Abundance and distribution of sperm whales in the Canary Islands : can sperm whales in the Archipelago sustain the current level of ship-strike mortalities?

Funding was provided through an agreement between the Canary Islands Government and the Spanish Ministries of the Environment and Defence. Additional survey effort on the Amanay, Banquete and Concepción seamounts was funded by the Fundación Biodiversidad-MAGRAMA via the LIFE-INDEMARES project.Sperm whales are present in the Canary Islands year-round, suggesting that the archipelago is an important area for this species in the North Atlantic. However, the area experiences one of the highest reported rates of sperm whale ship-strike in the world. Here we investigate if the number of sperm whales found in the archipelago can sustain the current rate of ship-strike mortality. The results of this study may also have implications for offshore areas where concentrations of sperm whales may coincide with high densities of ship traffic, but where ship-strikes may be undocumented. The absolute abundance of sperm whales in an area of 52933 km2, covering the territorial waters of the Canary Islands, was estimated from 2668 km of acoustic line-transect survey using Distance sampling analysis. Data on sperm whale diving and acoustic behaviour, obtained from bio-logging, were used to calculate g(0) = 0.92, this is less than one because of occasional extended periods when whales do not echolocate. This resulted in an absolute abundance estimate of 224 sperm whales (95% log-normal CI 120-418) within the survey area. The recruitment capability of this number of whales, some 2.5 whales per year, is likely to be exceeded by the current ship-strike mortality rate. Furthermore, we found areas of higher whale density within the archipelago, many coincident with those previously described, suggesting that these are important habitats for females and immature animals inhabiting the archipelago. Some of these areas are crossed by active shipping lanes increasing the risk of ship-strikes. Given the philopatry in female sperm whales, replacement of impacted whales might be limited. Therefore, the application of mitigation measures to reduce the ship-strike mortality rate seems essential for the conservation of sperm whales in the Canary Islands.Publisher PDFPeer reviewe

Environmental chemical stressors as epigenome modifiers:a new horizon in assessment of toxicological effects

In eukaryotic cells, chromatin transformation from euchromatin into heterochromatin as a means of controlling gene expression and replication has been known as the ?accessibility hypothesis?. The interplay of epigenetic changes including histone modifications, DNA methylation, RNA interference (RNAi) and other functional epigenetic components are intricate. It is believed that these changes are well-programmed, inherited and can be modified by environmental contaminant stressors. Environmentally-driven epigenetic alterations during development, e.g. embryonic, foetal or neonatal stage, may influence disease susceptibility in adulthood. Therefore, understanding how epigenome modifications develop in response to environmental chemicals and, how epigenetic-xenobiotic interactions influence human health will shed new insights into gene-environment interactions in the epidemiology of several diseases including cancer. In this review, we consider studies of chemical modifiers including nutritional and xenobiotic effects on epigenetic components in vitro or in vivo. By examining the most-studied epigenome modifications and how their respective roles are interlinked, we highlight the central role of xenbiotic-modified epigenetic mechanisms. A major requirement will be to study and understand effects following environmentally-relevant exposures. We suggest that the study of epigenetic toxicology will open up new opportunities to devise strategies for the prevention or treatment of at-risk populations

TBP Binding-Induced Folding of the Glucocorticoid Receptor AF1 Domain Facilitates Its Interaction with Steroid Receptor Coactivator-1

The precise mechanism by which glucocorticoid receptor (GR) regulates the transcription of its target genes is largely unknown. This is, in part, due to the lack of structural and functional information about GR's N-terminal activation function domain, AF1. Like many steroid hormone receptors (SHRs), the GR AF1 exists in an intrinsically disordered (ID) conformation or an ensemble of conformers that collectively appears to be unstructured. The GR AF1 is known to recruit several coregulatory proteins, including those from the basal transcriptional machinery, e.g., TATA box binding protein (TBP) that forms the basis for the multiprotein transcription initiation complex. However, the precise mechanism of this process is unknown. We have earlier shown that conditional folding of the GR AF1 is the key for its interactions with critical coactivator proteins. We hypothesize that binding of TBP to AF1 results in the structural rearrangement of the ID AF1 domain such that its surfaces become easily accessible for interaction with other coactivators. To test this hypothesis, we determined whether TBP binding-induced structure formation in the GR AF1 facilitates its interaction with steroid receptor coactivator-1 (SRC-1), a critical coactivator that is important for GR-mediated transcriptional activity. Our data show that stoichiometric binding of TBP induces significantly higher helical content at the expense of random coil configuration in the GR AF1. Further, we found that this induced AF1 conformation facilitates its interaction with SRC-1, and subsequent AF1-mediated transcriptional activity. Our results may provide a potential mechanism through which GR and by large other SHRs may regulate the expression of the GR-target genes

End-stage extension of the knee and its influence on tibial tuberosity-trochlear groove distance (TTTG) in asymptomatic volunteers

PURPOSE: Increased tibial tuberosity-trochlear groove distance (TTTG) is one potential correcting parameter in patients suffering from lateral patellar instability. It was hypothesized that end-stage extension of the knee might influence the TTTG distance on MR images. METHODS: Transverse T1-weighted MR images of the knee were acquired at full extension, 15° and 30° flexion of the knee in 30 asymptomatic volunteers. MRI parameters: slice thickness: 3 mm, matrix: 256 × 384, FOV: 150 × 150 mm. Two observers independently measured the TTTG at all positions. RESULTS: Mean TTTG for observer 1 was 15.1 ± 3.2 mm at full extension, 10.0 ± 3.5 mm at 15° flexion and 8.1 ± 3.4 mm at 30° flexion. Mean TTTG for observer 2: 14.8 ± 3.3 mm at full extension, 9.4 ± 3.0 mm at 15° flexion, 8.6 ± 3.4 mm at 30° flexion. Mean values were significantly different (p < 0.001) between full extension and 15° as well as 30° flexion for both observers. Mean values were significantly different (p < 0.001) between 15° and 30° for observer 1, but not for observer 2 (n.s.). Interobserver agreement was very good (intraclass correlation coefficient: 0.87-0.88; p < 0.001). CONCLUSIONS: The TTTG increases significantly at the end-stage extension of the knee. Therefore, the comparability of published TTTG values measured on radiographs, CT and MRI at various flexion/extension angles of the knee are limited. LEVEL OF EVIDENCE: Development of diagnostic criteria in a consecutive series of patients and a universally applied 'gold' standard, Level II

Rumination in bipolar disorder: evidence for an unquiet mind

Depression in bipolar disorder has long been thought to be a state characterized by mental inactivity. However, recent research demonstrates that patients with bipolar disorder engage in rumination, a form of self-focused repetitive cognitive activity, in depressed as well as in manic states. While rumination has long been associated with depressed states in major depressive disorder, the finding that patients with bipolar disorder ruminate in manic states is unique to bipolar disorder and challenges explanations put forward for why people ruminate. We review the research on rumination in bipolar disorder and propose that rumination in bipolar disorder, in both manic and depressed states, reflects executive dysfunction. We also review the neurobiology of bipolar disorder and recent neuroimaging studies of rumination, which is consistent with our hypothesis that the tendency to ruminate reflects executive dysfunction in bipolar disorder. Finally, we relate the neurobiology of rumination to the neurobiology of emotion regulation, which is disrupted in bipolar disorder

Anti-SARS-CoV-2 antibody responses are attenuated in patients with IBD treated with infliximab.

OBJECTIVE: Antitumour necrosis factor (anti-TNF) drugs impair protective immunity following pneumococcal, influenza and viral hepatitis vaccination and increase the risk of serious respiratory infections. We sought to determine whether infliximab-treated patients with IBD have attenuated serological responses to SARS-CoV-2 infections. DESIGN: Antibody responses in participants treated with infliximab were compared with a reference cohort treated with vedolizumab, a gut-selective anti-integrin α4β7 monoclonal antibody that is not associated with impaired vaccine responses or increased susceptibility to systemic infections. 6935 patients were recruited from 92 UK hospitals between 22 September and 23 December 2020. RESULTS: Rates of symptomatic and proven SARS-CoV-2 infection were similar between groups. Seroprevalence was lower in infliximab-treated than vedolizumab-treated patients (3.4% (161/4685) vs 6.0% (134/2250), p<0.0001). Multivariable logistic regression analyses confirmed that infliximab (vs vedolizumab; OR 0.66 (95% CI 0.51 to 0.87), p=0.0027) and immunomodulator use (OR 0.70 (95% CI 0.53 to 0.92), p=0.012) were independently associated with lower seropositivity. In patients with confirmed SARS-CoV-2 infection, seroconversion was observed in fewer infliximab-treated than vedolizumab-treated patients (48% (39/81) vs 83% (30/36), p=0.00044) and the magnitude of anti-SARS-CoV-2 reactivity was lower (median 0.8 cut-off index (0.2-5.6) vs 37.0 (15.2-76.1), p<0.0001). CONCLUSIONS: Infliximab is associated with attenuated serological responses to SARS-CoV-2 that were further blunted by immunomodulators used as concomitant therapy. Impaired serological responses to SARS-CoV-2 infection might have important implications for global public health policy and individual anti-TNF-treated patients. Serological testing and virus surveillance should be considered to detect suboptimal vaccine responses, persistent infection and viral evolution to inform public health policy. TRIAL REGISTRATION NUMBER: ISRCTN45176516