bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction Time as a Measure of Threshold and Suprathreshold Hearing. II. Subjects with Impaired Hearing
Authors: Pfingst B. E. , Hienz R. , Snyder J. , Miller J.
Published: May 2012

Reaction time has been used as a measure to evaluate hearing and hearing changes associated with drugs, lesions, and noise exposure. In this paper, experimentally produced hearing changes in monkeys are compared to hearing changes in man. Reaction time and other psychoacoustic measures are compared in human subjects. Temporary hearing loss was produced in monkey and man by exposure to pure tones one-half octave below a selected test frequency. Exposures produced threshold shifts and changes in the intensity function which were similar for both man and monkeys. These changes are similar to those reported by Moody [Adv. in Otorhinolaryngol. 20, (1973)] for the monkey and are comparable to hearing changes in human subjects with clinically diagnosed sensorineural hearing loss and recruitment. They can be contrasted to the hearing loss seen in man and monkey with a conductive loss. In the humans, the changes in hearing reflected in reaction time performance are similar to those observed in loudness matching studies in the laboratory and in the clinic. The results confirm that the reaction time task is indeed applicable to the experimental study of conductive and cochlear hearing losses and to physiological studies of threshold and loudness coding. [Work supported by PHS Grants NS 08181, RR 00166, NS S0637, and NS 05082.]
Will the Real Scatter Model Please Stand up?
Authors: Swarts R. L.
Published: May 2012

Mathematical modeling of the intersection of sound waves with roughened surfaces dates back almost a century to Rayleigh's work with sinusoidally corrugated surfaces. Since that time many models have been developed, differing in underlying principles and mathematical development. A critical problem facing an acoustician or engineer seeking to build equipment for use in the real world is deciding which model will yield the most accurate or most useful results. As yet this problem is unsolved. The purpose of this paper is to outline why this situation exists and what might be done about it. Although the material is tutorial in nature, it is nevertheless intended to be provocative. I will deal primarily with two distinctly different models. The first is the now traditional solution of the Helmholtz equation by way of the Kirchoff approximation and Eckart expansions. The second is the point scatterer model of Faure, Ol'shevski, and Middle-ton. The assumptions or approximations inherent to both are briefly discussed and the advantages and disadvantages of each indicated. In conclusion I outline areas where more work is needed to complete model development and adequately test their veracity.
Fluctuation of Acoustic Signals Propagated in the Ocean
Authors: Hurdle B. G.
Published: May 2012

One of the most prominent characteristics of acoustic signals transmitted from one point to another in the ocean is the fluctuation of the signal, in both space and time. This is true for both fixed and moving source and receiver. Postulated mechanisms and controlling parameters for various modes of propagation and types of environment are discussed. The environment includes the nature of reflectors and scatterers and their influence on the fluctuation. Examples of appropriate measures of fluctuation are offered. Experiments for testing mechanisms and obtaining descriptive data are discussed. Some problems of prediction are outlined.
Applications of Scattering Function Measurements
Authors: Thiele R.
Published: May 2012

Scattering functions of sound measurements in deep and shallow water are presented. Scattering functions of high resolution with respect to time and frequency can be used to resolve the multipath structure of the transmission and the delay of time-variant scattered energy, relative to the coherently reflected energy. From this, an estimate of the Doppler distribution of the angle-dependent surface scattering can be given. The time-variable weighting function is found, by this method, for a suitable time-frequency domain. This allows for any transmitted signal to simulate the received signal in this time-frequency region. Examples are given and discussed.
Measurement of the Ultrasonic Diffraction Loss for Circular Transducers
Authors: Brendel K.
Published: May 2012

For the determination of the radiated power of ultrasonic diagnostic equipment transducer calibrations in the megahertz frequency range are of special interest. To minimize the sound attenuation corrections and the orientation adjustment problems, calibrations are performed expediently in the nearfield using the self-reciprocity technique. Therey the knowledge of the effective ultrasonic diffraction loss in the field of the transducer is necessary. Measurements with different circular transducers have been performed at normalized distances zλ/a2 between 0.2 and 5, where z is the propagation distance, a is the transducer radius, and λ is the wavelength of the radiated sound wave. The results are compared with the calculated diffraction corrections by Khimunin [Acustica 28, No. 4, 173–181 (1972)] and Papadakis [J. Acoust. Soc. Am. 52, 847–849 (1972)]. It is shown that the agreement is better than ±0.5 dB.
A Comparison of Speech Sound Discrimination in Man and Monkey
Authors: Sinnott J. M. , Moody D. B. , Stebbins W. C.
Published: May 2012

Enhanced discrimination between speech sounds across phoneme boundaries relative to discrimination within phoneme categories based on identification defines categorical perception. The present experiment compared man and Old World monkey on speech sound discrimination and particularly on the ability to perceive categorically. Difference thresholds for three humans and four monkeys were determined on a synthetic speech sound continuum from “BA” to “DA.” Humans were instructed and monkeys conditioned with food reinforcement to indicate a stimulus change from a repetitive “BA” in a direction towards the other phoneme “DA,” or, from “DA” towards “BA.” In addition to percent correct discrimination data, reaction times to stimulus change were recorded. Thresholds, defined as 50% correct discrimination between speech sounds, were typically smaller for humans than for monkeys and tended to occur intraphonemically for humans, but at phoneme boundaries for monkeys. Human reaction times, however, were longer near threshold than were those for monkeys, presumably due to increased time required for discriminating within a phoneme category. In this experiment, therefore, the reaction time data provided better evidence for categorical perception in humans than did percent correct discrimination data. [Research supported by grants from NIH and University of Michigan.]
Contributions of Vowel and Nasal Sounds to Speaker Identification
Authors: Pfeifer Larry L.
Published: May 2012

Speaker identification techniques which extract speaker characteristics from single sound units can be applicable to both text-dependent and text-independent speech. Experiments have shown that identification accuracy improves if decisions are based upon combined information from several different sound units. With such techniques, it would be helpful if potential sound units could be rank ordered according to how much each contributes toward successful speaker identification. In text-independent speaker identification there is no control over the number of sound units in the test speech sample, so it would be beneficial if the probability of success could be predicted not only from the population size but also from the number and type of sound units available. Speech samples from ten male speakers are being used to evaluate ten non-diphthongized vowels and three nasals. Experimental results are presented on rank ordering these sounds and the determination of conditional probabilities based upon the selection of sounds. [Sponsored by Air Force Systems Command, Rome Air Development Center, Griffiss Air Force Base, New York 13441.]
An Improved System for Automatic Speaker Verification
Authors: Rosenberg A. E. , Sambur M. R.
Published: May 2012

The interactive automatic speaker verification system described by Lummis [“Implementation of an On-Line Speaker Verification Scheme,” J. Acoust. Soc. Am. 52, 181(A) (1972)] has been augmented to include linear prediction parameters in addition to the already existing pitch and intensity analysis of sentence-long utterances. This improved system has been evaluated on a new and enlarged speaker population. A method for selecting optimum speaker-dependent features has been incorporated in this system which significantly improves its performance. The evaluation indicated that the verification error rate was less than 1% with respect to casual impostors and less than 4% with respect to well-trained mimics.
Evidence for Phase Opposition between Inner and Outer Hair Cells
Authors: Sokolich W. G. , Zwislocki J. J.
Published: May 2012

Responses of single auditory-nerve fibers of normal and kanamycin-treated Mongolian gerbils indicate that inputs from inner and outer hair cells tend to cancel each other at frequencies below the characteristic frequency (CF). In normal animals, trapezoidal motion of the basilar membrane produces velocity and displacement responses which change systematically with CF. In kanamycin-treated animals, two types of abnormal responses nearly 180° out of phase with respect to each other are found. Latencies of these responses and anatomical changes generally produced by kanamycin indicate that one type is produced predominantly by the inner, the other predominantly by the outer hair cells. Normal firing patterns can be reconstructed from these two kinds of responses. They appear to result from an excitatory input from the inner hair cells and an inhibitory input from the outer hair cells. This interpretation is consistent with the generally found hair-cell directionality. The inferred interaction between the inner and outer hair cells points out a solution to the problem of neural sharpening of mechanical frequency analysis in the cochlea.
Effects of Behavioral Performance on Single Unit Responses in the Medial Geniculate and Inferior Colliculus
Authors: Ryan A. F. , Miller J. M.
Published: May 2012

The effects of behavioral performance upon single unit responses were studied in the medial geniculate nucleus (MGN) and the inferior colliculus (IC) of the awake primate. Seven rhesus monkeys were trained to respond in a simple reaction time task. This consisted of depressing a telegraph key, waiting for a variable period of time, and releasing the key to the onset of an acoustic stimulus. The animals were then implanted for chronic, single unit recording. The response of auditory single units was observed while the subjects responded to acoustic stimuli, and while the same stimuli were delivered as the animals sat passively. Spontaneous and evoked firing rates, initial latencies, temporal response patterns, and intensity functions were examined. Behavioral performance was found to consistently affect the firing pattern of many MGN and IC units. In general, single unit discharge rates were higher, and average initial latencies greater, during performance. More specific changes in response pattern were also noted in some single units. [This work was supported by grants from the National Institutes of Health.]
A Comparison of Ray Theory, Modified Ray Theory, and Normal Mode Theory for a Multiple Caustic Convergence Zone
Authors: Blatstein I. M. , Überall H.
Published: May 2012

Ray theory calculations done for a multiple caustic convergence zone generated by an arbitrary constant gradient profile do not provide an adequate description' of the sound field. Due in large part to ray theory deficiencies near caustics, ray computations show poor agreement when compared with normal mode calculations done using a finite difference approach [A. V. Newman and F. Ingenito, NRL Memo. Rep. 2381 (1972)]. When results from modified ray theory (D. A. Sachs and A. Silbiger, J. Acoust. Soc. Am. 49, 824 (1971)] are incorporated into the ray theory calculation, agreement with the normal mode results improves considerably. The oscillations present in the typical propagation loss versus range curve for a convergence zone are shown to be not only due to double arrivals to the right of a particular range minimum caustic, but also due to interference to the left of the caustic between its shadow zone contribution and real rays associated with the preceding caustic. [Supported in part by ONR and DNA (Subtask V99QAXNA003-04).]
Attenuation in Randomly Inhomogeneous Sound Channels
Authors: Mellen Robert H. , Browning David G. , Ross John M.
Published: May 2012

Estimates of the absorption of sound in sea water, based on sound channel experiments, can be seriously affected by scattering from random inhomogeneities in sound speed. Ray diffusion theory leads to an additional component of attenuation independent of frequency. Order-of-magnitude estimates of diffusion loss, calculated from perturbations in the sound speed profiles, are in reasonable agreement for a broad range of experimental data.
The Response Function for Sound Forward-Scattered by the Ocean Surface
Authors: Frisk G. V.
Published: May 2012

The power spectrum for sound forward-scattered by the ocean surface contains the discrete carrier frequency component with sidebands symmetrically positioned about the carrier. The scattered acoustic power in the sidebands is directly related to the ocean surface wave power spectrum through a response function which depends on the acoustic and surface wave frequencies. This response function has been calculated numerically for the case of small surface roughness and an omnidirectional source. The results are compared with relevant experimental results and other theoretical predictions.
A Mathematical Analysis of a Free-Flooded Finite-Length Radiating Magnetostrictive Shell
Authors: Hanish I. S. , Baier R. V. , King B. J. , Rogers Peter H. , Sinsky J. A.
Published: May 2012

A mathematical analysis with accompanying computer program of the electroacoustic performance of a single finite-length magnetostrictive circular cylinder submerged in an unbounded medium and radiating sound is presented. The cylinder is a thin hyperelastic orthotropic shell constructed of metal laminations and has unrestricted radius to length ratios. Wound toroidally with current carrying coils, it is magnetostrictively excited in axisymmetric modes over selected frequency ranges. In the analysis the vibration of the shell is developed in modes by means of dynamic equations with boundary conditions [Warburton, J. Mech. Eng. Sci. 7, 399 (1965)] and the magnetostriction transduction is described by a set of linearized constitutive relations, also modified to account for hysteresis and eddy currents. New definitions are constructed of modal electromechanical coupling coefficients and modal mass. For an input set of dimensions, electric drive, and selected frequency range, the computer program delivers in vacuo modal frequencies, modal shapes, surface velocities, and electrical and mechanical motional impedances. Typical examples of computer output are given together with a discussion of certain important “barrel modes.” Comparison is made with selected experimental results.
Real-Time Autocorrelation Predictive Coder
Authors: Goldberg A. J. , Ross M. J.
Published: May 2012

We describe a real-time autocorrelation predictive coding system for speech compression that has been implemented on a programmable signal processor having a word size of 16 bits and a multiply time of 750 nsec. This system employs the normal equations to generate an all-pole filter which, when impulsed, produces the least-squares approximation to the input signal. The technique uses a 6.4-kHz sampling rate on an input bandwidth of 3 kHz, a lOth-order predictive filter, an average magnitude difference function (AMDF) pitch extractor, and pitch synchronous interpolation of the gain and pitch parameters to produce transmission rates of 2.4 and 3.6 k bits/sec. The paper emphasizes the modifications needed to achieve real-time operation and the accuracy and timing requirements to extract pitch, calculate the autocorrelation and filter coefficients, and synthesize the output.
A Multiline Computer Voice Response System Utilizing ADPCM Coded Speech
Authors: Rosenthal L. H. , Rabiner L. R. , Schafer R. W.
Published: May 2012

An automatic voice response system is described which is capable of servicing up to ten independent output channels in real time. The system is implemented on a NOVA 800 minicomputer. Individual words and phrases are coded at a 24 000 bits/sec rate using adaptive, differential pulse-code modulation (ADPCM) techniques, and are stored on a fixed-head disk as a random-access vocabulary. The system was designed so that it is possible to create a new vocabulary for the system automatically from an analog tape recording with minimal operator intervention. Initial applications of the system are in computer-aided voice wiring and automatic directory assistance.
Fluid-Borne and Structure-Borne Noise from Valves and Orifices with Water Flow
Authors: Wilby J. F. , Rentz P. E.
Published: May 2012

Water flow through valves and orifice plates in a piping system is a source of high noise levels when cavitation occurs and, since the noise is propagated easily by the structure and fluid of the system, severe acoustic problems can arise. Laboratory measurements have been made to determine the fluid-borne and structure-borne noise characteristics of a series of valves and orifices in the pipe size range of 1 to 4 in., for flow speeds up to 16 ft/sec and pressures to 130 psig. The influence of parameters such as flow speed, pressure, orifice diameter, and valve size are considered with respect to level and frequency content of the noise propagating in upstream and downstream directions. The results show that, for example, orifice diameter and flow velocity have negligible effects on the dominant frequencies in the noise spectra. The use of flexible hoses to reduce noise propagation is discussed.
Auditory Cortex of the Tree Shrew (Tupaia glis)
Authors: Casseday J. H. , Oliver D. L. , Eisenman L. M.
Published: May 2012

This study is part of an overall effort to understand the evolution of the central auditory system. The tree shrew was studied because of its unique status in phylogeny—it resembles some of the earliest primates. Three methods of defining auditory cortex were compared: (1) cytoarchitecture of the cortex, (2) projections from the medial geniculate nucleus to the cortex, and (3) evoked potentials at the cortex in response to auditory stimuli. Analysis of cytoarchitecture revealed an area of neocortex that resembles primary auditory cortex in other mammals. Anterograde degeneration techniques showed that the projections from the medial geniculate nucleus to the cortex were coextensive with the area defined by cytoarchitecture. The main projection within this cortical area was to layer IV. Using macroelectrodes to record evoked potentials, it was found that this area of neocortex has a short latency response to auditory stimuli. We conclude that we have identified primary auditory cortex in the tree shrew. [Supported by grants from NSF and NIH.]
A Theoretical Model for Longitudinal Vibrations of a Towed Line Array
Authors: Africk S.
Published: May 2012

A towed array is modeled as a periodic arrangement of identical fluid-filled hose modules supporting two types of longitudinal waves —extensional waves in the hose wall and resonant breathing waves in the hose-and-fluid combination [D. Chase, BBN Rep. 2408 (1972)]. These waves are coupled at the module termini (end shells) where velocities in both types of waves coincide. The net force on an end shell is the sum of forces due to the arrival of both types of waves generated by vibrations of the two adjacent end shells. This dual-wave model is analogous to a system of masses connected by two springs of different stiffness. End shell motions are described by a superposition of “velocity amplitude waves” of frequency-dependent phase velocity propagating through them. If resonant breathing waves are lightly damped, in certain frequency intervals these waves are highly damped due to force cancellation. Within such stop bands, an array will be quiet in a narrow-band sense. Many features of measured low-frequency self noise are predicted by this model. [Supported by Naval Ship Systems Command.]
Fluctuations in the Propagation of Sound near the Ground
Authors: Embleton T. F. W. , Olson N. , Piercy J. E. , Rollin D. F.
Published: May 2012

The fluctuation in the propagation of a pure tone over a flat grassy surface from a source on the ground has been studied over ranges of frequency (300–4000 Hz) of the source as well as height (0–5 m) and distance (15–150 m) of the receiving microphone. Preliminary analysis of the records indicates that the standard deviation of signal level about the mean initially increases nearly linearly with distance as found by previous experimenters, but for longer distances saturates at ∼6 dB as found previously only in the propagation of light. The dependence on frequency found for the unsaturated region is considerably greater than the 7/12 power predicted for large-scale isotropic turbulence, in keeping with the reduced scale expected near the ground. Signal correlation along a wavefront has also been measured. The results place limitations on the use of coherent acoustic theory for the calculation of the attenuation of noise in practice by barriers and ground interference, as well as the use of modeling techniques for solving outdoor propagation problems.
Results of Measurement of Absorption and Sound Power with Modulated Reverberation
Authors: Cook Richard K.
Published: May 2012

Measurements of absorption A and sound power W0 have been made at various audio frequencies in the 425-m3 reverberation chamber of the Bureau. The modulated source of sound power was electroacoustical—an array of four loudspeakers having their audio input voltage waveforms amplitude-modulated at frequencies F = 0.1 to 0.4 Hz. The sound pressure |p2| was measured with an array of four microphones. A trihedral vane rotated at the center of the chamber. The phase φ was obtained by means of an analog computer (phase-meter) based on a least-squares principle of design. The results for the absorption cross section A are compared with cross sections obtained by the ASTM standard method of test based on the time decay of sound energy in a reverberation chamber. The recording phase meter displayed φ as a running function of time. From the recordings we obtained also (a) the influence of the vanes on diffusion, (b) the interaction between the loudspeaker source and the sound energy in the chamber, and (c) the relative effects of bands of noise and frequency modulation at various audio frequencies.
Acoustic Impedance Math Models for Polyurethane Foam Bulk Absorbers
Authors: Kirk J. J. , Olsen R. F.
Published: May 2012

Scottfelt, Grade 900, polyurethane foam is used by the Boeing Company as a relatively inexpensive test material for jet engine nacelle acoustic studies. The design and analysis of Scottfelt acoustic panels are facilitated by expressions relating panel material properties to acoustic impedance. Impedance math models originally developed for glass-fiber blankets and rigid frame materials were extended to Scottfelt, Grade 900, polyurethane foam and are compared to impedance tube measurements of many Scottfelt samples. The acoustic impedance of Scottfelt is controlled by firmness number and panel thickness. Panel impedance properties may also be controlled by stacking layers of foam with different firmnesses. Presented also is an application of a multidimensional impedance model for layered foam acoustic panels.
Effective Adjunctive Therapy by an Innate Defense Regulatory Peptide in a Preclinical Model of Severe Malaria
Authors: Achtman Ariel H. , Pilat Sandra , Law Charity W. , Lynn David J. , Janot Laure , Mayer Matt L. , Ma Shuhua , Kindrachuk Jason , Finlay B. Brett , Brinkman Fiona S. L. , Smyth Gordon K. , Hancock Robert E. W. , Schofield Louis
Published: May 2012

Anti-inflammatory drugs based on host defense peptides affected a host-directed therapy in an expanded murine model of severe malaria.
The Fanconi Anemia Pathway Limits Human Papillomavirus Replication
Authors: Hoskins Elizabeth E. , Morreale Richard J. , Werner Stephen P. , Higginbotham Jennifer M. , Laimins Laimonis A. , Lambert Paul F. , Brown Darron R. , Gillison Maura L. , Nuovo Gerard J. , Witte David P. , Kim Mi-Ok , Davies Stella M. , Mehta Parinda A. , Butsch Kovacic Melinda , Wikenheiser-Brokamp Kathryn A. , Wells Susanne I.
Published: May 2012

High-risk human papillomaviruses (HPVs) deregulate epidermal differentiation and cause anogenital and head and neck squamous cell carcinomas (SCCs). The E7 gene is considered the predominant viral oncogene and drives proliferation and genome instability. While the implementation of routine screens has greatly reduced the incidence of cervical cancers which are almost exclusively HPV positive, the proportion of HPV-positive head and neck SCCs is on the rise. High levels of HPV oncogene expression and genome load are linked to disease progression, but genetic risk factors that regulate oncogene abundance and/or genome amplification remain poorly understood. Fanconi anemia (FA) is a genome instability syndrome characterized at least in part by extreme susceptibility to SCCs. FA results from mutations in one of 15 genes in the FA pathway, whose protein products assemble in the nucleus and play important roles in DNA damage repair. We report here that loss of FA pathway components FANCA and FANCD2 stimulates E7 protein accumulation in human keratinocytes and causes increased epithelial proliferation and basal cell layer expansion in the HPV-positive epidermis. Additionally, FANCD2 loss stimulates HPV genome amplification in differentiating cells, demonstrating that the intact FA pathway functions to restrict the HPV life cycle. These findings raise the possibility that FA genes suppress HPV infection and disease and suggest possible mechanism(s) for reported associations of HPV with an FA cohort in Brazil and for allelic variation of FA genes with HPV persistence in the general population.
Structural and Biochemical Characterization of the Vaccinia Virus Envelope Protein D8 and Its Recognition by the Antibody LA5
Authors: Matho Michael H. , Maybeno Matt , Benhnia Mohammed Rafii-El-Idrissi , Becker Danielle , Meng Xiangzhi , Xiang Yan , Crotty Shane , Peters Bjoern , Zajonc Dirk M.
Published: May 2012

Smallpox vaccine is considered a gold standard of vaccines, as it is the only one that has led to the complete eradication of an infectious disease from the human population. B cell responses are critical for the protective immunity induced by the vaccine, yet their targeted epitopes recognized in humans remain poorly described. Here we describe the biochemical and structural characterization of one of the immunodominant vaccinia virus (VACV) antigens, D8, and its binding to the monoclonal antibody LA5, which is capable of neutralizing VACV in the presence of complement. The full-length D8 ectodomain was found to form a tetramer. We determined the crystal structure of the LA5 Fab-monomeric D8 complex at a resolution of 2.1 Å, as well as the unliganded structures of D8 and LA5-Fab at resolutions of 1.42 Å and 1.6 Å, respectively. D8 features a carbonic anhydrase (CAH) fold that has evolved to bind to the glycosaminoglycan (GAG) chondroitin sulfate (CS) on host cells. The central positively charged crevice of D8 was predicted to be the CS binding site by automated docking experiments. Furthermore, sequence alignment of various poxvirus D8 orthologs revealed that this crevice is structurally conserved. The D8 epitope is formed by 23 discontinuous residues that are spread across 80% of the D8 protein sequence. Interestingly, LA5 binds with a high-affinity lock-and-key mechanism above this crevice with an unusually large antibody-antigen interface, burying 2,434 Å2of protein surface.
Development and Validation of the Chinese Version of the Massachusetts General Hospital Acupuncture Sensation Scale: An Exploratory and Methodological Study
Authors: Yu David Tai Wai , Jones Alice Yee Man , Pang Marco Yiu Chung
Published: May 2012

Background

The Massachusetts General Hospital Acupuncture Sensation Scale (MASS) is a tool to measure needle sensations. The aims of the present study were to develop a Chinese version and to assess its psychometric properties.

Methods

This study was a methodological and exploratory study. The English version of the MASS was translated into Chinese using standardised translation procedures. Content validity was conducted by nine acupuncture experts. The prefinal Chinese version (C-MASS) was then administered to 30 acupuncture-naïve, healthy subjects. Electroacupuncture was performed on the right LI4 and LI11 acupoints for 30 min. A test–retest reliability measurement was administered 1–2 weeks later. Construct validity was examined by comparing results from C-MASS and the Short-Form McGill Pain Questionnaire (SF-MPQ). The construct validity was further assessed by the principle component analysis.

Results

C-MASS demonstrated a content validity ratio on relevance and importance from −0.04 to 1.00. Convergent validity was demonstrated by its significant association with the sensory dimension of SF-MPQ (γ=0.63, p<0.05). Discriminant validity was demonstrated by its low association with the affective dimension of SF-MPQ (γ=−0.3, p=0.111). A five-factor structure of C-MASS was established by factor analysis. C-MASS demonstrated good internal consistency (Cronbach's α=0.71) and test–retest reliability (intraclass correlation coefficient=0.92). Since the descriptor ‘sharp pain’ was not a valid needle sensation related to deqi, this was removed from C-MASS. We renamed the scale as the Modified MASS-Chinese version (C-MMASS).

Conclusions

A 12-descriptor C-MMASS was established and shown to be a reliable and valid tool in reporting needle sensations associated with deqi among healthy young Chinese people.
Clinical influences on antibiotic prescribing decisions for lower respiratory tract infection: a nine country qualitative study of variation in care
Authors: Brookes-Howell Lucy , Hood Kerenza , Cooper Lucy , Coenen Samuel , Little Paul , Verheij Theo , Godycki-Cwirko Maciek , Melbye Hasse , Krawczyk Jaroslaw , Borras-Santos Alicia , Jakobsen Kristin , Worby Patricia , Goossens Herman , Butler Christopher C
Published: May 2012

Objectives

There is variation in antibiotic prescribing for lower respiratory tract infections (LRTI) in primary care that does not benefit patients. This study aims to investigate clinicians' accounts of clinical influences on antibiotic prescribing decisions for LRTI to better understand variation and identify opportunities for improvement.

Design

Multi country qualitative interview study. Semi-structured interviews using open-ended questions and a patient scenario. Data were subjected to five-stage analytic framework approach (familiarisation, developing a thematic framework from the interview questions and emerging themes, indexing, charting and mapping to search for interpretations), with interviewers commenting on preliminary reports.

Setting

Primary care.

Participants

80 primary care clinicians randomly selected from primary care research networks based in nine European cities.

Results

Clinicians reported four main individual clinical factors that guided their antibiotic prescribing decision: auscultation, fever, discoloured sputum and breathlessness. These were considered alongside a general impression of the patient derived from building a picture of the illness course, using intuition and familiarity with the patient. Comorbidity and older age were considered main risk factors for poor outcomes. Clinical factors were similar across networks, apart from C reactive protein near patient testing in Tromsø. Clinicians developed ways to handle diagnostic and management uncertainty through their own clinical routines.

Conclusions

Clinicians emphasised the importance of auscultation, fever, discoloured sputum and breathlessness, general impression of the illness course, familiarity with the patient, comorbidity, and age in informing their antibiotic prescribing decisions for LRTI. As some of these factors may be overemphasised given the evolving evidence base, greater standardisation of assessment and integration of findings may help reduce unhelpful variation in management. Non-clinical influences will also need to be addressed.
A new user cohort study comparing the safety of long-acting inhaled bronchodilators in COPD
Authors: Jara Michele , Wentworth Charles , Lanes Stephan
Published: May 2012

Objective

To investigate a possible increased risk observed in tiotropium clinical trials of stroke and other adverse events.

Design

New users of long-acting anticholinergic therapy (tiotropium HandiHaler®) were compared with new users of long-acting β-agonist (LABA) monotherapy, and propensity scores were used to control confounding.

Setting

UK healthcare system general practitioner electronic medical record database.

Participants

10 840 patients newly prescribed tiotropium (n=4767) or LABA (n=6073), at least 40 years old, and not having asthma as their only respiratory illness.

Primary and secondary outcome measures

Incidence rates of total stroke, myocardial infarction, angina and other adverse events.

Results

Tiotropium was associated with increased rates of stroke (HR=1.49, 95% CI 0.91 to 2.45), angina (HR=1.38, 95% CI 0.88 to 2.16) and myocardial infarction (HR=1.26, 95% CI 0.72 to 2.21). Groups had similar rates of chronic obstructive pulmonary disease exacerbation (HR=0.95, 95% CI 0.80 to 1.12) and pneumonia (HR=0.96, 95% CI 0.58 to 1.58). Tiotropium was associated with a lower rate of total mortality (HR=0.70, 95% CI 0.56 to 0.89) and asthma exacerbations (HR=0.46, 95% CI 0.36 to 0.57) than users of LABA.

Conclusion

Small increased risks of serious ischaemic cardiovascular events have been reported with inhaled anticholinergic medication from randomised and nonrandomized studies of ipratropium, tiotropium HandiHaler® and tiotropium Respimat®. Additional research is needed to understand the full extent of cardiovascular effects of inhaled anticholinergic medications and the patients who may be most susceptible.
Keeping children safe at home: protocol for three matched case–control studies of modifiable risk factors for falls
Authors: Kendrick Denise , Maula Asiya , Stewart Jane , Clacy Rose , Coffey Frank , Cooper Nicola , Coupland Carol , Hayes Mike , McColl Elaine , Reading Richard , Sutton Alex , M L Towner Elizabeth , Craig Watson Michael ,   on behalf of the Keeping Children Safe Study Group
Published: May 2012

Background

Childhood falls result in considerable morbidity, mortality and health service use. Despite this, little evidence exists on protective factors or effective falls prevention interventions in young children.

Objectives

To estimate ORs for three types of medically attended fall injuries in young children in relation to safety equipment, safety behaviours and hazard reduction and explore differential effects by child and family factors and injury severity.

Design

Three multicentre case–control studies in UK hospitals with validation of parental reported exposures using home observations. Cases are aged 0–4 years with a medically attended fall injury occurring at home, matched on age and sex with community controls. Children attending hospital for other types of injury will serve as unmatched hospital controls. Matched analyses will use conditional logistic regression to adjust for potential confounding variables. Unmatched analyses will use unconditional logistic regression, adjusted for age, sex, deprivation and distance from hospital in addition to other confounders. Each study requires 496 cases and 1984 controls to detect an OR of 0.7, with 80% power, 5% significance level, a correlation between cases and controls of 0.1 and a range of exposure prevalences.

Main outcome measures

Falls on stairs, on one level and from furniture.

Discussion

As the largest in the field to date, these case control studies will adjust for potential confounders, validate measures of exposure and investigate modifiable risk factors for specific falls injury mechanisms. Findings should enhance the evidence base for falls prevention for young children.
Prasugrel is effective and safe for neurointerventional procedures
Authors: Stetler William R , Chaudhary Neeraj , Thompson Byron Gregory , Gemmete Joseph J , Maher Cormac O , Pandey Aditya S
Published: May 2012

Background

Clopidogrel bisulfate and aspirin are routinely administered as dual antiplatelet agents for many neurointerventional procedures, especially for intravascular stent placement. Many patients are non-responsive to clopidogrel, either secondary to drug interactions or from variations of cytochrome P450 enzymes. Prasugrel (brand name Effient, Eli Lilly and Company, Indianapolis, IN, USA) is a new antiplatelet agent that has been utilized extensively in patients undergoing cardiovascular procedures but its safety and efficacy during neurointerventional procedures have not been evaluated.

Objective

To examine whether prasugrel is a safe and effective alternative to clopidogrel for neurointerventional procedures, especially in those patients who are either non-responders or allergic to clopidogrel.

Methods

The medical records of all patients undergoing neurointerventional procedures at our institution who received prasugrel between January 2009 and July 2011 were retrospectively reviewed. A systematic chart review was performed and the following data were recorded: demographics, aneurysm location, endovascular techniques, peri- and post-procedural complications, hemorrhagic complications, clinical outcome and angiographic outcome.

Results

16 patients undergoing neurointerventional procedures received prasugrel over a 2 year interval. All patients who had follow-up studies of P2Y12 inhibition had immediate therapeutic response to prasugrel. There were no complications related to ischemic or intracranial hemorrhage.

Conclusion

Prasugrel is a viable alternative to clopidogrel for patients undergoing neurointerventional procedures who are non-responders to clopidogrel. Further study is needed to evaluate the safety, efficacy and cost-effectiveness of prasugrel compared with clopidogrel for patients undergoing neurointerventional procedures.
P126 Improving the management of antenatal women with positive syphilis serology within a genitourinary medicine service
Authors: Patel S , Aroney R , Bird M , Rice P , Hay P
Published: May 2012

Background

Congenital syphilis (STS) can be prevented through antenatal screening and treatment. The true incidence of congenital STS is unknown; ∼10 cases/yr have been reported to the HPA by GUM clinics (probably reflects 30%–50% of cases). An audit at our centre (∼5000 deliveries/yr) in 2004, highlighted suboptimal management of pregnant women with positive STS serology.

Methods

A pathway has subsequently been developed and we report our findings since June 2004. Antenatal screening results are reviewed by a multidisciplinary team (MDT: virology, GU, antenatal, paediatric) experienced in the management of syphilis. Our GU team manages all pregnant women with positive serology who undergo full evaluation (incl. an STI check), further tests or treatment as necessary and follow-up of the neonate.

Results

123 referrals (108 pregnant women with positive STS serology) were received by the GU department from June 2004 to December 2009. Of these referrals, 36% (44) had STS (1 primary, 1 secondary, 6 early latent, 36 late latent), 37% (46) were previously treated, and 27% (33) were biological false positives. Those with untreated STS—median age 30 (IQR 26–35); ethnicity: 45% (20) black African, 23% (10) black Caribbean, 18% (8) white other, 9% (4) Asian, 2% (1) black British, 2% (1) white British. All women attended the GU clinic for treatment and follow-up; with one exception who remained untreated (late latent STS) and was repatriated prior to delivery to Uganda in 2004. GU screens identified Chlamydia (3), TV (2), warts (2), herpes (1), BV (6), thrush (5) and hepatitis B (4) in those with untreated STS.

Discussion

Our innovative MDT approach where each positive antenatal STS result is managed by our GU team has resulted in prompt treatment of untreated cases, identification of untreated STIs, and no reported cases of congenital STS. Our effective robust pathway includes standardised communication with all relevant teams and we encourage its use nationally.
P136 Sexual health services have a key role in the diagnosis and initial assessment of hepatitis C
Authors: Donson H , Rogstad K E , Campbell L , Raza M , Cope A
Published: May 2012

Background

Hepatitis C is a major cause of liver disease, cirrhosis and liver cancer but is increasingly amenable to treatment. Sexual health services often have unique access to test patients within risk groups.

Aim

To assess the role of sexual health services in diagnosis and initial assessment of Hepatitis C (HCV).

Method

Patients diagnosed with HCV at a large inner city sexual health service from 1 July 2009 to 30 June 2011 were identified along with a control group of negative patients.

Results

4430 HCV tests were performed on 3395 patients. 53 (1.56%) were HCV antibody positive of which 26 (49%) were PCR positive with a detectable viral load. Where genotyping was performed the majority were 3A (50%), 1A (22%) or 1B (22%). The most common reasons for testing were intravenous drug use (64%), men who have sex with men (15%) and sexual intercourse with a known IVDU (9%). 27 patients were referred to HCV services of which only 18 (67%) attended. The main reasons documented for testing within the control group were related to the patient's country of origin (32%), country of origin of a sexual partner (24%) or for men who have sex with men (19%). 34 countries were given as potential sources of increased risk, however only nine patients or sexual partners of patients originated from the three countries of highest HCV prevalence.

Conclusion

Sexual health services provide a unique opportunity for HCV screening in those who may otherwise not be tested. Standardisation is required to clarify who constitutes high risk particularly related to country of origin of patient or sexual partner. Initial assessment of patients diagnosed with HCV in genitourinary medicine clinics may lead to more efficient and cost effective patient care.
P145 Audit of the use of microscopy in heterosexual male patients diagnosed with non-specific urethritis and chlamydial urethritis
Authors: Cucinella A , Priestley C J F
Published: May 2012

Background

In 2006 BASHH guidelines for STI testing stated that there is no need to do a urethral smear in asymptomatic men. However there are concerns that this could result in delayed treatment of Chlamydia, or failure to diagnose an STI (eg,Mycoplasma genitalium).

Aims

(1) To ascertain the female pathology associated with NGU. (2) To ascertain the number of women with significant pathology, (Chlamydia or PID) who attended only as a result of partner notification by a man with asymptomatic NGU. (3) To quantify the number of asymptomatic men who would have delayed treatment for chlamydia without immediate microscopy.

Methods

Note review of heterosexual males and their female contacts with NSU (100) and Chlamydia (50).

Results

74% of 100 men treated for NSU were asymptomatic. Of these, 38 attended as a contact of infection and would have been treated anyway without microscopy. Of the remaining 36, 3 female partners had uncomplicated chlamydia and 3 PID but had not sought help for pelvic pain prior to their attendance in GUM. Overall, 70% of partners of men with NSU had significant pathology: Diagnoses in female partners of men with NSU Non-specific PID 35 Chlamydial PID 4 Uncomplicated Chlamydia 6 Non-specific cervicitis 9 Epidemiological treatment 46 of 50 men treated for Chlamydia 42% were asymptomatic. 28 (56%) had evidence of urethritis and a further 11 (22%) without pus on microscopy had noticeable threads in their urine. 47 attended prior to or with their partner, and 15 (30%) were treated at their initial visit due to immediate microscopy. These patients would have had to have been recalled for treatment.

Conclusions

In our cohort, 70% of female partners of men with NSU had significant pathology. 6/36 (17%) might not have been treated had they not attended as a contact of NSU. Microscopy can result in earlier treatment of asymptomatic men with Chlamydia due to immediate diagnosis of NGU, and may still be of value in GUM clinics.
P155 Super accelerated course of hepatitis B Vaccine—10 years on, is it working?
Authors: Suchak T , Sankar K N
Published: May 2012

Background

In 2002 the super-accelerated hepatitis B vaccination schedule was introduced in GUM clinics. At that time an audit was undertaken in our department to evaluate completion of the vaccination schedule.

Aim

This study aims to see if and why things have changed 10 years on?

Methods

A computer search of those coded with P2 identified the first 100 patients who commenced hepatitis B vaccination from April 2011. Notes were analysed and data collected on indication for vaccination, number of vaccines administered and whether serological response to vaccine was measured. Results were then compared to the previous study done in 2002.

Results

In 2002, 116 patients commenced hepatitis B vaccination over a 12-month period; in 2011 there were 298. Five patients were excluded from the study as serological testing showed they were already immune or had active infection. The abstract P155 table 1 below shows the number of vaccines each person received. The proportion of MSM receiving three vaccines was 51.6%.

Abstract P155 Table 1

Comparison of number of Hepatitis B vaccines completed

200220111 vaccine only9.5%15.8%2 vaccines only18.1%24.2%3 vaccines72.4%60%Serological response measured33.6%29.4%

Discussion

The number of people being vaccinated against hepatitis B has increased significantly over 10 years in keeping with increased patient numbers. However the proportion of people completing three vaccines has significantly reduced, especially in MSM. This study has prompted us to look at the information and explanation given to patients before commencing an immunisation schedule. In addition, to improve compliance we will be encouraging each patient to make future appointments at initial visit. As automatic appointment SMS messages are sent out 24 h in advance, making appointments ensures a timely reminder of the due dose is sent. All patients should also receive written information about hepatitis B vaccination. With these measures in place we will hopefully improve patient uptake of all three hepatitis B vaccines. Future audit will see if we have been successful!