bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory-Driven AAC Practices With Adults Who Use Utterance-Based Systems: The Case of Conversational Rule Violations
Authors: Hoag Linda , Bedrosian Jan , McCoy Kathy
Published: September 2009

The purpose of this paper is to explore the pragmatic issue of when to use pre-constructed utterances by discussing a research project investigating messages that fail to meet either conventional standards of contextual appropriateness or timing. The use of pragmatic theory to systematically examine pre-constructed messages will be discussed, along with the outcomes of using messages that do not seem to follow pragmatic rules. The development of a hierarchy of types of rule violations will be described and the clinical implications of the hierarchy will be explored.
Communication Sampling and Analysis
Authors: Buzolich Marilyn Jean
Published: September 2009

Research has shown that communication sampling is important when analyzing communication behavior for individuals who have complex communication needs. Communication sampling and analysis (CSA) is an assessment tool designed for infants, toddlers, and children with multiple physical, sensory, speech, and/or cognitive, linguistic challenges. The purpose of the CSA is to capture and qualify the nature and extent of communication behavior of the communicatively challenged child with partners during interactive settings and contexts. This is important for establishing baseline levels of communicative functioning, setting goals for intervention, and evaluating the effectiveness of treatment. More reliability testing is needed to determine whether the direct sampling of communication behavior is a viable method for evaluation.
Attitudes Toward Children and Teens Who Use AAC: Have They Changed in 20 Years?
Authors: Beck Ann R.
Published: September 2009

Attitudes toward children and teens who use AAC have been an area of study for over 20 years. The factors of attitude and behavior are often driven by social pressure. In order to ensure that individuals with disabilities, including those who use AAC to communicate, do not face negative behaviors and limiting barriers based on attitudinal responses of their peers, it is important to continue the study of attitudes to gain knowledge of variables that influence, or help to form, peers' attitudes toward individuals with disabilities. We in the AAC community need to continue to explore and document strategies that are effective in increasing the positive nature of attitudes toward and the full social acceptance of individuals who use AAC by their peers and others in their environments.
Objective Measures and Programming Cochlear Implants
Authors: King Jack
Published: September 2009

Advances in cochlear implant technology have allowed for amazing outcomes for children with severe to profound hearing loss. As result, cochlear implants are now provided for some children prior to their first birthday and are also provided to children with multiple disabilities. Frequently, it is difficult to use conventional behavioral measures to set cochlear implant MAPs for these patients, so clinicians have often relied on objective measures as a guide to determining appropriate MAP levels. The following discussion reviews the advantages and limitations of using objective measures to administer audiological management for the pediatric cochlear implant patient.
Cochlear Implantation in Children Under 12 Months of Age
Authors: Gordon K. A.
Published: September 2009

Universal newborn hearing screening programs have resulted in earlier identification of children born with hearing loss. Because of the severity of their hearing impairment, some of these children receive limited benefit from hearing aids and are at risk for compromised speech, language, and auditory development. These children are often good candidates for cochlear implantation. A recent trend in pediatric hearing health care is the provision of a cochlear implant prior to one year of age for children who receive limited to no benefit from hearing aids. The following article discusses the benefits and limitations of cochlear implantation prior to one year of age and also discusses our clinical experiences with children who have received a cochlear implant prior to their first birthday.
Contemporary Considerations for Cochlear Implantation for Children With Multiple Disabilities
Authors: Waltzman Susan
Published: September 2009

Due to advances in cochlear implant technology and the remarkable outcomes often achieved by persons with severe to profound hearing loss, cochlear implant candidacy criteria has expanded since the first children were implanted almost twenty years ago. Evidence of this can be seen in the increased willingness to provide cochlear implants for children with multiple disabilities. Over the last decade, several reports have appeared in the peer-reviewed literature describing cochlear implant outcomes of children with multiple disabilities. This paper will summarize those reports, discuss realistic expectations of implantation for children with multiple disabilities, and describe contemporary management protocols for the otologic, audiologic, and rehabilitative management of children with multiple disabilities.
Hydrostatic pressure investigation of the spin crossover compound [Fe(PM−BiA)2(NCS)2] polymorph I using reflectance detection
Authors: Rotaru Aurelian , Varret François , Codjovi Epiphane , Boukheddaden Kamel , Linares Jorge , Stancu Alexandru , Guionneau Philippe , Létard Jean-François
Published: September 2009

We investigated by diffuse reflectivity the effect of hydrostatic pressure (1–1800 bar) on the thermal spin transition of Fe(PM−BiA)2(NCS)2 polymorph I, where PM=N-2-pyridylmethylene and BiA=4-aminobiphenyl. We evidenced the onset of a progressive transformation into a phase of higher cooperativity which cannot be assigned to polymorph II. This result is discussed with respect to previous pressure investigations.
Size-dependent interface band alignment between Si nanocrystals and lattice-matched Gd2O3
Authors: Afanas’ev V. V. , Badylevich M. , Stesmans A. , Laha A. , Osten H. J. , Fissel A.
Published: September 2009

Silicon nanocrystals embedded in a lattice-matched Gd2O3 matrix exhibit large size-dependent bandgap widening. Measurements of photocharging spectra of these crystals indicate only a marginal variation in the photoionization threshold energy. The latter suggests that most of the confinement-induced bandgap width variation is caused by the upward shift of the Si nanocrystal conduction band bottom.
Comparison study of finite element and basis set methods for finite size scaling
Authors: Antillon Edwin , Moy Winton , Wei Qi , Kais Sabre
Published: September 2009

We compare two methods of obtaining critical parameters for a quantum Hamiltonian using a finite size scaling approach. A finite element and basis set method were used in conjunction with the finite size scaling to obtain the critical parameters for the Hulthen potential. The critical parameters obtained analytically were the coupling constant λc=12, the critical exponents for the energy α=2 and for the “correlation length” ν=1. The extrapolated results for finite size scaling with the basis set method are λc=0.49999, α=1.9960, and ν=0.99910. The results for the finite element solutions are λc=0.50184, α=1.99993, and ν=1.00079 for the linear interpolation and λc=0.50000, α=2.00011, and ν=1.00032 for the Hermite interpolation. The results for each method compare very well with the analytical results obtained for the Hulthen potential. However, the finite element method is easier to implement and may be combined with ab initio and density functional theory to obtain quantum critical parameters for more complex systems.
Accurate ab initio quartic force fields for NH2− and CCH− and rovibrational spectroscopic constants for their isotopologs
Authors: Huang Xinchuan , Lee Timothy J.
Published: September 2009

A series of high-quality, purely ab initio, quartic force fields (QFFs), computed using a procedure we recently proposed, is reported for NH2− and CCH−. The singles and doubles coupled-cluster method with a perturbational estimate of the effects of connected triple excitations, denoted CCSD(T), was used with TZ, QZ, and 5Z quality basis sets and was combined with extrapolation to the one-particle basis-set limit, core-correlation effects, scalar relativistic effects, and higher-order correlation effects to yield accurate QFFs. A “best-guess” reference geometry was determined at the CCSD(T)/5Z level of theory. Analytical transformation removes nonzero gradients to facilitate a second-order perturbation theory spectroscopic analysis. The QFF is transformed into Morse/cosine coordinates in order to perform exact vibrational configuration interaction computations. Equilibrium structures, vibrational frequencies, rotational constants, and selected spectroscopic constants are reported in comparison with experimental values and previous theoretical studies. Higher-order correlation effects are found comparable to core-correlation effects in magnitude, e.g., ∼10 cm−1 for fundamentals, but are of opposite sign. For CCH−, a thorough discussion is presented on effective rotational constants B0. It is concluded that the “best” QFF should incorporate all the small corrections mentioned above. Correspondingly, the best vibrational fundamentals of CCH− are estimated at 502.0 cm−1 (ν2), 1800.9 cm−1 (ν3), and 3204.3 cm−1 (ν1), while the best vibrational fundamentals of NH2− are at 3118.5 cm−1 (ν1), 1447.8 cm−1 (ν2), and 3186.5 cm−1 (ν3). Excellent agreement with high-resolution experiments has been obtained for fundamentals—e.g., 1–3 cm−1 deviation for the symmetric and antisymmetric stretches of NH2−, 3121.93 cm−1 (ν1) and 3190.29 cm−1 (ν3), respectively. Isotopic effects are studied and presented to aid future experimental analyses. The present study should facilitate future characterizations of NH2− and CCH− from astronomical observations or other high-resolution laboratory studies.
Design and experimental tests of a novel neutron spin analyzer for wide angle spin echo spectrometers
Authors: Fouquet Peter , Farago Bela , Andersen Ken H. , Bentley Phillip M. , Pastrello Gilles , Sutton Iain , Thaveron Eric , Thomas Fréderic , Moskvin Evgeny , Pappas Catherine
Published: September 2009

This paper describes the design and experimental tests of a novel neutron spin analyzer optimized for wide angle spin echo spectrometers. The new design is based on nonremanent magnetic supermirrors, which are magnetized by vertical magnetic fields created by NdFeB high field permanent magnets. The solution presented here gives stable performance at moderate costs in contrast to designs invoking remanent supermirrors. In the experimental part of this paper we demonstrate that the new design performs well in terms of polarization, transmission, and that high quality neutron spin echo spectra can be measured.
Solution processed low-voltage organic transistors and complementary inverters
Authors: Ball James M. , Wöbkenberg Paul H. , Colléaux Florian , Heeney Martin , Anthony John E. , McCulloch Iain , Bradley Donal D. C. , Anthopoulos Thomas D.
Published: September 2009

We demonstrate electron and hole-transporting low-voltage transistors based on self-assembling monolayer (SAM) gate dielectrics and solution processed organic small-molecule semiconductors. The studied SAMs include methyl and carboxylic acid terminated molecules. Compared to methyl terminated alkylphosphonic acids, carboxylic acid terminated SAMs are found to exhibit increased surface energy. This enables solution processing of a wide range of small molecules onto the dielectric for the fabrication of low-voltage transistors. Using these transistors we demonstrate complementary inverters operating at voltages <2 V. This work is an important step toward realizing low-voltage organic electronics.
Defect states of chemical vapor deposition grown GaN nanowires: Effects and mechanisms in the relaxation of carriers
Authors: Tsokkou Demetra , Othonos Andreas , Zervos Matthew
Published: September 2009

Carrier relaxation in GaN nanowires, grown by atmospheric pressure chemical vapor deposition, via direct nitridation of Ga with NH3 at 950 °C has been investigated in detail. Differential absorption measurements reveal a large number of defect states located within the band gap. The relaxation dynamics of the photogenerated carriers suggest three distinct regions of energy states below the band edge identified as shallow donor states, midgap states, and deep acceptor states. Measurements suggest that Auger recombination is not a contributing factor in carrier relaxation even at the highest fluence (∼1 mJ/cm2) used in this work for carriers located within the conduction band. On the contrary, Auger recombination has been observed when probing the shallow donor states for fluences above 40 μJ/cm2. Measurements at the lowest fluence reveal a biexponential relaxation for the donor states with the fast component (∼50 ps) corresponding to the relaxation of carriers into the midgap states and the slow component of 0.65 ns associated with the relaxation into the deep acceptor states. Measurements reveal free-carrier absorption contribution from the deep acceptor states to the U-valley with an observed threshold limit of 3.5 eV suggesting the U-valley is located approximately 4.7 eV from the valence band.
Dynamical model of DNA-protein interaction: Effect of protein charge distribution and mechanical properties
Authors: Florescu Ana-Maria , Joyeux Marc
Published: September 2009

The mechanical model based on beads and springs, which we recently proposed to study nonspecific DNA-protein interactions [J. Chem. Phys. 130, 015103 (2009)], was improved by describing proteins as sets of interconnected beads instead of single beads. In this paper, we first compare the results obtained with the updated model with those of the original one and then use it to investigate several aspects of the dynamics of DNA sampling, which could not be accounted for by the original model. These aspects include the effect on the speed of DNA sampling of the regularity and/or randomness of the protein charge distribution, the charge and location of the search site, and the shape and deformability of the protein. We also discuss the efficiency of facilitated diffusion, that is, the extent to which the combination of 1D sliding along the DNA and 3D diffusion in the cell can lead to faster sampling than pure 3D diffusion of the protein.
Preferential positioning of a nanoparticle bound to a polymer: Exact enumeration of a self-avoiding walk chain model
Authors: Khoo Andy , Iwaki Takafumi , Shew Chwen-Yang , Yoshikawa Kenichi
Published: September 2009

A lattice chain model is extended to investigate the preferential position of a sticky sphere bound to a polymer chain, motivated by wrapping one nanosize core-histone with DNA to form a nucleosome structure. It was shown that the single bound histone is populated in DNA chain ends from the experiment by T. Sakaue et al. [Phys. Rev. Lett. 87, 078105 (2001)]. Here, the possible mechanisms are examined to elucidate such behavior. For neutral chains or ionic chains in high salt concentrations, spheres bound on the middle of chain may trigger conformational constraints to reduce conformational entropy. For ionic chains, the bound sphere can be driven to chain ends if its effective charge and the charge of chain monomers are of like charge. The two-dimensional chain is further studied to mimic the chromosome strongly adsorbed onto surfaces, of which behavior is similar to the three-dimensional case with minor difference due to surface confinement.
Coarse grained simulations of a small peptide: Effects of finite damping and hydrodynamic interactions
Authors: Winter Uwe , Geyer Tihamér
Published: September 2009

In the coarse grained Brownian dynamics (BD) simulation method the many solvent molecules are replaced by random thermal kicks and an effective friction acting on the particles of interest. For BD the friction has to be so strong that the particles’ velocities are damped much faster than the duration of an integration timestep. Here we show that this conceptual limit can be dropped with an analytic integration of the equations of damped motion. In the resulting Langevin integration scheme our recently proposed approximate form of the hydrodynamic interactions between the particles can be incorporated conveniently, leading to a fast multiparticle propagation scheme, which captures more of the short-time and short-range solvent effects than standard BD. Comparing the dynamics of a bead-spring model of a short peptide, we recommend to run simulations of small biological molecules with the Langevin type finite damping and to include the hydrodynamic interactions.
Toward strain resistant flexible organic thin film transistors
Authors: Jedaa Abdesselam , Halik Marcus
Published: September 2009

We suggest a molecular design for small molecules as polycrystalline organic semiconductors in flexible organic thin film transistor applications, providing an improved stability during substrate bending. A stable operation of alkyl-substituted sexithiophens was obtained under strain up to ±2.5%. The stability relates to the flexibility of the alkyl chain substitution, scales with their chain length, and outperforms those of pentacene devices. These findings were independent from the underlying dielectric layer.
Locally resonant phononic woodpile: A wide band anomalous underwater acoustic absorbing material
Authors: Jiang Heng , Wang Yuren , Zhang Milin , Hu Yanping , Lan Ding , Zhang Yinmin , Wei Bingchen
Published: September 2009

To meet the demand of modern acoustic absorbing material for which acoustic absorbing frequency region can be readily tailored, we introduced woodpile structure into locally resonant phononic crystal (LRPC) and fabricated an underwater acoustic absorbing material, which is called locally resonant phononic woodpile (LRPW). Experimental results show that LRPW has a strong capability of absorbing sound in a wide frequency range. Further theoretical research revealed that LRPC units and woodpile structure in LRPW play an important role in realization of wide band underwater strong acoustic absorption.
Accurate treatment of nonbonded interactions within systematic molecular fragmentation
Authors: Addicoat Matthew A. , Collins Michael A.
Published: September 2009

The accuracy of the systematic fragment approach to the estimation of molecular electronic energies is enhanced by a significantly improved treatment of nonbonded interactions between molecular fragments. Distributed electrostatic interactions, pairwise dispersion interactions, and many-body induction are evaluated from ab initio calculations of small molecular fragments. The accuracy of the complete approach is reported for a large sample of typical neutral organic molecules.
Nanofluidic electrokinetics in nanoparticle crystal
Authors: Chen Zhen , Wang Yunshan , Wang Wei , Li Zhihong
Published: September 2009

We scrutinize experimentally and theoretically the electrokinetics of a nanochannel network in a nanoparticle crystal. Conductance of the nanochannel network, a function of concentrations of the loaded electrolyte solutions, exhibits typical electrokinetic properties of individual nanochannel but with a much larger electrical signal. A widely accepted electrokinetic equation is used to elucidate the origin of the high throughput from a top-down perspective. Using a bottom-up analysis, a stepwise modeling process from individual nanochannel to highly ordered nanochannel network is proposed to render an in-depth view of the nanofluidics network.
Stimulated Raman scattering of laser from periodically spaced nanoparticles
Authors: Parashar J.
Published: September 2009

A periodic lattice of nanoparticles supports an electrostatic mode of space charge oscillations with frequency lying in a narrow band and varying periodically around ωpe∕3 with the wave number, where ωpe is the plasma frequency of electrons inside a nanoparticle. A laser impinged on such a lattice undergoes stimulated Raman scattering producing backward sideband electromagnetic radiation. The growth rate is maximum around the pump frequency ω0=0.75ωpe, and then decreases gradually.
Laser control of conical intersections: Quantum model simulations for the averaged loss-gain strategies of fast electronic deactivation in 1,1-difluoroethylene
Authors: González-Vázquez Jesús , González Leticia , Sola Ignacio R. , Santamaria J.
Published: September 2009

The enhancing and inhibition of population transfer via a conical intersection is demonstrated with quantum model calculations on the 1,1-difluoroethylene system. Averaged loss-gain strategies are achieved using strong laser pulses, which either trap the wave packet in the excited state, or accelerate the wave packet in the vicinity of the conical intersection.
Amorphous carbon and carbon nitride bottom gate thin film transistors
Authors: Miyajima Y. , Shkunov M. , Silva S. R. P.
Published: September 2009

Carbon based bottom gate thin film transistors were fabricated using pulsed laser deposited amorphous carbon (a-C) and amorphous carbon nitride (a-CNx) films. Both series of devices show p-type conduction in the active channel at high electric fields, for which the conduction mechanism may be fitted to Poole–Frenkel type behavior. The field effect mobilities were estimated to values of 2.5×10−3 cm2 V−1 S−1 at high fields. Nitrogen inclusion does not appear to affect the performance of the a-CNx at high fields since the current is postulated to be controlled by hole conduction states.
Graphene on gallium arsenide: Engineering the visibility
Authors: Friedemann M. , Pierz K. , Stosch R. , Ahlers F. J.
Published: September 2009

Graphene consists of single or few layers of crystalline ordered carbon atoms. Its visibility on oxidized silicon (Si/SiO2) enabled its discovery and spawned numerous studies of its unique electronic properties. The combination of graphene with the equally unique electronic material gallium arsenide (GaAs) has up to now lacked such easy visibility. Here we demonstrate that a deliberately tailored GaAs-aluminum arsenide (AlAs) multilayer structure makes graphene just as visible on GaAs as on Si/SiO2. We show that standard microscope images of exfoliated graphite on GaAs/AlAs suffice to identify mono-, bi-, and multilayers of graphene. Raman data confirm our results.
Origin of frequency-dependent line edge roughness: Monte Carlo and fast Fourier-transform studies
Authors: Saeki Akinori , Kozawa Takahiro , Tagawa Seiichi
Published: September 2009

The low-frequency line edge roughness (LER) of a chemically amplified resist (CAR) has a marked effect on the quality of electrical circuits, especially those produced by sub-30-nm-scale fabrication by extreme ultraviolet lithography. We examined the origin of frequency-dependent LER by Monte Carlo and dissolution simulations of a positive-tone CAR subjected to electron beam lithography. The correlation between frequency components and LER is highlighted to clarify which component is dominant. We found that the resist process parameters, such as the exposure dose, the base quencher, and the development, cause low-frequency LER even in the absence of mesoscale resist roughness.
Surfactant effect of arsenic doping on modification of ZnO (0001) growth kinetics
Authors: Ye J. D. , Tan S. T. , Pannirselvam S. , Choy S. F. , Sun X. W. , Lo G. Q. , Teo K. L.
Published: September 2009

The effect of arsenic doping on the growth kinetics of ZnO during metalorganic vapor phase epitaxy has been investigated. Arsenic was found to segregate to the growth surface and facilitate layer-by-layer growth. Such surfactant enhances the lateral expansion of the terraces preferential along [1¯1¯20] direction and also reduces the screw lattice distortion. Arsenic is expected to reduce the total surface energy and diffusion barrier of oxygen adatoms, hence producing Zn-rich surface condition on the growth front, in which two-dimensional growth is thermodynamically and kinetically favored. The origin of tiny hexagonal pits formed on the wide terrace is discussed in terms of the modified step-bunching mechanism.
Optimising horizontal and vertical partnership connections: bringing partnerships together to create a network advantage
Authors: Wallace Carolyn
Published: September 2009

Partnerships bring actors together to make horizontal connections between organisations. This has proven to be an effective model at the local level in Ireland. This paper explores possibilities for local partnerships to come together through a network to make vertical connections to national policy processes. It is written as a practice and innovation paper by the national coordinator of the Community Partnership Network in Ireland. A review of current practice and expectations of the Community Partnership Network indicates there has been greater success in providing support to members compared with impacts from strong vertical connections. This experience is common for a range of local actors in the community development sector in Ireland who find that there are insufficient meaningful connections between local and national institutions. This limits the opportunity for transfer of knowledge from the local level to inform national policy. Going forward, the notion of network advantage is explored as a means to make the necessary vertical connections. It is proposed that the outcomes from a network should cover the dimensions of: joint value creation, mutual capacity development and collective engagement with decision makers. There is real opportunity to apply this in Ireland as the three networks representing local development are about to merge into a single representative body for what are now local integrated development partnerships. Thinking about network advantage also provides possible application for creating stronger vertical linkages between local partnerships in Victoria, Australia and bodies at the state level, including the Victorian State Government.
Higher trends but larger uncertainty and geographic variability in 21st century temperature and heat waves
Authors: Ganguly Auroop R. , Steinhaeuser Karsten , Erickson David J. , Branstetter Marcia , Parish Esther S. , Singh Nagendra , Drake John B. , Buja Lawrence
Published: September 2009

Generating credible climate change and extremes projections remains a high-priority challenge, especially since recent observed emissions are above the worst-case scenario. Bias and uncertainty analyses of ensemble simulations from a global earth systems model show increased warming and more intense heat waves combined with greater uncertainty and large regional variability in the 21st century. Global warming trends are statistically validated across ensembles and investigated at regional scales. Observed heat wave intensities in the current decade are larger than worst-case projections. Model projections are relatively insensitive to initial conditions, while uncertainty bounds obtained by comparison with recent observations are wider than ensemble ranges. Increased trends in temperature and heat waves, concurrent with larger uncertainty and variability, suggest greater urgency and complexity of adaptation or mitigation decisions.
RETRACTED: XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors
Authors: Schlaberg Robert , Choe Daniel J. , Brown Kristy R. , Thaker Harshwardhan M. , Singh Ila R.
Published: September 2009

Xenotropic murine leukemia virus–related virus (XMRV) was recently discovered in human prostate cancers and is the first gammaretrovirus known to infect humans. While gammaretroviruses have well-characterized oncogenic effects in animals, they have not been shown to cause human cancers. We provide experimental evidence that XMRV is indeed a gammaretrovirus with protein composition and particle ultrastructure highly similar to Moloney murine leukemia virus (MoMLV), another gammaretrovirus. We analyzed 334 consecutive prostate resection specimens, using a quantitative PCR assay and immunohistochemistry (IHC) with an anti-XMRV specific antiserum. We found XMRV DNA in 6% and XMRV protein expression in 23% of prostate cancers. XMRV proteins were expressed primarily in malignant epithelial cells, suggesting that retroviral infection may be directly linked to tumorigenesis. XMRV infection was associated with prostate cancer, especially higher-grade cancers. We found XMRV infection to be independent of a common polymorphism in the
RNASEL
gene, unlike results previously reported. This finding increases the population at risk for XMRV infection from only those homozygous for the
RNASEL
variant to all individuals. Our observations provide evidence for an association of XMRV with malignant cells and with more aggressive tumors.
Fluorescent chlorophyll catabolites in bananas light up blue halos of cell death
Authors: Moser Simone , Müller Thomas , Holzinger Andreas , Lütz Cornelius , Jockusch Steffen , Turro Nicholas J. , Kräutler Bernhard
Published: September 2009

Breakdown of chlorophyll is a major contributor to the diagnostic color changes in fall leaves, and in ripening apples and pears, where it commonly provides colorless, nonfluorescent tetrapyrroles. In contrast, in ripening bananas (
Musa acuminata
) chlorophylls fade to give unique fluorescent catabolites (FCCs), causing yellow bananas to glow blue, when observed under UV light. Here, we demonstrate the capacity of the blue fluorescent chlorophyll catabolites to signal symptoms of programmed cell death in a plant. We report on studies of bright blue luminescent rings on the peel of very ripe bananas, which arise as halos around necrotic areas in ‘senescence associated’ dark spots. These dark spots appear naturally on the peel of ripe bananas and occur in the vicinity of stomata. Wavelength, space, and time resolved fluorescence measurements allowed the luminescent areas to be monitored on whole bananas. Our studies revealed an accumulation of FCCs in luminescent rings, within senescing cells undergoing the transition to dead tissue, as was observable by morphological textural cellular changes. FCCs typically are short lived intermediates of chlorophyll breakdown. In some plants, FCCs are uniquely persistent, as is seen in bananas, and can thus be used as luminescent in vivo markers in tissue undergoing senescence. While FCCs still remain to be tested for their own hypothetical physiological role in plants, they may help fill the demand for specific endogenous molecular reporters in noninvasive assays of plant senescence. Thus, they allow for in vivo studies, which provide insights into critical stages preceding cell death.
Reduced arsenic clearance and increased toxicity in aquaglyceroporin-9-null mice
Authors: Carbrey Jennifer M. , Song Linhua , Zhou Yao , Yoshinaga Masafumi , Rojek Aleksandra , Wang Yiding , Liu Yangjian , Lujan Heidi L. , DiCarlo Stephen E. , Nielsen Søren , Rosen Barry P. , Agre Peter , Mukhopadhyay Rita
Published: September 2009

Expressed in liver, aquaglyceroporin-9 (AQP9) is permeated by glycerol, arsenite, and other small, neutral solutes. To evaluate a possible protective role, AQP9-null mice were evaluated for in vivo arsenic toxicity. After injection with NaAsO
2
, AQP9-null mice suffer reduced survival rates (LD
50
, 12 mg/kg) compared with WT mice (LD
50
, 15 mg/kg). The highest tissue level of arsenic is in heart, with AQP9-null mice accumulating 10–20 times more arsenic than WT mice. Within hours after NaAsO
2
injection, AQP9-null mice sustain profound bradycardia, despite normal serum electrolytes. Increased arsenic levels are also present in liver, lung, spleen, and testis of AQP9-null mice. Arsenic levels in the feces and urine of AQP9-null mice are only ≈10% of the WT levels, and reduced clearance of multiple arsenic species by the AQP9-null mice suggests that AQP9 is involved in the export of multiple forms of arsenic. Immunohistochemical staining of liver sections revealed that AQP9 is most abundant in basolateral membrane of hepatocytes adjacent to the sinusoids. AQP9 is not detected in heart or kidney by PCR or immunohistochemistry. We propose that AQP9 provides a route for excretion of arsenic by the liver, thereby providing partial protection of the whole animal from arsenic toxicity.
Feeder-free derivation of induced pluripotent stem cells from adult human adipose stem cells
Authors: Sun Ning , Panetta Nicholas J. , Gupta Deepak M. , Wilson Kitchener D. , Lee Andrew , Jia Fangjun , Hu Shijun , Cherry Athena M. , Robbins Robert C. , Longaker Michael T. , Wu Joseph C.
Published: September 2009

Ectopic expression of transcription factors can reprogram somatic cells to a pluripotent state. However, most of the studies used skin fibroblasts as the starting population for reprogramming, which usually take weeks for expansion from a single biopsy. We show here that induced pluripotent stem (iPS) cells can be generated from adult human adipose stem cells (hASCs) freshly isolated from patients. Furthermore, iPS cells can be readily derived from adult hASCs in a feeder-free condition, thereby eliminating potential variability caused by using feeder cells. hASCs can be safely and readily isolated from adult humans in large quantities without extended time for expansion, are easy to maintain in culture, and therefore represent an ideal autologous source of cells for generating individual-specific iPS cells.
Universal non-Landau, self-organized, lattice disordering percolative dopant network sub-T
c
phase transition in ceramic superconductors
Authors: Phillips J. C.
Published: September 2009

Ceramic superconductors (cuprates, pnictides, etc.) exhibit universal features in both T
c
max
and in their planar lattice disordering measured by EXAFS, as reflected by three phase transitions. The two highest temperature transitions are known to be associated with formation of Jahn–Teller pseudogaps and superconductive gaps, with corresponding Landau order parameters, but no new gap is associated with the third transition below T
c
, and its origin is mysterious. It is argued that the third subT
c
transition is a dopant glass transition, which is remarkably similar to topological transitions previously observed in chalcogenide and oxide alloy network glasses (like window glass).
Quantum-mechanics-derived
13
C
α
chemical shift server (
Che
Shift) for protein structure validation
Authors: Vila Jorge A. , Arnautova Yelena A. , Martin Osvaldo A. , Scheraga Harold A.
Published: September 2009

A server (
Che
Shift) has been developed to predict
13
C
α
chemical shifts of protein structures. It is based on the generation of 696,916 conformations as a function of the φ, ψ, ω, χ1 and χ2 torsional angles for
all
20 naturally occurring amino acids. Their
13
C
α
chemical shifts were computed at the DFT level of theory with a small basis set and extrapolated, with an empirically-determined linear regression formula, to reproduce the values obtained with a larger basis set. Analysis of the accuracy and sensitivity of the
Che
Shift predictions, in terms of both the correlation coefficient
R
and the conformational-averaged rmsd between the observed and predicted
13
C
α
chemical shifts, was carried out for 3 sets of conformations: (
i
) 36 x-ray-derived protein structures solved at 2.3 Å or better resolution, for which sets of
13
C
α
chemical shifts were available; (
ii
) 15 pairs of x-ray and NMR-derived sets of protein conformations; and (
iii
) a set of decoys for 3 proteins showing an rmsd with respect to the x-ray structure from which they were derived of up to 3 Å. Comparative analysis carried out with 4 popular servers, namely SHIFTS, SHIFTX, SPARTA, and PROSHIFT, for these 3 sets of conformations demonstrated that
Che
Shift is the most sensitive server with which to detect subtle differences between protein models and, hence, to validate protein structures determined by either x-ray or NMR methods, if the observed
13
C
α
chemical shifts are available.
Che
Shift is available as a web server.
Language effects in addition: How you say it counts
Authors: Colomé àngels , Laka Itziar , Sebastián-Gallés Núria
Published: September 2009

This study aimed to investigate the role of language in calculation. Two populations were compared, one with a base-10 language, and another (Basque) in which number words are constructed by combining multiples of 20 and units or teens (e.g., “35” is said “twenty and fifteen”). Experiment 1 asked participants to verbally solve additions presented as Arabic digits. Basque participants solved the additions that consisted of a multiple of 20 and a teen (e.g., 20 + 15) faster than controls with identical answers (e.g., 25 + 10). No differences were found in the base-10 language group. Experiment 2 replicated this result even if participants had to type the answer on a numerical keypad, instead of saying it. Hence, the structure of number words in each of the languages influenced the way additions were solved, even if language was not necessary for conducting the task. Finally, in Experiment 3, both language groups performed a numerical comparison task in which no effects of the structure of number words were obtained. Results of the three experiments are discussed in light of current models of numerical cognition.
Selection of objects and tasks in working memory
Authors: Risse Sarah , Oberauer Klaus
Published: September 2009

When people hold several objects (such as digits or words) in working memory and select one for processing, switching to a new object takes longer than selecting the same object as that on the preceding processing step. Similarly, selecting a new task incurs task- switching costs. This work investigates the selection of objects and of tasks in working memory using a combination of object-switching and task-switching paradigms. Participants used spatial cues to select one digit held in working memory and colour cues to select one task (addition or subtraction) to apply to it. Across four experiments the mapping between objects and their cues and the mapping between tasks and their cues were varied orthogonally. When mappings varied from trial to trial for both objects and tasks, switch costs for objects and tasks were additive, as predicted by sequential selection or resource sharing. When at least one mapping was constant across trials, allowing learning of long-term associations, switch costs were underadditive, as predicted by partially parallel selection. The number of objects in working memory affected object-switch costs but not task-switch costs, counter to the notion of a general resource of executive attention.
The influence of visual contrast and case changes on parafoveal preview benefits during reading
Authors: Wang Chin-An , Inhoff Albrecht W.
Published: September 2009

Reingold and Rayner (2006) showed that the visual contrast of a fixated target word influenced its viewing duration, but not the viewing of the next (posttarget) word in the text that was shown in regular contrast. Configurational target changes, by contrast, influenced target and posttarget viewing. The current study examined whether this effect pattern can be attributed to differential processing of the posttarget word during target viewing. A boundary paradigm (Rayner, 1975) was used to provide an informative or uninformative posttarget preview and to reveal the word when it was fixated. Consistent with the earlier study, more time was spent viewing the target when its visual contrast was low and its configuration unfamiliar. Critically, target contrast had no effect on the acquisition of useful information from a posttarget preview, but an unfamiliar target configuration diminished the usefulness of an informative posttarget preview. These findings are consistent with Reingold and Rayner's (2006) claim that saccade programming and attention shifting during reading can be controlled by functionally distinct word recognition processes.
The nuclear receptor PPARγ selectively inhibits Th17 differentiation in a T cell–intrinsic fashion and suppresses CNS autoimmunity
Authors: Klotz Luisa , Burgdorf Sven , Dani Indra , Saijo Kaoru , Flossdorf Juliane , Hucke Stephanie , Alferink Judith , Novak Natalija , Beyer Marc , Mayer Gunter , Langhans Birgit , Klockgether Thomas , Waisman Ari , Eberl Gerard , Schultze Joachim , Famulok Michael , Kolanus Waldemar , Glass Christopher , Kurts Christian , Knolle Percy A.
Published: September 2009

T helper cells secreting interleukin (IL)-17 (Th17 cells) play a crucial role in autoimmune diseases like multiple sclerosis (MS). Th17 differentiation, which is induced by a combination of transforming growth factor (TGF)-β/IL-6 or IL-21, requires expression of the transcription factor retinoic acid receptor–related orphan receptor γt (RORγt). We identify the nuclear receptor peroxisome proliferator–activated receptor γ (PPARγ) as a key negative regulator of human and mouse Th17 differentiation. PPARγ activation in CD4+ T cells selectively suppressed Th17 differentiation, but not differentiation into Th1, Th2, or regulatory T cells. Control of Th17 differentiation by PPARγ involved inhibition of TGF-β/IL-6–induced expression of RORγt in T cells. Pharmacologic activation of PPARγ prevented removal of the silencing mediator for retinoid and thyroid hormone receptors corepressor from the RORγt promoter in T cells, thus interfering with RORγt transcription. Both T cell–specific PPARγ knockout and endogenous ligand activation revealed the physiological role of PPARγ for continuous T cell–intrinsic control of Th17 differentiation and development of autoimmunity. Importantly, human CD4+ T cells from healthy controls and MS patients were strongly susceptible to PPARγ-mediated suppression of Th17 differentiation. In summary, we report a PPARγ-mediated T cell–intrinsic molecular mechanism that selectively controls Th17 differentiation in mice and in humans and that is amenable to pharmacologic modulation. We therefore propose that PPARγ represents a promising molecular target for specific immunointervention in Th17-mediated autoimmune diseases such as MS.
Loss of SOCS3 expression in T cells reveals a regulatory role for interleukin-17 in atherosclerosis
Authors: Taleb Soraya , Romain Mélissa , Ramkhelawon Bhama , Uyttenhove Catherine , Pasterkamp Gerard , Herbin Olivier , Esposito Bruno , Perez Nicolas , Yasukawa Hideo , Van Snick Jacques , Yoshimura Akihiko , Tedgui Alain , Mallat Ziad
Published: September 2009

Atherosclerosis is an inflammatory vascular disease responsible for the first cause of mortality worldwide. Recent studies have clearly highlighted the critical role of the immunoinflammatory balance in the modulation of disease development and progression. However, the immunoregulatory pathways that control atherosclerosis remain largely unknown. We show that loss of suppressor of cytokine signaling (SOCS) 3 in T cells increases both interleukin (IL)-17 and IL-10 production, induces an antiinflammatory macrophage phenotype, and leads to unexpected IL-17–dependent reduction in lesion development and vascular inflammation. In vivo administration of IL-17 reduces endothelial vascular cell adhesion molecule–1 expression and vascular T cell infiltration, and significantly limits atherosclerotic lesion development. In contrast, overexpression of SOCS3 in T cells reduces IL-17 and accelerates atherosclerosis. We also show that in human lesions, increased levels of signal transducer and activator of transcription (STAT) 3 phosphorylation and IL-17 are associated with a stable plaque phenotype. These results identify novel SOCS3-controlled IL-17 regulatory pathways in atherosclerosis and may have important implications for the understanding of the increased susceptibility to vascular inflammation in patients with dominant-negative STAT3 mutations and defective Th17 cell differentiation.
Ciprofloxacin Resistance Among Nosocomial Pseudomonas aeruginosa and staphylococcus aureus in the United States
Authors: Coronado Victor G. , Edwards Jonathan R. , Culver David H. , Gaynes Robert P. ,   The National Nosocomial Infections Surveillance (NNIS) System
Published: September 2009

Objective:

We attempted to determine if an increase in resistance to ciprofloxacin occurred among nosocomial pathogens, especially Pseudomonas aeruginosa and Staphylococcus aureus.

Methods:

We examined 1989-1992 ciprofloxacin susceptibility results from 8,517 P aeruginosa and 9,021 S aureus isolates associated with nosocomial infections reported to the National Nosocomial Infections Surveillance System.

Results:

For S aureus, 27.1% of isolates were resistant to ciprofloxacin; of methicillin-resistant S aureus isolates, 80% also were resistant to ciprofloxacin. A logistic regression model found that ciprofloxacin resistance was more common among S aureus isolated from the urinary and respiratory tracts than from other sites of isolation, and among isolates that were methicillin resistant. After controlling for these factors, the model showed a 123% increase in the odds of ciprofloxacin resistance from 1989-1990 to 1991-1992. For P aeruginosa, 4.7% of the isolates were resistant to ciprofloxacin. Resistance varied by site of infection and rose most dramatically for respiratory tract isolates from 2.0% in 1989-1990 to 5.3% in 1991-1992.

Conclusion:

Resistance to ciprofloxacin is more frequent among nosocomial S aureus than among P aeruginosa and is increasing rapidly among S aureus isolates and from selected sites among P aeruginosa isolates.
A Pseudoepidemic Due to Laboratory Contamination Deciphered by Molecular Analysis
Authors: Morris Thomas , Brecher Stephen M. , Fitzsimmons Diarme , Durbin Annette , Arbeit Robert D. , Maslow Joel N.
Published: September 2009

Objective:

A clinical, microbiological, and molecular analysis to identify the source of a cluster of pseudoinfections.

Design:

Retrospective analysis of the cases, prospective epidemiologic survey, and laboratory investigation. Molecular analysis of the isolates was performed using pulsed-field gel electrophoresis (PFGE).

Setting:

A tertiary Veterans Affairs medical center.

Patients:

Three patients admitted over a Z-week period with musculoskeletal complaints had one or more joint fluid specimens submitted for culture. In each case, anaerobic chopped meat-glucose broth (CMGB) tubes yielded one or more organisms not typically associated with septic arthritis (Enterobacter cloacae, Enterococcus faecium, Enterococcus casseliflavus, Enterococcus faecalis, Escherichia hermannii, and Pseudomonas diminuti). The first three organisms were isolated from specimens from multiple patients. Two patients had multiple positive cultures; for two patients, separate cultures yielded additional organisms on solid media.

Results:

Laboratory investigation yielded an isolate of E faecium from 1 of 30 sham-inoculated CMGB tubes. PFGE analysis demonstrated that a single strain of E cloacae was isolated from four CMGB tubes representing all three patients, and a single strain of E faecium was isolated from CMGB tubes representing two patients and the sham-inoculated tube.

Conclusions:

The application of molecular typing clearly demonstrated clonality among the isolates and indicated that a common source of contamination, most likely the CMGB tubes, was responsible for these cases.
Epidemiologic Approaches to Quality Assessment
Authors: Simmons Bryan P , Kritchevsky Stephen B.
Published: September 2009

Hospital epidemiologists have an opportunity to apply their skills to hospital quality problems other than infection control. Soon, hospitals will be required to collect and report numerous quality indicators, whose results will require epidemiologic interpretation. For those who choose to make the transition into quality management, careful assessment and planning are needed to succeed.