Artículos científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14755

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A novel experimental approach to assess the effect of contamination events on the spatial distribution of organisms in lotic-estuarine landscapes
(ELSEVIER, 2025-12-19) Salvatierra, David; González, María Pilar; Echeverría-Sáenz, Silvia; Blasco, Julián; Araújo, Cristiano V.M.
The riverscape concept includes structural connectivity and functional interactions where upstream processes significantly influence downstream conditions. As such, a landscape perspective is necessary to evaluate the impact of contamination, because it can spread far beyond the release area, potentially reaching estuaries. Therefore, we hypothesized that contamination might affect freshwater organisms’ habitat selection in a simulated lotic-estuarine (flow-through) landscape, considering that the estuary zone acts as a stress factor by restricting the options of habitats while the non-contaminated upstream areas could serve as shelter zones to alleviate or even prevent the contamination exposure. The aim of this study was to provide a new method to evaluate the habitat selection response of aquatic organisms when exposed to a contamination event in a simulated lotic-estuarine landscape, including upstream and shelter zones as attractive habitats and an estuary zone. The freshwater shrimp Atyaephyra desmarestii was used as model test organism, copper was used as the contaminant, and the Heterogeneous Multi-Habitat Assay System (HeMHAS), was employed to simulate the lotic-estuarine landscape with a multiple connectivity setup. The results showed that contaminated conditions led shrimp to avoid the contaminated area and were carried towards the estuary region with the flow. However, in a static experiment (without flow), both estuary and contaminated regions were avoided and a preference for the shelter (clean) regions was observed. This study highlights the plasticity of organisms’ habitat selection behavior within a connected ecosystem, where contamination and salinity pressure together might have serious implications for the distribution of freshwater species. Further, the HeMHAS can successfully integrate flow in simulated heterogeneous landscapes to broad the understanding of contamination effects in aquatic lotic ecosystems.
Assessment of Dermal Pesticide Exposure with Fluorescent Tracer: a Modification of a Visual Scoring System for Developing Countries
(Oxford University Press, 2005-08-26) Aragón, Aurora; Blanco, Luis E.; Fúnez, Aura; Ruepert, Clemens; Lidén, Carola; Nise, Gun; Wesseling Hoogervors, Catharina
En 1988, Fenske presentó un método semicuantitativo de evaluación de la exposición dérmica basado en observaciones visuales de imágenes de fluorescencia. Adaptamos el método a las condiciones de trabajo de Nicaragua y evaluamos su desempeño. Treinta y dos agricultores aplicaron clorpirifos y metamidofos marcados con Tinopal CBS-X®. Se observaron los depósitos fluorescentes en la piel con una lámpara UV portátil en una habitación oscura plegable. Modificamos los dos componentes del sistema original: la extensión ponderando el tamaño de las partes del cuerpo expuestas según la superficie corporal total y la intensidad estableciendo criterios para leer las imágenes de fluorescencia. Esto dio como resultado puntajes de segmentos corporales (BSS) para partes corporales específicas, así como dos medidas de resumen, el área corporal contaminada (CBA) como el porcentaje de piel contaminada en relación con la superficie corporal total y el puntaje visual total (TVS) como un puntaje general que combina el alcance y la intensidad de la contaminación. El puntaje de intensidad se evaluó con análisis cuantitativos de residuos químicos. Las manos fueron las contaminadas con mayor frecuencia y la espalda tuvo el BSS más alto. El CBA varió entre 1 y 66% y el TVS entre 0,5 y 270. El agricultor con el TVS más alto obtuvo un puntaje de 60% del máximo posible. Los residuos aumentaron con el aumento de las intensidades de fluorescencia con algunos errores de clasificación. Las imágenes fluorescentes reflejaron las prácticas laborales y los mecanismos de contaminación. En conclusión, el puntaje visual, tal como lo modificamos, proporciona información sobre los segmentos del cuerpo que más contribuyen a la exposición dérmica y el grado de contaminación de la piel durante las aplicaciones de pesticidas. Los patrones de fluorescencia reflejan las vías de exposición. El sistema es de bajo costo y práctico para los países en desarrollo. Se recomiendan mejoras adicionales.
Drivers of international variation in prevalence of disabling low back pain: Findings from the Cultural and Psychosocial Influences on Disability study
(Wiley Online Library, 2018-06-08) Coggon, David; Ntani, Georgia; Palmer, Keith T.; Felli, Vanda E.; Harari, Florencia; Quintana , Leonardo; Felknor, Sarah; Rojas Garbanzo, Marianela; Cattrell, Anna; Vargas-Prada, Sergio; Bonzini, Matteo; Solidaki, Eleni; Merisalu, Eda; Habib, Rima R.; Sadeghian, Farideh; Muhammad Masood, Kadir; Warnakulasuriya, Sudath; Matsudaira, Ko; Nyantumbu-Mkhize, Busisiwe; Kelsall, Helen; Harcombe, Helen
Wide international variation in the prevalence of disabling low back pain (LBP) among working populations is not explained by known risk factors. It would be useful to know whether the drivers of this variation are specific to the spine or factors that predispose to musculoskeletal pain more generally. Baseline information about musculoskeletal pain and risk factors was elicited from 11 710 participants aged 20–59 years, who were sampled from 45 occupational groups in 18 countries. Wider propensity to pain was characterized by the number of anatomical sites outside the low back that had been painful in the 12 months before baseline (‘pain propensity index’). After a mean interval of 14 months, 9055 participants (77.3%) provided follow-up data on disabling LBP in the past month. Baseline risk factors for disabling LBP at follow-up were assessed by random intercept Poisson regression. After allowance for other known and suspected risk factors, pain propensity showed the strongest association with disabling LBP (prevalence rate ratios up to 2.6, 95% CI: 2.2–3.1; population attributable fraction 39.8%). Across the 45 occupational groups, the prevalence of disabling LBP varied sevenfold (much more than within-country differences between nurses and office workers), and correlated with mean pain propensity index (r = 0.58). Within our study, major international variation in the prevalence of disabling LBP appeared to be driven largely by factors predisposing to musculoskeletal pain at multiple anatomical sites rather than by risk factors specific to the spine. Our findings indicate that differences in general propensity to musculoskeletal pain are a major driver of large international variation in the prevalence of disabling low back pain among people of working age.
Reliability of a Visual Scoring System with Fluorescent Tracers to Assess Dermal Pesticide Exposure
(Oxford University Press, 2004-09-20) Aragon, Aurora; Blanco, Luis; Lopéz, Lylliam; Lidén, Carola; Nise, Gun; Wesseling Hoogervors, Catharina
We modified Fenske's semi-quantitative ‘visual scoring system’ of fluorescent tracer deposited on the skin of pesticide applicators and evaluated its reproducibility in the Nicaraguan setting. The body surface of 33 farmers, divided into 31 segments, was videotaped in the field after spraying with a pesticide solution containing a fluorescent tracer. A portable UV lamp was used for illumination in a foldaway dark room. The videos of five farmers were randomly selected. The scoring was based on a matrix with extension of fluorescent patterns (scale 0–5) on the ordinate and intensity (scale 0–5) on the abscissa, with the product of these two ranks as the final score for each body segment (0–25). Five medical students rated and evaluated the quality of 155 video images having undergone 4 h of training. Cronbach alpha coefficients and two-way random effects intraclass correlation coefficients (ICC) with absolute agreement were computed to assess inter-rater reliability. Consistency was high (Cronbach alpha = 0.96), but the scores differed substantially between raters. The overall ICC was satisfactory [0.75; 95% confidence interval (CI) = 0.62–0.83], but it was lower for intensity (0.54; 95% CI = 0.40–0.66) and higher for extension (0.80; 95% CI = 0.71–0.86). ICCs were lowest for images with low scores and evaluated as low quality, and highest for images with high scores and high quality. Inter-rater reliability coefficients indicate repeatability of the scoring system. However, field conditions for recording fluorescence should be improved to achieve higher quality images, and training should emphasize a better mechanism for the reading of body areas with low contamination.
The description of Anacroneuria suerre sp. nov. from Costa Rica (Plecoptera: Perlidae) and using nymphs in ecotoxicological studies
(Magnolia Press, 2019-05-20) Gutiérrez-Fonseca, Pablo E.; Echeverría-Sáenz, Silvia; Bravo, Francisco; Romero, David
The lack of nymph-adult associations limits our knowledge of the ecology, history and sensitivity of aquatic insects. In this study, the new species, Anacroneuria suerre sp. nov is described from Costa Rica based on the male, female, and nymphal stages. We briefly discuss the use of Plecoptera in ecotoxicological studies.
The Determinants of Dermal Exposure Ranking Method (DERM): A Pesticide Exposure Assessment Approach for Developing Countries
(Oxford University Press, 2008-07-07) Blanco, Luis E.; Aragón, Aurora; Lundberg, Ingvar; Wesseling Hoogervors, Catharina; Nise, Gun
Anewmethod for assessment of dermal exposure to pesticides in subsistence farmers by use of determinants of dermal exposure is described. The method, called the determinants of dermal exposureranking method(DERM),isacombinationofchecklists andexpert ratingassessment. Thus, determinants are listed in a form, which is used to check their presence and to assess them using a simple algorithm based on two factors, the type of transport process (T value) and the area of body surface exposed (Avalue). In addition, the type of clothing worn during applications is included as a protection factor. We applied the DERM to real pesticide applications, characterizing dermal exposure and comparing DERM estimates with earlier developed semiquantitative visual scores based on fluorescent tracer, the total visual score (TVS) and contaminated body area (CBA). DERM showed avery good level of agreement with both the TVS (r 5 0.69; P 5 0.000) and the CBA (r 5 0.67; P 5 0.000). DERM allowed identification of the determinants that had the highest effect on exposure and the farmers with the highest exposure. In conclusion, DERM provided information on the determinants responsible for dermal exposure in a group of subsistence farmers. This can be useful to design monitoring and preventive programs, define priorities for intervention and prioritize and select most adequate measurementstrategies. DERM promises to be a low-cost easy-to-use method to assess dermal exposure to pesticides in developing country conditions.

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