Trace elements in the culturally significant plant Sarracenia purpurea in proximity to dust sources in the oil sands region of Alberta, Canada.

Accessible populations of plants are critical to the meaningful exercise of Aboriginal and treaty rights in Canada. In the oil sands region of Alberta, populations of culturally significant plant species overlap with extensive oil and gas development. This has led to a host of questions and concerns related to plant health and integrity from both Indigenous communities and western scientists. Here, we assessed trace element concentrations in the northern pitcher-plant (tsala' t'ile; Sarracenia purpurea L.) with a focus on elements associated with fugitive dust and bitumen. Plant leaves were collected using clean methods and washed prior to analyses in an ultra-clean, metal-free laboratory. Pitcher-plant was an excellent model for assessing the impacts of industrial development on a culturally important, vulnerable species. Although concentrations of trace elements in pitcher-plant were low and not indicative of a toxicological concern, we saw clear dust signatures in plant tissues related to road and surface mine proximity. Elements associated with fugitive dust and bitumen extraction declined exponentially with increasing distance from a surface mine, a well-established regional pattern. However, our analyses also captured localized spikes in trace element concentrations within 300 m of unpaved roads. These local patterns are more poorly quantified at the regional scale but are indicative of the burden to Indigenous harvesters wishing to access plant populations that are not impacted by dust. Further work to directly quantify dust loads on culturally significant plants will help to define the amount of harvesting area lost to Indigenous communities due to dust impacts.

Conceptos generales en bioestadística y epidemiología clínica: error aleatorio y error sistemático / General concepts in biostatistics and clinical epidemiology: random error and systematic error

La investigación biomédica, particularmente la que involucra a seres humanos, está siempre sometida a fuentes de error que deben ser reconocidas. El error sistemático o sesgo, se asocia con debilidades en el diseño metodológico o de la fase de ejecución del estudio. Éste afecta su validez y se valora cualitativamente. Por su parte, el error aleatorio se relaciona con las variaciones producidas por el azar, el cual puede expresarse cuantitativamente, pero nunca eliminarse. Esta revisión es la primera entrega de una serie metodológica sobre conceptos generales en bioestadística y epidemiología clínica desarrollada por la Cátedra de Metodología de la Investigación Científica de la Universidad de Valparaíso, Chile. En este artículo se abordan los conceptos teóricos asociados al error, su evaluación y control. Finalmente, se discuten algunas controversias actuales en cuanto a su conceptualización, de relevancia para estudiantes de pre y posgrado de ciencias de la salud.

Biomedical research, particularly when it involves human beings, is always subjected to sources of error that must be recognized. Systematic error or bias is associated with problems in the methodological design or during the execu-tion phase of a research project. It affects its validity and is qualitatively ap-praised. On the other hand, random error is related to variations due to chance. It may be quantitatively expressed, but never removed. This review is the first of a methodological series on general concepts in biostatistics and clin-ical epidemiology developed by the Chair of Scientific Research Methodology at the School of Medicine, University of Valparaíso, Chile. In this article, we address the theoretical concepts of error, its evaluation, and control. Finally, we discuss some current controversies in its conceptualization that are relevant to undergraduate and graduate students of health sciences.

Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador.

Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg-1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0-20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg-1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate.

Características Antropométricas por Posición de Juego en Mujeres Futbolistas Chilenas de la Región de Valparaíso, Chile / Anthropometric Attributes by Playing Position in Chilean Female Football Players From the Valparaiso Region, Chile

Participaron del estudio 76 mujeres futbolistas de la región de Valparaíso, las edades fluctuaron entre los 18 y 30 años. Fueron evaluados los equipos femeninos profesionales de los clubes Everton, Santiago Wanderers y San Luis de Quillota, las selecciones de la universidades de Valparaíso, Técnica Federico Santa María y Universidad Viña del Mar. Las posiciones de juego fueron distribuidas en arqueras (n= 8), defensas (n= 25), volantes (n= 24) y delanteras (n= 18). Para la evaluación de la composición corporal se utilizó el protocolo establecido por la International Society for the Advancement of Kinanthropometry. Para determinar el somatotipo de las futbolistas fue utilizado el modelo de Heath & Carter. Se fraccionó el peso corporal total a través del método pentacompartimental diseñado por Kerr. Los resultados demuestran un somatotipo promedio mesomorfo endomorfo, la distribución por equipos evidencia diferencias significativas en el mesomorfismo entre los equipos Everton y Universidad Viña del Mar (p<0,014). Entre las posiciones arquera y delantera existieron diferencias significativas en las variables peso (p<0,030) y endomorfia (p<0,050). No existieron diferencias en el porcentaje de tejido adiposo, tejido muscular, sumatoria de pliegues y estatura por posición de juego. En lo que respecta a la distribución por posición de juego, se evidencia un somatotipo meso endomorfo en las posiciones arquera y defensa, en las posiciones volantes y delanteras se aprecia un somatotipo mesomorfo endomorfo, esto demuestra una diferenciación del somatotipo entre posiciones de juego defensivas y ofensivas encontrando un mayor predominio de la endomorfia en las posiciones defensivas en comparación con las de ataque. Según el método SANOVA se concluye que las futbolistas evaluadas en este estudio presentaron características antropométricas similares, no habiendo diferencias significativas entre equipos universitarios y profesionales, ni por posición de juego.

Seventy-six female football players from the Valparaiso Region. Players´ age fluctuated between 18 and 30 years participated in this research. Female professional teams from Everton, Santiago Wanderers and San Luis de Quillota clubs, as well as the teams from Federico Santa María Technical University and Viña del Mar University were evaluated. Playing positions were: goalkeepers (n= 8), defenders (n= 25), attacking midfielders (n= 24) and strikers (n= 18). To measure body composition the protocol established by the International Society for the Advancement of Kinanthropometry was used, according to the restricted profile described by Drinkwater and Norton & Olds. The Heath and Carter method was used to determine the somatotype of the female football players. Total body mass was divided using Kerr´s Five-Way Fractionation method. Results show an average somatotype of mesomorph and endomorph. In the distribution by teams, the results showed significant differences of mesomorph between the Everton Club and the Viña del Mar University (p<0.014). Between the goalkeepers and the strikers there were significant differences regarding weight (p<0.030) and endomorph (p<0.050). No differences in the percentage of adipose tissue, muscle tissue, the sum of folds and height in relation to playing position were found. Regarding the distribution by playing position, the results showed a meso-endomorph somatotype for the goalkeepers and defenders, and a mesomorph endomorph somatotype for the attacking midfielders and strikers. This reveals a differentiation of somatotypes between offensive and defensive playing positions, finding a higher prevalence of the endomorph somatotype in defensive playing positions compared to the attack positions. Using the SANOVA method, the study concludes that the anthropometric attributes of the female football players evaluated are similar, with no significant differences between university teams and professional teams or by playing position.

Perfil antropométrico por posición de juego en handbolistas chilenos / Anthropometric profile in Chilean handball players according to playing position

El objetivo fundamental de la presente investigación fue determinar el perfil antropométrico y su relación con la capacidad de salto en jugadores de balonmano varones de la región de Valparaíso y de la Selección Chilena, esto en relación a su posición en el campo de juego. Se valoraron 74 jugadores de la categoría cadetes, cuyas edades fluctuaron entre los 14 y los 16 años, pertenecientes a los equipos: Club Italiano Villa Alemana, Club Italiano Quillota, Club Luterano, Club Viña del Mar, Club San José y Selección Chilena. Los resultados arrojaron que en cuanto a las variables antropométricas, la Selección Chilena y el Club Italiano Villa Alemana, son los que poseen los parámetros que más se asemejan a los requeridos a nivel competitivo dentro de esta categoría. Al hacer referencia a las variables antropométricas se estimó que, en todos los grupos estudiados, la masa adiposa se relacionó negativamente con la altura de salto alcanzada. Mientras que la masa muscular presentó una alta correlación con el rendimiento en salto en la mayoría de los equipos. Los índices de correlación evidenciaron que un menor porcentaje de masa grasa y mayor porcentaje de masa muscular favorecen la altura de salto alcanzada en todas las posiciones de juego. Queda de manifiesto que la relación masa adiposa y masa muscular es un indicador importante a la hora de determinar el rendimiento en la capacidad de salto en deportistas con características similares a las de este estudio.

The primary purpose of this research was to determine the relationship between the anthropometric profile and jump capacity of male handball players from the Fifth Region of Chile and the National Handball Team and their specific position in the playing field. In the evaluation 74 handball players participated from the following teams: Club Italiano Villa Alemana, Club Italiano Quillota, Club Luterano, Club Viña del Mar, Club San José and the National Handball Team. Participants were in the cadet category aged 14 ­ 16. The results showed that within anthropometric variables, players from the Chilean Handball Team and the Club Italiano Villa Alemana are the closest to fulfilling all the criteria required to reach high competitive levels in this category. In reference to anthropometric variables, fat mass proved to be negatively related to jump height reached in all groups tested, while muscle mass presented significant correlation with the jump capacity in most of the teams. Regarding the somatotype, results obtained agree with the theoretical referents. These establish that handball player's somatotype is more likely to be mesomorph. The correlation indexes demonstrate that a lower fat mass percentage and a higher muscle mass percentage enhance the jump capacity in all playing positions. It is clear now that fat mass and muscle mass are important indicators when determining the jump capacity performance in players with similar characteristics of the ones in this study. This research is important in setting comparative parameters in the selection process and sport specialization regarding anthropometric characteristics and jump capacity according to specific position of handball players in the cadet category.

Biocatalytic synthesis of polypyrrole powder, colloids, and films using horseradish peroxidase.

Polypyrrole was synthesized in high yield by a biocatalytic method in mild aqueous media using hydrogen peroxide as oxidizer. A redox mediator, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) diammonium salt, was used to oxidize the pyrrole. ABTS is a very effective peroxidase substrate, which was enzymatically oxidized to generate a radical cation that in turn was able to chemically oxidize pyrrole. This indirect biocatalytic method was implemented because pyrrole is not a substrate of horseradish peroxidase, however, the polymerization process was successfully optimized and later adapted to prepare also polypyrrole thin films and water dispersible polypyrrole colloids. The polypyrrole powder and colloids were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, electrical conductivity, and thermogravimetric analysis. In addition, the deposition of the polypyrrole thin film was monitored using a quartz-crystal microbalance and its morphology studied by optical and scanning electron microscopy. The biocatalytic polymerization of pyrrole results in a polymer spectroscopically very similar to chemically synthesized polypyrrole.