Six Strategies for Rehabilitating Land Disturbed by Oil Development in Arctic Alaska

Oil development in arctic Alaska has left a range of disturbed lands that will eventually require rehabilitation. These lands include gravel roads and pads, gravel pits and overburden stockpiles, drilling reserve pits, occasional accidental spills, and other minor disturbances to the tundra. A long-term research program investigating site-specific and cost-effective methods for rehabilitating degraded lands for fish and wildlife habitat has developed six general strategies that are applicable to the range of disturbed conditions. These strategies include 1) flooding of gravel mine sites for fish habitat, 2) creation of wetlands in ponds perched on overburden stockpiles, 3) revegetation of thick gravel fill and overburden to compensate for lost wildlife habitat, 4) removal of gravel fill to help restore wet tundra habitats, 5) restoration of tundra on less severely modified habitats, and 6) remediation of areas contaminated by oil spills, seawater spills, and drilling mud. Although most techniques are in the early stage of evaluation, preliminary results suggest that successful methods are available to create diverse, productive, and self-sustaining communities that are useful to a range of wildlife.Key words: Arctic, Alaska, disturbance, habitat, tundra, oilfield, rehabilitation, revegetation, restoration, wetlandsL'exploitation du pétrole dans la zone arctique de l'Alaska a entraîné une gamme de perturbations sur des terrains qu'il va falloir un jour réhabiliter. Ces derniers comprennent les routes et plates-formes de gravier, les gravières et déblais des terrains de recouvrement, les bassins de réserve de forage, les terrains ayant été le site de déversements accidentels occasionnels et autres perburbations mineures de la toundra. Six stratégies générales applicables à la gamme des terres ayant subi des perturbations ont été développées grâce à un programme de recherche à long terme portant sur les méthodes - rentables et spécifiques à chaque site - de réhabilitation des terres dégradées pour la faune aquatique et terrestre. Ces stratégies comprennent 1) l'inondation de gravières pour l'habitat du poisson, 2) la création de terres humides dans les étangs situés en haut des déblais des terrains de recouvrement, 3) la restauration de la végétation sur les remblais de gravier et déblais épais, pour compenser la perte de l'habitat faunique, 4) l'enlèvement des remblais de gravier comme aide à la restauration des habitats de toundra humide, 5) la restauration de la toundra dans des habitats n'ayant pas subi de modifications aussi sérieuses, et 6) la décontamination de zones ayant subi des déversements de pétrole, d'eau de mer et de boue de forage. Bien que la plupart des techniques en soient au stade préliminaire de l'évaluation, les premiers résultats donnent à penser qu'il existe des moyens efficaces de créer des communautés diverses, productives et autorégulatrices qui permettent la présence d'une flore et d'une faune diversifiées.Mots clés: Arctic, Alaska, perturbation, habitat, toundra, gisement pétrolier, réhabilitation, revégétation, restauration, terres humide

Cosmic homogeneity demonstrated with luminous red galaxies

We test the homogeneity of the Universe at $z\sim 0.3$ with the Luminous Red Galaxy (LRG) spectroscopic sample of the Sloan Digital Sky Survey. First, the mean number $N(R)$ of LRGs within completely surveyed LRG-centered spheres of comoving radius $R$ is shown to be proportional to $R^3$ at radii greater than $R\sim 70 h^{-1} \mathrm{Mpc}$. The test has the virtue that it does not rely on the assumption that the LRG sample has a finite mean density; its results show, however, that there \emph{is} such a mean density. Secondly, the survey sky area is divided into 10 disjoint solid angular regions and the fractional rms density variations of the LRG sample in the redshift range $0.2<z<0.35$ among these ($\sim 2\times10^7 h^{-3} \mathrm{Mpc^3}$) regions is found to be 7 percent of the mean density. This variance is consistent with typical biased \lcdm models and puts very strong constraints on the quality of SDSS photometric calibration.Comment: submitted to Ap

Salsalate treatment improves glycemia without altering adipose tissue in nondiabetic obese hispanics.

ObjectiveSalsalate treatment has well-known effects on improving glycemia, and the objective of this study was to examine whether the mechanism of this effect was related to changes in adipose tissue.MethodsA randomized double-blind and placebo-controlled trial in obese Hispanics (18-35 years) was conducted. The intervention consisted of 4 g day(-1) of salsalate (n = 11) versus placebo (n = 13) for 4 weeks. Outcome measures included glycemia, adiposity, ectopic fat, and adipose tissue gene expression and inflammation.ResultsIn those receiving salsalate, plasma fasting glucose decreased by 3.4% (P &lt; 0.01), free fatty acids decreased by 42.5% (P = 0.06), and adiponectin increased by 27.7% (P &lt; 0.01). Salsalate increased insulin AUC by 38% (P = 0.01) and HOMA-B by 47.2% (P &lt; 0.01) while estimates of insulin sensitivity/resistance were unaffected. These metabolic improvements occurred without changes in total, abdominal, visceral, or liver fat. Plasma markers of inflammation/immune activation were unchanged following salsalate. Salsalate had no effects on adipose tissue including adipocyte size, presence of crown-like structures, or gene expression of adipokines, immune cell markers, or cytokines downstream of NF-κB with the exception of downregulation of IL-1β (P &lt; 0.01).ConclusionsFindings suggest that metabolic improvements in response to salsalate occurred without alterations in adiposity, ectopic fat, or adipose tissue gene expression and inflammation

Six Strategies for Rehabilitating Land Disturbed by Oil Development in Arctic Alaska

ABSTRACT. Oil development in arctic Alaska has left a range of disturbed lands that will eventually require rehabilitation. These lands include gravel roads and pads, gravel pits and overburden stockpiles, drilling reserve pits, occasional accidental spills, and other minor disturbances to the tundra. A long-term research program investigating site-specific and cost-effective methods for rehabilitating degraded lands for fish and wildlife habitat has developed six general strategies that are applicable to the range of disturbed conditions. These strategies include 1) flooding of gravel mine sites for fish habitat, 2) creation of wetlands in ponds perched on overburden stockpiles, 3) revegetation of thick gravel fill and overburden to compensate for lost wildlife habitat, 4) removal of gravel fill to help restore wet tundra habitats, 5) restoration of tundra on less severely modified habitats, and 6) remediation of areas contaminated by oil spills, seawater spills, and drilling mud. Although most techniques are in the early stage of evaluation, preliminary results suggest that successful methods are available to create diverse, productive, and self-sustaining communities that are useful to a range of wildlife

An M-theory Flop as a Large N Duality

We show how a recently proposed large $N$ duality in the context of type IIA strings with ${\cal N}=1$ supersymmetry in 4 dimensions can be derived from purely geometric considerations by embedding type IIA strings in M-theory. The phase structure of M-theory on $G_2$ holonomy manifolds and an $S^3$ flop are the key ingredients in this derivation.Comment: 17 pages, references added and correcte

The Ages of Galactic Bulge Stars with Realistic Uncertainties

Using modern isochrones with customized physics and carefully considered statistical techniques, we recompute the age distribution for a sample of 91 micro-lensed dwarfs in the Galactic bulge presented by Bensby et al. (2017) and do not produce an age distribution consistent with their results. In particular, our analysis finds that only 15 of 91 stars have ages younger than 7 Gyr, compared to their finding of 42 young stars in the same sample. While we do not find a constituency of very young stars, our results do suggest the presence of an $\sim8$ Gyr population at the highest metallicities, thus contributing to long-standing debate about the age--metallicity distribution of the Galactic bulge. We supplement this with attempts at independent age determinations from two sources of photometry, BDBS and \textit{Gaia}, but find that the imprecision of photometric measurements prevents reliable age and age uncertainty determinations. Lastly, we present age uncertainties derived using a first-order consideration of global modeling uncertainties in addition to standard observational uncertainties. The theoretical uncertainties are based on the known variance of free parameters in the 1D stellar evolution models used to generate isochrones, and when included, result in age uncertainties of $2$--$5$ Gyr for this spectroscopically well-constrained sample. These error bars, which are roughly twice as large as typical literature values, constitute realistic lower limits on the true age uncertainties.Comment: accepted to ApJ; revisions complet

On the mean-field spherical model

Exact solutions are obtained for the mean-field spherical model, with or without an external magnetic field, for any finite or infinite number N of degrees of freedom, both in the microcanonical and in the canonical ensemble. The canonical result allows for an exact discussion of the loci of the Fisher zeros of the canonical partition function. The microcanonical entropy is found to be nonanalytic for arbitrary finite N. The mean-field spherical model of finite size N is shown to be equivalent to a mixed isovector/isotensor sigma-model on a lattice of two sites. Partial equivalence of statistical ensembles is observed for the mean-field spherical model in the thermodynamic limit. A discussion of the topology of certain state space submanifolds yields insights into the relation of these topological quantities to the thermodynamic behavior of the system in the presence of ensemble nonequivalence.Comment: 21 pages, 5 figure

The Manifold Scattering Transform for High-Dimensional Point Cloud Data

The manifold scattering transform is a deep feature extractor for data defined on a Riemannian manifold. It is one of the first examples of extending convolutional neural network-like operators to general manifolds. The initial work on this model focused primarily on its theoretical stability and invariance properties but did not provide methods for its numerical implementation except in the case of two-dimensional surfaces with predefined meshes. In this work, we present practical schemes, based on the theory of diffusion maps, for implementing the manifold scattering transform to datasets arising in naturalistic systems, such as single cell genetics, where the data is a high-dimensional point cloud modeled as lying on a low-dimensional manifold. We show that our methods are effective for signal classification and manifold classification tasks.Comment: Accepted for publication in the TAG in DS Workshop at ICML. For subsequent theoretical guarantees, please see Section 6 of arXiv:2208.0856

Hospital evacuation planning tool for assistance devices (HEPTAD)

A new software tool, called HEPTAD (Hospital Evacuation Planning Tool for Assistance Devices), designed to aid evacuation planning in hospitals is described and demonstrated in this paper. The software can identify regions within a hospital geometry that are inappropriate for patients who require the use of specific movement assistance devices in the event of an emergency evacuation. Using the software, Hospital Emergency Coordinators can reduce the risk of allocating a bed to a patient from which they cannot be evacuated within a safe time. In addition, HEPTAD is designed to be a proof of concept for algorithms that will later be incorporated within the EXODUS egress model. HEPTAD utilises several techniques from autonomous robotics to generate the fastest viable egress route for movement assistance devices from every location in the geometry while considering device spatial constraints (size and shape) and kinematic constraints (maximum speeds, turning radius and holonomicity). It then uses the egress time of this route along with factors from space syntax (isovist and spaciousness) to analyse the emergency vulnerability of every location within the geometry