7 research outputs found
Upper susceptibility threshold limits with confidence intervals: a method to identify normal and abnormal population values for laboratory toxicological parameters, based on acetylcholinesterase activities in sea lice
No full text
The efficacy of emamectin benzoate against infestations of Lepeophtheirus salmonis on farmed Atlantic salmon (Salmo salar L) in Scotland, 2002-2006
No full textInfestations of the parasitic copepod Lepeophtheirus salmonis, commonly referred to as sea lice, represent a major challenge to commercial salmon aquaculture. Dependence on a limited number of theraputants to control such infestations has led to concerns of reduced sensitivity in some sea lice populations. This study investigates trends in the efficacy of the in-feed treatment emamectin benzoate in Scotland, the active ingredient most widely used across all salmon producing regions. Study data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. An epi-informatics approach was adopted whereby available farm records, descriptive epidemiological summaries and statistical linear modelling methods were used to identify factors that significantly affect sea lice abundance following treatment with emamectin benzoate (SLICEH, Schering Plough Animal Health). The results show that although sea lice infestations are reduced following the application of emamectin benzoate, not all treatments are effective. Specifically there is evidence of variation across geographical regions and a reduction in efficacy over time. Reduced sensitivity and potential resistance to currently available medicines are constant threats to maintaining control of sea lice populations on Atlantic salmon farms. There is a need for on-going monitoring of emamectin benzoate treatment efficacy together with reasons for any apparent reduction in performance. In addition, strategic rotation of medicines should be encouraged and empirical evidence for the benefit of such strategies more fully evaluated
Evidence for occurrence of an organophosphate-resistant type of acetylcholinesterase in strains of sea lice (Lepeophtheirus salmonis Kroyer)
No full textAcetylcholinesterase (AChE) is the target of a major pesticide family, the organophosphates, which were extensively used as control agents of sea lice on farmed salmonids in the early 1990s. From the mid-1990s the organophosphates dichlorvos and azamethiphos were seriously compromised by the development of resistance. AChE insensitive to organophosphate chemotherapeutants has been identified as a major resistance mechanism in numerous arthropod species, and in this study, target-site resistance was confirmed in the crustacean Lepeophtheirus salmonis Kroyer isolated from several fish-farming areas in Norway and Canada. A bimolecular rate assay demonstrated the presence of two AChE enzymes with different sensitivities towards azamethiphos, one that was rapidly inactivated and one that was very slowly inactivated. To our knowledge this is the first report of target-site resistance towards organophosphates in a third class of arthropods, the Crustacea. (C) 2004 Society of Chemical Industr
Analysis and management of resistance to chemotherapeutants in salmon lice, Lepeophtheirus salmonis (Copepoda: Caligidae)
No full textIn Northern Europe and Canada, the salmon louse, Lepeophtheirus salmonis (Kroyer), seriously affects the marine phase of salmon production. Although the problem is long-standing, the development of sustainable methods of pest management has been unable to keep pace with the intensification of production, leading to large-scale reliance on very few chemotherapeutants. This runs the risk of selecting for genetically determined resistance in target organisms. There are many examples of similar evolutionary adaptations in arthropod pests of arable crops, livestock and human health. Several hundred pest species are now documented as being resistant to one or more chemical classes of insecticides and acaricides. Many of these compounds are identical or closely related to ones currently employed against salmon lice. It is, therefore, opportune to consider what lessons have been learnt from contending with resistance in terrestrial organisms, the implications for sustainable use of chemotherapeutants in aquaculture, and the potential for developing effective resistance management strategies. An EU-funded project named SEARCH (QLK2-CT-2000-00809) has been initiated to explore in more detail the diagnosis, incidence, dynamics and management of resistance to chemotherapeutants in L salmonis. (C) 2002 Society of Chemical Industry
Complexes of Two Cohorts of CLIP Peptides and HLA-DQ2 of the Autoimmune DR3-DQ2 Haplotype Are Poor Substrates for HLA-DM
No full textMedición de actividad física en adolescentes, cuestionario Youth activity profile-spain durante el confinamiento, Chia 2020
No full textIntroducción: El Covid-19 ha traído periodos de confinamiento que han afectado los niveles de actividad física en adolescentes. Recientes estudios han determinado un descenso en la práctica de actividad física y un aumento en el comportamiento sedentario. Objetivo: Establecer los niveles de actividad física en adolescentes del municipio de Chía-Cundinamarca a través del cuestionario Youth Activity Profile-Spain durante el confinamiento del 2020. Materiales y métodos: Investigación con enfoque cuantitativo, a partir de un diseño no experimental y de tipo descriptivo a través del cuestionario autoadministrado YAP-S en formato virtual aplicado durante el periodo de confinamiento del 2020. 112 adolescentes de 12 a 17 años (56,25% femenino, 43,75% masculino) del municipio de Chía-Cundinamarca. Se registraron variables como: actividad física dentro y fuera de la jornada escolar, comportamiento sedentario, edad, peso, talla e índice de masa corporal. Se empleó el software R Studio y medidas de tendencia central para el análisis estadístico. Resultados: El 100% de los adolescentes reporta una actividad física mayor a 600 METs en una semana y un IMC normal. Se identificó una intensidad horaria en ambos géneros de más de 4 horas al día de uso de dispositivos electrónicos. Conclusiones: Los adolescentes de Chía-Cundinamarca presentan un nivel de actividad física moderado durante el confinamiento de 2020 cumpliendo con las recomendaciones de la OMS. A pesar del contexto en el cual se desarrolla este estudio, los adolescentes mantienen una práctica regular de actividad física.Introduction: Covid-19 has brought periods of confinement that have affected physical activity levels in adolescents. Recent studies have determined a decrease in the practice of physical activity and an increase in sedentary behavior. Objective: To establish physical activity levels in adolescents of the municipality of Chía-Cundinamarca through the Youth Activity Profile-Spain questionnaire during confinement of 2020. Materials and methods: Research with a quantitative approach, from a non-experimental and descriptive design through the YAP-S self-administered questionnaire in virtual format applied during the confinement period of 2020. 112 adolescents aged 12 to 17 years (56.25% female, 43.75% male) from the municipality of Chía-Cundinamarca. Variables such as: physical activity inside and outside the school day, sedentary behavior, age, weight, height and body mass index were recorded. The R Studio software and central tendency measures were used for statistical analysis. Results: 100% of adolescents report a physical activity greater than 600 METs in one week and a normal BMI. An hourly intensity in both genders of more than 4 hours a day of use of electronic devices was identified. Conclusions: Adolescents from Chía-Cundinamarca present a moderate level of physical activity during the 2020 confinement, complying with the WHO recommendations. Despite the context in which this study is developed, adolescents maintain a regular practice of physical activity.Incluye bibliografíaPregradoProfesional en Ciencias del DeporteCiencias del Deport
