bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastohydrodynamic Study of Blends of Bio‐Based Esters with Polyalphaolefin in the Low Film Thickness Regime
Authors: Bantchev Grigor B. , Biresaw Girma , Cermak Steven C.
Published: January 2012

The film thickness in elastohydrodynamic (EHD) conditions for soybean oil (SBO), oleic estolide ester (EST) and their binary blends with polyalphaolefins (PAO2 or PAO40) were studied at 30 and 100 °C. Changes with time, for up to 200 min, were monitored. SBO and its blends with the lower viscosity PAO2 showed initially good agreement with the Hamrock–Dowson (H–D) equation down to 1–3 nm film thickness. 60 min or more after the start of the measurements, boundary layers with thickness up to 4.7 nm were observed. The blend of SBO with the more viscous PAO40 showed initially a good agreement with H–D at 100 °C. Negative deviations in film thickness were observed 15 min after the start of the measurements. At extended periods of time, up to 200 min, they were less pronounced but still detectable. EST–PAO2 blend showed initially formation of boundary layers with thickness around 2 nm. The boundary layer at 30 °C did not change for 200 min, while at 100 °C showed a decrease in thickness and/or viscosity with time. The EST and the EST–PAO40 blends showed good agreement with the H–D equation and did not display a boundary or fractionation layer within 200 min.
How Many Independent Rice Vocabularies in Asia?
Authors: Sagart Laurent
Published: January 2012

The process of moving from collecting plants in the wild to cultivating and gradually domesticating them has as its linguistic corollary the formation of a specific vocabulary to designate the plants and their parts, the fields in which they are cultivated, the tools and activities required to cultivate them and the food preparations in which they enter. From this point of view, independent domestications of a plant can be expected to result in wholly independent vocabularies. Conversely, when cultivation of a plant spreads from one population to another, one expects elements of the original vocabulary to spread with cultivation practices. This paper examines the vocabularies of rice in Asian languages for evidence of linguistic transfers, concluding that there are at least two independent vocabularies of rice in Asia. This suggests at least two independent starts of cultivation and domestications of Asian rice.
ON SOME PEXIDER-TYPE FUNCTIONAL EQUATIONS CONNECTED WITH THE ABSOLUTE VALUE OF ADDITIVE FUNCTIONS. PART I
Authors: PRZEBIERACZ BARBARA
Published: January 2012

We investigate the Pexider-type functional equation where f,g,h are real functions defined on an abelian group G.
Identifying factors limiting legume biomass production in a heterogeneous on-farm environment
Authors: DOUXCHAMPS S. , FROSSARD E. , UEHLINGER N. , RAO I. , VAN DER HOEK R. , MENA M. , SCHMIDT A. , OBERSON A.
Published: January 2012

Multipurpose legumes provide a wide range of benefits to smallholder production systems in the tropics. The degree of system improvement after legume introduction depends largely on legume biomass production, which in turn depends on the legumes’ adaptation to environmental conditions. For Canavalia brasiliensis (canavalia), an herbaceous legume that has been recently introduced in the Nicaraguan hillsides, different approaches were tested to define the biophysical factors limiting biomass production on-farm, by combining information from topsoil chemical and physical properties, topography and soil profiles.

Canavalia was planted in rotation with maize during two successive years on 72 plots distributed over six farms and at contrasting landscape positions. Above-ground biomass production was similar for both years and varied from 448 to 5357 kg/ha, with an average of 2117 kg/ha. Topsoil properties, mainly mineral nitrogen (N; ranging 25–142 mg/kg), total N (Ntot; 415–2967 mg/kg), soil organic carbon (SOC; 3–38 g/kg) and pH (5·3–7·1), significantly affected canavalia biomass production but explained only 0·45 of the variation. Topography alone explained 0·32 of the variation in canavalia biomass production. According to soil profiles descriptions, the best production was obtained on profiles with a root aggregation index close to randomness, i.e. with no major obstacles for root growth. When information from topsoil properties, topography and soil profiles was combined through a stepwise multiple regression, the model explained 0·61 of the variation in canavalia biomass (P < 0·001) and included soil depth (0·5–1·70 m), slope position, amount of clay (19–696 kg/m2) and stones (7–727 kg/m2) in the whole profile, and SOC and N content in the topsoil. The linkages between topsoil properties, topography and soil profiles were further evaluated through a principal component analysis (PCA) to define the best landscape position for canavalia cultivation.

The three data sets generated and used in the present study were found to be complementary. The profile description demonstrated that studies documenting heterogeneity in soil fertility should also consider deeper soil layers, especially for deep-rooted plants such as canavalia. The combination of chemical and physical soil properties with soil profile and topographic properties resulted in a holistic understanding of soil fertility heterogeneity and shows that a landscape perspective must be considered when assessing the expected benefits from multipurpose legumes in hillside environments.
Prospective study of the risk of not using prophylactic antibiotics in nasal packing for epistaxis
Authors: Pepper C , Lo S , Toma A
Published: January 2012

Background:

There is wide variation in UK prescribing practice regarding prophylactic antibiotics for nasal packing in spontaneous epistaxis. There are few published cases of infective complications in such patients.

Method:

This prospective study examined 149 consecutive patients admitted to a tertiary otorhinolaryngology centre with spontaneous epistaxis, who underwent nasal packing, over a six-month period. In the first three-month period, 78 patients were routinely prescribed prophylactic antibiotics; in the second three months, 71 patients were not routinely prescribed antibiotics. Exclusion criteria included antibiotics prescribed for unrelated pathology and post-operative epistaxis. Signs and symptoms of acute otitis media, sinusitis and toxic shock syndrome were assessed using clinical examination and a questionnaire.

Results:

Fourteen of the 149 patients experienced otalgia, most commonly following posterior nasal packing. No patient in either group had evidence of any infective complication.

Conclusion:

We do not recommend the routine prescription of prophylactic antibiotics for patients undergoing nasal packing for spontaneous epistaxis.
A language for all the world
Authors: Edwards John
Published: January 2012

In the popular mind, constructing a language has always been seen as an odd activity, one that seems to fly in the face of ‘natural’ language dynamics. It is, nonetheless, a very old activity, and attention to its various stages is an important part of the study of linguistic history – and, indeed, of modern scientific development. The first stage involves attempts (highly speculative, of course) to recapture the originallingua humana, as spoken in the Garden of Eden. At a later stage, scholars tried to create entire languagesab ovo, motivated by the desire for a more logical and regular variety that would better reflect and channel scientific classification. Later still – and on into the modern era – ‘artificial’ languages have been assembled from pre-existing rules and components. At all stages, the work has been underpinned by hopes for a more practical medium, but there have also been expectations that a language that was both regular and widely shared would contribute to international harmony and understanding.
Eight years of Legionnaires' disease transmission in travellers to a condominium complex in Las Vegas, Nevada
Authors: SILK B. J. , MOORE M. R. , BERGTHOLDT M. , GORWITZ R. J. , KOZAK N. A. , THA M. M. , BROWN E. W. , WINCHESTER J. L. , LABUS B. J. , ROWLEY P. , MIDDAUGH J. P. , FIELDS B. S. , HICKS L. A.
Published: January 2012

Travel is a risk factor for Legionnaires' disease. In 2008, two cases were reported in condominium guests where we investigated a 2001 outbreak. We reinvestigated to identify additional cases and determine whether ongoing transmission resulted from persistent colonization of potable water. Exposures were assessed by matched case-control analyses (2001) and case-series interviews (2008). We sampled potable water and other water sources. Isolates were compared using sequence-based typing. From 2001 to 2008, 35 cases were identified. Confirmed cases reported after the cluster in 2001–2002 were initially considered sporadic, but retrospective case-finding identified five additional cases. Cases were more likely than controls to stay in tower 2 of the condominium [matched odds ratio (mOR) 6·1, 95% confidence interval (CI) 1·6–22·9]; transmission was associated with showering duration (mOR 23·0, 95% CI 1·4–384). We characterized a clinical isolate as sequence type 35 (ST35) and detected ST35 in samples of tower 2's potable water in 2001, 2002, and 2008. This prolonged outbreak illustrates the importance of striving for permanent Legionella eradication from potable water.
EFL learner collaborative interaction in Second Life
Authors: Peterson Mark
Published: January 2012

This paper reports on the task-based interaction of English as a Foreign Language (EFL) learners in the 3D multiuser virtual environment (MUVE) Second Life. The discussion first explores research on the precursors of MUVEs, text-based 2D virtual worlds known as MOOs. This is followed by an examination of studies on the use of MUVEs in Computer Assisted Language Learning (CALL). The discussion then focuses on an investigation of the Second Life-based text chat of learners located at a university in Japan. Data analysis reveals that the environment, and tasks, elicited types of collaborative interaction hypothesized as beneficial in the sociocultural account of language development. Collaborative interaction identified in the data involved peer-scaffolding focusing on lexis, and correction. The data further showed that the participants actively maintained a supportive atmosphere through the provision of utterances designed to signal interest, and the extensive use of positive politeness. These factors facilitated social cohesion, intersubjectivity, and the consistent production of coherent target language output focused on the tasks. Participant feedback was broadly positive, and indicates that specific features of Second Life such as individual avatars, coupled to the computer-based nature of the interaction, appeared to enhance discourse management, engagement, and participation. The findings suggest that Second Life provides an arena for learner centered social interaction that offers valuable opportunities for target language practice, and the development of autonomy. Areas of potential for future research are identified.
On the Importance of Getting Things Done
Authors: Mansbridge Jane
Published: January 2012

Trend plus inaction equals drift. When a trend has external causes and no one can act to intervene, that inaction leads to drift—the unimpeded trajectory of change. Drift in the United States produces the domination of American democracy by business interests. Drift in international decisions produces global warming. Specific institutional designs for government, such as the US separation of powers, can cause the inaction that facilitates drift. More fundamentally, ingrained patterns of thinking can cause inaction. Here I argue that the long and multifacetedresistance traditionin the West contributes to inaction by focusing on stopping, rather than using, coercion.
Sweating the Vote: Heat and Abstention in the US House of Representatives
Authors: Cohen Alexander
Published: January 2012

Several recent studies noted systematic links between weather conditions and voting turnout amid the mass public. This article extends this logic to the elite level by exploring the relationship between summer heat and abstentions in the US House of Representatives. In controlled multivariate regressions, heat is a significant predictor of abstentions across all votes held between 1991 and 2000. This finding provides new insight into legislative behavior as well as the motivation behind some abstentions, which could inform the understanding of the literature on legislative shirking.
Kosovo: The International Community's European Project
Authors: McKinna Anita
Published: January 2012

This article is about the post-war governance of Kosovo and the contradiction posed by the focus on multi-ethnicity on the one hand, and the development of a new Kosovar identity that transcends ethnicity on the other. Post-war Kosovo represents a bold experiment by the international community to create a society that adheres to European standards. The international administration has based its post-war reconstruction and governance of Kosovo on standards aimed at EU accession. To this end, since 1999 the international administration in Kosovo has pursued multi-ethnicity as a panacea. Far from creating the conditions conducive to greater inter-ethnic integration, the policies enacted supposedly in the name of multi-ethnicity have resulted in the further entrenchment of ethnic division. At the same time, the international administration has promoted a new Kosovo identity that transcends ethnicity and that fits with European standards. This article questions the international administration's approach in governing post-war Kosovo with the ultimate goal of EU accession. It argues that this approach has failed both in creating a more multi-ethnic society and in creating a new identity that is embraced by the people of Kosovo. This situation in turn raises questions as to whether there is a genuine will from the people of Kosovo to fulfil such standards, and therefore whether the goal of EU integration for Kosovo is a realistic one.
The Story of Staro Sajmište Concentration Camp, Produced/Producing Europe
Authors: Syrri Despina
Published: January 2012

This article aims at considering the story of the Belgrade Staro Sajmište Second World War concentration camp, as it unfolded since October 2007. At that point, it captured national and international headlines, as a range of actors rallied to ban the private use of this memory place for a concert by a British pop group. The article concentrates on patterns of construction of memory(ies), space and transfers of knowledge as well as power as the Staro Sajmište story is ‘uncovered’ to the public in mainstream mass media. The focus of inquiry extends beyond the official realm of memory to media representations as central aspects of contemporary manifestations of collective memory. The article intends to explore the construction of narratives, public discourse and identities that directly impact democratic practice and citizenship in the wake of the radical social and political change that Serbia has experienced in the recent past and during the Western Balkans European Union accession process. It demonstrates that the multiple (hi)stories and fractured mnemonic genealogies of Staro Sajmište produce, and are themselves produced by, the narrative of European participation and integration, in an interplay between different discursive layers, such as the national narrative, the international and European narrative and the local Jewish narrative, as well as practices of spatial reconstruction and consumerism. The article is informed by understandings of the Balkans as a space that is inside and outside Europe in many senses, traversed by flows of people, funding and ideas/imaginaries of Europe and European-ness, concretised in specific projects and the relations that constitute them.
Habermas’ Wrapped Reichstag: Limits and Exclusions in the Discourse of Post-secularism
Authors: Singh Aakash
Published: January 2012

Jürgen Habermas’ recent work attempts to find ‘inspiring energy’ in the religious traditions, but without disturbing the rationality and freedoms of enlightenment modernity. Rather, the secular would assimilate the religious like a blood infusion, becoming more vibrant and stronger, but not losing its hard-won advantage. For Habermas, the post-secular problem lies in how best to preserve the secular democratic institutions, and keep them from being ‘violated’ through religiously motivated politics. Habermas criticizes Nicholas Wolterstorff, who would allow the religious to overrun the political, potentially violating vulnerable democratic institutions such as the parliament. Habermas suggests use of an ‘institutional filter’ to protect parliament from violation. Throughout his post-secular writings, he persistently employs Victorian-like innuendo bestowing masculine ‘inspiring energy’, ‘vitality’, and danger onto religion, which runs the risk of ‘violating’ effeminate democratic institutions symbolized by the parliament; thus the prophylactic device, the ‘filter’, which protects her virtue. One is reminded of Christo's and Jeanne-Claude's ‘Wrapped Reichstag’: in contrast to the Bundestag of today, with its glass dome (representing transparency) open to the public, we find in Christo's and Jeanne-Claude's work an enclosed, protective environment, a filter or prophylactic. In this vein, this paper will attempt to tease out from the language, word-choice, metaphors, and discourse of Habermas’ (post)secular dialectics that the religious enters solely on terms set by the secular, and plurality solely on terms set by stability/security.
Self-Organizing Tissue-Engineered Constructs in Collagen Hydrogels
Authors: Gourdie Robert G. , Myers Tereance A. , McFadden Alex , Li Yin-xiong , Potts Jay D.
Published: January 2012

A novel self-organizing behavior of cellularized gels composed of collagen type 1 that may have utility for tissue engineering is described. Depending on the starting geometry of the tissue culture well, toroidal rings of cells or hollow spheroids were prompted to form autonomously when cells were seeded onto the top of gels and the gels released from attachment to the culture well 12 to 24 h after seeding. Cells within toroids assumed distinct patterns of alignment not seen in control gels in which cells had been mixed in. In control gels, cells formed complex three-dimensional arrangements and assumed relatively higher levels of heterogeneity in expression of the fibronectin splice variant ED-A—a marker of epithelial mesenchymal transformation. The tissue-like constructs resulting from this novel self-organizing behavior may have uses in wound healing and regenerative medicine, as well as building blocks for the iterative assembly of synthetic biological structures.
Sachiko Myoken und die Schneetanzblumen
Authors: Kirfel Bernhard
Published: January 2012

Zusammenfassung. Begrüßungen, gute Wünsche, Gratulationen, Geschichten, Erzählungen, Fabeln, vor allem Gedichte stärken den sozialen Zusammenhalt und üben bei innerer Überzeugung und geeigneter Technik eine therapeutische Wirkung auf Sender und Empfänger aus. Ein deutscher Tetraplegiker und eine gleich schwerstbehinderte Japanerin werden zueinander in Beziehung gesetzt. Diese findet angesichts der wie Kirschblütenblätter fallenden Schneeflocken ihre Bestimmung als Dichterin und Anwältin der Kleinen, jener versandet in Langeweile. Ein deutscher Hemiplegiker wird ebenfalls durch seine Behinderung zum Dichter und Heiler.
Summer to winter variability in mesospheric calcium ion distribution and its dependence on Sporadic E at Arecibo
Authors: Raizada Shikha , Tepley Craig A. , Williams Bifford P. , García Raúl
Published: January 2012

We present a new investigation of the variability in the metallic calcium ion concentration near the mesopause region, and its relation to the electron concentration during summer and winter seasons at the Arecibo Observatory. During the summer months the ion layer is broader, extending to 87–88 km compared with winter months where it occurs above this altitude around midnight. The concentration maximizes to ∼200 ions cm−3 around 90–95 km close to midnight during the summer. However, for the winter months, the peak occurs during the early morning hours in thin descending layers above 98 km. Summer to winter variation in the calcium ion to electron ratio displays an average value of ∼0.15 and 0.05 during these seasons, respectively. A good correlation between them suggests that Ca+ densities are directly related to the strength of the Sporadic E, which is stronger in the summer. The average abundance of ions is 5.7 × 107 cm−2 and 4.6 × 107 cm−2 during summer and winter months respectively, while that for electrons is 1.2 × 1010 ions cm−2 and 5.8 × 109 ion cm−2 for these seasons. Both Ca+ and Ne display strong descending layers at different altitudes during summer and winter. Calcium ion lifetimes against neutralization are a factor of two lower during the summer than in the winter months around 90 km but similar at altitudes exceeding 95 km.
A statistical analysis of the optical dayside open/closed field line boundary
Authors: Johnsen M. G. , Lorentzen D. A.
Published: January 2012

In the cusp, the equatorward boundary of the auroral 6300 Å[OI] red line emission can be used as a proxy for the dayside open/closed field line boundary (OCB). In this paper we perform a statistical study based on ground‐based optical data from Longyearbyen, Svalbard, covering a period of 15 auroral seasons from 1995 to 2009 (northern hemisphere, winter conditions), concentrating on the time period close to magnetic noon in the dayside part of the auroral oval. Acquiring the OCB latitude from these data, we have compared it to a variety of solar wind coupling functions and geomagnetic indices. The OCB is, according to our findings, located at 75.4 degrees MLAT. The diurnal movement of the OCB latitude follows the poleward edge of the Feldstein auroral oval, confirming the notion that its poleward part is on open field lines. A causal relationship between the latitudinal location of the OCB and the solar cycle is demonstrated. A dependency is clearly seen between the negative Bz component of the interplanetary magnetic field and the OCB latitude. However, when plotting the OCB latitude as function of coupling functions where the solar wind velocity also is taken into account, better correlations are obtained. We are in this work not able to find previously used coupling functions that clearly distinguishes themselves from the others with respect to correlation coefficients. Good correlations with geomagnetic indices such as AE, PC and SYM/H, suggests that both processes at the magnetopause and in the magnetotail are needed in order to best understand the latitudinal location of the dayside OCB.
A survey of plasma irregularities as seen by the midlatitude Blackstone SuperDARN radar
Authors: Ribeiro A. J. , Ruohoniemi J. M. , Baker J. B. H. , Clausen L. B. N. , Greenwald R. A. , Lester M.
Published: January 2012

The Super Dual Auroral Radar Network (SuperDARN) is a chain of HF radars that monitor plasma dynamics in the ionosphere. In recent years, SuperDARN has expanded to midlatitudes in order to provide enhanced coverage during geomagnetically active periods. A new type of backscatter from F region plasma irregularities with low Doppler velocity has been frequently observed on the nightside during quiescent conditions. Using three years of data from the Blackstone, VA radar, we have implemented a method for extracting this new type of backscatter from routine observations. We have statistically characterized the occurrence properties of the Sub Auroral Ionospheric Scatter (SAIS) events, including the latitudinal relationships to the equatorward edge of the auroral oval and the ionospheric projection of the plasmapause. We find that the backscatter is confined to local night, occurs on ≈70% of nights, is fixed in geomagnetic latitude, and is equatorward of both the auroral region and the plasmapause boundary. We conclude that SAIS irregularities are observed within a range of latitudes that is conjugate to the inner magnetosphere (plasmasphere).
Impact of modifying the longwave water vapor continuum absorption model on community Earth system model simulations
Authors: Turner D. D. , Merrelli A. , Vimont D. , Mlawer E. J.
Published: January 2012

The far‐infrared (wavelengths longer than 17μm) has been shown to be extremely important for radiative processes in the earth's atmosphere. The strength of the water vapor continuum absorption in this spectral region has largely been predicted using observations at other wavelengths that have been extrapolated using semiempirical approaches such as the Clough‐Kneizys‐Davies (CKD) family of models. Recent field experiments using new far‐infrared instrumentation have supported a factor of 2 decrease in the modeled strength of the foreign continuum at 50μm and a factor of 1.5 increase in the self‐continuum at 24μm in the Clough‐Kneizys‐Davies continuum model (CKD v2.4); these changes are incorporated in the Mlawer‐Tobin‐CKD continuum model (MT_CKD v2.4). The water vapor continuum in the Community Earth System Model (CESM v1.0) was modified to use the newer model, and the impacts of this change were investigated by comparing output from the original and modified CESM for 20 year integrations with prescribed sea surface temperatures. The change results in an increase in the net upward longwave flux of order 0.5 W m−2between 300 and 400 mb, and a decrease in this flux of about the same magnitude for altitudes below 600 mb. The radiative impact results in a small but statistically significant change in the mean temperature and humidity fields, and also a slight decrease (order 0.5%) of high‐cloud amount. The change in the cloud amount modified the longwave cloud radiative forcing, which partially offset the radiative heating caused by the change in the water vapor continuum absorption model.
Snowpack variations since AD 1150 in the Andes of Chile and Argentina (30°–37°S) inferred from rainfall, tree‐ring and documentary records
Authors: Masiokas M. H. , Villalba R. , Christie D. A. , Betman E. , Luckman B. H. , Le Quesne C. , Prieto M. R. , Mauget S.
Published: January 2012

The Andean snowpack is the main source of freshwater and arguably the single most important natural resource for the populated, semi‐arid regions of central Chile and central‐western Argentina. However, apart from recent analyses of instrumental snowpack data, very little is known about the long term variability of this key natural resource. Here we present two complementary, annually‐resolved reconstructions of winter snow accumulation in the southern Andes between 30°–37°S. The reconstructions cover the past 850 years and were developed using simple regression models based on snowpack proxies with different inherent limitations. Rainfall data from central Chile (very strongly correlated with snow accumulation values in the adjacent mountains) were used to extend a regional 1951–2010 snowpack record back to AD 1866. Subsequently, snow accumulation variations since AD 1150 were inferred from precipitation‐sensitive tree‐ring width series. The reconstructed snowpack values were validated with independent historical and instrumental information. An innovative time series analysis approach allowed the identification of the onset, duration and statistical significance of the main intra‐ to multi‐decadal patterns in the reconstructions and indicates that variations observed in the last 60 years are not particularly anomalous when assessed in a multi‐century context. In addition to providing new information on past variations for a highly relevant hydroclimatic variable in the southern Andes, the snowpack reconstructions can also be used to improve the understanding and modeling of related, larger‐scale atmospheric features such as ENSO and the PDO.
Simulated volcanic ash imagery: A method to compare NAME ash concentration forecasts with SEVIRI imagery for the Eyjafjallajökull eruption in 2010
Authors: Millington S. C. , Saunders R. W. , Francis P. N. , Webster H. N.
Published: January 2012

During volcanic eruptions that eject ash into the atmosphere Volcanic Ash Advisory Centers issue statements on the forecast dispersion of the ash so that the aviation industry can manage airspace to avoid aircraft encountering volcanic ash. Observations, such as those from satellites, are compared with the forecasts from an atmospheric dispersion model to assess the quality of the ash forecasts. A method has been developed to enable like‐with‐like comparison between satellite imagery of volcanic ash and simulated imagery using the forecast ash concentration data from an atmospheric dispersion model. The ash concentration and numerical weather prediction data are used as inputs to a radiative transfer model to simulate radiances. Simulated satellite images are created from these simulated radiances. Here, Spinning Enhanced Visible and Infrared Imager volcanic ash images based on infrared brightness temperatures for the Eyjafjallajökull eruption in 2010 are simulated. In addition to providing a useful tool for forecasters in a Volcanic Ash Advisory Center, the simulated images can be used to aid the understanding of how the ash affects the satellite imagery and also the physical properties of the ash.
On the probability of occurrence of extreme space weather events
Authors: Riley Pete
Published: January 2012

By virtue of their rarity, extreme space weather events, such as the Carrington event of 1859, are difficult to study, their rates of occurrence are difficult to estimate, and prediction of a specific future event is virtually impossible. Additionally, events may be extreme relative to one parameter but normal relative to others. In this study, we analyze several measures of the severity of space weather events (flare intensity, coronal mass ejection speeds, Dst, and >30 MeV proton fluences as inferred from nitrate records) to estimate the probability of occurrence of extreme events. By showing that the frequency of occurrence scales as an inverse power of the severity of the event, and assuming that this relationship holds at higher magnitudes, we are able to estimate the probability that an event larger than some criteria will occur within a certain interval of time in the future. For example, the probability of another Carrington event (based on Dst < −850 nT) occurring within the next decade is ∼12%. We also identify and address several limitations with this approach. In particular, we assume time stationarity, and thus, the effects of long‐term space climate change are not considered. While this technique cannot be used to predict specific events, it may ultimately be useful for probabilistic forecasting.
Depths and focal mechanisms of crustal earthquakes in the central Andes determined from teleseismic waveform analysis and InSAR
Authors: Devlin S. , Isacks B. L. , Pritchard M. E. , Barnhart W. D. , Lohman R. B.
Published: January 2012

We investigate the depths of crustal earthquakes (<80 km depth) of the central Andes (5°S to 35°S) to constrain the relationship between earthquake locations and inferred faults. We assemble parameters from 138 moderate‐sized (7.0 > Mw ≳ 5.5) earthquakes from the Global CMT catalog and previous work spanning 1944–2007. For 38 well‐recorded events, we use teleseismic P and SH waveforms to model the strike, dip, rake, focal depth, and source time function. We use InSAR observations of surface deformation from 9 earthquakes to compare inferred fault parameters with the waveform inversions and global catalogs to assess their accuracies. While the depths from the InSAR and waveform analyses generally agree within error, horizontal and depth errors in global catalogs are 10 to 50 km, as found elsewhere. As noted in previous work, the majority of crustal earthquakes occur in the Eastern Cordillera and foreland regions of the central Andes, although a few normal and strike‐slip earthquakes occur beneath the Altiplano plateau and in the forearc in southern Peru and northernmost Chile. We propose a new interpretation of one of the basement thrusts (Shira Mountain, Peru) as a pop up block on the basis of our new earthquake depths. We confirm that earthquakes in the flat slab areas of Peru and Argentina are within the sometimes aseismic lower crust. Lower crustal earthquakes are globally found in all types of tectonic settings only when the thermal lithosphere is more than 80 km thick and the amount of recent shortening/extension is <30%.
Predicting natural base‐flow stream water chemistry in the western United States
Authors: Olson John R. , Hawkins Charles P.
Published: January 2012

Robust predictions of stream solute concentrations expected under natural (reference) conditions would help establish more realistic water quality standards and improve stream ecological assessments. Models predicting solute concentrations from environmental factors would also help identify the relative importance of different factors that influence water chemistry. Although data are available describing the major factors controlling water chemistry (i.e., geology, climate, atmospheric deposition, soils, vegetation, topography), geologic maps do not adequately convey how rocks vary in their chemical and physical properties. We addressed this issue by associating rock chemical and physical properties with geological map units to produce continuous maps of percentages of CaO, MgO, S, uniaxial compressive strength, and hydraulic conductivity for western United States lithologies. We used catchment summaries of these geologic properties and other environmental factors to develop multiple linear regression (LR) and random forest (RF) models to predict base flow electrical conductivity (EC), acid neutralization capacity (ANC), Ca, Mg, and SO4. Models were derived from observations at 1414 reference‐quality streams. RF models were superior to LR models, explaining 71% of the variance in EC, 61% in ANC, 92% in Ca, 58% in Mg, and 74% in SO4 when assessed with independent observations. The root‐mean‐square error for predictions on validation sites were all <11% of the range of observed values. The relative importance of different environmental factors in predicting stream chemistry varied among models, but on average rock chemistry > temperature > precipitation > soil = atmospheric deposition > vegetation > amount of rock/water contact > topography.
Fructose 2,6-bisphosphate is essential for glucose-regulated gene transcription of glucose-6-phosphatase and other ChREBP target genes in hepatocytes
Authors: Arden Catherine , Tudhope Susan J. , Petrie John L. , Al-Oanzi Ziad H. , Cullen Kirsty S. , Lange Alex J. , Towle Howard C. , Agius Loranne
Published: January 2012

Glucose metabolism in the liver activates the transcription of various genes encoding enzymes of glycolysis and lipogenesis and also G6pc (glucose-6-phosphatase). Allosteric mechanisms involving glucose 6-phosphate or xylulose 5-phosphate and covalent modification of ChREBP (carbohydrate-response element-binding protein) have been implicated in this mechanism. However, evidence supporting an essential role for a specific metabolite or pathway in hepatocytes remains equivocal. By using diverse substrates and inhibitors and a kinase-deficient bisphosphatase-active variant of the bifunctional enzyme PFK2/FBP2 (6-phosphofructo-2-kinase–fructose-2,6-bisphosphatase), we demonstrate an essential role for fructose 2,6-bisphosphate in the induction of G6pc and other ChREBP target genes by glucose. Selective depletion of fructose 2,6-bisphosphate inhibits glucose-induced recruitment of ChREBP to the G6pc promoter and also induction of G6pc by xylitol and gluconeogenic precursors. The requirement for fructose 2,6-bisphosphate for ChREBP recruitment to the promoter does not exclude the involvement of additional metabolites acting either co-ordinately or at downstream sites. Glucose raises fructose 2,6-bisphosphate levels in hepatocytes by reversing the phosphorylation of PFK2/FBP2 at Ser32, but also independently of Ser32 dephosphorylation. This supports a role for the bifunctional enzyme as the phosphometabolite sensor and for its product, fructose 2,6-bisphosphate, as the metabolic signal for substrate-regulated ChREBP-mediated expression of G6pc and other ChREBP target genes.
Up-regulation of FOXP3 and induction of suppressive function in CD4+ Jurkat T-cells expressing hepatitis C virus core protein
Authors: Dominguez-Villar Margarita , Fernandez-Ponce Cecilia , Munoz-Suano Alba , Gomez Esperanza , Rodríguez-Iglesias Manuel , Garcia-Cozar Francisco
Published: January 2012

HCV (hepatitis C virus) infection is a serious health care problem that affects more than 170 million people worldwide. Viral clearance depends on the development of a successful cellular immune response against the virus. Interestingly, such a response is altered in chronically infected patients, leading to chronic hepatitis that can result in liver fibrosis, cirrhosis and hepatocellular carcinoma. Among the mechanisms that have been described as being responsible for the immune suppression caused by the virus, Treg-cells (regulatory T-cells) are emerging as an essential component. In the present work we aim to study the effect of HCV-core protein in the development of T-cells with regulatory-like function. Using a third-generation lentiviral system to express HCV-core in CD4+ Jurkat T-cells, we describe that HCV-core-expressing Jurkat cells show an up-regulation of FOXP3 (forkhead box P3) and CTLA-4 (cytotoxic T-lymphocyte antigen-4). Moreover, we show that HCV-core-transduced Jurkat cells are able to suppress CD4+ and CD8+ T-cell responses to anti-CD3 plus anti-CD28 stimulation.
Informational Masking and Spatial Hearing in Listeners With and Without Unilateral Hearing Loss
Authors: Rothpletz Ann M. , Wightman Frederic L. , Kistler Doris J.
Published: January 2012

Purpose

This study assessed selective listening for speech in individuals with and without unilateral hearing loss (UHL) and the potential relationship between spatial release from informational masking and localization ability in listeners with UHL.

Method

Twelve adults with UHL and 12 normal-hearing controls completed a series of monaural and binaural speech tasks that were designed to measure informational masking. They also completed a horizontal localization task.

Results

Monaural performance by participants with UHL was comparable to that of normal-hearing participants. Unlike the normal-hearing participants, the participants with UHL did not exhibit a true spatial release from informational masking. Rather, their performance could be predicted by head shadow effects. Performance among participants with UHL in the localization task was quite variable, with some showing near-normal abilities and others demonstrating no localization ability.

Conclusion

Individuals with UHL did not show deficits in all listening situations but were at a significant disadvantage when listening to speech in environments where normal-hearing listeners benefit from spatial separation between target and masker. This inability to capitalize on spatial cues for selective listening does not appear to be related to localization ability.
Cochlear Implant in the Second Year of Life: Lexical and Grammatical Outcomes
Authors: Caselli Maria Cristina , Rinaldi Pasquale , Varuzza Cristiana , Giuliani Anna , Burdo Sandro
Published: January 2012

Purpose

The authors studied the effect of the cochlear implant (CI) on language comprehension and production in deaf children who had received a CI in the 2nd year of life.

Method

The authors evaluated lexical and morphosyntactic skills in comprehension and production in 17 Italian children who are deaf (
M
= 54 months of age) with a CI and in 2 control groups of children with normal hearing (NH; 1 matched for chronological age and the other whose chronological age corresponded to the duration of CI activation). The authors also compared children with unilateral CI to children with bilateral CI.

Results

Children with CI appeared to keep pace with NH children matched for time since CI activation in terms of language acquisition, and they were similar to same-age NH children in lexical production. However, children with CI showed difficulties in lexical comprehension when a task required phonological discrimination as well as in grammar comprehension and production. Children with bilateral CI showed better comprehension than did children with unilateral CI; the 2 groups were similar for production.

Conclusions

Activation of CI in the 2nd year of life may provide children who are deaf with a good opportunity to develop language skills, although some limitations in phonological and morphological skills are still present 3 years after auditory reafferentation.
Written Narrative Characteristics in Adults With Language Impairment
Authors: Suddarth Rachael , Plante Elena , Vance Rebecca
Published: January 2012

Purpose

Adults with language-based disabilities are known to have deficits in oral language; however, less is known about their written language skills. Two studies were designed to characterize the writing of adults with language-based disabilities.

Method

In Study 1, 60 adults, 30 with language impairment and 30 with typical language, completed written narratives. Forty-one written language measures were analyzed. In Study 2, the measures that had the most potential for reliably indexing deficits were analyzed in an additional 77 adults.

Results

Three measures that showed significant between-group differences and had robust effect sizes in Study 1, total number of verbs, 1-part verbs, and errors, were applied to the samples in Study 2. A group difference for percentage of errors was replicated in the second sample. A discriminant analysis identified 75% of the adults with language impairment and 30% of the adults with typical language as having an impairment based on the percent of written errors.

Conclusions

The writing task revealed consistent group differences in written errors and is clinically applicable in describing a client’s writing. However, the number of written errors was not robust enough to identify whether an adult had a language impairment or not.
Asynchronous Vowel-Pair Identification Across the Adult Life Span for Monaural and Dichotic Presentations
Authors: Fogerty Daniel , Kewley-Port Diane , Humes Larry E.
Published: January 2012

Purpose

Temporal order abilities decrease with age. Declining temporal processing abilities may influence the identification of rapid vowel sequences. Identification patterns for asynchronous vowel pairs were explored across the life span.

Method

Young, middle-aged, and older listeners completed temporal order tasks for pairs of 70-ms and 40-ms vowel stimuli. For a given vowel duration, naturally spoken vowels were equated for duration, intensity, and fundamental frequency. Listeners completed monaural and dichotic temporal order tasks that involved identifying the vowel pair in the correct order. The stimulus onset asynchrony that yielded 50% accuracy for identifying the vowel pair in the correct order was used to equate performance among listeners. Vowel identification response patterns were determined at this stimulus onset asynchrony threshold.

Results

Vowel identification patterns were largely consistent across age groups. Older listeners were influenced by the order of certain vowel pairs. Not all vowel pairs were identified equally well. Vowel dominance patterns were also observed, with /a/ being identified most accurately for the vowel pairs tested. Formant dynamics explained, in part, identification and confusion patterns.

Conclusion

Vowel identification accuracy patterns were reasonably similar across the life span, regardless of presentation mode, vowel duration, or effect of considerable stimulus exposure. Large effects of vowel order were observed, particularly for older listeners.
Stability and properties of stationary state of one dimensional space charge limited current
Authors: Rokhlenko A. , Lebowitz J. L.
Published: January 2012

A linear stability analysis of the planar one dimensional space charge limited flow shows that the classical Child’s solution is stable in time. Small perturbations of the flow are accompanied by high frequency oscillations that decay exponentially. These oscillations should appear when the flow regime changes rapidly, and they might be detectable experimentally by their electromagnetic radiation. We also study the stationary state of more general space charge limited flow and obtain a relation between the current density and the electric field at the emitter surface for arbitrary emission laws and a fixed non-zero initial speed of electrons. In such a case there is the possibility of creation of electrostatic barriers for the emission and stationary flow regimes in this simple model.
Extended hydrodynamic approach to quantum-classical nonequilibrium evolution. II. Application to nonpolar solvation
Authors: Hughes Keith H. , Baxter Sean N. , Bousquet David , Ramanathan Padmanaban , Burghardt Irene
Published: January 2012

The mixed quantum-classical formulation derived in our companion paper [D. Bousquet, K. H. Hughes, D. Micha, and I. Burghardt, J. Chem. Phys. 134, 064116 (2011)]10.1063/1.3553174, which is based upon a hydrodynamic representation of the classical sector, is applied to nonequilibrium nonpolar solvation dynamics as exemplified by the solvation of the electronically excited NO molecule in a rare gas environment. Derived from a partition of the Hamiltonian into a primary (quantum) part and a secondary (classical) part the hydrodynamic equations are formulated for multi-quantum states and result in explicit equations of motion for populations and coherences. The hierarchy of hydrodynamic equations is truncated by the following approximate closure schemes: Gauss-Hermite closure, dynamical density functional theory approximation, and a generalized Maxwellian closure. A comparison of the dynamics using these three closure methods showed that the suitability of a particular closure scheme was dependent on the initial conditions and the nonequilibrium character of the dynamics.
Photoluminescence decay of direct and indirect transitions in Ge/SiGe multiple quantum wells
Authors: Giorgioni A. , Gatti E. , Grilli E. , Chernikov A. , Chatterjee S. , Chrastina D. , Isella G. , Guzzi M.
Published: January 2012

We present a detailed experimental study of the photoluminescence decay of direct Γ-Γ and indirect L-Γ transitions in compressively strained Ge/Si0.15Ge0.85 type I multiple quantum wells. The lifetime of the fundamental L-Γ indirect-gap related transition is in the 6 to 13 ns range at the lattice temperature of 14 K. These values are just one order of magnitude higher than those typical of type-I direct gap III-V quantum wells and are significantly shorter than those characteristic of type-II indirect gap SiGe/Si quantum wells. The measured decay times show a clear dependence on the quantum well width and lattice temperature. The decay of the Γ-Γ direct-gap related transition is dominated by the ultrafast electron scattering from Γ-type to L-type states of the conduction band.
Tunneling magnetoresistance oscillations due to charging effects in MgO double barrier magnetic tunnel junctions
Authors: Liu Ruisheng , Yang See-Hun , Jiang Xin , Topuria Teya , Rice Philip M. , Rettner Charles , Parkin Stuart
Published: January 2012

We observe single-electron tunneling effect and tunneling magnetoresistance (TMR) oscillations in MgO double barrier magnetic tunnel junctions patterned with electron beam lithography and argon ion milling. The TMR oscillations are induced by the interplay of single charge effect and spin-dependent tunneling. The oscillations and its period can be well-controlled by properly engineering the thickness of MgO tunnel barriers and the size of the tunnel junctions.