Potential of Pinus radiata, Eucalyptus globulus and Acacia dealbata for the long-term phytostabilization of copper mine tailings.

Many contaminated tailings throughout the world cause environmental and human-health related problems due to air and water drift. Tailing phytostabilization is a promising solution, but only certain plant species may tolerate and grow in these contaminated areas. We analyzed the chemical properties of a vegetated and unvegetated area in a tailing site in Central Chile. In addition, in the vegetated area we analyzed the metals content of roots, stems, and foliage in 41-years old plantations of Pinus radiata, Acacia dealbata, and Eucalyptus globulus (the only three species that survived from a total of 34 species planted), and determined height (H), and diameter at breast height (DBH). The results indicated that, except for pH, Se, Pb, and organic matter, all components (nutrients and metals) were two- to three- fold lower in the vegetated tailing compared to that of the unvegetated tailing. The analysis of plant tissues indicated that Cu was higher in the roots of P. radiata (2,073 mg kg-1) and lower in the stems of the same species (4.1 mg kg-1). However, the ability to take up and transport Cu to the shoots was higher in A. dealbata and lower in P. radiata (bioaccumulation factor of 0.19 and 0.06, respectively).

Here we present results for the first long-term phytostabilization project of copper mine tailings in Chile. From the 34 native and exotic species established in 1980 in a mine tailing disposal site with 1,000 mg Cu kg⁻¹, only the exotic Pinus radiata, Acacia dealbata and Eucalyptus globulus were able to survive and adapt to the tailing conditions the last 41 years. This corroborates their potential for the future phytostabilization of copper mine wastes.

A portrait of gestational diabetes mellitus in Brazil: A systematic review and meta-analysis.

The diagnostic criteria for gestational diabetes mellitus (GDM), a transient hyperglycemic state during pregnancy, has varied remarkably over time, resulting in a diversity of prevalence rates. The aim of this systematic literature review was to provide estimates of prevalence rates of GDM in Brazil according to different diagnostic criteria. We identified, reviewed, and extracted data from the scientific literature on studies estimating the prevalence of diabetes in pregnant women living in Brazil. The databases searched were PubMed, LILACS, SciELO, Embase, Web of Science, and Cochrane Library. We grouped studies by the source of information assessing GDM, patients' age, and criteria used to diagnose GDM. When three or more studies were available in a group, we calculated the pooled prevalence. The Joanna Briggs Institute (JBI) appraisal tool was used to assess the risk of bias. The data were reported according to the 2020 PRISMA recommendations. The study protocol was registered in PROSPERO. We identified 1,328 records and selected 21 studies involving 122,635 pregnant women. Studies in adults only, with primary data and laboratory measurements, and using the IADPSG criteria (n = 3) had a GDM prevalence of 18.0% (95% confidence interval [CI]: 16.0-20.1%) and included 6,243 participants. Estimates of self-reported GDM (n = 3; 10,136 participants of all ages) had a pooled GDM prevalence of 2.1% (95% CI: 1.5-5.2%), with high heterogeneity (I2 = 85.0%, p < 0.01). Studies including adolescents had consistently low prevalences. The prevalence of GDM in Brazil varied, was greater when the IADPSG criteria were applied, and depended on the methods used to obtain the GDM information and the age structure of the sample.

A portrait of gestational diabetes mellitus in Brazil: A systematic review and meta-analysis

ABSTRACT The diagnostic criteria for gestational diabetes mellitus (GDM), a transient hyperglycemic state during pregnancy, has varied remarkably over time, resulting in a diversity of prevalence rates. The aim of this systematic literature review was to provide estimates of prevalence rates of GDM in Brazil according to different diagnostic criteria. We identified, reviewed, and extracted data from the scientific literature on studies estimating the prevalence of diabetes in pregnant women living in Brazil. The databases searched were PubMed, LILACS, SciELO, Embase, Web of Science, and Cochrane Library. We grouped studies by the source of information assessing GDM, patients' age, and criteria used to diagnose GDM. When three or more studies were available in a group, we calculated the pooled prevalence. The Joanna Briggs Institute (JBI) appraisal tool was used to assess the risk of bias. The data were reported according to the 2020 PRISMA recommendations. The study protocol was registered in PROSPERO. We identified 1,328 records and selected 21 studies involving 122,635 pregnant women. Studies in adults only, with primary data and laboratory measurements, and using the IADPSG criteria (n = 3) had a GDM prevalence of 18.0% (95% confidence interval [CI]: 16.0-20.1%) and included 6,243 participants. Estimates of self-reported GDM (n = 3; 10,136 participants of all ages) had a pooled GDM prevalence of 2.1% (95% CI: 1.5-5.2%), with high heterogeneity (I2 = 85.0%, p < 0.01). Studies including adolescents had consistently low prevalences. The prevalence of GDM in Brazil varied, was greater when the IADPSG criteria were applied, and depended on the methods used to obtain the GDM information and the age structure of the sample.

The Recruitment of the Recalcitrant-Seeded Cryptocarya alba (Mol.) Looser, Established via Direct Seeding Is Mainly Affected by the Seed Source and Forest Cover.

Natural regeneration of recalcitrant-seeded tree species is strongly limited in Mediterranean-type climate zones due to increasing droughts imposed by climate change. Direct seeding can be a low-cost alternative to seedling establishment, but there is still limited information for some species. This study aimed to assess the effects of the seed source and forest cover on the germination and survival of the endemic Cryptocarya alba Mol. established through direct seeding. Three habitat types differing in forest cover were identified within the natural park Reserva Natural Altos de Cantillana, Metropolitan Region, Chile. The forest cover corresponded to open (canopy density <25%), semi-dense (canopy density around 50%), and dense forest (canopy density >75%). All forest cover had C. alba as one of the dominant species. At each habitat type, 38 families from four seed sources (Cuesta La Dormida (CD), Antumapu (AN), Cantillana (CA, local seed source) and Cayumanque (CY)) were directly seeded. Germination (Germin) and survival (Surv) were evaluated weekly during one growing season. There were significant differences between seed sources in Germin and Surv, with means values varying from 7.8% to 37% for Germin and 0% to 20% for Surv. The local seed source CA had the highest values in both traits. A significant variation was also observed between families within seed sources only for Germin. The dense forest cover had the highest Germin (22%) and Surv (55%) results compared to the other forest cover types, which was partially associated with differences in soil moisture, temperature, and bulk density. Due to the most frequent droughts in these Mediterranean-type climate zones, the use of local seeds on dense forest cover is recommended for the direct seeding of the species in the initial recruitment.

Effect of the Soil Matric Potential on the Germination Capacity of Prosopis chilensis, Quillaja saponaria and Cryptocarya alba from Contrasting Geographical Origins.

As a consequence of the megadrought in Central Chile, it is expected that most of the distribution of woody species will be narrowed in the northern limits because of restrictions imposed by soil matric potential on seed germination. In this study, we analyzed the effect of the soil matric potential on seed germination and initial recruitment of the sclerophyllous species Prosopis chilensis, Quillaja saponaria and Cryptocarya alba from contrasting geographic origins (i.e., seed sources). We evaluated the germination capacity (%) under different matric potentials (i.e., 0, -6, -33, -750 and -1250 kPa) for 100 days. Soil matric potential of -1250 kPa negatively affected the germination capacity of the three species. P. chilensis seeds stopped germinating under soil matric potential close to -1200 kPa, whereas in Q. saponaria and C. alba the complete inhibition of germination was under -1000 kPa. Seed sources also differed in their germination capacity by soil matric potential: northern seed sources of P. chilensis germinated with the lowest soil matric potential. There was no clear trend in Q. saponaria and C. alba, but in general, southern seed sources performed better than the northern ones. The results showed that Ñ°m in the soil played an important role in the germinative capacity against different seed source origins, but not in soils with a north-south gradient.

Phenotypic variation of fruit and ecophysiological traits among maqui (Aristotelia chilensis [Molina] Stuntz) provenances established in a common garden.

The domestication of forest species has traditionally relied on productivity issues. However, today there are concerns about the potential responses of natural populations and new cultivars to extreme climatic conditions derived from climate change and how to incorporate this knowledge into the domestication programs. Aristotelia chilensis (Molina) Stuntz ('Maqui') is a widely distributed native species in Chile. Its berry is considered a "super fruit" with an increasing interest in the food industry. This study investigated the phenotypic variation of growth, fruit, and ecophysiological traits of 20 A. chilensis clones originated from six provenances along the latitudinal gradient and established in a common-garden experiment in the Mediterranean zone of central Chile (center part of the species distribution). Differences among provenances were observed for most of the traits under study, especially between the northern and southernmost provenances (i.e., San Fernando versus Entre Lagos). Northern provenances showed higher development of vegetative tissue and fruit yield but lower intrinsic water use efficiency (WUEint) compared with southern ones. Clonal variation within provenances was found significant for the ripening index, WUEint, and fruit number and weight but not significant for traits related to the crown and leaf morphology. A genetic differentiation due to latitudinal cline was not evident in this study, but differences among provenances suggest local adaptation for some traits. The genotypic variation in productive traits must be considered in the outgoing domestication of the species and future selection programs.

Limited Phenotypic Variation in Vulnerability to Cavitation and Stomatal Sensitivity to Vapor Pressure Deficit among Clones of Aristotelia chilensis from Different Climatic Origins.

Aristotelia chilensis (Molina) Stuntz is a promising species in the food industry as it provides 'super fruits' with remarkable antioxidant activity. However, under the predicted climate change scenario, the ongoing domestication of the species must consider selecting the most productive genotypes and be based on traits conferring drought tolerance. We assessed the vulnerability to cavitation and stomatal sensitivity to vapor pressure deficit (VPD) in A. chilensis clones originated from provenances with contrasting climates. A nursery experiment was carried out for one growing season on 2-year-old potted plants. Measurements of stomatal conductance (gs) responses to VPD were taken in spring, summer, and autumn, whereas vulnerability to cavitation was evaluated at the end of spring. Overall, the vulnerability to cavitation of the species was moderate (mean P50 of -2.2 MPa). Parameters of the vulnerability curves (Kmax, P50, P88, and S50) showed no differences among clones or when northern and southern clones were compared. Moreover, there were no differences in stomatal sensitivity to VPD at the provenance or the clonal level. However, compared with other studies, the stomatal sensitivity was considered moderately low, especially in the range of 1 to 3 kPa of VPD. The comparable performance of genotypes from contrasting provenance origins suggests low genetic variation for these traits. Further research must consider testing on diverse environmental conditions to assess the phenotypic plasticity of these types of traits.

Multidimensional scale of perceived social support: evidence of validity and reliability in a Chilean adaptation for older adults.

BACKGROUND: Given the relevance of social support on the mental health of older adults, having an instrument to evaluate this variable is essential for research in the area. However, mainly, having instruments with suitable evidence of their psychometric properties is critical. For this reason, this study sought to evaluate the factorial and reliability structure of the Multidimensional Scale of Perceived Social Support within autonomous older adults from the Province of Concepción, Chile. METHODS: We surveyed 399 older adults using quote sampling. They answered a Spanish version of the Multidimensional Scale of Perceived Social Support, plus a sociodemographic questionnaire. We performed confirmatory factor analysis using Weighted Least Squares Means and Variances adjusted estimation (WLSMV) to compare the factor models proposes by previous studies. To evaluate reliability, we calculated Cronbach's alpha and McDonald's omega. RESULTS: The Confirmatory factor analysis found that the 3-factors models showed the best fist index between the models with CFI = 0.991, TLI = 0.989, and SRMR = 0.035, even though RMSEA were over the cutoff point. The factors presented reliabilities from α = 0.858 to α = 0.941, and from ω = 0.937 to ω = 0.972. CONCLUSIONS: The results support the existence of three factors for the Multidimensional Scale of Perceived Social Support (MSPSS), differentiating the support perceived from Family, Friends, and significant others. All factors present good or excellent reliability. This solution is theoretically consistent and coherent with the literature, and it presents evidence in favor of the use of MSPSS as a measurement to distinguish the support perceived source.

Influence of provenance origin on the early performance of two sclerophyllous Mediterranean species established in burned drylands.

Forest restoration have had limited success due to intense and prolonged droughts in Mediterranean-type ecosystems. In this context, knowledge of growth and physiology in seedlings of different provenances can be useful in the selection of appropriate seed sources for restoration. In this study we investigated variations in survival, growth, and leaf-level physiology of five provenances of Quillaja saponaria Mol. and five provenances of Cryptocarya alba Mol. originated from coastal and Pre Andean sites exhibiting latitudinal-related climate differences in central Chile. Seedlings were grown in a nursery on 600 mL pots for 18 months and then planted in a dryland site severely damaged by fire. One year after establishment, we measured survival, growth, and leaf-level physiology. We also analyzed the relationship between outplanting survival with seedling characteristics prior to planting, and the relationship between growth and survival with physiological traits and with climate variables. Growth and survival were similar among provenances of Q. saponaria and C. alba, with the exception of differing heights observed within the provenance of Q. saponaria. Initial root collar diameter of Q. saponaria was observed to be positively correlated to outplanting survival. With the exception of photosynthesis in Q. saponaria, all provenances of both species differed in the leaf-level physiological traits. Those provenances originating from interior dryland sites exhibited lower stomatal conductance and used water more efficiently. The opposite was true for provenances coming from coastal sites. In outplanting sites with Mediterranean-type climates that have been damage by severe fire, selections based on larger diameter seedlings, especially for Q. saponaria and from interior and pre-Andean provenances, will likely improve outplanting success.

Performance Assessment of Thermal Infrared Cameras of Different Resolutions to Estimate Tree Water Status from Two Cherry Cultivars: An Alternative to Midday Stem Water Potential and Stomatal Conductance.

The midday stem water potential (Ψs) and stomatal conductance (gs) have been traditionally used to monitor the water status of cherry trees (Prunus avium L.). Due to the complexity of direct measurement, the use of infrared thermography has been proposed as an alternative. This study compares Ψs and gs against crop water stress indexes (CWSI) calculated from thermal infrared (TIR) data from high-resolution (HR) and low-resolution (LR) cameras for two cherry tree cultivars: 'Regina' and 'Sweetheart'. For this purpose, a water stress-recovery cycle experiment was carried out at the post-harvest period in a commercial drip-irrigated cherry tree orchard under three irrigation treatments based on Ψs levels. The water status of trees was measured weekly using Ψs, gs, and compared to CWSIs, computed from both thermal cameras. Results showed that the accuracy in the estimation of CWSIs was not statistically significant when comparing both cameras for the representation of Ψs and gs in both cultivars. The performance of all evaluated physiological indicators presented similar trends for both cultivars, and the averaged differences between CWSI's from both cameras were 11 ± 0.27%. However, these CWSI's were not able to detect differences among irrigation treatments as compared to Ψs and gs.

Acuerdo Diagnóstico de Mediciones Óseas para Implantes Dentales Mediante Tomografía Computarizada de Haz Cónico / Diagnostic Agreement of Bone Measurements for Dental Implants by Cone-Beam Computed Tomography

RESUMEN: El objetivo de este estudio fue determinar el grado de concordancia entre profesionales para mediciones óseas mediante Tomografía Computarizada de Haz Cónico (CBCT). Para aquello, se realizó un estudio de Acuerdo Diagnóstico en el cual participaron 32 Cirujanos Dentistas de la Región de Los Ríos, dedicados al área de la implantología. Estos, realizaron mediciones de grosor buco-palatino, distancia mesio-distal y altura ósea en un examen de CBCT con un intervalo de 2 semanas con el fin de estimar el coeficiente de correlación intraclase (ICC). Mediante el método de BlandAltman, se realizó el análisis de las diferencias individuales para cada una de las mediciones señaladas. Finalmente, para establecer diferencias estadísticamente significativas entre las mediciones se realizó la prueba t-test para muestras pareadas, con un nivel de significancia estadística de p<0,05. El ICC para mediciones de grosor buco-palatino fue de 0,71, mientras que para las mediciones de distancia mesio-distal fue 0,79, y altura de 0,62. El ICC general para las tres mediciones fue de 0,97. No se encontraron diferencias estadísticamente significativas para las mediciones evaluadas. En conclusión, existe un alto grado de concordancia entre profesionales para mediciones óseas utilizando CBCT.

ABSTRACT: The aim of this study was to determine the degree of agreement between professionals for bone measurement analysis by Computed Beam Computed Tomography (CBCT). A diagnosis agreement study was carried out with the participation of 32 dental surgeons from the Los Ríos region, all specialists in implantology. The dental surgeons carried out measurements of bucco-palatal thickness, mesio-distal distance and height in a CBCT examination with a 2 week interval, in order to estimate intraclass correlation coefficient (ICC). Through the BlandAltman method the analysis of the individual differences for each of the indicated measurements was realized. Finally, to establish statistically significant differences between the measurements, t-test was performed for paired samples, with a statistical significance level of p <0.05. The ICC for buccopalatal thickness measurements was 0.71, while for the mesiodistal distance measurements it was 0.79, and height was 0.62. The general ICC for the three measurements was 0.97. No statistically significant differences were found in the evaluated measurements. In conclusion, there is a high level of agreement among professionals for measurements based on Cone Beam Computed Tomography (CBCT).

UV-Vis spectroscopic quantification of residual acetone during the development of nanoparticulate drug delivery systems.

Methods for nanoparticles preparation often employ organic solvents in order to solubilize the non-polar constituents of the final nanostructures. In the research process, nanoparticles are assayed as aqueous suspensions in several cases, so that an excessive residual concentration of the organic solvent needs to be avoided since may lead to undesired secondary effects during biological tests. Despite the importance, residual solvent concentration is rarely determined, making necessary the development of quantification methods suitable for this purpose. Acetone is frequently used in drug delivery systems preparation, being capable to exert significant toxicities both, in vitro and in vivo. Thus, a simple and inexpensive UV-Vis spectrophotometric method is proposed to directly determine acetone from nanoparticles suspensions employing its reaction with vanillin. Central composite designs were employed to correct and optimize the quantification method, which was then validated according to international guidelines. The optimized method resulted accurate, precise, and linear in the range of 10-50 µg/mL, with an R2 of 0.998 and limits of detection and quantification of 2.6 and 7.8 µg/mL, respectively. The effect of several surfactants employed during nanoparticles preparation was not detrimental to the method. The proposed procedure can be successfully applied to directly quantify acetone from nanoparticles suspensions.

Reducing classroom temperature in a tropical climate improved the thermal comfort and the performance of elementary school pupils.

A two-week-long intervention study was performed in two classrooms in an elementary school in Costa Rica. Split-cooling air-conditioning (AC) units were installed in both classrooms. During the first week, the air temperature was reduced in one classroom while in the other (placebo) classroom the fans were operated but no cooling was provided. During the second week, the conditions were exchanged to create a 2 × 2 crossover design in which each pupil was their own control. A total of 37 children performed tasks similar to school work and completed questionnaires reporting their thermal sensation and perceptions. Operating the AC units reduced classroom temperature by about 5 K, from about 30 to 25°C. Thermal sensations changed from hot to neutral and slightly cold, and the percentage of children rating the thermal conditions as acceptable increased significantly. Neutral temperature was estimated to be about 27°C. The 11-year-old children performed the language and logical-thinking tasks significantly better in terms of speed at the lower temperature, while the less able pupils performed better on all tasks at the lower temperature. There were no significant effects on accuracy. These results confirm published findings from moderate climates and extend their validity to the tropics. They indicate that acclimatization can increase the optimal temperature for learning.

Ventajas del alfa ordinal respecto al alfa de Cronbach ilustradas con la encuesta AUDIT-OMS

[RESUMEN]. Objetivos. Exponer las ventajas de la utilización del alfa ordinal para situaciones en que no se cumplan los supuestos del alfa de Cronbach y mostrar la utilidad del alfa ordinal con la versión chilena del AUDIT, así como proporcionar los comandos en el lenguaje de programación R para realizar los cálculos respectivos. Métodos. Se compararon el alfa de Cronbach y el alfa ordinal en el caso del cuestionario AUDIT aplicado a 419 estudiantes de una universidad chilena. Resultados. En todos los dominios, el alfa ordinal resultó ser mayor que el alfa de Cronbach, lo que es congruente con lo encontrado en la bibliografía. Al considerar el alfa ordinal se acepta la confiabilidad de cada uno de los dominios y de la encuesta completa, lo que no ocurre completamente al trabajar con el alfa de Cronbach. Conclusiones. Para tomar decisiones sobre la confiabilidad de una dimensión se debe considerar un índice que cumpla los supuestos necesarios para su utilización, ya que no hacerlo puede desembocar en conclusiones erróneas y afectar de manera notable el desarrollo de una investigación. Los valores del alfa de Cronbach subestiman la confiabilidad de un instrumento al trabajar con escalas ordinales.

[ABSTRACT]. Objectives. Demonstrate the advantages of using ordinal alpha when the assumptions for Cronbach’s alpha are not met; show the usefulness of ordinal alpha with the Chilean version of the WHO Alcohol Use Disorders Identification Test (AUDIT); and provide the commands in R programming language for performing the respective calculations. Methods. Cronbach’s alpha and ordinal alpha were compared in an AUDIT questionnaire administered to 419 students at a Chilean university. Results. In all domains, the result using ordinal alpha was greater than with Cronbach’s alpha. This finding was consistent with the literature on the subject. When ordinal alpha was chosen, the reliability of each domain and the survey as a whole was accepted, which does not always happen with Cronbach’s alpha. Conclusions. In making decisions about the reliability of a dimension, consideration should be given to an index that meets the required assumptions for using it in order to avoid erroneous conclusions that can have an appreciable effect on research. The values of Cronbach’s alpha underestimate the reliability of an instrument when working with ordinal scales.

[RESUMO]. Objetivos. Apresentar as vantagens do uso do alfa ordinal nos casos em que não são cumpridos os pressupostos do alfa de Cronbach e demonstrar a utilidade do alfa ordinal com a versão chilena do instrumento AUDIT e criar comandos na linguagem de programação R para realizar os respectivos cálculos. Métodos. Foi realizada a comparação entre o alfa de Cronbach e o alfa ordinal com o uso do instrumento AUDIT aplicado a 419 alunos de uma universidade chilena. Resultados. Em todos os domínios, o alfa ordinal foi maior que o alfa de Cronbach, o que é condizente com o descrito na literatura. Ao considerar o alfa ordinal, aceita-se a confiabilidade de cada um dos domínios e da pesquisa completa, o que não ocorre completamente quando se usa o alfa de Cronbach. Conclusões. Para tomar decisões sobre a confiabilidade de uma dimensão, deve-se considerar um índice que cumpra os pressupostos necessários para seu uso, porque do contrário pode-se chegar a conclusões errôneas e afetar consideravelmente o desenvolvimento de uma pesquisa. Os valores do alfa de Cronbach subestimam a confiabilidade do instrumento por se basear em escalas ordinais.

[Advantages of ordinal alpha versus Cronbach's alpha, illustrated using the WHO AUDIT testVantagens do alfa ordinal em relação ao alfa de Cronbach verificadas na pesquisa AUDIT-OMS]. / Ventajas del alfa ordinal respecto al alfa de Cronbach ilustradas con la encuesta AUDIT-OMS.

OBJECTIVES: Demonstrate the advantages of using ordinal alpha when the assumptions for Cronbach's alpha are not met; show the usefulness of ordinal alpha with the Chilean version of the WHO Alcohol Use Disorders Identification Test (AUDIT); and provide the commands in R programming language for performing the respective calculations. METHODS: Cronbach's alpha and ordinal alpha were compared in an AUDIT questionnaire administered to 419 students at a Chilean university. RESULTS: In all domains, the result using ordinal alpha was greater than with Cronbach's alpha. This finding was consistent with the literature on the subject. When ordinal alpha was chosen, the reliability of each domain and the survey as a whole was accepted, which does not always happen with Cronbach's alpha. CONCLUSIONS: In making decisions about the reliability of a dimension, consideration should be given to an index that meets the required assumptions for using it in order to avoid erroneous conclusions that can have an appreciable effect on research. The values of Cronbach's alpha underestimate the reliability of an instrument when working with ordinal scales.

OBJETIVOS: Apresentar as vantagens do uso do alfa ordinal nos casos em que não são cumpridos os pressupostos do alfa de Cronbach e demonstrar a utilidade do alfa ordinal com a versão chilena do instrumento AUDIT e criar comandos na linguagem de programação R para realizar os respectivos cálculos. MÉTODOS: Foi realizada a comparação entre o alfa de Cronbach e o alfa ordinal com o uso do instrumento AUDIT aplicado a 419 alunos de uma universidade chilena. RESULTADOS: Em todos os domínios, o alfa ordinal foi maior que o alfa de Cronbach, o que é condizente com o descrito na literatura. Ao considerar o alfa ordinal, aceita-se a confiabilidade de cada um dos domínios e da pesquisa completa, o que não ocorre completamente quando se usa o alfa de Cronbach. CONCLUSÕES: Para tomar decisões sobre a confiabilidade de uma dimensão, deve-se considerar um índice que cumpra os pressupostos necessários para seu uso, porque do contrário pode-se chegar a conclusões errôneas e afetar consideravelmente o desenvolvimento de uma pesquisa. Os valores do alfa de Cronbach subestimam a confiabilidade do instrumento por se basear em escalas ordinais.

Ventajas del alfa ordinal respecto al alfa de Cronbach ilustradas con la encuesta AUDIT-OMS / Advantages of ordinal alpha versus Cronbach's alpha, illustrated using the WHO AUDIT test / Vantagens do alfa ordinal em relação ao alfa de Cronbach verificadas na pesquisa AUDIT-OMS

RESUMEN Objetivos Exponer las ventajas de la utilización del alfa ordinal para situaciones en que no se cumplan los supuestos del alfa de Cronbach y mostrar la utilidad del alfa ordinal con la versión chilena del AUDIT, así como proporcionar los comandos en el lenguaje de programación R para realizar los cálculos respectivos. Métodos Se compararon el alfa de Cronbach y el alfa ordinal en el caso del cuestionario AUDIT aplicado a 419 estudiantes de una universidad chilena. Resultados En todos los dominios, el alfa ordinal resultó ser mayor que el alfa de Cronbach, lo que es congruente con lo encontrado en la bibliografía. Al considerar el alfa ordinal se acepta la confiabilidad de cada uno de los dominios y de la encuesta completa, lo que no ocurre completamente al trabajar con el alfa de Cronbach. Conclusiones Para tomar decisiones sobre la confiabilidad de una dimensión se debe considerar un índice que cumpla los supuestos necesarios para su utilización, ya que no hacerlo puede desembocar en conclusiones erróneas y afectar de manera notable el desarrollo de una investigación. Los valores del alfa de Cronbach subestiman la confiabilidad de un instrumento al trabajar con escalas ordinales.

ABSTRACT Objectives Demonstrate the advantages of using ordinal alpha when the assumptions for Cronbach's alpha are not met; show the usefulness of ordinal alpha with the Chilean version of the WHO Alcohol Use Disorders Identification Test (AUDIT); and provide the commands in R programming language for performing the respective calculations. Methods Cronbach's alpha and ordinal alpha were compared in an AUDIT questionnaire administered to 419 students at a Chilean university. Results In all domains, the result using ordinal alpha was greater than with Cronbach's alpha. This finding was consistent with the literature on the subject. When ordinal alpha was chosen, the reliability of each domain and the survey as a whole was accepted, which does not always happen with Cronbach's alpha. Conclusions In making decisions about the reliability of a dimension, consideration should be given to an index that meets the required assumptions for using it in order to avoid erroneous conclusions that can have an appreciable effect on research. The values of Cronbach's alpha underestimate the reliability of an instrument when working with ordinal scales.

RESUMO Objetivos Apresentar as vantagens do uso do alfa ordinal nos casos em que não são cumpridos os pressupostos do alfa de Cronbach e demonstrar a utilidade do alfa ordinal com a versão chilena do instrumento AUDIT e criar comandos na linguagem de programação R para realizar os respectivos cálculos. Métodos Foi realizada a comparação entre o alfa de Cronbach e o alfa ordinal com o uso do instrumento AUDIT aplicado a 419 alunos de uma universidade chilena. Resultados Em todos os domínios, o alfa ordinal foi maior que o alfa de Cronbach, o que é condizente com o descrito na literatura. Ao considerar o alfa ordinal, aceita-se a confiabilidade de cada um dos domínios e da pesquisa completa, o que não ocorre completamente quando se usa o alfa de Cronbach. Conclusões Para tomar decisões sobre a confiabilidade de uma dimensão, deve-se considerar um índice que cumpra os pressupostos necessários para seu uso, porque do contrário pode-se chegar a conclusões errôneas e afetar consideravelmente o desenvolvimento de uma pesquisa. Os valores do alfa de Cronbach subestimam a confiabilidade do instrumento por se basear em escalas ordinais.

Unusual alkaloids of the highland species Astragalus cryptanthus Wedd. (Fabaceae).

Two unusual caprolactam alkaloids, 3-(dimethylamino)hexahydro-2H-azepin-2-one and 3-(methylamino)-hexahydro-2H-azepin-2-one, were isolated from the aerial parts of Astragalus cryptanthus Wedd.; their structures were unambiguously determined based on data from extensive 1D and 2D NMR, GC-MS and FT-IR spectroscopic analyses. This is the first report of this alkaloid type in the genus Astragalus.

Comportamiento de las enzimas musculares sérica asociado al ascenso de 3428 m..s.n.m. en bicicleta / Behavior of srumm muscular enzymes associated with uphill cycling of 3428 m.a.s.l

Objetivo: Determinar el comportamiento de la Creatinfosfoquinasa (CPK) y lactato deshidrogenasa (LDH) luego de un ascenso en bicicleta de 3428 mts. en 63 kilómetros. Diseño: Ensayo de Campo. Población: Ciclistas mayores de 18 años, sin exclusión de género, que ascienden de Yolosa (1229 mts. s.n.m.) hasta la cumbre (4657 mts. s.n.m.). quienes fueron sometidos a mediciones antropométricas, dosificación de glucemia, Hto y Hb, oximetría, CPK y LDH antes y después del ascenso como marcadores de fatiga muscular. Sede: Hospital Obrero N° 1 de la Caja Nacional de Salud La Paz - Bolivia. Instituto de Investigación en Salud y Desarrollo (IINSAD). Estimación del tamaño de la muestra: No atingente Resultados: Los 43 sujetos presentaban un promedio de edad de 42 años, con un género masculino de 37 (86%). El promedio de talla es de 171 cm. y IMC de 23,200 para un porcentaje de grasa corporal promedio de 16. En relación a la procedencia 29 sujetos eran de La Paz (67,4%). Fueron clasificados en categorías según la edad y el nivel de entrenamiento de la manera siguiente: Categoría A11 sujetos (25,6%), categoría B 7 sujetos (16,3%), categoría C 14 sujetos (32,5%), categoría D 7 sujetos (16,3%) y 4 de categoría Elite (9,3%). Los promedios de FC basal y de llegada fueron 66 y 90 latidos respectivamente. La saturación de oxígeno basal y de llegada con unos promedios de 96% y 85% respectivamente. Los promedios de los valores séricos de las enzimas musculares fueron: lactato deshidrogenasa (LDH) basal 146 mg/dl comparado con 223 mg/dl de llegada y creatinfosfoquinasa (CPK) basal 187 mg/dl y 392 mg/dl de llegada. Todas las variables con un valor de p=0,001. Conclusión: La elevación de los valores séricos de enzimas de fatiga muscular en un grupo de ciclistas amateurs con entrenamiento permanente posterior al ascenso en bicicleta, parece tener relación inversamente proporcional con el entrenamiento. No se registro ningún evento negativo por el que este trabajo ...

Objectives: To determinate the behavior of creatine kinase (CK), lactate dehydrogenase (LH) after uphill cycling of 3428 meters in 63 kilometers. Design: Field test Population: Ciclists of 18 years of age or older, without gender exclusion, that ascent from Yolosa (1229 m.a.s.l) to the summit, La Cumbre (4657m.a.s.l). who underwent to anthropometric measurement, blood glucose, haematocrit, hemoglobin test, oximetry and serum CK and LH test as markers of muscle fatigue before and after uphill cycling. Venue: Hospital Obrero No. 1, Caja Nacional de Salud La Paz - Bolivia. Research Institute of Health and Development (IINSAD). Estimated size of the sample: Not outstanding Results: 43 subjects were studied, with an average age of 42 years, corresponding to 37 (86%) males. The average height was of171 cm and average BMI of 23.200 for an average body fat of 16%. In relation to provenance, 29 subjects were from La Paz, Bolivia (67,4%). Competitors were classified by age and training level on the following categories: A: 11 subjects (25,6%), B: 7 subjects (16,3%), C: 14 subjects (32,5%), D: 7 subjects (16,3%) and Elite: 4 subjects (9,3%). Average heart rate before and after the ascent was of 66 and 90 beats per minute respectively. Oximetry revealed a basal O2 saturation of96% and 85% after arrival. The average for serum muscle enzymes were: Basal LDH: 146 mg/dl, arrival LDH: 223 mg/dL, basal CK: 187 mg/dl and arrival CK: 392 mg/dL. All studied variables had a P value of 0,001. Conclusion: The increasing values of serum muscle enzymes to measure muscle fatigue in an amateur group of cyclists with consistent training after uphill cycling seem to have an inverse relationship with training. No negative event was observed, by which this work supports the practice of sports at high altitude.

Fluctuación poblacional de Haematobia irritans (Diptera: Muscidae) en un hato bovino en Tecomán, Colima, México / Population fluctuation of Haematobia irritans (Diptera: Muscidae) in a cattle herd in Tecoman, Colima, Mexico

The objective of the work was to study H. irritans population fluctuation in a cattle herd in Tecoman, Colima, Mexico. The cattle herd was visited weekly from March 2003 to May 2004; on each occasion, ten animals were randomly selected to estimate infestation by direct visualization method. Temperature and relative humidity (RH) were recorded daily. Population fluctuation was described and periods and population peaks were identified. Pearson's correlation analysis was calculated (P < 0.05) between temperature and RH, with fly average number per animal for each population period. H. irritans infestation had fluctuations, but with presence of flies all the year; the highest infestation was observed in summer, where two population peaks were present, with 236 and 120 flies per animal, respectively; the activity in autumn and winter also showed fluctuations and the population had an increment in spring, where a population peak could be observed, as well as at the beginning of the study (156 flies/animal) and at the end (323 flies/animal). In the first population period, a significant correlation coefficient (0.93) was found with temperature, similar situation was observed in the fourth period (-0.57); no significant coefficients were found in other population periods for the climatic factors in study.

El objetivo del trabajo fue estudiar la fluctuación poblacional de H. irritans en un hato de ganado bovino en el municipio de Tecomán, Colima, México. El hato fue visitado semanalmente de marzo de 2003 a mayo de 2004; en cada ocasión se seleccionaron al azar diez animales para estimar la infestación mediante el método de visualización directa. Se registró la temperatura y la humedad relativa (HR) diariamente. Se describió la fluctuación poblacional presentada y se identificaron los periodos y picos poblacionales. Se realizó un análisis de correlación de Pearson (P < 0.05) entre la temperatura y la HR, con los valores promedio del número de moscas por animal para cada uno de los periodos poblacionales. La infestación por H. irritans fue fluctuante, pero con presencia de moscas durante todo el año; los momentos de mayor infestación se observaron en verano, al presentarse dos picos poblacionales, con 236 y 120 moscas/animal; la actividad en otoño e invierno también fluctuó; se incrementó en primavera, durante la cual se observó un pico poblacional, tanto al inicio del estudio (156 moscas/animal) como al final (323 moscas/animal). Para el primer periodo poblacional se encontró un coeficiente de correlación significativo (0.93) con la temperatura, algo similar ocurrió para el cuarto periodo (-0.57); no fue posible detectar coeficientes significativos en otros periodos poblacionales para los factores climáticos en estudio.