bluuebunny/crossref_metadata_2025 huggingface dataset:
Designer Ge quantum dots on Si: A heterostructure configuration with enhanced optoelectronic performance
Authors: Kuo M. H. , Wang C. C. , Lai W. T. , George Tom , Li P. W.
Published: November 2012

An otherwise random, self-assembly of Ge quantum dots (QDs) on Si has been controlled by nano-patterning and oxidation to produce QDs with desired sizes, locations, and depths of penetration into the Si substrate. A heterostructure consisting of a thin amorphous interfacial oxide between the Ge QD and the Si substrate is shown to improve crystalline quality by de-coupling the lattice-matching constraint. A low dark current density of 1.1 μA/cm2 and a high photocurrent enhancement up to 35 000 and 1500, respectively, for 1.5 mW incident illumination at 850 nm and 1160 nm was measured on our Ge QD-based metal-oxide-semiconductor photodiodes.
Divertor conditions relevant for fusion reactors achieved with linear plasma generator
Authors: van Eck H. J. N. , Kleyn A. W. , Lof A. , van der Meiden H. J. , van Rooij G. J. , Scholten J. , Zeijlmans van Emmichoven P. A.
Published: November 2012

Intense magnetized hydrogen and deuterium plasmas have been produced with electron densities up to 3.6 × 1020 m−3 and electron temperatures up to 3.7 eV with a linear plasma generator. Exposure of a W target has led to average heat and particle flux densities well in excess of 4 MW m−2 and 1024 m−2 s−1, respectively. We have shown that the plasma surface interactions are dominated by the incoming ions. The achieved conditions correspond very well to the projected conditions at the divertor strike zones of fusion reactors such as ITER. In addition, the machine has an unprecedented high gas efficiency.
Measurements of the fast ion slowing-down times in the HL-2A tokamak and comparison to classical theory
Authors: Zhang Y. P. , Isobe M. , Liu Yi , Yuan G. L. , Yang J. W. , Song X. Y. , Song X. M. , Cao J. Y. , Lei G. J. , Wei H. L. , Li Y. G. , Shi Z. B. , Li X. , Yan L. W. , Yang Q. W. , Duan X. R. ,   HL-2A Team
Published: November 2012

Physics related to fast ions in magnetically confined fusion plasmas is a very important issue, since these particles will play an important role in future burning plasmas. Indeed, they will act as primary heating source and will sustain the self-ignited condition. To measure the fast ion slowing-down times in a magnetohydrodynamic-quiescent plasmas in different scenarios, very short pulses of a deuterium neutral beam, so-called “blip,” with duration of about 5 ms were tangentially co-injected into a deuterium plasmas at the HuanLiuqi-2A (commonly referred to as HL-2A) tokamak [L. W. Yan, Nucl. Fusion 51, 094016 (2011)]. The decay rate of 2.45 MeV D-D fusion neutrons produced by beam-plasma reactions following neutral beam termination was measured by means of a 235U fission chamber. Experimental results were compared with those predicted by a classical slowing-down model. These results show that the fast ions are well confined with a peaked profile and the ions are slowed down classically without significant loss in the HL-2A tokamak. Moreover, it has been observed that during electron cyclotron resonance heating the fast ions have a longer slowing-down time and the neutron emission rate decay time becomes longer.
The use of oil shale ash in the production of biodiesel from waste vegetable oil
Authors: Al-Otoom A. , Allawzi M. , Ajlouni A. , Abu-Alrub F. , Kandah M.
Published: November 2012

Oil shale ash obtained from combustion of local oil shale deposits was used in this study as a heterogeneous catalyst to produce biodiesel from waste vegetable oil (WVO). Two alcohols with high and low boiling points, ethanol and ethylene glycol, were used for oil shale catalytic esterification of the WVO. Results show that the esterification of wastes of oil utilizing wastes of oil shale combustion can be used to produce biodiesel. Additionally, it was found that in order to make the oil shale ash an effective catalyst for transesterification, high reaction temperature is required. Therefore, the results have indicated that high biodiesel yield is obtained when using ethylene glycol at high temperature, while the yield is low when solid catalytic reaction is performed using ethanol at low temperature. The maximum obtained yield was 75 wt. % utilizing ethylene glycol at 150 °C, whereas this yield decreased to 69.9 wt. % as the operating temperature was reduced to 100 °C. On the other hand, when using ethanol, the yield of biodiesel was relatively low (11 wt. % at 60 °C and 9 wt. % at 80 °C).
Equilibrium modeling and regression analysis of biomass gasification
Authors: Sreejith C. C. , Muraleedharan C. , Arun P.
Published: November 2012

In the perspective of fossil fuel depletion, global warming, climatic changes, and atmospheric pollution, the importance of renewable fuels is remarkable. Bio-hydrogen produced from locally available biomass is an efficient source of energy. For achieving hydrogen richness in gas mixture produced by thermo-chemical gasification of biomass, gasification agent used and its feed rate, and gasifier working conditions are prominent among many other factors. In the present work, formulation and simulation of a thermodynamic equilibrium model for biomass steam gasification, incorporating the yields of unconverted char and tar (in addition to gaseous products) based on equilibrium constant method is presented. The model is based on Redlich-Kwong real gas equation of state considering the equilibrium constants of two component reactions, namely methane formation and water gas shift. A generic method for the determination of equilibrium constants from the corresponding Gibbs free energy changes, incorporating real gas residual properties is adopted. Computations including solution of simultaneous non-linear equations are performed using Gauss–Newton algorithm. Producer gas composition, heating value of gas mixture (LHV), dry gas yield, and relative yields of gasification products are studied using apricot stones as the illustrative biomass material. Parametric variations with steam to biomass ratio (SBR) and temperature are analyzed and validated with reported experimental results on steam gasification. The richest hydrogen gas mixture (58.7% at SBR of 2.2) is predicted at 1000 K. SBR is found to be favorable to hydrogen concentration and combustible gas yield. But heating value (MJ/Nm3) can be enhanced with hike in temperature of gasification only. More than 45% (77% excluding steam) is dry gas in the products of gasification above 700 K. Regression analysis is performed using the data for thirty five biomass materials simulated by the real gas model. Based on the statistically tested regression model for accuracy, parametric correlations are formulated for LHV and product gas composition for steam gasification.
Error analysis for concentrated solar collectors
Authors: Bonanos A. M.
Published: November 2012

Error sources introduced into mirror tracking systems, arising from component limitations, construction and placement of the reflectors, and the discrete motion of the tracking system itself, are examined. The main mechanisms contributing to these sources are identified and modeled. The effect of these optical and geometrical errors is numerically simulated using a ray-tracing code and their relative significance is assessed.
Room temperature magnetoresistance in a polyimide-Co granular film synthesized by vapor deposition polymerization
Authors: Suzuki Kazuya Z. , Yanagihara Hideto , Niizeki Tomohiko , Kojio Ken , Kita Eiji
Published: November 2012

Magnetic and magnetotransport properties of pyromellitic dianhydride-4,4′-oxydianiline polyimide-Co granular thin films prepared by vapor deposition polymerization are investigated. The prepared sample is composed of Co particles with diameters of 2–3 nm homogeneously dispersed in a denatured polyimide matrix. The temperature dependence of the resistivity closely follows the T−1/2 law, suggesting that the dominant conduction mechanism is tunneling between metallic granules embedded in the insulating polyimide matrix. The magnetoresistances at 300 and 90 K are 2.6% and 3.0%, respectively. The results indicate that polyimide is a promising material for organic spintronics.
Feedback controller for destroying synchrony in an array of the FitzHugh–Nagumo oscillators
Authors: Tamaševičius Arūnas , Tamaševičiūtė Elena , Mykolaitis Gytis
Published: November 2012

We describe an implementation of an electronic feedback controller, destroying synchrony and/or suppressing the mean field in arrays of globally coupled nonidentical oscillators. We demonstrate that the mean field, either artificially nullified or fed back into the array with a negative sign can break up the phase synchronization. The experiments have been carried out with an array of thirty electronic oscillators, imitating dynamical behavior of the spiking neurons. We have found that the negative mean-field technique, depending on the control parameter, can either desynchronize or synchronize the oscillators, whereas in the both cases, it ensures low mean-field voltage.
Tunable Dirac cone in the rectangular symmetrical semiconductor quantum dots array
Authors: Peng Juan , Fu Zhen-Guo , Li Shu-Shen
Published: November 2012

We studied the electronic properties of a two-dimensional (2D) rectangular symmetrical semiconductor quantum dots (QD) lattice and found a type of tunable Dirac cone structure in its energy spectrum by using tight-binding method. We show that, by tuning the parameters of the QD lattice, the energy gap could be closed and form the Dirac cone. A phase diagram of transition from the gap opening to the gapless state is also obtained. Furthermore, we found the Dirac cone is anisotropic, implying direction-dependent electronic properties and conductivities. These findings may be useful for the development and application of high-speed semiconductor QD devices.
Band alignment in Ge/GeOx/HfO2/TiO2 heterojunctions as measured by hard x-ray photoelectron spectroscopy
Authors: Rumaiz A. K. , Woicik J. C. , Weiland C. , Xie Q. , Siddons D. P. , Jaffari G. H. , Detavernier C.
Published: November 2012

We investigate the interlayer (IL) thickness dependence of band offsets in a germanium based bilayer metal-oxide-semiconductor sandwich with an amorphous plasma enhanced atomic layer deposited (PE-ALD) HfO2 IL and PE-ALD grown TiO2 high k gate dielectric using hard x-ray photoelectron spectroscopy. The native Ge oxide shifts to higher oxidation state as the thickness of the IL layer was increased. The Hf 4f core line shows a broadening with increasing thickness, indicating the formation of Hf-Ge germanate. We observed a deviation from the bulk offset for films with ultra thin layers of HfO2.
Temporally resolved imaging on quenching and re-ignition of nanosecond underwater discharge
Authors: Yang Yong , Cho Young I. , Fridman Alexander
Published: November 2012

This paper presents the temporally resolved images of plasma discharge in de-ionized water. The discharge was produced by high voltage pulses with 0.3 ns rise time and 10 ns duration. The temporal resolution of the imaging system was one nanosecond. A unique three-stage process, including a fast ignition at the leading edge of the pulse, quenching at the plateau of the pulse, and self re-ignition at the trailing edge of the pulse, was observed in a single pulse cycle. The maximum measured propagation velocity of the plasma discharge was about 1000 km/s. The possibility of direct ionization in water under high reduced electric field conditions was discussed.

At the request of the authors, this article is being retracted effective 2 July 2013.
Contribution of an extrinsic mechanism for the electrical polarization in BiMn2O5 ceramics
Authors: Fier I. , Chinaglia D. L. , Walmsley L. , Pereira E. C. , Rabelo A. C. , Freitas R. G.
Published: November 2012

DC conductivity, frequency dependent dielectric constant and pyroelectric coefficients, obtained from thermal stimulated depolarization current curves, in BiMn2O5 ceramics in the range of temperatures from 10 K to 320 K are reported. The data could be explained if it is assumed that a dipole defect is formed due to an oxygen vacancy and two manganese ions which have their valence changed to accept an electron.
Stoloniferous octocorals (Anthozoa, Octocorallia) from South Africa, with descriptions of a new family of Alcyonacea, a new genus of Clavulariidae, and a new species of Cornularia (Cornulariidae)
Authors: McFadden Catherine S. , van Ofwegen Leen P.
Published: November 2012

We describe a new family and genus of stoloniferous octocorals (Alcyonacea) and a new genus of Clavulariidae from material collected in South Africa in 2008. Arulidae, fam. nov., is characterised by polyps whose tentacles are fused proximally to form an expanded oral membrane, and sclerites of a type (‘table-radiates’) that has not been recorded previously in Octocorallia. One species, Arula petunia, gen. nov., sp. nov., is described, and the possible existence of congeners elsewhere in the Indo-Pacific is discussed. Inconstantia, gen. nov., is erected for three new species of Clavulariidae that have no or only weak anthocodial armature. I. pannucea, sp. nov., and I. procera, sp. nov., both have tall, cylindrical calyces, while I. exigua, sp. nov., has low, retractile calyces. Despite these morphological differences that would normally place them in different subfamilies, all three species are nearly identical genetically. We also describe Cornularia pabloi, sp. nov., a new species of Cornulariidae from South Africa, and discuss an unidentified species of Carijoa with an unusual colony growth form. A molecular phylogenetic analysis of 130 octocoral taxa, including 15 genera of stoloniferans, supports the distinctions of these new taxa from existing families and genera, and highlights the polyphyletic distribution of the taxa attributed to family Clavulariidae.
Resilience of a eucalypt forest woody understorey to long-term (34 - 55 years) repeated burning in subtropical Australia
Authors: Lewis Tom , Debuse Valerie J.
Published: November 2012

We investigated the effects of annual burning since 1952, triennial burning since 1973, fire exclusion since 1946 and infrequent wildfire (one fire in 61 years) on woody understorey vegetation in a dry sclerophyll eucalypt forest, south-eastern Queensland, Australia. We determined the influence of these treatments, and other site variables (rainfall, understorey density, topsoil C : N ratio, tree basal area, distance to watercourse and burn coverage) on plant taxa density, richness and composition. The richness of woody understorey taxa 0–1 m in height was not affected by burning treatments, but richness of woody plants 1–7.5 m in height was lower in the annually burnt treatment than in the triennially burnt treatment from 1989 to 2007. Fire frequency and other site variables explained 34% of the variation in taxa composition (three taxon groups and 10 species), of which 33% of the explained variance was explained by fire treatment and 46% was explained by other site variables. Annual burning between 1974 and 1993 was associated with lower understorey densities mainly due to reduced densities of eucalypts 1–7.5 m in height. Triennial burning during the same period was associated with higher densities of eucalypts 0–7.5 m in height relative to the annually burnt and unburnt treatments. Most woody taxa persisted in the frequently burnt treatments through resprouting mechanisms (e.g. lignotuberous regeneration), and fire patchiness associated with low-intensity burning was also found to be important. Persistence of plants <1 m tall demonstrates the resilience of woody taxa to repeated burning in this ecosystem, although they mainly exist in a suppressed growth state under annual burning.
Direct three-dimensional visualization of membrane disruption by amyloid fibrils
Authors: Milanesi Lilia , Sheynis Tania , Xue Wei-Feng , Orlova Elena V. , Hellewell Andrew L. , Jelinek Raz , Hewitt Eric W. , Radford Sheena E. , Saibil Helen R.
Published: November 2012

Protein misfolding and aggregation cause serious degenerative conditions such as Alzheimer’s, Parkinson, and prion diseases. Damage to membranes is thought to be one of the mechanisms underlying cellular toxicity of a range of amyloid assemblies. Previous studies have indicated that amyloid fibrils can cause membrane leakage and elicit cellular damage, and these effects are enhanced by fragmentation of the fibrils. Here we report direct 3D visualization of membrane damage by specific interactions of a lipid bilayer with amyloid-like fibrils formed in vitro from β
2
-microglobulin (β
2
m). Using cryoelectron tomography, we demonstrate that fragmented β
2
m amyloid fibrils interact strongly with liposomes and cause distortions to the membranes. The normally spherical liposomes form pointed teardrop-like shapes with the fibril ends seen in proximity to the pointed regions on the membranes. Moreover, the tomograms indicated that the fibrils extract lipid from the membranes at these points of distortion by removal or blebbing of the outer membrane leaflet. Tiny (15–25 nm) vesicles, presumably formed from the extracted lipids, were observed to be decorating the fibrils. The findings highlight a potential role of fibrils, and particularly fibril ends, in amyloid pathology, and report a previously undescribed class of lipid–protein interactions in membrane remodelling.
Action control is mediated by prefrontal BDNF and glucocorticoid receptor binding
Authors: Gourley Shannon L. , Swanson Andrew M. , Jacobs Andrea M. , Howell Jessica L. , Mo Michelle , DiLeone Ralph J. , Koleske Anthony J. , Taylor Jane R.
Published: November 2012

Stressor exposure biases decision-making strategies from those based on the relationship between actions and their consequences to others restricted by stimulus-response associations. Chronic stressor exposure also desensitizes glucocorticoid receptors (GR) and diminishes motivation to acquire food reinforcement, although causal relationships are largely not established. We show that a history of chronic exposure to the GR ligand corticosterone or acute posttraining GR blockade with RU38486 makes rodents less able to perform actions based on their consequences. Thus, optimal GR binding is necessary for the consolidation of new response-outcome learning. In contrast, medial prefrontal (but not striatal) BDNF can account for stress-related amotivation, in that selective medial prefrontal cortical
Bdnf
knockdown decreases break-point ratios in a progressive-ratio task. Knockdown also increases vulnerability to RU38486. Despite the role of BDNF in dendritic spine reorganization, deep-layer spine remodeling does not obviously parallel progressive-ratio response patterns, but treatment with the Na
+
-channel inhibitor riluzole reverses corticosteroid-induced motivational deficits and restores prefrontal BDNF expression after corticosterone. We argue that when prefrontal neurotrophin systems are compromised, and GR-mediated hypothalamic-pituitary-adrenal axis feedback is desensitized (as in the case of chronic stress hormone exposure), amotivation and inflexible maladaptive response strategies that contribute to stress-related mood disorders result.
Cellular crowding imposes global constraints on the chemistry and evolution of proteomes
Authors: Levy Emmanuel D. , De Subhajyoti , Teichmann Sarah A.
Published: November 2012

In living cells, functional protein–protein interactions compete with a much larger number of nonfunctional, or promiscuous, interactions. Several cellular properties contribute to avoiding unwanted protein interactions, including regulation of gene expression, cellular compartmentalization, and high specificity and affinity of functional interactions. Here we investigate whether other mechanisms exist that shape the sequence and structure of proteins to favor their correct assembly into functional protein complexes. To examine this question, we project evolutionary and cellular abundance information onto 397, 196, and 631 proteins of known 3D structure from
Escherichia coli
,
Saccharomyces cerevisiae
, and
Homo sapiens
, respectively. On the basis of amino acid frequencies in interface patches versus the solvent-accessible protein surface, we define a propensity or “stickiness” scale for each of the 20 amino acids. We find that the propensity to interact in a nonspecific manner is inversely correlated with abundance. In other words, high abundance proteins have less sticky surfaces. We also find that stickiness constrains protein evolution, whereby residues in sticky surface patches are more conserved than those found in nonsticky patches. Finally, we find that the constraint imposed by stickiness on protein divergence is proportional to protein abundance, which provides mechanistic insights into the correlation between protein conservation and protein abundance. Overall, the avoidance of nonfunctional interactions significantly influences the physico-chemical and evolutionary properties of proteins. Remarkably, the effects observed are consistently larger in
E. coli
and
S. cerevisiae
than in
H. sapiens
, suggesting that promiscuous protein–protein interactions may be freer to accumulate in the human lineage.
Perfusable branching microvessel bed for vascularization of engineered tissues
Authors: Chiu Loraine L. Y. , Montgomery Miles , Liang Yan , Liu Haijiao , Radisic Milica
Published: November 2012

Vascularization is critical for the survival of engineered tissues in vitro and in vivo. In vivo, angiogenesis involves endothelial cell proliferation and sprouting followed by connection of extended cellular processes and subsequent lumen propagation through vacuole fusion. We mimicked this process in engineering an organized capillary network anchored by an artery and a vein. The network was generated by inducing directed capillary sprouting from vascular explants on micropatterned substrates containing thymosin β4-hydrogel. The capillary outgrowths connected between the parent explants by day 21, a process that was accelerated to 14 d by application of soluble VEGF and hepatocyte growth factor. Confocal microscopy and transmission electron microscopy indicated the presence of tubules with lumens formed by endothelial cells expressing CD31, VE-cadherin, and von Willebrand factor. Cardiac tissues engineered around the resulting vasculature exhibited improved functional properties, cell striations, and cell–cell junctions compared with tissues without prevascularization. This approach uniquely allows easy removal of the vasculature from the microfabricated substrate and easy seeding of the tissue specific cell types in the parenchymal space.
Kinetic characterization of the critical step in HIV-1 protease maturation
Authors: Sadiq S. Kashif , Noé Frank , De Fabritiis Gianni
Published: November 2012

HIV maturation requires multiple cleavage of long polyprotein chains into functional proteins that include the viral protease itself. Initial cleavage by the protease dimer occurs from within these precursors, and yet only a single protease monomer is embedded in each polyprotein chain. Self-activation has been proposed to start from a partially dimerized protease formed from monomers of different chains binding its own N termini by self-association to the active site, but a complete structural understanding of this critical step in HIV maturation is missing. Here, we captured the critical self-association of immature HIV-1 protease to its extended amino-terminal recognition motif using large-scale molecular dynamics simulations, thus confirming the postulated intramolecular mechanism in atomic detail. We show that self-association to a catalytically viable state requires structural cooperativity of the flexible β-hairpin “flap” regions of the enzyme and that the major transition pathway is first via self-association in the semiopen/open enzyme states, followed by enzyme conformational transition into a catalytically viable closed state. Furthermore, partial N-terminal threading can play a role in self-association, whereas wide opening of the flaps in concert with self-association is not observed. We estimate the association rate constant (
k
on
) to be on the order of ∼1 × 10
4
s
−1
, suggesting that N-terminal self-association is not the rate-limiting step in the process. The shown mechanism also provides an interesting example of molecular conformational transitions along the association pathway.
Targeted disruption of
Adamts16
gene in a rat genetic model of hypertension
Authors: Gopalakrishnan Kathirvel , Kumarasamy Sivarajan , Abdul-Majeed Shakila , Kalinoski Andrea L. , Morgan Eric E. , Gohara Amira F. , Nauli Surya M. , Filipiak Wanda E. , Saunders Thomas L. , Joe Bina
Published: November 2012

A disintegrin-like metalloproteinase with thrombospondin motifs–16 (
Adamts16
) is an important candidate gene for hypertension. The goal of the present study was to further assess the candidacy of
Adamts16
by targeted disruption of this gene in a rat genetic model of hypertension. A rat model was generated by manipulating the genome of the Dahl Salt–sensitive (S) rat using zinc-finger nucleases, wherein the mutant rat had a 17 bp deletion in the first exon of
Adamts16
, introducing a stop codon in the transcript. Systolic blood pressure (BP) of the homozygous
Adamts16

mutant

rats was lower by 36 mmHg compared with the BP of the S rats. The
Adamts16

mutant

rats exhibited significantly lower aortic pulse wave velocity and vascular media thickness compared with S rats. Scanning electron and fluorescence microscopic studies indicated that the mechanosensory cilia of vascular endothelial cells from the
Adamts16

mutant

rats were longer than that of the S rats. Furthermore,
Adamts16

mutant

rats showed splitting and thickening of glomerular capillaries and had a longer survival rate, compared with the S rats. Taken together, these physiological observations functionally link
Adamts16
to BP regulation and suggest the vasculature as the potential site of action of
Adamts16
to lower BP.
Genome streamlining and chemical defense in a coral reef symbiosis
Authors: Kwan Jason C. , Donia Mohamed S. , Han Andrew W. , Hirose Euichi , Haygood Margo G. , Schmidt Eric W.
Published: November 2012

Secondary metabolites are ubiquitous in bacteria, but by definition, they are thought to be nonessential. Highly toxic secondary metabolites such as patellazoles have been isolated from marine tunicates, where their exceptional potency and abundance implies a role in chemical defense, but their biological source is unknown. Here, we describe the association of the tunicate
Lissoclinum patella
with a symbiotic α-proteobacterium,
Candidatus
Endolissoclinum faulkneri, and present chemical and biological evidence that the bacterium synthesizes patellazoles. We sequenced and assembled the complete
Ca
. E. faulkneri genome, directly from metagenomic DNA obtained from the tunicate, where it accounted for 0.6% of sequence data. We show that the large patellazoles biosynthetic pathway is maintained, whereas the remainder of the genome is undergoing extensive streamlining to eliminate unneeded genes. The preservation of this pathway in streamlined bacteria demonstrates that secondary metabolism is an essential component of the symbiotic interaction.
Autophagy hijacked through viroporin-activated calcium/calmodulin-dependent kinase kinase-β signaling is required for rotavirus replication
Authors: Crawford Sue E. , Hyser Joseph M. , Utama Budi , Estes Mary K.
Published: November 2012

Significance

This study describes a unique mechanism of virus-initiated autophagy and exploitation of autophagy membranes for virus replication. Autophagy is a highly regulated cellular process in which cells destroy and recycle their own components in lysosomes. The mechanism most viruses use to induce autophagy is unknown. We show a rotavirus pore-forming protein activates a calcium-dependent signaling pathway to initiate autophagy. Rotavirus hijacks autophagy membranes to transport viral proteins to sites of virus replication for assembly of infectious particles and interferes with autophagy maturation. Inhibition of the signaling pathway blocks virus production, suggesting a therapeutic target to fight infection.
Universal brain systems for recognizing word shapes and handwriting gestures during reading
Authors: Nakamura Kimihiro , Kuo Wen-Jui , Pegado Felipe , Cohen Laurent , Tzeng Ovid J. L. , Dehaene Stanislas
Published: November 2012

Do the neural circuits for reading vary across culture? Reading of visually complex writing systems such as Chinese has been proposed to rely on areas outside the classical left-hemisphere network for alphabetic reading. Here, however, we show that, once potential confounds in cross-cultural comparisons are controlled for by presenting handwritten stimuli to both Chinese and French readers, the underlying network for visual word recognition may be more universal than previously suspected. Using functional magnetic resonance imaging in a semantic task with words written in cursive font, we demonstrate that two universal circuits, a shape recognition system (reading by eye) and a gesture recognition system (reading by hand), are similarly activated and show identical patterns of activation and repetition priming in the two language groups. These activations cover most of the brain regions previously associated with culture-specific tuning. Our results point to an extended reading network that invariably comprises the occipitotemporal visual word-form system, which is sensitive to well-formed static letter strings, and a distinct left premotor region, Exner’s area, which is sensitive to the forward or backward direction with which cursive letters are dynamically presented. These findings suggest that cultural effects in reading merely modulate a fixed set of invariant macroscopic brain circuits, depending on surface features of orthographies.
Variation in the schedules of somite and neural development in frogs
Authors: Sáenz-Ponce Natalia , Mitgutsch Christian , del Pino Eugenia M.
Published: November 2012

The timing of notochord, somite, and neural development was analyzed in the embryos of six different frog species, which have been divided into two groups, according to their developmental speed. Rapid developing species investigated wereXenopus laevis(Pipidae),Engystomops coloradorum, andEngystomops randi(Leiuperidae). The slow developers wereEpipedobates machalillaandEpipedobates tricolor(Dendrobatidae) andGastrotheca riobambae(Hemiphractidae). Blastopore closure, notochord formation, somite development, neural tube closure, and the formation of cranial neural crest cell-streams were detected by light and scanning electron microscopy and by immuno-histochemical detection of somite and neural crest marker proteins. The data were analyzed using event pairing to determine common developmental aspects and their relationship to life-history traits. In embryos of rapidly developing frogs, elongation of the notochord occurred earlier relative to the time point of blastopore closure in comparison with slowly developing species. The development of cranial neural crest cell-streams relative to somite formation is accelerated in rapidly developing frogs, and it is delayed in slowly developing frogs. The timing of neural tube closure seemed to be temporally uncoupled with somite formation. We propose that these changes are achieved through differential timing of developmental modules that begin with the elongation of the notochord during gastrulation in the rapidly developing species. The differences might be related to the necessity of developing a free-living tadpole quickly in rapid developers.
Amici fragili: the alliance between the Lega Nord and the Popolo della Libertà as seen by their representatives and members
Authors: Albertazzi Daniele
Published: November 2012

The alliance between the Lega Nord (LN) and Forza Italia (FI), later Popolo della Libertà (PDL), continued, uninterrupted, for over a decade, until November 2011. The problems that beset it under the fourth Berlusconi government are known; however, there is a lack of academic analysis of how such an alliance was seen and experienced by the people who made up the fabric of its constituent organisations. Based on interviews with institutional representatives and members from both parties, this article addresses the question of how people within them saw their ally and its leaders, and what they thought of the centre-right alliance under the fourth Berlusconi government. The analysis reveals that, although the LN's rhetoric, style and uncompromising stances on policy were the target of much criticism within the PDL, the latter nonetheless showed much respect for its ally, the way it was led, its ability to communicate effectively and its rootedness at the local level. However, LN members and representatives were, in turn, extremely critical of the PDL and its leader, and very much conceived of the alliance as a ‘marriage of convenience’. This notwithstanding, it is reasonable to expect that the PDL and the LN may find ways to rebuild their alliance in the future, if indeed the PDL continues to exist in its present form, due to their fundamental compatibility at the ideological level and their understanding of each other's priorities.
Lattice relaxation and its impact on magnetic properties of FePt thin film
Authors: Li H H , Dong K F , Hu J F , Zhou T J , Chow G M , Chen J S
Published: November 2012

The investigation on the lattice relaxation of FePt/TiN heteroepitaxial film was conducted by means of the thickness-dependent evolution of microstructure and magnetic properties. The critical thickness of FePt epitaxial growth on TiN was determined to be around 10 nm based on the lattice constant simulation according to equilibrium theory, which was consistent with the experimental value obtained from cross-sectional transmission electron microscope (TEM) measurements. Using high-resolution TEM images, the lattice relaxation mechanism of the FePt layer was clearly explained via the formation of edge dislocations at the critical thickness and the ensuing tilt of {1 1 1} lattice planes towards the film normal direction. It is found that the lattice relaxation caused the misorientation of the easy axes, and therefore in-plane magnetization increased and perpendicular anisotropy deteriorated with FePt thickness increasing from 10 to 40 nm.
Optimizing light absorption in quantum dot infrared photodetectors by tuning surface confinement of surface plasmonic waves
Authors: Liu Runyu , Vasinajindakaw Puminun , Gu Guiru , Vaillancourt Jarrod , Lu Xuejun
Published: November 2012

In this paper, we measured the transmission of the 2DSHA surface plasmonic structures and its variation with the hole diameters a of the 2DSHA structures. The relationship between the transmission and the hole diameters a is found to be different from the prediction of Bethe's diffraction theorem. We also found that the photocurrent of the quantum dot (QD) infrared photodetectors (QDIPs) with different QD active layer thicknesses show different dependence on the hole diameters a of the 2DSHA structures. The photocurrent of the QDIPs with 10 active QD layers (10-QDIPs) saturates and starts to decrease as the hole diameter a is larger than 1.6 µm, whereas that of the QDIPs with 20 active QD layers (20-QDIPs) increases linearly with the hole diameter. The difference in the hole-diameter dependence of the 10-QDIPs and the 20-QDIPs is attributed to the variation of the near-field spreading in the vertical (surface-normal) direction due to the change in the hole diameters. An over 6 time (6×) photocurrent enhancement is obtained by optimizing the hole diameter of the 2DSHA surface plasmonic structure.
A gain-coefficient switched Alexandrite laser
Authors: Lee Chris J , van der Slot Peter J M , Boller Klaus-J
Published: November 2012

We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.
Effects of elastic anisotropy in phononic band-gap plates with two-dimensional lattices
Authors: Hsu Jin-Chen
Published: November 2012

This study presents the effects of elastic anisotropy of constituent materials in square-lattice phononic-crystal plates. Using general elastodynamic calculations and the finite element (FE) method, this study analyses phononic-crystal plates constituted by (1) anisotropic scatterers embedded in an epoxy plate and (2) air holes etched on an anisotropic plate. The full band gaps can be modulated, opened and closed by changing the orientation of the square lattice relative to the crystallographic coordinate system of the anisotropic materials, and the elastic anisotropy varies the dispersion curves of the phononic-crystal plate waves with the rotation of the square lattice. Acoustic power transmission calculations show incident plate mode-dependent spectral gaps, the appearances of which in the frequency spectrum can also be modulated and shifted using elastic anisotropy. The effects of elastic anisotropy demonstrated here enable tailoring frequency band gaps and dispersion curves for functional control of acoustic-wave energy flows in phononic-crystal plates. Applications include acoustic waveguiding, confining, self-collimating and perfect acoustic focusing.
Experimental and analytical analyses of the thermal conductivities and high-temperature characteristics of silica aerogels based on microstructures
Authors: Zhao Jun-Jie , Duan Yuan-Yuan , Wang Xiao-Dong , Wang Bu-Xuan
Published: November 2012

An analytical heat transfer model based on scanning electron microscopy, Brunauer–Emmett–Teller and pycnometry measurements and a 3D random diffusion-limited cluster–cluster aggregation structure is proposed to calculate the temperature-dependent microstructural parameters and thermal conductivities of silica aerogels. This model is a pure prediction model, which does not need experimentally fitted empirical parameters and only needs four measured structural parameters as input parameters. This model can provide high-temperature microstructural and thermophysical properties as well as theoretical guidelines for material designs with optimum parameters. The results show that three stages occur during the thermal evolution processes of the aerogel structure with increasing temperature from 300 to 1500 K. The current analytical model is fully validated by experimental data. The constant structure assumptions used in previous heat transfer models are found to cause significant errors at higher temperatures as the temperature-dependent structure deformation significantly increases the aerogel thermal conductivity. The conductive and total thermal conductivities of silica aerogels after high-temperature heat treatments are much larger than those with no heat treatment.
Reproductive strategy, egg characteristics and embryonic development of Greenland halibut (Reinhardtius hippoglossoides)
Authors: Domínguez-Petit Rosario , Ouellet Patrick , Lambert Yvan
Published: November 2012

Domínguez-Petit, R., Ouellet, P., and Lambert, Y. 2013. Reproductive strategy, egg characteristics and embryonic development of Greenland halibut (Reinhardtius hippoglossoides). – ICES Journal of Marine Science, 70: 342–351. Despite the commercial importance of Greenland halibut (GH), important gaps exist in our knowledge of the reproductive and early life stage biology for this species. The present study examined through laboratory experiments the spawning strategy, realized fecundity, egg characteristics, biochemical composition, and embryonic development of GH. The results confirmed the hypothesis that GH is a single-batch spawner producing large eggs, resulting in low realized fecundity. Embryonic development and hatching time are highly dependent on incubation temperature; 50% hatching occurred after 46, 30, and 24 days at 2, 4, and 6°C, respectively. Few changes in the biochemical composition of the eggs are observed during embryonic development. Newly hatched larvae are not well developed, having a large yolk sac, no pigmentation and incomplete development of the jaws. Egg specific density confirmed the mesopelagic distribution of the eggs at sea. However, important buoyancy changes occurring in the last 3–4 days before hatching indicate that larvae hatch higher in the water column. These results are important for understanding advection and dispersion processes of GH eggs and larvae and the connectivity between spawning grounds and nursery areas.
Diverse host–virus interactions following caprine arthritis-encephalitis virus infection in sheep and goats
Authors: Rachid Antoine , Croisé Benoit , Russo Pierre , Vignoni Michel , Lacerenza Daniela , Rosati Sergio , Kuźmak Jacek , Valas Stephen
Published: November 2012

Interspecies transmissions substantially contribute to the epidemiology of small ruminant lentiviruses (SRLVs), including caprine arthritis encephalitis virus (CAEV) and visna-maëdi virus. However, comprehensive studies of host–virus interactions during SRLV adaptation to the new host are lacking. In this study, virological and serological features were analysed over a 6 month period in five sheep and three goats experimentally infected with a CAEV strain. Provirus load at the early stage of infection was significantly higher in sheep than in goats. A broad antibody reactivity against the matrix and capsid proteins was detected in goats, whereas the response to these antigens was mostly type-specific in sheep. The humoral response to the major immunodominant domain of the surface unit glycoprotein was type-specific, regardless of the host species. These species-specific immune responses were then confirmed in naturally infected sheep and goats using sera from mixed flocks in which interspecies transmissions were reported. Taken together, these results provide evidence that SRLV infections evolve in a host-dependent manner, with distinct host–virus interactions in sheep and goats, and highlight the need to consider both SRLV genotypes in diagnosis, particularly in sheep.
Comparative Analysis of 126 Cyanobacterial Genomes Reveals Evidence of Functional Diversity Among Homologs of the Redox-Regulated CP12 Protein
Authors: Stanley Desirée N. , Raines Christine A. , Kerfeld Cheryl A.
Published: November 2012

CP12 is found almost universally among photosynthetic organisms, where it plays a key role in regulation of the Calvin cycle by forming a ternary complex with glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase. Newly available genomic sequence data for the phylum Cyanobacteria reveals a heretofore unobserved diversity in cyanobacterial CP12 proteins. Cyanobacterial CP12 proteins can be classified into eight different types based on primary structure features. Among these are CP12-CBS (for cystathionine-β-synthase) domain fusions. CBS domains are regulatory modules for a wide range of cellular activities; many of these bind adenine nucleotides through a conserved motif that is also present in the CBS domains fused to CP12. In addition, a survey of expression data sets shows that the CP12 paralogs are differentially regulated. Furthermore, modeling of the cyanobacterial CP12 protein variants based on the recently available three-dimensional structure of the canonical cyanobacterial CP12 in complex with GAPDH suggests that some of the newly identified cyanobacterial CP12 types are unlikely to bind to GAPDH. Collectively these data show that, as is becoming increasingly apparent for plant CP12 proteins, the role of CP12 in cyanobacteria is likely more complex than previously appreciated, possibly involving other signals in addition to light. Moreover, our findings substantiate the proposal that this small protein may have multiple roles in photosynthetic organisms.
Therapeutic community residency and emotional management of female drug users
Authors: Colley Emma , Blackwell‐Young Julie
Published: November 2012

Purpose

The current study focused on five female offenders who completed the only female‐specific therapeutic community (TC) for drug addiction in the UK prison system. The aim of the study was to investigate the effect that such residency had on individuals' emotional management skills compared to when they were active drug users.

Design/methodology/approach

The study was based on a qualitative design, and interpretative phenomenological analysis (IPA) was used to produce idiographic results.

Findings

Results suggested that before TC residency all participants displayed problematic emotional management skills. However, during TC residency individuals witnessed elements of emotional healing and increased emotion connection. Additionally improvements were noted in emotional consideration, emotional communication, outward emotional displays and self‐worth.

Originality/value

Further developments in TC treatment are suggested concerning treatment length and further development of individuals' independent emotional management strategies.
Transfer of Technology to Canadian Manufacturing Industries Through Patents
Authors: Nikzad Rashid
Published: November 2012

This paper examines the determinants of foreign patent activity in the Canadian manufacturing sector at the industry level. Since foreign patenting is one of the channels of technology transfer to a country, this study could also show the transfer of foreign technology into Canadian industries measured by foreign patent activity. The paper suggests that the patent activity of foreign countries is the most important factor for receiving foreign patents in Canada. Moreover, imports and foreign direct investments are important vehicles this context. The distance between countries has a negative impact on receiving foreign patents. The impacts of R&D intensity and human capital on receiving foreign patents are mixed and insignificant, but industries with a higher R&D intensity are better recipients of foreign patents.
Practical management of the shocked neonate
Authors: Barker Claire L
Published: November 2012

The shocked neonate often causes anxiety in the ED. This article aims to provide a systematic, practical approach to recognition and initial management of these patients. Their resuscitation should follow a pattern of provision of oxygen, fluid resuscitation, blood glucose correction, inotropic support and ventilation. Practical tips for intravenous access and the rationale behind choice of inotrope and anaesthetic induction agent are discussed. The major underlying causes – sepsis, cardiac disease, metabolic disease and non‐accidental injury – along with their investigation and management are considered.
Cardiac arrest during sulprostone administration – a case report
Authors: LAMPATI L. , COLANTONIO L. B. , CALDERINI E.
Published: November 2012

Sulprostone, a synthetic prostaglandin analogue with potent uterotonic action, has been shown to have a low complication rate in a large series. We present a case of cardiac arrest in a parturient after Caesarean section during continuous infusion of intravenous sulprostone administered for atonic post‐partum haemorrhage. She had cardiopulmonary resuscitation for 25 min before spontaneous circulation returned. The sequence of events, the results of investigations carried out during the intensive care unit stay, and the presence of multiple cardiovascular risk factors, suggest that sulprostone caused coronary spasm, bradycardia, and subsequent asystole, similar to other cases described in the literature.