bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of quality on the demand for outpatient services in Cyprus
Authors: Hanson Kara , Yip Winnie C. , Hsiao William
Published: April 2004

Health policy reforms in a number of countries seek to improve provider quality by sharpening the incentives they face, for example by exposing them to greater competition. For this to succeed, patients must be responsive to quality in their choice of provider. This paper uses data from Cyprus to estimate the effect of quality on patients' choice between public and private outpatient care. It improves on the existing literature by using a more comprehensive set of quality attributes which allows the dimensions of quality that have the largest effect on patient choice of provider to be identified. We also introduce an innovative way of measuring patients' perceptions of quality in a household survey. We find that patients' choice of provider is sensitive to quality, and that interpersonal quality is more important than either technical quality or system‐related factors. Copyright © 2004 John Wiley & Sons, Ltd.
Estimation of snow depth over open prairie environments using GOES imager observations
Authors: Romanov Peter , Tarpley Dan
Published: April 2004

We assess the potential for estimating snow depth using observations in the visible and infrared spectral bands from the imager instrument onboard the Geostationary Operational Environmental Satellites (GOES). The approach makes use of a correlation between depth of the snowpack and satellite‐derived subpixel fractional snow cover over non‐forested and sparsely forested areas. To retrieve the snow depth we propose a simple analytical formula approximating the statistical relationship between the snow depth and the snow fraction.

The primary focus of this study was the US Great Plains and Canadian prairies area. Daily maps of snow depth at a spatial resolution of 4 km have been produced for this region for four winter seasons from late 1999 to the beginning of 2003. Validation of the algorithm developed was performed through comparison of the satellite‐based product with snow depth measurements made at first‐order synoptic stations, US Cooperative Network stations and Canadian climate stations. The accuracy of snow depth retrievals was found to be about 30% of the observed snow depth for snow depths below 30 cm. Copyright © 2004 John Wiley & Sons, Ltd.
Validation of VEGETATION, MODIS, and GOES + SSM/I snow‐cover products over Canada based on surface snow depth observations
Authors: Simic Anita , Fernandes Richard , Brown Ross , Romanov Peter , Park William
Published: April 2004

The ability to map the areal depletion of snow accurately is important for operational decision making (e.g. reservoir management), for correct specification of boundary conditions in numerical weather‐prediction models, and for modelling atmospheric, hydrological and ecological processes. A number of satellite‐derived snow‐cover products are available in real time; however, these can differ considerably due to variations in sensor and platform characteristics, data pre‐processing methods, and the particular snow‐cover classification algorithms employed. This article evaluates the performance of three daily snow‐cover products over Canada: (1) Terra Moderate Resolution Imaging Spectroradiometer (MODIS) snow‐cover maps provided at 500 m spatial resolution for 2001; (2) National Oceanic Atmospheric Administration (NOAA) GOES + SSM/I snow maps provided at 4 km resolution for 2001 (∼30 km resolution SSM/I data were used for cloud‐covered areas); (3) SPOT‐4 VEGETATION (VGT) snow maps derived at 1 km resolution for 2000. An evaluation of the snow‐cover products with daily surface snow depth observations collected from almost 2000 meteorological stations across Canada revealed that the VGT snow product used in this study may not be suitable for snow mapping in Canada because of a significant bias towards mapping snow‐free conditions. The MODIS and NOAA products showed similar reasonable levels of agreement with ground data, ranging from approximately 80% to 100% on a monthly basis. Somewhat lower agreement was found in January, when solar zenith angles are large, suggesting that better correction for tree and surface shadow effects is needed in current snow‐cover mapping algorithms. The lowest agreement was seen during snowmelt, mainly in forest areas. Comparison of MODIS agreement statistics between sparse and dense conifer regions indicated that the effect of non‐representativenes of surface snow depth observations was on the order of 10% disagreement. The NOAA product was found to be the most consistent among land cover types and had the highest percentage of cloud‐free pixels. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of the El Niño–southern oscillation on temperature, precipitation, snow water equivalent and resulting streamflow in the Upper Rio Grande river basin
Authors: Lee Songweon , Klein Andrew , Over Thomas
Published: April 2004

Snowmelt runoff dominates streamflow in the Upper Rio Grande (URG) basin of New Mexico and Colorado. Annual variations in streamflow timing and volume at most stations in the region are strongly influenced by the El Niño–southern oscillation (ENSO) through its modulation of the seasonal cycles of temperature and precipitation, and hence on snow accumulation and melting. After removing long‐term trends over the study period (water years 1952–99), the dependence of monthly temperature, precipitation, snow water equivalent (SWE) at snowcourse stations, and streamflow throughout the URG on ENSO was investigated using composite analyses of the detrended residuals and through dependence of the residuals on the Climate Prediction Center southern oscillation index during the preceding summer and fall. The climate of La Niña years was found to differ significantly from either El Niño or neutral years. Moreover, significant climatological ENSO‐related effects are confined to certain months, predominantly at the beginning and end of the winter season. In particular, March of La Niña years is significantly warmer and drier than during either El Niño or neutral years, and November of El Niño years is significantly colder and wetter. Differences in temperature and precipitation lead to significant differences in SWE and streamflow in the URG between the three ENSO phases. Copyright © 2004 John Wiley & Sons, Ltd.
Differential winter stemflow generation under contrasting storm conditions in a southern New England broad‐leaved deciduous forest
Authors: Levia Delphis F.
Published: April 2004

Despite the importance of stemflow as a hydroecological process, differential winter stemflow generation among and within precipitation types (e.g. snow, rain‐to‐snow) is poorly understood. The purpose of the present study is to understand winter stemflow generation better under contrasting meteorological conditions in a leafless deciduous forest. It is hypothesized that stemflow volume and production, expressed as a funnelling ratio, will differ significantly among and within precipitation event types. Acceptance of this hypothesis would mean that intra‐event meteorological conditions have a significant and discernible effect on stemflow production in deciduous forests, differentially affecting soil moisture, groundwater recharge, soil solution chemistry, and nutrient cycling. Stemflow volumes generated from seven canopy trees were monitored in a leafless deciduous forest of southern New England on a precipitation event basis over two successive winter seasons. Stemflow volume was found to differ significantly among different and same‐type precipitation events. A rain event that occurred on 8 December 1998 and snow‐to‐rain event on 18 January 1999 were of similar duration, magnitude, and intensity, yet produced stemflow volumes that differed by a factor of 4. For two snow‐to‐rain events, stemflow volumes differed by a factor of 11. Stemflow production even varies widely within a discrete precipitation event as a function of meteorological conditions. Significant differential stemflow yield under contrasting storm conditions obviates generalizations concerning stemflow production as a function of precipitation event type and necessitates a deeper, process‐level understanding of winter stemflow generation before modelling exercises are undertaken. Copyright © 2004 John Wiley & Sons, Ltd.
Reduced type I collagen utilization: A pathogenic mechanism in COL5A1 haplo‐insufficient Ehlers–Danlos syndrome
Authors: Wenstrup Richard J. , Florer Jane B. , Cole William G. , Willing Marcia C. , Birk David E.
Published: April 2004

To examine mechanisms by which reduced type V collagen causes weakened connective tissues in the Ehlers–Danlos syndrome (EDS), we examined matrix deposition and collagen fibril morphology in long‐term dermal fibroblast cultures. EDS cells with COL5A1 haplo‐insufficiency deposited less than one‐half of hydroxyproline as collagen compared to control fibroblasts, though total collagen synthesis rates are near‐normal because type V collagen represents a small fraction of collagen synthesized. Cells from patients with osteogenesis imperfecta (OI) and haplo‐insufficiency for proα1(I) chains of type I collagen also incorporated about one‐half the collagen as controls, but this amount was proportional to their reduced rates of total collagen synthesis. Collagen fibril diameter was inversely proportional to type V/type I collagen ratios (EDS > control > OI). However, a reduction of type V collagen, in the EDS derived cells, was associated with the assembly of significantly fewer fibrils compared to control and OI cells. These data indicate that in cell culture, the quantity of collagen fibrils deposited in matrix is highly sensitive to reduction in type V collagen, far out of proportion to type V collagen's contribution to collagen mass. © 2004 Wiley‐Liss, Inc.
Extracellular taurine in the substantia nigra: Taurine‐glutamate interaction
Authors: García Dopico José , Perdomo Díaz Juan , Alonso Teofilo Jorge , González Hernández Tomás , Castro Fuentes Rafael , Rodríguez Díaz Manuel
Published: April 2004

Taurine has been proposed as an inhibitory transmitter in the substantia nigra (SN), but the mechanisms involved in its release and uptake remain practically unexplored. We studied the extracellular pool of taurine in the rat's SN by using microdialysis methods, paying particular attention to the taurine–glutamate (GLU) interaction. Extracellular taurine increased after cell depolarization with high‐K+ in a Ca2+‐dependent manner, being modified by the local perfusion of GLU, GLU receptor agonists, and zinc. Nigral administration of taurine increased the extracellular concentration of γ‐aminobutyric acid (GABA) and GLU, the transmitters of the two main inputs of the SN. The modification of the glial metabolism with fluocitrate and L‐methionine sulfoximine also changed the extracellular concentration of taurine. The complex regulation of the extracellular pool of taurine, its interaction with GABA and GLU, and the involvement of glial cells in its regulation suggest a volume transmission role for taurine in the SN. © 2004 Wiley‐Liss, Inc.
Antimicrobial evaluation of fungal extracts produced by endophytic strains ofPhomopsissp.
Authors: Corrado Marcia , Rodrigues Katia F.
Published: April 2004

Crude extract of cultures of 13 fungal strains identified asPhomopsissp. and isolated as endophytes from the leaves ofAspidosperma tomentosumand twigs of Spondias mombinwere examined for their antibacterial and antifungal activities. The screening was conducted using the bioautographic TLC agar‐overlay technique against bacteria (E. coli,P. aeruginosa,S. aureus), yeast (C. albicans,S. cerevisiae), and readily adapted for use with filamentous fungi (A. niger,F. oxysporum). Three of the 13 extracts effectively inhibited the growth of all test‐organisms, indicating that they may represent a potential for pharmaceutical and/or agricultural applications and are worthy of further study. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Herstellung von hochporösen, endkonturnahen Titan‐Formkörpern für biomedizinische Anwendungen
Authors: Bram M. , Laptev A. , Buchkremer H.P. , Stöver D.
Published: April 2004

Die Herstellung hochporöser Titanformkörper über die Pulvermetallurgie unter Verwendung geeigneter Platzhalterwerkstoffe besitzt eine hohe Attraktivität für biomedizinische Anwendungen. Porositäten bis 75 % und definierte Porengrößen im Bereich von 0,1 bis 2 mm lassen sich direkt über das Mischungsverhältnis und die Partikelgröße des Platzhalters einstellen. Bis jetzt war eine endkonturnahe Formgebung von hochporösen Bauteilen nur eingeschränkt möglich, da bei der mechanischen Bearbeitung von gesinterten Formkörpern die Poren an der Oberfläche durch eine plastische Deformation der Titan‐Stege teilweise oder vollständig verschlossen wurden. Um dies zu vermeiden, wurde ein Verfahren entwickelt, bei dem die Endkontur bereits im ungesinterten Zustand durch eine mechanische Bearbeitung von gepressten Halbzeugen erreicht wird. Diese sog. Grünbearbeitung kann ohne zusätzliche organische Binder durchgeführt werden, da die Presslinge eine ausreichende Stabilität besitzen. Das Potential der neuen Herstellungsroute konnte erfolgreich am Prototyp einer Pfanne, die für den Einsatz in der Hüftendoprothetik vorgesehen ist, aufgezeigt werden. Zusätzlich wurden einige grundlegende Untersuchungen des hochporösen Titanwerkstoffs hinsichtlich seiner Eignung als Implantatwerkstoff durchgeführt.
Health outcomes among patients receiving oseltamivir
Authors: Enger Cheryl , Nordstrom Beth L. , Thakrar Bharat , Sacks Susan , Rothman Kenneth J.
Published: April 2004

Purpose

Oseltamivir was approved by the FDA for the treatment of influenza in 1999. The primary objective was to compare health outcomes among influenza patients who were treated with oseltamivir and those who were not.

Methods

The patient population included UnitedHealthcare members who received an influenza diagnosis during the 1999–2000 influenza season, divided into those who were dispensed oseltamivir on the same day (N = 3211) and those who were not dispensed oseltamivir (N = 19 985). Cardiovascular, neuropsychiatric and respiratory outcomes were assessed from medical claims for a 30‐day period.

Results

The adjusted incidence rate ratio for major cardiac outcome was 0.56 (95%CI: 0.34–0.93) in those without a positive history of major cardiac disease, indicating that those in the oseltamivir group tended to be at lower risk of cardiac outcomes than those without oseltamivir. The adjusted incidence rate ratio for major neuropsychiatric outcome was 0.72 (95%CI: 0.53–0.97) in the negative history of neuropsychiatric disease stratum. The incidence rate ratios for respiratory events were more variable.

Conclusions

There appears to be no increased risk of cardiac or neuropsychiatric outcomes among subjects with influenza who were treated with oseltamivir in comparison with those who were not. Copyright © 2003 John Wiley & Sons, Ltd.
Enhancing capillary liquid chromatography/tandem mass spectrometry of biogenic amines by pre‐column derivatization with 7‐fluoro‐4‐nitrobenzoxadiazole
Authors: Song Yaru , Quan Zhe , Evans Joseph L. , Byrd Edward A. , Liu Yi‐Ming
Published: April 2004

This paper describes a capillary liquid chromatography/tandem mass spectrometry (LC/MS/MS) determination of biogenic amines enhanced by pre‐column derivatization with 7‐fluoro‐4‐nitrobenzoxadiazole (NBD‐F). Biogenic amines including tryptamine, N‐methylsalsolinol, histamine, and agmatine were studied. The biogenic NBD‐amine derivatives could be quantitatively enriched in‐line on 20 × 0.25 mm capillary columns packed in‐house with 5 μm C8 silica particles. In an electrospray ionization (ESI) source these derivatives were ionized effectively, and collision‐induced dissociation (CID) produced predominant characteristic ions allowing sensitive MS/MS detection. Agmatine, a potential neurotransmitter/modulator, was taken as a reference compound to study the analytical figures of merit of the procedure. The detection limit of agmatine was estimated to be 0.6 ng/mL (signal‐to‐noise (S/N) = 3). A linear calibration curve in the range 15–1000 ng/mL agmatine with an r value of 0.9997 was obtained. Tissue samples of rat brain, stomach, and intestine were analyzed. Minimum sample pre‐treatment was needed. Each analysis was accomplished within ca. 12 min. The concentration of agmatine was found to be 0.246, 3.31, and 0.058 μg/g wet tissue in the brain, stomach, and intestine, respectively. Copyright © 2004 John Wiley & Sons, Ltd.
Studies of Thermobifida fusca plant cell wall degrading enzymes
Authors: Wilson David B.
Published: April 2004

SYNOPSIS: I have been studying the Thermobifida fusca cellulose degrading proteins for the past 25 years. In this period, we have purified and characterized the six extracellular cellulases and an intracellular β‐ glucosidase used by T. fusca for cellulose degradation, cloned and sequenced the structural genes encoding these enzymes, and helped to determine the 3‐dimensional structures of two of the cellulase catalytic domains. This research determined the mechanism of a novel class of cellulase, family 9 processive endoglucanases, and helped to show that there were two types of exocellulases, ones that attacked the non‐reducing ends of cellulose and ones that attacked the reducing ends. It also led to the sequencing of the T. fusca genome by the DOE Joint Genome Institute. We have studied the mechanisms that regulate T. fusca cellulases and have shown that cellobiose is the inducer and that cellulase synthesis is repressed by any good carbon source. A regulatory protein (CelR) that functions in the induction control has been purified, characterized, and its structural gene cloned and expressed in E. coli. I have also carried out research on two rumen bacteria, Prevotella ruminicola and Fibrobacter succinogenes, in collaboration with Professor James Russell, helping to arrange for the genomes of these two organisms to be sequenced by TIGR, funded by a USDA grant to the North American Consortium for Genomics of Fibrolytic Ruminal Biology. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 72–82; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20002
Innovative reactions mediated by zirconocene
Authors: Fujita Kazuya , Yorimitsu Hideki , Oshima Koichiro
Published: April 2004

Radical reactions mediated by Schwartz reagent and zirconocene(alkene) complex are firstly described. Schwartz reagent is a promising alternative to tributyltin hydride and the first transition metal hydrido complex used as a radical mediator in organic synthesis. A zirconocene(alkene) complex effects single electron transfer to alkyl halide to generate the corresponding alkyl radical. Secondly, serendipitous allylic CH bond activation of the coordinating alkene of zirconocene(alkene) complex and its application to organic synthesis are summarized. By utilizing equilibrium between zirconocene(alkene) and zirconocene 2‐alkenyl hydride, reaction of acid chloride with zirconocene(alkene) provides the corresponding homoallylic alcohol by sequential attacks of the hydride and 2‐alkenyl moieties. A set of hydride and 2‐alkenyl attacks on 1,4‐diketone yields 6‐heptene‐1,4‐diol derivative in high yield with high stereoselectivity. Selective capture of the hydride with diisopropyl ketone gives zirconocene 2‐alkenyl alkoxide, which is a useful reagent for stereoselective allylation of aldehyde and imine. α‐Halo carbonyl compounds undergo radical allylation with the zirconocene 2‐alkenyl alkoxide which serves as a substitute for allyltin. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 110–119; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20004
Sonographic findings in acute urinary retention secondary to retroverted gravid uterus: pathophysiology and preventive measures
Authors: Yang J.‐M. , Huang W.‐C.
Published: April 2004

Objectives

To explore the pathophysiology of acute urinary retention in women with a retroverted gravid uterus and to suggest measures to prevent its recurrence.

Methods

In five women with a retroverted gravid uterus and acute urinary retention necessitating catheterization, the morphology of the genitourinary system was assessed by using transabdominal, transvaginal and introital sonography.

Results

In the supine resting position, the cervix was displaced superiorly and anteriorly by the impacted and retroverted uterus so that it compressed the lower bladder, leading to obstruction of the internal urethral orifice. The upper bladder extended superiorly and overlay the uterus. During straining, urethral motion was not limited and there was an average rotational angle of the bladder neck of 32 °, ranging from 21 ° to 44 °. Increasing abdominal pressure further compressed the lower bladder. Measures suggested to the women for the prevention of urinary retention included limiting fluid intake before sleep, changing from the supine to the prone position before getting up and avoiding a Valsalva maneuver but performing a Credé maneuver during voiding. In all except one case these measures successfully prevented recurrence.

Conclusions

Acute urinary retention secondary to a retroverted gravid uterus is caused by a displaced cervix compressing the lower bladder and interfering with drainage to the urethra. The urethra itself is not compressed or distorted. Understanding the pathophysiology of the lower urinary tract may allow maneuvers which prevent acute urinary retention. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
CVD‐Diamantschleifstifte für den Werkzeug‐ und Formenbau. Abrasive Pencils for Tool and Die Making Coated by Diamond CVD
Authors: Hoffmeister Hans‐Werner , Illenseer Stephen , Gäbler Jan
Published: April 2004

Neuartige compeDIA®‐Diamantschleifstifte wurden hergestellt und für die Bearbeitung von Hartmetallformwerkzeugen erprobt. Zur Herstellung der Schleifstifte wurden Hartmetallgrundkörper angeschliffen und mit dem Heißdraht‐CVD‐Verfahren mit einem Diamantschleifbelag beschichtet. Die Erprobung der Schleifstifte erfolgte mit einer Ultrapräzisionsschleifmaschine an Hartmetallwerkstücken. Beurteilungskriterien waren Werkstückrauheit und Werkzeugstandzeit.Zur gezielten Einstellung der Schleifkörnung der Schleifstifte wurden die passenden Beschichtungsparameter erarbeitet und die Abhängigkeiten von wesentlichen Einflussgrößen bei der Beschichtung, wie Nenndurchmesser und Schleiflänge, ermittelt. Um die angeschliffenen Grundkörper mit ausreichender Schichthaftung beschichten zu können, wurde ein geeignetes Vorbehandlungsverfahren entwickelt und erprobt, das die durch das Anschleifen gestörte Randzone entfernt.

Die Beschichtungskosten liegen jedoch momentan noch unwirtschaftlich hoch. Durch eine Massenfertigung in Verbindung mit einer automatisierten Vorbehandlung und Beschichtung wäre es möglich die Kosten soweit zu senken, dass sie auf dem Niveau anderer Beschichtungen wie TiN oder TiAlN liegen.

Die CVD‐Diamantschleifstifte zeigten eine gute Eignung zur Herstellung von Formwerkzeugen für den Werkzeug‐ und Formenbau. Es ist zu erwarten, dass durch Weiterentwicklung der Werkzeuge und Prozessoptimierung die gefertigte Werkstückqualität verbessert werden kann und Rauhtiefen Ra < 0,3 μm erreicht werden. Die Standzeit konnte durch Optimierung der Beschichtungstechnologie auf anwendungsgerechte Werte gesteigert werden. Es wurden die Bearbeitungsparameterbereiche erarbeitet, mit denen die Schleifbearbeitung sinnvoll durchgeführt werden kann, ohne zum Werkzeugbruch zu führen. Anschließend wurde ein Spritzgussbauteil mit typischen Formelementen entworfen und ein entsprechender Formwerkzeugprototyp gefertigt.

Für den Werkzeug‐ und Formenbau wurden damit die grundlegenden Voraussetzungen erarbeitet, mit diesen innovativen Schleifstiften eine schnelle und flexible Bearbeitung von Formwerkzeugen aus Hartmetall zu realisieren. Gegenüber dem heute üblichen Formwerkzeugmaterial aus Messing können so deutliche Standzeitvorteile bei der Herstellung von Miniatur‐Serienteilen durch Ziehen, Tiefziehen oder Fließpressen erzielt werden.
Micro‐PIXE studies of low‐level gold solubility in natural magmas: Experiments on two felsic magmas
Authors: Stevens G. , Przybyłowicz W. J. , Martin L. E.
Published: April 2004

The limits of gold solubility in granitic magmas are poorly constrained, yet may be important for understanding the formation of several gold deposit types. This is largely due to the fact that this parameter cannot be readily measured in natural rocks. Experimental approaches are also difficult, as an analytical technique is required that combines a high level of spatial resolution (typically <5 µm) with the capability to measure gold in low concentrations. In an attempt to address this problem, experiments were conducted to investigate gold solubility in sulphur‐ and chlorine‐bearing granitic and syenitic magmas, and the products were analysed by micro‐PIXE (particle‐induced x‐ray emission). Starting glasses were synthesized from aluminosilicate gels fired at 1000°C, and were sealed within gold capsules, with 4.4 wt% H2O and variable proportions of either chlorine or sulphur as potential gold complexing agents. The initially gold free glasses were equilibrated with the pure gold capsules at conditions of 1.5 MPa, 750°C and at fO2≈NNO buffer, for a period of at least 150 h. All experiments produced quenched granitic and syenitic glasses containing a disseminated, high‐temperature silicate mineral assemblage, in addition to oxide and/or sulphide and small gold crystals. The gold, sulphur and chlorine concentrations of the glasses were analysed, and under the specific analytical conditions used in this study micro‐PIXE was able to detect gold in the glasses at levels as low as 2 ppm. The PIXE data demonstrate that, under the conditions used in this investigation, sulphur is a more effective complexing ligand than chlorine for incorporating gold into the melt structures, and that surprisingly high gold concentrations of up to 4400 ppm were attained in the syenitic magma with 1 wt% sulphur added. Thus, micro‐PIXE analysis has been shown to be capable of constraining the concentration of gold at the generally low values encountered in solubility studies on felsic natural magma compositions, thereby laying the groundwork for future research in this field using the PIXE technique. Copyright © 2004 John Wiley & Sons, Ltd.
EPMA mapping method for small particles of Al3Fe, Al6Fe, α‐AlFeSi and β‐AlFeSi in 1050‐H18 aluminum sheets
Authors: Osada Yoshio
Published: April 2004

We developed an EPMA mapping method for small AlaFebSic particles in 1050‐H18 aluminum sheet, which is one of the base materials coated by photoresist in advance called PS plate (pre‐sensitized printing plate). In this method, we used the ratios of relative x‐ray intensities, IFe/IAl and IFe/ISi instead of the mass ratios, Fe/Al and Fe/Si, of the main elements which constitute the particles and tried to determine the ratios of relative x‐ray intensities using Monte Carlo calculations. Furthermore, using this developed mapping method, we performed the mapping of small AlaFebSic particles such as Al3Fe (0–3%Si as impurities), Al6Fe (0–1%Si as impurities), α‐AlFeSi(Al8.3Fe2Si) and β‐AlFeSi(Al8.9Fe2Si2) in 1050‐H18 aluminum sheets. We found that the discrimination of these particles was achieved with this mapping method. We confirmed that this method is useful for the mapping of AlaFebSic particles in 1050‐H18 aluminum sheets. Copyright © 2004 John Wiley & Sons, Ltd.
International bilateral water treaty formation
Authors: Espey Molly , Towfique Basman
Published: April 2004

A logistic model is estimated to determine factors that have influenced the formation of bilateral international water treaties over the last 60 years. Results indicate that the larger a water basin is as a percent of a country's size, the more likely the country is to form a treaty regarding its management. On the other hand, the more control over the water basin any given country has, the less likely it will be involved in a treaty. The results also support aspects of two competing theories about the role of country differences, that in some cases they serve as obstacles to treaty formation yet in other cases they encourage treaty formation to formalize management when informal arrangements are not adequate.
Febrigenic signaling to the brain does not involve nitric oxide
Authors: Steiner Alexandre A , Rudaya Alla Y , Ivanov Andrei I , Romanovsky Andrej A
Published: April 2004

The involvement of peripheral nitric oxide (NO) in febrigenic signaling to the brain has been proposed because peripherally administered NO synthase (NOS) inhibitors attenuate lipopolysaccharide (LPS)‐induced fever in rodents. However, how the unstable molecule of NO can reach the brain to trigger fever is unclear. It is also unclear whether NOS inhibitors attenuate fever by blocking febrigenic signaling or, alternatively, by suppressing thermogenesis in brown fat.

Male Wistar rats were chronically implanted with jugular catheters; their colonic and tail skin temperatures (Tc and Tsk) were monitored.

Study 1 was designed to determine whether the relatively stable, physiologically relevant forms of NO, that is, S‐nitrosoalbumin (SNA) and S‐nitrosoglutathione (SNG), are pyrogenic and whether they enhance LPS fever. At a neutral ambient temperature (Ta) of 31°C, afebrile or LPS (1 μg kg−1, i.v.)‐treated rats were infused i.v. with SNA (0.34 or 4.1 μmol kg−1; the controls received NaNO2 and albumin) or SNG (10 or 60 μmol kg−1; the controls received glutathione). Tc of SNA‐ or SNG‐treated rats never exceeded that of the controls.

In Study 2, we tested whether the known fever‐attenuating effect of the NOS inhibitor N‐nitro‐L‐arginine methyl ester (L‐NAME) at a subneutral Ta (when fever is brought about by thermogenesis) also occurs at a neutral Ta (when fever is brought about by skin vasoconstriction). At a subneutral Ta of 24°C, L‐NAME (2.5 mg kg−1, i.v.) attenuated LPS (10 μg kg−1, i.v.) fever, presumably by inhibiting thermogenesis. At 31°C, L‐NAME enhanced LPS fever by augmenting skin vasoconstriction (Tsk fall).

In summary, both SNA and SNG had no pyrogenic effect of their own and failed to enhance LPS fever; peripheral L‐NAME attenuated only fever brought about by increased thermogenesis. It is concluded that NO is uninvolved in febrigenic signaling to the brain.

British Journal of Pharmacology (2004) 141, 1204–1213. doi:10.1038/sj.bjp.0705713
A critical ‘threshold’ of β2‐integrin engagement regulates augmentation of cytokine‐mediated superoxide anion release
Authors: Walker Trevor R , Ruchaud‐Sparagano Marie‐Helene , McMeekin Sarah R , Dransfield Ian
Published: April 2004

Neutrophil adhesion regulates a number of processes involved in the pathogenesis of inflammatory diseases including rheumatoid arthritis. Neutrophil destructive potential can be modulated by adhesion, allowing alteration of inflammatory cell behaviour while preserving antimicrobial defences. β2‐Integrin‐mediated neutrophil adhesion to albumin‐coated latex beads (ACLB) allows modulation of integrin clustering and ligation and analysis of the effects of adhesion on neutrophil responses. Tumour necrosis factor‐α (TNFα) enhanced neutrophil binding of different diameter ACLB equally, by almost four‐fold, and independently of bead size. Adhesion of neutrophils to ACLB caused a size‐dependent generation and release of O2− and also potentiated TNFα‐induced O2− release.

Binding of ACLB was not affected by disruption of cytoskeletal integrity with nocodazole or cytochalasin D or following blockade of tyrosine kinase activity. In contrast, tyrosine phosphorylation and an intact cytoskeleton were essential for adhesion‐ and cytokine‐induced O2− release from neutrophils. Inhibition of adhesion‐ and cytokine‐induced O2− release by 4‐amino‐5‐(4‐chlorophenyl)‐7‐(t‐butyl)pyrazol[3,4‐d]pyrimidine (PP2) indicated that a Src‐family tyrosine kinase was the principal regulatory pathway mediating this response in neutrophils, a distal role for p38 MAPK was revealed by use of SB203580.

Tyrosine phosphorylation of c‐Fgr, a Src‐family tyrosine kinase, occurred following ACLB adhesion and exposure to TNFα, and was susceptible to inhibition by PP2. We suggest that activation of the key regulatory enzyme c‐Fgr is achieved following ligation of a critical threshold of integrins following binding of large (>3 μm) ACLB.

British Journal of Pharmacology (2004) 141, 1131–1140. doi:10.1038/sj.bjp.0705715
Role of the epithelium and acetylcholine in mediating the contraction to 5‐hydroxytryptamine in the mouse isolated trachea
Authors: Moffatt James D , Cocks Thomas M , Page Clive P
Published: April 2004

The 5‐HT receptor subtype that mediates bronchocontraction and the involvement of neuronal and non‐neuronal acetylcholine was assessed in murine isolated tracheae.

Atropine (1–10 nM) caused a rightward shift of the methacholine concentration–effect curves (pA2=9.0) but reduced the maximum response to 5‐HT, suggesting that 5‐HT acts as an indirect agonist. The potency of 5‐HT receptor agonists (α‐methyl‐5‐HT∼5‐HT>5‐carboxamidotryptamine), together with the competitive antagonism of 5‐HT by ketanserin (pA2=9.4), suggests the involvement of the 5‐HT2A receptor.

While cholinergic twitch responses to electrical field stimulation were abolished by the fast sodium channel inhibitor tetrodotoxin (300 nM), as well as by combined blockade of N‐, P‐ and Q‐type voltage‐operated calcium channels by ω‐conotoxin GVIA (30 nM) and agatoxin IVA (100 nM), responses to 5‐HT were unaffected. Similarly, botulinum toxin A (50 nM) inhibited EFS twitch responses, but not contractions to 5‐HT.

Choline acetyltransferase immunoreactivity was localised to ganglia and nerve fibres as well as approximately half the epithelial cells in the preparation. Removal of the epithelial layer markedly attenuated the contractile response to 5‐HT, but had no effect on contractions to either methacholine or EFS.

These findings suggest that 5‐HT, acting at 5‐HT2A receptors on mouse tracheal epithelial cells, stimulates these cells to release acetylcholine, which then causes contraction of airway smooth muscle. This phenomenon should be borne in mind in when interpreting studies of murine models of airway disease.

British Journal of Pharmacology (2004) 141, 1159–1166. doi:10.1038/sj.bjp.0705720
To move or not to move?
Authors: Tamagnone Luca , Comoglio Paolo M
Published: April 2004

Semaphorins were discovered 11 years ago as molecular cues for axon guidance that are conserved from invertebrates to humans. More than 20 semaphorin genes have been identified in mammals and their protein products are now known to be involved in a range of processes from the guidance of cell migration to the regulation of the immune response, angiogenesis and cancer. Plexins, either alone or in association with neuropilins, constitute high‐affinity semaphorin receptors. However, other transmembrane molecules have been implicated in semaphorin receptor complexes, and interactions between plexins and a range of intracellular effectors have been reported. These data indicate that semaphorins might be able to elicit responses through more than one signalling pathway. Interestingly, according to recent findings, the semaphorin‐dependent control of cell migration crucially involves integrin‐based adhesive structures through which polarized cell‐membrane protrusion is coupled to cytoskeletal dynamics. This review focuses on the mechanisms whereby semaphorins are thought to regulate cell migration.
Low-band-gap, sublimable rhenium(I) diimine complex for efficient bulk heterojunction photovoltaic devices
Authors: Wong H. L. , Lam L. S. M. , Cheng K. W. , Man K. Y. K. , Chan W. K. , Kwong C. Y. , Djurišić A. B.
Published: April 2004

The use of chlorotricarbonyl rhenium(I) diimine complex as photosensitizing molecule in photovoltaic cells is demonstrated. Unlike other transition-metal-based sensitizers, the complex is sublimable and has low band gap. It also exhibits bipolar charge transport character with relatively high carrier mobilities on the order of 10−3 cm2 V−1 s−1. Multilayer heterojunction and bulk heterojunction devices with fullerene as the electron accepting molecule were prepared. For the bulk heterojunction devices, the fill factor and power conversion efficiency under simulated solar light illumination were 0.56 and 0.48%, respectively. Atomic force microscopic images showed that the complex dispersed evenly with fullerene molecules in solid state.
Stable differential phase shift quantum key distribution with a key creation efficiency of 3/4
Authors: Chen Xiuliang , Zhou Chunyuan , Wu Guang , Zeng Heping
Published: April 2004

In this letter, we demonstrate that a high key creation efficiency can be achieved in a stable differential phase shift quantum key distribution system by using three cascaded Mach–Zehnder interferometers. A pulse is split into four independent pulses, and the bit information is carried by one of the three phase differences between the sequential pulses. Any birefringence effects and polarization-dependent losses in the long-distance fiber are automatically compensated with a Faraday mirror. Due to the neatly use of three cascaded interferometers, the key creation efficiency reaches 3/4.
Raman scattering of folded acoustic phonons in self-assembled Si/Ge dot superlattices
Authors: Tan P. H. , Bougeard D. , Abstreiter G. , Brunner K.
Published: April 2004

Self-assembled Si/Ge dot multilayers with small, uncorrelated dots fabricated by molecular beam epitaxy in the Stranski–Krastanov growth mode are studied by Raman scattering of folded longitudinal acoustic (FLA) modes. The FLA Raman spectra are analyzed and modeled with respect to mode frequencies and the spectral envelope of mode intensities. The deduced average superlattice properties are consistent with results from atomic force microscopy. The simple Rytov model used for Si/Ge layer structures reproduces very well the frequencies of the FLA modes up to 150 cm−1. The nonlinearity of phonon dispersion curves in bulk Si for large momenta, however, becomes important for modeling the higher frequencies of observed FLA modes up to 22nd order. The effective dot layer width and an activation energy for thermal intermixing of 2.1±0.2 eV are determined from the spectral envelopes of FLA mode intensities of as-grown and annealed Si/Ge dot multilayers.
Amorphous boron carbon nitride as a pH sensor
Authors: Li C. L. , Huang B. R. , Chattopadhyay S. , Chen K. H. , Chen L. C.
Published: April 2004

Amorphous boron carbon nitride (a-BCxNy) has been used as the sensing membrane in an extended gate field effect transistor for the measurement of pH of solutions. The a-BCxNy material was produced by dual gun magnetron sputtering and has been found to be a stable and sensitive pH sensor with sensitivities in the range of 40 mV/pH. The pH sensitivity, however, increased with increasing carbon content of the a-BCxNy sensing membrane and reached a maximum of 46 mV/pH for a carbon concentration of 47 at. %. The response times of these sensors are close to 6 s. The drain current, which is an indicator of the pH, remained stable (fluctuation of few microamperes) over a period of 10 min in the phosphate solution with varied pH, demonstrating a good stability of the sensing membrane.
Order–disorder transition of anodic alumina nanochannel arrays grown under the guidance of focused-ion-beam patterning
Authors: Liu C. Y. , Datta A. , Liu N. W. , Peng C. Y. , Wang Y. L.
Published: April 2004

By anodizing an aluminum surface that has been patterned with different guiding lattices using a focused ion beam, the resulting anodic alumina nanochannel arrays exhibit different degree of order arrangement. Long-range order is achieved only when the guiding lattice is carefully matched to that of the self-organized hcp array formed locally in an unguided area. Lattice mismatch between the guiding and locally self-organized lattice leads to an order–disorder transition via the creation and annihilation of nanochannels. The driving force of the transition is attributed to the unbalance in the stress among the nanochannels.
On the origin of spin loss in GaMnN/InGaN light-emitting diodes
Authors: Buyanova I. A. , Izadifard M. , Chen W. M. , Kim J. , Ren F. , Thaler G. , Abernathy C. R. , Pearton S. J. , Pan C.-C. , Chen G.-T. , Chyi J.-I. , Zavada J. M.
Published: April 2004

Spin polarization of GaMnN/InGaN light-emitting diodes grown by molecular beam epitaxy is analyzed. In spite of the ferromagnetic behavior of the GaMnN spin injector, the diodes are shown to exhibit very low efficiency of spin injection. Based on resonant optical orientation spectroscopy, the spin loss in the structures is shown to be largely due to fast spin relaxation within the InGaN spin detector, which itself destroys any spin polarization generated by optical spin orientation or electrical spin injection.
Excimer-laser-induced activation of Mg-doped GaN layers
Authors: Lin Yow-Jon , Liu Wen-Fung , Lee Ching-Ting
Published: April 2004

In this study, we investigated the 248 nm excimer-laser-induced activation of the Mg-doped GaN layers. According to the observed photoluminescence results and the x-ray photoelectron spectroscopy measurements, we found that the dissociation of the Mg–H complexes and the formation of hydrogenated Ga vacancies (i.e., VGaH2) and/or the Ga vacancies occupied by interstitial Mg during the laser irradiation process, led to an increase in the hole concentration.
Effect of nitrogen on the optical properties of InGaAsN p-i-n structures grown on misoriented (111)B GaAs substrates
Authors: Miguel-Sánchez J. , Guzmán A. , Ulloa J. M. , Hierro A. , Muñoz E.
Published: April 2004

In this work, we demonstrate the growth, characterization, and processing of InGaAsN single quantum well p-i-n structures by solid-source molecular-beam epitaxy on misoriented GaAs (111)B substrates. Two different misorientations were studied simultaneously, 1° toward [−211] and 2° toward [2-1-1], the latter showing the highest optical quality. The roles of the arsenic flux, substrate misorientation, and amount of active nitrogen on the optical properties and crystal quality are discussed. We demonstrate photoluminescence emission at wavelength as long as 1.42 μm at 16 K on (111)B GaAs. Postgrowth rapid thermal annealing improves crystal quality and typical blueshifts of the peak emission are observed, like the case of (100).
Thermal conductivities of individual tin dioxide nanobelts
Authors: Shi Li , Hao Qing , Yu Choongho , Mingo Natalio , Kong Xiangyang , Wang Z. L.
Published: April 2004

We have measured the thermal conductivities of a 53-nm-thick and a 64-nm-thick tin dioxide (SnO2) nanobelt using a microfabricated device in the temperature range of 80–350 K. The thermal conductivities of the nanobelts were found to be significantly lower than the bulk values, and agree with our calculation results using a full dispersion transmission function approach. Comparison between measurements and calculation suggests that phonon–boundary scattering is the primary effect determining the thermal conductivities.
A distributed charge storage with GeO2 nanodots
Authors: Chang T. C. , Yan S. T. , Hsu C. H. , Tang M. T. , Lee J. F. , Tai Y. H. , Liu P. T. , Sze S. M.
Published: April 2004

In this study, a distributed charge storage with GeO2 nanodots is demonstrated. The mean size and aerial density of the nanodots embedded in SiO2 are estimated to be about 5.5 nm and 4.3×1011 cm−2, respectively. The composition of the dots is also confirmed to be GeO2 by x-ray absorption near-edge structure analyses. A significant memory effect is observed through the electrical measurements. Under the low voltage operation of 5 V, the memory window is estimated to ∼0.45 V. Also, a physical model is proposed to demonstrate the charge storage effect through the interfacial traps of GeO2 nanodots.
True molecular resolution in tapping-mode atomic force microscopy with high-resolution probes
Authors: Klinov Dmitry , Magonov Sergei
Published: April 2004

True molecular resolution was demonstrated in tapping-mode atomic force microscopy study of polydiacetylene crystal using carbon probes with an extremity of ∼1 nm. Images of the bc plane of the crystal, which were obtained at ambient conditions, reproduce the crystallographic molecular arrangement. The image features directly correspond to the edges of the individual side groups of the polymer chains, which form the crystal surface. In the consecutive images, the molecular-size defects have been observed on this surface as an additional proof of the true molecular resolution achieved with the probes.
On the feasibility of “measuring” crystal field parameters in a rotating-sample magnetometer
Authors: Kuz’min M. D.
Published: April 2004

It is argued that the crystal field parameters (CFPs) of rare-earth magnets can be determined by means of a rotating-sample magnetometer (RSM), recording the harmonics of magnetization Mn, n=2,4,6, in a constant magnetic field, as temperature varies. The process of “measuring” individual CFP of order n can be as direct as observing the slope of the Mn-vs-T−n dependence at sufficiently high temperatures, necessarily in the paramagnetic region. Although the basic idea of the RSM is anything but new, its implementation is greatly facilitated by the recent technological developments, such as digital lock-in amplifiers, miniature stepper motors, and high-performance permanent magnets.
Ferromagnetism at room temperature with a large magnetic moment in anatase V-doped TiO2 thin films
Authors: Hong Nguyen Hoa , Sakai Joe , Hassini Awatef
Published: April 2004

V-doped TiO2 thin films were grown by laser ablation on LaAlO3 substrates. In the chosen range of the growth conditions, all V:TiO2 films have an anatase structure and exhibit semiconducting and ferromagnetic behaviors at room temperature. V:TiO2 films have a giant magnetic moment and they seem to be far better ferromagnetic than Co/Fe/Ni-doped TiO2 films. This study has proved that a few percent of V substituting for Ti in TiO2 can result in a potential diluted magnetic semiconductor.
Synthesis and Properties of a Mesylated ArgoGel Resin
Authors: Sann Christine Le , Abell Andrew D.
Published: April 2004

Treatment of ArgoGel-OH with methanesulfonylchloride and triethylamine gives ArgoGel-OMs to which can be coupled the salt of a hydroxycarboxylic acid (quinates 1c, 3b, or sodium salicylate) and the caesium salt of N-Boc–amino acid. The phenoxide derived from 4-hydroxybenzyl alcohol can also be coupled to this new resin to give a Wang linker.
The Diastereoselective Syntheses of Enantiopure Benzo- and Naphtho-pyrans Related to the Aphid Insect Pigments
Authors: Giles Robin G. F.
Published: April 2004

An overview is presented of synthetic endeavours directed towards the assembly of the enantiopure quinone A and quinone A′, natural derivatives of the aphid insect pigments protoaphin-fb and protoaphin-sl. These are achieved through intramolecular diastereoselective cyclization of tethered phenolic lactaldehydes. The conformational implications of the cyclization process are discussed. Model reactions allow the formulation of a more concise, convergent route to these natural derivatives through the corresponding intermolecular reactions, in which the required complementary diastereoselectivity is provided by the choice of either titanium or magnesium phenolates for reaction with the ethoxyethyl-protected asymmetric lactaldehyde.