bluuebunny/crossref_metadata_2025 huggingface dataset:
Site‐specific encounters, norms and crowding of summer visitors at alpine ski areas
Authors: Needham Mark D. , Rollins Rick B. , Wood Colin J.B.
Published: December 2004

Operating chairlifts at alpine ski areas during the summer to accommodate tourism and recreation activities (e.g. hiking and mountain biking) is increasing in popularity. Increasing summer use, however, may affect the ability of ski areas to sustain acceptable social conditions (e.g. crowding). In addition, little is known about encounters, crowding or acceptable use levels at ski areas during the summer. This article addresses these issues using data from surveys of summer visitors (n = 548) conducted at five separate sites in the Whistler Mountain ski area in British Columbia, Canada. Photographs and Likert‐type scales measured visitors' encounters with others, perceived crowding and acceptance of use levels. Results showed that: (i) crowding and encounters differed among the sites; (ii) visitors at the backcountry sites rated encounters as less acceptable and possessed greater agreement regarding acceptable encounter levels compared with visitors at the more accessible sites; (iii) crowding and encounters were important indicators of summer use at each site; and (iv) visitors who felt more crowded encountered more people than their normative tolerances. Explanations for these findings and implications for managers and researchers are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Paths to deutero‐learning through successive process simulations: a case study
Authors: Haho Päivi
Published: December 2004

This paper discusses the dynamic interaction between organizational learning processes and their outcomes in the context of innovative business process development and change projects in a pharmaceutical company. Through the answers to the research questions, I wish to demonstrate the paths to deutero‐learning, which seldom can be empirically identified in an organization. The paper uses notions of strategic, operational and cultural outcomes—including their intangible and tangible manifestations—to explain different results in organizational learning processes.

From 1998 to 1999, the pharmaceutical case company applied an evolutionary, process simulation‐based business process development method. This method was used to invent and implement business process innovations in the New Product Development process, to shorten the time‐to‐market of its new medical entities. Successive process simulations guided and focused the business process development and actions on the strategically most valuable areas. The process simulations prepared the organization for the change, and promoted the implementation of the process outcomes.

The successive simulations have triggered and thereafter sustained individual and organizational learning. Thus, they have accelerated organizational learning processes and the development of knowledge and innovations. The case demonstrates efficient deutero‐learning, enabled through empowered successive process simulations. The results indicate that development projects are more successful, if there are intangible learning outcomes and systemic process learning at the early stages of the project. This also supports double‐loop learning in the business process development project and assists changes in norms to occur. Copyright © 2004 John Wiley & Sons, Ltd.
Simulated rainfall evaluation of revegetation/mulch erosion control in the Lake Tahoe Basin—1: method assessment
Authors: Grismer M. E. , Hogan M. P.
Published: December 2004

Revegetation of road cuts and fills is intended to stabilize those drastically disturbed areas so that sediment is not transported to adjacent waterways. Sediment has resulted in water quality degradation, an extremely critical issue in the Lake Tahoe Basin. Many revegetation efforts in this semiarid, subalpine environment have resulted in low levels of plant cover, thus failing to meet project goals. Further, no adequate physical method of assessing project effectiveness has been developed, relative to runoff or sediment movement. This paper describes the use of a portable rainfall simulator (RS) to conduct a preliminary assessment of the effectiveness of a variety of erosion‐control treatments and treatment effects on hydrologic parameters and erosion. The particular goal of this paper is to determine whether the RS method can measure revegetation treatment effects on infiltration and erosion. The RS‐plot studies were used to determine slope, cover (mulch and vegetation) and surface roughness effects on infiltration, runoff and erosion rates at several roadcuts across the basin. A rainfall rate of ≈60 mm h−1, approximating the 100‐yr, 15‐min design storm, was applied over replicated 0·64 m2 plots in each treatment type and over bare‐soil plots for comparison. Simulated rainfall had a mean drop size of ≈2·1 mm and approximately 70% of ‘natural’ kinetic energy. Measured parameters included time to runoff, infiltration, runoff/infiltration rate, sediment discharge rate and average sediment concentration as well as analysis of total Kjeldahl nitrogen (TKN) and dissolved phosphorus (TDP) from filtered (0·45 μm) runoff samples. Runoff rates, sediment concentrations and yields were greater from volcanic soils as compared to that from granitic soils for nearly all cover conditions. For example, bare soil sediment yields from volcanic soils ranged from 2–12 as compared to 0·3–3 g m−2 mm−1 for granitic soils. Pine‐needle mulch cover treatments substantially reduced sediment yields from all plots. Plot microtopography or roughness and cross‐slope had no effect on sediment concentrations in runoff or sediment yield. RS measurements showed discernible differences in runoff, infiltration, and sediment yields between treatments. Runoff nutrient concentrations were not distinguishable from that in the rainwater used. Copyright © 2004 John Wiley & Sons, Ltd.
On‐line detection of the gate freezing‐off time for injection molding
Authors: Chen Xi , Gao Furong
Published: December 2004

A robust on‐line detection system for estimating the gate freezing‐off time, which is useful for monitoring and control of injection molding, was developed based on an analysis of the correlation changes around the gate freeze‐off time, as reflected in the changes of the screw movement and nozzle pressure (NP). Experiments showed that the gate freezing‐off time can be accurately detected under different molding conditions. POLYM. ENG. SCI., 45:33–41, 2005. © 2004 Society of Plastics Engineers.
On the molecular structure that produces the phosphorescence of 7‐azaindole
Authors: Catalán J.
Published: December 2004

The structured phosphorescence with a 0–0 component at ∼430 nm exhibited by 7‐azaindole is not due to its monomer, its normal or tautomeric C2h dimer, or its oligomeric forms consisting of five monomers, but rather to a molecular structure resulting from the interaction of the C2h dimer with a polar molecule (7‐azaindole itself, another solute or the solvent). Such an interaction breaks the C2h symmetry of 7‐azaindole dimer, thereby facilitating the localization of the electronic excitation on one of the dimer molecules and resulting in the presence of dimers of C1 symmetry. Based on the results, the structure that produces this phosphorescence is a normal dimer exhibiting a double hydrogen bond but no symmetry constraint. Surprisingly, its first triplet state, T(DC1), is ∼20 kcal/mol below the first triplet state for the system of C2h symmetry. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A comparative review on leukocyte and tumor cell migration with regard to the regulation by serpentine receptor ligands
Authors: Entschladen Frank , Drell Theodore L. , Palm Daniel , Bastian Philipp , Potthoff Stefanie , Zänker Kurt S. , Lang Kerstin
Published: December 2004

Migration is an essential function of cells; it is involved in reproduction and embryogenesis, as well as in the cellular, immunological defense of an organism against pathogens. On the pathological site, migration of tumor cells represents a pernicious step in the progression of cancer, because it is the prerequisite for invasion and metastasis development. In either case, migration is not an intrinsic property, but a cell function which is regulated by extracellular signal substances. The most prominent of these regulatory factors are ligands to serpentine receptors, e.g. chemokines and neurotransmitters. Many types of chemokine and neurotransmitter receptors are expressed on leukocytes and tumor cells, constituing a highly integrated interaction‐network of tumor cells, the nervous system, and the immune system. In this review we summarize current knowledge on the regulation of leukocyte and tumor cell migration by such ligands to serpentine receptors, and we furthermore highlight the differences between these cells in the intracellular processing of the regulatory signals. With this knowledge of the differences in the regulation of leukocyte and tumor cell migration it might be possible to develop strategies to selectively inhibit tumor cell migration and metastasis development without an impairment of the physiological migration, e.g. of leukocytes.
Deconstructing the bomb: recent perspectives on nuclear history
Authors: HUGHES J.
Published: December 2004

John Canaday,The Nuclear Muse: Literature, Physics, and the First Atomic Bombs. Madison: University of Wisconsin Press, 2000. Pp. xviii+310. ISBN 0-299-16854-9. £19.50.

Septimus H. Paul,Nuclear Rivals: Anglo-American Atomic Relations 1941–1952. Columbus: Ohio State University Press, 2000. Pp. ix+266. ISBN 0-8142-0852-5. £31.95.

Peter Bacon Hales,Atomic Spaces: Living on the Manhattan Project. Urbana and Chicago: University of Illinois Press, 1997. Pp. 448. ISBN 0-252-02296-3. £22.00.

A decade after the end of the Cold War, the culture and technology of nuclear weapons had lost much of the overt sense of dread they once inspired. The decline in international tension following the end of the communist regimes of the Soviet bloc produced a massive shift in the ideology of the nuclear in the 1990s. The de-targeting and dismantling of large numbers of nuclear weapons and the demise of the threat of nuclear annihilation created new conditions both for international security and for the writing of nuclear history. With the declassification and release of large quantities of official documentation from the former adversaries, as well as the fiftieth anniversary of the bombings of Hiroshima and Nagasaki in 1995, a burst of histories of various aspects of the nuclear age have appeared over the last ten years, exploring not just the technopolitics, strategy and operational logistics of the Cold War and the arms race, but the cultural history of the nuclear age, its imagery, its architecture, its oppositional politics and its effects on the landscape, national and regional economies and cultures and indeed everyday life. At a time of global economic and political uncertainty and the emergent threat of capricious international terrorism and new nuclear proliferation, the apparent certainties of the Cold War now even evoke a certain nostalgia, and its artefacts and structures are being recast as ‘heritage’.
A new method for measuring deformation on volcanoes and other natural terrains using InSAR persistent scatterers
Authors: Hooper Andrew , Zebker Howard , Segall Paul , Kampes Bert
Published: December 2004

We present here a new InSAR persistent scatterer (PS) method for analyzing episodic crustal deformation in non‐urban environments, with application to volcanic settings. Our method for identifying PS pixels in a series of interferograms is based primarily on phase characteristics and finds low‐amplitude pixels with phase stability that are not identified by the existing amplitude‐based algorithm. Our method also uses the spatial correlation of the phases rather than a well‐defined phase history so that we can observe temporally‐variable processes, e.g., volcanic deformation. The algorithm involves removing the residual topographic component of flattened interferogram phase for each PS, then unwrapping the PS phases both spatially and temporally. Our method finds scatterers with stable phase characteristics independent of amplitudes associated with man‐made objects, and is applicable to areas where conventional InSAR fails due to complete decorrelation of the majority of scatterers, yet a few stable scatterers are present.
Particle‐in‐cell simulations of electron acceleration by a simple capacitative antenna in collisionless plasma
Authors: Dieckmann M. E. , Rowlands G. , Eliasson B. , Shukla P. K.
Published: December 2004

We examine the electron acceleration by a localized electrostatic potential oscillating at high frequencies by means of particle‐in‐cell (PIC) simulations, in which we apply oscillating electric fields to two neighboring simulation cells. We derive an analytic model for the direct electron heating by the externally driven antenna electric field, and we confirm that it approximates well the electron heating obtained in the simulations. In the simulations, transient waves accelerate electrons in a sheath surrounding the antenna. This increases the Larmor radii of the electrons close to the antenna, and more electrons can reach the antenna location to interact with the externally driven fields. The resulting hot electron sheath is dense enough to support strong waves that produce high‐energy sounder‐accelerated electrons (SAEs) by their nonlinear interaction with the ambient electrons. By increasing the emission amplitudes in our simulations to values that are representative for the ones of the sounder on board the OEDIPUS C (OC) satellites, we obtain electron acceleration into the energy range which is comparable to the 20 keV energies of the SAE observed by the OC mission. The emission also triggers stable electrostatic waves oscillating at frequencies close to the first harmonic of the electron cyclotron frequency. We find this to be an encouraging first step of examining SAE generation with kinetic numerical simulation codes.
Band alignment between (100)Si and complex rare earth∕transition metal oxides
Authors: Afanas’ev V. V. , Stesmans A. , Zhao C. , Caymax M. , Heeg T. , Schubert J. , Jia Y. , Schlom D. G. , Lucovsky G.
Published: December 2004

The electron energy band alignment between (100)Si and several complex transition∕rare earth (RE) metal oxides (LaScO3, GdScO3, DyScO3, and LaAlO3, all in amorphous form) is determined using a combination of internal photoemission and photoconductivity measurements. The band gap width is nearly the same in all the oxides (5.6–5.7eV) yielding the conduction and valence band offsets at the Si∕oxide interface of 2.0±0.1 and 2.5±0.1eV, respectively. However, band-tail states are observed and these are associated with Jahn-Teller relaxation of transition metal and RE cations which splits their d* states.
Room-temperature operations of memory devices based on self-assembled InAs quantum dot structures
Authors: Balocco C. , Song A. M. , Missous M.
Published: December 2004

Memory devices have been fabricated in high-electron-mobility transistors with embedded InAs quantum dots (QDs). We show that memory operations can be fully controlled by gate biases at room temperature, without the need for light excitations to erase memory states. Real-time measurements indicate a charge retention time of a few minutes. Neither such retention time nor the self-consistent simulations can justify the picture that the memory effect is due to charging/discharging of intrinsic QD states. Experiments at a series of gate biases point to the presence of deep levels coexisting in the QD layer(s), which are responsible for the memory effect.
Structure and intermixing of GaSb∕GaAs quantum dots
Authors: Timm R. , Eisele H. , Lenz A. , Becker S. K. , Grabowski J. , Kim T.-Y. , Müller-Kirsch L. , Pötschke K. , Pohl U. W. , Bimberg D. , Dähne M.
Published: December 2004

We present cross-sectional scanning tunneling microscopy results of GaSb quantum dots in GaAs, grown by metalorganic chemical vapor deposition. The size of the optically active quantum dots with base lengths of 4–8 nm and heights of about 2 nm is considerably smaller than previously published data obtained by other characterization methods. The local stoichiometry, obtained from atomically resolved images, shows a strong intermixing in the partly discontinuous wetting layer with an average GaSb content below 50%, while the GaSb content of the partly intermixed quantum dots is between 60% and 100%.
Theoretical study of coated spherical metallic nanoparticles for single-molecule surface-enhanced spectroscopy
Authors: Xu Hongxing
Published: December 2004

We investigate the possibility to use coated metallic nanoparticles for single-molecule surface-enhanced spectroscopy by extending the Mie theory. The aggregates of metallodielectric spheres of Au and Ag show a strong local intensity enhancement in the cavity between particles, which can result in up to a 1014-fold increase for surface-enhanced Raman scattering. We also examine the thickness of the coating layer, the size of the core, and the incident wavelength that determine the enhancement.
Magnetic properties arising from two additive contributions in soft magnetic nanocrystalline alloys
Authors: González J.
Published: December 2004

The behavior of different magnetic properties (saturation magnetization and magnetostriction) of Fe73.5Cu1Nb3Si13.5B9 nanocrystalline alloy exhibiting a biphase character has been assumed to be the algebraic sum of the contributions arising from the partial volume of both phases is investigated. Experimental results of the mentioned properties obtained in the classical mentioned nanocrystalline alloys seem to indicate the validity of the two volumetric contributions, although some discrepancies could suggest the relevance of another contribution coming from the surface region of the nanograins.
Zigzag-shaped magnetic sensors
Authors: da Silva F. C. S. , Uhlig W. C. , Kos A. B. , Schima S. , Aumentado J. , Unguris J. , Pappas D. P.
Published: December 2004

Magnetism in zigzag-shaped thin-film elements is investigated using scanning electron microscopy with polarization analysis, magnetotransport measurements, and micromagnetic simulations. We find that the angle of magnetization alternates along the length of the element, and is strongly correlated to the corrugated edges. We show that this simple and unique geometry can be used as a single-axis magnetic field sensor. In this configuration, the sensors are primarily sensitive to fields parallel to the applied current. Our results can be interpreted in terms of a coherent rotation model of the magnetization. These devices are scalable to nanometer dimensions.
Thermal properties of electrodeposited bismuth telluride nanowires embedded in amorphous alumina
Authors: Borca-Tasciuc D.-A. , Chen G. , Prieto A. , Martín-González M. S. , Stacy A. , Sands T. , Ryan M. A. , Fleurial J. P.
Published: December 2004

Bismuth telluride nanowires are of interest for thermoelectric applications because of the predicted enhancement in the thermoelectric figure-of-merit in nanowire structures. In this letter, we carried out temperature-dependent thermal diffusivity characterization of a 40nm diameter Bi2Te3 nanowires∕alumina nanocomposite. Measured thermal diffusivity of the composite decreases from 9.2×10−7m2s−1 at 150Kto6.9×10−7m2s−1 at 300K and is lower than thermal diffusivity of unfilled alumina templates. Effective medium calculations indicate that the thermal conductivity along nanowires axis is at least an order of magnitude lower than thermal conductivity of the bulk bismuth telluride.
Ultrasonic trapping of small particles by sharp edges vibrating in a flexural mode
Authors: Hu Junhui , Yang Jianbo , Xu Jun
Published: December 2004

Ultrasonic trapping of small particles by sharp edges vibrating in a flexural mode is reported. Two rectangular metal plates with a sharp edge are mechanically excited to vibrate in a flexural mode by the piezoelectric rings which are pressed between them by a bolt structure. Small particles such as mint seeds and flying color seeds can be attracted to the sharp edges of the plates. Relationship between input power applied to the piezoelectric rings and the number of trapped particles is experimentally investigated for mint seeds and flying color seeds in water and air. The result shows that for a given type of particle, there exists an input power at which the number of trapped particles is a maximum. Mechanism analysis shows that nodes or antinodes of acoustic pressure of the sound field near the sharp edges are responsible for the trapping.
Defects and strain relaxation in silicon-germanium-on-insulator formed by high-temperature oxidation
Authors: Bedell S. W. , Fogel K. , Sadana D. K. , Chen H.
Published: December 2004

SiGe layers were grown on silicon-on-insulator substrates and oxidized at temperatures from 1200 to 1300 °C to form silicon-germanium-on-insualtor (SGOI) layers. Strain relaxation of the SGOI film is shown to be dislocation mediated and the residual strain scaled with the final SGOI thickness in a manner consistent with equilibrium theory. Stacking faults (SF) are observed in the relaxed SGOI layer and their density increases exponentially with decreasing film thickness. In films below ∼500Å, the SF density becomes comparable with the dislocation density which may be responsible for differences between equilibrium and measured residual strain in thin SGOI layers.
Complex capacitance spectroscopy as a probe for oxidation process of AlOx-based magnetic tunnel junctions
Authors: Huang J. C. A. , Hsu C. Y.
Published: December 2004

Proper as well as under- and over-oxided CoFe−AlOx−CoFe magnetic tunnel junctions (MTJs) have been systematically investigated in a frequency range from 102 to 108Hz by complex capacitance spectroscopy. The dielectric relaxation behavior of the MTJs remarkably disobeys the typical Cole–Cole arc law probably due to the existence of imperfectly blocked Schottky barrier in the metal-insulator interface. The dielectric relaxation response can be successfully modeled on the basis of Debye relaxation by incorporating an interfacial dielectric contribution. In addition, complex capacitance spectroscopy demonstrates significant sensitivity to the oxidation process of metallic Al layers, i.e., almost a fingerprint of under, proper, and over oxidation. This technique provides a fast and simple method to inspect the AlOx barrier quality of MTJs.
Tuning the exciton-photon coupling in a strongly coupled organic microcavity containing an optical wedge
Authors: Wenus Jakub , Connolly Liam G. , Whittaker David M. , Skolnick Maurice S. , Lidzey David G.
Published: December 2004

We have fabricated strongly coupled organic microcavities by laminating an organic thin film between two dielectric mirrors. The organic film consisted of J aggregates of a cyanine dye suspended in a transparent matrix. By applying a nonuniform force across the substrate during lamination, the optical path length of the cavity changed linearly across the sample, thereby forming a wedge. This enabled cavity mode tuning by changing the position of the incident light beam with respect to the surface of the cavity. Transmission measurements are employed to investigate strong exciton-photon coupling in such microcavities. The results show a well-resolved anti-crossing behavior, which is confirmed by numerical analysis.
Low-frequency noise mechanisms in Si and pseudomorphic SiGe p-channel field-effect transistors
Authors: Prest M. J. , Bacon A. R. , Fulgoni D. J. F. , Grasby T. J. , Parker E. H. C. , Whall T. E. , Waite A. M.
Published: December 2004

Measurements of low frequency noise in Si and Si0.64Ge0.36 p-channel metal oxide semiconductor field effect transistors are compared with a model of carrier number fluctuations due to tunneling into an energy independent density of oxide trap states (Nox) and associated mobility fluctuations. The failure of the model to explain the data leads us to suggest that reduced noise in the SiGe device as compared to Si is primarily associated with an energy dependence of Nox and a displacement of the Fermi level at the SiO2 interface in the heterostructure relative to the Si control.
The subgap current in Nb∕AlOx∕Nb tunnel junctions
Authors: Milliken F. P. , Koch R. H. , Kirtley J. R. , Rozen J. R.
Published: December 2004

We have measured the subgap current at 0.8 K in several hysteretic 1.5×1.6 and 2.6×2.6μm2 Nb∕AlOx∕Nb tunnel junctions. In zero magnetic field, the critical current Ic∼8μA and the subgap resistance R∼0.3MΩ. When we apply a magnetic field, Ic can be as low as 1 nA, and R is larger than 1 GΩ. This means that in a superconducting qubit made using Nb tunnel junctions, the decoherence rate from the quasiparticle conductance may be as low as 1∕(100μs).
Optically switchable biphotonic photorefractive effect in dye-doped liquid crystal films
Authors: Lee Mei-Ru , Wang Jyun-Ruei , Lee Chia-Rong , Fuh Andy Y.-G.
Published: December 2004

This study reports the optically swichable photorefractive (PR) effect induced in a biphotonic grating in the presence of an applied dc voltage, in an azo-dye-doped liquid crystal (LC) film. When one green light is switched on (off), the PR grating can be turned on (off) by irradiating an interference field generated by two linearly polarized red lights. Experimental results demonstrate that such a PR effect follows primarily from a biphotonic process, with two mechanisms—the generation of green light-induced space charges by trans–cis isomerization, and the suppression of the formation of space charges by the red light in cis–trans back isomerization. These mechanisms apply to the dark and bright fringes of the red interference field, respectively. A spatially inhomogeneous space-charge field is then established to modulate the orientation of LCs, forming the PR grating in the presence of a dc voltage. Strong coupling of the two red lights is observable and measured dynamically during the formation of the PR grating in this study.
Investigations of Epilepsy with a Mutant Animal (EL Mouse) Model
Authors: Suzuki Jiro
Published: December 2004

Summary:  Purpose: The EL mouse model, with running fits and convulsions, has been useful for studying mechanisms of epilepsy, epileptogenesis, and ictogenesis.

Methods: The history of this model and recent key findings are described.

Results: Epileptogenesis has a hereditary component, and the genes responsible for it are presumed to be multiple. A seizure of an EL animal is precipitated by a rapid accelerating movement. Seizures develop in conjunction with aging of the mouse, repetition of stimuli, and with seizures themselves. This phenomenon represents a type of abnormal plasticity, which underlies epileptogenesis. The paroxysmal discharges in EL begin at parietal cortex, propagate to hippocampus, and then to the entire brain. Manifestation of a seizure requires a combination of several brain regions, termed the “focus complex.” A small but significant disorganization of hippocampal cytoarchitecture occurs, leading to higher excitability. Abnormally low GABAergic function in the parietal cortex and hippocampus develops with maturation of the EL mouse and with repetition of stimuli and seizures. Low superoxide dysmutase activity and abnormal eNOS function in hippocampus or parietal cortex may relate to epileptogenesis of EL. After seizures, immediate early genes (e.g., c‐fos and zif) expression and DNA fragmentation are observed, which play important roles in ictogenesis and epileptogenesis. All of these phenomena follow a process of development similar to that of the seizure itself.

Conclusions: Insights from the EL model suggest that epileptogenesis and ictogenesis in epilepsy can be viewed in terms of genetic predisposition and a new concept of abnormal plasticity.
Discontinuation and Duration of Antiepileptic Drug Therapy: A Retrospective Study of Factors for Specific Epileptic Syndromes
Authors: Kudo Tatsuya , Nishida Takuji , Yagi Kazuichi
Published: December 2004

Summary:  Purpose: To study factors associated with discontinuation of antiepileptic drugs (AEDs) in idiopathic generalized epilepsy (IGE) and symptomatic/cryptogenic localization‐related epilepsy (S/CLRE)

Methods: For the IGE study, 71 patients who were able to discontinue their AED (discontinued‐IGE group) were compared to 71 patients who continued AED therapy (continued‐IGE group) and 20 patients with seizure relapse after discontinuing AED (relapsed‐IGE group). For S/CLRE, 90 patients who were able to discontinue AED (discontinued‐S/CLRE group) were compared to 90 patients who continued AED (continued‐S/CLRE group) and 76 patients with benign childhood epilepsy with centrotemporal spikes who were able to discontinue AED (discontinued‐BECTS group).

Results: Compared to the continued‐IGE group, the discontinued‐IGE group showed a weaker seizure propensity, better response to AEDs, more frequent epileptiform discharge suppression, and lower frequency of generalized tonic–clonic seizures (GTCs). Compared to the relapse‐IGE group, the discontinued‐IGE group had more frequent epileptiform discharge suppression. The discontinued‐S/CLRE group showed a weaker seizure propensity, better response to AEDs, more frequent epileptiform discharge suppression, and less frequent symptomatic signs compared to the continued‐S/C LRE group. Notably, the age at epilepsy onset was not a critical factor for discontinuing AEDs in both IGE and S/CLRE. Although the discontinued‐S/CLRE group had more frequent symptomatic signs, older age at epilepsy onset and less frequent epileptiform discharge suppression than the discontinued‐BECTS group, no difference was found in seizure propensity and response to AEDs between the two groups.

Conclusions: Seizure propensity, epileptiform discharge, and response to AEDs should be considered to predict the possibility of terminating AED therapy in IGE or S/CLRE. In addition, attention should be paid to seizure pattern in IGE and symptomatic signs in LRE.
Effects of Seizures and Their Treatment on Fetal Brain
Authors: LaJoie Josiane , Moshé Solomon L.
Published: December 2004

Summary:  Purpose: To describe the effects of pregnancy on seizures, the effects of seizures during pregnancy on the fetus, and the effects of antiepileptic drugs (AEDs) on fetal brain and development.

Methods: The available literature was reviewed and summarized.

Results: There is a paucity of prospective studies. Retrospective studies indicate that, during pregnancy, alterations in seizure frequency can occur in an unpredictable fashion. Generalized tonic‐clonic seizures may have adverse effects on the fetus. It is unclear whether complex partial seizures or absence seizures have negative consequences. AEDs may have potentially detrimental effects on the fetus and its subsequent development, but the full spectrum and clinical significance are under investigation. Monotherapy is strongly encouraged.

Conclusions: Dealing with the pregnant epileptic patient is a difficult and challenging task. Although there are several risks for the mother and the fetus, most epileptic women bear normal, healthy children.
Can a positive photopatch test be elicited by subclinical irritancy or allergy plus suberythemal UV exposure?
Authors: Beattie P. E. , Traynor N. J. , Woods J. A. , Dawe R. S. , Ferguson J. , Ibbotson S. H.
Published: December 2004

Photopatch test (PhPT) interpretation is difficult and clinical relevance is not always apparent. A positive PhPT may reflect photocontact allergy or phototoxicity. We hypothesized that it may also reflect the additive or synergistic effects of a suberythemal reaction to a contact irritant [e.g. sodium lauryl sulfate (SLS)] or allergen (e.g. nickel) and suberythemal UV exposure. 10 nickel allergic volunteers had duplicate SLS and nickel series applied on either side of the back for 24 h and 48 h, respectively. After removal, one side was irradiated with 5 J/cm2 UVA or the dose below the minimal erythema dose for solar‐simulated radiation (SSR). The minimal irritancy dose (MID) for SLS and the minimal allergenic dose (MAD) for nickel were determined visually and objectively by erythema meter. While photoaugmentation of subclinical contact allergy or irritancy occurred in some subjects, photosuppression occurred in roughly an equal number. UVA changed the nickel MAD at 48 h in 2 of 5 volunteers but not the SLS MID. SSR changed the nickel MAD in 4 of 5 and the SLS MID in 3 of 5. 2 subjects (none after UVA) showed erythema only in the irradiated set of patches, which could have been interpreted as a positive PhPT. We have demonstrated photoaugmentation and photosuppression of contact allergy and irritancy, which could result in false‐positive or false‐negative interpretation of PhPTs.
POOR NUTRITIONAL STATUS AND INFLAMMATION: Linking Oxidative Stress and Inflammation in Kidney Disease: Which is the Chicken and Which is the Egg?
Authors: Himmelfarb Jonathan
Published: December 2004

For end‐stage renal disease (ESRD) patients, cardiovascular disease remains the single most common cause of excess morbidity and mortality. Furthermore, although the prevalence of traditional cardiovascular risk factors is high in the dialysis population, the extent and severity of associated cardiovascular morbidity and mortality remain disproportionate to traditional risk factor profiles. Consequently, considerable effort has been focused on “nontraditional” risk factors for cardiovascular events in this patient population. Among the examined nontraditional risk factors, increased oxidative stress as well as increased acute phase inflammation are postulated to be important contributors to uremic cardiovascular risk. Additional important uremic cardiovascular risk factors include malnutrition and endothelial dysfunction, both of which may be directly linked to the processes that cause increased oxidative stress and inflammation in uremia. In this context I review available data linking the pathogenesis of oxidative stress to acute phase inflammation and uremia. I also review data suggesting that oxidative stress in uremia directly contributes to the development of acute phase inflammation and that patients with higher levels of inflammation have higher levels of oxidative stress biomarkers. Similarly I review emerging data on the potential effects of antioxidant therapy on inflammatory biomarkers, as well as data suggesting that strategies to lower acute phase inflammation may also improve biomarkers of oxidative stress. Theoretical constructs evaluating the linkage of oxidative stress and inflammation in uremia and their contribution to the pathogenesis of atherosclerosis are suggested.
POOR NUTRITIONAL STATUS AND INFLAMMATION: The Dose of Dialysis in Hemodialysis Patients: Impact on Nutrition
Authors: Schulman Gerald
Published: December 2004

Multiple lines of evidence have indicated that the dose of hemodialysis impacts upon patient outcome. Among these outcome measures, nutrition is inextricably linked to the adequacy of the treatment. All of the methods of determining dialysis adequacy are based on assessing the removal of toxic substances retained in renal failure, the majority of which are derivatives of protein metabolism. Urea kinetics, employing urea as a surrogate for quantifying the elimination of small molecular weight nitrogenous substances, is the method that has been most thoroughly validated to date as defining a dose range for thrice‐weekly hemodialysis: Both inadequate and optimal levels of hemodialysis dose have been identified by prospective, randomized clinic trials utilizing Kt/Vurea as the index of adequacy. The impact of urea kinetics on nutritional status during thrice‐weekly hemodialysis is discussed. Recently, in an attempt to improve outcome beyond that achievable with thrice‐weekly hemodialysis, alternative regimens, consisting of daily treatments, have received increasing interest. In order to compare the dose of hemodialysis associated with these regimens with conventional thrice‐weekly regimens in terms of removal of small molecular weight substances, standard Kt/Vurea, a parameter that combines treatment dose with treatment frequency, and thus allows for various intermittent therapies to be compared to continuous therapy, must be used. In addition, membrane flux and middle molecule removal, factors that have not yet been well defined as parameters of adequacy during thrice‐weekly regimens, may be shown to be important indices with longer hemodialysis treatments, particularly daily nocturnal hemodialysis. The impact that these alternative regimens have had on nutritional status in hemodialysis patients and how they compare to conventional therapy are important considerations.
Alcohol-dependent patients attempting and not attempting suicide: a comparison
Authors: Pektaş Özkan , Mirsal Hasan , Kalyoncu Ayhan , Ünsalan Nasibe , Beyazyürek Mansur
Published: December 2004

Background:

Alcohol dependence is a psychiatric disorder associated with an increased risk of suicidal behaviour. This is also associated with an increased number of suicide risk factors.

Objective:

The current study examined the sociodemographic and clinical characteristics of a number of alcohol-dependent patients who attempted suicide.

Methods:

We studied a consecutive series of 377 alcohol-dependent patients in our in-patient clinics. Their alcohol-use histories were assessed through semistructured interviews. The Suicidal Behaviors Questionnaire, the Childhood Trauma Questionnaire, the Michigan Alcoholism Screening Test and the Hamilton Depression Rating Scale were administered to all patients. Serum total cholesterol levels, mean corpuscular volume, the liver enzymes gamma glutamyl transferase, aspartate aminotransferase and alanine aminotransferase were routinely measured. In the statistical analyses, Student's t-test and chi-squared tests were applied.

Results:

Of the 377 alcohol-dependent patients, 89 (23.6%) had histories of attempted suicide. Thirty-four (42.5%) of the 80 female alcohol-dependent patients and 55 (18.5%) of the 297 male alcohol-dependent patients had attempted suicide; this gender difference was statistically significant (χ2 = 27.7, P < 0.001). A greater proportion of the suicide attempters than of the non-attempters met the Diagnostic Statistical Manual IV criteria for another psychiatric disorder (60.6%, n = 54, vs. 40.6%, n = 117; χ2 = 14.8; df = 6; P < 0.05). The difference of total cholesterol levels between female (mean = 144.0, SD = 58.3; mean = 158.0, SD = 83.9; t = 4.5; P < 0.05) and male (mean = 133.7, SD = 50.5; mean = 163.6, SD = 69.7; t = 11.7; P < 0.01) attempters and non-attempters was statistically significant.

Conclusion:

These results suggest that suicide attempts in alcohol-dependent patients are associated with more profound biopsychosocial pathology and decreased serum cholesterol levels.
Contribution of the stress-induced degeneration of the locus coeruleus noradrenergic neurons to the pathophysiology of depression: a study on an animal model
Authors: Kitayama Isao T. , Otani Masato , Murase Sumio
Published: December 2004

A novel theory on the pathophysiology of depression would be expected to resolve a contradiction between therapeutic time lag and monoamine hypothesis. On the basis of the fact that a subgroup of depression appears during or after stress, we exposed rats to a long-term (2 weeks) forced walking stress and produced depression-model rats in one group and spontaneous recovery rats in another. The density of axon terminals of the locus coeruleus (LC) neurons in the frontal cortex stained by dopamine β-hydroxylase antiserum was lower in the depression-model rats than in the spontaneous recovery rats and in the control rats without stress. The density was higher in the model rats daily treated with imipramine than in those treated with saline. Morphological projection (MP) index (a percentage of horseradish peroxidase-positive LC cells in total number of LC cells) and electrophysiological projection index (a percentage of LC neurons activated antidromically by electrical stimulation of the cerebral cortex) were lower in the depression-model rats than in the recovery and control rats. MP index was higher in the imipramine-treated rats than that in the saline-treated rats. Electron microscopic examination of the LC disclosed such degenerative changes as low-dense areas without structure, aggregation of intracellular organs, destroyed membranes around the rough endoplasmic reticulum (rER), a decreased number of deformed subsurface cisterns, glia invaginated into the LC neurons and prominent appearance of microglia containing increased number of lipofustin or lysosome in the model rats, but not in the spontaneous recovery rats. These findings suggest that the terminals and cell bodies of the LC noradrenergic neurons degenerate in the stress-induced depression-model rats and regenerate in the imipramine-treated model rats. This degenerative change may possibly contribute to the decrease in synthesis and metabolism of noradrenaline (NA), the slowing of axonal flow, the accumulation of NA in the neurons, the decrease in discharge rate of LC neurons without stress and the increase in release of NA in response to an additional stress. It may also explain the therapeutic time lag that is required to repair the noradrenergic neurons.
Helicobacter pylori stool antigen test in patients with bleeding peptic ulcers
Authors: Lin Hwai‐Jeng , Lo Wen‐Ching , Perng Chin‐Lin , Li Anna Fen‐Yau , Tseng Guan‐Ying , Sun I‐Chen , Ou Yueh‐Hsing
Published: December 2004

Background.  Helicobacter pylori has been linked to chronic gastritis, peptic ulcers, gastric cancer and mucosa‐associated lymphoid tissue lymphoma. Invasive tests are less sensitive than noninvasive tests in diagnosing H. pylori infection in patients with bleeding peptic ulcers. The H. pylori stool antigen test has been useful in diagnosing H. pylori in patients with peptic ulcers before and after eradication of H. pylori. The aim of this study was to evaluate the H. pylori stool antigen test in patients with bleeding peptic ulcers.

Methods.  Patients with bleeding and nonbleeding peptic ulcers underwent a rapid urease test, histology, bacterial culture and H. pylori stool antigen test. Positive H. pylori infection was defined as a positive culture or both a positive histology and a positive rapid urease test. Helicobacter pylori stool antigen was assessed with a commercial kit (Diagnostec H. pylori antigen EIA Kit, Hong Kong).

Results.  Between October 2000 and April 2002, 93 patients with bleeding peptic ulcers (men/women: 78/15, gastric ulcer/duodenal ulcer: 58/35) and 59 patients with nonbleeding peptic ulcers (men/women: 47/12, gastric ulcer/duodenal ulcer: 30/29) were enrolled in this study. Forty‐seven (50.5%) patients with bleeding peptic ulcers and 30 (50.8%) patients with nonbleeding peptic ulcers, were found to be infected with H. pylori (p > .1). Helicobacter pylori stool antigen tests were positive in 54 (58.1%) and 30 (50.8%) patients with bleeding peptic ulcers and nonbleeding peptic ulcers, respectively (p > .1). The sensitivity (82% vs. 93%), specificity (68% vs. 93%), positive predictive value (74% vs. 93%), negative predictive value (77% vs. 93%) and diagnostic accuracy (75% vs. 93%) were all lower in patients with bleeding vs. nonbleeding peptic ulcers. The specificity, positive predictive value, and diagnostic accuracy of the H. pylori stool antigen test in patients with bleeding peptic ulcers were significantly lower than those in patients with nonbleeding peptic ulcers (p = .01, p = .02 and p = .003, respectively).

Conclusion.  The H. pylori stool antigen test is not reliable for diagnosing H. pylori infection in patients with bleeding peptic ulcers.
Multicenter Comparison of Rapid Lateral Flow Stool Antigen Immunoassay and Stool Antigen Enzyme Immunoassay for the Diagnosis of Helicobacter pylori Infection in Children
Authors: Kato Seiichi , Ozawa Kyoko , Okuda Masumi , Nakayama Yoshiko , Yoshimura Norikazu , Konno Mutsuko , Minoura Takanori , Iinuma Kazuie
Published: December 2004

Background and Aim.  The stool antigen enzyme immunoassay (EIA) methods are widely used for diagnosing Helicobacter pylori infection. Recently, a novel, rapid stool antigen test, the lateral flow immunoassay (LFI) method, has been developed. The primary purpose of this study was to compare the EIA method with the LFI method for the diagnosis of H. pylori infection in children.

Materials and Methods.  Stool specimens from children being evaluated for H. pylori infection were also examined using the LFI (ImmunoCard STAT! HpSA) and EIA methods (Premier Platinum HpSA). The sensitivity, specificity and accuracy of the test were based on the 13C‐labeled urea breath test.

Results.  One hundred and eighty‐two children and adolescents, 3–17 years of age (mean 9.2 years), were studied. In addition, 29 patients who received eradication therapy were re‐evaluated 2 or 3 months post‐treatment. The 13C‐labeled urea breath test was positive in 64 patients (35.2%). The sensitivity, specificity and accuracy of the LFI method were 90.6% (95% CI = 80.7–96.5%), 95.8% (92.1–99.4%), and 94.0% (90.5–97.4%), respectively and for the EIA method, sensitivity, specificity and accuracy were 96.8% (95% CI, 89.0–99.6%) and 99.2% (97.5–100%), and 98.3% (96.5–100%), respectively. There were no significant differences in results among the age groups 3–5, 6–10 and 11–17 years. As for the assessment of H. pylori eradication, the results of the LFI and EIA methods agreed with those of 13C‐urea breath test in 27/29 and 29/29 patients, respectively.

Conclusions.  The LFI stool antigen method showed a good sensitivity, specificity and accuracy for diagnosing H. pylori infection in children. This novel method may be useful in clinical practice as an office‐based test because it is rapid, reliable and easy to perform.
Comparison of two Different Stool Antigen Tests for the Primary Diagnosis of Helicobacter pylori Infection in Turkish Patients with Dyspepsia
Authors: Erzin Y. , Altun S. , Dobrucali A. , Aslan M. , Erdamar S. , Dirican A. , Kocazeybek B.
Published: December 2004

Aim.  To assess the reliability of two different enzyme immunoassays in detecting the Helicobacter pylori status in stool specimens of Turkish patients with dyspepsia.

Materials and methods.  One hundred and fifty‐one patients [74 with nonulcer dyspepsia (NUD), 64 with duodenal ulcer (DU) and 13 with gastric cancer] who were admitted to the endoscopy unit of Istanbul University, Cerrahpasa Medical Faculty for upper gastrointestinal endoscopy because of dyspepsia were enrolled in the study. Helicobacter pylori infection was confirmed in all patients by histology, rapid urease test and culture. A patient was classified as being H. pylori‐positive if the culture alone or both the histology and the rapid urease test were positive and as negative only if all of these tests remained negative. Stool samples were obtained from patients to assess the reliability of a monoclonal (FemtoLab H. pylori) and a polyclonal (Premier Platinum HpSA) stool antigen test and to compare the diagnostic accuracies of these two tests. A χ2 test was used for statistical comparisons.

Results.  Using cut‐off values of 0.19 for FemtoLab H. pylori and 0.16 for Premier Platinum HpSA, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 93%, 90%, 98%, 68% and 93% for the monoclonal test and 84%, 67%, 94%, 40% and 81% for the polyclonal test, respectively. The sensitivity, specificity, negative predictive value and diagnostic accuracy of the monoclonal test were significantly greater than those of the polyclonal test (χ2 = 3.98; p < .05 for sensitivity and χ2 = 15.67; p = .000 for specificity, χ2 = 15.78; p = .000 for negative predictive value and χ2 = 6.37; p = .012 for diagnostic accuracy). The bacterial load did not affect the sensitivity of either test.

Conclusions.  The monoclonal FemtoLab H pylori test, using a cut‐off 0.19, is a very sensitive, specific and easy to perform diagnostic tool for the primary diagnosis of H. pylori infection in Turkish patients with dyspepsia.