bluuebunny/crossref_metadata_2025 huggingface dataset:
A World of Chance
Authors: Brenner Reuven , Brenner Gabrielle A. , Brown Aaron
Published: July 2010

Although financial markets often try to distance themselves from gambling, the two factors have far more in common than usually thought. When, historically, there were no financial institutions such as banks, lotteries constituted the ways by which expensive items were disposed of, and governments raised money quickly. Gambling tables fulfilled roles that venture capital and banking do today. 'Gamblers' created clearinghouses and sustained liquidity. When those gamblers bet on price distributions in futures markets, they were redefined as 'speculators'. Today they are called 'hedge fund managers' or 'bankers'. Though the names have changed, the actions undertaken have essentially stayed the same. This book shows how discussion on 'chance', 'risk', 'gambling', 'insurance', and 'speculation' illuminates where societies stood, where we are today, and where we may be heading.
Why Women Protest
Authors: Baldez Lisa
Published: July 2010

Why do women protest? Under what conditions do women protest on the basis of their gender identity? Professor Baldez answers in terms of tipping, timing and framing. She relies on the concept of tipping to identify the point at which diverse organizations converge to form a women's movement. She argues that two conditions trigger this mobilization among women: partisan realignment, understood as the emergence of a new set of issues around which political elites define themselves, and women's decision to frame realignment in terms of widely held norms about gender difference. To illustrate these claims, she compares two very different women's movements in Chile: the mobilization of women against President Salvador Allende (1970–1973) and that against General Augusto Pinochet (1973–1990). Despite differences between these two movements, both emerged amidst a context of partisan realignment and framed their concerns in terms of women's exclusion from the political arena.
International Justice in Rwanda and the Balkans
Authors: Peskin Victor
Published: July 2010

Today's international war crimes tribunals lack police powers, and therefore must prod and persuade defiant states to co-operate in the arrest and prosecution of their own political and military leaders. Victor Peskin's comparative study traces the development of the capacity to build the political authority necessary to exact compliance from states implicated in war crimes and genocide in the cases of the International War Crimes Tribunals for the former Yugoslavia and Rwanda. Drawing on 300 in-depth interviews with tribunal officials, Balkan and Rwandan politicians, and Western diplomats, Peskin uncovers the politicized, protracted, and largely behind-the-scenes tribunal-state struggle over co-operation.
Gene expression and nitrogen loss in senescing root systems of red clover (Trifolium pratense)
Authors: WEBB K. J. , JENSEN E. F. , HEYWOOD S. , MORRIS S. M. , LINTON P. E. , HOOKER J. E.
Published: July 2010

Root system senescence and nitrogen (N) release from red clover (Trifolium pratenseL.) plants, grown under semi-sterile conditions and a controlled environment, were studied for 28 days following temporary or prolonged abiotic stress. Plants stressed temporarily, to simulate grazing, recovered with no additional N lost in leachate. In contrast, plants subjected to prolonged stress that simulated overwintering conditions and inhibited shoot re-growth survived stress lasting 7 days, but plant viability was reduced to 50% by 14 days and 0% at 21 days. There were no significant differences in root protein, catalase activity, root death index or total N loss in leachate over 21 days, but by 28 days total N loss in leachate increased to 214% above control levels, with a 433% increase in total oxidized N. This increase in N loss between 21 and 28 days indicated the start of cellular breakdown of the root system, coinciding with the failure of plants to recover.

Key enzyme activities and protein concentrations in nodules decreased rapidly over 10 days' prolonged stress. cDNA–amplified fragment length polymorphism (AFLP) analysis identified contaminating bacterial and fungal genes, along with plant gene sequences with consistent or altered expression profiles. Four plant sequences, glyceraldehyde-3-phosphate dehydrogenase (Tp-gapdh1), nodule senescence reduced (Tp-nsr1), nodule senescence enhanced (Tp-nse1) and a cysteine protease gene (Tp-cp8) were differentially expressed throughout the plant:Tp-nsr1 andTp-nse1 have potential as molecular markers for nodule senescence.

Root and nodule death in agricultural legumes, such as red clover, are implicated in N release into watercourses and the wider environment. Differences in the ability of these plants to survive prolonged stress lasting 14 days, and the delayed release of root N into leachate until 28 days after the stress, highlight the potential for the development of new red clover varieties with different rates of root system senescence.
Trends in cetacean sightings along the Galician coast, north-west Spain, 2003–2007, and inferences about cetacean habitat preferences
Authors: Pierce Graham J. , Caldas Mara , Cedeira Jose , Santos M. Begoña , Llavona Ángela , Covelo Pablo , Martinez Gema , Torres Jesus , Sacau Mar , López Alfredo
Published: July 2010

Since mid-2003, systematic monthly sightings surveys for cetaceans have been carried out in Galicia (north-west Spain) from observation points around the coastline, with the aim of providing baseline data on cetacean distribution and habitat use to underpin future conservation measures. Here we summarize results for September 2003 to October 2007. The most frequently recorded species were the bottlenose dolphin (Tursiops truncatus, seen during 10.7% of observation periods), common dolphin (Delphinus delphis, 3.7%), harbour porpoise (Phocoena phocoena, 1.6%), Risso's dolphin (Grampus griseus, 0.4%) and short-finned pilot whale (Globicephala melas, 0.2%). The three most common species showed different distribution patterns along the coast. In terms of habitat preferences, bottlenose dolphins were seen to be associated with more productive areas (areas with higher chlorophyll-a concentrations) where the continental shelf was wider while both common dolphins and harbour porpoises were seen most frequently in less productive areas where the continental shelf is narrowest. Possible reasons for differences in habitat use include differing diets. In Galician waters, all three main cetacean species feed primarily on fish that are common in shelf waters, and in the case of blue whiting (the most important species in the stomach contents of common and bottlenose dolphins) abundant also on the slope. All three cetaceans feed on blue whiting while scad is important in diets of common dolphin and porpoise. It is also possible that porpoises do not use areas frequented by bottlenose dolphins in order to avoid aggressive interactions. Retrospective evaluation of the sampling regime, using data from the 2500 observation periods during 2003–2007 suggests that the overall sightings rates for all species (taking into account observation time and between-site travel time) would be higher if average observation duration was increased to at least 40 minutes. On the other hand, confidence limits on sightings rates stabilized after around 1000 observation periods, suggesting that the number of sites visited or the frequency of visits could be substantially reduced.
Increased pregnancy weight gain in women with latent toxoplasmosis and RhD-positivity protection against this effect
Authors: KAŇKOVÁ Š. , ŠULC J. , FLEGR J.
Published: July 2010

Objective. RhD-positive subjects are protected against toxoplasmosis-associated impairment of psychomotor performance. Here we searched for RhD-positivity-associated maternal protection against the effects of toxoplasmosis. Methods. In the present retrospective cohort study, we analysed data from 785 (139 RhD-negative) Toxoplasma-free and 194 (27 RhD-negative) Toxoplasma-infected pregnant women. We searched for effects of toxoplasmosis and Rhd-phenotype on maternal weight before pregnancy, pregnancy weight gain, fetal ultrasound data (biparietal diameter, abdominal circumference, femur length) and on birth length and weight. Results. At pregnancy week 16, the RhD-negative mothers with toxoplasmosis gained more weight than others (P<0·001). The difference of about 1600 g remained approximately constant from pregnancy week 16 until the end of pregnancy. Neither toxoplasmosis nor RhD phenotype had any effect on fetal bioparameter data or birth length and weight. Conclusion. The most parsimonious explanation for the observed data is that the RhD-positive phenotype might protect infected subjects against a broad spectrum of detrimental effects of latent toxoplasmosis, including excessive gestational weight gain.
Motion and landscape: Otl Aicher, Günther Grzimek and the graphic and garden designs of the 1972 Munich Olympics
Authors: SCHILLER KAY , YOUNG CHRISTOPHER
Published: July 2010

This article focuses on Otl Aicher's design and Günther Grzimek's garden architecture for the 1972 Munich Olympics. We argue that the functionalist aesthetics of the Munich Olympic site should be interpreted as a translation into graphic and landscape design of 1960s progressivism in West German society and democracy. In the process Aicher and Grzimek somewhat paradoxically drew on the tradition of the Olympic Gesamtkunstwerk inaugurated in Berlin in 1936.
Prevalence of obesity and associated sociodemographic and lifestyle factors in Morocco
Authors: El Rhazi K , Nejjari C , Zidouh A , Bakkali R , Berraho M , Barberger Gateau P
Published: July 2010

Objective

In Morocco, the association between obesity/overweight and socio-demographic and lifestyle factors is poorly understood. The present study aimed to investigate this association in a representative sample of the Moroccan population aged 18 years and above.

Design

This is a cross-sectional study using a questionnaire including demographic, socio-economic and physical activity items. Height and weight were measured and BMI was computed. The association between obesity (BMI ≥ 30·0 kg/m2) or overweight (25·0 ≤ BMI < 29·9 kg/m2) and the other variables was analysed using multiple binomial logistic regression, separately in men and women.

Setting

The whole Moroccan territory.

Subjects

A total of 2891 subjects took part in the survey (1430 men and 1461 women).

Results

The prevalence of obesity was 20·9 % in women and 6·0 % in men (P < 0·0001). The prevalence of overweight was 32·9 % in women v. 26·8 % in men (P < 0·0001). In women, the risk of obesity and overweight increased with age, with the highest risk being in individuals aged 45–54 years (OR = 3·02, 95 % CI 2·06, 4·44) compared to individuals <35 years old. Married women were more prone to obesity and overweight (OR = 2·42, 95 % CI 1·50, 3·91) than single women. In men, the risk of obesity and overweight increased with average family income (OR = 2·62, 95 % CI 1·40, 4·87 for family income ≥5000 MAD/month compared to <2000 MAD/month) and in married persons (OR = 3·75, 95 % CI 1·78, 7·81) compared to single individuals.

Conclusions

These results contribute to target groups in whom prevention programmes could be implemented.
Free healthy breakfasts in primary schools: a cluster randomised controlled trial of a policy intervention in Wales, UK
Authors: Murphy Simon , Moore GF , Tapper K , Lynch R , Clarke R , Raisanen L , Desousa C , Moore L
Published: July 2010

Objective

The present study evaluated the impact of a national school programme of universal free healthy breakfast provision in Wales, UK.

Design

A cluster randomised controlled trial with repeated cross-sectional design and a 12-month follow-up. Primary outcomes were breakfast skipping, breakfast diet and episodic memory. Secondary outcomes were frequency of eating breakfast at home and at school, breakfast attitudes, rest-of-day diet and class behaviour.

Setting

Primary schools in nine local education authority areas.

Subjects

A total of 4350 students (aged 9–11 years) at baseline and 4472 at follow-up in 111 schools.

Results

Students in intervention schools reported significantly higher numbers of healthy food items consumed at breakfast and more positive attitudes towards breakfast eating at 12 months. Parents in intervention schools reported significantly higher rates of consumption of breakfast at school and correspondingly lower rates of breakfast consumption at home. No other significant differences were found.

Conclusions

The intervention did not reduce breakfast skipping; rather, pupils substituted breakfast at home for breakfast at school. However, there were improvements in children’s nutritional intake at breakfast time, if not the rest of the day, and more positive attitudes to breakfast, which may have implications for life-course dietary behaviours. There was no impact on episodic memory or classroom behaviour, which may require targeting breakfast skippers.
Expression and contribution of satellite glial cells purinoceptors to pain transmission in sensory ganglia: an update
Authors: Villa Giovanni , Fumagalli Marta , Verderio Claudia , Abbracchio Maria P. , Ceruti Stefania
Published: July 2010

The role of adenosine-5′-triphosphate (ATP) and of the ligand-gated P2X3receptor in neuronal dorsal root ganglia (DRG) pain transmission is relatively well established. Much less is known about the purinergic system in trigeminal ganglia (TG), which are involved in certain types of untreatable neuropathic and inflammatory pain, as well as in migraine. Emerging data suggest that purinergic metabotropic P2Y receptors on both neurons and satellite glial cells (SGCs) may also participate in both physiological and pathological pain development. Here, we provide an updated literature review on the role of purinergic signaling in sensory ganglia, with special emphasis on P2Y receptors on SGCs. We also provide new original data showing a time-dependent downregulation of P2Y2and P2Y4receptor expression and function in purified SGCs cultures from TG, in comparison with primary mixed neuron–SGCs cultures. These data highlight the importance of the neuron–glia cross-talk in determining the SGCs phenotype. Finally, we show that, in mixed TG cultures, both adenine and guanosine induce intracellular calcium transients in neurons but not in SGCs, suggesting that also these purinergic-related molecules can participate in pain signaling. These findings may have relevant implications for the development of new therapeutic strategies for chronic pain treatment.
Is Canada odd? A comparison of European and Canadian approaches to choice and regulation of the public/private divide in health care
Authors: Flood Colleen M. , Haugan Amanda
Published: July 2010

Choice is often touted as a means for change within health care systems. Yet ‘choice’, in this context, takes at least three distinct forms: choice between providers within a publicly funded health care system; choice between competing insurers within a universal plan; and, lastly, choice as between privately financed health care and universal public coverage. In Canada, it is this last form of choice that is under active debate; particularly in light of the Supreme Court of Canada’s decision inChaoulli, which found a regulation banning private health insurance for medically necessary care was unconstitutional. The argument is frequently made that Canada is an outlier from other countries in having regulation that effectively precludes this kind of choice. This issue is likely to become of concern again in upcoming constitutional challenges where applicants are looking to overturn through judicial challenges Canada’s medicare system. This article tests that argument of whether Canada truly is ‘odd’ from a comparative policy perspective by exploring regulation of choice of privately financed health care in several European countries – the Netherlands, Germany, Sweden, England and France. We highlight commonalities as well as differences, showing the extent to which these countries employ regulation to fetter growth of a large privately financed sector. The article’s thesis is that Canada, in employing more intrusive forms of regulation, is not an outlierper sebut at one point in a regulatory spectrum.
Streamer‐ and leader‐like processes in the upper atmosphere: Models of red sprites and blue jets
Authors: Raizer Y. P. , Milikh G. M. , Shneider M. N.
Published: July 2010

Models of red sprites and blue jets based on the concept of the streamer‐leader mechanism of the air breakdown are presented. Red sprites are interpreted as the downward streamers of varying cross sections launched from plasma patches in the lower ionosphere, which are caused by the electric field generated by the lightning discharge. Results of this streamer model are in good agreement with the observations of sprites. Blue jets are interpreted as produced by a bileader, whose top part is seen on photos of blue jets as a “trunk of a tree.” The upward leader is capped by its streamer zone seen as the tall and narrow “branches” of “the tree.” It is shown that the long upward streamers of blue jets can be sustained by the moderate cloud charge due to transfer of the high potential of the thundercloud edge by the upward leader tip. It is revealed that the critical external field ES required for an unlimited streamer growth satisfies the similarity law ES/N ∼ constant for a wide range of the molecular number density N. In addition, the streamer length is estimated along with the height from which the streamers can reach the ionosphere. The main unresolved problems in the field are discussed.
Solar flare detection sensitivity using the South America VLF Network (SAVNET)
Authors: Raulin Jean‐Pierre , Bertoni Fernando C. P. , Gavilán Hernan R. , Guevara‐Day Walter , Rodriguez Rodolfo , Fernandez Germán , Correia Emilia , Kaufmann Pierre , Pacini Alessandra , Stekel Tardelli R. C. , Lima Washington L. C. , Schuch Nelson J. , Fagundes Paulo R. , Hadano Rubens
Published: July 2010

We present recent observations of Sudden Phase Anomalies due to subionospheric propagation anomalies produced by solar X‐ray flares. We use the new South America VLF Network (SAVNET) to study 471 ionospheric events produced by solar flares during the period May 2006 to July 2009 which corresponds to the present minimum of solar activity. For this activity level, we find that 100% of the solar flares with a X‐ray peak flux above 5 × 10−7 W/m2 in the 0.1–0.8 nm wavelength range produce a significant ionospheric disturbance, while the minimum X‐ray flux needed to do so is about 2.7 × 10−7 W/m2. We find that this latter minimum threshold is dependent on the solar cycle, increasing when the Sun is more active, thus confirming that the low ionosphere is more sensitive during periods of low solar activity. Also, our findings are in agreement with the idea that the ionospheric D‐region is formed and maintained by the solar Lyman‐α radiation outside solar flare periods.
Impact of self‐attraction and loading on the annual cycle in sea level
Authors: Tamisiea M. E. , Hill E. M. , Ponte R. M. , Davis J. L. , Velicogna I. , Vinogradova N. T.
Published: July 2010

The annual exchange of water between the continents and oceans is observed by GPS, gravimetry, and altimetry. However, the global average amplitude of this annual cycle (observed amplitude of ∼8 mm) is not representative of the effects that would be observed at individual tide gauges or at ocean bottom pressure recorders because of self‐attraction and loading effects (SAL). In this paper, we examine the spatial variation of sea level change caused by the three main components that load the Earth and contribute to the water cycle: hydrology (including snow), the atmosphere, and the dynamic ocean. The SAL effects cause annual amplitudes at tide gauges (modeled here with a global average of ∼9 mm) to vary from less than 2 mm to more than 18 mm. We find a variance reduction (global average of 3 to 4%) after removing the modeled time series from a global set of tide gauges. We conclude that SAL effects are significant in places (e.g., the south central Pacific and coastal regions in Southeast Asia and west central Africa) and should be considered when interpreting these data sets and using them to constrain ocean circulation models.
Using fluorescence spectroscopy to trace seasonal DOM dynamics, disturbance effects, and hydrologic transport in the Florida Everglades
Authors: Larsen Laurel G. , Aiken George R. , Harvey Judson W. , Noe Gregory B. , Crimaldi John P.
Published: July 2010

Dissolved organic matter (DOM) quality reflects numerous environmental processes, including primary production and decomposition, redox gradients, hydrologic transport, and photochemistry. Fluorescence spectroscopy can detect groups of DOM compounds sensitive to these processes. However, different environmental gradients (e.g., redox, DOM provenance) can have confounding effects on DOM fluorescence spectra. This study shows how these confounding effects can be removed through discriminant analyses on parallel factor modeling results. Using statistically distinct end‐members, we resolve spatiotemporal trends in redox potential and DOM provenance within and between adjacent vegetation communities in the patterned ridge and slough landscape of the Everglades, where biogeochemical differences between vegetation communities affect net peat accretion rates and persistence of landscape structure. Source discrimination of DOM in whole‐water samples and peat leachates reveals strong temporal variability associated with seasonality and passage of a hurricane and indicates that hurricane effects on marsh biogeochemistry persist for longer periods of time (>1 year) than previously recognized. Using the DOM source signal as a hydrologic tracer, we show that the system is hydrologically well mixed when surface water is present, and that limited transport of flocculent detritus occurs in surface flows. Redox potential discrimination shows that vertical redox gradients are shallower on ridges than in sloughs, creating an environment more favorable to decomposition and diagenesis. The sensitivity, high resolution, rapidity, and precision of these statistical analyses of DOM fluorescence spectra establish the technique as a promising performance measure for restoration or indicator of carbon cycle processes in the Everglades and aquatic ecosystems worldwide.
Herpes simplex virus‐1 induces expression of a novel MxA isoform that enhances viral replication
Authors: Ku Chia‐Chi , Che Xi‐Bing , Reichelt Mike , Rajamani Jaya , Schaap‐Nutt Anne , Huang Ke‐Jung , Sommer Marvin H , Chen Yi‐Shun , Chen Yi‐Yuan , Arvin Ann M
Published: July 2010

MxA is an antiviral protein induced by interferon (IFN)‐α/β that is known to inhibit the replication of many RNA viruses. In these experiments, the 76‐kDa MxA protein expressed in IFN‐α‐treated cells was shown to have antiviral activity against herpes simplex virus‐1 (HSV‐1), a human DNA virus. However, MxA was expressed as a 56‐kDa protein in HSV‐1‐infected cells in the absence of IFN‐α. This previously unrecognized MxA isoform was produced from an alternatively spliced MxA transcript that had a deletion of Exons 14–16 and a frame shift altering the C‐terminus. The variant MxA (varMxA) isoform was associated with HSV‐1 regulatory proteins and virions in nuclear replication compartments. varMxA expression enhanced HSV‐1 infection as shown by a reduction in infectious virus titers from cells in which MxA had been inhibited by RNA interference and by an increase in HSV‐1 titers when the 56‐kDa varMxA was expressed constitutively. Thus, the human MxA gene encodes two MxA isoforms, which are expressed differentially depending on whether the stimulus is IFN‐α or HSV‐1. These findings show that alternative splicing of cellular mRNA can result in expression of a novel isoform of a host defense gene that supports instead of restricting viral infection.
Interleukin‐10 limits the expansion of immunoregulatory CD4−CD8− T cells in autoimmune‐prone non‐obese diabetic mice
Authors: Hillhouse Erin E , Beauchamp Claudine , Chabot‐Roy Geneviève , Dugas Véronique , Lesage Sylvie
Published: July 2010

Regulatory T cells appear to show great potential for use in cellular therapy. In particular, CD4−CD8− (double negative (DN)) T cells, which compose 1–3% of the total number of T lymphocytes, exhibit prominent antigen‐specific immune tolerance properties and confer immune tolerance in models of allografts and xenografts. We have recently shown that autoimmune‐diabetes‐prone mice carry fewer DN T cells and that this phenotype contributes to autoimmune‐prone diabetes susceptibility, suggesting that increasing DN T‐cell number in autoimmune‐prone individuals may be of therapeutic interest. To achieve this goal, we must first determine whether the remaining DN T cells in autoimmune‐prone mice are functional. In addition, we must identify the parameters that regulate the numbers of DN T cells. Herein, we evaluate the immunoregulatory properties of DN T cells in the autoimmune‐prone non‐obese diabetic (NOD) genetic background. Using 3A9 TCR transgenic mice, we show that DN T cells from both diabetes‐resistant B10.Br and genetically autoimmune‐prone NOD.H2k mice show an equivalent immunoregulatory potential on a per cell basis. However, upon stimulation, there is a 10‐fold increase in the number of 3A9 TCR transgenic DN T cells that produce interleukin10 (IL‐10) from NOD.H2k mice in comparison with B10.Br mice. We further showed that IL‐10 facilitates DN T‐cell apoptosis and thus may regulate the number of DN T cells. Taken together, our results show that, although reduced in number, DN T cells from mice carrying an autoimmune‐prone genetic background exhibit a potent cytotoxic potential and that DN T‐cell expansion is regulated, at least in part, by IL‐10.
Using Acoustic Phonetics in Clinical Practice
Authors: Neel Amy T.
Published: July 2010

Acoustic phonetics deals with the physical aspects of speech sounds associated with the production and perception of speech. Acoustic measurement techniques can be used by speech-language pathologists to assess and treat a variety of speech disorders. In this article, we will review the source-filter theory of speech production, acoustic theory of vowels, and acoustic properties of consonants. We will examine how visual displays of acoustic information in the form of waveforms, amplitude spectra, and spectrograms can be used to analyze aspects of speech that might be difficult to hear and serve to provide biofeedback to clients to improve their speech production.
Get Hip to the Data Acquisition Scene: Principles of Digital Signal Recording
Authors: Finan Donald S.
Published: July 2010

Use of the term “digital” has become ubiquitous. But what does it mean for a device to be “digital”? Computers process information by manipulating numbers (digits), and are therefore often referred to as digital systems. When the term “digital” is used to describe a device, the implication is that a computer is somehow involved. MP3 or iPod music players are digital devices, in that a computer was used to convert music to a numeric (digital) format so that it could be stored on a digital memory chip. This article will explore how computers capture real-world signals (such as acoustic speech signals), and why computer (digital) signal acquisition has advantages over older “analog” recording technologies. This article also will present information on potential error that can arise when converting analog signals to the digital domain.
Observation of low heat capacities for vapor-deposited glasses of indomethacin as determined by AC nanocalorimetry
Authors: Kearns Kenneth L. , Whitaker Katherine R. , Ediger M. D. , Huth Heiko , Schick Christoph
Published: July 2010

Highly stable glass films of indomethacin (IMC) with thicknesses ranging from 75 to 2900 nm were prepared by physical vapor deposition. Alternating current (AC) nanocalorimetry was used to evaluate the heat capacity and kinetic stability of the glasses as a function of thickness. Glasses deposited at a substrate temperature of 0.84Tg displayed heat capacities that were approximately 19 J/(mol  K) (4.5%) lower than glasses deposited at Tg (315 K) or the ordinary glass prepared by cooling the liquid. This difference in heat capacity was observed over the entire thickness range and is significantly larger than the ∼2 J/(mol K) (0.3%) difference previously observed between aged and ordinary glasses. The vapor-deposited glasses were isothermally transformed into the supercooled liquid above Tg. Glasses with low heat capacities exhibited high kinetic stability. The transformation time increased by an order of magnitude as the film thickness increased from 75 to 600 nm and was independent of film thickness for the thickest films. We interpret these results to indicate that the transformation of stable glass into supercooled liquid can occur by either a surface-initiated or bulk mechanism. In these experiments, the structural relaxation time of the IMC supercooled liquid was observed to be nearly independent of sample thickness.
On the form of the kinetic energy balance equation in the kinetic variational theory
Authors: Humenyuk Yosyp A. , Tokarchuk Mykhailo V.
Published: July 2010

An alternative balance equation for the kinetic energy density used in the kinetic variational theory (KVT) is proposed. The new equation is consistent with the well-known standard form interpreted in terms of a flux and a source for both a one-component fluid and a mixture. Within the proposed version, the KVT mean-field collision term produces contributions to the heat flux and the source of kinetic energy being absent in the original formulation. It is shown that the introduced modification can affect the KVT thermal conductivity of the mixture while for the one-component fluid it becomes important only in the second and higher orders in gradients.
Extrinsic contributions to photocurrents from quantum-wells
Authors: Giri Rakshyakar , Schwirzke-Schaaf Sandy , Tomm Jens W.
Published: July 2010

Photocurrent (PC) spectra representing the in-plane absorption of the quantum-wells (QWs) in diode lasers are monitored. Spectra from pristine and systematically aged devices are analyzed and aging-induced changes are explained within the frame of rate-equation models for nonequilibrium carriers. We conclude from the analysis of the PC phase behavior and from aging-induced changes in the QW PCs, these currents to be actually of extrinsic nature. This finding, however, does not prohibit the use of PC spectra for analytical purposes, e.g., when employing PC peak-positions or their shifts because the spectral shape of the extrinsic QW PCs is still governed by QW absorption. This holds for all photoelectric techniques if applied to the vertical transport in pin-structures, such as diode laser structures.
Switching-current reduction in perpendicular-anisotropy spin torque magnetic tunnel junctions
Authors: Heinonen O. G. , Dimitrov D. V.
Published: July 2010

Magnetic tunnel junctions with the magnetization perpendicular to the plane of the layers can be switched between configurations with parallel or antiparallel magnetization of the layers using spin-polarized currents. Here we use finite-temperature micromagnetic modeling to study the switching behavior of such structures. In particular, we examine the effect of materials properties, such as magnetization density and magnetic anisotropy, on the current and time needed for the magnetization to switch from the parallel configuration to the antiparallel configuration. In addition, we study the possibility of lowering the required current density through a so-called exchange-spring effect in one of the magnetic layers. For circular devices of 70 nm diameter, we find a range of materials properties for which a current density of 2.6 MA/cm2 can switch the magnetization configuration within 20 ns. However, for the parameters studied here, only small further reductions in the switching current density, to about 2.1 MA/cm2, are possible, at a price of increasing the allowed switching time to 40 ns.
Sensor shape design for piezoelectric cantilever beams to harvest vibration energy
Authors: Friswell Michael I. , Adhikari Sondipon
Published: July 2010

Energy harvesting for the purpose of powering low power electronic sensor systems has received explosive attention in the last few years. A common device uses the piezoelectric effect for a cantilever beams at resonance to harvest ambient vibration energy. However most of these devices have a rectangular piezoelectric patch covering all or part of the beam. This paper considers the optimum design of such a device, and in particular investigates the effect that the size and shape of piezoelectric sensor has on the harvested energy. It is shown that significant increases in harvested energy may be obtained by optimising the sensor design.
Variable percolation threshold of composites with fiber fillers under compression
Authors: Lin Chuan , Wang Hongtao , Yang Wei
Published: July 2010

The piezoresistant effect in conducting fiber-filled composites has been studied by a continuum percolation model. Simulation was performed by a Monte Carlo method that took into account both the deformation-induced fiber bending and rotation. The percolation threshold was found to rise with the compression strain, which explains the observed positive piezoresistive coefficients in such composites. The simulations unveiled the effect of the microstructure evolution during deformation. The fibers are found to align perpendicularly to the compression direction. As the fiber is bended, the effective length in making a conductive network is shortened. Both effects contribute to a larger percolation threshold and imply a positive piezoresistive coefficient according the universal power law.
Annealing induced extended defects in as-grown and ion-implanted 4H–SiC epitaxial layers
Authors: Nagano M. , Tsuchida H. , Suzuki T. , Hatakeyama T. , Senzaki J. , Fukuda K.
Published: July 2010

The formation of extended defects in the 4H–SiC epilayer induced by the implantation/annealing process was investigated using synchrotron reflection x-ray topography, KOH etching analysis, and transmission electron microscopy. High temperature annealing was performed for the 4H–SiC epilayer with or without the implantation of nitrogen or aluminum ions. Other than the formation of platelet extrinsic Frank-type faults in the implanted region as reported previously, we find the formation modes of extended defects in following three categories: (i) dislocation formation near the epilayer/substrate interface, (ii) dislocation formation near the implanted region, and (iii) the formation of Shockley-type defects near the surface. The defect morphology and process dependence of each type are also discussed.
Overlapping resonances in the resistance of superposition states to decoherence
Authors: Biswas Asoka , Shapiro Moshe , Brumer Paul
Published: July 2010

Overlapping resonances are shown to provide new insights into the extent of decoherence experienced by a system superposition state in the regime of strong system-environment coupling. As an example of this general approach, a generic system comprising spin-half particles interacting with a thermalized oscillator environment is considered. We find that (a) among the collection of parametrized Hamiltonians, the larger the overlapping resonances contribution, the greater the maximum possible purity, and (b) for a fixed Hamiltonian, the larger the overlapping resonances contribution, the larger the range of possible values of the purity as one varies the phases in the system superposition states. Systems displaying decoherence free subspaces show the largest overlapping resonances contribution.
Band structure and electrical properties of Gd-doped HfO2 high k gate dielectric
Authors: Xiong Yuhua , Tu Hailing , Du Jun , Ji Mei , Zhang Xinqiang , Wang Lei
Published: July 2010

Effects of Gd doping on band gap, band offset, oxygen vacancies, and electrical properties of amorphous HfO2 film have been studied. The results show that Gd incorporation helps increase band gap, conduction band offset and conduction band minimum, and reduce oxygen vacancies simultaneously. Kept at the same physical thickness of 5 nm, Gd-doped HfO2 gate dielectric has a leakage current density of 9.0×10−4 A/cm2 at 1 V gate voltage, one and a half orders of magnitude lower than that of the pure HfO2. Gd doping also enhances the dielectric constant. The capacitance equivalent thicknesses of 0.98 nm and 0.81 nm for HfO2 and Gd-doped HfO2 films, respectively, have been obtained.
Exciton and electron-hole plasma lasing in ZnO dodecagonal whispering-gallery-mode microcavities at room temperature
Authors: Dai J. , Xu C. X. , Wu P. , Guo J. Y. , Li Z. H. , Shi Z. L.
Published: July 2010

Dodecagonal ZnO microrods were fabricated by vapor transport method. A dodecagonal ZnO microrod with diameter of 6.35 μm was employed as a whispering gallery mode microcavity, the low threshold exciton lasing was stimulated. In another smaller microrod, the electron-hole plasma lasing was observed under intense excitation as the carrier density was larger than the Mott transition density. The interference condition in the dodecagonal cavity was deduced, and the mode structures were investigated. Compared to the hexagonal microcavity with same diameter, the dodecagonal microcavity has higher lasing performance.
Nitrogen and radiation effects during the active spike-growth phase on floret development and biomass partitioning in 2- and 6-rowed barley isolines
Authors: Arisnabarreta Sebastián , Miralles Daniel J.
Published: July 2010

The paramount importance of accumulated biomass in active-growing spikes over the number of grains per unit area has been well documented. However, it is not clear how different nitrogen (N) and radiation supplies during the active spike-growth phase alter the dynamics of floret primordia initiation and survival to establish the number of fertile florets and grains in 2- and 6-rowed barley. The objective of this paper was to evaluate how biomass and N partitioned between vegetative and reproductive organs alter the development of potential grains (i.e. floret primordia), when 2- and 6-rowed barley is grown under different radiation and N levels during their active spike-growth phase.
A field experiment was carried out using two near-isogenic lines differing in the spike type and grown under contrasting radiation and N levels around the active spike-growth phase. Floret primordia development and biomass and N partitioning towards vegetative and reproductive organs were analysed.
The results showed significant genotype × radiation × N level interactions on the dynamics of generation and abortion of reproductive structures. Under non-limiting N conditions, reductions in radiation levels strongly reduced the number of differentiated florets, although the effects were higher in 6- than in 2-rowed barley types. The higher the N supply, the higher the floret development stage reached when the spikes started growing at their maximum growth rates, increasing floret survival in that way. A threshold of floral development could not be found at any time in the crop cycle that guaranteed a fertile floret stage at heading. As it was not possible to identify a direct effect of N on the establishment of fertile florets, the efforts for further rising yield potential in barley should be focused on processes influencing partitioning of assimilates to reproductive growth during the critical period.
Novel barley (Hordeum vulgare L.) germplasm resistant to acidic soil
Authors: Moroni J. S. , Sato K. , Scott B. J. , Conyers M. , Read B. J. , Fisher R. , Poile G.
Published: July 2010

Improving the resistance of barley (Hordeum vulgare L.) to acidic soils is an important goal of several barley breeding programs around the world. The identification and utilisation of novel barley sources resistant to aluminium (Al) may provide a significant and rapid advance towards that goal. Barley standards and screening protocols for selecting barley germplasm resistant to Al in nutrient solution and acidic soil were reevaluated. The assays used were quantitative in nature and were suitable for genotypic- and seedling-based selections. Although there was a broad agreement between the solution culture assays and soil assays in the ranking of genotypes it obscured the fact that misclassification of genotypes is common. Brindabella was shown to be better suited than Dayton (the current barley standard resistant to Al) as the Australian standard for resistance to acidic soils. A seedling-based Al pulse-recovery assay and an acidic soil assay were used to characterise 41 genotypes from the South and East Asian Barley Core Collection (SEA-BCC). In addition, in the acidic soil assays several standard barley and wheat genotypes were included. Three SEA-BCC genotypes were more resistant than Dayton to acidic soil while several others were similar to Dayton. The most resistant SEA-BCC genotypes Honen, Ohichi and Zairai Tanbo were of Japanese origin. Misclassification of barley genotypes and wheat genotypes for resistance to soil acidity between solution culture and acid soil assay provided strong evidence for the unsuitability of solution culture assay. Although in solution culture several barley genotypes were sensitive relative to wheat, in acidic soil they were not different from wheat. While the quest for resistant barley to acidic soils similar or better than resistant wheat still continues, it may be an unnecessary endeavour.
Noachian and more recent phyllosilicates in impact craters on Mars
Authors: Fairén Alberto G. , Chevrier Vincent , Abramov Oleg , Marzo Giuseppe A. , Gavin Patricia , Davila Alfonso F. , Tornabene Livio L. , Bishop Janice L. , Roush Ted L. , Gross Christoph , Kneissl Thomas , Uceda Esther R. , Dohm James M. , Schulze-Makuch Dirk , Rodríguez J. Alexis P. , Amils Ricardo , McKay Christopher P.
Published: July 2010

Hundreds of impact craters on Mars contain diverse phyllosilicates, interpreted as excavation products of preexisting subsurface deposits following impact and crater formation. This has been used to argue that the conditions conducive to phyllosilicate synthesis, which require the presence of abundant and long-lasting liquid water, were only met early in the history of the planet, during the Noachian period (> 3.6 Gy ago), and that aqueous environments were widespread then. Here we test this hypothesis by examining the excavation process of hydrated minerals by impact events on Mars and analyzing the stability of phyllosilicates against the impact-induced thermal shock. To do so, we first compare the infrared spectra of thermally altered phyllosilicates with those of hydrated minerals known to occur in craters on Mars and then analyze the postshock temperatures reached during impact crater excavation. Our results show that phyllosilicates can resist the postshock temperatures almost everywhere in the crater, except under particular conditions in a central area in and near the point of impact. We conclude that most phyllosilicates detected inside impact craters on Mars are consistent with excavated preexisting sediments, supporting the hypothesis of a primeval and long-lasting global aqueous environment. When our analyses are applied to specific impact craters on Mars, we are able to identify both pre- and postimpact phyllosilicates, therefore extending the time of local phyllosilicate synthesis to post-Noachian times.
The SPRY domain–containing SOCS box protein SPSB2 targets iNOS for proteasomal degradation
Authors: Kuang Zhihe , Lewis Rowena S. , Curtis Joan M. , Zhan Yifan , Saunders Bernadette M. , Babon Jeffrey J. , Kolesnik Tatiana B. , Low Andrew , Masters Seth L. , Willson Tracy A. , Kedzierski Lukasz , Yao Shenggen , Handman Emanuela , Norton Raymond S. , Nicholson Sandra E.
Published: July 2010

Inducible nitric oxide (NO) synthase (iNOS; NOS2) produces NO and related reactive nitrogen species, which are critical effectors of the innate host response and are required for the intracellular killing of pathogens such as Mycobacterium tuberculosis and Leishmania major. We have identified SPRY domain–containing SOCS (suppressor of cytokine signaling) box protein 2 (SPSB2) as a novel negative regulator that recruits an E3 ubiquitin ligase complex to polyubiquitinate iNOS, resulting in its proteasomal degradation. SPSB2 interacts with the N-terminal region of iNOS via a binding interface on SPSB2 that has been mapped by nuclear magnetic resonance spectroscopy and mutational analyses. SPSB2-deficient macrophages showed prolonged iNOS expression, resulting in a corresponding increase in NO production and enhanced killing of L. major parasites. These results lay the foundation for the development of small molecule inhibitors that could disrupt the SPSB–iNOS interaction and thus prolong the intracellular lifetime of iNOS, which may be beneficial in chronic and persistent infections.
SNARE bundle and syntaxin N-peptide constitute a minimal complement for Munc18-1 activation of membrane fusion
Authors: Shen Jingshi , Rathore Shailendra S. , Khandan Lavan , Rothman James E.
Published: July 2010

Sec1/Munc18 (SM) proteins activate intracellular membrane fusion through binding to cognate SNAP receptor (SNARE) complexes. The synaptic target membrane SNARE syntaxin 1 contains a highly conserved Habc domain, which connects an N-peptide motif to the SNARE core domain and is thought to participate in the binding of Munc18-1 (the neuronal SM protein) to the SNARE complex. Unexpectedly, we found that mutation or complete removal of the Habc domain had no effect on Munc18-1 stimulation of fusion. The central cavity region of Munc18-1 is required to stimulate fusion but not through its binding to the syntaxin Habc domain. SNAP-25, another synaptic SNARE subunit, contains a flexible linker and exhibits an atypical conjoined Qbc configuration. We found that neither the linker nor the Qbc configuration is necessary for Munc18-1 promotion of fusion. As a result, Munc18-1 activates a SNARE complex with the typical configuration, in which each of the SNARE core domains is individually rooted in the membrane bilayer. Thus, the SNARE four-helix bundle and syntaxin N-peptide constitute a minimal complement for Munc18-1 activation of fusion.
Long astral microtubules uncouple mitotic spindles from the cytokinetic furrow
Authors: Rankin Kathleen E. , Wordeman Linda
Published: July 2010

Astral microtubules (MTs) are known to be important for cleavage furrow induction and spindle positioning, and loss of astral MTs has been reported to increase cortical contractility. To investigate the effect of excess astral MT activity, we depleted the MT depolymerizer mitotic centromere-associated kinesin (MCAK) from HeLa cells to produce ultra-long, astral MTs during mitosis. MCAK depletion promoted dramatic spindle rocking in early anaphase, wherein the entire mitotic spindle oscillated along the spindle axis from one proto-daughter cell to the other, driven by oscillations of cortical nonmuscle myosin II. The effect was phenocopied by taxol treatment. Live imaging revealed that cortical actin partially vacates the polar cortex in favor of the equatorial cortex during anaphase. We propose that this renders the polar actin cortex vulnerable to rupture during normal contractile activity and that long astral MTs enlarge the blebs. Excessively large blebs displace mitotic spindle position by cytoplasmic flow, triggering the oscillations as the blebs resolve.