Publications by authors named "Leonie-Sophia Poesch"

Aquatic habitat in the Greater Toronto Area has been subject to anthropogenic stressors. The subsequent aquatic habitat degradation that followed led to the Toronto and Region waterfront being listed as an Area of Concern in 1987. Thus, extensive shoreline and riparian habitat restoration have been implemented as part of the Toronto and Region Remedial Action Plan in conjunction with local stakeholders, ministries, and NGOs in an overall effort to increase fish, bird, and wildlife habitat.

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Biodiversity and mitigation banking has become a popular alternative offsetting mechanism, especially for freshwater species and systems. Central to this increase in popularity is the need for sound control mechanisms to ensure offset functionality. Two commonly used mechanisms are monitoring requirements and staggered release of bank credits over time.

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Mitigation banking is part of the ever-expanding global environmental market framework that aims to balance negative approved anthropogenic impacts versus third-party provided ecosystem benefits, sold in the form of credits. Given the need to conserve freshwater biodiversity and habitat, banking has received great traction for freshwater species and systems. While extensive reviews and studies have been conducted on evaluating if equivalency between impacts and offset can be achieved, there is almost no research being done on the way credits are being generated and banks are managed to inform future best practice and policy.

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Offsetting aims to compensate for negative impacts due to authorized anthropogenic impacts associated with development. While anchored into legislation, residual or chronic impacts can occur after offset establishment. Advice and best practice on how to approach these impacts is rare.

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The field of stable isotope ecology is moving away from lethal sampling (internal organs and muscle) towards non-lethal sampling (fins, scales and epidermal mucus). Lethally and non-lethally sampled tissues often differ in their stable isotope ratios due to differences in metabolic turnover rate and isotopic routing. If not accounted for when using non-lethal tissues, these differences may result in inaccurate estimates of resource use and trophic position derived from stable isotopes.

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There has been much written about the negative social and environmental impacts of large hydropower dams, particularly the impacts on people and the environment caused by flooding linked to the creation of large reservoirs. There has also long been recognition of the importance of Indigenous and local knowledge for understanding ecological processes and environmental impacts. In this paper, however, we focus on a topic that has received insufficient consideration: the downstream impacts of dams, and the role of Indigenous and local knowledge in assessing and addressing these impacts.

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Trace elements can accumulate in aquatic food webs, becoming potentially hazardous to wildlife and human health. Whereas many studies have examined mercury dynamics in freshwater environments, evidence for the bioaccumulative potential of other trace elements (e.g.

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Bioaccumulation of mercury in freshwater fish is a complex process driven by environmental and biological factors. In this study, we assessed mercury in fish from four tributaries to the Red Deer River, Alberta, Canada, which are characterized by high surface water mercury concentrations. We used carbon (δC) and nitrogen (δN) stable isotopes to examine relationships between fish total mercury (THg) concentrations, food web dynamics and patterns in unfiltered THg and methylmercury (MeHg) concentrations.

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Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare.

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The Lower Athabasca Region (LAR) is home to the largest bitumen deposit in Alberta, and has seen industrial development related to the extraction and processing of bituminous sands since the late 1960s. Along with industrial and economic growth related to oil sands development, environmental concerns have increased in recent decades, including those about potential effects on fish. We measured major and trace element concentrations in Trout-perch otoliths from the Athabasca and Clearwater Rivers in the LAR, to illustrate spatial variations and identify possible industrial impacts.

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It has been suggested that open pit mining and upgrading of bitumen in northern Alberta releases Tl and other potentially toxic elements to the Athabasca River and its watershed. We examined Tl and other trace elements in otoliths of Trout-perch (Percopsis omiscomaycus), a non-migratory fish species, collected along the Athabasca River. Otoliths were analyzed using ICP-QMS, following acid digestion, in the metal-free, ultraclean SWAMP laboratory.

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Selenium in the lower Athabasca River (Alberta, Canada) is of concern due to potential inputs from the weathering of shallow bitumen deposits and emissions from nearby surface mines and upgraders. Understanding the source of this Se, however, is complicated by contributions from naturally saline groundwater and organic matter-rich tributaries. As part of a two-year multi-disciplinary study to assess natural and anthropogenic inputs, Se and its chemical speciation were determined in water samples collected along a ∼125 km transect of the Athabasca River and associated tributaries.

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Objectives: Reference ranges of left ventricular (LV) parameters from cardiac magnetic resonance (CMR) were established to investigate the impact of ageing and hypertension as important determinants of cardiac structure and function.

Methods: One thousand five hundred twenty-five contrast-enhanced CMRs were conducted in the Study of Health in Pomerania. LV end-diastolic volume (LVEDV), end-systolic volume (LVESV), stroke volume (LVSV), ejection fraction (LVEF), and myocardial mass (LVMM) were determined using long- and short-axis steady-state free-precession sequences.

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Prussian carp () are one of the most noxious non-native species in Eurasia. Recently, Prussian carp, a non-native freshwater fish species, were genetically confirmed in Alberta, Canada and have been rapidly expanding their range in North America since establishment. Given their rapid range expansion, there is an increasing need to determine how Prussian carp may impact native species.

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Heart failure (HF) development is characterized by huge structural changes that are crucial for disease progression. Analysis of time dependent global proteomic adaptations during HF progression offers the potential to gain deeper insights in the disease development and identify new biomarker candidates. Therefore, hearts of TAC (transverse aortic constriction) and sham mice were examined by cardiac MRI on either day 4, 14, 21, 28, 42, and 56 after surgery (n = 6 per group/time point).

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With growth of the Canadian oil sands industry, concerns have been raised about possible seepage of toxic oil sands process-affected water (OSPW) into the Athabasca River (AR). A sampling campaign in fall 2015 was undertaken to monitor for anthropogenic seepage while also considering natural sources. Naphthenic acids (NAs) and thousands of bitumen-derived organics were characterized in surface water, groundwater, and OSPW using a highly sensitive online solid phase extraction-HPLC-Orbitrap method.

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Hydrologic alterations, such as dams, culverts or diversions, can introduce new selection pressures on freshwater fishes, where they are required to adapt to novel environmental conditions. Our study investigated how species adapt to natural and altered stream flow, where we use the threatened Rocky Mountain Sculpin ( sp.) as a model organism.

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Climate change is affecting many freshwater species, particularly fishes. Predictions of future climate change suggest large and deleterious effects on species with narrow dispersal abilities due to limited hydrological connectivity. In turn, this creates the potential for population isolation in thermally unsuitable habitats, leading to physiological stress, species declines or possible extirpation.

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Background: Access to highly specialized health care services and support to meet the patient's specific needs is critical for health outcome, especially during age-related transitions within the health care system such as with adolescents entering adult medicine. Being affected by an orphan disease complicates the situation in several important respects. Long distances to dedicated institutions and scarcity of knowledge, even among medical doctors, may present major obstacles for proper access to health care services and health chances.

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Confocal microscopy is widely used to measure the surface topography of specimen with a precision in the micrometer range. The measurement uncertainty and quality of the acquired data of confocal microscopy depends on various effects, such as optical aberrations, vibrations of the measurement setup and variations in the surface reflectivity. In this article, the influence of steep edges and undercuts on measurement results is examined.

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In this paper, a strategy for the calibration and the measurement process of a multi-sensor fringe projection unit is presented. The objective is the development of an easy to use calibration and measurement procedure. Only one simple geometrical calibration target is needed and the calibration of the projection unit is not mandatory.

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Laser triangulation is widely used to measure three-dimensional structure of surfaces. The technique is suitable for macroscopic and microscopic surface measurements. In this paper, the measurement uncertainty of laser triangulation is investigated on technical surfaces for microscopic measurement applications.

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The clinical efficiency of the highly potent antitumor agent doxorubicin is limited by cardiotoxic effects. In a murine doxorubicin cardiotoxicity model, increased endothelin-1 (ET-1) expression and cardioprotective effects of the dual ET-1 blocker bosentan were demonstrated. To date it is unclear if combined blocking of endothelin A/B receptors is necessary or whether selective inhibition of one of the ET-1 receptors is sufficient for the observed cardioprotection.

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