bluuebunny/crossref_metadata_2025 huggingface dataset:
Can a coupled meteorology-chemistry model reproduce the historical trend in aerosol direct radiative effects over the Northern Hemisphere?
Authors: Xing J. , Mathur R. , Pleim J. , Hogrefe C. , Gan C.-M. , Wong D. C. , Wei C.
Published: May 2015

Abstract. The ability of a coupled meteorology-chemistry model, i.e., WRF-CMAQ, in reproducing the historical trend in AOD and clear-sky short-wave radiation (SWR) over the Northern Hemisphere has been evaluated through a comparison of 21 year simulated results with observation-derived records from 1990–2010. Six satellite retrieved AOD products including AVHRR, TOMS, SeaWiFS, MISR, MODIS-terra and -aqua as well as long-term historical records from 11 AERONET sites were used for the comparison of AOD trends. Clear-sky SWR products derived by CERES at both TOA and surface as well as surface SWR data derived from seven SURFRAD sites were used for the comparison of trends in SWR. The model successfully captured increasing AOD trends along with the corresponding increased TOA SWR (upwelling) and decreased surface SWR (downwelling) in both eastern China and the northern Pacific. The model also captured declining AOD trends along with the corresponding decreased TOA SWR (upwelling) and increased surface SWR (downwelling) in eastern US, Europe and northern Atlantic for the period of 2000–2010. However, the model underestimated the AOD over regions with substantial natural dust aerosol contributions, such as the Sahara Desert, Arabian Desert, central Atlantic and north Indian Ocean. Estimates of aerosol direct radiative effect (DRE) at TOA are comparable with those derived by measurements. Compared to GCMs, the model exhibits better estimates of surface- aerosol direct radiative efficiency (Eτ). However, surface-DRE tends to be underestimated due to the underestimated AOD in land and dust regions. Further investigation of TOA-Eτ estimations as well as the dust module used for estimates of windblown-dust emissions is needed.
Methane-related changes in prokaryotes along geochemical profiles in sediments of Lake Kinneret (Israel)
Authors: Bar-Or I. , Ben-Dov E. , Kushmaro A. , Eckert W. , Sivan O.
Published: May 2015

Abstract. Microbial methane oxidation is the primary control on the emission of the greenhouse gas methane into the atmosphere. In terrestrial environments, aerobic methanotrophic bacteria are largely responsible for this process. In marine sediments, a coupling of anaerobic oxidation of methane (AOM) with sulfate reduction, often carried out by a consortium of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria, consumes almost all methane produced within those sediments. Motivated by recent evidence for AOM with iron(III) in Lake Kinneret sediments, the goal of the present study was to link the geochemical gradients in the lake porewater to the microbial community structure. Screening of archaeal 16S rRNA gene sequences revealed a shift from hydrogenotrophic to acetoclastic methanogens with depth. The observed changes in microbial community structure suggest possible direct and indirect mechanisms for the AOM coupled to iron reduction in deep sediments. The percentage of members of the Nitrospirales order increased with depth, suggesting their involvement in iron reduction together with Geobacter genus and "reverse methanogenesis". An indirect mechanism through sulfate and ANME seems less probable due to the absence of ANME sequences. This is despite the abundant sequences related to sulfate-reducing bacteria (Deltaproteobacteria) together with the occurrence of dsrA in the deep sediment that could indicate the production of sulfate (disproportionation) from S0 for sulfate-driven AOM. The presence of the functional gene pmoA in the deep anoxic sediment together with sequences related to Methylococcales suggests the existence of a second unexpected indirect pathway – aerobic methane oxidation pathway in an anaerobic environment.
Projected impacts of climate change and ocean acidification on the global biogeography of planktonic Foraminifera
Authors: Roy T. , Lombard F. , Bopp L. , Gehlen M.
Published: May 2015

Abstract. Planktonic Foraminifera are a major contributor to the deep carbonate flux and their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically based planktonic foraminifer model that incorporates three known major physiological drivers of their biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic Foraminifera under anthropogenic climate change and (ii) the alteration of the carbonate chemistry of foraminiferal habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of Foraminifera are simulated using temperature, plankton biomass and light from an Earth system model forced with a historical and a future (IPCC A2) high CO2 emission scenario. Foraminiferal abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. Temperature is the dominant control on the future change in the biogeography of Foraminifera. Yet food availability acts to either reinforce or counteract the temperature-driven changes. In the tropics and subtropics the largely temperature-driven shift to depth is enhanced by the increased concentration of phytoplankton at depth. In the higher latitudes the food-driven response partly offsets the temperature-driven reduction both in the subsurface and across large geographical regions. The large-scale rearrangements in foraminiferal abundance and the reduction in the carbonate ion concentrations in the habitat range of planktonic foraminifers – from 10–30 μmol kg−1 in their polar and subpolar habitats to 30–70 μmol kg−1 in their subtropical and tropical habitats – would be expected to lead to changes in the marine carbonate flux. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of the volume of their habitat drops below the calcite saturation horizon.
Providing Authentic(ated) Food
Authors: Manning Louise , Smith Robert
Published: May 2015

The 2013 horsemeat scandal and other such cases have led consumers to question their trust in extended global food supply chains. The aim of this research is to identify how small and medium-sized rural food retailers maintain food integrity with a market driver for cheaper food and the potential for food fraud. Qualitative interviews with industry insiders and analysis of data from rural food retail stores (n = 20) enabled a conceptual framework to be postulated. Adding value through Protected Geographical Indication (PGI) can deliver product differentiation, but also provides opportunities for food fraud/substitution if there is a large price differential between the niche and the standard product. Therefore value can be added to products by developing associated trust and social capital, but consumers must be safeguarded from making false assumptions on provenance or from potential food criminality and predatory, criminal entrepreneurs.
Farm Retailing: Motivations and Practice
Authors: Tonner Andrea , Wilson Juliette
Published: May 2015

This paper investigates rural diversification strategies, specifically focusing on farm retailing. The study reveals farmers' different motivations and experiences of structural diversification through both farmers' markets and wholly-owned farm shops. Using a qualitative study of eight farm businesses, the authors find that diversification is not always motivated by entrepreneurial objectives. Necessity (push) factors (such as agri-food market inequality) act as the catalysts transforming nascent diversification tendencies. Once the need for diversification is unlocked, farmers face an entrepreneurial choice: those with push motivations (such as risk reduction) choose non-entrepreneurial diversification in the form of farmers' markets, while those with pull motivations (such as business growth) exhibit characteristics of entrepreneurship and engage in entrepreneurial diversification in the form of on-farm retailing.
Microbrewing and Entrepreneurship
Authors: Danson Mike , Galloway Laura , Cabras Ignazio , Beatty Tina
Published: May 2015

This paper reports on an exploratory two-stage study of microbreweries in the UK. The first stage comprises an analysis of data from the Small Independent Breweries Association to offer an aggregate picture of the sector. The second stage reports on a qualitative study of the experiences of 14 microbreweries. The findings from the fieldwork show that the UK microbrewing sector is growing, that competitiveness within the brewing establishment is based on artisan manufacture, provenance and diversity rather than price, and that the sector is contestable but operates as a competitive fringe within the greater industry. The study illustrates that microbreweries can contribute to local economies and that, because of the innovation, diversity and growth in the sector, entrepreneurship is in evidence. While saturation seems a threat, the evidence presented here suggests that UK microbrewing is a healthy sector, with the prospect of ongoing growth and contribution.
Development of an Integrated Policy and Support Programme for Micro Rural Food Enterprises in an EU Peripheral Region
Authors: McAdam Rodney , Quinn Barry , McKitterick Lynsey , Dunn Adele , Patterson David
Published: May 2015

This case study explores how a peripheral rural region food support programme for small (micro) food enterprises was developed based on regional government food policy. An exploratory case study methodology is employed. The findings show that integration of policy and practice at a regional level should be reflected in the design and implementation of micro food business support programmes. This integration is essential to enable micro businesses to benefit from government aid in a collective manner which could not be achieved in government–micro-enterprise dyadic relationships.
Renal cell carcinoma and amyopathic dermatomyositis
Authors: Adili Anthony F. , Liaconis Haralambos , Gusenbauer Kaela , Kapoor Anil
Published: May 2015

Amyopathic dermatomyositis (dermatomyositis siné myositis) is a rare disorder with cutaneous lesions identical to those of classic dermatomyositis, but with no clinical evidence of myopathy. Association with malignancy has been suggested in a number of reports. We report the case of a 69-year-old man with a recent diagnosis of amyopathic dermatomyositis, who presented to the urology service with hematuria. Investigations revealed a 5.8- cm renal cell carcinoma and the patient underwent left radical nephrectomy without complication. To our knowledge, an association with renal cell carcinoma and amyopathic dermatomyositis has not been previously described.
Renal cell carcinoma after neuroblastoma: A case study and review of the literature
Authors: Wallace Brendan , Organ Michael , Bagnell Scott , Rendon Ricardo , Merrimen Jennifer
Published: May 2015

We present a case of renal cell carcinoma (RCC) arising in a 26-year-old patient with a history of neuroblastoma. RCC after a previous diagnosis of neuroblastoma is very uncommon, and there have only been 23 reported cases. Using the results of our patient workup, we hoped to determine whether there was a genetic predisposition or iatrogenic cause for the RCC. There is no clear explanation why neuroblastoma survivors are prone to developing RCC. However, genetic predisposition and previous treatment likely play a role. Since there have been few cases described, and few investigations into the genetics of this subtype of RCC, it remains important for individual cases to be added to the literature of this recently described and rare entity.
Oxygen Tension Regulates Human Mesenchymal Stem Cell Paracrine Functions
Authors: Paquet Joseph , Deschepper Mickael , Moya Adrien , Logeart-Avramoglou Delphine , Boisson-Vidal Catherine , Petite Hervé
Published: May 2015

Mesenchymal stem cells (MSCs) have captured the attention and research endeavors of the scientific world because of their differentiation potential. However, there is accumulating evidence suggesting that the beneficial effects of MSCs are predominantly due to the multitude of bioactive mediators secreted by these cells. Because the paracrine potential of MSCs is closely related to their microenvironment, the present study investigated and characterized select aspects of the human MSC (hMSC) secretome and assessed its in vitro and in vivo bioactivity as a function of oxygen tension, specifically near anoxia (0.1% O2) and hypoxia (5% O2), conditions that reflect the environment to which MSCs are exposed during MSC-based therapies in vivo. In contrast to supernatant conditioned media (CM) obtained from hMSCs cultured at either 5% or 21% of O2, CM from hMSCs cultured under near anoxia exhibited significantly (p < .05) enhanced chemotactic and proangiogenic properties and a significant (p < .05) decrease in the inflammatory mediator content. An analysis of the hMSC secretome revealed a specific profile under near anoxia: hMSCs increase their paracrine expression of the angiogenic mediators vascular endothelial growth factor (VEGF)-A, VEGF-C, interleukin-8, RANTES, and monocyte chemoattractant protein 1 but significantly decrease expression of several inflammatory/immunomodulatory mediators. These findings provide new evidence that elucidates aspects of great importance for the use of MSCs in regenerative medicine and could contribute to improving the efficacy of such therapies.

Significance

The present study investigated and characterized select aspects of the human mesenchymal stem cell (hMSC) secretome and assessed its in vitro and in vivo biological bioactivity as a function of oxygen tension, specifically near anoxia (0.1% O2) and hypoxia (5% O2), conditions that reflect the environment to which MSCs are exposed during MSC-based therapies in vivo. The present study provided the first evidence of a shift of the hMSC cytokine signature induced by oxygen tension, particularly near anoxia (0.1% O2). Conditioned media obtained from hMSCs cultured under near anoxia exhibited significantly enhanced chemotactic and proangiogenic properties and a significant decrease in the inflammatory mediator content. These findings provide new evidence that elucidates aspects of great importance for the use of MSCs in regenerative medicine, could contribute to improving the efficacy of such therapies, and most importantly highlighted the interest in using conditioned media in therapeutic modalities.
Transplantation of Induced Pluripotent Stem Cell-Derived Neural Stem Cells Mediate Functional Recovery Following Thoracic Spinal Cord Injury Through Remyelination of Axons
Authors: Salewski Ryan P. , Mitchell Robert A. , Li Lijun , Shen Carl , Milekovskaia Maria , Nagy Andras , Fehlings Michael G.
Published: May 2015

Neural stem cells (NSCs) from embryonic or fetal/adult tissue sources have shown considerable promise in regenerative strategies for traumatic spinal cord injury (SCI). However, there are limitations with their use related to the availability, immunogenicity, and uncertainty of the mechanisms involved. To address these issues, definitive NSCs derived from induced pluripotent stem (iPS) cells generated using a nonviral, piggyBac transposon approach, were investigated. Committed NSCs were generated from iPS cells using a free-floating neurosphere methodology previously described by our laboratory. To delineate the mechanism of action, specifically the role of exogenous myelination, NSCs derived from wildtype (wt) and nonmyelinating Shiverer (shi) iPS cell lines were used following thoracic SCI with subacute intraspinal transplantation. Behavioral, histological, and electrophysiological outcomes were analyzed to assess the effectiveness of this treatment. The wt- and shi-iPS-NSCs were validated and shown to be equivalent except in myelination capacity. Both iPS-NSC lines successfully integrated into the injured spinal cord and predominantly differentiated to oligodendrocytes, but only the wt-iPS-NSC treatment resulted in a functional benefit. The wt-iPS-dNSCs, which exhibited the capacity for remyelination, significantly improved neurobehavioral function (Basso Mouse Scale and CatWalk), histological outcomes, and electrophysiological measures of axonal function (sucrose gap analysis) compared with the nonmyelinating iPS-dNSCs and cell-free controls. In summary, we demonstrated that iPS cells can generate translationally relevant NSCs for applications in SCI. Although NSCs have a diverse range of functions in the injured spinal cord, remyelination is the predominant mechanism of recovery following thoracic SCI.

Significance

Gain-of-function/loss-of-function techniques were used to examine the mechanistic importance of graft-derived remyelination following thoracic spinal cord injury (SCI). The novel findings of this study include the first use of neural stem cells (NSCs) from induced pluripotent stem cells (iPSCs) derived using the clonal neurosphere expansion conditions, for the treatment of SCI, the first characterization and in vivo application of iPSCs from Shiverer mouse fibroblasts, and the first evidence of the importance of remyelination by pluripotent-sourced NSCs for SCI repair and regeneration.
Evaluating the Effectiveness of Cryopreserved Acellular Dermal Matrix in Immediate Expander-Based Breast Reconstruction: A Comparison Study
Authors: Kim So-Young , Lim So Young , Mun Goo-Hyun , Bang Sa-Ik , Oh Kap Sung , Pyon Jai-Kyong
Published: May 2015

Background CGCryoDerm was first introduced in 2010 and offers a different matrix preservation processes for freezing without drying preparation. From a theoretical perspective, CGCryoDerm has a more preserved dermal structure and more abundant growth factors for angiogenesis and recellularization. In the current study, the authors performed a retrospective study to evaluate freezing- and freeze-drying-processed acellular dermal matrix (ADM) to determine whether any differences were present in an early complication profile.

Methods Patients who underwent ADM-assisted tissue expander placement for two stage breast reconstruction between January of 2013 and March of 2014 were retrospectively reviewed and divided into two groups based on the types of ADM-assisted expander reconstruction (CGDerm vs. CGCryoDerm). Complications were divided into four main categories and recorded as follows: seroma, hematoma, infection, and mastectomy skin flap necrosis.

Results In a total of 82 consecutive patients, the CGCryoDerm group had lower rates of seroma when compared to the CGDerm group without statistical significance (3.0% vs. 10.2%, P=0.221), respectively. Other complications were similar in both groups. Reconstructions with CGCryoDerm were found to have a significantly longer period of drainage when compared to reconstructions with CGDerm (11.91 days vs. 10.41 days, P=0.043).

Conclusions Preliminary findings indicate no significant differences in early complications between implant/expander-based reconstructions using CGCryoderm and those using CGDerm.
Perspectives de chefs : points de vue de trois chefs d’orchestre québécois sur la notation musicale aujourd’hui
Authors: Brasset Marie-Pierre
Published: May 2015

La présente enquête porte sur la notation et offre la retranscription d’entretiens réalisés par la compositrice Marie-Pierre Brasset avec trois chefs d’orchestre de la scène de la création musicale contemporaine montréalaise, soit Lorraine Vaillancourt, Véronique Lacroix et Walter Boudreau. Dans ces entrevues menées individuellement, les chefs dévoilent la nature particulière de leur lien avec la notation et partagent diverses réflexions nourries de leur vaste expérience. Au fil des entretiens, les chefs ne manquent pas de souligner les écueils souvent rencontrés dans leur métier, mais expriment aussi leur admiration devant le haut degré de sophistication du système notationnel d’aujourd’hui.
Diagnostiquer la « schizophrénie spirituelle » du Canada français1 : la politique spirituelle de Claude Ryan, 1952-1958
Authors: Gauvreau Michael , Warren Jean-Philippe
Published: May 2015

Cet article analyse le rôle intellectuel de Claude Ryan dans une transformation culturelle de grande envergure au sein de l’Action catholique au Québec de 1945 à 1958. Durant ces années, la pensée de Ryan fut fortement influencée par de nouveaux courants de théologie catholique et la psychologie sociale dominant l’horizon de nombreux intellectuels américains. Sous son inspiration, l’Action catholique abandonne progressivement sa préoccupation initiale avec la réforme sociale, dominée par la « question des travailleurs » et la notion de la jeunesse comme classe à part dans la société moderne, pour une inquiétude centrée sur la classe moyenne québécoise, une orientation plus psychologique, centrée sur l’existence des mentalités religieuses et culturelles conflictuelles. Dès le milieu des années 1950, Ryan décerna dans ce conflit un vecteur dynamique de la sécularisation, mais il demeura plutôt optimiste que ces contemporains trouveraient, par le biais d’un catholicisme plus centré sur le spirituel, les ressources culturelles pour surmonter ce qu’il identifiait comme la « crise de l’adolescence » du Canada français.
La déploration, de Sarah Bernhardt à Al Pacino. Permanence et migration d’une posture codifiée (arts visuels, théâtre, cinéma1)
Authors: Damour Christophe
Published: May 2015

L’acteur demeure au coeur de la palette expressive d’artistes (qu’ils soient cinéastes, photographes ou metteurs en scène) recourant à des procédés rhétoriques similaires fondés sur la puissance iconique de certains gestes. Cet article ébauche une enquête figurative sur la reprise stylistique d’un motif partagé par différents champs scéniques et visuels (du théâtre classique au photojournalisme) et des cinématographies diverses (des cinémas muets européen et russe au cinéma hollywoodien contemporain) : la gestuelle codifiée et esthétisée de la déploration (affaissement, cris, mains portées aux tempes ou levées vers le ciel). L’analyse comparative et généalogique de telles survivances de la peinture romantique, de l’expressionnisme, de l’opéra et du mélodrame, qui révèle l’existence de véritables filiations artistiques, va ici de la Sarah Bernhardt de La Tosca (1887) au Pacino du troisième volet du Parrain (1990), en passant par certaines images-choc redondantes qui prolifèrent dans le champ médiatique.
Implications of freshwater flux data from the CMIP5 multimodel output across a set of Northern Hemisphere drainage basins
Authors: Bring Arvid , Asokan Shilpa M. , Jaramillo Fernando , Jarsjö Jerker , Levi Lea , Pietroń Jan , Prieto Carmen , Rogberg Peter , Destouni Georgia
Published: May 2015

The multimodel ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) synthesizes the latest research in global climate modeling. The freshwater system on land, particularly runoff, has so far been of relatively low priority in global climate models, despite the societal and ecosystem importance of freshwater changes, and the science and policy needs for such model output on drainage basin scales. Here we investigate the implications of CMIP5 multimodel ensemble output data for the freshwater system across a set of drainage basins in the Northern Hemisphere. Results of individual models vary widely, with even ensemble mean results differing greatly from observations and implying unrealistic long‐term systematic changes in water storage and level within entire basins. The CMIP5 projections of basin‐scale freshwater fluxes differ considerably more from observations and among models for the warm temperate study basins than for the Arctic and cold temperate study basins. In general, the results call for concerted research efforts and model developments for improving the understanding and modeling of the freshwater system and its change drivers. Specifically, more attention to basin‐scale water flux analyses should be a priority for climate model development, and an important focus for relevant model‐based advice for adaptation to climate change.
Persistent millennial‐scale climate variability in the eastern tropical North Pacific over the last two glacial cycles
Authors: Arellano‐Torres Elsa , Ganeshram Raja S. , Pichevin Laetitia E. , Salas‐de‐Leon David Alberto
Published: May 2015

High‐resolution sediment records from the eastern tropical North Pacific (ETNP) spanning the last ~240 ka B.P. were studied to document the nature of millennial‐scale climatic events in the tropical Pacific and to investigate teleconnection mechanisms. We present organic carbon (%OC) and diffuse spectral reflectivity records as indicative of upwelling and productivity changes off NW Mexico over the middle to late Pleistocene. The new productivity records document the persistence of abrupt millennial‐scale changes over the last two glacial cycles. Detailed spectral and wavelet time series analyses show the predominance of longer climatic cycles (2–6 ka) during the last and the penultimate glacial periods. The persistence of millennial variability during the penultimate glacial, in absence of large ice rafted debris events in the North Atlantic, suggests that freshwater input through ice sheet dynamics is not essential for millennial‐scale climate variability. Given the worldwide emerging picture of remarkable similar millennial‐scale records over long time periods, we suggest that the pacing of this climate variability may represent a natural resonance in the climate system, amplified by a tightly coupled oceanic and atmospheric teleconnection processes. We present a schematic scenario of millennial‐scale climate change depicting the role of the tropical Pacific in this global teleconnection system by linking productivity and upwelling changes in the ETNP with shifts in the position of the Intertropical Convergence Zone and the strength of the subtropical North Pacific High.
Dielectric properties of Jovian satellite ice analogs for subsurface radar exploration: A review
Authors: Pettinelli Elena , Cosciotti Barbara , Di Paolo Federico , Lauro Sebastian Emanuel , Mattei Elisabetta , Orosei Roberto , Vannaroni Giuliano
Published: May 2015

The first European mission dedicated to the exploration of Jupiter and its icy moons (JUpiter ICy moons Explorer—JUICE) will be launched in 2022 and will reach its final destination in 2030. The main goals of this mission are to understand the internal structure of the icy crusts of three Galilean satellites (Europa, Ganymede, and Callisto) and, ultimately, to detect Europa's subsurface ocean, which is believed to be the closest to the surface among those hypothesized to exist on these moons. JUICE will be equipped with the 9 MHz subsurface‐penetrating radar RIME (Radar for Icy Moon Exploration), which is designed to image the ice down to a depth of 9 km. Moreover, a parallel mission to Europa, which will host onboard REASON (Radar for Europa Assessment and Sounding: Ocean to Near‐surface) equipped with 9MHz and 60MHz antennas, has been recently approved by NASA. The success of these experiments strongly relies on the accurate prediction of the radar performance and on the optimal processing and interpretation of radar echoes that, in turn, depend on the dielectric properties of the materials composing the icy satellite crusts. In the present review we report a complete range of potential ice types that may occur on these icy satellites to understand how they may affect the results of the proposed missions. First, we discuss the experimental results on pure and doped water ice in the framework of the Jaccard theory, highlighting the critical aspects in terms of a lack of standard laboratory procedures and inconsistency in data interpretation. We then describe the dielectric behavior of extraterrestrial ice analogs like hydrates and icy mixtures, carbon dioxide ice and ammonia ice. Building on this review, we have selected the most suitable data to compute dielectric attenuation, velocity, vertical resolution, and reflection coefficients for such icy moon environments, with the final goal being to estimate the potential capabilities of the radar missions as a function of the frequency and temperature ranges of interest for the subsurface sounders. We present the different subsurface scenarios and associated radar signal attenuation models that have been proposed so far to simulate the structure of the crust of Europa and discuss the physical and geological nature of various dielectric targets potentially detectable with RIME. Finally, we briefly highlight several unresolved issues that should be addressed, in near future, to improve our capability to produce realistic electromagnetic models of icy moon crusts. The present review is of interest for the geophysical exploration of all solar system bodies, including the Earth, where ice can be present at the surface or at relatively shallow depths.
The emergence of topographic steady state in a perpetually dynamic self‐organized critical landscape
Authors: Reinhardt Liam , Ellis Michael A.
Published: May 2015

We conducted a series of four physical modeling experiments of mountain growth at differing rates of uplift and three distinct climates ranging from relatively wet to relatively dry. The spatial and temporal pattern of landscape behavior is characterized by ∼f−1 scaling in sediment discharge and power law scaling in the magnitude and frequency of ridge movement in all four experiments. We find that internally generated self‐organized critical (SOC) processes generate dynamically stable catchment geometries after ∼1 relief depths of erosion: these regularly spaced catchments have an average outlet‐spacing ratio of 2.16, well within the range of values reported in field studies. Once formed, large catchment bounding ridges oscillate about a critically balanced mean location, with occasional large‐scale changes in catchment size. Ridge movement appears to be driven by the competition for discharge as landslides push ridges back and forth. These dynamics lead to the emergence of a complex twofold scaling in catchment dynamics that is fully established by 1.8 relief depths of erosion; at this stage, a clear threshold has emerged separating two distinct scaling regimes, where large ridge mobility is insensitive to relief and small ridge mobility is relief dependent. Overall, we demonstrate that the development of dynamically stable large‐scale landforms is related to the emergence of a complex‐system hierarchy in topographic dynamics. Once formed, these landscapes do not evolve; statistical properties such as average topography and discharge become stationary while topography remains highly dynamic at smaller length scales.
Probabilistic inference of multi‐Gaussian fields from indirect hydrological data using circulant embedding and dimensionality reduction
Authors: Laloy Eric , Linde Niklas , Jacques Diederik , Vrugt Jasper A.
Published: May 2015

We present a Bayesian inversion method for the joint inference of high‐dimensional multi‐Gaussian hydraulic conductivity fields and associated geostatistical parameters from indirect hydrological data. We combine Gaussian process generation via circulant embedding to decouple the variogram from grid cell specific values, with dimensionality reduction by interpolation to enable Markov chain Monte Carlo (MCMC) simulation. Using the Matérn variogram model, this formulation allows inferring the conductivity values simultaneously with the field smoothness (also called Matérn shape parameter) and other geostatistical parameters such as the mean, sill, integral scales and anisotropy direction(s) and ratio(s). The proposed dimensionality reduction method systematically honors the underlying variogram and is demonstrated to achieve better performance than the Karhunen‐Loève expansion. We illustrate our inversion approach using synthetic (error corrupted) data from a tracer experiment in a fairly heterogeneous 10,000‐dimensional 2‐D conductivity field. A 40‐times reduction of the size of the parameter space did not prevent the posterior simulations to appropriately fit the measurement data and the posterior parameter distributions to include the true geostatistical parameter values. Overall, the posterior field realizations covered a wide range of geostatistical models, questioning the common practice of assuming a fixed variogram prior to inference of the hydraulic conductivity values. Our method is shown to be more efficient than sequential Gibbs sampling (SGS) for the considered case study, particularly when implemented on a distributed computing cluster. It is also found to outperform the method of anchored distributions (MAD) for the same computational budget.
Map of low‐frequency electromagnetic noise in the sky
Authors: Füllekrug Martin , Mezentsev Andrew , Watson Robert , Gaffet Stéphane , Astin Ivan , Smith Nathan , Evans Adrian
Published: May 2015

The Earth's natural electromagnetic environment is disturbed by anthropogenic electromagnetic noise. Here we report the first results from an electromagnetic noise survey of the sky. The locations of electromagnetic noise sources are mapped on the hemisphere above a distributed array of wideband receivers that operate in a small aperture configuration. It is found that the noise sources can be localized at elevation angles up to ∼60° in the sky, well above the horizon. The sky also exhibits zones with little or no noise that are found toward the local zenith and the southwest of the array. These results are obtained by a rigorous analysis of the residuals from the classic dispersion relation for electromagnetic waves using an array analysis of electric field measurements in the frequency range from ∼20 to 250 kHz. The observed locations of the noise sources enable detailed observations of ionospheric modification, for example, caused by particle precipitation and lightning discharges, while the observed exclusion zones enable the detection of weak natural electromagnetic emissions, for example, from streamers in transient luminous events above thunderclouds.
Spatial distribution of low‐energy plasma around comet 67P/CG from Rosetta measurements
Authors: Edberg N. J. T. , Eriksson A. I. , Odelstad E. , Henri P. , Lebreton J.‐P. , Gasc S. , Rubin M. , André M. , Gill R. , Johansson E. P. G. , Johansson F. , Vigren E. , Wahlund J. E. , Carr C. M. , Cupido E. , Glassmeier K.‐H. , Goldstein R. , Koenders C. , Mandt K. , Nemeth Z. , Nilsson H. , Richter I. , Wieser G. Stenberg , Szego K. , Volwerk M.
Published: May 2015

We use measurements from the Rosetta plasma consortium Langmuir probe and mutual impedance probe to study the spatial distribution of low‐energy plasma in the near‐nucleus coma of comet 67P/Churyumov‐Gerasimenko. The spatial distribution is highly structured with the highest density in the summer hemisphere and above the region connecting the two main lobes of the comet, i.e., the neck region. There is a clear correlation with the neutral density and the plasma to neutral density ratio is found to be ∼1–2·10−6, at a cometocentric distance of 10 km and at 3.1 AU from the Sun. A clear 6.2 h modulation of the plasma is seen as the neck is exposed twice per rotation. The electron density of the collisionless plasma within 260 km from the nucleus falls off with radial distance as ∼1/r. The spatial structure indicates that local ionization of neutral gas is the dominant source of low‐energy plasma around the comet.
The Alfvén mode gyrokinetic equation in finite‐pressure magnetospheric plasma
Authors: Klimushkin Dmitri Yu. , Mager Pavel N.
Published: May 2015

The paper is concerned with the derivation of the Alfvén mode equation in finite‐pressure space plasma in gyrokinetic approach. The long plasma approximation is used, where the bounce frequency is much lower than both wave and drift frequencies. The only ultralow frequency mode in the long plasma approximation is the Alfvén‐ballooning compressional mode, which is described by the Alfvénic dispersion relation with some additional (ballooning) terms caused by the field line curvature and plasma pressure effects. Due to these effects the Alfvén mode acquires also considerable parallel magnetic field component. The long plasma approximation allowed us to consider the correspondence between the gyrokinetic and MHD approaches for the Alfvén mode equation. It is shown that in 0 < β ≪ 1 case, MHD approach gives correct Alfvén wave description, where β is plasma to magnetic pressure ratio.
Strontium source and depth of uptake shifts with substrate age in semiarid ecosystems
Authors: Coble Ashley A. , Hart Stephen C. , Ketterer Michael E. , Newman Gregory S. , Kowler Andrew L.
Published: May 2015

Without exogenous rock‐derived nutrient sources, terrestrial ecosystems may eventually regress or reach a terminal steady state, but the degree to which exogenous nutrient sources buffer or slow to a theoretical terminal steady state remains unclear. We used strontium isotope ratios (87Sr/86Sr) as a tracer and measured 87Sr/86Sr values in aeolian dust, soils, and vegetation across a well‐constrained 3 Myr semiarid substrate age gradient to determine (1) whether the contribution of atmospheric sources of rock‐derived nutrients to soil and vegetation pools varied with substrate age and (2) to determine if the depth of uptake varied with substrate age. We found that aeolian‐derived nutrients became increasingly important, contributing as much as 71% to plant‐available soil pools and tree (Pinus edulis) growth during the latter stages of ecosystem development in a semiarid climate. The depth of nutrient uptake increased on older substrates, demonstrating that trees in arid regions can acquire nutrients from greater depths as ecosystem development progresses presumably in response to nutrient depletion in the more weathered surface soils. Our results demonstrate that global and regional aeolian transport of nutrients to local ecosystems is a vital process for ecosystem development in arid regions. Furthermore, these aeolian nutrient inputs contribute to deep soil nutrient pools, which become increasingly important for maintaining plant productivity over long time scales.
Ultrafine Grained Structures Resulting from SPD‐Induced Phase Transformation in Al–Zn Alloys
Authors: Sauvage Xavier , Murashkin Maxim Yu. , Straumal Boris B. , Bobruk Elena V. , Valiev Ruslan Z.
Published: May 2015

Three different Al–Zn alloys (2, 10, 30 wt% Zn) have been processed by severe plastic deformation (SPD) in the solutionized state to investigate the concomitant mechanisms of grain refinement and phase separation. The data of high resolution analytical transmission electron microscopy clearly reveal the key role of grain boundaries that promote Zn segregation and fast diffusion. Surprisingly, it is also shown that SPD carried out at 150 °C could give rise to a finer multiphase structure comparing to room temperature processing. Our observations seem to indicate that it resulted from a competition between the classical discontinuous precipitation of Zn and SPD‐induced dynamic precipitation.
Dispersible Plasmonic Doped Metal Oxide Nanocrystal Sensors that Optically Track Redox Reactions in Aqueous Media with Single‐Electron Sensitivity
Authors: Mendelsberg Rueben J. , McBride Patrick M. , Duong Jennifer T. , Bailey Mark J. , Llordes Anna , Milliron Delia J. , Helms Brett A.
Published: May 2015

Electron transfer in complex aqueous systems can be observed remotely with single‐electron sensitivity using locally dispersed nanostructures conferred with electronic charge concentration‐dependent plasmonic properties. When introduced to a system out of redox equilibrium, tin‐doped indium oxide nanocrystals undergo rapid multielectron transfer until redox equilibrium is reached; this modulates their free carrier concentration and plasmonic optical properties in the spectrally isolated near‐infrared. This capability is harnessed here to noninvasively track, model, and quantify electron transfer events reversibly for organic, inorganic, biogenic, and even living cells.
UV grafting process for synthetic drag reduction of biomimetic riblet surfaces
Authors: Chen Huawei , Che Da , Zhang Xin , Zhang Deyuan
Published: May 2015

Skin–friction drag accounts for a large portion of resistance encountered by water‐based vehicles, such as ships and submarines. Developing drag reduction methods to improve drag reduction performance has drawn worldwide attention recently. UV‐induced polymerization has been investigated as a way to graft the drag reduction agent PAM on to a PVC substrate with a biomimetic riblet surface. The effects of AM concentration and irradiation time on the grafting rate were explored to determine optimal grafting parameters. UV grafting polymerization was clarified by comparing the peak absorption variation of the infrared spectrum before and after grafting. The PAM thin film grafted on riblet surface was measured approximately 10 µm in thickness. A rotating disk apparatus was built to measure the synthetic drag reduction performance. The drag reduction rate of the grafted PAM riblet surface was tested at approximately 14%, higher than the 6% of the traditional riblet surface. Moreover, the excellent drag reduction performance of grafted PDMS riblet surface lasted for 12 days. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42303.
A conceptual model for video games and interactive media
Authors: Jett Jacob , Sacchi Simone , Lee Jin Ha , Clarke Rachel Ivy
Published: May 2015

In this article, we describe a conceptual model for video games and interactive media. Existing conceptual models such as the Functional Requirements for Bibliographic Records (FRBR) are not adequate to represent the unique descriptive attributes, levels of variance, and relationships among video games. Previous video game‐specific models tend to focus on the development of video games and their technical aspects. Our model instead attempts to reflect how users such as game players, collectors, and scholars understand video games and the relationships among them. We specifically consider use cases of gamers, with future intentions of using this conceptual model as a foundation for developing a union catalog for various libraries and museums. In the process of developing the model, we encountered many challenges, including conceptual overlap with and divergence from FRBR, entity scoping, complex relationships among entities, and the question of how to model additional content for game expansion. Future work will focus on making this model interoperable with existing ontologies as well as further understanding and description of content and relationships.
How much hybridization does machine translation Need?
Authors: Costa‐jussà Marta R.
Published: May 2015

Rule‐based and corpus‐based machine translation (MT) have coexisted for more than 20 years. Recently, boundaries between the two paradigms have narrowed and hybrid approaches are gaining interest from both academia and businesses. However, since hybrid approaches involve the multidisciplinary interaction of linguists, computer scientists, engineers, and information specialists, understandably a number of issues exist.

While statistical methods currently dominate research work in MT, most commercial MT systems are technically hybrid systems. The research community should investigate the benefits and questions surrounding the hybridization of MT systems more actively. This paper discusses various issues related to hybrid MT including its origins, architectures, achievements, and frustrations experienced in the community. It can be said that both rule‐based and corpus‐ based MT systems have benefited from hybridization when effectively integrated. In fact, many of the current rule/corpus‐based MT approaches are already hybridized since they do include statistics/rules at some point.
Fermi–Dirac, Bose–Einstein, Maxwell–Boltzmann, and computers
Authors: Fazarinc Zvonko
Published: May 2015

Few statistics other than the named three have opened the path to understanding of so many natural laws and formulas employed in the engineering practice. Engineers interested in origins of expressions they may be using in their work will find some of them in this paper. Planck's Radiation and Stefan–Boltzmann Laws, Maxwell's Velocity Distributions, P‐N diode equation, and intrinsic hole and electron concentrations in semiconductors are some examples. No new inventions are presented and the topics addressed are treated in books on statistical mechanics, thermodynamics, quantum and classical physics, chemistry and others. The contribution is an integration of a broad range of sciences underlying the formulas of interest under one roof of a relatively short paper. All derivations are done at the engineering level and originate in the first principles of conservation and quantization. Discrete mathematics is employed throughout and provides direct access to computerized experimentation. The appendixes assist the uninitiated in quantum physics and provide an ample collection of useful supporting material. © 2015 Wiley Periodicals, Inc. Comput. Appl. Eng. Educ. Comput Appl Eng Educ 23:746–759, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21647
Regulation task force report reveals costs, impact of compliance on higher ed world
Authors: Porter Michael
Published: May 2015

Almost every higher ed administrator is involved in federal government compliance efforts. Financial aid administrators must track and implement detailed Title IV regulations, and student life administrators must assess how specific Title IX guidance requirements are followed on their campuses. Security officials must stay attuned to the Clery Act and vagaries of the definitions of certain crimes and offenses. The list goes on and on.
Tread carefully when handling personnel‐related decisions
Authors: O'Brien Timothy
Published: May 2015

College administrators are called upon to make employment decisions on a very frequent basis.
Managed care, the legal system, and checklist medicine
Authors: Hoffman Sigalit
Published: May 2015

The scenario is one inpatient mental health professionals know well: they have finally begun to make inroads into treating a complicated patient and suddenly they find themselves at odds with a “peer” reviewer who just simply can't find a reason why their patient needs an inpatient level of care. The conversation begins courteously and then teeth become clenched, the pitch rises, and tempers may flare; one struggles to remain professional. The peer reviewer feigns surprise, then ignorance, and finally a complete and total lack of comprehension.
Elder Mediation and the Financial Abuse of Older People by a Family Member
Authors: Bagshaw Dale , Adams Valerie , Zannettino Lana , Wendt Sarah
Published: May 2015

This article analyzes quantitative and qualitative data collected from three Australian national online surveys with chief executive officers of organizations providing services to older people and their families and family mediation agencies, service providers working in those organizations, and older people and their relatives. Respondents were asked to identify risk factors for the financial abuse of older people by a family member, comment on the potential usefulness of elder mediation as a strategy to prevent this commonly reported form of abuse, identify the specialist knowledge and skills an elder mediator would need, and identify other factors to be considered.
Learn to view disability as an aspect of diversity to more fully integrate into your university
Authors: Sutton Halley
Published: May 2015

Donna Johnson, director of the Disability Resource Center at the University of Minnesota, Twin Cities, has helped integrate disability awareness into everyday campus life. Below, she explains her motivations for doing so, and the outcomes.
Consider possible impact on your procedures of best practices report for extended time for the LSAT
Authors: Masinter Michael R.
Published: May 2015

The outcome of legal proceedings about extended time on the Law School Admissions Test could have far‐reaching implications for how you determine students' eligibility for accommodations.