Welcome to Parks Stewardship Forum: An Introduction to the Journal from the Editors

An overview of Parks Stewardship Forum from the managing editors, published in the inaugural issue of the journal, whose theme is "Climate Change and Protected Places: Adapting to New Realities.

A Partial Magnetometer Survey of The Archaeological Conservancy’s Portion of the A. C. Saunders Site (41AN19)

The Texas Archeological Research Laboratory (TARL) at The University of Texas at Austin conducted a partial magnetometer survey of The Archaeological Conservancy-owned portion of the A. C. Saunders site (41AN19) during the period between 6-8 December 2005. This survey was sponsored by the Texas Department of Transportation Environmental Affairs Division (TxDOT/ENV) due to a proposed expansion of the right-of-way of U.S. Highway 175 and was conducted under a research design approved by The Archeological Conservancy and TxDOT/ENV. The work was conducted under the direction of Dale Hudler (Principal Investigator) from TARL with a joint TARL/Prewitt and Associates, Inc. field crew (Jonathan Jarvis, TARL and Tim Griffith, Prewitt and Associates, Inc.)

Let’s talk about sex(ual) wellbeing! Staff perceptions of implementing a novel service for people with Multiple Sclerosis

BACKGROUND: In people with multiple sclerosis (PwMS), a complex interplay of neurological dysfunction, polypharmacy and psychological issues, contrive to impair their sexual and reproductive wellbeing. Realising an unmet need, the Tayside MS service in collaboration with a sexual health clinician (LJ), established a ‘Pelvic Health Clinic’ to improve quality of life for PwMS. OBJECTIVE: To explore clinician's perceptions of implementing an MS Pelvic Health service with a view to establishing future outcomes for health care professionals about the utility in such a service. METHOD: In this small-scale qualitative case study, we explored clinician's perceptions of such a clinic adjunct. Semi-structured interviews were conducted, transcribed, and thematically analysed in a reflexive manner. RESULTS: Five participants consented. Ten sub-themes emerged, which were organised into three main themes: service tensions, patient needs and practitioner feelings. CONCLUSION: Clinicians highly valued the new MS ‘pelvic health clinic’. Knowing that there was a service available empowered clinicians to ask patients about sexual health needs. Specific referral criteria may help further develop the service and improve patient care. Staff welcome training and support in this area or the option to signpost onwards; either mechanism lends itself to enhancing MS patient needs

Computation and Numerical Simulation of Focused Undulator Radiation for Optical Stochastic Cooling

Optical stochastic cooling (OSC) is a promising technique for the cooling of dense particle beams. Its operation at optical frequencies enables obtaining a much larger bandwidth compared to the wellknown microwave-based stochastic cooling. In the OSC undulator radiation generated by a particle in an upstream \pickup" undulator is amplified and focused at the location of a downstream "kicker" undulator. Inside the kicker, a particle interacts with its own radiation field from the pickup. The resulting interaction produces a longitudinal kick with its value depending on the particles momentum which, when correctly phased, yields to longitudinal cooling. The horizontal cooling is achieved by introducing a coupling between longitudinal and horizontal degrees of freedom. Vertical cooling is achieved by coupling between horizontal and vertical motions in the ring. In this paper, we present formulae for computation of the corrective kick and validate them against numerical simulations performed using a wave-optics computer program.Comment: 9 pages, 7 figure

Role of Fiber Orientation in Atrial Arrythmogenesis

Electrical wave-front propagation in the atria is determined largely by local fiber orientation. Recent study suggests that atrial fibrillation (AF) progresses with enhanced anisotropy. In this work, a 3D rabbit atrial anatomical model at 20 × 20 × 20 μm3 resolution with realistic fiber orientation was constructed based on the novel contrast-enhanced micro-CT imaging. The Fenton-Karma cellular activation model was adapted to reproduce rabbit atrial action potential period of 80 ms. Diffusivities were estimated for longitudinal and transverse directions of the fiber orientation respectively. Pacing was conducted in the 3D anisotropic atrial model with a reducing S2 interval to facilitate initiation of atrial arrhythmia. Multiple simulations were conducted with varying values of diffusion anisotropy and stimulus locations to evaluate the role of anisotropy in initiating AF. Under physiological anisotropy conditions, a rapid right atrial activation was followed by the left atrial activation. Excitation waves reached the atrio-ventricular border where they terminated. Upon reduction of conduction heterogeneity, re-entry was initiated by the rapid pacing and the activation of both atrial chambers was almost simultaneous. Myofiber orientation is an effective mechanism for regulating atrial activation. Modification of myoarchitecture is proarrhythmic

The relative age effect reversal among the National Hockey League elite

Like many sports in adolescence, junior hockey is organized by age groups. Typically, players born after December 31st are placed in the subsequent age cohort and as a result, will have an age advantage over those players born closer to the end of the year. While this relative age effect (RAE) has been well-established in junior hockey and other professional sports, the long-term impact of this phenomenon is not well understood. Using roster data on North American National Hockey League (NHL) players from the 2008-2009 season to the 2015-2016 season, we document a RAE reversal—players born in the last quarter of the year (October-December) score more and command higher salaries than those born in the first quarter of the year. This reversal is even more pronounced among the NHL “elite.” We find that among players in the 90th percentile of scoring, those born in the last quarter of the year score about 9 more points per season than those born in the first quarter. Likewise, elite players in the 90th percentile of salary who are born in the last quarter of the year earn 51% more pay than players born at the start of the year. Surprisingly, compared to players at the lower end of the performance distribution, the RAE reversal is about three to four times greater among elite players

Effects of Cardiac Structural Remodelling During Heart Failure on Cardiac Excitation – Insights from a Heterogeneous 3D Model of the Rabbit Atria

Heart failure is a leading cause of morbidity and mortality in the western world. One of the effects of heart failure is the structural remodelling of cardiac tissue, including tissue dilation and development of fibrosis. It is therefore important to study these changes and their effect on cardiac activity, in order to gain a better understanding of the underlying mechanisms in arrhythmogenesis, which will hopefully enable us to develop better treatments for heart failure. In this study we developed biophysically detailed models of the rabbit atria for normal and heart failure conditions. These models were used to study the effects of structural remodelling of heart failure on cardiac excitation wave conduction. Anatomical reconstructions of the control and heart failure hearts were based on contrast enhanced micro-CT imaging. Fibre orientation was extracted from the control and heart failure datasets. Effects of heart failure geometry on the activation pattern of atrial excitation waves were analyzed. It was found that atrial activation time increased from the control to the heart failure case in both isotropic and anisotropic conditions, which is attributed primarily to the dilation of tissue caused by heart failure

Spatial Analyses of Oral Polio Vaccine Transmission in an Community Vaccinated With Inactivated Polio Vaccine.

Background: Understanding the spatial dynamics of oral polio vaccine (OPV) transmission will improve resource targeting. Mexico provides a natural laboratory, as it uses inactivated polio vaccine routinely as well as OPV bi-annually. Methods: Using geospatial maps, we measured the distance and density of OPV vaccinees' shedding in the areas nearest to unvaccinated households in 3 Mexican villages. Comparison of transmission to unvaccinated households utilized a mixed effects logistic regression with random effects for household and time, adjusted for age, gender, area, and running water. Results: The median distance from an unvaccinated household to its nearest OPV-shedding household was 85 meters (interquartile range, 46-145) and the median number of vaccinees shedding OPV within 200 m was 3 (2-6). Transmission to unvaccinated households occurred by day 1. There was no association (odds ratio [OR] 1.04; 95% credible interval [CrI] 0.92-1.16) between the distance from OPV shedding and the odds of transmission. The number of OPV vaccinees shedding within 200 m came close to a significant association with unvaccinated transmission (OR 0.93; CrI 0.84-1.01), but this was not the case for households 100 or 500 m apart. Results were consistent across the 3 villages. Conclusions: Geospatial analysis did not predict community transmission from vaccinated to unvaccinated households, because OPV use resulted in rapid, low transmission levels. This finding supports the global cessation of OPV

Cryogenic Fluid Management Technology and Nuclear Thermal Propulsion

Cryogenic fluid management (CFM) is critical to the success of future nuclear thermal propulsion powered vehicles. While this is an issue for any propulsion system utilizing cryogenic propellants, this is made more challenging by the radiation flux produced by the reactor in a nuclear thermal rocket (NTR). Managing the cryogenic fuel to prevent propellant loss to boil off and leakage is needed to limit the required quantity of propellant to a reasonable level. Analysis shows deposition of energy into liquid hydrogen fuel tanks in the vicinity of the nuclear thermal engine. This is on top of ambient environment sources of heat. Investments in cryogenic/thermal management systems (some of which are ongoing at various organizations) are needed in parallel to nuclear thermal engine development in order to one day see the successful operation of an entire stage. High durability, low thermal conductivity insulation is one developmental need. Light weight cryocoolers capable of removing heat from large fluid volumes at temperatures as low as approx. 20 K are needed to remove heat leak from the propellant of an NTR. Valve leakage is an additional CFM issue of great importance. Leakage rates of state of the art, launch vehicle size valves (which is approximately the size valves needed for a Mars transfer vehicle) are quite high and would result in large quantities of lost propellant over a long duration mission. Additionally, the liquid acquisition system inside the propellant tank must deliver properly conditioned propellant to the feed line for successful engine operation and avoid intake of warm or gaseous propellant. Analysis of the thermal environment and the CFM technology development are discussed in the accompanying presentation