Efectos de muestras de tallas erróneas sobre los valores estimados del crecimiento individual y la condición de los stocks

Despite its importance in fisheries studies, there is insufficient understanding on the effect of sampling error or bias on individual growth and other stock indicators. We show the influence of sample length distributions on parameter estimates, illustrating with an example. For the brown swimming crab, we simulated length samples in five configurations and estimated parameters of von Bertalanffy (k, L∞L∞ , t0), asymptotic weight ( W∞W∞ ), weight-length relationship (a, b), growth performance (ϕ’) and condition factor (Kn). Parameter estimates were compared with baseline values using relative bias, standard error and root mean square error. The results show that the accuracy and bias of parameter estimates depend on the lengths sampled. For example, the bias and accuracy of L∞L∞ and W∞W∞ vary inversely with sampled length, whereas combining length segments yields smaller biases of k and t0 than those of L∞L∞ and W∞W∞ . In general, the accuracy of parameter estimates does not always depend on sampling the entire length range, and errors are not the same for all parameters. These results are useful to guide sampling when resources are scarce. We discuss potential reasons for incomplete length sample structure and offer recommendations to obtain best estimates for parameters of interest.A pesar de su importancia en los estudios de pesquerías, aún no se comprende lo suficiente el efecto del error o del sesgo del muestreo en los parámetros de crecimiento individual y otros indicadores poblacionales. Utilizando un ejemplo, aquí se muestra la influencia de las distribuciones muestrales de longitud en las estimaciones de parámetros poblacionales. Para la jaiba café, simulamos muestreo de longitud en cinco configuraciones y estimamos parámetros de von Bertalanffy (k, L∞L∞ , t0), peso asintótico ( W∞W∞ ), relación peso-longitud (a, b), eficiencia de crecimiento (ϕ’), y factor de condición (Kn). Las estimaciones de los parámetros se compararon con valores de referencia utilizando el sesgo relativo, el error estándar y el error cuadrático medio. Los resultados muestran cómo la precisión y el sesgo de las estimaciones de parámetros dependen de las longitudes muestreadas. Por ejemplo, el sesgo y la precisión de L∞L∞ y W∞W∞ , varían inversamente con la longitud muestreada, mientras que la combinación de segmentos de longitud produce sesgos de k y t0 más pequeños que los de L∞L∞ y W∞W∞ . En general, la precisión de las estimaciones de los parámetros no siempre depende del muestreo de todo el rango de tallas disponible, y los errores no son los mismos para todos los parámetros. Estos resultados son útiles para guiar el muestreo cuando los recursos son escasos. Discutimos las posibles razones de la estructura de la muestra de longitud incompleta y ofrecemos recomendaciones para obtener las mejores estimaciones para los parámetros de interés

Fisheries and Biodiversity in the Upper Gulf of California, Mexico

The Upper Gulf of California (UGC) has been recognized by its high primary productivity and abundant fishing (Aragon-Noriega & Calderon-Aguilera, 2000). Sediments and nutrients from the Colorado River, and complex hydrodynamics render this as an Important site for spawning, mating and nursing for numerous species of commercial and ecological importance (Cudney & Turk, 1998; Ramirez-Rojo & Aragón-Noriega 2006). Temperature, salinity and abundance of nutrients in this region vary depending on fresh water runoff from the Colorado River (Alvarez-Borrego et al., 1975; Hernández-Ayón et al., 1993; Lavín & Sánchez, 1999). Commercial fishing of high market value resources such as shrimp takes place in the UGC by artisanal or small scale, and industrial fishing. Artisanal fishing is done on relatively small (30 feet) fiber glass boats or artisanal boats with outboard motors, usually operated by two fishers; their primary fishing gear is drift gillnets, which they use to catch croakers, Spanish mackerel and even shrimp. This type of fishing is carried out by cooperatives and individual fishers from the three ports of the UGC: Puerto Peñasco and El Golfo de Santa Clara, in the State of Sonora, and San Felipe, in Baja California. Because marine resources in the region are migratory, fisheries are seasonal generating bursts of accumulated fishing effort over a few months depending on availability of species (see Cudney & Turk 1998). Increasing demand of economically important species has motivated a steady rise in fishing effort and use of gear and fishing practices jeopardizing critical species such as totoaba, Totoaba macdonaldi, an endemic croaker declared under risk of extinction (Cisneros-Mata et al., 1995), and the rare vaquita, Phocoena sinus. Vaquita are accidentally caught in all kinds of gillnets used in the Upper Gulf (D’Agrosa et al., 1995; Blanco 2002)

Post-mortem findings in Spanish patients with COVID-19; a special focus on superinfections

IntroductionWhole-body autopsies may be crucial to understand coronavirus disease 2019 (COVID-19) pathophysiology. We aimed to analyze pathological findings in a large series of full-body autopsies, with a special focus on superinfections. MethodsThis was a prospective multicenter study that included 70 COVID-19 autopsies performed between April 2020 and February 2021. Epidemiological, clinical and pathological information was collected using a standardized case report form. ResultsMedian (IQR) age was 70 (range 63.75-74.25) years and 76% of cases were males. Most patients (90%,) had at least one comorbidity prior to COVID-19 diagnosis, with vascular risk factors being the most frequent. Infectious complications were developed by 65.71% of the patients during their follow-up. Mechanical ventilation was required in most patients (75.71%) and was mainly invasive. In multivariate analyses, length of hospital stay and invasive mechanical ventilation were significantly associated with infections (p = 0.036 and p = 0.013, respectively). Necropsy findings revealed diffuse alveolar damage in the lungs, left ventricular hypertrophy in the heart, liver steatosis and pre-infection arteriosclerosis in the heart and kidneys. ConclusionOur study confirms the main necropsy histopathological findings attributed to COVID-19 in a large patient series, while underlining the importance of both comorbid conditions and superinfections in the pathology

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

A medio siglo de manejo pesquero en el noroeste de México, el futuro de la pesca como sistema socioecológico

Abstract: Fisheries management in northwestern Mexico must fully recognize fisheries as part of socio-ecological systems. This study describes the evolution and status of fisheries management, including the interaction dynamics of management institutions with conservation organizations, and highlights the opportunities and challenges involved in achieving ecological and social sustainability. In this context, recognizing artisanal fisheries as a social, as well as economic, activity would facilitate the evolution of governance and management systems towards greater alignment with social objectives. This approach allows us to fully address key issues, including the challenges that indigenous fishing communities face and the expected impacts of climate change. The scientific knowledge and experience accumulated over five decades provides a significant capacity to develop new strategies for transitioning towards greater system sustainability. The success of this process will depend on the ability to consolidate a unified vision of desired benefits, particularly for fishing communities.Resumen: El manejo pesquero en el noroeste de México debe reconocer plenamente a la pesca como parte de un sistema socioecológico. Este estudio describe la evolución y situación del manejo, incluyendo la dinámica entre instituciones de manejo y organizaciones conservacionistas, resaltando oportunidades y retos para alcanzar la sustentabilidad ecológica y social. En este contexto, el reconocimiento de la pesca artesanal como actividad social además de económica, facilitaría la evolución de los esquemas de gobernanza y manejo para empatarlos con los objetivos sociales. Ello permite abordar de lleno temas de suma importancia, incluyendo los retos de las comunidades pesqueras indígenas, o los impactos anticipados del cambio climático. El conocimiento científico y la experiencia acumulados en cinco décadas representan una gran capacidad para desarrollar estrategias novedosas para transitar hacia la sustentabilidad del sistema. El éxito de este proceso dependerá de la habilidad para consolidar una visión unificada sobre los beneficios deseados, en especial, para las comunidades pesqueras

Análisis de actores de la pesquería de medusa en Guaymas, Sonora

El objetivo de esta investigación fue conocer el rol de los actores involucrados en la pesquería de medusa bola de cañón, en Guaymas, Sonora. Con el método bola de nieve se realizaron entrevistas semiestructuradas, luego se jerarquizaron mediante la red de poder/interés de cuatro cuadrantes, y se relacionaron con una matriz de vinculación. El resultado arrojó que el Instituto Nacional de Pesca, los compradores, procesadores, comercializadores y las cooperativas pesqueras son los actores clave, con mayor interés e influencia en el manejo de la pesquería. El presente análisis es útil para establecer y mejorar el manejo de la captura de medusa. Se concluye que existe una relación conflictiva y de poca cooperación entre los actores mencionados, lo cual impide que se respeten las estrategias de manejo para explotar la medusa en condiciones de sustentabilidad