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System Characteristics (system + characteristic)

Distribution by Scientific Domains

Life Sciences	29%
Business, Economics, Finance and Accounting	23%
Medical Sciences	17%
Information Science and Computing	11%

Selected Abstracts

Validation of a method to measure resident doctors' reflections on quality improvement

MEDICAL EDUCATION, Issue 3 2010
Christopher M Wittich
Medical Education 2010:44: 248,255 Objectives, Resident reflection on the clinical learning environment is prerequisite to identifying quality improvement (QI) opportunities and demonstrating competence in practice-based learning. However, residents' abilities to reflect on QI opportunities are unknown. Therefore, we developed and determined the validity of the Mayo Evaluation of Reflection on Improvement Tool (MERIT) for assessing resident reflection on QI opportunities. Methods, The content of MERIT, which consists of 18 items structured on 4-point scales, was based on existing literature and input from national experts. Using MERIT, six faculty members rated 50 resident reflections. Factor analysis was used to examine the dimensionality of MERIT instrument scores. Inter-rater and internal consistency reliabilities were calculated. Results, Factor analysis revealed three factors (eigenvalue; number of items): Reflection on Personal Characteristics of QI (8.5; 7); Reflection on System Characteristics of QI (1.9; 6), and Problem of Merit (1.5; 5). Inter-rater reliability was very good (intraclass correlation coefficient range: 0.73,0.89). Internal consistency reliability was excellent (Cronbach's , 0.93 overall and 0.83,0.91 for factors). Item mean scores were highest for Problem of Merit (3.29) and lowest for Reflection on System Characteristics of QI (1.99). Conclusions, Validity evidence supports MERIT as a meaningful measure of resident reflection on QI opportunities. Our findings suggest that dimensions of resident reflection on QI opportunities may include personal, system and Problem of Merit factors. Additionally, residents may be more effective at reflecting on ,problems of merit' than personal and systems factors. [source]

Situational and Demographic Influences on Transfer System Characteristics in Organizations

PERFORMANCE IMPROVEMENT QUARTERLY, Issue 3 2006
Hsin-Chih Chen
Transfer theories, which are closely related to evaluation theory, have been developed from a holistic perspective, but most of empirical transfer research has not effectively utilized holistic models to investigate transfer of learning until the late 1990s. Additionally, little has been done in examining the relationship between situational variables, demographic variables, and transfer system characteristics. This study contributes to transfer research by examining the combined effects of situational and demographic variables on a holistic model of perceived organizational transfer systems. A key finding was that demographic variables make only a marginal contribution to predicting transfer system characteristics when compared to situational variables. It seems clear that the differences in transfer system characteristics depend on diverse situational influences, primarily due to types of training programs and types of organizational cultures. This finding does not support one-size-fits-all transfer interventions. Future research may focus on investigating benchmark transfer practices in certain types of organizations or industries to empirically identify the true leverage points of a diagnosing instrument of transfer,the Learning Transfer System Inventory,for interventions and change. [source]

A performance comparison between the Earth Simulator and other terascale systems on a characteristic ASCI workload,

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 10 2005
Darren J. Kerbyson
Abstract This work gives a detailed analysis of the relative performance of the recently installed Earth Simulator and the next top four systems in the Top500 list using predictive performance models. The Earth Simulator uses vector processing nodes interconnected using a single-stage, cross-bar network, whereas the next top four systems are built using commodity based superscalar microprocessors and interconnection networks. The performance that can be achieved results from an interplay of system characteristics, application requirements and scalability behavior. Detailed performance models are used here to predict the performance of two codes representative of the ASCI workload, namely SAGE and Sweep3D. The performance models encapsulate fully the behavior of these codes and have been previously validated on many large-scale systems. One result of this analysis is to size systems, built from the same nodes and networks as those in the top five, that will have the same performance as the Earth Simulator. In particular, the largest ASCI machine, ASCI Q, is expected to achieve a similar performance to the Earth Simulator on the representative workload. Published in 2005 by John Wiley & Sons, Ltd. [source]

Importance of Perceived Personnel Selection System Fairness Determinants: Relations with Demographic, Personality, and Job Characteristics

INTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 1-2 2004
Chockalingam Viswesvaran
This study explored the relative importance attached to various perceived personnel selection fairness determinants (e.g., selection system content-based variables, features of selection system administration). We investigated how demographic variables (ethnicity and gender), individual differences characteristics (the Big Five and cognitive ability) and job characteristics (job complexity and domestic/expatriate assignment status) relate to the importance of ratings of perceived personnel selection system determinants. The results, especially for race/ethnicity analyses indicated that there might be differences across demographic groups in importance placed on different aspects of selection system characteristics. The magnitudes of the relationships were small to moderate for Asian,White and Hispanic,White comparisons. Asian,Hispanic and gender differences in importance assessments were small. Few individual differences variables (i.e., personality and cognitive ability) were associated with importance placed on various aspects of selection system characteristics. Notable exceptions were moderate positive relationships between general mental ability and importance of content-based selection system characteristics, and moderate negative relationships between emotional stability, conscientiousness and cognitive ability, and importance of selection system context variables. The complexity levels of the jobs held by respondents did not appreciably affect the importance placed on the different selection system characteristics. There were few notable differences between importance assessments for domestic versus expatriate positions. Implications for practice, especially managing cultural diversity in organizations, and for theory development are discussed. [source]

Potential Autonomous Selfing in Gesneria citrina (Gesneriaceae), a Specialized Hummingbird Pollinated Species with Variable Expression of Herkogamy

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 10 2009
Xin-Sheng Chen
Abstract Species with mixed mating systems often demonstrate variable expression of breeding system characteristics and thus represent the opportunity to understand the factors and mechanisms that promote both outcrossed and selfed seed production. Here, we investigate variation in levels of herkogamy (variation in stigma-anther separation distance) in a Puerto Rican population of hummingbird pollinated Gesneria citrina Urban. There is significant variation in herkogamy levels among individuals of this species and stigma-anther separation is negatively associated with the ability to set fruits and seeds in the absence of pollinators. The variation in levels of herkogamy may represent a mechanism to ensure the production of some self-fertilized progeny in the absence of hummingbird pollinators. We also describe a novel breeding system in G. citrina, where stamens elongate over time to reach stigma height, but stamen elongation is accelerated by pollination. These results suggest that once the flowers are pollinated, stamen elongation may favor increased pollen removal and siring success, while the reduction in stigma-anther distance no longer imposes the risk of interference between male and female functions. We discuss our findings of breeding system variation in the context of pollination system evolution in an island setting (Antillean islands). [source]

Tailoring the software maintenance process to better support complex systems evolution projects

JOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 1 2003
Paolo DonzelliArticle first published online: 30 JAN 200
Abstract When an organization considers the evolution of a software-intensive system, the selection of the software maintenance process to be adopted must include consideration of the particular technical criteria, such as the application domain, the size and complexity of the final product, the hosting system characteristics, etc, yet be driven by the specific organization's goals, environment and maturity. By describing and analysing a real project, this paper shows how different approaches and techniques, usually applied in isolation, can be selected, customized and combined to implement a software maintenance and evolution process that better satisfies the goals and meets the constraints of the organization. The project was undertaken to investigate the feasibility of enhancing an aircraft avionics system by integrating new capabilities and, eventually, to identify a quick, low-cost and low-risk solution. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Situational and Demographic Influences on Transfer System Characteristics in Organizations

Atmospheric CO2 concentration does not directly affect leaf respiration in bean or poplar

PLANT CELL & ENVIRONMENT, Issue 11 2001
S. Jahnke
Abstract It is a matter of debate if there is a direct (short-term) effect of elevated atmospheric CO2 concentration (Ca) on plant respiration in the dark. When Ca doubles, some authors found no (or only minor) changes in dark respiration, whereas most studies suggest a respiratory inhibition of 15,20%. The present study shows that the measurement artefacts , particularly leaks between leaf chamber gaskets and leaf surface, CO2 memory and leakage effects of gas exchange systems as well as the water vapour (,water dilution') effect on DCO2 measurement caused by transpiration , may result in larger errors than generally discussed. A gas exchange system that was used in three different ways , as a closed system in which Ca increased continuously from 200 to 4200 mmol (CO2) mol -1 (air) due to respiration of the enclosed leaf; as an intermittently closed system that was repeatedly closed and opened during Ca periods of either 350 or 2000 mmol mol -1, and as an open system in which Ca varied between 350 and 2000 mmol mol -1, is described. In control experiments (with an empty leaf chamber), the respective system characteristics were evaluated carefully. When all relevant system parameters were taken into account, no effects of short-term changes in CO2 on dark CO2 efflux of bean and poplar leaves were found, even when Ca increased to 4200 mmol mol -1. It is concluded that the leaf respiration of bean and poplar is not directly inhibited by elevated atmospheric CO2. [source]

Nonprofits as Local Government Service Contractors

PUBLIC ADMINISTRATION REVIEW, Issue 4 2009
Richard C. Feiock
Despite the growing role that contracts with nonprofits play in local service delivery, only limited attention has been directed to why some cities rely more on nonprofit organizations to produce services or how political institutions influence the role nonprofits play in service delivery. To investigate these issues, the authors present a transaction cost explanation that focuses on how political system characteristics and structures of service markets shape the costs of negotiating, monitoring, and enforcing contracts for local governments. The findings indicate that forms of government, mayoral turnover, racial segregation, and the market of nonprofit producers influence the role of nonprofits in delivering elder services, but decisions to contract exclusively with nonprofits are subject to different influences than decisions to jointly produce service with a nonprofit organization. [source]

Fault-tolerant procedures for redundant computer systems

QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 1 2009
Refik Samet
Abstract Real-time computer systems deployed in life-critical control applications must be designed to meet stringent reliability specifications. The minimum acceptable degree of reliability for systems of this type is ,7 nines', which is not generally achieved. This paper aims at contributing to the achievement of that degree of reliability. To this end, this paper proposes a classification scheme of the fault-tolerant procedures for redundant computer systems (RCSs). The proposed classification scheme is developed on the basis of the number of counteracted fault types. Table I is created to relate the characteristics of the RCSs to the characteristics of the fault-tolerant procedures. A selection algorithm is proposed, which allows designers to select the optimal type of fault-tolerant procedures according to the system characteristics and capabilities. The fault-tolerant procedure, which is selected by this algorithm, provides the required degree of reliability for a given RCS. According to the proposed graphical model only a part of the fault-tolerant procedure is executed depending on the absence or presence (type and sort) of faults. The proposed methods allow designers to counteract Byzantine and non-Byzantine fault types during degradation of RCSs from N to 3, and only the non-Byzantine fault type during degradation from 3 to 1 with optimal checkpoint time period. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Relationships between patient-centered cancer nursing interventions and desired health outcomes in the context of the health care system,

RESEARCH IN NURSING & HEALTH, Issue 1 2009
Laurel E. Radwin
Abstract A non-experimental longitudinal prospective study was conducted to examine the relationships between patient-centered nursing interventions (PCNIs), system characteristics, patient characteristics, and desired health outcomes (DHOs) for 173 hematology-oncology patients. Forty-nine nurse participants provided system characteristics data. Confirmatory factor analyses yielded parsimonious scales to operationalize the variables. In the path model, one PCNI,individualization,was positively related to three subsequent DHOs: authentic self-representation, optimism, and sense of well-being. Two additional PCNIs,responsiveness and proficiency,were positively related to subsequent trust in nurses. PCNIs did not vary with patient race, ethnicity, age, gender, or educational level. Patient-centeredness of care for cancer patients may be enhanced by quality improvement activities that measure and monitor these PCNIs and resultant outcomes. © 2008 Wiley Periodicals, Inc. Res Nurs Health 32:4,17, 2009 [source]

Distances to Emergency Department and to Primary Care Provider's Office Affect Emergency Department Use in Children

ACADEMIC EMERGENCY MEDICINE, Issue 5 2009
Annameika Ludwick MD
Abstract Objectives:, Patients of all ages use emergency departments (EDs) for primary care. Several studies have evaluated patient and system characteristics that influence pediatric ED use. However, the issue of proximity as a predictor of ED use has not been well studied. The authors sought to determine whether ED use by pediatric Medicaid enrollees was associated with the distance to their primary care providers (PCPs), distance to the nearest ED, and distance to the nearest children's hospital. Methods:, This historical cohort study included 26,038 children age 18 and under, assigned to 332 primary care practices affiliated with a Medicaid health maintenance organization (HMO). Predictor variables were distance from the child's home to his or her PCP site, distance from home to the nearest ED, and distance from home to the nearest children's hospital. The outcome variable was each child's ED use. A negative binomial model was used to determine the association between distance variables and ED use, adjusted for age, sex, and race, plus medical and primary care site characteristics previously found to influence ED use. Distance variables were divided into quartiles to test for nonlinear associations. Results:, On average, children made 0.31 ED visits/person/year. In the multivariable model, children living greater than 1.19 miles from the nearest ED had 11% lower ED use than those living within 0.5 miles of the nearest ED (risk ratio [RR] = 0.89, 95% CI = 0.81 to 0.99). Children living between 1.54 and 3.13 miles from their PCPs had 13% greater ED use (RR = 1.13, 95% CI = 1.03 to 1.24) than those who lived within 0.7 miles of their PCP. Conclusions:, Geographical variables play a significant role in ED utilization in children, confirming the importance of system-level determinants of ED use and creating the opportunity for interventions to reduce geographical barriers to primary care. [source]

Modeling of Product Removal during Enzymatic Conversions by Using Affinity Molecules

BIOTECHNOLOGY PROGRESS, Issue 6 2007
Daniël G. R. Halsema
The feasibility of using magnetic particles for in-line product isolation during enzymatic conversion was studied. A comparison was made between a process based on magnetic particles and a conventional adsorption column. The enzymatic reaction was described by two consecutive first-order reactions (synthesis and subsequent hydrolysis), while the adsorption of substrate and product was described by multicomponent Langmuir isotherms. The yield as well as synthesis/hydrolysis ratio were calculated for various system characteristics. The results show that magnetic particles are very effective when the affinity with the particles is specific and for enzymatic conversions involving low ratios of the rate of synthesis versus the rate of hydrolysis. For slow conversions and for low specific affinity molecules column separations are more appropriate. [source]

Fruit, Minerals, and Forest Elephant Trails: Do All Roads Lead to Rome?

BIOTROPICA, Issue 3 2004
Stephen Blake
ABSTRACT Tropical forests are among the most heterogeneous environments on earth, and food resources for many animals are patchy both in time and space. In Africa's equatorial forest, permanent trails created and maintained by forest elephants are conspicuous features. Trails may be several meters wide and continue for tens of kilometers. Speculation on which resources determine the distribution of trails has identified fruit, browse, and mineral deposits as candidates. In this study, the relationships between these habitat variables and elephant trails were investigated. The size of individual trails and the density of the trail system increased dramatically with proximity to mineral deposits. Fruit tree basal area decreased with perpendicular distance from trails, while that of non-fruit trees did not. Fruit tree abundance and basal area were significantly higher on trail intersections than random sites and increased with intersection size. No relationship was found between monocotyledon browse abundance and elephant trail system characteristics. Clumped resources, which are at least partially reliable, provide a high nutritional payback, and are not rapidly depleted and can thus be visited repeatedly, appear to influence permanent trail formation by forest elephants. Permanent trails may allow naive individuals or those with imperfect knowledge to locate and acquire important resources. [source]

Oil and Gas Accumulation in the Foreland Basins, Central and Western China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2010
Yan SONG
Abstract: Foreland basin represents one of the most important hydrocarbon habitats in central and western China. To distinguish these foreland basins regionally, and according to the need of petroleum exploration and favorable exploration areas, the foreland basins in central and western China can be divided into three structural types: superimposed, retrogressive and reformative foreland basin (or thrust belt), each with distinctive petroleum system characteristics in their petroleum system components (such as the source rock, reservoir rock, caprock, time of oil and gas accumulation, the remolding of oil/gas reservoir after accumulation, and the favorable exploration area, etc.). The superimposed type foreland basins, as exemplified by the Kuqa Depression of the Tarim Basin, characterized by two stages of early and late foreland basin development, typically contain at least two hydrocarbon source beds, one deposited in the early foreland development and another in the later fault-trough lake stage. Hydrocarbon accumulations in this type of foreland basin often occur in multiple stages of the basin development, though most of the highly productive pools were formed during the late stage of hydrocarbon migration and entrapment (Himalayan period). This is in sharp contrast to the retrogressive foreland basins (only developing foreland basin during the Permian to Triassic) such as the western Sichuan Basin, where prolific hydrocarbon source rocks are associated with sediments deposited during the early stages of the foreland basin development. As a result, hydrocarbon accumulations in retrogressive foreland basins occur mainly in the early stage of basin evolution. The reformative foreland basins (only developing foreland basin during the Himalayan period) such as the northern Qaidam Basin, in contrast, contain organic-rich, lacustrine source rocks deposited only in fault-trough lake basins occurring prior to the reformative foreland development during the late Cenozoic, with hydrocarbon accumulations taking place relatively late (Himalayan period). Therefore, the ultimate hydrocarbon potentials in the three types of foreland basins are largely determined by the extent of spatial and temporal matching among the thrust belts, hydrocarbon source kitchens, and regional and local caprocks. [source]

Rational Design of Ag/TiO2 Nanosystems by a Combined RF-Sputtering/Sol-Gel Approach

CHEMPHYSCHEM, Issue 18 2009
Lidia Armelao Dr.
Abstract The present work is devoted to the preparation of Ag/TiO2 nanosystems by an original synthetic strategy, based on the radio-frequency (RF) sputtering of silver particles on titania-based xerogels prepared by the sol,gel (SG) route. This approach takes advantage of the synergy between the microporous xerogel structure and the infiltration power characterizing RF-sputtering, whose combination enables the obtainment of a tailored dispersion of Ag-containing particles into the titania matrix. In addition, the system,s chemico-physical features can be tuned further through proper ex situ thermal treatments in air at 400 and 600,°C. The synthesized composites are extensively characterized by the joint use of complementary techniques, that is, X-ray photoelectron and X-ray excited Auger electron spectroscopies (XPS, XE-AES), secondary ion mass spectrometry (SIMS), glancing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FE,SEM), transmission electron microscopy (TEM), electron diffraction (ED), high-angle annular dark field scanning TEM (HAADF,STEM), energy-filtered TEM (EF,TEM) and optical absorption spectroscopy. Finally, the photocatalytic performances of selected samples in the decomposition of the azo-dye Plasmocorinth B are preliminarily investigated. The obtained results highlight the possibility of tailoring the system characteristics over a broad range, directly influencing their eventual functional properties. [source]

Ca2+ -independent phospholipase A2-dependent sustained Rho-kinase activation exhibits all-or-none response

GENES TO CELLS, Issue 9 2006
Akio Maeda
Sustained contraction of cells depends on sustained Rho-associated kinase (Rho-kinase) activation. We developed a computational model of the Rho-kinase pathway to understand the systems characteristics. Thrombin-dependent in vivo transient responses of Rho activation and Ca2+ increase could be reproduced in silico. Low and high thrombin stimulation induced transient and sustained phosphorylation, respectively, of myosin light chain (MLC) and myosin phosphatase targeting subunit 1 (MYPT1) in vivo. The transient phosphorylation of MLC and MYPT1 could be reproduced in silico, but their sustained phosphorylation could not. This discrepancy between in vivo and in silico in the sustained responses downstream of Rho-kinase indicates that a missing pathway(s) may be responsible for the sustained Rho-kinase activation. We found, experimentally, that the sustained phosphorylation of MLC and MYPT1 exhibit all-or-none responses. Bromoenol lactone, a specific inhibitor of Ca2+ -independent phospholipase A2 (iPLA2), inhibited sustained phosphorylation of MLC and MYPT1, which indicates that sustained Rho-kinase activation requires iPLA2 activity. Thus, the systems analysis of the Rho-kinase pathway identified a novel iPLA2-dependent mechanism of the sustained Rho-kinase activation, which exhibits an all-or-none response. [source]