bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the impact of food technology on the allergenicity of cow’s milk proteins
Authors: Heyman M.
Published: February 2011

The quantitative evaluation of the allergenicity of food proteins and the clinical tolerance towards antigens are problems the food industry and the clinicians have to face. The allergenicity of a protein depends on multiple factors, including the stability to digestion and the interaction with the intestinal environment. In addition to the possible reduction in allergenicity by technological treatments such as heat and enzymic hydrolysis, the complex interactions existing between the antigens, the intestinal epithelium and the underlying immune system, as well as the individual susceptibility to the sensitizing epitopes, have to be taken into account. Indeed, the intestinal cells are able to take up and process proteins, and possibly to present them directly to mucosal lymphocytes. On the other hand, pathophysiological conditions can modify the interactions between food antigens and the immune system. A large number of methods has been developed to assess the residual antigenicity of food proteins, based on the various immune responses leading to intestinal or extradigestive pathologies. Thus, the difficulty in measuring the residual allergenicity of hypoallergenic formulas is partly due to the physiology of the gastrointestinal tract, since an intricate network of interactions between enterocytes and immune cells governs the development of the immune response to food antigens. RésuméL’évaluation de l’allergénicité des aliments et leur bonne tolérance clinique est une question touchant à la fois les industriels de l’agro-alimentaire et les cliniciens. L’allergénicité d’une protéine dépend de multiples facteurs parmi lesquels la résistance à la digestion, les interactions avec le tractus digestif et les facteurs environnementaux. L’allergénicité d’un produit alimentaire peut être modifiée non seulement par les traitements technologiques industriels, mais aussi par le tractus gastrointestinal. La susceptibilité individuelle aux epitopes peptidiques formés est également un facteur primordial. En effet, les interactions complexes existant entre les antigènes, l’épithelium intestinal et le système immunitaire muqueux peuvent conduirent à des réponses immunitaires différentes selon les individus. De nombreuses méthodes existent pour mesurer l’antigénicité résiduelle des aliments, basées sur la nature des différentes réactions immunitaires anormales conduisant à une pathologie intestinale ou extradigestive. La difficulté de mesurer l’allergénicité résiduelle de formules hypoallergéniques repose donc sur les relations complexes entre les antigènes alimentaires, l’épithelium intestinal et le système immunitaire muqueux.
Antioxidants and lipoprotein metabolism
Authors: Chopra Mridula , Thurnham David I.
Published: February 2011

Lipoprotein metabolism plays a significant role in the pathogenesis of atherosclerosis and risk of vascular disease. Elevated levels of LDL and low levels of HDL are linked to the risk of cardiovascular disease. It is now widely accepted that oxidative modification of LDL affects the metabolism of lipoproteins, leading to their increased accumulation in arterial intima. The present paper will examine some of the accumulating evidence from studies showing relationships between dietary intake of antioxidant nutrients, i.e. vitamins E and C, the carotenoids and the flavonoids, and their influence on lipoprotein metabolism. In particular, the present paper will review the available literature on the affect of antioxidant supplementation on lipoprotein oxidation, and hence metabolism of LDL in human subjects.
Selenium and host defence towards viruses
Authors: Beck Melinda A.
Published: February 2011

The association between viral disease and nutrition has long been thought to be due to effects on the host immune system. This theory suggests that when a host is malnourished, the immune system is compromised, and thus increased susceptibility to viral infection will occur. However, the virus itself may also be affected by the nutritional status of the host. We have demonstrated that a normally-benign strain of coxsackievirus B3 (CVB3/0) becomes virulent in either Se-deficient or vitamin E-deficient mice. Although the deficient animals are immunosuppressed, the virus itself is also altered. Six nucleotide changes were found in the virus that replicated in the deficient mice, and once these mutations occurred, even mice with normal nutrition became susceptible to disease. Thus, the nutritional status of the host was able to transform an avirulent virus into a virulent one due to genomic changes in the virus. We believe that a common mechanism of oxidative stress is the underlying cause of the genetic changes. Both vitamin E and Se act as antioxidants, and benign virus inoculated into GSH peroxidase (EC 1.11.1.9)-knockout mice will also convert to virulence due to genomic changes. Our work points to the importance of host nutrition during a viral disease, not only from the perspective of the host, but from the perspective of the viral pathogen as well.
The influence of immigrant status and concentration on psychiatric disorder in Canada: a multi-level analysis
Authors: Menezes N. M. , Georgiades K. , Boyle M. H.
Published: February 2011

Background

Many studies have reported an increased incidence of psychiatric disorder (particularly psychotic disorders) among first generation adult immigrants, along with an increasing risk for ethnic minorities living in low-minority concentration neighborhoods. These studies have depended mostly on European case-based databases. In contrast, North American studies have suggested a lower risk for psychiatric disorder in immigrants, although the effect of neighborhood immigrant concentration has not been studied extensively.

Method

Using multi-level modeling to disaggregate individual from area-level influences, this study examines the influence of first generation immigrant status at the individual level, immigrant concentration at the neighborhood-level and their combined effect on 12-month prevalence of mood, anxiety and substance-dependence disorders and lifetime prevalence of psychotic disorder, among Canadians.

Results

Individual-level data came from the Canadian Community Health Survey (CCHS) 1.2, a cross-sectional study of psychiatric disorder among Canadians over the age of 15 years; the sample for analysis wasn=35 708. The CCHS data were linked with neighborhood-level data from the Canadian Census 2001 for multi-level logistic regression. Immigrant status was associated with a lower prevalence of psychiatric disorder, with an added protective effect for immigrants living in neighborhoods with higher immigrant concentrations. Immigrant concentration was not associated with elevated prevalence of psychiatric disorder among non-immigrants.

Conclusions

The finding of lower 12-month prevalence of psychiatric disorder in Canadian immigrants, with further lessening as the neighborhood immigrant concentration increases, reflects a model of person–environment fit, highlighting the importance of studying individual risk factors within environmental contexts.
Community Agency and Community Engagement: Re-theorising Participation in Governance
Authors: Eversole Robyn
Published: February 2011

Interest in participatory governance recognises that communities can make valuable contributions to governance, but attempts to strengthen community participation encounter obstacles theorised as failures or incompleteness of participatory governance. This paper offers an alternative approach, drawing on ethnographic field data from a decade of work in rural Australian communities. It shows the nature of the community agency that is at the heart of policy interest in participation and how it differs from government efforts at community engagement. These insights suggest a need to rethink participatory governance, not as a single process with multiple participants, but as the juxtaposition of different ways of governing. Doing so opens up the possibility of governments and communities working together in new ways, with governments not only valuing what communities can contribute in theory, but also recognising how diverse communities work in practice.
Risk, Regulation and Crisis: Comparing National Responses in Food Safety Regulation
Authors: Lodge Martin
Published: February 2011

The literature on risk regulation often assumes a direct link between public pressure and regulatory responses. This article investigates whether the direction of regulatory response is related to public argumentation as expressed in the national print media. Three approaches are explored: national policy patterns, political panics expressed in Pavlovian politics, and policy responses shaped by universal policy paradigms. It assesses these three approaches in comparative perspective by looking at scandals in food safety regulation in Denmark, Germany and the US, looking at argumentation patterns in the national print media and using a coding system derived from grid-group cultural theory and regulatory responses. While all three countries display mostly hierarchical argumentation patterns, their actual regulatory responses point to diverse patterns.
A symmetric parallel Schönflies-motion manipulator for pick-and-place operations
Authors: Altuzarra O. , Şandru B. , Pinto Ch. , Petuya V.
Published: February 2011

This paper presents a new symmetric parallel Schönflies-motion generator. The design is an evolution of a previous robot with linear inputs. The complete kinematic analysis of the 4-degree-of-freedom (dof) parallel manipulator is presented. The degrees of freedom are obtained from the Group Theory, the direct and inverse position problems are solved obtaining the manipulator's workspace, and the Jacobian analysis is presented. Then the isotropic configurations of the manipulator are discussed and the local dexterity map within the workspace is produced. Finally, two alternatives of a rotational mechanical device, which will increase the angular end-effector range, are proposed.
Performance of public health surveillance systems during the influenza A(H1N1) pandemic in the Americas: testing a new method based on Benford's Law
Authors: IDROVO A. J. , FERNÁNDEZ-NIÑO J. A. , BOJÓRQUEZ-CHAPELA I. , MORENO-MONTOYA J.
Published: February 2011

The A(H1N1) influenza pandemic has been a challenge for public health surveillance systems in all countries. An objective evaluation has not been conducted, as yet, of the performance of those systems during the pandemic. This paper presents an algorithm based on Benford's Law and the mortality ratio in order to evaluate the quality of the data and the sensitivity of surveillance systems. It analyses records of confirmed cases reported to the Pan American Health Organization by its 35 member countries between epidemiological weeks 13 and 47 in 2009. Seventeen countries did not fulfil Benford's Law, and mortality exceeded the regional average in 40% of the countries. The results suggest uneven performance by surveillance systems in the different countries, with the most frequent problem being low diagnostic coverage. Benford's Law proved to be a useful tool for the evaluation of a public health surveillance system's performance.
Textons and the Propagation of Space in Acousmatic Music
Authors: Nyström Erik
Published: February 2011

The concepts introduced by Smalley in the context of space-form (2007) have firmly put acousmatic music on a discourse of spatial exploration, holding much potential for the developing of aesthetics in new directions. This article approaches space from the low level of musical structure, with a multi-dimensional attitude to space-form, exploring spatial texture, a concept introduced by Smalley to describe the temporal formations of space in spectromorphology (1997). Spatial articulation is investigated in the context of granular-oriented textures, proposing a micro-spatial, perceptual morphology – the texton – as an aesthetic approach to acousmatic music. This follows Albert Bregman's speculation regarding equivalents to visual perception in texture, where the theory of textons was first developed by the neuroscientist Béla Julesz.

The article discusses acousmatic textons, in terms of intrinsic properties, the way they propagate in time, and how they organise in distributions to form spatial textures. The emergent macroscopic qualities of textonal formations are also reflected upon in the introduction of a group of textural states, where source-bonded spaces and abstract musical thinking coalesce.
Concretions in exhumed and inverted channels near Hanksville Utah: implications for Mars
Authors: Clarke Jonathan D. A. , Stoker Carol R.
Published: February 2011

The landscape near Hanksville, Utah, contains a diversity of Mars analogue features. These included segmented and inverted anastomosing palaeochannels exhumed from the Late Jurassic Brushy Basin Member of the Morrison Formation that hosts abundant small carbonate concretions. The exhumed and inverted channels closely resemble many seen on the surface of Mars in satellite imagery and which may be visited by surface missions in the near future. The channels contain a wealth of palaeoenvironmental information and are potentially of astrobiological interest, but intrinsically difficult terrain would make their study challenging on Mars. We show that an un-exhumed channel feature can be detected geophysically, and this may allow their study in more easily accessed terrain. The concretion's morphology and surface expression parallel the haematite ‘blue berries’ that are strewn across the surface of Meridiani Planum on Mars. They are best developed in poorly cemented medium to coarse channel sandstones and appear to have formed during deep burial.
A review of the literature on multiple symptoms, their predictors, and associated outcomes in patients with advanced cancer
Authors: Gilbertson-White Stephanie , Aouizerat Bradley E. , Jahan Thierry , Miaskowski Christine
Published: February 2011

Objective:

The findings from several studies suggest that palliative care patients with advanced cancer experience multiple symptoms, and that these symptoms may be related to demographic and clinical factors as well as to patient outcomes. However, no systematic review has summarized the findings from studies that assessed multiple symptoms, predictors, and outcomes in these patients. The purposes of this review, focused on palliative care patients with advanced cancer, are to: 1) describe the relationships among multiple symptoms; 2) describe the predictors of multiple symptoms; and 3) describe the relationships between multiple symptoms and patient outcomes.

Method:

Comprehensive literature searches were completed using the following databases: PubMed, Cumulative Index to Nursing and Allied Health Literature, and PsychInfo. The key words: cancer or advanced cancer or neoplasm, AND palliative care or terminal care or hospice or end-of-life, AND symptoms or multiple symptoms or symptom clusters were combined.

Results:

Twenty-two studies met the inclusion criteria and examined at least one of our purposes. The majority of these studies were descriptive and used one of four common symptom assessment scales. Fifty-six different signs and symptoms were evaluated across various dimensions (i.e., prevalence, severity, distress, frequency, control). Pain, dyspnea, and nausea were the only symptoms measured in all 22 studies. Relationships among concurrent symptoms were examined in nine studies. Relationships among symptoms and predictors (i.e., demographics, cancer type, healthcare delivery environment) were examined in seven studies. Relationships among symptoms and outcomes (i.e., functional status, psychological status, quality-of-life, survival time) were examined in 14 studies. Significant methodological variation was found among these studies.

Significance of results:

It is difficult to draw conclusions about the relationships among multiple symptoms, predictors, and outcomes due to the heterogeneity of these studies. Future research is needed to determine which symptoms and symptom dimensions to assess in order to better understand how multiple symptoms relate to each other as well to as predictors and outcomes in palliative care patients with advanced cancer.
The use of global abstractions: national income accounting in the period of imperial decline
Authors: Speich Daniel
Published: February 2011

This article explores the history of a conceptual world economic order of nations created by statistically minded economists over the last seventy years. Drawing upon work by Colin Clark, Richard Stone, and Simon Kuznets from the 1930s, 1940s, and 1950s, it reconstructs the rise of new economic indicators referring to economic inequality. Two forms of intellectual practice can be identified that characterized a remarkable shift in knowledge production in Anglo-American economics in the period of French and British imperial decline. One was new methods of counting and comparing income, which produced a sensational new view of the world as a place of enormous poverty. The other was the belief that these issues could be solved by applying a limited set of policy recommendations to all economies in the world.
Azinphos-methyl (AZM) phase-out: Actions and attitudes of apple growers in Washington State
Authors: Goldberger Jessica R. , Lehrer Nadine , Brunner Jay F.
Published: February 2011

The Environmental Protection Agency's phase-out of the pesticide azinphos-methyl (AZM) has encouraged the transition of apple pest management toward more environmentally and socially sustainable practices. This study reports on results of a 2009 survey of conventional apple growers in Washington State. Growers were asked about their approaches and attitudes toward the AZM phase-out and barriers to the adoption of reduced-risk insecticides (AZM-alternatives) as part of their integrated pest management (IPM) programs. Chi-square and analysis of variance (ANOVA) techniques were used to examine relationships between actions and attitudes toward the phase-out and grower characteristics. Results showed that Washington apple growers have begun eliminating AZM and adopting AZM-alternatives. However, larger growers (in terms of acreage and income) and growers more familiar with Washington State University's (WSU's) educational resources were more likely to have already reduced their AZM use. These results suggest that larger farms can play an important role in increasing the sustainability of conventional agriculture, despite a common association of sustainable agriculture with small farms. Results also suggest that agricultural extension services could be well served to extend their outreach to smaller growers and others lagging in the transition to more sustainable apple pest management.
Mindanao Dome variability over the last 160 kyr: Episodic glacial cooling of the West Pacific Warm Pool
Authors: Bolliet Timothé , Holbourn Ann , Kuhnt Wolfgang , Laj Carlo , Kissel Catherine , Beaufort Luc , Kienast Markus , Andersen Nils , Garbe‐Schönberg Dieter
Published: February 2011

We present sea surface, upper thermocline, and benthic δ18O data, as well as temperature and paleoproductivity proxy data, from the International Marine Global Change Study Program (IMAGES) Core MD06‐3067 (6°31′N, 126°30′E, 1575 m water depth), located in the western equatorial Pacific Ocean within the flow path of the Mindanao Current. Our records reveal considerable glacial‐interglacial and suborbital variability in the Mindanao Dome upwelling over the last 160 kyr. Dome activity generally intensified during glacial intervals resulting in cooler thermocline waters, whereas it substantially declined during interglacials, in particular in the early Holocene and early marine oxygen isotope stage (MIS) 5e, when upwelling waters did not reach the thermocline. During MIS 3 and MIS 2, enhanced surface productivity together with remarkably low SST and low upper ocean thermal contrast provide evidence for episodic glacial upwelling to the surface, whereas transient surface warming marks periodic collapses of the Mindanao Dome upwelling during Heinrich events. We attribute the high variability during MIS 3 and MIS 2 to changes in the El Niño Southern Oscillation state that affected boreal winter monsoonal winds and upper ocean circulation. Glacial upwelling intensified when a strong cyclonic gyre became established, whereas El Niño–like conditions during Heinrich events tended to suppress the cyclonic circulation, reducing Ekman transport. Thus, our findings demonstrate that variations in the Mindanao Dome upwelling are closely linked to the position and intensity of the tropical convection and also reflect far‐field influences from the high latitudes.
An auroral scintillation observation using precise, collocated GPS receivers
Authors: Garner T. W. , Harris R. B. , York J. A. , Herbster C. S. , Minter C. F. , Hampton D. L.
Published: February 2011

On 10 January 2009, an unusual ionospheric scintillation event was observed by a Global Positioning System (GPS) receiver station in Fairbanks, Alaska. The receiver station is part of the National Geospatial‐Intelligence Agency's (NGA) Monitoring Station Network (MSN). Each MSN station runs two identical geodetic‐grade, dual‐frequency, full‐code tracking GPS receivers that share a common antenna. At the Fairbanks station, a third separate receiver with a separate antenna is located nearby. During the 10 January event, ionospheric conditions caused two of the receivers to loose lock on a single satellite. The third receiver tracked through the scintillation. The region of scintillation was collocated with an auroral arc and a slant total electron content (TEC) increase of 5.71 TECu (TECu = 1016/m2). The response of the full‐code tracking receivers to the scintillation is intriguing. One of these receivers lost lock, but the other receiver did not. This fact argues that a receiver's internal state dictates its reaction to scintillation. Additionally, the scintillation only affected the L2 signal. While this causes the L1 signal to be lost on the semicodelessly receiver, the full‐code tracking receiver only lost the L1 signal when the receiver attempted to reacquire the satellite link.
Semianalytical solutions for cocurrent and countercurrent imbibition and dispersion of solutes in immiscible two‐phase flow
Authors: Schmid K. S. , Geiger S. , Sorbie K. S.
Published: February 2011

We derive a set of semianalytical solutions for the movement of solutes in immiscible two‐phase flow. Our solutions are new in two ways: First, we fully account for the effects of capillary and viscous forces on the transport for arbitrary capillary‐hydraulic properties. Second, we fully take hydrodynamic dispersion for the variable two‐phase flow field into account. The understanding of immiscible two‐phase flow and the simultaneous miscible displacement and mixing of components within a phase is important for many applications, including the location of nonaqueous phase liquids in the subsurface, the design of contaminant cleanup procedures, the sequestration of carbon dioxide, and enhanced oil‐recovery techniques. For purely advective transport we combine a known exact solution for the description of immiscible two‐phase flow with the method of characteristics for the advective transport equations to obtain solutions that describe cocurrent flow and countercurrent spontaneous imbibition and advective transport in one dimension. We show that for both cases the solute front can be located graphically by a modified Welge tangent. For the advective‐dispersive solute transport, we derive approximate analytical solutions by the method of singular perturbation expansion. On the basis of this, we obtain analytical expressions for the growth of the dispersive zone for the case with and without the influence of capillary pressure. We show that for the case of spontaneous countercurrent imbibition the order of magnitude of the growth rate is far smaller than that for the viscous limit. We give some illustrative examples and compare the analytical expressions with numerical reference solutions.
Obama Emphasizes Science and Innovation in State of the Union Address
Authors: Tretkoff Ernie
Published: February 2011

U.S. president Barack Obama emphasized innovation and competitiveness in his State of the Union address on 25 January. He also raised science and technology early in the hour‐long speech, noting that nations like China and India are focusing on math and science education and investing in research and technology. To be competitive with those countries, “we need to out‐innovate, out‐educate, and out‐build the rest of the world,” Obama said. “The first step in winning the future is encouraging American innovation.”
AGU Headquarters Now 100% Powered by Wind
Authors: Kauffman Sue
Published: February 2011

On 17 January, the electricity supplied to the AGU building at 2000 Florida Avenue, NW, in Washington, D. C., was switched from primarily conventional sources to 100% wind‐generated power. The AGU building uses approximately 1.8 million kilowatt‐hours of electricity per year at a total budgeted cost of $272,000. The increased cost through the end of 2011 is estimated to be $3900, or 1.4% of the total budgeted cost.
Integrating Paleoecological Databases
Authors: Blois Jessica , Goring Simon , Smith Alison
Published: February 2011

Neotoma Consortium Workshop; Madison, Wisconsin, 23–26 September 2010; Paleoecology can contribute much to global change science, as paleontological records provide rich information about species range shifts, changes in vegetation composition and productivity, aquatic and terrestrial ecosystem responses to abrupt climate change, and paleoclimate reconstruction, for example. However, while paleoecology is increasingly a multidisciplinary, multiproxy field focused on biotic responses to global change, most paleo databases focus on single‐proxy groups. The Neotoma Paleoecology Database (http://www.neotomadb.org) aims to remedy this limitation by integrating discipline‐specific databases to facilitate cross‐community queries and analyses. In September, Neotoma consortium members and representatives from other databases and data communities met at the University of Wisconsin‐Madison to launch the second development phase of Neotoma. The workshop brought together 54 international specialists, including Neotoma data stewards, users, and developers. Goals for the meeting were fourfold: (1) develop working plans for existing data communities; (2) identify new data types and sources; (3) enhance data access, visualization, and analysis on the Neotoma Web site; and (4) coordinate with other databases and cooperate in tool development and sharing.
AGU Endorses Interior Department's Scientific Integrity Plan
Authors: Cairns Ann
Published: February 2011

AGU has endorsed the U.S. Department of the Interior plan, released on 1 February, to ensure scientific and scholarly integrity throughout the agency's research and program operations (see the news item on page 46 of this Eos issue). “DOI's new plan recognizes the importance of scientific and scholarly integrity in building trust in science that informs public policy,” AGU president Michael J. McPhaden said. “Integrity of the scientific enterprise is essential for guiding the scientific community, policy makers, and the general public as we work together to meet global challenges related to climate change, natural hazards, and wise use of our natural resources.”
A high-vacuum deposition system for in situ and real-time electrical characterization of organic thin-film transistors
Authors: Quiroga Santiago David , Shehu Arian , Albonetti Cristiano , Murgia Mauro , Stoliar Pablo , Borgatti Francesco , Biscarini Fabio
Published: February 2011

We present a home-built high-vacuum system for performing organic semiconductor thin-film growth and its electrical characterization during deposition (real-time) or after deposition (in situ). Since the environment conditions remain unchanged during the deposition and electrical characterization process, a direct correlation between growth mode and electrical properties of thin film can be obtained. Deposition rate and substrate temperature can be systematically set in the range 0.1–10 ML/min and RT-150 °C, respectively. The sample-holder configuration allows the simultaneous electrical monitoring of up to five organic thin-film transistors (OTFTs). The OTFTs parameters such as charge carrier mobility μ, threshold voltage VTH, and the on–off ratio Ion/Ioff are studied as a function of the semiconductor thickness, with a submonolayer accuracy. Design, operation, and performance of the setup are detailed. As an example, the in situ and real-time electrical characterization of pentacene TFTs is reported.
Heterojunction plasmonic midinfrared detectors
Authors: Shishodia M. S. , Unil Perera A. G.
Published: February 2011

In view of the emergence of wide ranging applications in the areas such as environmental monitoring, medical diagnostics, defense, security and sensing etc., it is indispensable to develop resourceful mid-infrared photodetectors. In this article, we present potential design considerations exploiting plasmonic effects in the conventional heterojunction mid-infrared detectors, optimized for their operation in 8–14 μm spectral range. Design issues concerning GaAs-AlGaAs based plasmonic photodetectors are investigated using modal expansion method (MEM) in conjunction with Rayleigh expansion. Simple but insightful fitting expressions useful for designing practical photodetectors are presented. The effects of crucial design parameters on the photodetector performance are discussed in detail. Using metallic grating based plasmonic element, about 20 fold absorption enhancement is predicted, which is comparable or greater than that recently reported for InAs (Quantum Dots) and GaInNAs (Quantum Well) detectors. Photodetector designs showing considerable improvement in the responsivity and the specific detectivity, compared to their nonplasmonic but otherwise identical counterpart are presented.
Effect of interactions on edge property measurements in magnetic multilayers
Authors: Zhu M. , McMichael R. D.
Published: February 2011

This paper reports effects of inter-film interactions on static and dynamic magnetization behavior at film edges in magnetic trilayer stripe arrays under transverse applied fields. The trilayers consist of two magnetic films of Ni80Fe20, 10 nm and 20 nm thick that interact via dipolar fields across thin, nonmagnetic spacers from 1 nm to 20 nm thick. These trilayer films are patterned into stripe arrays by optical interference lithography. Ferromagnetic resonance spectra exhibit separate edge modes that are identified as excitation of edge modes primarily in one magnetic film or the other. When interlayer exchange is negligible, we observe several effects of dipolar edge-edge coupling including shifts of the edge saturation fields and changes in the mode intensity ratio relative to single-film edges. These interaction effects are reproduced by micromagnetic modeling and explained by simple models.
Modulation of whistler waves in nonthermal plasmas
Authors: Rios L. A. , Galvão R. M. O.
Published: February 2011

The modulation of whistler waves in nonthermal plasmas is investigated. The dynamics of the magnetized plasma is described by the fluid equations and the electron velocity distribution function is modeled via a nonthermal κ distribution. A multiscale perturbation analysis based on the Krylov–Bogoliubov–Mitropolsky method is carried out and the nonlinear Schrödinger equation governing the modulation of the high-frequency whistler is obtained. The effect of the superthermal electrons on the stability of the wave envelope and soliton formation is discussed and a comparison with previous results is presented.
Observation of anomalous Hall effect in EuO epitaxial thin films grown by a pulse laser deposition
Authors: Yamasaki T. , Ueno K. , Tsukazaki A. , Fukumura T. , Kawasaki M.
Published: February 2011

We have found that there is a narrow but distinct window in oxygen pressure for growing phase-pure epitaxial EuO films by a pulsed laser deposition. With finely decreasing the oxygen pressure, the electrical property is varied from insulating to metallic with an enhancement in Curie temperature from 70 to 120 K. The anomalous Hall contribution was clearly observed in Hall resistance at 5 K in the highest electron density sample. The saturated anomalous Hall conductivity (0.2 S/cm) is rather high in comparison with those of the other ferromagnetic oxides, probably due to strong spin-orbit coupling in EuO.
Resistive switching effects in single metallic tunneling junction with nanometer-scale gap
Authors: Mizukami Takahiro , Miyato Yuji , Kobayashi Kei , Matsushige Kazumi , Yamada Hirofumi
Published: February 2011

We fabricated a single tunneling junction with a nanometer-scale gap between Pt electrodes. We found that the gap distance became smaller after a current sweep, which was presumably caused by the migration of the Pt atoms at the anode. The junction showed a reproducible negative differential resistance characteristic after reduction in the gap. The junction also showed resistive switching characteristics with a resistance ratio of over 100 by applying voltage of different waveforms. The tunneling area and gap distance for on/off-state were quantitatively estimated by fitting the measured characteristics to the simple model as 100 nm2 and 0.8/1.2 nm, respectively.
Wide temperature polyimide/ZrO2 nanodielectric capacitor film with excellent electrical performance
Authors: Zou C. , Kushner D. , Zhang S.
Published: February 2011

In this letter, wide temperature dielectric properties and corona resistance of Upilex-S® polyimide (PI) films filled with Zirconium dioxide (ZrO2) nanoparticles were investigated. ZrO2/PI nanodielectrics exhibited the stable dielectric properties, high energy density and high charge-discharge efficiency below 300 °C. Testing of corona resistance showed even a small amount of nanofillers can improve the lifetime of PI significantly. Scanning electron microscopy with x-ray microanalysis (SEM-EDS) analysis suggested the higher thermal conductivity and evaporation of ZrO2 nanoparticles may induce this improvement. These high performance features make polyimide nanocomposites attractive for high energy density capacitor applications at high temperature.
Excited state coherent resonant electronic tunneling in quantum well-quantum dot hybrid structures
Authors: Mazur Yu. I. , Dorogan V. G. , Marega E. , Benamara M. , Zhuchenko Z. Ya. , Tarasov G. G. , Lienau C. , Salamo G. J.
Published: February 2011

A strong effect of a quantum well (QW) incorporated into a quantum dot (QD) structure on the density of states of the system and the efficiency of carrier transfer from the barrier material to QDs is revealed in InAs/GaAs–InGaAs/GaAs dot-well, tunnel-injection structures. When tuning the QW states in resonance with excited QD states, the carrier flux can be effectively controlled by varying the spacer thickness or barrier height. Enhanced carrier tunneling between QW and QD states is observed by means of photoluminescence excitation spectroscopy for reduced spacer thicknesses. Our results demonstrate that resonant coherent electron tunneling is substantially faster for the second than for the first QW subband and results in the formation of hybrid electronic states delocalized across the QW/QD interface.
Large amplitude magnetization dynamics and the suppression of edge modes in a single nanomagnet
Authors: Keatley P. S. , Gangmei P. , Dvornik M. , Hicken R. J. , Childress J. R. , Katine J. A.
Published: February 2011

Large amplitude magnetization dynamics of a single square nanomagnet have been studied by time-resolved Kerr microscopy. Experimental spectra revealed that only a single mode was excited for all bias field values. Micromagnetic simulations demonstrate that at larger pulsed field amplitudes the center mode dominates the dynamic response while the edge mode is almost completely suppressed. Controlled suppression of edge modes in a single nanomagnet has potential applications in the operation of nanoscale spin transfer torque oscillators and bistable switching devices for which the amplitude of the magnetization trajectory is often large and a more uniform dynamic response is desirable.
Effects of compulsory rural vocational training for Australian general practitioners: a qualitative study
Authors: Bayley Sarah A. , Magin Parker J. , Sweatman Jennifer M. , Regan Catherine M.
Published: February 2011

Background.
Increasing the recruitment of doctors, including general practitioners (GPs), to rural areas is recognised as a health priority internationally. Australian GP trainees (registrars) complete a mandatory minimum of 6 months training in a rural area. The rationale for this includes the expectation of increased likelihood of a future choice of rural practice location.

Method.
A qualitative study employing semistructured in-depth interviews and a modified grounded methodology. Participants were 15 registrars from an Australian GP postgraduate training program.

Results.
Though generally a rewarding clinical learning experience, negative aspects of the rural placement included the disruption to personal lives of rural relocation and the stresses involved in higher levels of clinical responsibility. These stressors could undermine rather than enhance clinical confidence. Anxiety and depression were accompaniments for some registrars. Intention to practice rurally was little influenced by this compulsory placement.

Conclusions.
Findings of positive effects on rural practice destination in studies of medical undergraduates should not be generalised to GP registrars. The positive clinical learning experience of most registrars in rural terms must be balanced with the social dislocation involved in rural relocation and the adverse effects of the rural experience, for some registrars, on professional confidence and psychological well being.

What is known about the topic?
The rationale for compulsory rural placements during general practitioner vocational training includes an assumption that this will increase rural GP workforce. Undergraduate training in rural environments is known to enhance recruitment to rural practice.

What does this paper add?
Despite considerable positive educational and training outcomes for many registrars, compulsory rural training placements cause significant social dislocation for many registrars and were in this study associated with psychological morbidity in some registrars. Placements are unlikely to significantly increase rural GP workforce.

What are the implications for practitioners?
Compulsory rural placements can be a negative experience for GP registrars. Findings of positive effects of rural training experience on career intentions and rural workplace destination in studies of medical undergraduates should not be generalised to compulsory rural placements for general practice registrars.
FGF4 and FGF8 comprise the wavefront activity that controls somitogenesis
Authors: Naiche L. A. , Holder Nakisha , Lewandoski Mark
Published: February 2011

Somites form along the embryonic axis by sequential segmentation from the presomitic mesoderm (PSM) and differentiate into the segmented vertebral column as well as other unsegmented tissues. Somites are thought to form via the intersection of two activities known as the clock and the wavefront. Previous work has suggested that fibroblast growth factor (FGF) activity may be the wavefront signal, which maintains the PSM in an undifferentiated state. However, it is unclear which (if any) of the FGFs expressed in the PSM comprise this activity, as removal of any one gene is insufficient to disrupt early somitogenesis. Here we show that when both
Fgf4
and
Fgf8
are deleted in the PSM, expression of most PSM genes is absent, including cycling genes, WNT pathway genes, and markers of undifferentiated PSM. Significantly, markers of nascent somite cell fate expand throughout the PSM, demonstrating the premature differentiation of this entire tissue, a highly unusual phenotype indicative of the loss of wavefront activity. When WNT signaling is restored in mutants, PSM progenitor markers are partially restored but premature differentiation of the PSM still occurs, demonstrating that FGF signaling operates independently of WNT signaling. This study provides genetic evidence that FGFs are the wavefront signal and identifies the specific FGF ligands that encode this activity. Furthermore, these data show that FGF action maintains WNT signaling, and that both signaling pathways are required in parallel to maintain PSM progenitor tissue.
Drought variability in the Pacific Northwest from a 6,000-yr lake sediment record
Authors: Nelson Daniel B. , Abbott Mark B. , Steinman Byron , Polissar Pratigya J. , Stansell Nathan D. , Ortiz Joseph D. , Rosenmeier Michael F. , Finney Bruce P. , Riedel Jon
Published: February 2011

We present a 6,000-yr record of changing water balance in the Pacific Northwest inferred from measurements of carbonate
δ
18
O and grayscale on a sediment core collected from Castor Lake, Washington. This subdecadally resolved drought record tracks the 1,500-yr tree-ring-based Palmer Drought Severity Index reconstructions of Cook et al. [Cook ER, Woodhouse CA, Eakin CM, Meko DM, Stahle DW (2004)
Science
306:1015–1018] in the Pacific Northwest and extends our knowledge back to 6,000 yr B.P. The results demonstrate that low-frequency drought/pluvial cycles, with occasional long-duration, multidecadal events, are a persistent feature of regional climate. Furthermore, the average duration of multidecadal wet/dry cycles has increased since the middle Holocene, which has acted to increase the amplitude and impact of these events. This is especially apparent during the last 1,000 yr. We suggest these transitions were driven by changes in the tropical and extratropical Pacific and are related to apparent intensification of the El Niño Southern Oscillation over this interval and its related effects on the Pacific Decadal Oscillation. The Castor Lake record also corroborates the notion that the 20th century, prior to recent aridity, was a relatively wet period compared to the last 6,000 yr. Our findings suggest that the hydroclimate response in the Pacific Northwest to future warming will be intimately tied to the impact of warming on the El Niño Southern Oscillation.
Mitigation of malicious attacks on networks
Authors: Schneider Christian M. , Moreira André A. , Andrade José S. , Havlin Shlomo , Herrmann Hans J.
Published: February 2011

Terrorist attacks on transportation networks have traumatized modern societies. With a single blast, it has become possible to paralyze airline traffic, electric power supply, ground transportation or Internet communication. How and at which cost can one restructure the network such that it will become more robust against a malicious attack? We introduce a new measure for robustness and use it to devise a method to mitigate economically and efficiently this risk. We demonstrate its efficiency on the European electricity system and on the Internet as well as on complex networks models. We show that with small changes in the network structure (low cost) the robustness of diverse networks can be improved dramatically whereas their functionality remains unchanged. Our results are useful not only for improving significantly with low cost the robustness of existing infrastructures but also for designing economically robust network systems.
Large-scale mechanical properties of
Xenopus
embryonic epithelium
Authors: Luu Olivia , David Robert , Ninomiya Hiromasa , Winklbauer Rudolf
Published: February 2011

Epithelia are planar tissues that undergo major morphogenetic movements during development. These movements must work in the context of the mechanical properties of epithelia. Surprisingly little is known about these mechanical properties at the time and length scales of morphogenetic processes. We show that at a time scale of hours,
Xenopus
gastrula ectodermal epithelium mimics an elastic solid when stretched isometrically; strikingly, its area increases twofold in the embryo by such pseudoelastic expansion. At the same time, the basal side of the epithelium behaves like a liquid and exhibits tissue surface tension that minimizes its exposed area. We measure epithelial stiffness (~1 mN/m), surface tension (~0.6 mJ/m
2
), and epithelium–mesenchyme interfacial tensions and relate these to the folding of isolated epithelia and to the extent of epithelial spreading on various tissues. We propose that pseudoelasticity and tissue surface tension are main determinants of epithelial behavior at the scale of morphogenetic processes.
Eradication of solid tumors using histone deacetylase inhibitors combined with immune-stimulating antibodies
Authors: Christiansen Ailsa J. , West Alison , Banks Kellie-Marie , Haynes Nicole M. , Teng Michele W. , Smyth Mark J. , Johnstone Ricky W.
Published: February 2011

Histone deacetylase inhibitors (HDACi) have been successfully used as monotherapies for the treatment of hematological malignancies; however, the single agent effects of HDACi against solid tumors are less robust. Using preclinical models of lymphoma, we have recently demonstrated that HDACi induce tumor cell-specific apoptosis and that this is essential for the therapeutic effects of these agents. Herein, we demonstrate that HDACi can be combined with immune-activating antibodies designed to promote the function of antigen-presenting cells (APCs) and enhance proliferation and survival of cytotoxic T cells (CTL) to stimulate a host antitumor immune response resulting in eradication of established solid tumors. This unique combination therapy was dependent on tumor cell apoptosis mediated by HDACi that stimulated the uptake of dead tumor cells by APCs. Tumor eradication was mediated by CD8+CTL that used perforin as the key immune effector molecule. This combination therapy was well tolerated and induced long-term immunological antitumor memory capable of mediating spontaneous tumor eradication upon rechallenge. These studies indicate that the ability of HDACi to mediate subtherapeutic levels of tumor cell apoptosis can be exploited by combining with antibodies that augment host antitumor immune responses to mediate robust and prolonged eradication of solid tumors.
Northern peatland initiation lagged abrupt increases in deglacial atmospheric CH
4
Authors: Reyes Alberto V. , Cooke Colin A.
Published: February 2011

Peatlands are a key component of the global carbon cycle. Chronologies of peatland initiation are typically based on compiled basal peat radiocarbon (
14
C) dates and frequency histograms of binned calibrated age ranges. However, such compilations are problematic because poor quality
14
C dates are commonly included and because frequency histograms of binned age ranges introduce chronological artefacts that bias the record of peatland initiation. Using a published compilation of 274 basal
14
C dates from Alaska as a case study, we show that nearly half the
14
C dates are inappropriate for reconstructing peatland initiation, and that the temporal structure of peatland initiation is sensitive to sampling biases and treatment of calibrated
14
C dates. We present revised chronologies of peatland initiation for Alaska and the circumpolar Arctic based on summed probability distributions of calibrated
14
C dates. These revised chronologies reveal that northern peatland initiation lagged abrupt increases in atmospheric CH
4
concentration at the start of the Bølling–Allerød interstadial (Termination 1A) and the end of the Younger Dryas chronozone (Termination 1B), suggesting that northern peatlands were not the primary drivers of the rapid increases in atmospheric CH
4
. Our results demonstrate that subtle methodological changes in the synthesis of basal
14
C ages lead to substantially different interpretations of temporal trends in peatland initiation, with direct implications for the role of peatlands in the global carbon cycle.