bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time-step limits for stable solutions of the ice-sheet equation
Authors: Hindmarsh Richard C. A. , Payne Antony J. 
Published: September 2017

Various spatial discretizations for the ice sheet are compared for accuracy against analytical solutions in one and two dimensions. The computational efficiency of various iterated and non-iterated marching schemes is compared.The stability properties of different marching schemes, with and without iterations on the non-linear equations, are compared. Newton–Raphson techniques permit the largest time steps. A new technique, which is based on the fact that the dynamics of unstable iterated maps contain information about where the unstable root lies, is shown to improve substantially the performance of Picard iteration at a negligible computational cost.
Increased ablation of Wisconsin ice in eastern north Greenland: observations and modelling
Authors: Bøggild Carl Egede , Oerter Hans , Tukiainen Tapani 
Published: September 2017

In Kronprins Christian Land at 80° N in eastern north Greenland, it has been observed that the surface of the Wisconsin ice is significantly darker than the Holocene ice found immediately upstream from a transition located 710 m from the ice margin. δ18O analysis has shown the dark surface is of Wisconsin origin. Deep ice cores from the Greenland ice sheet all indicate that the Wisconsin ice contains orders of magnitude more microparticles which could he the reason for the dark appearance of the Wisconsin surface.Photographic documentation, spectral surface-albedo measurements and satellite-image analysis all indicate a reduced albedo of Wisconsin ice. The effect of this reduced albedo is not confirmed by the ablation measurements. However, measurements of ablation variability within small test sites has documented that large errors will arise if only one stake per measuring point is used. Energy-balance calculations show ablation rates should be 10–70%, i.e. 1.8–8.4 mm d−1, respectively, less than experienced. Additionally, a satellite-image analysis shows even higher albedo contrasts 20–30 km to the south of our transect locality.Immediately after the termination of the ice age, most of the surface in the ablation zone consisted of this low-reflectance ice. So, in the early Holocene, the dark ice of Wisconsin origin is likely to have resulted in higher ablation rates than previously considered. This may probably partly explain the fast rate of retreat/disintegration of the ice sheets in the Northern Hemisphere, after the termination of the Wisconsin ice age.
Deformation rates in combined compression and shear for ice which is initially isotropic and after the development of strong anisotropy
Authors: Jun Li , Jacka T.H , Budd W.F. 
Published: September 2017

Laboratory-prepared fine-grained, initially isotropic polycrystalline ice samples were deformed under conditions of simple shear with simultaneous uniaxial compression at a constant temperature of −2.0°C. The aim was to investigate the effects of stress configuration on the flow rate of initially isotropic ice and on ice with subsequent stress and strain-induced anisotropy. Experiments were carried out for various combinations of shear and compression with shear stress ranging from 0 to 0.49 MPa and compressive stress ranging from 0 to 0.98 MPa, but such that for every experiment the octahedral shear stress was 0.4 MPa.The strain curves resulting from the experiments clearly exhibit minimum strain rates while the ice is still isotropic, and steady-state tertiary strain rates along with the development of steady-state anisotropic fabric patterns. With constant octahedral stress (root-mean-square of the principal stress deviators), the minimum octahedral shear-strain rate has no dependence on stress configuration. This result supports the hypothesis that the flow of isotropic ice is dependent only on the second invariant of the stress tensor. This fundamental assumption has been used to provide a general description of ice-flow behaviour independent of the stress configuration (e.g. Nye, 1953; Glen, 1958; Budd, 1969).For the tertiary flow of anisotropic ice, the octahedral strain rate is stress-state dependent as a consequence of the developed crystal-orientation fabric, which is also stress-state dependent, and which develops with strain and rotation. The present tests indicate that the enhancement factor for steady-state tertiary octahedral shear-strain rate depends on the shear or compression fraction and varies from about 10 for simple shear (with zero compression) to about 3 for uniaxial compression (with zero shear).
Ice-sheet models as tools for palaeoclimatic analysis: the example of the European ice sheet through the last glacial cycle
Authors: Boulton G. S. , Hulton N. , Vautravers M. 
Published: September 2017

A numerical model is used to simulate ice-sheet behaviour in Europe through the last glacial cycle. It is used in two modes: a forward mode, in which the model is driven by a proxy palaeoclimate record and the output compared with a geological reconstruction of ice-sheet fluctuation; and an inverse mode, in which we determine the climate function that would be required to simulate geologically reconstructed ice-sheet fluctuations.From these simulations it is concluded that extra-glacial climates may be poor predictors of ice-sheet surface climates, and that climatic transitions during the glacial period may have been much more rapid and the intensity of warming during the early Holocene much greater than hitherto supposed. Stronger climate forcing is required to drive ice-sheet expansion when sliding occurs at the bed compared with a non-sliding bed. Sliding ice sheets grow more slowly and decay more rapidly than non-sliding ice sheets with the same climate forcing.
Glacier Inventory in Chile: current status and recent glacier variations
Authors: Casassa Gino 
Published: September 2017

The glacier inventory in Chile covers all the arid north of the country (18° to 33° S) and the central part down to the lake district (33° to 41° 30′ S) except for the Río Maule and Río Itata basins (35° to 37° S). The most glaciated region of Chile is Patagonia, characterized by a wet climate, but glacier data are lacking over vast areas of this region. A total area of 5515 km2 has been inventoried in Chile; this does not include Hielo Patagónico Sur (southern Patagonia ice field), by far the largest glaciated area in Chile with an area of 13000km2, part of which is in Argentina. Including the uninventoried giaciers of Maule, Itata and Patagonia, the total glaciated area in Chile is estimated to be 201715 km2.Information on glacier variations in the north of Chile is very scarce. In the central and south-central parts, and especially in Patagonia where glacier variations have been most studied, there is ample evidence for general glacier retreat from a neoglacial maximum, although a few glacier advances have been reported. The generalized retreat might be a result of tropospheric warming observed in the second half of the 20th century.
Remote Sensing of the Ross Ice Streams and Adjacent Ross Ice Shelf, Antarctica
Authors: Bentley C.R. , Shabtaie S. , Blankenship D.D. , Rooney S.T. , Schultz D.G. , Anandakrishnan S. , Alley R.B. 
Published: September 2017

In the first few seasons of the Antarctic Siple Coast project, the University of Wisconsin has concentrated on radar and seismic studies. Highlights of the results to date include the delineation of ice streams A, B, and C and the ridges in between, determination of the surface elevations over the area, discovery of a much more advanced grounding line than previously recognized and recognition of a broad, flat, barely grounded “ice plain” just inside the grounding line. Complex zones between and adjoining some of the ice streams, characterized by an interspersal of undisturbed ice and crevassed patches, give the impression of being transformed from sheet flow into stream flow in a process of ice stream expansion. An indicated negative mass balance for ice stream B could be the result of this “activation” process. Ice stream C, currently stagnant, exhibits terraces and reversals of surface slope, associated with zones of strong, steady basal radar reflections. These features suggest that subglacial water has been trapped by reversals in the hydraulic pressure gradient.Low seismic P-wave and S-wave velocities in a meters-thick layer immediately below the ice strongly indicate a saturated sediment of such high porosity (~40%) and low effective (differential) pressure (~50 kPa, or 0.5% of the glaciostatic pressure) that it must be too weak not to be deforming. We presume this deforming layer to be a dilated till. Its base exhibits ridges and troughs parallel to the flow direction that resemble glacial megaflutes. We believe that at our site on the upper part of ice stream B the ice stream moves principally by deforming its bed. Analysis of seismographic recordings of micro-earthquakes that occur at the glacier bed shows that the micro-earthquakes are both small in energy and infrequent. This implies that virtually none of the energy of ice stream motion is dissipated by brittle fracture at the bed. If our models are correct, the subgiacial deforming till becomes increasingly soft down-glacier, and/or the ice becomes decoupled from the till by intervening water, until on the “ice plain” basal drag is less important than longitudinal stresses in the dynamic balance. Our models also imply that the “ice plains” rest on “till deltas” that have been formed by the deposition of till carried along beneath the ice streams, and that the till deltas, and the grounding lines that bound them, are currently advancing in front of the active ice streams.
Bio-based 3-hydroxypropionic Acid: A Review
Authors: Vidra Aladár , Németh Áron 
Published: September 2017

3-hydroxypropionic acid is a commercially valuable, important platform chemical. It can serve as a precursor for several key compound, such as acrylic acid, 1,3-propanediol, methyl acrylate, acrylamide, ethyl 3-HP, malonic acid, propiolactone and acrylonitrile. Several microorganisms can produce through a range of metabolic pathways. It is indispensable for the commercial production of 3-HP to use cheap and abundant substrates and also to produce in highly efficient processes which could result high yield, titer and productivity. Because of the fact, that natural microorganism do not perform these conditions, metabolic engineering and genetically engineered microorganism are widely used for research and production as well. Several metabolic pathways are introduced to utilize glucose or glycerol for 3-HP production. In this overview naturally producer microorganisms, synthetic biochemical pathways, results from the recent years and recovery of 3-HP are detailed.
SEROPREVALENCE OF TOXOPLASMOSIS IN WOMEN IN MYMENSINGH AND RANGPUR IN BANGLADESH: A HOSPITAL SURVEY
Authors: Margia U. H. , Begum N. , Hossain M. S. , Dey A. R. , Alam M. Z. 
Published: September 2017

Toxoplasmosis is a great zoonotic threat that affects human species specially women. It has got major health significance because it causes abortion in pregnant women. The aim of this study was to determine seroprevalence of toxoplasmosis in women in Mymensingh and Rangpur in Bangladesh and to identify possible risk factors associated with toxoplasmosis. In this study, 87 women of 15 to 45 years old were included. Among 87 women, 74.7% (n = 65) were seronegative and 25.3% were (n=22) seropositive for T. gondii IgG and IgM antibodies. However, seroprevalence was higher in women aged between 31-45years. Relationship between T. gondii antibody and pregnancy was found significant (p<0.05). This study also reveals that pregnant women are more susceptible to toxoplasmosis than non-pregnant women. Thusly, regular screening test for toxoplasmosis is necessary for pregnant women in Bangladesh.
Average Albedos of Close-in Super-Earths and Super-Neptunes from Statistical Analysis of Long-cadence Kepler Secondary Eclipse Data
Authors: Sheets Holly A. , Deming Drake 
Published: September 2017

Abstract
We present the results of our work to determine the average albedo for small, close-in planets in the Kepler candidate catalog. We have adapted our method of averaging short-cadence light curves of multiple Kepler planet candidates to long-cadence data, in order to detect an average albedo for the group of candidates. Long-cadence data exist for many more candidates than the short-cadence data, and so we separate the candidates into smaller radius bins than in our previous work: 1–2

, 2–4

, and 4–6

. We find that, on average, all three groups appear darker than suggested by the short-cadence results, but not as dark as many hot Jupiters. The average geometric albedos for the three groups are 0.11 ± 0.06, 0.05 ± 0.04, and 0.23 ± 0.11, respectively, for the case where heat is uniformly distributed about the planet. If heat redistribution is inefficient, the albedos are even lower, since there will be a greater thermal contribution to the total light from the planet. We confirm that newly identified false-positive Kepler Object of Interest (KOI) 1662.01 is indeed an eclipsing binary at twice the period listed in the planet candidate catalog. We also newly identify planet candidate KOI 4351.01 as an eclipsing binary, and we report a secondary eclipse measurement for Kepler-4b (KOI 7.01) of ∼7.50 ppm at a phase of ∼0.7, indicating that the planet is on an eccentric orbit.
ALMA Observations of the Archetypal “Hot Core” That Is Not: Orion-KL
Authors: Orozco-Aguilera M. T. , Zapata Luis A. , Hirota Tomoya , Qin Sheng-Li , Masqué Josep M 
Published: September 2017

Abstract
We present sensitive high angular resolution (∼0.″1–0.″3) continuum Atacama Large Millimeter/Submillimeter Array (ALMA) observations of the archetypal hot core located in the Orion Kleinmann-Low (KL) region. The observations were made in five different spectral bands (bands 3, 6, 7, 8, and 9) covering a very broad range of frequencies (149–658 GHz). Apart from the well-known millimeter emitting objects located in this region (Orion Source I and BN), we report the first submillimeter detection of three compact continuum sources (ALMA1–3) in the vicinities of the Orion-KL hot molecular core. These three continuum objects have spectral indices between 1.47 and 1.56, and brightness temperatures between 100 and 200 K at 658 GHz, suggesting that we are seeing moderate, optically thick dust emission with possible grain growth. However, as these objects are not associated with warm molecular gas, and some of them are farther out from the molecular core, we thus conclude that they cannot heat the molecular core. This result favors the hypothesis that the hot molecular core in Orion-KL core is heated externally.
Effects of Irradiation on the Evolution of Ultracompact X-Ray Binaries
Authors: Lü Guoliang , Zhu Chunhua , Wang Zhaojun , Iminniyaz Hoernisa 
Published: September 2017

Abstract
Using the Modules for Experiments in Stellar Astrophysics code, we investigate the influences of irradiation on ultracompact X-ray binary (UCXB) evolution. Although the persistent UCXBs have short orbital periods that result in high irradiation flux, the irradiation hardly affects the evolution of persistent sources because the white dwarfs (WDs) in these binaries have large masses that lead to very low irradiation depth. The irradiation has a significant effect on the transient sources during outburst phase. At the beginning of the outburst, high X-ray luminosity produces high radiation flux, which results in the significant expansion of WDs. Then, the irradiation triggers high mass-transfer rates, which can last several days for the transient sources with WDs whose masses are larger than

or several hundred years for those sources with WDs whose masses are less than

. The observed three persistent UCXBs, XTE J0929-314, 4U 1916-05, and SWIFT J1756.9-2508, may belong to the latter.
Longitudinal Study of Falls among HIV-Infected and Uninfected Women: The Role of Cognition
Authors: Sharma Anjali , Hoover Donald R , Shi Qiuhu , Holman Susan , Plankey Michael W , Tien Phyllis C , Weber Kathleen M , Floris-Moore Michelle , Bolivar Hector H , Vance David E , Golub Elizabeth T , Holstad Marcia McDonnell , Yin Michael T 
Published: September 2017

Background Although fracture rates are higher in HIV+ than HIV- women, whether HIV infection increases risk of falls is unclear. We determined the longitudinal occurrence and risk factors for falls in the Women's Interagency HIV Study (WIHS), and explored associations with cognitive complaints. Methods Recent (prior 6 months) self-reported falls were collected in 1,816 (1,250 HIV+; 566 HIV-) women over 24 months. Generalized estimating equation models using stepwise selection determined odds of any fall (versus none). Results HIV+ women were older than HIV- women (median 49 versus 47 years; P=0.0004), more likely to report neuropathy (20% versus 16%; P=0.023), and had greater central nervous system (CNS) medication use. At least one fall was reported in 41% HIV+ versus 42% HIV- women, including ≥2 falls in 25% HIV+ and 24% HIV-(overall P=0.30). Cognitive complaints were associated with falls among HIV+ (odds ratio [OR] 2.38; 95% CI 1.83, 3.09) and HIV- women (OR 3.43; 95% CI 2.37, 4.97); in adjusted models, cognitive complaints remained significant only in HIV- women (adjusted [aOR] 2.26; 95% CI 1.46, 3.48). Factors associated with any fall in adjusted analyses included: depressive symptoms and neuropathy (both HIV+ and HIV-); age, marijuana use, multiple CNS medications, and HCV infection (HIV+ only); and cognitive complaints, quality of life, hypertension and obesity (HIV- only). Conclusions Middle-aged HIV+ and HIV- women had similar fall rates. Among HIV+ women, factors affecting cognition such as age, depressive symptoms, marijuana use and multiple CNS medications were important predictors of falls, however, cognitive complaints were not.
Industrialisation et transformation structurelle : l’Afrique subsaharienne peut-elle se développer sans usines ?
Authors: Cadot Olivier , de Melo Jaime , Plane Patrick , Wagner Laurent , Woldemichael Martha Tesfaye 
Published: September 2017

Avec une croissance soutenue, une vague d’investissements directs étrangers sans précédent et un net recul de la pauvreté, le bilan des quinze dernières années est largement positif pour l’Afrique sub-saharienne. Ce regain de croissance, qui s’est accompagné de réformes économiques importantes, de progrès démocratiques et d’une moindre incidence des conflits, demeure cependant fragile. La transformation structurelle, qui historiquement a pris la forme, dans la plupart des pays aujourd’hui développés, d’un transfert de ressources du secteur primaire au secteur secondaire, puis tertiaire, semble, en Afrique, avoir « contourné » le secteur secondaire. En effet, qu’il s’agisse d’emplois ou de valeur ajoutée, le secteur manufacturier ne s’est jamais réellement développé en Afrique subsaharienne. Dans la plupart des pays, la tendance, que la croissance récente ne semble pas avoir inversée, est plutôt à la désindustrialisation. Parmi les facteurs contributifs largement documentés dans la littérature et dans les données, on compte au premier chef les incertitudes de l’environnement des affaires en présence de gouvernance publique défaillante, une relative cherté de la main-d’œuvre par rapport à ses qualifications, le manque d’infrastructures énergétiques et de transport (lié souvent à des problèmes de gouvernance) et le dysfonctionnement des marchés du crédit. Malgré l’amélioration récente du climat des affaires, peu de pays d’Afrique subsaharienne offrent des conditions attractives aux investisseurs du secteur manufacturier par rapport aux localisations alternatives, en particulier en Asie du Sud-Est. L’Afrique subsaharienne peut-elle alors se développer par les services ? Jusqu’à présent, les expériences nationales de développement « sans usines » sont trop rares et idiosyncrasiques pour servir de modèle ; cependant, en présence de progrès technique dans les services et en l’absence d’alternatives manufacturières crédibles, la question reste ouverte.
Les services peuvent-ils devenir un escalator de croissance pour les pays à faible revenu ?
Authors: Ghani Ejaz , O’Connell Stephen D. 
Published: September 2017

Plusieurs rapports de haut niveau s’inquiètent de la désindustrialisation prématurée dont semblent souffrir les pays à faible revenu, particulièrement en Afrique. Les derniers venus sur la voie du développement ont-ils manqué le bateau ? Leur croissance se fait-elle en l’absence de toute transformation structurelle ? Pas vraiment. Malgré la stagnation de leur secteur manufacturier, ces pays bénéficient de la Troisième révolution industrielle qui leur a permis de rattraper leur retard plus rapidement. Avec l’amplification mondiale de la production et de la commercialisation de services, fruit des progrès technologiques et de la mondialisation, les pays à faible revenu ont la possibilité de se développer plus rapidement grâce à l’amélioration de leur avantage comparatif. Cet avantage comparatif peut aussi bien concerner les services que le secteur manufacturier. Les escalators de croissance auxquels font face les lions africains pourraient simplement s’avérer différents de ceux qu’ont utilisés les tigres asiatiques.
La Guyane vue par les jésuites
Authors: Andriot Cédric 
Published: September 2017

L’auteur analyse le regard porté par les jésuites européens sur le territoire sud-américain de la Guyane depuis le milieu du xvii e siècle. Enfer ou paradis, la Guyane met à l’épreuve le projet missionnaire des religieux qui se vouent en priorité à l’évangélisation des Amérindiens. Leurs efforts pour décentrer leur regard, comprendre les « sauvages » et adapter leur action inspirée par le concile de Trente se heurtent à des limites. La maigreur des résultats, avant l’expulsion des jésuites en 1763, engendre une déception dans un contexte de compétition plus ou moins ouverte avec les autorités coloniales.
Les autorités spécialisées : Une nouveauté bienvenue dans la décentralisation au Liban ?
Authors: AbouAssi Khaldoun , O’M. Bowman Ann 
Published: September 2017

Les pays en transition sont confrontés à de nombreux défis politiques et économiques, qui sont souvent exacerbés par une corruption persistante et des conflits religieux fratricides. Au Liban, les gouvernements locaux existants se sont avérés inefficaces dans la prestation d’une série de services publics, en particulier ceux qui ont des retombées et des effets externes. Dans le présent article, nous proposons un changement structurel : l’introduction d’autorités locales spécialisées, chargées d’offrir un service unique en transcendant les frontières des différents gouvernements locaux. Cette proposition promet une solution innovante et pratique à certains problèmes existants ; de plus, elle permettra de répondre à certaines des complexités dans les milieux sociaux et politiques d’un pays caractérisé par des conflits intenses. Remarques à l’intention des praticiens Dans le présent article, nous proposons une recommandation stratégique afin d’aborder l’un des nombreux défis auxquels est confrontée la décentralisation au Liban. Les gouvernements locaux existants se sont avérés inefficaces dans la prestation d’une série de services publics, en particulier ceux qui ont des retombées et des effets externes. Nous proposons d’introduire des autorités locales spécialisées en guise de solution innovante et pratique à certains problèmes existants ; une méthode qui permettra par ailleurs de répondre à certaines des complexités dans les milieux sociaux et politiques d’un pays caractérisé par des conflits intenses. Nous proposons certains points de décision qui seront utiles aux décideurs et aux praticiens qui réfléchissent à des moyens de résoudre les problèmes actuels, les obstacles potentiels à la mise en œuvre et les facteurs d’atténuation.