The Characteristics and Potential Ecological Effects of the Exotic Crustacean Zooplankter Cercopagis Pengoi (Cladocera: Ceropagidae), a Recent Invader of Lake Erie

Author Institution: Department of Evolution, Ecology, and Organismal Biology, The Ohio State UniversityThe invasive zooplankter Cercopagis pengoi was recorded for the first time in Lake Erie during August 2001 following previous colonization of Lakes Ontario and Michigan. Cercopagis pengoi (Cladocera: Cercopagidae) is from the Ponto-Caspian region of Eurasia, as is a previous cercopagid invader, Bythotrephes longimanus. Cercopagis tolerates a wide range of salinities and temperatures, has many life history traits characteristic of a successful invader, and has previously invaded the Baltic Sea Cercopagis may affect native zooplankton populations and fish populations through both predation and competition, although the extent of these interactions is not yet known. More research regarding basic life history traits and ecology of Cercopagis is needed to assess the role it will play in Lake Erie

Transient social-ecological stability: The effects of invasive species and ecosystem restoration on nutrient management compromise in lake erie

Together, lake ecosystems and local human activity form complex social-ecological systems (SESs) characterized by feedback loops and discontinuous change. Researchers in diverse fields have suggested that complex systems do not have single stable equilibria in the long term because of inevitable perturbation. During this study, we sought to address the general question of whether or not stable social-ecological equilibria exist in highly stressed and managed lacustrine systems. Using an integrated human-biophysical model, we investigated the impacts of a species invasion and ecosystem restoration on SES equilibrium, defined here as a compromise in phosphorus management among opposing stakeholders, in western Lake Erie. Our integrated model is composed of a calibrated ecological submodel representing Sandusky Bay, and a phosphorus management submodel that reflects the societal benefits and costs of phosphorus regulation. These two submodels together form a dynamic feedback loop that includes freshwater ecology, ecosystem services, and phosphorus management. We found that the invasion of dreissenid mussels decreased ecosystem resistance to eutrophication, necessitating increased phosphorus management to preserve ecosystem services and thus creating the potential for a shift in social-ecological equilibrium. Additionally, our results suggest that net benefits in the region following the invasion of dreissenids may never again reach the pre-invasion level if on-site phosphorus control is the sole management lever. Further demonstrating transient system stability, large-scale wetland restoration shifted points of management compromise to states characterized by less on-site phosphorus management and higher environmental quality, resulting in a significant increase in net benefits in the region. We conclude that lacustrine SESs are open and dynamic, and we recommend that future models of these systems emphasize site-specific perturbation over equilibrium, thereby aiding the development of management plans for building system resistance to undesirable change that are both flexible and sustainable in an unknowable future. © 2010 by the author(s)

Seasonal abundance of small cladocerans in Lake Mangakaware, Waikato, New Zealand

The seasonal changes in the dynamics and life histories of the Cladocera in Lake Mangakaware, North Island, New Zealand, were studied over 19 months by sampling at weekly or 2-weekly intervals. Lake Mangakaware is a 13.3 ha polymictic lake with high nutrient status, low Secchi disc transparencies, and an unstable thermal regime. The four planktonic cladoceran species (Bosmina longirostris, B. meridionalis, Ceriodaphnia pulchella, and C. dubia) exhibited disjunct population maxima. Only B. longirostris was perennially present. All species exhibited low fecundities and low lipid content, indicating that food resources were limited and that competitive interactions and resistance to starvation were probably important in determining species success. Increases in body size in cooler seasons were unrelated to clutch size, giving further support for the view that available food was limited. These results are consistent with previous experimental findings that subtle differences in life history can determine seasonal success and the outcome of competition between similar species

Binary Star Orbits from Speckle Interferometry. VI. The Nearby Solar-Type Speckle-Spectroscopic Binary HR 6697

Interferometric, spectroscopic, astrometric, and photometric observations are presented for the nearby solar-type binary HR 6697. The system consists of a G0-2 V primary and a K2-S V secondary. From a combined solution of the speckle and spectroscopic data the orbital period is 881 days or 2.41 yr, the semimajor axis is 2.1 A.U., the eccentricity is 0.42, and the inclination is 68°. The masses and luminosities are 1.16±0.12 Msun, 0.77±0.05 Msun, 1.61±0.15 Lsun, and 0.17±0.05 Lsun. Two independent determinations of the parallax, a trigonometric parallax of 0 .0379±0 .0030, and an orbital parallax of 0 .0375±0 .0014, are in excellent agreement and give a mean distance of 26.6±0.9 pc. The system appears to be metal rich relative to the Sun, and space motions do not identify it with any moving group

Patient Priorities in Autoimmune Hepatitis: The Need for Better Treatments, More Education and Challenging Stigma

BACKGROUND: Data show that patients with autoimmune hepatitis have significantly reduced quality-of-life and that corticosteroids carry marked side effects. AIMS: This study explored patients’ experiences of autoimmune hepatitis and its treatments; key aspects for developing safe and effective new approaches to therapy. METHODS: An anonymised, internet-based survey collected data including patient demographics, treatments, side-effects, impact on day-to-day life, sources of support and attitudes towards autoimmune hepatitis between December 2019–January 2020. Semi-structured interviews were conducted with 13 patients to further explore their support networks, treatment experiences and health priorities. Descriptive and quantitative analyses were undertaken using R and free text responses were subject to thematic analysis. RESULTS: In total, 270 survey responses were received (median age 55 years and 94% female). Perceived medication side-effects were reported by 66% (169/257) and 73% responded negatively about their experience of corticosteroids. The majority (62·3% [(109/175]) would ‘definitely’ or ‘probably’ consider clinical trial participation to improve their care. Only 18·7% (31/166) reported access to a specialist liver nurse and nearly half were involved in support groups. Interview and survey data suggested that major issues were stigma, loss of control and fatigue. CONCLUSIONS: This study provides insights into the realities of living with autoimmune hepatitis with clear issues around lack of support networks, need for patient empowerment and stigma surrounding liver disease. Patient priorities are better therapies to slow disease progression, avoiding corticosteroids and minimising side-effects. Patient willingness to participate in trials suggests that they are achievable provided they have the right design and clinical endpoints

Bacterial Colony Counts During Vaginal Surgery

Objective: To describe the bacterial types and colony counts present before and during vaginal surgery. Methods: A descriptive study was undertaken of patients undergoing vaginal hysterectomy with or without reconstructive pelvic surgery. Aerobic and anaerobic bacterial cultures were obtained immediately before and throughout the surgical cases at preselected time intervals. Standard antimicrobial prophylaxis was administered in all cases. Mean total colony counts and mean anaerobic colony counts were determined by adding all colonies regardless of bacteria type. ‘Contamination’ was defined as ≥ 5000 colony-forming units/ml. Results: A total of 31 patients aged 26 to 82 years (mean age ± SD, 51 ± 15) were included. The highest total and anaerobic colony counts were found at the first intraoperative time interval. On the first set of cultures (30 minutes after the surgical scrub), 52% (16/31) of the surgical fields were contaminated, and at 90 minutes, 41% (12/29) were contaminated. A negligible number of subsequent cultures were contaminated. Conclusions: Any future interventions designed to minimize bacterial colony counts should focus on the first 30 to 90 minutes of surgery

Walking the walk: a phenomenological study of long distance walking

Evidence suggests that regular walking can elicit significant psychological benefits although little evidence exists concerning long distance walking. The purpose of this study was to provide detailed accounts of the experiences of long distance walkers. Phenomenological interviews were conducted with six long distance walkers. Data were transcribed verbatim before researchers independently analyzed the transcripts. Participants reported a cumulative effect with positive feelings increasing throughout the duration of the walk. Long distance walking elicited positive emotions, reduced the effects of life-stress, and promoted an increased sense of well-being and personal growth. Results are aligned to theories and concepts from positive psychology