bluuebunny/crossref_metadata_2025 huggingface dataset:
Nicotinic acetylcholine receptor and the structural basis of neuromuscular transmission: insights fromTorpedopostsynaptic membranes
Authors: Unwin Nigel
Published: September 2013

The nicotinic acetylcholine (ACh) receptor, at the neuromuscular junction, is a neurotransmitter-gated ion channel that has been fine-tuned through evolution to transduce a chemical signal into an electrical signal with maximum efficiency and speed. It is composed from three similar and two identical polypeptide chains, arranged in a ring around a narrow membrane pore. Central to the design of this assembly is a hydrophobic gate in the pore, more than 50 Å away from sites in the extracellular domain where ACh binds. Although the molecular properties of the receptor have been explored intensively over the last few decades, only recently have structures emerged revealing its complex architecture and illuminating how ACh entering the binding sites opens the distant gate. Postsynaptic membranes isolated from the (muscle-derived) electric organ of theTorpedoray have underpinned most of the structural studies: the membranes form tubular vesicles having receptors arranged on a regular surface lattice, which can be imaged directly in frozen physiological solutions. Advances in electron crystallographic techniques have also been important, enabling analysis of the closed- and open-channel forms of the receptor in unreacted tubes or tubes reacted briefly with ACh. The structural differences between these two forms show that all five subunits participate in a concerted conformational change communicating the effect of ACh binding to the gate, but that three of them (αγ, β and δ) play a dominant role. Flexing of oppositely facing pore-lining α-helices is the principal motion determining the closed/open state of the gate. These results together with the findings of biochemical, biophysical and other structural studies allow an integrated description of the receptor and of its mode of action at the synapse.
Ecological services performed by the bonobo (Pan paniscus): seed dispersal effectiveness in tropical forest
Authors: Beaune David , Bretagnolle François , Bollache Loïc , Bourson Chloé , Hohmann Gottfried , Fruth Barbara
Published: September 2013

Survival of Afrotropical primary forests depends not only on habitat protection but also on the protection of animal species such as frugivorous primates, recognized as the most important seed dispersers for many plants. Here we investigate seed-dispersal services by the bonobo (Pan paniscus) in an evergreen lowland tropical rain forest of the Congo Basin. In the long-term research site of LuiKotale, we investigated food habits and seed processing based on 22 mo of behavioural observation, seed trial experiment and long-term daily GPS tracking of a habituated ape community. Bonobos were mainly frugivores (66% of all feeding sessions), spending about 3.5 h d−1swallowing seeds that were transported for an average of 24 h in the gut. On average, an individual bonobo dispersed 172 kg y−1of seeds (or 220000 seeds y−1) of more than 91 plant species by endozoochory over an average distance of 1.2 km from the parent tree. Passed seeds germinated more rapidly, more successfully and had greater post-dispersal survival than unpassed seeds. Bonobo-dispersed plants accounted for 40% of tree species and 65% of individual trees in the study site (12 1-ha plots census). Since bonobos show little functional overlap with other frugivores, the loss of their seed-dispersal services is likely to affect forest structure and dynamics. Our results justify description of the threatened bonobo as a gardener of the Congo forest.
Overlap and resource sharing in coteries of fruit-eating birds
Authors: da Silva Adriano Marcos , de Melo Celine
Published: September 2013

A range of species eating the same fruit suggests that niche overlap can occur, along with potential competition among them. To test if the overlap in the coterie of fruit-eating birds is larger than would be expected by chance, we performed a comparison with coteries generated from the use of null models. The study was carried out in an area of savanna woodland of 127 ha in Uberlândia city, Brazil. Four individuals of five zoochorous plant species were selected and 60 h of focal observation was performed on each species. We recorded species of birds that consumed fruits and the quantity of fruit removed. We used an index of Proportional Similarity (PS) between each pair of plant species, using the relative proportion of fruit taken by each bird species of each plant. The mean value of observed PS was compared with the mean PS generated from randomizations. Thirty-six bird species were recorded eating fruits in the selected plant species. The mean overlap observed (PS = 0.183) was significantly higher (P = 0.032) than the mean overlap generated by the null models (PS = 0.123). This pattern suggests that competition is not an important factor in the formation of the coteries and there is sharing of resources. The abundance of fruits offered, especially in the rainy season, and the relatively low number of frugivorous species may be factors explaining the low influence of interactions and therefore the overlap between coteries.
Metabelian SL(n, ) representations of knot groups IV: twisted Alexander polynomials
Authors: BODEN HANS U. , FRIEDL STEFAN
Published: September 2013

In this paper we will study properties of twisted Alexander polynomials of knots corresponding to metabelian representations. In particular we answer a question of Wada about the twisted Alexander polynomial associated to the tensor product of two representations, and we settle several conjectures of Hirasawa and Murasugi.
Calling upon the Genius of Private Enterprise: The Housing and Urban Development Act of 1968 and the Liberal Turn to Public-Private Partnerships
Authors: von Hoffman Alexander
Published: September 2013

President Lyndon Johnson declared the Housing and Urban Development Act of 1968 to be “the most farsighted, the most comprehensive, the most massive housing program in all American history.” To replaceeveryslum dwelling in the country within ten years, the act turned from public housing, the government-run program started in the 1930s, toward private-sector programs using both nonprofit and for-profit companies. As a result, since its passage, for-profit businesses have developed the great majority of low-income residences in the United States. The law also helped popularize the idea of “public-private partnerships,” collaborations of government agencies and non-government entities—including for-profit companies—for social and urban improvements. Remarkably, political liberals supported the idea that private enterprise carry out social-welfare programs. This article examines the reasons that Democratic officials, liberals, and housing industry leaders united to create a decentralized, ideologically pluralistic, and redundant system for low-income housing. It shows that frustrations with the public housing program, the response to widespread violence in the nation's cities, and the popularity of corporate America pushed the turn toward the private sector. The changes in housing and urban policy made in the late 1960s, the article concludes, helped further distinguish the American welfare state and encourage the rise of neoliberalism in the United States.
A case report and epidemiological investigation of axillary lymph node abscess caused byCorynebacterium ulceransin an HIV-1-positive patient
Authors: YOSHIMURA Y. , TACHIKAWA N. , KOMIYA T. , YAMAMOTO A.
Published: September 2013

A human immunodeficiency virus-1 (HIV-1)-positive male undergoing antiretroviral therapy was diagnosed with an axillary lymph node abscess caused byCorynebacterium ulcerans, and an environmental survey revealed that the patient's cat as the source of infection.
Hepatitis E virus in England and Wales: indigenous infection is associated with the consumption of processed pork products
Authors: SAID B. , IJAZ S. , CHAND M. A. , KAFATOS G. , TEDDER R. , MORGAN D.
Published: September 2013

Indigenously acquired hepatitis E infections have increased substantially in England and Wales since 2010. Epidemiological investigations were undertaken to determine risk factors for the acquisition of infection. A case-control study (25 cases, 75 controls) was used to test the hypothesis that hepatitis E infection was related to consumption of pork products. In a multivariable model, consumption of pork pie [odds ratio (OR) 6·33, 95% confidence interval (CI) 1·41–28·48, P = 0·009] and consumption of ham and sausages purchased from a major UK supermarket chain (OR 10·12, 95% CI 1·68–60·81, P = 0·023) were significantly associated with indigenous infection. The consumption of sausages and ham purchased from the supermarket was highly correlated; however. separate models showed that each variable was significantly associated with infection (OR 7·59, 95% CI 1·81–31·84, P = 0·004 and OR 10·98, 95% CI 1·84–65·35, P = 0·003, respectively). Although contamination of sausages with HEV has previously been shown this study also raises concerns about other processed pork products and whether current practice in preparing these products is sufficient to prevent transmission of HEV.
On the Trail of the Triskeles: from the McDonald Institute to Archaic Greek Sicily
Authors: Wilson R.J.A.
Published: September 2013

The McDonald Institute and this journal have adopted as their logo a three-legged symbol, with wings on each heel, known in Graeco-Roman antiquity as the triskeles. The purpose of this article is to explore the meaning of the iconography of this emblem, and to investigate how and why it came to symbolize the islands of both Man and Sicily. It is suggested that the Isle of Man adopted the triskeles in 1266 when the control of the island passed from the Norse kings to Alexander III of Scotland; a possible connection with Sicily is tentatively explored. The Man triskeles is clothed in leg armour, however, and has spurs, not wings, on the ankles. In Sicily the triskeles is first attested in the seventh century BC and was gradually elaborated from the later fourth century BC onwards, first with the addition of wings to the feet, then with the use of a Medusa head at the centre, and finally with the adjunct of three barley ears to symbolize the agricultural fertility of the island. Widely adopted also on coinage in Athens and Asia Minor from the sixth century BC, the triskeles was probably in origin a sun symbol like the swastika.
Family structure and childhood obesity: results of the IDEFICS Project
Authors: Formisano Annarita , Hunsberger Monica , Bammann Karin , Vanaelst Barbara , Molnar Dénes , Moreno Luis A , Tornaritis Michael , Veidebaum Toomas , Lissner Lauren , Barba Gianvincenzo , Siani Alfonso
Published: September 2013

Objective

To analyse the association between family structure and adiposity in children.

Design

Cross-sectional and longitudinal analysis of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study cohort.

Setting

Primary schools and kindergartens.

Subjects

Children (n12 350; aged 7·9 (sd1·8) years) for the cross-sectional analysis and children (n5236; at baseline: normal weight, aged 5·9 (sd1·8) years) for the longitudinal study underwent anthropometry. Family structure was analysed as (i) number and type of cohabiting adults and (ii) number of siblings.

Results

In the cross-sectional analysis, after controlling for covariates, children living with grandparents had significantly higher BMIZ-score than those living with both parents (0·63; 95 % CI 0·33, 0·92v. 0·19; 95 % CI 0·17, 0·22;P< 0·01); in addition, the higher the number of siblings, the lower the BMIZ-score (only child = 0·31; 95 % CI 0·24, 0·38; 1 sibling = 0·19; 95 % CI 0·16, 0·23; 2 siblings = 0·15; 95 % CI 0·09, 0·20; >2 siblings = 0·07, 95 % CI 0·04, 0·19;P< 0·001). Over the 2-year follow-up, differences in weight gain were observed across family-structure categories. Further, the risk of incidence of overweight/obesity was significantly lower the higher the number of siblings living in the household (v. only child: 1 sibling = 0·74, 95 % CI 0·57, 0·96; 2 siblings = 0·63, 95 % CI 0·45, 0·88; >2 siblings = 0·40, 95 % CI 0·21, 0·77), independently of confounders.

Conclusions

The study suggests that an independent association between family structure and childhood obesity exists.
Psychopathy and Violent Reoffending in German-Speaking Countries
Authors: Mokros Andreas , Vohs Knut , Habermeyer Elmar
Published: September 2013

The Psychopathy Checklist-Revised (PCL-R) and its screening version, the PCL:SV, are clinical assessment instruments for the observer rating of psychopathic personality in offenders. Given the link between PCL-R/SV total scores and violent offending, these instruments have been incorporated into various risk assessment protocols in forensic psychology. The purpose of the present study was to examine the predictive validity of the PCL-R/SV instruments in German-speaking countries. We collated data from 11 published studies (total-N = 2,412 offenders). Based on suitable diagnostic cutscores for prototypical psychopathy, the proportions of true-positive and false-positive cases with respect to violent reoffending were compared. Overall, sensitivity was estimated at 27% and specificity at 88% for the PCL-R (or at 28% and 90% for the PCL:SV, respectively). At critical score levels, the odds for violent offense recidivism were more than two times higher than at subcritical levels for both instruments. A decision-theory analysis suggested that the implicit utility of false-positive risk assessments was about halfway between the minimal utility of false-negative assessments and the maximal utility of correct assessments. Both the PCL-R and its screening version are viable instruments for the prediction of violent offense recidivism in German-speaking countries.
Malignant H1299 tumour cells preferentially internalize iron-bound inositol hexakisphosphate
Authors: Helmis Christina , Blechner Christine , Lin Hongying , Schweizer Michaela , Mayr Georg W. , Nielsen Peter , Windhorst Sabine
Published: September 2013

In colon enterocytes and in well-differentiated colon cancer CaCo-2 cells, InsP6 (inositol hexakisphosphate) inhibits iron uptake by forming extracellular insoluble iron/InsP6 complexes. In this study, we confirmed that CaCo-2 cells are not able to take up iron/InsP6 but, interestingly, found that the cells are able to internalize metal-free and Cr3+-bound InsP6. Thus, the inability of CaCo-2 cells to take up iron/InsP6 complexes seems to be due to the iron-bound state of InsP6. Since recently we demonstrated that the highly malignant bronchial carcinoma H1299 cells internalize and process InsP6, we examined whether these cells may be able to take up iron/InsP6 complexes. Indeed, we found that InsP6 dose-dependently increased uptake of iron and demonstrated that in the iron-bound state InsP6 is more effectively internalized than in the metal-free or Cr3+-bound state, indicating that H1299 cells preferentially take up iron/InsP6 complexes. Electron microscope and cell fraction assays indicate that after uptake H1299 cells mainly stored InsP6/iron in lysosomes as large aggregates, of which about 10% have been released to the cytosol. However, this InsP6-mediated iron transport had no significant effects on cell viability. This result together with our finding that the well-differentiated CaCo-2 cells did not, but the malignant H1299 cells preferentially took up iron/InsP6, may offer the possibility to selectively transport cytotoxic substances into tumour cells.
Time-resolved fluorescence up-conversion study of radiative recombination dynamics in III-nitride light emitting diodes over a wide bias range
Authors: You Guanjun , Liu Jie , Jiang Zhenyu , Zhu Yiming , Chen Aping , Hu Yong , Xiong Feng , Henderson Ron H. , Zhuang Songlin , Xu Jian
Published: September 2013

The technique of femtosecond fluorescence up-conversion was employed to explore the transient photoluminescence and carrier decay dynamics in c-plane (In,Ga)N multi-quantum-well light emitting diodes over a wide bias range. By investigating the bias dependence of initial transient photoluminescence intensity and the luminescence lifetime, the field and carrier density effects on the radiative recombination coefficient were revealed for both low and high current injection conditions, and in good agreement with the theory.
Insights into the semiclassical Wigner treatment of bimolecular collisions
Authors: Bonnet L.
Published: September 2013

The semiclassical Wigner treatment of bimolecular collisions, proposed by Lee and Scully on a partly intuitive basis [J. Chem. Phys. 73, 2238 (1980)], is derived here from first principles. The derivation combines Heller's ideas [J. Chem. Phys. 62, 1544 (1975); Heller J. Chem. Phys. 65, 1289 (1976); Heller J. Chem. Phys. 75, 186 (1981)], the backward picture of molecular collisions [L. Bonnet, J. Chem. Phys. 133, 174108 (2010)] and the microreversibility principle.
Structural changes in the series of boron-carbon mixed clusters CxB10-x− (x = 3-10) upon substitution of boron by carbon
Authors: Popov Ivan A. , Popov Valery F. , Bozhenko Konstantin V. , Černušák Ivan , Boldyrev Alexander I.
Published: September 2013

We report a theoretical investigation on the ten-atom boron-carbon mixed clusters CxB10 − x− (x = 3-10), revealing a molecular wheel to monocyclic ring and linear species structural change as a function of x upon increasing the number of carbon atoms in the studied series. The unbiased searches for the global minimum structures of the clusters with x ranging from 3 to 9 were conducted using the Coalescence Kick program for different spin multiplicities. Subsequent geometry optimizations with follow-up frequency calculations at the hybrid density functional B3LYP/6-311+G(d) level of theory along with the single point coupled-cluster calculations (UCCSD(T)/aug-cc-pVTZ//B3LYP/6-311+G(d) and RCCSD(T)/aug-cc-pVTZ//B3LYP/6-311+G(d)) revealed that the C3B7− and C4B6− clusters possess planar distorted wheel-type structures with a single inner boron atom, similar to the recently reported CB9− and C2B8−. Going from C5B5− to C9B− inclusive, monocyclic and ring-like structures are observed as the most stable ones on the PES. The first linear species in the presented series is found for the C10− cluster, which is almost isoenergetic with the one possessing a monocyclic geometry. The classical 2c-2e σ bonds are responsible for the peripheral bonding in both carbon- and boron-rich clusters, whereas multicenter σ bonding (nc-2e bonds with n > 2) on the inner fragments in boron-rich clusters is found to be the effective tool to describe their chemical bonding nature. It was shown that the structural transitions in the CxB10-x− series occur in part due to the preference of carbon to form localized bonds, which are found on the periphery of the clusters. Chemical bonding picture of C10− is explained on the basis of the geometrical structures of the C10 and C102− clusters and their chemical bonding analyses.
An (ultra) high-vacuum compatible sputter source for oxide thin film growth
Authors: Mayr Lukas , Köpfle Norbert , Auer Andrea , Klötzer Bernhard , Penner Simon
Published: September 2013

A miniaturised CF-38 mountable sputter source for oxide and metal thin film preparation with enhanced high-vacuum and ultra-high-vacuum compatibility is described. The all home-built sputtering deposition device allows a high flexibility also in oxidic sputter materials, suitable deposition rates for preparation of films in the nm- and the sub-monolayer regime and excellent reliability and enhanced cleanliness for usage in UHV chambers. For a number of technologically important – yet hardly volatile – materials, the described source represents a significant improvement over thermal deposition techniques like electron-beam- or thermal evaporation, as especially the latter are no adequate tool to prepare atomically clean layers of refractory oxide materials. Furthermore, it is superior to commercially available magnetron sputter devices, especially for applications, where highly reproducible sub-monolayer thin film preparation under very clean UHV conditions is required (e.g., for studying phase boundary effects in catalysis). The device in turn offers the usage of a wide selection of evaporation materials and special target preparation procedures also allow the usage of pressed oxide powder targets. To prove the performance of the sputter-source, test preparations with technologically relevant oxide components, comprising ZrO2 and yttrium-stabilized ZrO2, have been carried out. A wide range of characterization methods (electron microscopy, X-ray photoelectron spectroscopy, low-energy ion scattering, atomic force microscopy, and catalytic testing) were applied to demonstrate the properties of the sputter-deposited thin film systems.
Quantum charge pumping in graphene-based devices: When lattice defects do help
Authors: Ingaramo Lucas H. , Foa Torres Luis E. F.
Published: September 2013

Quantum charge pumping, the quantum coherent generation of a dc current at zero bias through time-dependent potentials, provides outstanding opportunities for metrology and the development of nanodevices. The long electronic coherence times and high quality of the crystal structure of graphene may provide suitable building blocks for such quantum pumps. Here, we focus in adiabatic quantum pumping through graphene nanoribbons in the Fabry-Pérot regime highlighting the crucial role of defects by using atomistic simulations. We show that even a single defect added to the pristine structure may produce a two orders of magnitude increase in the pumped charge.
Temperature-dependent failure mechanism of SnAg solder joints with Cu metallization after current stressing: Experimentation and analysis
Authors: Lin C. K. , An Tsao Wei , Liang Y. C. , Chen Chih
Published: September 2013

Temperature-dependent electromigration failure was investigated in solder joints with Cu metallization at 126 °C, 136 °C, 158 °C, 172 °C, and 185 °C. At 126 °C and 136 °C, voids formed at the interface of Cu6Sn5 intermetallic compounds and the solder layer. However, at temperature 158 °C and above, extensive Cu dissolution and thickening of Cu6Sn5 occurred, and few voids were observed. We proposed a model considering the flux divergency at the interface. At temperatures below 131 °C, the electromigration flux leaving the interface is larger than the in-coming flux. Yet, the in-coming Cu electromigration flux surpasses the out-going flux at temperatures above 131 °C. This model successfully explains the experimental results.
Study on dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3 PbTiO3 single crystal with nano-patterned composite electrode
Authors: Chang Wei-Yi , Huang Wenbin , Bagal Abhijeet , Chang Chih-Hao , Tian Jian , Han Pengdi , Jiang Xiaoning
Published: September 2013

Effect of nano-patterned composite electrode and backswitching poling technique on dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3 PbTiO3 was studied in this paper. Composite electrode consists of Mn nano-patterns with pitch size of 200 nm, and a blanket layer of Ti/Au was fabricated using a nanolithography based lift-off process, heat treatment, and metal film sputtering. Composite electrode and backswitching poling resulted in 27% increase of d33 and 25% increase of dielectric constant, and we believe that this is attributed to regularly defined nano-domains and irreversible rhombohedral to monoclinic phase transition in crystal. The results indicate that nano-patterned composite electrode and backswitching poling has a great potential in domain engineering of relaxor single crystals for advanced devices.
Propagation of ion acoustic shock waves in negative ion plasmas with nonextensive electrons
Authors: Hussain S. , Akhtar N. , Mahmood S.
Published: September 2013

Nonlinear ion acoustic shocks (monotonic as well as oscillatory) waves in negative ion plasmas are investigated. The inertialess electron species are assumed to be nonthermal and follow Tsallis distribution. The dissipation in the plasma is considered via kinematic viscosities of both positive and negative ion species. The Korteweg-de Vries Burgers (KdVB) equation is derived using small amplitude reductive perturbation technique and its analytical solution is presented. The effects of variation of density and temperature of negative ions and nonthermal parameter q of electrons on the strength of the shock structures are plotted for illustration. The numerical solutions of KdVB equation using Runge Kutta method are obtained, and transition from oscillatory to monotonic shock structures is also discussed in detail for negative ions nonthermal plasmas.
Synchrotron radiation from a runaway electron distribution in tokamaks
Authors: Stahl A. , Landreman M. , Papp G. , Hollmann E. , Fülöp T.
Published: September 2013

The synchrotron radiation emitted by runaway electrons in a fusion plasma provides information regarding the particle momenta and pitch-angles of the runaway electron population through the strong dependence of the synchrotron spectrum on these parameters. Information about the runaway density and its spatial distribution, as well as the time evolution of the above quantities, can also be deduced. In this paper, we present the synchrotron radiation spectra for typical avalanching runaway electron distributions. Spectra obtained for a distribution of electrons are compared with the emission of mono-energetic electrons with a prescribed pitch-angle. We also examine the effects of magnetic field curvature and analyse the sensitivity of the resulting spectrum to perturbations to the runaway distribution. The implications for the deduced runaway electron parameters are discussed. We compare our calculations to experimental data from DIII-D and estimate the maximum observed runaway energy.
Comparison of thermal stabilities between Ge-Sb-Te and In-Sb-Te phase change materials
Authors: Tae Kim Yong , Kim Seong-Il
Published: September 2013

Crystallization temperatures, activation energies, and thermal diffusivities of In3Sb1Te2 (IST) and Ge2Sb2Te5 (GST) are investigated with a differential scanning calorimetry, a xenon laser flash, and a transmission electron microscopy. The activation energies for crystallizing the IST and the GST are 5.2 eV and 3.31 eV, respectively. The thermal diffusivity of the IST is about a half of the GST. The thermal diffusion length in the IST-phase change random access memory cell is relatively shorter than the GST due to lower thermal diffusivity. Experimental results reveal that the IST is more thermally stable than the GST.
Note: An object detection method for active camera
Authors: Chen Yong , Zhang Ronghua , Shang Lei , Hu Eric
Published: September 2013

To solve the problems caused by a changing background during object detection in active camera, this paper proposes a new method based on SURF (speeded up robust features) and data clustering. The SURF feature points of each image are extracted, and each cluster center is calculated by processing the data clustering of k adjacent frames. Templates for each class are obtained by calculating the histograms within the regions around the center points of the clustering classes. The window of the moving object can be located by finding the region that satisfies the histogram matching result between adjacent frames. Experimental results demonstrate that the proposed method can improve the effectiveness of object detection.
Orientation-dependent piezoelectric properties in lead-free epitaxial 0.5BaZr0.2Ti0.8O3-0.5Ba0.7Ca0.3TiO3 thin films
Authors: Luo B. C. , Wang D. Y. , Duan M. M. , Li S.
Published: September 2013

Orientation-engineered 0.5BaZr0.2Ti0.8O3-0.5Ba0.7Ca0.3TiO3 (BZT-BCT) thin films were deposited on La0.7Sr0.3MnO3-coated SrTiO3 single-crystalline (001), (110), and (111) substrates by off-axis radio-frequency magnetron sputtering. X-ray diffraction confirmed a highly epitaxial growth of all the as-deposited films. It is believed the strong orientation dependence of ferroelectric and piezoelectric properties on the films is attributed to the relative alignment of crystallites and spontaneous polarization vector. The optimal ferroelectric response lies in the [001] direction, whereas a comparatively large effective piezoelectric coefficient d33,eff of 100.1 ± 5 pm/V was attained in [111] BZT-BCT thin film, suggesting its potential application for high-performance lead-free piezoelectric devices.
Resistive magnetohydrodynamic simulations of helicity-injected startup plasmas in National Spherical Torus eXperiment
Authors: Hooper E. B. , Sovinec C. R. , Raman R. , Ebrahimi F. , Menard J. E.
Published: September 2013

The generation of helicity-injected startup plasmas in National Spherical Torus eXperiment (NSTX), including flux surface closure, is studied using resistive-magnetohydrodynamic simulations with plasma flows, currents, ohmic heating and anisotropic thermal conduction. An injection-voltage pulse shape is used that separates the injection and closure phases allowing elucidation of the physics. The formation of an X-point near the helicity-injection gap is triggered as the injector voltage drops to zero. Near the forming X-point, magnetic pressure due to toroidal field entrained in the E × B plasma flow from the helicity-injection gap drops, allowing resistive magnetic reconnection even though the total injected current is almost constant. Where appropriate, the simulations are compared with Transient Coaxial Helicity Injection experiments in the NSTX spherical tokamak, which have demonstrated the formation of a promising candidate for non-inductive startup plasmas [Raman et al., Phys. Rev. Lett. 90, 075005 (2003)].
Type-I quantum well cascade diode lasers emitting near 3 μm
Authors: Shterengas Leon , Liang Rui , Kipshidze Gela , Hosoda Takashi , Suchalkin Sergey , Belenky Gregory
Published: September 2013

Cascade GaSb-based type-I quantum well diode lasers were designed and fabricated. Cascade pumping was achieved utilizing efficient interband tunneling through "leaky" window in band alignment at GaSb/InAs heterointerface. The carrier recycling between stages was confirmed by twofold increase of the slope efficiency in two-stage devices as compared to reference single-stage lasers. Moderate internal optical loss increase was observed in cascade lasers with interband injector located near the optical mode peak. Cascade pumping scheme increased the continuous wave output power of room temperature operated 3 μm semiconductor lasers up to 590 mW and led to improved power conversion efficiency.
Finite element simulations of hydrodynamic trapping in microfluidic particle-trap array systems
Authors: Xu Xiaoxiao , Li Zhenyu , Nehorai Arye
Published: September 2013

Computational fluid dynamic (CFD) simulation is a powerful tool in the design and implementation of microfluidic systems, especially for systems that involve hydrodynamic behavior of objects such as functionalized microspheres, biological cells, or biopolymers in complex structures. In this work, we investigate hydrodynamic trapping of microspheres in a novel microfluidic particle-trap array device by finite element simulations. The accuracy of the time-dependent simulation of a microsphere's motion towards the traps is validated by our experimental results. Based on the simulation, we study the fluid velocity field, pressure field, and force and stress on the microsphere in the device. We further explore the trap array's geometric parameters and critical fluid velocity, which affect the microsphere's hydrodynamic trapping. The information is valuable for designing microfluidic devices and guiding experimental operation. Besides, we provide guidelines on the simulation set-up and release an openly available implementation of our simulation in one of the popular FEM softwares, COMSOL Multiphysics. Researchers may tailor the model to simulate similar microfluidic systems that may accommodate a variety of structured particles. Therefore, the simulation will be of particular interest to biomedical research involving cell or bead transport and migration, blood flow within microvessels, and drug delivery.
Diesel-like fuel production from catalytic cracking and esterification of waste oil
Authors: Chen J. , Jiang J. C. , Nie X. A. , Xu J. M. , Chang X. , Li K.
Published: September 2013

The process of producing diesel-like fuel from combination of catalytic cracking with catalytic esterification was studied. The optimal technological conditions were obtained as follows: CaO as cracking catalyst, distillation temperature 320 – 350 °C, cracking temperature 480 – 500 °C, adding rate of waste oil feedstock 35 g/h, and sodium bisulfate as esterification catalyst with the amount 3 wt. % of pyrolytic product, and molar ratio 0.4 (methanol to pyrolytic product). Results of Fourier transform infrared spectroscopy (FTIR) indicated that the fraction distribution of product was modified by catalytic cracking process, and gas chromatography-mass spectrometry (GC-MS) analysis showed the esterification products consist of alkanes, alkenes, aldehyde, and fatty acid methyl ester of short chains below C16. And the acid value of pyrolytic product from the esterification process decreased remarkably from 40 mg KOH/g to 1.6 mg KOH/g. The properties of the final fuel product were measured as follows: density of 850 kg/m3, viscosity of 3.05 mm2/s, freezing point of −9 °C, and cold filter plugging point of −4 °C, indicating that the fraction distribution, properties, and applicability of the product from combination process were also further improved.
Motion analysis on integrated transportation technique for offshore wind turbines
Authors: Zhang Puyang , Ding Hongyan , Le Conghuan , Huang Xu
Published: September 2013

With the current state of offshore wind turbine construction technology, a major marine spread is necessary for the installation of the foundation, tower, and turbine. It is advantageous for offshore installation to be integrated into a single operation. The large-scale composite bucket foundation is the basis for a one-step integrated transportation and installation technique using a specialized transport vessel. The proposed transportation and installation technique will minimize the offshore operation and maximize the proportion of work carried out onshore with consequent benefits in terms of cost, quality, and safety. The self-floating composite bucket foundation is towed into the semicircle groove of the vessel and connected to the wire ropes of a stationary crane. Then the tower and turbine are attached to the foundation at the shore and the entire unit consisting of the foundation, tower, and turbine is loaded out from the quayside, transported to the site and set down on the seabed. During transport, half of the unit's weight is taken by the hoisting system of the vessel, and the remaining half of the weight is supported by air cushions inside the composite bucket foundation. A detailed model is studied to determine the motions of the vessel with two units to confirm the viability and feasibility of such a method of integrated transportation. The draft and air cushion are two effect parameters used to determine the dynamical characteristics of the transportation structure system. The results show that a smaller draft and a greater air cushion positively contribute to a safe transportation process. The viability and feasibility of this method of integrated transportation are confirmed by determining the motions of the various elements proposed by the detailed model.
Spatial Impacts of High-Speed Railways in China: A Total-Travel-Time Approach
Authors: Wang James Jixian , Xu Jiang , He Jianfeng
Published: September 2013

In China the development of high-speed rail (HSR) is a national strategy for stimulating economic growth. Major decisions, such as determining which cities to connect and deciding the locations of stations, are made through a state-led planning process. Consequently, HSR stations are often located in urban edges. The connections of these stations with local transport infrastructure and services vary significantly. Passengers need to spend extra time to reach these stations before they can use the HSR. This paper examines the time savings due to the improved intercity connections brought by HSR. It goes on to investigate the user friendliness of HSR by measuring the total door-to-door travel time and accessibility. On the basis of data gathered from questionnaire surveys and from total travel time estimations, it is argued that the poor accessibility of HSR stations hinders the effectiveness of the HSR system.
Neighbourhood Effects on School Achievement: The Mediating Effect of Parenting and Problematic Behaviour?
Authors: Nieuwenhuis Jaap , Hooimeijer Pieter , van Dorsselaer Saskia , Vollebergh Wilma
Published: September 2013

Neighbourhood research hitherto has suggested that the neighbourhood in which youth grow up affects their educational achievement. However, the mechanisms though which the neighbourhood reaches these effects are still unclear. Family and individual characteristics seem important in explaining educational outcomes. We therefore propose two related mediating factors: Parenting strategies and problematic behaviour. We test this mediation using the 2009 Health Behaviour in School-aged Children data for the Netherlands ( N = 2683), in which adolescents are surveyed about their behaviour and relationships and, additionally, their parents are interviewed about their child and their parenting. These data are combined with data from Statistics Netherlands, which include neighbourhood-level information about real-estate value and ethnic variation of the neighbourhood population. The results show that the effects of the proportion of immigrant groups and the mean property values in the neighbourhood are unlikely to be mediated by parenting behaviours and problematic behaviour. The results also show that parents are likely to adapt their parenting behaviours to demographic neighbourhood characteristics. For example, parents in neighbourhoods with higher ethnic heterogeneity apply more protective parenting strategies.
Scalar Politics and the Region: Strategies for Transcending Pacific Island Smallness on a Global Environmental Governance Stage
Authors: Gruby Rebecca L , Campbell Lisa M
Published: September 2013

This paper examines the process through which a region was enacted and politically mobilized at the tenth meeting of the Conference of the Parties (CoP10) to the Convention on Biological Diversity (CBD). We draw on concepts from scalar politics and new regional geography, data collected as part of a collaborative event ethnography of CoP10, and interviews with Palauan delegates to theorize the enactment of an oceanic Pacific Region as a scalar strategy directed toward transcending the practical and imagined smallness of Pacific small island developing states (SIDS) within the CoP10 meeting context and global imaginations. We conclude that the Pacific Region construct enhances Pacific SIDS' capacity to participate in CoP10, although their collective influence remains relatively limited compared with others. Most significantly, the Pacific Region imaginary of a vast ocean space and network of people committed to the CBD and biodiversity conservation positions Pacific Islanders to play a pivotal role in conserving a significant portion of the world's oceans. In the context of increasing global attention to marine conservation, the enactment of such a Pacific Region is likely to aid in attracting international recognition, attention, and support. By conveying how and why a diverse group of state and nonstate actors enacted an international and oceanic region at CoP10, we contribute understanding of strategic regionalization within the scalar politics literature and further disrupt understandings of an ontologically given, land-based region conceptualized on continental or subcontinental spatial scales.
Contextualizing the State Mode of Production in the United States: Race, Space, and Civil Rights
Authors: Inwood Joshua
Published: September 2013

In 1967 Dr Martin Luther King Jr began organizing a “Poor People's Campaign” in an effort to bring 3000 families to Washington, DC to address widespread poverty in the US. King's efforts were the culmination of a political transformation that he underwent in the middle of the 1960s concerning his views on Vietnam and US global hegemony. I argue that by focusing on King and the US Poor People's Campaign we can better understand the changing coordinates of the US political economy, what has been termed the “state mode of production” or SMP Associated with the gradual decline of the Keynesian state, the SMP refers to new kinds of politicospatial arraignments that emerged during the 20th century and continue the process of capital accumulation. I maintain that in the United States the political-economic transformations encapsulated through the growth of the SMP are inseparable from the USA's racial legacy. Hence the failure of the US civil rights struggle to remake economic processes demonstrates the limits of social democratic movements to fully critique capitalism. For this reason King's efforts at leading the Poor People's Campaign are a model of social and political engagement that has purchase in the wake of current economic and political crises and is transforming contemporary economic processes across the globe.
Warm-phase ENSO events modulate the continental freshwater input and the trophic state of sediments in a large South American estuary
Authors: García-Rodríguez F. , Brugnoli E. , Muniz P. , Venturini N. , Burone L. , Hutton M. , Rodríguez M. , Pita A. , Kandratavicius N. , Pérez L. , Verocai J.
Published: September 2013

We studied the changes in geochemical variables in the middle section of Río de la Plata estuary during the 2009–2010 El Niño–Southern Oscillation (ENSO) event. Protein, organic matter, chlorophyll-a and phaeopigment content of surface sediments were significantly correlated with the increased continental freshwater input associated with high total monthly rainfall. During the warm-phase ENSO event, river flow was 5-fold larger than average historical levels, which led to a steady decrease in salinity values and the highest levels of geochemical variables. The evidence presented herein suggests that warm-phase ENSO events increase the trophic state of the sediments because of the increased freshwater input. Thus, our findings may be useful to anticipate potential eutrophication episodes in the study area.
Flow–ecology relationships: closing the loop on effective environmental flows
Authors: Davies Peter M. , Naiman Robert J. , Warfe Danielle M. , Pettit Neil E. , Arthington Angela H. , Bunn Stuart E.
Published: September 2013

Providing flows for biota and environmental processes is a challenging water management issue. For society the ability and willingness to allocate water to sustain the environment is increasingly competitive due to escalating demand and as a consequence of climate change. In response, an array of environmental flow (E-flow) methods have developed. Our view is that few E-flows have been implemented and even fewer evaluated in a research and management context. Much of our science effort in E-flows has been directed primarily at method development, with less attention being given to monitoring, evaluation and subsequent revision of E-flow strategies. Our objectives are to highlight the lack of connection between current trends in E-flow literature and theory with assessment of the efficacy and practical application of these methods. Specifically, effective E-flows need to be explicit about flow-ecology relationships to adequately determine the amount and timing of water required. We briefly outline the historical development of E-flows and discuss how serial development of methods and techniques has restricted implementation, evaluation and revision. We highlight areas where methods are lacking, such as incorporation of data on flow-ecology relationships into operational use of E-flow methods. We suggest four initial steps that will improve the applicability, implementation and ultimate success of E-flows.
Physical properties and organic carbon content of a Typic Hapludult soil fertilised with pig slurry and pig litter in a no-tillage system
Authors: Comin Jucinei José , Loss Arcângelo , da Veiga Milton , Guardini Renato , Schmitt Djalma Eugênio , Victoria de Oliveira Paulo Armando , Filho Paulo Belli , Couto Rafael da Rosa , Benedet Lucas , Júnior Vilmar Müller , Brunetto Gustavo
Published: September 2013

Applications of swine residues to the soil surface in a no-tillage system (NTS) may increase the organic carbon level and improve the physical properties of the soil. This study aimed to evaluate the effect of the continuous application of pig slurry (PS) and pig litter (PL) on the total organic carbon (TOC) content and physical properties of soil under NTS in Southern Brazil. In March 2010, after 8 years of cultivation of black oats (Avena strigosa)–maize (Zea mays), soil samples were collected in the 0–5, 5–10, 10–15, and 15–20 cm layers. The treatments consisted of a control plot (without manure application), plots with PS applications equivalent to one and two times the recommended rate of nitrogen (N) for maize and black oats (PS1X and PS2X, respectively), and plots with PL equivalent to one and two times the recommended rate of N for maize and black oats (PL1X and PL2X, respectively). The TOC, soil bulk density (BD), penetration resistance (PR), total porosity (TP), macro- and microporosity, distribution of pore diameters, and indices of aggregation and aggregate stability were evaluated. Differences were found between treatments for TOC, BD, macro- and microporosity, pore diameter, aggregation, and PR. Treatment with PL favoured the production of aggregates (diameter >4 mm) and increased the rates of aggregation and aggregate stability in the 10–15 and 15–20 cm layers and macroporosity in the 0–5 and 15–20 cm layers. Application of PL2X reduced PR by 34% and 20%, respectively, in the 5–10 and 10–15 cm layers. Eight years of adding PS to successive cultivations of black oats–maize soil managed under NTS produced no changes in the physical features or the TOC of the soil, whereas the application of PL produced improvements in physical attributes of the soil and increased soil TOC.
Benchmarks for evaluating socially assistive robotics
Authors: Feil-Seifer David , Skinner Kristine , Matarić Maja J.
Published: September 2013

Socially assistive robotics (SAR) is a growing area of research. Evaluating SAR systems presents novel challenges. Using a robot for a socially assistive task can have various benefits and ethical implications. Many questions are important to understanding whether a robot is effective for a given application domain. This paper describes several benchmarks for evaluating SAR systems. There exist numerous methods for evaluating the many factors involved in a robot’s design. Benchmarks from psychology, anthropology, medicine, and human–robot interaction are proposed as measures of success in evaluating a given SAR system and its impact on the user and broader population.
Introduction.
Authors: Bhargava A. , Srivastava S.
Published: September 2013

This chapter provides an overview of the geographical distribution, cultivation, nutritive value, and economic importance, and medicinal properties of Chenopodium quinoa.
Diseases and pests.
Authors: Bhargava A. , Srivastava S.
Published: September 2013

This chapter covers the diseases (caused by bacteria, fungi and viruses) and pests (insects, birds, rodents and nematodes) of Chenopodium quinoa. Information on their geographical distribution, economic importance (mainly based on the degree of crop damage) and management is provided. Breeding for improved resistance to some pests and diseases is discussed.
Transparency from production to consumption: new challenges for the quinoa market chain.
Authors: Martínez E. A. , Olguín P.
Published: September 2013

This chapter describes why quinoa is in such demand in the health food market and the particular situation of Chile compared with other countries in the international quinoa market. A new, transparent type of market is proposed to increase the sustainability and resilience of local and global market networks, including for quinoa.