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Liver transplants (LTs) are prioritized by mortality risk, which is estimated by MELD scores. Since hepatocellular carcinoma (HCC) patients present with lower MELD scores, they are allocated MELD exception points. Concerns persist that HCC recipients are over-prioritized, resulting in disproportionate waitlist mortality among non-HCC patients. We assessed whether the Median Meld at Transplant minus 3 (MMaT-3) scoring system would balance waitlist mortality and transplantation rates between HCC and non-HCC patients. We reviewed 266 patient charts listed for an LT from 2015 to 2023; 46.2% were listed in the MMaT-3 era. Amongst non-HCC patients, MMaT-3 implementation significantly increased 1-year transplant rate and reduced 1-year waitlist mortality among non-HCC patients (p = 0.003). Pre-MMaT-3 gaps in transplantation (p = 0.004) and waitlist dropout (p = 0.01) were eliminated post-implementation (p > 0.05). Amongst HCC patients, MMaT-3 implementation had no impact on the 1-year transplant rate (p = 0.92) or 1-year waitlist mortality (p = 0.66). Fine-gray proportional hazard multivariable analysis revealed that MMaT-3 significantly reduced waitlist mortality among non-HCC patients (asHR: 0.44, 95% CI [0.23, 0.83], p = 0.01) and limited impact on HCC patients (p = 0.31). MMaT-3 allocation did not significantly alter 2-year post-transplant survival for both populations. We show that the MMaT-3 system decreased the waitlist mortality of non-HCC patients with limited impacts on outcomes for HCC patients listed for an LT. [ABSTRACT FROM AUTHOR] more...

Fjords are deep nearshore zones that connect watersheds and oceans, typically behaving as an estuary. In some fjords, strong katabatic winds in winter (also known as Arctic outflow wind events) can lead to cooling and reoxygenation of subsurface waters, with effects lasting until the following autumn, as observed in 2019 in Bute Inlet, British Columbia, Canada. We used high-resolution, three-dimensional ocean model summer simulations to investigate the mechanisms allowing for the persistence of these cool, oxygen-rich subsurface conditions in Bute Inlet. The slow residual circulation underneath the brackish outflow (and consequent slow advection) in this long, deep fjord is a main reason why the cold subsurface water mass stays in place until conditions change in autumn (i.e., start of stronger wind mixing and reduced freshwater forcing). Another mechanism is a positive feedback provided by the presence of this subsurface water mass, since it further reduces the already weak residual circulation. These findings are applicable to any similar long, deep fjord that experiences katabatic winds in winter, and they could have implications not only for the preservation of water masses but other possible subsurface features (e.g., pollutant spills, planktonic larvae). Furthermore, the identification of mechanisms that permit persistent cold and oxygenated conditions is key to understanding potential areas of ecological refugia in a warming and deoxygenating ocean. [ABSTRACT FROM AUTHOR] more...

Fjords are common geomorphological coastal features in the mid- and high-latitudes, carved by glacial erosion. These deep nearshore zones connect watersheds and oceans, typically behaving as an estuary. Many fjords in the world have shown concerning warming and deoxygenation trends in their deep waters, sometimes at faster rates than the open ocean. While that is the case in several fjords of British Columbia (BC), Canada, some of the same fjords have shown that strong Arctic outflow wind events in winter can lead to cooling and reoxygenation of subsurface waters, with effects lasting until the following autumn. The latter was observed in Bute Inlet, BC in 2019. We used a high-resolution, three-dimensional ocean model to investigate the mechanisms allowing for the persistence of these subsurface conditions through the year. The presence of the subsurface cold water mass reduced the already weak residual circulation, changing its vertical structure from three to four layers. The reduction of mixing and advection allowed for the water mass to stay in place until autumn conditions arrived (i.e., strong wind mixing and reduced freshwater forcing). The identification of mechanisms that allow for the persistence of cold and oxygenated conditions are key to understand potential areas of ecological refugia in a warming and deoxygenating ocean. [ABSTRACT FROM AUTHOR] more...

PAUL HALSTEAD. Two oxen ahead. Pre-mechanized farming in the Mediterranean. xi+372 pages, numerous b&w illustrations, and tables. 2014. Chichester: Wiley-Blackwell; 978-1-4051-9283-5 hardback 60 [pounds sterling]. In Two oxen ahead, Halstead [...] more...

A coupled biophysical model of the Strait of Georgia (SoG), British Columbia, Canada, has been developed and successfully predicts the timing of the spring phytoplankton bloom. The physical model is a one-dimensional vertical mixing model, using a K-profile parametrization of the boundary layer, forced with high frequency meteorological data. The biological model includes one phytoplankton class (microphytoplankton) and one nutrient source (nitrate). The spring bloom in the SoG occurs when phytoplankton receive enough light that their growth rates exceed their loss rates. The amount of light that the phytoplankton receive is a function of solar radiation and the depth of mixing. The model was used to determine what physical factors are controlling the phytoplankton losses and the light received by the phytoplankton. Wind was found to control the spring bloom arrival time, with strong winds increasing the mixing-layer depth and delaying the bloom. The amount of incoming solar irradiance, through amount of cloud cover, had a secondary effect. The freshwater input (primarily Fraser River discharge) had an insignificant effect on the timing. Increased freshwater flux increases the buoyancy flux and thus decreases the mixing-layer depth but also increases the strength of the estuarine circulation, increasing the advective loss. Nous avons elabore un modele biophysique couple du detroit de Georgie (SoG), Colombie-Britannique, Canada, qui predit avec succes le moment de la proliferation printaniere du phytoplancton. Le modele physique est un modele de brassage vertical unidimensionnel, avec un parametrage du profil K de la couche limite, force par des donnees meteorologiques de haute frequence. Le modele biologique comprend une classe de phytoplancton (le microphytoplancton) et une source de nutriments (le nitrate). La proliferation printaniere dans le SoG se produit lorsque le phytoplancton recoit assez de lumiere pour que son taux de croissance surpasse son taux de perte. La quantite de lumiere recue par le phytoplankton est fonction de la radiation solaire et de la profondeur du brassage. Le modele a servi a determiner quels facteurs physiques controlent les pertes du phytoplancton et la lumiere recue par le phytoplancton. Le vent controle le moment de l'arrive e de la proliferation printaniere; cependant, les vents forts augmentent la profondeur de la couche de melange et retardent la proliferation. La quantite d'eclairement solaire incident a un effet secondaire selon l'importance de la couverture nuageuse. L'apport d'eau douce (principalement le debit du Fraser) a un effet negligeable sur le calendrier de la proliferation. L'apport accru d'eau douce augmente le flux de flottabilite et diminue ainsi la profondeur de la couche de melange, mais augmente aussi la force de la circulation dans l'estuaire, accroissant ainsi les pertes par advection. [Traduit par la Redaction], Introduction The Strait of Georgia (SoG) is a semi-enclosed, deep sea (maximum depth 400 m) located off the coast of mainland British Columbia, Canada (Fig. 1). In the southern SoG, [...] more...