Search PubMed⌕ Search

Biomedical subjects

E Salas

Publications and source records attributed to E Salas.

At least 19 recordsLinked to original sources
PubMed2001

To transfer or not to transfer? Investigating the combined effects of trainee characteristics, team leader support, and team climate.

Eighty pilots participated in a study of variables influencing the transfer process. Posttraining performance was assessed in a flight simulation under 1 of 2 conditions. Those in the maximum performance condition were made aware of the skill to be assessed and the fact that their teammates were confederates, whereas those in the typical performance condition were not. The results indicated that (a) simulator ratings correlated with a measure of transfer to the cockpit for those in the typical condition only; (b) team leader support, manipulated in a pretask brief, moderated the disparity between maximum and typical performance; (c) team climate mediated the impact of support on performance in the typical condition; (d) those with a stronger predisposition toward the trained skill viewed their climate as more supportive; and (e) perceptions of team climate were better predictors of performance for those with a more external locus of control.

Adult↗
PubMed2001

The science of training: a decade of progress.

This chapter reviews the training research literature reported over the past decade. We describe the progress in five areas of research including training theory, training needs analysis, antecedent training conditions, training methods and strategies, and posttraining conditions. Our review suggests that advancements have been made that help us understand better the design and delivery of training in organizations, with respect to theory development as well as the quality and quantity of empirical research. We have new tools for analyzing requisite knowledge and skills, and for evaluating training. We know more about factors that influence training effectiveness and transfer of training. Finally, we challenge researchers to find better ways to translate the results of training research into practice.

Cognition↗
PubMed2001

What determines whether observers recognize targeted behaviors in modeling displays?

Observational learning is based on a critical assumption that trainees can and do recognize critical modeled behaviors. This assumption has been virtually untested in applied settings. We studied the effects of work experience and instructions on the ability of 59 observers to recognize target behaviors in an observational learning paradigm similar to existing ones. Additionally, we investigated the effects of two key factors that were hypothesized to affect the recognition process in observational learning. The results indicated that only observers who had a minimum of work experience (i.e., intermediate and experienced observers in the study) were able to consistently recognize targeted behaviors. Additionally, recognition was influenced by the level of detail of instructions given to the participants. Finally, characteristics of the modeled behaviors greatly affected recognition: Overall, examples of negative behaviors were better recognized than were positive examples. Behaviors whose consequence was shown were also better recognized than those that were neither reinforced nor punished in the video. The results are discussed in terms of their implications for the design of observational learning as a training strategy in complex and applied social learning situations. The applications of this work include the design of training, and the training of evaluators and observers.

Aviation↗
PubMed2001

Does stress training generalize to novel settings?

Many high-stress task environments are complex and dynamic, and it is often difficult during training to anticipate the exact conditions that may be encountered in these settings. We conducted an empirical study to examine whether the positive effects of stress training that addressed one specific type of stressor and task would remain when trainees performed under a novel stressor or performed a novel task. Participants performed a laboratory task under stress conditions. Measures of task performance and self-reported stress were obtained at three performance trials: (a) prior to stress training, (b) after a stress training intervention targeted to that specific task environment, and (c) under novel stressor/task conditions. Results indicated that the beneficial effects of stress training were retained when participants performed under a novel stressor and performed a novel task. We discuss the implications of this study with regard to their application in the design of stress training and the transfer of learning to complex, dynamic task environments.

Adolescent↗
PubMed2000

Influence of residual stenosis in determining restenosis after cutting balloon angioplasty.

The cutting balloon is a new device for coronary angioplasty, which, by the combination of incision and dilatation of the plaque, is believed to minimize arterial wall trauma, the neoproliferative response, and subsequent restenosis. In this study, we sought to determine predictors of the restenosis using this technique. Seventy-seven patients underwent successful coronary angioplasty with cutting balloon alone. In 67 of these patients (87%), we performed a control angiogram at 6-month follow-up. Pre-, post-, and late angiographic results were evaluated by quantitative coronary analysis. Clinical and angiographic variables were correlated with restenosis as a binary variable and a continuous variable (late loss and late minimum luminal diameter). Univariate analysis showed that the immediate postprocedure minimum luminal diameter (MLD) was smaller in the restenotic group (defined as MLD > 50% by quantitative coronary angiography) than in the nonrestenotic group (1.90 +/- 0.47 mm vs. 2.19 +/- 0.56 mm, P < 0.05). In addition, the immediate percentage of stenosis was higher in the restenotic group than in the nonrestenotic group (37% +/- 10% vs. 27% +/- 11%, P < 0. 003). Multivariate analysis identified the immediate postcutting balloon percentage of stenosis as an independent determinant of binary restenosis (P < 0.008). When restenosis was defined as a continuous variable, the immediate postprocedure MLD was an independent predictor of late loss (P < 0.02) and of late MLD (P < 0. 0002). No clinical, preprocedure angiographic, or technical variables tested were associated with restenosis. The degree of postprocedural residual stenosis after cutting balloon angioplasty is predictive of late restenosis.

Adult↗
PubMed2000

The influence of shared mental models on team process and performance.

The influence of teammates' shared mental models on team processes and performance was tested using 56 undergraduate dyads who "flew" a series of missions on a personal-computer-based flight-combat simulation. The authors both conceptually and empirically distinguished between teammates' task- and team-based mental models and indexed their convergence or "sharedness" using individually completed paired-comparisons matrices analyzed using a network-based algorithm. The results illustrated that both shared-team- and task-based mental models related positively to subsequent team process and performance. Furthermore, team processes fully mediated the relationship between mental model convergence and team effectiveness. Results are discussed in terms of the role of shared cognitions in team effectiveness and the applicability of different interventions designed to achieve such convergence.

Achievement↗
PubMed2000

Sustained response to combination therapy in a patient with chronic hepatitis C and thrombocytopenia secondary to alpha-interferon.

Recent data suggest that hepatitis C viral (HCV) infection may induce a significant autoimmune reaction to platelets, but the mechanism is unknown. Many patients with chronic hepatitis C, in fact, have high levels of platelet-associated immunoglobulin G (PAIgG) and HCV-RNA is present in the platelets of 100% of those patients with thrombocytopenia and high PAIgG levels. Hepatitis C virus infection has been associated with the development of thrombocytopenic purpura, sometimes triggered during interferon (IFN) therapy. In such cases, the treatment of the underlying disease is a difficult problem to solve. We report the case of a patient with chronic hepatitis C, who developed life-threatening thrombocytopenic purpura after a prolonged course of IFN-alpha2b over a 4-year period. Treatment with anti-immunoglobulin gammaglobulin (Polyglobin; Química Farmaceutica Bayer, Barcelona, Spain) had a transient effect on the platelet count, but prolonged therapy with prednisone was necessary for definitive relief of the haematological complication. Two years later, the patient was treated with combined therapy, including ribavirin (1200 mg/day) and IFN-alpha2b (5 mU, t.i.w.) for 12 months. This therapy induced a sustained response, both biochemical and virological, without haematological complications. This observation suggests that ribavirin may be of benefit in the treatment of immune-mediated thrombocytopenia in patients with chronic hepatitis C, preventing the harmful effect of IFN-alpha but also allowing both drugs to be combined so as to increase the probability of sustained remission of the liver disease.

Antiviral Agents↗
PubMed2000

Teamwork in multi-person systems: a review and analysis.

As the scope and complexity of modern task demands exceed the capability of individuals to perform, teams are emerging to shoulder the burgeoning requirements. Accordingly, researchers have striven to understand and enhance human performance in team settings. The purpose of this review is to summarize that research, from the theoretical underpinnings that drive it, to the identification of team-level elements of success, to the methodologies and instruments that capture and measure those characteristics. Further specified are three important avenues to creating successful teams: team selection, task design and team training. In other words, one can select the right people, provide them with a task engineered for superior performance and train them in the appropriate skills to accomplish that task. Under task design, new technologies and automation are examined that both support and impede team functioning. Finally, throughout are provided critical remarks about what is known about teamwork and what is needed to be known to move the science and practice of team performance forward. The paper concludes with the identification of team issues that require further investigation.

Efficiency↗
PubMed2000

The mechanisms of platelet dysfunction during extracorporeal membrane oxygenation in critically ill neonates.

OBJECTIVE: Although bleeding associated with thrombocytopenia often complicates extracorporeal membrane oxygenation (ECMO), the mechanisms of platelet dysfunction during ECMO remain poorly understood. We investigated the role of matrix metalloproteinase (MMP)-2, which recently has been shown to mediate a novel pathway of platelet aggregation, in the platelet dysfunction induced by ECMO. DESIGN: Prospective longitudinal case study. SETTING: Level III neonatal intensive care unit. PATIENTS: Ten neonates treated with ECMO. INTERVENTION: ECMO procedure. MEASUREMENTS: Platelet counts and collagen-induced platelet aggregation ex vivo; plasma markers of platelet (soluble P-selectin) and endothelial (soluble E-selectin and total nitrite/nitrate) activation; plasma MMP-2 and MMP-9 activities; and concentrations of tissue inhibitors of MMPs. MAIN RESULTS: During ECMO, time-dependent platelet activation, as evidenced by thrombocytopenia, decreased platelet aggregation, and increased plasma soluble P-selectin concentrations were found in the absence of endothelial activation, as shown by normal plasma concentrations of soluble E-selectin and nitric oxide metabolites (nitrite/nitrate). There was a time-dependent increase in plasma MMP-2 but not MMP-9 activity; tissue inhibitors of MMPs were not detected. Plasma soluble P-selectin concentrations significantly correlated with simultaneous plasma MMP-2 (r2 = .37, p < .0001) but not with MMP-9 activities. Platelet dysfunction persisted despite repeated platelet transfusions to maintain platelet counts >100 x 10(9)/L. CONCLUSIONS: ECMO resulted in the activation of platelets but not endothelial cells. During ECMO, platelet dysfunction persisted despite platelet transfusions. MMP-2 may play a role in the development of platelet dysfunction caused by ECMO.

Analysis of Variance↗
PubMed2000

Measuring team knowledge.

Multioperator tasks often require complex cognitive processing at the team level. Many team cognitive processes, such as situation assessment and coordination, are thought to rely on team knowledge. Team knowledge is multifaceted and comprises relatively generic knowledge in the form of team mental models and more specific team situation models. In this methodological review paper, we review recent efforts to measure team knowledge in the context of mapping specific methods onto features of targeted team knowledge. Team knowledge features include type, homogeneity versus heterogeneity, and rate of knowledge change. Measurement features include knowledge elicitation method, team metric, and aggregation method. When available, we highlight analytical conclusions or empirical data that support a connection between team knowledge and measurement method. In addition, we present empirical results concerning the relation between team knowledge and performance for each measurement method and identify research and methodological needs. Addressing issues surrounding the measurement of team knowledge is a prerequisite to understanding team cognition and its relation to team performance and to designing training programs or devices to facilitate team cognition.

Cognitive Science↗
PubMed2000

The utility of event-based knowledge elicitation.

The purpose of this investigation was to describe and evaluate an event-based knowledge elicitation technique. With this approach experts are provided with deliberate and controlled job situations, allowing investigation of specific task aspects and the comparison of expert responses. For this effort a videotape was developed showing an instructor pilot and student conducting a training mission. Various job situations were depicted in the video to gather information pertinent to understanding team situational awareness. The videotape was shown to 10 instructors and 10 student aviators in the community, and responses to the videotape were collected using a questionnaire at predetermined stop points. Consistent with expectations, the results showed that more experienced respondents (i.e., instructors) identified a richer database of cues and were more likely than students to identify strategies for responding to the situations depicted, providing some empirical evidence for the validity of the event-based technique. This method may serve as a useful knowledge elicitation technique, especially in the later stages of a job analysis when focused information is sought.

Cognitive Science↗
PubMed2000

The design and delivery of crew resource management training: exploiting available resources.

Despite widespread acceptance throughout commercial and military settings, crew resource management (CRM) training programs have not escaped doubts about their effectiveness. The current state of CRM training is an example of how an entire body of pertinent research and development has not had the impact on practice that it could. In this paper we outline additional resources (i.e., principles, information, findings, and guidelines) from the team training and training effectiveness research literatures that can be used to improve the design and delivery of CRM training. Some of the resources discussed include knowledge about training effectiveness, training teamwork-related skills, scenario design, and performance measurement. We conclude with a discussion of emerging resources as well as those that need to be developed. The purpose of this paper is to provide the CRM training developer with better access to resources that can be applied to the design and delivery of CRM training programs.

Aircraft↗
PubMed1999

Radiosurgery: an effective treatment for cavernous sinus meningiomas?

Meningiomas involving the cavernous sinus present the neurosurgeon with different choices: observation, microsurgery, or radiosurgery. During the last decade, advances in microsurgical techniques have significantly lowered the treatment-related morbidity, and some neurosurgeons have reported long-term follow-up results. Recently, several radiosurgical series have reported excellent tumor control and good functional preservation for tumors in this area. Most of these series do not provide complete information about the patient's cranial nerve function, and objective and subjective outcome data. The follow-up provided has also been short, considering that meningiomas have a tendency to recur or regrow up to 20 years postoperatively. There is also the concern about those patients who fail radiosurgical treatment, since microsurgery does not yield good results in such cases. In this paper, several radiosurgical series are critically reviewed, with a discussion about the pros and cons of microsurgery versus radiosurgery. The authors suggest that a uniform reporting strategy be adopted by all surgeons treating tumors of this area, which will allow comparative studies to be conducted. Additionally, we suggest a treatment algorithm for cavernous sinus meningiomas, based on the patients age, occupation and preference, preoperative binocular function, and curability of the tumor.

Journal Article↗
PubMed1999

Increased nitric oxide synthase activity after canine cardiopulmonary bypass is suppressed by s-nitrosoglutathione.

OBJECTIVES: Hemodynamic instability and generalized organ dysfunction are common after cardiopulmonary bypass in human beings. Previous studies have suggested that alterations of nitric oxide metabolism may be associated with this impaired function. Using a canine model we tested whether nitric oxide synthase activity is increased after cardiopulmonary bypass. We also tested whether administration of a nitric oxide donor can influence nitric oxide synthase activity after cardiopulmonary bypass. METHODS: After induction of anesthesia, dogs were randomized to receive cardiopulmonary bypass (n = 12) or to serve as controls (n = 12). They were further randomized to receive a continuous infusion of a nitric oxide donor, S-nitrosoglutathione, or an equivalent volume of placebo. Cardiopulmonary bypass was maintained for 90 minutes, and then 4 hours later dogs were put to death. Cardiac and coronary artery sections were frozen in liquid nitrogen immediately after death for later determination of nitric oxide synthase activity using a citrulline assay. RESULTS: After cardiopulmonary bypass, 4 of 6 placebo-treated but only 2 of 6 S-nitrosoglutathione treated animals required phenylephrine infusion (3.1 +/- 3.1 microgram/min and 0.2 +/- 0.4 microgram/min, respectively, P =.05) to maintain a predetermined blood pressure. Furthermore, after cardiopulmonary bypass, Ca2+-dependent nitric oxide synthase activity in the left ventricle, atrium, and coronary artery did not increase compared with activity in the control animals, but Ca2+-independent nitric oxide synthase activity did increase (P =.005): left ventricle (+28.0% +/- 9.0%), atrium (+45.0% +/- 12.0%) and coronary artery (+17.0% +/- 12.0%). CONCLUSIONS: We have found that (1) cardiopulmonary bypass results in increased activity of Ca2+-independent nitric oxide synthase, (2) S-nitrosoglutathione can prevent the increase of Ca2+-independent nitric oxide synthase after cardiopulmonary bypass, and (3) Ca2+-independent nitric oxide synthase may contribute to hemodynamic dysfunction after cardiopulmonary bypass.

Animals↗
PubMed1999

Prevalence of temporomandibular joint disk displacement in infants and young children.

OBJECTIVE: The purpose of this study was to determine the prevalence of temporomandibular joint disk displacement in infants and young children. STUDY DESIGN: Magnetic resonance images were obtained of the temporomandibular joints in 30 infants and young children ranging in age from 2 months to 5 years (median age, 3 years; mean age, 2.5 years). RESULTS: All joints had normal superior disk position. The computed 95% confidence interval was 0.00-0.06, which implies a minimal probability that disk displacement would occur in this age group. CONCLUSIONS: The result contradicts previous suggestions that temporomandibular joint disk displacement could represent a congenital normal anatomic variant.

Argentina↗
PubMed1999

Monitoring of antimicrobial therapy by an integrated computer program.

OBJECTIVE: To assess the impact of the setting-up of a computer program designed by the Hospital Pharmacy Department as a tool that provides information for the antimicrobial therapy monitoring. To assess its influence on pharmaceutical costs. MATERIAL AND METHOD: The computer application for the follow-up of antimicrobial treatments integrates information from the Pharmacy Department and the Microbiology Laboratory and selects all patients to whom some controlled antibiotic has been prescribed. The pharmacist reviews all the controlled antibiotic treatments, suggests any change to the physician if needed and quantifies the economic impact of the accepted interventions. RESULTS: On average, 12.5% of controlled antibiotic treatments warranted a pharmaceutical intervention, and 92% of them were accepted. The most frequent interventions related to prescriptions were change of dosage and administration route and related to the disease were in respiratory and urinary tract infections. From the economic point of view, the accepted interventions represented a saving of 12,087,029 pesetas (83,359 $)/year, on average. CONCLUSION: The applied computer program resulted a useful tool for a clinical pharmacist to reach more correct antibiotical therapeutics and better cost-effectiveness relation. It also helped to achieve favorable clinical outcomes.

Anti-Bacterial Agents↗