Home About us Contact
|
Home About us Contact | ||
|
|
||
Several Researchers (several + researcher)
Selected AbstractsExamining Contextual Effects in a Practice Analysis: An Application of Dual ScalingEDUCATIONAL MEASUREMENT: ISSUES AND PRACTICE, Issue 3 2007André F. De Champlain Practice analyses are routinely used in support of the development of occupational and professional certification and licensure examinations. These analyses usually survey incumbents to obtain importance ratings of (1) specific tasks and (2) knowledge, skill, and ability (KSA) statements deemed by subject matter experts as essential to safe and effective practice. Several researchers have made important criticisms of traditional practice analysis procedures, particularly the lack of attention to contextual constructs and the resulting problematic interpretation of mean importance ratings. The present study provides a framework for assessing the impact of context in practice analysis studies. It focuses on a practice analysis of a health profession that sought to enhance the meaning of incumbents' importance ratings by embedding the statements in the context of patient acuities. Results indicate that incumbents' importance ratings varied as a function of patient acuity. Dual scaling analysis was used to obtain a multidimensional visual representation of the associations between importance ratings and contextual content. The implications of the contextual component of the study design for future practice analysis studies are discussed as well as possible applications of this approach to professions in education. [source] Transparent Photo-Stable Complementary Inverter with an Organic/Inorganic Nanohybrid Dielectric LayerADVANCED FUNCTIONAL MATERIALS, Issue 5 2009Min Suk Oh Abstract Transparent electronics has been one of the key terminologies forecasting the ubiquitous technology era. Several researchers have thus extensively developed transparent oxide-based thin-film transistors (TFTs) on glass and plastic substrates. However, work in transparent electronics has been limited mostly to high-voltage devices operating at more than a few tens of volts, and has mainly focused on transparent display drivers. Low-voltage logic devices, such as transparent complementary inverters, operating in an electrically stable and photo-stable manner, are now very necessary to practically realize transparent electronics. Electrically stable dielectrics with high strength and high capacitance must also be proposed to support this mission, and simultaneously these dielectrics must be compatible with both n- and p-channel TFTs in device fabrication. Here, a nanohybrid dielectric layer that is composed of multiple units of inorganic oxide and organic self-assembled monolayer is proposel to support a transparent complementary TFT inverter operating at 3,V. [source] Managing job stress in nursing: what kind of resources do we need?JOURNAL OF ADVANCED NURSING, Issue 1 2008Marieke Van Den Tooren Abstract Title.,Managing job stress in nursing: what kind of resources do we need? Aim., This paper is a report of a study to investigate the functionality of different kinds of job resources for managing job stress in nursing. Background., There is increasing recognition that healthcare staff, and especially nurses, are at high risk for burnout and physical complaints. Several researchers have proposed that job resources moderate the relationship between job demands and job-related outcomes, particularly when there is a match between the type of demands, resources, and outcomes. Method., Based on the Demand-Induced Strain Compensation Model, cross-sectional survey data were collected between November 2006 and February 2007 by a paper-and-pencil questionnaire. The final sample consisted of 69 nurses from a Dutch nursing home (response rate 59·4%). Data were analyzed by hierarchical regression analyses. Results., High physical demands had adverse effects on both physical complaints and emotional exhaustion (i.e. burnout), unless employees had high physical resources. A similar pattern was found for high physical demands and emotional resources in predicting emotional exhaustion. The likelihood of finding theoretically-valid moderating effects was related to the degree of match between demands, resources, and outcomes. Conclusion., Job resources do not randomly moderate the relationship between job demands and job-related outcomes. Both physical and emotional resources seem to be important stress buffers for human service employees such as nurses, and their moderating effects underline the importance of specific job resources in healthcare work. Job redesign in nursing homes should therefore primarily focus on matching job resources to job demands in order to diminish poor health and ill-being. [source] The psychometric properties of the Miller Behavioural Style Scale with adult daughters of women with early breast cancer: a literature review and empirical studyJOURNAL OF ADVANCED NURSING, Issue 2 2000Charlotte E. Rees BSc PhD The psychometric properties of the Miller Behavioural Style Scale with adult daughters of women with early breast cancer: a literature review and empirical study Several researchers have suggested that the information-seeking behaviours of patients need to be taken into consideration when assessing their information needs. This study reviews published evidence of the psychometric properties of the Miller Behavioural Style Scale, a tool commonly used to identify the information-seeking behaviours of individuals under threat, and examines its reliability and validity with adult daughters of women with early breast cancer. Ninety-seven adult daughters completed the MBSS and a 30-item, self-administered questionnaire, a tool designed to explore the information needs of adult daughters of women with breast cancer. The internal consistency of the monitoring and blunting sub-scales of the MBSS was ,=0·65 and 0·41 respectively. The blunting sub-scale fell substantially below acceptable limits and was discarded from subsequent analyses. The monitoring sub-scale possessed good test,retest reliability (n=17) with a 5-week time interval (r=0·71, P < 0·005), as measured using a Pearson's correlation coefficient. Furthermore, the majority (73·4%) of monitoring items possessed moderate or substantial test,retest reliability, as indicated by kappa coefficients. Finally, the monitoring sub-scale possessed good construct validity, both discriminant and convergent validity, as measured by the univariate associations between monitoring behaviour and selected items from the information questionnaire and a demographic questionnaire. In conclusion, adequate support exists for the psychometric properties of the monitoring sub-scale of the MBSS and its use with adult daughters of women with early breast cancer in future research. These findings have a number of implications for nursing research and these are discussed in this paper. [source] Familial (shared environmental and genetic) factors and the foetal origins of cardiovascular diseases and type 2 diabetes: a review of the literatureJOURNAL OF INTERNAL MEDICINE, Issue 3 2008N. Bergvall Abstract. Several researchers have argued that observed associations between birth weight and cardiovascular diseases, and type 2 diabetes, may be confounded by familial (shared environmental and genetic) factors. However, most studies have found that shared environmental factors, including socio-economic factors, do not influence the foetal origins of adult diseases. Results from two twin studies suggest that genetic factors may be of importance for the association between birth weight and risks of coronary heart disease, but findings from intergenerational studies are not consistent with genetic confounding. More studies have assessed the importance of genetic factors with respect to risk factors of coronary heart, including raised blood pressure and lipid levels. Recent findings suggest that the association between birth weight and hypertension is independent of genetic factors. In contrast, recent twin and intergenerational studies favour the hypothesis that the association between birth weight and risk of type 2 diabetes is confounded by genetic factors. [source] Natal homing in juvenile loggerhead turtles (Caretta caretta)MOLECULAR ECOLOGY, Issue 12 2004BRIAN W. BOWEN Abstract Juvenile loggerhead turtles (Caretta caretta) from West Atlantic nesting beaches occupy oceanic (pelagic) habitats in the eastern Atlantic and Mediterranean, whereas larger juvenile turtles occupy shallow (neritic) habitats along the continental coastline of North America. Hence the switch from oceanic to neritic stage can involve a trans-oceanic migration. Several researchers have suggested that at the end of the oceanic phase, juveniles are homing to feeding habitats in the vicinity of their natal rookery. To test the hypothesis of juvenile homing behaviour, we surveyed 10 juvenile feeding zones across the eastern USA with mitochondrial DNA control region sequences (N = 1437) and compared these samples to potential source (nesting) populations in the Atlantic Ocean and Mediterranean Sea (N = 465). The results indicated a shallow, but significant, population structure of neritic juveniles (,ST = 0.0088, P = 0.016), and haplotype frequency differences were significantly correlated between coastal feeding populations and adjacent nesting populations (Mantel test R2 = 0.52, P = 0.001). Mixed stock analyses (using a Bayesian algorithm) indicated that juveniles occurred at elevated frequency in the vicinity of their natal rookery. Hence, all lines of evidence supported the hypothesis of juvenile homing in loggerhead turtles. While not as precise as the homing of breeding adults, this behaviour nonetheless places juvenile turtles in the vicinity of their natal nesting colonies. Some of the coastal hazards that affect declining nesting populations may also affect the next generation of turtles feeding in nearby habitats. [source] The conceptualization and operationalization of race and ethnicity by health services researchersNURSING INQUIRY, Issue 2 2008Susan Moscou Racial and ethnic variables are routinely used in health services research. However, there is a growing debate within nursing and other disciplines about the usefulness of these variables in research. A qualitative study was undertaken (July 2004 , November 2004) to ascertain how researchers conceptualize and operationalize racial and ethnic data. Data were derived from interviews with 33 participants in academic health centers in differing geographic regions. Content analyses extracted manifest and latent meanings to construct categories depicting respondents' understandings of race and ethnicity in research. Race and ethnicity held several meanings but the subtext was often not clear because these terms were not operationalized. Measuring race and ethnicity quantitatively necessitated uniform classifications thus it was often necessary to impose a single racialized identity. Respondents recognized the problems with racial and ethnic variables but the majority still believed these variables were necessary and useful. Several researchers understood that racial and ethnic variables were used in ways that may stigmatize the populations studied. These respondents collected data on variables other than race and ethnicity to ascertain the causes of health differentials. The policy recommendation calls for a shift in thinking about how to use racial and ethnic variables in research. [source] Psychological interventions with siblings of pediatric cancer patients: a systematic reviewPSYCHO-ONCOLOGY, Issue 12 2009Alice Prchal Abstract Objective: Siblings of pediatric cancer patients have been shown to be at risk for developing emotional, behavioral, and social problems. There is a need for psychological interventions in this population. Several researchers have previously documented and evaluated their interventions with siblings. This paper aimed at reviewing the existing reports of evaluated psychological interventions with siblings of pediatric cancer patients and at outlining future directions. Methods: Research was conducted on several online bibliographic databases. Articles were selected on the basis of predefined criteria. If possible, effect sizes (ES) were calculated. Results: Fourteen studies representing 11 different sibling interventions met criteria for inclusion. One individual intervention, three camps, and seven groups were found. Objectives of interventions concentrated mainly on enhancing siblings' coping and improving their medical knowledge. In terms of outcome measures, most of the studies focused on psychological adjustment variables. Findings showed significant improvements in siblings' depression symptomatology, medical knowledge, and health-related quality of life. Findings were inconsistent with regard to anxiety, behavioral problems, social adjustment, self-esteem, and posttraumatic stress symptoms. Depending on the outcome variables, small to large ES were found. Satisfaction with the intervention was high in both siblings and parents. Conclusion: There is tentative evidence that psychological interventions with siblings of childhood cancer patients can effectively reduce psychological maladjustment and improve medical knowledge about cancer. However, the number of studies is small, and several methodological shortcomings have to be noted. In future, more randomized controlled trials need to be conducted in larger samples to extend the evidence base. Copyright © 2009 John Wiley & Sons, Ltd. [source] TYPES OF PUBLIC CAPITAL AND THEIR PRODUCTIVITY IN JAPANESE PREFECTURES*THE JAPANESE ECONOMIC REVIEW, Issue 2 2008IZUMI MIYARA Several researchers have studied the productivity of public capital in Japan but most have not paid attention to the types of public infrastructure or differences in production technology between prefectures. We estimate prefectural production functions with differently aggregated public capital. Through the model selection process, we examine the types of productive public capital. The empirical results show the production technologies used and how types of productive public capital differ between prefectures. [source] A simple hermetic sample holder for X-ray diffraction analysis of uranium hydrideJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2007Bingyun Ao In order to help resolve unknowns regarding aging effects of uranium during long-term storage of tritium, a number of experiments have been carried out by several researchers. However, almost no literature is available on the structural change of uranium tritide, mainly because its high toxicity and air-sensitivity render appropriate experiments very difficult. In this paper, a simple hermetic sample holder that fits the Philips X'Pert Pro X-ray diffractometer is described. It may be used to study the aging effects of uranium tritide during storage. The sample holder mainly consists of an aluminium container for sample storage and a Mylar window for X-ray measurements. This sample holder can also be used with other air-sensitive, radioactive and toxic materials. In this paper, the first results obtained from X-ray diffraction analysis of uranium hydride are presented. [source] Bond-based 3D-chiral linear indices: Theory and QSAR applications to central chirality codificationJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 15 2008Juan A. Castillo-Garit Abstract The recently introduced non-stochastic and stochastic bond-based linear indices are been generalized to codify chemical structure information for chiral drugs, making use of a trigonometric 3D-chirality correction factor. These improved modified descriptors are applied to several well-known data sets to validate each one of them. Particularly, Cramer's steroid data set has become a benchmark for the assessment of novel quantitative structure activity relationship methods. This data set has been used by several researchers using 3D-QSAR approaches such as Comparative Molecular Field Analysis, Molecular Quantum Similarity Measures, Comparative Molecular Moment Analysis, E-state, Mapping Property Distributions of Molecular Surfaces, and so on. For that reason, it is selected by us for the sake of comparability. In addition, to evaluate the effectiveness of this novel approach in drug design we model the angiotensin-converting enzyme inhibitory activity of perindoprilate's ,-stereoisomers combinatorial library, as well as codify information related to a pharmacological property highly dependent on the molecular symmetry of a set of seven pairs of chiral N -alkylated 3-(3-hydroxyphenyl)-piperidines that bind ,-receptors. The validation of this method is achieved by comparison with earlier publications applied to the same data sets. The non-stochastic and stochastic bond-based 3D-chiral linear indices appear to provide a very interesting alternative to other more common 3D-QSAR descriptors. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Integration of theory and practice in learning mental health nursingJOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 1 2002T. MUNNUKKA RN PhD(Nursing science) PhD(Education) This article describes an action research project that aimed at a better integration of theory and practice in the education of mental health nursing students. Two partners, an institute of nursing and health care and a university hospital, collaborated to develop a new educational programme for mental health nursing. The blocks of theoretical studies were implemented simultaneously with practical training, and the theory content was taught by nursing teachers as well as by nurse practitioners who worked on the teaching wards. In addition, the students had their own personal nurse-preceptors on the wards. The nurse managers were responsible for the educational level of the teaching wards and the director of nursing planned the teaching arrangements together with the nursing teachers. In all, the project involved over 50 different actors and several researchers. The results are encouraging: all the participants , students, preceptors, nurse managers and nursing teachers , found the project rewarding and they want to continue to develop and improve the level of teaching and learning in mental health nursing education. All the participants grew and developed professionally during the project. [source] Blur-generated non-separable space,time modelsJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 4 2000Patrick E. Brown Statistical space,time modelling has traditionally been concerned with separable covariance functions, meaning that the covariance function is a product of a purely temporal function and a purely spatial function. We draw attention to a physical dispersion model which could model phenomena such as the spread of an air pollutant. We show that this model has a non-separable covariance function. The model is well suited to a wide range of realistic problems which will be poorly fitted by separable models. The model operates successively in time: the spatial field at time t +1 is obtained by ,blurring' the field at time t and adding a spatial random field. The model is first introduced at discrete time steps, and the limit is taken as the length of the time steps goes to 0. This gives a consistent continuous model with parameters that are interpretable in continuous space and independent of sampling intervals. Under certain conditions the blurring must be a Gaussian smoothing kernel. We also show that the model is generated by a stochastic differential equation which has been studied by several researchers previously. [source] The ring grooming problemNETWORKS: AN INTERNATIONAL JOURNAL, Issue 3 2004Timothy Y. Chow Abstract The problem of minimizing the number of bidirectional SONET rings required to support a given traffic demand has been studied by several researchers. Here we study the related ring-grooming problem of minimizing the number of add/drop locations instead of the number of rings; in a number of situations this is a better approximation to the true equipment cost. Our main result is a new lower bound for the case of uniform traffic. This allows us to prove that a certain simple algorithm for uniform traffic is, in fact, a constant-factor approximation algorithm, and it also demonstrates that known lower bounds for the general problem,in particular, the linear programming relaxation,are not within a constant factor of the optimum. We also show that our results for uniform traffic extend readily to the more practically important case of quasi-uniform traffic. Finally, we show that if the number of nodes on the ring is fixed, then ring grooming is solvable in polynomial time; however, whether ring grooming is fixed-parameter tractable is still an open question. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(3), 194,202 2004 [source] Estimation of the day-specific probabilities of conception: current state of the knowledge and the relevance for epidemiological researchPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2006Courtney D. Lynch Summary Conception, as defined by the fertilisation of an ovum by a sperm, marks the beginning of human development. Currently, a biomarker of conception is not available; as conception occurs shortly after ovulation, the latter can be used as a proxy for the time of conception. In the absence of serial ultrasound examinations, ovulation cannot be readily visualised leaving researchers to rely on proxy measures of ovulation that are subject to error. The most commonly used proxy measures include: charting basal body temperature, monitoring cervical mucus, and measuring urinary metabolites of oestradiol and luteinising hormone. Establishing the timing of the ovulation and the fertile window has practical utility in that it will assist couples in appropriately timing intercourse to achieve or avoid pregnancy. Identifying the likely day of conception is clinically relevant because it has the potential to facilitate more accurate pregnancy dating, thereby reducing the iatrogenic risks associated with uncertain gestation. Using data from prospective studies of couples attempting to conceive, several researchers have developed models for estimating the day-specific probabilities of conception. Elucidating these will allow researchers to more accurately estimate the day of conception, thus spawning research initiatives that will expand our current limited knowledge about the effect of exposures at critical periconceptional windows. While basal body temperature charting and cervical mucus monitoring have been used with success in field-based studies for many years, recent advances in science and technology have made it possible for women to get instant feedback regarding their daily fertility status by monitoring urinary metabolites of reproductive hormones in the privacy of their own homes. Not only are innovations such as luteinising hormone test kits and digital fertility monitors likely to increase study compliance and participation rates, they provide valuable prospective data that can be used in epidemiological research. Although we have made great strides in estimating the timing and length of the fertile window, more work is needed to elucidate the day-specific probabilities of conception using proxy measures of ovulation that are inherently subject to error. Modelling approaches that incorporate the use of multiple markers of ovulation offer great promise to fill these important data gaps. [source] The Random-Facet simplex algorithm on combinatorial cubes,RANDOM STRUCTURES AND ALGORITHMS, Issue 3 2002Bernd Gärtner The RANDOM -FACET algorithm is a randomized variant of the simplex method which is known to solve any linear program with n variables and m constraints using an expected number of pivot steps which is subexponential in both n and m. This is the theoretically fastest simplex algorithm known to date if m , n; it provably beats most of the classical deterministic variants which require exp(,(n)) pivot steps in the worst case. RANDOM -FACET has independently been discovered and analyzed ten years ago by Kalai as a variant of the primal simplex method, and by Matous,ek, Sharir, and Welzl in a dual form. The essential ideas and results connected to RANDOM -FACET can be presented in a particularly simple and instructive way for the case of linear programs over combinatorialn - cubes. I derive an explicit upper bound of (1) on the expected number of pivot steps in this case, using a new technique of "fingerprinting" pivot steps. This bound also holds for generalized linear programs, similar flavors of which have been introduced and studied by several researchers. I then review an interesting class of generalized linear programs, due to Matous,ek, showing that RANDOM -FACET may indeed require an expected number of pivot steps in the worst case. The main new result of the paper is a proof that all actual linear programs in Matous,ek's class are solved by RANDOM -FACET with an expected polynomial number of pivot steps. This proof exploits a combinatorial property of linear programming which has only recently been discovered by Holt and Klee. The result establishes the first scenario in which an algorithm that works for generalized linear programs "recognizes" proper linear programs. Thus, despite Matous,ek's worst-case result, the question remains open whether RANDOM -FACET (or any other simplex variant) is a polynomial-time algorithm for linear programming. Finally, I briefly discuss extensions of the combinatorial cube results to the general case. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 20:353,381, 2002 [source] Skeletal age, dental age, and the maturation of KNM-WT 15000AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2004Shelley L. Smith Abstract The skeleton of the Homo erectus boy from West Lake Turkana, Kenya (KNM-WT 15000), is remarkably complete, and this individual has thus provided a case study for several researchers examining Homo erectus growth. Using data from a longitudinal study of Montreal French-Canadian children, it is shown that while dental and skeletal ages match reasonably well at the level of a sample of children, individuals can display differences between skeletal and dental ages of 2 years or more. Furthermore, the relationship between these two markers may change over time in individual children. It is also possible to find children with patterns of dental maturation similar to KNM-WT 15000's pattern in the Montreal sample. Therefore, neither the discrepancy between skeletal age and dental age alone nor the pattern of dental maturation as assessed by dental stages precludes a human-like pattern of growth, including an adolescent growth spurt, for this individual. Some indicators (e.g., estimated body size for predicted age, and enamel formation) do suggest possible growth-patterning differences from modern humans, and therefore earlier maturation is a reasonable hypothesis, but caution is warranted, given the large degree of modern human variation in developmental markers and the inherent uncertainty in precise estimation of KNM-WT 15000's maturational parameters. Am J Phys Anthropol, 2004. © 2004 Wiley-Liss, Inc. [source] Direct use of vegetable oil and animal fat as alternative fuel in internal combustion engineBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2008Pinaki Mondal Abstract Gradual depletion of world petroleum reserves and the impact of environmental pollution of increasing exhaust emissions lead to the search for a suitable alternative fuels for diesel engines. The substitution of conventional fuels (gasoline, diesel) by renewable biofuels is considered a potential way to reduce pollution and to support the sustainable development of a country. Direct use of vegetable oil and animal fat is a promising alternative to solve these problems. An exhaustive review of the experiments in this area, carried out by several researchers in last three decades, is presented here. Different problems associated with the direct use of vegetable oil and animal fat and potential solutions from both public and private sectors are discussed. Some engine manufacturers have started to launch full-warranty engines with vegetable oil as fuel. It is expected that the competitive engine market will witness more intense research, resulting in the launch of more vegetable-oil engines with full warranties. The steep rise in food prices in recent years is concerning policy-makers and has raised the old ,food vs fuel' debate. It has been concluded that vegetable oil can probably only substitute small to medium portions of petroleum-based fuel due to future severe land-usage competition from food sector. This calls for intense research initiatives into the production of suitable fuel from non-edible vegetable oil, grown in wasteland. In this regard, genetic engineering may prove to be extremely effective in developing ,designer fuel'. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd [source] | |||||||||||||||||||