bluuebunny/crossref_metadata_2025 huggingface dataset:
Are we overusing ultrasound in non-traumatic acute abdominal pain?
Authors: Raman S , Somasekar K , Winter R K , Lewis M H
Published: March 2004

Background

Ultrasound is being used increasingly in the assessment of acute non-traumatic abdominal pain as it is non-invasive and does not carry the risk of radiation. However, the inappropriate use of ultrasound can lead to a delayed or incorrect diagnosis, more work for the personnel involved, and increased hospital costs.

Methods

A prospective study was conducted to analyse the clinical indications for requesting an ultrasound in those admitted to a district general hospital with acute non-traumatic abdominal pain, and to assess whether there is a correlation between clinical and laboratory findings and ultrasound results. A total of 110 patients were studied during a three month period.

Results

The results suggest that ultrasound is useful in the investigation of suspected biliary colic and abdominal masses. However, the yield of ultrasound in other patients with acute non-traumatic abdominal pain is low. This study also suggests that the yield of “positive” reports on ultrasound is significantly higher in patients with localised abdominal pain and tenderness and in those with acute abdominal pain and a raised white cell count or raised liver function tests. The yield of positive reports in patients with acute abdominal pain was found to be lower those less than 25 years of age than in older patients.
Analgesia for patients with advanced disease: I
Authors: Hall E J , Sykes N P
Published: March 2004

This series of two articles explores the challenge of managing pain in patients with advanced malignant and non-malignant disease. Pain is a common symptom in advanced disease. Despite guidance from organisations such as the World Health Organisation, cancer pain is often inadequately managed. Managing pain in non-malignant conditions, such as end stage cardiac failure, presents an even greater challenge to healthcare professionals. This first article discusses epidemiology, definitions, pathophysiology, assessment, non-pharmacological approaches, the analgesic “ladder”, and opioids. The second article will examine the use of non-opioids, anaesthetic techniques, and analgesia in dying patients as well as discussing future directions.
SENSORY FEEDBACK IN CNN-BASED CENTRAL PATTERN GENERATORS
Authors: ARENA PAOLO , FORTUNA LUIGI , FRASCA MATTIA , PATANÉ LUCA
Published: March 2004

Central Pattern Generators (CPGs) are a suitable paradigm to solve the problem of locomotion control in walking robots. CPGs are able to generate feed-forward signals to achieve a proper coordination among the robot legs. In literature they are often modelled as networks of coupled nonlinear systems. However the topic of feedback in these systems is rarely addressed. On the other hand feedback is essential for locomotion. In this paper the CPG for a hexapod robot is implemented through Cellular Neural Networks (CNNs). Feedback is included in the CPG controller by exploiting the dynamic properties of the CPG motor-neurons, such as synchronization issue and local bifurcations. These universal paradigms provide the essential issues to include sensory feedback in CPG architectures based on coupled nonlinear systems. Experiments on a dynamic model of a hexapod robot are presented to validate the approach introduced.
ON STABILITY OF CELLULAR NEURAL NETWORKS WITH POLYNOMIAL INTERACTIONS
Authors: CORINTO FERNANDO , GILLI MARCO
Published: March 2004

Cellular neural/nonlinear networks (CNNs) are analog dynamic processor arrays, that present local interconnections. CNN models with polynomial interactions among the cells (Polynomial type CNNs) have been recently introduced. They are useful for solving some complex computational problems and for real-time implementation of PDE-based algorithms. This manuscript provides some simple and rigorous sufficient conditions for stability of polynomial type CNNs. A particular emphasis is given to conditions that can be expressed in terms of template elements, since they can be exploited for design purposes.
FINGERPRINT IMAGE ENHANCEMENT USING CNN FILTERING TECHNIQUES
Authors: SAATCI ERTUGRUL , TAVSANOGLU VEDAT
Published: March 2004

Due to noisy acquisition devices and variation in impression conditions, the ridgelines of fingerprint images are mostly corrupted by various kinds of noise causing cracks, scratches and bridges in the ridges as well as blurs. These cause matching errors in fingerprint recognition. For an effective recognition the correct ridge pattern is essential which requires the enhancement of fingerprint images. Segment by segment analysis of the fingerprint pattern yields various ridge direction and frequencies. By selecting a directional filter with correct filter parameters to match ridge features at each point, we can effectively enhance fingerprint ridges. This paper proposes a fingerprint image enhancement based on CNN Gabor-Type filters.
INFLUENCE OF SYSTEM NON-UNIFORMITY ON DYNAMIC PHENOMENA IN ARRAYS OF COUPLED NONLINEAR NETWORKS
Authors: GALIAS ZBIGNIEW , OGORZAŁEK MACIEJ J.
Published: March 2004

In this paper we investigate the influence of system non-uniformity on the existence and stability of synchronous motion in an array of bi–directionally coupled electronic circuits. In computer simulations we find the level of non-uniformity for which synchronous behavior is sustained. We also present several examples of attractors, which appear when the synchronous motions is no longer stable.
ACE16k: A 128×128 FOCAL PLANE ANALOG PROCESSOR WITH DIGITAL I/O
Authors: CEMBRANO GUSTAVO LIÑAN , RODRÍGUEZ-VÁZQUEZ ANGEL , ESPEJO MEANA SERVANDO , DOMÍNGUEZ-CASTRO RAFAEL
Published: March 2004

This paper presents a new generation 128×128 Focal-Plane Analog Programmable Array Processor -FPAPAP, from a system level perspective. It has been manufactured in a 0.35μm standard digital 1P-5M CMOS technology. It has been designed to achieve the high-speed and moderate-accuracy -8b- requirements of most real time -early-vision applications. External data interchange and control are completely digital. The chip contains close to four million transistors, 90% of them working in analog mode. It achieves peak computing values of 0.33TeraOPS while keeping power consumption at reasonable limits -82.5GOPS/W. Preliminary experimental results are also provided in the paper.
CNN UNIVERSAL MACHINE AS CLASSIFICATON PLATFORM: AN ART-LIKE CLUSTERING ALGORITHM
Authors: BÁLYA DÁVID
Published: March 2004

Fast and robust classification of feature vectors is a crucial task in a number of real-time systems. A cellular neural/nonlinear network universal machine (CNN-UM) can be very efficient as a feature detector. The next step is to post-process the results for object recognition. This paper shows how a robust classification scheme based on adaptive resonance theory (ART) can be mapped to the CNN-UM. Moreover, this mapping is general enough to include different types of feed-forward neural networks. The designed analogic CNN algorithm is capable of classifying the extracted feature vectors keeping the advantages of the ART networks, such as robust, plastic and fault-tolerant behaviors. An analogic algorithm is presented for unsupervised classification with tunable sensitivity and automatic new class creation. The algorithm is extended for supervised classification. The presented binary feature vector classification is implemented on the existing standard CNN-UM chips for fast classification. The experimental evaluation shows promising performance after 100% accuracy on the training set.
COO-FLOW: A PROCESS TECHNOLOGY TO SUPPORT COOPERATIVE PROCESSES
Authors: GRIGORI DANIELA , CHAROY FRANCOIS , GODART CLAUDE
Published: March 2004

In this paper we present a process management technology for the coordination of creative and large scale distributed processes. Our approach is the result of usage analysis in domains like Software Development, Architecture/Engineering/Construction, and e-Learning processes. The basic conclusions of these experiments are the following: (1) cooperative processes are described in the same way as production processes, but these descriptions are interpreted in a different way depending on the nature of the process, (2) the interpretation of process description depends mainly on the required flexibility of control flow and of data flow, and on the relationship between them, (3) the management of intermediate results is a central feature for supporting the cooperation inherent to these processes. COO-flow is a process technology that results from these studies. It is based on two complementing contributions: anticipation that allows succeeding activities to cooperate, and COO-transactions that allows parallel activities to cooperate. This paper introduces COO-flow characteristics, gives a (partial) formalization and briefly discusses its Web implementation.
TAGGING KNOWLEDGE ACQUISITION SESSIONS TO FACILITATE KNOWLEDGE TRACEABILITY
Authors: RICHTER HEATHER , ABOWD GREGORY , MILLER CHRIS , FUNK HARRY
Published: March 2004

Knowledge Acquisition (KA) is important throughout systems development for gathering expert domain knowledge that is incorporated into the requirements and design of a system. There are problems ensuring that accurate and useful knowledge is captured initially, refined as needed, and transferred to later development efforts in a usable format. We present a method, called tagging, for addressing these problems without undue burden on the KA practitioners, along with initial studies to examine the feasibility of real-time tagging and to inform the design of a tool called TAGGER. TAGGER operates by permitting KA discussions to be "tagged" as they happen with concepts and groupings relevant to software development.
A SYSTEMATIC DESIGN METHOD FOR HIGH QUALITY PROCESS-CONTROL SYSTEMS DEVELOPMENT
Authors: WANG DONGFENG , BASTANI FAROKH B. , YEN I-LING
Published: March 2004

Basically, the development of a software system contains specification, design, and implementation. Various specification mechanisms and design methods have been proposed to facilitate the implementation of software systems. However, high system quality cannot be easily assured because of some limitations of these current design methods as well as semantic gaps between the specification mechanisms and the design methods. In particular, manual effort is needed to transform the specification of a system into a design framework for the system. Considering these problems, in this paper, we propose a new system design method. This design method is systematic because by using it, the design framework of a system can be automatically created from the specification of the system. Also, the resulting design framework can support high quality assurance for the system. This design framework is a composition of several individual components, each of which can be completely independently developed and hardened. Further, the system properties (reliability, safety, liveness, etc.) can be mathematically inferred from the properties of the individual components. These components are referred to as IDEAL (Independently Developable End-user Assessable Logical) components and the design method is mainly targeted for continuous process-control systems. The paper develops the approach and illustrates it for a vehicle control system.
SUPPORTING ELICITATION AND SPECIFICATION OF SOFTWARE PROPERTIES THROUGH PATTERNS AND COMPOSITE PROPOSITIONS
Authors: MONDRAGÓN OSCAR A. , GATES ANN Q.
Published: March 2004

Prospec is a tool that assists practitioners in the elicitation and specification of system properties. Practitioners are guided by questions, definitions, and graphics. Prospec introduces the use of composite propositions to identify intended behavior when multiple conditions or events are considered. Multiple conditions or events may represent behavior such as sequences, concurrency, and non-determinism and may define the boundaries of scopes or type of patterns. Prospec is built upon the Specification Pattern System. The tool assists the analyst in making informed decisions about aspects of a specification that may have multiple interpretations. The end product of the tool is a formal specification in Future Interval Logic, Linear Temporal Logic, or Meta Event Definition Language.
NOTTINGHAM LIE ALGEBRAS WITH DIAMONDS OF FINITE TYPE
Authors: CARANTI A. , MATTAREI S.
Published: March 2004

We study a class of positively graded Lie algebras with a pattern of homogeneous components similar to that of the graded Lie algebra associated to the Nottingham group with respect to its lower central series.
PARTIAL ACTIONS OF GROUPS
Authors: KELLENDONK J. , LAWSON MARK V.
Published: March 2004

A partial action of a group G on a set X is a weakening of the usual notion of a group action: the function G×X→X that defines a group action is replaced by a partial function; in addition, the existence of g·(h·x) implies the existence of (gh)·x, but not necessarily conversely. Such partial actions are extremely widespread in mathematics, and the main aim of this paper is to prove two basic results concerning them. First, we obtain an explicit description of Exel's universal inverse semigroup [Formula: see text], which has the property that partial actions of the group G give rise to actions of the inverse semigroup [Formula: see text]. We apply this result to the theory of graph immersions. Second, we prove that each partial group action is the restriction of a universal global group action. We describe some applications of this result to group theory and the theory of E-unitary inverse semigroups.
EXISTENCE THEOREMS OF POSITIVE SOLUTIONS FOR FOURTH-ORDER FOUR-POINT BOUNDARY VALUE PROBLEMS
Authors: LIU YUJI , GE WEIGAO
Published: March 2004

In this paper, we study four-point boundary value problems for a fourth-order ordinary differential equation of the form [Formula: see text] with one of the following boundary conditions: [Formula: see text] or [Formula: see text] Growth conditions on f which guarantee existence of at least three positive solutions for the problems (E)–(B1) and (E)–(B2) are imposed.
ON SOME CLASSES OF LINEARIZABLE REACTION-CONVECTION-DIFFUSION EQUATIONS
Authors: RODRIGO M. , MIMURA M.
Published: March 2004

In this paper, we consider the class of equations ut=[F(x,u)ux+G(x,u)]x+H(x,u). Using hodograph and dependent variable transformations, we determine sufficient conditions on F, G, and H such that this equation is linearizable. We also derive a general quasilinear equation, which includes the Clarkson–Fokas–Ablowitz equation (SIAM J. Appl. Math.49 (1989), 1188–1209), that can be transformed into semilinear form.
QUALITATIVE BEHAVIOR OF SOLUTIONS OF A CERTAIN HYBRID SYSTEM
Authors: SEIFERT GEORGE
Published: March 2004

We study the qualitative behavior of solutions of a system of delay-differential equations of the form [Formula: see text] where α is a positive constant and [t] denotes the greatest integer in t for the specific case f(x)=βx-γx3. We are primarily interested in bounded positive solutions.
AN IMPROVED BIHARMONIC MODEL: INCORPORATING HIGHER-ORDER RESPONSES OF THE PLATE BENDING PHENOMENA
Authors: MADUREIRA ALEXANDRE L.
Published: March 2004

We modify the usual biharmonic model, still frequently used in the engineering community to model linearly elastic plates. In its traditional form, the biharmonic model diverges, in general, since it does not incorporate shear effects. Our changes make it convergent for all loads, under the usual assumption on how the loads depend on the thickness. The idea is to add "higher-order" terms that appear in the asymptotic expansion of the exact solution. The changes can be readily incorporated into engineering codes without degrading the computational performance.
MANIPULATION OF ATOMS AND MOLECULES FOR CONSTRUCTION OF NANOSYSTEMS: THE SCANNING TUNNELING MICROSCOPE AS AN OPERATIVE TOOL
Authors: BRAUN K.-F. , MORESCO F. , MORGENSTERN K. , FÖLSCH S. , REPP J. , HLA S. W. , MEYER G. , RIEDER K. H.
Published: March 2004

Controlled manipulations with scanning tunneling microscope (STM) down to the scale of small molecules and single atoms allow to build molecular and atomic nanosystems, leading to the fascinating possibility of creating manmade structures on atomic scale. Here we present a short review on investigations based on atomic scale manipulation. Upon soft lateral manipulation of adsorbed species, in which only tip/particle forces are used, three different manipulation modes can be discerned: pushing, pulling and sliding. Even the manipulation of strongly bound native substrate atoms is possible. We demonstrate applications as local analytic and synthetic chemistry tools, with important consequences on surface structure research. Vertical manipulation of Xe and CO leads to improved imaging with functionalized tips. With CO deliberately transferred to the tip, we have also succeeded to perform vibrational spectroscopy on single molecules. Furthermore, we describe how we have reproduced a full chemical reaction with single molecules, whereby all basic steps, namely preparation of the reactants, diffusion and association, are induced with the STM tip. Here also field and electron current effects are employed. Finally, we have extended the manipulation techniques to large specially designed molecules by performing lateral manipulation in constant height and realizing the principle of a conformational molecular switch. Artificial nanoscale structures built in atom by atom fashion can serve as quantum laboratories for investigations of various physical properties.
UTILIZING THE COULOMB FORCE ON A CARBON NANOTUBE TO ENHANCE THE RESOLUTION OF ELECTROSTATIC FORCE MICROSCOPE
Authors: HONG T. M. , WU CHIH-HUI , TSENG S. D. , GWO S.
Published: March 2004

Various sources, which affect the resolution of the electrostatic force microscope, are discussed. In addition to an overall hump due to the finite distribution of charges, we find that the electrostatic force versus lateral position plot shows better resolution in certain scanning directions, and in some others it may even exhibit misleadingly different amplitudes from different positions with the same magnitude of charge. Since the electric field measured experimentally is outside of the sample, we need to solve an integral equation to determine the charge distribution. But due to the finite resolution of the probe, the problem can be much simplified by discretizing the space and ending up with the simple process of inverting a matrix. The influence by the image charges from the conducting substrate is automatically taken care of. We describe analytic/numerical calculations for the charge distribution on the nanotube and its atomic force with a conducting surface or a charged cluster. Implication caused by the tilt of the nanotube is also discussed.
DESIGN AND CONSTRUCTION OF A SHORT-TIP TAPPING-MODE TUNING FORK NEAR-FIELD SCANNING OPTICAL MICROSCOPE
Authors: HUANG CHIEN-WEN , LU NIEN-HUA , CHEN CHIH-YEN , YU CHENG-FENG , KAO TSUNG-SHENG , FU YUAN-HSING , TSAI DIN-PING , WANG PEI
Published: March 2004

The design and construction of a tapping-mode tuning fork with a short fiber probe as the force sensing element for near-field scanning optical microscopy is reported. This type of near-field scanning optical microscopy provides a stable and high Q factor at the tapping frequency of the tuning fork, and thus gives high quality NSOM and AFM images of samples. We present results obtained by using the short tip tapping-mode tuning fork near-field scanning optical microscopy measurements performed on the endfaces of a single mode telecommunication optical fiber and a silica-based buried channel waveguide.
SYNTHESIS OF NANOSTRUCTURE CARBONACEOUS MATERIALS ON TIP USING PLASMA-CHEMICAL-VAPOR-DEPOSITION METHOD
Authors: FANG HUI-CHEN , HSIEH YUN-SHUO , TSAU YOU-MING , CHENG HSIU-FUNG , LIN I-NAN
Published: March 2004

Phase transformation of carbonaceous species under the action of high intensity plasma was studied by using a specially designed setup in which a Fe-needle was used as an antenna to absorb microwave and to induce local plasma in the vicinity of needle-tip. Using such a setup, carbon nanotubes have been successfully synthesized on the needle using diamond powder as carbon source and organic iron as catalyst. Variety of nano-structure carbonaceous materials were observed besides carbon nanotubes, e.g., diamond recrystallized as starfruit shaped geometry. Moreover, there exist other kinds of unknown nanostructures on the needle substrate. Some are long, thin, smooth, and some are planar. The characteristics of these unique nanostructured materials will be systematically investigated and the possible growth mechanism will be discussed.
CONDUCTIVITY CHARACTERIZATION USING STM OF POLYPYRROLE ULTRATHIN FILMS PREPARED FROM ADMICELLAR POLYMERIZATION
Authors: YUAN WEI-LI , LIN DING-YAO , CHIANG SEN-CHI
Published: March 2004

Recently admicellar polymerization (AP) has been used to prepare polypyrrole (PPy) ultrathin films of a few nanometers on graphite and mica with success. Surface morphologies of films characterized using atomic force microscopy (AFM) showed interlinked islands of PPy. The electron transport inside such an ultrathin film is believed to take both molecular conduction along the polymer backbones and tunneling conduction between the islands. Conductivity measurement of films formed on insulating mica and conducting indium tin oxide (ITO) glass was performed at controlled humidity using two probes, the needle tip of scanning tunneling microscopy (STM) and a specially designed "enclosing" electrode. The effects of probe spacing and configuration over thick and thin films on the I–V characteristic were studied. Ring configuration of outer electrode was found to form more conduction paths than gird and tube ones at the same probe spacing. Electroconducting films were compared in conductivity with insulating polystyrene (PS) films, showing the latter were without conductance. A model of power law for measuring PPy film conductivity was proposed.
SYNTHESIS AND ORGANIZATION OF II–VI LOW DIMENSION NANOMATERIALS IN NONIONIC AMPHIPHILIC TRIBLOCK COPOLYMER SYSTEMS
Authors: YANG CHUNG-SUNG , KU KUO-LUNG
Published: March 2004

A new synthetic route to prepare II–VI nanoscale materials, such as CdS nanorods and ZnSe nanoparticles is demonstrated and the advantage of using nonionic triblock copolymer systems,i.e., H (– OCH 2 CH 2)x[– OCH ( CH 3)– CH 2]y(– OCH 2 CH 2)y– OH , or ( EO )x( PO )y( EO )x as structure-directing agents in the synthesis of low dimension nanomaterials is introduced. The effect of (EO)/(PO) ratio in controlling the diameter and the morphology of the final product is addressed. The employ of F127 [( EO )106( PO )70( EO )106] as a surfactant-template to study the temperature-dependent size-selection of ZnSe nanoparticles is also presented. We observe that the larger ZnSe nanoparticles are arrested first by the hydrophilic fractions of triblock copolymers F127, while the smaller particles still remain their thermal motion in the aqueous phase.
OPTICAL PROPERTIES OF POPULATED InAs/GaAs QUANTUM DOTS
Authors: LEE JIA-REN , LU C.-R. , LEE W. I. , LEE S. C.
Published: March 2004

The optical properties of InAs/GaAs Quantum Dots have been studied by comparing the photoreflectance and photoluminescence spectra at different temperatures. The photoreflectance relative spectral intensity between the contributions from InAs wetting layer and the GaAs increases with the decreasing of temperature. The photoluminescence spectral profiles consist of contributions from the equal spacing energy levels of the InAs quantum dots. Since the quantum dot transitions were observed in the photoluminescence spectra and the wetting layer transitions were observed in the photoreflectance spectra, we propose that the Fermi level of the system is located between energy level of the wetting layer and the populated energy level of the quantum dots.
FABRICATION OF NEARFIELD OPTICAL PROBE ARRAY USING VARIOUS NANOFABRICATION PROCEDURES
Authors: CHOI S. S. , JUNG M. Y. , KIM J. W. , BOO J. H. , YANG J. S.
Published: March 2004

The nanosize silicon oxide aperture on the cantilever array has been successfully fabricated as nearfield optical probe. The various semiconductor processes were utilized for subwavelength size aperture fabrication. The anisotropic etching of the Si substrate by alkaline solutions followed by anisotropic crystal orientation dependent oxidation, anisotropic plasma etching, isotropic oxide etching was carried out. The 3 and 4 micron size dot array were patterned on the Si(100) wafer. After fabrication of the V-groove shape by anisotropic TMAH etching, the oxide growth at 1000° C was performed to have an oxide etch-mask. The oxide layer on the Si(111) plane have been utilized as an etch mask for plasma dry etching and water-diluted HF wet etching for nanosize aperture fabrication. The Au thin layer was deposited on the fabricated oxide nanosize aperture on the cantilever array. The 160 nm metal apertures on (5×1) cantilever array were successfully fabricated using electron beam evaporator.
NANOTUBE TIP FOR STM
Authors: MIZUTANI WATARU , ABE HIDEKAZU , YASUDA AYUMU , ANDO ATSUSHI , SHIMIZU TETSUO , TOKUMOTO HIROSHI
Published: March 2004

We are investigating electrical properties of multiwalled carbon nanotube (CNT) probes for scanning tunneling microscopy (STM). To improve the electrical conduction and reduce the contamination at the interface to the gold base, we selected conductive CNTs and heated the base and CNT during the CNT attaching process. Before STM measurements, the probes were cleaned by annealing in vacuum for 4–8 h. With these treatments, we found a small number of tips exhibiting linear metallic current–voltage (I–V) curves on Au(111), while all the CNT tips attached on gold (not heated) exhibited nonlinear I–V curves. We discuss the possibility that the metallic behavior of the CNT probes may be caused by the diffused gold atoms along the CNT surfaces by the long heat treatment.
NANOSTRUCTURED SnO2/C COMPOSITE ANODES IN LITHIUM-ION BATTERIES
Authors: HSIEH CHIEN-TE , CHEN JIN-MING , HUANG HSIU-WEN
Published: March 2004

Nanostructured SnO 2/ C composites used as anode materials were prepared by sol–gel synthesis to explore electrochemical properties in lithium-ion batteries. Surface characteristics of the SnO 2/ C nanocomposite were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that nanocrystalline SnO 2/ C with a grain size of 20–50 nm was uniformly dispersed on the carbon surface. After nanocrytalline SnO 2 coated onto carbon, the discharge capacity showed an increase up to 23%, i.e., from 300 to 370 mAh/g at a current density of 0.6 mA/cm2. The nanocomposite anode can achieve a fairly stable discharge capacity and excellent Coulombic efficiency (>99.5%) over 50 cycles. Cyclic voltammograms indicated that the improvements on capacity and cycleability were due to reversible alloying of nanosized Sn and Li on carbon surface.
ELECTROCHEMICAL STORAGE OF HYDROGEN IN CARBON NANOSTRUCTURES
Authors: YU M. S. , CHENG S. Y. , LIN Y. C. , HO W. C.
Published: March 2004

We have synthesized a set of nanostructured carbon samples including a variety of carbon nanotubes and carbonaceous particles, by catalytic thermal decomposition of CH4 on catalyst LaNi 5 powder with different reaction temperatures. Products obtained at reaction temperatures 550~900°C were characterized by means of HR-TEM, SEM and Raman Scattering. In addition, electrochemical charge–discharge cycling method was carried out at room temperature to measure the reversible hydrogen capacity in pressed electrodes containing mixture of catalyst, nanostructured carbon samples and carbonaceous particles. Results showed that the abundance ratio of well-crystallized graphite to amorphous carbon in each product increases with increasing reaction temperatures. This preliminary study showed also that the hydrogen storage capacity of synthesis products measured in an electrochemical half-cell at room temperature correlates with the nanostructure and morphology of the variety of nanostructured carbon samples. Additionally, the hydrogen adsorption capacity against specific surface area (BET) for synthesis products produced at temperatures higher than 670°C is ranging from 14 to 25 wt.%/(1000 m2/g).
He INCORPORATION INTO SMALL CAGE COMPOUNDS: A COMPUTATIONAL STUDY
Authors: SLANINA ZDENĚK , CHOW TAHSIN J.
Published: March 2004

Endohedral cage compounds have been considered as possible candidate species for molecular memories. One class of such endohedrals is represented by cage complexes with encapsulated He. They have been vigorously studied and recently He@C 20 H 20 has been prepared as the yet smallest member of the family. In this report, computations are carried out on three hypothetical endohedral systems: He@C 14 H 16 (iso-garudane and garudane cages), He@C 20, and compared with the available He@C 60 and He@C 20 H 20 species. Geometry optimizations are followed by computations of 3He NMR shifts — a useful tool for observation of He-encapsulates. The geometry optimizations can produce local energy minima for the endohedral systems, though He@C 14 H 16 must obviously be less likely than He@C 20 H 20 as they require a larger cage expansion. The computed 3He NMR shifts are quite sensitive to the cage environment. Kinetic stabilization of He-encapsulates is also discussed.
MAGNETIC FORCE MICROSCOPY STUDY IN PATTERNED PERMALLOY SUBMICRON-WIRES
Authors: HUANG E. W. , YU C. , LEE S. F. , YAO Y. D. , CHEN T. Y. , WONG M. S. , CHANG C. R. , HAN B. S. , MA Y. R.
Published: March 2004

Advances in real-time magnetic force microscopy (MFM) permit us to directly observe the domain structures under magnetic field, which enable us to understand magnetic phenomena in nanostructure with controlled shapes. Magnetoresistance change is a complementary way to understand the magnetization reversal process, e.g., domain wall formation and annihilation. Using systematic pattern design, we arrange Permalloy octagons in chains to study the associated domain configurations inferred from real-time MFM and MR loop
PITCH MEASUREMENT BY TRACEABLE ATOMIC FORCE MICROSCOPE
Authors: CHEN CHAO-JUNG , CHEN YEN-LIANG , CHANG LIANG-CHIH
Published: March 2004

A Traceable Atomic Force Microscope (TAFM) to calibrate the pitch standards is presented. The TAFM consists of an atomic force microscope, a three-axis active compensation flexure stage, two laser interferometers, an L-shape mirror, a vibration isolator, and a super-Invar metrology frame. A test specimen is laid on the same plane of laser interferometers to eliminate the Abbe-offset. The displacements of X and Y axes are taken by the laser interferometers, the Z movement is controlled by AFM cantilever and the displacement is taken by a capacitance sensor while the flexure stage moves the specimen in X and Y axes motions. A water circulator is used to control the TAFM at 20°C. Measuring results of a standard pitch sample show that this TAFM can be used for measuring of pitch standards. A pitch standard with nominal value of 292 nm was served as a test sample. The combined standard uncertainty was 1.2 nm.
A COMPARISON BETWEEN THE ATOMIC FORCE MICROSCOPY AND X-RAY REFLECTIVITY ON THE CHARACTERIZATION OF SURFACE ROUGHNESS
Authors: LEE CHIH-HAO , PEN WEN-YEN , LIN MING-ZHE , YU KUAN-LI , HSUEH JEN-CHUNG
Published: March 2004

Atomic force microscopy and X-ray reflectivity methods are used to characterize a surface morphology which includes the information of rms roughness, roughness exponent, and the height–height correlation length. Two major reasons to interpret the discrepancy of rms roughness data measured by AFM and X-ray reflectivity are (1) the bandpass of power spectra density is different and (2) the X-ray reflectivity probes the high density buried layer.
SCANNING PROBE ANALYSIS OF DEFECTS INDUCED BY SLIGHT IRON CONTAMINATION ON THERMALLY OXIDIZED p-TYPE SILICON WAFERS
Authors: CHANG M. N. , CHEN C. Y. , PAN F. M. , CHANG T. Y. , LEI T. F.
Published: March 2004

In this article, we have demonstrated the investigation of scanning probe microscopy on the defects induced by slight iron contamination on p-type Si wafers with ultrathin thermal oxide layer. Using scanning capacitance microscopy (SCM) associated with atomic force microscopy, it is revealed that iron contamination induces interface traps, which significantly perturb the depletion behavior of the silicon surface. Moreover, experimental results also indicate that iron contamination leads to the lifetime decrease and the density increase of minority carriers in the defect region. From the dC/dV–V profiles, the defect region with the highest density of the interface traps also has the highest density of the deep-level traps. At a proper dc bias, the defect region clearly exhibits an obvious contrast in the SCM images.
RESONANCE BAND IN Ge/Si SUPERLATTICE STUDIED BY RAMAN SCATTERING
Authors: LIN C. H. , CHEN B. , CHIA C. T. , CHENG H. H.
Published: March 2004

We have performed the low-frequency Raman measurement of MBE grown Ge/Si superlattice. Raman spectra were excited by He–Ne laser, and diode-pump YAG 532 nm laser, as well as several lines from Ar+ laser. Folded acoustic phonons of the Ge/Si superlattice were clearly found. The resonant effects were observed for the Ge/Si superlattices while the Raman spectra excited by the laser lines around 500 nm. A clearly resonance enhanced phonon signals are found for the spectrum excited by 532 nm laser line, and continuous emission can be clearly seen. By the continuous emission theory, we carried out a resonance band at 2.32 eV, which is closed to the E1 band of Germanium. Few weak resonant bands were also found near 2.32 eV, which may be related to confined band or the resonance band of interface layer between Si and Ge .
ELECTROREFLECTANCE CHARACTERIZATION OF THE Ge/Si GROOVE ISLAND STRUCTURES
Authors: CHEN YO-YU , LIN S. C. , LU C. R. , CHIA C. T. , CHANG H. H.
Published: March 2004

The optical properties of Ge/Si groove island structures were investigated by the electroreflectance spectroscopy at various temperatures. Optical transitions involving the groove islands near the spectral range of 2~2.5 eV were observed. When the Ge growth temperature is decreased, the three-dimensional growth of the Ge island on the wetting layer is suppressed and the Ge/Si intermixing formation of stacking grooves in the Si layers is enhanced. The corresponding spectral intensity is increased and the transition energy is reduced due to the quantum confinement effect.
Developing and Using the Guide to Community Preventive Services: Lessons Learned About Evidence-Based Public Health
Authors: Briss Peter A. , Brownson Ross C. , Fielding Jonathan E. , Zaza Stephanie
Published: March 2004

The Guide to Community Preventive Services (Community Guide) is being developed under the leadership of the independent, nonfederal Task Force on Community Preventive Services. The Task Force makes recommendations for the use of public health programs and policies based on scientific evidence about what practices have worked to improve health. The Community Guide thoroughly searches scientific literature for topic-relevant studies, evaluates their quality according to established criteria, and makes recommendations based on the overall strength of the body of evidence and the size and variability of reported effects. In addition, the Community Guide identifies promising interventions that have not been adequately researched, thus helping to inform the public health research agenda. The continuously updated and expanded body of recommendations and research agenda formulated by this rigorous process have been published on the Internet and in various publications since 1999 and constitute a highly valued and objective evidence-based resource for guiding current and future public health activities. More remains to be learned, however, on how best to disseminate Community Guide findings to key target audiences and encourage their use to inform practice, policy, and additional research.
Implications of the Precautionary Principle for Primary Prevention and Research
Authors: Grandjean Philippe
Published: March 2004

The precautionary principle (PP) is an extension of the public health presage that prevention is better than cure. The PP has recently achieved new relevance in regard to serious but uncertain threats to human health and the environment and has now entered national and international legislation. However, frameworks for its unambiguous application in practice are yet to be designed. They will depend on legal and cultural circumstances and are likely to involve pluralities of perspectives and stakeholder participation. The rules for causal reasoning and dose dependence need to be addressed and may be conveniently expressed in accordance with probability theory. Although the PP will allow action before convincing evidence is secured, it is not science averse. However, it provides an occasion to review environmental health research strategies, methodologies, and research-reporting traditions. From this perspective, current research is afflicted by important biases and insufficient focus on major environmental health problems.
Can Dementia Be Prevented? Brain Aging in a Population-Based Context
Authors: Haan Mary N. , Wallace Robert
Published: March 2004

As a consequence of global aging of the human population, the occurrence of cognitive impairment and dementia is rapidly becoming a significant burden for medical care and public health systems. By the year 2020, the WHO predicts there will be nearly 29 million demented people in both developed and developing countries. Primary and secondary prevention of dementia through individual and population-level interventions could reduce this imminent risk. Vascular risk factors such as type 2 diabetes, hypertension, dietary fat intake, high cholesterol, and obesity have emerged as important influences on the risk of both vascular and Alzheimer's dementia. Understanding the reasons for differences between populations in genetic vulnerability and environmental exposures may help to identify modifiable risk factors that may lead to effective prevention of vascular and Alzheimer's dementia.
Issues of Agricultural Safety and Health
Authors: Frank Arthur L. , McKnight Robert , Kirkhorn Steven R. , Gunderson Paul
Published: March 2004

▪ Abstract  Agricultural work is the most prevalent type of employment in the world. In the United States only a few are engaged in creating food and fiber for many. Agriculture includes farming, ranching, fishing, and forestry, and together they carry significant risk for the development of injury or illness. There are numerous special-population issues related to agriculture. Farmers are old and growing older, many workers are children, and migrant and seasonal help, often foreign born, make up a large percentage of the workforce. It has been only relatively recently that concerns of agricultural safety and health have become a major research focus in the United States.
Health Effects of Chronic Pesticide Exposure: Cancer and Neurotoxicity
Authors: Alavanja Michael C.R. , Hoppin Jane A. , Kamel Freya
Published: March 2004

Pesticides are widely used in agricultural and other settings, resulting in continuing human exposure. Epidemiologic studies indicate that, despite premarket animal testing, current exposures are associated with risks to human health. In this review, we describe the routes of pesticide exposures occurring today, and summarize and evaluate the epidemiologic studies of pesticide-related carcinogenicity and neurotoxicity in adults. Better understanding of the patterns of exposure, the underlying variability within the human population, and the links between the animal toxicology data and human health effects will improve the evaluation of the risks to human health posed by pesticides. Improving epidemiology studies and integrating this information with toxicology data will allow the human health risks of pesticide exposure to be more accurately judged by public health policy makers.
International Differences in Drug Prices
Authors: Wagner Judith L. , McCarthy Elizabeth
Published: March 2004

This paper addresses how and why drug prices differ across countries. Studies of international variation in drug prices reach varied conclusions owing to methodological and data disparities. Price differences do exist across countries, with the United States footing the highest bill, but the differences are not nearly as large as they appear at first glance.

The higher prices in the United States are concentrated among a subset of brand-name drugs and among those without insurance covering drugs. Some U.S. health plans obtain price concessions from manufacturers similar to those obtained by national governments. Price concessions occur whenever purchasers are willing to let price be a consideration in decisions about access and utilization.

In low-income countries the vast majority are unwilling to pay for effective drugs simply because they are unable to pay. Low-income nations need more price discrimination—and vastly lower prices—if they are ever to afford the world's most effective medicines.
Lessons Learned from Public Health Mass Media Campaigns: Marketing Health in a Crowded Media World
Authors: Randolph Whitney , Viswanath K.
Published: March 2004

Every year, new public health mass media campaigns are launched attempting to change health behavior and improve health outcomes. These campaigns enter a crowded media environment filled with messages from competing sources. Public health practitioners have to capture not only the attention of the public amid such competition, but also motivate them to change health behaviors that are often entrenched or to initiate habits that may be new or difficult. In what ways are public health mass media campaigns now attempting to succeed in a world crowded with media messages from a myriad of sources? What are the conditions that are necessary for a media campaign to successfully alter health behaviors and alter outcomes in the long term? To what extent can the successes and failures of previous campaigns be useful in teaching important lessons to those planning campaigns in the future? In this chapter we attempt to answer these questions, drawing from recent literature on public health mass media campaigns.
Economic Implications of Increased Longevity in the United States
Authors: Rice Dorothy P. , Fineman Norman
Published: March 2004

The elderly population in America is growing in size owing to declining death rates, increasing life expectancy, and the aging of the baby boomers. Although the prevalence of chronic illness and disability increases with age, successful aging in the elderly population is widespread, and the elderly are generally healthy. Indeed, the prevalence of disability among the elderly is declining, and expenditures for their care are increasingly concentrated at the end of life rather than during extra years of relatively healthy life. Nevertheless, health care costs will undoubtedly increase during the next 30 years as a result of the baby boomers entering late life. The economic and social impact of future growing health care expenditures for the elderly will be significant. Important policy issues will include the continued viability of the Medicare and Social Security programs, future needs for long-term care, improvement of the health status of the elderly, technological advances, the need for a geriatric work force, and development of viable strategies to pay for escalating medical care costs.
Assuring the Health of Immigrants: What the Leading Health Indicators Tell Us
Authors: Kandula Namratha R. , Kersey Margaret , Lurie Nicole
Published: March 2004

Over the past 20 years, the United States has experienced one of the largest waves of immigration in its history. Understanding the health status and needs of immigrants is important because of their growing numbers and their contribution to the health of the nation, but it is challenging because of gaps in national databases, the heterogeneity of immigrant populations, and uncertainty about how migration affects health. Healthy People 2010 outlines the nation's public health objectives for the current decade. It includes ten leading health indicators (LHIs) chosen because of their importance as public health issues, their ability to motivate action, and the availability of data to measure their progress. In this paper, we discuss the health of immigrants from the perspective of these LHIs, as they provide a framework for anticipating some of the future health needs of immigrants and help define priority areas for research and action.
Public Health Surveillance of Low-Frequency Populations
Authors: Andresen Elena M. , Diehr Paula H. , Luke Douglas A.
Published: March 2004

Public health agencies often require data that address the needs of special populations, such as minority groups. Sources of surveillance data often contain insufficient numbers of subjects to fully inform health agencies. In this review, we address the problems of and potential approaches for situations with insufficient surveillance data. We use the examples of race and ethnic minority groups throughout our discussion. However, many of the broad issues are applicable to other special groups with low frequency or who are especially hard to reach. Our recommendations are based, in part, on a symposium held in Missouri with the collaboration of state health agency, community, and academic research participants. We review problems in using existing data and collecting new data, especially from nonprobability samples. We also describe fieldwork issues for reaching and collecting information from special populations. Decisions among methods and solutions may require seeking additional resources for surveillance.
The Current State of Public Health in China
Authors: Lee Liming
Published: March 2004

In the past 50 years, China has made great achievements in controlling infectious diseases and improving the public's health and hygiene. However, in the twenty-first century, owing to the negative effects brought on by aging of the population and the burdens of diseases, urbanization, industrialization, and globalization, Chinese public health officials are encountering greater difficulties than ever. Old operating models of public health cannot meet present requirements. The main problems are poor capacity to respond to public health emergencies, severe inequality of health care services, and lagging development of public health information systems. Public health in China can gradually meet the requirements of social development and the increasing public demand for health care services only when the public health is directed by informatization, globalization, technification, and humanization.