Cambios en la cobertura del matorral seco montano del valle Chota (Imbabura y Carchi, Ecuador) entre 1990 y 2020

El cambio en el uso del suelo es uno de los principales conductores del cambio global, así como una causa de la pérdida de biodiversidad. En el norte del Ecuador, el matorral seco montano es un ecosistema característico de los valles interandinos y que se encuentra amenazado por la intervención antrópica. El presente trabajo estudió el cambio de la cobertura del matorral seco montano en el valle del río Chota en un periodo de 30 años y evaluó su estado de conservación. Se aplicó el método de clasificación supervisada en las imágenes satelitales LANDSAT de los años 1990, 2007 y 2020, para analizar las tasas de variación de las coberturas. El estado de conservación se determinó con una matriz de evaluación que consideró siete variables y 25 indicadores y la sobreposición de capas temáticas con SIG. Los resultados denotaron una pérdida del 20% de la cobertura del matorral seco montano, a un promedio anual de 231.83 ha/año (-0.75%) por causas antrópicas. Estas causas fueron responsables del cambio de cobertura de más de la mitad del 8.34% del área que ocupaba, principalmente la expansión de la frontera agrícola con un 3.96%. La presión y efecto de los factores antrópicos identificados causaron que el estado actual de conservación sea Regular. Se proponen tres estrategias de conservación: buenas prácticas agroecológicas, una gestión ambiental integral y la educación ambiental.

Land use change is one of the main drivers of global change, as well as a cause of biodiversity loss. In northern Ecuador, the montane dry scrub is a characteristic ecosystem of the inter-Andean valleys and is threatened by anthropogenic intervention. This study examined the change in montane dry scrub coverage in the Chota River Valley over a 30-year period and evaluated its conservation status. The supervised classification method was applied to LANDSAT satellite images from 1990, 2007, and 2020 to analyze the rates of coverage variation. The conservation status was determined using an evaluation matrix that considered seven variables and 25 indicators and the overlap of thematic layers with GIS. The results showed a loss of 20% of montane dry scrub coverage, at an annual average of 231.83 ha/year (-0.75%) due to anthropogenic causes. These causes were responsible for the coverage change of more than half of the 8.34% of the area it occupied, mainly the expansion of the agricultural frontier with 3.96%. The pressure and effect of the identified anthropogenic factors caused the current conservation status to be Regular. Three conservation strategies are proposed: good agroecological practices, comprehensive environmental management, and environmental education.

Norovirus compared to other relevant etiologies of acute gastroenteritis among families from a semirural county in Chile.

OBJECTIVE: To determine the dynamics of norovirus disease, a major cause of acute gastroenteritis (AGE), compared to other relevant etiologies, among families living in a lower middle income area. STUDY DESIGN: Families with three or more members and with one or more healthy children <24 months of age were followed for 1-2 years to detect any AGE. Stool samples were tested for viral and bacterial pathogens and a questionnaire was completed for those with norovirus or rotavirus AGE. RESULTS: Between April and June 2016, 110 families were enrolled, with 103 of them completing ≥12 months of follow-up. A total of 159 family AGE episodes were detected, mostly affecting one individual (92%). At least one pathogen was detected in 56% (94/169) of samples, of which 75/94 (80%) were sole infections. Norovirus was most common (n=26), followed closely by enteropathogenic Escherichia coli (EPEC) (n=25), rotavirus (n=24), and astrovirus (n=23). The annual incidence of family AGE was 0.77, and 0.12 for norovirus. Most norovirus AGE occurred in children <4 years old (96%). Only 13/159 (8%) index AGE cases resulted in a secondary case, of which four were associated with norovirus. The majority of norovirus strains were GII (85%), with a mild predominance of GII.4 (9/26; 35%); most norovirus isolates (69%) were recombinants. CONCLUSIONS: The family incidence of AGE in this lower middle income community was nearly one episode per year, mostly caused by viruses, specifically norovirus closely followed by rotavirus and astrovirus. Norovirus infections primarily affected children <4 years old and secondary cases were uncommon.

Parent reported outcomes to measure satisfaction, acceptability, and daily life impact after vaccination with whole-cell and acellular pertussis vaccine in Chile.

AIM: To compare parental satisfaction and impact on daily life among parents of children receiving whole-cell pentavalent + oral polio vaccine (Arm1) with an acellular hexavalent vaccine (Hexaxim; Arm2). METHODS: Self-administered electronic questionnaire at vaccination and one week later in six community health clinics of metropolitan Santiago, Chile, exploring parent-reported outcomes on satisfaction, acceptability, and impact on daily life after immunization. Univariate and multivariate analyses were conducted to determine differences in the responses in both groups (α = 0.05). RESULTS: The study enrolled 800 participants and 65% (222 in Arm1, 296 in Arm2) were included for according-to-protocol analysis. Demographic characteristics were comparable, except for a higher proportion of mothers answering the questionnaire at the 6-month visit. Regardless of the study arm, parental knowledge and perception of the immunization practices were good, and there were no differences in vaccination experiences in the prior 5 years. However, satisfaction with vaccination and intention to vaccinate were statistically significantly higher in Arm2 after the 6-month visit. Also, more parents in Arm2 reported no disruption in several aspects of the everyday activities of the parent, the child, and other children in the household. Parents in Arm2 were more likely to be satisfied with the vaccine received (OR 2.82; 95% CI, 1.22-7.07); return for other vaccine dose (OR 2.62; 95% CI, 1.45-4.84); follow a healthcare professional recommendation (OR 2.24; 95% CI, 1.57-3.21); and, to be confident that the vaccine will not disrupt the family's daily routine (OR 1.89; 95% CI, 1.32-2.71). CONCLUSIONS: Overall, satisfaction, intention for future vaccination, and lower impact on the family daily routine were significantly better in the group receiving the hexavalent vaccine. We also found that health care providers' recommendations to vaccinate and participants' access to health services were important factors favoring immunization.

Se Nanoparticles Induce Changes in the Growth, Antioxidant Responses, and Fruit Quality of Tomato Developed under NaCl Stress.

Nanotechnology represents an opportunity to improve the use of elements in agriculture. Selenium is an element that is beneficial to plants and essential to the human diet. The size of nanoparticles gives them characteristics that can enhance the benefits that selenium provides to plants. The objective of the present study was to determine the effects of selenium nanoparticles on the growth, antioxidant responses, and fruit quality of tomato developed under NaCl stress. Four doses of selenium nanoparticles (1, 5, 10, and 20 mg L-1) under NaCl stress, only NaCl, and a control were evaluated. The results showed that the impact of salinity on the growth of the tomato crop can be reduced with the application of selenium nanoparticles. However, the amount of both enzymatic and non-enzymatic compounds significantly increased in the leaves and fruits of tomato. The results suggest that the application of selenium nanoparticles generated a positive effect against salinity in the tomato crop; moreover, it had a positive impact on the content of beneficial biocompounds for human health in tomato fruits.

Desarrollo de una matriz conceptual para la innovación curricular en profesiones de la salud / Concept frame for curricular innovation in health care schools

We herein describe the conceptual dimension of the curricular innovation process carried out in the Faculty of Medicine of the University of Chile. We describe the context of innovation. The theoretical pertinence and relevance of a competence driven curriculum for health care professionals is discussed. The epistemological, ontological and didactic dimensions of the curricular innovation are examined. A main issue is the notion of competence and its significance in professional training. The curriculum is essentially considered as a moral endeavor, especially for health care professionals and their quest to improve the quality of life of the population.

[Concept frame for curricular innovation in health care schools]. / Desarrollo de una matriz conceptual para la innovación curricular en profesiones de la salud.

We herein describe the conceptual dimension of the curricular innovation process carried out in the Faculty of Medicine of the University of Chile. We describe the context of innovation. The theoretical pertinence and relevance of a competence driven curriculum for health care professionals is discussed. The epistemological, ontological and didactic dimensions of the curricular innovation are examined. A main issue is the notion of competence and its significance in professional training. The curriculum is essentially considered as a moral endeavor, especially for health care professionals and their quest to improve the quality of life of the population.

Inactivated poliovirus vaccine given alone or in a sequential schedule with bivalent oral poliovirus vaccine in Chilean infants: a randomised, controlled, open-label, phase 4, non-inferiority study.

BACKGROUND: Bivalent oral poliovirus vaccine (bOPV; types 1 and 3) is expected to replace trivalent OPV (tOPV) globally by April, 2016, preceded by the introduction of at least one dose of inactivated poliovirus vaccine (IPV) in routine immunisation programmes to eliminate vaccine-associated or vaccine-derived poliomyelitis from serotype 2 poliovirus. Because data are needed on sequential IPV-bOPV schedules, we assessed the immunogenicity of two different IPV-bOPV schedules compared with an all-IPV schedule in infants. METHODS: We did a randomised, controlled, open-label, non-inferiority trial with healthy, full-term (>2·5 kg birthweight) infants aged 8 weeks (± 7 days) at six well-child clinics in Santiago, Chile. We used supplied lists to randomly assign infants (1:1:1) to receive three polio vaccinations (IPV by injection or bOPV as oral drops) at age 8, 16, and 24 weeks in one of three sequential schedules: IPV-bOPV-bOPV, IPV-IPV-bOPV, or IPV-IPV-IPV. We did the randomisation with blocks of 12 stratified by study site. All analyses were done in a masked manner. Co-primary outcomes were non-inferiority of the bOPV-containing schedules compared with the all-IPV schedule for seroconversion (within a 10% margin) and antibody titres (within two-thirds log2 titres) to poliovirus serotypes 1 and 3 at age 28 weeks, analysed in the per-protocol population. Secondary outcomes were seroconversion and titres to serotype 2 and faecal shedding for 4 weeks after a monovalent OPV type 2 challenge at age 28 weeks. Safety analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01841671, and is closed to new participants. FINDINGS: Between April 25 and August 1, 2013, we assigned 570 infants to treatment: 190 to IPV-bOPV-bOPV, 192 to IPV-IPV-bOPV, and 188 to IPV-IPV-IPV. 564 (99%) were vaccinated and included in the intention-to-treat cohort, and 537 (94%) in the per-protocol analyses. In the IPV-bOPV-bOPV, IPV-IPV-bOPV, and IPV-IPV-IPV groups, respectively, the proportions of children with seroconversion to type 1 poliovirus were 166 (98·8%) of 168, 95% CI 95·8-99·7; 178 (100%), 97·9-100·0; and 175 (100%), 97·9-100·0. Proportions with seroconvsion to type 3 poliovirus were 163 (98·2%) of 166, 94·8-99·4; 177 (100%), 97·9-100·0, and 172 (98·9%) of 174, 95·9-99·7. Non-inferiority was thus shown for the bOPV-containing schedules compared with the all-IPV schedule, with no significant differences between groups. In the IPV-bOPV-bOPV, IPV-IPV-bOPV, and IPV-IPV-IPV groups, respectively, the proportions of children with seroprotective antibody titres to type 1 poliovirus were 168 (98·8%) of 170, 95% CI 95·8-99·7; 181 (100%), 97·9-100·0; and 177 (100%), 97·9-100·0. Proportions to type 3 poliovirus were 166 (98·2%) of 169, 94·9-99·4; 180 (100%), 97·9-100·0; and 174 (98·9%) of 176, 96·0-99·7. Non-inferiority comparisons could not be done for this outcome because median titres for the groups receiving OPV were greater than the assay's upper limit of detection (log2 titres >10·5). The proportions of children seroconverting to type 2 poliovirus in the IPV-bOPV-bOPV, IPV-IPV-bOPV, and IPV-IPV-IPV groups, respectively, were 130 (77·4%) of 168, 95% CI 70·5-83·0; 169 (96·0%) of 176, 92·0-98·0; and 175 (100%), 97·8-100. IPV-bOPV schedules resulted in almost a 0·3 log reduction of type 2 faecal shedding compared with the IPV-only schedule. No participants died during the trial; 81 serious adverse events were reported, of which one was thought to be possibly vaccine-related (intestinal intussusception). INTERPRETATION: Seroconversion rates against polioviruses types 1 and 3 were non-inferior in sequential schedules containing IPV and bOPV, compared with an all-IPV schedule, and proportions of infants with protective antibodies were high after all three schedules. One or two doses of bOPV after IPV boosted intestinal immunity for poliovirus type 2, suggesting possible cross protection. Additionally, there was evidence of humoral priming for type 2 from one dose of IPV. Our findings could give policy makers flexibility when choosing a vaccination schedule, especially when trying to eliminate vaccine-associated and vaccine-derived poliomyelitis. FUNDING: Bill & Melinda Gates Foundation.

[The educational change in medical schools]. / Cambio educativo en las Facultades de Medicina.

This paper reports the reflections of a group of members of the University of Chile Faculty of Medicine, about the changes in teaching methods that medical schools should incorporate. In a complex scenario, not only new and better knowledge should be transmitted to students but also values, principles, critical reasoning and leadership, among others. In the first part, a proposal to understand this educational development in the context of complex universities, incorporating pedagogical skills and reviewing institutional leadership, is carried out. In the second part, the training of teaching physicians, as part of the changes, is extensively discussed. Physicians hired as academics in the University should have the opportunity to work mainly as teachers and be relieved of research obligations. For them, teaching should become a legitimate area of academic development.

Determination of reactions between free radicals and selected Chilean wines and transition metals by ESR and UV-vis technique.

Four different types of Chilean wines (Cabernet Sauvignon, Merlot, Carmenere and Syrah) were selected and examined in their free radical scavenging capacities by electron spin resonance (ESR) and spectrophotometric methods. The free radical scavenging properties were evaluated against 2,2-diphenyl-1-picrylhydrazyl (DPPH*) radical, 2,6-di-tert-butyl-alpha-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-1-ylidene)-p-tolyloxy (Galvinoxyl) radical and hydroxyl radical (HO*). The possible effect on these scavenging properties of added transition metals to these wines was evaluated. Among the wines evaluated, Cabernet Sauvignon was the one with the highest activity against all radicals tested. The presence of added copper or iron to wines resulted in a reduced free radical scavenging capacity for all type of wines studied. The formation of redox inactive complexes between polyphenols of wine and transition metals is the possible cause of this reduction in antioxidant activity.

La necesidad de modificar la resolución administrativa No 1966/07 reglamentaria del Decreto Supremo No 29241 que determina el pago de las obligaciones de las entidades y/o empresas deudoras dentro un periodo de tres años

Se plantea la necesidad de modificar la resolución Administrativa No 1966/07 de fecha 9 de noviembre de 2007 dejando sin efectos la Escala de Pagos establecida en el artículo 4to de la Resolución Reglamentaria determinada para el pago de aportes devengados al sistema de reparto

A comparative study of two different methods for the detection of latent tuberculosis in HIV-positive individuals in Chile.

OBJECTIVE: To compare the performance of two tests for diagnosing latent tuberculosis (TB) infection in the HIV-positive population in Chile, in order to better identify the subjects who might benefit from TB chemoprophylaxis. DESIGN: This was a cross-sectional study among individuals attending three HIV outpatient clinics in Santiago, tested with a 2-TU purified protein derivative, QuantiFERON((R))-TB Gold 'in-tube' (QFT-G), and a chest X-ray. RESULTS: A total of 116 subjects were enrolled in the study, having a mean CD4 count of 393cells/microl (range 100-977). The tuberculin skin text (TST; 5mm cutoff) and QFT-G results were positive in 10.9% and 14.8% of the individuals, respectively, with moderate agreement between both tests (kappa=0.59). A history of both known TB exposure (odds ratio (OR) 3.46, 95% confidence interval (CI) 1.02-11.22) and past TB (OR 4.31, 95% CI 1.13-15.5) were associated with a positive QFT-G result. Only past TB was significantly associated with a positive TST result (OR 6.63, 95% CI 1.62-26.3). Among the subjects with TST<5mm, 8.2% were positive by QFT-G test. These individuals had a lower mean CD4 cell count than those detected positive by both tests (328cells/microl and 560cells/microl, respectively, p=0.03). CONCLUSIONS: In this population of HIV-infected individuals, QFT-G and TST showed an acceptable level of agreement, although QFT-G appears less affected by more advanced immunosuppression.

[Usefulness of the determination of IgG and IgM antibodies by ELISA and immunocapture in a clinical series of human brucellosis]. / Utilidad de la determinación de anticuerpos IgG e IgM por ELISA e inmunocaptura en una serie clínica de brucelosis humana.

INTRODUCTION: The diagnostic difficulties of brucellosis makes the evaluation of new diagnostic tests necessary. OBJECTIVES: Evaluation of different commercial tests in the serological diagnosis of brucellosis by ELISA and immunocapture antibodies in a clinical series of patients with brucellosis of the Health Network of the Catholic University of Chile. METHODS: All the serums received in the Laboratory of Microbiology for suspicion of brucellosis during five years were studied. Two groups were obtained, one that fulfilled diagnostic criteria for brucellosis [clinical evidence, and/or positive blood culture and/or seroagglutination test (SAT) in titers > 1/160] and the control group. Each serum sample was analyzed using irnmunocapture-agglutination test (Brucellacapt), ELISA IgM and IgG. RESULTS: Of 10 patients with brucellosis, the serologic results were: 8/10 positives for ELISA IgG, 7/10 for Brucellacapt and SAT, and 5/10 for ELISA IgM. DISCUSSION: ELISA IgG alone was superior than SAT. The combination ELISA IgG/ Brucellacapt reaches the best detection performance (9/10) and can be an alternative to SAT.

Utilidad de la determinación de anticuerpos IgG e IgM por ELISA e inmunocaptura en una serie clínica de brucelosis humana / Usefulness of the determination of IgG and IgM antibodies by ELISA and immunocapture in a clinical series of human brucellosis

Introducción: El diagnóstico de brucelosis continúa siendo complejo en la actualidad y se requieren nuevas pruebas de diagnóstico. Objetivo: Evaluar pruebas comerciales para la determinación serológica de anticuerpos anti Brucella sp mediante ELISA e inmunocaptura en una serie clínica de pacientes de la Red de Salud UC. Métodos: Estudio retrospectivo de pacientes cuyos sueros fueron recibidos en el laboratorio de Microbiología para estudio serológico de brucelosis. Se obtuvieron 2 grupos, aquellos que cumplían criterios diagnósticos de brucelosis [cuadro clínico compatible, y/o hemocultivo positivo y/o serología por seroaglutinación en tubo (SAT) en títulos > 1/160] y el grupo control. Todos los sueros se analizaron mediante aglutinación con inmunocaptura (Brucellacapt®), ELISA IgM y ELISA IgG. Resultados: De 10 pacientes con brucelosis, los resultados serológicos fueron: 8/10 positivos para ELISA IgG, 7/10 para Brucellacapt® y SAT y 5/10 para ELISA IgM. Discusión: ELISA IgG por si solo fue la mejor prueba para el diagnóstico de brucelosis. La combinación ELISA IgG+ Brucellacapt® alcanza un buen rendimiento de detección (9/10) y puede ser una alternativa a la SAT.

Introduction: The diagnostic difficulties of brucellosis makes the evaluation of new diagnostic tests necessary. Objectives: Evaluation of different commercial tests in the serological diagnosis of brucellosis by ELISA and immunocapture antibodies in a clinical series of patients with brucellosis of the Health Network of the Catholic University of Chile. Methods: All the serums received in the Laboratory of Microbiology for suspicion of brucellosis during five years were studied. Two groups were obtained, one that fulfilled diagnostic criteria for brucellosis [clinical evidence, and/or positive blood culture and/or seroagglutination test (SAT) in titers > 1/160] and the control group. Each serum sample was analyzed using irnmunocapture-agglutination test (Brucellacapt®), ELISA IgM and IgG. Results: Of 10 patients with brucellosis, the serologic results were: 8/10 positives for ELISA IgG, 7/10 for Brucellacapt® and SAT, and 5/10 for ELISA IgM. Discussion: ELISA IgG alone was superior than SAT. The combination ELISA IgG/ Brucellacapt® reaches the best detection performance (9/10) and can be an alternative to SAT.

[Mexican older adults with a wide socioeconomic perspective: health and aging]. / Adultos mayores mexicanos en contexto socioeconómico amplio: salud y envejecimiento.

OBJECTIVES: Describe the Estudio Nacional de Salud y Envejecimiento en México (ENASEM), also known by its name in English as the Mexican Health and Aging Study (MHAS). MATERIALS AND METHODS: This article summarizes the study design, its fieldwork protocol, survey contents, scope and analytical potential. It also presents descriptive results on selected topics. This is a prospective panel study on persons aged 50 or older in the year 2000. RESULTS: In the baseline survey, completed in 2001 with a national and urban-rural representation, about 15 200 interviews were completed. In the follow-up survey of the same persons in 2003, 90% of the attempted contacts resulted in successful interviews, and 546 interviews were completed about individuals who had died between the 2001 and 2003 visits. Descriptive results are presented on demographic characteristics, health, life style, institutional support, pensions, employment, family help, and two-year changes in health. CONCLUSIONS: There is evidence of large heterogeneity among older adults in Mexico, which is illustrated in a brief and precise way in the results presented. This study and its data bases have great analytical potential for exploring multiple dimensions in the health of older adults.

Adultos mayores mexicanos en contexto socioeconómico amplio: salud y envejecimiento / Mexican older adults with a wide socioeconomic perspective: health and aging

OBJETIVO: Describir el Estudio Nacional sobre Salud y Envejecimiento en México (ENASEM), conocido también por su nombre en inglés: Mexican Health and Aging Study (MHAS). MATERIAL Y MÉTODOS: Se hace una descripción del diseño del estudio, su trabajo de campo y contenido temático, sus alcances y potencial analítico. Se presentan resultados descriptivos acerca de temas selectos. Este es un estudio prospectivo de panel sobre personas de 50 años de edad o más en 2000. RESULTADOS: En la encuesta inicial, realizada en 2001 con representatividad nacional y en áreas urbanas y rurales, se entrevistó aproximadamente a 15 200 personas. La encuesta de seguimiento realizada en 2003 recontactó exitosamente a más de 90 por ciento de los individuos entrevistados en la encuesta inicial y se realizaron 546 entrevistas sobre personas fallecidas entre 2001 y 2003. Se presentan resultados descriptivos de características demográficas, de salud, estilo de vida, apoyo institucional, pensiones, empleo, ayudas familiares y cambios en la salud a dos años. CONCLUSIONES: Los adultos mayores en México presentan gran heterogeneidad, la cual se ilustra en forma concisa y breve en los resultados presentados. El estudio y las bases de datos derivadas tienen un gran potencial analítico para explorar múltiples dimensiones de la salud en adultos mayores.

OBJECTIVES: Describe the Estudio Nacional de Salud y Envejecimiento en México (ENASEM), also known by its name in English as the Mexican Health and Aging Study (MHAS). MATERIALS AND METHODS: This article summarizes the study design, its fieldwork protocol, survey contents, scope and analytical potential. It also presents descriptive results on selected topics.This is a prospective panel study on persons aged 50 or older in the year 2000. RESULTS: In the baseline survey, completed in 2001 with a national and urban-rural representation, about 15 200 interviews were completed. In the follow-up survey of the same persons in 2003, 90 percent of the attempted contacts resulted in successful interviews, and 546 interviews were completed about individuals who had died between the 2001 and 2003 visits. Descriptive results are presente donde mographic characteristics, health, life style, institutional support, pensions, employment, family help, and two-year changes in health. CONCLUSIONS: There is evidence of large heterogeneity among older adults in Mexico, which is illustrated in a brief and precise way in the results presented. This study and its data bases have great analytical potential for exploring multiple dimensions in the health of older adults.

Differential signalling for enhanced hexose uptake by interleukin (IL)-3 and IL-5 in male germ cells.

We studied the expression and function of the IL (interleukin)-3 and IL-5 family of receptors in male germ cells. RT (reverse transcription)-PCR showed expression of mRNAs encoding the alpha and beta subunits of the IL-3 and IL-5 receptors in human testis, and the presence of IL-3 and IL-5 receptors alpha and beta proteins was confirmed by immunoblotting with anti-alpha and anti-beta antibodies. The immunolocalization studies showed expression of these receptors in the germ line in the human testis and in human and bovine ejaculated spermatozoa. Functional studies with bull spermatozoa indicated that IL-3 signalled for increased uptake of hexoses in these cells at picomolar concentrations compatible with expression of functional high-affinity IL-3 receptors in these cells. In contrast, IL-5 failed to induce increased hexose uptake in bull spermatozoa. Experiments using HL-60 eosinophils that express functional IL-3 and IL-5 receptors confirmed that IL-3, but not IL-5, signalled for increased hexose uptake. Our findings suggest that differential signalling for increased hexose uptake by heteromeric high-affinity IL-3 and IL-5 receptors in mammalian spermatozoa is a property that depends on the identity of the alpha-subunit forming part of the alphabeta-complex and is not a property specific to the germ cells.

[Income and assets of the middle and old age Mexican population]. / Ingreso y bienes de la población de edad media y avanzada en México.

The purpose of this article is to describe the amount and types of income and assets that the middle and old age population receive and own in Mexico. We use data from the Mexican Health and Aging Study (MHAS) 2001; a prospective panel study with national representation of individuals aged 50 and older. The results confirm the hypotheses of the paper: that the distributions of income and wealth are biased in favor of certain groups, in particular those highly educated; that the majority of the wealth of individuals is in non-financial form; that family help is an important source of income; and that the association between wealth and health is positive in general, which is consistent with the international literature for other countries. In addition, we find that wealth is more equitably distributed than income. We conclude that the wealth indicator offers an additional dimension of analysis than income, with potential to contribute to studies of well-being of the population of middle and old age in Mexico.