Are Drinkers Prone To Engage In Risky Sexual Behaviors?

Sexually transmitted diseases pose an important public health problem around the world. Although many studies have explored the link between alcohol use and risky sexual practices, the unobserved differences among individuals make it difficult to assess whether the associations are casual in nature. In order to overcome these difficulties, we have obtained data from the Spanish Health and Sexual Behavior Survey (2003) in order to analyze risky sexual behaviors using four alternative methodologies: controlling results with a rich set of variables; identifying the impact of alcohol use while assuming there is an identical selection outcome for observed and unobserved variables; estimating alcohol consumption and risky sexual behaviors simultaneously based on instrumental variables; and using reduced-form equations to analyze the impact of alcohol prices and other alcohol policies on the likelihood of risky intercourse. We provide empirical evidence that alcohol abuse might increase the probability of risky sex and, more importantly, different alcohol policies are not only effective tools for reducing alcohol demand but also for controlling risky sexual behaviors.alcohol; sexually transmitted diseases; unobserved individual heterogeneity.

Fractional Integration and Structural Breaks in U.S. Macro Dynamics

This paper identifies structural breaks in the post-World War II joint dynamics of U.S. inflation, unemployment and the short-term interest rate. We derive a structural break-date procedure which allows for long-memory behavior in all three series and perform the analysis for alternative data frequencies. Both long-memory and short-run coefficients are relevant for characterizing the changing patterns of U.S. macroeconomic dynamics. We provide an economic interpretation of those changes by examining the link between macroeconomic events and structural breaks.Fractional integration, structural breaks, multivariate analysis, inflation dynamics

Technology Shocks and Hours Worked: A Fractional Integration Perspective

Previous research has found that the response of hours worked to a technology shock crucially depends on whether the variable hours is assumed to be an I(0) or an I(1) variable ex-ante. In this paper we employ a multivariate fractionally integrated model which allows us to determine simultaneously the order of integration of hours worked and the response of hours to a technology shock. We find that hours fall on impact in response to a positive technology shock.

PRICE DYNAMICS, INFORMATIONAL EFFICIENCY AND WEALTH DISTRIBUTION IN CONTINUOUS DOUBLE AUCTION MARKETS

This paper studies the properties of the continuous double auction trading mechanishm using an artificial market populated by heterogeneous computational agents. In particular, we investigate how changes in the population of traders and in market microstructure characteristics affect price dynamics, information dissemination and distribution of wealth across agents. In our computer simulated market only a small fraction of the population observe the risky asset’s fundamental value with noise, while the rest of agents try to forecast the asset’s price from past transaction data. In contrast to other artificial markets, we assume that the risky asset pays no dividend, so agents cannot learn from past transaction prices and subsequent dividend payments. We find that private information can effectively disseminate in the market unless market regulation prevents informed investors from short selling or borrowing the asset, and these investors do not constitute a critical mass. In such case, not only are markets less efficient informationally, but may even experience crashes and bubbles. Finally, increased informational efficiency has a negative impact on informed agents’ trading profits and a positive impact on artificial intelligent agents’ profits.

What drives information dissemination in continuous double auction markets?.

In this paper, we investigate further the way information disseminates from informed to uninformed traders in a market populated by heterogeneous boundedly rational agents. In order to achieve the goal, a computer simulated market where only a small fraction of the population observe the risky asset's fundamental value with noise was constructed, while the rest of agents try to forecast the asset's price from past transaction data. The paper departs from previous studies in that the risky asset does not pay a dividend every period, so agents cannot learn from past transaction prices and subsequent dividend payments. The main finding is that information can potentially disseminate in the market as long as: (1) informed investors' trades tilt transaction prices in the fundamental path direction; and (2) the median investor's expectation is very responsive to transaction prices. Otherwise, markets may display crashes or bubbles. It is found that the first condition requires a minimal amount of informed investors, and is severely limited by short selling and borrowing constraints.

Price dynamics, informational efficiency and wealth distribution in continuous double-auction markets.

This paper studies the properties of the continuous double-auction trading mechanism using an artificial market populated by heterogeneous computational agents. In particular, we investigate how changes in the population of traders and in market microstructure characteristics affect price dynamics, information dissemination, and distribution of wealth across agents. In our computer-simulated market only a small fraction of the population observe the risky asset's fundamental value with noise, while the rest of the agents try to forecast the asset's price from past transaction data. In contrast to other artificial markets, we assume that the risky asset pays no dividend, thus agents cannot learn from past transaction prices and subsequent dividend payments. We find that private information can effectively disseminate in the market unless market regulation prevents informed investors from short selling or borrowing the asset, and these investors do not constitute a critical mass. In such case, not only are markets less efficient informationally, but may even experience crashes and bubbles. Finally, increased informational efficiency has a negative impact on informed agents' trading profits and a positive impact on artificial intelligent agents' profits.Artificial financial markets; Information dissemination; Artificial neural networks; Heterogeneous agents;

Estudio de cohortes comparando los resultados obtenidos tras la estadificación y el tratamiento quirúrgico por laparotomía frente al realizado por laparoscopia en el cáncer primario de endometrio estadio I clínico

Consultable des del TDXTítol obtingut de la portada digitalitzadaEl cáncer de endometrio es actualmente la neoplasia más frecuente del tracto genital inferior en los países desarrollados. La estadificación es quirúrgico-patológica y se basa en el estudio de la pieza operatoria. El tratamiento estándar se realiza mediante laparotomía, si bien hay estudios que sugieren puede ser llevado a cabo mediante abordaje laparoscópico-vaginal, con igual radicalidad oncológica y sin mayor número de complicaciones. El propósito de este estudio fue describir la factibilidad y los resultados del abordaje quirúrgico laparoscópico en el tratamiento del cáncer de endometrio estadio I clínico, y compararlos con los obtenidos mediante laparotomía. El objetivo principal fue comparar los resultados en cuanto a supervivencia global, periodo libre de enfermedad y complicaciones. Otros objetivos fueron comparar los datos quirúrgicos, los ganglios retroperitoneales obtenidos y la estancia hospitalaria. La estadificación quirúrgica mediante ambos procedimientos incluyó la realización de citologías peritoneales, histerectomía extrafascial con salpingooforectomía bilateral, linfadenectomía pélvica bilateral ± paraaórtica y omentectomía y biopsias aleatorias en tipos histológicos de alto riesgo. La mayoría de datos se recogieron de forma prospectiva. Se incluyeron en el estudio todas las pacientes diagnosticadas de un cáncer primario de endometrio estadio I en el Hospital Materno-infantil Vall d'Hebron, en las cuales el primer tratamiento pretendió ser la cirugía. El análisis estadístico se realizó mediante el paquete SPSS 11.0. Se utilizaron pruebas de normalidad, pruebas no paramétricas, test de Kaplan y Meier para las estimaciones de supervivencia global y tiempo libre de enfermedad, log-rank test para la comparación univariante de las curvas de supervivencia y modelo de los riesgos proporcionales de Cox para el análisis multivariable. Entre enero/1995 y junio/2001 se incluyeron 371 pacientes con cáncer endometrial estadio I clínico. La estadificación se realizó mediante abordaje laparoscópico-vaginal en 55 pacientes (14,8%) y mediante laparotomía en 315 (84,9%). La edad media fue de 64,3 años y el índice de masa corporal medio de 30 (r, 18-57). Se realizó la cirugía de estadificación óptima en 367 pacientes (98,9%), sin diferencias significativas al comparar las dos vías de abordaje. La linfadenectomía (LND) pélvica se realizó en el 91,1% de las pacientes y la LND aórtica en el 50%. Hubo afectación ganglionar en 41 casos (11,1%) y 32 recurrencias a lo largo del seguimiento (8,6%). El tipo histológico más frecuente fue el endometrioide (74%), seguido del grupo de alto riesgo (seroso-papilar, célula clara y adenoescamoso) con un 16%. El 27,5% de los cánceres fueron mal diferenciados (G3). La distribución por estadios FIGO fue: estadio I (58%), II (24%), III (16%) y IV (2%). Con un seguimiento medio de 40,7 meses, la supervivencia global para el total de las pacientes fue del 92,2% (supervivencia media de 93 meses), siendo del 90,8% para las pacientes del grupo laparotómico y del 100% para las del laparoscópico. La comparación de las curvas de supervivencia entre las dos vías mostró un resultado estadísticamente no significativo (p=0,06). El tiempo libre de enfermedad para el total de pacientes fue del 91,4% (tiempo medio de 93,2 meses), siendo del 90,2% para el abordaje laparotómico y del 98,2% para el laparoscópico. Las curvas de tiempo libre de enfermedad tampoco difirieron (p=0,09). Diferenciando entre ambas vías de abordaje, se hallaron diferencias estadísticamente significativas (p<0,001) en cuanto a datos operatorios: el sangrado intraoperatorio medio, el número de transfusiones y la estancia hospitalaria media fueron menores en el grupo de laparoscopia. En cambio, el tiempo quirúrgico medio fue mayor en este grupo. El promedio de ganglios pélvicos y aórticos obtenidos fue superior en el grupo laparoscópico (p<0,001). El número de complicaciones fue similar con ambas vías (p=0,26). En el grupo laparoscópico no hubo ningún caso de conversión a laparotomía. Las dos poblaciones estudiadas fueron similares en características basales y en variables histopatológicas. En el análisis multivariable, ajustado para diferentes variables clínicas y morfológicas, las únicas variables con valor pronóstico independiente para supervivencia global fueron el grado mal diferenciado, la edad y el estadio IVa. Para tiempo libre de enfermedad lo fueron el tipo histológico de alto riesgo, la edad y el estadio IVa. Se concluye que la estadificación quirúrgica del cáncer de endometrio mediante abordaje laparoscópico-vaginal es factible y segura, con menor morbilidad y estancia hospitalaria. No obstante, se requiere un ensayo clínico que pueda confirmar estos resultados.Endometrial cancer is currently the most frequent malignancy of the female lower genital tract in developed countries. Stratification of tumor extension is based on surgical findings and pathological examination of the resected specimen. Routine treatment is carried out through a standard laparotomy, although some studies have suggested that the operation can be performed by laparoscopic-vaginal approach with the same level of oncological radicality and without increasing the rate of complications. The purpose of this study was to assess the feasibility of laparoscopy in the surgical treatment of clinical stage I endometrical carcinoma and to compare and the results obtained with those of laparotomy. The primary objective of the study was the comparison between both procedures in terms of overall survival, disease-free survival, and rate of complications. Secondary objectives included a comparison of surgical data, retrieved retroperitoneal lymph nodes, and length of hospital stay. Surgical stratification in both procedures included peritoneal cytology, extrafascial hysterectomy with bilateral salpingoophorectomy, bilateral pelvic lymphadenectomy ± para-aortic lymphadenectomy and omentectomy, and random biopsies in high-risk histological types. Most data were recorded prospectively. All patients with a diagnosis of primary endometrical carcinoma, stage I, attended at the Hospital Materno-infantil Vall d'Hebron in whom surgery was indicated as the primary treatment modality were included. The SPSS, version 11.0, software computer progarm was used for the analysis of data. Tests of normality, non-parametric tests, the Kaplan-Meier test for the analysis of overall survival and disease-free survival with the long-rank test for the comparison of survival curves, and a Cox proportional regression analysis were used. Between January 1995 and June 2001, a total of 371 patients with clinical stage I endometrial cancer were included. Stratification of the disease was made by the laparoscopic-vaginal approach in 55 patients (14.88%) and by laparotomy in 315 (84.9%). The mean age of the patients was 64.3 years and the body mass index 30 kg/m2 (range 18-57). Optimal stratification surgery was achieved in 367 patients (98.9%), without significant differences between both surgical routes. A total of 91.1% of patients underwent pelvic lymphadenectomy and 50% para-aortic lymphadenectomy. Positive lymph nodes were found in 41 cases (11.1%) and a total of 32 relapses (8.6%) were documented at follow-up. Edometrioid carcinoma was the most frequent (74%) histological type followed by the high-risk group (serous papillary, clear cell, and adenosquamous) (16%). In 27.3% of cases, the tumor was poorly differentiated (G3). Distribution of cases according to FIGO stage included stage I in 58% of cases, stage II in 24%, stage III in 16%, and stage IV in 2%. After a mean follow-up of 40.7 months, the overall survival rate was 92.2% (mean survival 93 months), with 90% for the laparotomy group and 100% for the laposcopic group. Differences in survival between both groups were not statistically significant (P=0.06). Disease-free survival for all patients was 91.4% (mean 93.2 months), with 92% for the laparotomy approach and 98.2% for the laparoscopic group. Differences in disease-free survival between both procedures were not statistically significant (P=0.09). However, there were significant differences (P<0.001) between both surgical routes with regard to operative data: mean blood loss, number of blood transfusions required, and mean length of hospital stay, which were lower in the laparoscopic group. In contrast, the mean surgical time was significantly longer in this group. The mean number of pelvic and aortic nodes recovered was higher in the laparoscopic group (P<0.001). The number of complications was similar for both routes (P=0.26). In patients undergoing surgery through the laparoscopic approach, no case of conversion to laparotomy was necessary. The two study populations were similar in baseline characteristics and histopathological variables. In the multivariate analysis and after adjusting for different clinical and morphological parameters, independent variables significantly associated with survival were poorly differentiated histological grade, age, and stage IVa, whereas independent predictors of disease-free survival were high-risk histological type, age, and stage IVa. It is concluded that surgical stratification of endometrial cancer by means of laparoscopic-vaginal approach is feasible and safe, with lower morbidity and shorter length of hospital stay. However, these results should be confirmed in the framework of a clinical trial

Price dynamics, informational efficiency and wealth distribution in continuous double auction markets

This paper studies the properties of the continuous double auction trading mechanishm using an artificial market populated by heterogeneous computational agents. In particular, we investigate how changes in the population of traders and in market microstructure characteristics affect price dynamics, information dissemination and distribution of wealth across agents. In our computer simulated market only a small fraction of the population observe the risky asset's fundamental value with noise, while the rest of agents try to forecast the asset's price from past transaction data. In contrast to other artificial markets, we assume that the risky asset pays no dividend, so agents cannot learn from past transaction prices and subsequent dividend payments. We find that private information can effectively disseminate in the market unless market regulation prevents informed investors from short selling or borrowing the asset, and these investors do not constitute a critical mass. In such case, not only are markets less efficient informationally, but may even experience crashes and bubbles. Finally, increased informational efficiency has a negative impact on informed agents' trading profits and a positive impact on artificial intelligent agents' profits

La campanilla de los apuros : juguete cómico en un acto

Representado por primera vez en el Teatro del Príncipe, el dia 28 de Abril de 1868.Copia digital : Junta de Castilla y León. Consejería de Cultura y Turismo, 201

Impact of a Localized Lean Six Sigma Implementation on Overall Patient Safety and Process Efficiency

Continuous quality improvement tools have been widely used in the Healthcare Industry to increase efficiency and patient safety as well as to reduce cost. This research explores the impact of a Lean Six Sigma (LSS) process improvement initiative on the overall process efficiency and patient safety in the Labor and Delivery (L+D) units of a large hospital provider. This study focuses on the application of a modeling and simulation methodology to investigate the influence of a localized process improvement intervention on the overall L+D unit output by considering patient flow, system capacity, and unit performance. The simulation models capacity profiles and patient flow through the system to determine patient throughput and waiting times. Baseline data was obtained from information systems logs from two Sentara Healthcare. Finally, the simulation analysis provides evidence to support decision making regarding process improvement implementation across the evaluated scenarios; the results evidence a significant time reduction, not only in the registration process but also in the “Time to Arrive to the Physician.