864 resultados para Role model
Resumo:
Three important goals in describing software design patterns are: generality, precision, and understandability. To address these goals, this paper presents an integrated approach to specifying patterns using Object-Z and UML. To achieve the generality goal, we adopt a role-based metamodeling approach to define patterns. With this approach, each pattern is defined as a pattern role model. To achieve precision, we formalize role concepts using Object-Z (a role metamodel) and use these concepts to define patterns (pattern role models). To achieve understandability, we represent the role metamodel and pattern role models visually using UML. Our pattern role models provide a precise basis for pattern-based model transformations or refactoring approaches.
Resumo:
This paper presents a way to describe design patterns rigorously based on role concepts. Rigorous pattern descriptions are a key aspect for patterns to be used as rules for model evolution in the MDA context, for example. We formalize the role concepts commonly used in defining design patterns as a role metamodel using Object-Z. Given this role metamodel, individual design patterns are specified generically as a formal pattern role model using Object-Z. We also formalize the properties that must be captured in a class model when a design pattern is deployed. These properties are defined generically in terms of role bindings from a pattern role model to a class model. Our work provides a precise but abstract approach for pattern definition and also provides a precise basis for checking the validity of pattern usage in designs.
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The extraordinary growth of the Irish economy since the mid-1990s - the 'Celtic Tiger' - has attracted a great deal of interest, commentary and research. Indeed, many countries look to Ireland as an economic development role model, and it has been suggested that Ireland might provide key lessons for other EU members as they seek to achieve the objectives set out in the Lisbon Agenda. Much of the discussion of Ireland's growth has focused on its possible triggers: the long term consequences of the late 1980s fiscal stabilisation; EU structural funds; education; wage moderation; and devaluation of the Irish punt. The industrial policy perspective has highlighted the importance of inflows of foreign direct investment, but a notable absence from the discourse on the 'Celtic Tiger' has been any mention of the role of new business venture creation and entrepreneurship. In this paper we use unpublished Irish VAT data for the years 1988 to 2004 to provide the first detailed look at national trends in business birth and death rates in Ireland over the 'take-off' period. We also use sub-national VAT data to shed light on spatial trends in new venture creation. Our overall conclusions are that new business formation made no detectable contribution to the acceleration of Ireland's growth in the late 1990s, although we do find evidence of spatial convergence in per capita business stocks.
Resumo:
The extraordinary growth of the Irish economy since the mid-1990s—the ‘Celtic Tiger’—has attracted a great deal of interest, commentary and research. Indeed, many countries look to Ireland as an economic development role model, and it has been suggested that Ireland might provide key lessons for other EU members as they seek to achieve the objectives set out in the Lisbon Agenda. Much of the discussion of Ireland’s growth has focused on its possible triggers: the long-term consequences of the late 1980s fiscal stabilisation, EU structural funds, education, wage moderation and devaluation of the Irish punt. The industrial policy perspective has highlighted the importance of inflows of foreign direct investment, but a notable absence from the discourse on the ‘Celtic Tiger’ has been any mention of the role of new business venture creation and entrepreneurship. In this paper we use unpublished Irish VAT data for the years 1988–2004 to provide the first detailed look at national trends in business birth and death rates in Ireland over the ‘take-off’ period. We also use sub-national VAT data to shed light on spatial trends in new venture creation. Our overall conclusions are that new business formation made no detectable contribution to the acceleration of Ireland’s growth in the late 1990s, although we do find evidence of spatial convergence in per capita business stocks.
Resumo:
Exposure to counter-stereotypic gender role models (e.g., a woman engineer) has been shown to successfully reduce the application of biased gender stereotypes. We tested the hypothesis that such efforts may more generally lessen the application of stereotypic knowledge in other (non-gendered) domains. Specifically, based on the notion that counter-stereotypes can stimulate a lesser reliance on heuristic thinking, we predicted that contesting gender stereotypes would eliminate a more general group prototypicality bias in the selection of leaders. Three studies supported this hypothesis. After exposing participants to a counter-stereotypic gender role model, group prototypicality no longer predicted leadership evaluation and selection. We discuss the implications of these findings for groups and organizations seeking to capitalize on the benefits of an increasingly diverse workforce.
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The educational process is characterised by multiple outcomes such as the achievement of academic results of various standards and non-academic achievements. This paper shows how data envelopment analysis (DEA) can be used to guide secondary schools to improved performance through role-model identification and target setting in a way which recognises the multi-outcome nature of the education process and reflects the relative desirability of improving individual outcomes. The approach presented in the paper draws from a DEA-based assessment of the schools of a local education authority carried out by the authors. Data from that assessment are used to illustrate the approach presented in the paper. (Key words: Data envelopment analysis, education, target setting.)
Resumo:
During the past few years there has been a drastic shortage of registered nurses in the field. The shortage appears to have affected the field of psychiatric mental health nursing most intensely. The psychiatric nursing shortage is a multifaceted problem grounded in decreasing federal funds for advanced clinical training, inadequate undergraduate psychiatric experiences, lack of a well prepared articulate role model, the integrated curriculum and the confusion and blurring associated with the roles and functions of the psychiatric mental health nurse.^ This dissertation will describe the current nursing shortage; the decline in enrollment to nursing programs; the history of psychiatric nursing as a discipline; the shortage of psychiatric mental health nurses; factors contributing to the psychiatric nursing shortage and a plan for a solution to the nursing shortage in psychiatry.^ The paper focuses on an evaluation conducted on an internship curriculum designed to facilitate effective nursing care in the treatment of clients who exhibit emotional problems. The purpose of this study was to attract and retain nurses to employment opportunities in four Hospital Corporation of America (HCA) facilities, using a six week internship program.^ The study will yield an analysis of the effect of combining psychodynamic principles and knowledge with skills in the clinical area. The demands of educational practice have been merged with the discipline of psychiatric nursing in the development of this curriculum. ^
Resumo:
This study explores women's perceptions of what made them successful doctoral students and what strategies they used to cope and succeed in the academic environment of an off-campus program in South Florida. The study's theoretical framework was built on Bandura's (1997) theory regarding ways self-efficacy influences choices made and effort expended; and Gilligan (1982), Belenky et al. (1986) and other feminists' theories concerning how women learn. ^ The study included data obtained from individual, semi-structured interviews with 10 participants, documents spanning the 10 years of the program and interviews with founding faculty members. For each, academic resilience was built on (a) viewing that working on the degree was personally fulfilling; (b) believing she possessed a strong sense of academic confidence; (c) priding herself on having self discipline; (d) seeing herself as a role model; and (e) being motivated by a personal or career goal. ^ Strategies the participants used to overcome roadblocks included (a) time management—finding time for personal, professional, and academic duties; (b) focus—making the dissertation a priority; (c) collaboration—utilizing both personal and programmatic assistance; (d) and advocacy—acting on their individual needs. ^ Results of the study indicated that the program at the satellite campus provided structural resources that satisfied basic needs and strengthened the students' self-efficacy. This helped them become successful doctoral graduates. The women had personal fortitude and strong self-efficacy to complete the doctoral journey. They understood that their success was primarily based on the support they received from people: families, peers, and their major professors. Participants suggested that successful women students ascertain whether they have time and resources to devote to an extended study, an understanding family, and the resilience to overcome roadblocks along the way. ^
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Teachers can have a profound effect on us all, both good and bad. In this paper the effect two individual midwives had on my evolution as a midwife will be examined. They were very different: one was formal and the other informal. The classroom was the setting for one, the clinical area for the other. Each had her own unique style and way of looking at the world. One was very different from the other in manner and in approach. However they each shared a philosophy of women centred, normal birth which they espoused in all aspects of their working lives.
Resumo:
Sympathetic hyperactivity (SH) and renin angiotensin system (RAS) activation are commonly associated with heart failure (HF), even though the relative contribution of these factors to the cardiac derangement is less understood. The role of SH on RAS components and its consequences for the HF were investigated in mice lacking alpha(2A) and alpha(2C) adrenoceptor knockout (alpha(2A)/alpha(2C) ARKO) that present SH with evidence of HF by 7 mo of age. Cardiac and systemic RAS components and plasma norepinephrine (PN) levels were evaluated in male adult mice at 3 and 7 mo of age. In addition, cardiac morphometric analysis, collagen content, exercise tolerance, and hemodynamic assessments were made. At 3 mo, alpha(2A)/alpha(2C)ARKO mice showed no signs of HF, while displaying elevated PN, activation of local and systemic RAS components, and increased cardiomyocyte width (16%) compared with wild-type mice (WT). In contrast, at 7 mo, alpha(2A)/alpha(2C)ARKO mice presented clear signs of HF accompanied only by cardiac activation of angiotensinogen and ANG II levels and increased collagen content (twofold). Consistent with this local activation of RAS, 8 wk of ANG II AT(1) receptor blocker treatment restored cardiac structure and function comparable to the WT. Collectively, these data provide direct evidence that cardiac RAS activation plays a major role underlying the structural and functional abnormalities associated with a genetic SH-induced HF in mice.
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This study evaluated the influence of gastrointestinal environmental factors (pH, digestive enzymes, food components, medicaments) on the survival of Lactobacillus casei Shirota and Lactobacillus casei LC01, using a semi-dynamic in vitro model that simulates the transit of microorganisms through the human GIT. The strains were first exposed to different simulated gastric juices for different periods of time (0, 30, 60 and 120 min), and then to simulated intestinal fluids for zero, 120, 180 and 240 min, in a step-wise format. The number of viable cells was determined after each step. The influence of food residues (skim milk) in the fluids and resistance to medicaments commonly used for varied therapeutic purposes (analgesics, antiarrhythmics, antibiotics, antihistaminics, proton pump inhibitors, etc.) were also evaluated. Results indicated that survival of both cultures was pH and time dependent, and digestive enzymes had little influence. Milk components presented a protective effect, and medicaments, especially anti-inflammatory drugs, influenced markedly the viability of the probiotic cultures, indicating that the beneficial effects of the two probiotic cultures to health are dependent of environmental factors encountered in the human gastrointestinal tract.
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The three possible disulfide bonded isomers of alpha-conotoxin GI have been selectively synthesised and their structures determined by H-1 NMR spectroscopy. alpha-Conotoxin GI derives from the venom of Conus geographus and is a useful neuropharmacological tool as it selectively binds to the nicotinic acetylcholine receptor (nAChR), a ligand-gated ion channel involved in nerve signal transmission. The peptide has the sequence ECCNPACGRHYSC-NH2, and the three disulfide bonded isomers are referred to as GI(2-7;3-13), GI(2-13;3-7) and GI(2-3;7-13). The NMR structure for the native isomer GI(2-7;3-13) is of excellent quality, with a backbone pairwise RMSD of 0.16 Angstrom for a family of 35 structures, and comprises primarily a distorted 3(10),, helix between residues 5 to 11. The two non-native isomers exhibit multiple conformers in solution, with the major populated forms being different in structure both from each other and from the native form. Structure-activity relationships for the native GI(2-7;3-13) as well as the role of the disulfide bonds on folding and stability of the three isomers are examined. It is concluded that the disulfide bonds in alpha-conotoxin GI play a crucial part in determining both the structure and stability of the peptide. A trend for increased conformational heterogeneity was observed in the order of GI(2-7;3-13) < GI(2-13;3-7) < GI(2-3;7-13). It was found that the peptide bond joining Cys2 to Cys3 in GI(2-3;7-13) is predominantly trans, rather than cis as theoretically predicted. These structural data are used to interpret the varying nAChR binding of the non-native forms. A model for the binding of native GI(2-7;3-13) to the mammalian nAChR is proposed, with an alpha-subunit binding face made up of Cys2, Asn4, Pro5, Ala6 and Cys7 and a selectivity face, comprised of Arg9 and His10. These two faces orient the molecule between the alpha and delta subunits of the receptor. The structure of the CCNPAC sequence of the native GI(2-7;3-13) is compared to the structure of the identical sequence from the toxic domain of heat-stable enterotoxins, which forms part of the receptor binding region of the enterotoxins, but which has a different disulfide connectivity. (C) 1998 Academic Press Limited.
Resumo:
Many Archean cratons are surrounded by Proterozoic mobile belts that have experienced episodes of tectonic re-activation over their lifetimes. This suggests that mobile belt lithosphere may be associated with long lived, inherited weakness. It is proposed that the proximity of this weakness can increase the longevity of deep Archean lithosphere by buffering Archean cratons from mantle derived stresses. The physical plausibility of this idea is explored through numerical simulations of mantle convection that include continents and allow for material rheologies that model the combined brittle and ductile behavior of the lithosphere. Within the simulations, the longevity of deep cratonic lithosphere does increase if it is buffered by mobile belts that can fail at relatively low stress levels.
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This paper examines whether social support is a boundary-determining criterion in the job strain model of Karasek (1979). The particular focus is the extent to which different sources of social support, work overload and task control influence job satisfaction, depersonalization and supervisor assessments of work performance. Hypotheses are tested using prospective survey data from 80 clerical staff in a university setting. Results revealed 3-way interactions among levels of support (supervisor, co-worker, non-work), perceived task control and work overload on levels of work performance and employee adjustment (self-report). After controlling for levels of negative affect in all analyses, there was evidence that high levels of supervisor support mitigated against the negative effects of high strain jobs on levels of job satisfaction and reduced reported levels of depersonalization. Moreover, high levels of non-work support and co-worker support also mitigated against the negative effects of high strain jobs on levels of work performance. The results are discussed in terms of the importance of social support networks both at, and beyond, the work context.
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IRI is closely related to sepsis in ITx setting. Complete understanding of the mechanisms involved in IRI development may improve outcomes. Ortothopic ITx without immunosuppression was performed in order to characterize IRI-associated mucosal damage. Twenty pigs underwent ITx. Two groups were assigned to different CI times: G1: 90 min and, G2: 180 min. Euro-Collins was used as preservation solution. Jejunal fragments were collected at donor laparotomy, 30 min, and 3 days after reperfusion. IRI assessment involved: histopathologic analysis, quantification of MPO-positive cells through immunohistochemical studies, quantification of epithelial apoptotic cells using TUNEL staining, and quantification of IL-6, ET-1, Bak, and Bcl-XL genes expression by RT-PCR. Neutrophilic infiltration increased in a similar fashion in both groups, but lasted longer in G2. Apoptosis detected by TUNEL staining increased and anti-apoptotic gene Bcl-XL expression decreased significantly in G1, 3 days after surgery. Endothelin-1 and IL-6 genes expression increased 30 min after the procedure and returned to baseline 3 days after surgery. In conclusion, IL-6 and ET-1 are involved precociously in the development of intestinal IRI. Apoptosis was more frequently detected in G1 grafts by TUNEL-staining and by RT-PCR.