bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance Sampling for Portfolio Credit Risk
Authors: Glasserman Paul , Li Jingyi
Published: November 2005

Monte Carlo simulation is widely used to measure the credit risk in portfolios of loans, corporate bonds, and other instruments subject to possible default. The accurate measurement of credit risk is often a rare-event simulation problem because default probabilities are low for highly rated obligors and because risk management is particularly concerned with rare but significant losses resulting from a large number of defaults. This makes importance sampling (IS) potentially attractive. But the application of IS is complicated by the mechanisms used to model dependence between obligors, and capturing this dependence is essential to a portfolio view of credit risk. This paper provides an IS procedure for the widely used normal copula model of portfolio credit risk. The procedure has two parts: One applies IS conditional on a set of common factors affecting multiple obligors, the other applies IS to the factors themselves. The relative importance of the two parts of the procedure is determined by the strength of the dependence between obligors. We provide both theoretical and numerical support for the method.
Agency Problems in Law Enforcement: Theory and Application to the U.S. Coast Guard
Authors: Gawande Kishore , Bohara Alok K.
Published: November 2005

We study two issues in the enforcement of public law. The first is whether the system of inspections and penalties set by the regulator is effective. The second is whether a better system of inspections and penalties can be designed, given the institutional constraints under which the regulator must function. We study these issues in the context of oil spill prevention activities of the U.S. Coast Guard (USCG), the agency entrusted with the enforcement of maritime pollution laws. A theoretically optimal contract that mixes penalties based on the amount of pollution ex post with penalties based on the extent of noncompliance ex ante is derived. The effectiveness of USCG inspections and penalties in reducing oil spills is then econometrically studied using microlevel data on a panel of U.S. flag tank vessels. Whether the optimal penalty can potentially improve the effectiveness of compliance inspections in reducing oil spills is examined in the light of the empirical results and recent developments in the economics and public management literature on effective incentive contracting. Among our findings is the potential for combining unilateral incentive-based methods with cooperative methods based on reciprocity to solve the complex problem of law enforcement.
Step-Level Reasoning and Bidding in Auctions
Authors: Gneezy Uri
Published: November 2005

Step-level models of reasoning (SLR) proved to be very successful in predicting behavior in the beauty contest game. Recently, a quantified version of the model was suggested as a more general model of thinking. In particular, it was found that the distribution of choices could be represented by a Poisson distribution. I test the model in stylized first- and second-price common-value sealed-bid auctions. Equilibrium, for both auction types, prescribes that players undercut each other and profits are small. The SLR prediction, on the other hand, is different for the two auctions. Nash equilibrium predicts the outcomes poorly; the SLR model predicts the outcomes well in the second-price auction. However, while bids in the first-price auction could be represented by a Poisson distribution, this could not be attributed to step-level reasoning.
Mometasone Furoate Improves Congestion in Patients with Moderate-to-Severe Seasonal Allergic Rhinitis
Authors: Berger William E , Nayak Anjuli S , Staudinger Heribert W
Published: November 2005

BACKGROUND

A recent survey estimated that 85% of patients with allergic rhinitis experience nasal congestion. This symptom considerably impacts quality of life.

OBJECTIVE

To evaluate the effectiveness of mometasone furoate nasal spray (MFNS) in subjects with seasonal allergic rhinitis (SAR) experiencing moderate-to-severe nasal congestion.

METHODS

Data were obtained from 4 randomized, double-blind, placebo-controlled studies of MFNS 200 μg once daily in patients with SAR. Subject-evaluated nasal congestion score data (score range 0–3) from subjects receiving MFNS or placebo were analyzed as a pool and grouped according to baseline score (all pts. with scores >2.5, >2.75, or 3.0). The 2-week average change in score from baseline was analyzed.

RESULTS

Significant improvements in mean nasal congestion score were seen with MFNS (n = 490) versus placebo (n = 492; p < 0.001). Overall, there was a 27% improvement in this score in patients receiving MFNS versus 13% with placebo. MFNS produced significant reductions in the nasal congestion score compared with placebo, even in patients with the most severe baseline congestion (0.98 vs 0.52; p < 0.001). Improvements in scores from baseline of 32%, 33%, and 34% were seen with MFNS versus 22%, 21%, and 18% with placebo (for baseline scores of >2.5, >2.75, or 3.0, respectively), confirming the effectiveness of MFNS regardless of congestion severity. This represents an improvement approximating a decrease from severe to moderate congestion or from moderate-to-severe to mild-to-moderate congestion. MFNS was well tolerated.

CONCLUSIONS

MFNS 200 μg once daily produces statistically significant improvements in nasal congestion score compared with placebo, alleviating severe congestion in patients with moderate-to-severe SAR.
Dynamik von MEMS-Bausteinen berührungslos charakterisieren (Non-contact Characterization of MEMS Dynamics)
Authors: Dräbenstedt Alexander , Heimes Frank , Hettwer Dirk , Rembe Christian , Steger Heinrich , Wörtge Michael
Published: November 2005

Ein neues kombiniertes Messverfahren eröffnet wichtige Analysemöglichkeiten für Mikrosysteme. Mit Hilfe der im Out-of-plane-Bereich extrem empfindlichen Laser-Doppler-Technik werden auf Grund von immer vorhandenen parasitären Kopplungen auch In-plane-Resonanzen identifiziert. Mittels Videostroboskopie können die In-plane-Schwingungen dann genau vermessen werden. Der sich letztendlich ergebende Datensatz mit In-plane- und Out-of-plane-Daten ist äußerst wichtig für den Abgleich von Simulationsmodellen zur Modalanalyse von Mikrosystemen.
Optischer Näherungssensor basierend auf organischen Halbleitermaterialien (Optical Proximity Sensor based on Polymer Semiconductors)
Authors: Winnewisser Carsten , Bürgi Lukas , Pfeiffer Reto , Mücklich Mario , Metzler Peter , Kiy Michael
Published: November 2005

Ein optischer Berührungs- und Näherungssensor wird in diesem Beitrag vorgestellt. Dieser Sensor basiert auf der monolithischen Integration polymerer Leuchtdioden (PLEDs) und polymerer Photodioden, wobei die organischen Halbleitermaterialien aus der flüssigen Phase verarbeitet wurden. Damit zeigt sich das zukünftige Potential integrierter optoelektronischer Systeme, wie z.B. berührungssensitive Monitore oder biochemische Sensoren auf flexiblen Substraten, die mittels spezialisierter Drucktechnologien im Rolle-zu-Rolle-Prozess herstellbar sein könnten.
Neues magnetoinduktives Sensor-Prinzip und seine Umsetzung in Sensoren für industrielle Anwendungen (A new Magneto-Inductive Sensing Principle and its Implementation in Sensors for Industrial Applications)
Authors: Jagiella Manfred , Fericean Sorin
Published: November 2005

Für die Positionsrückmeldung bei Stellantrieben in industriellen Systemen werden heute vorzugsweise berührungslose Wegmesssysteme eingesetzt. Linearbewegungen im Bereich bis 200 mm erfordern fast immer Kompromisse in Bezug auf Größe, Messbereich, Robustheit und Kosten. Der Beitrag stellt eine Innovation in diesem Bereich vor: Ein neues magnetoinduktives Sensorprinzip und ein Wegmesssystem, das speziell für Positionieraufgaben in dem oben genannten Bereich entwickelt wurde. Das System besteht aus einem schlanken, quaderförmigen Sensor mit vollständig integrierter Auswertungselektronik und einem dauermagnetischen Geber, dessen Position in ein absolutes, zum Weg proportionales Standardsignal umgewandelt wird.
Programmable Angular System with Online Diagnosis (Programmierbares Winkelmesssystem mit Online-Diagnose)
Authors: Harmansa Adrian , Butzmann Stefan
Published: November 2005

A programmable angular measurement system with online diagnosis is presented. The actual measurement principle is based on the anisotropic magnetoresistive effect. The sensing element provides a sine- and a cosine-signal related to the applied magnetic field angle. The signal conditioning algorithm calculates the magnetic field angle from these signals by using the CORDIC algorithm. Additionally, a variety of diagnosis features are implemented in order to ensure a fail-safe operation of the device. The sensor is thus particularly suited for applications under harsh environmental conditions as found in automobiles.
Abgassensoren zur Verbrennungsregelung von Kleinfeuerungsanlagen (Flue Gas Sensors for Combustion Control in Small Furnaces)
Authors: Hoefer Ulrich
Published: November 2005

Abgassensoren, die für die Verbrennungsoptimierung geeignet sind, basieren bisher meist auf der bekannten λ-Sonde aus ZrO2, wie sie in ähnlicher Art massenhaft in Kraftfahrzeugen eingesetzt wird. Für den Einsatz in anderen Verbrennungsprozessen wie z.B. Brennwertkesseln oder anderen Kleinfeuerungsanlagen sind sie aus unterschiedlichen Gründen nicht geeignet. Hier setzt eine Neuentwicklung eines auf Ga2O3 (Galliumoxid) basierenden Halbleitergassensors an, der einige Vorteile in sich vereint und somit das Anwendungsfeld der Verbrennungsoptimierung von Gasbrennwertgeräten und anderen Kleinfeuerungsanlagen erschließt.
Erratum
Authors: Bruet B.J.F. , Qi H.J. , Boyce M.C. , Panas R. , Tai K. , Frick L. , Ortiz C.
Published: November 2005

“Nanoscale Morphology and Indentation of Individual Nacre Tablets from the Gastropod Mollusc Trochus Niloticus” [J. Mater. Res. 20, 2400 (2005)]
Structural Variants in Attempted Heteroepitaxial Growth of B12As2 on 6H–SiC (0001)
Authors: Michael J.R. , Aselage T.L. , Emin David , Kotula P.G.
Published: November 2005

Boron sub-arsenide, B12As2, is based on twelve-atom clusters of boron atoms and two-atom As–As chains. By contrast, SiC is a tetrahedrally bonded covalent semiconductor. Despite these fundamental differences, the basal plane hexagonal lattice constant of boron sub-arsenide is twice that of SiC. This coincidence suggests the possibility of heteroepitaxial growth of boron sub-arsenide films on properly aligned SiC. However, there are a variety of incommensurate alignments by which heteroepitaxial growth of B12As2 on (0001) 6H–SiC can occur. In this study, we first used geometrical crystallographic considerations to describe the possible arrangements of B12As2 on (0001) 6H–SiC. We identified four translational and two rotational variants. We then analyzed electron backscattered diffraction and transmission electron microscopy images for evidence of distinct domains of such structural variants. Micron-scale regions with each of the two possible rotational alignments of B12As2 icosahedra with the SiC surface were seen. On a finer length scale (100–300 nm) within these regions, boron-rich boundaries were found, consistent with those between pairs of the four equivalent translational variants associated with a two-to-one lattice match. Boron-carbide reaction layers were also observed at interfaces between SiC and B12As2.
A New Method for Direct Preparation of Tin Dioxide Nanocomposite Materials
Authors: Miller T.A. , Bakrania S.D. , Perez C. , Wooldridge M.S.
Published: November 2005

In the current work, a novel combustion method is demonstrated for the direct synthesis of nanocomposite materials. Specifically doped tin dioxide (SnO2) powders were selected for the demonstration studies due to the key role SnO2 plays in semiconductor gas sensors and the strong sensitivity of doped SnO2 to nanocomposite properties. The synthesis approach combines solid and gas-phase precursors to stage the decomposition and particle nucleation processes. A range of synthesis conditions and four material systems were examined in the study: gold–tin dioxide, palladium–tin dioxide, copper–tin dioxide, and aluminum–tin dioxide. Several additive precursors were considered including four metal acetates and two pure metals. The nanocomposite materials produced were examined for morphology, phase, composition, and lattice spacing using transmission and scanning electron microscopy, x-ray diffractometry, and energy-dispersive spectroscopy. The results using the combustion synthesis approach indicate good control of the nanocomposite properties, such as the average SnO2 crystallite size, which ranged from 5.8 to 17 nm.
Continuous Strain Bursts in Crystalline and Amorphous Metals During Plastic Deformation by Nanoindentation
Authors: Li H. , Ngan A.H.W. , Wang M.G.
Published: November 2005

Using depth-sensing indentation with sub-nanometer displacement resolution, the plastic deformation of a range of materials, including a metallic glass, amorphous selenium, Ni3Al, pure Nb, Al, Cu, and Zn metals, and an Al-Mg alloy, has been investigated at room temperature. In amorphous selenium, even the sub-nanometer displacement resolution of the nanoindentation technique cannot reveal any strain burst during deformation at room temperature. In all other metals studied, what may appear to be smooth load-displacement curves at macroscopic scale during indentation deformation in fact turn out to consist of a continuous series of random bursts of the nanometer scale. The occurrence probability of the bursts is found to decrease at increasing burst size. In all of the crystalline metals and alloys studied, the size distribution of the strain bursts seems to follow an exponential law with a characteristic length scale. The absence of the self-organized critical behavior is likely a result of the small size of the strained volume in the nanoindentation situation, which gives rise to a constraint of a characteristic strain. In the metallic glass sample, due to the limited range of the burst sizes encountered, whether the deformation bursts follow an exponential or a power-law behavior corresponding to self-organized criticality is inconclusive. From a theoretical viewpoint based on the Shannon entropy, the exponential distribution is the most likely distribution at a given mean burst size, and this is thought to be the reason for its occurrence in different materials.
Shear Strength of Sn–3.5Ag Solder Bumps Formed on Ni/Au and Organic Solderability Preservative Surface-Finished Bond Pads After Multiple Reflow Steps
Authors: Lee Jung-Sub , Chu Kun-Mo , Jeon Duk Young
Published: November 2005

Sn–3.5Ag solder bumps were formed on electroless Ni/immersion Au (Ni/Au) and organic solderability preservative (OSP) surface-finished bond pads, respectively. The shear strength of the solder bumps was measured as a function of reflow steps. Fracture surfaces and interfacial microstructures were investigated by scanning electron microscope. The shear strength of Ni/Au samples increased up to the seventh reflow step and subsequently decreased after the tenth reflow step. Spalling of Ni3Sn4 intermetallic compounds (IMCs) and the P-rich Ni layer strengthened and weakened the bond, respectively. For OSP samples, although Cu6Sn5 IMCs grew as the reflow step was repeated, no remarkable change in shear strength was observed. Interfacial fractures of OSP samples occurred at the interface between Cu6Sn5 IMC and Cu3Sn IMC. Fracture surfaces of OSP samples showed concave pits that consisted of a Cu3Sn bottom and an Sn wall. The pits were formed by separation of Cu6Sn5 IMC from Cu3Sn IMC and the molten Sn channel between the Cu6Sn5 IMC grains.
Thick Pb(Zr,Ti)O3films fabricated by inducing residual compressive stress during the annealing process
Authors: Lee Jae-Wung , Choi Jong-Jin , Park Gun-Tae , Park Chee-Sung , Kim Hyoun-Ee
Published: November 2005

The effects of residual stress induced during the annealing process on the microstructural evolution and electrical properties of Pb(Zr,Ti)O3(PZT) films were investigated. PZT films were deposited on platinized silicon substrates by the radio frequency magnetron sputtering method using a single oxide target. Compressive stress was induced in the film by bending the silicon substrate during sputtering using a specially designed substrate holder and subsequently annealing the film without the holder. Without the residual stress, the PZT film was severely cracked when it was thicker than 2 μm due to the thermal expansion mismatch between the PZT and the Si substrate. On the other hand, when the residual stress was applied, no cracks were detected in the film for thicknesses of up to 4 μm. The suppression of crack formation was attributed to the residual compressive stress that compensated for the tensile stress generated during and/or after the annealing process. The electrical properties of the PZT film with the residual stress were improved compared to those of the PZT film without the residual stress.
Strain Rate Sensitivity of a Nanocrystalline Cu–Ni–P Alloy
Authors: Chen J. , Shi Y.N. , Lu K.
Published: November 2005

Nanoindentation technique was used to measure the strain rate sensitivity (m) of a nanocrystalline Cu-Ni-P alloy prepared by means of electrodeposition. The m value decreases from 0.034 to 0.018 when the nominal grain size increases from 7 nm to 33 nm. Both m values of the alloy are obviously lower than those of the pure Cu with similar grain size, implying that P segregation at grain boundaries might play a key role in retarding grain boundary activities as compared to pure Cu samples.
Cubic (Mg,Zn)O Nanowire Growth Using Catalyst-Driven Molecular Beam Epitaxy
Authors: Heo Y.W. , Tien L-C. , Norton D.P.
Published: November 2005

We report on the growth of Mg-rich cubic (Mg,Zn)O nanowires using a catalysis-driven molecular-beam-epitaxy method. Nanowires were grown on both Si and Al2O3 substrates coated with a nominally 2-nm-thick layer of Ag. The (Mg,Zn)O nanowires were grown with a Zn and Mg cation flux, with an O2/O3 mixture serving as the oxidizing species. The growth temperature was 400 °C. Under these conditions, nanowires were observed to grow on the Ag sites. The nanowire diameter was on the order of 90 nm. (Mg,Zn)O nanowires as long as 2 μm were realized. High-resolution transmission electron microscope imagery shows the nanowires had single-phase cubic rock salt structure (Mg,Zn)O with a growth direction along the [100]. The presence and compositional distribution of Mg and Zn in the single nanowire were confirmed using a compositional line-scan, profiled across the nanowire, by energy dispersive spectrometry with scanning transmission electron microscopy.
Determining the Instantaneous Modulus of Viscoelastic Solids Using Instrumented Indentation Measurements
Authors: Cheng Yang-Tse , Ni Wangyang , Cheng Che-Min
Published: November 2005

Instrumented indentation is often used in the study of small-scale mechanical behavior of “soft” matters that exhibit viscoelastic behavior. A number of techniques have recently been proposed to obtain the viscoelastic properties from indentation load–displacement curves. In this study, we examine the relationships between initial unloading slope, contact depth, and the instantaneous elastic modulus for instrumented indentation in linear viscoelastic solids using either conical or spherical indenters. In particular, we study the effects of “hold-at-the-peak-load” and “hold-at-the-maximum-displacement” on initial unloading slopes and contact depths. We then discuss the applicability of the Oliver–Pharr method (Refs. 29, 30) for determining contact depth that was originally proposed for indentation in elastic and elastic-plastic solids and recently modified by Ngan et al. (Refs. 20–23) for viscoelastic solids. The results of this study should help facilitate the analysis of instrumented indentation measurements in linear viscoelastic solids.
Photosensitizers Derived from 132‐Oxo‐methyl Pyropheophorbide‐a: Enhanced Effect of Indium(III) as a Central Metal in In Vitro and In Vivo Photosensitizing Efficacy
Authors: Rosenfeld Andrew , Morgan Janet , Goswami Lalit N. , Ohulchanskyy Tymish , Zheng Xiang , Prasad Paras N. , Oseroff Allan , Pandey Ravindra K.
Published: November 2005

The effects of an additional keto group on absorption wavelength and the corresponding metal complexes Zn(II), Cu(II) In(III) on singlet oxygen production and photodynamic efficacy were examined among the alkyl ether analogs of pyropheophorbide‐a. For the preparation of the desired photosensitizers, the methyl 132‐oxo‐pyropheophorbide‐a obtained by reacting methyl pyropheophorbide‐a with aqueous LiOH‐THF was converted into a series of alkyl ether analogs. These compounds were evaluated for photophysical properties and in vitro (by means of the MTT assay and intracellular localization in RIF cells) and in vivo (in C3H mice implanted with RIF tumors) photosensitizing efficacy. Among the alkyl ether derivatives, the methyl 3‐decyloxyethyl‐3‐devinyl‐132‐oxo‐pyropheophorbide‐a was found to be most effective and the insertion of In(III) into this analog further enhanced its in vitro and in vivo photosensitizing efficacy. Fluorescence microscopy showed that, in contrast to the hexyl and dodecyl ether derivatives of HPPH (which localize in mitochondria and lysosomes, respectively), the diketo‐analogs and their In(III) complexes localized in Golgi bodies. The preliminary in vitro and in vivo results suggest that, in both free‐base and metalated analogs, the introduction of an additional keto group at the five‐member exocyclic ring in pyropheophorbide‐a diminishes its photosensitizing efficacy. This may be due to a shift in subcellular localization from mitochondria to the Golgi bodies. The further introduction of In(III) enhances photoactivity, but not by shifting the localization of the photosensitizer.
Behaviour of plain and steel-fibre-reinforced high-strength concrete under uniaxial and biaxial compression
Authors: Lim D. H. , Nawy E. G.
Published: November 2005

The purpose of this study was to investigate the mechanical characteristics of plain and steel-fibre-reinforced high-strength concrete under uniaxial and biaxial loading conditions. A number of plain and steel-fibre-reinforced high-strength concrete cubes having 28 days compressive strength of 82·7 MPa (12 000 psi) were made and tested. Four principal compression ratios (σ2/σ1 = 0·00, 0·50, 0·75 and 1·00), and four fibre concentrations (Vf = 0·0, 0·5, 1·0 and 1·5%) were selected as major test variables. From the test results, it was found that confinement stress in the minor stress direction has a pronounced effect on the strength and deformational behaviour and both the stiffness and ultimate strength of the plain and steel-fibre-reinforced high-strength concrete increased. The maximum increase of ultimate strength occurred at a biaxial stress ratio of 0·5 (σ2/σ1 = 0·5) in the plain high-strength concrete and the value recorded was 30% over the strength under the uniaxial condition. The failure modes of plain high-strength concrete under uniaxial compression were shown as splitting type but steel fibre concrete specimens under the biaxial condition showed a shear-type failure. The values of elastic modulus were also examined and found to be higher than those from the ACI and CEB expressions under the biaxial compression condition.
Experimental studies on creep of sealed concrete under multiaxial stresses
Authors: Kim J. K. , Kwon S. H. , Kim S. Y. , Kim Y. Y.
Published: November 2005

The majority of research studies and prediction models on the creep of concrete have been concerned with the uniaxial stress state. Research on creep under multiaxial stresses, however, has been relatively scarce even though concrete is subjected to multiaxial stresses in many structural members and structures. Although some experiments on the multiaxial creep of concrete have been performed, the results of these experiments, which mainly considered low-strength concrete, are controversial. Consequently, for today's standards and practice—and for a better understanding of the properties of concrete—more experimental data are needed on the multiaxial creep of concrete with various strengths. In this study, multiaxial creep tests with 27 cubic specimens (200 mm × 200 mm × 200 mm) were carried out for three different strengths of concrete, namely 26, 44 and 54 MPa, and creep strains were measured in three principal directions. From the measured strains, Poisson's ratio at initial loading was obtained, as was Poisson's ratio resulting from creep strain and Poisson's ratio resulting from the combined creep strain and elastic strain. These Poisson's ratios were approximately equal for each concrete mix. The Poisson's ratio at initial loading and the Poisson's ratio for the combined strain increased slightly as the strength of the concrete increased. The volumetric creep strain and deviatoric creep strain were linearly proportional to volumetric stress and deviatoric stress, respectively.
Analyzing effects of pesticides on invertebrate communities in streams
Authors: Liess Matthias , Ohe Peter Carsten Von Der
Published: November 2005

The aim of this investigation was to find patterns in aquatic invertebrate community composition that are related to the effects of pesticides. Investigations were carried out in 20 central European streams. To reduce the site-specific variation of community descriptors due to environmental factors other than pesticides, species were classified and grouped according to their vulnerability to pesticides. They were classified as species at risk (SPEAR) and species not at risk (SPEnotAR). Ecological traits used to define these groups were sensitivity to toxicants, generation time, migration ability, and presence of aquatic stages during time of maximum pesticide application. Results showed that measured pesticide concentrations of 1 : 10 of the acute 48-h median lethal concentration (LC50) of Daphnia magna led to a short- and long-term reduction of abundance and number of SPEAR and a corresponding increase in SPEnotAR. Concentrations of 1 : 100 of the acute 48-h LC50 of D. magna correlated with a long-term change of community composition. However, number and abundance of SPEAR in disturbed stream sections are increased greatly when undisturbed stream sections are present in upstream reaches. This positive influence compensated for the negative effect of high concentrations of pesticides through recolonization. The results emphasize the importance of considering ecological traits and recolonization processes on the landscape level for ecotoxicological risk assessment.
Patterns of nestin expression in human skin
Authors: Wang Yun , Zhang Yi , Zeng Yijun , Zheng Yehua , Fu Gang , Cui Zhihong , Yang Tian
Published: November 2005

Nestin, a member of the sixth class of intermediate filament proteins, has long been known not only as a specific marker for central nervous system stem cells, but also as an indicator of the degree of neural stem cell differentiation. Immunohistochemical analysis showed nestin expression in the epidermis and the upper two‐third of the hair follicle in non‐balding human scalp skin, but not in the lower third of the follicle. Expression was very weak in the sebaceous gland. The level of nestin mRNA transcription was much higher in the bulge region of the follicle than in the sebaceous gland. These results show that the pattern of nestin expression is related to the differentiation of epidermal stem cells.
Comparison of a low carbohydrate–low fiber diet and a moderate carbohydrate–high fiber diet in the management of feline diabetes mellitus
Authors: Bennett Nicole , Greco Deborah S. , Peterson Mark E. , Kirk Claudia , Mathes Mark , Fettman Martin J.
Published: November 2005

This study compared the effects of a moderate carbohydrate–high fiber (MC–HF) food and a low carbohydrate–low fiber (LC–LF) food on glycemic control in cats with diabetes mellitus. Sixty-three diabetic cats (48 male castrated, 15 female spayed) were randomly assigned to be fed either a canned MC–HF ( n=32) food or a canned LC–LF ( n=31) food for 16 weeks. Owners were blinded to the type of diet fed. CBC, urinalysis, serum chemistry panel, fructosamine concentration and thyroxine concentration were determined on initial examination, and a complete blood count, serum chemistry panel, urinalysis and serum fructosamine concentration were repeated every 4 weeks for 16 weeks. Insulin doses were adjusted as needed to resolve clinical signs and lower serum fructosamine concentrations. Serum glucose ( P=0.0001) and fructosamine ( P=0.0001) concentrations significantly decreased from week 0 to week 16 in both dietary groups. By week 16, significantly more of the cats fed the LC–LF food (68%, 22/31), compared to the cats fed the MC–HF food (41%, 13/32), had reverted to a non-insulin-dependent state ( P=0.03). Cats in both groups were successfully taken off of insulin regardless of age, sex, type of insulin administered or duration of clinical disease before entering the study. There was no significant difference in the initial or final mean body weights or in the mean change in body weight from week 0 to week 16 between dietary groups. Diabetic cats in this study were significantly more likely to revert to a non-insulin-dependent state when fed the canned LC–LF food versus the MC–HF food.
The supply base and its complexity: Implications for transaction costs, risks, responsiveness, and innovation
Authors: Choi Thomas Y. , Krause Daniel R.
Published: November 2005

A supply base is defined as the portion of a supply network that is actively managed by a buying company. The buying company, referred to as the focal company, manages the suppliers in the supply base through contracts and purchasing of parts, materials, and services. To facilitate better management of a supply base, we observe “complexity” as a key area of managerial consideration and apply the literature on complexity to the supply base. Supply base complexity is conceptualized in three dimensions: (1) the number of suppliers in the supply base, (2) the degree of differentiation among these suppliers, and (3) the level of inter‐relationships among the suppliers. Four propositions have been formulated in terms of four major areas of research within supply chain management—transaction costs, supply risk, supplier responsiveness, and supplier innovation. Corollary propositions are also stated. Although a reduction in complexity may lead to lower transaction costs and increased supplier responsiveness, in certain circumstances it may also increase supply risk and reduce supplier innovation. Therefore, reducing supply base complexity in general may be a cost‐efficient approach, but blindly reducing it may potentially decrease the buying company's overall competitiveness.
Postsurgical Follow‐Up of Children with Tympanostomy Tubes: Results of the American Academy of Otolaryngology‐Head and Neck Surgery Pediatric Otolaryngology Committee National Survey
Authors: Derkay Craig S. , Carron Jeffrey D. , Wiatrak Brian J. , Choi Sukgi S. , Jones Jacqueline E.
Published: November 2005

Postsurgical follow‐up of children with tympanostomy tubes is becoming a contentious issue in this era of managed care. Primary care providers believe themselves to be capable of evaluating these children. Otolaryngologists, on the other hand, have more specialized equipment available to them (suction apparatus, otomicroscopes, audiology devices, etc) for treating suppurative infections and monitoring the tympanic membrane for structural changes. In addition, the otolaryngologist is placed in an uncomfortable legal and ethical position if access to the patient with a tube‐related complication is denied by the primary care provider. Attempts to develop an American Academy of Otolaryngology‐Head and Neck Surgery (AAO‐HNS) policy statement have been hampered by a lack of data on the incidence and severity of tube‐related complications and the role that otolaryngologists can play in reducing these sequelae. A survey designed by the AAO‐HNS Pediatric Otolaryngology Committee was distributed to 1000 board‐certified otolaryngologists and all members of the American Society of Pediatric Otolaryngologists and the American Academy of Pediatrics‐Otolaryngology Section regarding current practice patterns and practitioners' experiences with tympanostomy tube complications. Specific information regarding complications that could have been avoided with earlier otolaryngology referral was also obtained. The results of the survey and its implications for AAO‐HNS policy are presented.
Preapplication of Mitomycin C for Enhanced Patency of Myringotomy
Authors: Estrem Scott A. , Baker Terry J.
Published: November 2005

OBJECTIVES

Ventilation tubes are the mainstay of surgical treatment for eustachian tube dysfunction and have been used successfully for many years. Certain disadvantages of ventilation tubes, however, have prompted research into alternative techniques including laser myringotomy. We investigated the use of KTP laser myringotomy in conjunction with topical mitomycin C to delay healing and prolong the patency of the myringotomy.

METHODS

Twenty myringotomies were created in 10 Sprague‐Dawley rats. A solution of mitomycin C was applied to the intact tympanic membrane for 15 minutes. The solution was then suctioned free, and a myringotomy was created with a KTP laser. Fifty‐three rats with saline application serving as controls from a previous study were used to allow statistical assessment.

RESULTS

The myringotomies remained open for a median of 9.5 weeks. Control myringotomies, which received saline solution instead of mitomycin C, healed within a median of 1.5 weeks. The difference was statistically significant at P < 0.0001. No complications were noted.

CONCLUSION

Topically administered mitomycin C before laser myringotomy is effective in prolonging the patency of laser myringotomies in rats. The patency rate is similar to that achieved in experiments in which topical mitomycin C is placed into the myringotomy site created by the laser.
Octreotide Scintigraphy for the Detection of Paragangliomas
Authors: Telischi Fred F. , Bustillo Andres , Whiteman Michelle L. H. , Serafini Aldo N. , Reisberg Michael J. , Gomez‐Marin Orlando , Civantos Francisco J. , Balkany Thomas J.
Published: November 2005

Paragangliomas are neuroendocrine tumors located primarily in the head and neck region, but they can also occur at other sites. Confirming the preoperative diagnosis and detecting synchronous tumors may be difficult in some patients. Octreotide is a somatostatin analog that, when coupled to a radioisotope, produces a scintigraphic image of tumors expressing somatostatin type 2 receptors. Paragangliomas, like many neuroendocrine tumors, have been found to have a high density of somatostatin type 2 receptors on the cell surface. This study compared the results of preoperative octreotide scintigraphy with the histopathology in 21 patients who underwent surgery for presumed head and neck paragangliomas. Octreotide scan findings were positive in 16 patients with paragangliomas and negative in 3 patients with other pathology. One false‐positive and 1 false‐negative result were obtained. Thus, this test had an accuracy of 90%, a sensitivity of 94%, and a specificity of 75%. Previously unidentified synchronous tumors were identified in 5 patients. On the basis of this series of patients, octreotide scintigraphy appears to be a reliable test to detect paragangliomas and may be quite helpful in preoperative planning.
Potential Role of Growth Factors and Extracellular Matrix in Wound Healing after Laryngotracheal Reconstruction
Authors: Walner David L. , Heffelfinger Sue C. , Stern Yoram , Abrams Mark J. , Miller Mary Ann , Cotton Robin T.
Published: November 2005

Laryngotracheal reconstruction (LTR) has been used for more than 20 years to treat infants and children with subglottic stenosis. Results after pediatric LTR have been satisfactory; however, approximately 10% of children have recurrent airway narrowing after LTR. The purpose of our study was to determine whether a correlation existed between specific growth factors and extracellular matrix in patients with adequate wound healing capability as compared with patients with poor wound healing capability. Histologic sections from 27 patients who underwent LTR were cut, and immunohistochemical staining was performed for transforming growth factor‐β, platelet‐derived growth factor, fibronectin, tenascin, transforming growth factor‐α, and vascular endothelial growth factor. Results showed that patients with adequate wound healing capability had a positive correlation with vasculature fibronectin, vasculature tenascin, and stromal fibronectin. Patients with poor wound healing capability had a positive correlation with stromal vascular endothelial growth factor.
Approaches to the Sellar and Parasellar Region: A Retrospective Comparison of the Endonasal‐Transsphenoidal and Sublabial‐Transsphenoidal Approaches
Authors: Spencer William R. , Levine Jonathan M. , Couldwell William T. , Brown‐Wagner Marie , Moscatello Augustine
Published: November 2005

Tumors of the hypophysis are often managed surgically by the neurosurgeon and the otolaryngologist. Three widely used anterior routes to the sella are the endonasal (transcolumellar) transsphenoidal, sublabial transsphenoidal, and transethmoidal approaches. We reviewed the charts of 60 patients who underwent surgery, 42 transcolumellar and 18 sublabial, for sellar and parasellar adenomas and compared the two transsphenoidal approaches. None of the patients in our study underwent the transethmoidal approach. Furthermore, 26 of the patients underwent an extensive interview to assess postoperative progress. Clinically, neither approach had any significant complications, and none of the patients in either group reported significant postoperative morbidity. On the basis of these results, we believe there is minimal difference in patient subjective reports and objective morbidity when comparing the sublabial and transcolumellar approaches.
Endoscopically Guided Sinonasal Cultures: A Direct Comparison with Maxillary Sinus Aspirate Cultures
Authors: Vogan Jonathan C. , Bolger William E. , Keyes Alan S.
Published: November 2005

Sinusitis is a common medical problem that can at times be challenging to treat. Although most cases respond to empiric therapy, success is not achieved universally. If empiric therapy fails, it is important to identify the causative bacterial pathogen. Antral puncture is the traditional diagnostic method to recover and identify pathogens in sinusitis; however, it remains a painful, invasive test with potential complications. In contrast, rigid sinonasal endoscopy permits recovery of mucopus emanating from the sinus ostia with little pain and few possible complications. Endoscopy also affords important visual information that can confirm or refute a historical/clinical diagnosis of sinusitis. Although previous studies have shown poor correlation between nasal cavity swab cultures and maxillary sinus aspiration cultures, few investigations have compared endoscopically guided middle meatal cultures with cultures obtained from maxillary sinus aspiration. Thirteen patients with maxillary sinusitis in one or both sinuses underwent endoscopically guided culture of the middle meatus and maxillary sinus puncture with aspiration and culture (16 total study samples). Results from the microbiologic analysis were compared. Endoscopically guided middle meatal cultures accurately identified the predominant bacterial pathogen and correlated with the cultures from maxillary sinus aspiration in more than 90% of infections. These preliminary results suggest that endoscopically guided sinonasal cultures hold promise as a viable alternative to maxillary sinus aspiration. Endoscopically guided cultures appear to be an effective, noninvasive diagnostic tool for otolaryngologists managing sinusitis.
Management of Chyle Fistulization in Association with Neck Dissection
Authors: Gregor R. T.
Published: November 2005

Chylous fistula after neck dissection is a relatively rare but potentially lethal complication. Sequelae range from severe fluid, electrolyte, and protein loss to fistula formation, skin‐flap necrosis, and carotid blowout. A thorough knowledge of the anatomy is essential to avoid injury to the thoracic duct or right lymph duct. After surgery, drainage of large amounts of fluid, particularly if milky, may alert the surgeon to the danger of chylous leakage. Certain diagnosis, however, is not so easy. Once the diagnosis is made, the management has to address the immediate and late effects of the loss of chyle into an operative site. This article seeks to examine these factors through review of the literature and personal experience with the problem. Total parenteral nutrition allows for control of the fluid and protein loss while avoiding flow of chyle, and in most cases it results in resolution. In those cases that do not resolve, fibrin glue with some type of mesh and muscle flaps usually succeed in closure.
Clinical Experiences of Removing Foreign Bodies in the Airway and Esophagus with a Rigid Endoscope: A Series of 3217 Cases from 1970 to 1996
Authors: Hsu Wei‐Chung , Sheen Tzung‐Shiahn , Lin Chia‐Der , Tan Ching‐Ting , Yeh Te‐Huei , Lee Shiann‐Yann
Published: November 2005

This study examined 11,333 rigid endoscopy procedures performed in the Department of Otolaryngology, National Taiwan University Hospital, during a 27‐year period from 1970 to 1996. Among these cases, 3217 were performed to remove foreign bodies from the airway (459 cases, 14.3%) and esophagus (2758 cases, 85.7%). Retrospective analysis of these data revealed that peanuts (217 cases) and animal bones (1184 cases) were the most frequent foreign bodies encountered in the airway and esophagus, respectively. The successful rate of removal of these foreign bodies was 99.9% (3213/3217). The complication rate was only 0.2% (8/3217), and the mortality rate was less than 0.1% (2/3217). On the basis of these results, we conclude that foreign bodies in the airway and esophagus can be removed safely under direct visualization through rigid endoscopy with relatively few complications. A significant finding in this study is the declining trend in the number of cases in recent years. Despite the decline in the number of procedures, endoscopic removal of foreign bodies remains as a vital skill of the aerodigestive tract surgeon.
Diagnosis and treatment of uncomplicated acute bacterial rhinosinusitis: Summary of the Agency for Health Care Policy and Research evidence‐based report
Authors: Benninger Michael S. , Holzer Susan E. Sedory , Lau Joseph
Published: November 2005

PURPOSE

The goal was to critically examine evidence regarding the performance of diagnostic tests and the efficacy of antibiotic and other treatments for uncomplicated acute bacterial rhinosinusitis (ABR).

METHODS

Scientific literature was reviewed, and meta‐analysis methods were used to assess diagnostic test and antibiotic efficacy. A decision analysis and cost‐effective analysis were performed.

RESULTS

Although more sensitive than clinical examination for diagnosis of ABR, sinus radiograms are not cost‐effective as an initial management strategy. Antibiotics reduce the incidence of clinical failures by one half compared to no treatment and, when coupled with clinical criteria‐based diagnosis, present the most cost‐effective treatment strategy. However, without antibiotics, symptoms in two thirds of patients improve by 14 days with no serious complications. The risk of treatment failure does not differ significantly between amoxicillin or folate inhibitors and newer, more expensive antibiotics.

CONCLUSIONS

The current literature shows that treatment of uncomplicated ABR with amoxicillin or folate inhibitors and based on clinical criteria is the most cost‐effective strategy. (Otolaryngol Head Neck Surg 2000;122:1‐7.)
Outpatient cochlear implantation in the pediatric population
Authors: Liu James H. , Roland Peter S. , Waller Melissa A.
Published: November 2005

Studies have shown that the incidence of complications in pediatric cochlear implant surgery is related to the age of the child, with a higher complication rate in younger patients. Consequently, many surgeons advocate admitting these children overnight. We began our pediatric cochlear implant program starting in June 1991 using the Nucleus 22‐channel cochlear implant. To date, 65 children have undergone implantation, all on an outpatient basis. To evaluate safety, complication rate, and patient satisfaction, we gave the parents of the patients a questionnaire survey to complete. All patient charts were also retrospectively reviewed. More than 90% of parents surveyed responded that they were satisfied with the outpatient treatment of their children. There were no perioperative complications or read‐missions. Cochlear implantation can be safely and effectively performed on an outpatient basis without an increase in morbidity. Day surgery reduces hospital costs at least $2500. (Otolaryngol Head Neck Surg 2000;122:19‐22.)
Squamous cell carcinoma of the tongue in young adults: Increasing incidence and factors that predict treatment outcomes
Authors: Myers Jeffrey N. , Elkins Tina , Roberts Dianna , Byers Robert M.
Published: November 2005

OBJECTIVE

This study was designed to determine whether the incidence of squamous cell carcinoma of the oral tongue (SCCOT) in young adults has changed during the past 25 years and to determine prognostic factors for young adult patients (aged < 40 years) with SCCOT.

METHODS AND PATIENTS

A retrospective review of young adults with SCCOT who sought treatment at the M. D. Anderson Cancer Center between 1973 and 1995 was undertaken.

RESULTS

The percentage of young adult SCCOT patients at M. D. Anderson increased from 4% in 1971 to 18% in 1993. T stage, N stage, perineural invasion, and lymphatic invasion were all associated with decreased survival. Patients who received a neck dissection as part of their primary treatment had a better chance of survival than patients who did not.

CONCLUSIONS

The incidence of SCCOT in the young adult population is increasing in the United States. Appropriate surgical management for young adults with SCCOT includes resection of the primary tumor along with a selective node dissection. (Otolaryngol Head Neck Surg 2000;122:44‐51.)
Expression of nm23 antimetastatic gene product in head and neck squamous cell carcinoma
Authors: Song Angie U. , Mais Daniel D. , Groo Stephen , Wright James R. , Yoshida Glen Y.
Published: November 2005

The nm23 gene has been implicated as a suppressor gene involved in the control of the metastatic process of malignant cells. Reduced levels of nm23 gene product have been found in tumor cells with high metastatic potential such as several types of rodent tumors and human breast, colorectal, and lung carcinoma. This pilot study examines the expression of the nm23 gene product compared with nodal status in 70 consecutive patients with squamous cell carcinomas of the head and neck. Immunohistochemical staining was carried out on these tumor tissues with a monoclonal antibody to nm23‐H1 peptide sequence. The tissues were scored from 0 to 2 by 2 independent observers. Reduced immunoreactivity, grades 0 and 1, was observed in 30 patients with positive nodal status (N = 34, 88%). Strong immunoreactivity, grade 2, was observed in 20 patients with negative nodal status (N = 36, 56%). Reduced expression of nm23 gene product was observed in patients with positive lymph node metastasis (P = 0.0006, χ2). However, no significant differences in survival of these groups based on nm23 expression could be shown with the Kaplan‐Meier analysis. This initial finding in the difference of nm23 gene product expression in patients with differing lymph node status is exciting but must be further validated with future studies. (Otolaryngol Head Neck Surg 2000;122:96‐9.)