The Autobot-WQ: A portable, low-cost autosampler to provide new insight into urban spatio-temporal water quality dynamics

Urbanization and the increase in urban land cover are growing concerns associated with numerous negative impacts on surface water quality. Currently, many emerging contaminants are difficult to measure with no field deployable sensors currently available. Hence, discrete grab samples are required for subsequent laboratory analysis. To capture the spatiotemporal variability in pollution pulses, autosamplers can be used, but commercial offerings are both expensive and have a large footprint. This can be problematic in urban environments where there is a high density of point source inputs and risk of vandalism or theft. Here, we present a small and robust low-cost autosampler that is ideally suited for deployment in urban environments. The design is based on “off the shelf” open-source hardware components and software and requires no prior engineering, electronics, or computer programming experience to build. The autosampler uses a small peristaltic pump to enable collection of 14 small volume samples (50 mL) and is housed in a small footprint camera case. To illustrate the technology, we present two use cases for rapid sampling of stormwater pulses of: 1) an urban river channel and 2) green roof runoff. When compared with a commercial autosampler, our device showed comparable results and enabled us to capture temporal dynamics in key water quality parameters (e.g., dissolved organic matter) following rain events in an urban stream. Water quality differences associated with differing green roof design/maintenance regimes (managed and unmanaged vegetation) were captured using the autosampler, highlighting how unmanaged vegetation has a greater potential for mitigating the rapid runoff and peaked pollutant inputs associated with impervious surfaces. These two case studies show that our portable autosampler provides capacity to improve understanding of the impact of urban design and infrastructure on water quality and can lead to the development of more effective mitigation solutions. Finally, we discuss opportunities for further technical refinement of our autosampler and applications to improve environmental monitoring. We propose a holistic monitoring approach to address some of the outstanding challenges in urban areas and enable monitoring to shift from discrete point sources towards characterization of catchment or network scale dynamics

The Importance of Including Water Temperature Simulations in a 2D Fish Habitat Model for the St. Lawrence River

Extreme climatic conditions likely caused a massive fish mortality during the summer of 2001 in the St. Lawrence River. To corroborate this hypothesis, we used a physical habitat simulation approach incorporating hydraulic and water temperature models. Spawning Habitat Suitability Indices (HSI) for common carp (Cyprinus carpio) were developed using fuzzy logic and applied to the model outputs to estimate habitat weighted usable area during the event. The results revealed that areas suitable for common carp spawning (HSI > 0.3) were severely reduced by high water temperatures, which exceeded 28 °C during the mortality event. During the mortality event, the amount of suitable habitat was reduced to ≤200 ha/day, representing less than 15% of the maximum potential suitable habitat in the study reach. In addition, the availability of cooler habitats that could have been used as thermal refuges was also reduced. These results indicate that the high water temperature in spawning areas and reduced accessibility to thermal refuge habitats exposed the carp to substantial physiological and environmental stress. The high water temperatures were highly detrimental to the fish and eventually led to the observed mortalities. This study demonstrates the importance of including water temperature in habitat suitability models

Advancing river corridor science beyond disciplinary boundaries with an inductive approach to catalyze hypothesis generation

A unified conceptual framework for river corridors requires synthesis of diverse site-, method- and discipline-specific findings. The river research community has developed a substantial body of observations and process-specific interpretations, but we are still lacking a comprehensive model to distill this knowledge into fundamental transferable concepts. We confront the challenge of how a discipline classically organized around the deductive model of systematically collecting of site-, scale-, and mechanism-specific observations begins the process of synthesis. Machine learning is particularly well-suited to inductive generation of hypotheses. In this study, we prototype an inductive approach to holistic synthesis of river corridor observations, using support vector machine regression to identify potential couplings or feedbacks that would not necessarily arise from classical approaches. This approach generated 672 relationships linking a suite of 157 variables each measured at 62 locations in a 5th order river network. Eighty four percent of these relationships have not been previously investigated, and representing potential (hypothetical) process connections. We document relationships consistent with current understanding including hydrologic exchange processes, microbial ecology, and the River Continuum Concept, supporting that the approach can identify meaningful relationships in the data. Moreover, we highlight examples of two novel research questions that stem from interpretation of inductively-generated relationships. This study demonstrates the implementation of machine learning to sieve complex data sets and identify a small set of candidate relationships that warrant further study, including data types not commonly measured together. This structured approach complements traditional modes of inquiry, which are often limited by disciplinary perspectives and favor the careful pursuit of parsimony. Finally, we emphasize that this approach should be viewed as a complement to, rather than in place of, more traditional, deductive approaches to scientific discovery

Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR Cascade Inhibitors: How Mutations Can Result in Therapy Resistance and How to Overcome Resistance

The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Integral components of these pathways, Ras, B-Raf, PI3K, and PTEN are also activated/inactivated by mutations. These pathways have profound effects on proliferative, apoptotic and differentiation pathways. Dysregulation of these pathways can contribute to chemotherapeutic drug resistance, proliferation of cancer initiating cells (CICs) and premature aging. This review will evaluate more recently described potential uses of MEK, PI3K, Akt and mTOR inhibitors in the proliferation of malignant cells, suppression of CICs, cellular senescence and prevention of aging. Ras/Raf/MEK/ERK and Ras/PI3K/PTEN/Akt/mTOR pathways play key roles in the regulation of normal and malignant cell growth. Inhibitors targeting these pathways have many potential uses from suppression of cancer, proliferative diseases as well as aging

Brook and Brown Trout Thermal Habitat Use During the Summer

We measured the thermal regimes of key trout (Salvelinus fontinalis and Salmo trutta) habitats during summer 2016 (from June to August) in three different tributaries of Loyalsock Creek: Little Bear Creek, Dry Run and Ogdonia Creek. Within each stream, five eaches were selected for electrofishing surveys conducted in mi-June and end of August to evaluate: 1) the number of fish by age class and 2) their use of the thermal habitat. The habitat position of each fish sampled was noted during each survey. The results howed that Little Bear Creek is significantly colder than Ogdonia Creek and Dry Run (p \u3c 1.78E-06). Ogdonia Creek presents the warmest temperature regime of the three studied streams (p= 0.00296), with maximum daily values up to 22.03 and 24.90oC from upstream to downstream; reaching the critical thermal tolerance value for brook trout. Brook trout juvenile abundance is statistically different across the three streams (p \u3c 0.003), with Dry Run having the highest abundance. At the beginning of the summer, there were less adult and juvenile brook trout in Ogdonia Creek. While in August, Ogdonia had the higher brook trout juvenile abundance, especially in the upper stream sites (p \u3c 0.05). Brown trout abundances were different for Little Bear and Dry Run at the beginning of the summer (p \u3c 0.05), with Little Bear Creek having the lower values. By August, only Ogdonia Creek showed a higher abundance of young of the year brown trout. Young of the year brown trout almost always occupy the top part of the riffles when both species are present and show higher weight values then brook trout. By August, more young of the year brook trout are observed at the edges of cooler pools, leaving the warmer riffles. From the position recorded and the abundances per sites at the beginning and the end of the summer, the brook trout seem to display more movements toward the cooler pool and upstream reaches. Those results are important to understand the dynamics between both species. Brook trout seem to move toward the cooler upstream reaches throughout the summer, which are known to have less aquatic macroinvertebrate abundance. This adds to the extra energetic expenditures from moving upstream, therefore potentially affecting the growth of brook trout compared to brown trout, which seem to be able to exploit the same thermal habitat throughout the summer

Advancing ecohydraulics and ecohydrology by clarifying the role of their component interdisciplines

Increasing awareness of the complexity of river ecosystems has led to the emergence of integrative disciplines that combine topics in river physical and ecological processes, exemplified by the disciplines of ecohydrology, hydroecology and ecohydraulics. However, the names of these disciplines are often referred to interchangeably without attention paid to their meaning. This ambiguity impairs the efficient development and widespread promotion of these fields of study and their applications. To address this issue, we strive to clarify the definitions and contributions of the different disciplines. This is done by exploring their interrelationships and providing a reference for the integration of disciplines in these evolving fields. Finally, we advocate for ecohydrology and ecohydraulics to be considered complementary, and not duplicative, disciplines within river science. We further argue that awareness of their similarities and differences is important to address key issues in river science and to ensure ecohydraulics finds its positioning with respect to other disciplines, as well as current and emerging societal and scientific challenges, such as climate change.Advancing ecohydraulics and ecohydrology by clarifying the role of their component interdisciplinesacceptedVersio

Riparian Land Cover, Water Temperature Variability, and Thermal Stress for Aquatic Species in Urban Streams

Thermal regime warming and increased variability can result in human developed watersheds due to runoff over impervious surfaces and influence of stormwater pipes. This study quantified relationships between tree canopy, impervious surface, and water temperature in stream sites with 4 to 62% impervious land cover in their “loggersheds” to predict water temperature metrics relevant to aquatic species thermal stress thresholds. This study identified significant (≥0.7, p < 0.05) negative correlations between water temperature and percent tree canopy in the 5 m riparian area and positive correlations between water temperature and total length of stormwater pipe in the loggershed. Mixed-effects models predicted that tree canopy cover in the 5 m riparian area would reduce water temperatures 0.01 to 6 °C and total length of stormwater pipes in the loggershed would increase water temperatures 0.01 to 2.6 °C. To our knowledge, this is the first time that the relationship between stormwater pipes and water temperature metrics has been explored to better understand thermal dynamics in urban watersheds. The results highlight important aspects of thermal habitat quality and water temperature variability for aquatic species living in urban streams based on thermal thresholds relevant to species metabolism, growth, and life history

Advancing ecohydraulics and ecohydrology by clarifying the role of their component interdisciplines

Increasing awareness of the complexity of river ecosystems has led to the emergence of integrative disciplines that combine topics in river physical and ecological processes, exemplified by the disciplines of ecohydrology, hydroecology and ecohydraulics. However, the names of these disciplines are often referred to interchangeably without attention paid to their meaning. This ambiguity impairs the efficient development and widespread promotion of these fields of study and their applications. To address this issue, we strive to clarify the definitions and contributions of the different disciplines. This is done by exploring their interrelationships and providing a reference for the integration of disciplines in these evolving fields. Finally, we advocate for ecohydrology and ecohydraulics to be considered complementary, and not duplicative, disciplines within river science. We further argue that awareness of their similarities and differences is important to address key issues in river science and to ensure ecohydraulics finds its positioning with respect to other disciplines, as well as current and emerging societal and scientific challenges, such as climate change