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Recent studies have highlighted the importance of salmon (genus Oncorhynchus Suckley, 1861) in the diet of bears, and of bears as consumers and key agents supporting the transport of salmon-derived nutrients to riparian ecosystems. Salmon abundance and human disturbance are known influences on bear ecology and behaviour, though few studies have quantified shifts in bear diet due to these effects. We used stable isotope analysis to investigate how salmon escapement and human presence influenced the proportion of salmon in the diet of American black bears (Ursus americanus Pallas, 1780) in two locations in coastal British Columbia, Canada. We found that salmon constituted a small proportion of black bear diet across sexes and ecosystems, while bears appeared to gain a similar amount of energy and lean mass from terrestrial sources. Salmon consumption was not related to the total annual abundance of salmon in a watershed but was significantly lower in large streams with regular human presence, suggesting that human disturbance can cause a dietary shift in bears that could have important consequences to their fitness. We also observed that the isotopic signatures of key bear foods did not vary between foliage and fruit, simplifying data collection for future isotopic studies on bear diet. Key words: behavioural response, dietary shift, ecosystem management, foraging, marine-derived nutrients, Oncorhynchus spp., Pacific salmon, stable isotope analysis, Ursus americanus, American black bear Des études récentes ont souligné l'importance des saumons (genre Oncorhynchus Suckley, 1861) dans le régime alimentaire des ours et celle des ours comme consommateurs et agents de soutien clés du transport de nutriments dérivés des saumons vers les écosystèmes riverains. S'il est établi que l'abondance des saumons et les perturbations d'origine humaine influencent l'écologie et le comportement des ours, peu d'études ont quantifié les changements du régime alimentaire d'ours découlant de ces effets. Nous utilisons l'analyse d'isotopes stables pour examiner l'influence de l'échappement de saumons et de la présence humaine sur la proportion de saumons dans le régime alimentaire d'ours noirs (Ursus americanus Pallas, 1780) en deux endroits le long de la côte de la Colombie-Britannique (Canada). Nous constatons que les saumons représentent une petite proportion du régime alimentaire des ours noirs des deux sexes et dans différents écosystèmes, les ours semblant obtenir des quantités similaires d'énergie et de masse maigre de sources terrestres. La consommation de saumons n'est pas reliée à l'abondance annuelle totale de saumons dans un bassin versant, mais est significativement plus faible dans les grands cours d'eau caractérisés par une présence humaine régulière, ce qui indiquerait que les perturbations d'origine humaine peuvent causer un changement du régime alimentaire des ours qui peut avoir d'importantes conséquences sur leur aptitude. Nous observons également que les feuilles et les fruits d'aliments clés des ours ont des signatures isotopiques semblables, ce qui simplifie la collecte de données pour des études isotopiques futures sur le régime alimentaire des ours. [Traduit par la Rédaction] Mots-clés : réaction comportementale, changement du régime alimentaire, gestion des écosystèmes, quête de nourriture, nutriments d'origine marine, Oncorhynchus spp., saumon du Pacifique, analyse d'isotopes stables, Ursus americanus, ours noir, Introduction The prominence of ecosystem management has led some authors (Hilderbrand et al. 2004; Piccolo et al. 2009; Lincoln et al. 2020) to call for the management of Pacific salmon [...]

Background: The guaiac faecal occult blood test (gFOBT) has been proved as a screening investigation for colorectal cancer, but has disadvantages. Newer faecal immunochemical tests (FITs) have many advantages, but yield higher positivity rates qnd are expensive. A two-tier reflex follow-up of gFOBT-positive individuals with a FIT before colonoscopy has been advocated as an efficient and effective approach. Methods: A new simple and stable card collection FIT was evaluated. Results: 1124 individuals who were 9FOBT positive were asked to provide samples. 558 individuals participated, 320 refused and 246 did not return samples. No evidence of sampling bias was found. 302 individuals tested FIT negative and 256 tested positive. In the 302 FIT-negative individuals, 2 (0.7%) had cancer and 12 (4.0%) had large or multiple (high-risk) adenomatous polyps. In contrast, of 254 positive individuals, 47 (18.5%) had cancer and 54 (21.3%) had high-risk polyps. 93 (30.8%) of the FIT-negative individuals had a normal colonoscopy, but only 34 (13.4%) of the FIT-positive individuals had no pathology. Sensitivity, specificity, and positive and negative likelihood ratios (and 95% CIs) for cancer were 95.9% (84.8 to 99.3), 59.2% (54.7 to 63.5), 2.35 (2.08 to 2.65) and 0.07 (0.02 to 0.27), and for cancer and high-risk polyps were 87.8% (80.1 to 92.9), 65.3% (60.6 to 69.7), 2.53 (2.19 to 2.93) and 0.19 (0.11 to 0.31), respectively. Conclusions: A two-tier reflex screening algorithm, in which gFOBT-positive participants are tested with a FIT, is effective in identifying individuals at high risk of significant colorectal neoplasia. This strategy is transferable across different FIT formats. This approach has been adopted for the Scottish Bowel Screening Programme. [ABSTRACT FROM AUTHOR]