Movement patterns, behavior, and habitat use of female moose on Joint Base Elmendorf-Richardson, AK

2016 Spring.Includes bibliographical references.Joint Base Elmendorf-Richardson (JBER), which is a combined United States Army/Air Force installation, and neighboring Anchorage, Alaska, support a population of moose Alces alces (Linnaeus, 1758) that inhabit a fragmented landscape of habitat types interspersed with human development. Because development plans in support of the military mission may have significant impacts on moose movement in the area, JBER and Alaska Department of Fish and Game (ADF&G) biologists began a study of moose habitat use and behavior on JBER. In order to help identify behaviors in wild radio-collared moose captured on JBER, we tested Telonics tri-axial accelerometers for accuracy in the detection of activity and the identification of behaviors in radio-collared moose. Direct observations of three captive animals fitted with radio collars containing accelerometers allowed us to calibrate activity readings to observed behaviors. We developed four datasets in order to test whether readings from this type of accelerometer could identify specific behaviors (browsing, grazing, walking, standing, lying), behavior categories (feeding, traveling, resting), or simply when moose were active or inactive. Multiple threshold criteria were tested in order to maximize correlation to observed behaviors. The highest overall accuracy was achieved when using threshold criteria to characterize behaviors as active (92.29% accuracy) or inactive (90.64% accuracy). A Fisher’s Exact Test indicated that there was no significant difference between observed behaviors and those correctly classified using threshold criteria for either active (p = .9728) or inactive (p = .9431) behaviors, indicating that our threshold criteria is correctly classifying these behaviors. In the next phase of this study, we collected 244,957 GPS locations from 18 female moose captured on JBER and fitted with GPS collars equipped with the same model tri-axial accelerometer used in the captive trials. Data from the accelerometers were used to characterize moose behavior as active or inactive. GPS locations, along with behavior patterns and movement characteristics, were used to rank JBER habitat types. Turning angle and speed were calculated between successive locations for each animal across the animal’s home range. Values were pooled for all animals and used to assess movement characteristics by season and habitat type. The highest velocity recorded for a 60 minute period was 1.50 m/s (5.40 kph), and 99.50% of all steps had velocities < 0.26 m/s (0.94 kph). Turning angle groups did not vary among either habitat types (p = 1.00) or seasons (p = 0.99). A new, intuitive home range estimation method, Dynamic Potential Path Area (dynPPA), was used to incorporate behavioral states into the delineation of animal home ranges. We delineated dynPPA home ranges by season for each moose, and used this technique in combination with Jacobs Index (which measures utilization in relation to availability) to determine habitat preference. Seasonal dynPPA home range sizes averaged 15.28 km2 in summer (SD = 6.43) and 23.25 km2 in winter (SD = 7.97). Habitat types most often used by moose on JBER included mixed deciduous/conifer (38.23% of summer locations and 30.03% of winter locations occurred within this habitat type), shrublands (15.04% of summer locations and 28.57% of winter locations), and deciduous forest (21.89% of summer locations and 19.08% of winter locations). While individual moose differed in habitat selection (F = 1.73, df = 17, p < 0.01), the most preferred habitat (according to Jacobs Index) on JBER in relation to its availability within the home range was shrublands

Maximum Entropy Regularisation Applied to Ultrasonic Image Reconstruction

Image reconstruction, in common with many other inverse problems, is often mathematically ill-posed in the sense that solutions are neither stable nor unique. Ultrasonic image reconstruction is particularly notorious in this regard, with narrow transducer bandwidths and limited - sometimes sparsely sampled apertures posing formidable difficulties for conventional signal processing. To overcome these difficulties, some form of regularisation is mandatory, whereby the ill-posed problem is restated as a closely related, well-posed problem, and then solved uniquely. This thesis explores the application of maximum entropy (MaxEnt) regularisation to the problem of reconstructing complex-valued imagery from sparsely sampled coherent ultrasonic field data, with particular emphasis on three-dimensional problems in the non-destructive evaluation (NDE) of materials. MaxEnt has not previously been applied to this class of problem, and yet in comparison with many other approaches to image reconstruction, it emerges as the clear leader in terms of resolution and overall image quality. To account for this performance, it is argued that the default image model used with MaxEnt is particularly meaningful in cases of ultrasonic scattering by objects embedded in homogeneous media. To establish physical and mathematical insights into the forward problem, linear equations describing scattering from both penetrable and impenetrable objects are first derived using the Born and physical optics approximations respectively. These equations are then expressed as a shift-invariant computational model that explicitly incorporates sparse sampling. To validate this model, time-domain scattering responses are computed and compared with analytical solutions for a simple canonical test case drawn from the field of NDE. The responses computed via the numerical model are shown to accurately reproduce the analytical responses. To solve inverse scattering problems via MaxEnt, the robust Cambridge algorithm is generalised to the complex domain and extended to handle broadband (multiple-frequency) data. Two versions of the augmented algorithm are then compared with a range of other algorithms, including several linearly regularised algorithms and lastly, due to its acknowledged status as a competitor with MaxEnt in radio-astronomy, the non-linear CLEAN algorithm. These comparisons are made through simulated 3-D imaging experiments under conditions of both complete and sparse aperture sampling with low and high levels of additive Gaussian noise. As required in any investigation of inverse problems, the experimental confirmation of algorithmic performance is emphasised, and two common imaging geometries relevant to NDE are selected for this purpose. In monostatic synthetic aperture imaging experiments involving side-drilled holes in an aluminium plate and test objects immersed in H2O, MaxEnt image reconstruction is demonstrated to be robust against grating-lobe and side-lobe formation, in addition to temporal bandwidth restriction. This enables efficient reconstruction of 2-D and 3-D images from small numbers of discrete samples in the spatial and frequency domains. The thesis concludes with a description of the design and testing of a novel polyvinylidene fluoride (PVDF) bistatic array transducer that offers advantages over conventional point-sampled arrays in terms of construction simplicity and signal-to-noise ratio. This ultra-sparse orthogonal array is the only one of its kind yet demonstrated, and was made possible by MaxEnt signal processing

Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models

Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined into a tracer known as atmospheric potential oxygen (APO ≈ O2/N2 + CO2) that is conservative with respect to terrestrial biological activity. Consequently, APO reflects primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. (1998), we present a set of APO observations for the years 1996-2003 with unprecedented spatial coverage. Combining data from the Princeton and Scripps air sampling programs, the data set includes new observations collected from ships in the low-latitude Pacific. The data show a smaller interhemispheric APO gradient than was observed in past studies, and different structure within the hemispheres. These differences appear to be due primarily to real changes in the APO field over time. The data also show a significant maximum in APO near the equator. Following the approach of Gruber et al. (2001), we compare these observations with predictions of APO generated from ocean O2 and CO2 flux fields and forward models of atmospheric transport. Our model predictions differ from those of earlier modeling studies, reflecting primarily the choice of atmospheric transport model (TM3 in this study). The model predictions show generally good agreement with the observations, matching the size of the interhemispheric gradient, the approximate amplitude and extent of the equatorial maximum, and the amplitude and phasing of the seasonal APO cycle at most stations. Room for improvement remains. The agreement in the interhemispheric gradient appears to be coincidental; over the last decade, the true APO gradient has evolved to a value that is consistent with our time-independent model. In addition, the equatorial maximum is somewhat more pronounced in the data than the model. This may be due to overly vigorous model transport, or insufficient spatial resolution in the air-sea fluxes used in our modeling effort. Finally, the seasonal cycles predicted by the model of atmospheric transport show evidence of an excessive seasonal rectifier in the Aleutian Islands and smaller problems elsewhere. Copyright 2006 by the American Geophysical Union

Dimer-mediated cation diffusion in the stoichiometric ionic conductor Li3N

Non-equilibrium molecular dynamics has been used to model cation diffusion in stoichiometric Li3N over the temperature range 50 &lt; T/K &lt; 800. The resulting diffusion coefficients are in excellent agreement with the available experimental data. We present a detailed atomistic account of the diffusion process. Contrary to the conclusions drawn from previous studies, our calculations show that it is unnecessary to invoke the presence of a small concentration of intrinsic defects in order to initiate diffusion. The structure can be considered to consist of alternating layers of composition Li2N and Li. As the temperature increases an increasing number of cations leave the Li2N layers and migrate either to the interlayer space or to the Li layer. Those that move into the interlayer space form Li2 dimers with cations in the Li2N layers and those that move into the neighboring layer form dimers with cations therein. The two types of dimer are aligned parallel and perpendicular to [001], respectively and have lifetimes of ∼3 ps. The vacancies so created facilitate rapid diffusion in the Li2N layers and the interlayer cation motion results in slower diffusion perpendicular to the layers

Diffusion in Li₂O studied by non-equilibrium molecular dynamics for 873 &lt;T/K &lt;1603

The use of non-equilibrium molecular dynamics facilitates the calculation of the cation diffusion constant of Li2O at temperatures too low to be accessible by other methods. Excellent agreement with experimental diffusion coefficients has been obtained over the temperature range 873 < T/K < 1603. Diffusion below 1200 K was shown to be dominated by a concerted nearest-neighbour hopping process, whereas in the high-temperature superionic region an additional mechanism involving a six-coordinate interstitial cation site in the anti-fluorite structure becomes increasingly dominant. Our model thus accounts for the transition from the superionic regime to the non-superionic regime.</p

COVID-19 and financial toxicity in patients with renal cell carcinoma

PURPOSE To ascertain renal cell carcinoma (RCC) financial toxicity on COVID-19 during the COVID-19 crisis as patients are struggling with therapeutic and financial implications. METHODS An online survey was conducted from March 22 to March 25, 2020. It included baseline demographic, clinicopathologic, treatment-related information, anxiety levels related to COVID-19, questions related to financial concerns about COVID-19 as well as the validated 11-item COST measure. RESULTS Five-hundred-and-thirty-nine patients (39%:58% male:female) from 14 countries responded. 23% of the patients did not feel in control of their financial situation but 8% reported being very satisfied with their finances. The median COST score was 21.5 (range 1-44). Metastatic patients who have not started systemic therapy had a COST score (19.8 range 2-41) versus patients on oral systemic therapy had a COST score (23.9 range 4-44). Patients in follow-up after surgery had a median COST score at 20.8 (range 1-40). A low COST scores correlated (p < 0.001) were female gender (r = 0.108), younger age (r = 0.210), urban living situation (r = 0.68), a lower educational level (r = 0.155), lower income (r = 0.165), higher anxiety about acquiring COVID-19 (r = 0.198), having metastatic disease (r = 0.073) and a higher distress score about cancer progression (r = 0.224). CONCLUSION Our data highlight severe financial impact of COVID-19. Acknowledging financial hardship and thorough counseling of cancer patients should be part of the conversation during the pandemic. Treatment and surveillance of RCC patients might have to be adjusted to contemplate financial and medical needs

Measurements and models of the atmospheric Ar/N2 ratio

The Ar/N2 ratio of air measured at 6 globally distributed sites shows annual cycles with amplitudes of 12 to 37 parts in 106. Summertime maxima reflect the atmospheric Ar enrichment driven by seasonal warming and degassing of the oceans. Paired models of air-sea heat fluxes and atmospheric tracer transport predict seasonal cycles in the Ar/N2 ratio that agree with observations, within uncertainties

Ba4Ru3O10.2(OH)1.8 : a new member of the layered hexagonal perovskite family crystallised from water

A new barium ruthenium oxyhydroxide Ba4Ru3O10.2(OH)1.8 crystallises under hydrothermal conditions at 200 °C: powder neutron diffraction data show it adopts an 8H hexagonal perovskite structure with a new stacking sequence, while high resolution electron microscopy reveals regions of ordered layers of vacant Ru sites, and magnetometry shows antiferromagnetism with TN = 200(5) K

The metabolome regulates the epigenetic landscape during naive-to-primed human embryonic stem cell transition.

For nearly a century developmental biologists have recognized that cells from embryos can differ in their potential to differentiate into distinct cell types. Recently, it has been recognized that embryonic stem cells derived from both mice and humans exhibit two stable yet epigenetically distinct states of pluripotency: naive and primed. We now show that nicotinamide N-methyltransferase (NNMT) and the metabolic state regulate pluripotency in human embryonic stem cells (hESCs).  Specifically, in naive hESCs, NNMT and its enzymatic product 1-methylnicotinamide are highly upregulated, and NNMT is required for low S-adenosyl methionine (SAM) levels and the H3K27me3 repressive state. NNMT consumes SAM in naive cells, making it unavailable for histone methylation that represses Wnt and activates the HIF pathway in primed hESCs. These data support the hypothesis that the metabolome regulates the epigenetic landscape of the earliest steps in human development