Fine-scale foraging habitat selection by two diving central place foragers in the Northeast Atlantic.

Habitat selection and spatial usage are important components of animal behavior influencing fitness and population dynamic. Understanding the animal-habitat relationship is crucial in ecology, particularly in developing strategies for wildlife management and conservation. As this relationship is governed by environmental features and intra- and interspecific interactions, habitat selection of a population may vary locally between its core and edges. This is particularly true for central place foragers such as gray and harbor seals, where, in the Northeast Atlantic, the availability of habitat and prey around colonies vary at local scale. Here, we study how foraging habitat selection may vary locally under the influence of physical habitat features. Using GPS/GSM tags deployed at different gray and harbor seals' colonies, we investigated spatial patterns and foraging habitat selection by comparing trip characteristics and home-range similarities and fitting GAMMs to seal foraging locations and environmental data. To highlight the importance of modeling habitat selection at local scale, we fitted individual models to colonies as well as a global model. The global model suffered from issues of homogenization, while colony models showed that foraging habitat selection differed markedly between regions for both species. Despite being capable of undertaking far-ranging trips, both gray and harbor seals selected their foraging habitat depending on local availability, mainly based on distance from the last haul-out and bathymetry. Distance from shore and tidal current also influenced habitat preferences. Results suggest that local conditions have a strong influence on population spatial ecology, highlighting the relevance of processes occurring at fine geographical scale consistent with management within regional units.

Form, function, and divergence of a generic fin shape in small cetaceans.

Tail flukes as well as the dorsal fin are the apomorphic traits of cetaceans which appeared during the evolutionary process of adaptation to the aquatic life. Both appendages present a wing-like shape associated with lift generation and low drag. We hypothesized that the evolution of fins as lifting structures led to a generic wing design, where the dimensionless parameters of the fin cross-sections are invariant with respect to the body length and taxonomy of small cetaceans (Hypothesis I). We also hypothesized that constraints on variability of a generic fin shape are associated with the primary function of the fin as a fixed or flapping hydrofoil (Hypothesis II). To verify these hypotheses, we examined how the variation in the fin's morphological traits is linked to the primary function, species and body length. Hydrodynamic characteristics of the fin cross-sections were examined with the CFD software and compared with similar engineered airfoils. Generic wing design of both fins was found in a wing-like planform and a streamlined cross-sectional geometry optimized for lift generation. Divergence in a generic fin shape both on the planform and cross-sectional level was found to be related with the fin specialization in fixed or flapping hydrofoil function. Cross-sections of the dorsal fin were found to be optimized for the narrow range of small angles of attack. Cross-sections of tail flukes were found to be more stable for higher angles of attack and had gradual stall characteristics. The obtained results provide an insight into the divergent evolutionary pathways of a generic wing-like shape of the fins of cetaceans under specific demands of thrust production, swimming stability and turning control.

Trophic niche overlap between sympatric harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) at the southern limit of their European range (Eastern English Channel).

Sympatric harbour (Phoca vitulina) and grey seals (Halichoerus grypus) are increasingly considered potential competitors, especially since recent local declines in harbour seal numbers while grey seal numbers remained stable or increased at their European core distributions. A better understanding of the interactions between these species is critical for conservation efforts. This study aimed to identify the trophic niche overlap between harbour and grey seals at the southern limit of their European range, in the Baie de Somme (BDS, Eastern English Channel, France), where numbers of resident harbour seals and visiting grey seals are increasing exponentially. Dietary overlap was identified from scat contents using hierarchical clustering. Isotopic niche overlap was quantified using δ13C and δ15N isotopic values from whiskers of 18 individuals, by estimating isotopic standard ellipses with a novel hierarchical model developed in a Bayesian framework to consider both intraindividual variability and interindividual variability. Foraging areas of these individuals were identified from telemetry data. The three independent approaches provided converging results, revealing a high trophic niche overlap due to consumption of benthic flatfish. Two diet clusters were dominated by either small or large benthic flatfish; these comprised 85.5% [CI95%: 80.3%-90.2%] of harbour seal scats and 46.8% [35.1%-58.4%] of grey seal scats. The narrower isotopic niche of harbour seals was nested within that of grey seals (58.2% [22.7%-100%] overlap). Grey seals with isotopic values similar to harbour seals foraged in coastal waters close to the BDS alike harbour seals did, suggesting the niche overlap may be due to individual grey seal strategies. Our findings therefore provide the basis for potential competition between both species (foraging on benthic flatfish close to the BDS). We suggest that a continued increase in seal numbers and/or a decrease in flatfish supply in this area could cause/amplify competitive interactions and have deleterious effects on harbour seal colonies.

Predicting the exposure of diving grey seals to shipping noise.

There is high spatial overlap between grey seals and shipping traffic, and the functional hearing range of grey seals indicates sensitivity to underwater noise emitted by ships. However, there is still very little data regarding the exposure of grey seals to shipping noise, constraining effective policy decisions. Particularly, there are few predictions that consider the at-sea movement of seals. Consequently, this study aimed to predict the exposure of adult grey seals and pups to shipping noise along a three-dimensional movement track, and assess the influence of shipping characteristics on sound exposure levels. Using ship location data, a ship source model, and the acoustic propagation model, RAMSurf, this study estimated weighted 24-h sound exposure levels (10-1000 Hz) (SELw). Median predicted 24-h SELw was 128 and 142 dB re 1 µPa2s for the pups and adults, respectively. The predicted exposure of seals to shipping noise did not exceed best evidence thresholds for temporary threshold shift. Exposure was mediated by the number of ships, ship source level, the distance between seals and ships, and the at-sea behaviour of the seals. The results can inform regulatory planning related to anthropogenic pressures on seal populations.

The development of a regional referral pathway for locally recurrent rectal cancer: A Delphi consensus study.

BACKGROUND: The management of patients with locally recurrent rectal cancer (LRRC) is often complex and requires multidisciplinary input whereas only few patients are referred to a specialist centre. The aim of this study was to design a regional referral pathway for LRRC, in Nouvelle Aquitaine (South-West, France). METHODS: In 2016, we conducted with a Study Steering Committee (SC) a three phase mixed-methods study including identification of key factors, identification of key stakeholders and Delphi voting consensus. During three rounds of Delphi voting, a consensus was defined as favorable, if at least 80% of participating experts rate the factor, below or equal to 3/10 using a Likert scale, or consider it as "useful" using a binary scale (third round only). Finally, the SC drafted guidelines. RESULTS: Among the 423 physicians involved in 29 regional digestive Multi-Disciplinary Team (MDT) meeting, 59 participants (from 26 MDT meeting) completed all three rounds of Delphi voting. Thirteen out of twenty initially selected factors reached a favorable consensus. All patients with a LRRC need to be included into a referral pathway. Patients with a central pelvic recurrence offered curative treatment in their local hospital and patients with unresectable metastatic disease were excluded of the referral. Key performance indicators were also agreed including the time to referral and completion of pelvic MRI-, CT-, PET-scan prior to MDT referral. CONCLUSION: The development of this referral pathway represents an innovative health service, which will improve the management of patients with LRRC in France.

Characterization of hypertrophic cardiomyopathy according to global, regional, and multi-layer longitudinal strain analysis, and prediction of sudden cardiac death.

To evaluate the severity of hypertrophic cardiomyopathy (HCM) according to global, regional, and multi-layer longitudinal strain (LS) analysis using speckle-tracking echocardiography. From February 2007 to November 2014, we prospectively evaluated 375 consecutive HCM patients referred to our specialized cardiomyopathy center. Demographics, clinical, and rest and exercise echocardiographic parameters were collected according to a completely standardized protocol. Global, regional, and multilayer strain analyses were performed. Correlations between LS and other characteristics were evaluated, and we assessed their prognostic value to predict sudden cardiac death (SCD) or appropriate implantable cardioverter defibrillator (ICD) shocks during follow-up, using Cox proportional hazards analyses. We finally included 217 patients (50.1 ± 15.6 years, 67% male) but only 179 (82%) had LS analysis of sufficient quality. An inverse relation was observed between the mean basal left ventricular (LV) LS and diastolic parameters [E/Ea (r = - 0.30) and left atrium indexed volume (r = - 0.23)], as well as between the resting LV outflow-tract maximal gradient (r = - 0.26) or during peak exercise (r = - 0.20). Mean LS in the LV hypertrophic area was particularly related with maximal wall thickness (r = - 0.47) and transmural global LS with the degree of myocardial fibrosis in cardiac magnetic resonance (r = - 0.32). During a median follow-up of 2.8 ± 1.5 years, mean transmural LS in the hypertrophic area was predictor of SCD and appropriate ICD shock (10 events/179 patients, hazard ratio = 0.83 [95% CI 0.72-0.95], p = 0.01). Basal LS and hypertrophic area LS are valuable parameters to evaluate HCM severity. Mean hypertrophic area LS particularly seems predictive of SCD occurrence and appropriate ICD shocks.

[Day clinic, a gateway towards risk reduction]. / Hôpital de jour, une passerelle vers la réduction des risques.

The addictology day clinic at Fernand-Widal hospital in Paris caters mainly for patients suffering from alcohol dependence. The aim is to consolidate the withdrawal which has taken place, to help reduce risks and harm and to support people waiting for follow-up care.

Upright treadmill vs. semi-supine bicycle exercise echocardiography to provoke obstruction in symptomatic hypertrophic cardiomyopathy: a pilot study.

Aims: Recent findings regarding hypertrophic cardiomyopathy (HCM) haemodynamics emphasized the relationship between symptoms, left ventricular outflow tract obstruction (LVOTO), and the preload condition as the venous return level. As various types of exercises have different effects on peripheral vascular beds, this study sought to compare upright treadmill exercise echocardiography (EE) to semi-supine bicycle EE in maximum provoked LVOTO in HCM patients. Methods and results: Semi-supine bicycle and upright treadmill EE were prospectively performed in HCM patients with New York Heart Association functional Class II. Maximal LVOT gradient at rest in the supine and standing position, and during Valsalva manoeuvre, LVOT gradients of both semi-supine bicycle and treadmill exercise at peak and post-exercise, maximal exercise levels, and blood pressure adaptation were recorded. One patient was excluded for not sufficient image quality during treadmill. We studied 22/23 patients (mean age: 54.9 ± 12.3 yrs; 55% male). The supine position at rest displayed a mean maximal LVOT gradient of 46.1 ± 44.8 mmHg, which increased to 51.6 ± 41.2 mmHg during Valsalva (P = 0.066), and to 55.1 ± 37.8 mmHg in the standing position (P = 0.053). Mean maximal peak exercise LVOT gradient with semi-supine bicycle was significantly lower than in treadmill EE (54.6 ± 38.2 mmHg vs. 87.5 ± 42.1 mmHg, respectively, P < 0.01). Among these patients, 41% exhibited LVOT gradient ≥ 30 mmHg at rest. Moreover, 41% exhibited LVOT gradient ≥ 50 mmHg during Valsalva, 55% in resting standing position, 41% at peak semi-supine bicycle exercise, 91% at peak treadmill exercise, and 95% in standing position during treadmill recovery period. Conclusion: This pilot study may suggest treadmill's greater value compared to semi-supine bicycle EE for determining maximum LVOT gradient in HCM.