THE EFFECTIVENESS OF TROUT HABITAT RESTORATION IN EUSTACHE CREEK, A FORMERLY PLACER-MINED STREAM IN WESTERN MONTANA

Thompson, Emily, Master of Science, July 2010 Environmental Studies The Effectiveness of Trout Habitat Restoration in Eustache Creek, a Formerly Placer-Mined Stream in Western Montana Committee Chair: Dr. Daniel Spencer Aquatic ecosystems in the western U.S. have been severely degraded over the last century by anthropogenic activities such as mining, logging and grazing. Habitat heterogeneity in streams of the western United States has been lost as a result of both in-stream activities (i.e. dredging and straightening channels) and riparian zone activities (i.e. logging and vegetation removal). A commonly stated objective of stream channel restoration projects is to restore stream habitat quality and thereby improve aquatic species habitat and ultimately increase fish populations. The Ninemile drainage of the Clark Fork River watershed was historically a thriving native Bull trout and Westslope cutthroat trout (WCT) fishery. Intensive mining and logging activities throughout the watershed have severely impaired native fish habitat and reduced fish populations. In 2006, Lolo National Forest partnered with Trout Unlimited to restore a 1.3-mile section of Eustache Creek at the headwaters of the Ninemile drainage. This study used pre- and post-restoration habitat and fish sampling data from 2005-2009 to analyze changes in habitat quality and fish abundance in three reaches of Eustache Creek. Habitat quality was assessed using six metrics: width to depth ratio, percent of pool habitat (based on site area), residual pool depth, large woody debris per 100 meters, large woody debris median diameter and percent fine sediment in pool tails. A repeated measures ANOVA model was used to detect significant increases in habitat quality and fish populations over the four-year period in Eustache Creek. A univariate ANOVA model was created to detect significant relationships between individual habitat quality variables and fish populations. Overall, statistical analysis does not necessarily point to a significant increase in habitat quality for Eustache Creek, and the restored stream condition is still far from its reference condition. However, a non-statistical assessment of trends in individual habitat metrics shows an improvement in trout habitat quality. There was a significant increase in total fish densities in Eustache Creek over the study period. Additionally, there was a significant increase in total WCT, Adult WCT, and Adult Eastern Brook trout (EBT) densities over time. However, there was no statistically significant difference in total fish density, total WCT density, adult WCT density, total EBT density and adult EBT density between reference and treatment reaches, indicating that the increased fish populations may reflect the influence of external factors such as climatic variability rather than the improvement in habitat quality. No habitat variables are significantly correlated to total fish density. There was a statistically weak positive correlation between percent pool habitat and total fish density. While Eustache Creek appears to be trending toward improved fish habitat, the high variability of the habitat and fish data within certain reaches, including the reference reach, from year to year suggest that the stream is a seasonally and environmentally dynamic system to which fish populations are quite sensitive, and that recovery will be a long term process. Fish density in this watershed could be influenced by other factors of habitat quality such as food, stream temperature and seasonal and environmental variation. Best measures of habitat quality in this study were percent pool habitat, LWD frequency and LWD median diameter. Recommendations for future monitoring include: 1) continue monitoring for the next 15-20 years, 2) collect more pre-project data, 3) increase the number of sampling sites, 4) maintain consistency in sampling dates, number of netters and number of ele

A-Polynomials of fillings of the Whitehead sister

Knots obtained by Dehn filling the Whitehead sister link include some of the smallest volume twisted torus knots. Here, using results on A-polynomials of Dehn fillings, we give formulas to compute the A-polynomials of these knots. Our methods also apply to more general Dehn fillings of the Whitehead sister link complement.Comment: 15 pages, 11 figure

Remodeling of an in vitro microvessel exposed to cyclic mechanical stretch.

In the lung, vascular endothelial cells experience cyclic mechanical strain resulting from rhythmic breathing motions and intraluminal blood pressure. Mechanical stress creates evident physiological, morphological, biochemical, and gene expression changes in vascular endothelial cells. However, the exact mechanisms of the mechanical signal transduction into biological response remain to be clarified. Besides, the level of mechanical stress is difficult to determine due to the complexity of the local distension patterns in the lung and thus assumed to be the same as the one acting on the alveolar epithelium. Existing in vitro models used to investigate the effect of mechanical stretch on endothelial cells are usually limited to two-dimensional (2D) cell culture platforms, which poorly mimic the typical three-dimensional structure of the vessels. Therefore, the development of an advanced in vitro vasculature model that closely mimics the dynamic of the human lung vasculatures is highly needed. Here, we present the first study that investigates the interplay of the three-dimensional (3D) mechanical cyclic stretch and its magnitude with vascular endothelial growth factor (VEGF) stimulation on a 3D perfusable vasculature in vitro. We studied the effects of the cyclic strain on a perfusable 3D vasculature, either made of human lung microvascular endothelial cells or human umbilical vein endothelial cells embedded in a gel layer. The in vitro 3D vessels underwent both in-vivo-like longitudinal and circumferential deformations, simultaneously. Our results showed that the responses of the human lung microvascular endothelial cells and human umbilical vein endothelial cells to cyclic stretch were in good agreement. Although our 3D model was in agreement with 2D model in predicting a cytoskeletal remodeling in response to different magnitudes of cyclic stretch, however we observed several phenomena in 3D model that 2D model was unable to predict to. Angiogenic sprouting induced by VEGF decreased significantly in presence of cyclic stretch. Similarly, while treatment with VEGF increased vascular permeability, the cyclic stretch restored vascular barrier tightness and significantly decreased vascular permeability. One of the major findings of this study was that a 3D microvasculature can be exposed to a much higher mechanical cyclic stress level than reported in the literature without any dysfunction of its barrier. For higher magnitudes of the cyclic stretch, the applied longitudinal strain level was 14% and the associated circumferential strain reached the equivalent of 63%. In sharp contrast with our findings, such strain typically leads to the disruption of the endothelial barrier in a 2D stretching assay and is considered pathological. This highlights the importance of 3D modeling to investigate mechanobiology effects rather than using a simple endothelial monolayer which truly recapitulates the in vivo situation

New times, new politics: history and memory during the final years of the CPGB

This article examines the relationship between collective memory, historical interpretation and political identity. It focuses on the dissolution of the Communist Party of Great Britain (CPGB) as constructed through collective narrative memory, and on Marxist interpretations of history. The divisions within the party and the wider Marxist community, stretching from 1956 until 1991, were often framed around questions of historical interpretation. The events of 1989–1991 created an historical and mnemonic crisis for CPGB members who struggled to reconcile their past identities with their present situation. Unlike the outward-facing revisionism of other political parties, this was an intensely personal affair. The solution for many was to emphasise the need to find new ways to progress socialist aims, without relying on a discredited grand narrative. In contrast, other Communist parties, such as the Communist Party of Britain, which had been established (or ‘re-established’) in 1988, fared rather better. By adhering to the international party line of renewal and continued struggle, the party was able to hold its narrative together, condemning the excesses of totalitarian regimes, while reaffirming the need for international class struggle

Microstructure, Elastic and Inelastic Properties of Partially Graphitized Biomorphic Carbons

The microstructural characteristics and amplitude dependences of the Young’s modulus E and internal friction (logarithmic decrement δ) of biocarbon matrices prepared by beech wood carbonization at temperatures Tcarb = 850–1600°C in the presence of a nickelcontaining catalyst have been studied. Using Xray diffraction and electron microscopy, it has been shown that the use of a nickel catalyst during carbon ization results in a partial graphitization of biocarbons at Tcarb ≥ 1000°C: the graphite phase is formed as 50 to 100nm globules at Tcarb = 1000°C and as 0.5 to 3.0μm globules at Tcarb = 1600°C. It has been found that the measured dependences E(Tcarb) and δ(Tcarb) contain three characteristic ranges of variations in the Young’s modulus and logarithmic decrement with a change in the carbonization temperature: E increases and δ decreases in the ranges Tcarb 1300°C; in the range 1000 < Tcarb < 1300°C, E sharply decreases and δ increases. The observed behavior of E(Tcarb) and δ(Tcarb) for biocarbons carbonized in the presence of nickel correlates with the evolution of their microstructure. The largest values of E are obtained for samples with Tcarb = 1000 and 1600°C. However, the samples with Tcarb = 1600°C exhibit a higher suscep tibility to microplasticity due to the presence of a globular graphite phase that is significantly larger in size and total volume.Peer reviewe

The feasibility of brief dog assisted therapy on university students stress levels: The PAwS study.

Background: Pet therapy is becoming increasingly popular and is used in a variety of ways from encouraging communication in older adults to improving wellbeing in those with serious mental illness. Increasingly Universities have been offering pet therapy to students in an effort to reduce stress. However, little evidence currently exists to support the effectiveness of reducing measurable stress levels after a standalone drop-in unstructured session. The University of Sheffield’s Counselling Service works in partnership with Guide Dogs for the Blind to give students access to calm, well-trained animals for informal group stress relief. Aims: To assess the feasibility of implementing and evaluating unstructured group interventions with a Guide Dog in training within the university student population. Methods: One hundred and thirty-one students who attended pet therapy at the University Counselling Service were recruited on a voluntary basis to take part in the research. Stress, measured on the state trait anxiety inventory, and blood pressure were taken before and after a 15-min intervention. Results: All measures showed a statistically significant reduction immediately after the intervention. Conclusion: Short interactions with a Guide Dog in training appear to reduce stress in University students. A controlled study is required to investigate further

The Texas Community-Engagement Research Alliance Against COVID-19 in Disproportionately Affected Communities (TX CEAL) Consortium

The coronavirus disease 2019 (COVID-19) pandemic requires urgent implementation of effective community-engaged strategies to enhance education, awareness, and inclusion of underserved communities in prevention, mitigation, and treatment efforts. The Texas Community-Engagement Alliance Consortium was established with support from the United States’ National Institutes of Health (NIH) to conduct community-engaged projects in selected geographic locations with a high proportion of medically underserved minority groups with a disproportionate burden of COVID-19 disease and hospitalizations. The purpose of this paper is to describe the development of the Consortium. The Consortium organized seven projects with focused activities to address COVID-19 clinical and vaccine trials in highly affected counties, as well as critical statewide efforts. Five Texas counties (Bexar, Dallas, Harris, Hidalgo, and Tarrant) were chosen by NIH because of high concentrations of underserved minority communities, existing community infrastructure, ongoing efforts against COVID-19, and disproportionate burden of COVID-19. Policies and practices can contribute to disparities in COVID-19 risk, morbidity, and mortality. Community engagement is an essential element for effective public health strategies in medically underserved minority areas. Working with partners, the Consortium will use community engagement strategies to address COVID-19 disparities