Geology of the athabasca oil sands

In-place bitumen resources in the Alberta oil sands are estimated at 1350 billion barrels. Open-pit mining and hot water extraction methods, which involve the handling of huge tonnages of earth materials, are being employed in the two commercial plants now operating. In situ recovery methods will be required to tap the 90 percent of reserves that are too deeply buried to be surface mined. Development of in situ technologies will be painstaking and expensive, and success will hinge on their compatibility with extremely complex geological conditions in the subsurface.     

Connectivity and habitat type shape divergent dispersal behavior in a desert-dwelling fish

Context

Dispersal has important fitness consequences for individuals, populations, and species. Despite growing theoretical insights into the evolution of dispersal, its behavioral underpinnings remain empirically understudied, limiting our understanding of the extent and impact of responses to landscape-level heterogeneity of environments, and increasing the risk of inferring species-level responses from biased population sampling.

Objectives

We asked if predictable ecological variation among naturally fragmented arid waterbodies is correlated with disparate dispersal responses of populations of the desert goby Chlamydogobius eremius, which naturally inhabits two habitat “types” (permanent springs, ephemeral rivers), and different levels of hydrological connectivity (high and low) that potentially convey different costs and benefits of dispersal.

Methods

To test for possible behavioral divergence between such populations, we experimentally compared the movement behaviors (correlates of emigration and exploration) of wild-caught fish. We used two biologically relevant spatial scales to test movement relevant to different stages of the dispersal process.

Results

Behavior differed at both spatial scales, suggesting that alternative dispersal strategies enable desert gobies to exploit diverse habitat patches. However, while emigration was best predicted by the connectivity (flood risk) of fish habitats, exploration was linked to their habitat type (spring versus river).

Conclusions

Our findings demonstrate that despite a complex picture of ecological variation, key landscape factors have an overarching effect on among-population variation in dispersal traits. Implications include the maintenance of within-species variation, potentially divergent evolutionary trajectories of naturally or anthropogenically isolated populations, and the direction of future experimental studies on the ecology and evolution of dispersal behavior.

     

Turbine entrainment and passage of potadromous fish through hydropower dams: Developing conceptual frameworks and metrics for moving beyond turbine passage mortality

Potadromous fishes are vulnerable to involuntary entrainment through hydropower turbines. However, turbines can also provide a downstream passage route for potadromous fish. Here, we review evidence for turbine entrainment and passage in potadromous fish, and evaluate the effects of these processes on upstream and downstream populations. We develop conceptual frameworks and metrics to quantify vulnerability to turbine entrainment removals, and to quantify the efficiency of turbines as a downstream passage route. We highlight factors that influence these processes and provide case‐studies demonstrating their applicability. We found that juvenile potadromous fish are being entrained through turbines at rates high enough to impact upstream populations. Given that juvenile passage survival is often high, we argue that turbines provide an important downstream passage route for potadromous fish. We show that entrainment vulnerability is likely a function of interactions between in‐reservoir fish behaviour, habitat configuration and operations and thus not well captured by passage mortality estimates. Similarly, we show that while passage mortality can limit downstream passage efficiency, passage success is also dependent on reservoir and forebay navigation, along with survival and fitness in the downstream river. We advocate for a shift in focus away from estimates of passage mortality and injury, which have previously accounted for the majority of turbine passage research. Instead, we recommend an approach that focusses on quantification of the factors that influence downstream passage efficiency and entrainment vulnerability. Moreover, we highlight the need to better understand the broader scale impacts of these events on upstream and downstream populations.     

Is it time to define veterinary professionalism?

The medical profession has spent much time and many resources engaging in a discourse of medical professionalism and debating the appropriate attitudes and behavior of physicians, but little has been published concerning the concept of veterinary professionalism. Physicians are commonly examined by social scientists and educationalists to establish definitions of medical professionalism in order to teach and assess these values within curricula. This challenging process has not been without criticism, however, with some calling the numerous definitions unhelpful, especially when these behaviors are not demonstrated in practice or the wider sociological implications of medical professionalism are ignored. Veterinary curricula often include professional skills, and there has been some discussion about their inclusion as well as the scope of veterinary surgeons and their role in society. Despite this, no true definition of veterinary professionalism exists, and the teaching of the values and behaviors expected of veterinary professionals may not be explicit. Regardless of the difficulties of engaging in such a discourse, perhaps it is time that this occurred and a realistic and usable definition of veterinary professionalism is established. This is a period of change for the veterinary profession, and a teachable and assessable definition can provide some clarity and assist educators within ever evolving veterinary curricula.     

Ice crystal concentration in cumulus clouds: influence of the drop spectrum

Secondary ice crystals are thrown off when supercooled cloud drops are captured and freeze on a moving target in a cloud at -5 degrees C. The rate of production of these ice crystals is proportional to the rate of accretion of drops of the diameter >/=24 micrometers.     

Trace fossils from the athabasca oil sands, alberta, Canada

A diverse and well-preserved ichnofossil suite has been identified from surface exposures of the middle and upper parts of the Lower Cretaceous McMurray Formation. The suite, consisting of representatives of at least ten ichnogenera, is one of the few clues to the original biotic component of the deposit. The distribution and abundance of these biogenic structures present strong evidence that the deep channel complex in which the sediments were deposited was closely associated with a nearby marine shoreline.     

Enhancing clinical learning in the workplace: a qualitative study

Workplace learning (WPL) is seen as an essential component of clinical veterinary education by the veterinary profession. This study sought to understand this type of learning experience more deeply. This was done utilising observations of students on intramural rotations (IMR) and interviews with students and clinical staff. WPL was seen as an opportunity for students to apply knowledge and develop clinical and professional skills in what is generally regarded as a safe, authentic environment. Clinical staff had clear ideas of what they expected from students in terms of interest, engagement, professionalism, and active participation, where this was appropriate. In contrast, students often did not know what to expect and sometimes felt under-prepared when entering the workplace, particularly in a new species area. With the support of staff acting as mentors, students learned to identify gaps in their knowledge and skills, which could then be addressed during specific IMR work placements. Findings such as these illustrate both the complexities of WPL and the diversity of different workplace settings encountered by the students.