bluuebunny/crossref_metadata_2025 huggingface dataset:
Introducing a Novel Analysis Technique for Osseointegrated Dental Implants Retrieved 29 Years Postsurgery
Authors: Sarve Hamid , Friberg Bertil , Borgefors Gunilla , Johansson Carina B.
Published: December 2011

Purpose: To investigate osseointegration of oral implants, which were retrieved from a patient after 29 years in situ, we use novel three‐dimensional analysis methods and visualization techniques that supplement conventional two‐dimensional analysis.

Materials and Methods: The sample processing involved nondecalcification and embedment in resin. Conventional two‐dimensional histomorphometrical methods were conducted. Additionally, the quantification was extended to three‐dimensional by using synchrotron radiation micro‐computed tomography (SRµCT) technique and two relevant visualization methods for the three‐dimensional data were introduced.

Results: The three‐dimensional results involved three‐dimensional quantification and visualization of two implant samples with methods beyond state‐of‐the‐art. Traditional two‐dimensional histomorphometrical results revealed a mean bone‐implant contact (BIC) of about 50%. In most samples, bone area (BA) was lower inside the treads compared with out‐folded mirror images, which were confirmed by the three‐dimensional quantification. The BIC along four selected regions showed highest percentages in the bottom/valley region and lowest in the thread‐peak region. Qualitative observations revealed ongoing bone remodeling areas in all samples. The apical hole demonstrated high osseointegration.

Conclusion: The novel techniques including an animation and an out‐folding of BIC and BA enabled a simultaneous visualization of the three‐dimensional material obtained from SRµCT data. However, the two‐dimensional histological sections were needed for qualitative and quantitative evaluation of osseointegration and, thus, both methods are considered equally important.
In Vitro Measurements of Precision of Fit of Implant‐Supported Frameworks. A Comparison between “Virtual” and “Physical” Assessments of Fit Using Two Different Techniques of Measurements
Authors: Jemt Torsten , Hjalmarsson Lars
Published: December 2011

Background: Comparisons between different techniques measuring fit of implant‐supported frameworks are few.

Purpose: The purpose of this study was to compare data on precision of fit from two highly accurate measuring techniques and, also, to compare results using software programs for fit assessments considering both a “virtual” as well as a “physical” (i.e., more clinical) situation.

Materials and Methods: Five computer numerical control‐milled titanium frameworks (Procera® Implant Bridge, Nobel Biocare AB, Göteborg, Sweden) were fabricated from individual model/pattern measurements, simulating a clinical situation. Measurements of fit between frameworks and models were performed by means of a coordinate measuring machine (CMM; Zeiss Prismo Vast, Carl Zeiss Industrielle Messtechnik GmbH, Oberkochen, Germany) linked to a computer and an optical, high‐resolution, three‐dimensional scanner (Atos 4M SO, GOM International AG, Widen, Switzerland). Collected data on distortions between frameworks and models were analyzed and compared between the two measurement techniques. A comparison between “virtual” and “physical” fit assessments was also performed, based on data from the three‐dimensional scanner.

Results: When using “virtual” fit assessment programs, overall mean three‐dimensional distortion between implant and framework center points in absolute figures was 37 (SD 22) and 14 µm (SD 8) for the CMM and three‐dimensional scanning measurements, respectively. Corresponding mean three‐dimensional distortion when using a “physical” fit assessment program in the scanner was 43 µm (SD 24) (p < 0.001). Mean horizontal (x‐axis) measurements of the distance between the two terminal implants of the models and the frameworks were 33.772 and 33.834 mm for the CMM technique. Corresponding measurements for the three‐dimensional scanner was 33.798 and 33.806 mm, respectively. Horizontal distances from the three‐dimensional scanner were, for most measurements, greater than for the CMM measurements.

Conclusion: Measurements of fit between frameworks and models may vary depending on what technique is used and how fit assessments regarding “virtual” or “physical” fit is approached.
Timing of Implant Placement and Augmentation with Bone Replacement Material: Clinical Assessment at 8 and 16 Months
Authors: Artzi Zvi , Nemcovsky Carlos E. , Tal Haim , Kozlovsky Avital
Published: December 2011

Purpose: The purpose of this study is to evaluate implants placed at different times of bone augmentation.

Materials and Methods: Four implants were placed in seven dogs: one at a 6‐month bovine mineral grafted site (6‐month Bio‐Oss® grafted site [6mBio]), one at a grafted membrane‐protected simultaneously augmented (Fresh Bio‐Oss® grafted site [FrBio]) site, one at a clotted (nongrafted clotted membrane‐protected site [Clot]) membrane‐protected site, and one at a pristine (nongrafted uncovered site [Cont]) site. Implants were exposed after 6 months. The same protocol was repeated on the contralateral side, at a delay of 8 months. Peri‐implant care was performed throughout the hygienic phase (2 and 10 months, respectively) every 48 to 72 hours. Probing depth and bleeding on probing were recorded. Implant stability was determined by a Periotest® (Medizintechnik Gulden, Modautal, Germany). Statistical analysis was conducted using analysis of variance with repeated measures.

Results: Average probing depth at the simultaneously grafted sites was 2.21 mm and 2.03 mm at 8 and 16 months, respectively. At the 6‐month grafted sites, it was 1.96 mm and 1.57 mm. At the Clot sites, it was 2.68 mm and 2.07 mm, and 2.21 mm and 1.82 mm at the Cont sites, respectively. The average bleeding on probing was 0.50 and 0.42 at the FrBio sites, and 0.35 and 0.07 at the 6mBio sites during the respective periods. At the Clot sites, it was 0.50 and 0.28, and at the Cont sites, 0.43 and 0.21, respectively. Probing depth significantly reduced over the time at 6mBio, Clot, and Cont sites (p < .03). Average implant stability score at the FrBio sites was −0.24 and −0.27, and −0.50 and −0.46 at the 6mBio sites, at 8 and 16 months, respectively. At the Clot sites, it was −0.35 and −0.46. Cont sites averaged −0.37 at both periods. Implant stability was significantly higher (p < .005) comparing 6mBio over FrBio, 6mBio over Cont, and Clot over FrBio sites.

Conclusions: Immediate and delayed augmentations are safe modes. Probing depth and bleeding indices gradually improved along time. Implant stability was higher at the delayed mode.
Cytosolic, but not mitochondrial, oxidative stress is a likely contributor to cardiac hypertrophy resulting from cardiac specific GLUT4 deletion in mice
Authors: Li Yan , Wende Adam R. , Nunthakungwan Orathai , Huang Yujia , Hu Eric , Jin Huifeng , Boudina Sihem , Abel E. Dale , Jalili Thunder
Published: December 2011

We hypothesized that oxidative stress may contribute to the development of hypertrophy observed in mice with cardiac specific ablation of the insulin sensitive glucose transporter 4 gene (GLUT4, G4H−/−). Measurements of oxidized glutathione (GSSG) in isolated mitochondria and whole heart homogenates were increased resulting in a lower ratio of reduced glutathione (GSH) to GSSG. Membrane translocation of the p67phox subunit of cardiac NADPH oxidase 2 (NOX2) was markedly increased in G4H−/− mice, suggesting elevated activity. To determine if oxidative stress was contributing to cardiac hypertrophy, 4‐week‐old control (Con) and G4H−/− mice were treated with either tempol (T, 1 mm, drinking water), a whole cell antioxidant, or Mn(III) tetrakis (4‐benzoic acid) porphyrin chloride (MnTBAP, 10 mg·kg−1, intraperitoneally), a mitochondrial targeted antioxidant, for 28 days. Tempol attenuated cardiac hypertrophy in G4H−/− mice (heart : tibia, Con 6.82 ± 0.35, G4H−/− 8.83 ± 0.34, Con + T 6.82 ± 0.46, G4H−/− + T 7.57 ± 0.3), without changing GSH : GSSG, glutathione peroxidase 4 or membrane translocation of the p67phox. Tempol did not modify phosphorylation of glycogen synthase kinase 3β or thioredoxin‐2. In contrast, MnTBAP lowered mitochondrial GSSG and improved GSH : GSSG, but did not prevent hypertrophy, indicating that mitochondrial oxidative stress may not be critical for hypertrophy in this model. The ability of tempol to attenuate cardiac hypertrophy suggests that a cytosolic source of reactive oxygen species, probably NOX2, may contribute to the hypertrophic phenotype in G4H−/− mice.
Computational study of the covalent bonding of microcystins to cysteine residues – a reaction involved in the inhibition of the PPP family of protein phosphatases
Authors: Pereira Susana R. , Vasconcelos Vítor M. , Antunes Agostinho
Published: December 2011

Microcystins (MCs) are cyclic peptides, produced by cyanobacteria, that are hepatotoxic to mammals. The toxicity mechanism involves the potent inhibition of protein phosphatases, as the toxins bind the catalytic subunits of five enzymes of the phosphoprotein phosphatase (PPP) family of serine/threonine‐specific phosphatases: Ppp1 (aka PP1), Ppp2 (aka PP2A), Ppp4, Ppp5 and Ppp6. The interaction with the proteins includes the formation of a covalent bond with a cysteine residue. Although this reaction seems to be accessory for the inhibition of PPP enzymes, it has been suggested to play an important part in the biological role of MCs and furthermore is involved in their nonenzymatic conjugation to glutathione. In this study, the molecular interaction of microcystins with their targeted PPP catalytic subunits is reviewed, including the relevance of the covalent bond for overall inhibition. The chemical reaction that leads to the formation of the covalent bond was evaluated in silico, both thermodynamically and kinetically, using quantum mechanical‐based methods. As a result, it was confirmed to be a Michael‐type addition, with simultaneous abstraction of the thiol hydrogen by a water molecule, transfer of hydrogen from the water to the α,β‐unsaturated carbonyl group of the microcystin and addition of the sulfur to the β‐carbon of the microcystin moiety. The calculated kinetics are in agreement with previous experimental results that had indicated the reaction to occur in a second step after a fast noncovalent interaction that inhibited the enzymes per se.
Testing the cosmic distance duality with X-ray gas mass fraction and supernovae data
Authors: Gonçalves R. S. , Holanda R. F. L. , Alcaniz J. S.
Published: December 2011

In this Letter, we discuss a new cosmological-model-independent test for the cosmic distance duality relation (CDDR), η=DL(L)(1 +z)−2/DA(z) = 1, where DA(z) and DL(z) are the angular diameter and luminosity distances, respectively. Using the general expression for X-ray gas mass fraction (fgas) of galaxy clusters, fgas∝DLDA1/2, we show that fgas observations jointly with Type Ia supernovae (SNe Ia) data furnish a validity test for the CDDR. To perform our analysis, we use 38 fgas measurements recently studied by two groups considering different assumptions to describe the clusters and two subsamples of SNe Ia distance luminosity extracted from the Union2 compilation. In our test, we consider the η parameter as a function of the redshift parametrized by two different functional forms. It is found that the La Roque et al. sample is in perfect agreement with the duality relation (η= 1), whereas the Ettori et al. sample presents a significant conflict.
What Is the Impact of Health Reforms on Uncompensated Care in Critical Access Hospitals? A 5‐Year Forecast in Washington State
Authors: Coyne Joseph , Fry Benjamin , Murphy Sean , Smith Gary , Short Robert
Published: December 2011

Context: The 2008 financial crisis had a far‐reaching impact on nearly every sector of the economy. As unemployment increased so did the uninsured. Already operating on a slim margin and poor payer mix, many critical access hospitals are facing a tough road ahead.

Purpose: We seek to examine the increasing impact of uncompensated care on the revenues earned by Washington's critical access hospitals; to forecast uncompensated care to the year 2014; and to forecast the financial impact on rural hospital uncompensated care of HR 3590, the Affordable Care Act (ACA).

Findings: For critical access hospitals in the state of Washington, total uncompensated care increased by almost $16 million, a 22% increase from 2008 to 2009. By 2014, total uncompensated care is forecast to more than double from 2009, totaling $174 million annually without health reforms. Using the Urban Institute's Health Insurance Policy Simulation Model, uncompensated care is forecast to fall by $106 million in 2014, thereby reducing the uncompensated care percentage from 5.31% to 2.07%.

Conclusions: Policy makers and health care managers should note that a substantial portion of the newly insured from the ACA will most likely be Medicaid participants. Given this source of lower revenue per case, critical access hospital administrators should seek additional public and private sources of revenue. Most importantly, rural hospital managers must maintain or improve their cost efficiency, while serving the needs of their rural population as we move closer toward the implementation of health reforms.
Not by science alone: why orangutan conservationists must think outside the box
Authors: Meijaard Erik , Wich Serge , Ancrenaz Marc , Marshall Andrew J.
Published: December 2011

Orangutan survival is threatened by habitat loss and illegal killing. Most wild populations will disappear over the next few decades unless threats are abated. Saving orangutans is ultimately in the hands of the governments and people of Indonesia and Malaysia, which need to ensure that habitats of viable orangutan populations are protected from deforestation and well managed to ensure no hunting takes place. Companies working in orangutan habitat also have to play a much bigger role in habitat management. Although the major problems and the direct actions required to solve them—reducing forest loss and hunting—have been known for decades, orangutan populations continue to decline. Orangutan populations in Sumatra and Borneo have declined by between 2,280 and 5,250 orangutans annually over the past 25 years. As the total current population for the two species is some 60,000 animals in an area of about 90,000 km2, there is not much time left to make conservation efforts truly effective. Our review discusses what has and has not worked in conservation to guide future conservation efforts.
Genetic and phenotypic differentiation in endemic Scaptotrigona hellwegeri (Apidae: Meliponini): implications for the conservation of stingless bee populations in contrasting environments
Authors: QUEZADA‐EUÁN JOSE JAVIER G. , MAY‐ITZÁ WILLIAM de J. , RINCÓN MANUEL , DE LA RÚA PILAR , PAXTON ROBERT J.
Published: December 2011

Abstract.  1. The western forests of Mexico are rich in species of stingless bee, possibly a consequence of the diverse habitats found across different altitudes of the Trans‐Mexican Volcanic Belt (TMVB) and the Pacific coast (PAC).

2. Scaptotrigona hellwegeri is an example of a stingless bee species found across the TMVB and PAC. It is currently considered a single species. Its TMVB populations have become rare and rapidly impacted by human‐modified habitats. Translocation of S. hellwegeri colonies from the PAC tropical lowlands to TMVB subtropical highlands has been considered, as colonies at PAC are more abundant and even used in stingless beekeeping.

3. Morphometric analyses of meristic characters plus genetic analysis at microsatellite loci and sequencing of the cox1 region of mtDNA were used to evaluate phenotypic and genetic differentiation in S. hellwegeri from TMVB and PAC.

4. Significant morphometric differences were detected between S. hellwegeri from TMVB and PAC. Corrected nuclear multilocus F′ST was 0.592 (P < 0.01), supporting the view that TMVB and PAC populations are markedly genetically differentiated. A 573 bp sequence of the cox1 region of mtDNA showed six sites of divergence, with sequence divergence between PAC and TMVB populations of 1.1%.

5. Our morphometric and genetic results make evident that S. hellwegeri from TMVB and PAC are significantly differentiated and represent two genetic lineages. An immediate recommendation is to restrict the movement of colonies from the lowland PAC regions to TMVB, where colonies are currently scarce.
Endobronchial ultrasound with transbronchial needle aspiration (EBUS‐TBNA) vs blind transbronchial needle aspiration in the evaluation of patients with enlarged mediastinal/hilar lymph nodes or masses
Authors: Hermes Andreas
Published: December 2011

Please cite this paper as: Hermes A. Endobronchial ultrasound with transbronchial needle aspiration (EBUS‐TBNA) vs blind transbronchial needle aspiration in the evaluation of patients with enlarged mediastinal/hilar lymph nodes or masses. Clin Respir J 2012; 6: 1–2.
The neural correlates of impaired collision avoidance in hemianopic patients
Authors: Papageorgiou Eleni , Hardiess Gregor , Wiethölter Horst , Ackermann Hermann , Dietz Klaus , Mallot Hanspeter A. , Schiefer Ulrich
Published: December 2011

Purpose:  The aim of this study was to assess the brain regions associated with impaired performance in a virtual, dynamic collision avoidance task, in a group of patients with homonymous visual field defects (HVFDs) because of unilateral vascular brain lesions.

Methods:  Overall task performance was quantitatively assessed as the number of collisions while crossing an intersection at two levels of traffic density. Twenty‐six patients were divided into two subgroups using the median split method: patients with ‘performance above average’ (HVFDA, i.e. lower number of collisions) and patients with ‘performance below average’ (HVFDB, i.e. higher number of collisions). In order to identify the anatomical structures that might be specifically affected in HVFDB patients but spared in HVFDA patients, overlap, subtraction and voxel‐based lesion‐symptom mapping analyses were performed using the MRIcron software.

Results:  No significant difference in collision avoidance between patients with left‐ and right‐hemispheric lesions was revealed. Separate lesion analysis in 12 patients with right‐ and 14 patients with left‐hemispheric lesions showed that the cortical structures associated with impaired collision avoidance were the parieto‐occipital region and posterior cingulate gyrus in the right hemisphere and the inferior occipital cortex and parts of the fusiform (occipito‐temporal) gyrus in the left hemisphere.

Conclusion:  In the present collision avoidance paradigm, impaired performance of patients with right‐hemispheric lesions is associated with damage in the dorsal processing stream and potential impact on the visual spatial working memory (WM), while impaired performance of patients with left‐hemispheric lesions is associated with damage in the ventral stream and potential impact on the visual object WM.
Weight‐based high‐ and low‐dose ribavirin in combination with peginterferon α‐2b therapy for genotype 2 chronic hepatitis C: A randomized trial
Authors: Kagawa Tatehiro , Kojima Sei‐ichiro , Shiraishi Koichi , Takashimizu Shinji , Nagata Naruhiko , Shiozawa Hirokazu , Nishizaki Yasuhiro , Ikeda Akihiko , Tei Yoshihiro , Atsukawa Kazuhiro , Kamochi Jun‐ichiro , Wasada Mitsuru , Numata Makoto , Arase Yoshitaka , Hirose Shunji , Yamada Takuji , Hata Yasuo , Watanabe Norihito , Morizane Toshio , Mine Tetsuya
Published: December 2011

Aim:  The optimal ribavirin dose in the treatment of patients infected with hepatitis C virus (HCV) genotype 2 remains to be elucidated. We aimed to seek the optimal ribavirin dose required for this genotype in a randomized trial.

Methods:  We compared the efficacy and tolerability of the 24‐week peginterferon α‐2b (1.5 µg/kg/week) therapy in combination with a weight‐based higher dose (600–1000 mg) and lower dose (400–800 mg) of ribavirin for genotype 2 patients. Noninferior margin was set at 10%.

Results:  A total of 120 patients were randomized to a higher‐dose or a lower‐dose group. Sustained virological response (SVR) by intention‐to‐treat analysis was achieved in 47/58 (81.0%, 90% confidential interval [CI]: 72.6–89.5) patients in the higher‐dose group and 41/60 (68.3%, 90% CI: 58.5–78.2) patients in the lower‐dose group (difference, −12.7%; 90% CI, −25.7 to 0.3). Relapse rates were 10% and 21.6% in the higher‐dose and the lower‐dose groups, respectively. Multiple logistic regression analysis showed that ribavirin dose/kg body weight was the only significant predictor of SVR (≥9.5 mg/kg per day vs <9.5 mg/kg per day; odds ratio = 3.34; 95% CI, 1.41–7.92; P = 0.006). Twenty‐one (36.2%) in the higher‐dose group required ribavirin dose reduction because of anemia, whereas seven patients (11.7%) did in the lower‐dose group (P < 0.01). Three of the higher‐dose group and two of the lower‐dose group required premature termination of therapy.

Conclusions:  Weight‐based lower‐dose ribavirin regimen was not equivalent to the higher‐dose counterpart in the treatment of HCV genotype 2. We discourage treating these patients with low‐dose ribavirin regimens. The peginterferon therapy in combination with ribavirin at a weight‐based higher dose (600–1000 mg) remains the standard‐of‐care treatment for this genotype.
Creating Value Beyond the Product Through Services
Authors: Heapy Joe
Published: December 2011

Companies challenged by an increasingly knowledgeable customer base, a product that is rapidly becoming a commodity, and a world of technological convergence will find some good advice here about products, services, and innovation.
Development of Virtual Ping-Pong Game with 6-DOF Tracking System
Authors: Kuo Tai-Hong , Tsai Chia-Chang , Fang Jing-Jing
Published: December 2011

This study presents a novel computer-based virtual ping-pong game. The integrated system employs a multimedia paddle and a tracking device on PC to generate a more sophisticated 6-degree-of-freedom data using either of magnet or optics. The lab-made paddle embeds a Bluetooth module, vibration motor, LED, and mini-speaker. Advantages of this webcam-based game are wireless, robust to electromagnetic interference, and low cost. The game software includes comprehensive physical modeling of most of the parameters of a real ping-pong game. Build up of the overall system is inexpensive and sufficiently accurate for game play. It presents a more functional and realistic feeling in playing computer game compared to existing commercial systems.
Adaptive bandwidth measurements of importance functions for speech intelligibility prediction
Authors: Whitmal Nathaniel A. , DeRoy Kristina
Published: December 2011

The Articulation Index (AI) and Speech Intelligibility Index (SII) predict intelligibility scores from measurements of speech and hearing parameters. One component in the prediction is the “importance function,” a weighting function that characterizes contributions of particular spectral regions of speech to speech intelligibility. Previous work with SII predictions for hearing-impaired subjects suggests that prediction accuracy might improve if importance functions for individual subjects were available. Unfortunately, previous importance function measurements have required extensive intelligibility testing with groups of subjects, using speech processed by various fixed-bandwidth low-pass and high-pass filters. A more efficient approach appropriate to individual subjects is desired. The purpose of this study was to evaluate the feasibility of measuring importance functions for individual subjects with adaptive-bandwidth filters. In two experiments, ten subjects with normal-hearing listened to vowel-consonant-vowel (VCV) nonsense words processed by low-pass and high-pass filters whose bandwidths were varied adaptively to produce specified performance levels in accordance with the transformed up-down rules of Levitt [(1971). J. Acoust. Soc. Am. 49, 467–477]. Local linear psychometric functions were fit to resulting data and used to generate an importance function for VCV words. Results indicate that the adaptive method is reliable and efficient, and produces importance function data consistent with that of the corresponding AI/SII importance function.
Analysis of the effects of physical task stress on the speech signal
Authors: Godin Keith W. , Hansen John H. L.
Published: December 2011

Physical task stress is known to affect the fundamental frequency and other measurements of the speech signal. A corpus of physical task stress speech is analyzed using a spectrum F-ratio and frame score distribution divergences. The measurements differ between phone classes, and are greater for vowels and nasals than for plosives and fricatives. In further analysis, frame score distribution divergences are used to measure the spectral dissimilarity between neutral and physical task stress speech. Frame scores are the log likelihood ratios between Gaussian mixture models (GMMs) of physical task stress and of neutral speech. Mel-frequency cepstral coefficients are used as the acoustic feature inputs to the GMMs. A Laplacian distribution is fitted to the frame scores for each of ten phone classes, and the symmetric Kullback–Leibler divergence is employed to measure the change in distribution from neutral to physical task stress. The results suggest that the spectral dissimilarity is greatest for the second level of a four level exertion measurement, and that spectral dissimilarity is greater for nasal phones than for plosives and fricatives. Further, the results suggest that different phone classes are affected differently by physical task stress.
Effects of cross-language voice training on speech perception: Whose familiar voices are more intelligible?
Authors: Levi Susannah V. , Winters Stephen J. , Pisoni David B.
Published: December 2011

Previous research has shown that familiarity with a talker’s voice can improve linguistic processing (herein, “Familiar Talker Advantage”), but this benefit is constrained by the context in which the talker’s voice is familiar. The current study examined how familiarity affects intelligibility by manipulating the type of talker information available to listeners. One group of listeners learned to identify bilingual talkers’ voices from English words, where they learned language-specific talker information. A second group of listeners learned the same talkers from German words, and thus only learned language-independent talker information. After voice training, both groups of listeners completed a word recognition task with English words produced by both familiar and unfamiliar talkers. Results revealed that English-trained listeners perceived more phonemes correct for familiar than unfamiliar talkers, while German-trained listeners did not show improved intelligibility for familiar talkers. The absence of a processing advantage in speech intelligibility for the German-trained listeners demonstrates limitations on the Familiar Talker Advantage, which crucially depends on the language context in which the talkers’ voices were learned; knowledge of how a talker produces linguistically relevant contrasts in a particular language is necessary to increase speech intelligibility for words produced by familiar talkers.
A transport model and numerical simulation of the high-frequency dynamics of three-dimensional beam trusses
Authors: Le Guennec Yves , Savin Éric
Published: December 2011

The theory of microlocal analysis shows that the energy density associated with the high-frequency vibrations of a three-dimensional Timoshenko beam satisfies a Liouville-type transport equation. In the present application, the material of the beam is assumed to be isotropic. Its parameters are allowed to vary along the beam axis at length scales much larger than the wavelength of the high-frequency waves traveling in it. Moreover, the curvature and torsion of the beam are accounted for. The first part of the paper focuses on the derivation of the transport model for a single three-dimensional beam. In order to extend this model to beam trusses, the reflection/transmission phenomena of the energy fluxes at junctions of beams are described by power flow reflection/transmission operators in a subsequent part. For numerical simulations, a discontinuous Galerkin finite element method is used on account of the discontinuities of the energy density field at the junctions. Thus, a complete mechanical–numerical modeling of the linear transient dynamics of beam trusses is proposed. It is illustrated by numerical examples highlighting some remarkable features of high-frequency vibrations: The onset of a diffusive regime characterized by energy equipartition rules at late times. Energy diffusion is prompted by the multiple reflection/transmission of waves at the junctions, with possible mode (polarization) conversions. This is the regime applicable to the statistical energy analysis of structural acoustics systems. The main purpose of this research is to develop an effective strategy to simulate and predict the transient response of beam trusses impacted by acoustic or mechanical shocks.
Detection of pulse trains in the electrically stimulated cochlea: Effects of cochlear health
Authors: Pfingst Bryan E. , Colesa Deborah J. , Hembrador Sheena , Kang Stephen Y. , Middlebrooks John C. , Raphael Yehoash , Su Gina L.
Published: December 2011

Perception of electrical stimuli varies widely across users of cochlear implants and across stimulation sites in individual users. It is commonly assumed that the ability of subjects to detect and discriminate electrical signals is dependent, in part, on conditions in the implanted cochlea, but evidence supporting that hypothesis is sparse. The objective of this study was to define specific relationships between the survival of tissues near the implanted electrodes and the functional responses to electrical stimulation of those electrodes. Psychophysical and neurophysiological procedures were used to assess stimulus detection as a function of pulse rate under the various degrees of cochlear pathology. Cochlear morphology, assessed post-mortem, ranged from near-normal numbers of hair cells, peripheral processes and spiral ganglion cells, to complete absence of hair cells and peripheral processes and small numbers of surviving spiral ganglion cells. The psychophysical and neurophysiological studies indicated that slopes and levels of the threshold versus pulse rate functions reflected multipulse integration throughout the 200 ms pulse train with an additional contribution of interactions between adjacent pulses at high pulse rates. The amount of multipulse integration was correlated with the health of the implanted cochlea with implications for perception of more complex prosthetic stimuli.
Measurement of viscoelastic properties from the vibration of a compliantly supported beam
Authors: Park Jeongwon , Lee Jepil , Park Junhong
Published: December 2011

A laboratory method is presented by which the viscoelastic properties of compliant materials are measured over a wide frequency range. The test setup utilizes a flexible beam clamped at one end and excited by a shaker at the free end. A small specimen of a compliant material is positioned to support the beam near its midpoint. The deformation from gravity is minimized since the specimen is not loaded by an attached mass. Forced vibration responses measured at two locations along the beam are used to derive a transfer function from which the dynamic properties of compliant materials are directly determined by use of a theoretical procedure investigating the effects of specimen stiffness on the propagation of flexural waves. Sensitivity of the measured properties to experimental uncertainties is investigated. Young’s moduli and associated loss factors are determined for compliant materials ranging from low-density closed-cell foams to high-density damping materials. The method is validated by comparing the measured viscoelastic properties to those from an alternative dynamic test method.
Localization of a small change in a multiple scattering environment without modeling of the actual medium
Authors: Rakotonarivo S. T. , Walker S. C. , Kuperman W. A. , Roux P.
Published: December 2011

A method to actively localize a small perturbation in a multiple scattering medium using a collection of remote acoustic sensors is presented. The approach requires only minimal modeling and no knowledge of the scatterer distribution and properties of the scattering medium and the perturbation. The medium is ensonified before and after a perturbation is introduced. The coherent difference between the measured signals then reveals all field components that have interacted with the perturbation. A simple single scatter filter (that ignores the presence of the medium scatterers) is matched to the earliest change of the coherent difference to localize the perturbation. Using a multi-source/receiver laboratory setup in air, the technique has been successfully tested with experimental data at frequencies varying from 30 to 60 kHz (wavelength ranging from 0.5 to 1 cm) for cm-scale scatterers in a scattering medium with a size two to five times bigger than its transport mean free path.
Absolute pitch correlates with high performance on interval naming tasks
Authors: Dooley Kevin , Deutsch Diana
Published: December 2011

Absolute pitch, the rare ability to identify or produce a musical tone without a reference tone, has been shown to be advantageous in some musical tasks; however, its relevance in musical contexts primarily involving relative pitch has been questioned. To explore this issue, 36 trained musicians—18 absolute pitch possessors and 18 non-possessors with equivalent age of onset and duration of musical training—were tested on interval naming tasks requiring only relative pitch. The intervals to be named were either ascending or descending with separation ranging from 1 to 12 semitones and equally involved all 12 pitch classes. Three different conditions were employed; these used brief sine waves, piano tones, and piano tones preceded by a V7-I chord cadence so as to establish a tonal context. The possession of absolute pitch was strongly correlated with enhanced performance on all these tests of relative pitch. Furthermore, no evidence was found that this absolute pitch avantage depended on key, interval size, or musical context.
Where the ocean influences the impulse response and its effect on synchronous changes of acoustic travel time
Authors: Spiesberger John L.
Published: December 2011

In 1983, sounds at 133 Hz, 0.06 s resolution were transmitted in the Pacific for five days at 2 min intervals over 3709 km between bottom-mounted instruments maintained with atomic clocks. In 1989, a technique was developed to measure changes in acoustic travel time with an accuracy of 135 microseconds at 2 min intervals for selected windows of travel time within the impulse response. The data have short-lived 1 to 10 ms oscillations of travel time with periods less than a few days. Excluding tidal effects, different windows exhibited significant synchronized changes in travel time for periods shorter than 10 h. In the 1980s, this phenomenon was not understood because internal waves have correlation lengths of a few kilometers which are smaller than the way sound was thought to sample the ocean along well-separated and distinct rays corresponding to different windows. The paradox’s resolution comes from modern theories that replace the ray-picture with finite wavelength representations that predict sound can be influenced in the upper ocean over horizontal scales such as 20 km or more. Thus, different windows are influenced by the same short-scale fluctuations of sound speed. This conclusion is supported by the data and numerical simulations of the impulse response.
An exact method of regularity analysis for auditory brainstem neurons (L)
Authors: Wright M. C. M. , Bleeck S. , Winter I. M.
Published: December 2011

The standard regularity analysis for spike trains in cochlear nucleus neurons evoked by tonebursts first proposed by Bourk is widely used, primarily as one of the criteria for classification of such neurons. It is shown that this procedure does not estimate quite what it is supposed to, and introduces unnecessary noise to its results due to its use of bins. Instead the desired quantities (mean and coefficient of variation of the lengths of all inter-spike intervals in progress as a function of time since stimulus onset) can all be exactly calculated directly from the spike train without the need for data binning. The implications for classification and other studies are discussed.
Evaluation of the effective speed of sound in phononic crystals by the monodromy matrix method (L)
Authors: Kutsenko A. A. , Shuvalov A. L. , Norris A. N.
Published: December 2011

A scheme for evaluating the effective quasistatic speed of sound c in two- and three-dimensional periodic materials is reported. The approach uses a monodromy-matrix operator to enable direct integration in one of the coordinates and exponentially fast convergence in others. As a result, the solution for c has a more closed form than previous formulas. It significantly improves the efficiency and accuracy of evaluating c for high-contrast composites as demonstrated by a two-dimensional scalar-wave example with extreme behavior.
Further assessment of forward pressure level for in situ calibration
Authors: Scheperle Rachel A. , Goodman Shawn S. , Neely Stephen T.
Published: December 2011

Quantifying ear-canal sound level in forward pressure has been suggested as a more accurate and practical alternative to sound pressure level (SPL) calibrations used in clinical settings. The mathematical isolation of forward (and reverse) pressure requires defining the Thévenin-equivalent impedance and pressure of the sound source and characteristic impedance of the load; however, the extent to which inaccuracies in characterizing the source and/or load impact forward pressure level (FPL) calibrations has not been specifically evaluated. This study examined how commercially available probe tips and estimates of characteristic impedance impact the calculation of forward and reverse pressure in a number of test cavities with dimensions chosen to reflect human ear-canal dimensions. Results demonstrate that FPL calibration, which has already been shown to be more accurate than in situ SPL calibration, can be improved particularly around standing-wave null frequencies by refining estimates of characteristic impedance. Better estimates allow FPL to be accurately calculated at least through 10 kHz using a variety of probe tips in test cavities of different sizes, suggesting that FPL calibration can be performed in ear canals of all sizes. Additionally, FPL calibration appears a reasonable option when quantifying the levels of extended high-frequency (10–18 kHz) stimuli.
Acoustic insertion loss due to two dimensional periodic arrays of circular cylinders parallel to a nearby surface
Authors: Krynkin Anton , Umnova Olga , Vicente Sánchez-Pérez Juan , Yung Boon Chong Alvin , Taherzadeh Shahram , Attenborough Keith
Published: December 2011

The acoustical performances of regular arrays of cylindrical elements, with their axes aligned and parallel to a ground plane, have been investigated through predictions and laboratory experiments. Semi-analytical predictions based on multiple scattering theory and numerical simulations based on a boundary element formulation have been made. Measurements have been made in an anechoic chamber using arrays of (a) cylindrical acoustically-rigid scatterers (PVC pipes) and (b) thin elastic shells. Insertion loss (IL) spectra due to the arrays have been measured without and with ground planes for several receiver heights. Data and predictions have been compared. The minima in the excess attenuation spectrum i.e., attenuation maxima due to the ground alone resulting from destructive interference between direct and ground-reflected sound waves, tend to have an adverse influence on the band gaps (BG) related to a periodic array in the free field when these two effects coincide. On the other hand, the presence of rigid ground may result in an IL for an array near the ground similar to or, in the case of the first BG, greater than that resulting from a double array, equivalent to the original array plus its ground plane mirror image, in the free field.
Three-Dimensional Docking in the MAPK p38α
Authors: Goldsmith Elizabeth J.
Published: December 2011

Structural analysis reveals the mode of interaction between a mitogen-activated protein kinase and its inactivating phosphatase.
The increased PDGF-A, PDGF-B and FGF-2 expression in recurrence of salivary gland pleomorphic adenoma
Authors: Soares Andresa Borges , Demasi Ana Paula , Tincani Alfio Jose , Martins Antonio Santos , Altemani Albina , de Araújo Vera Cavalcanti
Published: December 2011

Background

Pleomorphic adenoma (PA) is the most common salivary gland tumour. Although classified as benign, it has a tendency to recur (recurrent pleomorphic adenomas (RPA)), as well as the ability to undergo malignant transformation. It has been suggested that mutations in various families of growth factors and growth factor receptions are involved in the autonomous growth of tumour cells. The aim of the present study was to investigate the participation of platelet-derived growth factor (PDGF)-A, PDGF-B, PDGF-Rα, fibroblast growth factor (FGF)-2, Flg and BEK in PA, RPA and recurrent pleomorphic adenoma with malignant transformation (TRPA).

Methods

18 cases of PA, 16 cases of RPA and two cases of RPA with focal malignant transformation (TRPA) were analysed for growth factor expression utilising immunohistochemical techniques via tissue microarray.

Results

There was a significant difference in PDGF-A, PDGF-B, PDGF-Rα, FGF-2, Flg and BEK expression in all groups. When comparing non-recurrent with recurrent tumours, PDGF-A, PDGF-B, PDGF-Rα, FGF-2, Flg and BEK reactivity in RPA was stronger than that observed in PA. All proteins were highly expressed in TRPA.

Conclusions

This research suggests that PDGF-A, PDGF-B, PDGF-Rα, FGF-2, BEK and Flg can be related to the recurrence of PA. In addition, this study shows that TRPA cells overexpress all growth factors, which has been reported in association with the malignant transformation.
HIV testing: getting the message across—a survey of knowledge, attitudes and practice among non-HIV specialist physicians
Authors: Hunter Ewan , Perry Meghan , Leen Clifford , Premchand Nikhil
Published: December 2011

Introduction

26% of people living with HIV in the UK remain undiagnosed and over 50% of adults with HIV are significantly immunocompromised at the time of diagnosis. Current guidelines recommend routine testing in all patients presenting with a range of conditions in low prevalence areas (<2/1000).

Methods

The authors conducted an online survey of the knowledge, attitudes and practice of non-HIV specialist physicians with regard to HIV testing in two areas of the UK with a lower prevalence of HIV. Key outcomes included recognition of recommended clinical indications for HIV testing and perceived barriers to performing HIV tests more routinely. All responses were collected in July 2009.

Results

Recommended indications for HIV testing were identified by 0–43.7% of 119 respondents. 47.9% cited a low prevalence of HIV as a barrier to routine testing. 88% of 60 consultant physicians were unaware of current guidelines on testing for HIV.

Conclusion

The authors found a low awareness of current guidance on testing for HIV and a high level of perceived barriers to testing. Reducing the high number of late diagnoses is a clinical and public health priority. To achieve this, the authors recommend improved policy dispersal coupled with education that targets perceived barriers to testing.
GRAPHENE: SYNTHESIS, FUNCTIONALIZATION AND PROPERTIES
Authors: RAO C. N. R. , SUBRAHMANYAM K. S. , RAMAKRISHNA MATTE H. S. S. , MAITRA URMIMALA , MOSES KOTA , GOVINDARAJ A.
Published: December 2011

Graphenes with varying number of layers can be synthesized by different strategies. Thus, single-layer graphene is obtained by the reduction of single layer graphene oxide, CVD and other methods besides micromechanical cleavage. Few-layer graphenes are prepared by the conversion of nanodiamond, arcdischarge of graphite and other means. We briefly present the various methods of synthesis and the nature of graphenes obtained. We then discuss the various properties of graphenes. The remarkable property of graphene of quenching fluorescence of aromatic molecules is shown to be associated with photo-induced electron transfer, on the basis of fluorescence decay and time-resolved transient absorption spectroscopic measurements. The interaction of electron donor and acceptor molecules with few-layer graphene samples has been discussed. Decoration of metal nano-particles on graphene sheets and the resulting changes in electronic structure are examined. Few-layer graphenes exhibit ferromagnetic features along with antiferromagnetic properties, independent of the method of preparation. Graphene-like MoS2and WS2have been prepared by chemical methods, and the materials are characterized by electron microscopy, atomic force microscopy (AFM) and other methods. Boron nitride analogues of graphene have been obtained by a simple chemical procedure starting with boric acid and urea and have been characterized by various techniques.
CROSS-SECTION FOR DOUBLE CHARMONIUM PRODUCTION IN ELECTRON–POSITRON ANNIHILATION AT ENERGY $\sqrt{s} = 10.6 {\rm GeV}$
Authors: MENGESHA ELIAS , BHATNAGAR SHASHANK
Published: December 2011

In this work we study the process e++e-→J/Ψ+ηc at energy [Formula: see text] observed recently at B-factories whose measurements were made by Babar and Belle groups. We calculate the cross-section for this process in the Bethe–Salpeter formalism under Covariant Instantaneous Anstaz. To simplify our calculation, the heavy quark approximation is employed in the quark and gluon propagators. In the exclusive process of e+e- annihilation into two heavy quarkonia, the cross-section calculated in this scenario is compatible with the experimental data of Babar and Belle.
Recent Progress in Physics of High-Temperature Superconductors
Authors: Tohyama Takami
Published: December 2011

One hundred years after the discovery of superconductivity, we are now facing a new era that demands an increase in the superconducting transition temperatureTc. In addition to copper-based superconductors, iron-based superconductors that have been discovered recently have been considered high-temperature superconductors. The similarity and difference between the two high-Tcsystems are discussed on the basis of our recent theoretical and experimental understandings. While the pairing mechanism and non-Fermi liquid behaviors in transport properties may have a common origin between the two systems, the strengths of electron correlation are different: Cuprate is a doped Mott insulator, while iron pnictide is an itinerant system with a weak correlation. Pseudogap phenomena in hole-doped cuprates and their absence in electron-doped cuprate are regarded as a consequence of a strong correlation. Recent topics in cuprates about electron–hole asymmetry and pseudogap phenomenon are reviewed from a theoretical viewpoint. For iron pnictides, anisotropic behaviors in antiferromagnetic phases and new iron-selenide superconductors are discussed.