemical fragments and two experimentally known synthetic routes to design in silico a large database of synthetically realistic PPN materials. All structures from our database of 18,000 materials have been relaxed with semiempirical electronic structure methods and characterized with Grand-canonical Monte Carlo simulations for methane uptake and deliverable (working) capacity. A number of novel structure-property relationships that govern methane storage performance were identified. The relationships are translated into experimental guidelines to realize the ideal PPN structure. We found that cooperative methane-methane attractions were present in all of the best-performing materials, highlighting the importance of guest interaction in the design of optimal materials for methane storage.
[Relationship between the prone position and achieving head control at 3 months].
Pérez-Machado, J L; Rodríguez-Fuentes, G
2013-10-01
Owing to the significant increase of mild motor delays and the strong intolerance of infants to be placed on prone position observed in the Physiotherapy Unit of the Maternal and Children's University Hospital of the Canaries (HUMIC), a study was conducted to determine whether positioning infants in the prone position while awake affected the achievement and quality of head control at three months. A prospective comparative practice-based study of a representative sample of 67 healthy infants born in the HUMIC, and divided into an experimental group (n = 35) and control group (n = 32). The Alberta Infant Motor Scale (AIMS) and a parent questionnaire were used as measurement tools. The intervention consisted of regular home visits to the experimental group (from the first to the third month). The two groups were evaluated in their homes at the end of 3 months. The differences in mean raw score of the AIMS at 3 months were, 16.26 in the experimental group and 10.38 in control group (P<.001). The percentile mean was 94 in the experimental group, and less than 50 (42) in the control group. All of the experimental group babies achieved the head control, with only 8 in the control group (25%). The significant findings suggest a direct relationship between the time spent in the prone position when the baby is awake and the achievement of head control at three months. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.
Simkin, Samuel M.; Allen, Edith B.; Bowman, William D.; Clark, Christopher M.; Belnap, Jayne; Brooks, Matthew L.; Cade, Brian S.; Collins, Scott L.; Geiser, Linda H.; Gilliam, Frank S.; Jovan, Sarah E.; Pardo, Linda H.; Schulz, Bethany K.; Stevens, Carly J.; Suding, Katharine N.; Throop, Heather L.; Waller, Donald M.
2016-01-01
Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We assessed the effect of N deposition on herbaceous richness for 15,136 forest, woodland, shrubland, and grassland sites across the continental United States, to address how edaphic and climatic conditions altered vulnerability to this stressor. In our dataset, with N deposition ranging from 1 to 19 kg N⋅ha−1⋅y−1, we found a unimodal relationship; richness increased at low deposition levels and decreased above 8.7 and 13.4 kg N⋅ha−1⋅y−1 in open and closed-canopy vegetation, respectively. N deposition exceeded critical loads for loss of plant species richness in 24% of 15,136 sites examined nationwide. There were negative relationships between species richness and N deposition in 36% of 44 community gradients. Vulnerability to N deposition was consistently higher in more acidic soils whereas the moderating roles of temperature and precipitation varied across scales. We demonstrate here that negative relationships between N deposition and species richness are common, albeit not universal, and that fine-scale processes can moderate vegetation responses to N deposition. Our results highlight the importance of contingent factors when estimating ecosystem vulnerability to N deposition and suggest that N deposition is affecting species richness in forested and nonforested systems across much of the continental United States.
Woolf-King, Sarah E.; Maisto, Stephen A.
2014-01-01
African American adults are disproportionately affected by HIV in the United States, underscoring the need for additional research on barriers to condom use. Guided by the theory of gender and power, this experimental study used a series of vignettes to test causal hypotheses regarding the influence of event-level alcohol use (present and absent), partner type (serious and casual), and relationship power (low and equal) on perceived difficulty implementing condom use. A total of 299 (151 women and 148 men) heterosexual African American adults indicated how “difficult” it would be to use a condom after reading 8 hypothetical sexual encounters, presented in a random order. A 2 x 2 x 2 x 2 repeated measures analysis of covariance (ANCOVA) with one between subjects factor (gender) and one covariate (condom use self-efficacy) was used to estimate the effects of these variables on an index of perceived difficultly. The women in the study reported significantly higher ratings of difficulty implementing condom use in vignettes characterized by low relationship power (p < .001) and presence of alcohol use (p < .001); the manipulated independent variables did not produce any main effects for men. Both men and women’s ratings of perceived difficulty decreased as condom use self-efficacy increased (p < .001). This is the first study to use an experimental methodology to test hypotheses about barriers to condom use among a community-based sample of African American adults. These data can be used to enhance existing HIV prevention interventions. PMID:25277692
Calculating the Solubilities of Drugs and Drug-Like Compounds in Octanol.
Alantary, Doaa; Yalkowsky, Samuel
2016-09-01
A modification of the Van't Hoff equation is used to predict the solubility of organic compounds in dry octanol. The new equation describes a linear relationship between the logarithm of the solubility of a solute in octanol to its melting temperature. More than 620 experimentally measured octanol solubilities, collected from the literature, are used to validate the equation without using any regression or fitting. The average absolute error of the prediction is 0.66 log units. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.
The NACA Impact Basin and Water Landing Tests of a Float Model at Various Velocities and Weights
NASA Technical Reports Server (NTRS)
Batterson, Sidney A
1944-01-01
The first data obtained in the United States under the controlled testing conditions necessary for establishing relationships among the numerous parameters involved when a float having both horizontal and vertical velocity contacts a water surface are presented. The data were obtained at the NACA impact basin. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant. Analysis of the experimental results indicated that the maximum impact normal acceleration was proportional to the square of the resultant velocity, that increases in float weight resulted in decreases in the maximum impact normal acceleration, and that an increase in the flight-path angle caused increased impact normal acceleration.
Harter, James K; Schmidt, Frank L; Hayes, Theodore L
2002-04-01
Based on 7,939 business units in 36 companies, this study used meta-analysis to examine the relationship at the business-unit level between employee satisfaction-engagement and the business-unit outcomes of customer satisfaction, productivity, profit, employee turnover, and accidents. Generalizable relationships large enough to have substantial practical value were found between unit-level employee satisfaction-engagement and these business-unit outcomes. One implication is that changes in management practices that increase employee satisfaction may increase business-unit outcomes, including profit.
Examining the relationships between span of control and manager job and unit performance outcomes.
Wong, Carol A; Elliott-Miller, Pat; Laschinger, Heather; Cuddihy, Michael; Meyer, Raquel M; Keatings, Margaret; Burnett, Camille; Szudy, Natalie
2015-03-01
Our aim was to examine the combination of frontline manager (FLM) personal characteristics and span of control (SOC) on their job and unit performance outcomes. Healthcare downsizing and reform have contributed to larger spans for FLMs in Canadian hospitals and increased concerns about manager workload. Despite a heightened awareness of SOC issues among decision makers, there is limited empirical evidence related to the effects of SOC on outcomes. A non-experimental predictive survey design was used to examine FLM SOC in 14 Canadian academic hospitals. Managers (n = 121) completed an online survey of work characteristics and The Ottawa Hospital (TOH) SOC tool. Unit turnover data were collected from organisational databases. The combination of SOC and core self-evaluation significantly predicted role overload, work control and job satisfaction, but only SOC predicted unit adverse outcomes and neither significantly predicted unit turnover. The findings contribute to an understanding of connections between the combination of SOC and core self-evaluation and manager job and unit performance outcomes. Organisational strategies to create manageable FLM SOC are essential to ensure exemplary job and unit outcomes. Core self-evaluation is a personality characteristic that may enhance manager performance in the face of high spans of control. © 2013 John Wiley & Sons Ltd.
Robert, Benoît; Perrin, Marc-Antoine; Barrio, Maria; Tamarit, Josep-Lluis; Coquerel, Gérard; Ceolin, René; Rietveld, Ivo B
2016-01-01
Two polymorphs of the 1:1 fumarate salt of 1,4-diazabicyclo[3.2.2]nonane-4-carboxylic acid 4-bromophenyl ester, developed for the treatment of cognitive symptoms of schizophrenia and Alzheimer disease, have been characterized. The 2 crystal structures have been solved, and their phase relationships have been established. The space group of form I is P2₁/c with a unit-cell volume of 1811.6 (5) Å(3) with Z = 4. The crystals of form I were 2-component nonmerohedral twins. The space group of form II is P2₁/n with a unit-cell volume of 1818.6 (3) Å(3) with Z = 4. Relative stabilities have been inferred from experimental and topological P-T diagrams exhibiting an overall enantiotropic relationship between forms I and II although the solid-solid transition has never been observed. The slope of the I-II equilibrium in the P-T diagram is negative, form II is the stable phase below the solid-solid transition temperature of 371 K, and form I exhibits a stable melting equilibrium. The I-II transition temperature has been obtained from the intersection of the sublimation curves of the 2 solid forms. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.
Gast, Richard K; Guraya, Rupa; Guard, Jean; Holt, Peter S
2011-06-01
Contamination of eggs by Salmonella Enteritidis has been a prominent cause of human illness for several decades and is the focus of a recently implemented national regulatory plan for egg-producing flocks in the United States. Salmonella Heidelberg has also been identified as an egg-transmitted pathogen. The deposition of Salmonella strains inside eggs is a consequence of reproductive tract colonization in infected laying hens, but prior research has not determined the relationship between the numbers of Salmonella that colonize reproductive organs and the associated frequency of egg contamination. In the present study, groups of laying hens in two trials were experimentally infected with large oral doses of strains of Salmonella Enteritidis (phage type 13a), Salmonella Heidelberg, or Salmonella Hadar. Reproductive tissues of selected hens were cultured to detect and enumerate Salmonella at 5 days postinoculation, and the interior contents of eggs laid between 6 and 25 days postinoculation were tested for contamination. Significantly more internally contaminated eggs were laid by hens infected with Salmonella Enteritidis (3.58%) than with strains of either Salmonella Heidelberg (0.47%) or Salmonella Hadar (0%). However, no significant differences were observed between Salmonella strains in either isolation frequency or the number of colony-forming units (CFU) isolated from ovaries or oviducts. Salmonella isolation frequencies ranged from 20.8% to 41.7% for ovaries and from 8.3% to 33.3% for oviducts. Mean Salmonella colonization levels ranged from 0.10 to 0.51 log CFU/g for ovaries and from 0.25 to 0.46 log CFU/g for oviducts. Although parallel rank-orders were observed for Salmonella enumeration (in both ovaries and oviducts) and egg contamination frequency, a statistically significant relationship could not be established between these two parameters of infection.
USDA-ARS?s Scientific Manuscript database
A number of recent soil biota studies have deviated from the standard experimental approach of generating a distinct data value for each experimental unit (e.g. Yang et al., 2013; Gundale et al., 2014). Instead, these studies have mixed together soils from multiple experimental units (i.e. sites wi...
Binary Interval Search: a scalable algorithm for counting interval intersections.
Layer, Ryan M; Skadron, Kevin; Robins, Gabriel; Hall, Ira M; Quinlan, Aaron R
2013-01-01
The comparison of diverse genomic datasets is fundamental to understand genome biology. Researchers must explore many large datasets of genome intervals (e.g. genes, sequence alignments) to place their experimental results in a broader context and to make new discoveries. Relationships between genomic datasets are typically measured by identifying intervals that intersect, that is, they overlap and thus share a common genome interval. Given the continued advances in DNA sequencing technologies, efficient methods for measuring statistically significant relationships between many sets of genomic features are crucial for future discovery. We introduce the Binary Interval Search (BITS) algorithm, a novel and scalable approach to interval set intersection. We demonstrate that BITS outperforms existing methods at counting interval intersections. Moreover, we show that BITS is intrinsically suited to parallel computing architectures, such as graphics processing units by illustrating its utility for efficient Monte Carlo simulations measuring the significance of relationships between sets of genomic intervals. https://github.com/arq5x/bits.
Resource availability controls fungal diversity across a plant diversity gradient
Waldrop, M.P.; Zak, D.R.; Blackwood, C.B.; Curtis, C.D.; Tilman, D.
2006-01-01
Despite decades of research, the ecological determinants of microbial diversity remain poorly understood. Here, we test two alternative hypotheses concerning the factors regulating fungal diversity in soil. The first states that higher levels of plant detritus production increase the supply of limiting resources (i.e. organic substrates) thereby increasing fungal diversity. Alternatively, greater plant diversity increases the range of organic substrates entering soil, thereby increasing the number of niches to be filled by a greater array of heterotrophic fungi. These two hypotheses were simultaneously examined in experimental plant communities consisting of one to 16 species that have been maintained for a decade. We used ribosomal intergenic spacer analysis (RISA), in combination with cloning and sequencing, to quantify fungal community composition and diversity within the experimental plant communities. We used soil microbial biomass as a temporally integrated measure of resource supply. Plant diversity was unrelated to fungal diversity, but fungal diversity was a unimodal function of resource supply. Canonical correspondence analysis (CCA) indicated that plant diversity showed a relationship to fungal community composition, although the occurrence of RISA bands and operational taxonomic units (OTUs) did not differ among the treatments. The relationship between fungal diversity and resource availability parallels similar relationships reported for grasslands, tropical forests, coral reefs, and other biotic communities, strongly suggesting that the same underlying mechanisms determine the diversity of organisms at multiple scales. ?? 2006 Blackwell Publishing Ltd/CNRS.
Predicting the bioconcentration factor of highly hydrophobic organic chemicals.
Garg, Rajni; Smith, Carr J
2014-07-01
Bioconcentration refers to the process of uptake and buildup of chemicals in living organisms. Experimental measurement of bioconcentration factor (BCF) is time-consuming and expensive, and is not feasible for a large number of chemicals of regulatory concern. Quantitative structure-activity relationship (QSAR) models are used for estimating BCF values to help in risk assessment of a chemical. This paper presents the results of a QSAR study conducted to address an important problem encountered in the prediction of the BCF of highly hydrophobic chemicals. A new QSAR model is derived using a dataset of diverse organic chemicals previously tested in a United States Environmental Protection Agency laboratory. It is noted that the linear relationship between the BCF and hydrophobic parameter, i.e., calculated octanol-water partition coefficient (ClogP), breaks down for highly hydrophobic chemicals. The parabolic QSAR equation, log BCF=3.036 ClogP-0.197 ClogP(2)-0.808 MgVol (n=28, r(2)=0.817, q(2)=0.761, s=0.558) (experimental log BCF range=0.44-5.29, ClogP range=3.16-11.27), suggests that a non-linear relationship between BCF and the hydrophobic parameter, along with inclusion of additional molecular size, weight and/or volume parameters, should be considered while developing a QSAR model for more reliable prediction of the BCF of highly hydrophobic chemicals. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
NASA Astrophysics Data System (ADS)
Li, X. G.; Long, X. Y.; Jiang, H. Q.; Long, H. B.
2018-05-01
The splice is the weakest part of the entire steel cord conveyor belt. And it occurs steel cord twitch fault frequently. If this fault cannot be dealt with timely and accurately, broken belt accidents would be occurred that affecting the safety of production seriously. In this paper, we investigate the steel cord pullout of the steel cord conveyor belt splice by using ABAQUS software. We selected the strength of steel cord conveyor belt ST630, the same as experiment sample in type specification. The finite element model consists of rubber, steel cord and failure unit. And the failure unit is used to simulate the bonding relationship between the steel cord and the rubber. Mooney-Rivlin hyper-elastic model for rubber was employed in the numerical simulations. The pullout force of length 50.0 mm single steel cord, on both sides of a single steel cord and on both sides of the double steel cords each impacted at steel cord conveyor belt splice were numerically computer and typical results obtained have been validated by experimental result. It shows that the relative error between simulation results and experimental results is within 10% and can be considered that the simulation model is reliable. A new method is provided for studying the steel cord twitch fault of the steel cord conveyor belt splice.
The effect of nurse manager turnover on patient fall and pressure ulcer rates.
Warshawsky, Nora; Rayens, Mary Kay; Stefaniak, Karen; Rahman, Rana
2013-07-01
The purpose of this study was to explore the effects of nurse manager turnover on the occurrence of adverse events. Nurse managers create professional nurse practice environments to support the provision of quality patient outcomes. Inconsistent findings were reported in the literature testing the relationship between nurse managers and patient outcomes. All prior studies assumed stable nursing management. A longitudinal quasi-experimental study of 23 nursing units in two hospitals was used to determine whether unit characteristics, including nurse manager turnover, have an effect on patient falls or pressure ulcers. Statistical analyses included repeated measures and hierarchical modelling. Patients in medical/surgical units experienced more falls than in intensive care units (F1,11 = 15.9, P = 0.002). Patients in units with a nurse manager turnover [odds ratio: 3.16; 95% confidence interval: 1.49-6.70] and intensive care units (odds ratio: 2.70; 95% confidence interval: 1.33-5.49) were more likely to develop pressure ulcers. Nurse manager turnover and intensive care unit status were associated with more pressure ulcers. Medical/surgical unit status was associated with more falls. The study was limited by a small sample size. Nurse manager turnover may negatively impact patient outcomes. Stable nursing management, strategic interim management and long-term succession planning may reduce adverse patient events. © 2013 John Wiley & Sons Ltd.
Optimized Laplacian image sharpening algorithm based on graphic processing unit
NASA Astrophysics Data System (ADS)
Ma, Tinghuai; Li, Lu; Ji, Sai; Wang, Xin; Tian, Yuan; Al-Dhelaan, Abdullah; Al-Rodhaan, Mznah
2014-12-01
In classical Laplacian image sharpening, all pixels are processed one by one, which leads to large amount of computation. Traditional Laplacian sharpening processed on CPU is considerably time-consuming especially for those large pictures. In this paper, we propose a parallel implementation of Laplacian sharpening based on Compute Unified Device Architecture (CUDA), which is a computing platform of Graphic Processing Units (GPU), and analyze the impact of picture size on performance and the relationship between the processing time of between data transfer time and parallel computing time. Further, according to different features of different memory, an improved scheme of our method is developed, which exploits shared memory in GPU instead of global memory and further increases the efficiency. Experimental results prove that two novel algorithms outperform traditional consequentially method based on OpenCV in the aspect of computing speed.
The relationship between organizational culture and family satisfaction in critical care.
Dodek, Peter M; Wong, Hubert; Heyland, Daren K; Cook, Deborah J; Rocker, Graeme M; Kutsogiannis, Demetrios J; Dale, Craig; Fowler, Robert; Robinson, Sandra; Ayas, Najib T
2012-05-01
Family satisfaction with critical care is influenced by a variety of factors. We investigated the relationship between measures of organizational and safety culture, and family satisfaction in critical care. We further explored differences in this relationship depending on intensive care unit survival status and length of intensive care unit stay of the patient. Cross-sectional surveys. Twenty-three tertiary and community intensive care units within three provinces in Canada. One thousand two-hundred eighty-five respondents from 2374 intensive care unit clinical staff, and 880 respondents from 1381 family members of intensive care unit patients. None. Intensive care unit staff completed the Organization and Management of Intensive Care Units survey and the Hospital Survey on Patient Safety Culture. Family members completed the Family Satisfaction in the Intensive Care Unit 24, a validated survey of family satisfaction. A priori, we analyzed adjusted relationships between each domain score from the culture surveys and either satisfaction with care or satisfaction with decision-making for each of four subgroups of family members according to patient descriptors: intensive care unit survivors who had length of intensive care unit stay <14 days or >14 days, and intensive care unit nonsurvivors who had length of stay <14 days or ≥14 days. We found strong positive relationships between most domains of organizational and safety culture, and satisfaction with care or decision-making for family members of intensive care unit nonsurvivors who spent at least 14 days in the intensive care unit. For the other three groups, there were only a few weak relationships between domains of organizational and safety culture and family satisfaction. Our findings suggest that the effect of organizational culture on care delivery is most easily detectable by family members of the most seriously ill patients who interact frequently with intensive care unit staff, who are intensive care unit nonsurvivors, and who spend a longer time in the intensive care unit. Positive relationships between measures of organizational and safety culture and family satisfaction suggest that by improving organizational culture, we may also improve family satisfaction.
Beyer, Kirsten M. M.; Kaltenbach, Andrea; Szabo, Aniko; Bogar, Sandra; Nieto, F. Javier; Malecki, Kristen M.
2014-01-01
Green space is now widely viewed as a health-promoting characteristic of residential environments, and has been linked to mental health benefits such as recovery from mental fatigue and reduced stress, particularly through experimental work in environmental psychology. Few population level studies have examined the relationships between green space and mental health. Further, few studies have considered the role of green space in non-urban settings. This study contributes a population-level perspective from the United States to examine the relationship between environmental green space and mental health outcomes in a study area that includes a spectrum of urban to rural environments. Multivariate survey regression analyses examine the association between green space and mental health using the unique, population-based Survey of the Health of Wisconsin database. Analyses were adjusted for length of residence in the neighborhood to reduce the impact of neighborhood selection bias. Higher levels of neighborhood green space were associated with significantly lower levels of symptomology for depression, anxiety and stress, after controlling for a wide range of confounding factors. Results suggest that “greening” could be a potential population mental health improvement strategy in the United States. PMID:24662966
NASA Astrophysics Data System (ADS)
Lazić, Anita M.; Božić, Bojan Đ.; Vitnik, Vesna D.; Vitnik, Željko J.; Rogan, Jelena R.; Radovanović, Lidija D.; Valentić, Nataša V.; Ušćumlić, Gordana S.
2017-01-01
The structure-property relationship of newly synthesized 3-(4-substituted benzyl)-1,3-diazaspiro [4.4]nonane-2,4-diones was studied by experimental and calculated methods. The prepared compounds were characterized by UV-Vis, FT-IR, 1H NMR and 13C NMR spectroscopy and elemental analysis. The crystal structure was elucidated by single-crystal X-ray diffraction. The 3-benzyl-1,3-diazaspiro[4.4]nonane-2,4-dione crystallizes in triclinic P-1 space group, with two crystallographically independent molecules in the asymmetric unit. Cyclopentane ring adopts an envelope conformation. A three-dimensional crystal packing is governed by hydrogen N-H⋯O bonds, numerous C-H⋯O/N and C-H … π interactions between neighboring molecules. Density functional theory (DFT) calculations with B3LYP and M06-2X methods using 6-311++G(d,p) basis set were performed to provide structural and spectroscopic information. Comparisons between experimental and calculated UV-Vis spectral properties suggest that the monomeric form of the investigated spirohydantoins is dominant in all used solvents. The effects of substituents on the absorption spectra of spirohydantoins are interpreted by correlation of absorption frequencies with Hammett equation. The lipophilicities of the investigated molecules were estimated by calculation of their log P values. Some of the spirohydantoins synthesized in this work, exhibit the lipophilicities comparable to the standard medicine anticonvulsant drug Phenytoin. The results obtained in this investigation afford guidelines for the preparation of new derivatives of spirohydantoin as potential anticonvulsant agents and for better understanding the structure-activity relationship.
NASA Astrophysics Data System (ADS)
Urbahs, A.; Urbaha, M.; Carjova, K.
2017-10-01
The theoretical calculation for development of planetary gear unit of wind turbine (WT) and its experimental tests are presented in the paper. Development of experimental prototypes from composite materials is essential to determine capability of element and its impact on feature. Two experimental scale prototypes of planetary gear unit for WT were developed for such purposes. Hall transducer, servomechanisms and optical tachometers were used to obtain results, comparison analysis of theoretical and actual data was performed as well as quality assessment of experimental prototypes of planetary gear unit. After kinematic and load analysis as well as control of rotation frequency, it is possible to declare that the unit is able to operate at designated quality. Theoretical calculations and test results obtained are used for industrial WT prototype development.
Establishing a Rational New Zealand/United States Defense Relationship
1994-01-01
5500 Standard Form 298 (Rev. 2-89) Prescribed by ANSI Std. Z39-16 298-102 1~4CJC SRATGYESSAY WRCITING COMIPETITION ENTRY ESTABLISHING A RATIONAL NEW...AJBAvailability Codjes ALABAMA ABSTRACT TITLE: E lishng a Rational New Zealand/United States Defense Relationship AUTHOR.- Richard J. Newlands, Wing...Current Stetu of the New Zealand/United States Relationship 12 OutstandItg Issues .1 Toward a Rational New Zealan/Unted States Defense Relationship .16
Physiological Event Prediction in Evaluations of Underwater Breathing Apparatus
2016-10-25
Navy Experimental Diving Unit TA 15-02 321 Bullfinch Rd. NEDU TR 16-04 Panama City, FL 32407-7015 October 2016 Physiological...Event Prediction in Evaluations of Underwater Breathing Apparatus NAVY EXPERIMENTAL DIVING UNIT Author...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Navy Experimental
DOE Office of Scientific and Technical Information (OSTI.GOV)
Maughan, Annalise E.; Ganose, Alex M.; Bordelon, Mitchell M.
Vacancy-ordered double perovskites of the general formula, A2BX6, are a family of perovskite derivatives composed of a face-centered lattice of nearly isolated [BX6] units with A-site cations occupying the cuboctahedral voids. Despite the presence of isolated octahedral units, the close-packed iodide lattice provides significant electronic dispersion, such that Cs2SnI6 has recently been explored for applications in photovoltaic devices. To elucidate the structure-property relationships of these materials, we have synthesized the solid solution Cs2Sn1-xTexI6. However, even though tellurium substitution increases electronic dispersion via closer I-I contact distances, the substitution experimentally yields insulating behavior from a significant decrease in carrier concentration andmore » mobility. Density functional calculations of native defects in Cs2SnI6 reveal that iodine vacancies exhibit a low enthalpy of formation and the defect energy level is a shallow donor to the conduction band, rendering the material tolerant to these defect states. The increased covalency of Te-I bonding renders the formation of iodine vacancy states unfavorable, and is responsible for the reduction in conductivity upon Te substitution. Additionally, Cs2TeI6 is intolerant to the formation of these defects, as the defect level occurs deep within the band gap and thus localizes potential mobile charge carriers. In these vacancy-ordered double perovskites, the close-packed lattice of iodine provides significant electronic dispersion, while the interaction of the B- and X-site ions dictates the properties as they pertain to electronic structure and defect tolerance. This simplified perspective -- based on extensive experimental and theoretical analysis -- provides a platform from which to understand structure-property relationships in functional perovskite halides.« less
Kemp, Matthew W; Lazarus, Benjamin M; Perron, Gabriel G; Hanage, William P; Chapman, Elaine
2014-01-01
The ability to form multiple learning relationships is a key element of the doctoral learning environment in the biomedical sciences. Of these relationships, that between student and supervisor has long been viewed as key. There are, however, limited data to describe the student perspective on what makes this relationship valuable. In the present study, we discuss the findings of semi-structured interviews with biomedical Ph.D. students from the United Kingdom and the United States to: i) determine if the learning relationships identified in an Australian biomedical Ph.D. cohort are also important in a larger international student cohort; and ii) improve our understanding of student perceptions of value in their supervisory relationships. 32 students from two research intensive universities, one in the United Kingdom (n = 17), and one in the United States (n = 15) were recruited to participate in a semi-structured interview. Verbatim transcripts were transcribed, validated and analysed using a Miles and Huberman method for thematic analysis. Students reported that relationships with other Ph.D. students, post-doctoral scientists and supervisors were all essential to their learning. Effective supervisory relationships were perceived as the primary source of high-level project guidance, intellectual support and confidence. Relationships with fellow students were viewed as essential for the provision of empathetic emotional support. Technical learning was facilitated, almost exclusively, by relationships with postdoctoral staff. These data make two important contributions to the scholarship of doctoral education in the biomedical sciences. Firstly, they provide further evidence for the importance of multiple learning relationships in the biomedical doctorate. Secondly, they clarify the form of a 'valued' supervisory relationship from a student perspective. We conclude that biomedical doctoral programs should be designed to contain a minimum level of formalised structure to promote the development of multiple learning relationships that are perceived as key to student learning.
Kemp, Matthew W.; Lazarus, Benjamin M.; Perron, Gabriel G.; Hanage, William P.; Chapman, Elaine
2014-01-01
Objective The ability to form multiple learning relationships is a key element of the doctoral learning environment in the biomedical sciences. Of these relationships, that between student and supervisor has long been viewed as key. There are, however, limited data to describe the student perspective on what makes this relationship valuable. In the present study, we discuss the findings of semi-structured interviews with biomedical Ph.D. students from the United Kingdom and the United States to: i) determine if the learning relationships identified in an Australian biomedical Ph.D. cohort are also important in a larger international student cohort; and ii) improve our understanding of student perceptions of value in their supervisory relationships. Study Design 32 students from two research intensive universities, one in the United Kingdom (n = 17), and one in the United States (n = 15) were recruited to participate in a semi-structured interview. Verbatim transcripts were transcribed, validated and analysed using a Miles and Huberman method for thematic analysis. Results Students reported that relationships with other Ph.D. students, post-doctoral scientists and supervisors were all essential to their learning. Effective supervisory relationships were perceived as the primary source of high-level project guidance, intellectual support and confidence. Relationships with fellow students were viewed as essential for the provision of empathetic emotional support. Technical learning was facilitated, almost exclusively, by relationships with postdoctoral staff. Conclusions These data make two important contributions to the scholarship of doctoral education in the biomedical sciences. Firstly, they provide further evidence for the importance of multiple learning relationships in the biomedical doctorate. Secondly, they clarify the form of a ‘valued’ supervisory relationship from a student perspective. We conclude that biomedical doctoral programs should be designed to contain a minimum level of formalised structure to promote the development of multiple learning relationships that are perceived as key to student learning. PMID:25054473
Use of physical restraints in adult critical care: a bicultural study.
Martin, Beth; Mathisen, Lars
2005-03-01
Although controversial, physical restraints are commonly used in adult critical care units in the United States to prevent treatment interference and self-inflicted harm. Use of physical restraints in Norwegian hospitals is very limited. In the United States, an experimental design for research on use of restraints has not seemed feasible. However, international research provides an opportunity to compare and contrast practices. To describe the relationship between patients' characteristics, environment, and use of physical restraints in the United States and Norway. Observations of patients and chart data were collected from 2 intensive care units (n = 50 patients) in Norway and 3 (n = 50 patients) in the United States. Sedation was measured by using the Sedation-Agitation Scale. The Nine Equivalents of Nursing Manpower Use Score was used to indicate patients' acuity level. Restraints were in use in 39 of 100 observations in the United States and not at all in Norway (P = .001). Categories of patients were balanced. In the Norwegian sample, the median Nine Equivalents of Nursing Manpower Use Score was higher (37 vs 27 points, P < .001), patients were more sedated (P < .001), and nurse-to-patient ratios were higher (1.05:1 vs 0.65:1, P < .001). Seven incidents of unplanned device removal were reported in the US sample. Critical care units with similar technology and characteristics of patients vary between nations in restraint practices, levels of sedation, and nurse-to-patient ratios. Restraint-free care was, in this sample, safe in terms of treatment interference.
NASA Technical Reports Server (NTRS)
Mackay, N. G.; Green, S. F.; Gardner, D. J.; Mcdonnell, J. A. M.
1995-01-01
Interpretation of the wealth of impact data available from the Long Duration Exposure Facility, in terms of the absolute and relative populations of space debris and natural micrometeoroids, requires three dimensional models of the distribution of impact directions, velocities and masses of such particles, as well as understanding of the impact processes. Although the stabilized orbit of LDEF provides limited directional information, it is possible to determine more accurate impact directions from detailed crater morphology. The applicability of this technique has already been demonstrated but the relationship between crater shape and impactor direction and velocity has not been derived in detail. We present the results of impact experiments and simulations: (1) impacts at micron dimensions using the Unit's 2MV Van de Graaff accelerator; (2) impacts at mm dimensions using a Light Gas Gun; and (3) computer simulations using AUTODYN-3D from which an empirical relationship between crater shape and impactor velocity, direction and particle properties we aim to derive. Such a relationship can be applied to any surface exposed to space debris or micrometeoroid particles for which a detailed pointing history is available.
Shrager, Jeff; Billman, Dorrit; Convertino, Gregorio; Massar, J P; Pirolli, Peter
2010-01-01
Science is a form of distributed analysis involving both individual work that produces new knowledge and collaborative work to exchange information with the larger community. There are many particular ways in which individual and community can interact in science, and it is difficult to assess how efficient these are, and what the best way might be to support them. This paper reports on a series of experiments in this area and a prototype implementation using a research platform called CACHE. CACHE both supports experimentation with different structures of interaction between individual and community cognition and serves as a prototype for computational support for those structures. We particularly focus on CACHE-BC, the Bayes community version of CACHE, within which the community can break up analytical tasks into "mind-sized" units and use provenance tracking to keep track of the relationship between these units. Copyright © 2009 Cognitive Science Society, Inc.
[A new machinability test machine and the machinability of composite resins for core built-up].
Iwasaki, N
2001-06-01
A new machinability test machine especially for dental materials was contrived. The purpose of this study was to evaluate the effects of grinding conditions on machinability of core built-up resins using this machine, and to confirm the relationship between machinability and other properties of composite resins. The experimental machinability test machine consisted of a dental air-turbine handpiece, a control weight unit, a driving unit of the stage fixing the test specimen, and so on. The machinability was evaluated as the change in volume after grinding using a diamond point. Five kinds of core built-up resins and human teeth were used in this study. The machinabilities of these composite resins increased with an increasing load during grinding, and decreased with repeated grinding. There was no obvious correlation between the machinability and Vickers' hardness; however, a negative correlation was observed between machinability and scratch width.
Social and Spatial Networks: Kinship Distance and Dwelling Unit Proximity in Rural Thailand
Verdery, Ashton M.; Entwisle, Barbara; Faust, Katherine; Rindfuss, Ronald R.
2013-01-01
We address a long hypothesized relationship between the proximity of individuals' dwelling units and their kinship association. Better understanding this relationship is important because of its implications for contact and association among members of a society. In this paper, we use a unique dataset from Nang Rong, Thailand which contains dwelling unit locations (GPS) and saturated kinship networks of all individuals living in 51 agricultural villages. After presenting arguments for a relationship between individuals’ dwelling unit locations and their kinship relations as well as the particulars of our case study, we introduce the data and describe our analytic approach. We analyze how kinship - considered as both a system linking collections of individuals in an extended kinship network and as dyadic links between pairs of individuals -patterns the proximity of dwelling units in rural villages. The results show that in general, extended kin live closer to one another than do unrelated individuals. Further, the degree of relatedness between kin correlates with the distance between their dwelling units. Close kin are more likely to co-reside, a fact which drives much of the relationship between kinship relatedness and dwelling unit proximity within villages. There is nevertheless suggestive evidence of a relationship between kinship association and dwelling unit proximity among kin who do not live together. PMID:23956489
In situ measurement of radioactive contamination of bottom sediments.
Zhukouski, A; Anshakou, O; Kutsen, S
2018-04-30
A gamma spectrometric method is presented for in situ radiation monitoring of bottom sediments with contaminated layer of unknown thickness to be determined. The method, based on the processing of experimental spectra using the results of their simulation by the Monte Carlo method, is proposed and tested in practice. A model for the transport of gamma radiation from deposited radionuclides 137 Cs and 134 Cs to a scintillation detection unit located on the upper surface of the contaminated layer of sediments is considered. The relationship between the effective radius of the contaminated site and the thickness of the layer has been studied. The thickness of the contaminated layer is determined by special analysis of experimental and thickness-dependent simulated spectra. The technique and algorithm developed are verified as a result of full-scale studies performed with the submersible gamma-spectrometer. Copyright © 2018 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Chen, Wei; Xu, Yue; Zhang, Huaxin; Liu, Peng; Jiao, Guohua
2016-09-01
Laser scanners are critical components in material processing systems, such as welding, cutting, and drilling. To achieve high-accuracy processing, the laser spot size should be small and uniform in the entire objective flat field. However, traditional static focusing method using F-theta objective lens is limited by the narrow flat field. To overcome these limitations, a dynamic focusing unit consisting of two lenses is presented in this paper. The dual-lens system has a movable plano-concave lens and a fixed convex lens. As the location of the movable optical elements is changed, the focal length is shifted to keep a small focus spot in a broad flat processing filed. The optical parameters of the two elements are theoretical analyzed. The spot size is calculated to obtain the relationship between the moving length of first lens and the shift focus length of the system. Also, the Zemax model of the optical system is built up to verify the theoretical design and optimize the optical parameter. The proposed lenses are manufactured and a test system is built up to investigate their performances. The experimental results show the spot size is smaller than 450um in all the 500*500mm 2 filed with CO2 laser. Compared with the other dynamic focusing units, this design has fewer lenses and no focusing spot in the optical path. In addition, the focal length minimal changes with the shit of incident laser beam.
ERIC Educational Resources Information Center
Yeager, John L.; Kissel, Mary Ann
The relationship betwee n a composite of student entry characteristics--unit pretest score, number of skills to be mastered in the unit, the student's intelligence quotient and age, units previously mastered--and the amount of time required to complete one of four units of D or E level mathematics was investigated. Beta weights for the regression…
The roles of unit leadership and nurse-physician collaboration on nursing turnover intention.
Galletta, Maura; Portoghese, Igor; Battistelli, Adalgisa; Leiter, Michael P
2013-08-01
To report a study of the relationship between variables at the group and individual level with nurses' intention to leave their unit. Workplaces are collective environments where workers constantly interact with each other. The quality of working relationship employees develop at the unit-level influences both employee outcomes and unit performance by shaping employee attitudes. The study was a cross-sectional design with self-administered questionnaires. A questionnaire including measures of leader-member exchange and nurse-physician collaboration analysed at group-level and affective commitment and turnover intention analysed at individual level, was administered individually to 1018 nurses in five Italian hospitals. Data were collected in 2009. A total of 832 nurses (81·7% response rate) completed questionnaires. The results showed that affective commitment at individual level completely mediated the relationship between leader-member exchange at group-level and nursing turnover intention. Furthermore, the cross-level interaction was significant: at individual level, the nurses with high levels of individual affective commitment towards their unit showed low levels of turnover intention and this relationship was stronger when the nurse-physician collaboration at group-level was high. This study showed the importance for organizations to implement management practices that promote both high-quality nurse-supervisor and nurse-physician relationships, because they increase nurses' identification with their units. Individual affective commitment is an important quality for retaining a workforce and good nurses' relationship at group-level relationships with both supervisors and physicians are instrumental in developing identification with the work unit. Thus, the quality of relationship among staff members is an important factor in nurses' decision to leave. © 2012 Blackwell Publishing Ltd.
Protein folding and misfolding: mechanism and principles
Englander, S. Walter; Mayne, Leland; Krishna, Mallela M. G.
2012-01-01
Two fundamentally different views of how proteins fold are now being debated. Do proteins fold through multiple unpredictable routes directed only by the energetically downhill nature of the folding landscape or do they fold through specific intermediates in a defined pathway that systematically puts predetermined pieces of the target native protein into place? It has now become possible to determine the structure of protein folding intermediates, evaluate their equilibrium and kinetic parameters, and establish their pathway relationships. Results obtained for many proteins have serendipitously revealed a new dimension of protein structure. Cooperative structural units of the native protein, called foldons, unfold and refold repeatedly even under native conditions. Much evidence obtained by hydrogen exchange and other methods now indicates that cooperative foldon units and not individual amino acids account for the unit steps in protein folding pathways. The formation of foldons and their ordered pathway assembly systematically puts native-like foldon building blocks into place, guided by a sequential stabilization mechanism in which prior native-like structure templates the formation of incoming foldons with complementary structure. Thus the same propensities and interactions that specify the final native state, encoded in the amino-acid sequence of every protein, determine the pathway for getting there. Experimental observations that have been interpreted differently, in terms of multiple independent pathways, appear to be due to chance misfolding errors that cause different population fractions to block at different pathway points, populate different pathway intermediates, and fold at different rates. This paper summarizes the experimental basis for these three determining principles and their consequences. Cooperative native-like foldon units and the sequential stabilization process together generate predetermined stepwise pathways. Optional misfolding errors are responsible for 3-state and heterogeneous kinetic folding. PMID:18405419
Mark, Barbara A; Hughes, Linda C; Belyea, Michael; Chang, Yunkyung; Hofmann, David; Jones, Cheryl B; Bacon, Cynthia T
2007-01-01
Hospital nurses have one of the highest work-related injury rates in the United States. Yet, approaches to improving employee safety have generally focused on attempts to modify individual behavior through enforced compliance with safety rules and mandatory participation in safety training. We examined a theoretical model that investigated the impact on nurse injuries (back injuries and needlesticks) of critical structural variables (staffing adequacy, work engagement, and work conditions) and further tested whether safety climate moderated these effects. A longitudinal, non-experimental, organizational study, conducted in 281 medical-surgical units in 143 general acute care hospitals in the United States. Work engagement and work conditions were positively related to safety climate, but not directly to nurse back injuries or needlesticks. Safety climate moderated the relationship between work engagement and needlesticks, while safety climate moderated the effect of work conditions on both needlesticks and back injuries, although in unexpected ways. DISCUSSION AND IMPACT ON INDUSTRY: Our findings suggest that positive work engagement and work conditions contribute to enhanced safety climate and can reduce nurse injuries.
Binary Interval Search: a scalable algorithm for counting interval intersections
Layer, Ryan M.; Skadron, Kevin; Robins, Gabriel; Hall, Ira M.; Quinlan, Aaron R.
2013-01-01
Motivation: The comparison of diverse genomic datasets is fundamental to understand genome biology. Researchers must explore many large datasets of genome intervals (e.g. genes, sequence alignments) to place their experimental results in a broader context and to make new discoveries. Relationships between genomic datasets are typically measured by identifying intervals that intersect, that is, they overlap and thus share a common genome interval. Given the continued advances in DNA sequencing technologies, efficient methods for measuring statistically significant relationships between many sets of genomic features are crucial for future discovery. Results: We introduce the Binary Interval Search (BITS) algorithm, a novel and scalable approach to interval set intersection. We demonstrate that BITS outperforms existing methods at counting interval intersections. Moreover, we show that BITS is intrinsically suited to parallel computing architectures, such as graphics processing units by illustrating its utility for efficient Monte Carlo simulations measuring the significance of relationships between sets of genomic intervals. Availability: https://github.com/arq5x/bits. Contact: arq5x@virginia.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23129298
Conditions affecting the formation of chlorinated carbon compounds during carbochlorination
NASA Astrophysics Data System (ADS)
Landsberg, A.; Wilson, R. D.; Burns, W.
1988-06-01
The Bureau of Mines, United States Department of the Interior, has conducted an extensive study of the relationship between various metal oxide carbochlorination reactions and carbon compound byproducts. Experiments in which oxides of titanium, zirconium, and aluminum with graphite, charcoal, metallurgical coke, and pctroleum coke were chlorinated at 600° to 1000 °C produced 136 identified and quantified carbon byproduct compounds. The 20 most abundant of these compounds were correlated with reactants and reaction conditions. Experimental results support a proposed carbochlorination reaction with an initial chlorine-carbon step followed by a reaction between the resulting chlorine-carbon products and the metal oxide.
Insulin resistance and bone: a biological partnership.
Conte, Caterina; Epstein, Solomon; Napoli, Nicola
2018-04-01
Despite a clear association between type 2 diabetes (T2D) and fracture risk, the pathogenesis of bone fragility in T2D has not been clearly elucidated. Insulin resistance is the primary defect in T2D. Insulin signalling regulates both bone formation and bone resorption, but whether insulin resistance can affect bone has not been established. On the other hand, evidence exists that bone might play a role in the regulation of glucose metabolism. This article reviews the available experimental and clinical evidence on the interplay between bone and insulin resistance. Interestingly, a bilateral relationship between bone and insulin resistance seems to exist that unites them in a biological partnership.
Study on safety operation for large hydroelectric generator unit
NASA Astrophysics Data System (ADS)
Yan, Z. G.; Cui, T.; Zhou, L. J.; Zhi, F. L.; Wang, Z. W.
2012-11-01
Hydroelectric generator unit is a complex mechanical system which is composed of hydraulic turbine and electric generator. Rotary system is supported by the bearing bracket and the reinforced concrete structures, and vibration problem can't be avoided in the process of operating. Many large-scale hydroelectric units have been damaged because of the vibration problem in recent years. As the increase of the hydraulic turbine unit capacity and water head, the safe operation of hydraulic turbine has become a focus research in many countries. The operating characteristics of the hydraulic turbine have obvious differences at different working conditions. Based on the combination of field measurement and theoretical calculation, this paper shows a deep research on the safe operation of a large-scale Francis turbine unit. Firstly, the measurements of vibration, swing, pressure fluctuation and noise were carried out at 4 different heads. And also the relationships between vibrations and pressure fluctuations at different heads and working conditions were analysed deeply. Then the scientific prediction of safe operation for the unit at high head were done based on the CFD numerical calculation. Finally, this paper shows the division of the operating zone for the hydroelectric unit. According to the experimental results (vibrations, swings, pressure fluctuations and noise) as well as the theoretical results, the operating zone of the unit has been divided into three sections: prohibited operating zone, transition operating zone and safe operating zone. After this research was applied in the hydropower station, the security and economic efficiency of unit increased greatly, and enormous economic benefits and social benefits have been obtained.
Authentic leadership and nurses' voice behaviour and perceptions of care quality.
Wong, Carol A; Spence Laschinger, Heather K; Cummings, Greta G
2010-11-01
The purpose of the present study was to test a theoretical model linking authentic leadership with staff nurses' trust in their manager, work engagement, voice behaviour and perceived unit care quality. Authentic leadership is a guide for effective leadership needed to build trust and healthier work environments because there is special attention given to honesty, integrity and high ethical standards in the development of leader-follower relationships. A non-experimental, predictive survey design was used to test the hypothesized model in a random sample of 280 (48% response rate) registered nurses working in acute care hospitals in Ontario. The final model fitted the data acceptably (χ(2)=17.24, d.f.=11, P=0.10, IFI=0.99, CFI=0.99, RMSEA=0.045). Authentic leadership significantly and positively influenced staff nurses' trust in their manager and work engagement which in turn predicted voice behaviour and perceived unit care quality. These findings suggest that authentic leadership and trust in the manager play a role in fostering trust, work engagement, voice behaviour and perceived quality of care. Nursing leaders can improve care quality and workplace conditions by paying attention to facilitating genuine and positive relationships with their staff. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.
Spatial relationships between alcohol-related road crashes and retail alcohol availability.
Morrison, Christopher; Ponicki, William R; Gruenewald, Paul J; Wiebe, Douglas J; Smith, Karen
2016-05-01
This study examines spatial relationships between alcohol outlet density and the incidence of alcohol-related crashes. The few prior studies conducted in this area used relatively large spatial units; here we use highly resolved units from Melbourne, Australia (Statistical Area level 1 [SA1] units: mean land area=0.5 km(2); SD=2.2 km(2)), in order to assess different micro-scale spatial relationships for on- and off-premise outlets. Bayesian conditional autoregressive Poisson models were used to assess cross-sectional relationships of three-year counts of alcohol-related crashes (2010-2012) attended by Ambulance Victoria paramedics to densities of bars, restaurants, and off-premise outlets controlling for other land use, demographic and roadway characteristics. Alcohol-related crashes were not related to bar density within local SA1 units, but were positively related to bar density in adjacent SA1 units. Alcohol-related crashes were negatively related to off-premise outlet density in local SA1 units. Examined in one metropolitan area using small spatial units, bar density is related to greater crash risk in surrounding areas. Observed negative relationships for off-premise outlets may be because the origins and destinations of alcohol-affected journeys are in distal locations relative to outlets. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Nitta, Naotaka; Ishiguro, Yasunao; Sasanuma, Hideki; Taniguchi, Nobuyuki; Akiyama, Iwaki
2015-01-01
Acoustic radiation force impulse (ARFI) has recently been used for tissue elasticity measurement and imaging. On the other hand, it is predicted that a rise in temperature occurs. In-situ measurement of temperature rise in animal experiments is important, yet measurement using thermocouples has some problems such as position mismatch of the temperature measuring junction of the thermocouple and the focal point of ultrasound. Therefore, an in-situ measurement system for solving the above problems was developed in this study. The developed system is composed mainly of an ultrasound irradiation unit including a custom-made focused transducer with a through hole for inserting a thin-wire thermocouple, and a temperature measurement unit including the thermocouple. The feasibility of the developed system was evaluated by means of experiments using a tissue-mimicking material (TMM), a TMM containing a bone model or a chicken bone, and an extracted porcine liver. The similarity between the experimental results and the results of simulation using a finite element method (FEM) implied the reasonableness of in-situ temperature rise measured by the developed system. The developed system will become a useful tool for measuring in-situ temperature rise in animal experiments and obtaining findings with respect to the relationship between ultrasound irradiation conditions and in-situ temperature rise.
Fitts Cochrane, Jean; Lonsdorf, Eric; Allison, Taber D; Sanders-Reed, Carol A
2015-09-01
Challenges arise when renewable energy development triggers "no net loss" policies for protected species, such as where wind energy facilities affect Golden Eagles in the western United States. When established mitigation approaches are insufficient to fully avoid or offset losses, conservation goals may still be achievable through experimental implementation of unproven mitigation methods provided they are analyzed within a framework that deals transparently and rigorously with uncertainty. We developed an approach to quantify and analyze compensatory mitigation that (1) relies on expert opinion elicited in a thoughtful and structured process to design the analysis (models) and supplement available data, (2) builds computational models as hypotheses about cause-effect relationships, (3) represents scientific uncertainty in stochastic model simulations, (4) provides probabilistic predictions of "relative" mortality with and without mitigation, (5) presents results in clear formats useful to applying risk management preferences (regulatory standards) and selecting strategies and levels of mitigation for immediate action, and (6) defines predictive parameters in units that could be monitored effectively, to support experimental adaptive management and reduction in uncertainty. We illustrate the approach with a case study characterized by high uncertainty about underlying biological processes and high conservation interest: estimating the quantitative effects of voluntary strategies to abate lead poisoning in Golden Eagles in Wyoming due to ingestion of spent game hunting ammunition.
Applying Quality Function Deployment Model in Burn Unit Service Improvement.
Keshtkaran, Ali; Hashemi, Neda; Kharazmi, Erfan; Abbasi, Mehdi
2016-01-01
Quality function deployment (QFD) is one of the most effective quality design tools. This study applies QFD technique to improve the quality of the burn unit services in Ghotbedin Hospital in Shiraz, Iran. First, the patients' expectations of burn unit services and their priorities were determined through Delphi method. Thereafter, burn unit service specifications were determined through Delphi method. Further, the relationships between the patients' expectations and service specifications and also the relationships between service specifications were determined through an expert group's opinion. Last, the final importance scores of service specifications were calculated through simple additive weighting method. The findings show that burn unit patients have 40 expectations in six different areas. These expectations are in 16 priority levels. Burn units also have 45 service specifications in six different areas. There are four-level relationships between the patients' expectations and service specifications and four-level relationships between service specifications. The most important burn unit service specifications have been identified in this study. The QFD model developed in the study can be a general guideline for QFD planners and executives.
ERIC Educational Resources Information Center
Sankey, Sarita Marie
2010-01-01
The purpose of this study was to examine the relationship between acculturation level and posttraumatic stress disorder (PTSD) prevalence in Central American immigrants in the United States. Central American immigrants represent a population that is a part of the Latino/Hispanic Diaspora in the United States. By the year 2050 the United States…
ERIC Educational Resources Information Center
Rothbaum, Fred; Pott, Martha; Azuma, Hiroshi; Miyake, Kazuo; Weisz, John
2000-01-01
Compares paths of development in Japan (symbiotic harmony) and the United States (generative tension) of parent-child and adult mate relationships, challenging assumptions that certain processes are central in all relationships or that U.S. relationships are less valued or weaker than Japan's. Suggests need to investigate processes underlying, and…
Bennett, C R; Grussing, P G; Hutchinson, R A; Stewart, J E
1988-08-01
Relationships between hospital pharmacists' perceptions of their own and their immediate supervisors' leadership styles and their perceptions of the effectiveness of their work units were examined. Pharmacists practicing in 12 large Chicago-area hospitals were asked to complete a four-part questionnaire that consisted of demographic questions, the LEADSelf instrument, the LEADOther instrument, and a measure of perceived work unit effectiveness. Respondents' primary, secondary, and combination leadership styles and their degree of style adaptability were determined and compared with the primary, secondary, and combination leadership styles and style adaptability of their immediate supervisors and with their perceptions of the effectiveness of their work units. Pharmacists involved in providing clinical or drug information services and pharmacists responsible for purchasing activities perceived their work units to be most and least effective, respectively. Most respondents perceived their primary leadership style to be high task-high relationship, but only 32% perceived their immediate supervisors to exhibit this style. Pharmacists who perceived their immediate supervisors to have high relationship leadership styles (based on primary and combination style classifications) had significantly more favorable perceptions of the effectiveness of their work units than did pharmacists who perceived their supervisors to exhibit low relationship styles. Respondents' perceptions of their supervisors' style adaptability were positively and significantly correlated with their perceptions of work-unit effectiveness. Respondents who thought their supervisors' leadership styles were more adaptable than their own had the most favorable perceptions of work-unit effectiveness.(ABSTRACT TRUNCATED AT 250 WORDS)
NASA Astrophysics Data System (ADS)
Li, WeiBin; Lan, Ding; Sun, ZhiBin; Geng, BaoMing; Wang, XiaoQing; Tian, WeiQian; Zhai, GuangJie; Wang, YuRen
2016-05-01
To study the self-assembly behavior of colloidal spheres in the solid/liquid interface and elucidate the mechanism of liquid crystal phase transition under microgravity, a Colloidal Material Box (CMB) was designed which consists of three modules: (i) colloidal evaporation experimental module, made up of a sample management unit, an injection management unit and an optical observation unit; (ii) liquid crystal phase transition experimental module, including a sample management unit and an optical observation unit; (iii) electronic control module. The following two experimental plans will be performed inside the CMB aboard the SJ-10 satellite in space. (i) Self-assembly of colloidal spheres (with and without Au shell) induced by droplet evaporation, allowing observation of the dynamic process of the colloidal spheres within the droplet and the change of the droplet outer profile during evaporation; (ii) Phase behavior of Mg2Al LDHs suspensions in microgravity. The experimental results will be the first experimental observations of depositing ordered colloidal crystals and their self-assembly behavior under microgravity, and will illustrate the influence of gravity on liquid crystal phase transition.
Physiologically based pharmacokinetic modeling of PLGA nanoparticles with varied mPEG content
Li, Mingguang; Panagi, Zoi; Avgoustakis, Konstantinos; Reineke, Joshua
2012-01-01
Biodistribution of nanoparticles is dependent on their physicochemical properties (such as size, surface charge, and surface hydrophilicity). Clear and systematic understanding of nanoparticle properties’ effects on their in vivo performance is of fundamental significance in nanoparticle design, development and optimization for medical applications, and toxicity evaluation. In the present study, a physiologically based pharmacokinetic model was utilized to interpret the effects of nanoparticle properties on previously published biodistribution data. Biodistribution data for five poly(lactic-co-glycolic) acid (PLGA) nanoparticle formulations prepared with varied content of monomethoxypoly (ethyleneglycol) (mPEG) (PLGA, PLGA-mPEG256, PLGA-mPEG153, PLGA-mPEG51, PLGA-mPEG34) were collected in mice after intravenous injection. A physiologically based pharmacokinetic model was developed and evaluated to simulate the mass-time profiles of nanoparticle distribution in tissues. In anticipation that the biodistribution of new nanoparticle formulations could be predicted from the physiologically based pharmacokinetic model, multivariate regression analysis was performed to build the relationship between nanoparticle properties (size, zeta potential, and number of PEG molecules per unit surface area) and biodistribution parameters. Based on these relationships, characterized physicochemical properties of PLGA-mPEG495 nanoparticles (a sixth formulation) were used to calculate (predict) biodistribution profiles. For all five initial formulations, the developed model adequately simulates the experimental data indicating that the model is suitable for description of PLGA-mPEG nanoparticle biodistribution. Further, the predicted biodistribution profiles of PLGA-mPEG495 were close to experimental data, reflecting properly developed property–biodistribution relationships. PMID:22419876
Cortical modulation of the nucleus of the optic tract in the rabbit.
Pettorossi, V E; Troiani, D
1983-09-01
We analyzed in rabbits the relationships between the temporooccipital nystagmogenic cortex (NGC)--the region sited at the border between cortical areas 17, 21, and 22--and the nucleus of the optic tract (NOT). Two experimental approaches were used: (a) eye movement analysis before and after electrolytic lesion of the NOT region provided an indication of the importance of the NOT for the interaction between the ocular nystagmus elicited by natural optokinetic stimulation (OKN) and the nystagmus evoked by electrical stimulation of the nystagmogenic area; (b) NOT direction-selective and velocity-sensitive units were tested with single shock or repetitive electrical stimulation of the nystagmogenic region. Single-shock stimulation evoked single or multiple spikes in 50% of NOT units analyzed and repetitive stimuli induced prolonged facilitation and inhibitory rebounds in 70% of the units tested. Comparison of orthodromic activation latencies of the NOT cells (3.2 and 6.1 ms) after cortical stimulation and of antidromic activation latencies of cortical nystagmogenic units (2.6 ms) after NOT shocks, suggested monosynaptic as well as polysynaptic connections between the temporooccipital cortex and the NOT. The existence of such cortical-NOT linkage indicates that the NOT is intercalated between the cortex and the oculomotor centers and represents the most probable site of interaction of the cortical nystagmus pathway with the optokinetic reflex arc.
Relationships Among the Energy, Emergy, and Money Flows of the United States From 1900 to 2011
In this paper, we examine the relationships among the energy, emergy, and money flows of the United States from 1900 to 2011. To establish a theoretical basis for understanding these relationships, Energy Systems Language models of the resource base for the World System and of e...
Prefrontal single-unit firing associated with deficient extinction in mice
Fitzgerald, Paul J; Whittle, Nigel; Flynn, Shaun M; Graybeal, Carolyn; Pinard, Courtney; Gunduz-Cinar, Ozge; Kravitz, Alexxai; Singewald, Nicolas; Holmes, Andrew
2014-01-01
The neural circuitry mediating fear extinction has been increasingly well studied and delineated. The rodent infralimbic subregion (IL) of the ventromedial prefrontal cortex (vmPFC) has been found to promote extinction, whereas the prelimbic cortex (PL) demonstrates an opposing, pro-fear, function. Studies employing in vivo electrophysiological recordings have observed that while increased IL single-unit firing and bursting predicts robust extinction retrieval, increased PL firing can correlate with sustained fear and poor extinction. These relationships between single-unit firing and extinction do not hold under all experimental conditions, however. In the current study, we further investigated the relationship between vmPFC and PL single-unit firing and extinction using inbred mouse models of intact (C57BL/6J, B6) and deficient (129S1/SvImJ, S1) extinction strains. Simultaneous single-unit recordings were made in the PL and vmPFC (encompassing IL) as B6 and S1 mice performed extinction training and retrieval. Impaired extinction retrieval in S1 mice was associated with elevated PL single-unit firing, as compared to firing in extinguishing B6 mice, consistent with the hypothesized pro-fear contribution of PL. Analysis of local field potentials also revealed significantly higher gamma power in the PL of Sthan B6 mice during extinction training and retrieval. In the vmPFC, impaired extinction in S1 mice was also associated with exaggerated single-unit firing, relative to B6 mice. This is in apparent contradiction to evidence that IL activity promotes extinction, but could reflect a (failed) compensatory effort by the vmPFC to mitigate fear-promoting activity in other regions, such as the PL or amygdala. In support of this hypothesis, augmenting IL activity via direct infusion of the GABAA receptor antagonist picrotoxin rescued impaired extinction retrieval in S1 mice. Chronic fluoxetine treatment produced modest reductions in fear during extinction retrieval and increased the number of Zif268-labeled cells in layer II of IL, but failed to increase vmPFC single-unit firing. Collectively, these findings further support the important contribution these cortical regions play in determining the balance between robust extinction on the one hand, and sustained fear on the other. Elucidating the precise nature of these roles could help inform understanding of the pathophysiology of fear-related anxiety disorders. PMID:24231425
Butler, Ashleigh E; Hall, Helen; Copnell, Beverley
2018-06-01
When a child dies in the intensive care unit, many bereaved parents want relationships with their child's health care staff to continue in the form of follow-up care. However, the nature of these relationships and how they change across the parents' bereavement journey is currently unknown. This article explores early and ongoing relationships between parents and health care staff when a child dies in intensive care. Constructivist grounded theory methods were used to recruit 26 bereaved parents from four Australian pediatric intensive care units into the study. Data were collected via audio-recorded, semistructured interviews and analyzed using the constant comparative methods and theoretical memoing. Findings show that these relationships focus on Gradually disengaging, commonly moving through three phases after the child dies: Saying goodbye, Going home, and Seeking supports. These findings provide guidance to health care staff on what families need as they leave the intensive care unit and move through bereavement.
Investigations of a Complex, Realistic Task: Intentional, Unsystematic, and Exhaustive Experimenters
ERIC Educational Resources Information Center
McElhaney, Kevin W.; Linn, Marcia C.
2011-01-01
This study examines how students' experimentation with a virtual environment contributes to their understanding of a complex, realistic inquiry problem. We designed a week-long, technology-enhanced inquiry unit on car collisions. The unit uses new technologies to log students' experimentation choices. Physics students (n = 148) in six diverse high…
A sEMG model with experimentally based simulation parameters.
Wheeler, Katherine A; Shimada, Hiroshima; Kumar, Dinesh K; Arjunan, Sridhar P
2010-01-01
A differential, time-invariant, surface electromyogram (sEMG) model has been implemented. While it is based on existing EMG models, the novelty of this implementation is that it assigns more accurate distributions of variables to create realistic motor unit (MU) characteristics. Variables such as muscle fibre conduction velocity, jitter (the change in the interpulse interval between subsequent action potential firings) and motor unit size have been considered to follow normal distributions about an experimentally obtained mean. In addition, motor unit firing frequencies have been considered to have non-linear and type based distributions that are in accordance with experimental results. Motor unit recruitment thresholds have been considered to be related to the MU type. The model has been used to simulate single channel differential sEMG signals from voluntary, isometric contractions of the biceps brachii muscle. The model has been experimentally verified by conducting experiments on three subjects. Comparison between simulated signals and experimental recordings shows that the Root Mean Square (RMS) increases linearly with force in both cases. The simulated signals also show similar values and rates of change of RMS to the experimental signals.
ERIC Educational Resources Information Center
Iowa State Univ. of Science and Technology, Ames. Dept. of Home Economics Education.
The 2-part student workbook for mainstreamed learning and mentally disabled high school students contains 12 units intended to provide supplementary instruction in the Contemporary Parenting Choices Curriculum in the home economics class. This unit, the third in the Relationships part of the workbook, focuses on understanding sexuality with…
Defense.gov Special Report: Travels With Mullen - June 2011
Stories U.S., U.K. Military Relationship Essential, Mullen Says LONDON, June 10, 2011 - The military relationship between the United States and the United Kingdom is second to none in terms of strength and is bilateral relationship with Egypt's armed forces, continuing a practice that has endured for 30 years
ERIC Educational Resources Information Center
Lakatos, Patricia P.; Matic, Tamara; Carson, Melissa C.; Williams, Marian E.
2017-01-01
Infants are born primed to develop attachment relationships. However, when infants are hospitalized in the neonatal intensive care unit at birth, the stress and trauma associated with the highly specialized medical environment can threaten the development of a nurturing and secure caregiving relationship. Infant mental health is an evidence-based…
OMEGA (Offshore Membrane for Enclosing Algae). NASA-NAVY: A Strategic Planning Discussion
NASA Technical Reports Server (NTRS)
Trent, Jonathan
2010-01-01
This briefing packet provides a short introduction to OMEGA and a truncated version of our project approach, with an example of the kind of work break down structure (WBS) used to guide our Phase I activities. It is meant to give you an impression of how we are approaching the challenge of creating the world's first marine photobioreactor (PBR) that will scale to address the strategic energy problems confronting the United States and the world. Some of our conceptual PBR designs and plans for logistics are included to communicate the path we have taken. We have also included an aerial photograph of the experimental tanks we are using at the Cal Fish and Game, followed by concluding remarks. The overarching purpose of the strategic planning discussion in Norfolk is to establish the relationship between the NASA OMEGA Team and the Navy, to unite the strengths of both agencies, and to map a mutual way forward along the project's established critical path.
MGUPGMA: A Fast UPGMA Algorithm With Multiple Graphics Processing Units Using NCCL
Hua, Guan-Jie; Hung, Che-Lun; Lin, Chun-Yuan; Wu, Fu-Che; Chan, Yu-Wei; Tang, Chuan Yi
2017-01-01
A phylogenetic tree is a visual diagram of the relationship between a set of biological species. The scientists usually use it to analyze many characteristics of the species. The distance-matrix methods, such as Unweighted Pair Group Method with Arithmetic Mean and Neighbor Joining, construct a phylogenetic tree by calculating pairwise genetic distances between taxa. These methods have the computational performance issue. Although several new methods with high-performance hardware and frameworks have been proposed, the issue still exists. In this work, a novel parallel Unweighted Pair Group Method with Arithmetic Mean approach on multiple Graphics Processing Units is proposed to construct a phylogenetic tree from extremely large set of sequences. The experimental results present that the proposed approach on a DGX-1 server with 8 NVIDIA P100 graphic cards achieves approximately 3-fold to 7-fold speedup over the implementation of Unweighted Pair Group Method with Arithmetic Mean on a modern CPU and a single GPU, respectively. PMID:29051701
MGUPGMA: A Fast UPGMA Algorithm With Multiple Graphics Processing Units Using NCCL.
Hua, Guan-Jie; Hung, Che-Lun; Lin, Chun-Yuan; Wu, Fu-Che; Chan, Yu-Wei; Tang, Chuan Yi
2017-01-01
A phylogenetic tree is a visual diagram of the relationship between a set of biological species. The scientists usually use it to analyze many characteristics of the species. The distance-matrix methods, such as Unweighted Pair Group Method with Arithmetic Mean and Neighbor Joining, construct a phylogenetic tree by calculating pairwise genetic distances between taxa. These methods have the computational performance issue. Although several new methods with high-performance hardware and frameworks have been proposed, the issue still exists. In this work, a novel parallel Unweighted Pair Group Method with Arithmetic Mean approach on multiple Graphics Processing Units is proposed to construct a phylogenetic tree from extremely large set of sequences. The experimental results present that the proposed approach on a DGX-1 server with 8 NVIDIA P100 graphic cards achieves approximately 3-fold to 7-fold speedup over the implementation of Unweighted Pair Group Method with Arithmetic Mean on a modern CPU and a single GPU, respectively.
Partitioning of polar and non-polar neutral organic chemicals into human and cow milk.
Geisler, Anett; Endo, Satoshi; Goss, Kai-Uwe
2011-10-01
The aim of this work was to develop a predictive model for milk/water partition coefficients of neutral organic compounds. Batch experiments were performed for 119 diverse organic chemicals in human milk and raw and processed cow milk at 37°C. No differences (<0.3 log units) in the partition coefficients of these types of milk were observed. The polyparameter linear free energy relationship model fit the calibration data well (SD=0.22 log units). An experimental validation data set including hormones and hormone active compounds was predicted satisfactorily by the model. An alternative modelling approach based on log K(ow) revealed a poorer performance. The model presented here provides a significant improvement in predicting enrichment of potentially hazardous chemicals in milk. In combination with physiologically based pharmacokinetic modelling this improvement in the estimation of milk/water partitioning coefficients may allow a better risk assessment for a wide range of neutral organic chemicals. Copyright © 2011 Elsevier Ltd. All rights reserved.
Role of carbohydrate metabolism in grass tetany
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, J.K.; Madsen, F.C.; Lentz, D.E.
1977-01-01
Clinical hypomagnesemia is confined primarily to beef cattle in the United States but also occurs in dairy cattle in other countries, probably due to different management practices. During periods when grass tetany is likely, early vegetative temperate zone grasses are usually low in total readily available carbohydrates and magnesium but high in potassium and nitrogen. The tetany syndrome may include hypoglycemia and ketosis, suggesting an imbalance in intermediary energy metabolism. Many enzyme systems critical to cellular metabolism, including those which hydrolyze and transfer phosphate groups, are activated by Mg. Thus, by inference, Mg is required for normal glucose utilization, fat,more » protein, nucleic acid and coenzyme synthesis, muscle contraction, methyl group transfer, and sulfate, acetate, and formate activation. Numerous clinical and experimental studies suggest an intimate relationship between metabolism of Mg and that of carbohydrate, glucagon, and insulin. The objective is to review this literature and suggest ways in which these relationships might contribute to a chain of events leading to grass tetany.« less
The role of "evidence" in recovery from mental illness.
Tanenbaum, Sandra J
2006-12-01
Evidence-based practice (EBP), a derivative of evidence-based medicine (EBM), is ascendant in the United States' mental health system; the findings of randomized controlled trials and other experimental research are widely considered authoritative in mental health practice and policy. The concept of recovery from mental illness is similarly pervasive in mental health programming and advocacy, and it emphasizes consumer expertise and self-determination. What is the relationship between these two powerful and potentially incompatible forces for mental health reform? This paper identifies four attempts, in the mental health literature, to delineate the role of "evidence" in recovery. One is the strong version of evidence-based practice-an applied science model-and three others address weaknesses in the first by limiting the authority of probabilistic findings. The paper also offers a fifth version, based on the concept of communicative accountability, which is derived from Habermas' work on communicative action. The fifth version responds to the other four and emphasizes learning, disclosure and respect in clinical and other helping relationships.
Modeling of weld bead geometry for rapid manufacturing by robotic GMAW
NASA Astrophysics Data System (ADS)
Yang, Tao; Xiong, Jun; Chen, Hui; Chen, Yong
2015-03-01
Weld-based rapid prototyping (RP) has shown great promises for fabricating 3D complex parts. During the layered deposition of forming metallic parts with robotic gas metal arc welding, the geometry of a single weld bead has an important influence on surface finish quality, layer thickness and dimensional accuracy of the deposited layer. In order to obtain accurate, predictable and controllable bead geometry, it is essential to understand the relationships between the process variables with the bead geometry (bead width, bead height and ratio of bead width to bead height). This paper highlights an experimental study carried out to develop mathematical models to predict deposited bead geometry through the quadratic general rotary unitized design. The adequacy and significance of the models were verified via the analysis of variance. Complicated cause-effect relationships between the process parameters and the bead geometry were revealed. Results show that the developed models can be applied to predict the desired bead geometry with great accuracy in layered deposition with accordance to the slicing process of RP.
The theory of granular packings for coarse soils
NASA Astrophysics Data System (ADS)
Yanqui, Calixtro
2013-06-01
Coarse soils are substances made of grains of different shape, size and orientation. In this paper, new massive-measurable grain indexes are defined to develop a simple and systematic theory for the ideal packing of grains. First, a linear relationship between an assemblage of monodisperse spheres and an assemblage of polydisperse grains is deduced. Then, a general formula for the porosity of linearly ordered packings of spheres in contact is settled down by the appropriated choosing of eight neighboring spheres located at the vertices of the unit parallelepiped. The porosity of axisymmetric packings of grains, related to sand piles and axisymmetric compression tests, is proposed to be determined averaging the respective linear parameters. Since they can be tested experimentally, porosities of the densest state and the loosest state of a granular soil can be used to verify the accuracy of the present theory. Diagrams for these extreme quantities show a good agreement between the theoretical lines and the experimental data, no matter the dependency on the protocols and mineral composition.
Leake, R; Friend, R; Wadhwa, N
1999-01-01
Laboratory studies show that strategic self-presentations strongly influence private self-evaluations. The present study experimentally manipulated self-presentations of dialysis patients' coping skills in order to influence their adjustment. In all, 42 renal dialysis patients matched for diabetes, gender, and dialysis years were randomly assigned to 3 conditions; adjustment was assessed at baseline, post-intervention, and 1 month follow-up. Patients in a self-presentation condition selectively presented themselves as successful copers in a videotaped interview, ostensibly as part of a training program for new patients. Patients in a problem disclosure condition discussed problems with managing their illness. Control group patients viewed a medical videotape about adjusting to dialysis. Patients in the self-presentation condition reported better adjustment, fewer physical symptoms, and more coping skills 1 month later, compared with patients in the other 2 conditions. In addition, coping skills were shown to mediate the relationship between strategic self-presentation and adjustment.
Effects of fatigue on motor unit firing rate versus recruitment threshold relationships.
Stock, Matt S; Beck, Travis W; Defreitas, Jason M
2012-01-01
The purpose of this study was to examine the influence of fatigue on the average firing rate versus recruitment threshold relationships for the vastus lateralis (VL) and vastus medialis. Nineteen subjects performed ten maximum voluntary contractions of the dominant leg extensors. Before and after this fatiguing protocol, the subjects performed a trapezoid isometric muscle action of the leg extensors, and bipolar surface electromyographic signals were detected from both muscles. These signals were then decomposed into individual motor unit action potential trains. For each subject and muscle, the relationship between average firing rate and recruitment threshold was examined using linear regression analyses. For the VL, the linear slope coefficients and y-intercepts for these relationships increased and decreased, respectively, after fatigue. For both muscles, many of the motor units decreased their firing rates. With fatigue, recruitment of higher threshold motor units resulted in an increase in slope for the VL. Copyright © 2011 Wiley Periodicals, Inc.
2011-12-01
Anglo - Saxon ally over Nasser and the canal.55 In 2010, in a speech at Chatham House, Liberal Democrat Nick Clegg suggested that “what...strategic culture, and as an expression of shared values and institutions the character of which is vital for those charged with service in an Anglo ...American context as well as NATO. 14. SUBJECT TERMS United Kingdom, United States, Special Relationship, Anglo - American Relations, Iraq, Afghanistan
The Stephen F. Austin Experimental Forest
Cary C. Russell; Ronald E. Thill; David L. Kulhavy
2002-01-01
On December 14, 1944, the Seventy-Eighth United States Congress passed a bill that authorized the transfer of 2,560 acres in Nacogdoches County, Texas, to the research branch of the United States Forest Service (USFS). This land became the Stephen F. Austin Experimental Forest (SFAEF) on September 19. 1945. One of eighty-one federal experimental forests and ranges...
Fujimura, J H
1996-01-01
This paper presents a narrative history of technologies in cancer research circa 1920-1978 and a theoretical perspective on the complex, intertwined relationships between scientific problems, material practices and technologies, concepts and theories, and other historical circumstances. The history presents several active lines of research and technology development in the genetics of cancer in the United States which were constitutive of proto-oncogene work in its current form. I write this history from the perspective of technology development. Scientists participating in cancer research created tools with which to study their problems of interest, but the development of the tools also influenced the questions asked and answered in the form of concepts and theories developed. These tools included genetic ideas of the 1920s, inbred mouse colonies, chemicals and antibiotics developed during World War Two, tissue cultures and their technical procedures, and viruses. I examine these tools as standardized experimental systems that standardized materials as well as practices in laboratories. Inbred animals, tissue culture materials and methods, and tumor viruses as experimental systems gave materiality to "genes' and "cancer'. They are technical-natural objects that stand-in for nature in the laboratory.
Miller, Stephen; Pike, James; Stacy, Alan W; Xie, Bin; Ames, Susan L
2017-06-01
Despite the general trend of declining use of traditional cigarettes among young adults in the United States, alternative high school students continue to smoke cigarettes and electronic cigarettes at rates much higher than do students attending regular high schools. Challenging life circumstances leading to elevated levels of negative affect may account for increased smoking behavior in this population. Further, a belief in the negative affect-reducing qualities of nicotine may mediate this effect. The current study tested the hypothesis that negative reinforcing outcome expectancies mediate the relationship between negative affect on smoking susceptibility in nonusers, smoking frequency in users, and smoking experimentation in the overall sample. Results support the hypothesis that negative affect in alternative high school students is correlated with smoking experimentation, smoking willingness, and smoking frequency and that the relationship between negative affect and smoking behavior outcomes is mediated by negative reinforcing outcome expectancies (i.e., beliefs in the negative affect-reducing effects of smoking). This finding was supported for both cigarettes and electronic cigarettes and coincides with a rapid increase in the number of high school students nationally who have experimented with electronic cigarettes. Future antismoking initiatives directed at at-risk youth should consider integrating healthier negative affect reduction techniques to counter the use of nicotine products. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Fire danger rating in the United States of America: An evolution since 1916
Colin C. Hardy; Charles E. Hardy
2007-01-01
Fire scientists in the United States began exploring the relationships of fire-danger and hazard with weather, fuel moisture, and ignition probabilities as early as 1916. Many of the relationships identified then persist today in the form of our National Fire-Danger-Rating System. This paper traces the evolution of fire-danger rating in the United States, including...
32 CFR 700.601 - Relationship and operation as a service in the Navy.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 32 National Defense 5 2010-07-01 2010-07-01 false Relationship and operation as a service in the Navy. 700.601 Section 700.601 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND OFFICIAL RECORDS UNITED STATES NAVY REGULATIONS AND OFFICIAL RECORDS The United States Coast Guard (When...
ERIC Educational Resources Information Center
Iowa State Univ. of Science and Technology, Ames. Dept. of Home Economics Education.
The 2-part student workbook for mainstreamed learning and mentally disabled high school students contains 12 units intended to provide supplementary instruction in the Contemporary Parenting Choices Curriculum in the home economics class. This unit, the fourth in the Relationships part of the workbook, focuses on understanding the married and…
Dealing with time-varying recruitment and length in Hill-type muscle models.
Hamouda, Ahmed; Kenney, Laurence; Howard, David
2016-10-03
Hill-type muscle models are often used in muscle simulation studies and also in the design and virtual prototyping of functional electrical stimulation systems. These models have to behave in a sufficiently realistic manner when recruitment level and contractile element (CE) length change continuously. For this reason, most previous models have used instantaneous CE length in the muscle׳s force vs. length (F-L) relationship, but thereby neglect the instability problem on the descending limb (i.e. region of negative slope) of the F-L relationship. Ideally CE length at initial recruitment should be used but this requires a multiple-motor-unit muscle model to properly account for different motor-units having different initial lengths when recruited. None of the multiple-motor-unit models reported in the literature have used initial CE length in the muscle׳s F-L relationship, thereby also neglecting the descending limb instability problem. To address the problem of muscle modelling for continuously varying recruitment and length, and hence different values of initial CE length for different motor-units, a new multiple-motor-unit muscle model is presented which considers the muscle to comprise 1000 individual Hill-type virtual motor-units, which determine the total isometric force. Other parts of the model (F-V relationship and passive elements) are not dependent on the initial CE length and, therefore, they are implemented for the muscle as a whole rather than for the individual motor-units. The results demonstrate the potential errors introduced by using a single-motor-unit model and also the instantaneous CE length in the F-L relationship, both of which are common in FES control studies. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
1981-01-01
The results of the free space reactor experimental work are summarized. Overall, the objectives were achieved and the unit can be confidently scaled to the EPSDU size based on the experimental work and supporting theoretical analyses. The piping and instrumentation of the fluidized bed reactor was completed.
Experimental Model School Unit. Application for Continuation Grant. P.L. 89-10 ESEA, Title III.
ERIC Educational Resources Information Center
Charlotte-Mecklenburg Public Schools, Charlotte, NC.
This application for continuation of an ESEA, Title III, grant to the Charlotte-Mecklenburg, N.C., Schools' Experimental Model School Unit (a senior high school and its two junior high and six elementary feeder schools with a program of research, experimentation, innovation, and dissemination designed to act as a catalyst for curriculum,…
Laws, Holly; Mazure, Carolyn M; McKee, Sherry A; Park, Crystal L; Hoff, Rani
2016-09-01
Few studies have examined the impact of military sexual trauma (MST) on social functioning during deployment. Yet consideration of unit relationships during deployment may be important, given that military unit cohesion and support can provide protective effects against the stress of combat, and reduce the likelihood of developing posttraumatic stress disorder. Although prior research has posited that depleted social resources are one pathway through which MST is associated with posttraumatic stress symptoms (PTSS), no studies have statistically tested this theory. This study examined the association of MST and PTSS and evaluated the potential mediating role of decreased unit relationship quality. Mediational analyses were conducted on a sample of veterans following discharge from military service (N = 818; 328 women, 490 men). Women were significantly more likely to experience MST than men. As hypothesized, experiences of MST during deployment were associated with higher PTSS. MST experiences were associated with less trust in and support from one's military unit, which partially mediated the association between MST and PTSS. The indirect effect of MST on PTSS through lower unit relationship quality accounted for 20.4% of the total effect of MST on PTSS. While the retrospective study design precludes tests of causality, mediational findings provided statistical evidence that lower unit relationship quality partially explains the association between MST and PTSS. This finding is consistent with interpersonal theories of trauma response suggesting that the deleterious effects of MST may be in part due to its erosion of social resources during deployment. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Lee, Jaeyoon; Sohn, Young Woo; Kim, Minhee; Kwon, Seungwoo; Park, In-Jo
2018-01-01
The main purpose of this study was to investigate the impact of perceived HR practices on affective commitment and turnover intention. This study explored which HR practices were relatively more important in predicting affective commitment and turnover intention. A total of 302 employees from the United States and 317 from South Korea completed the same questionnaires for assessing the aforementioned relationships. The results illustrated that among perceived HR practices, internal mobility had the most significant association with turnover intention in both the United States and South Korea. While internal mobility was a stronger predictor of affective commitment for the United States sample, training was the most important variable for predicting affective commitment in South Korea. The second purpose of the study was to examine whether individuals’ positive affect influences the relationship between perceived HR practices and affective commitment and turnover intention. In the United States, positive affect moderated the relationship between perceived HR practices and affective commitment and turnover intention such that the relationships were stronger for individuals reporting high positive affect relative to those reporting low positive affect. However, these relationships were not significant in South Korea. We discuss the implications of these results, study limitations, and practical suggestions for future research. PMID:29867647
NASA Astrophysics Data System (ADS)
Yu, Jian; An, Fei-fei; Cao, Fei
2014-05-01
In this paper, ferroelectric phase transitions of Pb0.6-xCaxBi0.4(Ti0.75Zn0.15Fe0.1)O3 with x ≤ 0.20 ceramics were experimentally measured and a change from first-order to relaxor was found at a critical composition x ˜ 0.19. With increasing Ca content of x ≤ 0.18, Curie temperature and tetragonality was found decrease but piezoelectric constant and dielectric constant increase in a quadratic polynomial relationship as a function of x, while the ferroic Curie temperature and ferroelastic ordering parameter of tetragonality are correlated in a quadratic polynomial relationship. Near the critical composition of ferroic phase transition from first-order to relaxor, the Pb0.42Ca0.18Bi0.4(Ti0.75Zn0.15Fe0.1)O3 and 1 mol % Nb + 0.5 mol % Mg co-doped Pb0.44Ca0.16Bi0.4(Ti0.75Zn0.15Fe0.1)O3 ceramics exhibit a better anisotropic piezoelectric properties than those commercial piezoceramics of modified-PbTiO3 and PbNb2O6. At last, those factors including reduced mass of unit cell, mismatch between cation size and anion cage size, which affect ferroic Curie temperature and ferroelastic ordering parameter (tetragonality) of tetragonal ABO3 perovskites, are analyzed on the basis of first principle effective Hamiltonian and the reduced mass of unit cell is argued a more universal variable than concentration to determine Curie temperature in a quadratic polynomial relationship over various perovskite-structured solid solutions.
On the physics of unstable infiltration, seepage, and gravity drainage in partially saturated tuffs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Faybishenko, B.; Bodvarsson, G.S.; Salve, R.
2002-04-01
To improve understanding of the physics of dynamic instabilities in unsaturated flow processes within the Paintbrush nonwelded unit (PTn) and the middle nonlithophysal portion of the Tonopah Spring welded tuff unit (TSw) of Yucca Mountain, we analyzed data from a series of infiltration tests carried out at two sites (Alcove 4 and Alcove 6) in the Exploratory Studies Facility, using analytical and empirical functions. The analysis of infiltration rates measured at both sites showed three temporal scales of infiltration rate: (1) a macro-scale trend of overall decreasing flow, (2) a meso-scale trend of fast and slow motion exhibiting three-stage variationsmore » of the flow rate (decreasing, increasing, and [again] decreasing flow rate, as observed in soils in the presence of entrapped air), and (3) micro-scale (high frequency) fluctuations. Infiltration tests in the nonwelded unit at Alcove 4 indicate that this unit may effectively dampen episodic fast infiltration events; however, well-known Kostyakov, Horton, and Philip equations do not satisfactorily describe the observed trends of the infiltration rate. Instead, a Weibull distribution model can most accurately describe experimentally determined time trends of the infiltration rate. Infiltration tests in highly permeable, fractured, welded tuff at Alcove 6 indicate that the infiltration rate exhibits pulsation, which may have been caused by multiple threshold effects and water-air redistribution between fractures and matrix. The empirical relationships between the extrinsic seepage from fractures, matrix imbibition, and gravity drainage versus the infiltration rate, as well as scaling and self-similarity for the leading edge of the water front are the hallmark of the nonlinear dynamic processes in water flow under episodic infiltration through fractured tuff. Based on the analysis of experimental data, we propose a conceptual model of a dynamic fracture flow and fracture-matrix interaction in fractured tuff, incorporating the time dependent processes of water redistribution in the fracture-matrix system.« less
Alexandrou, Markos A.; Cardinale, Bradley J.; Hall, John D.; Delwiche, Charles F.; Fritschie, Keith; Narwani, Anita; Venail, Patrick A.; Bentlage, Bastian; Pankey, M. Sabrina; Oakley, Todd H.
2015-01-01
The competition-relatedness hypothesis (CRH) predicts that the strength of competition is the strongest among closely related species and decreases as species become less related. This hypothesis is based on the assumption that common ancestry causes close relatives to share biological traits that lead to greater ecological similarity. Although intuitively appealing, the extent to which phylogeny can predict competition and co-occurrence among species has only recently been rigorously tested, with mixed results. When studies have failed to support the CRH, critics have pointed out at least three limitations: (i) the use of data poor phylogenies that provide inaccurate estimates of species relatedness, (ii) the use of inappropriate statistical models that fail to detect relationships between relatedness and species interactions amidst nonlinearities and heteroskedastic variances, and (iii) overly simplified laboratory conditions that fail to allow eco-evolutionary relationships to emerge. Here, we address these limitations and find they do not explain why evolutionary relatedness fails to predict the strength of species interactions or probabilities of coexistence among freshwater green algae. First, we construct a new data-rich, transcriptome-based phylogeny of common freshwater green algae that are commonly cultured and used for laboratory experiments. Using this new phylogeny, we re-analyse ecological data from three previously published laboratory experiments. After accounting for the possibility of nonlinearities and heterogeneity of variances across levels of relatedness, we find no relationship between phylogenetic distance and ecological traits. In addition, we show that communities of North American green algae are randomly composed with respect to their evolutionary relationships in 99% of 1077 lakes spanning the continental United States. Together, these analyses result in one of the most comprehensive case studies of how evolutionary history influences species interactions and community assembly in both natural and experimental systems. Our results challenge the generality of the CRH and suggest it may be time to re-evaluate the validity and assumptions of this hypothesis. PMID:25473009
Jiangying, Liu; Dimin, Xu; Youcai, Zhao; Shaowei, Chen; Guojian, Li; Qi, Zhou
2004-09-01
Parameters about composition of refuse such as mass percentage of biodegradable matter, volatile solid, organic carbon, cellulose, total sugar, and settlement were monitored and analyzed in a large-scale experimental unit. The empirical formulas between composition and refuse age were established in terms of the data obtained from the experimental unit and verified by comparing with the corresponding parameters of refuse in the closed landfill units from 1991 until 1994 in the Shanghai Laogang Municipal Landfill. Furthermore, the long-term prediction for the composition of refuse was made, and it was predicted that the half-life is 7 to 11 years for biodegradable matter, 9 to 12 years for organic carbon or volatile solid, 7 to 16 years for cellulose, and 4 to 6 years for total sugar. In addition, a mathematical model, based on the mechanism of refuse biodegradation in the landfill, was developed to simulate the relationship between the settlement and the refuse age and manifests the secondary settlement potential. The mathematical model was proved not only to be reliable but also should be accurate for predicting the settlement of the landfill. The secondary settlement, which mainly results from the slow and gradual biodegradation of refuse, is linear with respect to the exponent of refuse age. Finally, according to the settlement model and empirical biodegradation formulas, it may be predicted that, 79.4% of biodegradable matter, 92.9% of total sugar, 72.7% of volatile solid and organic carbon, and 73.1% of cellulose will be biodegraded and that 79% of the maximum secondary settlement potential will occur before the Shanghai Laogang Municipal Landfill is in a high stabilization situation, i.e., approximately 21 years after final closure.
Bayesian Dose-Response Modeling in Sparse Data
NASA Astrophysics Data System (ADS)
Kim, Steven B.
This book discusses Bayesian dose-response modeling in small samples applied to two different settings. The first setting is early phase clinical trials, and the second setting is toxicology studies in cancer risk assessment. In early phase clinical trials, experimental units are humans who are actual patients. Prior to a clinical trial, opinions from multiple subject area experts are generally more informative than the opinion of a single expert, but we may face a dilemma when they have disagreeing prior opinions. In this regard, we consider compromising the disagreement and compare two different approaches for making a decision. In addition to combining multiple opinions, we also address balancing two levels of ethics in early phase clinical trials. The first level is individual-level ethics which reflects the perspective of trial participants. The second level is population-level ethics which reflects the perspective of future patients. We extensively compare two existing statistical methods which focus on each perspective and propose a new method which balances the two conflicting perspectives. In toxicology studies, experimental units are living animals. Here we focus on a potential non-monotonic dose-response relationship which is known as hormesis. Briefly, hormesis is a phenomenon which can be characterized by a beneficial effect at low doses and a harmful effect at high doses. In cancer risk assessments, the estimation of a parameter, which is known as a benchmark dose, can be highly sensitive to a class of assumptions, monotonicity or hormesis. In this regard, we propose a robust approach which considers both monotonicity and hormesis as a possibility. In addition, We discuss statistical hypothesis testing for hormesis and consider various experimental designs for detecting hormesis based on Bayesian decision theory. Past experiments have not been optimally designed for testing for hormesis, and some Bayesian optimal designs may not be optimal under a wrong parametric assumption. In this regard, we consider a robust experimental design which does not require any parametric assumption.
NASA Astrophysics Data System (ADS)
Sweijen, Thomas; Aslannejad, Hamed; Hassanizadeh, S. Majid
2017-09-01
In studies of two-phase flow in complex porous media it is often desirable to have an estimation of the capillary pressure-saturation curve prior to measurements. Therefore, we compare in this research the capability of three pore-scale approaches in reproducing experimentally measured capillary pressure-saturation curves. To do so, we have generated 12 packings of spheres that are representative of four different glass-bead packings and eight different sand packings, for which we have found experimental data on the capillary pressure-saturation curve in the literature. In generating the packings, we matched the particle size distributions and porosity values of the granular materials. We have used three different pore-scale approaches for generating the capillary pressure-saturation curves of each packing: i) the Pore Unit Assembly (PUA) method in combination with the Mayer and Stowe-Princen (MS-P) approximation for estimating the entry pressures of pore throats, ii) the PUA method in combination with the hemisphere approximation, and iii) the Pore Morphology Method (PMM) in combination with the hemisphere approximation. The three approaches were also used to produce capillary pressure-saturation curves for the coating layer of paper, used in inkjet printing. Curves for such layers are extremely difficult to determine experimentally, due to their very small thickness and the presence of extremely small pores (less than one micrometer in size). Results indicate that the PMM and PUA-hemisphere method give similar capillary pressure-saturation curves, because both methods rely on a hemisphere to represent the air-water interface. The ability of the hemisphere approximation and the MS-P approximation to reproduce correct capillary pressure seems to depend on the type of particle size distribution, with the hemisphere approximation working well for narrowly distributed granular materials.
NASA Technical Reports Server (NTRS)
Swickrath, Michael J.; Anderson, Molly; McMillin, Summer; Broerman, Craig
2010-01-01
Controlling carbon dioxide (CO2) and humidity levels in a spacesuit is critical to ensuring both the safety and comfort of an astronaut during extra-vehicular activity (EVA). Traditionally, this has been accomplished utilizing non-regenerative lithium hydroxide (LiOH) or regenerative metal oxide (MetOx) canisters which pose a significant weight burden. Although such technology enables air revitalization, the volume requirements to store the waste canisters as well as the mass to transport multiple units become prohibitive as mission durations increase. Consequently, motivation exists toward developing a fully regenerative technology for environmental control. The application of solid amine materials with vacuum swing adsorption technology has shown the capacity to control CO2 and concomitantly manage humidity levels through a fully regenerative cycle eliminating mission constraints imposed with non-regenerative technologies. Experimental results for full-size and sub-scale test articles have been collected and are described herein. In order to accelerate the developmental efforts, an axially-dispersed plug ow model with an accompanying energy balance has been established and correlated with the experimental data. The experimental and simulation results display good agreement for a variety of ow rates (110-170 SLM), replicated metabolic challenges (100-590 Watts), and atmosphere pressures under consideration for the spacesuit (248 and 760 mm Hg). The relationship between swing adsorption cycles for an outlet criterion of 6.0 mm Hg of CO2 partial pressure has been established for each metabolic challenge. In addition, variable metabolic profiles were imposed on the test articles in order to assess the ability of the technology to transition to new operational constraints. The advent of the model provides the capacity to apply computer-aided engineering practices to support the ongoing efforts to optimize and mature this technology for future application to space exploration.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Silva, Daniel L., E-mail: dlsilva.physics@gmail.com, E-mail: deboni@ifsc.usp.br; Instituto de Física, Universidade de São Paulo, CP 66318, 05314-970 São Paulo, SP; Fonseca, Ruben D.
2015-02-14
This paper reports on the static and dynamic first-order hyperpolarizabilities of a class of push-pull octupolar triarylamine derivatives dissolved in toluene. We have combined hyper-Rayleigh scattering experiment and the coupled perturbed Hartree-Fock method implemented at the Density Functional Theory (DFT) level of theory to determine the static and dynamic (at 1064 nm) first-order hyperpolarizability (β{sub HRS}) of nine triarylamine derivatives with distinct electron-withdrawing groups. In four of these derivatives, an azoaromatic unit is inserted and a pronounceable increase of the first-order hyperpolarizability is reported. Based on the theoretical results, the dipolar/octupolar character of the derivatives is determined. By using amore » polarizable continuum model in combination with the DFT calculations, it was found that although solvated in an aprotic and low dielectric constant solvent, due to solvent-induced polarization and the frequency dispersion effect, the environment substantially affects the first-order hyperpolarizability of all derivatives investigated. This statement is supported due to the solvent effects to be essential for the better agreement between theoretical results and experimental data concerning the dynamic first-order hyperpolarizability of the derivatives. The first-order hyperpolarizability of the derivatives was also modeled using the two- and three-level models, where the relationship between static and dynamic first hyperpolarizabilities is given by a frequency dispersion model. Using this approach, it was verified that the dynamic first hyperpolarizability of the derivatives is satisfactorily reproduced by the two-level model and that, in the case of the derivatives with an azoaromatic unit, the use of a damped few-level model is essential for, considering also the molecular size of such derivatives, a good quantitative agreement between theoretical results and experimental data to be observed.« less
Organizational effects on patient satisfaction in hospital medical-surgical units.
Bacon, Cynthia Thornton; Mark, Barbara
2009-05-01
The purpose of this study was to examine the relationships between hospital context, nursing unit structure, and patient characteristics and patients' satisfaction with nursing care in hospitals. Although patient satisfaction has been widely researched, our understanding of the relationship between hospital context and nursing unit structure and their impact on patient satisfaction is limited. The data source for this study was the Outcomes Research in Nursing Administration Project, a multisite organizational study conducted to investigate relationships among nurse staffing, organizational context and structure, and patient outcomes. The sample for this study was 2,720 patients and 3,718 RNs in 286 medical-surgical units in 146 hospitals. Greater availability of nursing unit support services and higher levels of work engagement were associated with higher levels of patient satisfaction. Older age, better health status, and better symptom management were also associated with higher levels of patient satisfaction. Organizational factors in hospitals and nursing units, particularly support services on the nursing unit and mechanisms that foster nurses' work engagement and effective symptom management, are important influences on patient satisfaction.
Fling, Brett W; Knight, Christopher A; Kamen, Gary
2009-08-01
As a part of the aging process, motor unit reorganization occurs in which small motoneurons reinnervate predominantly fast-twitch muscle fibers that have lost their innervation. We examined the relationship between motor unit size and the threshold force for recruitment in two muscles to determine whether older individuals might develop an alternative pattern of motor unit activation. Young and older adults performed isometric contractions ranging from 0 to 50% of maximal voluntary contraction in both the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles. Muscle fiber action potentials were recorded with an intramuscular needle electrode and motor unit size was computed using spike-triggered averaging of the global EMG signal (macro EMG), which was also obtained from the intramuscular needle electrode. As expected, older individuals exhibited larger motor units than young subjects in both the FDI and the TA. However, moderately strong correlations were obtained for the macro EMG amplitude versus recruitment threshold relationship in both the young and older adults within both muscles, suggesting that the size principle of motor unit recruitment seems to be preserved in older adults.
Effects of learning climate and registered nurse staffing on medication errors.
Chang, Yunkyung; Mark, Barbara
2011-01-01
Despite increasing recognition of the significance of learning from errors, little is known about how learning climate contributes to error reduction. The purpose of this study was to investigate whether learning climate moderates the relationship between error-producing conditions and medication errors. A cross-sectional descriptive study was done using data from 279 nursing units in 146 randomly selected hospitals in the United States. Error-producing conditions included work environment factors (work dynamics and nurse mix), team factors (communication with physicians and nurses' expertise), personal factors (nurses' education and experience), patient factors (age, health status, and previous hospitalization), and medication-related support services. Poisson models with random effects were used with the nursing unit as the unit of analysis. A significant negative relationship was found between learning climate and medication errors. It also moderated the relationship between nurse mix and medication errors: When learning climate was negative, having more registered nurses was associated with fewer medication errors. However, no relationship was found between nurse mix and medication errors at either positive or average levels of learning climate. Learning climate did not moderate the relationship between work dynamics and medication errors. The way nurse mix affects medication errors depends on the level of learning climate. Nursing units with fewer registered nurses and frequent medication errors should examine their learning climate. Future research should be focused on the role of learning climate as related to the relationships between nurse mix and medication errors.
Adirectional temporal zones in quantum physics and brain physiology
NASA Astrophysics Data System (ADS)
Ruhnau, Eva; Pöppel, Ernst
1991-08-01
Change in space and time of an observed object creates a logistical problem for our brain because the temporal central availability is undefined. As solution we claim the existence of elementary integration units (EIUs) which are defined as zones of simultaneity; i.e., within such an EIU the before-after relationship has to be abandoned. Experimental evidence points to a duration of the EIUs of the order of 30 msec. In considering a delayed choice experiment in physics, we propose that a similar renunciation of the before-after relation leads to a deeper understanding of the individuality of processes in quantum theory. In short, “time” may be more momentous than its usual appearance as a real-valued parameter demonstrates.
Qian, Jing; Wang, Bin; Han, Zhuo; Song, Baihe
2017-01-01
This research elucidates the role of ethical leadership in employee feedback seeking by examining how and when ethical leadership may exert a positive influence on feedback seeking. Using matched reports from 64 supervisors and 265 of their immediate employees from a hotel group located in a major city in China, we proposed and tested a moderated mediation model that examines leader-member exchange (LMX) as the mediator and emotional intelligence as well as work-unit structure as double moderators in the relationships between ethical leadership and followers' feedback-seeking behavior from supervisors and coworkers. Our findings indicated that (1) LMX mediated the positive relationship between ethical leadership and feedback seeking from both ethical leaders and coworkers, and (2) emotional intelligence and work-unit structure served as joint moderators on the mediated positive relationship in such a way that the relationship was strongest when the emotional intelligence was high and work-unit structure was more of an organic structure rather than a mechanistic structure.
NASA Astrophysics Data System (ADS)
Song, Huixu; Shi, Zhaoyao; Chen, Hongfang; Sun, Yanqiang
2018-01-01
This paper presents a novel experimental approach and a simple model for verifying that spherical mirror of laser tracking system could lessen the effect of rotation errors of gimbal mount axes based on relative motion thinking. Enough material and evidence are provided to support that this simple model could replace complex optical system in laser tracking system. This experimental approach and model interchange the kinematic relationship between spherical mirror and gimbal mount axes in laser tracking system. Being fixed stably, gimbal mount axes' rotation error motions are replaced by spatial micro-displacements of spherical mirror. These motions are simulated by driving spherical mirror along the optical axis and vertical direction with the use of precision positioning platform. The effect on the laser ranging measurement accuracy of displacement caused by the rotation errors of gimbal mount axes could be recorded according to the outcome of laser interferometer. The experimental results show that laser ranging measurement error caused by the rotation errors is less than 0.1 μm if radial error motion and axial error motion are under 10 μm. The method based on relative motion thinking not only simplifies the experimental procedure but also achieves that spherical mirror owns the ability to reduce the effect of rotation errors of gimbal mount axes in laser tracking system.
Wiegand, Iris; Bader, Regine; Mecklinger, Axel
2010-11-11
Recent research has shown that familiarity contributes to associative memory when the to-be-associated stimuli are unitized during encoding. However, the specific processes underlying familiarity-based recognition of unitized representations are still indefinite. In this study, we present electrophysiologically dissociable early old/new effects, presumably related to two different kinds of familiarity inherent in associative recognition tasks. In a study-test associative recognition memory paradigm, we employed encoding conditions that established unitized representations of two pre-experimentally unrelated words, e.g. vegetable-bible. We compared event-related potentials (ERP) during the retrieval of these unitized word pairs using different retrieval cues. Word pairs presented in the same order as during unitization at encoding elicited a parietally distributed early old/new effect which we interpret as reflecting conceptually driven familiarity for newly formed concepts. Conversely, word pairs presented in reversed order only elicited a topographically dissociable early effect, i.e. the mid-frontal old/new effect, the putative correlate of experimental familiarity. The late parietal old/new effect, the putative ERP correlate of recollection, was obtained irrespective of word order, though it was larger for words presented in same order. These results indicate that familiarity may not be a unitary process and that different task demands can promote the assessment of conceptually driven familiarity for novel unitized concepts or experimentally-induced increments of experimental familiarity, respectively. Copyright © 2010 Elsevier B.V. All rights reserved.
Mace-Vadjunec, Daneen; Hileman, Barbara M; Melnykovich, M Ben; Hanes, Marina C; Chance, Elisha A; Emerick, Eric S
2015-01-01
We assessed our level I trauma center's employees' perception of inter- and intradepartmental relationships to determine whether employees who work less often with patients feel less involved-the silo effect. We prospectively evaluated employees who provide direct patient care using the Trauma System Survey tool. Of 1155 employees, 699 responded. Combined interdepartmental relationships showed that 93% believed their unit communicated well with other units, and 86% thought other units communicated well with their unit. However, 69% experienced miscommunication between units. To reduce silos, communication is key. Training and multiunit events may help reduce these silos further.
A Novel Analysis Method for Paired-Sample Microbial Ecology Experiments.
Olesen, Scott W; Vora, Suhani; Techtmann, Stephen M; Fortney, Julian L; Bastidas-Oyanedel, Juan R; Rodríguez, Jorge; Hazen, Terry C; Alm, Eric J
2016-01-01
Many microbial ecology experiments use sequencing data to measure a community's response to an experimental treatment. In a common experimental design, two units, one control and one experimental, are sampled before and after the treatment is applied to the experimental unit. The four resulting samples contain information about the dynamics of organisms that respond to the treatment, but there are no analytical methods designed to extract exactly this type of information from this configuration of samples. Here we present an analytical method specifically designed to visualize and generate hypotheses about microbial community dynamics in experiments that have paired samples and few or no replicates. The method is based on the Poisson lognormal distribution, long studied in macroecology, which we found accurately models the abundance distribution of taxa counts from 16S rRNA surveys. To demonstrate the method's validity and potential, we analyzed an experiment that measured the effect of crude oil on ocean microbial communities in microcosm. Our method identified known oil degraders as well as two clades, Maricurvus and Rhodobacteraceae, that responded to amendment with oil but do not include known oil degraders. Our approach is sensitive to organisms that increased in abundance only in the experimental unit but less sensitive to organisms that increased in both control and experimental units, thus mitigating the role of "bottle effects".
Hedayati, Reza
2016-01-01
Abstract Recent developments in additive manufacturing techniques have motivated an increasing number of researchers to study regular porous biomaterials that are based on repeating unit cells. The physical and mechanical properties of such porous biomaterials have therefore received increasing attention during recent years. One of the areas that have revived is analytical study of the mechanical behavior of regular porous biomaterials with the aim of deriving analytical relationships that could predict the relative density and mechanical properties of porous biomaterials, given the design and dimensions of their repeating unit cells. In this article, we review the analytical relationships that have been presented in the literature for predicting the relative density, elastic modulus, Poisson's ratio, yield stress, and buckling limit of regular porous structures based on various types of unit cells. The reviewed analytical relationships are used to compare the mechanical properties of porous biomaterials based on different types of unit cells. The major areas where the analytical relationships have improved during the recent years are discussed and suggestions are made for future research directions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3164–3174, 2016. PMID:27502358
United States Military Support to American Strategic Goals in the Philippines
2012-12-14
UNITED STATES MILITARY SUPPORT TO AMERICAN STRATEGIC GOALS IN THE PHILIPPINES A thesis presented to the Faculty of the U.S... Philippines 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Maj James Coughlin, USAF 5d. PROJECT... Philippines . This relationship traces back to the Manila Bay in 1898. In the years since 1898, the United States’ role in the relationship between the
Urban Multi-Unit Community Colleges: Adaptation for the '70s.
ERIC Educational Resources Information Center
Palola, Ernest G.; Oswald, Arthur R.
This study examines the relationship between the organizational structure of multi-unit community college districts and the performance of urban campuses in serving disadvantaged students. Emphasis is on the expanding functions and changing structure of urban community colleges, the relationship between district office and district colleges, and…
Butler, Ashleigh E; Hall, Helen; Copnell, Beverley
2018-01-01
To explore bereaved parents' interactions with healthcare providers when a child dies in a paediatric intensive care unit. Although most children admitted to a paediatric intensive care unit will survive, 2-5% will die during their stay. The parents of these children interact and form relationships with numerous healthcare staff during their child's illness and death. Although previous studies have explored the parental experience of child death in intensive care generally, the nature of their relationships with healthcare providers during this time remains unknown. This study used a constructivist grounded theory approach. Data were collected via semi-structured, audio-recorded interviews with 26 bereaved parents from four paediatric intensive care units over 18 months in 2015-2016. Constant comparative analysis and theoretical memos were used to analyse the data. The theory "Transitional togetherness" demonstrates the changing nature of the parent-healthcare provider relationship across three key phases of the parents' journey. Phase one, "Welcoming expertise," focuses on the child's medical needs, with the healthcare provider dominant in the relationship. Phase two, "Becoming a team," centres around the parents' need to recreate a parental role and work collaboratively with healthcare providers. Finally, "Gradually disengaging" describes the parents' desire for the relationship to continue after the child's death as a source of support until no longer needed. Findings from this study offer valuable insights into the changing nature of the parent-healthcare provider relationship and highlight the key foci of the relationship at each stage of the parental journey. © 2017 John Wiley & Sons Ltd.
The relationship between nurse staffing and failure to rescue: where does it matter most?
Talsma, AkkeNeel; Jones, Katherine; Guo, Ying; Wilson, Deleise; Campbell, Darrell A
2014-09-01
This study further expands on the relationship between nurse staffing levels and patient outcomes, in particular, failure to rescue. Many studies are based on single-site hospitals or single-year data, thus limiting the generalizations of the findings. The purpose was to evaluate in a multisite multiyear study the relationship between unit-level nurse staffing and FTR mortality, for ICU and non-ICU patients. Using administrative and actual unit level nurse staffing data, we used AHRQ 2003 Patient Safety Indicator (2003) software and matched those with the patient's discharge month. Fixed effects multilevel logistic analyses were used to take into account the hierarchical structure of the database and patient clustering within units. We controlled for patient demographics, clinical conditions, and CCS categories. The majority (94%) of cases were discharged from general care units, ICUs reported higher nurse staffing levels based on patient complexity. Expired cases were 3 years older, male, and nonwhite. For general care discharges, the relationship between RN level HPPD approached significance (P = 0.07), suggesting increased odds of higher FTR mortality with higher staffing levels. We did not observe any of the expected associations between the nurse staffing variables and FTR for either general care unit or ICU discharges. The comprehensive risk adjustments provided adequate "leveling of the playing field" to evaluate the impact of unit-based nurse staffing levels on FTR mortality. Future studies should evaluate the influence of unit environment and patient risk.
Comparison of Co-Temporal Modeling Algorithms on Sparse Experimental Time Series Data Sets.
Allen, Edward E; Norris, James L; John, David J; Thomas, Stan J; Turkett, William H; Fetrow, Jacquelyn S
2010-01-01
Multiple approaches for reverse-engineering biological networks from time-series data have been proposed in the computational biology literature. These approaches can be classified by their underlying mathematical algorithms, such as Bayesian or algebraic techniques, as well as by their time paradigm, which includes next-state and co-temporal modeling. The types of biological relationships, such as parent-child or siblings, discovered by these algorithms are quite varied. It is important to understand the strengths and weaknesses of the various algorithms and time paradigms on actual experimental data. We assess how well the co-temporal implementations of three algorithms, continuous Bayesian, discrete Bayesian, and computational algebraic, can 1) identify two types of entity relationships, parent and sibling, between biological entities, 2) deal with experimental sparse time course data, and 3) handle experimental noise seen in replicate data sets. These algorithms are evaluated, using the shuffle index metric, for how well the resulting models match literature models in terms of siblings and parent relationships. Results indicate that all three co-temporal algorithms perform well, at a statistically significant level, at finding sibling relationships, but perform relatively poorly in finding parent relationships.
Sensitivity of cell-based biosensors to environmental variables.
Gilchrist, Kristin H; Giovangrandi, Laurent; Whittington, R Hollis; Kovacs, Gregory T A
2005-01-15
Electrically active living cells cultured on extracellular electrode arrays are utilized to detect biologically active agents. Because cells are highly sensitive to environmental conditions, environmental fluctuations can elicit cellular responses that contribute to the noise in a cell-based biosensor system. Therefore, the characterization and control of environmental factors such as temperature, pH, and osmolarity is critical in such a system. The cell-based biosensor platform described here utilizes the measurement of action potentials from cardiac cells cultured on electrode arrays. A recirculating fluid flow system is presented for use in dose-response experiments that regulates temperature within +/-0.2 degrees C, pH to within +/-0.05 units, and allows no significant change in osmolarity. Using this system, the relationship between the sensor output parameters and environmental variation was quantified. Under typical experimental conditions, beat rate varied approximately 10% per degree change in temperature or per 0.1 unit change in pH. Similar relationships were measured for action potential amplitude, duration, and conduction velocity. For the specific flow system used in this work, the measured environmental sensitivity resulted in an overall beat rate variation of +/-4.7% and an overall amplitude variation of +/-3.3%. The magnitude of the noise due to environmental sensitivity has a large impact on the detection capability of the cell-based system. The significant responses to temperature, pH, and osmolarity have important implications for the use of living cells in detection systems and should be considered in the design and evaluation of such systems.
The relationship between employees' perceptions of safety and organizational culture.
O'Toole, Michael
2002-01-01
With limited resources to help reduce occupational injuries, companies struggle with how to best focus these resources to achieve the greatest reduction in injuries for the optimal cost. Safety culture has been identified as a critical factor that sets the tone for importance of safety within an organization. An employee safety perception survey was conducted, and injury data were collected over a 45-month period from a large ready-mix concrete producer located in the southwest region of the United States. The results of this preliminary study suggest that the reductions in injuries experienced at the company locations was strongly impacted by the positive employee perceptions on several key factors. Management's commitment to safety was the factor with the greatest positive perception by employees taking the survey. This study was set up as a pilot project and did not unitize an experimental design. That weakness reduces the strength of these findings but adds to the importance of expanding the pilot project with an appropriate experimental design. Management leadership has been identified, along with several other factors, to influence employee perceptions of the safety management system. Those perceptions, in turn, appear to influence employee decisions that relate to at-risk behaviors and decisions on the job. The results suggest that employee perceptions of the safety system are related to management's commitment to safety, which, in turn, appear to be related to injury rates. Management should focus on how to best leverage these key factors to more positively impact injury rates within their companies.
Stock, Matt S; Mota, Jacob A
2017-12-01
Muscle fatigue is associated with diminished twitch force amplitude. We examined changes in the motor unit recruitment versus derecruitment threshold relationship during fatigue. Nine men (mean age = 26 years) performed repeated isometric contractions at 50% maximal voluntary contraction (MVC) knee extensor force until exhaustion. Surface electromyographic signals were detected from the vastus lateralis, and were decomposed into their constituent motor unit action potential trains. Motor unit recruitment and derecruitment thresholds and firing rates at recruitment and derecruitment were evaluated at the beginning, middle, and end of the protocol. On average, 15 motor units were studied per contraction. For the initial contraction, three subjects showed greater recruitment thresholds than derecruitment thresholds for all motor units. Five subjects showed greater recruitment thresholds than derecruitment thresholds for only low-threshold motor units at the beginning, with a mean cross-over of 31.6% MVC. As the muscle fatigued, many motor units were derecruited at progressively higher forces. In turn, decreased slopes and increased y-intercepts were observed. These shifts were complemented by increased firing rates at derecruitment relative to recruitment. As the vastus lateralis fatigued, the central nervous system's compensatory adjustments resulted in a shift of the regression line of the recruitment versus derecruitment threshold relationship. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.
Lin, Chenxi; Martínez, Luis Javier; Povinelli, Michelle L
2013-09-09
We design silicon membranes with nanohole structures with optimized complex unit cells that maximize broadband absorption. We fabricate the optimized design and measure the optical absorption. We demonstrate an experimental broadband absorption about 3.5 times higher than an equally-thick thin film.
Neuroticism and proxemic behavior.
De Julio, S; Duffy, K
1977-08-01
The relationship between proxemic behavior and neuroticism was examined. 50 male and 43 female subjects individually self-selected seats in a classroom where they were administered the Eysenck Personality Inventory by one of four experimenters (two male, two female). A significant relationship was found between proxemic distance and both neuroticism and experimenter's sex.
Zheng, Jingming; Ma, Keping
2006-07-01
This paper reviewed the theoretical, observational, and experimental studies on the relationships between biodiversity and invasiveness within plant communities. The contradictory conclusions made from these studies were summarized and analyzed, and suggestions were put forward to improve future researches. In theoretical studies, models were highly simplified and depended on unrealistic assumptions, e. g., single mechanism of biodiversity formation, balance between communities status, and similar characters of alien and native species, which limited the credibility of research conclusions. Most of the observational studies were not directly exploring the relationships between biodiversity and invasiveness, but inferring from invasion patterns occurred in nature. Different research scales always resulted in contradictory conclusions. In small-scale research where some biotic factors dominated species interaction, the relationships between biodiversity and invasiveness might be negative, while in larger-scale research, other co-varying extrinsic factors might override those biotic factors in small-scale research, and the relationships between biodiversity and invasiveness might be positive. Although most experimental studies were conducted in small scale and extrinsic influences were ruled out, some mistakes might still happen when constructing biodiversity gradients in the experimental communities. Among these mistakes, sampling effect was the most common one, and the others included building communities with same species abundance but varying richness and density. Some suggestions were put forward on improving the study of the relationships between biodiversity and invasiveness in plant communities. In future researches, we should integrate observational study with experimental study, pay more attention to research scale, avoid sampling effect, and couple model with experimental design.
Houhamdi, Linda; Raoult, Didier
2006-04-01
The human body louse, the natural vector of Rickettsia prowazekii, is able to experimentally transmit the normally flea-borne rickettsia R. typhi, suggesting that the relationships between the body louse and rickettsiae are not specific. We used our experimental infection model to test the ability of body lice to transmit two prevalent tick-borne rickettsiae. Each of two rabbits was made bacteremic by injecting intravenously 2 x 10(6) plaque-forming units of either R. rickettsii or R. conorii. Four hundred body lice were infected by feeding on the bacteremic rabbit and were compared with 400 uninfected lice. Each louse group was fed once a day on a separate seronegative rabbit. The survival of infected lice was not different from that of uninfected controls. Lice remained infected for their lifespan, excreted R. rickettsii and R. conorii in their feces, but did not transmit the infection to their progeny. The nurse rabbit of uninfected lice remained asymptomatic and seronegative. Those rabbits used to feed infected lice developed bacteremia and seroconverted. Although the body louse is not a known vector of spotted fevers, it was able in our study to acquire, maintain, and transmit both R. rickettsii and R. conorii.
Malaysia and the United States 2004-2005: The Best of Times?
2005-02-01
SPECIAL ASSESSMENT F E B R U A R Y 2 0 0 5 The Asia-Pacific and the United States 2004–2005 Malaysia and the United States 2004–2005: The Best of...Times? I A N S T O R E Y K E Y F I N D I N G S l Malaysia and the United States have a robust relationship underpinned by strong fundamentals that...positives in the relationship, such as shared values and beliefs, and has praised Malaysia for its leadership role in Southeast Asia and the wider Islamic
NASA Technical Reports Server (NTRS)
Maestrello, L.
1973-01-01
By measurement and analysis, the relationship between the distribution of the outflow of acoustic energy over the jet boundary and the far-field intensity is considered. The physical quantity used is the gradient of the pressure evaluated on a geometrical plane at the smallest possible radial distance from the jet axis, but outside the vortical region, in the area where the homogeneous wave equation is reasonably well satisfied. The numerical and experimental procedures involved have been checked out by using a known source. Results indicate that the acoustic power output per unit length of the jet, in the region from which the sound emanates, peaks at approximately 9 diameters downstream. The acoustic emission for a jet Strouhal number of about 0.3 exceeds the emission for all other Strouhal numbers nearly everywhere along the measurement plane. However, the far-field peak intensity distribution obtained from the contribution of each station was found to depend on the spatial extent of the region where sound emanates from the jet, which, in turn, depends more on the far-field angle than on the Strouhal number.
NASA Astrophysics Data System (ADS)
Al-Mandwee, Samir F.
The objective of this dissertation was to quantitatively study Iraqi students (N=90) who arrived in the U.S.A. in the last 20 years. A non-experimental, descriptive research design was used for this study, which took place in one of three high schools in a large Midwestern suburban school district, during the 2013--2014 academic year. Three factors, including the students' perception of the value of education, the parental support, and the peer support, were examined using the Facilitating Conditions Questionnaire. The three subscales were part of a larger self-administered questionnaire used by McInerney (1997). In addition to the FCQ survey, a student demographic questionnaire was also used in the survey. Quantitative data from the FCQ survey reported that the students' perception of the value of education and their perception of peer support had a significant relationship with science academic achievement, which was measured for two semesters. Moreover, their peer support was the only predictor for science achievement.
Vibration and noise analysis of a gear transmission system
NASA Technical Reports Server (NTRS)
Choy, F. K.; Qian, W.; Zakrajsek, J. J.; Oswald, F. B.
1993-01-01
This paper presents a comprehensive procedure to predict both the vibration and noise generated by a gear transmission system under normal operating conditions. The gearbox vibrations were obtained from both numerical simulation and experimental studies using a gear noise test rig. In addition, the noise generated by the gearbox vibrations was recorded during the experimental testing. A numerical method was used to develop linear relationships between the gearbox vibration and the generated noise. The hypercoherence function is introduced to correlate the nonlinear relationship between the fundamental noise frequency and its harmonics. A numerical procedure was developed using both the linear and nonlinear relationships generated from the experimental data to predict noise resulting from the gearbox vibrations. The application of this methodology is demonstrated by comparing the numerical and experimental results from the gear noise test rig.
Graphical Models for Quasi-Experimental Designs
ERIC Educational Resources Information Center
Kim, Yongnam; Steiner, Peter M.; Hall, Courtney E.; Su, Dan
2016-01-01
Experimental and quasi-experimental designs play a central role in estimating cause-effect relationships in education, psychology, and many other fields of the social and behavioral sciences. This paper presents and discusses the causal graphs of experimental and quasi-experimental designs. For quasi-experimental designs the authors demonstrate…
Fatigue Strength Estimation Based on Local Mechanical Properties for Aluminum Alloy FSW Joints
Sillapasa, Kittima; Mutoh, Yoshiharu; Miyashita, Yukio; Seo, Nobushiro
2017-01-01
Overall fatigue strengths and hardness distributions of the aluminum alloy similar and dissimilar friction stir welding (FSW) joints were determined. The local fatigue strengths as well as local tensile strengths were also obtained by using small round bar specimens extracted from specific locations, such as the stir zone, heat affected zone, and base metal. It was found from the results that fatigue fracture of the FSW joint plate specimen occurred at the location of the lowest local fatigue strength as well as the lowest hardness, regardless of microstructural evolution. To estimate the fatigue strengths of aluminum alloy FSW joints from the hardness measurements, the relationship between fatigue strength and hardness for aluminum alloys was investigated based on the present experimental results and the available wide range of data from the references. It was found as: σa (R = −1) = 1.68 HV (σa is in MPa and HV has no unit). It was also confirmed that the estimated fatigue strengths were in good agreement with the experimental results for aluminum alloy FSW joints. PMID:28772543
NASA Astrophysics Data System (ADS)
OBeirne, M. D.; Werne, J. P.; Van Dongen, B.; Gilhooly, W., III
2017-12-01
Sulfurization of carbohydrates has been suggested as an important mechanism for the preservation of organic matter in anoxic/euxinic depositional environments. In this study, glucose was sulfurized under laboratory conditions at room temperature (24°C) using three commercially available sulfides - ammonium sulfide ([NH4]2S), sodium sulfide (Na2S), and sodium hydrosulfide (NaHS), each mixed with elemental sulfur to produce polysulfide solutions. The reaction products were analyzed using Fourier transform infrared spectroscopy (FTIR), which revealed structural differences among the products formed via the three sulfide reactants. Additionally, analysis of the bulk sulfur isotope compositions of reactants and products was used to determine the fractionation(s) associated with abiotic sulfur incorporation into organic matter. Samples from both modern (Mahoney Lake, British Colombia, Canada) and ancient (Jurassic aged Blackstone Band from the Kimmeridge Clay Formation, Dorset, United Kingdom) euxinic systems were also analyzed for comparison to laboratory samples. Results from this study provide experimental evidence for the structural and sulfur isotopic relationships of sulfurized organic matter in the geosphere.
PACS—Realization of an adaptive concept using pressure actuated cellular structures
NASA Astrophysics Data System (ADS)
Gramüller, B.; Boblenz, J.; Hühne, C.
2014-10-01
A biologically inspired concept is investigated which can be utilized to develop energy efficient, lightweight and applicational flexible adaptive structures. Building a real life morphing unit is an ambitious task as the numerous works in the particular field show. Summarizing fundamental demands and barriers regarding shape changing structures, the basic challenges of designing morphing structures are listed. The concept of Pressure Actuated Cellular Structures (PACS) is arranged within the recent morphing activities and it is shown that it complies with the underlying demands. Systematically divided into energy-related and structural subcomponents the working principle is illuminated and relationships between basic design parameters are expressed. The analytical background describing the physical mechanisms of PACS is presented in concentrated manner. This work focuses on the procedure of dimensioning, realizing and experimental testing of a single cell and a single row cantilever made of PACS. The experimental outcomes as well as the results from the FEM computations are used for evaluating the analytical methods. The functionality of the basic principle is thus validated and open issues are determined pointing the way ahead.
Fatigue Strength Estimation Based on Local Mechanical Properties for Aluminum Alloy FSW Joints.
Sillapasa, Kittima; Mutoh, Yoshiharu; Miyashita, Yukio; Seo, Nobushiro
2017-02-15
Overall fatigue strengths and hardness distributions of the aluminum alloy similar and dissimilar friction stir welding (FSW) joints were determined. The local fatigue strengths as well as local tensile strengths were also obtained by using small round bar specimens extracted from specific locations, such as the stir zone, heat affected zone, and base metal. It was found from the results that fatigue fracture of the FSW joint plate specimen occurred at the location of the lowest local fatigue strength as well as the lowest hardness, regardless of microstructural evolution. To estimate the fatigue strengths of aluminum alloy FSW joints from the hardness measurements, the relationship between fatigue strength and hardness for aluminum alloys was investigated based on the present experimental results and the available wide range of data from the references. It was found as: σ a ( R = -1) = 1.68 HV ( σ a is in MPa and HV has no unit). It was also confirmed that the estimated fatigue strengths were in good agreement with the experimental results for aluminum alloy FSW joints.
ERIC Educational Resources Information Center
Hwang, Seog Joo
2013-01-01
This study investigates what are the relationships between different leader behaviors (i.e. supportive, participative, and controlling leader behaviors) and follower creativity, and whether the relationships differ between South Korea and the United States. Although creativity research suggests that supportive leader behaviors tend to enhance…
Ethnic and Cultural Focus in Airport Driver Training
ERIC Educational Resources Information Center
Cokley, John; Rankin, William
2009-01-01
A series of linked relationships is advanced which together suggest changes should be made to training programs for airside drivers at major airports in the United States, Australia and the United Kingdom. Overall, the links suggest a relationship between the number of airside incidents such as collisions at airports, the ethnic diversity evident…
22 CFR 1104.11 - Relationship to section 106 of the National Historic Preservation Act.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Relationship to section 106 of the National Historic Preservation Act. 1104.11 Section 1104.11 Foreign Relations INTERNATIONAL BOUNDARY AND WATER COMMISSION, UNITED STATES AND MEXICO, UNITED STATES SECTION PROTECTION OF ARCHAEOLOGICAL RESOURCES § 1104.11...
Teaching, Academic Achievement, and Attitudes toward Mathematics in the United States and Nigeria
ERIC Educational Resources Information Center
Perry, S. Marshall; Catapano, Michael; Ramon, Olosunde Gbolagade
2016-01-01
This paper explores the relationships among attitudes toward mathematics, teaching, and academic achievement in mathematics. Based on the contextual and social nature of academic self-concept, two complementary studies are discussed. The first study from the northeastern United States examined the relationships among these variables in 84 high…
We have examined relationships between summer (JuneAugust) average concentrations of total nitrogen (TN) and chlorophyll a (chl a) concentrations in the near-shore Mid-Atlantic Bight and nine bays and estuaries in the eastern United States: Boston Harbor/Massachusetts Bay, Long I...
22 CFR 1104.11 - Relationship to section 106 of the National Historic Preservation Act.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Relationship to section 106 of the National Historic Preservation Act. 1104.11 Section 1104.11 Foreign Relations INTERNATIONAL BOUNDARY AND WATER COMMISSION, UNITED STATES AND MEXICO, UNITED STATES SECTION PROTECTION OF ARCHAEOLOGICAL RESOURCES § 1104.11...
Static and Current Electricity.
ERIC Educational Resources Information Center
Schlenker, Richard M.; Murtha, Kathy T.
This is a copy of the script for the electrical relationships unit in an auto-tutorial physical science course for non-science majors, offered at the University of Maine at Orono. The unit includes 15 simple experiments designed to allow the student to discover various fundamental electrical relationships. The student has the option of reading the…
Qian, Jing; Wang, Bin; Han, Zhuo; Song, Baihe
2017-01-01
This research elucidates the role of ethical leadership in employee feedback seeking by examining how and when ethical leadership may exert a positive influence on feedback seeking. Using matched reports from 64 supervisors and 265 of their immediate employees from a hotel group located in a major city in China, we proposed and tested a moderated mediation model that examines leader-member exchange (LMX) as the mediator and emotional intelligence as well as work-unit structure as double moderators in the relationships between ethical leadership and followers’ feedback-seeking behavior from supervisors and coworkers. Our findings indicated that (1) LMX mediated the positive relationship between ethical leadership and feedback seeking from both ethical leaders and coworkers, and (2) emotional intelligence and work-unit structure served as joint moderators on the mediated positive relationship in such a way that the relationship was strongest when the emotional intelligence was high and work-unit structure was more of an organic structure rather than a mechanistic structure. PMID:28744251
2013-01-01
Background The end-systolic pressure-volume relationship is often considered as a load-independent property of the heart and, for this reason, is widely used as an index of ventricular contractility. However, many criticisms have been expressed against this index and the underlying time-varying elastance theory: first, it does not consider the phenomena underlying contraction and second, the end-systolic pressure volume relationship has been experimentally shown to be load-dependent. Methods In place of the time-varying elastance theory, a microscopic model of sarcomere contraction is used to infer the pressure generated by the contraction of the left ventricle, considered as a spherical assembling of sarcomere units. The left ventricle model is inserted into a closed-loop model of the cardiovascular system. Finally, parameters of the modified cardiovascular system model are identified to reproduce the hemodynamics of a normal dog. Results Experiments that have proven the limitations of the time-varying elastance theory are reproduced with our model: (1) preload reductions, (2) afterload increases, (3) the same experiments with increased ventricular contractility, (4) isovolumic contractions and (5) flow-clamps. All experiments simulated with the model generate different end-systolic pressure-volume relationships, showing that this relationship is actually load-dependent. Furthermore, we show that the results of our simulations are in good agreement with experiments. Conclusions We implemented a multi-scale model of the cardiovascular system, in which ventricular contraction is described by a detailed sarcomere model. Using this model, we successfully reproduced a number of experiments that have shown the failing points of the time-varying elastance theory. In particular, the developed multi-scale model of the cardiovascular system can capture the load-dependence of the end-systolic pressure-volume relationship. PMID:23363818
Moynihan, Mary M; Banyard, Victoria L; Cares, Alison C; Potter, Sharyn J; Williams, Linda M; Stapleton, Jane G
2015-01-01
Colleges and universities are high-risk settings for sexual and relationship violence. To address these problems, institutions of higher education have implemented prevention programs, many of which train students as potential bystanders who can step in to help diffuse risky situations, identify and challenge perpetrators, and assist victims. The impact of bystander sexual and relationship violence prevention programs on long-term behavior of bystanders has remained a key unanswered question for those who seek to offer the most effective programs as well as for policy makers. In this study, the researchers experimentally evaluated the effectiveness of the Bringing in the Bystander® in-person program. Participants were 948 1st-year college students of whom 47.8% were women and 85.2% identified as White (15% also identified as Hispanic in a separate question) between the ages of 18 and 24 at two universities (one a rural, primarily residential campus and the other an urban, highly commuter campus) in the northeastern United States. To date, this is the first study to have found positive behavior changes as long-lasting as 1 year following an educational workshop focusing on engaging bystanders in preventing sexual and relationship violence. Even so, many questions remain to be answered about prevention and intervention of this type. More prospective research is needed on bystander-focused prevention of these forms of violence to help understand and better predict the complicated relationships both between and among the attitudes and behaviors related to preventing sexual and relationship violence. In this regard, we make specific recommendations for designing and evaluating programs based on our findings relating to the importance of moderators, especially two key understudied ones, readiness to help and opportunity to intervene. © The Author(s) 2014.
A novel analysis method for paired-sample microbial ecology experiments
Olesen, Scott W.; Vora, Suhani; Techtmann, Stephen M.; ...
2016-05-06
Many microbial ecology experiments use sequencing data to measure a community s response to an experimental treatment. In a common experimental design, two units, one control and one experimental, are sampled before and after the treatment is applied to the experimental unit. The four resulting samples contain information about the dynamics of organisms that respond to the treatment, but there are no analytical methods designed to extract exactly this type of information from this configuration of samples. Here we present an analytical method specifically designed to visualize and generate hypotheses about microbial community dynamics in experiments that have paired samplesmore » and few or no replicates. The method is based on the Poisson lognormal distribution, long studied in macroecology, which we found accurately models the abundance distribution of taxa counts from 16S rRNA surveys. To demonstrate the method s validity and potential, we analyzed an experiment that measured the effect of crude oil on ocean microbial communities in microcosm. Our method identified known oil degraders as well as two clades, Maricurvus and Rhodobacteraceae, that responded to amendment with oil but do not include known oil degraders. Furthermore, our approach is sensitive to organisms that increased in abundance only in the experimental unit but less sensitive to organisms that increased in both control and experimental units, thus mitigating the role of bottle effects .« less
A novel analysis method for paired-sample microbial ecology experiments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Olesen, Scott W.; Vora, Suhani; Techtmann, Stephen M.
Many microbial ecology experiments use sequencing data to measure a community s response to an experimental treatment. In a common experimental design, two units, one control and one experimental, are sampled before and after the treatment is applied to the experimental unit. The four resulting samples contain information about the dynamics of organisms that respond to the treatment, but there are no analytical methods designed to extract exactly this type of information from this configuration of samples. Here we present an analytical method specifically designed to visualize and generate hypotheses about microbial community dynamics in experiments that have paired samplesmore » and few or no replicates. The method is based on the Poisson lognormal distribution, long studied in macroecology, which we found accurately models the abundance distribution of taxa counts from 16S rRNA surveys. To demonstrate the method s validity and potential, we analyzed an experiment that measured the effect of crude oil on ocean microbial communities in microcosm. Our method identified known oil degraders as well as two clades, Maricurvus and Rhodobacteraceae, that responded to amendment with oil but do not include known oil degraders. Furthermore, our approach is sensitive to organisms that increased in abundance only in the experimental unit but less sensitive to organisms that increased in both control and experimental units, thus mitigating the role of bottle effects .« less
Whitman, Daniel S; Caleo, Suzette; Carpenter, Nichelle C; Horner, Margaret T; Bernerth, Jeremy B
2012-07-01
This article uses meta-analytic methods (k = 38) to examine the relationship between organizational justice climate and unit-level effectiveness. Overall, our results suggest that the relationship between justice and effectiveness is significant (ρ = .40) when both constructs are construed at the collective level. Our results also indicate that distributive justice climate was most strongly linked with unit-level performance (e.g., productivity, customer satisfaction), whereas interactional justice was most strongly related to unit-level processes (e.g., organizational citizenship behavior, cohesion). We also show that a number of factors moderate this relationship, including justice climate strength, the level of referent in the justice measure, the hierarchical level of the unit, and how criteria are classified. We elaborate on these findings and attempt to provide a clearer direction for future research in this area. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
NASA Astrophysics Data System (ADS)
Frank, T. D.; Patanarapeelert, K.; Beek, P. J.
2008-05-01
We derive a fundamental relationship between the mean and the variability of isometric force. The relationship arises from an optimal collection of active motor units such that the force variability assumes a minimum (optimal isometric force). The relationship is shown to be independent of the explicit motor unit properties and of the dynamical features of isometric force production. A constant coefficient of variation in the asymptotic regime and a nonequilibrium fluctuation-dissipation theorem for optimal isometric force are predicted.
Global geological mapping of Ganymede
NASA Astrophysics Data System (ADS)
Patterson, G. Wesley; Collins, Geoffrey C.; Head, James W.; Pappalardo, Robert T.; Prockter, Louise M.; Lucchitta, Baerbel K.; Kay, Jonathan P.
2010-06-01
We have compiled a global geological map of Ganymede that represents the most recent understanding of the satellite based on Galileo mission results. This contribution builds on important previous accomplishments in the study of Ganymede utilizing Voyager data and incorporates the many new discoveries that were brought about by examination of Galileo data. We discuss the material properties of geological units defined utilizing a global mosaic of the surface with a nominal resolution of 1 km/pixel assembled by the USGS with the best available Voyager and Galileo regional coverage and high resolution imagery (100-200 m/pixel) of characteristic features and terrain types obtained by the Galileo spacecraft. We also use crater density measurements obtained from our mapping efforts to examine age relationships amongst the various defined units. These efforts have resulted in a more complete understanding of the major geological processes operating on Ganymede, especially the roles of cryovolcanic and tectonic processes in the formation of might materials. They have also clarified the characteristics of the geological units that comprise the satellite's surface, the stratigraphic relationships of those geological units and structures, and the geological history inferred from those relationships. For instance, the characteristics and stratigraphic relationships of dark lineated material and reticulate material suggest they represent an intermediate stage between dark cratered material and light material units.
Zadpoor, Amir Abbas; Hedayati, Reza
2016-12-01
Recent developments in additive manufacturing techniques have motivated an increasing number of researchers to study regular porous biomaterials that are based on repeating unit cells. The physical and mechanical properties of such porous biomaterials have therefore received increasing attention during recent years. One of the areas that have revived is analytical study of the mechanical behavior of regular porous biomaterials with the aim of deriving analytical relationships that could predict the relative density and mechanical properties of porous biomaterials, given the design and dimensions of their repeating unit cells. In this article, we review the analytical relationships that have been presented in the literature for predicting the relative density, elastic modulus, Poisson's ratio, yield stress, and buckling limit of regular porous structures based on various types of unit cells. The reviewed analytical relationships are used to compare the mechanical properties of porous biomaterials based on different types of unit cells. The major areas where the analytical relationships have improved during the recent years are discussed and suggestions are made for future research directions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3164-3174, 2016. © 2016 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc.
Safety leadership: extending workplace safety climate best practices across health care workforces.
McCaughey, Deirdre; Halbesleben, Jonathon R B; Savage, Grant T; Simons, Tony; McGhan, Gwen E
2013-01-01
Hospitals within the United States consistently have injury rates that are over twice the national employee injury rate. Hospital safety studies typically investigate care providers rather than support service employees. Compounding the lack of evidence for this understudied population is the scant evidence that is available to examine the relationship of support service employees'perceptions of safety and work-related injuries. To examine this phenomenon, the purpose of this study was to investigate support service employees' perceptions of safety leadership and social support as well as the relationship of safety perception to levels of reported injuries. A nonexperimental survey was conducted with the data collected from hospital support service employees (n = 1,272) and examined. (1) relationships between safety leadership (supervisor and organization) and individual and unit safety perceptions; (2) the moderating effect of social support (supervisor and coworker) on individual and unit safety perceptions; and (3) the relationship of safety perception to reported injury rates. The survey items in this study were based on the items from the AHRQ Patient Safety Culture Survey and the U.S. National Health Care Surveys. Safety leadership (supervisor and organization) was found to be positively related to individual safety perceptions and unit safety grade as was supervisor and coworker support. Coworker support was found to positively moderate the following relationships: supervisor safety leadership and safety perceptions, supervisor safety leadership and unit safety grade, and senior management safety leadership and safety perceptions. Positive employee safety perceptions were found to have a significant relationship with lower reported injury rates. These findings suggest that safety leadership from supervisors and senior management as well as coworker support has positive implications for support service employees' perceptions of safety, which, in turn, are negatively related to lower odds of reporting injuries.
Experimental Study on Relationship between NOx Emission and Fuel Consumption of a Diesel Engine
NASA Astrophysics Data System (ADS)
Ning, Ping; Liu, Chunjiang; Feng, Zhiqiang; Xia, Yijiang
2018-01-01
For YC6112 diesel engine assembled Delphl model single fuel pump electric controlled, in the premise of not changing its overall unit structure parameters of other systems, three different types of camshaft for single pumps, two kinds of fuel injectors, two types of superchargers and some phase shifting angle of different camshafts were chosen to match with the engine precisely, the experiments under thirteen kinds of working conditions for the engine with different matching were carried out, the change regulation between NOX emission and fuel consumption for the engine with different kinds of configurations was analyzed. The experiment results show the NOX emission and fuel consumption can be reduced greatly by configuring proper camshaft, fuel injectors and superchargers with YC6112 diesel engine.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-10
... Whitney A Subsidiary of United Technologies Corporation Far Group and Experimental Test Group East... Technologies Corporation, FAR Group and Experimental Test Group, supplies/supports and operates as an extension... Test Group. The amended notice applicable to TA-W-75,152 is hereby issued as follows: ``All workers of...
Gulberti, Alessandro; Zittel, Simone; Tudor Jones, Adam A.; Fickel, Ulrich; Münchau, Alexander; Köppen, Johannes A.; Gerloff, Christian; Westphal, Manfred; Buhmann, Carsten; Hamel, Wolfgang; Engel, Andreas K.
2014-01-01
Parkinson's disease (PD) is a heterogeneous disorder that leads to variable expression of several different motor symptoms. While changes in firing rate, pattern, and oscillation of basal ganglia neurons have been observed in PD patients and experimental animals, there is limited evidence linking them to specific motor symptoms. Here we examined this relationship using extracellular recordings of subthalamic nucleus neurons from 19 PD patients undergoing surgery for deep brain stimulation. For each patient, ≥10 single units and/or multi-units were recorded in the OFF medication state. We correlated the proportion of neurons displaying different activities with preoperative Unified Parkinson's Disease Rating Scale subscores (OFF medication). The mean spectral power at sub-beta frequencies and percentage of units oscillating at beta frequencies were positively correlated with the axial and limb rigidity scores, respectively. The percentage of units oscillating at gamma frequency was negatively correlated with the bradykinesia scores. The mean intraburst rate was positively correlated with both bradykinesia and axial scores, while the related ratio of interspike intervals below/above 10 ms was positively correlated with these symptoms and limb rigidity. None of the activity parameters correlated with tremor. The grand average of all the significantly correlated subthalamic nucleus activities accounted for >60% of the variance of the combined bradykinetic-rigid and axial scores. Our results demonstrate that the occurrence of alterations in the rate and pattern of basal ganglia neurons could partly underlie the variability in parkinsonian phenotype. PMID:24790198
ERIC Educational Resources Information Center
Rhys, Garel
An international team of researchers studied the following aspects of training in the United Kingdom's motor vehicle repair and sales sector: structure and characteristics; institutional and social context; relationship to the labor market; changing structural, economic, and organizational conditions; and training/recruitment and relationship to…
Relationship between crown dieback and drought in the southeastern United States
Michael K. Crosby; Zhaofei Fan; Martin A. Spetich; Theodor D. Leininger; Xingang Fan
2012-01-01
Forest Health and Monitoring (FHM) and Palmer's Drought Severity Index (PDSI) data were obtained for 11 states in the southeastern United States to assess the relationship between drought and crown dieback. Correlation analyses were performed at the species group and ecoregion levels within the study area. The results indicate a negative correlation between...
ERIC Educational Resources Information Center
Zenone, Anna
1981-01-01
Analyzes a type of conversational exchange where the participants focus on a given subject or theme contributing personal views to the discussion. Characterizes the relationship among the participants as a "cooperative conflict," examining the internal structure of speech acts and their illocutory functions, particularly the initiatory…
ERIC Educational Resources Information Center
Jambunathan, Saigeetha
2006-01-01
The purpose of the present study is to examine the relationship between parenting attitudes of Asian Indian mothers living in the United States and their preschool children's perception of self-competence. Twenty-eight Asian Indian mothers and their preschool-aged children living in the United States participated in the study. The parenting…
Quality of nursing diagnoses: evaluation of an educational intervention.
Florin, Jan; Ehrenberg, Anna; Ehnfors, Margareta
2005-01-01
To investigate the effects on the quality of nursing diagnostic statements in patient records after education in the nursing process and implementation of new forms for recording. Quasi-experimental design. Randomly selected patient records reviewed before and after intervention from one experimental unit (n = 70) and three control units (n = 70). A scale with 14 characteristics pertaining to nursing diagnoses was developed and used together with the instrument (CAT-CH-ING) for record review. Quality of nursing diagnostic statements improved in the experimental unit, whereas no improvement was found in the control units. Serious flaws in the use of the etiology component were found. CONCLUSION. Nurses must be more concerned with the accuracy and quality of the nursing diagnoses and the etiology component needs to be given special attention. Education of RNs in nursing diagnostic statements and peer review using standardized evaluation instruments can be means to further enhance RNs' documentation practice.
A Low Cost Environmentally Benign Waste Lubricants Recycling/Re-refining Technology.
1999-05-01
EXPERIMENTAL 3 2.1 Ceramic Membrane Ultrafiltration Pilot Unit 3 2.2 Polishing/Finishing Pilot Unit 3 2.3 Feed Samples 3 2.4 Sample...development of an additional 2 to 3 sites in the US. 2. EXPERIMENTAL 2.1. Ceramic Membrane Ultrafiltration Pilot Unit A photograph of the pilot...scale ceramic membrane system used in this work is shown in Figure la. Samples of spent turbine oil were charged to the feed tank and heated to 150°C
NASA Astrophysics Data System (ADS)
Matthews, G. Peter; Maurizio Laudone, G.; Whalle, W. Richard; Bird, Nigel; Gregory, Andrew; Cardenas, Laura; Misselbrook, Tom
2010-05-01
Nitrous oxide is the fourth most important greenhouse gas. It is 300 times more potent than carbon dioxide, and two-thirds of anthropogenic nitrous oxide is emitted by agricultural land. This presentation will begin with a brief overview of the laboratory measurements of nitrous oxide emission from carefully characterised soils, presented in more detail by Cardenas et al.. The measurements were made in a twelve-chamber, gas chromatographic apparatus at North Wyke Research (formerly IGER). The presentation will then continue with a description of a void network model of sufficient accuracy and authenticity that it can be used to explain and predict the nitrous oxide production, and the modelling of the biological, chemical and physical processes for the production of nitrous oxide within the constructed network. Finally, conclusions will be drawn from a comparison of the model results with experiment. The void network model Nitrous oxide is produced by microbial activity located in ‘hotspots' within the microstructure of soil, and nutrients and gases flow or diffuse to and from these hotspots through the water or gas-filled macro-porosity. It is clear, therefore, that a network model to describe and explain nitrous oxide production must encompass the full size range of pore space active within the process, which covers 6 orders of magnitude, and must make realistic suppositions about the positional relationship of the hotspots relative to the soil macro-porosity. Previous experimental (Tsakiroglou, C. D. et al, European J.Soil Sci., 2008) and theoretical approaches to the modelling of soil void structure cannot generally meet these two requirements. We have therefore built on the success of the previous uni-porous model of soil (Matthews, G. P. et al, Wat.Resour.Res, 2010), and the concept of a critical percolation path, to develop a dual porous model (Laudone, G. M. et al, European J.Soil Sci., 2010) with the following features: • A porous unit cell, with periodic boundary conditions, and with a critical percolation path with the correct percolation characteristics and void volume of the macro-porosity of the soil. • A solid phase between the pores of the large unit cell, with the correct volume of the fraction of larger soil aggregates (larger 1 mm). • All the remaining pores of the large unit cell, which are not part of the critical percolation path, filled with smaller unit cells, which account for the micro-porosity of the soil sample. We describe the construction of a model that closely matches the following characteristics of a specific example of typical arable soil, taken from the Warren field of the Rothamsted experimental farm at Woburn, although the model can be used for a wide range of soils: (i) macroporosity and microporosity as measured by the water retention curve, (ii) the shape of the water retention characteristic under a wide range of tensions, (iii) the soil texture, and (iv) the extent of irreducible water content. Process model We will describe the insertion of Michaelis-Menten kinetics and Crank-Nicholson diffusion equations into the precisely scaled model, building on previous diffusion modelling (Laudone, G. M. et al, Chem.Eng.Sci., 2008). Comparison with experiment A comparison with experimental results sheds light on (i) the positional relationships of aerobic and anaerobic bacteria relative to the critical percolation path, (ii) the relationship between the critical percolation path and the preferential / critical flow path (Figure 4), (iii) the extent of ignorance about the reaction kinetics of some of the fundamental processes occurring, (iv) the soil conditions that cause nitrous oxide emission, and (v) the effect of soil compaction on the emission. Acknowledgement This presentation is a summary of the some of the work of the BBSRC funded U.K. soil research consortium "Soil Programme for Quality and Resilience" (BB/E001793/1 and others), of which Matthews is principal investigator.
Nursing job satisfaction, certification and healthcare-associated infections in critical care.
Boev, Christine; Xue, Ying; Ingersoll, Gail L
2015-10-01
The purpose of this study was to examine the relationship between nursing job satisfaction and healthcare-associated infections (HAIs) in adult critical care. Multilevel modelling was used to examine the relationship between nursing job satisfaction and two HAIs, ventilator-associated pneumonia (VAP) and central-line associated bloodstream infections (CLABSI). Units with nurses that reported satisfaction with organisational policies were associated with a 6.08 decrease in VAP (p=0.013) and units with nurses reporting favourable perception of task requirements were associated with a 7.02 decrease in VAP (.014). Positive perception of organisational policies was associated with lower rates of CLABSI (p=0.002). Unexpected findings include a positive relationship between perception of pay and autonomy and CLABSI as well as perception of interactions and VAP. Units with a higher proportion of Critical Care Registered Nurse (CCRN) certified nurses were associated with lower rates of both CLABSI (p<0.001) and VAP (p=0.037). This study provides preliminary evidence to support the relationship between nursing job satisfaction and HAIs in critical care, although some relationships were counterintuitive. A secondary finding included significant relationships between CCRN certified nurses and HAIs. Copyright © 2015 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Hernandez, K. F.; Shah-Fairbank, S.
2016-12-01
The San Dimas Experimental Forest has been designated as a research area by the United States Forest Service for use as a hydrologic testing facility since 1933 to investigate watershed hydrology of the 27 square mile land. Incorporation of a computer model provides validity to the testing of the physical model. This study focuses on San Dimas Experimental Forest's Bell Canyon, one of the triad of watersheds contained within the Big Dalton watershed of the San Dimas Experimental Forest. A scaled physical model was constructed of Bell Canyon to highlight watershed characteristics and each's effect on runoff. The physical model offers a comprehensive visualization of a natural watershed and can vary the characteristics of rainfall intensity, slope, and roughness through interchangeable parts and adjustments to the system. The scaled physical model is validated and calibrated through a HEC-HMS model to assure similitude of the system. Preliminary results of the physical model suggest that a 50-year storm event can be represented by a peak discharge of 2.2 X 10-3 cfs. When comparing the results to HEC-HMS, this equates to a flow relationship of approximately 1:160,000, which can be used to model other return periods. The completion of the Bell Canyon physical model can be used for educational instruction in the classroom, outreach in the community, and further research using the model as an accurate representation of the watershed present in the San Dimas Experimental Forest.
ERIC Educational Resources Information Center
Houlihan, Christina; McLeod, Shannon
This curriculum unit and 1-hour videotape are designed to help students understand the purpose and functions of the United Nations (UN) and explore the relationship between the United Nations and the United States. The UN's role in the global counterterrorism campaign serves as a case study for the unit. The students are asked to develop a basic…
The work-family interface in the United States and Singapore: conflict across cultures.
Galovan, Adam M; Fackrell, Tamara; Buswell, Lydia; Jones, Blake L; Hill, E Jeffrey; Carroll, Sarah June
2010-10-01
This article examines the work-family interface in a cross-cultural comparison between two nationally representative samples from the United States (n = 1,860) and Singapore (n = 1,035) with emphasis on work-family conflict. Family-to-work conflict was negatively related to marital satisfaction in both Singapore and the United States, although the effect was stronger in the United States. Similarly, family-to-work conflict was positively related to job satisfaction in the United States but was negatively related in Singapore. As expected, schedule flexibility was negatively related to depression in the United States, but in Singapore the relationship was positive. These findings suggest that theoretical relationships in the work-family interface developed in the more culturally individualistic West may need to be adapted when studying populations in the more collectivist East.
ERIC Educational Resources Information Center
Perrett, Jamis J.
2012-01-01
This article demonstrates how textbooks differ in their description of the term "experimental unit". Advanced Placement Statistics teachers and students are often limited in their statistical knowledge by the information presented in their classroom textbook. Definitions and descriptions differ among textbooks as well as among different…
ERIC Educational Resources Information Center
Mead, John D.; Dengerink, Harold A.
1977-01-01
The major intent of this research was to provide a further test of the relationships between physiological arousal and event probability by experimentally generating subjective expectancies for shock. The relationship of event probability to stress was discussed with respect to length of the anticipatory periods and methods used to establish…
David C. Lightfoot
1986-01-01
An inventory of Orthoptera (grasshoppers and crickets) at the H.J. Andrews Experimental Forest, near Blue River, Oregon, was conducted to determine the species present and ecological relationships. A key for identification and an annotated list are presented. From qualitative assessments of successional habitat relationships, generalized species associations of forest...
ERIC Educational Resources Information Center
Güroglu, Berna; Will, Geert-Jan; Klapwijk, Eduard T.
2013-01-01
The current study presents a novel experimental design to examine how "real-life" peer relationships modulate altruistic punishment of bullies and compensation of victims after "observed" ostracism. Twenty-four participants (age 20) were invited to an experimental session in groups of three classmates and two unfamiliar peers,…
Prompting children to reason proportionally: Processing discrete units as continuous amounts.
Boyer, Ty W; Levine, Susan C
2015-05-01
Recent studies reveal that children can solve proportional reasoning problems presented with continuous amounts that enable intuitive strategies by around 6 years of age but have difficulties with problems presented with discrete units that tend to elicit explicit count-and-match strategies until at least 10 years of age. The current study tests whether performance on discrete unit problems might be improved by prompting intuitive reasoning with continuous-format problems. Participants were kindergarten, second-grade, and fourth-grade students (N = 194) assigned to either an experimental condition, where they were given continuous amount proportion problems before discrete unit proportion problems, or a control condition, where they were given all discrete unit problems. Results of a three-way mixed-model analysis of variance examining school grade, experimental condition, and block of trials indicated that fourth-grade students in the experimental condition outperformed those in the control condition on discrete unit problems in the second half of the experiment, but kindergarten and second-grade students did not differ by condition. This suggests that older children can be prompted to use intuitive strategies to reason proportionally. (c) 2015 APA, all rights reserved).
ERIC Educational Resources Information Center
Waller, Martha W.; Iritani, Bonita J.; Christ, Sharon L.; Clark, Heddy Kovach; Moracco, Kathryn E.; Halpern, Carolyn Tucker; Flewelling, Robert L.
2012-01-01
Greater access to alcohol has been widely found to be associated with many negative outcomes including violence perpetration. This study examines the relationship between alcohol outlet density, alcohol use, and intimate partner violence (IPV) victimization among young women in the United States. A direct association between alcohol outlet density…
ERIC Educational Resources Information Center
Unsworth, Sara; Riggs, Eric M.; Chavez, Marc
2012-01-01
Native American nations in the United States have a unique legal status that is rooted in a complex relationship between the United States federal government, individual state and local governments and tribal authorities. Although geosciences are often at the center of these relationships, especially as they pertain to the development of natural…
Susan Will-Wolf; Mark J. Ambrose; Randall S. Morin
2011-01-01
We have investigated relationships between one simple indicator of lichen species diversity and environmental variables in forests across the coterminous United States. We want to know whether this indicator can help quantify the influence that factors such as climate and air quality have on lichen biodiversity at large scales and whether it will be useful in...
Uneasy Terrain: Image, Text, Landscape, and Contemporary Indigenous Artists in the United States
ERIC Educational Resources Information Center
Ohnesorge, Karen
2008-01-01
Like many contemporary Indigenous artists in the United States, Flathead artist Jaune Quick-to-See Smith seeks to clarify existing relationships among race, place, and economics as well as to create new relationships. In particular, she and her peers combine image and text to interrogate the genre of landscape painting as a stage for fantasies of…
ERIC Educational Resources Information Center
Inoue, Yasuhiro
A study examined the relationship between Japanese adolescents' media exposure, images of the United States, and their attitudes towards the United States and its people by surveying Japanese junior high school students. By using cultivation theory, the study hypothesized that an image of a dangerous America would be partly attributed to Japanese…
ERIC Educational Resources Information Center
Hergenrather, Kenneth C.; Zeglin, Robert J.; McGuire-Kuletz, Maureen; Rhodes, Scott D.
2015-01-01
Purpose: To explore employment as a social determinant of health through examining the relationship between employment status and mental health. Method: The authors conducted a systematic review of 48 longitudinal studies conducted in Australia, Canada, Croatia, Germany, Ireland, Israel, the Netherlands, Norway, United Kingdom, and United States…
Developing Career Education; K-2 Instructional Units.
ERIC Educational Resources Information Center
Nebraska State Dept. of Education, Lincoln. Div. of Vocational Education.
The guide presents instructional units aimed at developing career education for grades K-2. Each unit provides detailed objectives, activities, resources, and evaluations, and in some units the objectives are further detailed in relationship to the following subjects: mathematics, language arts, social studies, guidance, music, physical education,…
Tong, Mingming; Cole, Katie; Brito-Parada, Pablo R; Neethling, Stephen; Cilliers, Jan J
2017-04-18
Pseudo-two-dimensional (2D) foams are commonly used in foam studies as it is experimentally easier to measure the bubble size distribution and other geometric and topological properties of these foams than it is for a 3D foam. Despite the widespread use of 2D foams in both simulation and experimental studies, many important geometric and topological relationships are still not well understood. Film size, for example, is a key parameter in the stability of bubbles and the overall structure of foams. The relationship between the size distribution of the films in a foam and that of the bubbles themselves is thus a key relationship in the modeling and simulation of unstable foams. This work uses structural simulation from Surface Evolver to statistically analyze this relationship and to ultimately formulate a relationship for the film size in 2D foams that is shown to be valid across a wide range of different bubble polydispersities. These results and other topological features are then validated using digital image analysis of experimental pseudo-2D foams produced in a vertical Hele-Shaw cell, which contains a monolayer of bubbles between two plates. From both the experimental and computational results, it is shown that there is a distribution of sizes that a film can adopt and that this distribution is very strongly dependent on the sizes of the two bubbles to which the film is attached, especially the smaller one, but that it is virtually independent of the underlying polydispersity of the foam.
Bonolis, Luisa
2014-07-01
During the 1920s and 1930s, Italian physicists established strong relationships with scientists from other European countries and the United States. The career of Bruno Rossi, a leading personality in the study of cosmic rays and an Italian pioneer of this field of research, provides a prominent example of this kind of international cooperation. Physics underwent major changes during these turbulent years, and the traditional internationalism of physics assumed a more institutionalized character. Against this backdrop, Rossi's early work was crucial in transforming the study of cosmic rays into a branch of modern physics. His friendly relationships with eminent scientists--notably Enrico Fermi, Walther Bothe, Werner Heisenberg, Hans Bethe, and Homi Bhabha--were instrumental both for the exchange of knowledge about experimental practices and theoretical discussions, and for attracting the attention of physicists such as Arthur Compton, Louis Leprince-Ringuet, Pierre Auger and Patrick Blackett to the problem of cosmic rays. Relying on material from different archives in Europe and the United States, this case study aims to provide a glimpse of the intersection between national and international dimensions during the 1930s, at a time when the study of cosmic rays was still very much in its infancy, strongly interlaced with nuclear physics, and full of uncertain, contradictory, and puzzling results. Nevertheless, as a source of high-energy particles it became a proving ground for testing the validity of the laws of quantum electrodynamics, and made a fundamental contribution to the origins of particle physics.
Variation: Use It or Misuse It--Replication and Its Variants
ERIC Educational Resources Information Center
Drummond, Gordon B.; Vowler, Sarah L.
2012-01-01
In this article, the authors talk about variation and how variation between measurements may be reduced if sampling is not random. They also talk about replication and its variants. A replicate is a repeated measurement from the same experimental unit. An experimental unit is the smallest part of an experiment or a study that can be subject to a…
Me and My Environment, Unit V: Air and Water in My Environment, Experimental Edition 1973-74.
ERIC Educational Resources Information Center
Biological Sciences Curriculum Study, Boulder, CO.
The experimental 1973-74 edition of Unit V consists of 35 life science curriculum activities intended for 13- to 16-year-old educable mentally handicapped adolescents. The role of the teacher in continuing field trials is noted and environmental themes and elements, inquiry skills, problem solving skills, and applicational behaviors and attitudes…
Boise Basin Experimental Forest (Idaho)
Russell T. Graham; Theresa B. Jain
2004-01-01
The Boise Basin Experimental Forest was established in 1933 to study ponderosa pine. It consists of 3,537 ha with elevations ranging from 1,200 to 3,630 m. Boise Basin is divided into three units surrounding Idaho City in southern Idaho. Idaho City was a booming mining town in the 1870s and the surrounding forests supplied material to the community. Two units were...
ERIC Educational Resources Information Center
Jackson, Christa; Wilhelm, Jennifer Anne; Lamar, Mary; Cole, Merryn
2015-01-01
This study investigated sixth-grade middle-level students' geometric spatial development by gender and race within and between control and experimental groups at two middle schools as they participated in an Earth/Space unit. The control group utilized a regular Earth/Space curriculum and the experimental group used a National Aeronautics and…
ERIC Educational Resources Information Center
Biological Sciences Curriculum Study, Boulder, CO.
The experimental 1973-74 edition of Unit IV consists of 28 life science curriculum activities for 13- to 16-year-old educable mentally handicapped children. The role of the teacher in continuing field trials is noted and environmental themes and elements, inquiry skills, problem solving skills, and applicational behaviors and attitudes are…
Iron and obesity in females in the United States.
Neymotin, Florence; Sen, Urmimala
2011-01-01
Since the late 1980s, the United States has witnessed a dramatic increase in average BMI levels and the proportion of individuals categorized as obese. Obesity is a major risk factor for a variety of illnesses, and an increase in obesity is, therefore, implicated in increased health-care costs in the United States. These ultimately translate to a major health and economic problem for the United States. The present analysis examines a pathway to increased levels of obesity as of yet almost entirely unexplored. Specifically, we examine the relationship between obesity and iron deficiency via analyses of blood samples. The current analysis employs public-use data files from the continuous National Health and Nutrition Examination Survey (NHANES) (1999-2006) survey to determine the relationship between obesity and an individual's iron blood content. Results suggest a negative relationship between levels of iron blood content and individual BMI after controlling for other individual characteristics. These results hold for nearly all eight panels tested in the ordinary least squares (OLS) regressions.
Happell, Brenda
2006-05-01
Bridging the theory-practice gap has historically been acknowledged as a priority for the nursing profession. Enhancing nurses' attitudes regarding the relevance of theory to practice has been considered as crucial in order that the relationship between theory and practice becomes strong and complimentary. A review of the literature suggests that strategies such as joint clinical and academic positions have not had a significant impact in this respect. Nursing Clinical Development Units (NCDUs) were introduced in the United Kingdom as an initiative to promote the recognition and utilisation of research findings as an inherent component of nursing practice. However, there is limited literature addressing the impact of NCDUs on relationships between academia and the clinical field. The aim of this paper is to present the findings of a qualitative evaluation conducted with participants (n=14) of an NCDU program in Victoria, Australia. The findings suggest that this initiative can significantly enhance relationships with, and attitudes towards, academia.
NASA Astrophysics Data System (ADS)
Ayyoub, Abdellatif; Er-Raki, Salah; Khabba, Saïd; Merlin, Olivier; César Rodriguez, Julio; Ezzahar, Jamal; Bahlaoui, Ahmed; Chehbouni, Abdelghani
2016-04-01
The present work aims to develop a simple approach relating normalized daily sap flow (per unit of leaf area) and daily ET0 (mm/day) calculated by two methods: FAO-Penman-Monteith (FAO-PM) and Hargreaves-Samani (HARG). The data sets used for developing this approach are taken from three experimental sites (olive trees, cv. "Oleaeuropaea L.", olive trees, cv. "Arbequino" and citrus trees cv. "Clementine Afourar") conducted in the Tensift region around Marrakech, Morocco and one experimental site (pecan orchard, cv. "Caryaillinoinensis, Wangenh. K. Koch") conducted in the Yaqui Valley, northwest of Mexico). The results showed that the normalized daily sap flow (volume of transpired water per unit of leaf area) was linearly correlated with ET0 (mm per day) calculated by FAO-PM method. The coefficient of determination (R2) and the slope of this linear regression varied between 0.71 and 0.97 and between 0.30 and 0.35, respectively, depending on the type of orchards. For HARG method, the relationship between both terms is also linear but with less accuracy (R2 =0.7) as expected due to the underestimation of ET0 by this method. Afterward, the validation of the developed linear relationship was performed over an olive orchard ("Oleaeuropaea L.") where the measurements of sap flow were available for another (2004) cropping season. The scatter plot between the normalized measured and estimated sap flow based on FAO-PM method reveals a very good agreement (slope = 1, with R2 = 0.83 and RMSE=0.14 L/m2 leaf area). However, for the estimation of normalized sap flow based on HARG method, the correlation is more scattered with some underestimation (5%). A further validation wasperformed using the measurements of evapotranspiration (ET) by eddy correlation system and the results showed that the correlation between normalized measured ET and estimated normalized sap flow is best when using FAO-PM method (RMSE=0.33 L/m2 leaf area) for estimating ET0 than when using HARG method (RMSE= 0.51 L/m2 leaf area). Finally, the performance of the developed approach was compared to the traditional dual crop coefficient scheme for estimating plant transpiration. Cross-comparison of these two approaches with the measurements data gave satisfactory results with an average value of RMSE equal to about 0.37 mm/day for both approaches.
Drach-Zahavy, Anat; Trogan, Revital
2013-10-01
This study embraced a unit-level diversity perspective to examine interpersonal aggression, as experienced or witnessed by individual team members. Specifically, our aim was to explore the moderating role of a unit's diversity climate in the link between unit-level surface diversity in terms of ethnicity, sex, age, and tenure, and individual-level perceptions of interpersonal aggression. We tested our hypotheses with 30 nursing units using the Mixed-Linear Model procedure appropriate for nested samples. Results demonstrated that diversity climate moderated the relationships between tenure and ethnic unit diversity and interpersonal aggression, experienced or witnessed among individual team members. Moreover, regardless of the level of diversity climate, age diversity was positively linked to interpersonal aggression, whereas sex diversity was negatively linked to it. These findings imply that the unit's context affects interpersonal aggression and provides important theoretical and practical implications to proactively prevent interpersonal aggression.
Scaffolding software: How does it influence student conceptual understanding and motivation?
NASA Astrophysics Data System (ADS)
Butler, Kyle A.
The purpose of this study was to determine the influence of scaffolding software on student conceptual understanding and motivation. This study also provides insight on how students use the scaffolding features found in Artemis and the extent to which features show a relationship to student conceptual understanding and motivation. A Randomized Solomon Four Group Design was used in this study. As students worked through a project based unit over photosynthesis, the students performed information seeking activities that were based on their own inquiry. For this purpose, the students in the experimental group used an example of scaffolding software called Artemis, while the students in the control group used a search engine of their choice. To measure conceptual understanding, the researcher analyzed student generated concept maps on photosynthesis using three different methods (quantitative, qualitative, hierarchical). To measure motivation, the researcher used a survey that measured motivation on five different indicators: intrinsic goal orientation, extrinsic goal orientation, task value, control of learning beliefs, self-efficacy for learning and performance. Finally, the researcher looked at the relationship and influence of the scaffolding features on two student performance scores at the end of the unit. This created a total of ten dependent variables in relationship to the treatment. Overall, the students used the collaborative features 25% of the time, the maintenance features 0.84% of the time, the organizational features 16% of the time, the saving/viewing features 7% of the time and the searching features 51% of the time. There were significant correlations between the saving/viewing features hits and the students' task value (r = .499, p < .05), the searching features hits and the students' self-efficacy for learning and performance (r = .553, p < .01), the collaborative features hits and the students' essay performance scores (r = .519, p < .05) and the maintenance features time and the qualitative analysis of the concept maps (r = .576, p < .01). Finally, the results indicated that the scaffolding features in Artemis did not influence student conceptual understanding and motivation.
The relationship between offspring size and fitness: integrating theory and empiricism.
Rollinson, Njal; Hutchings, Jeffrey A
2013-02-01
How parents divide the energy available for reproduction between size and number of offspring has a profound effect on parental reproductive success. Theory indicates that the relationship between offspring size and offspring fitness is of fundamental importance to the evolution of parental reproductive strategies: this relationship predicts the optimal division of resources between size and number of offspring, it describes the fitness consequences for parents that deviate from optimality, and its shape can predict the most viable type of investment strategy in a given environment (e.g., conservative vs. diversified bet-hedging). Many previous attempts to estimate this relationship and the corresponding value of optimal offspring size have been frustrated by a lack of integration between theory and empiricism. In the present study, we draw from C. Smith and S. Fretwell's classic model to explain how a sound estimate of the offspring size--fitness relationship can be derived with empirical data. We evaluate what measures of fitness can be used to model the offspring size--fitness curve and optimal size, as well as which statistical models should and should not be used to estimate offspring size--fitness relationships. To construct the fitness curve, we recommend that offspring fitness be measured as survival up to the age at which the instantaneous rate of offspring mortality becomes random with respect to initial investment. Parental fitness is then expressed in ecologically meaningful, theoretically defensible, and broadly comparable units: the number of offspring surviving to independence. Although logistic and asymptotic regression have been widely used to estimate offspring size-fitness relationships, the former provides relatively unreliable estimates of optimal size when offspring survival and sample sizes are low, and the latter is unreliable under all conditions. We recommend that the Weibull-1 model be used to estimate this curve because it provides modest improvements in prediction accuracy under experimentally relevant conditions.
Nemec, Kristine T.; Allen, Craig R.; Helzer, Christopher J.; Wedin, David A.
2013-01-01
In recent years, agricultural producers and non-governmental organizations and agencies have restored thousands of hectares of cropland to grassland in the Great Plains of the United States. However, little is known about the relationships between richness and seeding density in these restorations and resistance to invasive plant species. We assessed the effects of richness and seeding density on resistance to invasive and other unseeded plant species in experimental tallgrass prairie plots in central Nebraska. In 2006, twenty-four 55 m × 55 m plots were planted with six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Conservation Reserve Program mix, CP25), at low and high seeding densities. There was a significant negative relationship between richness and basal cover of unseeded perennial forbs/legumes and unseeded perennial/annual grasses, abundance of bull thistle (Cirsium vulgare), and the number of inflorescences removed from smooth brome (Bromus inermis) transplants. Invasion resistance may have been higher in the high richness treatments because of the characteristics of the dominant species in these plots or because of greater interspecific competition for limiting resources among forbs/legumes with neighboring plants belonging to the same functional group. Seeding density was not important in affecting invasion resistance, except in the cover of unseeded grasses. Increasing seed mix richness may be more effective than increasing the seeding density for decreasing invasion by unseeded perennial species, bull thistle, and smooth brome.
Ugurluoglu, Ozgur; Ugurluoglu Aldogan, Ece; Dilmac, Elife
2013-01-01
Organizational learning is the process of increasing effective organizational activities through knowledge and understanding. Innovation is the creation of any product, service or process, which is new to a business unit. Significant amount of research on organizational learning place a central meaning on the fact that there is a positive relationship between organizational learning and innovation. Both organizational learning and innovation are essential for organizations to prepare for change. The aim of this study is to determine to what extent the identified learning organization dimensions are associated with innovation. The study used a quantitative non-experimental design employing statistical analysis via multiple regression and correlation methods to identify the relationships between the variables examined. Because the research was conducted in a non-experimental way, learning organization dimensions are referred to as predictor variables, and innovation is referred to as the criterion variable. Watkins and Marsick's Dimensions of the Learning Organization Questionnaire was used in the study. Questionnaires were distributed to 498 hospital managers and, 243 valid responses were used in this study. Therefore, 243 hospital managers working at 250 Ministry of Health (public) hospitals across Turkey participated in the study. Results demonstrate that there are significant and positive correlations between learning organization dimensions and innovation. Intercorrelations between learning organization dimensions and correlations between learning organization dimensions and innovation were average and high, respectively. Results further indicate that the dimensions of the learning organizations explained 66.5% of the variance for the innovation. Copyright © 2012 John Wiley & Sons, Ltd.
Kramer, Christian; Fuchs, Julian E; Liedl, Klaus R
2015-03-23
Nonadditivity in protein-ligand affinity data represents highly instructive structure-activity relationship (SAR) features that indicate structural changes and have the potential to guide rational drug design. At the same time, nonadditivity is a challenge for both basic SAR analysis as well as many ligand-based data analysis techniques such as Free-Wilson Analysis and Matched Molecular Pair analysis, since linear substituent contribution models inherently assume additivity and thus do not work in such cases. While structural causes for nonadditivity have been analyzed anecdotally, no systematic approaches to interpret and use nonadditivity prospectively have been developed yet. In this contribution, we lay the statistical framework for systematic analysis of nonadditivity in a SAR series. First, we develop a general metric to quantify nonadditivity. Then, we demonstrate the non-negligible impact of experimental uncertainty that creates apparent nonadditivity, and we introduce techniques to handle experimental uncertainty. Finally, we analyze public SAR data sets for strong nonadditivity and use recourse to the original publications and available X-ray structures to find structural explanations for the nonadditivity observed. We find that all cases of strong nonadditivity (ΔΔpKi and ΔΔpIC50 > 2.0 log units) with sufficient structural information to generate reasonable hypothesis involve changes in binding mode. With the appropriate statistical basis, nonadditivity analysis offers a variety of new attempts for various areas in computer-aided drug design, including the validation of scoring functions and free energy perturbation approaches, binding pocket classification, and novel features in SAR analysis tools.
Keenan, Kevin G; Valero-Cuevas, Francisco J
2007-09-01
Computational models of motor-unit populations are the objective implementations of the hypothesized mechanisms by which neural and muscle properties give rise to electromyograms (EMGs) and force. However, the variability/uncertainty of the parameters used in these models--and how they affect predictions--confounds assessing these hypothesized mechanisms. We perform a large-scale computational sensitivity analysis on the state-of-the-art computational model of surface EMG, force, and force variability by combining a comprehensive review of published experimental data with Monte Carlo simulations. To exhaustively explore model performance and robustness, we ran numerous iterative simulations each using a random set of values for nine commonly measured motor neuron and muscle parameters. Parameter values were sampled across their reported experimental ranges. Convergence after 439 simulations found that only 3 simulations met our two fitness criteria: approximating the well-established experimental relations for the scaling of EMG amplitude and force variability with mean force. An additional 424 simulations preferentially sampling the neighborhood of those 3 valid simulations converged to reveal 65 additional sets of parameter values for which the model predictions approximate the experimentally known relations. We find the model is not sensitive to muscle properties but very sensitive to several motor neuron properties--especially peak discharge rates and recruitment ranges. Therefore to advance our understanding of EMG and muscle force, it is critical to evaluate the hypothesized neural mechanisms as implemented in today's state-of-the-art models of motor unit function. We discuss experimental and analytical avenues to do so as well as new features that may be added in future implementations of motor-unit models to improve their experimental validity.
Small angle x-ray scattering of chromatin. Radius and mass per unit length depend on linker length.
Williams, S P; Langmore, J P
1991-01-01
Analyses of low angle x-ray scattering from chromatin, isolated by identical procedures but from different species, indicate that fiber diameter and number of nucleosomes per unit length increase with the amount of nucleosome linker DNA. Experiments were conducted at physiological ionic strength to obtain parameters reflecting the structure most likely present in living cells. Guinier analyses were performed on scattering from solutions of soluble chromatin from Necturus maculosus erythrocytes (linker length 48 bp), chicken erythrocytes (linker length 64 bp), and Thyone briareus sperm (linker length 87 bp). The results were extrapolated to infinite dilution to eliminate interparticle contributions to the scattering. Cross-sectional radii of gyration were found to be 10.9 +/- 0.5, 12.1 +/- 0.4, and 15.9 +/- 0.5 nm for Necturus, chicken, and Thyone chromatin, respectively, which are consistent with fiber diameters of 30.8, 34.2, and 45.0 nm. Mass per unit lengths were found to be 6.9 +/- 0.5, 8.3 +/- 0.6, and 11.8 +/- 1.4 nucleosomes per 10 nm for Necturus, chicken, and Thyone chromatin, respectively. The geometrical consequences of the experimental mass per unit lengths and radii of gyration are consistent with a conserved interaction among nucleosomes. Cross-linking agents were found to have little effect on fiber external geometry, but significant effect on internal structure. The absolute values of fiber diameter and mass per unit length, and their dependencies upon linker length agree with the predictions of the double-helical crossed-linker model. A compilation of all published x-ray scattering data from the last decade indicates that the relationship between chromatin structure and linker length is consistent with data obtained by other investigators. Images FIGURE 1 PMID:2049522
Practical Nursing, Volume I. Health Occupations Education.
ERIC Educational Resources Information Center
Rogers, Helen W.; And Others
This curriculum guide provides teachers with up-to-date information and skill-related applications needed by the practical nurse. The volume contains three sections and 24 instructional units: Personal Vocational Relationships (6 units), Nutrition (3 units), and Basic Nursing Principles and Applied Skills (15 units covering such topics as…
Coordinating Units at the Candy Depot
ERIC Educational Resources Information Center
Norton, Anderson; Boyce, Steven; Hatch, Jennifer
2015-01-01
In general, units coordination refers to the relationships that students can maintain between various units when working within a numerical situation. It is critical that middle school students learn to coordinate three levels of units not only because of their importance in understanding fractions but also because of their implications for…
Ecology of Missouri Forests. Instructional Unit. Conservation Education Series.
ERIC Educational Resources Information Center
Jackson, Jim
This unit is designed to help science, social studies, vocational agriculture, and other teachers incorporate forest ecology concepts into their subject matter. The unit includes: (1) topic outline; (2) unit objectives; (3) background information on climate and soils, levels of a deciduous forest, age classes, food and energy relationships, forest…
Developing Career Education; Grades 3-6 Instructional Units.
ERIC Educational Resources Information Center
Nebraska State Dept. of Education, Lincoln. Div. of Vocational Education.
The guide presents instructional units aimed at developing career education for grades 3-6. Each unit provides detailed objectives, activities, resources, and evaluations, and in some units the objectives are further detailed in relationship to the following subjects: mathematics, language arts, social studies, guidance, music, physical education,…
Coupled analysis on landscape pattern and hydrological processes in Yanhe watershed of China.
Li, J; Zhou, Z X
2015-02-01
As a typical experimental Soil and Water Conservation District, Yanhe watershed has long been plagued by soil erosion due to severe human disturbances. Exerting remote sensing (RS) and geographic information system (GIS) technology, this paper firstly analyzed and simulated ecological hydrological process in Yanhe watershed based on SWAT model, constructed a comprehensive landscape indices which was closely related to soil erosion, and reflected the coupling relationship between regional landscape pattern change and soil erosion. The results are as follows: (1) Areas of different land use types remained relatively stable from 1990 to 2000 and then changed drastically from 2000 to 2010, which was characterized by lawn expansion and cultivated land shrinkage. (2) In terms of the spatial heterogeneity of hydrological response unit (HRUs), the correlation coefficient of seven selected landscape indices and runoff was very small, and cannot pass all significant testing. But correlation between the indices and sediment yield except for Total Core Area (TCA) and Interspersion and Juxtaposition Index (IJI) was remarkable. (3) According to 'the source-sink' theory of soil erosion, new landscape index-slope-HRU landscape index (SHLI) was built, and reflected the relationship between landscape pattern and soil erosion processes to a certain extent. (4) Coupling relationship between SHLI in 2010 and annual sediment was very prominent. In the sub-basin scale, SHLI has obvious regional differentiation from annual sediment. Copyright © 2014 Elsevier B.V. All rights reserved.
Modelling Of Anticipated Damage Ratio On Breakwaters Using Fuzzy Logic
NASA Astrophysics Data System (ADS)
Mercan, D. E.; Yagci, O.; Kabdasli, S.
2003-04-01
In breakwater design the determination of armour unit weight is especially important in terms of the structure's life. In a typical experimental breakwater stability study, different wave series composed of different wave heights; wave period and wave steepness characteristics are applied in order to investigate performance the structure. Using a classical approach, a regression equation is generated for damage ratio as a function of characteristic wave height. The parameters wave period and wave steepness are not considered. In this study, differing from the classical approach using a fuzzy logic, a relationship between damage ratio as a function of mean wave period (T_m), wave steepness (H_s/L_m) and significant wave height (H_s) was further generated. The system's inputs were mean wave period (T_m), wave steepness (H_s/L_m) and significant wave height (H_s). For fuzzification all input variables were divided into three fuzzy subsets, their membership functions were defined using method developed by Mandani (Mandani, 1974) and the rules were written. While for defuzzification the centroid method was used. In order to calibrate and test the generated models an experimental study was conducted. The experiments were performed in a wave flume (24 m long, 1.0 m wide and 1.0 m high) using 20 different irregular wave series (P-M spectrum). Throughout the study, the water depth was 0.6 m and the breakwater cross-sectional slope was 1V/2H. In the armour layer, a type of artificial armour unit known as antifer cubes were used. The results of the established fuzzy logic model and regression equation model was compared with experimental data and it was determined that the established fuzzy logic model gave a more accurate prediction of the damage ratio on this type of breakwater. References Mandani, E.H., "Application of Fuzzy Algorithms for Control of Simple Dynamic Plant", Proc. IEE, vol. 121, no. 12, December 1974.
Johnson, P.T.J.; Lunde, K.B.; Thurman, E.M.; Ritchie, E.G.; Wray, S.N.; Sutherland, D.R.; Kapfer, J.M.; Frest, T.J.; Bowerman, J.; Blaustein, A.R.
2002-01-01
Parasites and pathogens can influence the survivorship, behavior, and very structure of their host species. For example, experimental studies have shown that trematode parasites can cause high frequencies of severe limb malformations in amphibians. In a broad-scale field survey covering parts of California, Oregon, Washington, Idaho, and Montana, we examined relationships between the frequency and types of morphological abnormalities in amphibians and the abundance of trematode parasite infection, pH, concentrations of 61 pesticides, and levels of orthophosphate and total nitrate. We recorded severe malformations at frequencies ranging from 1% to 90% in nine amphibian species from 53 aquatic systems. Infection of larvae by the trematode Ribeiroia ondatrae was associated with, and functionally related to, higher frequencies of amphibian limb malformations than found in uninfected populations (≤5%). Parasites were concentrated around the basal tissue of hind limbs in infected anurans, and malformations associated with infection included skin webbings, supernumerary limbs and digits, and missing or malformed hind limbs. In the absence of Ribeiroia, amphibian populations exhibited low (0-5%) frequencies of abnormalities involving missing digits or distal portions of a hind limb. Species were affected differentially by the parasite, and Ambystoma macrodactylum, Hyla regilla, Rand aurora, R. luteiventris, and Taricha torosa typically exhibited the highest frequencies of abnormalities. None of the water-quality variables measured was associated with malformed amphibians, but aquatic snail hosts (Planorbella spp.) were significant predictors of the presence and abundance of Ribeiroia infection. Morphological comparisons of adult specimens of Ribeiroia collected from different sites and raised in experimental definitive hosts suggested that all samples represented the same species - R. ondatrae. These field results, coupled with experimental research on the effects of Ribeiroia on amphibians, demonstrate that Ribeiroia infection is an important and widespread cause of amphibian limb malformations in the western United States. The relevance of trematode infection to declines of amphibian populations and the influence of habitat modification on the pathology and life cycle of Ribeiroia are emphasized as areas requiring further research.
ERIC Educational Resources Information Center
Leslie, Hewlett Steve
2017-01-01
The purpose of the study was to examine the relationship of gender equity to faculty compensation, career advancement, and access to leadership roles in colleges of business in Finland, Jamaica and the United States. This quantitative study, anchored by feminist, human capital and socialization theories supported the emergence of a conceptual…
ERIC Educational Resources Information Center
Bell, Darnell Brushawn
2011-01-01
The purpose of the study was to understand the relationships among facility conditions, school climate, and school safety of high school tenth graders in the United States. Previous research on the quality of educational facilities influence on student achievement has varied. Recent research has suggested that the quality of educational facilities…
Kramer, Michael S; Fombonne, Eric; Igumnov, Sergei; Vanilovich, Irina; Matush, Lidia; Mironova, Elena; Bogdanovich, Natalia; Tremblay, Richard E; Chalmers, Beverley; Zhang, Xun; Platt, Robert W
2008-03-01
The objective of this study was to assess the long-term effects of breastfeeding on child behavior and maternal adjustment. We followed up children who were in the Promotion of Breastfeeding Intervention Trial, a cluster-randomized trial of a breastfeeding promotion intervention based on the World Health Organization/United Nations Children's Fund Baby-Friendly Hospital Initiative. A total of 17,046 healthy, breastfeeding mother-infant pairs were enrolled from 31 Belarussian maternity hospitals and affiliated polyclinics; 13,889 (81.5%) were followed up at 6.5 years. Mothers and teachers completed the Strengths and Difficulties Questionnaire and supplemental questions bearing on internalizing and externalizing behavioral problems. Mothers also responded to questions concerning their relationships to their partner and child and their breastfeeding of subsequently born children. The experimental intervention led to a large increase in exclusive breastfeeding at 3 months (43.3% vs 6.4%) and a significantly higher prevalence of any breastfeeding at all ages up to and including 12 months. No significant treatment effects were observed on either the mother or the teacher Strengths and Difficulties Questionnaire ratings of total difficulties, emotional symptoms, conduct problems, hyperactivity, peer problems, or prosocial behavior or on the supplemental behavioral questions. We found no evidence of treatment effects on the parent's marriage or on the mother's satisfaction with her relationships with her partner or child, but the experimental intervention significantly increased the duration of any breastfeeding, and mothers in the experimental group were nearly twice as likely to breastfeed exclusively the next-born child for at least 3 months. On the basis of the largest randomized trial ever conducted in the area of human lactation, we found no evidence of risks or benefits of prolonged and exclusive breastfeeding for child and maternal behavior. Breastfeeding promotion does, however, favorably affect breastfeeding of the subsequent child.
Evaluation of selected chemical processes for production of low-cost silicon, phase 3
NASA Technical Reports Server (NTRS)
Blocher, J. M., Jr.; Browning, M. F.; Seifert, D. A.
1981-01-01
A Process Development Unit (PDU), which consisted of the four major units of the process, was designed, installed, and experimentally operated. The PDU was sized to 50MT/Yr. The deposition took place in a fluidized bed reactor. As a consequences of the experiments, improvements in the design an operation of these units were undertaken and their experimental limitations were partially established. A parallel program of experimental work demonstrated that Zinc can be vaporized for introduction into the fluidized bed reactor, by direct induction-coupled r.f. energy. Residual zinc in the product can be removed by heat treatment below the melting point of silicon. Current efficiencies of 94 percent and above, and power efficiencies around 40 percent are achievable in the laboratory-scale electrolysis of ZnCl2.
Palter, S F
1996-05-01
The modern clinical trial is a form of human experimentation. There is a long history of disregard for individual rights of the patient in this context, and special attention must be paid to ethical guidelines for these studies. Clinical trials differ in basic ways from clinical practice. Foremost is the introduction of outside interests, beyond those of the patient's health, into the doctor-patient therapeutic alliance. Steps must be taken to protect the interests of the patient when such outside influence exists. Kantian moral theory and the Hippocratic oath dictate that the physician must respect the individual patient's rights and hold such interests paramount. These principles are the basis for informed consent. Randomization of patients is justified when a condition of equipoise exists. The changing nature of health care delivery in the United States introduces new outside interests into the doctor-patient relationship.
Experimental Study on Scale-Up of Solid-Liquid Stirred Tank with an Intermig Impeller
NASA Astrophysics Data System (ADS)
Zhao, Hongliang; Zhao, Xing; Zhang, Lifeng; Yin, Pan
2017-02-01
The scale-up of a solid-liquid stirred tank with an Intermig impeller was characterized via experiments. Solid concentration, impeller just-off-bottom speed and power consumption were measured in stirred tanks of different scales. The scale-up criteria for achieving the same effect of solid suspension in small-scale and large-scale vessels were evaluated. The solids distribution improves if the operating conditions are held constant as the tank is scaled-up. The results of impeller just-off-bottom speed gave X = 0.868 in the scale-up relationship ND X = constant. Based on this criterion, the stirring power per unit volume obviously decreased at N = N js, and the power number ( N P) was approximately equal to 0.3 when the solids are uniformly distributed in the vessels.
Diesel-fired self-pumping water heater
NASA Astrophysics Data System (ADS)
Gertsmann, Joseph
1994-07-01
The object of this project was to study the feasibility of pumping and heating water by sustained oscillatory vaporization and condensation in a fired heat exchanger. Portable field liquid fueled water heaters would facilitate heating water for sanitation, personal hygiene, food service, laundry, equipment maintenance, and decontamination presently available only from larger, less portable, motorized pumping units. The technical tasks consisted of: development of an analytical model, operation of proof-of-principal prototypes, and determination of the thermal and mechanical relationships to evaluate operating range and control characteristics. Four successive pump models were analyzed and tested. The final analytical model gave reasonable agreement with the experimental results, indicating that the actual pumping effect was an order of magnitude lower than originally anticipated. It was concluded that a thermally-activated self pumping water heater based on the proposed principle is not feasible.
Spatial relationship between climatic diversity and biodiversity conservation value.
Wang, Junjun; Wu, Ruidong; He, Daming; Yang, Feiling; Hu, Peijun; Lin, Shiwei; Wu, Wei; Diao, Yixin; Guo, Yang
2018-06-04
Capturing the full range of climatic diversity in a reserve network is expected to improve the resilience of biodiversity to climate change. Therefore, a study on systematic conservation planning for climatic diversity that explicitly or implicitly hypothesizes that regions with higher climatic diversity will support greater biodiversity is needed. However, little is known about the extent and generality of this hypothesis. This study utilized the case of Yunnan, southwest China, to quantitatively classify climatic units and modeled 4 climatic diversity indicators, including the variety of climatic units (VCU), rarity of climatic units (RCU), endemism of climatic units (ECU) and a composite index of climatic units (CICD). We used 5 reliable priority conservation area (PCA) schemes to represent the areas with high biodiversity conservation value. We then investigated the spatial relationships between the 4 climatic diversity indicators and the 5 PCA schemes and assessed the representation of climatic diversity within the existing nature reserves. The CICD exhibited the best performance for indicating high conservation value areas, followed by the ECU and RCU. However, contrary to conventional knowledge, VCU did not show a positive association with biodiversity conservation value. The rarer or more endemic climatic units tended to have higher reserve coverage than the more common units. However, only 28 units covering 10.5% of the land in Yunnan had more than 17% of their areas protected. In addition to climatic factors, topography and human disturbances also significantly affected the relationship between climatic diversity and biodiversity conservation value. This analysis suggests that climatic diversity can be an effective surrogate for establishing a more robust reserve network under climate change in Yunnan. Our study improves the understanding of the relationship between climatic diversity and biodiversity and helps build an evidence-based foundation for systematic conservation planning that targets climatic diversity in response to climate change. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Grizzle, Jerry W; Zablah, Alex R; Brown, Tom J; Mowen, John C; Lee, James M
2009-09-01
This empirical study evaluated the moderating effects of unit customer orientation (CO) climate and climate strength on the relationship between service workers' level of CO and their performance of customer-oriented behaviors (COBs). In addition, the study examined whether aggregate COB performance influences unit profitability. Building on multisource, multilevel data, the study's results suggest that the influence of employee CO on employee COB performance is positive when the unit's CO climate is relatively high and that the constructs are unrelated when unit CO climate is relatively low. In addition, the data reveal that unit COB performance influences unit profitability by enhancing revenues without a concomitant increase in costs. The study's results underscore the theoretical importance of considering cross-level influencers of employee-level relationships and suggest that managers should focus on creating a climate that is supportive of COBs if their units are to profit from the recruitment, hiring, and retention of customer-oriented employees.
A multi-functional high voltage experiment apparatus for vacuum surface flashover switch research.
Zeng, Bo; Su, Jian-cang; Cheng, Jie; Wu, Xiao-long; Li, Rui; Zhao, Liang; Fang, Jin-peng; Wang, Li-min
2015-04-01
A multifunctional high voltage apparatus for experimental researches on surface flashover switch and high voltage insulation in vacuum has been developed. The apparatus is composed of five parts: pulse generating unit, axial field unit, radial field unit, and two switch units. Microsecond damped ringing pulse with peak-to-peak voltage 800 kV or unipolar pulse with maximum voltage 830 kV is generated, forming transient axial or radial electrical field. Different pulse waveforms and field distributions make up six experimental configurations in all. Based on this apparatus, preliminary experiments on vacuum surface flashover switch with different flashover dielectric materials have been conducted in the axial field unit, and nanosecond pulse is generated in the radial field unit which makes a pulse transmission line in the experiment. Basic work parameters of this kind of switch such as lifetime, breakdown voltage are obtained.
ERIC Educational Resources Information Center
Hagan, Margaret Stanley
1992-01-01
Discusses the research methodology of the longitudinal study that makes up this monograph issue. Discusses (1) subjects; (2) experimental procedure; (3) assessment measures of demographic factors, children's adjustment, adult depression, marital relationship, parent-child relationship, sibling relationship, and family interactions; and (5)…
The Sources of the Relationship between Sustained Attention and Reasoning
ERIC Educational Resources Information Center
Ren, Xuezhu; Schweizer, Karl; Xu, Fen
2013-01-01
Although a substantial relationship of sustained attention and reasoning was consistently found, little is known about what drives this relationship. The present study aims at revealing the underlying sources that are responsible for the relationship by means of an integrative approach combining experimental manipulation and psychometric modeling.…
Kritchevsky, S. B.; Braun, B. I.; Wong, E. S.; Solomon, S. L.; Steele, L.; Richards, C.; Simmons, B. P.
2001-01-01
The Evaluation of Processes and Indicators in Infection Control (EPIC) study assesses the relationship between hospital care and rates of central venous catheter-associated primary bacteremia in 54 intensive-care units (ICUs) in the United States and 14 other countries. Using ICU rather than the patient as the primary unit of statistical analysis permits evaluation of factors that vary at the ICU level. The design of EPIC can serve as a template for studies investigating the relationship between process and event rates across health-care institutions. PMID:11294704
Weaver, John Michael
2015-01-01
This research explored federal intervention with the particular emphasis on examining how a collaborative relationship between Department of Defense (DOD) and Homeland Security (DHS) led to greater effectiveness between these two federal departments and their subordinates (United States Northern Command and Federal Emergency Management Agency, respectively) during the preparation and response phases of the disaster cycle regarding US continental-based hurricanes. Through the application of a two-phased, sequential mixed methods approach, this study determined how their relationship has led to longitudinal improvements in the years following Hurricane Katrina, focusing on hurricanes as the primary unit of analysis.
Serological Relationships Among Feline Caliciviruses
Povey, R. C.
1974-01-01
A total of 46 strains of feline calicivirus isolates from the United Kingdom, United States, Australia, and New Zealand were used in an investigation of their serological relationships based on the serum neutralization test. Although demonstrable antigenic variation exists between these isolates, it is shown that significant in vitro cross-activity exists between all these isolates to greater or lesser extent. All isolates tested may be regarded as serological variants of a single serotype of feline calicivirus. It is postulated that this relationship would provide for considerable cross-protection during successive exposures of cats to various feline caliciviruses. PMID:4435957
Relationship of health workers with their organization and work: a cross-cultural study.
Yepes-Baldó, Montserrat; Romeo, Marina; Berger, Rita
2016-01-01
We analyzed the differences, by Student's t-test and ANOVA, between nurses and physicians from Portugal, Poland, Spain, and United Kingdom regarding their relationship with their work and organization. In total, 1,401 professionals answered the HSA-QHPR questionnaire. There are different levels of connection between physicians and nurses. The United Kingdom has the lowest levels of connection with the work while Portugal has the highest levels of relationship with the organization. The results provide guidelines for the development of policies and differential strategies aimed at improving the quality of healthcare service.
Relationship of health workers with their organization and work: a cross-cultural study
Yepes-Baldó, Montserrat; Romeo, Marina; Berger, Rita
2016-01-01
ABSTRACT We analyzed the differences, by Student’s t-test and ANOVA, between nurses and physicians from Portugal, Poland, Spain, and United Kingdom regarding their relationship with their work and organization. In total, 1,401 professionals answered the HSA-QHPR questionnaire. There are different levels of connection between physicians and nurses. The United Kingdom has the lowest levels of connection with the work while Portugal has the highest levels of relationship with the organization. The results provide guidelines for the development of policies and differential strategies aimed at improving the quality of healthcare service. PMID:27191154
Applicability of Different Hydraulic Parameters to Describe Soil Detachment in Eroding Rills
Wirtz, Stefan; Seeger, Manuel; Zell, Andreas; Wagner, Christian; Wagner, Jean-Frank; Ries, Johannes B.
2013-01-01
This study presents the comparison of experimental results with assumptions used in numerical models. The aim of the field experiments is to test the linear relationship between different hydraulic parameters and soil detachment. For example correlations between shear stress, unit length shear force, stream power, unit stream power and effective stream power and the detachment rate does not reveal a single parameter which consistently displays the best correlation. More importantly, the best fit does not only vary from one experiment to another, but even between distinct measurement points. Different processes in rill erosion are responsible for the changing correlations. However, not all these procedures are considered in soil erosion models. Hence, hydraulic parameters alone are not sufficient to predict detachment rates. They predict the fluvial incising in the rill's bottom, but the main sediment sources are not considered sufficiently in its equations. The results of this study show that there is still a lack of understanding of the physical processes underlying soil erosion. Exerted forces, soil stability and its expression, the abstraction of the detachment and transport processes in shallow flowing water remain still subject of unclear description and dependence. PMID:23717669
NASA Astrophysics Data System (ADS)
Jang, Jeong-yoon; Hand, Brian
2017-12-01
This study investigated the value of using a scaffolded critique framework to promote two different types of writing—argumentative writing and explanatory writing—with different purposes within an argument-based inquiry approach known as the Science Writing Heuristic (SWH) approach. A quasi-experimental design with sixth and seventh grade students taught by two teachers was used. A total of 170 students participated in the study, with 87 in the control group (four classes) and 83 in the treatment group (four classes). All students used the SWH templates as an argumentative writing to guide their written work and completed these templates during the SWH investigations of each unit. After completing the SWH investigations, both groups of students were asked to complete the summary writing task as an explanatory writing at the end of each unit. All students' writing samples were scored using analytical frameworks developed for the study. The results indicated that the treatment group performed significantly better on the explanatory writing task than the control group. In addition, the results of the partial correlation suggested that there is a very strong significantly positive relationship between the argumentative writing and the explanatory writing.
Epidemiological, evolutionary and co-evolutionary implications of context-dependent parasitism
Vale, Pedro F.; Wilson, Alastair J.; Best, Alex; Boots, Mike; Little, Tom J.
2013-01-01
Victims of infection are expected to suffer increasingly as parasite population growth increases. Yet, under some conditions, faster growing parasites do not appear to cause more damage and infections can be quite tolerable. We studied these conditions by assessing how the relationship between parasite population growth and host health is sensitive to environmental variation. In experimental infections of the crustacean Daphnia magna and its bacterial parasite Pasteuria ramosa we show how easily an interaction can shift from a severe interaction, i.e. when host fitness declines substantially with each unit of parasite growth, to a tolerable relationship by changing only simple environmental variables: temperature and food availability. We explored the evolutionary and epidemiological implications of such a shift by modelling pathogen evolution and disease spread under different levels of infection severity, and find that environmental shifts that promote tolerance ultimately result in populations harbouring more parasitized individuals. We also find that the opportunity for selection, as indicated by the variance around traits, varied considerably with the environmental treatment. Thus our results suggest two mechanisms that could underlie co-evolutionary hot- and coldspots: spatial variation in tolerance and spatial variation in the opportunity for selection. PMID:21460572
Epidemiological, evolutionary, and coevolutionary implications of context-dependent parasitism.
Vale, Pedro F; Wilson, Alastair J; Best, Alex; Boots, Mike; Little, Tom J
2011-04-01
Abstract Victims of infection are expected to suffer increasingly as parasite population growth increases. Yet, under some conditions, faster-growing parasites do not appear to cause more damage, and infections can be quite tolerable. We studied these conditions by assessing how the relationship between parasite population growth and host health is sensitive to environmental variation. In experimental infections of the crustacean Daphnia magna and its bacterial parasite Pasteuria ramosa, we show how easily an interaction can shift from a severe interaction, that is, when host fitness declines substantially with each unit of parasite growth, to a tolerable relationship by changing only simple environmental variables: temperature and food availability. We explored the evolutionary and epidemiological implications of such a shift by modeling pathogen evolution and disease spread under different levels of infection severity and found that environmental shifts that promote tolerance ultimately result in populations harboring more parasitized individuals. We also find that the opportunity for selection, as indicated by the variance around traits, varied considerably with the environmental treatment. Thus, our results suggest two mechanisms that could underlie coevolutionary hotspots and coldspots: spatial variation in tolerance and spatial variation in the opportunity for selection.
Wang, T H-H; Du, P; Angeli, T R; Paskaranandavadivel, N; Erickson, J C; Abell, T L; Cheng, L K; O'Grady, G
2018-01-01
Gastric slow wave dysrhythmias are accompanied by deviations in frequency, velocity, and extracellular amplitude, but the inherent association between these parameters in normal activity still requires clarification. This study quantified these associations using a joint experimental-theoretical approach. Gastric pacing was conducted in pigs with simultaneous high-resolution slow wave mapping (32-256 electrodes; 4-7.6 mm spacing). Relationships between period, velocity, and amplitude were quantified and correlated for each wavefront. Human data from two existing mapping control cohorts were analyzed to extract and correlate these same parameters. A validated biophysically based ICC model was also applied in silico to quantify velocity-period relationships during entrainment simulations and velocity-amplitude relationships from membrane potential equations. Porcine pacing studies identified positive correlations for velocity-period (0.13 mm s -1 per 1 s, r 2 =.63, P<.001) and amplitude-velocity (74 μV per 1 mm s -1 , r 2 =.21, P=.002). In humans, positive correlations were also quantified for velocity-period (corpus: 0.11 mm s -1 per 1 s, r 2 =.16, P<.001; antrum: 0.23 mm s -1 per 1 s, r 2 =.55; P<.001), and amplitude-velocity (94 μV per 1 mm s -1 , r 2 =.56; P<.001). Entrainment simulations matched the experimental velocity-period relationships and demonstrated dependence on the slow wave recovery phase. Simulated membrane potential relationships were close to these experimental results (100 μV per 1 mm s -1 ). These data quantify the relationships between slow wave frequency, velocity, and extracellular amplitude. The results from both human and porcine studies were in keeping with biophysical models, demonstrating concordance with ICC biophysics. These relationships are important in the regulation of gastric motility and will help to guide interpretations of dysrhythmias. © 2017 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Mori, H.; Trevisan, L.; Sakaki, T.; Cihan, A.; Smits, K. M.; Illangasekare, T. H.
2013-12-01
Multiphase flow models can be used to improve our understanding of the complex behavior of supercritical CO2 (scCO2) in deep saline aquifers to make predictions for the stable storage strategies. These models rely on constitutive relationships such as capillary pressure (Pc) - saturation (Sw) and relative permeability (kr) - saturation (Sw) as input parameters. However, for practical application of these models, such relationships for scCO2 and brine system are not readily available for geological formations. This is due to the complicated and expensive traditional methods often used to obtain these relationships in the laboratory through high pressure and/or high-temperature controls. A method that has the potential to overcome the difficulty in conducting such experiments is to replicate scCO2 and brine with surrogate fluids that capture the density and viscosity effects to obtain the constitutive relationships under ambient conditions. This study presents an investigation conducted to evaluate this method. An assessment of the method allows us to evaluate the prediction accuracy of multiphase models using the constitutive relationships developed from this approach. With this as a goal, the study reports multiple laboratory column experiments conducted to measure these relationships. The obtained relationships were then used in the multiphase flow simulator TOUGH2 T2VOC to explore capillary trapping mechanisms of scCO2. A comparison of the model simulation to experimental observation was used to assess the accuracy of the measured constitutive relationships. Experimental data confirmed, as expected, that the scaling method cannot be used to obtain the residual and irreducible saturations. The results also showed that the van Genuchten - Mualem model was not able to match the independently measured kr data obtained from column experiments. Simulated results of fluid saturations were compared with saturation measurements obtained using x-ray attenuations. This comparison demonstrated that the experimentally derived constitutive relationships matched the experimental data more accurately than the simulation using constitutive relationships derived from scaling methods and van Genuchten - Mualem model. However, simulated imbibition fronts did not match well, suggesting the need for further study. In general, the study demonstrated the feasibility of using surrogate fluids to obtain both Pc - Sw and kr - Sw relationships to be used in multiphase models of scCO2 migration and entrapment.
Restoring the Unwritten Alliance in Brazil -- United States Relations
2012-03-23
improve U.S. relations with Brazil will cause its leaders to seek more advantageous relationships elsewhere--to the detriment of the United States...substantially improve U.S. relations with Brazil will cause its leaders to seek more advantageous relationships elsewhere--to the detriment of the...security improvements throughout the country. Additionally, a new oil field has been discovered off the coast of Rio de Janeiro. This discovery has drawn
ERIC Educational Resources Information Center
Harnisch, Delwyn L.; Ryan, Katherine E.
A study was made of cross-cultural patterns of achievement motivation in relationship to the mathematics achievement of Japanese and American boys and girls approximately 16 years of age. Sample sizes were 9,582 for the United States subjects (specifically, from Illinois) and 1,700 for the participants from Japan. Data came from performance on the…
United States-Canada Trade and Economic Relationship: Prospects and Challenges
2008-01-29
gap has proven worrisome to Canadian policymakers as it raises questions about Canadian productivity and competitiveness (see box). In terms of...While Canada suffers from productivity problems in other sectors of its economy, its automotive plants are among the most competitive in North America...Canadian tourists spent 56% of their tourist dollars in the United States that year.15 Investment The U.S.-Canada economic relationship is characterized by
ERIC Educational Resources Information Center
1997
The second of three interactive staff development units on discipline in early childhood classrooms, this multi-media pack explores the importance of the relationship between the teacher and child to discipline. The 25-minute teaching videotape notes the need to build a relationship with a child by interacting at times other than when the child is…
Encoding of speed and direction of movement in the human supplementary motor area
Tankus, Ariel; Yeshurun, Yehezkel; Flash, Tamar; Fried, Itzhak
2010-01-01
Object The supplementary motor area (SMA) plays an important role in planning, initiation, and execution of motor acts. Patients with SMA lesions are impaired in various kinematic parameters, such as velocity and duration of movement. However, the relationships between neuronal activity and these parameters in the human brain have not been fully characterized. This is a study of single-neuron activity during a continuous volitional motor task, with the goal of clarifying these relationships for SMA neurons and other frontal lobe regions in humans. Methods The participants were 7 patients undergoing evaluation for epilepsy surgery requiring implantation of intracranial depth electrodes. Single-unit recordings were conducted while the patients played a computer game involving movement of a cursor in a simple maze. Results In the SMA proper, most of the recorded units exhibited a monotonic relationship between the unit firing rate and hand motion speed. The vast majority of SMA proper units with this property showed an inverse relation, that is, firing rate decrease with speed increase. In addition, most of the SMA proper units were selective to the direction of hand motion. These relationships were far less frequent in the pre-SMA, anterior cingulate gyrus, and orbitofrontal cortex. Conclusions The findings suggest that the SMA proper takes part in the control of kinematic parameters of end-effector motion, and thus lend support to the idea of connecting neuroprosthetic devices to the human SMA. PMID:19231930
Zang, Yinyin; Gallagher, Thea; McLean, Carmen P; Tannahill, Hallie S; Yarvis, Jeffrey S; Foa, Edna B
2017-03-01
The personal resources of social support, unit cohesion, and trait resilience have been found to be associated with posttraumatic stress disorder (PTSD) severity among military personnel. However, the underlying mechanisms of these relationships are unclear. We hypothesized that negative posttraumatic cognitions, which are associated with PTSD, mediate the relationships between these personal resources and PTSD. The relationship between PTSD symptom severity and a latent factor comprised of social support, unit cohesion, and trait resilience was evaluated using cross-sectional data from 366 treatment-seeking active duty military personnel with PTSD following deployments to or near Iraq or Afghanistan. Structural equation modeling (SEM) was used to test whether posttraumatic cognitions mediated this relationship. The SEM model indicated that (1) a robust latent variable named personal resources (indicated by social support, unit cohesion, and trait resilience) was negatively associated with PTSD severity; (2) personal resources were negatively associated with negative posttraumatic cognitions; (3) negative posttraumatic cognitions fully mediated the association between personal resources and PTSD severity. The final SEM mediation model showed a highly satisfactory fit [χ 2 (22) = 16.344, p = 0.798; χ 2 /df = 0.743; CFI = 1; RMSEA = 0.000]. These findings suggest that among active duty military personnel seeking treatment for PTSD, personal resources (social support, unit cohesion, and trait resilience) may mitigate PTSD severity by reducing negative posttraumatic cognitions. Copyright © 2016 Elsevier Ltd. All rights reserved.
Patient relationship management: an overview and study of a follow-up system.
Oinas-Kukkonen, Harri; Räisänen, Teppo; Hummastenniemi, Niko
2008-01-01
Customer relationship management research is utilized to explain the need for a more patient-oriented support in patient care. This article presents a European study on how various hospital units of a single healthcare organization have utilized a patient relationship management system--in particular a patient treatment follow-up system--and how it affects patient care and the knowledge work performed by the medical staff. Eight physicians were interviewed at a university hospital on whether patient treatment was improved through a follow-up system that had been in use in the case organization for three years. The interviewees represented various hospital units, and all of them had used the system at their own unit. The results indicate that it is possible to improve patient care through more personalized treatment. The follow-up treatment system seems to be a tool to create and maintain better communication with the patients rather than just a technological solution. It may help better understand and analyze both individual patients and patient groups. For individual physicians it provides a way to reflect professional skills. The system was lacking in its support for one-to-one communication with patients. Nevertheless, the system is an example of patient relationship management which may help healthcare units to move towards a more patient-oriented care.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-29
..., modeling, and scientific knowledge about the relationships between pollutants and visibility impairment..., proposed amendment for reasonable progress are: City of Gainesville Deerhaven unit 5; Florida Power & Light (FP&L) Manatee units 1, 2; FP&L Turkey Point units 1, 2; Gulf Power Company Crist unit 7; Lakeland...
Rosenthal, Lisa; Starks, Tyrel J
2015-12-01
Interracial and same-sex romantic relationships are more common and socially accepted in the United States than ever before; yet, stigmatization of these relationships persists, with consequences for relationship dynamics. We conducted an online survey study with adults living in the United States in interracial and same-sex relationships to examine associations of relationship stigma from family, friends, and public with several relationship outcomes (i.e., investment, satisfaction, intimate partner aggression victimization and perpetration, commitment, intimacy, trust, passion, love, sexual communication, and sexual satisfaction), as well as the potential buffering roles of egalitarianism and dyadic coping. Regression analyses with 480 participants support that above and beyond individually experienced discrimination and other well-known predictors of relationship outcomes, relationship stigma from friends in particular was associated with lower relationship commitment, trust, love, and sexual communication, as well as greater odds of intimate partner aggression victimization. Egalitarianism and dyadic coping moderated some of the associations of relationship stigma from family, friends, and public with relationship outcomes, supporting their potential roles as buffers. These findings suggest many avenues for future research and implications for clinicians working with interracial and same-sex couples, individuals in those couples, and their families. Given increasing prevalence of interracial and same-sex relationships and marriages, more work should continue to explore these couples' experiences and how best to support them. (c) 2015 APA, all rights reserved).
Optimizing Experimental Designs: Finding Hidden Treasure.
USDA-ARS?s Scientific Manuscript database
Classical experimental design theory, the predominant treatment in most textbooks, promotes the use of blocking designs for control of spatial variability in field studies and other situations in which there is significant variation among heterogeneity among experimental units. Many blocking design...
Profiles of equilibrium constants for self-association of aromatic molecules
NASA Astrophysics Data System (ADS)
Beshnova, Daria A.; Lantushenko, Anastasia O.; Davies, David B.; Evstigneev, Maxim P.
2009-04-01
Analysis of the noncovalent, noncooperative self-association of identical aromatic molecules assumes that the equilibrium self-association constants are either independent of the number of molecules (the EK-model) or change progressively with increasing aggregation (the AK-model). The dependence of the self-association constant on the number of molecules in the aggregate (i.e., the profile of the equilibrium constant) was empirically derived in the AK-model but, in order to provide some physical understanding of the profile, it is proposed that the sources for attenuation of the equilibrium constant are the loss of translational and rotational degrees of freedom, the ordering of molecules in the aggregates and the electrostatic contribution (for charged units). Expressions are derived for the profiles of the equilibrium constants for both neutral and charged molecules. Although the EK-model has been widely used in the analysis of experimental data, it is shown in this work that the derived equilibrium constant, KEK, depends on the concentration range used and hence, on the experimental method employed. The relationship has also been demonstrated between the equilibrium constant KEK and the real dimerization constant, KD, which shows that the value of KEK is always lower than KD.
Davidson, Ian J
2018-05-01
This article is a cocitation network analysis of The Journal of Abnormal and Social Psychology ( JASP ) from 1925 to 1942. The analysis was conducted to help shed light on the historical roots of the intellectual and institutional relationships among social, personality, and abnormal psychology. JASP was a main venue for the boundary work of early- to mid-twentieth-century American psychologists. One of the main goals of these various research communities was to appropriate psychoanalytic and sociological concepts into preferred methods and approaches that favored an individualistic, quantifiable, and ultimately normal subject. Five major research communities are identified using the citations, and historically contextualized: Community #1, Measuring Social Aspects; Community #2, Psychometrics; Community #3, Operationalizing Psychoanalysis; Community #4, Introversion Studies; and Community #5, Experimental Social Psychology. This analysis demonstrates how disciplinary psychologists, at least within JASP , were united by the work of delimiting their research from closely aligned fields studying the same concepts-even while psychologists' methodological commitments to experimentalism or psychological testing might have ostensibly divided them. Possible future research incorporating post-World War II research and dynamic networking approaches is recommended. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Experimental sleep restriction causes endothelial dysfunction in healthy humans.
Calvin, Andrew D; Covassin, Naima; Kremers, Walter K; Adachi, Taro; Macedo, Paula; Albuquerque, Felipe N; Bukartyk, Jan; Davison, Diane E; Levine, James A; Singh, Prachi; Wang, Shihan; Somers, Virend K
2014-11-25
Epidemiologic evidence suggests a link between short sleep duration and cardiovascular risk, although the nature of any relationship and mechanisms remain unclear. Short sleep duration has also been linked to an increase in cardiovascular events. Endothelial dysfunction has itself been implicated as a mediator of heightened cardiovascular risk. We sought to determine the effect of 8 days/8 nights of partial sleep restriction on endothelial function in healthy humans. Sixteen healthy volunteers underwent a randomized study of usual sleep versus sleep restriction of two-thirds normal sleep time for 8 days/8 nights in a hospital-based clinical research unit. The main outcome was endothelial function measured by flow-mediated brachial artery vasodilatation (FMD). Those randomized to sleep restriction slept 5.1 hours/night during the experimental period compared with 6.9 hours/night in the control group. Sleep restriction was associated with significant impairment in FMD (8.6±4.6% during the initial pre-randomization acclimation phase versus 5.2±3.4% during the randomized experimental phase, P=0.01) whereas no change was seen in the control group (5.0±3.0 during the acclimation phase versus 6.73±2.9% during the experimental phase, P=0.10) for a between-groups difference of -4.40% (95% CI -7.00 to -1.81%, P=0.003). No change was seen in non-flow mediated vasodilatation (NFMD) in either group. In healthy individuals, moderate sleep restriction causes endothelial dysfunction. ClinicalTrials.gov. Unique identifier: NCT01334788. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
Evaluation of Selected Chemical Processes for Production of Low-cost Silicon, Phase 3
NASA Technical Reports Server (NTRS)
Blocher, J. M., Jr.; Browning, M. F.
1979-01-01
The construction of the 50 MT Si/year experimental process system development unit was deferred until FY 1980, and the fluidized bed, zinc vaporizer, by-product condenser, and electrolytic cell were combined with auxiliary units, capable of supporting 8-hour batchwise operation, to form the process development unit (PDU), which is scheduled to be in operation by October 1, 1979. The design of the PDU and objectives of its operation are discussed. Experimental program support activities described relate to: (1) a wetted-wall condensor; (2) fluidized-bed modeling; (3) zinc chloride electrolysis; and (4) zinc vaporizer.
Dose-response relationships for carcinogens: a review.
Zeise, L; Wilson, R; Crouch, E A
1987-01-01
We review the experimental evidence for various shapes of dose-response relationships for carcinogens and summarize those experiments that give the most information on relatively low doses. A brief review of some models is given to illustrate the shapes of dose-response curve expected from them. Our major interest is in the use of dose-response relationships to estimate risks to humans at low doses, and so we pay special attention to experimentally observed and theoretically expected nonlinearities. There are few experimental examples of nonlinear dose-response relations in humans, but this may simply be due to the limitations in the data. The several examples in rodents, even though for high dose data, suggest that nonlinearity is common. In some cases such nonlinearities may be rationalized on the basis of the pharmacokinetics of the test compound or its metabolites. PMID:3311725
A tribal abstraction network for SNOMED CT target hierarchies without attribute relationships.
Ochs, Christopher; Geller, James; Perl, Yehoshua; Chen, Yan; Agrawal, Ankur; Case, James T; Hripcsak, George
2015-05-01
Large and complex terminologies, such as Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT), are prone to errors and inconsistencies. Abstraction networks are compact summarizations of the content and structure of a terminology. Abstraction networks have been shown to support terminology quality assurance. In this paper, we introduce an abstraction network derivation methodology which can be applied to SNOMED CT target hierarchies whose classes are defined using only hierarchical relationships (ie, without attribute relationships) and similar description-logic-based terminologies. We introduce the tribal abstraction network (TAN), based on the notion of a tribe-a subhierarchy rooted at a child of a hierarchy root, assuming only the existence of concepts with multiple parents. The TAN summarizes a hierarchy that does not have attribute relationships using sets of concepts, called tribal units that belong to exactly the same multiple tribes. Tribal units are further divided into refined tribal units which contain closely related concepts. A quality assurance methodology that utilizes TAN summarizations is introduced. A TAN is derived for the Observable entity hierarchy of SNOMED CT, summarizing its content. A TAN-based quality assurance review of the concepts of the hierarchy is performed, and erroneous concepts are shown to appear more frequently in large refined tribal units than in small refined tribal units. Furthermore, more erroneous concepts appear in large refined tribal units of more tribes than of fewer tribes. In this paper we introduce the TAN for summarizing SNOMED CT target hierarchies. A TAN was derived for the Observable entity hierarchy of SNOMED CT. A quality assurance methodology utilizing the TAN was introduced and demonstrated. © The Author 2014. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
ERIC Educational Resources Information Center
Schoon, Kenneth J., Ed.; Wiles, Clyde A., Ed.
This booklet contains mathematics unit plans for Biology, Chemistry, and Physical Science developed by PACE (Promoting Academic Excellence In Mathematics, Science & Technology for Workers of the 21st Century). Each unit plan contains suggested timing, objectives, skills to be acquired, workplace relationships, learning activities with suggested…
39 CFR 221.6 - Field organization.
Code of Federal Regulations, 2014 CFR
2014-07-01
...). (d) Customer Service District Offices. Functional units and reporting relationships are as follows: (1) Functional units. The 80 district offices coordinate the day-to-day management of post offices... units. Areas are responsible for: (i) Customer service districts (CSDs). (ii) Post offices (POs). (iii...
39 CFR 221.6 - Field organization.
Code of Federal Regulations, 2012 CFR
2012-07-01
...). (d) Customer Service District Offices. Functional units and reporting relationships are as follows: (1) Functional units. The 80 district offices coordinate the day-to-day management of post offices... units. Areas are responsible for: (i) Customer service districts (CSDs). (ii) Post offices (POs). (iii...
39 CFR 221.6 - Field organization.
Code of Federal Regulations, 2013 CFR
2013-07-01
...). (d) Customer Service District Offices. Functional units and reporting relationships are as follows: (1) Functional units. The 80 district offices coordinate the day-to-day management of post offices... units. Areas are responsible for: (i) Customer service districts (CSDs). (ii) Post offices (POs). (iii...
Satz, Alexander L
2016-07-11
Simulated screening of DNA encoded libraries indicates that the presence of truncated byproducts complicates the relationship between library member enrichment and equilibrium association constant (these truncates result from incomplete chemical reactions during library synthesis). Further, simulations indicate that some patterns observed in reported experimental data may result from the presence of truncated byproducts in the library mixture and not structure-activity relationships. Potential experimental methods of minimizing the presence of truncates are assessed via simulation; the relationship between enrichment and equilibrium association constant for libraries of differing purities is investigated. Data aggregation techniques are demonstrated that allow for more accurate analysis of screening results, in particular when the screened library contains significant quantities of truncates.
Experimental Methods to Characterize Nonlinear Vibration of Flapping Wing Micro Air Vehicles
2007-03-01
EXPERIMENTAL METHODS TO CHARACTERIZE NONLINEAR VIBRATION OF FLAPPING WING MICRO AIR VEHICLES THESIS Adam P. Tobias, Captain, USAF...AFIT/GAE/ENY/07-M23 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio...author and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the United States Government
Experimental Investigation of Irregular Wave Cancellation Using a Cycloidal Wave Energy Converter
2012-07-01
83388 EXPERIMENTAL INVESTIGATION OF IRREGULAR WAVE CANCELLATION USING A CYCLOIDAL WAVE ENERGY CONVERTER Stefan G. Siegel∗ Department of Aeronautics...United States Air Force Academy Air Force Academy, Colorado, 80840 USA Email: stefan @siegels.us Casey Fagley Department of Aeronautics United States Air...would like to acknowledge fruitful discussion with Dr. Jürgen Seidel and Dr. Tiger Jeans. This material is based upon activities supported by the
NASA Technical Reports Server (NTRS)
1981-01-01
Technical readiness for the production of photovoltaic modules using single crystal silicon dendritic web sheet material is demonstrated by: (1) selection, design and implementation of solar cell and photovoltaic module process sequence in a Module Experimental Process System Development Unit; (2) demonstration runs; (3) passing of acceptance and qualification tests; and (4) achievement of a cost effective module.
DIUx Commercial Solutions Opening: How to Guide
2016-11-30
Secretary Carter charged the Defense Innovation Unit Experimental (DIUx) to “develop new partnerships with the private sector in communities in Silicon...founded the Defense Innovation Unit Experimental (DIUx) to accelerate innovation to the warfighter. In the past, government funding spurred significant...philosophy on OTs. These are guiding principles through which DIUx designed the CSO that can easily be adopted by others as an additional tool in the
NASA Astrophysics Data System (ADS)
Heron, Lory Elen
This study investigated the premise that the use of constructivist teaching strategies (independent variable) in high school science classrooms can cultivate positive attitudes toward science (dependent variable) in high school students. Data regarding the relationship between the use of constructivist strategies and change in student attitude toward science were collected using the Science Attitude Assessment Tool (SAAT) (Heron & Beauchamp, 1996). The format of this study used the pre-test, post-test, control group-experimental group design. The subjects in the study were high school students enrolled in biology, chemistry, or environmental science courses in two high schools in the western United States. Ten teachers and twenty-eight classes, involving a total of 249 students participated in the study. Six experimental group teachers and four control group teachers were each observed an average of six times using the Science Observation Guide (Chapman, 1995) to measure the frequency of observed constructivist behaviors. The mean for the control group teachers was 12.89 and the mean for experimental group teachers was 20.67; F(1, 8) = 16.2, p =.004, revealing teaching behaviors differed significantly between the two groups. After a four month experimental period, the pre-test and post-test SAAT scores were analyzed. Students received a score for their difference in positive attitude toward science. The null hypothesis stating there would be no change in attitude toward science as a subject, between students exposed to constructivist strategies, and students not exposed to constructivist strategies was rejected F(1, 247) = 8.04, p =.005. The control group had a generally higher reported grade in their last science class than the experimental group, yet the control group attitude toward science became more negative (-1.18) while attitude toward science in the experimental group became more positive (+1.34) after the four-month period. An analysis of positive attitude toward science vs. gender was undertaken. An initial significant difference in positive attitude toward science between females and males in the experimental group was established (p =.05). There was no significant difference in positive attitude toward science between those same females and males after the experimental period. Consistent with other results, attitudes toward science for both males and females in the control group became less positive after the study, while males and females in the experimental group had a more positive attitude toward science after four months of using constructivist strategies. Looking at females only, the control group started out with a significantly more positive attitude toward science (mean = 43.40) compared to the experimental group (mean = 39.26, p =.0261). Although a significant difference in positive attitude between females in both groups was not found after the treatment period, the mean attitude score for females in the experimental group increased 2.044, while the mean attitude score for females in the control group decreased by 1.750. Constructivist strategies and their relationship with fostering positive attitudes toward science, might prove a viable solution for addressing the major concern of gender equity and enrollment in higher level science and mathematics courses.
Patterns of shading tolerance determined from experimental light reduction studies of seagrasses
An extensive review of the experimental literature on seagrass shading evaluated the relationship between experimental light reductions, duration of experiment and seagrass response metrics to determine whether there were consistent statistical patterns. There were highly signif...
The role of trait mindfulness in the pain experience of adolescents.
Petter, Mark; Chambers, Christine T; McGrath, Patrick J; Dick, Bruce D
2013-12-01
Trait mindfulness appears to mitigate pain among adult clinical populations and has a unique relationship with pain catastrophizing. However, little is understood about this phenomenon among adolescents. The association between trait mindfulness and pain in both real-world and experimental contexts was examined in a community sample of adolescents. Participants were 198 adolescents who completed measures of trait mindfulness, pain catastrophizing, and pain interference, as well as an interview on day-to-day pain before undergoing an acute experimental pain task. Following the task, they provided ratings of pain intensity and state catastrophizing. Results showed that with regard to day-to-day pains, mindfulness was a significant and unique predictor of pain interference, and this relationship was partially mediated by pain catastrophizing. Mindfulness also had an indirect relationship with experimental pain intensity and tolerance. These associations were mediated by catastrophizing during the pain task. These findings highlight the association between trait mindfulness and both real-world and experimental pain and offer insight into how mindfulness may affect pain among youth. Findings are discussed in the context of current psychological models of pediatric pain and future avenues for research. This article highlights the association between trait mindfulness and pain variables among adolescents in both real-world and experimental pain settings. These findings offer further evidence of the unique relationship between trait mindfulness and pain catastrophizing in affecting pain variables across pain contexts and populations. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.
Enabling Housing Cooperatives: policy lessons from Sweden, India and the United States.
Ganapati, Sukumar
2010-01-01
Housing cooperatives became active in urban areas in Sweden, India and the United States during the interwar period. Yet, after the second world war, while housing cooperatives grew phenomenally nationwide in Sweden and India, they did not do so in the United States. This article makes a comparative institutional analysis of the evolution of housing cooperatives in these three countries. The analysis reveals that housing cooperatives' relationship with the state and the consequent support structures explain the divergent evolution. Although the relationships between cooperatives and the state evolved over time, they can be characterized as embedded autonomy, overembeddedness and disembeddedness in Sweden, India and the United States respectively. Whereas the consequent support structures for housing cooperatives became well developed in Sweden and India, such structures have been weak in the United States. The article highlights the need for embedded autonomy and the need for supportive structures to enable the growth of housing cooperatives.
Pereira, Isabel; Veloso, Ana; Silva, Isabel Soares; Costa, Patricio
2017-05-18
This study explored the relationship between organizational commitment and job satisfaction among workers in family health units. Six family health units in the North of Portugal participated, including 105 health professionals (physicians, nurses, and clinical secretaries). The study used the Portuguese adaptations of the Organizational Commitment Scale by Meyer & Allen (1997) and the Job Satisfaction Survey (Spector, 1985). The results suggest a positive association between organizational commitment and job satisfaction. The professionals are moderately satisfied and committed to the family health units; the most satisfactory aspects are the nature of the work, relationship to coworkers, and communication, while pay is the most unsatisfactory. The affective component of the commitment appears, highlighting the professionals' involvement in (and identification with) the family health units project. The linear regression model proved significant, and organizational commitment explains 22.7% of the variance in job satisfaction. For this sample, organizational commitment predicts job satisfaction.
Intimate partner violence, depression, and barriers to service utilization in Arab American women.
Kulwicki, Anahid; Ballout, Suha; Kilgore, Colleen; Hammad, Adnan; Dervartanian, Hermine
2015-01-01
How intimate partner violence (IPV), depression, and barriers to services affect Arab American women in the United States is not very well documented. This cross-sectional exploratory descriptive study examines (a) the relationship between depression and IPV and (b) whether living in the United States 10 or more years decreases barriers to reporting intimate partner violence and depression in a sample (N = 312) of Arab American women 19 years and older. Findings demonstrate significant relationships between women who were at risk for IPV and depression scores (r = .44, p < .001), and number of years living in the United States and barriers to service (r = .25, p < .001). There was a significant negative relationship between barriers to service and depression (r = -.30, p < .001), and barriers to service and IPV (r = -.23, p < .001), and number of years living in the United States and depression (r = .25, p < .001). Findings underscore the importance of screening referral and follow-up for Arab American women experiencing IPV and depression. © The Author(s) 2014.
Improved rapid magnitude estimation for a community-based, low-cost MEMS accelerometer network
Chung, Angela I.; Cochran, Elizabeth S.; Kaiser, Anna E.; Christensen, Carl M.; Yildirim, Battalgazi; Lawrence, Jesse F.
2015-01-01
Immediately following the Mw 7.2 Darfield, New Zealand, earthquake, over 180 Quake‐Catcher Network (QCN) low‐cost micro‐electro‐mechanical systems accelerometers were deployed in the Canterbury region. Using data recorded by this dense network from 2010 to 2013, we significantly improved the QCN rapid magnitude estimation relationship. The previous scaling relationship (Lawrence et al., 2014) did not accurately estimate the magnitudes of nearby (<35 km) events. The new scaling relationship estimates earthquake magnitudes within 1 magnitude unit of the GNS Science GeoNet earthquake catalog magnitudes for 99% of the events tested, within 0.5 magnitude units for 90% of the events, and within 0.25 magnitude units for 57% of the events. These magnitudes are reliably estimated within 3 s of the initial trigger recorded on at least seven stations. In this report, we present the methods used to calculate a new scaling relationship and demonstrate the accuracy of the revised magnitude estimates using a program that is able to retrospectively estimate event magnitudes using archived data.
Utilization of Navy Selected Reserve Personnel in Defense Contract Management Command Reserve Units
1993-06-17
and gaining commands reporting sound working relationships tended to agree not only on current utilization, but future utilization as wel]. This...QiISLI 5 ousin9. Ay te iisues Upositive or- ngegativej. concgrriing. Naval Reserve part icipatioContract~ S Managmnt ? This question wag designed as a...working relationship with their gaining command tended to fit into the satisfied category. However, those units which indicated a somewhat strained
ERIC Educational Resources Information Center
Dryden-Peterson, Sarah
2018-01-01
This article explores the types of family-school relationships that promote academic, socio-economic, and social and emotional well-being of black African immigrant children in the United States. The data are ethnographic, drawing on one year of participant observation and interviews at two elementary schools. The findings are also set within the…
The Role of the Unit in Physics and Psychometrics
ERIC Educational Resources Information Center
Humphry, Stephen M.
2011-01-01
The purpose of this article is to examine the role of the unit in physics in order to clarify the role of the unit in psychometrics. Based on this examination, metrological conventions are used to formulate the relationship between discrimination and the unit of a scale in item response theory. Seminal literature in two lines of item response…
The Metric System of Measurement (SI). Federal Register Notice of December 10, 1976.
ERIC Educational Resources Information Center
National Bureau of Standards (DOC), Washington, DC.
This document provides a diagram illustrating the relationships between base units in the metric system and derived units with special names. Twenty-one derived units are included. The base units used are: measures of mass, length, time, amount of substance, electric current, thermo-dynamic temperature, luminous intensity, and plane and solid…
ERIC Educational Resources Information Center
Bear, George G.; Yang, Chunyan; Glutting, Joseph; Huang, Xishan; He, Xianyou; Zhang, Wei; Chen, Dandan
2014-01-01
Several previous studies have found that Chinese students perceive teacher-student relationships and student-student relationships more favorably than American students. In this study we examined if the same holds true with respect to teachers' perceptions. Also examined were both students' and teachers' perceptions of conduct problems. The sample…
ERIC Educational Resources Information Center
Glover, Joan
2012-01-01
This participatory action research study explored principal/teacher relationships in an ameliorable career/technical school located in the mid-west United States. This study examined how teachers in this school perceive their relationship with the principal and how a principal perceives her relationship with the teachers. This empirical inquiry…
THE MISUSE OF HYDROLOGIC UNIT MAPS FOR EXTRAPOLATION, REPORTING, AND ECOSYSTEM MANAGEMENT
The use of watersheds to conduct research on land-water relationships has expanded recently to include both extrapolation and reporting of water resource information and ecosystem management. More often than not, hydrologic units, and hydrologic unit codes (HUCs) in particular, a...
46 CFR 108.503 - Relationship to international standards.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Relationship to international standards. 108.503 Section 108.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Lifesaving Equipment § 108.503 Relationship to international standards. For...
Kang, Seung-Wan; Lee, Soojin; Choi, Suk Bong
2017-05-01
This study tested a multilevel model examining the effect of nursing leader's behavioral integrity and intragroup relationship conflict on staff nurses' intent to remain. In the challenging situation of nursing shortage, nurse executives are required to focus on the retention of nurses. No previous studies have examined the impact of nursing leader's behavioral integrity and intragroup relationship conflict on nurses' intention to remain. A cross-sectional survey of 480 RNs in 34 nursing units of a large public hospital in South Korea was conducted to test the hypothesized multilevel model. Nursing leader's behavioral integrity was positively related to nurses' intention to remain (b = 0.34, P < .001). This relationship was enhanced when the level of intragroup relationship conflict was high (b = 0.21, P < .05). Nursing leaders assigned to units with a high level of intragroup relationship conflict should endeavor to maintain their behavioral integrity to promote nurses' intention to remain.
Human motor unit recordings: origins and insight into the integrated motor system.
Duchateau, Jacques; Enoka, Roger M
2011-08-29
Soon after Edward Liddell [1895-1981] and Charles Sherrington [1857-1952] introduced the concept of a motor unit in 1925 and the necessary technology was developed, the recording of single motor unit activity became feasible in humans. It was quickly discovered by Edgar Adrian [1889-1977] and Detlev Bronk [1897-1975] that the force exerted by muscle during voluntary contractions was the result of the concurrent recruitment of motor units and modulation of the rate at which they discharged action potentials. Subsequent studies found that the relation between discharge frequency and motor unit force was characterized by a sigmoidal function. Based on observations on experimental animals, Elwood Henneman [1915-1996] proposed a "size principle" in 1957 and most studies in humans focussed on validating this concept during various types of muscle contractions. By the end of the 20th C, the experimental evidence indicated that the recruitment order of human motor units was determined primarily by motoneuron size and that the occasional changes in recruitment order were not an intended strategy of the central nervous system. Fundamental knowledge on the function of Sherrington's "common final pathway" was expanded with observations on motor unit rotation, minimal and maximal discharge rates, discharge variability, and self-sustained firing. Despite the great amount of work on characterizing motor unit activity during the first century of inquiry, however, many basic questions remain unanswered and these limit the extent to which findings on humans and experimental animals can be integrated and generalized to all movements. 2011 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Stock, M.
2013-02-01
Since 1889 the international prototype of the kilogram has served as the definition of the unit of mass in the International System of Units (SI). It is the last material artefact to define a base unit of the SI, and it influences several other base units. This situation is no longer acceptable in a time of ever increasing measurement precision. It is therefore planned to redefine the unit of mass by fixing the numerical value of the Planck constant. At the same time three other base units, the ampere, the kelvin and the mole, will be redefined. As a first step, the kilogram redefinition requires a highly accurate determination of the Planck constant in the present SI system, with a relative uncertainty of the order of 1 part in 108. The most promising experiment for this purpose, and for the future realization of the kilogram, is the watt balance. It compares mechanical and electrical power and makes use of two macroscopic quantum effects, thus creating a relationship between a macroscopic mass and the Planck constant. In this paper the background for the choice of the Planck constant for the kilogram redefinition is discussed and the role of the Planck constant in physics is briefly reviewed. The operating principle of watt balance experiments is explained and the existing experiments are reviewed. An overview is given of all presently available experimental determinations of the Planck constant, and it is shown that further investigation is needed before the redefinition of the kilogram can take place. This article is based on a lecture given at the International School of Physics ‘Enrico Fermi’, Course CLXXXV: Metrology and Physical Constants, held in Varenna on 17-27 July 2012. It will also be published in the proceedings of the school, edited by E Bava, M Kühne and A M Rossi (IOS Press, Amsterdam and SIF, Bologna).
Nazemi, S Majid; Amini, Morteza; Kontulainen, Saija A; Milner, Jaques S; Holdsworth, David W; Masri, Bassam A; Wilson, David R; Johnston, James D
2015-08-01
Quantitative computed tomography based subject-specific finite element modeling has potential to clarify the role of subchondral bone alterations in knee osteoarthritis initiation, progression, and pain initiation. Calculation of bone elastic moduli from image data is a basic step when constructing finite element models. However, different relationships between elastic moduli and imaged density (known as density-modulus relationships) have been reported in the literature. The objective of this study was to apply seven different trabecular-specific and two cortical-specific density-modulus relationships from the literature to finite element models of proximal tibia subchondral bone, and identify the relationship(s) that best predicted experimentally measured local subchondral structural stiffness with highest explained variance and least error. Thirteen proximal tibial compartments were imaged via quantitative computed tomography. Imaged bone mineral density was converted to elastic moduli using published density-modulus relationships and mapped to corresponding finite element models. Proximal tibial structural stiffness values were compared to experimentally measured stiffness values from in-situ macro-indentation testing directly on the subchondral bone surface (47 indentation points). Regression lines between experimentally measured and finite element calculated stiffness had R(2) values ranging from 0.56 to 0.77. Normalized root mean squared error varied from 16.6% to 337.6%. Of the 21 evaluated density-modulus relationships in this study, Goulet combined with Snyder and Schneider or Rho appeared most appropriate for finite element modeling of local subchondral bone structural stiffness. Though, further studies are needed to optimize density-modulus relationships and improve finite element estimates of local subchondral bone structural stiffness. Copyright © 2015 Elsevier Ltd. All rights reserved.
Yoon, Hee Sang; Kim, Gyung Hee; Kim, Jiyoung
2011-12-01
The purpose of this study was to examine the effectiveness of an interpersonal relationship program on interpersonal relationships, self-esteem, and depression in nursing students. This was a quasi-experiment with a nonequivalent control group pre-posttest design. Sixty-four nursing students participated in the study with 31 in the experimental group and 33 in the control group. They were from 3 different colleges of nursing located in Seoul. The interpersonal relationship program was held 10 times over 10 weeks, taking 90 minutes per session. The interpersonal relationship change scale developed by Schlein and Guemey, Rosenberg's self-esteem scale, and CED-S for depression were the instruments used in the study. The data collection period was from January 4 to March 8, 2011, and the collected data were analyzed with SPSS 14.0 using the Χ(2)-test, t-test, and paired t-test. The results showed a significant difference between the experimental group and the control group in terms of the degree of interpersonal relationships, self-esteem, and depression. The results indicate that interpersonal relationship programs have positive effects for improving interpersonal relationships and self-esteem, and decreasing depression in nursing students.
Effken, Judith A.; Carley, Kathleen M.; Gephart, Sheila; Verran, Joyce A.; Bianchi, Denise; Reminga, Jeff; Brewer, Barbara
2011-01-01
Purpose We used Organization Risk Analyzer (ORA), a dynamic network analysis tool, to identify patient care unit communication patterns associated with patient safety and quality outcomes. Although ORA had previously had limited use in healthcare, we felt it could effectively model communication on patient care units. Methods Using a survey methodology, we collected communication network data from nursing staff on seven patient care units on two different days. Patient outcome data were collected via a separate survey. Results of the staff survey were used to represent the communication networks for each unit in ORA. We then used ORA's analysis capability to generate communication metrics for each unit. ORA's visualization capability was used to better understand the metrics. Results We identified communication patterns that correlated with two safety (falls and medication errors) and five quality (e.g., symptom management, complex self care, and patient satisfaction) outcome measures. Communication patterns differed substantially by shift. Conclusion The results demonstrate the utility of ORA for healthcare research and the relationship of nursing unit communication patterns to patient safety and quality outcomes. PMID:21536492
Context matters: the impact of unit leadership and empowerment on nurses' organizational commitment.
Laschinger, Heather K Spence; Finegan, Joan; Wilk, Piotr
2009-05-01
The aim of this study was to test a multilevel model linking unit-level leader-member exchange quality and structural empowerment to nurses' psychological empowerment and organizational commitment at the individual level of analysis. Few studies have examined the contextual effects of unit leadership on individual nurse outcomes. Workplace empowerment has been related to retention outcomes such as organizational commitment in several studies, but few have studied the impact of specific unit characteristics within which nurses work on these outcomes. We surveyed 3,156 nurses in 217 hospital units to test the multilevel model. A multilevel path analysis revealed significant individual and contextual effects on nurses' organizational commitment. Both unit-level leader-member exchange quality and structural empowerment had significant direct effects on individual-level psychological empowerment and organizational commitment. Psychological empowerment mediated the relationship between core self-evaluations and organizational commitment at the individual level of analysis. The contextual effects of positive supervisor relationships and their influence on empowering working conditions at the unit level and, subsequently, nurses' organizational commitment highlight the importance of leadership for creating conditions that result in a committed nursing workforce.
Phillip E. Farnes; Raymond C. Shearer; Ward W. McCaughey; Katherine J. Hansen
1995-01-01
There are two experimental forests in Montana established by the U.S. Department of Agriculture, Forest Service, Intermountain Research Station (INT). Both experimental forests are administered by INT's Research work Unit, RWU-4151, Silviculture of Subalpine Forest Ecosystems. Tenderfoot Creek Experimental Forest (TCEF) is east of the continental Divide and is...
The Effects of a Premarital Relationship Enrichment Program on Relationship Satisfaction
ERIC Educational Resources Information Center
Yilmaz, Tugba; Kalkan, Melek
2010-01-01
The aim of this study is to investigate the effects of a premarital relationship enrichment program on relationship satisfaction among couples. The experimental and control groups were totally composed of 20 individuals. In order to test whether there are any significant differences between the scores of pre-test and post-test within the control…
Detection and analysis of part load and full load instabilities in a real Francis turbine prototype
NASA Astrophysics Data System (ADS)
Presas, Alexandre; Valentin, David; Egusquiza, Eduard; Valero, Carme
2017-04-01
Francis turbines operate in many cases out of its best efficiency point, in order to regulate their output power according to the instantaneous energy demand of the grid. Therefore, it is of paramount importance to analyse and determine the unstable operating points for these kind of units. In the framework of the HYPERBOLE project (FP7-ENERGY-2013-1; Project number 608532) a large Francis unit was investigated numerically, experimentally in a reduced scale model and also experimentally and numerically in the real prototype. This paper shows the unstable operating points identified during the experimental tests on the real Francis unit and the analysis of the main characteristics of these instabilities. Finally, it is shown that similar phenomena have been identified on previous research in the LMH (Laboratory for Hydraulic Machines, Lausanne) with the reduced scale model.
Marihuana, Alcohol and Tobacco: Reassessment of a Presumed Relationship.
ERIC Educational Resources Information Center
Dull, R. Thomas; Williams, Franklin P., III
1981-01-01
Concludes little relationship exists between the three substances marihuana, alcohol and tobacco. Youthful subjects tend to overestimate the relationships between the three substances and cannot be generalized to other populations. Suggests an explanation of this youthful association focuses on simultaneous experimentation rather than causal…
Learning and performance under alternative instructional manifestations of experimental practice
NASA Astrophysics Data System (ADS)
Ford, Michael J.
Before we can understand how students learn "to do" science, we must make explicit our assumptions about what scientific practice is. This study compares the learning outcomes of two sixth-grade instructional units on experimentation, each based on a particular characterization of practice. In one unit, instruction focused on acquisition and application of the control of variables strategy (CVS; Chen & Klahr, 1999), which is consistent with a popular conception of science education, stemming from Piaget, as the mastery of logical forms. In the other unit, students designed experimental apparatus to answer a target question, and instruction emphasized practices of rendering and transforming the material world in ways that support scientific understanding. Students in both groups were assessed for CVS acquisition and subsequent experimental performance on a novel task, and group performances on these assessments different across instructional conditions. I will argue that student understandings of goals, norms of instructional expectation, and strategies explain these differences, in some cases by supporting performance and in other cases by hindering it. I will also argue that the results question the role typically attributed to logical method in learning to design experiments.
NASA Astrophysics Data System (ADS)
Wang, Zengwei; Zhu, Ping; Liu, Zhao
2018-01-01
A generalized method for predicting the decoupled transfer functions based on in-situ transfer functions is proposed. The method allows predicting the decoupled transfer functions using coupled transfer functions, without disassembling the system. Two ways to derive relationships between the decoupled and coupled transfer functions are presented. Issues related to immeasurability of coupled transfer functions are also discussed. The proposed method is validated by numerical and experimental case studies.
Method and apparatus for determination of mechanical properties of functionally-graded materials
Giannakopoulos, Antonios E.; Suresh, Subra
1999-01-01
Techniques for the determination of mechanical properties of homogenous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.
ERIC Educational Resources Information Center
McLean, Scott; Thompson, Gordon; Jonker, Peter
2006-01-01
In this paper, we describe the outreach and engagement movement in the United States and explore the implications of this movement for university continuing education units in Canada. Across the United States, major universities have adopted the vocabulary of "outreach and engagement" to foster a shift in the relationships of those…
Understanding the Relationship Between Food Variety, Food Intake, and Energy Balance.
Raynor, Hollie A; Vadiveloo, Maya
2018-03-01
In accordance with US dietary guidance, incorporating variety into the diet can align with energy balance, though greater food variety in some categories may make energy balance more challenging. Thus, experimental and epidemiologic evidence is summarized on the relationship between food variety, food and energy intake, and energy balance. Lab-based, experimental research consistently demonstrates that greater variety within foods or sensory characteristics of food increases food and energy intake within an eating occasion. Epidemiologic evidence is less consistent, potentially driven by differing methodologies, particularly in defining and measuring food variety. Moreover, the effect of variety on energy balance appears to be moderated by food energy density. Integrating insights from experimental and epidemiologic research are essential for strengthening food variety guidance including developing evidence-based definitions of food variety, understanding moderators of the relationship, and developing practical guidance interpretable to consumers.
Experimental Investigation of Triplet Correlation Approximations for Fluid Water.
Pallewela, Gayani N; Ploetz, Elizabeth A; Smith, Paul E
2018-08-25
Triplet correlations play a central role in our understanding of fluids and their properties. Of particular interest is the relationship between the pair and triplet correlations. Here we use a combination of Fluctuation Solution Theory and experimental pair radial distribution functions to investigate the accuracy of the Kirkwood Superposition Approximation (KSA), as given by integrals over the relevant pair and triplet correlation functions, at a series of state points for pure water using only experimental quantities. The KSA performs poorly, in agreement with a variety of other studies. Several additional approximate relationships between the pair and triplet correlations in fluids are also investigated and generally provide good agreement for the fluid thermodynamics for regions of the phase diagram where the compressibility is small. A simple power law relationship between the pair and triplet fluctuations is particularly successful for state points displaying low to moderately high compressibilities.
Examining the Relationships Between Education, Social Networks and Democratic Support With ABM
NASA Technical Reports Server (NTRS)
Drucker, Nick; Campbell, Kenyth
2011-01-01
This paper introduces an agent-based model that explores the relationships between education, social networks, and support for democratic ideals. This study examines two factors thai affect democratic support, education, and social networks. Current theory concerning these two variables suggests that positive relationships exist between education and democratic support and between social networks and the spread of ideas. The model contains multiple variables of democratic support, two of which are evaluated through experimentation. The model allows individual entities within the system to make "decisions" about their democratic support independent of one another. The agent based approach also allows entities to utilize their social networks to spread ideas. Current theory supports experimentation results. In addion , these results show the model is capable of reproducing real world outcomes. This paper addresses the model creation process and the experimentation procedure, as well as future research avenues and potential shortcomings of the model
The inpatient psychiatric unit as both a safe and unsafe place: implications for absconding.
Muir-Cochrane, Eimear; Oster, Candice; Grotto, Jessica; Gerace, Adam; Jones, Julia
2013-08-01
Absconding from acute psychiatric inpatient units is a significant issue with serious social, economic, and emotional costs. A qualitative study was undertaken to explore the experiences of people (n = 12) who had been held involuntarily under the local mental health act in an Australian inpatient psychiatric unit, and who had absconded (or attempted to abscond) during this time. The aim of the study was to explore why people abscond from psychiatric inpatient units, drawing on published work from health geography on the significance of the person-place encounter, and in particular the concept of 'therapeutic landscapes'. The findings show that the inpatient unit is perceived as a safe or unsafe place, dependent on the dialectical relationship between the physical, individual, social, and symbolic aspects of the unit. Consumers absconded when the unit was perceived as unsafe. Forming a therapeutic relationship with staff, familiarity with the unit, a comfortable environment, and positive experiences with other consumers all supported perceptions that the unit was safe, decreasing the likelihood of absconding. Findings extend existing work on the person-place encounter within psychiatric inpatient units, and bring new knowledge about the reasons why consumers abscond. Implications for practice are discussed. © 2012 The Authors; International Journal of Mental Health Nursing © 2012 Australian College of Mental Health Nurses Inc.
Optimization of Operating Parameters for Minimum Mechanical Specific Energy in Drilling
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hamrick, Todd
2011-01-01
Efficiency in drilling is measured by Mechanical Specific Energy (MSE). MSE is the measure of the amount of energy input required to remove a unit volume of rock, expressed in units of energy input divided by volume removed. It can be expressed mathematically in terms of controllable parameters; Weight on Bit, Torque, Rate of Penetration, and RPM. It is well documented that minimizing MSE by optimizing controllable factors results in maximum Rate of Penetration. Current methods for computing MSE make it possible to minimize MSE in the field only through a trial-and-error process. This work makes it possible to computemore » the optimum drilling parameters that result in minimum MSE. The parameters that have been traditionally used to compute MSE are interdependent. Mathematical relationships between the parameters were established, and the conventional MSE equation was rewritten in terms of a single parameter, Weight on Bit, establishing a form that can be minimized mathematically. Once the optimum Weight on Bit was determined, the interdependent relationship that Weight on Bit has with Torque and Penetration per Revolution was used to determine optimum values for those parameters for a given drilling situation. The improved method was validated through laboratory experimentation and analysis of published data. Two rock types were subjected to four treatments each, and drilled in a controlled laboratory environment. The method was applied in each case, and the optimum parameters for minimum MSE were computed. The method demonstrated an accurate means to determine optimum drilling parameters of Weight on Bit, Torque, and Penetration per Revolution. A unique application of micro-cracking is also presented, which demonstrates that rock failure ahead of the bit is related to axial force more than to rotation speed.« less
NASA Technical Reports Server (NTRS)
Blocher, J. M., Jr.; Browning, M. F.
1979-01-01
The construction and operation of an experimental process system development unit (EPSDU) for the production of granular semiconductor grade silicon by the zinc vapor reduction of silicon tetrachloride in a fluidized bed of seed particles is presented. The construction of the process development unit (PDU) is reported. The PDU consists of four critical units of the EPSDU: the fluidized bed reactor, the reactor by product condenser, the zinc vaporizer, and the electrolytic cell. An experimental wetted wall condenser and its operation are described. Procedures are established for safe handling of SiCl4 leaks and spills from the EPSDU and PDU.
Mesenchymal progenitor cells for the osteogenic lineage.
Ono, Noriaki; Kronenberg, Henry M
2015-09-01
Mesenchymal progenitors of the osteogenic lineage provide the flexibility for bone to grow, maintain its function and homeostasis. Traditionally, colony-forming-unit fibroblasts (CFU-Fs) have been regarded as surrogates for mesenchymal progenitors; however, this definition cannot address the function of these progenitors in their native setting. Transgenic murine models including lineage-tracing technologies based on the cre-lox system have proven to be useful in delineating mesenchymal progenitors in their native environment. Although heterogeneity of cell populations of interest marked by a promoter-based approach complicates overall interpretation, an emerging complexity of mesenchymal progenitors has been revealed. Current literatures suggest two distinct types of bone progenitor cells; growth-associated mesenchymal progenitors contribute to explosive growth of bone in early life, whereas bone marrow mesenchymal progenitors contribute to the much slower remodeling process and response to injury that occurs mainly in adulthood. More detailed relationships of these progenitors need to be studied through further experimentation.
Structures composing protein domains.
Kubrycht, Jaroslav; Sigler, Karel; Souček, Pavel; Hudeček, Jiří
2013-08-01
This review summarizes available data concerning intradomain structures (IS) such as functionally important amino acid residues, short linear motifs, conserved or disordered regions, peptide repeats, broadly occurring secondary structures or folds, etc. IS form structural features (units or elements) necessary for interactions with proteins or non-peptidic ligands, enzyme reactions and some structural properties of proteins. These features have often been related to a single structural level (e.g. primary structure) mostly requiring certain structural context of other levels (e.g. secondary structures or supersecondary folds) as follows also from some examples reported or demonstrated here. In addition, we deal with some functionally important dynamic properties of IS (e.g. flexibility and different forms of accessibility), and more special dynamic changes of IS during enzyme reactions and allosteric regulation. Selected notes concern also some experimental methods, still more necessary tools of bioinformatic processing and clinically interesting relationships. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Design of a High Thermal Gradient Bridgman Furnace
NASA Technical Reports Server (NTRS)
LeCroy, J. E.; Popok, D. P.
1994-01-01
The Advanced Automated Directional Solidification Furnace (AADSF) is a Bridgman-Stockbarger microgravity processing facility, designed and manifested to first fly aboard the second United States Microgravity Payload (USMP-2) Space Shuttle mission. The AADSF was principally designed to produce high axial thermal gradients, and is particularly suitable for metals solidification experiments, including non-dilute alloys. To accommodate a wider range of experimental conditions, the AADSF is equipped with a reconfigurable gradient zone. The overall design of the AADSF and the relationship between gradient zone design and furnace performance are described. Parametric thermal analysis was performed and used to select gradient zone design features that fulfill the high thermal gradient requirements of the USMP-2 experiment. The thermal model and analytical procedure, and parametric results leading to the first flight gradient zone configuration, are presented. Performance for the USMP-2 flight experiment is also predicted, and analysis results are compared to test data.
NASA Astrophysics Data System (ADS)
Farace, Paolo
2014-11-01
A two-steps procedure is presented to convert dual-energy CT data to stopping power ratio (SPR), relative to water. In the first step the relative electron density (RED) is calculated from dual-energy CT-numbers by means of a bi-linear relationship: RED = a HUscH + b HUscL + c, where HUscH and HUscL are scaled units (HUsc = HU + 1000) acquired at high and low energy respectively, and the three parameters a, b and c has to be determined for each CT scanner. In the second step the RED values were converted into SPR by means of published poly-line functions, which are invariant as they do not depend on a specific CT scanner. The comparison with other methods provides encouraging results, with residual SPR error on human tissue within 1%. The distinctive features of the proposed method are its simplicity and the generality of the conversion functions.
Mutual Information Rate and Bounds for It
Baptista, Murilo S.; Rubinger, Rero M.; Viana, Emilson R.; Sartorelli, José C.; Parlitz, Ulrich; Grebogi, Celso
2012-01-01
The amount of information exchanged per unit of time between two nodes in a dynamical network or between two data sets is a powerful concept for analysing complex systems. This quantity, known as the mutual information rate (MIR), is calculated from the mutual information, which is rigorously defined only for random systems. Moreover, the definition of mutual information is based on probabilities of significant events. This work offers a simple alternative way to calculate the MIR in dynamical (deterministic) networks or between two time series (not fully deterministic), and to calculate its upper and lower bounds without having to calculate probabilities, but rather in terms of well known and well defined quantities in dynamical systems. As possible applications of our bounds, we study the relationship between synchronisation and the exchange of information in a system of two coupled maps and in experimental networks of coupled oscillators. PMID:23112809
Structural evolution and properties of small-size thiol-protected gold nanoclusters
NASA Astrophysics Data System (ADS)
Ma, Miaomiao; Liu, Liren; Zhu, Hengjiang; Lu, Junzhe; Tan, Guiping
2018-07-01
Ligand-protected gold clusters are widely used in biosensors and catalysis. Understanding the structural evolution of these kinds of nanoclusters is important for experimental synthesis. Herein, based on the particle swarm optimisation algorithm and density functional theory method, we use [Au1(SH)2]n, [Au2(SH)3]n, [Au3(SH)4]n (n = 1-3) as basic units to research the structural evolution relationships from building blocks to the final whole structures. Results show that there is a 'line-ring-core' structural evolution pattern in the growth process of the nanoclusters. The core structures of the ligand-protected gold clusters consist of Au3, Au4, Au6 and Au7 atoms. The electronics and optics analysis reflects that stability and optical properties gradually enhance with increase in size. These results can be used to understand the initial growth stage and design new ligand-protected nanoclusters.
Compressive Behavior of Frame-Stiffened Composite Panels
NASA Technical Reports Server (NTRS)
Yovanof, Nicolette P.; Jegley, Dawn C.
2011-01-01
New technologies are being developed under NASA's Environmentally Responsible Aviation (ERA) Program aimed at reducing fuel burn and emissions in large commercial aircraft. A Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept is being developed which offers advantages over traditional metallic structure. In this concept a stitched carbon-epoxy material system is employed with the potential for reducing the weight and cost of transport aircraft structure by eliminating fasteners and producing a more damage tolerant design. In addition, by adding unidirectional carbon rods to the top of stiffeners and minimizing the interference between the sandwich frames and the rod-stiffened stringers, the panel becomes more structurally efficient. This document describes the results of experimentation on a PRSEUS panel in which the frames are loaded in unidirectional compression beyond the local buckling of the skin of a Hybrid Wing Body (HWB) aircraft. A comparison with analytical predictions and the relationship between these test results and the global aircraft design is presented.
Adaptive upstream optical power adjustment depending on required power budget in PON access
NASA Astrophysics Data System (ADS)
Yeh, C. H.; Chow, C. W.; Liu, Y. L.
2012-11-01
According to the present passive optical network (PON) standard, the fiber transmission lengths are from 500 m to 20 km between the optical line terminal (OLT) and different optical network units (ONUs). It will result in difference power losses (ΔPloss) from 4 to 5 dB. Hence, we propose to adjust adaptively the output optical power of the upstream laser diode (LD) depending on the different fiber lengths. With the different fiber transmission lengths, we can properly adjust the bias current and modulation index of upstream LD for energy-saving. We characterize and analyze experimentally the relationship of output optical power and modulation amplitude Vamp under different fiber transmissions in PON access. Moreover, due to the adaptive power control of upstream signal, the optical upstream equalization also can be retrieved with power variation of 1.1 dB in this experiment.
Farace, Paolo
2014-11-21
A two-steps procedure is presented to convert dual-energy CT data to stopping power ratio (SPR), relative to water. In the first step the relative electron density (RED) is calculated from dual-energy CT-numbers by means of a bi-linear relationship: RED=a HUscH+b HUscL+c, where HUscH and HUscL are scaled units (HUsc=HU+1000) acquired at high and low energy respectively, and the three parameters a, b and c has to be determined for each CT scanner. In the second step the RED values were converted into SPR by means of published poly-line functions, which are invariant as they do not depend on a specific CT scanner. The comparison with other methods provides encouraging results, with residual SPR error on human tissue within 1%. The distinctive features of the proposed method are its simplicity and the generality of the conversion functions.
Real-time speech-driven animation of expressive talking faces
NASA Astrophysics Data System (ADS)
Liu, Jia; You, Mingyu; Chen, Chun; Song, Mingli
2011-05-01
In this paper, we present a real-time facial animation system in which speech drives mouth movements and facial expressions synchronously. Considering five basic emotions, a hierarchical structure with an upper layer of emotion classification is established. Based on the recognized emotion label, the under-layer classification at sub-phonemic level has been modelled on the relationship between acoustic features of frames and audio labels in phonemes. Using certain constraint, the predicted emotion labels of speech are adjusted to gain the facial expression labels which are combined with sub-phonemic labels. The combinations are mapped into facial action units (FAUs), and audio-visual synchronized animation with mouth movements and facial expressions is generated by morphing between FAUs. The experimental results demonstrate that the two-layer structure succeeds in both emotion and sub-phonemic classifications, and the synthesized facial sequences reach a comparative convincing quality.
ERIC Educational Resources Information Center
Moon, Jeong-hwa; Pearl, Joseph H.
1991-01-01
Older Korean immigrants (n=137) completed Dean's Alienation Scale (DAS) to examine relationship of alienation to place of residence, gender, age, years of education, time in United States, and living arrangements. Found significant relationships between DAS subscales and place of residence, age, time in United States, and whether living with or…
Portoghese, Igor; Galletta, Maura; Battistelli, Adalgisa; Leiter, Michael P
2015-09-01
To analyse nursing turnover intention from the unit by using multilevel approach, examining at the individual level, the relationships between job characteristics, job satisfaction and turnover intention, and at the group level the role of leader-member exchange. Research on nursing turnover has given little attention to the effects of multilevel factors. Aggregated data of 935 nurses nested within 74 teams of four Italian hospitals were collected in 2009 via a self-administered questionnaire. Hierarchical linear modelling showed that job satisfaction mediated the relationship between job characteristics and intention to leave at the individual level. At the unit level, leader-member exchange was directly linked to intention to leave. Furthermore, cross-level interaction revealed that leader-member exchange moderated the relationship between job characteristics and job satisfaction. This study supported previous research in single-level turnover studies concerning the key role of job satisfaction, providing evidence that job characteristics are important in creating motivating and satisfying jobs. At the unit-level, leader-member exchange offers an approach to understand the role of unit-specific conditions created by leaders on nurses' workplace wellbeing. This study showed that it is important for nursing managers to recognise the relevance of implementing management practices that foster healthy workplaces centred on high-quality nurse-supervisor relationships. © 2014 John Wiley & Sons Ltd.
Yoshioka, Sumie; Aso, Yukio; Kojima, Shigeo
2003-06-01
To examine whether the glass transition temperature (Tg) of freeze-dried formulations containing polymer excipients can be accurately predicted by molecular dynamics simulation using software currently available on the market. Molecular dynamics simulations were carried out for isomaltodecaose, a fragment of dextran, and alpha-glucose, the repeated unit of dextran. in the presence or absence of water molecules. Estimated values of Tg were compared with experimental values obtained by differential scanning calorimetry (DSC). Isothermal-isobaric molecular dynamics simulations (NPTMD) and isothermal molecular dynamics simulations at a constant volume (NVTMD) were carried out using the software package DISCOVER (Material Studio) with the Polymer Consortium Force Field. Mean-squared displacement and radial distribution function were calculated. NVTMD using the values of density obtained by NPTMD provided the diffusivity of glucose-ring oxygen and water oxygen in amorphous alpha-glucose and isomaltodecaose, which exhibited a discontinuity in temperature dependence due to glass transition. Tg was estimated to be approximately 400K and 500K for pure amorphous a-glucose and isomaltodecaose, respectively, and in the presence of one water molecule per glucose unit, Tg was 340K and 360K, respectively. Estimated Tg values were higher than experimentally determined values because of the very fast cooling rates in the simulations. However, decreases in Tg on hydration and increases in Tg associated with larger fragment size could be demonstrated. The results indicate that molecular dynamics simulation is a useful method for investigating the effects of hydration and molecular weight on the Tg of lyophilized formulations containing polymer excipients. although the relationship between cooling rates and Tg must first be elucidated to predict Tg vales observed by DSC measurement. January 16.
NASA Astrophysics Data System (ADS)
McMillan, Norman; O'Neill, Martina; Smith, Stephen; Hammond, John; Riedel, Sven; Arthure, Kevin; Smith, S.
2009-05-01
A TLDA-microvolume (transmitted light drop analyser) accessory for use with a standard UV-visible fibre spectrophotometer is described. The physics of the elegantly simple optical design is described along with the experimental testing of this accessory. The modelling of the arrangement is fully explored to investigate the performance of the drop spectrophotometer. The design optimizes the focusing to deliver the highest quality spectra, rapid and simple sample handling and, importantly, no detectable carryover on the single quartz drophead. Results of spectral measurements in a laboratory providing NIST standards show the closest correlation between modelled pathlength and experimental measurement for different drop volumes in the range 0.7-3 µl. This instrument accessory delivers remarkably accurate and reproducible results that are good enough to allow the accessory to be used for rapid pipette calibration to avoid the laborious weighing methods currently employed. Measurements on DNA standards and proteins are given to illustrate the main application area of biochemistry for this accessory. The accessory has a measurement range of at least 0-60 A units without sample dilution and, since there exists an accurate volume-pathlength relationship, the drop volume used in any specific measurement or assay should be optimized to minimize the photometric error. Studies demonstrate that the cleaning of the drophead with lab wipes results in no measurable carryover. This important practical result is confirmed from direct reading of the accessory and an analytical balance which was used to perform carryover studies. For further information on the TLDA please contact: Drop Technology, Unit 2, Tallaght Business Park, Whitestown, Dublin 24, Republic of Ireland. email: info@droptechnology.com.
Genung, Mark A; Fox, Jeremy; Williams, Neal M; Kremen, Claire; Ascher, John; Gibbs, Jason; Winfree, Rachael
2017-07-01
The relationship between biodiversity and the stability of ecosystem function is a fundamental question in community ecology, and hundreds of experiments have shown a positive relationship between species richness and the stability of ecosystem function. However, these experiments have rarely accounted for common ecological patterns, most notably skewed species abundance distributions and non-random extinction risks, making it difficult to know whether experimental results can be scaled up to larger, less manipulated systems. In contrast with the prolific body of experimental research, few studies have examined how species richness affects the stability of ecosystem services at more realistic, landscape scales. The paucity of these studies is due in part to a lack of analytical methods that are suitable for the correlative structure of ecological data. A recently developed method, based on the Price equation from evolutionary biology, helps resolve this knowledge gap by partitioning the effect of biodiversity into three components: richness, composition, and abundance. Here, we build on previous work and present the first derivation of the Price equation suitable for analyzing temporal variance of ecosystem services. We applied our new derivation to understand the temporal variance of crop pollination services in two study systems (watermelon and blueberry) in the mid-Atlantic United States. In both systems, but especially in the watermelon system, the stronger driver of temporal variance of ecosystem services was fluctuations in the abundance of common bee species, which were present at nearly all sites regardless of species richness. In contrast, temporal variance of ecosystem services was less affected by differences in species richness, because lost and gained species were rare. Thus, the findings from our more realistic landscapes differ qualitatively from the findings of biodiversity-stability experiments. © 2017 by the Ecological Society of America.
NASA Astrophysics Data System (ADS)
Gaillard, Fabrice; Pichavant, Michel; Scaillet, Bruno
2003-11-01
The critical role of iron on crystal-silicate liquid relationships and melt differentiation is mainly controlled by the redox conditions prevailing in magmas, but the presently available database merely constrains the thermodynamic properties of iron-bearing components in strongly reduced and anhydrous molten silicate where iron is in the ferrous form. This paper provides new standard states for pure ferrous (FeOliq) and ferric (Fe2O3liq) molten iron oxides and extends the experimental database towards oxidizing and water-bearing domains. Iron-iridium, iron-platinum alloys, magnetite or hematite were equilibrated with synthetic silicic liquids at high temperature and high pressure under controlled oxygen fugacity (fO2) to determine activity-composition relationships for FeOliq and Fe2O3liq. Between 1000 and 1300°C, the fO2 ranges from that in air to 3-log units below that of the nickel-nickel oxide buffer (NNO). Experiments were performed on both anhydrous and hydrous melts containing up to 6-wt.% water. Incorporation of water under reducing conditions increases the activity coefficient of FeOliq but has an opposite effect on Fe2O3liq. As calcium is added to system, the effect of water becomes weaker and is inverted for Fe2O3liq. Under oxidizing conditions, water has a negligible effect on both activities of FeOliq and Fe2O3liq. In contrast, changes in redox conditions dominate the activity coefficients of both FeOliq and Fe2O3liq, which increase significantly with increasing fO2. The present results combined with the previous work provide a specific database on the energetics of iron in silicate melts that cover most of the condition prevailing in natural magmas.
Physical education, school physical activity, school sports and academic performance
Trudeau, François; Shephard, Roy J
2008-01-01
Background The purpose of this paper is to review relationships of academic performance and some of its determinants to participation in school-based physical activities, including physical education (PE), free school physical activity (PA) and school sports. Methods Linkages between academic achievement and involvement in PE, school PA and sport programmes have been examined, based on a systematic review of currently available literature, including a comprehensive search of MEDLINE (1966 to 2007), PSYCHINFO (1974 to 2007), SCHOLAR.GOOGLE.COM, and ERIC databases. Results Quasi-experimental data indicate that allocating up to an additional hour per day of curricular time to PA programmes does not affect the academic performance of primary school students negatively, even though the time allocated to other subjects usually shows a corresponding reduction. An additional curricular emphasis on PE may result in small absolute gains in grade point average (GPA), and such findings strongly suggest a relative increase in performance per unit of academic teaching time. Further, the overwhelmingly majority of such programmes have demonstrated an improvement in some measures of physical fitness (PF). Cross-sectional observations show a positive association between academic performance and PA, but PF does not seem to show such an association. PA has positive influences on concentration, memory and classroom behaviour. Data from quasi-experimental studies find support in mechanistic experiments on cognitive function, pointing to a positive relationship between PA and intellectual performance. Conclusion Given competent providers, PA can be added to the school curriculum by taking time from other subjects without risk of hindering student academic achievement. On the other hand, adding time to "academic" or "curricular" subjects by taking time from physical education programmes does not enhance grades in these subjects and may be detrimental to health. PMID:18298849
ERIC Educational Resources Information Center
Grove, Cornelius Lee; Hansel, Bettina
Developed as orientation materials for foreign students coming to the United States to study English, this manual contains six units to acquaint students with U.S. history, government, and culture. The first unit introduces students to the daily routines and interpersonal relationships of U.S. people. Unit 2 examines the origins and significance…
Non-Research-Related Physician-Industry Relationships of Radiologists in the United States.
Harvey, H Benjamin; Alkasab, Tarik K; Pandharipande, Pari V; Halpern, Elkan F; Prabhakar, Anand M; Oklu, Rahmi; Rosenthal, Daniel I; Hirsch, Joshua A; Gazelle, G Scott; Brink, James A
2015-11-01
To evaluate non-research-related, physician-industry financial relationships in the United States, in 2013, as reported pursuant to the Physician Payments Sunshine Act (a provision of the Affordable Care Act). In September 2014, CMS released the first five months (August 2013 to December 2013) of data disclosing physician-industry financial relationships. The frequency and value of non-research-related transfers in radiology were calculated and compared with those for 19 other specialties. Subanalyses of the frequency and value of such transfers in radiology were performed, based on state of licensure, radiologic subspecialty, nature of payment, manufacturer identity, and drug or device involved. A total of 7.4% (2,654 of 35,768) of radiologists from the United States had reportable non-research-related financial relationship(s) with industry during the 5-month period, the second-lowest level among the medical specialties evaluated. The average value of non-research-related transfers of value to radiologists, excluding royalties and licenses, was low ($438.71; SD: $2,912.15; median: $43.85), with <4% of radiologists receiving >$10 per month. Of all categories, that of food and beverage had the most transfers of value (86.0%; 5,655 of 6,577); royalties and licensure were associated with the greatest average value ($27,072.34; SD: $67,524.92). Although high-value relationships were rare, 57.8% (26 of 45) of radiologists who received a value >$1,000 per month held leadership positions in imaging enterprises. Less than 4% of radiologists have non-research-related financial relationships with industry that are valued at >$10 per month, suggesting that meaningful, deleterious effects of such relationships on radiology practice, if present, are infrequent. Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.
Stratigraphy and evolution of emerged Pleistocene reefs at the Red Sea coast of Sudan
NASA Astrophysics Data System (ADS)
Hamed, Basher; Bussert, Robert; Dominik, Wilhelm
2016-02-01
Emerged Pleistocene coral reefs constitute a prominent landform along the Red Sea coast of Sudan. They are well exposed with a thickness of up to 12 m and extend over a width of about 3 km parallel to the coastline. Four major reef units that represent different reef zones are distinguished. Unit 1 is located directly at the coastline and is assigned to the rock-reef rim, while unit 2 represents the reef-front zone. Unit 3 is attributed to the reef-flat zone and unit 4 to the back-reef zone. The stratigraphic position and age of the four units respectively the facies zones are based on field relationships and δ18O analysis. Results of δ18O analysis of coral, gastropod and bivalve samples were correlated to previous age dating of correlative reefs in Sudan and other parts of the Red Sea region. Estimation of reef ages was mainly based on δ18O values of the reef-front zone (unit 2) and the observed sedimentary succession of the reefs. δ18O values of two Porites coral samples from the reef-front zone strongly suggest equivalent ages of 120 and 122 ka that correspond to marine isotope stage MIS 5.5. Based on δ18O values and the field relationship to the reef-front zone, ages of reef-flat zone (unit 3) and back-reef zone (unit 4) could be assigned to MIS 9 and MIS 7 respectively. MIS 5.1 is suggested for the reef-rock rim (unit 1). The relationship of the reef zones to individual MIS might be explained by the predominance of a specific zone during a certain stage, while other facies were less well developed and/or later eroded by wave action. The reef unit most distal from the recent coastline formed during interglacial stage MIS 7, while former studies assign this unit to interglacial stage MIS 9. Unique flourishing, high diversity and excellent preservation of corals in the back-reef unit of MIS 7 reflect growth in troughs landward of the oldest reef-flat formed during previous interglacial stage MIS 9.
Lamar, Joanne
2012-01-01
To address an increase in patient transfers to the intensive care unit because of respiratory distress, a respiratory care bundle utilizing incentive spirometry was developed for a medical general practice unit. This resulted in decreased respiratory complications over 12 months.
NASA Astrophysics Data System (ADS)
Spurgin, C. B.
1986-03-01
The author discusses the concept of dimensions of a physical quantity, and the relationship between derived units (expressed in terms of their base units) and the dimensions of the derived quantities. He calls for the replacement of 'dimensions' by base units in the GCE A-level syllabus and provides some recommendations to GCE examining boards.
12 CFR 404.12 - General provisions.
Code of Federal Regulations, 2010 CFR
2010-01-01
... and Banking EXPORT-IMPORT BANK OF THE UNITED STATES INFORMATION DISCLOSURE Access to Records Under the..., at the Export-Import Bank of the United States (Ex-Im Bank). (b) Relationship to the Freedom of... designated alternate. (e) Ex-Im Bank address. The Export-Import Bank of the United States is located at 811...
The United Nations: Its Role and Place in African Education.
ERIC Educational Resources Information Center
Muyumba, Francois N.
1994-01-01
Describes the paradoxical relationship between the United Nations and African nations. Asserts that the search for democracy, justice, equity, and education has forced many states to look with interest at the pedagogy of liberation. Discusses what is being taught about the United Nations in African schools. (CFR)
75 FR 48412 - Notice of Open Meetings To Prepare 2010 Report to Congress
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-10
... United States and the People's Republic of China [that] shall include a full analysis, along with... the following topics: The United States-China trade and economic relationship, including the... Kong. China's control of information and its impact on the United States, including China's ``state...
Native American Career Education Unit. Living with the Land.
ERIC Educational Resources Information Center
Far West Lab. for Educational Research and Development, San Francisco, CA.
One of twelve instructional units in the Native American Career Education (NACE) program, this unit is intended to help Indian junior high school students understand concepts involved in the management of natural resources, especially as they relate to traditional Indian values; understand the relationship between basic needs, resources, and waste…
DefenseLink Feature: Travels with Gates
. Story India Visit Aimed at Long-Term Relationship Defense Secretary Robert M. Gates walks with Indian developing a long-term relationship with India. Story Gates Looks to Strengthen Ties with India NEW DELHI longstanding relationship between Australia and the United States and pledged continued cooperation between the
50 CFR 100.13 - Board/agency relationships.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Board/agency relationships. 100.13 Section 100.13 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Structure § 100.13 Board/agency relationships. (a) General. (1) The Board, in making decisions or...
50 CFR 100.13 - Board/agency relationships.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Board/agency relationships. 100.13 Section 100.13 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Structure § 100.13 Board/agency relationships. (a) General. (1) The Board, in making decisions or...
ERIC Educational Resources Information Center
Phillips, Shelley
Topics related to characteristics of mother/daughter relationships in contemporary patriarchal societies are discussed in this seminar paper. The first section describes cases intended to illustrate ways patriarchal social structures limit contemporary mother/daughter relationships, provides a brief historical contrast, and suggests possible…
Pushed to the Margins--Sex and Relationships in Greek Primary Textbooks
ERIC Educational Resources Information Center
Gerouki, Margarita
2008-01-01
In 2001, the Greek Government introduced sex and gender relationships education as a thematic unit for interdisciplinary Health Education activities. However, the diffusion of such programmes remains extremely limited. The present paper discusses how sex and relationships issues are presented in contemporary Greek primary school textbooks since…
Code of Federal Regulations, 2011 CFR
2011-07-01
... that 12-month period at the maximum design heat input capacity. In the case of steam generating units... generating unit. Combustion research means the experimental firing of any fuel or combination of fuels in a steam generating unit for the purpose of conducting research and development of more efficient...
Code of Federal Regulations, 2010 CFR
2010-07-01
... that 12-month period at the maximum design heat input capacity. In the case of steam generating units... generating unit. Combustion research means the experimental firing of any fuel or combination of fuels in a steam generating unit for the purpose of conducting research and development of more efficient...
Results of the Thailand Warm-Cloud Hygroscopic Particle Seeding Experiment.
NASA Astrophysics Data System (ADS)
Silverman, Bernard A.; Sukarnjanaset, Wathana
2000-07-01
A randomized, warm-rain enhancement experiment was carried out during 1995-98 in the Bhumibol catchment area in northwestern Thailand. The experiment was conducted in accordance with a randomized, floating single-target design. The seeding targets were semi-isolated, warm convective clouds, contained within a well-defined experimental unit, that, upon qualification, were selected for seeding or not seeding with calcium chloride particles in a random manner. The seeding was done by dispensing the calcium chloride particles at an average rate of 21 kg km1 per seeding pass into the updrafts of growing warm convective clouds (about 1-2 km above cloud base) that have not yet developed or, at most, have just started to develop a precipitation radar echo. The experiment was carried out by the Bureau of Royal Rainmaking and Agricultural Aviation (BRRAA) of the Ministry of Agriculture and Cooperatives as part of its Applied Atmospheric Resources Research Program, Phase 2.During the 4 yr of the experiment, a total of 67 experimental units (34 seeded and 33 nonseeded units) were qualified in accordance with the experimental design. Volume-scan data from a 10-cm Doppler radar at 5-min intervals were used to track each experimental unit, from which various radar-estimated properties of the experimental units were obtained. The statistical evaluation of the experiment was based on a rerandomization analysis of the single ratio of seeded to unseeded experimental unit lifetime properties. In 1997, the BRRAA acquired two sophisticated King Air 350 cloud-physics aircraft, providing the opportunity to obtain physical measurements of the aerosol characteristics of the environment in which the warm clouds grow, of the hydrometeor characteristics of seeded and unseeded clouds, and of the calcium chloride seeding plume dimensions and particle size distribution-information directly related to the effectiveness of the seeding conceptual model that was not directly available up to then.The evaluation of the Thailand warm-rain enhancement experiment has provided statistically significant evidence and supporting physical evidence that the seeding of warm convective clouds with calcium chloride particles produced more rain than was produced by their unseeded counterparts. An exploratory analysis of the time evolution of the seeding effects resulted in a significant revision to the seeding conceptual model.
Jafarzadeh-Kashi, Tahereh Sadat; Erfan, Mohmmad; Kalbasi, Salmeh; Ghadiri, Malihe; Rakhshan, Vahid
2014-10-01
Polymerization of bonding agents (BA) is a critical factor in determining the success of bonded restorations. We aimed to assess the effects of two light curing units and two temperatures on the extent of polymerization (EP) of a commercial BA and an experimental BA. Forty BA specimens were randomly divided into 8 subgroups of n = 5 to compare the polymerization of two BAs (experimental/Scotchbond) based on the variables: temperature (23/37 °C) and light-curing unit (quartz-tungsten-halogen/light-emitting diode). The EP (%) was measured using differential scanning calorimetry, and analyzed using the t-test, two- and three-way analyses of variance (ANOVA), and the Bonferroni test (α = 0.05). There were significant differences between the EP results between the two BAs (P = 0.012) and due to the different temperatures (P = 0.001), but not between the different light-curing units (P = 0.548). The interaction between BA and temperature was significant (P < 0.001). The other interactions were nonsignificant. The two light-curing units had similar effects on the EP. The EP values were better when curing was performed at human body temperature.
Contractile properties of rat, rhesus monkey, and human type I muscle fibers
NASA Technical Reports Server (NTRS)
Widrick, J. J.; Romatowski, J. G.; Karhanek, M.; Fitts, R. H.
1997-01-01
It is well known that skeletal muscle intrinsic maximal shortening velocity is inversely related to species body mass. However, there is uncertainty regarding the relationship between the contractile properties of muscle fibers obtained from commonly studied laboratory animals and those obtained from humans. In this study we determined the contractile properties of single chemically skinned fibers prepared from rat, rhesus monkey, and human soleus and gastrocnemius muscle samples under identical experimental conditions. All fibers used for analysis expressed type I myosin heavy chain as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Allometric coefficients for type I fibers from each muscle indicated that there was little change in peak tension (force/fiber cross-sectional area) across species. In contrast, both soleus and gastrocnemius type I fiber maximal unloaded shortening velocity (Vo), the y-intercept of the force-velocity relationship (Vmax), peak power per unit fiber length, and peak power normalized for fiber length and cross-sectional area were all inversely related to species body mass. The present allometric coefficients for soleus fiber Vo (-0.18) and Vmax (-0.11) are in good agreement with published values for soleus fibers obtained from common laboratory and domesticated mammals. Taken together, these observations suggest that the Vo of slow fibers from quadrupeds and humans scale similarly and can be described by the same quantitative relationships. These findings have implications in the design and interpretation of experiments, especially those that use small laboratory mammals as a model of human muscle function.
Are Examiners' Judgments in OSCE-Style Assessments Influenced by Contrast Effects?
Yeates, Peter; Moreau, Marc; Eva, Kevin
2015-07-01
Laboratory studies have shown that performance assessment judgments can be biased by "contrast effects." Assessors' scores become more positive, for example, when the assessed performance is preceded by relatively weak candidates. The authors queried whether this effect occurs in real, high-stakes performance assessments despite increased formality and behavioral descriptors. Data were obtained for the 2011 United Kingdom Foundational Programme clinical assessment and the 2008 University of Alberta Multiple Mini Interview. Candidate scores were compared with scores for immediately preceding candidates and progressively distant candidates. In addition, average scores for the preceding three candidates were calculated. Relationships between these variables were examined using linear regression. Negative relationships were observed between index scores and both immediately preceding and recent scores for all exam formats. Relationships were greater between index scores and the average of the three preceding scores. These effects persisted even when examiners had judged several performances, explaining up to 11% of observed variance on some occasions. These findings suggest that contrast effects do influence examiner judgments in high-stakes performance-based assessments. Although the observed effect was smaller than observed in experimentally controlled laboratory studies, this is to be expected given that real-world data lessen the strength of the intervention by virtue of less distinct differences between candidates. Although it is possible that the format of circuital exams reduces examiners' susceptibility to these influences, the finding of a persistent effect after examiners had judged several candidates suggests that the potential influence on candidate scores should not be ignored.
Central Nervous System Oxygen Toxicity in Closed-Circuit Scuba Divers
1986-03-01
CENTRAL NERVOUS SYSTEM OXYGEN TOXICITY IN CLOSED -CIRCUIT SCUBA DIVERS III By F. K. Butler, Jr., LCDR, MC, USN NAVY EXPERIMENTAL DIVING UNIT DTIC...PANAMA CITY. FLORIDA 321407 IN. aLV OMW Vol NAVY EXPERIMENTAL DIVING UNIT REPORT NO. 5-86 CENTRAL NERVOUS SYSTEM OXYGEN TOXICITY IN CLOSED -CIRCUIT SCUBA...BUTLER, Jr. J . .d.M. HAMILTON LCDR, MC, USK CDR, MC, USK CDR, USKN Medical Research Officer Senior Medical Officer Comanding Officer UNCLASSIFIED 4
Impact of organizational policies and practices on workplace injuries in a hospital setting.
Tveito, T H; Sembajwe, G; Boden, L I; Dennerlein, J T; Wagner, G R; Kenwood, C; Stoddard, A M; Reme, S E; Hopcia, K; Hashimoto, D; Shaw, W S; Sorensen, G
2014-08-01
This study aimed to assess relationships between perceptions of organizational practices and policies (OPP), social support, and injury rates among workers in hospital units. A total of 1230 hospital workers provided survey data on OPP, job flexibility, and social support. Demographic data and unit injury rates were collected from the hospitals' administrative databases. Injury rates were lower in units where workers reported higher OPP scores and high social support. These relationships were mainly observed among registered nurses. Registered nurses perceived coworker support and OPP as less satisfactory than patient care associates (PCAs). Nevertheless, because of the low number of PCAs at each unit, results for the PCAs are preliminary and should be further researched in future studies with larger sample sizes. Employers aiming to reduce injuries in hospitals could focus on good OPP and supportive work environment.
Lin, Tzu-Ching; Lin, Huey-Shyan; Cheng, Su-Fen; Wu, Li-Min; Ou-Yang, Mei-Chen
2016-04-01
This study aimed to examine the relationship between work stress and depression; and investigate the mediating effect of occupational burnout among nurses in paediatric intensive care units. The relationships among work stress, occupational burnout and depression level have been explored, neither regarding occupational burnout as the mediating role that causes work stress to induce depression nor considering the paediatric intensive care unit context. A cross-sectional correlational design was conducted. One hundred and forty-four female paediatric intensive care unit nurses from seven teaching hospitals in southern Taiwan were recruited as the participants. Data were collected by structured questionnaires including individual demographics, the Nurse Stress Checklist, the Occupational Burnout Inventory and the Taiwan Depression Questionnaire. The results indicated that after controlling for individual demographic variables, the correlations of work stress with occupational burnout, as well as work stress and occupational burnout with depression level were all positive. Furthermore, occupational burnout may exert a partial mediating effect on the relationship between work stress and depression level. This study provides information about work stress, occupational burnout and depression level, and their correlations, as well as the mediating role of occupational burnout among paediatric intensive care unit nurses. It suggests government departments and hospital administrators when formulating interventions to prevent work stress and occupational burnout. These interventions can subsequently prevent episodes of depression in paediatric intensive care unit nurses, thereby providing patients with a safe and high-quality nursing environment. © 2016 John Wiley & Sons Ltd.
Divergent Vegetation Growth Patterns Relative to Bioinfiltration Unit Size and Plant Placement
In 2009, the U.S. Environmental Protection Agency constructed six experimental bioinfiltration units at the Edison Environmental Center in Edison, New Jersey. They were designed as two sets of three bioinfiltration units with drainage area to surface area ratios of 5.5:1, 11:1, ...
Code of Federal Regulations, 2012 CFR
2012-07-01
... that 12-month period at the maximum design heat input capacity. In the case of steam generating units... gas to a steam generating unit. Combustion research means the experimental firing of any fuel or combination of fuels in a steam generating unit for the purpose of conducting research and development of more...
Code of Federal Regulations, 2014 CFR
2014-07-01
... that 12-month period at the maximum design heat input capacity. In the case of steam generating units... gas to a steam generating unit. Combustion research means the experimental firing of any fuel or combination of fuels in a steam generating unit for the purpose of conducting research and development of more...
Code of Federal Regulations, 2013 CFR
2013-07-01
... that 12-month period at the maximum design heat input capacity. In the case of steam generating units... gas to a steam generating unit. Combustion research means the experimental firing of any fuel or combination of fuels in a steam generating unit for the purpose of conducting research and development of more...
Views of Intimate Partner Violence in Same- and Opposite-Sex Relationships
ERIC Educational Resources Information Center
Sorenson, Susan B.; Thomas, Kristie A.
2009-01-01
Attitudes toward same-sex intimate relationships and intimate partner violence (IPV) are changing. Little research, however, has examined norms about IPV in same-sex relationships. Using a fractional factorial (experimental vignette) design, we conducted random-digit-dialed interviews in four languages with 3,679 community-residing adults.…
Revisiting the Relationship between Exercise Heart Rate and Music Tempo Preference
ERIC Educational Resources Information Center
Karageorghis, Costas I.; Jones, Leighton; Priest, David-Lee; Akers, Rose I.; Clarke, Adam; Perry, Jennifer M.; Reddick, Benjamin T.; Bishop, Daniel T.; Lim, Harry B. T.
2011-01-01
In the present study, we investigated a hypothesized quartic relationship (meaning three inflection points) between exercise heart rate (HR) and preferred music tempo. Initial theoretical predictions suggested a positive linear relationship (Iwanaga, 1995a, 1995b); however, recent experimental work has shown that as exercise HR increases, step…
Experimental aeroelasticity in wind tunnels - History, status, and future in brief
NASA Technical Reports Server (NTRS)
Ricketts, Rodney H.
1993-01-01
The state of the art of experimental aeroelasticity in the United States is assessed. A brief history of the development of ground test facilities, apparatus, and testing methods is presented. Several experimental programs are described that were previously conducted and helped to improve the state of the art. Some specific future directions for improving and enhancing experimental aeroelasticity are suggested.
Murray, Heather
2015-01-01
This article focuses on gay professor-student relationships in the United States, during and post gay liberation. Exploring personal writings, student periodicals, and academic documents between the late 1960s and the 1990s, I argue that interactions between gay professors and their students illuminate an ambiguous affectionate relationship wherein the closeness was based just as much on different generational sensibilities as the individuals themselves. Further, I show that these relationships suggest a therapeutic potential to education through the articulation of personal knowledge in the classroom, one that was increasingly open to challenge in the 1980s and 1990s.
Pérez-Escobar, Oscar Alejandro; Balbuena, Juan Antonio; Gottschling, Marc
2016-01-01
Phylogenetic relationships inferred from multilocus organellar and nuclear DNA data are often difficult to resolve because of evolutionary conflicts among gene trees. However, conflicting or "outlier" associations (i.e., linked pairs of "operational terminal units" in two phylogenies) among these data sets often provide valuable information on evolutionary processes such as chloroplast capture following hybridization, incomplete lineage sorting, and horizontal gene transfer. Statistical tools that to date have been used in cophylogenetic studies only also have the potential to test for the degree of topological congruence between organellar and nuclear data sets and reliably detect outlier associations. Two distance-based methods, namely ParaFit and Procrustean Approach to Cophylogeny (PACo), were used in conjunction to detect those outliers contributing to conflicting phylogenies independently derived from chloroplast and nuclear sequence data. We explored their efficiency of retrieving outlier associations, and the impact of input data (unit branch length and additive trees) between data sets, by using several simulation approaches. To test their performance using real data sets, we additionally inferred the phylogenetic relationships within Neotropical Catasetinae (Epidendroideae, Orchidaceae), which is a suitable group to investigate phylogenetic incongruence because of hybridization processes between some of its constituent species. A comparison between trees derived from chloroplast and nuclear sequence data reflected strong, well-supported incongruence within Catasetum, Cycnoches, and Mormodes. As a result, outliers among chloroplast and nuclear data sets, and in experimental simulations, were successfully detected by PACo when using patristic distance matrices obtained from phylograms, but not from unit branch length trees. The performance of ParaFit was overall inferior compared to PACo, using either phylograms or unit branch lengths as input data. Because workflows for applying cophylogenetic analyses are not standardized yet, we provide a pipeline for executing PACo and ParaFit as well as displaying outlier associations in plots and trees by using the software R. The pipeline renders a method to identify outliers with high reliability and to assess the combinability of the independently derived data sets by means of statistical analyses. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Estimating Risk from Ambient Concentrations of Acrolein across the United States
Woodruff, Tracey J.; Wells, Ellen M.; Holt, Elizabeth W.; Burgin, Deborah E.; Axelrad, Daniel A.
2007-01-01
Background Estimated ambient concentrations of acrolein, a hazardous air pollutant, are greater than the U.S. Environmental Protection Agency (EPA) reference concentration throughout the United States, making it a concern for human health. However, there is no method for assessing the extent of risk under the U.S. EPA noncancer risk assessment framework. Objectives We estimated excess risks from ambient concentrations of acrolein based on dose–response modeling of a study in rats with a relationship between acrolein and residual volume/total lung capacity ratio (RV/TLC) and specific compliance (sCL), markers for altered lung function. Methods Based on existing literature, we defined values above the 90th percentile for controls as “adverse.” We estimated the increase over baseline response that would occur in the human population from estimated ambient concentrations of acrolein, taken from the U.S. EPA’s National-Scale Air Toxics Assessment for 1999, after standard animal-to-human conversions and extrapolating to doses below the experimental data. Results The estimated median additional number of adverse sCL outcomes across the United States was approximately 2.5 cases per 1,000 people. The estimated range of additional outcomes from the 5th to the 95th percentile of acrolein concentration levels across census tracts was 0.28–14 cases per 1,000. For RV/TLC, the median additional outcome was 0.002 per 1,000, and the additional outcome at the 95th percentile was 0.13 per 1,000. Conclusions Although there are uncertainties in estimating human risks from animal data, this analysis demonstrates a method for estimating health risks for noncancer effects and suggests that acrolein could be associated with decreased respiratory function in the United States. PMID:17431491
R2 dark energy in the laboratory
NASA Astrophysics Data System (ADS)
Brax, Philippe; Valageas, Patrick; Vanhove, Pierre
2018-05-01
We analyze the role, on large cosmological scales and laboratory experiments, of the leading curvature squared contributions to the low-energy effective action of gravity. We argue for a natural relationship c0λ2≃1 at low energy between the R2 coefficients c0 of the Ricci scalar squared term in this expansion and the dark energy scale Λ =(λ MPl)4 in four-dimensional Planck mass units. We show how the compatibility between the acceleration of the expansion rate of the Universe, local tests of gravity and the quantum stability of the model all converge to select such a relationship up to a coefficient which should be determined experimentally. When embedding this low-energy theory of gravity into candidates for its ultraviolet completion, we find that the proposed relationship is guaranteed in string-inspired supergravity models with modulus stabilization and supersymmetry breaking leading to de Sitter compactifications. In this case, the scalar degree of freedom of R2 gravity is associated to a volume modulus. Once written in terms of a scalar-tensor theory, the effective theory corresponds to a massive scalar field coupled with the universal strength β =1 /√{6 } to the matter stress-energy tensor. When the relationship c0λ2≃1 is realized, we find that on astrophysical scales and in cosmology the scalar field is ultralocal and therefore no effect arises on such large scales. On the other hand, the scalar field mass is tightly constrained by the nonobservation of fifth forces in torsion pendulum experiments such as Eöt-Wash. It turns out that the observation of the dark energy scale in cosmology implies that the scalar field could be detectable by fifth-force experiments in the near future.
Lopes, Pietro P.; Strmcnik, Dusan; Tripkovic, Dusan; ...
2016-03-07
The development of alternative energy systems for clean production, storage and conversion of energy is strongly dependent on our ability to understand, at atomic-molecular-levels, functional links between activity and stability of electrochemical interfaces. Whereas structure-activity relationships are rapidly evolving, the corresponding structure-stability relationships are still missing. Primarily, this is because there is no adequate experimental approach capable of monitoring in situ stability of well-defined single crystals. Here, by blending the power of Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) connected to a stationary probe to measure in situ and real time dissolution rates of surface atoms (at above 0.4 pg cm-2s-1 levels)more » and a rotating disk electrode method for monitoring simultaneously the kinetic rates of electrochemical reactions in a single unite, it was possible to establish almost “atom-by-atom” the structure-stability-activity relationships for platinum single crystals in both acidic and alkaline environments. Furthermore, we found that the degree of stability is strongly dependent on the coordination of surface atoms (less coordinated yields less stable), the nature of covalent (adsorption of hydroxyl, oxygen atoms and halides species), and non-covalent interactions (interactions between hydrated Li cations and surface oxide), the thermodynamic driving force for Pt complexation (Pt ion speciation in solution) and the nature of the electrochemical reaction (the oxygen reduction/evolution and CO oxidation reactions). Consequently, these findings are opening new opportunities for elucidating key fundamental descriptors that govern both activity and stability trends, that ultimately, will assist to develop real energy conversion and storage systems.« less
Carson, Valerie; Janssen, Ian
2012-10-01
There is evidence to suggest that excessive television viewing is an independent determinant of obesity in young people. However, the pathways between television viewing and obesity are not fully understood. Therefore, the purpose of this study was to examine whether the relationship between television and body mass index (BMI) is mediated by television snacking and junk food consumption. Results are based on 15,973 youth in grades 6-10 who participated in the Canadian 2009/2010 health behaviour in school-aged children survey (HBSC). Participants self-reported their weight and height and BMI z-scores were calculated based on World Health Organization growth standards. Participants reported the frequency of snacking while watching television and the frequency of eating junk food (sweets, soft drinks, baked goods, French fries, potato chips). Total hours per week of television were calculated. A contemporary multiple mediation analysis was used to examine associations. A modest positive relationship was observed between television viewing and BMI. The mean BMI z-score was 0.15 units higher in youth in the highest television viewing quartile by comparison with the youth in the lowest quartile. However, contrary to our hypothesis, television snacking and junk food consumption were not significant positive mediators of the television and BMI relationship. The pathways between television viewing and obesity are complicated and remain poorly understood. Future research using longitudinal or experimental designs, more precise measurement tools and formal mediation analyses is needed. This research should consider mediators related to both energy intake and expenditure. © 2012 The Authors. Pediatric Obesity © 2012 International Association for the Study of Obesity.
Journeys and Destinations: The Challenge of Change. A Language Arts Unit for Grades 2-3.
ERIC Educational Resources Information Center
Cawley, Carol; And Others
This unit of study for high-ability language arts students in grades 2-3 uses an inquiry-based approach to investigate literature in an interdisciplinary curriculum. The guiding theme of the unit is the recognition of change as a concept that affects people and their relationships as well as the world around them. The unit provides the vehicle for…
van Beek, Adriana P A; Wagner, Cordula; Spreeuwenberg, Peter P M; Frijters, Dinnus H M; Ribbe, Miel W; Groenewegen, Peter P
2011-06-01
The behaviour of individuals is affected by the social networks in which they are embedded. Networks are also important for the diffusion of information and the influence of employees in organisations. Yet, at the moment little is known about the social networks of nursing staff in healthcare settings. This is the first study that investigates informal communication and advice networks of nursing staff in long-term care. We examine the structure of the networks, how they are related to the size of units and characteristics of nursing staff, and their relationship with job satisfaction. We collected social network data of 380 nursing staff of 35 units in group projects and psychogeriatric units in nursing homes and residential homes in the Netherlands. Communication and advice networks were analyzed in a social network application (UCINET), focusing on the number of contacts (density) between nursing staff on the units. We then studied the correlation between the density of networks, size of the units and characteristics of nursing staff. We used multilevel analyses to investigate the relationship between social networks and job satisfaction of nursing staff, taking characteristics of units and nursing staff into account. Both communication and advice networks were negatively related to the number of residents and the number of nursing staff of the units. Communication and advice networks were more dense when more staff worked part-time. Furthermore, density of communication networks was positively related to the age of nursing staff of the units. Multilevel analyses showed that job satisfaction differed significantly between individual staff members and units and was influenced by the number of nursing staff of the units. However, this relationship disappeared when density of communication networks was added to the model. Overall, communication and advice networks of nursing staff in long-term care are relatively dense. This fits with the high level of cooperation that is needed to provide good care to residents. Social networks are more dense in small units and are also shaped by characteristics of staff members. The results furthermore show that communication networks are important for staff's job satisfaction.
2011-01-01
Background The behaviour of individuals is affected by the social networks in which they are embedded. Networks are also important for the diffusion of information and the influence of employees in organisations. Yet, at the moment little is known about the social networks of nursing staff in healthcare settings. This is the first study that investigates informal communication and advice networks of nursing staff in long-term care. We examine the structure of the networks, how they are related to the size of units and characteristics of nursing staff, and their relationship with job satisfaction. Methods We collected social network data of 380 nursing staff of 35 units in group projects and psychogeriatric units in nursing homes and residential homes in the Netherlands. Communication and advice networks were analyzed in a social network application (UCINET), focusing on the number of contacts (density) between nursing staff on the units. We then studied the correlation between the density of networks, size of the units and characteristics of nursing staff. We used multilevel analyses to investigate the relationship between social networks and job satisfaction of nursing staff, taking characteristics of units and nursing staff into account. Results Both communication and advice networks were negatively related to the number of residents and the number of nursing staff of the units. Communication and advice networks were more dense when more staff worked part-time. Furthermore, density of communication networks was positively related to the age of nursing staff of the units. Multilevel analyses showed that job satisfaction differed significantly between individual staff members and units and was influenced by the number of nursing staff of the units. However, this relationship disappeared when density of communication networks was added to the model. Conclusions Overall, communication and advice networks of nursing staff in long-term care are relatively dense. This fits with the high level of cooperation that is needed to provide good care to residents. Social networks are more dense in small units and are also shaped by characteristics of staff members. The results furthermore show that communication networks are important for staff's job satisfaction. PMID:21631936
The effect of head nurse behaviors on nurse job satisfaction and performance.
Sorrentino, E A; Nalli, B; Schriesheim, C
1992-01-01
Many nursing executives ponder the repeated problems at the unit level and occasionally surmise that effective supervision at that level holds the key to quality patient care. These pragmatic concerns, while commonplace, have yet to be explored empirically. The relationship of head nurse direction and support on subordinate job satisfaction and performance is not clearly understood. This study examines these relationships in the context of three moderating factors--role clarity, job anxiety, and unit size. Additionally, head nurse support is examined as a moderator of relationships between head nurse direction and subordinate satisfaction and job performance. Using a sample of 103 registered nurses in a medium-capacity metropolitan general hospital, the results show some significant correlations between head nurse behavior and job satisfaction and performance, and in moderating the effects of job anxiety, unit size, and support. The study highlights the need for replication in other settings. Additionally, other variables relevant to job satisfaction and performance such as life stressors (death or illness in the family) require investigation. The findings of this study reveal implications for management at the unit level and the importance of understanding subordinate behaviors in the context of head nurse support and direction.
Understanding Skill in EVA Mass Handling. Volume 1; Theoretical and Operational Foundations
NASA Technical Reports Server (NTRS)
Riccio, Gary; McDonald, Vernon; Peters, Brian; Layne, Charles; Bloomberg, Jacob
1997-01-01
This report describes the theoretical and operational foundations for our analysis of skill in extravehicular mass handling. A review of our research on postural control, human-environment interactions, and exploratory behavior in skill acquisition is used to motivate our analysis. This scientific material is presented within the context of operationally valid issues concerning extravehicular mass handling. We describe the development of meaningful empirical measures that are relevant to a special class of nested control systems: manual interactions between an individual and the substantial environment. These measures are incorporated into a unique empirical protocol implemented on NASA's principal mass handling simulator, the precision air-bearing floor, in order to evaluate skill in extravehicular mass handling. We discuss the components of such skill with reference to the relationship between postural configuration and controllability of an orbital replacement unit, the relationship between orbital replacement unit control and postural stability, the relationship between antecedent and consequent movements of an orbital replacement unit, and the relationship between antecedent and consequent postural movements. Finally, we describe our expectations regarding the operational relevance of the empirical results as it pertains to extravehicular activity tools, training, monitoring, and planning.
NbF5 and TaF5: Assignment of 19F NMR resonances and chemical bond analysis from GIPAW calculations
NASA Astrophysics Data System (ADS)
Biswal, Mamata; Body, Monique; Legein, Christophe; Sadoc, Aymeric; Boucher, Florent
2013-11-01
The 19F isotropic chemical shifts (δiso) of two isomorphic compounds, NbF5 and TaF5, which involve six nonequivalent fluorine sites, have been experimentally determined from the reconstruction of 1D 19F MAS NMR spectra. In parallel, the corresponding 19F chemical shielding tensors have been calculated using the GIPAW method for both experimental and DFT-optimized structures. Furthermore, the [M4F20] units of NbF5 and TaF5 being held together by van der Waals interactions, the relevance of Grimme corrections to the DFT optimization processes has been evaluated. However, the semi-empirical dispersion correction term introduced by such a method does not show any significant improvement. Nonetheless, a complete and convincing assignment of the 19F NMR lines of NbF5 and TaF5 is obtained, ensured by the linearity between experimental 19F δiso values and calculated 19F isotropic chemical shielding σiso values. The effects of the geometry optimizations have been carefully analyzed, confirming among other matters, the inaccuracy of the experimental structure of NbF5. The relationships between the fluorine chemical shifts, the nature of the fluorine atoms (bridging or terminal), the position of the terminal ones (opposite or perpendicular to the bridging ones), the fluorine charges, the ionicity and the length of the M-F bonds have been established. Additionally, for three of the 19F NMR lines of NbF5, distorted multiplets, arising from 1J-coupling and residual dipolar coupling between the 19F and 93Nb nuclei, were simulated yielding to values of 93Nb-19F 1J-coupling for the corresponding fluorine sites.
The New Migrants from Asia: Vietnamese in the United States.
ERIC Educational Resources Information Center
Do, Hien Duc
1996-01-01
Presents instructional materials for a unit of study reexamining the effects of the Vietnam War on the Vietnamese migration to the United States. These materials discuss the historical background of this migration as well as the development of Vietnamese American communities and their relationship to other Asian American communities. (MJP)
Fictional Narrative as Speech Event.
ERIC Educational Resources Information Center
Myers, Miles A.
The issue addressed in this paper is the relationship between form in fictional prose and form in other uses of language, particularly those uses important in composition theory. Form in composition theory has traditionally had two ways of identifying units of analysis: (1) the sentence and semantic units, and (2) pragmatic and rhetorical units.…
Higher Education, Democratization, and the Corps
ERIC Educational Resources Information Center
Weber, Jerome C.
2011-01-01
In recent years, colleges and universities in the United States have had an on-again, off-again relationship with Reserve Officers' Training Corps (ROTC) units on their campuses. This article discusses the history of how these units came into being and the benefits of having ROTC to the students, the institution, and the nation. While there is…
Using Film with Poetry: A Unit Approach.
ERIC Educational Resources Information Center
Lemley, Raymond E.
1970-01-01
Four short, inexpensive films used in conjunction with specific poems provide the basis for individual lessons or a single unit whose theme explicates man and his relationship to other men. "Two Castles," a simple film depicting the foolhardiness of pride is recommended for use in teaching an introductory unit on poetry. "The Wall," a film…
Guided Inquiry Learning Unit on Aquatic Ecosystems for Seventh Grade Students
ERIC Educational Resources Information Center
To-im, Jongdee; Ruenwongsa, Pintip
2009-01-01
Using mini-aquaria experiments, a learning unit on the effects of light period on aquatic ecosystems was developed for 7th grade students. This guided inquiry unit was aimed at helping students understand basic ecological principles involved in relationships among physical, chemical, and biological components in aquatic ecosystems. It involved…
Rouner, Donna; Slater, Michael; Long, Marilee; Stapel, Linda
2010-01-01
Using a nationally representative sample, this study examined the relationship between amount of alcohol and tobacco advertising and related news-editorial content. This study found less tobacco and alcohol advertising in newspapers than did previous research and no relationship between coverage and number of advertisements. PMID:21499450
Rouner, Donna; Slater, Michael; Long, Marilee; Stapel, Linda
2009-03-01
Using a nationally representative sample, this study examined the relationship between amount of alcohol and tobacco advertising and related news-editorial content. This study found less tobacco and alcohol advertising in newspapers than did previous research and no relationship between coverage and number of advertisements.
ERIC Educational Resources Information Center
Boyer, Wanda
2006-01-01
This research examines 480 current event-explanation units using the CAVE technique (Schulman, Castellon, & Seligman, 1989) to note the relationship between positive and negative explanatory style and achievement of prospective early childhood and upper elementary female teachers. This study found a significant positive relationship between…
8 CFR 207.7 - Derivatives of refugees.
Code of Federal Regulations, 2011 CFR
2011-01-01
... to the United States once the Form I-730 has been approved, provided that the relationship of spouse... Form I-730 shall remain valid for the duration of the relationship to the refugee and, in the case of a... least 2 years; (3) A stepchild, if the marriage that created this relationship took place after the...
8 CFR 207.7 - Derivatives of refugees.
Code of Federal Regulations, 2010 CFR
2010-01-01
... to the United States once the Form I-730 has been approved, provided that the relationship of spouse... Form I-730 shall remain valid for the duration of the relationship to the refugee and, in the case of a... least 2 years; (3) A stepchild, if the marriage that created this relationship took place after the...
12 CFR 407.7 - Relationship to Freedom of Information Act.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Relationship to Freedom of Information Act. 407.7 Section 407.7 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES REGULATIONS GOVERNING PUBLIC OBSERVATION OF EX-IM BANK MEETINGS § 407.7 Relationship to Freedom of Information Act. Nothing in...
42 CFR 1007.9 - Relationship to, and agreement with, the Medicaid agency.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 5 2010-10-01 2010-10-01 false Relationship to, and agreement with, the Medicaid agency. 1007.9 Section 1007.9 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES STATE MEDICAID FRAUD CONTROL UNITS § 1007.9 Relationship to, and...
Quality of Grandparent-Grandchild Relationship in Asian-Indian Immigrant Families
ERIC Educational Resources Information Center
Saxena, Divya; Sanders, Gregory F.
2009-01-01
A sample of 112 Asian-Indian Immigrant grandchildren, age 10-16 years, from different parts of the United States completed survey questionnaires regarding the quality of relationship with their grandparents in India. The study explored the factors that affected the quality of relationship between two different generations living at considerable…
Teacher-Child Relationships in Turkish and United States Schools: A Cross-Cultural Study
ERIC Educational Resources Information Center
Beyazkurk, Derya; Kesner, John E.
2005-01-01
Recent educational research utilising Bowlby's attachment theory has focused on children's interpersonal relationships with their teachers. Research in this area has indicated that the security of the teacher-child relationship influences children's development in many of the same ways as secure parent-child attachments. The purpose of this study…
Sibling Relationships in Rural African American Families.
ERIC Educational Resources Information Center
Brody, Gene H.; Stoneman, Zolinda; Smith, Trellis; Gibson, Nicole Morgan
1999-01-01
A family process model was used to link mothers' and fathers' psychological functioning to sibling relationship quality in a sample of 9- to 12-year-old African American youth (N=85) living in the rural Southeastern United States. Better parental psychological functioning was linked to more supportive relationships in the family, and youth in…
Watersheds and fisheries relationships: State of knowledge, southwestern United States
John N. Rinne; Daniel G. Neary
2000-01-01
The relationships and interactions of stream courses, their watersheds, and their aquatic biota have become a contemporary paradigm. Principles and practices of these relationships are generally understood, however, understanding their implications at a landscape scale is embryonic. Because of the threatened and declining status of the native fish fauna of the...
Blue Ridge layout and stand measurements
Robert O. Curtis; Dean S. DeBell; David D. Marshall; Jeffrey D. DeBell; Leslie C. Brodie
2004-01-01
This chapter describes the experimental site, the physical arrangement of treatment units and of measurement plots within units, and the silvicultural operations and vegetation measurements carried out from establishment in 1997-98 through 2002.
Phylogenomic analyses reveal novel relationships among snake families.
Streicher, Jeffrey W; Wiens, John J
2016-07-01
Snakes are a diverse and important group of vertebrates. However, relationships among the major groups of snakes have remained highly uncertain, with recent studies hypothesizing very different (and typically weakly supported) relationships. Here, we address family-level snake relationships with new phylogenomic data from 3776 nuclear loci from ultraconserved elements (1.40million aligned base pairs, 52% missing data overall) sampled from 29 snake species that together represent almost all families, a dataset ∼100 times larger than used in previous studies. We found relatively strong support from species-tree analyses (NJst) for most relationships, including three largely novel clades: (1) a clade uniting the boas, pythons and their relatives, (2) a clade placing cylindrophiids and uropeltids with this clade, and (3) a clade uniting bolyeriids (Round Island boas) with pythonids and their relatives (xenopeltids and loxocemids). Relationships among families of advanced snakes (caenophidians) were also strongly supported. The results show the potential for phylogenomic analyses to resolve difficult groups, but also show a surprising sensitivity of the analyses to the inclusion or exclusion of outgroups. Copyright © 2016 Elsevier Inc. All rights reserved.
Boundary conditions for the Swain-Schaad relationship as a criterion for hydrogen tunneling.
Kohen, Amnon; Jensen, Jan H
2002-04-17
Hydrogen quantum mechanical tunneling has been suggested to play a role in a wide variety of hydrogen-transfer reactions in chemistry and enzymology. An important experimental criterion for tunneling is based on the breakdown of the semiclassical prediction for the relationship among the rates of the three isotopes of hydrogen (hydrogen -H, deuterium -D, and tritium -T). This is denoted the Swain-Schaad relationship. This study examines the breakdown of the Swain-Schaad relationship as criterion for tunneling. The semiclassical (no tunneling) limit used hereto (e.g., 3.34, for H/T to D/T kinetic isotope effects), was based on simple theoretical considerations of a diatomic cleavage of a stable covalent bond, for example, a C-H bond. Yet, most experimental evidence for a tunneling contribution has come from breakdown of those relationship for a secondary hydrogen, that is, not the hydrogen whose bond is being cleaved but its geminal neighbor. Furthermore, many of the reported experiments have been mixed-labeling experiments, in which a secondary H/T kinetic isotope effect was measured for C-H cleavage, while the D/T secondary effect accompanied C-D cleavage. In experiments of this type, the breakdown of the Swain-Schaad relationship indicates both tunneling and the degree of coupled motion between the primary and secondary hydrogens. We found a new semiclassical limit (e.g., 4.8 for H/T to D/T kinetic isotope effects), whose breakdown can serve as a more reliable experimental evidence for tunneling in this common mixed-labeling experiment. We study the tunneling contribution to C-H bond activation, for which many relevant experimental and theoretical data are available. However, these studies can be applied to any hydrogen-transfer reaction. First, an extension of the original approach was applied, and then vibrational analysis studies were carried out for a model system (the enzyme alcohol dehydrogenase). Finally, the effect of complex kinetics on the observed Swain-Schaad relationship was examined. All three methods yield a new semiclassical limit (4.8), above which tunneling must be considered. Yet, it was found that for many cases the original, localized limit (3.34), holds fairly well. For experimental results that are between the original and new limits (within statistical errors), several methods are suggested that can support or exclude tunneling. These new and clearer criteria provide a basis for future applications of the Swain-Schaad relationship to demonstrate tunneling in complex systems.
Passaro, Antony D; Vettel, Jean M; McDaniel, Jonathan; Lawhern, Vernon; Franaszczuk, Piotr J; Gordon, Stephen M
2017-03-01
During an experimental session, behavioral performance fluctuates, yet most neuroimaging analyses of functional connectivity derive a single connectivity pattern. These conventional connectivity approaches assume that since the underlying behavior of the task remains constant, the connectivity pattern is also constant. We introduce a novel method, behavior-regressed connectivity (BRC), to directly examine behavioral fluctuations within an experimental session and capture their relationship to changes in functional connectivity. This method employs the weighted phase lag index (WPLI) applied to a window of trials with a weighting function. Using two datasets, the BRC results are compared to conventional connectivity results during two time windows: the one second before stimulus onset to identify predictive relationships, and the one second after onset to capture task-dependent relationships. In both tasks, we replicate the expected results for the conventional connectivity analysis, and extend our understanding of the brain-behavior relationship using the BRC analysis, demonstrating subject-specific BRC maps that correspond to both positive and negative relationships with behavior. Comparison with Existing Method(s): Conventional connectivity analyses assume a consistent relationship between behaviors and functional connectivity, but the BRC method examines performance variability within an experimental session to understand dynamic connectivity and transient behavior. The BRC approach examines connectivity as it covaries with behavior to complement the knowledge of underlying neural activity derived from conventional connectivity analyses. Within this framework, BRC may be implemented for the purpose of understanding performance variability both within and between participants. Published by Elsevier B.V.
United Kingdom Automobile Insurance Market
DOT National Transportation Integrated Search
1979-05-01
The report represents a limited study of the United Kingdom Automobile Insurance Industry: (1) the structure, size, and relationships within the industry; (2) the basis of premium calculation, rate structure, types of policies, and payment of compens...
McNair, Norma; Baird, Jennifer; Grogan, Tristan R; Walsh, Catherine M; Liang, Li-Jung; Worobel-Luk, Pamela; Needleman, Jack; Nuckols, Teryl K
2016-09-01
The aim of this study is to examine the relationship between nursing time use and perceptions of missed care. Recent literature has highlighted the problem of missed nursing care, but little is known about how nurses' time use patterns are associated with reports of missed care. In 15 nursing units at 2 hospitals, we assessed registered nurse (RN) perceptions of missed care, observed time use by RNs, and examined the relationship between time spent and degree of missed care at the nursing unit level. Patterns of time use were similar across hospitals, with 25% of time spent on documentation. For 6 different categories of nursing tasks, no association was detected between time use, including time spent on documentation, and the degree of missed care at the nursing unit level. Nursing time use cannot fully explain variation in missed care across nursing units. Further work is needed to account for patterns of missed care.
Griffith, James
2015-01-01
A behavioral health concern for the US military has been suicide, largely due to its increased prevalence in the last several years during US involvement in the Iraq and Afghanistan wars. Using hierarchical linear modeling (HLM), the present study examined relationships among combat exposure, postdeployment stressors, social support, and unit cohesion. Survey data were obtained from 4,567 soldiers who were members of 50 company-sized units. At the individual level, combat exposure and postdeployment stressors were associated with suicidal thoughts. Postdeployment social support was associated with fewer suicidal thoughts. There was no evidence of the stress-buffering effect of social support. At the group level, reduced risk for suicidal thoughts was associated with units having higher than average cohesion. Reduced risk for suicidal thoughts in conjunction with combat experiences was observed in units having higher than average cohesion, though not reaching a traditional level of statistical significance.
NASA Astrophysics Data System (ADS)
Rooney, M.; Stambaugh, M. C.
2016-12-01
Wildfire occurrence in the forested ecosystems of the southcentral United States is driven by conditions of drought. Historically, fire intervals varied temporally and spatially - forced by climate, humans, and environmental conditions. Thus, proxy records are required to assess the relationships between fire occurrence, drought, and the El Niño Southern Oscillation (ENSO). Fire scar data from tree-rings are well-suited to assess historical fire regimes in this region, paired with reconstructions of drought and ENSO that have been developed from networks of ring-width chronologies across the United States. This study combines fire-scar data from twelve different sites in the southcentral United States, including two new fire-history reconstructions. Fire data incorporates 665 fires across Eastern Oklahoma and Northern Texas from 1637-2014. These robust reconstructions of post oak (Quercus stellata) evaluate the variability in fire activity and its association to drought and ENSO. Climate-explained growth variance in post-oak chronologies is strong in this region, providing powerful proxy information in the derived chronologies. In general, most fires occur during the La Niña portion of the ENSO cycle. Many severe fires correspond with drought, and results from super-posed epoch analysis suggest a significant relationship between fire event years and drought conditions in the full period of record. Analysis reveals differences in the relationships of fire, drought and ENSO through time, corresponding to changes in human settlement in the region. Understanding the spatial and temporal relationships that exist between fire occurrence, drought, and ENSO aid in quantifying disturbance characteristics and their associations to climate in the forested ecosystems of the southcentral United States.
The relationship between patient data and pooled clinical management decisions.
Ludbrook, G I; O'Loughlin, E J; Corcoran, T B; Grant, C
2013-01-01
A strong relationship between patient data and preoperative clinical decisions could potentially be used to support clinical decisions in preoperative management. The aim of this exploratory study was to determine the relationship between key patient data and pooled clinical opinions on management. In a previous study, panels of anaesthetists compared the quality of computer-assisted patient health assessments with outpatient consultations and made decisions on the need for preoperative tests, no preoperative outpatient assessment, possible postoperative intensive care unit/high dependency unit requirements and aspiration prophylaxis. In the current study, the relationship between patient data and these decisions was examined using binomial logistic regression analysis. Backward stepwise regression was used to identify independent predictors of each decision (at P >0.15), which were then incorporated into a predictive model. The number of factors related to each decision varied: blood picture (four factors), biochemistry (six factors), coagulation studies (three factors), electrocardiography (eight factors), chest X-ray (seven factors), preoperative outpatient assessment (17 factors), intensive care unit requirement (eight factors) and aspiration prophylaxis (one factor). The factor types also varied, but included surgical complexity, age, gender, number of medications or comorbidities, body mass index, hypertension, central nervous system condition, heart disease, sleep apnoea, smoking, persistent pain and stroke. Models based on these relationships usually demonstrated good sensitivity and specificity, with receiver operating characteristics in the following areas under curve: blood picture (0.75), biochemistry (0.86), coagulation studies (0.71), electrocardiography (0.90), chest X-ray (0.85), outpatient assessment (0.85), postoperative intensive care unit requirement (0.88) and aspiration prophylaxis (0.85). These initial results suggest modelling of patient data may have utility supporting clinicians' preoperative decisions.
Holt, N. C.; Wakeling, J. M.; Biewener, A. A.
2014-01-01
The output of skeletal muscle can be varied by selectively recruiting different motor units. However, our knowledge of muscle function is largely derived from muscle in which all motor units are activated. This discrepancy may limit our understanding of in vivo muscle function. Hence, this study aimed to characterize the mechanical properties of muscle with different motor unit activation. We determined the isometric properties and isotonic force–velocity relationship of rat plantaris muscles in situ with all of the muscle active, 30% of the muscle containing predominately slower motor units active or 20% of the muscle containing predominately faster motor units active. There was a significant effect of active motor unit type on isometric force rise time (p < 0.001) and the force–velocity relationship (p < 0.001). Surprisingly, force rise time was longer and maximum shortening velocity higher when all motor units were active than when either fast or slow motor units were selectively activated. We propose this is due to the greater relative effects of factors such as series compliance and muscle resistance to shortening during sub-maximal contractions. The findings presented here suggest that recruitment according to the size principle, where slow motor units are activated first and faster ones recruited as demand increases, may not pose a mechanical paradox, as has been previously suggested. PMID:24695429
Holt, N C; Wakeling, J M; Biewener, A A
2014-05-22
The output of skeletal muscle can be varied by selectively recruiting different motor units. However, our knowledge of muscle function is largely derived from muscle in which all motor units are activated. This discrepancy may limit our understanding of in vivo muscle function. Hence, this study aimed to characterize the mechanical properties of muscle with different motor unit activation. We determined the isometric properties and isotonic force-velocity relationship of rat plantaris muscles in situ with all of the muscle active, 30% of the muscle containing predominately slower motor units active or 20% of the muscle containing predominately faster motor units active. There was a significant effect of active motor unit type on isometric force rise time (p < 0.001) and the force-velocity relationship (p < 0.001). Surprisingly, force rise time was longer and maximum shortening velocity higher when all motor units were active than when either fast or slow motor units were selectively activated. We propose this is due to the greater relative effects of factors such as series compliance and muscle resistance to shortening during sub-maximal contractions. The findings presented here suggest that recruitment according to the size principle, where slow motor units are activated first and faster ones recruited as demand increases, may not pose a mechanical paradox, as has been previously suggested.
Relationship with BSE (Mad Cow Disease)
... consistent with known incubation periods for CJD. An experimental study reported in June 1996 showed that three ... of CJD (Nature 1996;383:685-90). An experimental study involving inoculation of a panel of inbred ...
NASA Astrophysics Data System (ADS)
Mahaut, Fabien; Bertrand, François; Coussot, Philippe; Chateau, Xavier; Ovarlez, Guillaume
2008-07-01
We study experimentally and theoretically the behavior of suspensions of noncolloidal particles in yield stress fluids. We develop procedures and materials that allow focusing on the purely mechanical contribution of the particles to the yield stress fiuid behavior, allowing relating the macroscopic properties of these suspensions to the mechanical properties of the yield stress fluid and the particle volume fraction. We find that the elastic modulus/concentration relationship follows a Krieger-Dougherty law, and show that the yield stress/concentration relationship is related to the elastic modulus/concentration relationship through a very simple law, in agreement with a micromechanical analysis. We finally present evidence for shear-induced migration in the flows of these suspensions.
Use of Physio-Hydrological Units for SMOS Validation at the Valencia Anchor Station Study Area
NASA Astrophysics Data System (ADS)
Millán-Scheiding, C.; Antolín, C.; Marco, J.; Soriano, M. P.; Torre, E.; Requena, F.; Carbó, E.; Cano, A.; Lopez-Baeza, E.
2009-04-01
The SMOS space mission will soil moisture over the continents and ocean surface salinity with the sufficient resolution to be used in global climate change studies. With the aim of validating SMOS land data and products at the Valencia Anchor Station site (VAS) in a Mediterranean Ecosystem area of Spain, we have designed a sample methodology using a subdivision of the landscape in environmental units related to the spatial variability of soil moisture (Millán-Scheiding, 2006; Lopez-Baeza, et al. 2008). These physio-hydrological units are heterogeneously structured entities which present a certain degree of internal uniformity of hydrological parameters. The units are delimited by integrating areas with the same physio-morphology, soil type, vegetation, geology and topography (Flugel, et al 2003; Millán-Scheiding et al, 2007). Each of these units presented over the same pedological characteristics, vegetation cover, and landscape position should have a certain degree of internal uniformity in its hydrological parameters and therefore similar soil moisture (SM). The main assumption for each unit is that the dynamical variation of the hydrological parameters within one unit should be minimum compared to the dynamics of another unit. This methodology will hopefully provide an effective sampling design consisting of a reduced number of measuring points, sparsely distributed over the area, or alternatively, using SM validation networks where each sampling point is located where it is representative of the mean soil moisture of a complete unit area. The Experimental Plan for the SMOS Validation Rehearsal Campaign at the VAS area of April-May 2008 used this environmental subdivision in the selection and sampling of over 21.000 soil moisture points in a control area of 10 x 10 km2. The ground measurements were carried out during 4 nights corresponding to a drying out period of the soil. The sampling consisted of 700 plots with 4 volumetric SM cylinders and 7 Delta-T Theta Probe measurements (with 3 repetitions each), covering the whole area. This experimental campaign permits the characterization of the soil moisture distribution within each physio-hydrological unit and results in a soil moisture map of the VAS site. All of it used for the validation of the aircraft observations done throughout the campaign. The ground measurement results obtained indicate that soil properties and vegetation cover are the parameters of the physio-hydrological units that most influence the moisture of the soil. This relationship will permit a more simple delimitation of the physio-hydrological Units and a reduction of the number of sample points for the calibration/validation of SMOS products. References: Lopez-Baeza, E., R. Acosta, M.C. Antolin, F. Belda, A. Cano, E. Carbo, M. Crapeau, A. Fidalgo S. Juglea, Y. Kerr, B. Martinez, C. Millan-Scheiding, D. Rodriguez, K. Saleh, J. Sanchis, J.-P. Wigneron(10), Other Contributors: J.E. Balling, C. Domenech, EOLAB, A.G. Ferreira J. Ferrer, J. Grant, J. Marco C. Narbon, B. Navascues, OCEANSNELL, E. Rodriguez-Camino, N. Skou, S. Søbjærg, P. Soriano, J. Tamayo, S. Tauriainen, E. Torre G. Torregrosa, A. Velazquez Blazquez, S. Vidal (2008): Validation of SMOS Products over Mediterranean Ecosystem Vegetation at the Valencia Anchor Station Reference Area. SMOS Cal/Val AO I.D. no. 3252. Experimental Plan SMOS Validation Rehearsal Campaign. University of Valencia, April 2008 Millan-Scheiding, C. (2006): Aproximación a la Humedad del Suelo en el Altiplano de Requena-Utiel. Preparación para la Campaña de Cal/Val de la Misión Espacial SMOS. Trabajo de Investigación de III Ciclo. Universidad de Valencia. Millán-Scheiding, C., C. Antolín, A. Cano, E. López-Baeza (2007): Uso de Unidades Fisio-Hidrológicas en la Monitorización de la Humedad del Suelo con SMOS. III Simposio Nacional sobre el Control de la Degradación de Suelos y la Desertificación. Costa Calma (Pájara), Fuerteventura, 16 al 20 de Septiembre 2007
The Structure of the Protonated Serine Octamer.
Scutelnic, Valeriu; Perez, Marta A S; Marianski, Mateusz; Warnke, Stephan; Gregor, Aurelien; Rothlisberger, Ursula; Bowers, Michael T; Baldauf, Carsten; von Helden, Gert; Rizzo, Thomas R; Seo, Jongcheol
2018-06-20
The amino acid serine has long been known to form a protonated "magic-number" cluster containing eight monomer units that shows an unusually high abundance in mass spectra and has a remarkable homochiral preference. Despite many experimental and theoretical studies, there is no consensus on a Ser 8 H + structure that is in agreement with all experimental observations. Here, we present the structure of Ser 8 H + determined by a combination of infrared spectroscopy and ab initio molecular dynamics simulations. The three-dimensional structure that we determine is ∼25 kcal mol -1 more stable than the previous most stable published structure and explains both the homochiral preference and the experimentally observed facile replacement of two serine units.
Relationship between the tensile strengths and diameters of human umbilical cords.
Fernando, D M G; Gamage, S M K; Ranmohottige, S; Weerakkody, I; Abeyruwan, H; Parakrama, H
2018-05-01
Mothers of alleged infanticides might claim that umbilical cord broke during precipitate delivery causing injuries detected on baby at autopsy. There is paucity of evidence regarding this possibility. The objective of the study was to determine relationship between tensile strength and diameter or weight per unit length of cord. Diameters and weights per unit length of fresh umbilical cords were determined. Tensile strengths were measured by Hounsfield Testing Machine. Relationship between tensile strength versus cord diameter and weight per unit length were analyzed. Of 122 cords, average tensile strength, diameter and weight per centimeter were 50.4 N, 7.73 mm and 6.87 g respectively. The tensile strengths were directly proportional to diameter. There was no association between tensile strength and weight per centimeter. Measurement of the diameter of cord is important during autopsy to predict tensile strength and thereby to presume whether cord could have broken by the weight of the baby. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
NASA Technical Reports Server (NTRS)
1983-01-01
The process technology for the manufacture of semiconductor-grade silicon in a large commercial plant by 1986, at a price less than $14 per kilogram of silicon based on 1975 dollars is discussed. The engineering design, installation, checkout, and operation of an Experimental Process System Development unit was discussed. Quality control of scaling-up the process and an economic analysis of product and production costs are discussed.
Experimental study of air delivery into water-conveyance system of the radial-axial turbine
NASA Astrophysics Data System (ADS)
Maslennikova, Alexandra; Platonov, Dmitry; Minakov, Andrey; Dekterev, Dmitry
2017-10-01
The paper presents an experimental study of oscillatory response in the Francis turbine of hydraulic unit. The experiment was performed on large-scale hydrodynamic test-bench with impeller diameter of 0.3 m. The effect of air injection on the intensity of pressure pulsations was studied at the maximum pressure pulsations in the hydraulic unit. It was revealed that air delivery into the water-conveyance system of the turbine results in almost two-fold reduction of pressure pulsations.
NASA Technical Reports Server (NTRS)
1980-01-01
The design, fabrication, and installation of an experimental process system development unit (EPSDU) were analyzed. Supporting research and development were performed to provide an information data base usable for the EPSDU and for technological design and economical analysis for potential scale-up of the process. Iterative economic analyses were conducted for the estimated product cost for the production of semiconductor grade silicon in a facility capable of producing 1000-MT/Yr.
ERIC Educational Resources Information Center
Liou, Wei-Kai; Bhagat, Kaushal Kumar; Chang, Chun-Yen
2018-01-01
The aim of this study is to design and implement a digital interactive globe system (DIGS), by integrating low-cost equipment to make DIGS cost-effective. DIGS includes a data processing unit, a wireless control unit, an image-capturing unit, a laser emission unit, and a three-dimensional hemispheric body-imaging screen. A quasi-experimental study…
Reverse genetics: Its origins and prospects
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berg, P.
1991-04-01
The nucleotide sequence of a gene and its flanking segments alone will not tell us how its expression is regulated during development and differentiation, or in response to environmental changes. To comprehend the physiological significance of the molecular details requires biological analysis. Recombinant DNA techniques provide a powerful experimental approach. A strategy termed reverse genetics' utilizes the analysis of the activities of mutant and normal genes and experimentally constructed mutants to explore the relationship between gene structure and function thereby helping elucidate the relationship between genotype and phenotype.
NASA Astrophysics Data System (ADS)
Miralles, Francesc
2018-06-01
Objective. The motor unit number index (MUNIX) is a technique based on the surface electromyogram (sEMG) that is gaining acceptance as a method for monitoring motor neuron loss, because it is reliable and produces less discomfort than other electrodiagnostic techniques having the same intended purpose. MUNIX assumes that the relationship between the area of sEMG obtained at increasing levels of muscle activation and the values of a variable called ‘ideal case motor unit count’ (ICMUC), defined as the product of the ratio between area and power of the compound muscle action potential (CMAP) by that of the sEMG, is described by a decreasing power function. Nevertheless, the reason for this comportment is unknown. The objective of this work is to investigate if the definition of MUNIX could derive from more basic properties of the sEMG. Approach. The CMAP and sEMG epochs obtained at different levels of muscle activation from (1) the abductor pollicis brevis (APB) muscle of persons with and without a carpal tunnel syndrome (CTS) and (2) from a computer model of sEMG generation previously published were analysed. Main results. MUNIX reflects the power relationship existing between the area and power of a sEMG. The exponent of this function was smaller in patients with motor CTS than in the rest of the subjects. The analysis of the relationship between the area and power of a sEMG could aid in distinguishing a MUNIX reduction due to a motoneuron loss from that due to a loss of muscle fibre. Significance. MUNIX is derived from the relationship between the area and power of a sEMG. This relationship changes when there is a loss of motor units (MUs), which partially explains the diagnostic sensibility of MUNIX. Although the reasons for this change are unknown, it could reflect an increase in the proportion of MUs of great amplitude.
Parrott, Fiona R
2010-12-01
Research into the character of social relationships in psychiatric inpatient facilities has focused on face-to-face interaction between individuals and within groups in the communal areas of wards. Using theories developed in material culture and media studies, this article argues that patients' relationships to goods, namely, photographs, cards and gifts from family or friends, televisions and radios, are important mediators and constituents of sociability. In an ethnographic study of a medium-secure psychiatric unit, I show how these goods are put to use in private space in ways that reflect and mitigate the constraints of incarceration and stigmatization. The data were derived from 3 months of participant observation on a male and a female ward at a unit in the south of England, including a series of anthropological interviews with 19 patients. This article highlights two important findings. First, potentially isolating activities are perceived by patients as sociable, in that watching television and looking at photographs in their room helps to counter feelings of loneliness and isolation. Second, potentially sociable activities, exchanging goods or watching the communal television, are often practiced in such a way as to maintain distance between patients in acknowledgment of the constrained and volatile nature of these relationships. This suggests that patients aspire to retain a sense of the artificiality of their situation, preferring to confine their notion of 'real' relationships to those that exist outside the institution.
Impact from Magnitude-Rupture Length Uncertainty on Seismic Hazard and Risk
NASA Astrophysics Data System (ADS)
Apel, E. V.; Nyst, M.; Kane, D. L.
2015-12-01
In probabilistic seismic hazard and risk assessments seismic sources are typically divided into two groups: fault sources (to model known faults) and background sources (to model unknown faults). In areas like the Central and Eastern United States and Hawaii the hazard and risk is driven primarily by background sources. Background sources can be modeled as areas, points or pseudo-faults. When background sources are modeled as pseudo-faults, magnitude-length or magnitude-area scaling relationships are required to construct these pseudo-faults. However the uncertainty associated with these relationships is often ignored or discarded in hazard and risk models, particularly when faults sources are the dominant contributor. Conversely, in areas modeled only with background sources these uncertainties are much more significant. In this study we test the impact of using various relationships and the resulting epistemic uncertainties on the seismic hazard and risk in the Central and Eastern United States and Hawaii. It is common to use only one magnitude length relationship when calculating hazard. However, Stirling et al. (2013) showed that for a given suite of magnitude-rupture length relationships the variability can be quite large. The 2014 US National Seismic Hazard Maps (Petersen et al., 2014) used one magnitude-rupture length relationship (Somerville, et al., 2001) in the Central and Eastern United States, and did not consider variability in the seismogenic rupture plane width. Here we use a suite of metrics to compare the USGS approach with these variable uncertainty models to assess 1) the impact on hazard and risk and 2) the epistemic uncertainty associated with choice of relationship. In areas where the seismic hazard is dominated by larger crustal faults (e.g. New Madrid) the choice of magnitude-rupture length relationship has little impact on the hazard or risk. However away from these regions, the choice of relationship is more significant and may approach the size of the uncertainty associated with the ground motion prediction equation suite.
Experimental Testing of a Van De Graaff Generator as an Electromagnetic Pulse Generator
2016-07-01
EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR THESIS...protection in the United States AFIT-ENP-MS-16-S-075 EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR...RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENP-MS-16-S-075 EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR
Frisch, Johanna U.; Häusser, Jan A.; van Dick, Rolf; Mojzisch, Andreas
2015-01-01
In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress. In order to study the interplay between these variables, this protocol describes two effective experimental manipulations of social relationships and supportive behavior in the laboratory. In the present article, these two manipulations are implemented in the Trier Social Stress Test (TSST)—a standard stress induction paradigm in which participants are subjected to a simulated job interview. More precisely, we propose (a) a manipulation of the relationship between different protagonists in the TSST by making a shared social identity salient and (b) a manipulation of the behavior of the TSST-selection committee, which acts either supportively or unsupportively. These two experimental manipulations are designed in a modular fashion and can be applied independently of each other but can also be combined. Moreover, these two manipulations can also be integrated into other stress protocols and into other standardized social interactions such as trust games, negotiation tasks, or other group tasks. PMID:26649856
Mechanical properties of triaxially braided composites: Experimental and analytical results
NASA Technical Reports Server (NTRS)
Masters, John E.; Foye, Raymond L.; Pastore, Christopher M.; Gowayed, Yasser A.
1992-01-01
This paper investigates the unnotched tensile properties of two-dimensional triaxial braid reinforced composites from both an experimental and analytical viewpoint. The materials are graphite fibers in an epoxy matrix. Three different reinforcing fiber architectures were considered. Specimens were cut from resin transfer molded (RTM) composite panels made from each braid. There were considerable differences in the observed elastic constants from different size strain gage and extensometer readings. Larger strain gages gave more consistent results and correlated better with the extensometer readings. Experimental strains correlated reasonably well with analytical predictions in the longitudinal, zero degree, fiber direction but not in the transverse direction. Tensile strength results were not always predictable even in reinforcing directions. Minor changes in braid geometry led to disproportionate strength variations. The unit cell structure of the triaxial braid was discussed with the assistence of computer analysis of the microgeometry. Photomicrographs of the braid geometry were used to improve upon the computer graphics representations of unit cells. These unit cells were used to predict the elastic moduli with various degrees of sophistication. The simple and the complex analyses were generally in agreement but none adequately matched the experimental results for all the braids.
Mechanical properties of triaxially braided composites: Experimental and analytical results
NASA Technical Reports Server (NTRS)
Masters, John E.; Foye, Raymond L.; Pastore, Christopher M.; Gowayed, Yasser A.
1992-01-01
The unnotched tensile properties of 2-D triaxial braid reinforced composites from both an experimental and an analytical viewpoint are studied. The materials are graphite fibers in an epoxy matrix. Three different reinforcing fiber architectures were considered. Specimens were cut from resin transfer molded (RTM) composite panels made from each braid. There were considerable differences in the observed elastic constants from different size strain gage and extensometer reading. Larger strain gages gave more consistent results and correlated better with the extensometer reading. Experimental strains correlated reasonably well with analytical predictions in the longitudinal, 0 degrees, fiber direction but not in the transverse direction. Tensile strength results were not always predictable even in reinforcing directions. Minor changes in braid geometry led to disproportionate strength variations. The unit cell structure of the triaxial braid was discussed with the assistance of computer analysis of the microgeometry. Photomicrographs of braid geometry were used to improve upon the computer graphics representations of unit cells. These unit cells were used to predict the elastic moduli with various degrees of sophistication. The simple and the complex analyses were generally in agreement but none adequately matched the experimental results for all the braids.
Zhao, Hongwei; Fu, Lu; Ren, Luquan; Huang, Hu; Fan, Zunqiang; Li, Jianping; Qu, Han
2013-01-01
In this paper, a novel piezo-driven rotary actuator with the changeable clamping radius is developed based on the inchworm principle. This actuator mainly utilizes three piezoelectric actuators, a flexible gripper, a clamping block, and a rotor to achieve large stroke rotation with high resolution. The design process of the flexible gripper consisting of the driving unit and the clamping unit is described. Lever-type mechanisms were used to amplify the micro clamping displacements. The amplifying factor and parasitic displacement of the lever-type mechanism in the clamping unit was analyzed theoretically and experimentally. In order to investigate the rotation characteristics of the actuator, a series of experiments was carried out. Experimental results indicate that the actuator can rotate at a speed of 77,488 μrad/s with a driving frequency of 167 Hz. The rotation resolution and maximum load torque of the actuator are 0.25 μrad and 37 N mm, respectively. The gripper is movable along the z direction based on an elevating platform, and the clamping radius can change from 10.6 mm to 25 mm. Experimental results confirm that the actuator can achieve different rotation speeds by changing the clamping radius.
Union Underground: Political Issues. Comparing Political Experiences, Experimental Edition.
ERIC Educational Resources Information Center
Gillespie, Judith A.; Lazarus, Stuart
This is the third unit to the second-semester "Comparing Political Experiences" course which focuses on a specific, controversial, political issue. The unit analyzes the concept of political maintenance by studying the United Mine Workers of America (UMWA) between 1918 and 1975 and its fight to secure mine safety standards. A documentary…
Modern Problems: Sociology Units. An Experimental Program for Grade 12.
ERIC Educational Resources Information Center
Carlson, Marshall; Fennig, Lois
GRADES OR AGES: Grade 12. SUBJECT MATTER: Sociology; modern problems. ORGANIZATION AND PHYSICAL APPEARANCE: The guide contains two units, one on the problems of minority groups and the other on social pathology. Sub-sections of unit 2 include crime and criminals, criminal investigation, gun control, U.S. criminal law, criminal procedure,…
Clean Air Now: Political Issues. Comparing Political Experiences, Experimental Edition.
ERIC Educational Resources Information Center
Gillespie, Judith A.; Lazarus, Stuart
The fourth unit to the second-semester "Comparing Political Experiences" course focuses on a specific, controversial, political issue. Using a documentary approach, this unit analyzes the concept of political change by examining the changes in Riverside, California, as that community confronts the issue of smog. The unit is divided into…
NASA Astrophysics Data System (ADS)
Moore, David G.; Stair, Sarah L.; Jack, David A.
2018-04-01
Ultrasound techniques are capable of monitoring changes in the time-of-flight as a material is exposed to different thermal environments. The focus of the present study is to identify the phase of a material via ultrasound compression wave measurements in a through transmission experimental setup as the material is heated from a solid to a liquid and then allowed to re-solidify. The present work seeks to expand upon the authors' previous research, which proved this through transmission phase monitoring technique was possible, by considering different experimental geometries. The relationship between geometry, the measured speed of sound, and the temperature profile is presented. The use of different volumes helps in establishing a baseline understanding of which aspects of the experiment are geometry dependent and which are independent. The present study also investigates the relationship between the heating rate observed in the experiment and the measured speed of sound. The trends identified between the experimental geometry, heat rate and ultrasound wave speed measurement assist in providing a baseline understanding of the applicability of this technique to various industries, including the polymer industry and the oil industry.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moore, David G.; Stair, Sarah Louise; Jack, David A.
Ultrasound techniques are capable of monitoring changes in the time-of-flight as a material is exposed to different thermal environments. The focus of the present study is to identify the phase of a material via ultrasound compression wave measurements in a through transmission experimental setup as the material is heated from a solid to a liquid and then allowed to re-solidify. The present work seeks to expand upon the authors’ previous research, which proved this through transmission phase monitoring technique was possible, by considering different experimental geometries. The relationship between geometry, the measured speed of sound, and the temperature profile ismore » presented. The use of different volumes helps in establishing a baseline understanding of which aspects of the experiment are geometry dependent and which are independent. The present study also investigates the relationship between the heating rate observed in the experiment and the measured speed of sound. Lastly, the trends identified between the experimental geometry, heat rate and ultrasound wave speed measurement assist in providing a baseline understanding of the applicability of this technique to various industries, including the polymer industry and the oil industry.« less
Moore, David G.; Stair, Sarah Louise; Jack, David A.
2018-04-01
Ultrasound techniques are capable of monitoring changes in the time-of-flight as a material is exposed to different thermal environments. The focus of the present study is to identify the phase of a material via ultrasound compression wave measurements in a through transmission experimental setup as the material is heated from a solid to a liquid and then allowed to re-solidify. The present work seeks to expand upon the authors’ previous research, which proved this through transmission phase monitoring technique was possible, by considering different experimental geometries. The relationship between geometry, the measured speed of sound, and the temperature profile ismore » presented. The use of different volumes helps in establishing a baseline understanding of which aspects of the experiment are geometry dependent and which are independent. The present study also investigates the relationship between the heating rate observed in the experiment and the measured speed of sound. Lastly, the trends identified between the experimental geometry, heat rate and ultrasound wave speed measurement assist in providing a baseline understanding of the applicability of this technique to various industries, including the polymer industry and the oil industry.« less
Prediction of Human Activity by Discovering Temporal Sequence Patterns.
Li, Kang; Fu, Yun
2014-08-01
Early prediction of ongoing human activity has become more valuable in a large variety of time-critical applications. To build an effective representation for prediction, human activities can be characterized by a complex temporal composition of constituent simple actions and interacting objects. Different from early detection on short-duration simple actions, we propose a novel framework for long -duration complex activity prediction by discovering three key aspects of activity: Causality, Context-cue, and Predictability. The major contributions of our work include: (1) a general framework is proposed to systematically address the problem of complex activity prediction by mining temporal sequence patterns; (2) probabilistic suffix tree (PST) is introduced to model causal relationships between constituent actions, where both large and small order Markov dependencies between action units are captured; (3) the context-cue, especially interactive objects information, is modeled through sequential pattern mining (SPM), where a series of action and object co-occurrence are encoded as a complex symbolic sequence; (4) we also present a predictive accumulative function (PAF) to depict the predictability of each kind of activity. The effectiveness of our approach is evaluated on two experimental scenarios with two data sets for each: action-only prediction and context-aware prediction. Our method achieves superior performance for predicting global activity classes and local action units.
The experience of the nurse at triage influences the timing of CPAP intervention.
MacGeorge, Jane M; Nelson, Katherine M
2003-10-01
Increasing attention in the last decade has shown that intervention of continuous positive airway pressure therapy (CPAP) in cardiogenic pulmonary oedema (CPO) markedly improves the outcome of patients presenting with acute respiratory failure. This study used a non-experimental correlational design to research the relationship between the experience of the nurse, with the application of CPAP to patients presenting to a metropolitan emergency department with CPO and to establish what difference, if any, CPAP made to outcomes. A retrospective audit of records was used to extract data on all 54 patients that received CPAP over a 12-month period. The primary outcome measures were off CPAP within 2 h, transfer to intensive care unit (ICU) or cardiac care unit (CCU) and secondary outcome measures were length of hospital stay and death. There was a trend towards more experienced nurses attending patients who required immediate treatment or treatment within 10 min. These patients were more likely to be recognised at triage as requiring CPAP therapy. The early application of CPAP reduced hospital mortality, length of stay, and the need for intubation and ventilation. Attention needs to be given on how best to educate nurses so that more patients presenting with acute respiratory failure can benefit from nurses' decision-making regarding the commencement of CPAP.
Kraus, Michael W.; Adler, Nancy; David Chen, Teh-Way
2012-01-01
Objective Lower subjective socioeconomic status (SSS) consistently shows associations with poorer health with the strongest relationships emerging with global self-rated health. Though often interpreted as reflecting the impact of low SSS on health, the association could also arise from confounding SSS with negative affect. In this research we sought to determine if negative affect confounds, or alternatively, is on the causal pathway linking SSS to self-rated health. Methods 300 adult participants—recruited from throughout the United States—were randomized to experience sadness, shame, or a neutral mood induction wherein they wrote about and visualized a particularly emotionally evocative event. Participants subsequently completed measures of SSS, self-rated health, depression, and negative mood. Results Consistent with predictions, neither SSS scores nor the association of SSS with self-rated health, depression, and chronic negative affect differed by mood induction condition, controlling for demographic factors that covary with SSS (e.g., age, gender, education, income). Moreover, chronic negative affect partially explained the relationship between SSS and self-rated health, independent of manipulated mood. Conclusions These findings support the utility of the measurement of SSS, and provide evidence suggesting that chronic negative affect is a likely mediator of the SSS association with global health rather than a confounder. PMID:22329426
Health effects of nanomaterials.
Tetley, T D
2007-06-01
With the rapid growth of nanotechnology and future bulk manufacture of nanomaterials comes the need to determine, understand and counteract any adverse health effects of these materials that may occur during manufacture, during use, or accidentally. Nanotechnology is expanding rapidly and will affect many aspects of everyday life; there are already hundreds of products that utilize nanoparticles. Paradoxically, the unique properties that are being exploited (e.g. high surface reactivity and ability to cross cell membranes) might have negative health impacts. The rapid progress in development and use of nanomaterials is not yet matched by toxicological investigations. Epidemiological studies implicate the ultrafine (nano-sized) fraction of particulate air pollution in the exacerbation of cardiorespiratory disease and increased morbidity. Experimental animal studies suggest that the increased concentration of nanoparticles and higher reactive surface area per unit mass, alongside unique chemistry and functionality, is important in the acute inflammatory and chronic response. Some animal models have shown that nanoparticles which are deposited in one organ (e.g. lung and gut) may access the vasculature and target other organs (e.g. brain and liver). The exact relationship between the physicochemistry of a nanoparticle, its cellular reactivity, and its biological and systemic consequences cannot be predicted. It is important to understand such relationships to enjoy the benefits of nanotechnology without being exposed to the hazards.
Song, Zhongchang; Zhang, Yu; Berggren, Per; Wei, Chong
2017-02-01
Computed tomography (CT) imaging and ultrasound experimental measurements were combined to reconstruct the acoustic properties (density, velocity, and impedance) of the head from a deceased Indo-Pacific humpback dolphin (Sousa chinensis). The authors extracted 42 soft forehead tissue samples to estimate the sound velocity and density properties at room temperature, 25.0 °C. Hounsfield Units (HUs) of the samples were read from CT scans. Linear relationships between the tissues' HUs and velocity, and HUs and density were revealed through regression analyses. The distributions of the head acoustic properties at axial, coronal, and sagittal cross sections were reconstructed, suggesting that the forehead soft tissues were characterized by low-velocity in the melon, high-velocity in the muscle and connective tissues. Further, the sound velocities of melon, muscle, and connective tissue pieces were measured under different temperatures to investigate tissues' velocity response to temperature. The results demonstrated nonlinear relationships between tissues' sound velocity and temperature. This study represents a first attempt to provide general information on acoustic properties of this species. The results could provide meaningful information for understanding the species' bioacoustic characteristics and for further investigation on sound beam formation of the dolphin.
Linear control of a boiler-turbine unit: analysis and design.
Tan, Wen; Fang, Fang; Tian, Liang; Fu, Caifen; Liu, Jizhen
2008-04-01
Linear control of a boiler-turbine unit is discussed in this paper. Based on the nonlinear model of the unit, this paper analyzes the nonlinearity of the unit, and selects the appropriate operating points so that the linear controller can achieve wide-range performance. Simulation and experimental results at the No. 4 Unit at the Dalate Power Plant show that the linear controller can achieve the desired performance under a specific range of load variations.
Speed of the bacterial flagellar motor near zero load depends on the number of stator units.
Nord, Ashley L; Sowa, Yoshiyuki; Steel, Bradley C; Lo, Chien-Jung; Berry, Richard M
2017-10-31
The bacterial flagellar motor (BFM) rotates hundreds of times per second to propel bacteria driven by an electrochemical ion gradient. The motor consists of a rotor 50 nm in diameter surrounded by up to 11 ion-conducting stator units, which exchange between motors and a membrane-bound pool. Measurements of the torque-speed relationship guide the development of models of the motor mechanism. In contrast to previous reports that speed near zero torque is independent of the number of stator units, we observe multiple speeds that we attribute to different numbers of units near zero torque in both Na + - and H + -driven motors. We measure the full torque-speed relationship of one and two H + units in Escherichia coli by selecting the number of H + units and controlling the number of Na + units in hybrid motors. These experiments confirm that speed near zero torque in H + -driven motors increases with the stator number. We also measured 75 torque-speed curves for Na + -driven chimeric motors at different ion-motive force and stator number. Torque and speed were proportional to ion-motive force and number of stator units at all loads, allowing all 77 measured torque-speed curves to be collapsed onto a single curve by simple rescaling. Published under the PNAS license.
Speed of the bacterial flagellar motor near zero load depends on the number of stator units
Nord, Ashley L.; Sowa, Yoshiyuki; Steel, Bradley C.; Lo, Chien-Jung; Berry, Richard M.
2017-01-01
The bacterial flagellar motor (BFM) rotates hundreds of times per second to propel bacteria driven by an electrochemical ion gradient. The motor consists of a rotor 50 nm in diameter surrounded by up to 11 ion-conducting stator units, which exchange between motors and a membrane-bound pool. Measurements of the torque–speed relationship guide the development of models of the motor mechanism. In contrast to previous reports that speed near zero torque is independent of the number of stator units, we observe multiple speeds that we attribute to different numbers of units near zero torque in both Na+- and H+-driven motors. We measure the full torque–speed relationship of one and two H+ units in Escherichia coli by selecting the number of H+ units and controlling the number of Na+ units in hybrid motors. These experiments confirm that speed near zero torque in H+-driven motors increases with the stator number. We also measured 75 torque–speed curves for Na+-driven chimeric motors at different ion-motive force and stator number. Torque and speed were proportional to ion-motive force and number of stator units at all loads, allowing all 77 measured torque–speed curves to be collapsed onto a single curve by simple rescaling. PMID:29078322
Fear of predation drives stable and differentiated social relationships in guppies
Heathcote, Robert J. P.; Darden, Safi K.; Franks, Daniel W.; Ramnarine, Indar W.; Croft, Darren P.
2017-01-01
Social relationships can have important consequences for fitness in animals. Whilst numerous studies have shown that individuals often join larger groups in response to perceived predation risk (i.e. fear of predation), the importance of predation risk in driving the formation and stability of social relationships within groups has been relatively ignored. We experimentally tested how predation threat influenced fine-scale social network structure using Trinidadian guppies (Poecilia reticulata). When perceived predation risk was high, individuals developed stable and more differentiated social ties compared to when perceived risk was low. Intriguingly, social differentiation coincided with shoals being somewhat smaller under high-perceived risk, suggesting a possible conflict between forming stable social relationships and larger social groups. Individuals most at risk of predation (large and bold individuals) showed the most exaggerated responses in several social measures. Taken together, we provide the first experimental evidence that proximate risk of predation can increase the intensity of social relationships and fine-scale social structure in animal populations. PMID:28150706
Fear of predation drives stable and differentiated social relationships in guppies.
Heathcote, Robert J P; Darden, Safi K; Franks, Daniel W; Ramnarine, Indar W; Croft, Darren P
2017-02-02
Social relationships can have important consequences for fitness in animals. Whilst numerous studies have shown that individuals often join larger groups in response to perceived predation risk (i.e. fear of predation), the importance of predation risk in driving the formation and stability of social relationships within groups has been relatively ignored. We experimentally tested how predation threat influenced fine-scale social network structure using Trinidadian guppies (Poecilia reticulata). When perceived predation risk was high, individuals developed stable and more differentiated social ties compared to when perceived risk was low. Intriguingly, social differentiation coincided with shoals being somewhat smaller under high-perceived risk, suggesting a possible conflict between forming stable social relationships and larger social groups. Individuals most at risk of predation (large and bold individuals) showed the most exaggerated responses in several social measures. Taken together, we provide the first experimental evidence that proximate risk of predation can increase the intensity of social relationships and fine-scale social structure in animal populations.
Learning Effects of an Experimental EFL Program in Second Life
ERIC Educational Resources Information Center
Wang, Charles Xiaoxue; Calandra, Brendan; Hibbard, Susan T.; McDowell Lefaiver, Mary L.
2012-01-01
This paper reports on the effects an experimental English as a Foreign Language (EFL) program in Second Life (SL) had on Chinese student EFL learning. The study took an evaluative approach using quasi-experimental design with participants from one Chinese university and one American university in the southeastern United States. Results indicated…
NASA Astrophysics Data System (ADS)
Zhe Sun, Phillip; Lu, Jie; Wu, Yin; Xiao, Gang; Wu, Renhua
2013-09-01
Chemical exchange saturation transfer (CEST) is a magnetic resonance imaging (MRI) contrast mechanism that can detect dilute CEST agents and microenvironmental properties, with a host of promising applications. Experimental measurement of the CEST effect is complex, and depends on not only CEST agent concentration and exchange rate, but also experimental parameters such as RF irradiation amplitude and scheme. Although echo planar imaging (EPI) has been increasingly used for CEST MRI, the relationship between CEST effect and repetition time (TR), RF irradiation duty cycle (DC) and EPI flip angle (α) has not been fully evaluated and optimized to enhance CEST MRI sensitivity. In addition, our study evaluated gradient echo CEST-EPI by quantifying the CEST effect and its signal-to-noise ratio per unit time (SNRput) as functions of TR, DC and α. We found that CEST effect increased with TR and DC but decreased with α. Importantly, we found that SNRput peaked at intermediate TRs of about twice the T1 and α, at approximately 75°, and increased with RF DC. The simulation results were validated using a dual-pH creatine-gel CEST phantom. In summary, our study provides a useful framework for optimizing CEST MRI experiments.
A Quantitative Model for the Prediction of Sooting Tendency from Molecular Structure
DOE Office of Scientific and Technical Information (OSTI.GOV)
St. John, Peter C.; Kairys, Paul; Das, Dhrubajyoti D.
Particulate matter emissions negatively affect public health and global climate, yet newer fuel-efficient gasoline direct injection engines tend to produce more soot than their port-fuel injection counterparts. Fortunately, the search for sustainable biomass-based fuel blendstocks provides an opportunity to develop fuels that suppress soot formation in more efficient engine designs. However, as emissions tests are experimentally cumbersome and the search space for potential bioblendstocks is vast, new techniques are needed to estimate the sooting tendency of a diverse range of compounds. In this study, we develop a quantitative structure-activity relationship (QSAR) model of sooting tendency based on the experimental yieldmore » sooting index (YSI), which ranks molecules on a scale from n-hexane, 0, to benzene, 100. The model includes a rigorously defined applicability domain, and the predictive performance is checked using both internal and external validation. Model predictions for compounds in the external test set had a median absolute error of ~3 YSI units. An investigation of compounds that are poorly predicted by the model lends new insight into the complex mechanisms governing soot formation. Predictive models of soot formation can therefore be expected to play an increasingly important role in the screening and development of next-generation biofuels.« less
Lung Morphometry with Hyperpolarized 129Xe: Theoretical Background
Sukstanskii, A.L.; Yablonskiy, D.A.
2011-01-01
The 3He lung morphometry technique, based on MRI measurements of hyperpolarized 3He gas diffusion in lung airspaces, provides unique information on the lung microstructure at the alveolar level. In vivo 3D tomographic images of standard morphological parameters (airspace chord length, lung parenchyma surface-to-volume ratio, number of alveoli per unit volume) can be generated from a rather short (several seconds) MRI scan. The technique is based on a theory of gas diffusion in lung acinar airways and experimental measurements of diffusion attenuated MRI signal. The present work aims at developing the theoretical background of a similar technique based on hyperpolarized 129Xe gas. As the diffusion coefficient and gyromagnetic ratio of 129Xe gas are substantially different from those of 3He gas, the specific details of the theory and experimental measurements with 129Xe should be amended. We establish phenomenological relationships between acinar airway geometrical parameters and the diffusion attenuated MR signal for human and small animal lungs, both normal lungs and lungs with mild emphysema. Optimal diffusion times are shown to be about 5 ms for human and 1.3 ms for small animals. The expected uncertainties in measuring main morphometrical parameters of the lungs are estimated in the framework of Bayesian probability theory. PMID:21713985
A Quantitative Model for the Prediction of Sooting Tendency from Molecular Structure
St. John, Peter C.; Kairys, Paul; Das, Dhrubajyoti D.; ...
2017-07-24
Particulate matter emissions negatively affect public health and global climate, yet newer fuel-efficient gasoline direct injection engines tend to produce more soot than their port-fuel injection counterparts. Fortunately, the search for sustainable biomass-based fuel blendstocks provides an opportunity to develop fuels that suppress soot formation in more efficient engine designs. However, as emissions tests are experimentally cumbersome and the search space for potential bioblendstocks is vast, new techniques are needed to estimate the sooting tendency of a diverse range of compounds. In this study, we develop a quantitative structure-activity relationship (QSAR) model of sooting tendency based on the experimental yieldmore » sooting index (YSI), which ranks molecules on a scale from n-hexane, 0, to benzene, 100. The model includes a rigorously defined applicability domain, and the predictive performance is checked using both internal and external validation. Model predictions for compounds in the external test set had a median absolute error of ~3 YSI units. An investigation of compounds that are poorly predicted by the model lends new insight into the complex mechanisms governing soot formation. Predictive models of soot formation can therefore be expected to play an increasingly important role in the screening and development of next-generation biofuels.« less
NASA Astrophysics Data System (ADS)
Zhao, Yong; Xia, Feng; Hu, Hai-feng; Chen, Mao-qing
2017-11-01
A novel refractive index (RI) sensor based on photonic crystal fiber Mach-Zehnder interferometer (PCF-MZI) was proposed. It was realized by cascading a section of PCF with half-taper collapse regions (HTCRs) between two single mode fibers (SMFs). The relationship between RI sensitivity and interference length of the PCF-MZI was firstly investigated. Both simulation and experimental results showed that RI sensitivity increased with the increase of interference length. Afterwards, influence of HTCR parameters on RI sensitivity was experimentally investigated to further improve the sensitivity. With intensification of arc discharge intensity in HTCR fabrication process, HTCR with larger maximum taper diameter and longer collapsed region length was obtained, which enhanced evanescent field of the PCF-MZI and then generated higher RI sensitivity. Consequently, a high RI sensitivity of 181.96 nm/refractive index unit (RIU) was achieved in the RI range of 1.3333-1.3574. Increasing arc discharge intensity in HTCR fabrication process has the capacity to improve RI sensitivity of PCF-MZI and meanwhile provides higher mechanical strength and longer sensor life compared to the traditional method of tapering the fiber, which improves the RI sensitivity at the cost of reducing mechanical strength of the sensor. This PCF-MZI was characterized by high RI sensitivity, ease of fabrication, high mechanical strength, and robustness.
Update on fertility preservation in young women undergoing breast cancer and ovarian cancer therapy.
Lambertini, Matteo; Ginsburg, Elizabeth S; Partridge, Ann H
2015-02-01
The purpose of the article is to review the available options for fertility preservation in patients with breast and ovarian cancer, and the special issues faced by BRCA mutation carriers. Future fertility is an important consideration for many young patients with cancer. There are both experimental and standard available strategies for patients with breast and ovarian cancer to preserve fertility, and each has potential advantages and disadvantages. Embryo cryopreservation is widely available with a highly successful track record. Improvements in laboratory techniques have led to oocyte cryopreservation recently being recategorized as nonexperimental. Conservative gynecologic surgery is a standard consideration for patients with stage I ovarian cancer who desire future fertility. Ovarian tissue cryopreservation as well as ovarian suppression with luteinizing hormone-releasing hormone analogs during chemotherapy are considered experimental methods at this time, although recent data suggest both safety and efficacy for the use of luteinizing hormone-releasing hormone analogs in women receiving (neo)adjuvant chemotherapy for breast cancer. Special issues should be considered for women with BRCA mutations because of the need to undergo preventive surgery at young age. Multidisciplinary teams and well functioning relationships between the oncology and reproductive units are crucial to manage the fertility issues of young women with cancer.
Defense.gov Special Report: Travels With Carter - July 2015 2
Reaffirms Bilateral Relationship With Jordanian Leaders Defense Secretary Ash Carter reaffirmed the relationship between the United States and Jordan in a meeting with Gen. Mashal al-Zaben, King Abdullah II's
Design Issues and Inference in Experimental L2 Research
ERIC Educational Resources Information Center
Hudson, Thom; Llosa, Lorena
2015-01-01
Explicit attention to research design issues is essential in experimental second language (L2) research. Too often, however, such careful attention is not paid. This article examines some of the issues surrounding experimental L2 research and its relationships to causal inferences. It discusses the place of research questions and hypotheses,…
Leadership-organizational culture relationship in nursing units of acute care hospitals.
Casida, Jesus; Pinto-Zipp, Genevieve
2008-01-01
The phenomena of leadership and organizational culture (OC) has been defined as the driving forces in the success or failure of an organization. Today, nurse managers must demonstrate leadership behaviors or styles that are appropriate for the constantly changing, complex, and turbulent health care delivery system. In this study, researchers explored the relationship between nurse managers' leadership styles and OC of nursing units within an acute care hospital that had achieved excellent organizational performance as demonstrated by a consistent increase in patient satisfaction ratings. The data from this study support that transformational and transactional contingent reward leaderships as nurse manager leadership styles that are associated with nursing unit OC that have the ability to balance the dynamics of flexibility and stability within their nursing units and are essential for maintaining organizational effectiveness. It is essential for first-line nursing leaders to acquire knowledge and skills on organizational cultural competence.
Fritts, Sarah; Moorman, Christopher; Grodsky, Steven; Hazel, Dennis; Homyack, Jessica; Farrell, Chris; Castleberry, Steven
2016-04-01
Forests are a major supplier of renewable energy; however, gleaning logging residues for use as woody biomass feedstock could negatively alter habitat for species dependent on downed wood. Biomass Harvesting Guidelines (BHGs) recommend retaining a portion of woody biomass on the forest floor following harvest. Despite BHGs being developed to help ensure ecological sustainability, their contribution to biodiversity has not been evaluated experimentally at operational scales. We compared herpetofauanal evenness, diversity, and richness and abundance of Anaxyrus terrestris and Gastrophryne carolinensis among six treatments that varied in volume and spatial arrangement of woody biomass retained after clearcutting loblolly pine (Pinus taeda) plantations in North Carolina, USA (n = 4), 2011-2014 and Georgia (n = 4), USA 2011-2013. Treatments were: (1) biomass harvest with no BHGs, (2) 15% retention with biomass clustered, (3) 15% retention with biomass dispersed, (4) 30% retention with biomass clustered, (5) 30% retention with biomass dispersed, and (6) no biomass harvest. We captured individuals with drift fence arrays and compared evenness, diversity, and richness metrics among treatments with repeated-measure, linear mixed-effects models. We determined predictors of A. terrestris and G. carolinensis abundances using a priori candidate N-mixture models with woody biomass volume, vegetation structure, and groundcover composition as covariates. We had 206 captures of 25 reptile species and 8710 captures of 17 amphibian species during 53690 trap nights. Herpetofauna diversity, evenness, and richness were similar among treatments. A. terrestris abundance was negatively related to volume of retained woody biomass in treatment units in North Carolina in 2013. G. carolinensis abundance was positively related with volume of retained woody debris in treatment units in Georgia in 2012. Other relationships between A. terrestris and G. carolinensis abundances and habitat metrics were weak or absent. The lack of consistent community or population responses suggests the addition of a woody biomass harvest to a clearcut in pine plantations does not impact herpetofauna use of Coastal Plain loblolly plantations in the southeastern United States. We recommend additional research to examine relationships between woody biomass harvesting and rarer species or amphibians with high desiccation risk, particularly in other regions and harvesting systems.
Lopes, F; Ruh, K; Combs, D K
2015-04-01
The experimental objective was to validate an in vitro model to predict total-tract neutral detergent fiber (NDF) digestibility in dairy cattle. Twenty-one diets from 7 studies conducted at University of Wisconsin-Madison were analyzed for in vitro fiber digestibility. Forages varied among diets (corn, alfalfa, tall and meadow fescue, and wheat straw silages) and nutrient composition (ranges: NDF = 22.5 to 33.8%; crude protein = 15.8 to 18.9%; nonfiber carbohydrates = 38.0 to 51.0%). Total-tract NDF digestibility (TTNDFD) observed in in vivo trials was determined using different markers as described in the individual studies. The in vitro TTNDFD model predicted total-tract fiber digestibility from the proportion of total NDF potentially digestible (pdNDF), rate of pdNDF degradation, and rate of passage of pdNDF. The model predicted TTNDFD similar to in vivo measurements. The relationship between TTNDFD measured in vivo and TTNDFD predicted by the in vitro assay was significant (R(2) = 0.68). The relationship between in vitro 30-h NDF digestibility values and in vivo total-tract NDF digestibility values was not significant, whereas in vitro 48-h NDF digestibility values were correlated (R(2) = 0.30) with in vivo TTNDFD measurements. Indigestible NDF (iNDF) showed a negative relationship (R(2) = 0.40) with TTNDFD in vivo. Each 1-percentage-unit increase of iNDF resulted in a decrease of 0.96 percentage units of total-tract NDF digestibility; however, iNDF by itself was not a good predictor of TTNDFD because of the difference among the means. This study showed that an in vitro TTNDFD model that uses iNDF, pdNDF, and rates of pdNDF digestion and passage can predict (R(2) = 0.68) total-tract NDF digestibility. Most importantly, we demonstrated the ability to predict total-tract fiber digestibility from a model based on in vitro NDF degradation, which could improve our ability to optimize forage utilization and milk production. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Zero-lag synchronization in coupled time-delayed piecewise linear electronic circuits
NASA Astrophysics Data System (ADS)
Suresh, R.; Srinivasan, K.; Senthilkumar, D. V.; Raja Mohamed, I.; Murali, K.; Lakshmanan, M.; Kurths, J.
2013-07-01
We investigate and report an experimental confirmation of zero-lag synchronization (ZLS) in a system of three coupled time-delayed piecewise linear electronic circuits via dynamical relaying with different coupling configurations, namely mutual and subsystem coupling configurations. We have observed that when there is a feedback between the central unit (relay unit) and at least one of the outer units, ZLS occurs in the two outer units whereas the central and outer units exhibit inverse phase synchronization (IPS). We find that in the case of mutual coupling configuration ZLS occurs both in periodic and hyperchaotic regimes, while in the subsystem coupling configuration it occurs only in the hyperchaotic regime. Snapshots of the time evolution of outer circuits as observed from the oscilloscope confirm the occurrence of ZLS experimentally. The quality of ZLS is numerically verified by correlation coefficient and similarity function measures. Further, the transition to ZLS is verified from the changes in the largest Lyapunov exponents and the correlation coefficient as a function of the coupling strength. IPS is experimentally confirmed using time series plots and also can be visualized using the concept of localized sets which are also corroborated by numerical simulations. In addition, we have calculated the correlation of probability of recurrence to quantify the phase coherence. We have also analytically derived a sufficient condition for the stability of ZLS using the Krasovskii-Lyapunov theory.
Influence of light curing and sample thickness on microhardness of a composite resin
Aguiar, Flávio HB; Andrade, Kelly RM; Leite Lima, Débora AN; Ambrosano, Gláucia MB; Lovadino, José R
2009-01-01
The aim of this in vitro study was to evaluate the influence of light-curing units and different sample thicknesses on the microhardness of a composite resin. Composite resin specimens were randomly prepared and assigned to nine experimental groups (n = 5): considering three light-curing units (conventional quartz tungsten halogen [QTH]: 550 mW/cm2 – 20 s; high irradiance QTH: 1160 mW/cm2 – 10 s; and light-emitting diode [LED]: 360 mW/cm2 – 40 s) and three sample thicknesses (0.5 mm, 1 mm, and 2 mm). All samples were polymerized with the light tip 8 mm away from the specimen. Knoop microhardness was then measured on the top and bottom surfaces of each sample. The top surfaces, with some exceptions, were almost similar; however, in relation to the bottom surfaces, statistical differences were found between curing units and thicknesses. In all experimental groups, the 0.5-mm-thick increments showed microhardness values statistically higher than those observed for 1- and -2-mm increments. The conventional and LED units showed higher hardness mean values and were statistically different from the high irradiance unit. In all experimental groups, microhardness mean values obtained for the top surface were higher than those observed for the bottom surface. In conclusion, higher levels of irradiance or thinner increments would help improve hybrid composite resin polymerization. PMID:23674901
Zheng, Jie; Liang, Guizhao
2015-01-01
Phenolic acids and derivatives have potential biological functions, however, little is known about the structure-activity relationships and the underlying action mechanisms of these phenolic acids to date. Herein we investigate the structure-thermodynamics-antioxidant relationships of 20 natural phenolic acids and derivatives using DPPH• scavenging assay, density functional theory calculations at the B3LYP/6-311++G(d,p) levels of theory, and quantitative structure-activity relationship (QSAR) modeling. Three main working mechanisms (HAT, SETPT and SPLET) are explored in four micro-environments (gas-phase, benzene, water and ethanol). Computed thermodynamics parameters (BDE, IP, PDE, PA and ETE) are compared with the experimental radical scavenging activities against DPPH•. Available theoretical and experimental investigations have demonstrated that the extended delocalization and intra-molecular hydrogen bonds are the two main contributions to the stability of the radicals. The C = O or C = C in COOH, COOR, C = CCOOH and C = CCOOR groups, and orthodiphenolic functionalities are shown to favorably stabilize the specific radical species to enhance the radical scavenging activities, while the presence of the single OH in the ortho position of the COOH group disfavors the activities. HAT is the thermodynamically preferred mechanism in the gas phase and benzene, whereas SPLET in water and ethanol. Furthermore, our QSAR models robustly represent the structure-activity relationships of these explored compounds in polar media. PMID:25803685
Chen, Yuzhen; Xiao, Huizhi; Zheng, Jie; Liang, Guizhao
2015-01-01
Phenolic acids and derivatives have potential biological functions, however, little is known about the structure-activity relationships and the underlying action mechanisms of these phenolic acids to date. Herein we investigate the structure-thermodynamics-antioxidant relationships of 20 natural phenolic acids and derivatives using DPPH• scavenging assay, density functional theory calculations at the B3LYP/6-311++G(d,p) levels of theory, and quantitative structure-activity relationship (QSAR) modeling. Three main working mechanisms (HAT, SETPT and SPLET) are explored in four micro-environments (gas-phase, benzene, water and ethanol). Computed thermodynamics parameters (BDE, IP, PDE, PA and ETE) are compared with the experimental radical scavenging activities against DPPH•. Available theoretical and experimental investigations have demonstrated that the extended delocalization and intra-molecular hydrogen bonds are the two main contributions to the stability of the radicals. The C = O or C = C in COOH, COOR, C = CCOOH and C = CCOOR groups, and orthodiphenolic functionalities are shown to favorably stabilize the specific radical species to enhance the radical scavenging activities, while the presence of the single OH in the ortho position of the COOH group disfavors the activities. HAT is the thermodynamically preferred mechanism in the gas phase and benzene, whereas SPLET in water and ethanol. Furthermore, our QSAR models robustly represent the structure-activity relationships of these explored compounds in polar media.
van de Streek, Jacco; Neumann, Marcus A
2010-10-01
This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 A either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect.
NASA Astrophysics Data System (ADS)
Griffin, Leslie Little
The purpose of this study was to determine the relationship of selected cognitive abilities and physical science misconceptions held by preservice elementary teachers. The cognitive abilities under investigation were: formal reasoning ability as measured by the Lawson Classroom Test of Formal Reasoning (Lawson, 1978); working memory capacity as measured by the Figural Intersection Test (Burtis & Pascual-Leone, 1974); verbal intelligence as measured by the Acorn National Academic Aptitude Test: Verbal Intelligence (Kobal, Wrightstone, & Kunze, 1944); and field dependence/independence as measured by the Group Embedded Figures Test (Witkin, Oltman, & Raskin, 1971). The number of physical science misconceptions held by preservice elementary teachers was measured by the Misconceptions in Science Questionnaire (Franklin, 1992). The data utilized in this investigation were obtained from 36 preservice elementary teachers enrolled in two sections of a science methods course at a small regional university in the southeastern United States. Multiple regression techniques were used to analyze the collected data. The following conclusions were reached following an analysis of the data. The variables of formal reasoning ability and verbal intelligence were identified as having significant relationships, both individually and in combination, to the dependent variable of selected physical science misconceptions. Though the correlations were not high enough to yield strong predictors of physical science misconceptions or strong relationships, they were of sufficient magnitude to warrant further investigation. It is recommended that further investigation be conducted replicating this study with a larger sample size. In addition, experimental research should be implemented to explore the relationships suggested in this study between the cognitive variables of formal reasoning ability and verbal intelligence and the dependent variable of selected physical science misconceptions. Further research should also focus on the detection of a broad range of science misconceptions among preservice elementary teachers.
Sánchez-Hernández, Rosa M; Martínez-Tur, Vicente; González-Morales, M Gloria; Ramos, José; Peiró, José M
2009-08-01
This article examines links between disconfirmation of expectations and functional and relational service quality perceived by employees and customer satisfaction. A total of 156 employees, who were working in 52 work units, participated in the research study. In addition, 517 customers who were assisted by these work units were surveyed. Using a cross-level approach, we used a random coefficient model to test the aforementioned relationships. A strong relationship between disconfirmation of expectations and customer satisfaction was observed. Also, the results confirmed that functional service quality maintains an additional and significant association with customer satisfaction. In contrast, there were no significant relationships between relational service quality and customer satisfaction. The article concludes with a discussion of these results.
Interventions for acute stroke management in Africa: a systematic review of the evidence.
Baatiema, Leonard; Chan, Carina K Y; Sav, Adem; Somerset, Shawn
2017-10-24
The past decades have witnessed a rapid evolution of research on evidence-based acute stroke care interventions worldwide. Nonetheless, the evidence-to-practice gap in acute stroke care remains variable with slow and inconsistent uptake in low-middle income countries (LMICs). This review aims to identify and compare evidence-based acute stroke management interventions with alternative care on overall patient mortality and morbidity outcomes, functional independence, and length of hospital stay across Africa. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. An electronic search was conducted in six databases comprising MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, Academic Search Complete and Cochrane Library for experimental and non-experimental studies. Eligible studies were abstracted into evidence tables and their methodological quality appraised using the Joanna Briggs Institute checklist. Data were analysed and presented narratively with reference to observed differences in patient outcomes, reporting p values and confidence intervals for any possible relationship. Initially, 1896 articles were identified and 37 fully screened. Four non-experimental studies (three cohort and one case series studies) were included in the final review. One study focused on the clinical efficacy of a stroke unit whilst the remaining three reported on thrombolytic therapy. The results demonstrated a reduction in patient deaths attributed to stroke unit care and thrombolytic therapy. Thrombolytic therapy was also associated with reductions in symptomatic intracerebral haemorrhage (SICH). However, the limited eligible studies and methodological limitations compromised definitive conclusions on the extent of and level of efficacy of evidence-based acute stroke care interventions across Africa. Evidence from this review confirms the widespread assertion of low applicability and uptake of evidence-based acute stroke care in LMICs. Despite the limited eligible studies, the overall positive patient outcomes following such interventions demonstrate the applicability and value of evidence-based acute stroke care interventions in Africa. Health policy attention is thus required to ensure widespread applicability of such interventions for improved patients' outcomes. The review findings also emphasises the need for further research to unravel the reasons for low uptake. PROSPERO CRD42016051566.
Lab and Pore-Scale Study of Low Permeable Soils Diffusional Tortuosity
NASA Astrophysics Data System (ADS)
Lekhov, V.; Pozdniakov, S. P.; Denisova, L.
2016-12-01
Diffusion plays important role in contaminant spreading in low permeable units. The effective diffusion coefficient of saturated porous medium depends on this coefficient in water, porosity and structural parameter of porous space - tortuosity. Theoretical models of relationship between porosity and diffusional tortuosity are usually derived for conceptual granular models of medium filled by solid particles of simple geometry. These models usually do not represent soils with complex microstructure. The empirical models, like as Archie's law, based on the experimental electrical conductivity data are mostly useful for practical applications. Such models contain empirical parameters that should be defined experimentally for given soil type. In this work, we compared tortuosity values obtained in lab-scale diffusional experiments and pore scale diffusion simulation for the studied soil microstructure and exanimated relationship between tortuosity and porosity. Samples for the study were taken from borehole cores of low-permeable silt-clay formation. Using the samples of 50 cm3 we performed lab scale diffusional experiments and estimated the lab-scale tortuosity. Next using these samples we studied the microstructure with X-ray microtomograph. Shooting performed on undisturbed microsamples of size 1,53 mm with a resolution ×300 (10243 vox). After binarization of each obtained 3-D structure, its spatial correlation analysis was performed. This analysis showed that the spatial correlation scale of the indicator variogram is considerably smaller than microsample length. Then there was the numerical simulation of the Laplace equation with binary coefficients for each microsamples. The total number of simulations at the finite-difference grid of 1753 cells was 3500. As a result the effective diffusion coefficient, tortuosity and porosity values were obtained for all studied microsamples. The results were analyzed in the form of graph of tortuosity versus porosity. The 6 experimental tortuosity values well agree with pore-scale simulations falling in the general pattern that shows nonlinear decreasing of tortuosity with decreasing of porosity. Fitting this graph by Archie model we found exponent value in the range between 1,8 and 2,4. This work was supported by RFBR via grant 14-05-00409.
Explaining the United States-Israel Relationship
2013-06-01
OF ACRONYMS AND ABBREVIATIONS AMRAAM Advanced Medium Range Air-to-Air Missiles BARD Binational Agricultural Research and Development BIRD ...United States- Israel Binational Industrial Research and Development ( BIRD ) along with the Binational Agricultural R&D Foundation (BARD) and the...foreign oil. In 2007, the BIRD Energy program was created, which has already received millions in investments for joint United States-Israel
ERIC Educational Resources Information Center
Hopson, Dan; And Others
Two marine science units comprise this manual for teachers of elementary school students. Unit 1, "Shore Communities," involves mapping exercises and other investigations of the ecology of the intertidal zone. Unit 2, "The Glacier," focuses on glacial geology and the relationship of glaciers to the marine environment. Each unit…
The United States and World Development: Agenda 1980.
ERIC Educational Resources Information Center
Sewell, John W.; And Others
This publication examines global problems facing the United States and offers a specific short-term program of action to deal with some of the problems. There are three major parts. Part I describes political and economic developments in both rich and poor countries and comments on the recent record of the United States in its relationships with…
40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.
Code of Federal Regulations, 2013 CFR
2013-07-01
... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...
40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.
Code of Federal Regulations, 2010 CFR
2010-07-01
... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...
40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.
Code of Federal Regulations, 2012 CFR
2012-07-01
... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...
40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.
Code of Federal Regulations, 2014 CFR
2014-07-01
... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...
40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.
Code of Federal Regulations, 2011 CFR
2011-07-01
... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...
Accepting Credit Responsibility: Teacher Guide. Family Financial Education Program 2.
ERIC Educational Resources Information Center
Continental Illinois National Bank and Trust Co., Chicago.
The teacher's guide is for a high school unit on accepting credit responsibility, part of family financial education program which also includes a unit on managing personal income. The components of the unit, correlated with a planned instructional program in any area of economics, can be used to reinforce certain relationships and concepts which…
Defense.gov Special Report: Travels with Gates - October 2010
issues. Story MIA Issue Aided U.S.-Vietnam Relationship HANOI, Vietnam, Oct. 11, 2010 - Efforts to recover those missing from the Vietnam War have helped to transform the U.S.-Vietnamese relationship since . Gates noted the level of cooperation in the military relationship between the United States and Vietnam
ERIC Educational Resources Information Center
Liao, Hui; Chuang, Aichia
2007-01-01
This longitudinal field study integrates the theories of transformational leadership (TFL) and relationship marketing to examine how TFL influences employee service performance and customer relationship outcomes by transforming both (at the micro level) the service employees' attitudes and (at the macro level) the work unit's service climate.…
Across Racial/Ethnic Boundaries: Investigating Intimate Violence within a National Sample
ERIC Educational Resources Information Center
Carbone-Lopez, Kristin
2013-01-01
The number of interracial relationships in the United States continues to increase. The fact is, though, that race remains a significant influence in the lives of individuals and in their relationships. Although there is evidence that relationships that cross racial/ethnic boundaries may be at greater risk for conflict and dissolution, there have…
ERIC Educational Resources Information Center
Huntley, Tabo; Whitehead, Amy; Cullinane, Danny; Nixon, Sarah; Huntley, Emma
2017-01-01
Research within Higher Education in the United Kingdom has reported conflicting findings when investigating the relationship between undergraduate entry routes and gender, with successful performances across the degree cycle. This paper adds to this body of knowledge and examines the relationship between entry routes and gender on student outcomes…
ERIC Educational Resources Information Center
Battle, Gary M.; Allen, Frank H.; Ferrence, Gregory M.
2010-01-01
A series of online interactive teaching units have been developed that illustrate the use of experimentally measured three-dimensional (3D) structures to teach fundamental chemistry concepts. The units integrate a 500-structure subset of the Cambridge Structural Database specially chosen for their pedagogical value. The units span a number of key…
Hierarchical control of motor units in voluntary contractions.
De Luca, Carlo J; Contessa, Paola
2012-01-01
For the past five decades there has been wide acceptance of a relationship between the firing rate of motor units and the afterhyperpolarization of motoneurons. It has been promulgated that the higher-threshold, larger-soma, motoneurons fire faster than the lower-threshold, smaller-soma, motor units. This relationship was based on studies on anesthetized cats with electrically stimulated motoneurons. We questioned its applicability to motor unit control during voluntary contractions in humans. We found that during linearly force-increasing contractions, firing rates increased as exponential functions. At any time and force level, including at recruitment, the firing rate values were inversely related to the recruitment threshold of the motor unit. The time constants of the exponential functions were directly related to the recruitment threshold. From the Henneman size principle it follows that the characteristics of the firing rates are also related to the size of the soma. The "firing rate spectrum" presents a beautifully simple control scheme in which, at any given time or force, the firing rate value of earlier-recruited motor units is greater than that of later-recruited motor units. This hierarchical control scheme describes a mechanism that provides an effective economy of force generation for the earlier-recruited lower force-twitch motor units, and reduces the fatigue of later-recruited higher force-twitch motor units-both characteristics being well suited for generating and sustaining force during the fight-or-flight response.
Atomistic determination of flexoelectric properties of crystalline dielectrics
NASA Astrophysics Data System (ADS)
Maranganti, R.; Sharma, P.
2009-08-01
Upon application of a uniform strain, internal sublattice shifts within the unit cell of a noncentrosymmetric dielectric crystal result in the appearance of a net dipole moment: a phenomenon well known as piezoelectricity. A macroscopic strain gradient on the other hand can induce polarization in dielectrics of any crystal structure, even those which possess a centrosymmetric lattice. This phenomenon, called flexoelectricity, has both bulk and surface contributions: the strength of the bulk contribution can be characterized by means of a material property tensor called the bulk flexoelectric tensor. Several recent studies suggest that strain-gradient induced polarization may be responsible for a variety of interesting and anomalous electromechanical phenomena in materials including electromechanical coupling effects in nonuniformly strained nanostructures, “dead layer” effects in nanocapacitor systems, and “giant” piezoelectricity in perovskite nanostructures among others. In this work, adopting a lattice dynamics based microscopic approach we provide estimates of the flexoelectric tensor for certain cubic crystalline ionic salts, perovskite dielectrics, III-V and II-VI semiconductors. We compare our estimates with experimental/theoretical values wherever available and also revisit the validity of an existing empirical scaling relationship for the magnitude of flexoelectric coefficients in terms of material parameters. It is interesting to note that two independent groups report values of flexoelectric properties for perovskite dielectrics that are orders of magnitude apart: Cross and co-workers from Penn State have carried out experimental studies on a variety of materials including barium titanate while Catalan and co-workers from Cambridge used theoretical ab initio techniques as well as experimental techniques to study paraelectric strontium titanate as well as ferroelectric barium titanate and lead titanate. We find that, in the case of perovskite dielectrics, our estimates agree to an order of magnitude with the experimental and theoretical estimates for strontium titanate. For barium titanate however, while our estimates agree to an order of magnitude with existing ab initio calculations, there exists a large discrepancy with experimental estimates. The possible reasons for the observed deviations are discussed.
Veterinary Fusarioses within the United States
USDA-ARS?s Scientific Manuscript database
Multilocus DNA sequence data was used to retrospectively assess the genetic diversity and evolutionary relationships of 67 Fusarium strains from veterinary sources, most of which were from the United States. Molecular phylogenetic analyses revealed that the strains comprised 23 phylogenetically dist...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-17
... new communities. The government is committed to continue to spend heavily in the education, health... relationship is going through a massive transformation. The United States posted a trade surplus with Qatar of...
DEVELOPMENT OF NITROGEN LOAD-REPONSE RELATIONSHIPS FOR ESTUARIES
A research program is currently underway to meet the United States Environmental Protection Agency's need to develop nutrient criteria for estuarine and coastal marine waters. This research is intended to develop nitrogen load-response relationships for submerged aquatic vegetati...
DefenseLink.mil - Special Report - Travels With Mullen
about Kosovo, the chairman of the Joint Chiefs of Staff said today, but they recognize the relationship , 2008 Â The military-to-military relationship between the United States and Serbia is growing closer
Andrew. Youngblood
2011-01-01
The United States Department of Agriculture (USDA) Forest Service celebrated the 100th anniversary of its network of experimental forests in 2008. For a century, the network of experimental forests have contributed immensely, both in the US and around the world, to the practical understanding of the environment and to the formation of management approaches and policies...
Automotive Fuel Economy and Emissions Experimental Data
DOT National Transportation Integrated Search
1979-02-01
The purpose of this effort was to generate experimental data to support an assessment of the relationship between automobile fuel economy and emission control systems. Tests were made at both the engine and vehicle levels. Detailed investigations wer...
Bacteriological comparison of ultrasonic and hand instrumentation of root canals in dogs.
DeNunzio, M S; Hicks, M L; Pelleu, G B; Kingman, A; Sauber, J J
1989-07-01
This study compared the effectiveness of hand and ultrasonic instrumentation for removing a standardized inoculum of pigmented Serratia marcescens from the root canal system of premolars in dogs. Forty-four premolars from nine beagle dogs were divided into two experimental groups of 20 and 24 teeth, respectively. The experimental teeth were inoculated with approximately 10 colony-forming units of S. marcescens. After the bacterial were allowed to colonize for 1 wk, the experimental teeth were instrumented with either hand instruments or the Cavi-Endo device. The teeth were extracted, crushed, and assayed for recoverable colony-forming units of S. marcescens. Statistical comparisons of the ratio of inoculated to recovered colony-forming untis were made. The results indicated that the difference between the positive controls and the experimental groups was significant. There was no significant difference between the two instrumentation groups.
Fulian; Gooch; Fisher; Stevens; Compton
2000-08-01
The development and application of a new electrochemical device using a computer-aided design strategy is reported. This novel design is based on the flow of electrolyte solution past a microwire electrode situated centrally within a large duct. In the design stage, finite element simulations were employed to evaluate feasible working geometries and mass transport rates. The computer-optimized designs were then exploited to construct experimental devices. Steady-state voltammetric measurements were performed for a reversible one-electron-transfer reaction to establish the experimental relationship between electrolysis current and solution velocity. The experimental results are compared to those predicted numerically, and good agreement is found. The numerical studies are also used to establish an empirical relationship between the mass transport limited current and the volume flow rate, providing a simple and quantitative alternative for workers who would prefer to exploit this device without the need to develop the numerical aspects.
ERIC Educational Resources Information Center
Kuwik, Paul David
The purpose of the study was to determine whether exposing junior high school students to a unit on design in construction technology and to a unit on design in manufacturing technology significantly affects their achievement on a test measuring "Technological Principles of Design" when compared to a group of junior high school students exposed…
Mechanisms involved in the psychological distress of Black Caribbeans in the United States
NASA Astrophysics Data System (ADS)
Govia, Ishtar O.
The mental health of ethnic minorities in the United States is of urgent concern. The accelerated growth of groups of ethnic minorities and immigrants in the United States and the stressors to which they are exposed, implores academic researchers to investigate more deeply health disparities and the factors that exacerbate or minimize such inequalities. This dissertation attended to that concern. It used data from the National Survey of American Life (NSAL), the first survey with a national representative sample of Black Caribbeans, to explore mechanisms that involved in the psychological distress of Black Caribbeans in the United States. In a series of three studies, the dissertation investigated the role and consequence of (1) chronic discrimination, immigration factors, and closeness to ethnic and racial groups; (2) personal control and social support; and (3) family relations and social roles in the psychological distress of Black Caribbeans. Study 1 examined how the associations between discrimination and psychological distress were buffered or exacerbated by closeness to ethnic group and closeness to racial group. It also examined how these associations differed depending on immigration factors. Results indicated that the buffering or exacerbating effect of ethnic and racial group closeness varied according to the type of discrimination (subtle or severe) and were more pronounced among those born in the United States. Using the stress process framework, Study 2 tested moderation and mediation models of the effects of social support and personal control in the association between discrimination and distress. Results from a series of analyses on 579 respondents suggested that personal control served as a mediator in this relationship and that emotional support exerted a direct distress deterring function. Study 3 investigated sex differences in the associations between social roles, intergenerational family relationship perceptions and distress. Results suggested that positive relationships with an adult son/daughter and with a father, and negative relationships with a mother increased men's distress. Few social roles increased the negative effect that women and men's relationships with an adult son/daughter had on their distress. Multiple roles also increased the negative effect that women's relationships with an adult son/daughter had on their distress. On the other hand, few social roles decreased the distress associated with men's high conflict relationships with mothers. The findings from these three studies suggested that modeling immigrant and ethnic minority mental health requires sensitivity to their immigrant and ethnic minority statuses and to the contexts in which these group members carry out their daily activities.
Effects of an Elementary Language Arts Unit on Critical Thinking, Reading, and Writing
ERIC Educational Resources Information Center
Duesbery, Luke; Justice, Paul
2015-01-01
Teaching young students to think critically has always been important, however, as the United States transitions to a national set of learning standards which emphasizes higher-order thinking, it becomes essential. In this quasi-experimental study we evaluate the effects of exposure to the Journeys and Destinations (J&D) unit from the William…
A Comparative View of Aging. An Experimental Unit, Second Edition, Revised.
ERIC Educational Resources Information Center
Smith, Gary R.
Showing a variety of learned behavior about aging, activities in this unit are designed to help high-school students become aware that their views (preconceptions) on aging are not universally held. Objectives of the unit include achievement of global perspective on aging and its problems, understanding of the effects of population growth and…
Design of prototype charged particle fog dispersal unit
NASA Technical Reports Server (NTRS)
Collins, F. G.; Frost, W.; Kessel, P.
1981-01-01
The unit was designed to be easily modified so that certain features that influence the output current and particle size distribution could be examined. An experimental program was designed to measure the performance of the unit. The program described includes measurements in a fog chamber and in the field. Features of the nozzle and estimated nozzle characteristics are presented.
Correlating off-axis tension tests to shear modulus of wood-based panels
Edmond P. Saliklis; Robert H. Falk
2000-01-01
The weakness of existing relationships correlating off-axis modulus of elasticity E q to shear modulus G 12 for wood composite panels is demonstrated through presentation of extensive experimental data. A new relationship is proposed that performs better than existing equations found in the literature. This relationship can be manipulated to calculate the shear modulus...
1984-08-17
AD-i5 81@ FASEB (FEDERATION OF AMERICAN SOCIETIES FOR EXPERIMENTAL BIOLOGY ) SUMMER..CU) FEDERATION OF AMERICAN SOCIETIES FOR EXPERIMENTAL BIOLOGY BET...UNIT NUMBERS Robert W. Krauss, Executive Director I * LEO Federation of American Societies for Experimental, NR 685-003 * Biology , 9650 Rockville Pike...Bethesda, MD 20814 *.CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE ’%Federation f American Societies for I Experimental Biology , 9650
History of the Penobscot Experimental Forest, 1950-2010
Laura S. Kenefic; John C. Brissette
2014-01-01
Though the U.S. Department of Agriculture, Forest Service has been studying the forests of the northeastern United States since the late 1800s, long-term studies were not common until experimental forests were introduced in the 20th century. These forests were established for long-term experimentation, and research questions were defined by local forest management...
ERIC Educational Resources Information Center
Diab, Nuwar Mawlawi
2011-01-01
This paper reports on a quasi-experimental study comparing the effects of peer-editing to self-editing on improving students' revised drafts. The study involved two intact classes (experimental and control groups) of an English course. The experimental group practiced peer-editing while the control group engaged in self-editing. After receiving…
Experimental studies of dead-wood biodiversity - A review identifying global gaps in knowledge
Sebastian Seibold; Claus Bässler; Roland Brandl; Martin M. Gossner; Simon Thorn; Michael D. Ulyshen; Jörg Müller
2015-01-01
The importance of dead wood for biodiversity is widely recognized but strategies for conservation exist only in some regions worldwide. Most strategies combine knowledge from observational and experimental studies but remain preliminary as many facets of the complex relationships are unstudied. In this first global review of 79 experimental studies addressing...
Some Dimensions of Auditory Sonar Signal Perception and Their Relationships to Target Classification
1981-02-13
a priori how the sample of experimental stimuli related to the classification stereotypes of experienced sonar personnel, Question 6 was addressed by...projections on some of the experimentally identified dimensions are associ- ated with a high degree of classification success, but signals that lack ,strong...11 Hypotheses ......................... 11 Procedure ....... .. .. ......................... 11 Experimental Stimuli