bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of mask patterns in fabrication of Si nanotip arrays
Authors: Cho Si‐Hyeong , Lee Jung‐Hwan , Park Jin‐Goo
Published: March 2013

Different shapes of silicon (Si) nanotip arrays using reactive ion etching with various mask patterns were fabricated, and the surface profile, surface roughness and quantitative etch characteristics of the Si nanotip were characterised. It was found that the geometry as well as etch characteristics of Si nanotip arrays could be modified by changing the initial mask patterns. Pyramidal and conical shaped Si nanotips could be obtained from square and circular mask patterns, respectively. The alternate square array pattern resulted in a Si nanotip with a wavy array whereas the honeycomb mask pattern resulted in a Si nanotip in a hexagonal array. In terms of etch rate, the circular pattern mask showed faster etching than the square patterns. Also, the parallel pattern showed faster etching than the alternate pattern under the same conditions. The tip size and height of Si nanotip structures determined by atomic force microscopy measurement were in the range of 50–80 and 450–750 nm, respectively.
An AFM/STM multi‐mode nanofabrication approach allowing in situ surface modification and characterisation
Authors: Hu Weihua , Bain J. , Ricketts D.
Published: March 2013

A report is presented on a new multi‐mode nanofabrication method that uses a compliant conductive atomic force microscope (AFM) probe for both AFM and scanning tunnelling microscope (STM) operation and it is demonstrated that these modes can be switched ‘on‐the‐fly’ during the measurement or fabrication of nanostructures. The authors oxidised Ti with the same conductive AFM probe in AFM and STM modes, alternately in a continuous writing step. An in‐plane Ti–TiOx–Ti junction was fabricated by combining AFM and STM modes and electrically characterised by taking current images in conductive AFM mode. After measurement, additional features were written to increase the electrical isolation, thus realising in situ nanoscale modification.
The effects of capillary forces on the axisymmetric propagation of two-phase, constant-flux gravity currents in porous media
Authors: Golding Madeleine J. , Huppert Herbert E. , Neufeld Jerome A.
Published: March 2013

The effects of capillary forces on the propagation of two-phase, constant-flux gravity currents in a porous medium are studied analytically and numerically in an axisymmetric geometry. The fluid within a two-phase current generally only partially saturates the pore space it invades. For long, thin currents, the saturation distribution is set by the vertical balance between gravitational and capillary forces. The capillary pressure and relative permeability of the fluid in the current depend on this saturation. The action of capillary forces reduces the average saturation, thereby decreasing the relative permeability throughout the current. This results in a thicker current, which provides a steeper gradient to drive flow, and a more blunt-nose profile. The relative strength of gravity and capillary forces remains constant within a two-phase gravity current fed by a constant flux and spreading radially, due to mass conservation. For this reason, we use an axisymmetric representation of the framework developed by Golding et al. [“Two-phase gravity currents in porous media,” J. Fluid Mech. 678, 248–270 (2011)]10.1017/jfm.2011.110, to investigate the effect on propagation of varying the magnitude of capillary forces and the pore-size distribution. Scaling analysis indicates that axisymmetric two-phase gravity currents fed by a constant flux propagate like t1/2, similar to their single-phase counterparts [S. Lyle, H. E. Huppert, M. Hallworth, M. Bickle, and A. Chadwick, “Axisymmetric gravity currents in a porous medium,” J. Fluid Mech. 543, 293–302 (2005)]10.1017/S0022112005006713, with the effects of capillary forces encapsulated in the constant of proportionality. As a practical application of our new concepts and quantitative evaluations, we discuss the implications of our results for the process of carbon dioxide (CO2) sequestration, during which gravity currents consisting of supercritical CO2 propagate in rock saturated with aqueous brine. We apply our two-phase model including capillary forces to quantitatively assess seismic images of CO2 spreading at Sleipner underneath the North Sea.
Optimal volume Wegner estimate for random magnetic Laplacians on ${\mathbb {Z}}^2$Z2
Authors: Hasler David , Luckett Daniel
Published: March 2013

We consider a two dimensional magnetic Schrödinger operator on a square lattice with a spatially stationary random magnetic field. We prove a Wegner estimate with optimal volume dependence. The Wegner estimate holds around the spectral edges, and it implies Hölder continuity of the integrated density of states in this region. The proof is based on the Wegner estimate obtained in Erdős and Hasler [“Wegner estimate for random magnetic Laplacians on ${\mathbb {Z}}^2$Z2,” Ann. Henri Poincaré 12, 1719–1731 (2012)]10.1007/s00023-012-0177-9.
Diffusion, thermal diffusion, and Soret coefficients and optical contrast factors of the binary mixtures of dodecane, isobutylbenzene, and 1,2,3,4-tetrahydronaphthalene
Authors: Gebhardt M. , Köhler W. , Mialdun A. , Yasnou V. , Shevtsova V.
Published: March 2013

We have measured the Soret (ST), diffusion (D), and thermal diffusion (DT) coefficients of the three binary benchmark mixtures of dodecane (C12), isobutylbenzene, and 1,2,3,4-tetrahydronaphthalene at T = 25°C for at least five different concentrations each, covering the entire binary composition range. The two different optical techniques employed, optical beam deflection and optical digital interferometry, are in good to excellent agreement. Additionally, we have carefully measured the optical contrast factors (∂n/∂c)p, T and (∂n/∂T)p, c. If the temperature and composition dependence of the mixture density is taken into account, both the Lorentz-Lorenz (LL) and the Looyenga (LO) equations give reasonable predictions of (∂n/∂c)p, T. In case of (∂n/∂T)p, c, only the LO equation yields good predictions in case of constant molecular polarizabilities αi of the pure compounds. If the apparent temperature dependence of αi is explicitly taken into account, excellent predictions are obtained both from the LL and the LO equations.
Alloying-related trends from first principles: An application to the Ti–Al–X–N system
Authors: Holec David , Zhou Liangcai , Rachbauer Richard , Mayrhofer Paul H.
Published: March 2013

Tailoring and improving material properties by alloying is a long-known and used concept. Recent research has demonstrated the potential of ab initio calculations in understanding the material properties at the nanoscale. Here, we present a systematic overview of alloying trends when early transition metals (Y, Zr, Nb, Hf, and Ta) are added in the Ti1−xAlxN system, routinely used as a protective hard coating. The alloy lattice parameters tend to be larger than the corresponding linearised Vegard's estimation, with the largest deviation more than 2.5% obtained for Y0.5Al0.5N. The chemical strengthening is most pronounced for Ta and Nb, although also causing smallest elastic distortions of the lattice due to their atomic radii being comparable with Ti and Al. This is further supported by the analysis of the electronic density of states. Finally, mixing enthalpy as a measure of the driving force for decomposition into the stable constituents is enhanced by adding Y, Zr, and Nb, suggesting that the onset of spinodal decomposition will appear in these cases for lower thermal loads than for Hf and Ta alloyed Ti1−xAlxN.
Phase transition of ferroelectric (LixNa1−x)NbO3 films with 0 ≤ x ≤ 0.13 by applying an electric field
Authors: Kohori Akihiro , Yamazoe Seiji , Imai Takahito , Adachi Hideaki , Wada Takahiro
Published: March 2013

We fabricated 001-oriented (LixNa1−x)NbO3 (LNN) films with 0 ≤ x ≤ 0.13 on (001)SrTiO3 substrates by pulsed laser deposition. From the structural and electrical studies, we found that the crystal structure of the LNN film changed by applying an electric field, and the newly formed metastable phases did not return to the original phase. The ferroelectric properties were drastically changed by the phase transition induced by applying electric field. The induced metastable phase returned to the initial phase by heating. Finally, we first determined the phase relation in the LNN film between applying electric field and chemical composition (Li content, x).
Magnetic control of relaxor features in BaZr0.5Ti0.5O3 and CoFe2O4 composite
Authors: Usman Muhammad , Mumtaz Arif , Raoof Sobia , Hasanain S. K.
Published: March 2013

We report the effect of magnetic field on the dielectric response in a relaxor ferroelectric and ferromagnetic composite (BaZr0.5Ti0.5O3)0.65-(CoFe2O4)0.35. Relaxor characteristics such as dielectric peak temperature and activation energy show a dependence on applied magnetic fields. This is explained in terms of increasing magnetic field induced frustration of the polar nanoregions comprising the relaxor. The results are also consistent with the mean field formalism of dipolar glasses. It is found that the variation of the spin glass order parameter q(T) is consistent with increased frustration and earlier blocking of nanopolar regions with increasing magnetic field.
Magnetism and multiplets in metal-phthalocyanine molecules
Authors: Kitaoka Y. , Sakai T. , Nakamura K. , Akiyama T. , Ito T.
Published: March 2013

Magnetism and multiplets for metal-phthalocyanine (MPc) molecules with transition-metals (M) of Mn and Co were investigated based on the constraint density functional theory calculations by imposing density matrix constraint on the d-orbital occupation numbers. For the MnPc, the ground state is found to be the 4Eg state with the perpendicular magnetic anisotropy with respect to the molecular plane, while for the CoPc, the ground state is the 2A1g state with a planar magnetic anisotropy.
Traveling wave current drive theory for an arbitrary m-polar configuration
Authors: Duarte V. N. , Clemente R. A. , Farengo R.
Published: March 2013

An extension of the formalism employed to describe current drive in magnetized plasmas by means of traveling magnetic fields (or double-helix configuration) is presented. In all previous theoretical studies, only driving fields with dipolar topology have been employed and the figure of merit of the current drive mechanism has never been analyzed in terms of the dissipation in the power feeding circuit. In this paper, we show how to express the model equations in terms of the current amplitude in the coils, for an arbitrary number of equally spaced coils wound around the plasma column. We present a brief review of the existing theory and a theoretical formulation, valid for an arbitrary m-polar helical symmetry, which removes the above mentioned complications and limitations. In the limit of straight coils, our magnetic field expression agrees exactly with well-established results of the literature for rotating magnetic field current drive. Finally, we present initial numerical results from a recently developed code which consistently compares the steady driven nonlinear Hall currents and steady fields, corresponding to different configurations in terms of the Ohmic dissipation in the helical coils and discuss future perspectives.
Theoretical modeling of the complexes of iron impurities and oxygen vacancies in SrTiO3
Authors: Blokhin Evgeny , Kotomin Eugene , Kuzmin Alexei , Purans Juris , Evarestov Robert , Maier Joachim
Published: March 2013

The combined use of ab initio quantum mechanical and x-ray absorption near edge structure (XANES) methods confirms that the oxygen vacancies (VO) are located in the first coordination shell of Fe3+ ions in the cathodic region of electrocolored Fe3+-doped SrTiO3. The binding energy of such a complex is estimated as ∼0.4 eV. The lattice distortions obtained in ab initio modeling and extended x-ray absorption fine structure experiments are in agreement. The predicted distortions make a minor effect on a simulated XANES signal, and its shape mainly depends on the presence of VO in the Fe3+ first coordination shell. Additionally, formation of the Fe3+–VO complex leads to disappearance of the phonon frequencies in the range of 620–760 cm−1 of the calculated phonon spectrum.
Note: Detecting flow velocity with high purity semiconducting single-walled carbon nanotubes
Authors: Lee Seungho , Jung Wonsuk , Woo Ju Yeon , Kim Soohyun , Han Chang-Soo
Published: March 2013

We report the measurement of fluid velocity on a semiconducting single-walled carbon nanotubes film in a microfluidic channel. To investigate the mechanism related to electrical signal change, we performed various experiments along with changing the flow velocity, the ion concentration and liquid viscosity, etc. Our result suggests that the sensing of flow velocity is a closely related to a pulsating asymmetrical thermal ratchet model. The electric signal change was strongly dependent on the electrode alignment, and the channel width of the sample. As the result, we achieved highly sensitive detection of the fluid, roughly 4 times greater than previous results.
Development of stress-induced curved actuators for a tunable THz filter based on double split-ring resonators
Authors: Lin Yu-Sheng , Qian You , Ma Fusheng , Liu Zhen , Kropelnicki Piotr , Lee Chengkuo
Published: March 2013

Using stress-induced curved cantilevers to form double split-ring resonator (DSRR) in three-dimensional configuration, an electrically tunable microelectromechanical system (MEMS) based out-of-plane metamaterials THz filter is experimentally demonstrated and characterized. While the achieved tunable range for the resonant frequency is 0.5 THz at 20 V bias, quality factor of the resonant frequency is improved as well. This MEMS based THz filter using released DSRR structures shows its potential in tunable metamaterials applications such as sensors, optical switches, and filters.
Power transmission and group delay in gain-assisted plasmon-induced transparency
Authors: Deng Zi-Lan , Dong Jian-Wen , Wang He-Zhou , Cheng S. H. , Li Jensen
Published: March 2013

A gain-assisted plasmonic waveguide with two detuned resonators is investigated in the plasmon-induced transparency window. Phase map is employed to study power transmittance and group delay for varying gain coefficients and frequency detunings of the two resonators. The gain coefficient for lasing oscillation condition is analytically shown to vary quadratically with the frequency detuning. In the amplification regime below the lasing threshold, the spectrum implies not only large group delay, but also high transmittance and narrow linewidth. This is in contrast to those in the loss-compensation regime and the passive case in which there always exists a trade-off between the linewidth and the peak transmittance.
Bias stress effect in polyelectrolyte-gated organic field-effect transistors
Authors: Sinno H. , Fabiano S. , Crispin X. , Berggren M. , Engquist I.
Published: March 2013

A main factor contributing to bias stress instability in organic transistors is charge trapping of mobile carriers near the gate insulator-semiconductor interface into localized electronic states. In this paper, we study the bias stress behavior in low-voltage (p-type) polyelectrolyte-gated organic field effect transistors (EGOFETs) at various temperatures. Stressing and recovery in these EGOFETs are found to occur six orders of magntiude faster than typical bias stress/recovery reported for dielectric-gated OFETs. The mechanism proposed for EGOFETs involves an electron transfer reaction between water and the charged semiconductor channel that promotes the creation of extra protons diffusing into the polyelectrolyte.
Ewe nutrition during pregnancy and birthweight of lambs has minimal impact on fat and eye muscle depth in Merino progeny
Authors: Paganoni B. L. , Oldham C. M. , Ferguson M. B. , Thompson A. N. , Vercoe P. E. , Gordon D. G.
Published: March 2013

The hypothesis tested in this experiment was that Merino lambs with lower birthweights, due to poor ewe nutrition during pregnancy, would have more fat and less muscle than Merino lambs with higher birthweights. At two sites (Victoria and Western Australia) in each of 2 years, a wide range in the liveweight profiles of ewes was generated during pregnancy and lactation by varying the amount of supplements fed and feed on offer grazed. Progeny had fat and muscle depth at the C-site measured at various ages from 8 to 28 months of age. Across the four experiments, there were differences of 0.5 kg in birthweights and 8 kg in weaning weights between extreme treatments. The effects on the depth of fat and muscle were very small with fat depth increasing by 0.1–0.2 mm (5–7%) and muscle depth increasing by 0.2–0.7 mm (1–3%) when birthweights decreased by 1 kg. The effects of birthweight on fat depth are consistent with our hypothesis whereas the effects of birthweight on muscle depth are in contrast to our hypothesis. Nevertheless, the impacts of birthweight on the depth of fat and muscle measured at the C-site of progeny from Merino ewes, is unlikely to be of any commercial significance within the range of nutritional scenarios during pregnancy and lactation that are likely to be experienced within the Australian sheep industry.
Immunosympathectomy as the first phenotypic knockout with antibodies
Authors: Cattaneo Antonino
Published: March 2013

In a PNAS Classic Article published in 1960, Rita Levi-Montalcini offered formal and conclusive proof that endogenous NGF was responsible for the survival of sympathetic neurons in vivo. Thus ended an experimental tour de force lasting a decade, starting with the demonstration that a humoral factor, produced from a tumor transplanted in a chicken embryo, was responsible for stimulating outgrowth of nerve fibers from sympathetic and sensory neurons. From a more general methodological point of view, this work provided a breakthrough in the quest to achieve targeted loss of function and experimentally validate the function of biological molecules. Finally, this work provided an example of the ablation of a specific neuronal subpopulation in an otherwise intact nervous system, an immunological knife of unsurpassed effectiveness and precision. The novelty and the importance of the PNAS Classic Article is discussed here, collocating it within the context of the particular moment of the NGF discovery saga, of Rita Levi-Montalcini's scientific and academic career, and of the general scientific context of those years. This seminal work, involving the use of antibodies for phenotypic knockout in vivo, planted seeds that were to bear new fruit many years later with the advent of monoclonal antibodies and recombinant antibody technologies.
Integrin-dependent force transmission to the extracellular matrix by α-actinin triggers adhesion maturation
Authors: Roca-Cusachs Pere , del Rio Armando , Puklin-Faucher Eileen , Gauthier Nils C. , Biais Nicolas , Sheetz Michael P.
Published: March 2013

Significance

Mechanical forces transmitted between a cell and its surrounding extracellular matrix determine functions like proliferation or differentiation, and drive processes in development, tumorigenesis, and wound healing. However, the molecules involved in this force transmission remain unclear. Here we show that forces exerted by cells are transmitted to the extracellular matrix through α-actinin molecules via the transmembrane protein integrins. Furthermore, this transmission enables the growth and maturation of adhesion sites to the matrix, and takes place in competition with another molecule submitted to force, talin. This force regulation mechanism may help us understand the role of force in different biological scenarios.
Biological Consequences of the Coaster Brook Trout Restoration Stocking Program in Lake Superior Tributaries within Pictured Rocks National Lakeshore
Authors: Leonard Jill B. K. , Stott Wendylee , Loope Delora M. , Kusnierz Paul C. , Sreenivasan Ashwin
Published: March 2013

The coaster Brook Trout Salvelinus fontinalis is a Lake Superior ecotype representing intraspecific variation that has been impacted by habitat loss and overfishing. Hatchery strains of Brook Trout derived from populations in Lake Superior were stocked into streams within Pictured Rocks National Lakeshore, Michigan, as part of an effort to rehabilitate adfluvial coaster Brook Trout. Wild and hatchery Brook Trout from three streams (Mosquito River, Hurricane River, and Sevenmile Creek) were examined for movement behavior, size, physiology, and reproductive success. Behavior and size of the stocked fish were similar to those of wild fish, and less than 15% of the stocked, tagged Brook Trout emigrated from the river into which they were stocked. There was little evidence of successful reproduction by stocked Brook Trout. Similar to the results of other studies, our findings suggest that the stocking of nonlocal Brook Trout strains where a local population already exists results in limited natural reproduction and should be avoided, particularly if the mechanisms governing the ecotype of interest are poorly understood.

Received April 1, 2012; accepted November 26, 2012
Bigenomic transcriptional regulation of all thirteen cytochrome c oxidase subunit genes by specificity protein 1
Authors: Dhar Shilpa S. , Johar Kaid , Wong-Riley Margaret T. T.
Published: March 2013

Cytochrome c oxidase (COX) is one of only four known bigenomic proteins, with three mitochondria-encoded subunits and 10 nucleus-encoded ones derived from nine different chromosomes. The mechanism of regulating this multi-subunit, bigenomic enzyme is not fully understood. We hypothesize that specificity protein 1 (Sp1) functionally regulates the 10 nucleus-encoded
COX
subunit genes directly and the three mitochondrial
COX
subunit genes indirectly by regulating mitochondrial transcription factors A and B (
TFAM
,
TFB1M
and
TFB2M
) in neurons. By means of
in silico
analysis, electrophoretic mobility shift and supershift assays, chromatin immunoprecipitation, RNA interference and over-expression experiments, the present study documents that Sp1 is a critical regulator of all 13
COX
subunit genes in neurons. This regulation is intimately associated with neuronal activity. Silencing of Sp1 prevented the upregulation of all
COX
subunits by KCl, and over-expressing Sp1 rescued all
COX
subunits from being downregulated by tetrodotoxin. Thus, Sp1 and our previously described nuclear respiratory factors 1 and 2 are the three key regulators of all 13
COX
subunit genes in neurons. The binding sites for Sp1 on all 10 nucleus-encoded
COX
subunits,
TFAM
,
TFB1M
and
TFB2M
are highly conserved among mice, rats and humans.
Characterization of a novel flavivirus isolated from Culex (Melanoconion) ocossa mosquitoes from Iquitos, Peru
Authors: Evangelista Julio , Cruz Cristhopher , Guevara Carolina , Astete Helvio , Carey Cristiam , Kochel Tadeusz J. , Morrison Amy C. , Williams Maya , Halsey Eric S. , Forshey Brett M.
Published: March 2013

We describe the isolation and characterization of a novel flavivirus, isolated from a pool of Culex (Melanoconion) ocossa Dyar and Knab mosquitoes collected in 2009 in an urban area of the Amazon basin city of Iquitos, Peru. Flavivirus infection was detected by indirect immunofluorescent assay of inoculated C6/36 cells using polyclonal flavivirus antibodies (St. Louis encephalitis virus, yellow fever virus and dengue virus type 1) and confirmed by RT-PCR. Based on partial sequencing of the E and NS5 gene regions, the virus isolate was most closely related to the mosquito-borne flaviviruses but divergent from known species, with less than 45 and 71 % pairwise amino acid identity in the E and NS5 gene products, respectively. Phylogenetic analysis of E and NS5 amino acid sequences demonstrated that this flavivirus grouped with mosquito-borne flaviviruses, forming a clade with Nounané virus (NOUV). Like NOUV, no replication was detected in a variety of mammalian cells (Vero-76, Vero-E6, BHK, LLCMK, MDCK, A549 and RD) or in intracerebrally inoculated newborn mice. We tentatively designate this genetically distinct flavivirus as representing a novel species, Nanay virus, after the river near where it was first detected.
Whole genomic analysis of a porcine-like human G5P[6] rotavirus strain isolated from a child with diarrhoea and encephalopathy in Japan
Authors: Komoto Satoshi , Maeno Yoshimasa , Tomita Mayuko , Matsuoka Tsuyoshi , Ohfu Masaharu , Yodoshi Toshifumi , Akeda Hideki , Taniguchi Koki
Published: March 2013

An unusual rotavirus strain, Ryukyu-1120, with G5P[6] genotypes (RVA/Human-wt/JPN/Ryukyu-1120/2011/G5P[6]) was identified in a stool specimen from a hospitalized child aged 4 years who showed diarrhoea and encephalopathy. In this study, we sequenced and characterized the complete genome of strain Ryukyu-1120. On whole genomic analysis, this strain was found to have a unique genotype constellation: G5-P[6]-I5-R1-C1-M1-A8-N1-T1-E1-H1. The VP6 and NSP1 genotypes I5 and A8 are those commonly found in porcine strains. Furthermore, phylogenetic analysis indicated that each of the 11 genes of strain Ryukyu-1120 appeared to be of porcine origin. Thus, strain Ryukyu-1120 was found to have a porcine rotavirus genetic backbone and is likely to be of porcine origin. To our knowledge, this is the first report of whole-genome-based characterization of the emerging G5P[6] strains in Asian countries. Our observations will provide important insights into the origin of G5P[6] strains and the dynamic interactions between human and porcine rotavirus strains.
High-spatial-resolution mapping of superhydrophobic cicada wing surface chemistry using infrared microspectroscopy and infrared imaging at two synchrotron beamlines
Authors: Tobin Mark J. , Puskar Ljiljana , Hasan Jafar , Webb Hayden K. , Hirschmugl Carol J. , Nasse Michael J. , Gervinskas Gediminas , Juodkazis Saulius , Watson Gregory S. , Watson Jolanta A. , Crawford Russell J. , Ivanova Elena P.
Published: March 2013

The wings of some insects, such as cicadae, have been reported to possess a number of interesting and unusual qualities such as superhydrophobicity, anisotropic wetting and antibacterial properties. Here, the chemical composition of the wings of the Clanger cicada (Psaltoda claripennis) were characterized using infrared (IR) microspectroscopy. In addition, the data generated from two separate synchrotron IR facilities, the Australian Synchrotron Infrared Microspectroscopy beamline (AS-IRM) and the Synchrotron Radiation Center (SRC), University of Wisconsin-Madison, IRENI beamline, were analysed and compared. Characteristic peaks in the IR spectra of the wings were assigned primarily to aliphatic hydrocarbon and amide functionalities, which were considered to be an indication of the presence of waxy and proteinaceous components, respectively, in good agreement with the literature. Chemical distribution maps showed that, while the protein component was homogeneously distributed, a significant degree of heterogeneity was observed in the distribution of the waxy component, which may contribute to the self-cleaning and aerodynamic properties of the cicada wing. When comparing the data generated from the two beamlines, it was determined that the SRC IRENI beamline was capable of producing higher-spatial-resolution distribution images in a shorter time than was achievable at the AS-IRM beamline, but that spectral noise levels per pixel were considerably lower on the AS-IRM beamline, resulting in more favourable data where the detection of weak absorbances is required. The data generated by the two complementary synchrotron IR methods on the chemical composition of cicada wings will be immensely useful in understanding their unusual properties with a view to reproducing their characteristics in, for example, industry applications.
An evaluation of the collaborative mode of professional development for teachers in special schools in Hong Kong
Authors: Ho Fuk‐chuen , Arthur‐Kelly Michael
Published: March 2013

This study, by Fuk‐chuen Ho of the Hong Kong Institute of Education and Michael Arthur‐Kelly of the University of Newcastle, aimed to evaluate the effectiveness of a professional development programme for in‐service teachers in Hong Kong special schools. The goal of the programme was to deliver a field‐based mode of training for teachers in special schools. A school cluster system was set up, with the goal of providing participants with a platform through which it is possible to conduct an interactive exchange of ideas, resources, services and expertise, mutually addressing the issues pertaining to children with special needs. Twelve school clusters were organised. Participants in this study included four educators from teacher training institutions, 31 expert teachers from supporting schools, and 101 trainees from participating schools. The most significant response came from trainees, because the participating schools had the opportunity to apply the learned skills in their own classrooms.
‘Why should I be like bloody Rain Man?!’ Navigating the autistic identity
Authors: MacLeod Andrea , Lewis Ann , Robertson Christopher
Published: March 2013

This article explores the views of six higher education students with autism/Asperger syndrome. The research draws upon social identity theory to explore how participants made meaning of their label. There was consensus that information given at the point of diagnosis generally did not reflect their individual experiences. First‐hand accounts tended to be perceived as more personally relevant. The ‘Asperger’ identity was generally framed as fragile and inconsistent, leading some individuals to distance themselves from it. This may be problematic for a group that is already disadvantaged and isolated. However, participants conveyed strong self‐images regardless of how and whether they identified with their diagnosis, which was attributed to their relative privilege in achieving higher education and therefore experiencing success and achievement related to their personal strengths. In this article, Andrea MacLeod, Ann Lewis and Christopher Robertson, from the University of Birmingham, call for researchers and relevant services to involve autistic individuals directly in fostering a constructive ‘autism identity’.
Spectral preferences ofLycorma delicatula(Hemiptera:Fulgoridae)
Authors: Jang Yikweon , An Hyon‐Gyong , Kim Hyojoong , Kim Kwang‐Ho
Published: March 2013

Many insects prefer lights with certain spectral properties, and such preferences may be associated with behavioral contexts such as mating, host finding or dispersal.Lycorma delicatula(Hemiptera:Fulgoridae) is a newly invasive species inKorea and is spreading rapidly. It is diurnal and may rely on visual cues for orientation. We conducted a series of three phototaxis experiments to understand spectral preferences inL. delicatula: light/dark choice,UV/white light choice, and color preference experiments. Nymphs of the third and final stages as well as adults were used for these experiments. In the light/dark choice, the orientation ofL. delicatulawas bimodal between the white light and darkness, for all stages and both sexes. In a choice ofUV(395–410 nm wavelengths) vs. white light,L. delicatulaof both sexes and all stages preferred theUVlight. In the color preference experiment where insects had a choice of four colors in a circular arena,L. delicatulastayed significantly longer in the blue light than in white, yellow or green lights. Overall, nymphs and adults ofL. delicatulaoriented toward lights with shorter wavelengths, and this orientation was consistent throughout all stages, regardless of sex. It is necessary to investigate the behavioral contexts under whichL. delicatulaprefers theUVand blue lights.
Zooplankton species richness–productivity relationship: Confronting monotonic positive and hump‐shaped models from a local perspective
Authors: Simões Nadson R. , Colares Maria Alice Mendes , Lansac‐Tôha Fábio A. , Bonecker Claudia C.
Published: March 2013

This study examined two models that are most frequently used to describe the relationship between species richness and productivity (SPR): monotonic positive and hump‐shaped models. We assessed zooplankton community diversity in response to algal productivity. The relationship between net primary productivity (NPP) and rarefied species richness was examined by fitting the data to two models and comparing them using theAkaike information criterion (AICc). Macrophyte banks with the highest net primary productivity had the highest zooplankton abundance. Our results pointed to a hump‐shaped model as the best fit to describe the relationship between zooplankton species richness and primary productivity (ΔAICc > 4). Thus, the diversity was lower at the extremes of productivity and higher at intermediate levels of productivity. We suggest that this relationship might occur because when the resource supply rates are low, environmental conditions are stressful, whereas a high availability of resources enhances competitive exclusion. Two observations supported this statement: (i) the total abundance of the community positively correlated withNPP(P < 0.05), indicating that less productive sites had few consumers and the raised productivity tended to favour the total abundance; (ii)NPPwas negatively correlated with evenness (P < 0.05), indicating that productivity increased the dominance of certain species in the communities. Therefore, we challenged two of the models most frequently used to explainSPR, and discuss some mechanisms underlying a hump‐shapedSPR.
Total Synthetic Protoapigenone WYC02 Inhibits Cervical Cancer Cell Proliferation and Tumour Growth through PIK3 Signalling Pathway
Authors: Chen Yun‐Ju , Kay Nari , Yang Jinn‐Moon , Lin Chih‐Ta , Chang Hsueh‐Ling , Wu Yang‐Chang , Fu Chi‐Feng , Chang Yu , Lo Steven , Hou Ming‐Feng , Lee Yi‐Chen , Hsieh Ya‐Ching , Yuan Shyng‐Shiou
Published: March 2013

Flavonoids have been intensively explored for their anticancer activity. In this study, a total synthetic flavonoid protoapigenone, known as WYC02, was analysed for its potential anticancer activity on human cervical cancer cells as well as the underlying mechanisms for these effects. The site‐moiety maps are used to explore the binding site similarity, pharmacophore and docking pose similarity. The effect of WYC02 on cell viability, migration, invasion and apoptosis as well as the underlying mechanisms was analysed in vitro using human cervical cancer cells. The effect of WYC02 on in vivo tumour growth was assessed in a tumour xenograft study. WYC02 inhibited cell proliferation, MMPs activity, migration and invasion in cervical cancer cells. We speculated that WYC02 might inhibit the activities of PIK3 family proteins, including PIK3CA, PIK3CB, PIK3CD and PIK3CG. Indeed, WYC02 decreased the expression of PIK3 family proteins, especially PIK3CG, through ubiquitination and inhibited the activities of PIK3CG and PIK3 downstream molecules AKT1 and MTOR in cervical cancer cells. Furthermore, PIK3 signalling pathway was involved in the inhibitory effect of WYC02 on cervical cancer cell proliferation and tumour growth in vitro and in vivo. WYC02 inhibits cervical cancer cell proliferation and tumourigenesis via PIK3 signalling pathway and has the potential to be developed as a chemotherapeutic agent in cervical cancer.
Plexiform neurofibroma affecting the upper parietal scalp, with cerebellar hamartoma: role of histopathology, colour Doppler imaging and magnetic resonance imaging
Authors: Sehgal V. N. , Oberai R. , Venkatash P. , Sharma S. , Verma P. , Chatterji K.
Published: March 2013

We report a patient with plexiform neurofibroma, which is pathognomonic for neurofibromatosis type 1 (NF1) affecting the upper parietal region of the scalp. Cerebellar hamartoma was present, a finding that, to our knowledge, has not been reported previously. We highlight the role of histopathology, ultrasonography, colour Doppler imaging and magnetic resonance imaging, in addition to the seven existing criteria, for the diagnosis of NF1.
Seven years' experience of Mohs micrographic surgery in a UK centre, and development of a UK minimum dataset and audit standards
Authors: Macfarlane L. , Waters A. , Evans A. , Affleck A. , Fleming C.
Published: March 2013

Background

Mohs micrographic surgery (MMS) is the gold-standard treatment for high-risk basal cell carcinomas and a variety of other cutaneous tumours, including dermatofibromasarcoma protuberans and microcystic adnexal carcinoma. Previous large-scale case series, audits and reviews have allowed evaluation of MMS outcomes, such as BCC recurrence rates. However, to date there has been no systematic UK MMS audit, and certain important aspects of care, such as postoperative functional outcomes, have not yet been subject to scrutiny.

Aims

To review audit data from our centre, and from this to develop a minimum dataset and audit standards for UK MMS centres, on behalf of the British Society of Dermatological Surgery (BSDS).

Methods

An MMS database was developed locally and modified in response to repeated audit cycles since the introduction of the MMS service. A minimum dataset was developed using this experience.

Results

In our department, primary BCC recurrence rates are reassuringly low at 0.3%, at both 2 and 5 years. Histopathological discordance is < 2%, and aesthetic and functional outcomes at 3 months are good.

Conclusions

The collation of audit data has been simplified by use of the minimum dataset, which we propose for all UK MMS centres, on behalf of the BSDS.
Impact of Epoetin Alfa on Left Ventricular Structure, Function, and Pressure Volume Relations as Assessed by Cardiac Magnetic Resonance: The Heart Failure Preserved Ejection Fraction (HFPEF) Anemia Trial
Authors: Green Philip , Babu Benson A. , Teruya Sergio , Helmke Stephen , Prince Martin , Maurer Mathew S.
Published: March 2013

Anemia, a common comorbidity in older adults with heart failure and a preserved ejection fraction (HFPEF), is associated with worse outcomes. The authors quantified the effect of anemia treatment on left ventricular (LV) structure and function as measured by cardiac magnetic resonance (CMR) imaging. A prospective, randomized single‐blind clinical trial (NCT NCT00286182) comparing the safety and efficacy of epoetin alfa vs placebo for 24 weeks in which a subgroup (n=22) had cardiac magnetic resonance imaging (MRI) at baseline and after 3 and 6 months to evaluate changes in cardiac structure and function. Pressure volume (PV) indices were derived from MRI measures of ventricular volume coupled with sphygmomanometer‐measured pressure and Doppler estimates of filling pressure. The end‐systolic and end‐diastolic PV relations and the area between them as a function of end‐diastolic pressure, the isovolumic PV area (PVAiso), were calculated. Patients (75±10 years, 64% women) with HFPEF (EF=63%±15%) with an average hemoglobin of 10.3±1.1 gm/dL were treated with epoetin alfa using a dose‐adjusted algorithm that increased hemoglobin compared with placebo (P<.0001). As compared with baseline, there were no significant changes in end‐diastolic (−7±8 mL vs −3±8 mL, P=.81) or end‐systolic (−0.4±2 mL vs −0.7±5 mL, P=.96) volumes at 6‐month follow‐up between epoetin alfa compared with placebo. LV function as measured based on EF (−1.5%±1.6% vs −2.6%±3.3%, P=.91) and pressure volume indices (PVAiso‐EDP at 30 mm Hg, −5071±4308 vs −1662±4140, P=.58) did not differ between epoetin alfa and placebo. Administration of epoetin alfa to older adult patients with HFPEF resulted in a significant increase in hemoglobin, without evident change in LV structure, function, or pressure volume relationships as measured quantitatively using CMR imaging.
MATERNAL LABOR SUPPLY AND THE AVAILABILITY OF PUBLIC PRE‐K: EVIDENCE FROM THE INTRODUCTION OF PREKINDERGARTEN INTO AMERICAN PUBLIC SCHOOLS
Authors: SALL SEAN P.
Published: March 2013

In the 1980s and 1990s, many states and districts began to provide funding for prekindergarten (PK) programs for the first time. This paper takes advantage of the staggered timing in program funding to investigate the effect that increased availability of PK programs has on the labor supply of mothers with 4‐year‐olds. I find that mothers with a 4‐year‐old and no younger children were significantly more likely to be in the labor force and employed once PK became available. Mothers with a 4‐year‐old and other younger children were also significantly more likely to be in the labor force and employed. (JEL I20, J01, J20)
Using neutral cline decay to estimate contemporary dispersal: a generic tool and its application to a major crop pathogen
Authors: Rieux A. , Lenormand T. , Carlier J. , de Lapeyre de Bellaire L. , Ravigné V.
Published: March 2013

Dispersal is a key parameter of adaptation, invasion and persistence. Yet standard population genetics inference methods hardly distinguish it from drift and many species cannot be studied by direct mark‐recapture methods. Here, we introduce a method using rates of change in cline shapes for neutral markers to estimate contemporary dispersal. We apply it to the devastating banana pestMycosphaerella fijiensis, a wind‐dispersed fungus for which a secondary contact zone had previously been detected using landscape genetics tools. By tracking the spatio‐temporal frequency change of 15 microsatellite markers, we find that σ, the standard deviation of parent–offspring dispersal distances, is 1.2 km/generation1/2. The analysis is further shown robust to a large range of dispersal kernels. We conclude that combining landscape genetics approaches to detect breaks in allelic frequencies with analyses of changes in neutral genetic clines offers a powerful way to obtain ecologically relevant estimates of dispersal in many species.
Adenosine‐5′‐phosphosulfate – a multifaceted modulator of bifunctional 3′‐phospho‐adenosine‐5′‐phosphosulfate synthases and related enzymes
Authors: Mueller Jonathan W. , Shafqat Naeem
Published: March 2013

All sulfation reactions rely on active sulfate in the form of 3′‐phospho‐adenosine‐5′‐phosphosulfate (PAPS). In fungi, bacteria, and plants, the enzymes responsible for PAPS synthesis, ATP sulfurylase and adenosine‐5′‐phosphosulfate (APS) kinase, reside on separate polypeptide chains. In metazoans, however, bifunctional PAPS synthases catalyze the consecutive steps of sulfate activation by converting sulfate to PAPS via the intermediate APS. This intricate molecule and the related nucleotides PAPS and 3′‐phospho‐adenosine‐5′‐phosphate modulate the function of various enzymes from sulfation pathways, and these effects are summarized in this review. On the ATP sulfurylase domain that initially produces APS from sulfate and ATP, APS acts as a potent product inhibitor, being competitive with both ATP and sulfate. For the APS kinase domain that phosphorylates APS to PAPS, APS is an uncompetitive substrate inhibitor that can bind both at the ATP/ADP‐binding site and the PAPS/APS‐binding site. For human PAPS synthase 1, the steady‐state concentration of APS has been modelled to be 1.6 μm, but this may increase up to 60 μm under conditions of sulfate excess. It is noteworthy that the APS concentration for maximal APS kinase activity is 15 μm. Finally, we recognized APS as a highly specific stabilizer of bifunctional PAPS synthases. APS most likely stabilizes the APS kinase part of these proteins by forming a dead‐end enzyme–ADP–APS complex at APS concentrations between 0.5 and 5 μm; at higher concentrations, APS may bind to the catalytic centers of ATP sulfurylase. Based on the assumption that cellular concentrations of APS fluctuate within this range, APS can therefore be regarded as a key modulator of PAPS synthase functions.
Comparative study of the microvascular blood flow in the intestinal wall, wound contraction and fluid evacuation during negative pressure wound therapy in laparostomy using the V.A.C. abdominal dressing and the ABThera open abdomen negative pressure therapy system
Authors: Lindstedt Sandra , Malmsjö Malin , Hlebowicz Joanna , Ingemansson Richard
Published: March 2013

To compare the changes in microvascular blood flow in the small intestinal wall, wound contraction and fluid evacuation, using the established V.A.C. abdominal dressing (VAC dressing) and a new abdominal dressing, the ABThera open abdomen negative pressure therapy system (ABThera dressing), in negative pressure wound therapy (NPWT). Midline incisions were made in 12 pigs, which were subjected to treatment with NPWT using the VAC or ABThera dressing. The microvascular blood flow in the intestinal wall, were measured before and after the application at topical negative pressures of −50, −75 and −125 mmHg, using laser Doppler velocimetry. Wound contraction and fluid evacuation were also measured. Baseline blood flow was defined as 100% in all settings. The blood flow was significantly reduced, to 64·6 ± 6·7% (P < 0·05) after the application of −50 mmHg using the VAC dressing, and to 65·3 ± 9·6% (P < 0·05) after the application of −50 mmHg with the ABThera dressing. The blood flow was significantly reduced, to 39·6 ± 6·7% (P < 0·05) after the application of −125 mmHg using VAC, and to 40·5 ± 6·2% (P < 0·05) after the application of −125 mmHg with ABThera. No significant difference in the reduction in blood flow could be observed between the two groups. The ABThera system gave significantly better fluid evacuation from the wound compared to the VAC system. There was no difference between the dressings regarding the reduction in blood flow, but the ABThera dressing afforded better drainage of the abdomen and better wound contraction than the VAC dressing.
Low molecular weight heparin improves healing of chronic venous ulcers especially in the elderly
Authors: Serra Raffaele , Buffone Gianluca , Molinari Vincenzo , Montemurro Rossella , Perri Paolo , Stillitano Domenico M , Amato Bruno , de Franciscis Stefano
Published: March 2013

Venous ulcers are common, especially in the elderly, accounting for more than 50% of all lower extremity ulcers with important socioeconomic problems. Improving extracellular matrix functioning, by heparin administration, seems to be a way to support wound healing. A total of 284 patients with venous ulcers were recruited in a 4‐year period. All patients were subjected to the most appropriate treatment after considering their preference (compression therapy followed or not by vein surgery). Patients were randomised into two groups of 142 persons in each (group A and group B as cases and controls, respectively). Patients of group A, in addition to the basic treatment as described earlier, received administration of nadroparin 2850 IU/0.3 ml through subcutaneous injection once a day for 12 months, whereas group B patients received basic treatment alone. Healing was assessed by means of direct ulcer tracing with computerised planimetry. Group A showed a healing rate of 83·80% at 12 months, whereas that of group B was 60·56%. Results by age group surprisingly showed that the group of older patients took the most advantage from long‐term treatment with low molecular weight heparin; this group also had lowest recurrence rate.
Oesophageal involvement in bullous pemphigoid
Authors: Maharshak N. , Sagi M. , Santos E. , Sprecher E. , Goldberg I.
Published: March 2013

Bullous pemphigoid (BP) is an acquired autoimmune disease that predominantly affects older people. Mucosal involvement is rare in BP. We report an unusual case of an elderly patient with BP with involvement of the oesophagus presenting as gastrointestinal (GI) bleeding. Although mucosal involvement is typically rare in BP, it should be considered in the differential diagnosis of GI bleeding in patients affected with the disease.