ABSTRACT We report a narrowband blue multi‐resonance (MR) fluorescent emitter, BN‐TPh‐TPA, designed to suppress thermally activated delayed fluorescence (TADF) to extend organic light‐emitting diode (OLED) operational lifetime. By introducing a 5‐phenylbenzo[b]thiophene unit into the DABNA core, BN‐TPh‐TPA achieves an enlarged singlet‐triplet energy gap (∆ E ST ) that renders reverse intersystem crossing (rISC) energetically unfavorable while retaining deep‐blue, narrow emission. In sensitizer‐free OLEDs, using an exciplex host, BN‐TPh‐TPA delivers a substantially extended operational lifetime at 10 mA/cm 2 (LT 50 = 90 h), representing an approximately threefold improvement over the TADF‐active MR emitter, t‐DABNA (LT 50 = 27 h). In phosphor‐sensitized fluorescence (PSF) OLEDs operated at the same current density, BN‐TPh‐TPA likewise exhibits an improved LT 50 of 108 h compared with 80 h for t‐DABNA. Transient photoluminescence and electroluminescence (TrEL/TrPL) measurements confirm the absence of an rISC‐mediated delayed fluorescence component and a markedly shorter decay time for BN‐TPh‐TPA. Magneto‐electroluminescence (MEL) analysis further indicates that TADF activity influences the dominant triplet‐related bimolecular interaction pathway under electrical driving, providing mechanistic insight into the enhanced device stability.
Pacific salmon have experienced declining abundance and unpredictable returns, yet remain vital to livelihoods, food security, and cultures of coastal communities around the Pacific Rim, creating a need for reliable and timely monitoring to inform sustainable fishery management. Currently, spawning salmon abundance is often monitored with in-river video or sonar cameras. However, reviewing video for estimates of salmon abundance from these programs requires thousands of hours of staff time, and data are typically not available until after the fishing season is completed. Computer vision deep learning can enable rapid and reliable processing of data, with potentially transformative applications in salmon population assessment and fishery management. Working with two First Nations fishery programs in British Columbia, Canada, we developed, trained, and tested deep learning models to perform object detection and multi-object tracking for automated video enumeration of salmon passing two First Nation-run weirs. We gathered and annotated more than 500,000 frames of video data encompassing 12 species, including seven species of anadromous salmonids, and trained models for multi-object tracking and species detection. Our top performing model achieved a mean average precision (mAP) of 67.6%, and species-specific mAP scores > 90% for coho and > 80% for sockeye salmon when trained with a combined dataset of Kitwanga and Bear Rivers' salmon annotations. We also tested and deployed a prototype for a real-time monitoring system that can perform computer vision deep learning analyses on site. Computer vision models and off-grid monitoring systems show promise for automated counting and species identification. A key future priority will be working with stewardship practitioners and fishery managers to apply salmon computer vision, testing and applying edge-capable computing solutions for in-situ analysis at remote sites, and developing tools for independent user-led computer vision analysis by non-computer scientists. These efforts can advance in-season monitoring and decision making to support adaptive management of sustainable wild salmon fisheries.
Assessment of risk from industrial developments often relies on simple habitat descriptions for focal species. However, simple habitat metrics may not be accurate predictors of locations that species actually use. Understanding the nature of habitat is particularly pressing for estuaries, as they are among the most degraded ecosystems globally but provide critical rearing habitat for many species, including Pacific salmon. Canadian environmental impact assessment approaches use simple habitat-type models to assess risk from developments and assume that different species of salmon rely on the same habitat. This study asked what combination of habitat type and biophysical covariates best predicted use of estuary habitat by juvenile salmon and two dominant small pelagic fish. Fish were sampled via purse seine throughout the Skeena River estuary (British Columbia, Canada) for 2 years across different habitat types (eelgrass, open water, sandy banks, and rocky shores). Simple habitat-type models were compared with models with more complex biophysical variables to predict the variability in relative abundance of juvenile Chinook (Oncorhynchus tshawytscha), coho (Oncorhynchus kisutch), and sockeye (Oncorhynchus nerka) salmon, along with pelagic fish species Pacific herring (Clupea pallasii) and surf smelt (Hypomesus pretiosus). The combination of variables that best predicted abundance differed across fish species. Pelagic fish were associated with near-shore sites, increased temperature (herring), and increased salinity (smelt). Juvenile coho and sockeye salmon (but not Chinook), were more abundant in higher turbid waters. Chinook and sockeye salmon used eelgrass habitat more frequently than other habitat types, whereas coho salmon were more abundant in areas with high macroalgae cover. Models with these variables had greater predictive power than those using habitat type alone for juvenile salmon. Simple classifications of estuary habitat currently used in environmental risk assessment may not reflect the complex nature of fish-habitat associations. Understanding biophysical factors associated with estuary fish abundance can inform management of estuary habitat to support their nursery function for important fish.
The usefulness of the apparent redox potential discontinuity(aRPD) in assessments of marine benthic habitat quality was explored at two intertidal mudflats along the north Pacific coast of Canada. Two transects were established at each intertidal site, with three sediment biogeochemistry cores collected from each transect four times over the summer of 2016. Measurements of the sediment pore water dissolved oxygen(DO) content and redox(Eh) conditions were taken at the surface of the core(measured vertically), as well as at increasing depths(1 cm between readings) into the sediment(measured horizontally through predrilled holes in the biogeochemistry corer). While oxic, anoxic, oxidized, and reduced sediment pore water was observed above and below the aRPD, in general, sediment above the aRPD had higher DO content, and higher Eh values than sediment below the aRPD. Therefore, the aRPD depth can be used as a relative indicator of sediment pore water DO and Eh conditions: sediment with a deeper aRPD depth has more available DO, and the pore water has higher Eh values(more oxidized or less reduced) than sediment with a shallower aRPD depth. As such, the aRPD depth is a useful parameter to include in models that assess the quality of marine benthic habitats.
La prévalence du SAS en population cardiologique est élevée mais les ressources polygraphiques insuffisantes. Un nouveau questionnaire (QS) est donc proposé pour dépister les SAS significatifs en cardiologie libérale. Un QS en 2 parties a été testé : 1 autoquestionnaire de 27 items sur les symptômes diurnes et nocturnes, 2 remplie par le médecin comportant 21 items et les résultats des mesures anthropométriques, pression artérielle. Une polygraphie (Cidelec, Nox, Somnolab, Embletta) a été réalisée et relue de manière centralisée. 12 cardiologues ont recruté 215 patients (66 % d’Hommes, âge moyen 61 ans) porteurs d’hypertension artérielle (65 %), de maladie coronaire (16 %), d’AC/FA (25 %), d’insuffisance cardiaque (10 %) ou d’AVC (15 %). 63 % des patients avaient un SAS : modéré (15 < IAH < 30) chez 25 %, sévère (IAH > 30) chez 38 %. 5 % avaient des apnées centrales. Les symptômes diurnes liés à la sévérité étaient : « fatigue au réveil » et « envie de dormir dans la journée » et les plaintes nocturnes « ronflement », « pause respiratoire » et « étouffement ». La sévérité était liée au sexe M, à l’IMC, aux périmètres abdominal et cervical, à la PAS, à l’oedème des MI, au diabète associé, à la prise d’hypnotiques et d’antalgiques. L’ IAH évalué par le lecteur de référence était supérieur à la mesure du cardiologue (31 ± 19 vs 28 ± 19/h) (p < 0,0001). Un QS simplifié peut permettre au cardiologue de suspecter un patient SAS pour réaliser une PG. Les IAH déterminés par le lecteur de référence sont en moyenne supérieurs aux mesures des cardiologues.
