Using Column Generation to Solve Extensions to the Markowitz Model

We introduce a solution scheme for portfolio optimization problems with cardinality constraints. Typical portfolio optimization problems are extensions of the classical Markowitz mean-variance portfolio optimization model. We solve such type of problems using a method similar to column generation. In this scheme, the original problem is restricted to a subset of the assets resulting in a master convex quadratic problem. Then the dual information of the master problem is used in a sub-problem to propose more assets to consider. We also consider other extensions to the Markowitz model to diversify the portfolio selection within the given intervals for active weights.Comment: 16 pages, 3 figures, 2 tables, 1 pseudocod

The Environment Of Professional Practice And Burnout In Nurses In Primary Healthcare.

to assess how nurses perceive autonomy, control over the environment, the professional relationship between nurses and physicians and the organizational support and correlate them with burnout, satisfaction at work, quality of work and the intention to quit work in primary healthcare. cross-sectional and correlation study, using a sample of 198 nurses. The tools used were the Nursing Work Index Revised, Maslach Burnout Inventory and a form to characterize the nurses. To analyze the data, descriptive statistics were applied and Spearman's correlation coefficient was used. the nurses assessed that the environment is partially favorable for: autonomy, professional relationship and organizational support and that the control over this environment is limited. Significant correlations were evidenced between the Nursing Work Index Revised, Maslach Burnout Inventory and the variables: satisfaction at work, quality of care and the intent to quit the job. the nurses' perceptions regarding the environment of practice are correlated with burnout, satisfaction at work, quality of care and the intent to quit the job. This study provides support for the restructuring of work processes in the primary health care environment and for communication among the health service management, human resources and occupational health areas.22926-3

Burnout e estresse em enfermeiros de um hospital universitário de alta complexidade

Estudo transversal, analítico e correlacional que objetivou investigar a existência de Burnout em amostra de 149 enfermeiros de um hospital universitário de alta complexidade, no período de outubro a dezembro de 2008, correlacionando-o com estressores do ambiente de trabalho hospitalar. Foram aplicados o inventário de Burnout de Maslach, o inventário de estresse em enfermeiros e uma ficha de caracterização dos sujeitos. Os resultados indicaram a presença das três dimensões sugestivas de Burnout em 7,3% dos enfermeiros (quartil) e 10,22% (tercil), bem como a correlação entre domínios dos inventários. A vulnerabilidade para esse tipo de adoecimento em enfermeiros foi potencializada pela vivência de estresse no ambiente de trabalho.This cross-sectional, analytical and correlational study investigated the existence of Burnout based on a sample of 149 nurses of a university tertiary hospital from October to December 2008 and correlate Burnout with stressors in the hospital work environment. The Maslach Burnout Inventory, the Nurses Stress Inventory and a questionnaire to characterize the subjects were applied. The results indicated the presence of Burnout in 7.3% of nurses (quartile) and 10.22% (tercile), and also a correlation among the inventories domains. Vulnerability to this type of illness among nurses was increased by stress experienced in the work environment.Se trata de un estudio transversal, analítico y de correlación que tuvo por objetivo investigar la existencia de Burnout en una muestra de 149 enfermeros de un hospital universitario de alta complejidad, en el período de octubre a diciembre de 2008, correlacionándolo con factores de estrés del ambiente de trabajo hospitalario. Fueron aplicados el Inventario de Burnout de Maslach, el Inventario de Estrés en Enfermeros y una ficha de caracterización de los sujetos. Los resultados indicaron la presencia de las tres dimensiones indicativas de Burnout en 7,3% de los enfermeros (cuartil) y 10,22% (tercil), así como la correlación entre dominios de los inventarios. La vulnerabilidad para ese tipo de enfermedad, en enfermeros, fue potencializada por la existencia de factores de estrés en el ambiente de trabajo

Burnout y estrés en enfermeros de un hospital universitario de alta complejidad

This cross-sectional, analytical and correlational study investigated the existence of Burnout based on a sample of 149 nurses of a university tertiary hospital from October to December 2008 and correlate Burnout with stressors in the hospital work environment. The Maslach Burnout Inventory, the Nurses? Stress Inventory and a questionnaire to characterize the subjects were applied. The results indicated the presence of Burnout in 7.3% of nurses (quartile) and 10.22% (tercile), and also a correlation among the inventories? domains. Vulnerability to this type of illness among nurses was increased by stress experienced in the work environment.Estudo transversal, analítico e correlacional que objetivou investigar a existência de Burnout em amostra de 149 enfermeiros de um hospital universitário de alta complexidade, no período de outubro a dezembro de 2008, correlacionando-o com estressores do ambiente de trabalho hospitalar. Foram aplicados o inventário de Burnout de Maslach, o inventário de estresse em enfermeiros e uma ficha de caracterização dos sujeitos. Os resultados indicaram a presença das três dimensões sugestivas de Burnout em 7,3% dos enfermeiros (quartil) e 10,22% (tercil), bem como a correlação entre domínios dos inventários. A vulnerabilidade para esse tipo de adoecimento em enfermeiros foi potencializada pela vivência de estresse no ambiente de trabalho.Se trata de un estudio transversal, analítico y de correlación que tuvo por objetivo investigar la existencia de Burnout en una muestra de 149 enfermeros de un hospital universitario de alta complejidad, en el período de octubre a diciembre de 2008, correlacionándolo con factores de estrés del ambiente de trabajo hospitalario. Fueron aplicados el Inventario de Burnout de Maslach, el Inventario de Estrés en Enfermeros y una ficha de caracterización de los sujetos. Los resultados indicaron la presencia de las tres dimensiones indicativas de Burnout en 7,3% de los enfermeros (cuartil) y 10,22% (tercil), así como la correlación entre dominios de los inventarios. La vulnerabilidad para ese tipo de enfermedad, en enfermeros, fue potencializada por la existencia de factores de estrés en el ambiente de trabajo.1084109

Burnout And Stress Among Nurses In A University Tertiary Hospital.

This cross-sectional, analytical and correlational study investigated the existence of Burnout based on a sample of 149 nurses of a university tertiary hospital from October to December 2008 and correlate Burnout with stressors in the hospital work environment. The Maslach Burnout Inventory, the Nurses' Stress Inventory and a questionnaire to characterize the subjects were applied. The results indicated the presence of Burnout in 7.3% of nurses (quartile) and 10.22% (tercile), and also a correlation among the inventories' domains. Vulnerability to this type of illness among nurses was increased by stress experienced in the work environment.181084-9

Insulin-like Growth Factor I—Releasing Alginate-Tricalciumphosphate Composites for Bone Regeneration

Purpose: Development and characterization of an in situ-forming, osteoconductive, and growth factor-releasing bone implant. Methods: Injectable in situ-forming scaffolds were prepared from a 2% (m/v) alginate solution, tricalciumphosphate (TCP) granules, and poly(lactide-co-glycolide) microspheres (MS), loaded with the osteoinductive growth factor insulin-like growth factor I (IGF-I). Scaffolds were prepared by mixing the components followed by hydrogel formation through calcium carbonate-induced physical cross-linking of the alginate at slightly acidic pH. Physical-chemical properties and cell biocompatibility using osteoblast-like cells (MG-63 and Saos-2) of these scaffolds were investigated. Results: The addition of TCP to the alginate resulted in reduced swelling and gelation time and an increase in stiffness. Osteoblast-like cells (MG-63 and Saos-2) did not show toxic reactions and adhered circumferentially to the TCP granules surface. The addition of the IGF-I MS resulted in an up to sevenfold increased proliferation rate of MG-63 cells as compared to scaffold preparations without IGF-I MS. The alkaline phosphate (ALP) activity—a parameter for osteblastic activity—increased with increasing amounts of TCP in Saos-2 loaded composite scaffolds. Conclusions: A prototype in situ-hardening composite system for conformal filling of bone defects supporting osteoblastic activity for further clinical testing in relevant fracture models was developed and characterize

El ambiente de la práctica profesional y el síndrome de burnout en enfermeros en la atención básica

OBJETIVOS: avaliar percepções dos enfermeiros sobre autonomia, controle sobre o ambiente, relação profissional entre enfermeiro e médico e suporte organizacional e correlacioná-las com Burnout, satisfação no trabalho, qualidade do cuidado e intenção de deixar o trabalho, na atenção básica. MÉTODO: estudo transversal e correlacional, com amostra de 198 enfermeiros. Foram utilizados o Nursing Work Index Revised, o Inventário de Burnout de Maslach e uma ficha de caracterização do enfermeiro. Para análise dos dados, foi realizada estatística descritiva e utilizado o coeficiente de correlação de Spearman. RESULTADOS: os enfermeiros avaliaram que o ambiente é parcialmente favorável para: autonomia, relação profissional e suporte organizacional e que há pouco controle sobre o mesmo. Evidenciaram-se correlações significativas entre o Nursing Work Index Revised, o Inventário de Burnout de Maslach e as variáveis: satisfação no trabalho, qualidade de cuidado e intenção de deixar o trabalho. CONCLUSÃO: percepções dos enfermeiros acerca do ambiente da prática correlacionam-se com Burnout, satisfação no trabalho, qualidade do cuidado e intenção de deixar o trabalho. Este estudo fornece subsídios para reestruturação de processos de trabalho no ambiente da atenção básica e para comunicação entre as áreas de gestão de serviços de saúde, recursos humanos e saúde do trabalhador.OBJETIVOS: evaluar percepciones de los enfermeros sobre autonomía, control sobre el ambiente, relación profesional entre enfermero y médico y soporte organizacional y correlacionarlas con el síndrome de burnout, la satisfacción en el trabajo, la calidad del cuidado y la intención de dejar el trabajo, en la atención básica. MÉTODO: estudio transversal y de correlación, con muestra de 198 enfermeros. Fueron utilizados el Nursing Work Index Revised, el Inventario de Burnout de Maslach y una ficha de caracterización del enfermero. El análisis de los datos fue realizado con estadística descriptiva y se utilizó el coeficiente de correlación de Spearman. RESULTADOS: los enfermeros evaluaron que el ambiente es parcialmente favorable para: autonomía, relación profesional y soporte organizacional y que existe poco control sobre el mismo. Se evidenciaron correlaciones significativas entre el Nursing Work Index Revised, el Inventario de Burnout de Maslach y las variables: satisfacción en el trabajo, calidad del cuidado e intención de dejar el trabajo. CONCLUSIÓN: las percepciones de los enfermeros acerca del ambiente de la práctica se correlacionan con burnout, satisfacción en el trabajo, calidad del cuidado e intención de dejar el trabajo. Este estudio ofrece subsidios para la reestructuración de procesos de trabajo en el ambiente de la atención básica y para comunicación entre las áreas de administración de servicios de salud, recursos humanos y salud del trabajador.OBJECTIVES: to assess how nurses perceive autonomy, control over the environment, the professional relationship between nurses and physicians and the organizational support and correlate them with burnout, satisfaction at work, quality of work and the intention to quit work in primary healthcare. METHOD: cross-sectional and correlation study, using a sample of 198 nurses. The tools used were the Nursing Work Index Revised, Maslach Burnout Inventory and a form to characterize the nurses. To analyze the data, descriptive statistics were applied and Spearman's correlation coefficient was used. RESULTS: the nurses assessed that the environment is partially favorable for: autonomy, professional relationship and organizational support and that the control over this environment is limited. Significant correlations were evidenced between the Nursing Work Index Revised, Maslach Burnout Inventory and the variables: satisfaction at work, quality of care and the intent to quit the job. CONCLUSION: the nurses' perceptions regarding the environment of practice are correlated with burnout, satisfaction at work, quality of care and the intent to quit the job. This study provides support for the restructuring of work processes in the primary health care environment and for communication among the health service management, human resources and occupational health areas