bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of glucocorticoids on sex steroid synthesis in cultured Taenia crassiceps Wake Forest University (WFU) cysticerci
Authors: Hinojosa L. , Valdez R.A. , Salvador V. , Rodríguez A.G. , Willms K. , Romano M.C.
Published: December 2011

We have shown previously that cultured Taenia crassiceps Wake Forest University (WFU) and Taenia solium cysticerci, as well as the adult worms, synthesize sex steroid hormones from [3H]steroid precursors and that androgens and oestrogens influence the in vitro development of the parasites. Glucocorticoids (GCs) are used to control the inflammation caused by T. solium cysticerci in the brain. These steroids stimulate oestrogen synthesis in several tissues. Since there is no information on the effect of GC on the endocrine function of cysticerci, we investigated the effect of natural and synthetic GCs on the synthesis of oestrogens in cultured T. crassiceps WFU cysticerci. The cysticerci were obtained from the peritoneal cavity of infected female BALB/c mice; the cysts were washed extensively and pre-cultured in Dulbecco's Modified Eagle's Medium (DMEM) plus antibiotics for 5 days. The parasites were further cultured with different doses of corticosterone, dexamethasone or the vehicle for 5 days. [3H]Dehydroepiandrosterone (3H-DHEA) was added to the media and the cysticerci were further incubated for 6 or 24 h. Media were then removed and the steroids ether-extracted. Aliquots of the media were seeded on silica gel plates and developed in solvent systems. Parasites incubated in the presence of 3H-DHEA synthesized [3H]androstenediol, [3H]testosterone and [3H]17β-oestradiol ([3H]17β-E2). The addition of 100 nm or higher corticosterone doses to the media increased [3H]17β-E2 synthesis fourfold after 24 h. Dexamethasone also increased [3H]17β-E2 synthesis. The experiments presented here show for the first time that corticosterone and the synthetic GC dexamethasone modulate the synthesis of oestrogens by cysticerci.
The Lecanora dispersa group (Lecanoraceae)
in Argentina
Authors: DE LA ROSA Iris Nadia , MESSUTI María Inés , ŚLIWA Lucyna
Published: December 2011

A preliminary study of the Lecanora dispersa group in Argentina is
presented. Two species (L. dispersa and L. hagenii) have
been previously recorded and their known distribution is extended, one species (L.
semipallida) is a new record from Argentina, and five taxa (L.
flowersiana, L. persimilis L. torrida, L.
wetmorei and L. zosterae var. zosterae) are
reported for the first time from South America. Three species (L.
albescens, L. crenulata and L. populicola)
previously recorded for Argentina have not been confirmed as occurring in this country.
Lecanora aff. fugiens is also treated and compared to
the related species. The morphology, anatomy, secondary metabolites, distribution and
ecology of the nine studied taxa are described and discussed, and a key to the taxa is
included.
Simultaneous non-vanishing of GL(3) × GL(2) and GL(2) L-functions
Authors: KHAN RIZWANUR
Published: December 2011

Fix g a Hecke–Maass form for SL3(). In the family of holomorphic newforms f of fixed weight and large prime level q, we find the average value of the product $L(\half,g\times f)L(\half,f)$. From this we derive a result on the simultaneous non-vanishing of these L-functions at the central point.
Well-posed two-point initial-boundary value problems with arbitrary boundary conditions
Authors: SMITH DAVID A.
Published: December 2011

We study initial-boundary value problems for linear evolution equations of arbitrary spatial order, subject to arbitrary linear boundary conditions and posed on a rectangular 1-space, 1-time domain. We give a new characterisation of the boundary conditions that specify well-posed problems using Fokas' transform method. We also give a sufficient condition guaranteeing that the solution can be represented using a series.

The relevant condition, the analyticity at infinity of certain meromorphic functions within particular sectors, is significantly more concrete and easier to test than the previous criterion, based on the existence of admissible functions.
Healthcare policy tools as determinants of health-system efficiency: evidence from the OECD
Authors: Wranik Dominika
Published: December 2011

This paper assesses which policy-relevant characteristics of a healthcare system contribute to health-system efficiency. Health-system efficiency is measured using the stochastic frontier approach. Characteristics of the health system are included as determinants of efficiency. Data from 21 OECD countries from 1970 to 2008 are analysed. Results indicate that broader health-system structures, such as Beveridgian or Bismarckian financing arrangements or gatekeeping, are not significant determinants of efficiency. Significant contributors to efficiency are policy instruments that directly target patient behaviours, such as insurance coverage and cost sharing, and those that directly target physician behaviours, such as physician payment methods. From the perspective of the policymaker, changes in cost-sharing arrangements or physician remuneration are politically easier to implement than changes to the foundational financing structure of the system.
THE PURE LOGIC OF GROUND
Authors: FINE KIT
Published: December 2011

I lay down a system of structural rules for various notions of ground and establish soundness and completeness.
NOAA issues scientific integrity policy
Authors: Showstack Randy
Published: December 2011

The U.S. National Oceanic and Atmospheric Administration (NOAA) announced the agency's first‐ever scientific integrity policy at a 7 December news briefing at the AGU Fall Meeting in San Francisco, Calif. The policy follows a December 2010 White House memorandum that issued guidance to federal agencies implementing scientific integrity policies (see “White House issues scientific integrity policies,” Eos Trans. AGU, 91(51), 503, doi:10.1029/2010EO510003, 2010). The purpose of the NOAA policy is “to promote a continuing culture of scientific excellence and integrity, and to establish a policy on the integrity of scientific activities that the agency conducts and uses to inform management and policy decisions,” the agency's administrative order states. “In addition, the intent of the policy is to strengthen widespread confidence—from scientists, to decisionmakers, to the general public—in the quality, validity, and reliability of NOAA science and to denote the agency's commitment to a culture of support for excellence of NOAA's principal science asset, its employees.”
Deforestation contributed to droughts that influenced Maya decline
Authors: Balcerak Ernie
Published: December 2011

New studies show that deforestation throughout much of southern Mexico in pre‐Columbian times contributed to droughts that led to the decline of the Maya and Aztec civilizations. Significant droughts are known to have affected these civilizations between about 800 and 950 C.E.; it has been debated whether solar forcing, random natural variability, or clearing of rain forests to create pasture or farmlands primarily caused these droughts. Reconstructions of past land cover can be made based on population estimates. Central America was significantly deforested by Maya and Aztec societies before Europeans arrived about 1500 C.E. Forest then recovered as native populations declined, although more deforestation has been taking place in recent years.
New images of asteroid Vesta
Authors: Balcerak Ernie
Published: December 2011

Observations from NASA's Dawn spacecraft, which entered orbit around asteroid Vesta in July, show that the asteroid “is one of the most colorful objects in the solar system,” according to Vishnu Reddy of the Max Planck Institute for Solar System Research, Katlenburg‐Lindau, Germany. Vesta, one of the largest asteroids in the belt between Mars and Jupiter, has a surface that is heavily weathered and covered with many impact craters. The new images, in both visible and infrared light, show that Vesta has a variety of rock and mineral types, including iron‐containing pyroxene. Other asteroids do not have as much variety.
Subsurface structure affects landslide susceptibility
Authors: Schultz Colin
Published: December 2011

The likelihood of landslides on an exposed bedrock hill is dependent on the strength of the bedrock as well as the slope of the hill. In general, stronger rocks provide increased resilience against landslides and are capable of supporting steeper slopes. But for the hills of Fiordland and the Southern Alps in New Zealand that experience repeated landslides, these simple proxy measures do not tell the whole story. The hills in these two regions have similar slopes, despite the fact that they are formed from rocks with significantly different inherent strengths, and the landslides in the Southern Alps are both more powerful and more common than those in Fiordland.
Urban emission hot spots as sources for remote aerosol deposition
Authors: Kunkel D. , Lawrence M. G. , Tost H. , Kerkweg A. , Jöckel P. , Borrmann S.
Published: December 2011

Large point sources such as major population centers (MPCs) emit pollutants which can be deposited nearby or transported over long distances before deposition. We have used tracer simulations of aerosols emitted from MPCs worldwide to assess the fractions which are deposited at various distances away from their source location. Considering only source location, prevailing meteorology, and the aerosol size and solubility, we show that fine aerosol particles have a high potential to pollute remote regions. About half of the emitted mass of aerosol tracers with an ambient diameter ≤1.0 μm is typically deposited in regions more than 1000 km away from the source. Furthermore, using the Köppen‐Geiger climate classification to categorize the sources into various climate classes we find substantial differences in the deposition potential between these classes. Tracers originating in arid regions show the largest remote deposition potentials, with values more than doubled compared to the smallest potentials from tracers in tropical regions. Seasonal changes in atmospheric conditions lead to variations in the remote deposition potentials. On average the remote deposition potentials in summer correspond to about 70–80% of the values in winter, with a large spread among the climate classes. For tracers from tropical regions the summer remote deposition values are only about 31% of the winter values, while they are about 95% for tracers from arid regions.
A novel back‐trajectory analysis of the origin of black carbon transported to the Himalayas and Tibetan Plateau during 1996–2010
Authors: Lu Zifeng , Streets David G. , Zhang Qiang , Wang Siwen
Published: December 2011

Black carbon (BC) deposited on snow and ice accelerates glacier melting and contributes to climate change of the Himalayas and Tibetan Plateau (HTP). Taking into account emissions, hydrophilic‐to‐hydrophobic conversion, and removal processes of BC, a novel back‐trajectory approach is developed to study the origin of BC reaching the HTP. The results indicate that BC received by the HTP increased by 41% from 1996 to 2010, implying that the BC problem is accelerating in the HTP region. South Asia and East Asia are the main source regions, accounting for 67% and 17% of BC transported to the HTP on an annual basis, followed by Former USSR (∼8%), Middle East (∼4%), Europe (∼2%), and Northern Africa (∼1%). BC reaching the HTP is high in winter and low in summer, and the relative contributions of different source regions vary with seasons. We show the seasonal spatial distribution of BC sources directly on a 0.5° × 0.5° grid, which provides information to policymakers about the best target areas for mitigating the climate changes and other effects on the HTP.
Effect of global mass conservation among geophysical fluids on the seasonal length of day variation
Authors: Yan Haoming , Chao Benjamin F.
Published: December 2011

Geophysical fluids models for the atmosphere, ocean, and land hydrology usually do not properly enforce the conservation of mass either individually or collectively. Called the global mass balance (GMB) effect, these errors, if not corrected, will significantly affect the determination of the effect of geophysical fluids on the variation in the Earth's rotation rate or length of day (LOD). Here we analyze the seasonal budget of the excitation sources for LOD variation in comparison with corresponding observations. We find that (1) the combined mass‐induced excitations of LOD variation by geophysical fluids are brought to much better agreement with the observed upon accounting for the GMB effect; (2) the above can be further improved to almost perfect closure if the motion term of the atmospheric angular momentum (to be removed from the observed LOD variation in obtaining the mass‐induced LOD variation) is magnified by 7%, corroborating the finding of Chao and Yan (2010); and (3) the above quantities all agree remarkably well with the equivalent LOD variation determined via J2 variation from satellite laser ranging observations, indicating the usefulness of the latter as an independent measurement for mass transports in the geophysical fluids.
Flexible distributed-feedback colloidal quantum dot laser
Authors: Chen Yujie , Guilhabert Benoit , Herrnsdorf Johannes , Zhang Yanfeng , Mackintosh Allan R. , Pethrick Richard A. , Gu Erdan , Laurand Nicolas , Dawson Martin D.
Published: December 2011

By fabricating a submicron-scale grating structure on a bendable polymer substrate, we demonstrate a flexible distributed-feedback colloidal quantum dot laser. This laser uses cadmium selenide/zinc sulfide core-shell nanostructures, operating in transverse electric polarized multiple-modes, and has a typical threshold pump fluence of ∼4 mJ/cm2.
Extraction of the spin torque non-adiabaticity from thermally activated domain wall hopping
Authors: Heinen J. , Hinzke D. , Boulle O. , Malinowski G. , Swagten H. J. M. , Koopmans B. , Ulysse C. , Faini G. , Kläui M.
Published: December 2011

We investigate the non-adiabaticity of current-induced domain wall motion by time resolved analysis of thermally activated domain wall motion between two metastable states within a Co/Pt multilayer wire with a strong uniaxial perpendicular anisotropy. By measuring the dwell times for which the domain wall remains in one state, we deduce the non-adiabaticity factor β using two independent approaches: (i) the dependence of the dwell times on the injected current and (ii) the current-field equivalency. The comparison of the results allows us to gauge their reliability and the observed differences highlight the importance of the two dimensional (2D) nature of the domain wall.
The graviton propagator in de Donder gauge on de Sitter background
Authors: Miao S. P. , Tsamis N. C. , Woodard R. P.
Published: December 2011

We construct the graviton propagator on de Sitter background in exact de Donder gauge. We prove that it must break de Sitter invariance, just like the propagator of the massless, minimally coupled scalar. Our explicit solutions for its two scalar structure functions preserve spatial homogeneity and isotropy so that the propagator can be used within the larger context of inflationary cosmology; however, it is simple to alter the residual symmetry. Because our gauge condition is de Sitter invariant (although no solution for the propagator can be) renormalization should be simpler using this propagator than one based on a noncovariant gauge. It remains to be seen how other computational steps compare.
Macroion solutions in the cell model studied by field theory and Monte Carlo simulations
Authors: Lue Leo , Linse Per
Published: December 2011

Aqueous solutions of charged spherical macroions with variable dielectric permittivity and their associated counterions are examined within the cell model using a field theory and Monte Carlo simulations. The field theory is based on separation of fields into short- and long-wavelength terms, which are subjected to different statistical-mechanical treatments. The simulations were performed by using a new, accurate, and fast algorithm for numerical evaluation of the electrostatic polarization interaction. The field theory provides counterion distributions outside a macroion in good agreement with the simulation results over the full range from weak to strong electrostatic coupling. A low-dielectric macroion leads to a displacement of the counterions away from the macroion.
Time-resolved femtosecond optical characterization of multi-photon absorption in high-pressure-grown Al0.86Ga0.14N single crystals
Authors: Zhang Jie , Belousov Andrey , Karpiński Janusz , Batlogg Bertram , Wicks Gary , Sobolewski Roman
Published: December 2011

We report our experimental studies on time-resolved pump–probe spectroscopy in high-quality Al0.86Ga0.14N single crystals, grown using a solution technique in a high-nitrogen-gas-pressure system. Our optical measurements were performed using a non-traditional, two-beam [one ultraviolet (UV) and one infrared (IR)], femtosecond pump–probe approach, in which the photon energies of both beams were below the bandgap of the sample and each electron–hole pair was generated by a multi-photon process of absorption of a pump photon together with another photon produced by second harmonic generation from two probe photons. Temporal scanning of the probe while monitoring the normalized transient differential transmissivity (ΔT/T) signal, produced a 310-fs-wide, Gaussian-shaped correlation signal caused by the multi-photon absorption process, followed by a >100-ps-long relaxation of photo-excited carriers. By studying the ΔT/T correlation signal amplitude dependence on the pump-power intensity and wavelength, the multi-photon absorption was determined to be predominantly caused by absorption of a pump photon and a second harmonic photon from the probe.
Linear and nonlinear intersubband optical properties of Si quantum dot embedded in oxide, nitride, and carbide matrix
Authors: Anchala  , Purohit S. P. , Mathur K. C.
Published: December 2011

In this paper we study the linear and nonlinear intersubband optical properties of a nanocrystalline singly charged Si semiconductor quantum dot surrounded by an amorphous matrix of silicon dioxide, silicon nitride, and silicon carbide. A finite barrier height is considered at the interface of the dot and matrix. We also consider the effect of self-energy associated with the surface polarization due to the charging of the dot and the size dependent dielectric constant of the dot. The effect of the surrounding matrix is investigated on the linear and nonlinear absorption coefficient, refractive index changes, nonlinear susceptibility, and photoelectric cross section. Using the effective mass approximation (EMA) results are obtained for different dot radii, photon energies, and intensities. It is noted that an increase in barrier height due to the surrounding matrix leads to blueshift in peak positions of absorption coefficients and refractive index change.
A novel zirconium Kα imager for high energy density physics research
Authors: Akli K. U. , del Rio M. Sanchez , Jiang S. , Storm M. S. , Krygier A. , Stephens R. B. , Pereira N. R. , Baronova E. O. , Theobald W. , Ping Y. , McLean H. S. , Patel P. K. , Key M. H. , Freeman R. R.
Published: December 2011

We report on the development and characterization of a zirconium Kα imager for high energy density physics research. The imager consists of a spherically bent quartz crystal operating at 15.7 keV photon energy. We compare the performance of the imager in terms of integrated reflectivity (Rint) and temperature dependent collection efficiency (ηTe) to that of the widely used Cu Kα imager. Our collisional-radiative simulations show that the new imager can be reliably used up to 250 eV plasma temperature. Monte Carlo simulations show that for a 25 μm thick tracer layer of zirconium, the contribution to Kα production from photo-pumping is only 2%. We present, for the first time, 2D spatially resolved images of zirconium plasmas generated by a high intensity short pulse laser interacting with Zr solid targets.
Measurement of axial neutral density profiles in a microwave discharge ion thruster by laser absorption spectroscopy with optical fiber probes
Authors: Tsukizaki Ryudo , Koizumi Hiroyuki , Nishiyama Kazutaka , Kuninaka Hitoshi
Published: December 2011

In order to reveal the physical processes taking place within the “μ10” microwave discharge ion thruster, internal plasma diagnosis is indispensable. However, the ability of metallic probes to access microwave plasmas biased at a high voltage is limited from the standpoints of the disturbance created in the electric field and electrical isolation. In this study, the axial density profiles of excited neutral xenon were successfully measured under ion beam acceleration by using a novel laser absorption spectroscopy system. The target of the measurement was metastable Xe I 5p5(2P03/2)6s[3/2]02 which absorbed a wavelength of 823.16 nm. Signals from laser absorption spectroscopy that swept a single-mode optical fiber probe along the line of sight were differentiated and converted into axial number densities of the metastable neutral particles in the plasma source. These measurements revealed a 1018 m−3 order of metastable neutral particles situated in the waveguide, which caused two different modes during the operation of the μ10 thruster. This paper reports a novel spectroscopic measurement system with axial resolution for microwave plasma sources utilizing optical fiber probes.
Fabrication of nanoscale patterns in lithium fluoride crystal using a 13.5 nm Schwarzschild objective and a laser produced plasma source
Authors: Wang Xin , Mu Baozhong , Jiang Li , Zhu Jingtao , Yi Shengzhen , Wang Zhanshan , He Pengfei
Published: December 2011

Lithium fluoride (LiF) crystal is a radiation sensitive material widely used as EUV and soft x-ray detector. The LiF-based detector has high resolution, in principle limited by the point defect size, large field of view, and wide dynamic range. Using LiF crystal as an imaging detector, a resolution of 900 nm was achieved by a projection imaging of test meshes with a Schwarzschild objective operating at 13.5 nm. In addition, by imaging of a pinhole illuminated by the plasma, an EUV spot of 1.5 μm diameter in the image plane of the objective was generated, which accomplished direct writing of color centers with resolution of 800 nm. In order to avoid sample damage and contamination due to the influence of huge debris flux produced by the plasma source, a spherical normal-incidence condenser was used to collect EUV radiation. Together with a description of experimental results, the development of the Schwarzschild objective, the influence of condenser on energy density and the alignment of the imaging system are also reported.
On the existence of a third-order phase transition beyond the Andrews critical point: A molecular dynamics study
Authors: Wang Han , Site Luigi Delle , Zhang Pingwen
Published: December 2011

The possibility of the existence of a gas-liquid third order phase transition for fluids is becoming a subject of growing interest. Experimental work suggests its existence for specific systems while recent theoretical models claim its universality. In this work, we employ Molecular Dynamics and investigate the third-order phase transition beyond the Andrews critical point by treating a system of Lennard-Jones particles along three isotherms. Two partial derivatives of the Gibbs free energy are measured, namely the molar constant pressure heat capacity and isothermal compressibility. The convergence of these simulations with respect to the system size as well as the cut-off radius is carefully checked. The obtained results show that partial derivatives certainly do not present sharp cusp singularities at the maxima, and actually suggest that there are no singularities at all. On these basis we then conclude that a third-order phase transition in the considered temperature region: T* ⩾ 1.36 may indeed not exist.
Single x-ray transmission system for bone mineral density determination
Authors: Jimenez-Mendoza Daniel , Espinosa-Arbelaez Diego G. , Giraldo-Betancur Astrid L. , Hernandez-Urbiola Margarita I. , Vargas-Vazquez Damian , Rodriguez-Garcia Mario E.
Published: December 2011

Bones are the support of the body. They are composed of many inorganic compounds and other organic materials that all together can be used to determine the mineral density of the bones. The bone mineral density is a measure index that is widely used as an indicator of the health of the bone. A typical manner to evaluate the quality of the bone is a densitometry study; a dual x-ray absorptiometry system based study that has been widely used to assess the mineral density of some animals’ bones. However, despite the success stories of utilizing these systems in many different applications, it is a very expensive method that requires frequent calibration processes to work properly. Moreover, its usage in small species applications (e.g., rodents) has not been quite demonstrated yet. Following this argument, it is suggested that there is a need for an instrument that would perform such a task in a more reliable and economical manner. Therefore, in this paper we explore the possibility to develop a new, affordable, and reliable single x-ray absorptiometry system. The method consists of utilizing a single x-ray source, an x-ray image sensor, and a computer platform that all together, as a whole, will allow us to calculate the mineral density of the bone. Utilizing an x-ray transmission theory modified through a version of the Lambert-Beer law equation, a law that expresses the relationship among the energy absorbed, the thickness, and the absorption coefficient of the sample at the x-rays wavelength to calculate the mineral density of the bone can be advantageous. Having determined the parameter equation that defines the ratio of the pixels in radiographies and the bone mineral density [measured in mass per unit of area (g/cm2)], we demonstrated the utility of our novel methodology by calculating the mineral density of Wistar rats’ femur bones.
Ultraviolet-vacuum ultraviolet photoluminescence and x ray radioluminescence of Ce3+-doped Ba3MgSi2O8
Authors: Ding Xuemei , Liang Hongbin , Hou Dejian , Su Qiang , Dorenbos Pieter , Sun Shuaishuai , Tao Ye
Published: December 2011

Ce3+-doped Ba3MgSi2O8 phosphors were prepared by a solid-state reaction route. The photoluminescence properties in the vacuum ultraviolet-vis spectral range and the x ray excited radioluminescence were investigated. Ce3+ ions were found to enter three different sites in the host lattice. Five excitation bands and two emission bands of Ce(1)3+ centers were observed in the spectra. For Ce(2)3+ and Ce(3)3+ centers, the lowest 5d excitation bands and the emission bands were determined. The light yields of samples under x ray excitation were estimated by comparing the integrated emission intensities of our samples with that of BaF2.
Dielectric relaxation and alternating current conductivity of polyvinylidene fluoride doped with lanthanum chloride
Authors: Hassen A. , Hanafy T. , El-Sayed S. , Himanshu A.
Published: December 2011

X-ray diffraction (XRD), dielectric constant (ɛ′), dielectric loss factor (ɛ″), and ac conductivity (σac) of pure and LaCl3-doped polyvinylidene fluoride (PVDF) have been carried out. The dielectric properties have been studied in the temperature and frequency ranges; 140–450 K and 0.1−1000 kHz, respectively. XRD results reveal that pure and LaCl3-PVDF samples are in the α-phase. The incorporation of La3+ ions within the PVDF polymer matrix forms complexes which reduce the order structure of PVDF. Three relaxation processes, namely; ρ, αa, and αc were observed for pure PVDF. The first relaxation can be explained based on space charge formation or Maxwell-Wagner polarization. The second one occurs around the glass transition temperature, Tg, and is related to the micro-Brownian motion of the main polymer chain. It becomes broad and shifted to higher temperatures with the doping of LaCl3. The third process appears below the melting temperature of PVDF and can be attributed to molecular motions of the main polymer chain. The behavior of the ac conductivity shows that the conduction mechanism of pure, 5 wt. % and 10 wt. % of LaCl3-doped PVDF samples is follows the correlated barrier hopping (CBH) model, while 3 wt. % of LaCl3-doped PVDF exhibits a small polaron tunneling (SPT) conduction.
Control of ferromagnetism at room temperature in (Ti,Co)O2−δ via chemical doping of electron carriers
Authors: Yamada Y. , Fukumura T. , Ueno K. , Kawasaki M.
Published: December 2011

Ferromagnetism at room temperature in (Ti,Co)O2 − δ was controlled by changing its electron density via chemical doping, where the oxygen vacancy δ served as an electron donor. With increasing the electron density, the ferromagnetic anomalous Hall effect and magnetization emerged from a paramagnetic state, while undergoing an insulator to metal transition. This result supports that the electron carriers mediated the ferromagnetic exchange interaction and is consistent with the electric field effect study on the ferromagnetism recently reported [Y. Yamada, K. Ueno, T. Fukumura, H. T. Yuan, H. Shimotani, Y. Iwasa, L. Gu, S. Tsukimoto, Y. Ikuhara, and M. Kawasaki, Science 332, 1065 (2011)].
High performance single In2Se3 nanowire photodetector
Authors: Li Q. L. , Li Y. , Gao J. , Wang S. D. , Sun X. H.
Published: December 2011

The single indium selenide (In2Se3) nanowire photodetectors were fabricated, and the performance characteristics of the nanowire devices were systematically investigated. The single In2Se3 nanowire photodetectors show high and stable photoresponse in wide light wavelength (254-800 nm) and temperature range (7-300 K). The spectra response indicates that the absorption coefficient of the In2Se3 nanowires at certain wavelength dominates the performance of the devices. The good linearity of the photocurrents with the incident irradiation over a wide wavelength range has been obtained, demonstrating that the In2Se3 nanowire photodetectors work in a typical light-dependent resistor mode.
Low-operating voltage and stable organic field-effect transistors with poly (methyl methacrylate) gate dielectric solution deposited from a high dipole moment solvent
Authors: Ukah N. B. , Granstrom J. , Sanganna Gari R. R. , King G. M. , Guha S.
Published: December 2011

A low-operating voltage and stable pentacene field-effect transistor (FET) employing thin low-dielectric constant gate layer of poly (methyl methacrylate) (PMMA) dissolved in propylene carbonate (PC) has been realized. This device exhibiting high field-effect mobility, a threshold voltage of −1 V, and a small sub-threshold slope at operating voltages below −3 V is compared with an FET cast from PMMA film dissolved in a low dipole moment solvent. The negligible hysteresis and excellent electrical stability of FETs under gate bias stress with the use of PC are traceable to the low density of trap states in PMMA bulk and at the interfaces.
Electromechanical stability in charge-controlled dielectric elastomer actuation
Authors: Li Bo , Zhou Jinxiong , Chen Hualing
Published: December 2011

Deformation of dielectric elastomer under a voltage load is large but is limited by the pull-in instability. A recent experiment showed that by spraying charges on the dielectric, a large deformation is obtained without pull-in. We propose a thermodynamic model to describe the electromechanical stability of charge-controlled actuation, with particular emphasis on the electrostatic energy created by constant charges and its coupling with the deformation. We examine the electrostatic stress induced by charges and compare it with the Maxwell stress. The mechanism in the stabilization when spraying charges is interpreted and is different from the previous conclusion on strain-stiffening.
Accounting for China's Import Growth: A Structural Decomposition for 1997–2005
Authors: Pei Jiansuo , Dietzenbacher Erik , Oosterhaven Jan , Yang Cuihong
Published: December 2011

This paper applies structural decomposition analysis to Chinese input–output tables in order to disentangle and quantify the sources of China's import growth and China's growth in vertical specialization: that is, China's incorporation into the global supply chain. China's exports and the role of processing trade therein have increased substantially in the last decade. Yet, they account for only one third of China's import growth from 1997 to 2005. Instead, the volume growth of China's domestic final demand is found to be most important. Moreover, compared with other countries, the structural change in input–output coefficients and in the commodity composition of domestic final demand turns out to be surprisingly important. Looking only at vertical specialization, it is concluded that more than half of its growth, from 21% in 1997 to 30% in 2005, is due to the growth of China's import ratios.
Synthesis and X-Ray Crystal Structure of Cynandione B Analogues
Authors: Hong Lisa P. T. , White Jonathan M. , Donner Christopher D.
Published: December 2011

The synthesis of analogues of cynandione B, a phenolic acetophenone from Cynanchum taiwanianum, is described. The one-step conversion of benzochromenones to the heptacyclic spiroacetal core of cynandione B using methylmagnesium bromide is investigated and structural requirements for this novel transformation established. X-ray crystal structure analysis has established the relative configuration in these unusual heterocycles.
A regional analysis of contraction rate in written Standard American English
Authors: Grieve Jack
Published: December 2011

The goal of this study is to determine if various measures of contraction rate are regionally patterned in written Standard American English. In order to answer this question, this study employs a corpus-based approach to data collection and a statistical approach to data analysis. Based on a spatial autocorrelation analysis of the values of eleven measures of contraction across a 25 million word corpus of letters to the editor representing the language of 200 cities from across the contiguous United States, two primary regional patterns were identified: easterners tend to produce relatively few standard contractions (not contraction, verb contraction) compared to westerners, and northeasterners tend to produce relatively few non-standard contractions (to contraction, non-standard not contraction) compared to southeasterners. These findings demonstrate that regional linguistic variation exists in written Standard American English and that regional linguistic variation is more common than is generally assumed.
Exploring the effect of regulatory focus on ad attitudes: The moderating roles of message sidedness and argument quality
Authors: Kao Danny Tengti
Published: December 2011

This research explores the interaction effects of message sidedness and argument quality of ads on how either promotion‐focused or prevention‐focused individuals engender their ad attitudes. Two hundred and forty undergraduates were randomly assigned to a 2 (regulatory focus: prevention‐focus/promotion‐focus) × 2 (message sidedness: one‐sided messages/two‐sided messages) × 2 (argument quality (AQ): weak/strong) between‐subjects design. Results indicate that promotion‐focused individuals tend to engender more favourable attitudes to weak AQ ads than strong AQ ads, whereas prevention‐focused individuals tend to engender more favourable attitudes to strong AQ ads than weak AQ ads. In addition, results indicate more favourable attitudes for one‐sided messages over two‐sided messages for promotion‐focused individuals, as well as more favourable attitudes for two‐sided messages over one‐sided messages for prevention‐focused individuals. Furthermore, one‐sided messages result in more favourable ad attitudes when linked with weak AQ for promotion‐focused individuals; in contrast, two‐sided messages elicit more favourable ad attitudes when linked with strong AQ for prevention‐focused individuals. Results suggest that message sidedness and argument quality are closely related to regulatory focus, which has a direct impact on ad attitudes. Practical implications, theoretical contributions, limitations and directions for future research are discussed.
Transformative shifts in art history teaching: the impact of standards‐based assessment
Authors: Ormond Barbara
Published: December 2011

This article examines pedagogical shifts in art history teaching that have developed as a response to the implementation of a standards‐based assessment regime. The specific characteristics of art history standards‐based assessment in the context of New Zealand secondary schools are explained to demonstrate how an exacting form of assessment has led teachers to transform their practices to target precise assessment outcomes. The article also examines the complexities of facilitating effective learning for a skills‐focused assessment programme alongside an existing and demanding art history content prescription, and discusses how assessment has, unintentionally, created shifts in the knowledge expectations of both students and teachers. Learning activities are included to illustrate how a high level of precision in alignment between assessment and pedagogy has the potential to enhance understanding in relation to standards‐based achievement.
Hardiness and anxiety interpretation: An investigation into coping usage and effectiveness
Authors: Hanton Sheldon , Neil Richard , Evans Lynne
Published: December 2011

The purpose of this study was to examine the interactive effects of hardiness (high vs. low hardiness) and anxiety direction (facilitators vs. debilitators) on performers' competitive anxiety intensity responses, self‐confidence levels and the frequency and effectiveness of coping usage. Significant interaction effects showed that the high hardiness/facilitators reported the greatest use of planning, active coping and effort strategies during stressful competitive situations and viewed this use as more effective in dealing with these situations than the other groups. Main effects for hardiness on the competitive anxiety response and self‐confidence revealed the high hardiness group to have lower levels of worry and somatic anxiety and higher levels of self‐confidence than the low hardiness group. These findings have important implications for the development of hardiness‐related coping strategies in sport performers.
Gummed-Up Memory: Chewing Gum Impairs Short-Term Recall
Authors: Kozlov Michail D. , Hughes Robert W. , Jones Dylan M.
Published: December 2011

Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal–articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity. Experiment 3 demonstrated that manual tapping produces a similar pattern of impairment to that of chewing gum. These results clearly qualify the assertion that chewing gum improves short-term memory. They also pose a problem for short-term memory theories asserting that forgetting is based on domain-specific interference given that chewing does not interfere with verbal memory any more than tapping. It is suggested that tapping and chewing reduce the general capacity to process sequences.
Response-level probability effects on reaction time: Now you see them, now you don't
Authors: Katzner Steffen , Miller Jeff
Published: December 2011

Many reaction time (RT) experiments have tested for response-level probability effects. Their results have been mixed, which is surprising because psychophysiological studies provide clear evidence of motor-level changes associated with an anticipated response. A survey of the designs used in the RT studies reveals many potential problems that could conceal the effects of response probability. We report five new RT experiments testing for response-level probability effects with the most promising of the previous designs—that of Blackman (1972)—and with new designs. Some of these experiments yield evidence of response-level probability effects, but others do not. It appears that response-level probability effects are present primarily in simple tasks with a strong emphasis on response preparation, possibly because participants only expend effort on response preparation in these tasks.
Distinct intracellular motifs of Delta mediate its ubiquitylation and activation by Mindbomb1 and Neuralized
Authors: Daskalaki Aikaterini , Shalaby Nevine A. , Kux Kristina , Tsoumpekos Giorgos , Tsibidis George D. , Muskavitch Marc A.T. , Delidakis Christos
Published: December 2011

DSL proteins are transmembrane ligands of the Notch receptor. They associate with a RING (really interesting new gene) family E3 ubiquitin ligase, either Neuralized (Neur) or Mindbomb 1 (Mib1), as a prerequisite to signaling. Although Neur and Mib1 stimulate internalization of DSL ligands, it is not known how ubiquitylation contributes to signaling. We present a molecular dissection of the intracellular domain (ICD) of Drosophila melanogaster Delta (Dl), a prototype DSL protein. Using a cell-based assay, we detected ubiquitylation of Dl by both Neur and Mib1. The two enzymes use distinct docking sites and displayed different acceptor lysine preferences on the Dl ICD. We generated Dl variants that selectively perturb its interactions with Neur or Mib1 and analyzed their signaling activity in two in vivo contexts. We found an excellent correlation between the ability to undergo ubiquitylation and signaling. Therefore, ubiquitylation of the DSL ICD seems to be a necessary step in the activation of Notch.
Lipid traffic: Osh4p makes an unexpected exchange
Authors: Levine Tim P.
Published: December 2011

A new study in this issue (De Saint-Jean et al. 2011. J. Cell Biol. http://dx.doi.org/jcb.201104062) reveals that the sterol transfer protein Osh4p can also transport the signaling phospholipid phosphatidylinositol 4-phosphate (PI(4)P), which binds to the same site in Osh4p as sterol. This finding helps explain some previously published studies and also indicates that lipid/sterol exchange could contribute to establishing a sterol gradient in cells.
Disentangling viscosity and hysteretic dissipative components in dynamic nanoscale interactions
Authors: Gadelrab Karim R , Santos Sergio , Souier Tewfik , Chiesa Matteo
Published: December 2011

The mechanisms through which energy is dissipated in nanoscale dynamic interactions might involve tens or hundreds of atoms and might be diverse. Here, a method is presented that provides the means to disentangle, with the use of common experimental parameters, short and long range viscosity and hysteretic dissipative components. While the approach is general, the experimental study is directed to show the mechanisms of energy dissipation between a silicon atomic force microscope tip and a carbon nanotube and a quartz surface. By stabilizing the tip in situ, quantitative information is found in a reproducible manner where the magnitude of energy dissipated remains constant in experiments thus allowing comparative studies.
Alcohol consumption and the intention to engage in unprotected sex: systematic review and meta‐analysis of experimental studies
Authors: Rehm Jürgen , Shield Kevin D. , Joharchi Narges , Shuper Paul A.
Published: December 2011

Aims  To review and analyse in experimentally controlled studies the impact of alcohol consumption on intentions to engage in unprotected sex. To draw conclusions with respect to the question of whether alcohol has an independent effect on the incidence of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs).

Methods  A systematic review and meta‐analysis of randomized controlled studies examined the association between blood alcohol content (BAC) and self‐perceived likelihood of using a condom during intercourse. The systematic review and meta‐analysis were conducted according to internationally standardized protocols (Preferred Reporting Items for Systematic Reviews and Meta‐Analyses: PRISMA). The meta‐analysis included an estimate of the dose–response effect, tests for publication bias and sensitivity analyses.

Results  Of the 12 studies included in the quantitative synthesis, our pooled analysis indicated that an increase in BAC of 0.1 mg/ml resulted in an increase of 5.0% (95% CI: 2.8–7.1%) in the indicated likelihood (indicated by a Likert scale) of engaging in unprotected sex. After adjusting for potential publication bias, this estimate dropped to 2.9% (95% CI: 2.0–3.9%). Thus, the larger the alcohol intake and the subsequent level of BAC, the higher the intentions to engage in unsafe sex. The main results were homogeneous, persisted in sensitivity analyses and after correction for publication bias.

Conclusions  Alcohol use is an independent risk factor for intentions to engage in unprotected sex, and as risky sex intentions have been shown to be linked to actual risk behavior, the role of alcohol consumption in the transmission of HIV and other STIs may be of public health importance.
Serine protease Per a 10 from Periplaneta americana bias dendritic cells towards type 2 by upregulating CD86 and low IL‐12 secretions
Authors: Goel C. , Govindaraj D. , Singh B. P. , Farooque A. , Kalra N. , Arora N.
Published: December 2011

Background

Serine protease activity of Per a 10 from Periplaneta americana induces airway inflammation and systemic Th2 response towards self and bystander allergen.

Objective

In the present study the effect of proteolytic activity of Per a 10 allergen on dendritic cells (DCs) polarization and consequent T cell response was investigated.

Methods

Non‐atopic subjects with no family history of asthma/allergy were recruited for the study. CD14+ peripheral blood monocytes were purified, differentiated to immature DCs and stimulated with proteolytically active/inactivated native or recombinant Per a 10. DCs phenotype was analysed with flow cytometry and antigen presenting function assessed by co‐culturing with autologous CD4+ T cells. Cytokine levels were determined using ELISA.

Results

Immature DCs differentiated into mature CD14‐CD83+HLA‐DR+ cells after incubating with proteolytically active/inactivated or recombinant Per a 10. Proteolytically active Per a 10 induced significant CD86 up‐regulation on DCs compared to inactivated or recombinant Per a 10 lacking enzymatic activity. Proteolytic activity of Per a 10 showed dose‐dependent effect on expression of CD80, CD86, CD83, CD1a and HLA‐DR. However, no significant differences were observed phenotypically in active or inactive forms except for CD86. Active Per a 10 stimulated DCs secreted significantly low IL‐12 (P < 0.01) and high IL‐6, compared to inactive forms of Per a 10. Naive CD4+ T cells primed with active Per a 10 pulsed DCs also secreted significantly less IL‐12 (P < 0.01) and high IL‐4, IL‐5 plus IL‐6 (P < 0.01); in contrast to DCs pulsed with inactivated or recombinant Per a 10.

Conclusion and clinical relevance

Proteolytic activity of Per a 10 modulates DCs towards type 2 by CD86 up‐regulation, high IL‐6 and reduced IL‐12 secretions. Proteolytically inactive Per a 10 can be further explored for immunotherapy.