bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization of Nogo and its receptor in the optic pathway of mouse embryos
Authors: Wang Jun , Chan Chung‐Kit , Taylor Jeremy S.H. , Chan Sun‐On
Published: January 2008

We have investigated the localization of Nogo, an inhibitory protein acting on regenerating axons in the adult central nervous system, in the embryonic mouse retinofugal pathway during the major period of axon growth into the optic chiasm. In the retina, Nogo protein was localized on the neuroepithelial cells at E12 and at later stages (E13–E17) on radial glial cells. Colocalization studies showed expression of Nogo on vimentin‐positive glia in the retina and at the optic nerve head but not on most of the TuJ1‐ and islet‐1‐immunoreactive neurons. Only a few immature neurons in the ventricular and peripheral regions of the E13 retina were immunoreactive to Nogo. In the ventral diencephalon, Nogo was expressed on radial glia, most strongly on the dense radial glial midline raphe within the chiasm where uncrossed axons turn and in the initial segment of the optic tract. In vitro studies showed that the Nogo receptor (NgR) was expressed on the neurites and growth cones from both the ventral temporal and dorsal nasal quadrant of the retina. In the optic pathway, NgR staining was obvious in the vitreal regions of the retina and on axons in the optic stalk and the optic tract, but not in the chiasm. These expression patterns suggest an interaction of Nogo with its receptor in the mouse retinofugal pathway, which may be involved in guiding axons into the optic pathway and in governing the routing of axons in the optic chiasm. © 2008 Wiley‐Liss, Inc.
Corrosion resistance of PANi‐coated steel in simulated PEMFC anodic environment
Authors: Huang Naibao , Liang Chenghao , Yi Baolian
Published: January 2008

By using electrochemical techniques, the corrosion resistance of polyaniline (PANi)‐coated 1Cr18Ni9Ti stainless steel was investigated in simulated proton exchange membrane fuel cell (PEMFC) anodic environment. The results indicated that the compact conductive PANi film could be obtained on 1Cr18Ni9Ti steel by pulse potentiostatic method (PPSM). When steel was coated with conductive PANi, its corrosion potential was improved from −350 to 250 mV in simulated corrosion solution. During the potentiostatic polarization in PEMFC's anodic operation environment, the film is stable and there is no degradation of the PANi film. The film has no effect on the performance of the fuel cell. Further effort to improve the performance of conductive polymer coatings and to estimate the long‐term performance in actual PEMFC environment is desirable.
The study of immersion chloride extraction of iron artifacts
Authors: Liu J. , Li Y.
Published: January 2008

The chloride extraction rules of iron artifacts were studied by immersion methods. Different chloride extraction results between the alkaline solution and a washing solution were obtained. The microstructure and the anti‐corrosion performance of the samples before and after treatment, were, respectively studied by the scanning electron microscope (SEM) and the potentiodynamic scanning method. The results indicated that Cl− removed according to the diffusion law. The microstructure of the samples transformed after treatment. The rusts became more compact, and the porosity also increased. The chloride extraction effect in the washing solution was better than that in the NaOH solution.
The inhibition effect of the new Schiff base, namely 2,2′‐[bis‐N(4‐choloro benzaldimin)]‐1,1′‐dithio against mild steel corrosion
Authors: Hosseini S. M. A. , Azimi A.
Published: January 2008

2,2′‐[bis‐N(4‐choloro benzaldimin)]‐1,1′‐dithio has been synthesized and its inhibiting action on the corrosion of mild steel in 0.5 M sulfuric acid was investigated by various corrosion monitoring techniques, such as weight loss and potentiodynamic polarization techniques. The experimental results suggest that this compound is a good corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. This organic compound is a mixed type inhibitor in the acid solution, and its adsorption on the mild steel surface is also found to obey the Langmuir adsorption isotherm.
Thermally Induced Polymerization of Muconic Esters in the Solid State Studied by Infrared Microscope Spectroscopy under Temperature Control
Authors: Ueno Takako , Furukawa Daisuke , Matsumoto Akikazu
Published: January 2008

The polymerization mechanism and kinetics for the thermally induced solid‐state polymerization of muconic esters are revealed by infrared microscope spectroscopy using single crystals under temperature control combined with X‐ray diffraction measurements. In the present study, a definite induction period during the initial stage of the solid‐state polymerization of di(4‐chlorobenzyl) and di(4‐bromobenzyl) (Z,Z)‐muconates upon heating in the dark is observed. Such a polymerization behavior is uniquely observed for the shrinking‐type polymerization of these monomers, but not for the expanding polymerization of bis(3,4‐methylenedioxybenzyl) (E,E)‐muconate. The reaction mechanism is discussed on the basis of the experimental results for the kinetic analysis of the polymerization by infrared spectroscopy as well as structural determination by X‐ray diffraction measurements.

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Control of the Dynamic Motion of a Gel Actuator Driven by the Belousov‐Zhabotinsky Reaction
Authors: Maeda Shingo , Hara Yusuke , Yoshida Ryo , Hashimoto Shuji
Published: January 2008

A novel self‐oscillating gel actuator with gradient structure, which generates a pendulum motion by fixing one edge of the gel without external stimuli was achieved. The gel was synthesized by copolymerizing the ruthenium catalyst for the Belousov‐Zhabotinsky reaction with N‐isopropylacrylamide and 2‐acrylamido‐2‐methylpropane sulfonic acid. Furthermore, we clarified that the period and amplitude for the self‐oscillating behavior of the gel actuator are controllable by changing the composition, temperature, and size of the gel. The maximum amplitude of the novel gel actuator is about a 100 times larger than that of the conventional self‐oscillating gel system.

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Klebtechnik – multifunktionales Fügen für den nachhaltigen Werkstoffeinsatz im 21. Jahrhundert
Authors: Gegner J.
Published: January 2008

Kleben erfüllt die Schlüsselvoraussetzungen für die nachhaltige Fügetechnik des 21. Jahrhunderts: Es können unterschiedliche Werkstoffe mit integrierten Zusatzfunktionen gewichtssparend verbunden werden. Der Übersichtsartikel behandelt einleitend Ursprung und wirtschaftliche Stellung der Klebtechnik. Verfahren der Oberflächenbehandlung und Bedeutung von Adhäsion und Kohäsion werden diskutiert. Die Einteilung der Klebstoffe erfolgt nach dem Abbindemechanismus. Die richtige Auswahl wird erläutert. Wichtig für die Bewertung des Klebens ist der Vergleich mit anderen Fügetechniken. Die geometrische Fugengestaltung basiert auf Konstruktionsleitlinien: Man vermeide Spannungsspitzen und maximiere die Klebfläche. Einfache Hinweise zur Festigkeitsberechnung erleichtern die Dimensionierung. Die Werkstoffprüfung in der Klebtechnik wird beschrieben. Der Zugscherversuch mit dicken Fügeteilen eignet sich zur in‐situ‐Bestimmung mechanischer Kennwerte. Anwendungen des Klebens aus Luft‐ und Raumfahrt und dem Transportwesen werden vorgestellt. Neben diesen traditionellen Industriezweigen öffnen sich neue Märkte in Branchen wie Elektronik und Medizin. Chemisch härtende Produkte lösen dank hoher Festigkeit und Verformbarkeit anspruchsvolle Aufgaben in der Kleb‐ und Dichttechnik.
Entwicklung von Diffusionsschichten auf Nickelbasiswerkstoffen für den Einsatz in chlorhaltigen Hochtemperaturprozessen
Authors: Rammer B. , Weber T. , Schütze M.
Published: January 2008

Für ein neuartiges, bei der BAM Berlin [1] entwickeltes Verfahrenskonzept zur Abscheidung von Schwermetallen aus Klärschlammaschen werden hoch chlorhaltige Atmosphären (bis 20 % Chlor in trockener Luft) bei Temperaturen bis zu 1000 °C benötigt. Derzeit befinden sich keine Werkstoffe auf dem Markt, die unter diesen Bedingungen über einen langen Zeitraum stabil sind.

Im Rahmen eines Forschungsprojektes soll die Korrosionsbeständigkeit von Nickelbasislegierungen gegen Hochtemperaturchlorkorrosion durch Aufbringen von aluminium‐ und /oder siliziumhaltigen Diffusionsschichten optimiert werden. Dabei kommt das Pack Cementation‐ bzw. Pulverpackverfahren zum Einsatz. Das zu beschichtende Material wird in ein Pulver, bestehend aus dem Beschichtungsmetall, einem Halogenlieferanten (z. B. Ammoniumchlorid) und Aluminiumoxid als Füllmaterial eingebettet. Während eines mehrstündigen Glühprozesses bei Temperaturen von etwa 800 bis 1000 °C kommt es zur Bildung gasförmiger Metallhalogenide. Sie diffundieren durch die Pulverpackung und werden am Substrat unter Abscheidung des Beschichtungsmetalls zersetzt. Die nachfolgende Festphasendiffusion führt zur Ausbildung von Diffusionsschichten.

Thermodynamisch gesehen scheinen Werkstoffe mit hohen Gehalten an Aluminium und Silizium die Voraussetzung zu bieten, durch langsam wachsende, stabile Oxide die erforderliche Korrosionsbeständigkeit zu gewährleisten. Das tatsächliche Werkstoffverhalten soll in Auslagerungsversuchen unter chlorhaltiger Atmosphäre ermittelt werden.
Innovative Methode zur Partikelklassifizierung beim thermischen Spritzen
Authors: Zimmermann S. , Landes K. , Schein J.
Published: January 2008

Die Entwicklung und der Einsatz von Beschichtungsverfahren zur Veredlung und Verbesserung von Oberflächen gewinnt aufgrund wachsender Kosten‐/ Zeit‐ und Ressourcenknappheit immer mehr an Bedeutung. Der Prozess des Beschichtens muss möglichst autark ablaufen, eventuelle auftretende Störungen sollen durch entsprechende Diagnostiken registriert und gegebenenfalls nachreguliert werden. Die hier beschriebene Diagnostikmethode PSI (Particle Shape Imaging) untersucht daher das Verhalten des Beschichtungsmaterials während des Prozesses und liefert physikalische Parametergrößen zu dessen Optimierung. Dabei handelt es sich um eine Laser‐Schattenbild‐Methode, die von individuellen Partikeln Bilder aufnimmt und mit speziell entwickelter Bildverarbeitung analysiert. Durch neue Partikelklassifizierungen (z. B. durch Fourieranalyse der Oberflächenkontur) ermöglicht das PSI, Rückschlüsse und Aussagen über den Aufschmelzgrad der Partikel. Als zusätzliches Ergebnis des Bildbearbeitungsalgorithmus liefert das PSI die physikalischen Parameter Form, Größe, Geschwindigkeit und Position. Mit geeigneter Darstellung werden diese Ergebnisse zusammengefasst und liefern so einen wesentlichen Beitrag zum Prozessverständnis.
Status quo und Trends der Galvanotechnik
Authors: Lampke Th. , Steger H. , Zacher M. , Steinhäuser S. , Wielage B.
Published: January 2008

Die Galvanotechnik ist nach wie vor eines der am häufigsten angewandten Oberflächenveredelungsverfahren. Neben der Automobilindustrie, einer der größten Abnehmer galvanotechnischer Oberflächen, sind für den hohen Umsatz und die Entwicklung der Galvanotechnik die Bereiche Elektrotechnik und Elektronik, Bauwesen, Maschinenbau, Luft‐ und Raumfahrttechnik, die Schmuckbranche sowie die Medizintechnik (z.B. Dentalprothetik) verantwortlich. Ständig steigende Rohstoffpreise, strengere gesetzliche Regelungen (z. B. EU‐Altauto‐Verordnung), wachsende Anforderungsprofile der Kunden hinsichtlich Qualität und Funktionalität sowie steigendes Umweltbewusstsein stellen die Galvanotechnik vor immer neue Herausforderungen, die sich als Innovationstreiber herausstellen. Dieser Beitrag vermittelt einen Überblick zum Status quo der Galvanotechnik. Im Weiteren werden ausgewählte aktuelle Trends aufgezeigt.
Thermisches Spritzen vanadiumkarbidverstärkter Eisenbasisschichten
Authors: Wielage B. , Schuberth S. , Grund T.
Published: January 2008

Mittels HVOF‐Spritzverfahren hergestellte Cermet‐Schichten für den Verschleißschutz, wie die Systeme WC‐Co(Cr) und Cr3C2‐NiCr, haben in der Vergangenheit eine breite industrielle Anwendung gefunden. Durch den Einsatz chromhaltiger Matrizes weisen sie neben der hervorragenden Verschleißbeständigkeit auch eine gute Korrosionsbeständigkeit auf. In der gegenwärtigen Forschung im Bereich der Pulvermetallurgie und des Plasma‐Pulver‐Auftragschweißens wurden Eisenbasislegierungen mit hohem Chrom‐ und Vanadiumgehalt entwickelt, welche über ähnliche Eigenschaften verfügen und sich damit als kostengünstige Alternative zu den etablierten Cermet‐Schichten anbieten. HVOF‐gespritzte Schichten dieser Eisenbasislegierungen werden hinsichtlich ihrer wirtschaftlichen Verarbeitbarkeit und ihrer Korrosions‐ und Verschleißeigenschaften untersucht.
Untersuchungen zum Erosionsverschleiß an schweißtechnisch hergestellten Beschichtungen
Authors: Wesling V. , Reiter R. , Oligmüller J.
Published: January 2008

Mit Erosions‐ bzw. Strahlverschleiß wird die Verschleißart bezeichnet, bei der der Werkstoffabtrag durch frei fliegende, stoßende und furchende Teilchen verursacht wird.

Insbesondere lufttechnische Systeme, wie z. B. Großventilatoren oder Förderrohrleitungen, unterliegen Erosionsverschleiß, wenn im Gasstrom Feststoffe, wie z. B. Rohmehl‐, Zement‐, Klinker‐ oder Kohlestäube mitgeführt werden.

Hohe Partikelbelastung in Kombination mit hohen Zirkulargeschwindigkeiten verursachen massive Verschleißerscheinungen an den ihnen ausgesetzten Bauteilen.

Eine zielsichere Auslegung Erosionsverschleiß ausgesetzter Anlagen ist im Projektierungs‐ bzw. Auslegungsstadium nur eingeschränkt möglich. Bislang basieren die Verschleißschutzlösungen größtenteils auf umfangreichen zeit‐ und kostenintensiven Industrieerprobungen seitens der Anlagenhersteller und Betreiber.

Im Rahmen der hier vorgestellten Untersuchungen soll über Erfahrungen bei der Laborprüfung unterschiedlicher innovativer Werkstoffkonzepte zum Auftragschweißen von Baustählen und Feinkornbaustählen mit praxisnahen Medien unter industriellen Randbedingungen berichtet werden. Einflussgrößen auf die Beständigkeit derartiger Verbundwerkstoffe werden vorgestellt.
Mikrostruktur und Eigenschaften HVOF‐gespritzter Schichten im System TiO2– Cr2O3
Authors: Stahr C. C. , Berger L.‐M. , Thiele S.
Published: January 2008

Thermisch gespritzte Titanoxidschichten besitzen gute tribologische Eigenschaften und sind auf Grund ihres Sauerstoffdefizites elektrisch leitfähig. Die Fehlstellen im Sauerstoffuntergitter können sich in sogenannten kristallografischen Scherebenen anordnen. Diese Strukturen sind unter der Bezeichnung Magnéli‐Phasen bekannt. Da im Hochtemperatureinsatz in sauerstoffhaltiger Atmosphäre eine vollständige Oxidation bis hin zur Bildung von TiO2erfolgen kann, ist der Einsatzbereich eingeschränkt. Auf der titanoxidreichen Seite des Systems TiO2‐Cr2O3bilden sich ähnliche Phasen wie im System Ti‐O, die nach Literaturangaben auch bei hohen Temperaturen an der Luft stabil sind und daher eine Langzeitstabilität der Schichteigenschaften erwarten lassen. In dieser Arbeit werden erste Resultate systematischer Untersuchungen an HVOF‐gespritzten Schichten aus dem System TiO2‐Cr2O3vorgestellt.
Adverse events associated with prolonged antibiotic use
Authors: Meropol Sharon B. , Chan K. Arnold , Chen Zhen , Finkelstein Jonathan A. , Hennessy Sean , Lautenbach Ebbing , Platt Richard , Schech Stephanie D. , Shatin Deborah , Metlay Joshua P.
Published: January 2008

Purpose

The Infectious Diseases Society of America and US CDC recommend 60 days of ciprofloxacin, doxycycline, or amoxicillin for anthrax prophylaxis. It is not possible to determine severe adverse drug event (ADE) risks from the few people thus far exposed to anthrax prophylaxis. This study's objective was to estimate risks of severe ADEs associated with long‐term ciprofloxacin, doxycycline, and amoxicillin exposure using three large databases: one electronic medical record (General Practice Research Database) and two claims databases (UnitedHealthcare, HMO Research Network).

Methods

We include office visit, hospital admission and prescription data for 1/1/1999–6/30/2001. Exposure variable was oral antibiotic person‐days (pds). Primary outcome was hospitalization during exposure with ADE diagnoses: anaphylaxis, phototoxicity, hepatotoxicity, nephrotoxicity, seizures, ventricular arrhythmia, or infectious colitis.

Results

We randomly sampled 999 773, 1047 496, and 1819 004 patients from Databases A, B, and C respectively. 33 183 amoxicillin, 15 250 ciprofloxacin and 50 171 doxycycline prescriptions continued ≥30 days. ADE hospitalizations during long‐term exposure were not observed in Database A. ADEs during long‐term amoxicillin were seen only in Database C with 5 ADEs or 1.2(0.4–2.7) ADEs/100 000 pds exposure. Long‐term ciprofloxacin showed 3 and 4 ADEs with 5.7(1.2–16.6) and 3.5(1.0–9.0) ADEs/100 000 pds in Databases B and C, respectively. Only Database B had ADEs during long‐term doxycycline with 3 ADEs or 0.9(0.2–2.6) ADEs/100 000 pds. For most events, the incidence rate ratio, comparing >28 versus 1–28 pds exposure was <1, showing limited evidence for cumulative dose‐related ADEs from long‐term exposure.

Conclusions

Long‐term amoxicillin, ciprofloxacin, and doxycycline appear safe, supporting use of these medications if needed for large‐scale post‐exposure anthrax prophylaxis. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of colloid suspensions of humic acids upon the alkaline fading of carbocations
Authors: Arias‐Estevez M. , Astray G. , Cid A. , Fernández‐Gándara D. , García‐Río L. , Mejuto J. C.
Published: January 2008

The influence of humic substances (HSs) upon the alkaline hydrolysis of crystal violet (CV) and malachite green (MG) has been studied. Important inhibition of hydrolysis reaction has been reported. This inhibition has been explained in terms of association of reactants to the humic substances. Kinetic results have been modelized using the micellar pseudophase model. Copyright © 2008 John Wiley & Sons, Ltd.
Facile synthesis of core‐shell organic–inorganic hybrid nanoparticles with amphiphilic polymer shell by one‐step sol–gel reactions
Authors: Marini M. , Toselli M. , Borsacchi S. , Mollica G. , Geppi M. , Pilati F.
Published: January 2008

Organic–inorganic hybrid core‐shell nanoparticles with diameters ranging from 100 to 1000 nm were prepared by a one‐pot synthesis based on base catalyzed sol–gel reactions using tetraethoxysilane and a triethoxysilane‐terminated polyethylene‐b‐poly(ethylene glycol) as reactants. Data from TEM, TGA, and solid‐state NMR analysis are in agreement with the formation of core‐shell nanoparticles with an inorganic‐rich core and an external shell consisting of an amphiphilic block copolymer monolayer. The influence of the organic–inorganic ratio, solution concentration, and postcuring temperature on core and shell dimensions of the nanospheres were investigated by TEM microscopy. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1699–1709, 2008
Synthesis and photorefractivity of poly[methyl‐3‐(7‐dibenzo[a,g]carbazolyl)‐propylsiloxane]
Authors: Moon In Kyu , Choi Chil‐Sung , Kim Nakjoong
Published: January 2008

7H‐Dibenzo[a,g]carbazole‐substituted polysiloxane (PSX‐[a,g]BCz) has been synthesized by hexachloroplatinate (IV) hydrate polymerization from poly(methylhydrosiloxane) and 7‐ally‐7H‐dibenzo[a,g]carbazole. PSX‐[a,g]BCz composite showed large orientational birefringences because of both large dipole moments and high‐polarizability anisotropies of P‐IP‐DC chromophore associated with the effective conjugation along the polyene. The 50‐μm thick photorefractive material containing 30 wt % 2‐[3‐[(E)‐2(piperidino)‐1‐ethenyl]‐5,5‐dimethyl]‐2‐cyclohexenyliden]malononitrile showed a diffraction efficiency of 51% at 55 V/μm, which corresponded to a Δn of 3.45 × 10−3. PSX‐[a,g]BCz composite shows a fast time constant of 0.42 s at 34 °C and 55 V/μm, which corresponded to the space‐charge field of 12 V/μm under 70 V/μm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1783–1791, 2008
Hydrogen incorporation in ultrananocrystalline diamond/amorphous carbon films
Authors: Kulisch W. , Sasaki T. , Rossi F. , Popov C. , Sippel C. , Grambole D.
Published: January 2008

The incorporation of hydrogen within ultrananocrystalline diamond/amorphous carbon composite films has been investigated by nuclear reaction analysis (NRA) and Fourier transform infrared spectroscopy (FTIR). The film bulk contains ca. 7.5–8% H (for a deposition temperature of 600 °C), while the H concentration in the surface region is considerably higher. FTIR measurements show that the hydrogen‐rich surface is formed right at the beginning of the deposition process and grows outward as the film thickness increases. It can thus be concluded that surface hydrogen species play an active role in the formation of ultrananocrystalline diamond/amorphous carbon films. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrospray photoionization (ESPI) liquid chromatography/mass spectrometry for the simultaneous analysis of cyclodextrin and pharmaceuticals and their binding interactions
Authors: Short Luke C. , Syage Jack A.
Published: January 2008

We report on the use of a multimode electrospray ionization/atmospheric pressure photoionization source (ESI/APPI or ESPI for short) with liquid chromatography/mass spectrometry (LC/MS) to measure all components of a mixed‐polarity liquid sample containing: (1) low‐polarity component (hormone, pharmaceutical or sterol), (2) polar component (cyclodextrin substrate), and (3) bound polar complex. The ESPI source has several advantages over both single ESI and multimode electrospray ionization/chemical ionization (ESCI) analysis, including an enhanced bound‐complex detection and better performance at lower solvent flow rates. Relative binding constants are determined with (i) ESI mode, resulting in relative R(ESI‐MS) values, and (ii) both ESI and APPI modes, providing relative KD values. We find that low molecular‐substitution (Ms) values of cyclodextrin, i.e., Ms = 0.4, preferentially bind to the low‐polarity compounds tested. This investigation is intended to demonstrate the feasibility of ESPI as an additional tool for investigating mixed‐polarity binding systems, providing mass‐specific data for all solution components, both polar and non‐polar. Copyright © 2008 John Wiley & Sons, Ltd.
Teachers respond functionally to student gender differences in a technology course
Authors: Voyles Martha M. , Fossum Tim , Haller Susan
Published: January 2008

This study examines teacher–student interactions and selected student gender differences with volunteer boys and recruited girls in a technology class. The participants were teachers and triads of girls and boys in single‐gender sections of a technology course where the students built, designed features for, and programmed Lego robots. We analyzed transcripts of videotapes of instruction; teacher, parent, and student interviews; student questionnaires; and final programs. Girls and boys differed in a number of ways, and teachers explained their differing interactions with boys and girls as functional responses to those differences. At the end of the course, volunteer boys and recruited girls did not differ in achievement or interest in the course. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 322–345, 2008
Motivation in high school science students: A comparison of gender differences in life, physical, and earth science classes
Authors: Britner Shari L.
Published: January 2008

The aims of this study were to examine self‐efficacy and other motivation variables among high school science students (n = 502); to determine the degree to which each of the four hypothesized sources of self‐efficacy makes an independent contribution to students' science self‐efficacy beliefs; to examine possible differences between life, physical, and Earth science classes; and to investigate patterns of gender differences that may vary among the fields of science. In Earth science classes, girls earned higher grades and reported stronger science self‐efficacy. In life science classes, girls earned higher grades but did not report stronger self‐efficacy, and did report higher science anxiety. In physical science, there were no gender differences in grades or self‐efficacy, but girls again reported higher levels of science anxiety. For boys across science fields, science self‐efficacy significantly predicted course grades and mastery experiences was the only significant predictor of self‐efficacy. For girls, self‐efficacy was also the strongest predictor of science grade across fields. Mastery experiences significantly predicted self‐efficacy in Earth science for girls, but social persuasions, vicarious experiences, and physiological states were better predictors of science self‐efficacy in life and physical science classes. Results support (Bandura, A., 1997) hypothesized sources of self‐efficacy, previous research findings on self‐efficacy in the domain of science, and validate the suggestion made by Lau and Roeser (2002) to disaggregate data by science field. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 955–970, 2008
The Assumption of Proportional Components when Candecomp is Applied to Symmetric Matrices in the Context of Indscal
Authors: Dosse Mohammed Bennani , Berge Jos M. F.
Published: January 2008

The use of Candecomp to fit scalar products in the context of INDSCAL is based on the assumption that the symmetry of the data matrices involved causes the component matrices to be equal when Candecomp converges. Ten Berge and Kiers gave examples where this assumption is violated for Gramian data matrices. These examples are believed to be local minima. It is now shown that, in the single-component case, the assumption can only be violated at saddle points. Chances of Candecomp converging to a saddle point are small but still nonzero.
Compression Neuropathy of the Radial Nerve Due to Ganglion Cysts
Authors: Lifchez Scott D. , Dzwierzynski William W. , Sanger James R.
Published: January 2008

Ganglions of the upper extremity are common. Radial nerve dysfunction, particularly radial sensory dysfunction, is a rare finding in association with a ganglion. We present our experience with two such ganglia and a review of the literature.
Molecular Dynamics Simulation of Nanoindentation-induced Mechanical Deformation and Phase Transformation in Monocrystalline Silicon
Authors: Lin Yen-Hung , Jian Sheng-Rui , Lai Yi-Shao , Yang Ping-Feng
Published: January 2008

This work presents the molecular dynamics approach toward mechanical deformation and phase transformation mechanisms of monocrystalline Si(100) subjected to nanoindentation. We demonstrate phase distributions during loading and unloading stages of both spherical and Berkovich nanoindentations. By searching the presence of the fifth neighboring atom within a non-bonding length, Si-III and Si-XII have been successfully distinguished from Si-I. Crystallinity of this mixed-phase was further identified by radial distribution functions.
Using evolutionary costs to enhance the efficacy of malaria control via genetically manipulated mosquitoes
Authors: KOELLA JACOB C. , ZAGHLOUL LAMIA
Published: January 2008

An earlier mathematical model exploring the use of genetically manipulated mosquitoes for malaria control suggested that the prevalence of malaria is reduced significantly only if almost all mosquitoes become completely resistant to malaria. Central to the model was the ‘cost of resistance’: the reduction of a resistant mosquito's evolutionary fitness in comparison with a sensitive one's. Here, we consider the possibility of obtaining more optimistic outcomes by taking into account the epidemiological (in addition to the evolutionary) consequences of a cost of resistance that decreases the life-span of adult mosquitoes (the most relevant parameter for the parasite's epidemiology). There are two main results. First, if despite its cost, resistance is fixed in the population, increasing the cost of resistance decreases the intensity of transmission. However, this epidemiological effect is weak if resistance is effective enough to be considered relevant for control. Second, if the cost of resistance prevents its fixation, increasing it intensifies transmission. Thus, the epidemiological effect of the cost of resistance cannot compensate for the lower frequency of resistant mosquitoes in the population. Overall, our conclusion remains pessimistic: so that genetic manipulation can become a promising method of malaria control, we need techniques that enable almost all mosquitoes to be almost completely resistant to infection.
Metazoan-protozoan parasite co-infections and host body weight in St Kilda Soay sheep
Authors: CRAIG B. H. , TEMPEST L. J. , PILKINGTON J. G. , PEMBERTON J. M.
Published: January 2008

For hundreds of years, the unmanaged Soay sheep population on St Kilda has survived despite enduring presumably deleterious co-infections of helminth, protozoan and arthropod parasites and intermittent periods of starvation. Important parasite taxa in young Soay sheep are strongyles (Trichostrongylus axei, Trichostrongylus vitrinus and Teladorsagia circumcincta), coccidia (11 Eimeria species) and keds (Melophagus ovinus) and in older animals, Teladorsagia circumcincta. In this research, associations between the intensity of different parasite taxa were investigated. Secondly, the intensities of different parasite taxa were tested for associations with variation in host weight, which is itself a determinant of over-winter survival in the host population. In lambs, the intensity of strongyle eggs was positively correlated with that of Nematodirus spp. eggs, while in yearlings and adults strongyle eggs and coccidia oocysts were positively correlated. In lambs and yearlings, of the parasite taxa tested, only strongyle eggs were significantly and negatively associated with host weight. However, in adult hosts, strongyles and coccidia were independently and negatively associated with host weight. These results are consistent with the idea that strongyles and coccidia are exerting independent selection on Soay sheep.
Particular generalisation: the Antarctic Treaty of 1959 in relation to the anti-nuclear movement
Authors: Moore Jason Kendall
Published: January 2008

This article presents the US role in the formation of the Antarctic Treaty of 1959 in relation to the era's anti-nuclear movement. The purpose is two-fold: to highlight the strategic orientation of US Antarctic policy, suggesting that it was less enlightened than it is frequently portrayed; and to highlight the influence of the anti-nuclear movement upon the treaty's inclusion of a test ban which the United States initially opposed, hoping to reserve the right to conduct nuclear tests. The treaty is depicted as a particular generalisation: one aspect of the cold war that gains significance when scrutinised in relation to another that is much better-known.
Human geographies of sea ice: freeze/thaw processes around Igloolik, Nunavut, Canada
Authors: Laidler Gita J. , Ikummaq Theo
Published: January 2008

Sea ice has been, and continues to be, an integral component of life in the Inuit community of Igloolik, Nunavut. Located on an island of the same name off the northeastern coast of Melville Peninsula, extensive ice formation occurs in Fury and Hecla Strait. This creates an important travel and hunting platform, and enables access to Baffin Island, the mainland, moving ice, hunting and fishing grounds, and nearby communities. With the combined importance, dynamism, and continuous use of this frozen ocean environment, local Inuit elders and hunters have developed a detailed and nuanced understanding of sea ice conditions, freeze/thaw processes, and the influences of winds and currents on ice conditions. Working collaboratively with the community of Igloolik since February 2004, we present the results of 24 semi-directed interviews and 4 sea ice trips to provide a baseline understanding of local freezing processes (near-shore, open water, sea ice thickening, landfast ice, tidal cracks, floe edge, and moving ice), melting processes (snow melt, water accumulation and drainage, and break-up), wind influences on sea ice (wind direction and strength affecting sea ice formation and movement), and, current influences on sea ice (tidal variations and current strength affecting sea ice formation, movement, and polynya size/location). Strong emphasis is placed on Inuktitut terminology and spatial delineations of localised ice conditions and features. Therefore, this paper provides insights into local scale ice conditions and dynamics around Igloolik that are not captured in regional scale studies of Foxe Basin and/or Fury and Hecla Strait. Results have the potential to inform future research efforts on local/regional sea ice monitoring, the relationship between Inuit knowledge, language, and the environment, and addressing community interests through targeted studies.
The cruise of MS Golden Princess in Antarctic waters, January 2007
Authors: Bertram Esther , Gunn Caroline , Stonehouse Bernard
Published: January 2008

In January 2007, MS Golden Princess, carrying 2425 passengers and a crew of approximately 1100, became the largest ship to sail Antarctic waters within the northern limit of pack ice. This note describes the ship and its itinerary, discusses aspects of the cruise, and comments on the use of large cruise liners in Antarctic waters.
Exploring policy-makers’ perspectives on disinvestment from ineffective healthcare practices
Authors: Elshaug Adam G. , Hiller Janet E. , Moss John R.
Published: January 2008

Objectives:Many existing healthcare interventions diffused before modern evidence-based standards of clinical- and cost-effectiveness. Disinvestment from ineffective or inappropriately applied practices is growing as a priority for international health policy, both for improved quality of care and sustainability of resource allocation. Australian policy stakeholders were canvassed to assess their perspectives on the challenges and the nature of disinvestment.

Methods:Senior health policy stakeholders from Australia were criterion and snow-ball sampled (to identify opinion leaders). Participants were primed with a potential disinvestment case study and took part in individual semistructured interviews that focused on mechanisms and challenges within health policy to support disinvestment. Interviews were taped and transcribed for thematic analysis. Participant comments were de-identified.

Results:Ten stakeholders were interviewed before saturation was reached. Three primary themes were identified. (i) The current focus on assessment of new and emerging health technologies/practices and lack of attention toward existing practices is due to resource limitations and methodological complexity. Participants considered a parallel model to that of Australia's current assessment process for new medical technologies is best-positioned to facilitate disinvestment. (ii) To advance the disinvestment agenda requires an explicit focus on the potential for cost-savings coupled with improved quality of care. (iii) Support (financial and collaborative) is needed for research advancement in the methodological underpinnings associated with health technology assessment and for disinvestment specifically.

Conclusions:In this exploratory study, stakeholders support the notion that systematic policy approaches to disinvestment will improve equity, efficiency, quality, and safety of health care, as well as sustainability of resource allocation.
Valuing care recipient and family caregiver time: A comparison of methods
Authors: Guerriere Denise N. , Tranmer Jennifer E. , Ungar Wendy J. , Manoharan Venika , Coyte Peter C.
Published: January 2008

Objectives:The purpose of this study is to compare the approaches used for valuing family caregiver and care recipient time devoted to providing and receiving care.

Methods:Valuation approaches were operationalized within a cohort of cystic fibrosis care recipients (n= 110). Base-case analyses, grounded in human capital theory, applied earnings estimates to caregiving time to impute the market value of time lost from labor. Unpaid labor and leisure time was valued with a replacement cost (homemaker's wage rate). Total time costs were computed and sensitivity analyses were conducted to describe the effects of alternative valuation methods on total costs.

Results:The mean time cost per care recipient–caregiver dyad over 28 days was $2,026CAD. The majority (76 percent) of time costs were due to losses from unpaid labor and leisure time. Varying the valuation of paid labor time did not result in significantly different total time costs (p= .0877). However, varying the method of valuing unpaid labor and leisure time did significantly affect total costs (p< .0001).

Conclusions:Care recipients and caregivers primarily lost time from unpaid labor and leisure in the treatment of cystic fibrosis. Moreover, when the above losses were aggregated, the method of valuation greatly influenced overall results. The findings clearly indicate that omitting caregiver and unpaid labor and leisure costs may result in an inaccurate assessment of ambulatory and home-based healthcare programs.
Patient preferences for pharmacogenetic screening in depression
Authors: Herbild Louise , Gyrd-Hansen Dorte , Bech Mickael
Published: January 2008

Objectives:The aims of this study were to estimate preferences and willingness-to-pay (WTP) for genetic screening for CYP2D6 polymorphisms among a group of former and currently depressed patients.

Methods:A Web-based discrete choice questionnaire was sent to 89 respondents, age 18–65. Four attributes were included: (i) shifts in antidepressant medication before symptom relief, (ii) time with antidepressant medication without symptom relief, (iii) time with antidepressant medication without symptoms but with adverse side-effects, (iv) cost of genetic screening. We used a switching model with two scenarios, one representing patients’ own treatment history and the other a treatment scenario with genetic screening.

Results:In a main-effects model involving the four attributes all coefficients had the expected sign, indicating that as the number of shifts, price or time without symptom relief, and/or dosage-adjustments increased, the likelihood of choosing the screening test decreased. Price and number of shifts in medicine were significant. Marginal WTP for 5 percent probability of a reduction of one in antidepressant shifts was DKK2,599 (€350).

Conclusions:Patients value reductions in shifts in antidepressants and price when choosing between genetic screening and no screening. They do not focus on how the reductions are provided, nor do they value the genetic information the test provides irrespective of its effect on outcome. Given, that the test is able to provide a reduction of one shift in the number of antidepressant shifts with a probability of 5 percent, WTP for the test exceeds its cost.
Biomedical literature search protocols: Consensus statement from the documentation units of the Spanish health technology assessment agencies
Authors: Guemes-Careaga Itziar , Gutiérrez-Ibarluzea Iñaki
Published: January 2008

Objectives:The aims of this study were, first, to define the main advantages and disadvantages of using bibliographic search protocols; second, to define a series of criteria that could aid in prioritizing the information resources to be consulted for each research project; and third, to rank these criteria.

Methods:First, a survey was e-mailed to the Spanish Health Technology Assessment Agencies (AUnETS) group, with the aim of evaluating the usefulness of using bibliographic search protocols. Second, a consensus group meeting with the information specialists of the AUnETS group was organized, where SWOT analysis technique (strengths, weaknesses, opportunities, and threats) was used, also to discuss the utility of using search protocols. Third, the same group designed a final prioritization criteria questionnaire intended for Health Technology Assessment International's Information Resources Group (HTAi IRG), based on a draft version written by the information specialist from the Basque Office for HTA. Finally, this questionnaire was e-mailed to the HTAi IRG experts, and their responses were analyzed.

Results:Some of the advantages defined were systematization of the searches and transparency and repeatability of the process. The perceived disadvantages were inflexibility to be adapted to some situations, inability to establish time frameworks and the difficulty of incorporating experts’ opinions into closed protocols. Five areas of prioritization criteria were defined: study topic; characteristics of the database and other information resources; database interface; characteristics of the organization; kind of research output for which the information is intended. A ranked list of prioritization criteria was established based on the responses of the HTAi IRG group.

Conclusions:The information specialists consulted agreed that search protocols are useful tools for guiding systematic searches. The twenty-one prioritization criteria defined will be used by the information specialists for determining, which databases to consult.
Senior residents’ perceived need of and preferences for “smart home” sensor technologies
Authors: Demiris George , Hensel Brian K. , Skubic Marjorie , Rantz Marilyn
Published: January 2008

Objectives:The goal of meeting the desire of older adults to remain independent in their home setting while controlling healthcare costs has led to the conceptualization of “smart homes.” A smart home is a residence equipped with technology that enhances safety of residents and monitors their health conditions. The study aim is to assess older adults’ perceptions of specific smart home technologies (i.e., a bed sensor, gait monitor, stove sensor, motion sensor, and video sensor).

Methods:The study setting is TigerPlace, a retirement community designed according to the Aging in Place model. Focus group sessions with fourteen residents were conducted to assess perceived advantages and concerns associated with specific applications, and preferences for recipients of sensor-generated information pertaining to residents’ activity levels, sleep patterns and potential emergencies. Sessions were audio-taped; tapes were transcribed, and a content analysis was performed.

Results:A total of fourteen older adults over the age of 65 participated in three focus group sessions Most applications were perceived as useful, and participants would agree to their installation in their own home. Preference for specific sensors related to sensors’ appearance and residents’ own level of frailty and perceived need. Specific concerns about privacy were raised.

Conclusions:The findings indicate an overall positive attitude toward sensor technologies for nonobtrusive monitoring. Researchers and practitioners are called upon to address ethical and technical challenges in this emerging domain.
WELFARE-MAXIMIZING OPERATIONAL MONETARY AND TAX POLICY RULES
Authors: KOLLMANN ROBERT
Published: January 2008

This paper computes welfare-maximizing monetary and tax policy feedback rules in a calibrated dynamic general equilibrium model with sticky prices. The government makes exogenous final good purchases, levies a proportional income tax, and issues nominal one-period bonds. A quadratic approximation method is used to solve the model and to compute household welfare. Optimized policy has a strong anti-inflation stance and implies persistent fluctuations of the tax rate and of public debt. Very simple optimized policy rules, under which the interest rate just responds to inflation and the tax rate just responds to public debt, yield a welfare level very close to that generated by richer rules.
INTRODUCTION TO SPECIAL ISSUE: DYNAMIC MACROECONOMIC THEORY
Authors: JENSEN HENRIK , SØRENSEN PETER NORMAN , WHITTA-JACOBSEN HANS JØRGEN
Published: January 2008

This issue collects 11 articles at the frontier of the field of Dynamic Macroeconomic Theory.

A majority of the articles discuss theoretical issues related to monetary policy. Many rich economies have now enjoyed a long period of stable monetary conditions, but many researchers remain puzzled as to what are the main mechanisms driving monetary stability. The field is of great importance to policymakers, and this issue's dynamic approaches will advance the debate. The other articles touch on other, equally inherently dynamic issues of macroeconomics, relating to growth, business cycles, and the role of credit. In light of the hard constraints we imposed on the length of the contributed articles, we will let the articles speak for themselves, and hope that the reader will enjoy this research sample as much as we do.
A review of the biology of bovine herpesvirus type 1 (BHV-1), its role as a cofactor in the bovine respiratory disease complex and development of improved vaccines
Authors: Jones Clinton , Chowdhury Shafiqul
Published: January 2008

Infection of cattle by bovine herpesvirus type 1 (BHV-1) can lead to upper respiratory tract disorders, conjunctivitis, genital disorders and immune suppression. BHV-1-induced immune suppression initiates bovine respiratory disease complex (BRDC), which costs the US cattle industry approximately 3 billion dollars annually. BHV-1 encodes at least three proteins that can inhibit specific arms of the immune system: (i) bICP0 inhibits interferon-dependent transcription, (ii) the UL41.5 protein inhibits CD8+T-cell recognition of infected cells by preventing trafficking of viral peptides to the surface of the cells and (iii) glycoprotein G is a chemokine-binding protein that prevents homing of lymphocytes to sights of infection. Following acute infection of calves, BHV-1 can also infect and induce high levels of apoptosis of CD4+T-cells. Consequently, the ability of BHV-1 to impair the immune response can lead to BRDC. Following acute infection, BHV-1 establishes latency in sensory neurons of trigeminal ganglia (TG) and germinal centers of pharyngeal tonsil. Periodically BHV-1 reactivates from latency, virus is shed, and consequently virus transmission occurs. Two viral genes, the latency related gene and ORF-E are abundantly expressed during latency, suggesting that they regulate the latency-reactivation cycle. The ability of BHV-1 to enter permissive cells, infect sensory neurons and promote virus spread from sensory neurons to mucosal surfaces following reactivation from latency is also regulated by several viral glycoproteins. The focus of this review is to summarize the biology of BHV-1 and how this relates to BRDC.
Histophilus somnihost–parasite relationships
Authors: Corbeil Lynette B.
Published: January 2008

Histophilus somni(Haemophilus somnus) is one of the key bacterial pathogens involved in the multifactorial etiology of the Bovine Respiratory Disease Complex. This Gram negative pleomorphic rod also causes bovine septicemia, thrombotic meningencephalitis, myocarditis, arthritis, abortion and infertility, as well as disease in sheep, bison and bighorn sheep. Virulence factors include lipooligosaccharide, immunoglobulin binding proteins (as a surface fibrillar network), a major outer membrane protein (MOMP), other outer membrane proteins (OMPs) and exopolysaccharide. Histamine production, biofilm formation and quorum sensing may also contribute to pathogenesis. Antibodies are very important in protection as shown in passive protection studies. The lack of long-term survival of the organism in macrophages, unlike facultative intracellular bacteria, also suggests that antibodies should be critical in protection. Of the immunoglobulin classes, IgG2 antibodies are most implicated in protection and IgE antibodies in immunopathogenesis. The immunodominant antigen recognized by IgE is the MOMP and by IgG2 is a 40 kDa OMP. Pathogenetic synergy of bovine respiratory syncytial virus (BRSV) andH. somniin calves can be attributed, in part at least, to the higher IgE anti-MOMP antibody responses in dually infected calves. Other antigens are probably involved in stimulating host defense or immunopathology as well.