Effects Of Intertidal Position On The Response To Oxygen And Desiccation Stress In The Common Acorn Barnacle, Balanus Glandula

Sessile invertebrates in the rocky intertidal experience intermittent periods of air exposure due to tidal flux, presenting risks of temperature extremes, hypoxia, nutrient limitation, and most dangerously, desiccation. Microscale variation in severity and frequency of these risks is widely dependent on vertical position within the intertidal zone. Common acorn barnacles (Balanus glandula) have a wide vertical distribution in the intertidal, creating large differences in microhabitat between the highest and lowest individuals in the population. This study set out to explore whether tidal position dependent differences exist in the response to oxygen and desiccation stress in B. glandula. We hypothesized that B. glandula from relatively high tidal heights, which are exposed to the air for a greater duration, will be better suited to tolerate anoxic and desiccation stress than conspecifics from lower tidal heights. To explore this, we compared responses of B. glandula collected from high and low intertidal positions to A) anoxia (0 mg O2/L) and hypoxia (≤ 2 mg O2/L) on survival, behavior (closed opercular plates, cirral beating, pneumostome formation), enzyme activity (lactate dehydrogenase (LDH), superoxide dismutase (SOD)), and tissue-lactate accumulation, in addition to B) the effects of humid (98% RH) and dry (32% RH) air emersion (at 17˚C) on survival, opercular behavior (open/closed), evaporative water loss (EWL) rates, and tissue-lactate accumulation. Relative to barnacles from the low intertidal, we found that barnacles from the high intertidal survive longer during anoxia and air emersion stress, close their operculum sooner in dry air, lose more water during air exposure at any humidity level, and tend to accumulate less D-lactate. We suspect that high intertidal B. glandula can survive desiccation longer by ejecting stores of mantle cavity fluid, thereby creating a moist lung-like, air-filled internal environment, then remaining largely closed and metabolically inactive when in air to avoid drying out and becoming anoxic. These differences may reflect plasticity or selective pressure in response to environmental stress during development and highlight the potential importance of microscale stress heterogeneity in influencing species climate change tolerance and potential distribution patterns

Playing at Sevens: The Impulse Load and Movement Demands of Men’s Collegiate Rugby

Rugby sevens is a widely practiced sport that combines high-speed anaerobic activity with positional specific play and many body impacts. Despite its popularity and its intense physical demands on the body, many of these demands have not been fully explored. An investigation into the specifics of these physical demands can aid coaches and athletes in training and preparation for future matches. The purpose of this study was to quantify the Impulse Load and movement dynamics placed on American rugby players during competition. With this data, position specific information was compared to determine differences in physical demands. Fourteen male collegiate rugby sevens players were assigned a microsenor device and bioharness prior to testing. Time motion analysis data was collected using these microsenor devices. Acceleration data was used to calculate Impulse Load and GPS data was used to quantify total distance and distance in six speed zones. The devices were placed on each player, securely fastened around the chest, and worn for the duration of the warm-up and two competitive matches, for a period of 1 hour and 47 minutes. Players were monitored using 5Hz global positioning systems (GPS) and 100Hz triaxial accelerometers. Players were further analyzed and divided by playing position (forwards and backs). The contrasts in physical demands based on position can provide feedback to coaches on position-specific training.Faculty Advisor: Brandi Eveland-Sayer

Chiral and Gluon Condensates at Finite Temperature

We investigate the thermal behaviour of gluon and chiral condensates within an effective Lagrangian of pseudoscalar mesons coupled to a scalar glueball. This Lagrangian mimics the scale and chiral symmetries of QCD. (Submitted to Z. Phys. C)Comment: 20 pages + 7 figures (uuencoded compressed postscript files), University of Regensburg preprint TPR-94-1

Kohlenstoffbilanzen von renaturierten Hangmooren im Hunsrück, Rheinland-Pfalz

In Moorböden ist ein Großteil des terrestrischen Kohlenstoffs gespeichert. Drainage für land- oder forstwirtschaftliche Nutzung von Mooren führt zu einer Freisetzung von Kohlenstoff aus dem Boden in die Atmosphäre. Renaturierung von genutzten Mooren ist ein weitverbreitetes Steuerungsinstrument um die Treibhausgasemissionen von Moorböden zu reduzieren. Dieses Projekt zielt darauf ab, die Kohlenstoffbilanzen von renaturierten Hangmooren zu quantifizieren. Die sogenannten Hangbrücher im Nationalpark Hunsrück-Hochwald sind charakteristisch für die Region. Sie wurden seit dem 19. Jahrhundert mit Gräben für die forstwirtschaftliche Nutzung (Fichte) entwässert. Seit einigen Jahren werden sie im Rahmen von verschiedenen Projekten durch Grabenverschlüsse wiedervernässt. Außerdem wurde die Entnahme von standortsfremder Bestockung mittels Seilkran durchgeführt. Sechs Moore mit unterschiedlichen Degradierungsstadien wurden ausgewählt und verschiedene bodenchemische, -physikalische und -hydrologische Parameter aufgenommen. Die Ausdehnung der Moorflächen und die Kohlenstoffvorräte (Boden und Holz) werden erfasst und in ein Moorkataster überführt. Geoelektrische Sondierungen und Kartierungen werden zur Charakterisierung des oberflächennahen Untergrundes der Moorwälder und Hangmoore sowie zur Erfassung der hydrologischen Situation der Moorstandorte durchgeführt. Des Weiteren werden luftgestützte Laserscanaufnahmen für hochaufgelöste Geländemodelle und eine Abschätzung des Holzvorrates der Moore verwendet. Das Gesamtziel einer flächendeckenden Kohlenstoffbilanzierung wird erreicht, indem wir auf der Grundlage des Moorkatasters ein Upscaling der Kohlenstoffvorräte bei unterschiedlichen Renaturierungsszenarien durchführen. Das Moorkataster bietet außerdem die Möglichkeit die erhobenen Daten für ein Langzeitmonitoring der Flächen zu nutzen und dient dabei als Grundlage für weitere Untersuchungen

Modelling the QCD Phase Transition with an Effective Lagrangian of Light and Massive Hadrons

The temperature dependence of quark and gluon condensates in QCD as precursor of the chiral and deconfining phase transition is modelled with a conformally extended non-linear sigma-model including broken chiral and scale invariance. The model is further enlarged by including (free) heavier hadrons. Within this frame we then study the interplay of QCD scale breaking effects and heavier hadrons in chiral symmetry restoration.Comment: 23 pages, LaTeX, 5 figures, uses epsfig.st

Early anthropogenic transformation of the Danube-Black Sea system

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 2 (2012): 582, doi:10.1038/srep00582.Over the last century humans have altered the export of fluvial materials leading to significant changes in morphology, chemistry, and biology of the coastal ocean. Here we present sedimentary, paleoenvironmental and paleogenetic evidence to show that the Black Sea, a nearly enclosed marine basin, was affected by land use long before the changes of the Industrial Era. Although watershed hydroclimate was spatially and temporally variable over the last ~3000 years, surface salinity dropped systematically in the Black Sea. Sediment loads delivered by Danube River, the main tributary of the Black Sea, significantly increased as land use intensified in the last two millennia, which led to a rapid expansion of its delta. Lastly, proliferation of diatoms and dinoflagellates over the last five to six centuries, when intensive deforestation occurred in Eastern Europe, points to an anthropogenic pulse of river-borne nutrients that radically transformed the food web structure in the Black Sea.This study was supported by grants OISE 0637108, EAR 0952146, OCE 0602423 and OCE 0825020 from the National Science Foundation and grants from the Woods Hole Oceanographic Institution

The Vital Role of Social Workers in Community Partnerships: The Alliance for Gay, Lesbian, Bisexual, Transgender and Questioning Youth

The account of The Alliance for Gay, Lesbian, Bisexual, Transgender, and Questioning (GLBTQ) Youth formation offers a model for developing com- munity-based partnerships. Based in a major urban area, this university-community collaboration was spearheaded by social workers who were responsible for its original conceptualization, for generating community support, and for eventual staffing, administration, direct service provision, and program evaluation design. This article presents the strategic development and evolution of this community- based service partnership, highlighting the roles of schools of social work, academics, and social work students in concert with community funders, practitioners and youth, in responding to the needs of a vulnerable population