bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a Novel 4-DOF Kinematotropic Hybrid Parallel Manipulator
Authors: Zeng Qiang , Fang Yuefa , Ehmann Kornel F.
Published: December 2011

This paper presents a novel 4-DOF kinematotropic hybrid parallel manipulator. The topological structure allows for the realization of two translatory and two rotary output motions. Both the translations and rotations take place only in two orthogonal axes. The rotations are designed to possess the kinematotropic property, namely the output mobility of the manipulator can be changed while the topological structure remains invariable. In the process of the topological synthesis, two types of topological arrangements of the kinematotropic hybrid parallel manipulators are developed in the form of multiply moving platforms and subchains based on displacement group theory and mathematical logic. Kinematic modeling of the most feasible kinematotropic hybrid parallel manipulator is performed by obtaining its kinematic forward and inverse solutions and velocities. Suitable drive methods are also defined. At last, a prototype of the analyzed kinematotropic hybrid parallel manipulator is built to evaluate the feasibility of the developed design method, validate the kinematic modeling, and establish the manipulator’s kinematotropic properties.
Growth characteristics, material properties, and optical properties of zinc oxysulfide films deposited by atomic layer deposition
Authors: Bakke Jonathan R. , Tanskanen Jukka T. , Hägglund Carl , Pakkanen Tapani A. , Bent Stacey F.
Published: December 2011

Zinc oxysulfide—Zn(O,S)—is a wide bandgap semiconductor with tunable electronic and optical properties, making it of potential interest as a buffer layer for thin film photovoltaics. Atomic layer deposition (ALD) of ZnS, ZnO, and Zn(O,S) films from dimethylzinc, H2O, and H2S was performed, and the deposited films were characterized by means of x-ray diffraction, x-ray photoelectron spectroscopy, and spectroscopic ellipsometry. With focus on the investigation of Zn(O,S) film growth characteristics and material properties, the ZnO/(ZnO + ZnS) ALD cycle ratios were systematically varied from 0 (ZnS ALD) to 1 (ZnO ALD). Notably, a strong effect ofthematerial properties on the optical characteristics is confirmed for the ternary films. The Zn(O,S) ALD growth and crystal structure resemble those of ZnS up to a 0.6 cycle ratio, at whichpoint XPS indicates 10% oxygen is incorporated into the film. For higher cycle ratios thefilm structure becomes amorphous, which is confirmed with XRD patterns and also reflected inthe optical constants as determined by spectroscopic ellipsometry; in particular, the optical bandgap transforms from direct type for the (cubic) ZnS like phase to a more narrow bandgap withamorphous characteristics, causing bandgap bowing. A direct bandgap is recovered atyethigherZnO/(ZnO + ZnS) cycle ratios, whereproperties converge toward ZnO ALD in termsof film growth rate, crystallinity, and composition.
A SUMOylation-Dependent Transcriptional Subprogram Is Required for Myc-Driven Tumorigenesis
Authors: Kessler Jessica D. , Kahle Kristopher T. , Sun Tingting , Meerbrey Kristen L. , Schlabach Michael R. , Schmitt Earlene M. , Skinner Samuel O. , Xu Qikai , Li Mamie Z. , Hartman Zachary C. , Rao Mitchell , Yu Peng , Dominguez-Vidana Rocio , Liang Anthony C. , Solimini Nicole L. , Bernardi Ronald J. , Yu Bing , Hsu Tiffany , Golding Ido , Luo Ji , Osborne C. Kent , Creighton Chad J. , Hilsenbeck Susan G. , Schiff Rachel , Shaw Chad A. , Elledge Stephen J. , Westbrook Thomas F.
Published: December 2011

Taking the Myc

Despite nearly 30 years of research into the mechanisms by which Myc oncogene dysregulation contributes to tumorigenesis, there are still no effective therapies that inhibit Myc activity.

Kessler
et al.

(p.
348
, published online 8 December; see the Perspective by

Evan

) searched for gene products that support Myc-driven tumorigenesis. One pharmacologically tractable target that emerged from the screen was the SUMO-activating enzyme complex SAE1/2, which catalyzes a posttranslational modification (SUMOylation) that alters protein behavior and function. SUMOylation was found to control the Myc transcriptional response, and its inhibition caused mitotic defects and apoptosis in Myc-dependent breast cancer cells.
Sucrose Efflux Mediated by SWEET Proteins as a Key Step for Phloem Transport
Authors: Chen Li-Qing , Qu Xiao-Qing , Hou Bi-Huei , Sosso Davide , Osorio Sonia , Fernie Alisdair R. , Frommer Wolf B.
Published: December 2011

That Sweet Sensation

Photosynthesis in the leaf generates sucrose that must be transported via the phloem to other parts of the plant in order, for example, to be incorporated into harvestable produce. Studying
Arabidopsis
and rice,

Chen
et al.

(p. 207, published online 8 December; see the Perspective by

Braun

) identified the SWEET family of sucrose efflux transporters that are responsible for carrying sucrose out of the leaf cells. When the transporters were disabled, sucrose accumulated in the leaves. Functioning properly, the SWEET transporters carry sucrose across the plasma membrane and other transporters move it further into the phloem.
Cytoplasmic Dynein Moves Through Uncoordinated Stepping of the AAA+ Ring Domains
Authors: DeWitt Mark A. , Chang Amy Y. , Combs Peter A. , Yildiz Ahmet
Published: December 2011

Doing the Side Step

The molecular motor, dynein, contains two ring domains responsible for its movement along the microtubule. However, how the rings move relative to each other during processive motility and whether dynein processivity requires interhead coordination are unclear. To directly observe how dynein “walks” along microtubules,

DeWitt
et al.

(p.
221
, published online 8 December) performed advanced fluorescence-imaging studies to follow both motor domains of a single dynein motor at nanometer resolution. The data suggest that the two heads do not cooperate during movement, which suggests a fundamentally different mechanism of motility from that observed for other microtubule-based motors.
Rescuers may vary their side of approach to a casualty without impact on cardiopulmonary resuscitation performance
Authors: Jones Christopher M , Thorne Christopher J , Colter Penelope S , Macrae Alison , Brown Gregory A , Hulme Jonathan
Published: December 2011

Aim

To determine whether cardiopulmonary resuscitation (CPR) performance is influenced by a rescuer's preferred side of approach.

Methods

Eighty-three first-year healthcare students were enrolled in a prospective randomised crossover study comparing chest compression quality during uninterrupted chest compression CPR after approach from both their preferred and non-preferred sides.

Results

Chest compression quality was not dependent on rescuers' sidedness preference; neither mean compression rate and depth nor hand positioning differed between sides of approach.

Conclusions

No link exists between the side from which a rescuer approaches, or prefers to approach, a casualty and chest compression quality.
Safety and efficiency of triaging low urgent self-referred patients to a general practitioner at an acute care post: an observational study
Authors: van der Straten Lieke M , van Stel Henk F , Spee Frans J M , Vreeburg Marleen E , Schrijvers Augustinus J P , Sturms Leontien M
Published: December 2011

Objective

To assess the safety and efficiency of triaging low urgent self-referred patients at the emergency department (ED) to a general practitioner (GP) based on the Manchester triage system (MTS).

Methods

All self-referred patients in the evening, night and weekends were included in this prospective observational study. Patients were triaged by an ED nurse according to the MTS and allocated to a GP or the ED according to a predefined care scheme. For patients treated by the GP, assessments were made of safety as measured by hospitalisation and return to the ED within 2 weeks, and efficiency as measured by referral to the ED.

Results

In 80% of cases allocation of the self-referrals to the ED or GP was according to a predefined scheme. Of the 3129 low urgent self-referred patients triaged to the GP, 2840 (90.8%) were sent home, 202 (6.5%) were directly referred to the ED, 36 (1.2%) were hospitalised. Within a random sample of low urgent patients sent home by the GP (222 of 2840), 8 (3.6%) returned to the ED within 2 weeks. Against the agreed MTS scheme, the ED also directly treated 664 low urgent patients, mainly for extremity problems (n=512). Despite the care agreements, 227 urgent patients were treated by the GP, with a referral rate to the ED of 18.1%, a hospitalisation rate of 4.0% and a 4.5% return rate to the ED within 2 weeks.

Conclusions

Low urgent self-referrals, with the exception of extremity problems, were shown to be treated efficiently and safely by a GP. A selected group of more urgent patients also seem to be handled adequately by the GP. Triage of low urgent patients with extremity problems and reasons for nurses not following a predefined triage allocation scheme need further elaboration.
ON-CHIP INDUCTORS OPTIMIZATION FOR ULTRA WIDE BAND LOW NOISE AMPLIFIERS
Authors: PINO J. DEL , KHEMCHANDANI SUNIL L. , DÍAZ-ORTEGA ROBERTO , PULIDO R. , GARCÍA-VÁZQUEZ H.
Published: December 2011

In this work, the influence of the inductor quality factor in wide band low noise amplifiers has been studied. Electromagnetic simulations have been used to model the integrated inductor broad band response. The influence of the quality factor on LNA performance of the inductors that compound the impedance matching networks, inductive degeneration and broadband load has been studied, obtaining design guidelines for optimizing the amplifier gain flatness. Using this guidelines, an LNA with wideband input matching, shunt-peaking load, and an output buffer was designed. Using Austria Mikro Systems BiCMOS 0.35 m process, a prototype has been fabricated achieving the following measured specifications: maximum gain of 12.5 dB at 3.4 GHz with a -3 dB bandwidth of 1.7–5.3 GHz, noise figure from 4.3 to 5.2 dB, and unity gain at 9.4 GHz.
ARCTANGENT ARCHITECTURE FOR HIGH SPEED AND HIGH PRECISION DATA
Authors: TAGZOUT SAMIR , BELOUCHRANI ADEL
Published: December 2011

The Arctangent function is used in several signal processing applications and it is widely needed for hardware implementations. However, it often constitutes the performance bottleneck because of its inaccuracy and/or its poor performances. We present a generic VLSI design to respond to some applications' need of fast Arctangent functions handling high precision data. The method presented here contrasts with the usual Look Up table based solutions which allow the output customization but limit the precision of the corresponding tangent input. Detailed logical design and FPGA implementation results are provided to show our solution as the best candidate to comply with fast execution as well as high precision for both input and output data.
AN EFFICIENT REVERSE CONVERTER FOR THE NEW FOUR-MODULI SET {22n, 2n+1 - 1, 2n/2 + 1, 2n/2 - 1}
Authors: NOORIMEHR MOHAMMADREZA , HOSSEINZADEH MEHDI , FARSHIDI REZA
Published: December 2011

In this paper, the new four-moduli set {22n, 2n+1 - 1, 2n/2 + 1, 2n/2 - 1} for even n is introduced. This moduli set has 4n-bit dynamic range and well-formed moduli which result in increased performance of RNS arithmetic unit. Then, an efficient reverse converter is presented based on New Chinese remainder theorem2 (New CRT-II) for proposed moduli set. The converter is ROM-free and based on carry save adders and modular adders which can be efficiently implemented by VLSI circuits. The presented reverse converter for moduli set {22n, 2n+1 - 1,2n/2 + 1, 2n/2 - 1} has lower delay and hardware cost in comparison to the reverse converter of the latest introduced four-moduli set {2n - 1, 2n, 2n + 1, 2n+1 - 1} with 4n-bit dynamic range.
UNIT COMMITMENT WITH SECURITY ASSESSMENT USING CHAOTIC PSO ALGORITHM
Authors: GAING ZWE-LEE , LIN GAI-NENG
Published: December 2011

This paper proposes solving short-term unit commitment (UC) problems with security constraints by hybrid chaotic particle swarm optimization (CPSO). The objective of security-constrained UC (SC-UC) is to minimize the total generation cost, which is the sum of both transition cost and production cost of the scheduled combination units. The proposed CPSO method, which involves the chaotic map and the chaotic turbulence, can avoid premature convergence of PSO and escape local minima. Moreover, the proposed hybrid CPSO method has the ability of solving both the continuous and the discrete optimal programming problems. Two power systems are demonstrated for verifying the feasibility and effectiveness of the proposed method in solving SC-UC problems with constraints of a nonlinear generator and operation security assessment taken into consideration. The simulation results show that the proposed CPSO-based SC-UC method is indeed capable of obtaining efficiently high-quality UC solutions and enhancing the system security of UC operation.
A METHOD FOR FACE RECOGNITION USING IMAGE REGISTRATION
Authors: GILLAN STEVEN , AGATHOKLIS PANAJOTIS
Published: December 2011

This paper presents a technique for face recognition that is based on image registration. The face recognition technique consists of three parts: a training part, an image registration part and a post-processing part. The image registration technique is based on finding a set of feature points in the two images and using these feature points for registration. This is done in four steps. In the first, images are filtered with the Mexican-hat wavelet to obtain the feature point locations. In the second, the Zernike moments of neighborhoods around the feature points are calculated and compared in the third step to establish correspondence between feature points in the two images. In the fourth, the transformation parameters between images are obtained using an iterative least squares technique to eliminate outliers.1,2 During training, a set of images are chosen as the training images and the Zernike moments for the feature points of the training images are obtained and stored. The choice of training images depends on the changes of poses and illumination that are expected. In the registration part, the transformation parameters to register the training images with the images under consideration are obtained. In the post-processing, these transformation parameters are used to determine whether a valid match is found or not.

The performance of the proposed method is evaluated using various face databases3–5 and it is compared with the performance of existing techniques. Results indicate that the proposed technique gives excellent results for face recognition in conditions of varying pose, illumination, background and scale.
A RAIL-TO-RAIL BUFFER AMPLIFIER FOR LCD DRIVER
Authors: LU CHIH-WEN , HSIAO CHING-MIN
Published: December 2011

A high-speed low-power rail-to-rail buffer amplifier, which is suitable for liquid crystal display driver applications, is proposed. An offset voltage is intentionally built in the second stage to cut off the transistors of last stage from the output node in the stable state and hence achieve low dc power consumption. The input referred offset voltage due to the built-in offset is very small. The buffer draws little current while static but has a large driving capability while transient. An experimental prototype buffer amplifier implemented in a 0.35-μm CMOS technology demonstrates that the circuit can operate under a wide power supply range. Quiescent current of 5 μA is measured. The buffer exhibits the settling time of 1.5 μs for a voltage swing of 0.1 ~ (VDD – 0.1) V under a 600 pF capacitance load. The area of this buffer is 30 × 98 μm2. The measured data show that the proposed output buffer amplifier is very suitable for LCD driver applications.
A SIMULATION NETWORK MODEL TO EVALUATE RFID MIDDLEWARES
Authors: RYU WOOSEOK , KWON JOONHO , HONG BONGHEE
Published: December 2011

High-performance radio-frequency identification (RFID) is a challenging issue for large-scale enterprises. As a key component of an RFID system, RFID middleware is an important factor to measure the performance of the system. To evaluate the feasibility of an RFID middleware, the performance of the RFID middleware should be carefully evaluated in various RFID-enabled business environments. However, the construction of an RFID testbed requires a lot of time, money, and human resources because it involves numerous tagged items and a large number of deployed readers. We must provide a meaningful input tag stream representing various business activities, rather than random data. This paper presents a novel simulation model for the virtual construction of RFID testbeds. To ensure the semantic validity of the input tag stream, the proposed RFID simulation network (RSN) extends Petri nets by including sets of functions that represent unique characteristics of RFID environments such as the uncertainty of communications and tag movement patterns. By configuring appropriate functions, the RSN automatically generates an input tag stream that matches the distribution of real data. We demonstrate that the RSN model correctly reflects data from real-world environments by comparing input tag streams from real RFID equipment and from the RSN model.
WEIGHTED-EDGE-COLORING OF k-DEGENERATE GRAPHS AND BIN-PACKING
Authors: HUC FLORIAN
Published: December 2011

The weighted-edge-coloring problem of an edge-weighted graph whose weights are between 0 and 1, consists in finding a coloring using as few colors as possible and satisfying the following constraints: the sum of weights of edges with the same color and incident to the same vertex must be at most 1. In 1991, Chung and Ross conjectured that if G is bipartite, then [Formula: see text] colors are always sufficient to weighted-edge-color (G,w), where [Formula: see text] is the maximum of the sums of the weights of the edges incident to a vertex. We prove this is true for edge-weighted graphs with multiple edges whose underlying graph is a tree. We further generalise this conjecture to non-bipartite graphs and prove the generalised conjecture for simple edge-weighted outerplanar graphs. Finally, we introduce a list version of this coloring together with the list-bin-packing problem, which allows us to obtain new results concerning the original coloring for a specific class of graphs, namely the k-weight-degenerate weighted graph.
GAUSSIAN GEOMETRIC DISCORD
Authors: ADESSO GERARDO , GIROLAMI DAVIDE
Published: December 2011

We extend the geometric measure of quantum discord, introduced and computed for two-qubit states, to quantify non-classical correlations in composite Gaussian states of continuous variable systems. We lay the formalism for the evaluation of a Gaussian geometric discord in two-mode Gaussian states, and present explicit formulas for the class of two-mode squeezed thermal states. In such a case, under physical constraints of bounded mean energy, geometric discord is shown to admit upper and lower bounds for a fixed value of the conventional (entropic) quantum discord. We finally discuss alternative geometric approaches to quantify Gaussian quadrature correlations.
NON-MARKOVIAN DYNAMICS OF SYSTEM-RESERVOIR ENTANGLEMENT
Authors: PLASTINA F. , MANISCALCO S.
Published: December 2011

Using an exact approach, we study the dynamics of entanglement between two qubits coupled to independent reservoirs and between the two, initially disentangled, reservoirs. We also describe the transfer of bipartite entanglement from the two qubits to their respective reservoirs focussing on the case of two atoms inside two different leaky cavities with a specific attention to the role of the detuning. We present a scheme to prepare the cavity fields in a maximally entangled state, without direct interaction between the cavities, by exploiting the initial qubits entanglement. We discuss a deterministic protocol, working in the presence of cavity losses, for the generation of a W-state of one qubit and two cavity fields and we describe a probabilistic scheme to entangle one of the atoms with the reservoir (cavity field) of the other atom.
CHARACTERIZING QUANTUMNESS VIA ENTANGLEMENT CREATION
Authors: GHARIBIAN SEVAG , PIANI MARCO , ADESSO GERARDO , CALSAMIGLIA JOHN , HORODECKI PAWEŁ
Published: December 2011

In [Piani et al., PRL106 (2011) 220403], an activation protocol was introduced which maps the general non-classical (multipartite) correlations between given systems into bipartite entanglement between the systems and local ancillae by means of a potentially highly entangling interaction. Here, we study how this activation protocol can be used to entangle the starting systems themselves via entanglement swapping through a measurement on the ancillae. Furthermore, we bound the relative entropy of quantumness (a naturally arising measure of non-classicality in the scheme of Piani et al. above) for a special class of separable states, the so-called classical–quantum states. In particular, we fully characterize the classical–quantum two-qubit states that are maximally non-classical.
AN EFFICIENT PROTOCOL FOR QUANTUM SECURE DIALOGUE WITH AUTHENTICATION BY USING SINGLE PHOTONS
Authors: NASERI MOSAYEB
Published: December 2011

An efficient protocol for quantum secure dialogue by using single photons is proposed. Comparing with the previous protocols, in the proposed protocol, no classical message has been exchanged during the decoding of the secret messages, so the present scheme has not only overcome the drawback "information leakage" or "classical correlation" but also it possesses the characters of security and maximum efficiency. The other highlight of our protocol is that, in this method one party is able to first read the message received from the other party before sending another message back in reply.
NONLINEAR EFFECTS ON THE ENTANGLEMENT BETWEEN QUANTIZED ELECTROMAGNETIC FIELDS AND 3-LEVEL ATOMS
Authors: VASEGHI B. , REZAEI G. , KHORSHIDIAN S.
Published: December 2011

In this paper, we study the entanglement dynamics, its measure, and mean photon number of the field in the interaction between a quantized electromagnetic field and a 3-level atom surrounded by a nonlinear Kerr-like medium. Using the density matrix approach, we have calculated the time evolution of the entanglement and its magnitude at an arbitrary time, for different nonlinear coupling constant. Moreover, to show the effects of nonlinearity on the atom–field interaction and its relation with the entanglement the mean photon number of the field is also presented as a function of nonlinear coupling strength, χ. The results show that, envelope of entanglement fluctuation, their duration and amplitude strongly depend on the nonlinear coupling strength. Since the entanglement decreases with increasing nonlinearity, the mean number of photons reaches a constant value as a result of absorption increment by the surrounding medium.
Cofacial tris-porphyrins with anthracenic spacer
Authors: Rein Régis , Solladié Nathalie
Published: December 2011

In order to check if the parallel orientation of the chlorophylls in the light harvesting antennae of the photosynthetic system plays a key role in the efficiency of the energy transfer process, we synthesized three rigid tris-porphyrins bearing di-ethynyl-anthracenic spacers. The synthesis of this family of trimers in which porphyrins are held in a cofacial orientation by an anthracenic spacer is here described, as well as the NMR comparison between the different porphyrinic wires. This constitutes a first step toward the elaboration of more sophisticated light collecting devices. More specifically, these trimers, in which the porphyrins are held in a parallel conformation, constitute an approach toward the synthesis of rigid molecular wires.
Local tetrahydrobiopterin administration augments reflex cutaneous vasodilation through nitric oxide-dependent mechanisms in aged human skin
Authors: Stanhewicz Anna E. , Bruning Rebecca S. , Smith Caroline J. , Kenney W. Larry , Holowatz Lacy A.
Published: December 2011

Functional constitutive nitric oxide synthase (NOS) is required for full expression of reflex cutaneous vasodilation that is attenuated in aged skin. Both the essential cofactor tetrahydrobiopterin (BH4) and adequate substrate concentrations are necessary for the functional synthesis of nitric oxide (NO) through NOS, both of which are reduced in aged vasculature through increased oxidant stress and upregulated arginase, respectively. We hypothesized that acute local BH4 administration or arginase inhibition would similarly augment reflex vasodilation in aged skin during passive whole body heat stress. Four intradermal microdialysis fibers were placed in the forearm skin of 11 young (22 ± 1 yr) and 11 older (73 ± 2 yr) men and women for local infusion of 1) lactated Ringer, 2) 10 mM BH4, 3) 5 mM ( S)-(2-boronoethyl)-l-cysteine + 5 mM Nω-hydroxy-nor-l-arginine to inhibit arginase, and 4) 20 mM NG-nitro-l-arginine methyl ester (l-NAME) to inhibit NOS. Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasodilation was induced. After a 1.0°C rise in oral temperature (Tor), mean body temperature was clamped and 20 mM l-NAME was perfused at each site. Cutaneous vascular conductance was calculated (CVC = LDF/mean arterial pressure) and expressed as a percentage of maximum (%CVCmax; 28 mM sodium nitroprusside and local heat, 43°C). Vasodilation was attenuated at the control site of the older subjects compared with young beginning at a 0.3°C rise in Tor. BH4 and arginase inhibition both increased vasodilation in older (BH4: 55 ± 5%; arginase-inhibited: 47 ± 5% vs. control: 37 ± 3%, both P < 0.01) but not young subjects compared with control (BH4: 51 ± 4%CVCmax; arginase-inhibited: 55 ± 4%CVCmax vs. control: 56 ± 6%CVCmax, both P > 0.05) at a 1°C rise in Tor. With a 1°C rise in Tor, local BH4 increased NO-dependent vasodilation in the older (BH4: 31.8 ± 2.4%CVCmax vs. control: 11.7 ± 2.0%CVCmax, P < 0.001) but not the young (BH4: 23 ± 4%CVCmax vs. control: 21 ± 4%CVCmax, P = 0.718) subject group. Together these data suggest that reduced BH4 contributes to attenuated vasodilation in aged human skin and that BH4 NOS coupling mechanisms may be a potential therapeutic target for increasing skin blood flow during hyperthermia in older humans.
Evaluating bronchodilator effects in chronic obstructive pulmonary disease using diffusion-weighted hyperpolarized helium-3 magnetic resonance imaging
Authors: Kirby Miranda , Heydarian Mohammadreza , Wheatley Andrew , McCormack David G. , Parraga Grace
Published: December 2011

The objective of this study was to evaluate the regional effects of bronchodilator administration in chronic obstructive pulmonary disease (COPD) using hyperpolarized helium-3 (3He) MRI apparent diffusion coefficient (ADC). Ten COPD ex-smokers provided written, informed consent and underwent diffusion-weighted, hyperpolarized 3He MRI, spirometry, and plethysmography before and 25 ± 2 min after bronchodilator administration. Pre- and postsalbutamol whole-lung (WL) ADC maps were generated and registered together to identify the lung regions containing the 3He signal at both time points, and mean ADC within those regions of interest (ROI) was determined for a measurement of previously ventilated ROI ADC (ADCP). Lung ROI with 3He signal at both time points was used as a binary mask on postsalbutamol WL ADC maps to obtain an ADC measurement for newly ventilated ROI (ADCN). Postsalbutamol, no significant differences were detected in WL ADC ( P = 0.516). There were no significant differences between ADCN and ADCP postsalbutamol ( P = 1.00), suggesting that the ADCN lung regions were not more emphysematous than the lung ROI participating in ventilation before bronchodilator administration. Postsalbutamol, a statistically significant decrease in ADCP ( P = 0.01) was detected, and there were significant differences between ADCP in the most anterior and most posterior image slices ( P = 0.02), suggesting a reduction in regional gas trapping following bronchodilator administration. Regional evaluation of tissue microstructure using hyperpolarized 3He MRI ADC provides insights into lung alterations that accompany improvements in regional 3He gas distribution after bronchodilator administration.
Spike-field activity in parietal area LIP during coordinated reach and saccade movements
Authors: Hagan Maureen A. , Dean Heather L. , Pesaran Bijan
Published: December 2011

The posterior parietal cortex is situated between visual and motor areas and supports coordinated visually guided behavior. Area LIP in the intraparietal sulcus contains representations of visual space and has been extensively studied in the context of saccades. However, area LIP has not been studied during coordinated movements, so it is not known whether saccadic representations in area LIP are influenced by coordinated behavior. Here, we studied spiking and local field potential (LFP) activity in area LIP while subjects performed coordinated reaches and saccades or saccades alone to remembered target locations to test whether activity in area LIP is influenced by the presence of a coordinated reach. We find that coordination significantly changes the activity of individual neurons in area LIP, increasing or decreasing the firing rate when a reach is made with a saccade compared with when a saccade is made alone. Analyzing spike-field coherence demonstrates that area LIP neurons whose firing rate is suppressed during the coordinated task have activity temporally correlated with nearby LFP activity, which reflects the synaptic activity of populations of neurons. Area LIP neurons whose firing rate increases during the coordinated task do not show significant spike-field coherence. Furthermore, LFP power in area LIP is suppressed and does not increase when a coordinated reach is made with a saccade. These results demonstrate that area LIP neurons display different responses to coordinated reach and saccade movements, and that different spike rate responses are associated with different patterns of correlated activity. The population of neurons whose firing rate is suppressed is coherently active with local populations of LIP neurons. Overall, these results suggest that area LIP plays a role in coordinating visually guided actions through suppression of coherent patterns of saccade-related activity.
Enhanced intrinsic excitability and EPSP-spike coupling accompany enriched environment-induced facilitation of LTP in hippocampal CA1 pyramidal neurons
Authors: Malik Ruchi , Chattarji Sumantra
Published: December 2011

Environmental enrichment (EE) is a well-established paradigm for studying naturally occurring changes in synaptic efficacy in the hippocampus that underlie experience-induced modulation of learning and memory in rodents. Earlier research on the effects of EE on hippocampal plasticity focused on long-term potentiation (LTP). Whereas many of these studies investigated changes in synaptic weight, little is known about potential contributions of neuronal excitability to EE-induced plasticity. Here, using whole-cell recordings in hippocampal slices, we address this gap by analyzing the impact of EE on both synaptic plasticity and intrinsic excitability of hippocampal CA1 pyramidal neurons. Consistent with earlier reports, EE increased contextual fear memory and dendritic spine density on CA1 cells. Furthermore, EE facilitated LTP at Schaffer collateral inputs to CA1 pyramidal neurons. Analysis of the underlying causes for enhanced LTP shows EE to increase the frequency but not amplitude of miniature excitatory postsynaptic currents. However, presynaptic release probability, assayed using paired-pulse ratios and use-dependent block of N-methyl-d-aspartate receptor currents, was not affected. Furthermore, CA1 neurons fired more action potentials (APs) in response to somatic depolarization, as well as during the induction of LTP. EE also reduced spiking threshold and after-hyperpolarization amplitude. Strikingly, this EE-induced increase in excitability caused the same-sized excitatory postsynaptic potential to fire more APs. Together, these findings suggest that EE may enhance the capacity for plasticity in CA1 neurons, not only by strengthening synapses but also by enhancing their efficacy to fire spikes—and the two combine to act as an effective substrate for amplifying LTP.
Pathophysiology of the Peritoneal Membrane during Peritoneal Dialysis: The Role of Hyaluronan
Authors: Yung Susan , Chan Tak Mao
Published: December 2011

During peritoneal dialysis (PD), constant exposure of mesothelial cells to bioincompatible PD solutions results in the denudation of the mesothelial monolayer and impairment of mesothelial cell function. Hyaluronan, a major component of extracellular matrices, is synthesized by mesothelial cells and contributes to remesothelialization, maintenance of cell phenotype, and tissue remodeling and provides structural support to the peritoneal membrane. Chronic peritoneal inflammation is observed in long‐term PD patients and is associated with increased hyaluronan synthesis. During inflammation, depolymerization of hyaluronan may occur with the generation of hyaluronan fragments. In contrast to native hyaluronan which offers a protective role to the peritoneum, hyaluronan fragments exacerbate inflammatory and fibrotic processes and therefore assist in the destruction of the tissue. This paper will discuss the contribution of mesothelial cells to peritoneal membrane alterations that are induced by PD and the putative role of hyaluronan in these processes.
Glutamate Transporter GLT-1 Upregulation Attenuates Visceral Nociception and Hyperalgesia via Spinal Mechanisms Not Related to Anti-Inflammatory or Probiotic Effects
Authors: Lin Y. , Roman K. , Foust K. D. , Kaspar B. K. , Bailey M. T. , Stephens R. L.
Published: December 2011

Visceral pain is the most common reason for physician visits in US. Glutamate is the major excitatory neurotransmitter and mediates visceral nociceptive neuro-transmission and hypersensitivity. Removal of extracellular glutamate is predominantly mediated by glial glutamate transporter-1 (GLT-1). The pharmacological approach to up-regulate GLT-1 by 1 week administration of ceftriaxone (CTX) has been successful to mitigate visceral nociception. The present study shows that intrathecal delivery of selective GLT-1 antagonist dihydrokainate reversed CTX-blunted visceral nociceptive response, suggesting a spinal site of action. The role of GLT-1 up-regulation in animal models of colitis was studied. CTX treatment reversed TNBS-induced visceral hypersensitivity. In addition, CTX treatment initiated one week after the onset of DSS-induced visceral inflammation also attenuated visceral hypersensitivity, revealing a potential therapeutic effect. Cephalothin, a cephalosporin antibiotic lacking GLT-1 induction activity, failed to attenuate visceral nociception. CTX-induced changes in fecal microbiota do not support a role of probiotic effects in mitigating visceral nociception/hypersensitivity. Finally, adeno-associated virus serotype 9-mediated GLT-1 over-expression was effective to mitigate visceromotor response to 60 mmHg colo-rectal distension. These studies indicate that GLT-1 over-expression is a novel and effective method to attenuate visceral nociception, and is deserving of further study as a translationally relevant approach to treat visceral pain.
Advances in Application of Natural Clay and Its Composites in Removal of Biological, Organic, and Inorganic Contaminants from Drinking Water
Authors: Srinivasan Rajani
Published: December 2011

Natural clays are abundantly available low-cost natural resource which is nontoxic to ecosystem. Over the recent years, research on the modification of clay to increase their adsorbent capacity to remove other contaminants from drinking water other than metals is in progress. This paper reviews the recent development of natural clays and their modified forms as adsorbing agents for treating drinking water and their sources. This paper describes the versatile nature of natural clay and their ability to adsorb variety of contaminants ranging from inorganic to emerging, which are present in the drinking water. The properties and modification of the natural clay and its significance in removing a specific type of contaminant are described. The adsorbing efficiency of the natural and modified clay in the purification of drinking water, when compared to existing technologies, materials, and methods was found to be significantly higher or comparable.
Repeatedly Nondiagnostic Thyroid Fine-Needle Aspirations Do Not Modify Malignancy Risk
Authors: Jo Vickie Y. , VanderLaan Paul A. , Marqusee Ellen , Krane Jeffrey F.
Published: December 2011

Objective: Thyroid nodules with nondiagnostic (ND) fine-needle aspirations (FNA) typically undergo repeat sampling. While repeat FNA is often diagnostic, little is known regarding the significance of repeatedly ND aspirates. Limited data suggest there is very low, if any, risk of malignancy for repeatedly ND FNAs. Study Design: We performed a retrospective analysis of ND thyroid FNAs over a nearly 6-year period at our institution to further address this question. Results: There were 834 ND thyroid FNAs, representing 694 distinct thyroid nodules. Repeat FNA was performed after an initial ND aspirate in 52% of cases (363/694); 19% (70/363) had at least one additional ND diagnosis on repeat FNA. Surgical follow-up was available for 57 cases. Malignancy was identified histologically in 21% (9/42) of nodules after a single ND FNA and in 20% (3/15) of nodules with 2 or more repeatedly ND aspirates. Accounting for all benign cytologic follow-up, the overall risk of malignancy was 4% [12/303; 3.5% (9/255) following a single ND FNA and 6.3% (3/48) after repeated ND FNAs]. Conclusion: We observed no modification of malignancy risk when repeated FNAs were ND. Clinical management for an ND aspirate should remain repeat aspiration along with clinical and sonographic correlation.
Cytologic Features of Focal Papillary Thyroid Carcinoma Arising within Follicular Adenoma: A Masked Cytomorphologic Analysis of 17 Cases
Authors: Ono J.C. , Wilbur D.C. , Lee H. , Yang J. , Krane J.F. , Bongiovanni M. , Faquin W.C.
Published: December 2011

Background/Objective: Focal papillary thyroid carcinoma (PTC) arising within a follicular adenoma (PTCFA) represents a clinically significant, but rare, histopathologic subset of papillary carcinomas whose cytologic features have not been well described. This uncommon presentation of PTC may contribute to a subset of thyroid aspirates interpreted as ‘atypia of undetermined significance/follicular lesion of undetermined significance’ (AUS/FLUS). Study Design: Seventeen fine-needle aspiration biopsy (FNAB) cases diagnosed as ‘PTCFA’ on corresponding surgical excision were identified from the archival records of 2 large academic medical centers. A control group of 40 FNAB comprised of 20 follicular adenomas (FA) and 20 PTC was identified (based on the corresponding surgical pathology diagnosis) for comparison. All 57 FNAB were reviewed in a masked fashion and scored for a series of 31 cytomorphologic features. The intraclass correlation between diagnostic categories and overall agreement between cytopathologists was statistically evaluated. Results: Aspirates of PTCFA were originally diagnosed as ‘negative’ (n = 3), ‘AUS/FLUS’ (n = 7), ‘suspicious for a follicular neoplasm’ (n = 3), ‘suspicious for malignancy’ (n = 3), and ‘malignant’ (n = 1). On masked review, the most common cytomorphologic features of PTCFA were a nonmacrofollicular cytoarchitectural pattern (71%), medium-large cell size (74%), and micronucleoli (79%). Intranuclear pseudoinclusions and a papillary architecture were absent in 85 and 88% of the cases, respectively. Relative to the 2 control groups, the PTCFA cases demonstrated overlapping features between FA and PTC for the majority of the 31 examined cytomorphologic features. Conclusion: PTCFA represent a rare subset of PTC that is difficult to recognize as PTC by FNAB. Most cases exhibit overlapping features between a benign thyroid nodule and conventional PTC, and they are often interpreted as ‘AUS/FLUS’.
Variability in the Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance Diagnosis in the Bethesda System for Reporting Thyroid Cytopathology: Sources and Recommendations
Authors: Ohori N. Paul , Schoedel Karen E.
Published: December 2011

Objective: Of the 6 categories in the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), the atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) category has received the most attention. The objectives of this study were to review the use of the AUS/FLUS category in recent studies, to search for likely sources of the variability in its use, and to address possible methods for improvement. Study Design: A PubMed search was performed to retrieve peer-reviewed articles that have comprehensively detailed the incidence and outcome of AUS/FLUS and other BSRTC categories. Related thyroid cytology articles on the BSRTC were also included. Results: Recent series that reported experiences with the BSRTC categories showed that the AUS/FLUS category exhibited a marked variability in incidence (0.7–18%) and malignant outcome (6–48%) in resection specimens. Review of the literature revealed institutional differences in technical aspects, interpretation and application of criteria, analysis of outcome data, and clinicopathologic interactions. Conclusions: A heightened awareness of technical issues, diagnostic borders of AUS/FLUS, and clinical management may aid in diagnostic refinement and help avoid overuse of this category.
Resolution of Mitochondrial Oxidative Stress Rescues Coronary Collateral Growth in Zucker Obese Fatty Rats
Authors: Pung Yuh Fen , Rocic Petra , Murphy Michael P. , Smith Robin A.J. , Hafemeister Jennifer , Ohanyan Vahagn , Guarini Giacinta , Yin Liya , Chilian William M.
Published: December 2011

Objective—

We have previously found abrogated ischemia-induced coronary collateral growth in Zucker obese fatty (ZOF) rats compared with Zucker lean (ZLN) rats. Because ZOF rats have structural abnormalities in their mitochondria suggesting dysfunction and also show increased production of O
2
̇̄, we hypothesized that mitochondrial dysfunction caused by oxidative stress impairs coronary collateral growth in ZOF.

Methods and Results—

Increased levels of reactive oxygen species were observed in aortic endothelium and smooth muscle cells in ZOF rats compared with ZLN rats. Reactive oxygen species levels were decreased by the mitochondria-targeted antioxidants MitoQuinone (MQ) and MitoTempol (MT) as assessed by MitoSox Red and dihydroethidine staining. Lipid peroxides (a marker of oxidized lipids) were increased in ZOF by ≈47% compared with ZLN rats. The elevation in oxidative stress was accompanied by increased antioxidant enzymes, except glutathione peroxidase-1, and by increased uncoupling protein-2 in ZOF versus ZLN rats. In addition, elevated respiration rates were also observed in the obese compared with lean rats. Administration of MQ significantly normalized the metabolic profiles and reduced lipid peroxides in ZOF rats to the same level observed in lean rats. The protective effect of MQ also suppressed the induction of uncoupling protein-2 in the obese rats. Resolution of mitochondrial oxidative stress by MQ or MT restored coronary collateral growth to the same magnitude observed in ZLN rats in response to repetitive ischemia.

Conclusion—

We conclude that mitochondrial oxidative stress and dysfunction play a key role in disrupting coronary collateral growth in obesity and the metabolic syndrome, and elimination of the mitochondrial oxidative stress with MQ or MT rescues collateral growth.
A Buddhist Response to Ancient-style Learning: Qisong's Conception of Political Order
Authors: Skonicki Douglas
Published: December 2011

This article focuses on the political thought of the Song-dynasty Chan monk Qisong (1007-1072). In opposition to earlier studies, which have tended to view Qisong's political theorizing simply as an offshoot of his philosophical syncretism, it is contended here that his political arguments played an important role in his refutation of the Ancient-style Learning movement's attacks against Buddhism. As is well known, several Song-dynasty proponents of Ancient-style Learning impugned Buddhism for the negative impact it exerted on Chinese social and political culture. Qisong responded to their attacks by crafting a comprehensive political theory, which sought to demonstrate not only that Ancient-style Learning thinkers had misunderstood the dao and proper governance, but also that Buddhist institutions were indispensable to the creation of political order.
Exploring e-learning development: studies of ICT access and educational usage in Latin America
Authors: Chin-Roemer Robin , DeCrease Ben , Gomez Ricardo
Published: December 2011

This paper examines how the accelerating spread of Information and Communication Technologies (ICTs) in developing countries can be correlated to an increase in the potential for the implementation of e-learning programs and pedagogies. Using data from a University of Washington team’s 2008 landscape study of public access venues, as well as a review of literature in the fields of ICT and e-learning, this document surveys the progress of Latin America and analyzes useful directions for research within and across the topics of e-learning and ICT.
Labor Market Transition and the Impact of Education on Real Per Capita Household Consumption Expenditure in Vietnam
Authors: Kinh Hoang Van , Westbrook Daniel
Published: December 2011

The degree to which the impact of schooling on real per capita household consumption expenditure (rpce) depends on the intensity of local labor market activity was estimated and changes in that relationship during a substantial part of Vietnam’s transition period (1993–2004 were documented). Key variables in the analysis are the years of schooling attained by the best-educated member of each household, an index of labor market activity at the commune level, and the interaction between the two. As schooling is likely to be endogenous, average educational attainment of others in the same age, gender, and commune cohort was used as an instrumental variable (IV). The estimated impact of educational attainment on rpce is economically substantial, statistically significant, increasing over time, and is powerfully enhanced by increasing labor market activity.