The halo effect, private knowledge and retirement fund choice: A theoretical model for the case of México’s Afores

Empirical evidence shows that Mexican workers frequently chose a lower-yielding retirement savings manager over a higher-yielding one, damaging their prospects for retirement income. This research paper shows that such puzzling behavior can occur as a product of the unobservable private history between workers and the companies clustered around a common brand-name, in an example of what is known as the halo effect. To support this hypothesis, a theoretical model of private knowledge and subjective probability with long-term commitment is built. Results are consistent with the idea that private-knowledge-induced halo effect can produce a rational decision process to yield an apparently irrational outcome

Passive Portfolio Management by Indexing: A Performance Analysis of High, Medium and Low Capitalization Indices in Mexico

En una gestión pasiva de inversiones mediante indexación, el desempeño del portafolio dependerá en gran medida de la habilidad para elegir el mejor índice. En este trabajo, se estudia el desempeño de cuatro de los principales índices bursátiles en México con la intención de seleccionar el mejor de ellos para una estrategia de inversión pasiva. Para resolver esta pregunta, a partir de la razón de Sortino, se propone la sustitución del exceso de retorno promedio por una definición de probabilidad de acierto y el uso de la máxima desviación estándar sobre el retorno objetivo negativo. Las nuevas medidas de desempeño arrojan resultados diferentes a los resultados de la medida tradicional de Sortino, siendo el IPC large cap el mejor índice para una estrategia pasiva, en términos de su relación riesgo-rendimiento y objetivo de rentabilidadIn a passive investing strategy through indexation, the portfolio performance will depend largely on the ability to choose the best index. In this paper, we study the performance of four of the main stock indices in Mexico with the intention of selecting the best one for a passive investing strategy. To solve this question, departing from the Sortino ratio , a definition of probability of success substitutes the average excess return over a target and the use of the maximum standard deviation on the negative target return. The new per- formance measure gives different results to those of the traditional Sortino ratio, with the IPC large cap being the best index for a passive strategy, in terms of risk-reward ratio and return target

Stability behaviour of composite magnetorheological fluids by an induction method

Este artículo puede consultarse en la siguiente dirección de la editorial: http://jim.sagepub.com/content/early/2015/03/26/1045389X15577656.full.pdf+htmlIn this work we study the stability behaviour of composite magnetorheological (MR) fluids consisting of magnetic (iron) and non-magnetic (poly (methylmethacrylate), PMMA) particles dispersed in mineral oil. Because of the opacity of the suspensions, optical methods traditionally employed for evaluation of the gravitational settling in colloidal suspensions are not suitable for sedimentation follow-up in this case. For this reason, we use an alternative method based on the evaluation of the resonant frequency of the inductance of a thin coil surrounding the sample The movement of the coil along the height of the container at specified steps and time intervals allows obtaining information about the local volume fraction of particles inside the tube. The obtained successive profiles for the multi-component suspensions show a decrease of the iron particle settling and of the initial rate of settling as the PMMA volume fraction is increased. Finally, the increase of the PMMA concentration gives rise to an improvement of the rheological properties upon magnetic field application for a given concentration of iron. Both a strongrheological response and a good colloidal stability are essential for practical applications.Proyectos PE2012-FQM694 (Junta de Andalucía, Spain)y FIS2013-47666-C3-1-R (Ministerio de Economía y Competitividad, Spain). L. R.-A. agrradece a la Universidad de Granada su contrato puente (Plan Propio de Investigación, UGR)

Comportamiento sísmico y alternativas de Rehabilitación de edificaciones en adobe y tapia Pisada con base en modelos a escala reducida Ensayados en mesa vibratoria

El presente artículo resume los resultados principales de una investigación tendiente a determinar las principales características y propiedades mecánicas de los elementos estructurales que conforman las edificaciones en tierra y a partir de esta información plantear alternativas de rehabilitación sísmica acordes con las características y entorno de este tipo de construcciones en Colombia. Las medidas de rehabilitación planteadas que consisten básicamente en reforzamiento con mallas de acero y pañetes a base de cal y reforzamiento con elementos de madera confinantes, fueron sometidas a un programa experimental mediante la realización de ensayos sobre probetas sometidas a diferentes tipos de solicitaciones, ensayos sobre muros a escala natural sometidos a cargas en el plano y perpendiculares al plano, ensayos de modelos a escala 1:5 sometidos a la acción de mesa vibratoria y ensayos de viviendas a escala 1:1.5 sometidas a carga cíclica horizontal. Los resultados de la investigación permiten establecer las ventajas y desventajas de cada uno de los sistemas de rehabilitación analizados. Se encuentra que, a pesar de la alta vulnerabilidad sísmica de estos sistemas constructivos, el método de rehabilitación con elementos de madera confinantes representa una alternativa viable y atractiva para la disminución del riesgo en este tipo de construcciones

Frequency of use and preferences for information and communication technologies in patients with sleep apnea: A multicenter, multinational, observational cross-sectional survey study

Background: Obstructive sleep apnea (OSA) is a condition characterized by repeated episodes of partial or complete obstruction of the upper airway during sleep. An accessible method to facilitate self-management education is through information and communication technologies (ICTs). Purpose: To assess the frequency of and preferences for ICT use in patients with sleep apnea. Methods: A multicenter, multinational, observational cross-sectional survey study was conducted between 2018 and 2019 in sleep units in different countries of Latin America, including patients of both genders older than 18 years with a diagnosis of sleep apnea. Participants were asked to complete 20 questions in a self-administered survey about the frequency of use of ICTs and their preferences for receiving disease-related information. Results: A total of 435 patients participated in the study, with a mean age of 59.1 ± 14.0; 62.5% (n = 272) were males. Most patients had access to cellphones (92.4%, n = 402), smartphone (83.0%, n = 361) and an internet connection (82.3%, n = 358). One-to-one ICTs were regarded as the most frequently used ICT type, as 75.4% (n = 328) of participants reported using them daily (χ2(4) = 848.207, p =.000). With respect to categories of interest, one-to-one ICTs were also the best rated ICT type to receive (59.1%, n = 257; χ2(2) = 137.710, p =.000) and ask physicians (57.0%, n = 248; χ2(2) = 129.145, p =.000) information about OSA. Finally, older adults and those with lower educational levels were found to be less likely to use and be interested in ICTs. Conclusion: Most patients have access to different ICTs and often use them to seek and receive medical information. The preferred ICTs include those in the one-to-one category (WhatsApp, email) and the one-to-many category (web browsers) for general health and OSA-related informatio

Eating Disorder symptomatology: prevalence among Latino college freshmen students

This study investigated the prevalence of eating disorder symptoms in first-year students at the University of Puerto Rico. Responses to the Bulimia Test Revised (BULIT-R), the Eating Attitudes Test (EAT-26), and the Beck Depression Inventory (BDI) were analyzed in a sample of 2,163 freshman students. The percentage of students at or above the clinical cut-off points was 3.24% for the BULIT-R and 9.59% for the EAT-26, and 1.88% met the cut-off point for both instruments. The 36.44% of the students who screen positive on eating disorders measures scored 18 or more on the BDI and 5.93% on this group presented high suicidal risk based on their responses to BDI items assessing suicidal thoughts. Eating disorder symptoms occur frequently in Puerto Rican college students, and prevention, detection, and treatment efforts are needed

Human papillomavirus infections in women seeking cervical Papanicolaou cytology of Durango, Mexico: prevalence and genotypes

BACKGROUND: HPV infection in women from developing countries is an important public health problem. Therefore, we sought to determine the prevalences of HPV infection and HPV genotypes in a female population of Durango City, Mexico. Also to determine whether any socio-demographic characteristic from the women associated with HPV infection exists. METHODS: Four hundred and ninety eight women seeking cervical Papanicolaou examination in three public Health Centers were examined for HPV infection. All women were tested for HPV DNA PCR by using HPV universal primers. In addition, all positive HPV DNA PCR samples were further analyzed for genotyping of HPV genotype 16, 18 and 33. Socio-demographic characteristics from each participant were also obtained. RESULTS: Twenty-four out of four hundred and ninety-eight (4.8%) women were found infected by HPV. HPV genotype 16 was found in 18 out of the 24 (75%) infected women. Two of them were also coinfected by HPV genotype 18 (8.3%). In the rest 6 PCR positive women, genotyping for HPV genotypes 16, 18 and 33 were negative. CONCLUSION: The prevalence of HPV in women of Durango City is low; however, most infected women have high risk HPV genotype. The women who were studied showed low frequency of risk factors for HPV infection and this may explain the low prevalence of HPV infection. The high frequency of high risk HPV genotypes observed might explain the high rate of mortality for cervical cancer in our region

Respiratory viruses detected in Mexican children younger than 5 years old with community-acquired pneumonia: a national multicenter study

Background: Acute respiratory infections are the leading cause of mortality in children worldwide, especially in developing countries. Pneumonia accounts for 16% of all deaths of children under 5 years of age and was the cause of death of 935 000 children in 2015. Despite its frequency and severity, information regarding its etiology is limited. The aim of this study was to identify respiratory viruses associated with community-acquired pneumonia (CAP) in children younger than 5 years old. Methods: One thousand four hundred and four children younger than 5 years of age with a clinical and/or radiological diagnosis of CAP in 11 hospitals in Mexico were included. Nasal washes were collected, placed in viral medium, and frozen at �70 C until processing. The first 832 samples were processed using the multiplex Bio-Plex/Luminex system and the remaining 572 samples using the Anyplex multiplex RT-PCR. Clinical data regarding diagnosis, clinical signs and symptoms, radiographic pattern, and risk factors were obtained and recorded. Results: Of the samples tested, 81.6% were positive for viruses. Respiratory syncytial virus (types A and B) was found in 23.7%, human enterovirus/rhinovirus in 16.6%, metapneumovirus in 5.7%, parainfluenza virus (types 1–4) in 5.5%, influenza virus (types A and B) in 3.6%, adenovirus in 2.2%, coronavirus (NL63, OC43, 229E, and HKU1) in 2.2%, and bocavirus in 0.4%. Co-infection with two or more viruses was present in 22.1%; 18.4% of the samples were negative. Using biomass for cooking, daycare attendance, absence of breastfeeding, and co-infections were found to be statistically significant risk factors for the presence of severe pneumonia. Conclusions: Respiratory syncytial virus (types A and B), human enterovirus/rhinovirus, and metapneumovirus were the respiratory viruses identified most frequently in children younger than 5 years old with CAP. Co-infection was present in an important proportion of the children

Memoria del I Coloquio de verano de investigación de la Escuela de Negocios de ITESO, 2022

Esta memoria recoge cinco de las ponencias presentadas en el Coloquio de investigación de verano de la ENI, 2022. Son una muestra del trabajo de investigación que hacemos en el Departamento de Economía, Administración y Mercadología (DEAM), en el Centro Universidad Empresa (CUE) y en el Centro para la Gestión de la Innovación y la Tecnología (CEGINT); una investigación con una orientación principalmente práctica y aplicada, enfocada a las micro, pequeñas y medianas empresas y a su contexto socioeconómico. Esperamos que puedan ser ocasión de diálogo y de contribución no sólo al campo académico en el que nos desenvolvemos, sino también a las realidades mismas en las que queremos colaborar para apoyar los esfuerzos hacia una economía y una sociedad más justas y más humanas.ITESO, A.C