bluuebunny/crossref_metadata_2025 huggingface dataset:
Intimate partner violence and psychoemotional disturbance among pregnant women admitted to hospital with prenatal complications
Authors: Salazar‐Pousada Danny , Astudillo Cesar , Gonzaga Martha , Hidalgo Luis , Pérez‐López Faustino R. , Chedraui Peter
Published: June 2012

Objective

To assess intimate partner violence (IPV) and psychoemotional disturbance among pregnant women in a low‐income setting.

Methods

In total, 283 pregnant women with high‐risk prenatal complications were surveyed via the 20‐item Self‐Reporting Questionnaire (SRQ‐20) and the Violence against Women screening tool. A total SRQ‐20 score of at least 7 was defined as indicating psychoemotional disturbance.

Results

Median age of participants was 24 years, 65 (23.0%) came from marginal areas, 6 (2.1%) had no education, and 75 (26.5%) had fewer than 5 prenatal visits. Median gestational age at survey was 33 weeks, with 224 (79.2%) admitted for treatment of threatened preterm labor. Median age of partner was 27 years, and 72 (25.5%) consumed alcohol on a daily basis. Ninety‐eight (34.6%) pregnant women experienced at least 1 type of physical abuse or violence during the current pregnancy. Median total SRQ‐20 score was 7. Overall, 145 (51.2%) had scores of 7 or higher. Total SRQ‐20 scores positively correlated with the presence of IPV (number of positive items) and parity, and inversely correlated with maternal education level and gestational age at survey.

Conclusion

IPV was highly prevalent and significantly correlated with female psychoemotional disturbance.
Evaluation of coagulation abnormalities among women with vaginal bleeding in the first trimester of pregnancy
Authors: Kovač Vilma , Vlaisavljević Veljko , Reljič Milan
Published: June 2012

Objective

To compare blood coagulation parameters between pregnant women with vaginal bleeding in the first trimester of pregnancy and pregnant women with normal pregnancy in the first trimester.

Methods

A prospective controlled study of 98 women in the first trimester of vital pregnancy was conducted at the University Medical Centre Maribor, Slovenia. The study group comprised women with vaginal bleeding (n = 50) while the control group women with normal pregnancy, admitted for artificial abortion (n = 48). Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration, number of platelets, hemogram, coagulation factor VIII (FVIII) and von Willebrand factor (VWF) activity were compared between the 2 groups.

Results

No significant between‐group differences were detected in mean PT, fibrinogen concentration, FVIII, and VWF activity. Mean aPTT was significantly higher in the control group than the study group (32.47 versus 30.46 seconds; P < 0.05). The mean number of platelets was significantly lower in the study group than the control group (181.69 versus 203.52 × 109/L; P < 0.05). All measured coagulation parameters, except VWF activity, were within normal ranges.

Conclusion

Coagulation abnormalities are rarely the cause of vaginal bleeding in the first trimester of pregnancy among women with no previous symptoms of bleeding disorders.
Embolization to treat pelvic congestion syndrome and vulval varicose veins
Authors: van der Vleuten Carine J.M. , van Kempen Janneke A.L. , Schultze‐Kool Leo J.
Published: June 2012

Objective

To evaluate the efficacy of embolization for treating the symptoms of pelvic congestion syndrome (PCS).

Methods

Twenty‐one women with PCS who were treated with embolization at Radboud University Nijmegen Medical Centre between 2003 and 2008 were sent a questionnaire about their symptoms before embolization, 2 months after the first embolization, and at the time the survey was conducted.

Results

All patients completed the questionnaire. Two months after the first embolization, 14 (66.7%) women had some degree of improvement of symptoms. Nine (42.9%) patients underwent a second embolization. At the time the survey was conducted, 16 (76.2%) patients had some degree of improvement of symptoms. In addition to improvements in varicose veins and pelvic pain, there was improvement of hemorrhoids.

Conclusion

Embolization of pelvic varicosities may be an effective treatment in a well‐selected group of patients with PCS. If there is no improvement of symptoms after initial embolization, a second procedure is unlikely to be effective.
The Malabar Muslims
Authors: Lakshmi L. R. S.
Published: June 2012

The Muslims of Kerala, primarily in the northern region of the state called Malabar, are referred to as Mappillas. This book is a study of the social and institutional changes of the Malabar Muslims during the colonial period. It presents the Mappilla community in a wider Indian context and analyses its social, economic, religious, theological, political and educational aspects in detail. Particular emphasis has been laid on their women who are socially more powerful than their counterparts in the rest of the subcontinent. The Mappilla tharavaadus, which are matrilineal joint families, and kaarnotis, the female matrilineal heads of these families, are central to the understanding of the social history of this community. The British colonial system disrupted this traditional social order. The book argues that Mappillas do not per se represent a monolithic community, but show inter- and intra-regional variations and social hierarchies. The position and status of the Mappilla community in the twenty-first century has been compared with its Muslim counterparts in the other regions of the country. The book would be of interest to academics, researchers and graduate students of South Asian History and Sociology. NGOs working on the social welfare of minorities and general readers interested in the Islamic community of the west coast of India will find this book useful.
Multidimensional nonlinear mirror‐mode structures in the Earth's magnetosheath
Authors: Shoji Masafumi , Omura Yoshiharu , Lee Lou‐Chuang
Published: June 2012

We performed two‐dimensional (2D) and three‐dimensional (3D) hybrid simulations in open boundary models to study the nonlinear mirror‐mode structures driven by the temperature anisotropy (T⊥/T∥> 1) of protons in the magnetosheath. In the open systems, because of the propagation of EMIC waves, we obtain the clearer non‐propagating mirror‐mode structures. We analyzed the relation between the mirror instability and the magnetic peaks and dips observed in the magnetosheath. In the 2D open boundary model with low beta (β∥ ≲ 1), we obtain fine structures of the magnetic dips at the nonlinear stage. In the 3D model, on the other hand, the mirror instability makes the magnetic peak structures with the same parameters. The parametric analysis indicates that the magnetic peaks also arise in both 2D and 3D high beta cases (β∥ ⪆ 1) as shown by the Cluster observations. In the high beta cases, the high mobility of the protons helps continuous coalescence of the diamagnetic currents inside the magnetic dips. The coalescence makes the magnetic dips larger and shallower. Between the large and shallow magnetic dips, the magnetic peaks appear in the high beta cases. In the 3D models, because degree of freedom increases in the perpendicular direction, the continuous coalescence can take place even in the low beta cases. Thus, the magnetic peaks appear in the 3D models in both cases.
Microtopography alters self‐organized vegetation patterns in water‐limited ecosystems
Authors: McGrath Gavan S. , Paik Kyungrock , Hinz Christoph
Published: June 2012

In terrestrial systems limited by water availability the spatial distribution of vegetation can self‐organize into a mosaic of vegetated patches and bare soil. Spatially extensive competition for water and short‐range facilitation underpin many models that describe the process of vegetation pattern formation. Earlier studies investigating this self‐organized patchiness have largely considered smooth landscapes. However, topographic variations can significantly alter the redistribution of surface water flow and therefore the pattern‐forming process. Here, we consider how microtopographic variations, at the scale of individual plants, alters self‐organized vegetation patterns with the use of a simple ecohydrological model. We show that increasing microtopography can induce a change from banded vegetation, oriented across the slope, to irregular drainage patterns, oriented in the downslope direction. The mechanism responsible is shown to be a change in the spatial redistribution of infiltration around plants and plant patches. Only small increases in microtopography are required to cause banded systems with weak facilitation to change to downslope‐oriented patterns. When non‐periodic boundary conditions were considered, band orientation tended to become oblique to the topographic contour and in some circumstances their migration upslope ceased. These results suggest that diffusive sediment transport processes may be essential for the maintenance of regular periodic vegetation patterns, which implies that erosion may be critical for understanding the susceptibility of these ecosystems to catastrophic shifts.
Effects of gas escape and crystallization on the complexity of conduit flow dynamics during lava dome eruptions
Authors: Kozono T. , Koyaguchi T.
Published: June 2012

We investigated the coupled effects of gas escape and crystallization on the dynamics of lava dome eruptions using a one‐dimensional conduit flow model. The relationship between chamber pressure pch and mass flow rate q for steady conduit flow commonly has a regime of negative differential resistance (i.e., dpch/dq < 0), which causes a transition from lava dome to explosive eruption. Two positive‐feedback mechanisms that result in negative differential resistance have been identified. First, effective magma viscosity decreases with increasing q because of a delay of crystallization, leading to reduced viscous wall friction (feedback 1). Second, magma porosity increases with increasing q because of less efficient gas escape, leading to reduced gravitational load (feedback 2). For high‐phenocryst‐content magma (volume fraction >0.5), feedback 1 is the main mechanism that forms negative differential resistance. In this case, the transition from lava dome to explosive eruption occurs when the magma supply rate exceeds a fixed critical value. For low‐phenocryst‐content magma (volume fraction <0.5), feedback 2 plays a key role so that the transition is controlled by the permeability of the surrounding rocks; the critical magma supply rate remarkably decreases with decreasing permeability. Transition due to feedback 2 is associated with a change in the chemical composition of volcanic gas, a drastic increase in magma porosity from nearly 0 to greater than 0.8, and overpressure at a shallower level, which can be detected from geochemical and geophysical field observations.
Copy Number Variations Associated With Obesity‐Related Traits in African Americans: A Joint Analysis Between GENOA and HyperGEN
Authors: Zhao Wei , Wineinger Nathan E. , Tiwari Hemant K. , Mosley Thomas H. , Broeckel Ulrich , Arnett Donna K. , Kardia Sharon L.R. , Kabagambe Edmond K. , Sun Yan V.
Published: June 2012

Obesity is a highly heritable trait and a growing public health problem. African Americans (AAs) are a genetically diverse, yet understudied population with a high prevalence of obesity (BMI >30 kg/m2). Recent studies based upon single‐nucleotide polymorphisms (SNPs) have identified genetic markers associated with obesity. However, a large proportion of the heritability of obesity remains unexplained. Copy number variation (CNV) has been cited as a possible source of missing heritability in common diseases such as obesity. We conducted a CNV genome‐wide association study of BMI in two African‐American cohorts from Genetic Epidemiology Network of Arteriopathy (GENOA) and Hypertension Genetic Epidemiology Network (HyperGEN). We performed independent and identical association analyses in each study, then combined the results in a meta‐analysis. We identified three CNVs associated with BMI, obesity, and other obesity‐related traits after adjusting for multiple testing. These CNVs overlap the PARK2, GYPA, and SGCZ genes. Our results suggest that CNV may play a role in the etiology of obesity in AAs.
Sudden transitions and grand variations in the solar dynamo, past and future
Authors: De Jager Cornelis , Duhau Silvia
Published: June 2012

The solar dynamo is the exotic dance of the sun’s two major magnetic field components, the poloidal and the toroidal, interacting in anti-phase. On the basis of new data on the geomagnetic aa index, we improve our previous forecast of the properties of the current Schwabe cycle #24. Its maximum will occur in 2013.5 and the maximum sunspot number Rmax will then be 62 ± 12, which is within the bounds of our earlier forecasts. The subsequent analysis, based on a phase diagram, which is a diagram showing the relation between maximum sunspot numbers and minimum geomagnetic aa index values leads to the conclusion that a new Grand Episode in solar activity has started in 2008. From the study of the natural oscillations in the sunspot number time series, as found by an analysis based on suitable wavelet base functions, we predict that this Grand Episode will be of the Regular Oscillations type, which is the kind of oscillations that also occurred between 1724 and 1924. Previous expectations of a Grand (Maunder-type) Minimum of solar activity cannot be supported. We stress the significance of the Hallstatt periodicity for determining the character of the forthcoming Grand Episodes. No Grand Minimum is expected to occur during the millennium that has just started.
A transportable spectrometer for in situ and local measurements of iodine monoxide at mixing ratios in the 10−14 range
Authors: Méjean Guillaume , Grilli Roberto , Abd Alrahman Chadi , Ventrillard Irène , Kassi Samir , Romanini Daniele
Published: June 2012

We present a robust, compact, and transportable instrument that measures the iodine monoxide atmospheric radical at extremely low concentration, down to 40 ppqv (parts per quadrillion by volume, 1:1015). As nitrogen dioxide is strongly absorbed in the same spectral region it could be simultaneously measured down to 4 pptv (parts per trillion by volume, 1:1012). Relying on “mode locked cavity-enhanced absorption spectroscopy,” the instrument makes use of a free-running commercial femtosecond Titane Saphir laser. We demonstrate that this multiplex detection scheme provides shot noise limited spectra for acquisition times as long as 5 min. Moreover, this instrument is very versatile as it can be potentially tuned from the infrared to the ultraviolet (1080-340 nm) to reach various molecular absorptions. It has been recently deployed at the Station Biologique de Roscoff on the North West Atlantic coast of France.
Compressibility and strength of nanocrystalline tungsten boride under compression to 60 GPa
Authors: Dong Haini , Dorfman Susannah M. , Chen Ying , Wang Haikuo , Wang Jianghua , Qin Jiaqian , He Duanwei , Duffy Thomas S.
Published: June 2012

The compression behavior and stress state of nanocrystalline tungsten boride (WB) were investigated using radial x-ray diffraction (RXRD) in a diamond-anvil cell under non-hydrostatic compression up to 60.4 GPa. The compression properties and stress state are analyzed using lattice strain theory. Experiments were conducted at beamline X17C of the National Synchrotron Light Source. The radial x-ray diffraction data yield a bulk modulus that is qualitatively consistent with density functional theory calculations and demonstrate that WB is a highly incompressible material. A maximum differential stress, t, of about 14 GPa can be supported by nanocrystalline WB at the highest pressure. This corresponds to about 5% of the shear modulus, G, which is smaller than the values of t/G (∼8%–10%) observed for BC2N, B6O, TiB2, and γ-Si3N4 at high pressures. Thus, while WB is highly incompressible, its strength is relatively low at high pressures compared to other hard ceramics.
Atomic structure of Ca40+XMg25Cu35−X metallic glasses
Authors: Senkov O. N. , Cheng Y. Q. , Miracle D. B. , Barney E. R. , Hannon A. C. , Woodward C. F.
Published: June 2012

The atomic structures of four Ca40+XMg25Cu35−X (X = 0, 5, 10, and 20 at. %) ternary metallic glasses have been determined using a synergistic combination of neutron diffraction, ab initio molecular dynamics (MD) simulation, and constrained reverse Monte Carlo modeling. It is described as close-packing of efficiently packed Cu-centered clusters that have Ca, Mg, and Cu atoms in the first coordination shell. The close-packed arrangement of the clusters provides a characteristic medium range order in these alloys. An average coordination number (CN) of 10 (with about 5–7 Ca, 2–3 Mg, and 1–2 Cu atoms) is most common for the Cu-centered clusters. The average coordination numbers around Mg and Ca are 12–13 (∼6–8 Ca, 3 Mg, and 1–4 Cu) and 13–15 (7–9 Ca, 3–4 Mg, and 2–5 Cu), respectively, and they are composition dependent. Strong interaction of Cu with Mg and Ca results in pair bond shortening. Icosahedral short range order does not dominate in these amorphous alloys, although polytetrahedral packing and five-fold bond configurations resulting in pentagonal bi-pyramids have been found to be the most common nearest atom configurations.
Work function measurements on nano-crystalline zinc oxide surfaces
Authors: Gutmann S. , Conrad M. , Wolak M. A. , Beerbom M. M. , Schlaf R.
Published: June 2012

The work function of nano-crystalline zinc oxide (ZnO) thin films was examined using photoemission spectroscopy (PES). Colloidally dispersed ZnO nano-particles were electrospray-deposited in vacuum to form nano-crystalline thin films. The samples showed an immediate work function reduction by 0.35 eV during ultraviolet photoemission spectroscopy (UPS) measurements. This artifact was detected and quantified through low intensity x-ray photoemission spectroscopy (LIXPS) measurements, which use a very low photon flux. This prevented significant photochemical changes on the measured surface, i.e. the true work function unaffected by the UPS artifact can be measured. Annealing of an identical sample removed all ambient contamination from the ZnO surface with the effect to prevent the work function lowering artifact. This allowed the conclusion that ambient contamination is essential for the artifact to occur, similar to what was observed earlier on indium tin oxide and TiO2 surfaces. In an additional experiment, exposure of the annealed sample to the ambient resulted in a sample that again showed the artifact further demonstrating the necessity of water to be present. This experiment also demonstrated that the solubility enhancing surfactant shell of the nano-crystals does not play a significant role in the artifact, since it was removed during the annealing process.
Enhanced tunnel transport in disordered carbon superlattice structures incorporated with nitrogen
Authors: Katkov Mikhail V. , Bhattacharyya Somnath
Published: June 2012

The possibility for enhanced tunnel transport through the incorporation of nitrogen in a quasi-one dimensional superlattice structure of amorphous carbon (a−C) made of sp2−C and sp3−C rich phases is shown by using a tight-binding model. The proposed superstructure can be described by a set of disordered graphite-like carbon clusters (acting as quantum wells) separated by a thin layer of diamond-like carbon (barriers) where the variation of the width and depth of the carbon clusters significantly control the electron transmission peaks. A large structural disorder in the pure carbon system, introduced through the variation of the bond length and associated deformation potential for respective carbon phases, was found to suppress the sharp features of the transmission coefficients. A small percentage of nitrogen addition to the carbon clusters can produce a distinct transmission peak at the low energy; however, it can be practically destroyed due to increase of the level of disorder of carbon sites. Whereas pronounced resonance peaks, both for C and N sites can be achieved through controlling the arrangement of the nitrogen sites of increased concentration within the disordered sp2−C clusters. The interplay of disorder associated with N and C sites illustrated the tunable nature of resistance of the structures as well as their characteristic times.
Pressure-induced positive electrical resistivity coefficient in Ni-Nb-Zr-H glassy alloy
Authors: Fukuhara M. , Gangli C. , Matsubayashi K. , Uwatoko Y.
Published: June 2012

Measurements under hydrostatic pressure of the electrical resistivity of (Ni0.36Nb0.24Zr0.40)100−xHx (x = 9.8, 11.5, and 14) glassy alloys have been made in the range of 0–8 GPa and 0.5–300 K. The resistivity of the (Ni0.36Nb0.24Zr0.40)86H14 alloy changed its sign from negative to positive under application of 2–8 GPa in the temperature range of 300–22 K, coming from electron-phonon interaction in the cluster structure under pressure, accompanied by deformation of the clusters. In temperature region below 22 K, the resistivity showed negative thermal coefficient resistance by Debye-Waller factor contribution, and superconductivity was observed at 1.5 K.
Addition of dispersive terms to the method of averaged Lagrangian
Authors: Sedletsky Yu. V.
Published: June 2012

Whitham's method of averaged Lagrangian is applied to the problem of Stokes waves on the surface of a layer of ideal fluid. We derive a Lagrangian which contains additional terms with \documentclass[12pt]{minimal}\begin{document}$a_ {x} ^ {2}$\end{document}ax2 and aaxx besides nonlinear terms of Whitham with a2 and a4, a being the wave amplitude. These terms with derivatives appear after taking into account (1) additional terms in the Stokes expansions with the same approximation as the one was taken into consideration by Whitham; (2) supplementary slow (in comparison to the rapid phase oscillations) dependence of the amplitudes of harmonics on coordinates and time. We demonstrate the need for the account of such terms in the Lagrangian for obtaining the correct coefficients of dispersive terms of evolution equations from the corresponding variational equations.
Absolute sensitivity calibration of vacuum and extreme ultraviolet spectrometer systems and Zeff measurement based on bremsstrahlung continuum in HL-2A tokamak
Authors: Zhou Hangyu , Cui Zhengying , Morita Shigeru , Fu Bingzhong , Goto Motoshi , Sun Ping , Dong Chunfeng , Gao Yadong , Xu Yuan , Lu Ping , Yang Qingwei , Duan Xuru
Published: June 2012

A grazing-incidence flat-field extreme ultraviolet (EUV) spectrometer has been newly developed in HL-2A tokamak. Typical spectral lines are observed from intrinsic impurities of carbon, oxygen, iron, and extrinsic impurity of helium in the wavelength range of 20 Å–500 Å. Bremsstrahlung continuum is measured at different electron densities of HL-2A discharges to calibrate absolute sensitivity of the EUV spectrometer system and to measure effective ionic charge, Zeff. The sensitivity of a vacuum ultraviolet (VUV) spectrometer system is also absolutely calibrated in overlapped wavelength range of 300 Å–500 Å by comparing the intensity between VUV and EUV line emissions.
Etching suspended superconducting tunnel junctions from a multilayer
Authors: Nguyen H. Q. , Pascal L. M. A. , Peng Z. H. , Buisson O. , Gilles B. , Winkelmann C. B. , Courtois H.
Published: June 2012

A method to fabricate large-area superconducting hybrid tunnel junctions with a suspended central normal metal part is presented. The samples are fabricated by combining photo-lithography and chemical etch of a superconductor—insulator—normal metal multilayer. The process involves few fabrication steps, is reliable and produces extremely high-quality tunnel junctions. Under an appropriate voltage bias, a significant electronic cooling is demonstrated. We analyze semi-quantitatively the thermal behavior of a typical device.
Electrical conductivity of cationized ferritin decorated gold nanoshells
Authors: Cortez Rebecca , Slocik Joseph M. , Van Nostrand Joseph E. , Halas Naomi J. , Naik Rajesh R.
Published: June 2012

We report on a novel method of controlling the resistance of nanodimensional, gold-coated SiO2 nanoparticles by utilizing biomolecules chemisorbed to the nanoshell surface. Local electronic transport properties of gold-coated nanoshells were measured using scanning conductance microscopy. These results were compared to transport properties of identical gold nanoshells biofunctionalized with cationized ferritin protein both with and without an iron oxide core (apoferritin). Measured resistances were on the order of mega-ohms. White light irradiation effects on transport properties were also explored. The results suggest that the light energy influences the nanoshells’ conductivity. A mechanism for assembly of gold nanoshells with cationized ferritin or cationized apoferritin is proposed to explain the resistivity dependence on irradiation.
The influence of the substrate thermal conductivity on scanning thermochemical lithography
Authors: Tolk Marten , Fenwick Oliver , Ahmad Sadi , Cacialli Franco
Published: June 2012

We present a joint experimental and computational study of the role of the substrate thermal conductivity on scanning thermochemical lithography (SThL) of thin organic films. We aim this study at lithography of the luminescent conjugated polymer poly(p-phenylene vinylene) (PPV) from its soluble precursor poly(p-xylene tetrahydrothiophenium chloride) (PXT), but our results provide relevant insights into the SThL of thermosensitive polymers in general, and into a wide range of nanoscale thermal and thermochemical processes in thin films. As high thermal conductivity substrates we used gold films on silicon, and indium-tin oxide (ITO) films on glass, successfully patterning PPV on both substrates. We find that a higher probe temperature (>300 °C instead of ≈250 °C) is necessary for lithography of PXT films on ITO compared to those on fused silica (for the same scanning speed and comparable precursor thickness). Surprisingly, however, our experiments show that minimum feature sizes are nearly independent of the underlying substrate. While a lateral resolution (full width at half maximum, FWHM) of 37 nm was achieved previously on fused silica for a 40 nm thick PXT film, we obtain here a FWHM of 36 nm for a 35 nm thick PXT layer on ITO. We compare our experiments with finite element simulations and gain further insight into the possibilities of thermochemical lithography, the necessary minimum probe temperature and the highest attainable resolutions. The model shows that for high thermal conductivity substrates there should be a region of unconverted polymer near the polymer-substrate interface. Our experiments demonstrate that patterned features are able to adhere to the substrate despite this unconverted layer, thus allowing SThL to work on very high thermal conductivity substrates such as gold. Our model builds on this experimental finding and accounts for the experimental lack of dependence of lateral size with substrate conductivity, i.e. it predicts that the minimum feature size increases only slightly for increasing thermal conductivities of the substrates.
Development of a stable dielectric-barrier discharge enhanced laminar plasma jet generated at atmospheric pressure
Authors: Tang Jie , Li Shibo , Zhao Wei , Wang Yishan , Duan Yixiang
Published: June 2012

A stable nonthermal laminar atmospheric-pressure plasma source equipped with dielectric-barrier discharge was developed to realize more efficient plasma generation, with the total energy consumption reduced to nearly 25% of the original. Temperature and emission spectra monitoring indicates that this plasma is uniform in the lateral direction of the jet core region. It is also found that this plasma contains not only abundant excited argon atoms but also sufficient excited N2 and OH. This is mainly resulted from the escape of abundant electrons from the exit, due to the sharp decrease of sustaining voltage and the coupling between ions and electrons.
Evidence of anomalous refraction of self-assembled curved gold nanowires
Authors: Belardini A. , Pannone F. , Leahu G. , Larciprete M. C. , Centini M. , Sibilia C. , Martella C. , Giordano M. , Chiappe D. , Buatier de Mongeot F.
Published: June 2012

Resonant metallic nanostructures, located at the interface between two dielectrics, can produce abrupt phase discontinuities on propagating light that will be anomalously refracted by following the generalized Snell’s law. In this work, we show evidence of anomalous refraction arising when such an interface is nano-patterned with self-assembled bent gold nano-wires having sub-wavelength periodicity.
Fatigue effect in ferroelectric crystals: Growth of the frozen domains
Authors: Shur V. Ya. , Akhmatkhanov A. R. , Baturin I. S.
Published: June 2012

The model of the fatigue effect during cyclic switching caused by growth of the frozen domain area with charged domain walls has been proposed. It was claimed on the basis of the previous experimental results that for switching in increasing field the frozen domain area started to grow at the given sub-threshold field value and stopped at the threshold field. The influence of the shape and frequency of the field pulses used for cyclic switching has been considered. The uniaxial ferroelectric stoichiometric lithium tantalate single crystals produced by vapor transport equilibration with record low value of coercive field have been chosen as a model material for experimental verification of the model. The formation of the charged domain walls as a result of cyclic switching has been revealed by analysis of the domain images obtained by optical and Raman confocal microscopy. It has been shown that the fatigue degree is equal to the fraction of the frozen domain area. The experimental dependence of the switched charge on the cycle number has been successfully fitted by modified Kolmogorov-Avrami formula. The experimentally observed frequency independence of fatigue profile for rectangular pulses and frequency dependence for triangular pulses has been explained by proposed model.
Elastically bounded flapping wing for energy harvesting
Authors: Boragno C. , Festa R. , Mazzino A.
Published: June 2012

In this Letter, we present and discuss an energy harvesting device, based on a wing elastically bounded to a fixed support. Large amplitude and periodic oscillations can be induced when this system is subject to wind, if a few parameters are carefully set. A linear stability analysis as well as two-dimensional numerical simulations confirms the existence of instability regions in the parameter space. In order to harvest energy by using this system, different methods are considered. Preliminary results obtained by an electromagnetic coupling are presented.
Soft x-ray tomography for real-time applications: present status at Tore Supra and possible future developments
Authors: Mazon D. , Vezinet D. , Pacella D. , Moreau D. , Gabelieri L. , Romano A. , Malard P. , Mlynar J. , Masset R. , Lotte P.
Published: June 2012

This paper is focused on the soft x-ray (SXR) tomography system setup at Tore Supra (DTOMOX) and the recent developments made to automatically get precise information about plasma features from inverted data. The first part describes the main aspects of the tomographic inversion optimization process. Several observations are made using this new tool and a set of shape factors is defined to help characterizing the emissivity field in a real-time perspective. The second part presents a detailed off-line analysis comparing the positions of the magnetic axis obtained from a magnetic equilibrium solver, and the maximum of the reconstructed emissivity field for ohmic and heated pulses. A systematic discrepancy of about 5 cm is found in both cases and it is shown that this discrepancy increases during sawtooth crashes. Finally, evidence of radially localized tungsten accumulation with an in–out asymmetry during a lower hybrid current drive pulse is provided to illustrate the DTOMOX capabilities for a precise observation of local phenomena.
Mechanisms of heat transport across a nano-scale gap in heat assisted magnetic recording
Authors: Budaev Bair V. , Bogy David B.
Published: June 2012

This paper compares different mechanisms of heat transport across nano-scale gaps and discusses the role of electromagnetic phenomena in heat transport in general nano-scale layered structures. The results of the analysis suggest that heat transfer across sub-5 nm gaps like that appearing in prototypes of heat assisted magnetic recording (HAMR) systems is dominated by direct intermolecular interactions between the separated bodies and is little affected by electromagnetic radiation. The analysis further suggests that local heating for HAMR with sub-5 nm spacing can be more efficiently achieved by a Joule heater that is simpler to fabricate than laser-based optical systems and is less destructive for the nano-scale transducers than laser radiation, which may lead to their structural damage and short duration life of nanoscale transducers.
Phase coexistence and ferroelastic texture in high strain (1−x)Ba(Zr0.2Ti0.8)O3–x(Ba0.7Ca0.3)TiO3 piezoceramics
Authors: Ehmke Matthias C. , Ehrlich Steven N. , Blendell John E. , Bowman Keith J.
Published: June 2012

Dielectric permittivity and x-ray diffraction measurements were used to identify a region of phase coexistence between the rhombohedral and tetragonal phases near the morphotropic phase boundary in (1−x)Ba(Zr0.2Ti0.8)O3–x(Ba0.7Ca0.3)TiO3 (BZT-BCT). This phase coexistence prevails over a considerable composition and temperature range and is bounded by single rhombohedral or tetragonal phases. The maximum piezoelectric response measured in terms of maximum strain divided by maximum electric field, Smax/Emax, is extraordinarily high, with the largest value of 1310 pm/V for x = 0.45. Electrical poling induces ferroelastic domain textures in both the rhombohedral and tetragonal phases simultaneously, which increases the piezoelectric performance significantly. The stability of that ferroelastic texture is limited by the phase transition at the morphotropic phase boundary, suggesting coupling between both coexisting phases and limiting potential applications. The results were confirmed using in situ temperature dependent synchrotron x-ray diffraction. The findings indicate that the BZT-BCT system is considerably more complex than discussed in initial reports and that this complexity is likely related to the impressive properties that have been previously reported.
Controlled growth and multi-photon luminescence of hexagonal arrays of Au nanoparticles on anodic aluminum oxide templates
Authors: Li Jian-Bo , Yu Ying , Peng Xiao-Niu , Yang Zhong-Jian , Zhou Zhang-Kai , Zhou Li
Published: June 2012

Au nanoparticles were deposited onto anodic aluminum oxide (AAO) templates by using a rotating sputtering technique. Interestingly, hexagonal arrays of Au nanoparticles were obtained at an appropriate rotating rate and deposition time. Strong three-photon luminescence was observed from the hexagonally arrayed Au nanoparticles, which is attributed to the strong enhancements of local electromagnetic fields at both excitation and emission wavelengths. Our findings provide a new method to prepare Au nanoparticle arrays with large field enhancements and could have prospective applications in plasmonic nanodevices, such as surface-enhanced Raman scattering substrates, and biosensors.
Differentiated embryo-chondrocyte expressed gene 1 regulates p53-dependent cell survival versus cell death through macrophage inhibitory cytokine-1
Authors: Qian Yingjuan , Jung Yong-Sam , Chen Xinbin
Published: June 2012

Activation of p53 upon DNA damage induces an array of target genes, leading to cell cycle arrest and/or apoptosis. However, the mechanism by which the cell fate is controlled by p53 remains to be clarified. Previously, we showed that DEC1, a basic helix–loop–helix transcription factor and a target of p53, is capable of inducing cell cycle arrest and mediating DNA damage-induced premature senescence. Here, we found that ectopic expression of DEC1 inhibits, whereas knockdown of DEC1 enhances, DNA damage-induced cell death. Surprisingly, we showed that the anti–cell-death activity of DEC1 is p53 dependent, but DEC1 does not directly modulate p53 expression. Instead, we showed that DEC1 inhibits the ability of p53 to induce macrophage inhibitory cytokine-1 (MIC-1), but not other prosurvival/proapoptotic targets, including p21 and Puma. Importantly, we showed that upon binding to their respective response elements on the
MIC-1
promoter, DEC1 and p53 physically interact on the
MIC-1
promoter via the basic helix–loop–helix domain in DEC1 and the tetramerization domain in p53, which likely weakens the DNA-binding activity of p53 to the
MIC-1
promoter. Finally, we found that depletion of MIC-1 abrogates the ability of DEC1 to attenuate DNA damage-induced cell death. Together, we hypothesize that DEC1 controls the response of p53-dependent cell survival vs. cell death to a stress signal through MIC-1.
Biofuels: the food versus fuel debate.
Authors: Timilsina G. R.
Published: June 2012

The increase in prices of food commodities since 2001, culminating in the food crisis of 2007/08 gave birth to the food versus fuel debate. Several studies over the past few years have pointed to biofuels as one of the culprits of the food crisis; although the magnitudes of impact in these studies vary widely depending on the underlying assumptions and structure of the models used for the analysis. The food versus fuel debate will accelerate if the expansion of crop-based or first-generation biofuels continues without appropriate arrangements for food security given that the global food demand is projected to double by 2050. The existing literature, in general, does not favour a large-scale diversion of food commodities towards production of biofuels at the global scale because it does not help much to substitute a significant portion of fossil fuels: instead, it simply puts substantial pressure on the global food supply. However, in some countries and regions where land supply is not an issue, production of biofuels should not be ruled out. Moreover, if regulated properly, biofuels could provide incentives to utilize abandoned and marginal lands for agricultural production, help improve agriculture intensification and generate employment in rural areas. In response to the food versus fuel debate, many countries have now focused on advanced biofuels that do not directly compete with food supply, although they do through land reallocations. Some countries have also designed policy framework to protect crop lands and natural forests from biofuel expansion. Some literature argues that intensification of agricultural, particularly in developing countries, would help address the food versus fuel debate, whereas others contend that any increase in agricultural production must be focused on meeting the growing food demand.
Technology imports, product exports and firms’ R&D investment: an empirical analysis of firms in the Chinese high technology sector
Authors: Millman Cindy , Li Zhengwei , Chi Renyong
Published: June 2012

New trade theory emphasises the important role that international trade plays in advancing technologies. This study examines the impact of international trade on firm research and development investment (RDI). Specifically, it analyses the impact of technology imports and product exports respectively on firm RDI in the high technology sector of China. The hypotheses are tested against 1111 firms in the high technology sector in Zhejiang province. Neither technology imports nor product exports have a positive impact on firm RDI at an aggregated level. However, disembodied technology imports have a significant positive impact on firm RDI, while non-high technology product exports show a significant negative impact.
Sildenafil enhances systolic adaptation, but does not prevent diastolic dysfunction, in the pressure‐loaded right ventricle
Authors: Borgdorff Marinus A.J. , Bartelds Beatrijs , Dickinson Michael G. , Boersma Bibiche , Weij Michel , Zandvoort Andre , Silljé Herman H.W. , Steendijk Paul , de Vroomen Maartje , Berger Rolf M.F.
Published: June 2012

Aim

Right ventricular (RV) failure due to pressure or volume overload is a major risk factor for early mortality in congenital heart disease and pulmonary hypertension, but currently treatments are lacking. We aimed to demonstrate that the phosphodiesterase 5A inhibitor sildenafil can prevent adverse remodelling and improve function in chronic abnormal RV overload, independent from effects on the pulmonary vasculature.

Methods and results

In rat models of either pressure or volume overload, we performed pressure–volume studies to measure haemodynamic effects and voluntary exercise testing as clinical outcome after 4 weeks of sildenafil (or vehicle) administration. In the pressure‐loaded right ventricle, sildenafil enhanced contractility [end‐systolic elastance (mmHg/mL) 247 ±68 vs.155 ±71, sildenafil vs. vehicle, P < 0.05], prevented RV dilatation [end‐diastolic volume (μL) 733 ±50 vs. 874 ±39, P < 0.05], reduced wall stress [peak wall stress (mmHg) 323 ±46 vs. 492 ±62, P < 0.05], and partially preserved exercise tolerance [running distance (%) –33 ±15 vs. –62 ±12, P < 0.05]. Protein kinase A was not activated by sildenafil and thus did not mediate the observed effects. In contrast, protein kinase G‐1 was activated by sildenafil, but hypertrophy was not inhibited. Importantly, sildenafil did not prevent diastolic dysfunction, whereas RV fibrosis appeared to be increased in sildenafil‐treated rats. In the volume‐loaded right ventricle, sildenafil treatment did not show any beneficial effects.

Conclusion

We demonstrate sildenafil to have beneficial, afterload‐independent effects on the pressure‐loaded right ventricle, but not on the volume‐loaded right ventricle. These results indicate that sildenafil may offer a specific treatment for the pressure‐loaded right ventricle, although persistent diastolic dysfunction and RV fibrosis could be of concern.
Brevibacterium ammoniilyticum sp. nov., an ammonia-degrading bacterium isolated from sludge of a wastewater treatment plant
Authors: Kim Jinsoo , Srinivasan Sathiyaraj , You Taek , Bang John J. , Park Sujeong , Lee Sang-Seob
Published: June 2012

A Gram-stain-positive, non-motile, chemo-organotrophic, mesophilic, aerobic bacterium, designated A1T, was isolated from sludge of a wastewater treatment plant. Strain A1T showed good ability to degrade ammonia and grew well on media amended with methanol and ammonia. Strain A1T grew with 0–11 % (w/v) NaCl, at 20–42 °C, but not <15 or >45 °C and at pH 6–10 (optimum pH 8.0–9.0). The isolate was catalase-positive and oxidase-negative. The DNA G+C content was 70.7 mol%. A comparative analysis of 16S rRNA gene sequences revealed that strain A1T formed a distinct phyletic lineage in the genus

Brevibacterium

and showed high sequence similarity with

Brevibacterium casei

NCDO 2048T (96.9 %),

Brevibacterium celere

KMM 3637T (96.9 %) and

Brevibacterium sanguinis

CF63T (96.4 %). DNA–DNA hybridization revealed <43 % DNA–DNA relatedness between the isolate and its closest phylogenetic relatives. The affiliation of strain A1T with the genus

Brevibacterium

was supported by the chemotaxonomic data: predominant quinone menaquinone MK-7(H2); polar lipid profile containing diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid; characteristic cell-wall diamino acid meso-diaminopimelic acid; whole-cell sugars galactose, xylose and ribose; absence of mycolic acids; and major fatty acids iso-C15 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The results of physiological and biochemical tests allowed phenotypic differentiation of strain A1T from members of the genus

Brevibacterium

. On the basis of the results in this study, a novel species, Brevibacterium ammoniilyticum sp. nov., is proposed. The type strain is A1T ( = KEMC 41-098T  = JCM 17537T  = KACC 15558T).
Inhibiting PKMζ reveals dorsal lateral and dorsal medial striatum store the different memories needed to support adaptive behavior
Authors: Pauli Wolfgang M. , Clark Alexandra D. , Guenther Heidi J. , O’Reilly Randall C. , Rudy Jerry W.
Published: June 2012

Evidence suggests that two regions of the striatum contribute differential support to instrumental response selection. The dorsomedial striatum (DMS) is thought to support expectancy-mediated actions, and the dorsolateral striatum (DLS) is thought to support habits. Currently it is unclear whether these regions store task-relevant information or just coordinate the learning and retention of these solutions by other brain regions. To address this issue, we developed a two-lever concurrent variable-interval reinforcement operant conditioning task and used it to assess the trained rat’s sensitivity to contingency shifts. Consistent with the view that these two regions make different contributions to actions and habits, injecting the NMDA antagonist DL-AP5 into the DMS just prior to the shift impaired the rat’s performance but enhanced performance when injected into the DLS. To determine if these regions support memory content, we first trained rats on a biased concurrent schedule (Lever 1: VI 40″ and Lever 2: VI 10″). With the intent of “erasing” the memory content stored in striatum, after this training we inhibited the putative memory-maintenance protein kinase C isozyme protein kinase Mζ (PKMζ). Infusing zeta inhibitory peptide (ZIP) into the DLS enhanced the rat’s ability to adapt to the contingency shift 2 d later, whereas injecting it into the DMS had the opposite effect. Infusing GluR23Yinto the DMS 1 h before ZIP infusions prevented ZIP from impairing the rat’s sensitivity to the contingency shift. These results support the hypothesis that the DMS stores information needed to support actions and the DLS stores information needed to support habits.
Dopamine induces LTP differentially in apical and basal dendrites through BDNF and voltage-dependent calcium channels
Authors: Navakkode Sheeja , Sajikumar Sreedharan , Korte Martin , Soong Tuck Wah
Published: June 2012

The dopaminergic modulation of long-term potentiation (LTP) has been studied well, but the mechanism by which dopamine induces LTP (DA-LTP) in CA1 pyramidal neurons is unknown. Here, we report that DA-LTP in basal dendrites is dependent while in apical dendrites it is independent of activation of L-type voltage-gated calcium channels (VDCC). Activation via NMDAR is critical for the induction of DA-LTP in both apical and basal dendrites, but only BDNF is required for the induction and maintenance of DA-LTP in apical dendrites. We report that dopaminergic modulation of LTP is lamina-specific at the Schaffer collateral/commissural synapses in the CA1 region.
Structure ofLeishmania majorcysteine synthase
Authors: Fyfe Paul K. , Westrop Gareth D. , Ramos Tania , Müller Sylke , Coombs Graham H. , Hunter William N.
Published: June 2012

Cysteine biosynthesis is a potential target for drug development against parasiticLeishmaniaspecies; these protozoa are responsible for a range of serious diseases. To improve understanding of this aspect ofLeishmaniabiology, a crystallographic and biochemical study ofL. majorcysteine synthase has been undertaken, seeking to understand its structure, enzyme activity and modes of inhibition. Active enzyme was purified, assayed and crystallized in an orthorhombic form with a dimer in the asymmetric unit. Diffraction data extending to 1.8 Å resolution were measured and the structure was solved by molecular replacement. A fragment of γ-poly-D-glutamic acid, a constituent of the crystallization mixture, was bound in the enzyme active site. Although a D-glutamate tetrapeptide had insignificant inhibitory activity, the enzyme was competitively inhibited (Ki= 4 µM) by DYVI, a peptide based on the C-terminus of the partner serine acetyltransferase with which the enzyme forms a complex. The structure surprisingly revealed that the cofactor pyridoxal phosphate had been lost during crystallization.