bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges in implementing government-directed VTE guidance for medical patients: a mixed methods study
Authors: Basey Avril Janette , Krska Janet , Kennedy Tom D , Mackridge Adam John
Published: November 2012

Background

Implementing venous thromboembolism (VTE) risk assessment guidance on admission to hospital has proved difficult worldwide. In 2010, VTE risk assessment in English hospitals was linked to financial sanctions. This study investigated possible barriers and facilitators for VTE risk assessment in medical patients and evaluated the impact of local and national initiatives.

Setting

Acute Medical Unit in one English National Health Service university teaching hospital.

Methods

This was a mixed methods study; National Research Ethics Service approval was granted. Data were collected over four 1-week periods; November 2009 (1), January 2010 (2), April 2010 (3) and April 2011 (4). Case notes for all medical patients admitted during these periods were reviewed. Thirty-six staff were observed admitting 71 of these patients; 24 observed staff participated in a structured interview.

Results

876 case notes were reviewed. In total, 82.1% of patients had one or more VTE risk factors and 25.3% one or more bleeding risks. VTE risk assessment rose from a baseline of 6.9–19.6%, following local initiatives, and to 98.7% following financially sanctioned government targets. A similar increase in appropriate prescribing of prophylaxis was seen, but inappropriate prescribing also rose. No staff observed in period 1 conducted VTE risk assessment, risk-assessment forms were largely ignored or discarded during period 2; and electronic recording systems available during period 3 were not accessed. Few patients were asked any VTE-related questions in periods 1, 2 or 3.

Interviewees’ actual knowledge of VTE risk was not related to perceived knowledge level. Eight of the 24 staff interviewed were aware of national policies or guidance: none had seen them. Principal barriers identified to risk assessment were: involvement of multiple staff in individual admissions; interruptions; lack of policy awareness; time pressure and complexity of tools.

Conclusions

National financial sanctions appear effective in implementing guidance, where other local measures have failed.
Risk of developing tuberculosis after brief exposure in Norwegian children: results of a contact investigation
Authors: Døllner Henrik , Ramm Christina Terez , Harstad Ingunn , Afset Jan Egil , Sagvik Eli
Published: November 2012

Objective

Prolonged exposure to adults with pulmonary tuberculosis is a risk factor for infecting children. We have studied to what extent a brief exposure may increase the risk of being infected in children.

Design

Observational study of a tuberculosis contact investigation.

Setting

7 day-care centres and 4 after-school-care centres in Norway.

Participants

606 1-year-old to 9-year-old children who were exposed briefly to a male Norwegian with smear-positive pulmonary tuberculosis.

Main outcome measures

Number of children with latent and active tuberculosis detected by routine clinical examination, chest x-ray and use of a Mantoux tuberculin skin test (TST) and an interferon-γ release assay (IGRA).

Results

The children were exposed to a mean of 6.9 h (range 3–18 h). 2–3 months after the exposure, 11 children (1.8%) had a TST ≥6 mm, 6 (1.0%) had TST 4–5 mm, and 587 (97.2%) had a negative TST result. Two children (0.3%) with negative chest x-rays who were exposed 4.75 and 12 h, respectively, had a positive IGRA test result, and were diagnosed with latent tuberculosis. None developed active tuberculosis.

Conclusions

Children from a high-income country attending day-care and after-school-care centres had low risk of being infected after brief exposure less than 18 h to an adult day-care helper with smear-positive pulmonary tuberculosis.
Stratigraphic restriction of stromatolites in a Middle and Upper Ordovician foreland-platform succession (Ottawa Embayment, eastern Ontario)
Authors: Nehza Odette , Dix George R.
Published: November 2012

Stromatolites are abundant and widely distributed within two narrow stratigraphic intervals in Middle (Darriwilian) and Upper (lower Turinian) Ordovician strata of the Laurentian foreland interior in the Ottawa Embayment, eastern Ontario. These lithostratigraphic markers coincide with rapid, tectonically driven flooding of the foreland interior and may identify an opportunistic microbial response to nutrient loading with shallow (peritidal, subtidal) marine reworking of terrestrial or nutrient-rich coastal systems. The remaining (Chatfieldian–Edenian) foreland-platform succession represents deeper-water deposition in response to elevated subsidence rates along the Laurentian margin. Stromatolites are absent in this higher-energy setting, but microbial calcite is preserved as coccoid-like microencrustations on skeletal debris. Stromatolites of Darriwilian age are dolomitic, occur in the Carillon Formation, and are part of a regional (200+ km) onlap of peritidal sediment during onset of Taconic orogenesis. Stratiform to large (2 m diameter) low-relief domal stromatolites contain rhythmic laminations of inclusion-rich and -poor dolomicrospar grouped by Fe-oxide-stained erosional surfaces. Domal forms also contain thrombolitic microstructure. Patterns of lamination and stable (C, O) isotopes suggest a balance between abiotic and microbial carbonate production, likely influenced by water depth and temperature. Stromatolites of Turinian age are calcitic and form a regional (80+ km) thin (<8 m) subtidal biostromal unit in the lowermost Pamelia Formation. Their occurrence defines an abrupt vertical transition from initial intrabasinal transgressive subtidal phosphatic siliciclastics and carbonates to an interbasinal stratigraphy of peritidal lime mudstone. Arrhythmic laminations of microbial peloid packstone, with possible eukaryote alga moulds, and locally evaporitic spongiostromate microstructure identify salinity and energy as primary depositional controls. The stromatolite–?eukaryotic association is similar to some modern subtidal microstructures and is part of the reef-community diversification in the Ordovician.
A new ceratopsid from the Foremost Formation (middle Campanian) of Alberta
Authors: Ryan Michael J. , Evans David C. , Shepherd Kieran M.
Published: November 2012

Xenoceratops foremostensis gen. et. sp. nov., a new centrosaurine ceratopsid from the Foremost Formation (Campanian) of Alberta, is described based on frill material from at least three adult-sized individuals collected from a low-density bone bed. The material can be assigned to Centrosaurinae based on features of the preserved squamosal. Although the parietals are incomplete, the shape of the diagnostic parietal can be inferred from several overlapping serial elements. The parietal of the new taxon shares with all other centrosaurines, except Centrosaurus apertus , spike-like ornamentation at the posterolateral (P3) locus under traditional coding methods. At approximately 78 Ma, it is the oldest known Canadian ceratopsid, approximately 0.5 Ma older than Albertaceratops from the lower Oldman Formation of Canada and approximately 1.0 Ma younger than Diabloceratops from the Wahweap Formation of Utah. A phylogenetic analysis resolves the new taxon as the basalmost centrosaurine and places Centrosaurus brinkmani as the sister taxon to Styracosaurus albertensis . The type species of Centrosaurus brinkmani is moved to a new genus.
LITTLE RIP COSMOLOGICAL MODELS WITH TIME-DEPENDENT EQUATION OF STATE
Authors: BREVIK I. , OBUKHOV V. V. , OSETRIN K. E. , TIMOSHKIN A. V.
Published: November 2012

Specific dark energy models, leading to the Little Rip (LR) cosmology in the far future, are investigated. Conditions for the occurrence of LR in terms of the parameters present in the proposed equation of state for the dark energy cosmic fluid are studied. Estimates about the time needed before the occurrence of the small singularity in the standard LR model in which the universe approaches the de Sitter spacetime asymptotically, are given.
DESIGN DEPENDENT CUTOFF FREQUENCY OF NANOTRANSISTORS NEAR THE ULTIMATE PERFORMANCE LIMIT
Authors: KORDROSTAMI ZOHEIR , SHEIKHI M. HOSSEIN , ZARIFKAR ABBAS
Published: November 2012

We have studied the effect of different structural designs of double gate MOSFETs (DG–MOSFETs) and carbon nanotube field effect transistors (CNTFETs) on the cutoff frequency (fT). The effects of metallic contacts with Schottky barriers, gate work function, dual material gate (DMG), halo doped channel and lightly doped drain and source (LDDS) architectures on the fT have been investigated for DG–MOSFETs and CNTFETs and the design dependent fT for both types of transistors has been studied for the first time. The simulations are based on the Schrödinger–Poisson solvers developed for each nanotransistor separately. The ballistic limit has been studied as the ultimate performance limit of the DG–MOSFETs and CNTFETs. The results of this paper, for the first time, show how some designations used for modification of short channel effects or current–voltage characteristics affect the fT. The results revealed that the cutoff frequencies of both types of the transistors exhibit the same behavior with changing design parameters. We have shown that the Schottky barriers, parasitic capacitances and halo doping reduce the fT and have proposed the DMG and LDDS artchitectures as ways to increase the fT for DG–MOSFETs and CNTFETs for the first time.
THREE-BODY INTERACTIONS BEYOND THE GROSS–PITAEVSKII EQUATION AND MODULATIONAL INSTABILITY OF BOSE–EINSTEIN CONDENSATES
Authors: BELOBO DIDIER BELOBO , BEN-BOLIE GERMAIN HUBERT , KOFANE TIMOLEON CREPIN
Published: November 2012

Beyond the mean-field theory, a new model of the Gross–Pitaevskii equation (GPE) that describes the dynamics of Bose–Einstein condensates (BECs) is derived using an appropriate phase-imprint on the old wavefunction. This modified version of the GPE in addition to the two-body interactions term, also takes into account effects of the three-body interactions. The three-body interactions consist of a quintic term and the delayed nonlinear response of the condensate system term. Then, the modulational instability (MI) of the new GPE confined in an attractive harmonic potential is investigated. The analytical study shows that the three-body interactions destabilize more the condensate system while the external potential alleviates the instability. Numerical results confirm the theoretical predictions. Further numerical investigations of the behavior of solitons reveal that the three-body interactions enhance the appearance of solitons, increase the number of solitons generated and deeply change the lifetime of solitons. Moreover, the external potential delays the appearance of solitons. Besides, a new initial condition is introduced which enables to increase the number of solitons created and deeply affects the trail of chains of solitons generated. Moreover, the MI of a condensate without the external potential, and in a repulsive potential is also investigated.
TRANSITION TO CHAOS IN A CURVED CARBON NANOTUBE UNDER HARMONIC EXCITATION
Authors: GENG YIXIANG , ZHANG LIXIANG
Published: November 2012

The chaotic behavior of a carbon nanotube with waviness along its axis is investigated. The equation of motion involves a quadratic and cubic terms due to the curved geometry and the mid-plane stretching. Melnikov method is applied for the system, and Melnikov criterion for global homoclinic bifurcations is obtained analytically. The numerical solution of the system using a fourth-order-Runge–Kutta method confirms the analytical predictions and shows that the transition from regular to chaotic motion is often associated with increasing the energy of an oscillator. Moreover, a detailed numerical study of the periodic attractor in the period window is also carried out.
THEORETICAL INSIGHTS ON MEASURING QUANTUM CORRELATIONS
Authors: GIROLAMI DAVIDE , VASILE RUGGERO , ADESSO GERARDO
Published: November 2012

We review a recently developed theoretical approach to the experimental detection and quantification of bipartite quantum correlations (QCs) between a qubit and a d-dimensional system. Specifically, introducing a properly designed measure Q, the presented scheme allows us to quantify general QCs for arbitrary states of 2⊗d systems without the need to fully reconstruct them by tomographic techniques. We take in exam the specifics of the required experimental architecture in nuclear magnetic resonance (NMR) and optical settings. Finally we extend this approach to models of open system dynamics and discuss possible advantages and limitations in such a context.
DETERMINISTIC INITIALIZATION OF THE K-MEANS ALGORITHM USING HIERARCHICAL CLUSTERING
Authors: CELEBI M. EMRE , KINGRAVI HASSAN A.
Published: November 2012

K-means is undoubtedly the most widely used partitional clustering algorithm. Unfortunately, due to its gradient descent nature, this algorithm is highly sensitive to the initial placement of the cluster centers. Numerous initialization methods have been proposed to address this problem. Many of these methods, however, have superlinear complexity in the number of data points, making them impractical for large data sets. On the other hand, linear methods are often random and/or order-sensitive, which renders their results unrepeatable. Recently, Su and Dy proposed two highly successful hierarchical initialization methods named Var-Part and PCA-Part that are not only linear, but also deterministic (nonrandom) and order-invariant. In this paper, we propose a discriminant analysis based approach that addresses a common deficiency of these two methods. Experiments on a large and diverse collection of data sets from the UCI machine learning repository demonstrate that Var-Part and PCA-Part are highly competitive with one of the best random initialization methods to date, i.e. k-means++, and that the proposed approach significantly improves the performance of both hierarchical methods.
MULTI-ORIENTED TEXT DETECTION IN SCENE IMAGES
Authors: BASAVANNA M. , SHIVAKUMARA P. , SRIVATSA S. K. , KUMAR G. HEMANTHA
Published: November 2012

We present a new run-length based method for multi-oriented text detection in scene images. We consider one ideal Sobel edge image of the horizontal text image to compute run-lengths for multi-oriented text images. Then the method proposes a Max–Min clustering to find ideal run-lengths that represents text pixel from an array of run-lengths of ideal image. The run-lengths computed for the input multi-oriented and horizontal text images are matched with the ideal run-lengths given by the Max–Min clustering to find potential run-lengths. The boundary growing method is introduced to traverse multi-oriented text lines given by the potential run-lengths and then the method eliminates false positives to clear the background using angle-proximity features of the text blocks. The non-horizontal text image is rotated to horizontal direction based on angle of the text lines to ease the implementation. The method explore new idea based on zero-crossing to separate text lines from the touching text lines given by the boundary growing method. The proposed method is tested on our own multi-oriented scene data captured by high resolution camera and mobile camera, and the benchmark database (ICDAR 2003 competition scene images) to evaluate the performance of the proposed method. The results are compared with the existing methods to show that the proposed method outperforms the existing methods in terms of measures.
PERIODIC ORBITS ASSOCIATED WITH THE LIBRATION POINTS OF THE HOMOGENEOUS ROTATING GRAVITATING TRIAXIAL ELLIPSOID
Authors: ROMANOV VOLODYMYR A. , DOEDEL EUSEBIUS J.
Published: November 2012

We present computational results for the families of periodic orbits that emanate from the five libration points of the homogeneous gravitating triaxial ellipsoid rotating around its small axis, as well as for various secondary bifurcating families. Possible applications of our results include research on the motion of stars and clusters in elliptical galaxies, and the design of space missions to the vicinity of small bodies (asteroids) and their libration points. The numerical continuation and bifurcation algorithms employed in our study are based on boundary value techniques, as implemented in the AUTO software tool.
HYSTERESIS OF PERIODIC AND CHAOTIC PASSIVE Q-SWITCHING SELF-PULSATIONS IN A MOLECULAR LASER MODEL, AND THE STARK EFFECT AS A CODIMENSION-2 PARAMETER
Authors: DOEDEL EUSEBIUS J. , PANDO L. CARLOS L.
Published: November 2012

We give a systematic comparison of a molecular model for a CO 2 laser with a fast saturable absorber and a reduced version of this model. Overall, we find that there is good agreement between these models. We use numerical continuation algorithms to analyze the bifurcation structure of the equations, and complement the results by numerical simulations to model possible experiments. Our study predicts the existence of isolas of periodic passive Q-switching self-pulsations and a rich structure of Q-intervals of stability for these periodic orbits, where Q represents the incoherent pump of the laser. These intervals correspond to the observed phenomenon known as period-adding cascades. Computed loci of codimension-1 bifurcations show that a small shift of a secondary parameter in the reduced model with respect to that of the complete model substantially improves their quantitative agreement. This parameter is associated with the action of the Stark effect in the absorber. We also discuss a necessary condition for chaotic windows to arise as Q changes.
NONLINEAR SECOND SOUND WAVES IN SUPERFLUID HELIUM: INSTABILITIES, TURBULENCE AND ROGUE WAVES
Authors: GANSHIN ANDREY N. , EFIMOV VICTOR B. , KOLMAKOV GERMAN V. , MEZHOV-DEGLIN LEONID P. , McCLINTOCK PETER V. E.
Published: November 2012

Recent work on nonlinear second sound wave propagation and acoustic turbulence in superfluid 4 He is reviewed. Observations of direct and inverse turbulent energy cascades are described. The direct cascade arises due to the strong nonlinear dependence of the second sound wave velocity on its amplitude. The flux of energy injected at the driving frequency is transformed via successively higher harmonics until it is eventually attenuated by viscous dissipation at the short-wavelength edge of the spectrum. The onset of the inverse cascade occurs above a critical driving energy density, and it is accompanied by giant waves that constitute an acoustic analogue of the rogue waves that occasionally appear on the surface of the ocean. The theory of the phenomena is outlined and shown to be in good agreement with the experiments.
AN EXCITABLE ELECTRONIC CIRCUIT AS A SENSORY NEURON MODEL
Authors: MEDEIROS BRUNO N. S. , MINCES VICTOR , MINDLIN GABRIEL B. , COPELLI MAURO , LEITE JOSÉ R. RIOS
Published: November 2012

An electronic circuit device, inspired on the FitzHugh–Nagumo model of neuronal excitability, was constructed and shown to operate with characteristics compatible with those of biological sensory neurons. The nonlinear dynamical model of the electronics quantitatively reproduces the experimental observations on the circuit, including the Hopf bifurcation at the onset of tonic spiking. Moreover, we have implemented an analog noise generator as a source to study the variability of the spike trains. When the circuit is in the excitable regime, coherence resonance is observed. At sufficiently low noise intensity the spike trains have Poisson statistics, as in many biological neurons. The transfer function of the stochastic spike trains has a dynamic range of 6 dB, close to experimental values for real olfactory receptor neurons.
EFFECTS OF QUANTIZATION, DELAY AND INTERNAL RESISTANCES IN DIGITALLY ZAD-CONTROLLED BUCK CONVERTER
Authors: HOYOS FREDY EDIMER , BURBANO DANIEL , ANGULO FABIOLA , OLIVAR GERARD , TORO NICOLAS , TABORDA JOHN ALEXANDER
Published: November 2012

Zero Average Dynamics (ZAD) strategy has been reported in the last decade as an alternative control technique for power converters, and a lot of work has been devoted to analyze it. From a theoretical point of view, this technique has the advantage that it guarantees fixed switching frequency, low output error and robustness, however, no high correspondence between numerical and experimental results has been obtained. These differences are basically due to model assumptions; in particular, all elements in the circuit were modeled as ideal elements and simulations and conclusions about steady state stability and transitions to chaos have been carried out with this ideal model. Regarding the practical point of view and the digital implementation, we include in this paper internal resistances, quantization effects and 1-period delay to the model. This paper shows in an experimental and numerical way the effects of these elements to the model and their incidence in the results. Now, experimental and numerical analyses fully agree.
REGULARIZATION OF TUNNELING RATES WITH QUANTUM CHAOS
Authors: PECORA LOUIS M. , LEE HOSHIK , WU DONG-HO
Published: November 2012

We study tunneling in various shaped, closed, two-dimensional, flat-potential, double wells by calculating the energy splitting between symmetric and antisymmetric state pairs. For shapes that have regular or nearly regular classical behavior (e.g. rectangular or circular) the tunneling rates vary greatly over wide ranges often by several orders of magnitude. However, for well shapes that admit more classically chaotic behavior (e.g. the stadium, the Sinai billiard) the range of tunneling rates narrows, often by orders of magnitude. This dramatic narrowing appears to come from destabilization of periodic orbits in the regular wells that produce the largest and smallest tunneling rates and causes the splitting versus energy relation to take on a possibly universal shape. It is in this sense that we say the quantum chaos regularizes the tunneling rates.
MAXIMIZATION OF EIGENVALUES OF ONE-DIMENSIONAL p-LAPLACIAN WITH INTEGRABLE POTENTIALS
Authors: MENG GANG , YAN PING , ZHANG MEIRONG
Published: November 2012

In this paper we will use variational methods and limiting approaches to give a complete solution to the maximization problems of the Dirichlet/Neumann eigenvalues of the one-dimensional p-Laplacian with integrable potentials of fixed L1-norm.
ON KNOT FLOER HOMOLOGY FOR SOME FIBERED KNOTS
Authors: ROBERTS LAWRENCE
Published: November 2012

We use knot Floer surgery exact sequences and torsion invariants to compute the knot Floer homology of certain fibered knots in the double cover of S3 branched along the closure of an alternating braid.
GROUPOID SYMMETRY AND CONSTRAINTS IN GENERAL RELATIVITY
Authors: BLOHMANN CHRISTIAN , FERNANDES MARCO CEZAR BARBOSA , WEINSTEIN ALAN
Published: November 2012

When the vacuum Einstein equations are cast in the form of Hamiltonian evolution equations, the initial data lie in the cotangent bundle of the manifold [Formula: see text] of Riemannian metrics on a Cauchy hypersurface Σ. As in every Lagrangian field theory with symmetries, the initial data must satisfy constraints. But, unlike those of gauge theories, the constraints of general relativity do not arise as momenta of any Hamiltonian group action. In this paper, we show that the bracket relations among the constraints of general relativity are identical to the bracket relations in the Lie algebroid of a groupoid consisting of diffeomorphisms between space-like hypersurfaces in spacetimes. A direct connection is still missing between the constraints themselves, whose definition is closely related to the Einstein equations, and our groupoid, in which the Einstein equations play no role at all. We discuss some of the difficulties involved in making such a connection. In an appendix, we develop some aspects of diffeology, the basic framework for our treatment of function spaces.
MULTIPLE-TARGET CLASSIFICATION AND TRACKING FOR MOBILE ROBOTS USING A 2D LASER RANGE SCANNER
Authors: KONDAXAKIS POLYCHRONIS , BALTZAKIS HARIS
Published: November 2012

In human–robot interaction developments, detection, tracking and identification of moving objects (DATMO) constitute an important problem. More specifically, in mobile robots this problem becomes harder and more computationally expensive as the environments become dynamic and more densely populated. The problem can be divided into a number of sub-problems, which include the compensation of the robot's motion, measurement clustering, feature extraction, data association, targets' trajectory estimation and finally, target classification. Here, a mobile robot uses 2D laser range data to identify and track moving targets. A Joint Probabilistic Data Association with Interacting Multiple Model (JPDA-IMM) tracking algorithm associates the available laser data to track and provide an estimated state vector of targets' position and velocity. Potential moving objects are initially learned in a supervised manner and later on are autonomously classified in real-time using a trained Fuzzy ART neural network classifier. The recognized targets are fed back to the tracker to further improve the track initiation process. The resulting technique introduces a computationally efficient approach to already existing target-tracking and identification research, which is especially suited for real time application scenarios.
THE DESIGN OF THE iCub HUMANOID ROBOT
Authors: PARMIGGIANI ALBERTO , MAGGIALI MARCO , NATALE LORENZO , NORI FRANCESCO , SCHMITZ ALEXANDER , TSAGARAKIS NIKOS , VICTOR JOSÉ SANTOS , BECCHI FRANCESCO , SANDINI GIULIO , METTA GIORGIO
Published: November 2012

This article describes the hardware design of the iCub humanoid robot. The iCub is an open-source humanoid robotic platform designed explicitly to support research in embodied cognition. This paper covers the mechanical and electronic design of the first release of the robot. A series upgrades developed for the second version of the robot (iCub2), which are aimed at the improvement of the mechanical and sensing performance, are also described.
MODELING AND TESTING PROXEMIC BEHAVIOR FOR HUMANOID ROBOTS
Authors: TORTA ELENA , CUIJPERS RAYMOND H. , JUOLA JAMES F. , VAN DER POL DAVID
Published: November 2012

Humanoid robots that share the same space with humans need to be socially acceptable and effective as they interact with people. In this paper we focus our attention on the definition of a behavior-based robotic architecture that (1) allows the robot to navigate safely in a cluttered and dynamically changing domestic environment and (2) encodes embodied non-verbal interactions: the robot respects the users personal space (PS) by choosing the appropriate distance and direction of approach. The model of the PS is derived from human–robot interaction tests, and it is described in a convenient mathematical form. The robot's target location is dynamically inferred through the solution of a Bayesian filtering problem. The validation of the overall behavioral architecture shows that the robot is able to exhibit appropriate proxemic behavior.
MODULES SATISFYING EXTENSION CONDITIONS UNDER MONOMORPHISM OF THEIR CLOSED SUBMODULES
Authors: Quynh Truong Cong , Tin Phan Hong
Published: November 2012

A right R-module N is called pseudo M-injective if for any submodule A of M, every monomorphism from A to N, can be extended to a homomorphism from M to N. Module M is called pseudo injective if M is pseudo M-injective. Some characterizations of classes modules and its applications to classical rings are studied. In this paper, we consider some generalizations pseudo injective modules under monomorphism of their closed submodules. Their properties are studied.
ANALYTICITY OF SEMIGROUPS GENERATED BY SECOND-ORDER DIFFERENTIAL OPERATORS ON WEIGHTED L2-SPACES
Authors: Rabaoui R. , Saddi A.
Published: November 2012

We study a family of second-order differential operators with unbounded coefficients (and possibly singular). We show that such operators generate analytic semigroups on L2((0, w), ρ2dx), 0 < w ≤ ∞, where dx denotes the Lebesgue measure. The choice of the weight ρ2will depend on the form of the considered operator and on its coefficients.
TOPOLOGICAL CHARACTERIZATION OF DUALLY NORMAL ALMOST DISTRIBUTIVE LATTICES
Authors: Rao G. C. , Rafi N. , Bandaru Ravi Kumar
Published: November 2012

A dually normal almost distributive lattice is characterized topologically in terms of its maximal ideals and prime ideals. Some necessary and sufficient conditions for the space of maximal ideals to be dually normal are obtained.
CONTINUOUS GENERALIZED (θ, ϕ)-SEPARATING DERIVATIONS ON ARCHIMEDEAN ALMOST f-ALGEBRAS
Authors: Toumi Mohamed Ali
Published: November 2012

Let A be an ℓ-algebra and let θ and ϕ be two endomorphisms of A. The couple (θ, ϕ) is called to be separating if xy = 0 implies θ(x)ϕ(y) = 0. If in addition θ and ϕ are ring endomorphisms of A, then the couple (θ, ϕ) is said to be ring-separating. An additive mapping δ : A → A is called (θ, ϕ)-separating derivation on A if there exists a (θ, ϕ)-separating couple with δ(xy) = δ(x)θ(y) + ϕ(x)δ(y), holds for all x, y ∈ A. If an addition θ, ϕ and δ are continuous, then δ is called a continuous (θ, ϕ)-ring-separating derivation. If in addition the couple (θ, ϕ) is ring-separating then δ is called a continuous (θ, ϕ)-ring-separating derivation. An additive mapping F : A → A is called a continuous generalized (θ, ϕ)-separating derivation on A if F is continuous mapping and if there exists a derivation d : A → A such that θ and ϕ are continuous, (θ, ϕ) is a separating couple and F(xy) = F(x)θ(y) + ϕ(x)d(y), holds for all x, y ∈ A. In this paper, we give a description of continuous (θ, ϕ)-ring-separating derivations on some ℓ-algebras. This generalizes a well-known theorem by Colville, Davis, and Keimel [Positive derivations on f-rings, J. Austral. Math. Soc23 (1977) 371–375] and generalizes the results of Boulabiar in [Positive derivations on almost f-rings, Order19 (2002) 385–395], Ben Amor [On orthosymmetric bilinear maps, Positivity14(1) (2010) 123–130] and Toumi et al. in [Order bounded derivations on Archimedean almost f-algebras, Positivity14(2) (2010) 239–245]. Moreover, inspiring from [Toumi, Order-bounded generalized derivations on Archimedean almost f-algebras, Commun. Algebra38(1) (2010) 154–164], it is shown that the notion of continuous generalized (θ, ϕ)-separating derivation on an archimedean almost f-algebra A is the concept of generalized θ-multiplier, that is an additive mapping satisfying F(xyz) = F(x)θ(yz), for all x, y, z ∈ A. In the case where A is an archimedean f-algebra, the situation improves. Indeed, the collection of all continuous generalized (θ, ϕ)-separating derivation on A coincides with the concept of θ-multiplier, that is an additive mapping satisfying F(xy) = F(x)θ(y), for all x, y ∈ A. If in addition A is a Dedekind complete vector lattice and θ is a positive mapping, then the set of all order bounded generalized of the form (θ, ϕ)-separating derivations on A, under composition, is an archimedean lattice-ordered algebra.
Benefits of a 3D geological model for major tunnelling works: an example from Farringdon, east–central London, UK
Authors: Aldiss D. T. , Black M. G. , Entwisle D. C. , Page D. P. , Terrington R. L.
Published: November 2012

In the design of major construction works, the better the ground conditions are known, the more control there is on the assessment of risks for construction, contract and personnel, and ultimately on final costs. Understanding of the ground conditions is usually expressed as a conceptual ground model that is informed by the results of desk study and of dedicated ground investigation. Using the GSI3D software, a 3D geological model (a model composed of attributed solid volumes, rather than of surfaces) can be constructed that exactly honours geologists’ interpretations of the data. The data are used in their true 3D position. The 3D model of faulted Lambeth Group (Palaeogene) strata in the area of the proposed new Crossrail Farringdon underground station, in central London, has several types of benefit. These include allowing optimum use of available ground investigation data, including third party data, with confidence. The model provides an understanding of the local geological structure that had not been possible using other commonly used methods: in particular, it shows the likely distribution of numerous water-bearing coarse deposits and their faulted offsets, which has potentially significant effects on groundwater control. The model can help to focus ground investigation, constrain design and control risk.
Acid-sensing ion channels (ASICs) are differentially modulated by anions dependent on their subunit composition
Authors: Kusama Nobuyoshi , Gautam Mamta , Harding Anne Marie S. , Snyder Peter M. , Benson Christopher J.
Published: November 2012

Acid-sensing ion channels (ASICs) are sodium channels gated by extracellular protons. ASIC1a channels possess intersubunit Cl−-binding sites in the extracellular domain, which are highly conserved between ASIC subunits. We previously found that anions modulate ASIC1a gating via these sites. Here we investigated the effect of anion substitution on native ASICs in rat sensory neurons and heterologously expressed ASIC2a and ASIC3 channels by whole cell patch clamp. Similar to ASIC1a, anions modulated the kinetics of desensitization of other ASIC channels. However, unlike ASIC1a, anions also modulated the pH dependence of activation. Moreover, the order of efficacy of different anions to modulate ASIC2a and -3 was very different from that of ASIC1a. More surprising, mutations of conserved residues that form an intersubunit Cl−-binding site in ASIC1a only partially abrogated the effects of anion modulation of ASIC2a and had no effect on anion modulation of ASIC3. The effects of anions on native ASICs in rat dorsal root ganglion neurons mimicked those in heterologously expressed ASIC1a/3 heteromeric channels. Our data show that anions modulate a variety of ASIC properties and are dependent on the subunit composition, and the mechanism of modulation for ASIC2a and -3 is distinct from that of ASIC1a. We speculate that modulation of ASIC gating by Cl− is a novel mechanism to sense shifts in extracellular fluid composition.
ROS production as a common mechanism of ENaC regulation by EGF, insulin, and IGF-1
Authors: Ilatovskaya Daria V. , Pavlov Tengis S. , Levchenko Vladislav , Staruschenko Alexander
Published: November 2012

The epithelial Na+ channel (ENaC) is a key transporter participating in the fine tuning of Na+ reabsorption in the nephron. ENaC activity is acutely upregulated by epidermal growth factor (EGF), insulin, and insulin-like growth factor-1 (IGF-1). It was also proposed that reactive oxygen species (ROS) have a stimulatory effect on ENaC. Here we studied whether effects of EGF, insulin, and IGF-1 correlate with ROS production in the mouse cortical collecting duct (mpkCCDc14) cells. Western blotting confirmed the expression of the NADPH oxidase complex subunits in these cells. Treatment of mpkCCDc14 cells with EGF, insulin, or IGF-1 evoked an increase in ROS production as measured by CM-H2DCF-DA fluorescence. ROS production caused by a xanthine-xanthine oxidase reaction also resulted in a significant elevation in short-circuit current through the mpkCCDc14 monolayer. Transepithelial current measurements showed an acute increase of amiloride-sensitive current through the mpkCCDc14 monolayer in response to EGF, insulin, or IGF-1. Pretreatment with the nonselective NADPH oxidase activity inhibitor apocynin blunted both ROS production and increase in ENaC-mediated current in response to these drugs. To further test whether NADPH oxidase subunits are involved in the effect of EGF, we used a stable M-1 cell line with a knockdown of Rac1, which is one of the key subunits of the NADPH oxidase complex, and measured amiloride-sensitive currents in response to EGF. In contrast to control cells, EGF had no effect in Rac1 knockdown cells. We hypothesize that EGF, insulin, and IGF-1 have a common stimulatory effect on ENaC mediated by ROS production.
Temporal delays and individual variation in antidiuretic response to desmopressin
Authors: Juul Kristian Vinter , Erichsen Lars , Robertson Gary L.
Published: November 2012

This study aimed to estimate the relationship between pharmacokinetics and the antidiuretic effect of desmopressin. In the investigator-blind, randomized, parallel group study, 5 dose groups and 1 placebo group, each consisting of 12 healthy, overhydrated, nonsmoking male subjects 18–55 yr of age were infused intravenously over 2 h with placebo or 30, 60, 125, 250, and 500 ng desmopressin in 50 ml of normal saline. Plasma desmopressin and urine osmolality rose by variable amounts during the infusions of 60, 125, 250, and 500 ng desmopressin. Plotting mean urine osmolality against the concurrent mean plasma desmopressin yielded a temporal delay between pharmacokinetic (PK) and -dynamic (PD) responses in all dose groups. Using simulation from the indirect-response model, assuming a constant (4 ng/ml) desmopressin concentration, this delay between PK and PD was estimated at 4 h (10th-90th percentile: 1.8–8.1). Within each group, however, there were large individual variations (2- to 10-fold) in the magnitude and duration of the antidiuretic effect. The antidiuretic effect of intravenous desmopressin in water-loaded healthy adults varies considerably due largely to factors other than individual differences in pharmacokinetics. The antidiuretic effect is time as well as dose dependent and may be self-amplifying. The most likely explanation for these findings is that the time required for a given level of plasma desmopressin to exert its maximum antidiuretic effect varies markedly from person to person due to individual differences in the kinetics of one or more of the intracellular mechanisms that promote the reabsorption of solute-free water by principal cells in renal collecting tubules.
Novelty is not enough: laser-evoked potentials are determined by stimulus saliency, not absolute novelty
Authors: Ronga I. , Valentini E. , Mouraux A. , Iannetti G. D.
Published: November 2012

Event-related potentials (ERPs) elicited by transient nociceptive stimuli in humans are largely sensitive to bottom-up novelty induced, for example, by changes in stimulus attributes (e.g., modality or spatial location) within a stream of repeated stimuli. Here we aimed 1) to test the contribution of a selective change of the intensity of a repeated stimulus in determining the magnitude of nociceptive ERPs, and 2) to dissect the effect of this change of intensity in terms of “novelty” and “saliency” (an increase of stimulus intensity is more salient than a decrease of stimulus intensity). Nociceptive ERPs were elicited by trains of three consecutive laser stimuli (S1-S2-S3) delivered to the hand dorsum at a constant 1-s interstimulus interval. Three, equally spaced intensities were used: low (L), medium (M), and high (H). While the intensities of S1 and S2 were always identical (L, M, or H), the intensity of S3 was either identical (e.g., HHH) or different (e.g., MMH) from the intensity of S1 and S2. Introducing a selective change in stimulus intensity elicited significantly larger N1 and N2 waves of the S3-ERP but only when the change consisted in an increase in stimulus intensity. This observation indicates that nociceptive ERPs do not simply reflect processes involved in the detection of novelty but, instead, are mainly determined by stimulus saliency.
Interaction of anesthetics with neurotransmitter release machinery proteins
Authors: Xie Zheng , McMillan Kyle , Pike Carolyn M. , Cahill Anne L. , Herring Bruce E. , Wang Qiang , Fox Aaron P.
Published: November 2012

General anesthetics produce anesthesia by depressing central nervous system activity. Activation of inhibitory GABAA receptors plays a central role in the action of many clinically relevant general anesthetics. Even so, there is growing evidence that anesthetics can act at a presynaptic locus to inhibit neurotransmitter release. Our own data identified the neurotransmitter release machinery as a target for anesthetic action. In the present study, we sought to examine the site of anesthetic action more closely. Exocytosis was stimulated by directly elevating the intracellular Ca2+ concentration at neurotransmitter release sites, thereby bypassing anesthetic effects on channels and receptors, allowing anesthetic effects on the neurotransmitter release machinery to be examined in isolation. Three different PC12 cell lines, which had the expression of different release machinery proteins stably suppressed by RNA interference, were used in these studies. Interestingly, there was still significant neurotransmitter release when these knockdown PC12 cells were stimulated. We have previously shown that etomidate, isoflurane, and propofol all inhibited the neurotransmitter release machinery in wild-type PC12 cells. In the present study, we show that knocking down synaptotagmin I completely prevented etomidate from inhibiting neurotransmitter release. Synaptotagmin I knockdown also diminished the inhibition produced by propofol and isoflurane, but the magnitude of the effect was not as large. Knockdown of SNAP-25 and SNAP-23 expression also changed the ability of these three anesthetics to inhibit neurotransmitter release. Our results suggest that general anesthetics inhibit the neurotransmitter release machinery by interacting with multiple SNARE and SNARE-associated proteins.
Aerothermal Analysis of a Turbine Casing Impingement Cooling System
Authors: Da Soghe Riccardo , Facchini Bruno , Micio Mirko , Andreini Antonio
Published: November 2012

Heat transfer and pressure drop for a representative part of a turbine active cooling system were numerically investigated by means of an in-house code. This code has been developed in the framework of an internal research program and has been validated by experiments and CFD. The analysed system represents the classical open bird cage arrangement that consists of an air supply pipe with a control valve and the present system with a collector box and pipes, which distribute cooling air in circumferential direction of the casing. The cooling air leaves the ACC system through small holes at the bottom of the tubes. These tubes extend at about 180° around the casing and may involve a huge number of impinging holes; as a consequence, the impinging jets mass flow rate may vary considerably along the feeding manifold with a direct impact on the achievable heat transfer levels. This study focuses on the performance, in terms of heat transfer coefficient and pressure drop, of several impinging tube geometries. As a result of this analysis, several design solutions have been compared and discussed.
Molecular Biologic Approach to the Diagnosis of Pancreatic Carcinoma Using Specimens Obtained by EUS-Guided Fine Needle Aspiration
Authors: Kato Kiyohito , Kamada Hideki , Fujimori Takayuki , Aritomo Yuuichi , Ono Masahiro , Masaki Tsutomu
Published: November 2012

We review the utility of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), a rapid, safe, cost-effective, and accurate diagnostic modality for evaluating pancreatic tumors. EUS-FNA is currently used for the diagnosis and staging of pancreatic tumors. The sensitivity of EUS-FNA for pancreatic malignancy ranges from 75% to 94%, and its specificity approaches 100% in most studies. However, EUS-FNA has some limitations in the diagnosis of well-differentiated or early-stage cancers. Recent evidence suggests that molecular biological analysis using specimens obtained by EUS-FNA improves diagnostic sensitivity and specificity, especially in borderline cytological cases. It was also reported that additional information regarding patient response to chemotherapy, surgical resectability, time to metastasis, and overall survival was acquired from the genetic analysis of specimens obtained by EUS-FNA. Other studies have revealed that the analysis of KRAS, MUC, p53, p16, S100P, SMAD4, and microRNAs is helpful in making the diagnosis of pancreatic carcinoma. In this paper, we describe the present state of genetic diagnostic techniques for use with EUS-FNA samples in pancreatic diseases. We also discuss the role of molecular biological analyses for the diagnosis of pancreatic carcinoma.
Generalized Caratheodory Extension Theorem on Fuzzy Measure Space
Authors: Şahin Mehmet , Olgun Necati , Akyıldız F. Talay , Karakuş Ali
Published: November 2012

Lattice‐valued fuzzy measures are lattice‐valued set functions which assign the bottom element of the lattice to the empty set and the top element of the lattice to the entire universe, satisfying the additive properties and the property of monotonicity. In this paper, we use the lattice‐valued fuzzy measures and outer measure definitions and generalize the Caratheodory extension theorem for lattice‐valued fuzzy measures.
Generalized Difference Spaces of Non‐Absolute Type of Convergent and Null Sequences
Authors: Sönmez Abdulcabbar , Başar Feyzi
Published: November 2012

The aim of the present paper is to introduce the spaces and cλ(B) of generalized difference sequences which generalize the paper due to Mursaleen and Noman (2010). These spaces are the BK‐spaces of non‐absolute type and norm isomorphic to the spaces c0 and c, respectively. Furthermore, we derive some inclusion relations determine the α‐, β‐, and γ‐duals of those spaces, and construct their Schauder bases. Finally, we characterize some matrix classes from the spaces , and cλ(B) to the spaces ℓp, c0, and c.
Bilateral Knee Pain Associated with Bone Infarction in a Patient with Behcet's Disease
Authors: Oktayoglu Pelin , Cevik Figen , Tahtasiz Mehmet , Em Serda , Bozkurt Mehtap , Kapukaya Ahmet , Nas Kemal
Published: November 2012

We describe a 31-years-old female patient with severe pain in both knees who had been diagnosed as Behcet’s disease (BD) for 12 years. She had had a history of complications due to BD including superior vena cava thrombosis, pulmonary thromboembolism, uveitis, and erythema nodosum and has reported the administration of corticosteroid therapy irregularly. After radiologic evaluation, she has been diagnosed with bone infarction of both left and right knee with the existance of lupus anticoagulants (LA) positivity. Severe joint pain without the evidence of arthritis must alert the clinician to the possibility of bone necrosis of the extremity, although those may rarely occur bilateral in BD.
On Asymptotically Quasi‐ϕ‐Nonexpansive Mappings in the Intermediate Sense
Authors: Qin Xiaolong , Wang Lin
Published: November 2012

A projection iterative process is investigated for the class of asymptotically quasi‐ϕ‐nonexpansive mappings in the intermediate sense. Strong convergence theorems of common fixed points of a family of asymptotically quasi‐ϕ‐nonexpansive mappings in the intermediate sense are established in the framework of Banach spaces.
OECD/NRC PSBT Benchmark: Investigating the CATHARE2 Capability to Predict Void Fraction in PWR Fuel Bundle
Authors: Del Nevo A. , Rozzia D. , Moretti F. , D’Auria F.
Published: November 2012

Accurate prediction of steam volume fraction and of the boiling crisis (either DNB or dryout) occurrence is a key safety-relevant issue. Decades of experience have been built up both in experimental investigation and code development and qualification; however, there is still a large margin to improve and refine the modelling approaches. The qualification of the traditional methods (system codes) can be further enhanced by validation against high-quality experimental data (e.g., including measurement of local parameters). One of these databases, related to the void fraction measurements, is the pressurized water reactor subchannel and bundle tests (PSBT) conducted by the Nuclear Power Engineering Corporation (NUPEC) in Japan. Selected experiments belonging to this database are used for the OECD/NRC PSBT benchmark. The activity presented in the paper is connected with the improvement of current approaches by comparing system code predictions with measured data on void production in PWR-type fuel bundles. It is aimed at contributing to the validation of the numerical models of CATHARE 2 code, particularly for the prediction of void fraction distribution both at subchannel and bundle scale, for different test bundle configurations and thermal-hydraulic conditions, both in steady-state and transient conditions.