Prey and seasonal abundance of killer whales at sub-Antarctic Marion Island

The diet of killer whales Orcinus orca was investigated from 48 predation events observed during 823 sightings at sub-Antarctic Marion Island between 2006 and 2009. From these events, there were 10 cases where prey could be identified. Killer whales fed on fur seals Arctocephalus tropicalis, elephant seals Mirounga leonina and penguins. Constant effort (dedicated) observations (259 hours, 2008–2009) showed that the peak in killer whale abundance was between September and December with a secondary peak between April and May, which coincided with peaks in the abundance of seals and penguins.The Department of Science and Technology (administered through the National Research Foundation) for funding the marine mammal monitoring programme at Marion Island.http://www.tandfonline.com/loi/tams20nf201

Measuring DNA modifications with the comet assay: a compendium of protocols

The comet assay is a versatile method to detect nuclear DNA damage in individual eukaryotic cells, from yeast to human. The types of damage detected encompass DNA strand breaks and alkali-labile sites (e.g., apurinic/apyrimidinic sites), alkylated and oxidized nucleobases, DNA-DNA crosslinks, UV-induced cyclobutane pyrimidine dimers and some chemically induced DNA adducts. Depending on the specimen type, there are important modifications to the comet assay protocol to avoid the formation of additional DNA damage during the processing of samples and to ensure sufficient sensitivity to detect differences in damage levels between sample groups. Various applications of the comet assay have been validated by research groups in academia, industry and regulatory agencies, and its strengths are highlighted by the adoption of the comet assay as an in vivo test for genotoxicity in animal organs by the Organisation for Economic Co-operation and Development. The present document includes a series of consensus protocols that describe the application of the comet assay to a wide variety of cell types, species and types of DNA damage, thereby demonstrating its versatility.We thank the hCOMET project (COST Action, CA 15132) for support. A. Azqueta thanks the Ministry of Science and Innovation (AGL2015-70640-R and PID2020-115348RB-I00) of the Spanish Government. S.G. thanks the national funds (OE), through FCT— Fundação para a Ciência e a Tecnologia (IP, in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of 29 August, changed by Law 57/2017, of 19 July) for personal support. V.M.d.A. thanks the National Council of Technological and Scientific Development (CNPq—304203/2018-1) for personal support. D.M. thanks the program ‘Ayudas para la formación de profesorado universitario (FPU)’ of the Spanish Government for the predoctoral grant received. N.O. thanks the NIEHS Superfund Research Program ES ES027707 for personal support. J.S.-S. thanks the Government of Navarra for the predoctoral grant received. V.V. thanks the Ministerio de Educación, Cultura y Deporte (‘Beatriz Galindo’ program, BEAGAL18/00142) of the Spanish Government for personal support. M.S.C. acknowledges personal support from the National Institute of Environmental Health Sciences of the National Institutes of Health under award number: 1R41ES030274-01. This paper reflects the views of the authors and does not necessarily reflect those of the US Food and Drug Administration or the National Institutes of Health

Suicidal ideation in a European Huntington's disease population

BACKGROUND: Previous studies indicate increased prevalences of suicidal ideation, suicide attempts, and completed suicide in Huntington's disease (HD) compared with the general population. This study investigates correlates and predictors of suicidal ideation in HD. METHODS: The study cohort consisted of 2106 HD mutation carriers, all participating in the REGISTRY study of the European Huntington's Disease Network. Of the 1937 participants without suicidal ideation at baseline, 945 had one or more follow-up measurements. Participants were assessed for suicidal ideation by the behavioural subscale of the Unified Huntington's Disease Rating Scale (UHDRS). Correlates of suicidal ideation were analyzed using logistic regression analysis and predictors were analyzed using Cox regression analysis. RESULTS: At baseline, 169 (8.0%) mutation carriers endorsed suicidal ideation. Disease duration (odds ratio [OR]=0.96; 95% confidence interval [CI]: 0.9-1.0), anxiety (OR=2.14; 95%CI: 1.4-3.3), aggression (OR=2.41; 95%CI: 1.5-3.8), a previous suicide attempt (OR=3.95; 95%CI: 2.4-6.6), and a depressed mood (OR=13.71; 95%CI: 6.7-28.0) were independently correlated to suicidal ideation at baseline. The 4-year cumulative incidence of suicidal ideation was 9.9%. Longitudinally, the presence of a depressed mood (hazard ratio [HR]=2.05; 95%CI: 1.1-4.0) and use of benzodiazepines (HR=2.44; 95%CI: 1.2-5.0) at baseline were independent predictors of incident suicidal ideation, whereas a previous suicide attempt was not predictive. LIMITATIONS: As suicidal ideation was assessed by only one item, and participants were a selection of all HD mutation carriers, the prevalence of suicidal ideation was likely underestimated. CONCLUSIONS: Suicidal ideation in HD frequently occurs. Assessment of suicidal ideation is a priority in mutation carriers with a depressed mood and in those using benzodiazepines