Moose, Caribou, and Grizzly Bear Distribution in Relation to Road Traffic in Denali National Park, Alaska

Park managers are concerned that moose (Alces alces), caribou (Rangifer tarandus), and grizzly bears (Ursus arctos) may be avoiding areas along the 130 km road through Denali National Park as a result of high traffic volume, thus decreasing opportunities for visitors to view wildlife. A wildlife monitoring system was developed in 1996 that used 19 landscape level view sheds, stratified into four sections based on decreasing traffic along the road corridor. Data were collected from 22 samplings of all viewsheds during May-August in 1996 and 1997. In 1997, nine backcountry viewsheds were established in three different areas to determine whether density estimates for each species in the backcountry were higher than those for the same animals in similar road-corridor areas. Densities higher than those in the road corridor were found in one backcountry area for moose and in two backcountry areas for grizzly bears. None of the backcountry areas showed a higher density of caribou. We tested hypotheses that moose, caribou, and grizzly bear distributions were unrelated to the road and traffic. Moose sightings were lower than expected within 300 m of the road. More caribou and grizzly bears than expected occurred between 601 and 900 m from the road, while more moose and fewer caribou than expected occurred between 900 and 1200 m from the road. Bull moose in stratum 1 were distributed farther from the road than bulls and cows in stratum 4; cows in stratum 1 and bul1s in stratum 2 were distributed farther from the road than cows in stratum 4. Grizzly bears in stratum 2 were distributed farther from the road than bears in stratum 3. The distribution of moose sightings suggests traffic avoidance, but the spatial pattern of preferred forage may have had more of an influence. Caribou and grizzly bear distributions indicated no pattern of traffic avoidance.Les gérants du parc s'inquiètent du fait que l'orignal (Alces alces), le caribou (Rangifer tarandus) et le grizzli (Ursus arctos) pourraient éviter les zones bordant les 130 km de la route qui traverse le parc national Denali, en raison du volume élevé de circulation, ce qui diminue aussi pour les visiteurs les chances de voir la faune. Un système de surveillance de la faune a été mis sur pied en 1996, système qui faisait appel à 19 cabanes d'observation installées de niveau avec le paysage, réparties en quatre sections déterminées selon la décroissance de circulation le long du corridor routier. En 1996 et 1997, on a collecté les données de mai à août provenant de 22 échantillons prélevés à toutes les cabanes. En 1997, neuf cabanes d'arrière-pays ont été installées dans trois zones différentes, afin de déterminer si les estimations des densités pour chaque espèce étaient plus élevées dans l'arrière-pays que dans des zones semblables agissant comme corridors routiers. On a trouvé des densités plus élevées que celles dans le corridor routier pour l'orignal dans une zone d' arrière-pays, et pour le grizzli dans deux zones d'arrière-pays. Aucune des zones d'arrière-pays n'a montré une densité plus élevée pour le caribou. Nous avons testé les hypothèses que les distributions d'orignal, de caribou et de grizzli ne sont pas reliées à la présence de la route ni à la circulation. Les observations d'orignaux étaient moindres que prévu dans la zone s'étendant jusqu'à 300 m de la route. Il y avait plus de caribous et de grizzlis que prévu dans la zone s'étendant de 601 à 900 m de la route, tandis qu'il y avait plus d'orignaux et moins de caribous que prévu dans la zone s'étendant de 900 à 1200 m de la route. Les orignaux mâles dans la strate 1 étaient distribués plus loin de la route que les orignaux mâles et les femelles dans la strate 4; les femelles dans la strate 1 et les mâles dans la strate 2 étaient distribués plus loin de la route que les femelles dans la strate 4. Les grizzlis dans la strate 2 étaient distribués plus loin de la route que les ours dans la strate 3. La distribution des observations d'orignaux suggère que ces animaux évitent la circulation, mais la répartition spatiale de leurs herbes de prédilection pourrait constituer une influence majeure. La distribution du caribou et du grizzli n'a révélé aucun schéma d'évitement de la circulation

Testing the extraction of past seawater Nd isotopic composition from North Atlantic deep sea sediments and foraminifera

Neodymium isotopes provide a paleoceanographic proxy for past deep water circulation and local weathering changes and have been measured on various authigenic marine sediment components, including fish teeth, ferromanganese oxides extracted by acid-reductive leaching, cleaned foraminifera, and foraminifera with Fe-Mn oxide coatings. Here we compare Nd isotopic measurements obtained from ferromanganese oxides leached from bulk sediments and planktonic foraminifera, as well as from oxidatively-reductively cleaned foraminiferal shells from sediment cores in the North Atlantic. Sedimentary volcanic ash contributes a significant fraction of the Nd when the ferro-manganese (Fe-Mn) oxide coatings are leached from bulk sediments. Reductive leachates of marine sediments from North Atlantic core tops near Iceland, or directly downstream from Iceland-Scotland Overflow Waters, record ɛNd values that are significantly higher than seawater, indicating that volcanic material is easily leached by acid-reductive methods. The ɛNd values from sites more distal to Iceland are similar to modern seawater values, showing little contamination from Iceland-derived volcanogenic material. In all comparisons, core top planktonic foraminifera ɛNd values more closely approximate modern deep seawater than the bulk sediment reductive leached value suggesting that the foraminifera provide a route toward quantifying the Nd isotopic signature of deep North Atlantic water masses

Large well-relaxed models of vitreous silica, coordination numbers and entropy

A Monte Carlo method is presented for the simulation of vitreous silica. Well-relaxed networks of vitreous silica are generated containing up to 300,000 atoms. The resulting networks, quenched under the BKS potential, display smaller bond-angle variations and lower defect concentrations, as compared to networks generated with molecular dynamics. The total correlation functions T(r) of our networks are in excellent agreement with neutron scattering data, provided that thermal effects and the maximum inverse wavelength used in the experiment are included in the comparison. A procedure commonly used in experiments to obtain coordination numbers from scattering data is to fit peaks in rT(r) with a gaussian. We show that this procedure can easily produce incorrect results. Finally, we estimate the configurational entropy of vitreous silica.Comment: 7 pages, 4 figures (two column version to save paper

Quantum Lattice Solitons

The number state method is used to study soliton bands for three anharmonic quantum lattices: i) The discrete nonlinear Schr\"{o}dinger equation, ii) The Ablowitz-Ladik system, and iii) A fermionic polaron model. Each of these systems is assumed to have $f$-fold translational symmetry in one spatial dimension, where $f$ is the number of freedoms (lattice points). At the second quantum level $(n=2)$ we calculate exact eigenfunctions and energies of pure quantum states, from which we determine binding energy $(E_{\rm b})$, effective mass $(m^{*})$ and maximum group velocity $(V_{\rm m})$ of the soliton bands as functions of the anharmonicity in the limit $f \to \infty$. For arbitrary values of $n$ we have asymptotic expressions for $E_{\rm b}$, $m^{*}$, and $V_{\rm m}$ as functions of the anharmonicity in the limits of large and small anharmonicity. Using these expressions we discuss and describe wave packets of pure eigenstates that correspond to classical solitons.Comment: 21 pages, 1 figur

Interpolatory methods for H∞\mathcal{H}_\infty model reduction of multi-input/multi-output systems

We develop here a computationally effective approach for producing high-quality $\mathcal{H}_\infty$-approximations to large scale linear dynamical systems having multiple inputs and multiple outputs (MIMO). We extend an approach for $\mathcal{H}_\infty$ model reduction introduced by Flagg, Beattie, and Gugercin for the single-input/single-output (SISO) setting, which combined ideas originating in interpolatory $\mathcal{H}_2$-optimal model reduction with complex Chebyshev approximation. Retaining this framework, our approach to the MIMO problem has its principal computational cost dominated by (sparse) linear solves, and so it can remain an effective strategy in many large-scale settings. We are able to avoid computationally demanding $\mathcal{H}_\infty$ norm calculations that are normally required to monitor progress within each optimization cycle through the use of "data-driven" rational approximations that are built upon previously computed function samples. Numerical examples are included that illustrate our approach. We produce high fidelity reduced models having consistently better $\mathcal{H}_\infty$ performance than models produced via balanced truncation; these models often are as good as (and occasionally better than) models produced using optimal Hankel norm approximation as well. In all cases considered, the method described here produces reduced models at far lower cost than is possible with either balanced truncation or optimal Hankel norm approximation

A conservative control strategy for variable-speed stall-regulated wind turbines

Simulation models of a variable-speed, fixed-pitch wind turbine were investigated to evaluate the feasibility of constraining rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. Using the developed models, simulations were conducted of operation in turbulent winds. Results indicated that rotor speed and power output were well regulated. Preliminary investigations of system dynamics showed that, compared to fixed-speed operation, variable-speed operation caused cyclic loading amplitude to be reduced for the turbine blades and low-speed shaft and slightly increased for the tower loads. This result suggests a favorable impact on fatigue life from implementation of the proposed control strategy

Relative sea-level change in Newfoundland, Canada during the past ∼3000 years

Several processes contributing to coastal relative sea-level (RSL) change in the North Atlantic Ocean are observed and/or predicted to have distinctive spatial expressions that vary by latitude. To expand the latitudinal range of RSL records spanning the past ∼3000 years and the likelihood of recognizing the characteristic fingerprints of these processes, we reconstructed RSL at two sites (Big River and Placentia) in Newfoundland from salt-marsh sediment. Bayesian transfer functions established the height of former sea level from preserved assemblages of foraminifera and testate amoebae. Age-depth models constrained by radiocarbon dates and chronohorizons estimated the timing of sediment deposition. During the past ∼3000 years, RSL rose by ∼3.0 m at Big River and by ∼1.5 m at Placentia. A locally calibrated geotechnical model showed that post-depositional lowering through sediment compaction was minimal. To isolate and quantify contributions to RSL from global, regional linear, regional non-linear, and local-scale processes, we decomposed the new reconstructions (and those in an expanded, global database) using a spatio-temporal statistical model. The global component confirms that 20th century sea-level rise occurred at the fastest, century-scale rate in over 3000 years (P > 0.999). Distinguishing the contributions from local and regional non-linear processes is made challenging by a sparse network of reconstructions. However, only a small contribution from local-scale processes is necessary to reconcile RSL reconstructions and modeled RSL trends. We identified three latitudinally-organized groups of sites that share coherent regional non-linear trends and indicate that dynamic redistribution of ocean mass by currents and/or winds was likely an important driver of sea-level change in the North Atlantic Ocean during the past ∼3000 years

Effect of controlled disorder on quasiparticle thermal transport in Bi2_2Sr2_2CaCu2_2O8_8

Low temperature thermal conductivity, $\kappa$, of optimally-doped Bi2212 was studied before and after the introduction of point defects by electron irradiation. The amplitude of the linear component of $\kappa$ remains unchanged, confirming the universal nature of heat transport by zero-energy quasiparticles. The induced decrease in the absolute value of $\kappa$ at finite temperatures allows us to resolve a nonuniversal term in $\kappa$ due to conduction by finite-energy quasiparticles. The magnitude of this term provides an estimate of the quasiparticle lifetime at subkelvin temperatures.Comment: 5 pages including 2 .eps figuer

Adoption of technology enabled care to support the management of children and teenagers in rheumatology services: a protocol for a mixed-methods systematic review

Introduction COVID-19 catalysed a rapid move to provide care away from the hospital using online communication platforms. Technology enabled care (TEC) continues to be an important driver in progressing future healthcare services. Due to the complex and chronic nature of conditions seen within paediatric rheumatology, TEC may lead to better outcomes. Despite some growth in published literature into the adoption of TEC in paediatric rheumatology, there is limited synthesis. The aim of this review is to provide a comprehensive understanding and evaluation of the adoption of TEC by patients in paediatric rheumatology services, to establish best practices. Methods and analysis This proposed mixed-methods systematic review will be conducted by searching a wide variety of healthcare databases, grey literature resources and associated charities and societies, for articles reported in English language. Data extraction will include population demographics, technology intervention, factors affecting adoption of intervention and consequent study outcomes. A parallel-results convergent synthesis design is planned, with independent syntheses of quantitative and qualitative data, followed by comparison of the findings of each synthesis using a narrative approach. Normalisation process theory will be used to identify, characterise and explain implementation factors. The quality of included articles will be assessed using the Mixed Methods Appraisal Tool for research papers and the Authority, Accuracy, Coverage, Objectivity, Date, Significance checklist for grey literature. Overall confidence in quality and strength of evidence will be assessed using the Confidence in the Evidence from Reviews of Qualitative Research tool. Ethics and dissemination Ethical approval is not required due to the nature of this mixed-methods systematic review. The findings will be disseminated via a peer-reviewed journal, relevant conferences and any other methods (eg, via NHS Trust or NIHR YouTube channels) as advised by paediatric rheumatology patients