Occurrence, source estimation, and risk assessment of Polycyclic Aromatic Hydrocarbons in coastal seawaters from the Quintero Industrial Complex (Valparaíso, Chile).

In the 1960s, the Quintero industrial complex was inaugurated in Chile. This began a history of dramatic anthropogenic impacts on the Chilean coast. Among the known, we could mention high atmospheric emissions of chemicals due to combustion processes and frequent oil spills. For this reason, we surveyed the concentrations of fifteen EPAPAHs in the surface coastal waters of the Quintero Bay area in 2015. The levels found are in the range of the highest levels when reviewing the literature (0.97 µg L-1 up to 9.84 µg L-1). The highest levels were found in the vicinity of the industrial complex and decreased in the other two zones. The concentration of individual compounds significantly exceeds the levels recommended by the EPA (Environmental Protection Agency) and the EU water framework directive (WFD). The risk estimations revealed that PAH concentrations represent high-risk for wildlife. Molecular ratios of PAHs were used to identify the possible sources, being these were mainly of pyrogenic origin, agreeing with an origin in the combustion of wood, coal, grass, and fossil fuels. This study contributes to the first data for surface water in a country's highly impacted industrial coastal area.

Description of the larva of Micrathyria paulsoni González-Soriano, 2020 (Odonata: Libellulidae).

The last instar larva of Micrathyria paulsoni González-Soriano, 2020 is described and illustrated in detail based on specimens collected in Veracruz State, Mexico. It is compared with the larvae of M. didyma (Selys in Sagra, 1857) and M. hypodidyma Calvert, 1906, all of them belonging into the "Micrathyria didyma" group. The main structural features of M. paulsoni larva are 910 long premental setae plus 45 small setae, palpal setae 10, legs banded, a large, submedian, dark spot on each side of a pale middorsal line on S69, S89 with a posterolateral spine, larger in S9.

Report on G4-Med, a Geant4 benchmarking system for medical physics applications developed by the Geant4 Medical Simulation Benchmarking Group.

BACKGROUND: Geant4 is a Monte Carlo code extensively used in medical physics for a wide range of applications, such as dosimetry, micro- and nanodosimetry, imaging, radiation protection, and nuclear medicine. Geant4 is continuously evolving, so it is crucial to have a system that benchmarks this Monte Carlo code for medical physics against reference data and to perform regression testing. AIMS: To respond to these needs, we developed G4-Med, a benchmarking and regression testing system of Geant4 for medical physics. MATERIALS AND METHODS: G4-Med currently includes 18 tests. They range from the benchmarking of fundamental physics quantities to the testing of Monte Carlo simulation setups typical of medical physics applications. Both electromagnetic and hadronic physics processes and models within the prebuilt Geant4 physics lists are tested. The tests included in G4-Med are executed on the CERN computing infrastructure via the use of the geant-val web application, developed at CERN for Geant4 testing. The physical observables can be compared to reference data for benchmarking and to results of previous Geant4 versions for regression testing purposes. RESULTS: This paper describes the tests included in G4-Med and shows the results derived from the benchmarking of Geant4 10.5 against reference data. DISCUSSION: Our results indicate that the Geant4 electromagnetic physics constructor G4EmStandardPhysics_option4 gives a good agreement with the reference data for all the tests. The QGSP_BIC_HP physics list provided an overall adequate description of the physics involved in hadron therapy, including proton and carbon ion therapy. New tests should be included in the next stage of the project to extend the benchmarking to other physical quantities and application scenarios of interest for medical physics. CONCLUSION: The results presented and discussed in this paper will aid users in tailoring physics lists to their particular application.

Neutron spectra around a tandem linear accelerator in the generation of (18)F with a bonner sphere spectrometer.

A Bonner sphere spectrometer was used to measure the neutron spectra produced at the collision of protons with an H2(18)O target at different angles. A unique H2(18)O target to produce (18)F was designed and placed in a Tandem linear particle accelerator which produces 8.5MeV protons. The neutron count rates measured with the Bonner spheres were unfolded with the MAXED code. With the GEANT4 Monte Carlo code the neutron spectrum induced in the (p, n) reaction was estimated, this spectrum was used as initial guess during unfolding. Although the cross section of the reaction (18)O(p,n)(18)F is well known, the neutron energy spectra is not correctly defined and it is necessary to verify the simulation with measurements. For this reason, the sensitivity of the unfolding method to the initial spectrum was analyzed applying small variation to the fast neutron peak.

Clinical interview skills and identification of emotional disorders in primary care.

OBJECTIVE: The aim of this research was to study the relationship between the clinical interview skills of primary care physicians and their psychodiagnostic ability during office visits. METHOD: Ten doctors took part in the study, and 233 patients were assessed. The patients were seen and diagnosed by their physicians and interviewed afterward by a psychiatrist using the Present State Examination. All the interviews with the primary care physicians were recorded on videotape, and the Physician's Skills Observation Scale was used to analyze 10 interviews per doctor, five psychiatric cases and five nonpsychiatric cases. RESULTS: The physician's active listening (eye contact, posture, and absence of verbal interruptions) and ability to ask questions with psychological content were associated with the ability to identify the patient's emotional problems. This association was shown to be independent of the physician's characteristics (social, academic, attitudinal, and professional), the sociodemographic characteristics of the patients, the time spent in exploration during the office visit, and the severity of the emotional or somatic disorder. CONCLUSIONS: The findings of this research highlight the need to train primary care physicians in specific interview skills, in order to improve their ability to identify mental disorders in their practices.

The influence of culture on cognition.

This article presents a theoretical and methodological framework that seeks to integrate multiple sources of pertinent data that must be taken into account to interpret neuropsychological test results of individuals of non-European ancestry. It is proposed that cultural factors have a determining influence on an individual's behavior regardless of the neurophysiological status of the brain. A differentiation is made between the effects of culture/language and socioeconomic level on cognitive testing results and suggestions are made to assist in discriminating between these variables. Taking as illustration the assessment of Latino patients, focus is given to the accurate neuropsychological evaluation of individuals with little education, of non-European cultures, and with a primary language other than English.

Comparison of aceclofenac with piroxicam in the treatment of osteoarthritis.

A multicentre, double-blind, randomised, parallel group study was undertaken to investigate the efficacy and safety of aceclofenac (123 patients, 100 mg twice daily) in comparison to piroxicam (117 patients, 20 mg once daily and placebo once daily) in patients with osteoarthritis of the knee. The treatment period of two months was preceded by a washout period of one week duration. On completion of the study, patients in both aceclofenac and piroxicam-treated groups exhibited significant improvement in pain intensity and functional capacity of the affected knee, as represented by the Osteoarthritis Severity Index (OSI) (p < 0.0001 and p < 0.001 respectively). This was further substantiated following the patient's assessment of pain intensity using the Visual Analogue Scale (VAS), in which significant improvements were demonstrated at all time points for each treatment group (p < 0.001). Although both treatment groups showed a significant improvement in all investigator's clinical assessments (functional exploration of the knee, knee flexion and extension (EXT)), there were no significant differences between the groups. There was, however, a more rapid improvement in knee flexion in the aceclofenac group after 15 days of treatment. Both aceclofenac and piroxicam were well tolerated by patients, the most commonly reported adverse events being gastrointestinal, although their incidence was low. Only 24 patients on aceclofenac, as opposed to 33 on piroxicam complained of dyspepsia, epigastralgia and pyrosis. While 7 patients in each group were withdrawn because of adverse events, only one patient with piroxicam was withdrawn because of severe upper gastrointestinal bleeding. Twice as many reports of fecal blood loss were made in the piroxicam group in comparison to the aceclofenac group. In summary, this study confirms the therapeutic efficacy of aceclofenac and suggests that it is a well-tolerated alternative NSAID to piroxicam in the treatment of osteoarthritis.

Manganese micro-nodules on ancient brick walls.

Romans, Jews, Arabs and Christians built the ancient city of Toledo (Spain) with bricks as the main construction material. Manganese micro-nodules (circa 2 microm in diameter) have grown under the external bio-film surface of the bricks. Recent anthropogenic activities such as industrial emissions, foundries, or traffic and housing pollution have further altered these old bricks. The energy-dispersive X-ray microanalyses (XPS) of micro-nodules show Al, Si, Ca, K, Fe and Mn, with some carbon species. Manganese atoms are present only as Mn(4+) and iron as Fe(3+) (FeOOH-Fe(2)O(3) mixtures). The large concentration of alga biomass of the River Tagus and the Torcón and Guajaraz reservoirs suggest manganese micro-nodules are formed either from water solutions rich in anthropogenic MnO(4)K in a reduction environment (from Mn(7+) to Mn(4+)) or by oxidation mechanisms from dissolved Mn(2+) (from Mn(2+) to Mn(4+)) linked to algae biofilm onto the ancient brick surfaces. Ancient wall surfaces were also studied by scanning electron microscopy (SEM-EDS) and X-ray diffraction (XRD). Chemical and biological analyses of the waters around Toledo are also analysed for possible sources of manganese. Manganese micro-nodules on ancient brick walls are good indicators of manganese pollution.

Luminescence emission spectra in the temperature range of the structural phase transitions of Na2SO4.

The spectral properties of Na2SO4 have been studied by means of infrared stimulated luminescence (IRSL), thermoluminescence (TL) and radioluminescence (RL) in the range of 200-800 nm. The observed changes in the RL emission spectra after an annealing treatment (400 degrees C for 1 h) could be linked to thermal phase transformations and alkali self-diffusion through the lattice of this salt. Despite the complexity of the luminescence spectra structure, five emission bands peaked at 330, 345, 385, 460 and 630 nm could be distinguished. The UV-blue TL emission of this material exhibits a maximum peaked at 230 degrees C which is well correlated with the differential thermal analysis (DTA) and can be associated with the thermal transformation of the orthorhombic sodium sulphate (Na2SO4) V (thenardite) phase into Na2SO4 III, II and I phases. Taking into account the observed changes on the structural phase transition by X-ray diffraction (XRD) from 16 degrees C onwards, this material does not show satisfactory features for radiation dosimetry, but could be employed for temperature calibration of TL readers.

Cultural issues in an Outpatient Program for stimulant abusers.

Cocaine abuse has created widespread problems, especially in poor urban ethnic minority communities. This article discusses the cultural issues in delivering a cocaine treatment program to a predominantly minority patient population. The Stimulant Treatment Outpatient Program (STOP) of San Francisco General Hospital's Substance Abuse Services was established in 1990 as a public service clinic. Many program elements apply equally well to various cultural groups, including individual and group counseling, limited time in treatment, and crisis intervention. Culturally linked clinical issues include provision of a supportive infrastructure, role models in leadership positions, understanding the cultural influences in patients' lives, and establishing communication links with Cultural themes are discussed as they apply to treating African-Americans, Latinos, Asian-Americans, Native Americans, and clients of different genders. Programmatic outcome indicators, including program attrition, suggest that different cultural groups benefit differentially from the treatment.

[Changes in calcium, phosphate, magnesium and sodium content in bones of ovariectomized rats]. / Variaciones en el contenido de calcio, fosfato, magnesio y sodio en huesos de ratas ovariectomizadas.

Bilateral ovariectomies (OVX) or sham surgeries-respectively-were performed in two lots of ten female Wistar rats, 90 days old. Food was available ad libitum to sham rats, and it was restricted to OVX ones. At 15, 30, 45 and 90 days, a segment of their tails was sectioned. At 180 days all rats were sacrificed and the left femurs were excised. With the tail's bones and the femurs we determined Ca++, PO4(-3), Mg++ y Na+ concentration. After 15 days, no significant differences inter lots were observed (p < 0.05) in all ions contents. After 30 days Ca++ value was significantly less (p < 0.05) in the OVX rats than in the sham ones. After 45 days all the analyzed OVX rats ions were significantly less (p < 0.05) than the sham values. That difference inter lots was greater after 90 days. Finally, day 180th gave a decrease in the OVX rat values-from the femur-as follows: for Ca++ 31%, for PO4(-3) 29%, for Mg++ 31.6% and for Na+ 29%. Our results shown that in 90 days old ovariectomized rats, the concentration of calcium, phosphate, magnesium and sodium in the tail bones is a good indicator of bone mass loss, after 45 days of ovariectomy.

Evaluación de la intervención de fisioterapia en los pacientes con sarcopenia y fractura de cadera: una revisión sistemática / Evaluation of physiotherapy intervention in patients with sarcopenia and hip fracture: A systematic review

Introducción La sarcopenia en los pacientes con fractura de cadera es cada vez más habitual en la población envejecida, aumentando el riesgo de hospitalización, dependencia y mortalidad. Objetivos Valorar el tratamiento de fisioterapia más efectivo en los pacientes con sarcopenia y fractura de cadera a través de la revisión de evidencia sistemática. Métodos Se realizó una búsqueda entre febrero y mayo de 2022 en 8 bases de datos electrónicas (Pubmed, Scopus, PEDro, Web of Science, Cochrane, Google Scholar y Springer Link), con el fin de extraer ensayos clínicos publicados en los últimos 12 años en español e inglés. Resultados Se seleccionaron 3 ensayos clínicos que cumplían los criterios de inclusión. En todos ellos las intervenciones de fisioterapia incluían ejercicio aeróbico, de fuerza, de alta intensidad, de movilizaciones y combinados. La calidad metodológica se evaluó con la escala PEDro (puntuación media entre 6 y 10). Uno de los estudios no encuentra diferencias entre el tratamiento estándar y el grupo que recibe además entrenamiento progresivo de fuerza muscular. Otro constata una mejora a corto plazo en el grupo que recibe además del tratamiento convencional entrenamiento en cinta rodante con soporte del peso corporal durante el ejercicio con seguimiento a los 3 y 6 meses. El estudio que suplementa con aminoácidos esenciales es el único que constata una mejoría en los pacientes con sarcopenia. Conclusión Los pacientes con sarcopenia y fractura de cadera, pueden tener una mejor evolución si combinan ejercicios de fisioterapia con un protocolo nutricional. Son necesarias más investigaciones metodológicamente rigurosas sobre este tema para poder ampliar la evidencia. (AU)

Introduction Sarcopenia in patients with hip fracture is increasingly common in the elderly population, increasing the risk of hospitalization, dependency, and mortality. Objectives To assess the most effective physiotherapy treatment in patients with sarcopenia and hip fracture through systematic evidence review. Methods Electronic databases were searched from February to May 2022 using Pubmed, Scopus, PEDro, Web of Science, Cochrane, Google Scholar, and Springer Link in order to extract randomized clinical trials published in full text both English and Spanish for the last 12 years. Results Three clinical trials that met the inclusion criteria were selected. In all of them, the physiotherapy interventions included aerobic, strength, high intensity, mobilization, and combined exercises. Methodological quality was assessed using the PEDro scale (average score between 6 and 10). One of the studies found no differences between the standard treatment and the group that also received progressive muscle strength training. Another found a short-term improvement in the group that received, in addition to conventional treatment, treadmill training with body weight support during exercise with follow-up that was not maintained at three and six months. The study that supplements with essential amino acids is the only one that confirms an improvement in patients with sarcopenia. Conclusion Patients with sarcopenia and hip fracture may have a better evolution if they combine physiotherapy exercises with a nutritional protocol. More methodologically rigorous research on this topic is needed to expand the evidence. (AU)

Evaluación de la intervención de fisioterapia en los pacientes con sarcopenia y fractura de cadera: una revisión sistemática / Evaluation of physiotherapy intervention in patients with sarcopenia and hip fracture: A systematic review

Introducción La sarcopenia en los pacientes con fractura de cadera es cada vez más habitual en la población envejecida, aumentando el riesgo de hospitalización, dependencia y mortalidad. Objetivos Valorar el tratamiento de fisioterapia más efectivo en los pacientes con sarcopenia y fractura de cadera a través de la revisión de evidencia sistemática. Métodos Se realizó una búsqueda entre febrero y mayo de 2022 en 8 bases de datos electrónicas (Pubmed, Scopus, PEDro, Web of Science, Cochrane, Google Scholar y Springer Link), con el fin de extraer ensayos clínicos publicados en los últimos 12 años en español e inglés. Resultados Se seleccionaron 3 ensayos clínicos que cumplían los criterios de inclusión. En todos ellos las intervenciones de fisioterapia incluían ejercicio aeróbico, de fuerza, de alta intensidad, de movilizaciones y combinados. La calidad metodológica se evaluó con la escala PEDro (puntuación media entre 6 y 10). Uno de los estudios no encuentra diferencias entre el tratamiento estándar y el grupo que recibe además entrenamiento progresivo de fuerza muscular. Otro constata una mejora a corto plazo en el grupo que recibe además del tratamiento convencional entrenamiento en cinta rodante con soporte del peso corporal durante el ejercicio con seguimiento a los 3 y 6 meses. El estudio que suplementa con aminoácidos esenciales es el único que constata una mejoría en los pacientes con sarcopenia. Conclusión Los pacientes con sarcopenia y fractura de cadera, pueden tener una mejor evolución si combinan ejercicios de fisioterapia con un protocolo nutricional. Son necesarias más investigaciones metodológicamente rigurosas sobre este tema para poder ampliar la evidencia. (AU)

Introduction Sarcopenia in patients with hip fracture is increasingly common in the elderly population, increasing the risk of hospitalization, dependency, and mortality. Objectives To assess the most effective physiotherapy treatment in patients with sarcopenia and hip fracture through systematic evidence review. Methods Electronic databases were searched from February to May 2022 using Pubmed, Scopus, PEDro, Web of Science, Cochrane, Google Scholar, and Springer Link in order to extract randomized clinical trials published in full text both English and Spanish for the last 12 years. Results Three clinical trials that met the inclusion criteria were selected. In all of them, the physiotherapy interventions included aerobic, strength, high intensity, mobilization, and combined exercises. Methodological quality was assessed using the PEDro scale (average score between 6 and 10). One of the studies found no differences between the standard treatment and the group that also received progressive muscle strength training. Another found a short-term improvement in the group that received, in addition to conventional treatment, treadmill training with body weight support during exercise with follow-up that was not maintained at three and six months. The study that supplements with essential amino acids is the only one that confirms an improvement in patients with sarcopenia. Conclusion Patients with sarcopenia and hip fracture may have a better evolution if they combine physiotherapy exercises with a nutritional protocol. More methodologically rigorous research on this topic is needed to expand the evidence. (AU)

Pixelated CdTe detectors to overcome intrinsic limitations of crystal based positron emission mammographs.

A positron emission mammograph (PEM) is an organ dedicated positron emission tomography (PET) scanner for breast cancer detection. State-of-the-art PEMs employing scintillating crystals as detection medium can provide metabolic images of the breast with significantly higher sensitivity and specificity with respect to standard whole body PET scanners. Over the past few years, crystal PEMs have dramatically increased their importance in the diagnosis and treatment of early stage breast cancer. Nevertheless, designs based on scintillators are characterized by an intrinsic deficiency of the depth of interaction (DOI) information from relatively thick crystals constraining the size of the smallest detectable tumor. This work shows how to overcome such intrinsic limitation by substituting scintillating crystals with pixelated CdTe detectors. The proposed novel design is developed within the Voxel Imaging PET (VIP) Pathfinder project and evaluated via Monte Carlo simulation. The volumetric spatial resolution of the VIP-PEM is expected to be up to 6 times better than standard commercial devices with a point spread function of 1 mm full width at half maximum (FWHM) in all directions. Pixelated CdTe detectors can also provide an energy resolution as low as 1.5% FWHM at 511 keV for a virtually pure signal with negligible contribution from scattered events.

Changes of somatotype in high school students, V region, Chile: 1985-2010.

OBJECTIVE: To determine the trend of high school students from Valparaíso Chile by means of an anthropometrical somatotype. MATERIAL AND METHODS: two samples of students during the years 1984-1985 (86 men and 71 women) and 2009-2010 (77 men and 86 women) between 15 and 18 years of age have been studied. Somatotype was estimated by the Heath-Carter anthropometric method. RESULTS: significant differences were found in all the variables of the somatotype during the periods studied (p < 0.01), except for height (p = 0.176) and humeral breadth in women (p = 0.067). Important distinctions were also found in the endomorphic, mesomorphic and ectomorphic components (p < 0.01). Men measurements registered remarkable differences in all the variables (p < 0.01), with the exception of weight (p = 0.156), calf breadth (p = 0.906) and arm breadth in contraction (p = 0.284). Measurement results of endomorphic (p < 0.01), ectomorphic (p < 0.01) and mesomorfic components (p < 0.05) revealed considerable differences. During the period 1984-1985, men classified as balanced mesomorph 2.7-4.8-3.1 which switched to mesomorph-endomorph 3.8-4.3-2.5 in the period 2009-2010. And the population of women in the 1984-1985 period is classified as mesomorph-endomorph 4.2-4.7-2.1 and changes to a mesomorphic-endomorph biotype 6.6-4.1-1.3 in the 2009-2010. CONCLUSIONS: the somatotype of the adolescent population, especially women in Valparaiso, Chile has changed to a predominant endomorphic biotype, and its mesomorphic component has decreased. A high relative adiposity contributes to increase the probability for these people to suffer non-transmissible chronic diseases and cardiovascular issues.

Validation of a small-animal PET simulation using GAMOS: a GEANT4-based framework.

Monte Carlo-based modelling is a powerful tool to help in the design and optimization of positron emission tomography (PET) systems. The performance of these systems depends on several parameters, such as detector physical characteristics, shielding or electronics, whose effects can be studied on the basis of realistic simulated data. The aim of this paper is to validate a comprehensive study of the Raytest ClearPET small-animal PET scanner using a new Monte Carlo simulation platform which has been developed at CIEMAT (Madrid, Spain), called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations). This toolkit, based on the GEANT4 code, was originally designed to cover multiple applications in the field of medical physics from radiotherapy to nuclear medicine, but has since been applied by some of its users in other fields of physics, such as neutron shielding, space physics, high energy physics, etc. Our simulation model includes the relevant characteristics of the ClearPET system, namely, the double layer of scintillator crystals in phoswich configuration, the rotating gantry, the presence of intrinsic radioactivity in the crystals or the storage of single events for an off-line coincidence sorting. Simulated results are contrasted with experimental acquisitions including studies of spatial resolution, sensitivity, scatter fraction and count rates in accordance with the National Electrical Manufacturers Association (NEMA) NU 4-2008 protocol. Spatial resolution results showed a discrepancy between simulated and measured values equal to 8.4% (with a maximum FWHM difference over all measurement directions of 0.5 mm). Sensitivity results differ less than 1% for a 250-750 keV energy window. Simulated and measured count rates agree well within a wide range of activities, including under electronic saturation of the system (the measured peak of total coincidences, for the mouse-sized phantom, was 250.8 kcps reached at 0.95 MBq mL(-1) and the simulated peak was 247.1 kcps at 0.87 MBq mL(-1)). Agreement better than 3% was obtained in the scatter fraction comparison study. We also measured and simulated a mini-Derenzo phantom obtaining images with similar quality using iterative reconstruction methods. We concluded that the overall performance of the simulation showed good agreement with the measured results and validates the GAMOS package for PET applications. Furthermore, its ease of use and flexibility recommends it as an excellent tool to optimize design features or image reconstruction techniques.

Changes of somatotype in high school students, V region, Chile: 1985-2010 / Desplazamiento del somatotipo de estudiantes de enseñanza secundaria, V región, Chile: 1985-2010

Objective: To determine the trend of high school students from Valparaíso Chile by means of an anthropometrical somatotype Material and methods: two samples of students during the years 1984-1985 (86 men and 71 women) and 2009-2010 (77 men and 86 women) between 15 and 18 years of age have been studied. Somatotype was estimated by the Heath-Carter anthropometric method. Results: significant differences were found in all the variables of the somatotype during the periods studied(p < 0.01), except for height (p = 0.176) and humeral breadth in women (p = 0.067). Important distinctions were also found in the endomorphic, mesomorphic andectomorphic components (p < 0.01). Men measurements registered remarkable differences in all the variables (p <0.01), with the exception of weight (p = 0.156), calf breadth (p = 0.906) and arm breadth in contraction (p =0.284). Measurement results of endomorphic (p<0.01),ectomorphic (p < 0.01) and mesomorfic components (p <0.05) revealed considerable differences. During the period 1984-1985, men classified as balanced mesomorph 2.7-4.8-3.1 which switched to mesomorph-endomorph 3.8-4.3-2.5 in the period 2009-2010.And the population of women in the 1984-1985 period is classified as mesomorph-endomorph 4.2-4.7-2.1 and changes to a mesomorphic-endomorph biotype 6.6-4.1-1.3 in the 2009-2010.Conclusions: the somatotype of the adolescent population, especially women in Valparaiso, Chile has changedto a predominant endomorphic biotype, and its mesomorphic component has decreased. A high relative adiposity contributes to increase the probability for these people to suffer non-transmissible chronic diseases and cardiovascular issues (AU)

Objetivo: Determinar la tendencia de una población de estudiantes de educación secundaria de Valparaíso, Chilea través del somatotipo. Material y métodos: Se han estudiado dos muestras de estudiantes durante los períodos 1984-1985 (hombres 86y mujeres 71) y 2009-2010 (hombres 77 y mujeres 86) de15 a 18 años. Se registraron los datos antropométricos para evaluar el somatotipo antropométrico de Heath Carter. Resultados: Para todas las variables del somatotipo de Heath-Carter se encontraron diferencias significativas entre los períodos estudiados (p < 0,01) excepto para talla(p = 0,176) y diámetro humeral (p = 0,067) en mujeres,para los componentes endomorfo, mesomorfo y ectomorfo también se registran diferencias significativas (p <0,01). En hombres, se registran diferencias significativas para todas las variables (p < 0,01) con excepción de peso(p = 0,156), perímetro de pierna (p=906) y perímetro de brazo en contracción (p = 0,284). También se observan diferencias significativas en los componentes endomorfo(p < 0,01), ectomorfo (p < 0,01) y mesomorfo (p < 0,05). La población de mujeres del periodo 1984-1985 se clasifica como endomorfo-mesomorfo 4,2-4,7-2,1 y cambia a un perfil endo-mesomórfico 6,6-4,1-1,3 en el 2009-2010. En los hombres en el periodo 1984-1985 se clasifica como mesomorfismo balaceado 2,7-4,8-3,1 y cambia a un endomorfo-mesomorfo 3,8-4,3-2,5 en el periodo 2009-2010. Conclusiones: El somatotipo de la población de adolescentes de Valparaíso, Chile se ha desplazado hacia un biotipo predominantemente endomorfo sobre todo en mujeres y ha disminuido su componente mesomórfico. Este perfil con una alta adiposidad relativa contribuye a aumentar las probabilidades de que esta población sufra enfermedades crónicas no transmisibles y cardiovasculares (AU)

The role of Joule heating in dispersive mixing effects in electrophoretic cells: hydrodynamic considerations.

The analysis described in this contribution is focused on the effect of Joule heating generation on the hydrodynamics of batch electrophoretic cells (i.e., cells that do not display a forced convective term in the motion equation). The hydrodynamics of these cells is controlled by the viscous forces and by the buoyancy force caused by the temperature gradients due to the Joule heating generation. The analysis is based on differential models that lead to analytical and/or asymptotic solutions for the temperature and velocity profiles of the cell. The results are useful in determining the characteristics of the temperature and velocity profiles inside the cell. Furthermore, the results are excellent tools to be used in the analysis of the dispersive-mixing of solute when Joule heating generation must be accounted for. The analysis is performed by identifying two sequentially coupled problems. Thus, the "carrier fluid problem" and the "solute problem" are outlined. The former is associated with all the factors affecting the velocity profile and the latter is related to the convective-diffusion aspects that control the spreading of the solute inside the cell. The analysis of this contribution is centered on the discussion of the "carrier fluid problem" only. For the boundary conditions selected in the contribution, the study leads to the derivation of an analytical temperature and a "universal" velocity profile that feature the Joule heating number. The Grashof number is a scaling factor of the actual velocity profile. Several characteristics of these profiles are studied and some numerical illustrations have been included.