bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Prophylaxis Topical Antibiotics in Cardiac Device Implantation
Authors: KHALIGHI KOROUSH , AUNG THEIN TUN , ELMI FARHAD
Published: October 2013

Background

Combined systemic and topical antibiotic prophylaxes are used in cardiac electronic implantable device (CEID) procedures, but very few studies have assessed prophylactic use of topical antibiotics after CEID implantation.

Objective

To evaluate the efficacy of topical antibiotic prophylaxis in the prevention of surgical site infection after CEID implantation procedures.

Methods

This was a prospective randomized, placebo‐controlled, single‐center, single‐operator study. All patients (n = 1,008) received standard systemic antibiotic prophylaxis. Patients were randomized into four groups and received various topical prophylaxes after procedure. All patients were followed for at least 12 months. Surgical site inflammation and infection were graded based on degree of inflammation, discharge, wound culture, and blood culture.

Result

Fifty‐eight patients developed surgical site inflammation and infection. Fourteen patients had culture‐positive wound infections. Among them, 13 patients had superficial wound infections with Staphylococcus species. Only one had pocket infection with Pseudomonas bacteremia. The surgical site infection rate was higher in those with longer procedural time, associated with 2.3 times more likelihood of infection (P = 0.01). Patients with an associated malignancy were associated with 3.6 times more likelihood of infection (P < 0.01).

Conclusions

Careful skin preparation prior to incision is important, whereas the use of topical antibiotics after closure has not shown significant benefit. Patients with malignancy and longer procedural times are more likely to develop infection. There is a trend for less infection with cephalic approach. Systemic antibiotics with staphylococcal coverage are needed as most of the wound culture positive infections are caused by Staphylococcus species.
The Fate of Nontargeted Endocardial Leads during the Extraction of One or More Targeted Leads in Pediatrics and Congenital Heart Disease
Authors: McCANTA ANTHONY C. , TANEL RONN E. , GRALLA JANE , RUNCIMAN DAVID MARTIN , COLLINS KATHRYN K.
Published: October 2013

Introduction

Extraction of targeted endocardial leads can lead to inadvertent damage or dislodgement of nontargeted leads, though the frequency of this has not been reported in pediatrics and congenital heart disease (CHD).

Methods

This is a retrospective review of lead extraction procedures from 2002 to 2010 from two pediatric and CHD centers evaluating unplanned interventions on nontargeted leads during the extraction of one or more targeted leads.

Results

Nontargeted leads were present in the 22 lead extraction procedures performed on 20 patients with median age 15 years (interquartile range, 11.5–18.5 years): 11 (55%) with structurally normal hearts and nine (45%) with CHD. Twenty of 23 targeted leads (86%) were extracted with complete success. Of the 22 nontargeted leads, including 17 atrial leads and five ventricular leads, seven (32%) required further intervention including: five extracted due to damage, dislodgement, or change in device location; one abandoned due to damage; and one dislodged requiring a second procedure for repositioning. The remaining 15 nontargeted leads (68%) were unharmed. Nontargeted leads requiring further intervention had a shorter lead duration in situ (median 2 years, interquartile range 0.5–3.5 years) than unharmed nontargeted leads (median 6.6 years, interquartile range 4.1–9.1 years; P = 0.01). Age at extraction, CHD, implantable cardioverter defibrillator leads, atrial lead position, or primary extraction modality did not predict further intervention for nontargeted leads. Major complications occurred in one procedure (4.5%) with no deaths.

Conclusions

In pediatrics and CHD, nontargeted leads are frequently damaged or dislodged during the extraction of targeted leads. The risk of lead damage or dislodgement has implications for procedural planning and counseling for patients and families of pediatric and CHD patients requiring lead extraction.
Oldest known avian footprints from Australia: Eumeralla Formation (Albian), Dinosaur Cove, Victoria
Authors: Martin Anthony J. , Vickers‐Rich Patricia , Rich Thomas H. , Hall Michael
Published: October 2013

Two thin‐toed tridactyl tracks in a fluvial sandstone bed of the Eumeralla Formation (Albian) at Dinosaur Cove (Victoria, Australia) were likely made by avian trackmakers, making these the oldest known fossil bird tracks in Australia and the only Early Cretaceous ones from Gondwana. These tracks, which co‐occur on the same surface with a slightly larger nonavian theropod track, are distinguishable by their anisodactyl form, hallux impressions and wide digit II–IV divarication angles. A lengthy hallux impression and other deformational structures associated with one track indicate foot movement consistent with an abrupt stop, suggesting its tracemaker landed after either flight or a hop. The single nonavian theropod track is similar to other tracks described from the Eumeralla Formation at another locality. The avian footprints are larger than most Early Cretaceous avian tracks recorded worldwide, indicating sizeable enantiornithine or ornithurine species in formerly polar environments of Australia. The avian tracks further supplement scant body fossil evidence of Early Cretaceous birds in southern Australia, which includes a furcula from the Wonthaggi Formation. Because of this discovery, Dinosaur Cove, previously known for its vertebrate body fossils, is added to a growing list of Early Cretaceous vertebrate tracksites in southern Australia.
A wide range of cultivated legume species act as alternative hosts for the pea aschochyta blight fungus, Didymella pinodes
Authors: Le May C. , Guibert M. , Baranger A. , Tivoli B.
Published: October 2013

Ascochyta blight, caused by the polyphagous fungus Didymella pinodes, is one of the most economically damaging diseases of pea. Susceptibility/resistance of several legume species to several D. pinodes isolates from pea was assessed under controlled environmental conditions to test the hypothesis that D. pinodes was host‐specific. Forty‐three cultivars of five legume species (pea, common vetch, clover, alfalfa and faba bean) typically grown in temperate climates were screened with four pea‐infecting isolates from France, and one pea‐infecting isolate from Australia. Seven days after inoculation, disease incidence and necrosis were measured on foliar organs to estimate aggressiveness of the isolates. Cultivars of each legume species displayed differential resistance/susceptibility to each isolate as indicated by significant cultivar × isolate interactions in anova. Faba bean, common vetch, alfalfa and clover cultivars were consistently less susceptible than pea cultivars regardless of the inoculated isolate. The behaviour of D. pinodes isolates also indicated various patterns of disease development according to the legume species and the cultivars. Genetic distance between the five legume species was not correlated with overall differences in susceptibility, indicating that D. pinodes is not specialized to pea and shows a wide host range among legume species. Disease risk assessment in the pea crop should therefore consider the vicinity of cultivated and wild legume species that may serve as alternative hosts for D. pinodes.
Construction of a cassava PR protein‐interacting network during Xanthomonas axonopodis pv. manihotis infection
Authors: Román V. , Bossa‐Castro A. M. , Vásquez A. , Bernal V. , Schuster M. , Bernal N. , López C.
Published: October 2013

Pathogenesis‐related (PR) proteins are inducible antimicrobial defence proteins whose specific function in immunity or in other plant processes have not been deeply studied. Genes coding for PRs have been reported in different plant species with numerous homologous proteins belonging to the same functional protein family. Previously some PR candidate genes were identified in response to cassava bacterial blight (CBB) caused by Xanthomonas axonopodis pv. manihotis (Xam): the genes for hevamine (HEV), chitinase (CHI) and sulphite reductase (SiR) were induced in a resistant cassava cultivar during the response to Xam. To understand their functional roles in defence responses, a protein–protein interaction map was generated based on yeast two‐hybrid (Y2H) assays of these candidate PR proteins. The results showed that the cassava PRs interact with each other and, although hevamine and chitinase belong to the same class of chitinases, they share only four interactors. Co‐regulated expression of PRs and their interactors was observed and similar ontology terms were identified for interactors. Furthermore, an overlap between immune and other metabolic pathways was noticed based on other bioinformatics studies. These results therefore shed more light on the possible function of PR proteins.
Implementing Open Innovation in the Public Sector: The Case of Challenge.gov
Authors: Mergel Ines , Desouza Kevin C.
Published: October 2013

As part of the Open Government Initiative, the Barack Obama administration has called for new forms of collaboration with stakeholders to increase the innovativeness of public service delivery. Federal managers are employing a new policy instrument calledChallenge.govto implement open innovation concepts invented in the private sector to crowdsource solutions from previously untapped problem solvers and to leverage collective intelligence to tackle complex social and technical public management problems. The authors highlight the work conducted by the Office of Citizen Services and Innovative Technologies at the General Services Administration, the administrator of theChallenge.govplatform. Specifically, this Administrative Profile features the work of Tammi Marcoullier, program manager forChallenge.gov,and Karen Trebon, deputy program manager, and their role as change agents who mediate collaborative practices between policy makers and public agencies as they navigate the political and legal environments of their local agencies. The profile provides insights into the implementation process of crowdsourcing solutions for public management problems, as well as lessons learned for designing open innovation processes in the public sector.
Uncertainty Quantification in the Ensemble Kalman Filter
Authors: Sætrom Jon , Omre Henning
Published: October 2013

The ensemble Kalman filter (EnKF) provides an approximate, sequential Monte Carlo solution to the recursive data assimilation algorithm for hidden Markov chains. The challenging conditioning step is approximated by a linear updating, and the updating weights, termed Kalman weights, are inferred from the ensemble members. The EnKF scheme is known to provide unstable predictions and to underestimate the prediction intervals, and even sometimes to diverge. The underlying cause for these shortcomings is poorly understood. We find that the ensemble members couple in the conditioning procedure and that the coupling increase multiplicatively in the recursive conditioning steps. Under reasonable Gauss‐independence assumptions, exact expressions for this correlation are developed. Moreover, expressions for the precision of the predictions and the downward bias in the empirical variance introduced in one conditioning step are found. These results are confirmed by a Gauss‐linear simulation study. Furthermore, we quantitatively evaluate an alternative, improved EnKF scheme on the basis of transformations of ensemble members under the same Gauss‐independent assumptions. The scheme is compared with the frequently used ensemble inflation scheme.
Social Movements and Tactical Choice
Authors: Larson Jeff A.
Published: October 2013

For much of the past 40 years, the study of social movement tactics has viewed organizers' choices as driven by a desire to maximize efficacy and efficiency within a context of scarce resources and structural constraints. As sociologists increasingly turned toward culture, a new orientation emerged to view tactical choice as a process of gathering, interpreting, and evaluating information within dynamic, uncertain, and often‐contradictory contexts. The importance of the cultural turn has been amply demonstrated in studies of such things as identities, emotions, and collective action frames, but the full implications of its insights continue to be discovered. Four insights in particular warrant greater attention: many core concepts in the study of social movements have an interpretive, subjective, and contingent nature; tactics are a means of communication; social structures are imbued with culture, and culture is thoroughly structured; and social movements sometimes behave irrationally, and what appears to be irrational behavior often is in fact rational. I briefly discuss three areas of scholarship – collective identities, diffusion, and institutional fields – that demonstrate innovative ways that sociologists continue to combine and incorporate these insights and point the way toward a more sophisticated understanding of social movements and tactical choice.
Community Media Studies: An Overview
Authors: Howley Kevin
Published: October 2013

This essay provides an overview of the field of community media studies. Like the study of “alternative media,” “citizens' media,” “independent,” and “radical” media – to mention but a few of the terms applied to participatory communication projects – academic inquiry into the structures, forms, and practices of community media has surged in recent years. While scholars often use these labels interchangeably, this essay focuses on academic and practitioner perspectives that explicitly and purposefully employ the term “community media.” The overview identifies and briefly considers three prominent conceptual frameworks – media democratization, civil society, and the symbolic construction of community – which shape and inform this vibrant field of study. This overview concludes with some thoughts on the limits and possibilities of community media theory, and practice, in the new millennium.
Intolerance Toward Immigrants in Switzerland: Diminished Threat Through Social Contacts?
Authors: Freitag Markus , Rapp Carolin
Published: October 2013

Intolerance toward immigrants has recently reached noticeable highs in Switzerland. Referring to the conflict theory, the perception of a specific group as a threat tends to lead to intolerance toward that group. The expectation of a negative relationship between threat and tolerance is nevertheless not assumed to be universally valid for all members of society. In particular, the contact theory assumes that intercultural encounters should promote positive attitudes toward culturally different individuals and groups. Using a new and unique data set, our Heckman selection models reveal that Swiss who view rising immigration to mean a loss of economic privileges and an erosion of Swiss cultural values are less tolerant toward immigrants. Moreover, our results indicate that contact with immigrants may moderate this effect. However, not all group settings are able to reduce the perceived threats in a similar way, and not all sorts of social contact are able to foster tolerance toward immigrants.
Humanitarianism as liberal diagnostic: humanitarian reason and the political rationalities of the liberal will‐to‐care
Authors: Reid‐Henry S M
Published: October 2013

Images of catastrophe and the suffering of others form an important part of the contemporary western imagination. Such images trace the geography of an uneven world at the same time as they assert the moral and political horizons of liberal forms of care towards it. Drawing upon Foucault's notion of political rationality, I revisit the emergence of this distinctively liberal moral geography to show how a modern form of ‘humanitarian reason’ (Fassin 2011) developed in concert with the rise of capitalism and the liberal state. In particular, I explore the processes that, during the course of the long 19th century, invoked both a market‐driven moral economy and a state‐driven political morality within humanitarian endeavour. The final part of the paper then applies these reflections on humanitarianism's past to its much‐debated present. I move away from what is sometimes a rather binary focus on humanitarianism as a problem of Western intervention in other spaces to draw attention instead to its strategic function as a ‘liberal diagnostic’: a recursive moral practice that helps constitute a liberal politics as much as it projects that politics onto other people and places. I sketch out the implications of this by examining some of the ways that contemporary humanitarianism fulfils this role with respect to issues of global order and capital accumulation.
Gated/gating community: the settlement complex in the West Bank
Authors: Handel Ariel
Published: October 2013

The claim that the settlements in the West Bank are gated communities might seem trivial. Those settlements are an explicit example of a community featuring, on the one hand, social cohesion based on shared values, while, on the other hand, self‐isolation with the help of fences and a stress on the ‘security of the community’. The argument of this paper, however, is different. The paper suggests that the settlement layout in the West Bank is not just an aggregate of 124 ‘legal’ gated communities and a similar number of ‘illegal outposts’, but rather a single, contiguous gated community gating, in turn, Palestinian ‘islands’ within it. The reading I will offer seeks to look at the space in question through a careful reading of its use values. The emphasis is put on the question of mobilities in order to show how the fortressed points turn into an exclusionary web by means of separated roads and movement restrictions. By analysing the combined system of settlements, roads, military legislation, spatial design and applied violence, the paper shows how the few hundred points consolidate into one coherent spatial system. The paper wishes to contribute to the spatial analysis of the now 45‐year‐old Israeli occupation of the West Bank, to the growing study of politics of mobility and to the discourse of gated communities by adding colonialism and violence to the mostly neoliberal explanations of the phenomenon.
Evaluation of two chlorhexidine – alcohol‐based skin disinfectants in blood donation setting
Authors: So B. K. L. , Chu C. C. Y. , Ho P. L. , Chow K. H. , Leung J. N. S. , Lee I. Y. M. , Lin C. K. , Lee C. K.
Published: October 2013

Background

Source reduction is important in minimizing bacterial‐contaminated risk of blood products, but previous evaluation of chlorhexidine (CHX) was confounded by inability of Tween and lecithin to neutralize CHX. The study aims to address this limitation and also evaluates the effectiveness of two CHX–alcohol‐based skin disinfectants in blood donation setting.

Methods

A two‐stage observational study was conducted. A single step 2% chlorhexidine gluconate/70% isopropyl alcohol brush (CHX/IPA‐1) was first compared with current skin disinfection procedure consisting of sequential application of 10% povidone‐iodine and 70% isopropyl alcohol (PI/IPA). Standard plates with conventional neutralizers (0·3% Tween‐80, 0·1% lecithin) were used to enumerate residual bacterial counts. Then, CHX/IPA‐1 was compared with another applicator CHX/IPA‐2 with identical disinfectant contents using in‐house plates with neutralizers (3% Tween‐80, 0·3% lecithin, 0·1% histidine, 0·5% sodium thiosulphate, 3% saponin, 1% ether sulphate) having enhanced ability to neutralize CHX.

Results

All three products were found to reduce plate counts by > 2 log10 after disinfection. The CHX/IPA‐1 group gave fewer residual bacterial growth on standard plates than PI/IPA group (5·9% vs. 61·7%, P < 0·001). With the use of in‐house plates, residual bacterial growth was of no difference in both CHX/IPA‐1 and CHX/IPA‐2 groups (42·5% vs. 49·4%, P = 0·26).

Conclusion

Good efficacy was observed with one‐stage application of CHX/IPA in predonation skin disinfection and it could replace PI/IPA. However, the efficacy of CHX/IPA could be grossly overestimated in testing with standard plates because of insufficient neutralization.
Physiological roles of glucocorticoids during early embryonic development of the zebrafish (Danio rerio)
Authors: Wilson K. S. , Matrone G. , Livingstone D. E. W. , Al‐Dujaili E. A. S. , Mullins J. J. , Tucker C. S. , Hadoke P. W. F. , Kenyon C. J. , Denvir M. A.
Published: October 2013

Key points

Glucocorticoids are known to be present in the developing zebrafish embryo but little is known about their physiological role at this early stage.

The zebrafish embryo demonstrates a functional glucocorticoid system from around 48 h post fertilisation.

This system and the stress response is amenable to pharmacological and genetic manipulation in a manner predicted by mammalian physiology.

Glucocorticoids play a key developmental role in hatching, swimming and stress response.

The zebrafish embryo is a relevant model for the study of glucocorticoid physiology.

Abstract While glucocorticoids (GCs) are known to be present in the zebrafish embryo, little is known about their physiological roles at this stage. We hypothesised that GCs play key roles in stress response, hatching and swim activity during early development. To test this, whole embryo cortisol (WEC) and corticosteroid‐related genes were measured in embryos from 6 to 120 h post fertilisation (hpf) by enzyme linked immunosorbent assay (ELISA) and quantitative real‐time polymerase chain reaction (qRT‐PCR). Stress response was assessed by change in WEC following stirring, hypoxia or brief electrical impulses applied to the bathing water. The impact of pharmacological and molecular GC manipulation on the stress response, spontaneous hatching and swim activity at different stages of development was also assessed. WEC levels demonstrated a biphasic pattern during development with a decrease from 0 to 36 hpf followed by a progressive increase towards 120 hpf. This was accompanied by a significant and sustained increase in the expression of genes encodingcyp11b1(GC biosynthesis),hsd11b2(GC metabolism) andgr(GC receptor) from 48 to 120 hpf. Metyrapone (Met), an inhibitor of 11β‐hydroxylase (encoded bycyp11b1), andcyp11b1morpholino (Mo) knockdown significantly reduced basal and stress‐induced WEC levels at 72 and 120 hpf but not at 24 hpf. Spontaneous hatching and swim activity were significantly affected by manipulation of GC action from approximately 48 hpf onwards. We have identified a number of key roles of GCs in zebrafish embryos contributing to adaptive physiological responses under adverse conditions. The ability to alter GC action in the zebrafish embryo also highlights its potential value for GC research.
Heat Transfer Evaluation on Curved Boundaries in Thermal Lattice Boltzmann Equation Method
Authors: Li Like , Mei Renwei , Klausner James F.
Published: October 2013

An efficient and accurate approach for heat transfer evaluation on curved boundaries is proposed in the thermal lattice Boltzmann equation (TLBE) method. The boundary heat fluxes in the discrete velocity directions of the TLBE model are obtained using the given thermal boundary condition and the temperature distribution functions at the lattice nodes close to the boundary. Integration of the discrete boundary heat fluxes with effective surface areas gives the heat flow rate across the boundary. For lattice models with square or cubic structures and uniform lattice spacing the effective surface area is constant for each discrete heat flux, thus the heat flux integration becomes a summation of all the discrete heat fluxes with constant effective surface area. The proposed heat transfer evaluation scheme does not require a determination of the normal heat flux component or a surface area approximation on the boundary; thus, it is very efficient in curved-boundary simulations. Several numerical tests are conducted to validate the applicability and accuracy of the proposed heat transfer evaluation scheme, including: (i) two-dimensional (2D) steady-state thermal flow in a channel, (ii) one-dimensional (1D) transient heat conduction in an inclined semi-infinite solid, (iii) 2D transient heat conduction inside a circle, (iv) three-dimensional (3D) steady-state thermal flow in a circular pipe, and (v) 2D steady-state natural convection in a square enclosure with a circular cylinder at the center. Comparison between numerical results and analytical solutions in tests (i)–(iv) shows that the heat transfer is second-order accurate for straight boundaries perpendicular to one of the discrete lattice velocity vectors, and first-order accurate for curved boundaries due to the irregularly distributed lattice fractions intersected by the curved boundary. For test (v), the computed surface-averaged Nusselt numbers agree well with published results.
Blood Cell Adhesion on a Polymeric Heart Valve Leaflet Processed Using Magnetic Abrasive Finishing
Authors: Boggs Taylor , Carroll Robin , Tran-Son-Tay Roger , Yamaguchi Hitomi , Al-Mousily Faris , DeGroff Curt
Published: October 2013

Polymeric heart valves have the potential to improve hemodynamic function without the complications associated with bioprosthetic and mechanical heart valves, but they have exhibited issues that need to be addressed including calcification, hydrolysis, low durability, and the adhesion of blood cells on the valves. These issues are attributed to the valves' material properties and surface conditions in addition to the hemodynamics. To overcome these issues, a new stentless, single-component trileaflet polymeric heart valve with engineered leaflet surface texture was designed, and prototypes were fabricated from a simple polymeric tube. The single-component structure features a trileaflet polymeric valve and conduit that are made of a single tube component to eliminate complications possibly caused by the interaction of multiple materials and components. This paper focuses on the leaflet surface modification and the effects of leaflet surface texture on blood cell adhesion to the leaflet surface. Silicone rubber was chosen as the working material. A magnetic abrasive finishing (MAF) process was used to alter the inner surface of the tubular mold in contact with the silicone leaflets during the curing process. It was hypothesized that the maximum profile height Rz of the mold surface should be smaller than the minimum platelet size of 1 μm to prevent platelets (1–3 μm in diameter) from becoming lodged between the peaks. Cell adhesion studies using human whole blood flushed at low shear stresses over leaflet surfaces with six different textures showed that adhesion of the platelets and red blood cells is greatly influenced by both surface roughness and lay. Leaflets replicated from MAF-produced mold surfaces consisting of short asperities smaller than 1 μm reduced blood cell adhesion and aggregation. Cell adhesion studies also found that either mold or leaflet surface roughness can be used as a measure of cell adhesion.
Robust Reliability Based Optimal Design of H∞ Control of Parametric Uncertain Systems
Authors: Guo Shu-Xiang
Published: October 2013

An efficient nonprobabilistic robust reliability method for H∞ robust controller design of parametric uncertain systems is presented by describing the uncertain parameters as interval variables. Design optimization of H∞ robust controller is carried out by solving a robust reliability based optimization problem, by which the disturbance attenuation, control cost, and robust reliability can be taken into account simultaneously. By the method, a robust reliability measure of an uncertain control system satisfying required H∞ robust performance can be obtained, and the robustness bounds of uncertain parameters such that the control cost of the system is guaranteed can be provided. The presented formulations are in the framework of linear matrix inequality and thus can be carried out conveniently. The presented method provides an essential basis for reasonable tradeoff between reliability and control cost in controller design of uncertain systems. Active control design of vehicle suspension is employed for illustrating the effectiveness and feasibility of the presented method.
Novel magnetomechanical MR compatible vibrational device for producing kinesthetic illusion during fMRI
Authors: Carr Sarah J. , Borreggine Kristin , Heilman Jeremiah , Griswold Mark , Walter Benjamin L.
Published: October 2013

Purpose:

Functional MRI (fMRI) can provide insights into the functioning of the sensorimotor system, which is of particular interest in studying people with movement disorders or chronic pain conditions. This creates a demand for manipulanda that can fit and operate within the environment of a MRI scanner. Here, the authors present a magnetomechanical device that delivers a vibrotactile sensation to the skin with a force of approximately 9 N.

Methods:

MRI compatibility of the device was tested in a 3 T scanner using a phantom to simulate the head. Preliminary investigation into the effectiveness of the device at producing cortical and subcortical activity was also conducted with a group of seven healthy subjects. The vibration was applied to the right extensor carpi ulnaris tendon to induce a kinesthetic illusion of flexion and extension of the wrist.

Results:

The MRI compatibility tests showed the device did not produce image artifacts and the generated electromagnetic field did not disrupt the static magnetic field of the scanner or its operation. The subject group results showed activity in the contralateral putamen, premotor cortex, and dorsal lateral prefrontal cortex. Ipsilaterally, there was increased activity in the superior and inferior parietal lobules. Areas that activated bilaterally included the thalamus, anterior cingulate, secondary somatosensory areas (S2), temporal lobes, and visual association areas.

Conclusions:

This device offers an effective tool with precise control over the vibratory stimulus, delivering higher forces than some other types of devices (e.g., piezoelectric actuators). It can be useful for investigating sensory systems and sensorimotor integration.
Algorithmic scatter correction in dual‐energy digital mammography
Authors: Chen Xi , Nishikawa Robert M. , Chan Suk‐tak , Lau Beverly A. , Zhang Lei , Mou Xuanqin
Published: October 2013

Purpose:

Small calcifications are often the earliest and the main indicator of breast cancer. Dual‐energy digital mammography (DEDM) has been considered as a promising technique to improve the detectability of calcifications since it can be used to suppress the contrast between adipose and glandular tissues of the breast. X‐ray scatter leads to erroneous calculations of the DEDM image. Although the pinhole‐array interpolation method can estimate scattered radiations, it requires extra exposures to measure the scatter and apply the correction. The purpose of this work is to design an algorithmic method for scatter correction in DEDM without extra exposures.

Methods:

In this paper, a scatter correction method for DEDM was developed based on the knowledge that scattered radiation has small spatial variation and that the majority of pixels in a mammogram are noncalcification pixels. The scatter fraction was estimated in the DEDM calculation and the measured scatter fraction was used to remove scatter from the image. The scatter correction method was implemented on a commercial full‐field digital mammography system with breast tissue equivalent phantom and calcification phantom. The authors also implemented the pinhole‐array interpolation scatter correction method on the system. Phantom results for both methods are presented and discussed. The authors compared the background DE calcification signals and the contrast‐to‐noise ratio (CNR) of calcifications in the three DE calcification images: image without scatter correction, image with scatter correction using pinhole‐array interpolation method, and image with scatter correction using the authorsˈ algorithmic method.

Results:

The authorsˈ results show that the resultant background DE calcification signal can be reduced. The root‐mean‐square of background DE calcification signal of 1962μm with scatter‐uncorrected data was reduced to 194 μm after scatter correction using the authorsˈ algorithmic method. The range of background DE calcification signals using scatter‐uncorrected data was reduced by 58% with scatter‐corrected data by algorithmic method. With the scatter‐correction algorithm and denoising, the minimum visible calcification size can be reduced from 380 to 280 μm.

Conclusions:

When applying the proposed algorithmic scatter correction to images, the resultant background DE calcification signals can be reduced and the CNR of calcifications can be improved. This method has similar or even better performance than pinhole‐array interpolation method in scatter correction for DEDM; moreover, this method is convenient and requires no extra exposure to the patient. Although the proposed scatter correction method is effective, it is validated by a 5‐cm‐thick phantom with calcifications and homogeneous background. The method should be tested on structured backgrounds to more accurately gauge effectiveness.
Blending underwater acoustics and acoustical oceanography
Authors: Duda Timothy
Published: October 2013

Acoustical oceanography, which is the use of sound to probe ocean processes, had been in practice for many years before Hank Medwin spearheaded the creation of the ASA Acoustical Oceanography Technical Committee (AOTC). It has blossomed since that time, aided by interactions fostered by AOTC activities. The differences between acoustical oceanography and underwater acoustics are subtle and may not exist rigorously, particularly when propagation and scattering processes are exploited. However, the different foci of the two groups and the wealth of topics to be explored and researched each support the notion of two ASA groups devoted to ocean acoustics. In a similar fashion, AOTC interactions with many other committees foster progress. A review will be given of how underwater sound generation, propagation, and scattering knowledge, fundamental to UW, have been turned around to investigate the ocean, with a focus on work since the creation of the AOTC. Current trends in expeditionary oceanography and persistent monitoring will be covered, as well as the potential role of acoustics in future ocean observatory systems.
Effects of residential audible distractions on the performance and perception of home office workers.
Authors: Wagner Alicia J. , Wang Lily M.
Published: October 2013

This research examines the effects that typical residential audible distractions have on task performance and subjective perception of home office workers when transmitted across various residential wall constructions. Previous studies have investigated how speech, music, and office equipment noises may deteriorate one’s performance, but few have presented these distractions in such a way as to imitate the home office environment or used audible distractions that are characteristic of a residential setting. In this study, subjects performed math, verbal, and typing tasks over 1 h while exposed to four types of audible distractions: (1) pop music, (2) television, (3) conversation, and (4) a potpourri of kitchen, pet, and children’s noises. A short questionnaire was also administered to determine subjective perception under the different noise signals. Statistical analyses of the results indicate that none of the audible distractions caused a significantly different effect on task performance. The loudest distraction (music), however, was subjectively rated to be most distracting, while the signal with the most variation in time (potpourri) was considered to be the most annoying.
Assessing noise impacts on wildlife under the National Environmental Policy Act.
Authors: Wisdom Sheyna
Published: October 2013

Under the National Environmental Policy Act, authors must address environmental impacts of various anthropogenic actions on wildlife. One such impact of increasing awareness and concern is effect noise on wildlife, both during construction and operation of the project. However, biologists often have difficulty in understanding the fundamentals of acoustics and noise analysts often have difficulty in understanding the biological implications of increased noise on wildlife. As a result, inappropriate weighting metrics (such as A-weighted decibel) or time descriptors (e.g., community noise equivalent level) are often used erroneously to assess noise impacts on wildlife. Noise exposure thresholds on wildlife exist for marine mammals and fish, as mandated by the National Marine Fisheries Service. However, no such thresholds exist for terrestrial wildlife. This talk provides specific examples of how noise impacts on wildlife have been assessed using GIS-based technology, industry-accepted noise propagation models, and peer-reviewed literature in the absence of management guidelines. Examples include assessing construction noise impacts on the California coastal gnatcatcher in southern California, aircraft noise impacts on sage grouse in central California, and helicopter disturbance on caribou in Alaska.
Nonlinear acoustic phenomena in viscous thermally relaxing fluids: Shock bifurcation and the emergence of diffusive solitons.
Authors: Jordan Pedro
Published: October 2013

In this talk, we will consider the propagation of finite-amplitude acoustic waves in fluids that exhibit both viscosity and thermal relaxation. Under the assumption that the thermal flux vector is given by the Maxwell–Cattaneo law, which is a well known generalization of Fourier's law that includes the effects of thermal inertia, we derive the weakly nonlinear equation of motion in terms of the acoustic potential. We then use singular surface theory to determine how an input signal in the form of a shock wave evolves over time and for different values of the Mach number. Then, numerical methods are used to illustrate our analytical findings. In particular, it is shown that the shock amplitude exhibits a transcritical bifurcation; that a stable nonzero equilibrium solution is possible, and that a Taylor shock (i.e., a diffusive soliton), in the form of a “tanh” profile, can emerge from behind the input shock wave. Finally, an application related to the kinematic-wave theory of traffic flow is noted. [Work supported by ONR/NRL funding (PE 061153N)].
Human detection algorithm for seismic and ultrasonic detectors.
Authors: Ekimov Alexander E. , Sabatier James M.
Published: October 2013

Range detection methodologies for human acoustic signals are discussed. Seismic, passive, and active Doppler ultrasonic sensors are used in the presented methods. The algorithm developed for recognition of human’s presence in the measured signals is based on detection of the specific acoustic signatures resulting from specific human motion characteristics. These signatures have two characteristic times, T1 (the footstep repetition time, which is equal to the time of the whole body periodic motion) and T2 (the footstep duration time). The footstep duration time is equal to the time interval for a single footstep from “heel strike” to “toe slap and weight transfer.” Taking advantage of these times in signal processing for optimization of the signal-to-noise ratio and applying a procedure of cadence frequency detection allow recognition of human presence in the analyzed signals. This algorithm was tested and it was experimentally demonstrated that cadence frequencies for walking human and their harmonics for seismic and ultrasonic signatures (passive and active Doppler signatures) were the same. Cadence frequencies were stable and had no detectable variation in time for a regular walking style. This stability feature potentially may be used for human tracking. [Work supported by the Department of the Army, Army Research Office, Contract No. W911NF-04-1-0190.]
Active noise control for a short duct.
Authors: Kim Ho-Wuk , Lee Sang-Kwon
Published: October 2013

Finite impulse response (FIR) filter for an adaptive filter algorithm is mostly used for an active noise control system. However, an FIR filter needs to be larger in size of the filter length than of its infinite impulse response (IIR) filter. Therefore, the control system using the FIR adaptive filter has slow calculation time. In the active noise control system of the short duct, the reference signal can be affected by the output signal, so IIR filter for the ARMA system can be more suitable for the active noise control of the short duct than FIR filter for the MA system. In this paper, the recursive LMS filter, which is the adaptive IIR filter, is applied for the active noise control inside the short duct. For faster convergence and more accurate control, a variable step size algorithm is introduced for this recursive LMS filter (R-VSSLMS filter). Using this algorithm and considering the secondary path, the filtered-u R-VSSLMS is conducted successfully on the real experiment in the short duct. The performance of the active control using the filtered-u R-VSSLMS filter is compared with the performance of the active control using a filtered-x LMS filter.
The speech intelligibility index standard and its relationship to the articulation index, and the speech transmission index
Authors: Pavlovic Chaslav
Published: October 2013

The history of the Speech Intelligibility Index (SII) Standard (ANSI S3.5-1997) and its relationship to the Articulation Index (AI) and the Speech Transmission Index (STI) are reviewed. The SII Standard defines a method for computing a physical measure (SII) that is highly correlated with the intelligibility of speech. The SII is calculated from acoustical measurements of speech and noise. The standard is a revision of the ANSI S3.5-1969, ‘‘American National Standard Methods for the Calculation of the Articulation Index.’’ In that sense the AI and the SII are one and the same thing. In addition, however, SII incorporates the Speech Transmission Index procedures appropriate for many conditions of use where the traditional AI does not apply [H. J. M. Steeneken, and T. Houtgast, ‘‘A physical method for measuring speech-transmission quality.’’ J. Acoust. Soc. Am. 67, 318–326 (1980)]. Other changes of the Standard are due to new data which have been accumulated since 1969 for various parameters and procedures used in the calculations. These include spread of masking, standard speech spectrum level, and relative importance of various frequencies to speech intelligibility. In addition, the SII calculation details have been adapted to computer implementation rather than to manual chart-type computations.
Generalizing timbre space data across stimulus contexts: The meta-analytic approach
Authors: McAdams Stephen , Giordano Bruno L.
Published: October 2013

Studies of the multidimensionality of the complex auditory attribute called timbre often represent the perceptual structure in terms of a spatial model in which distance has a monotonic relation to perceived dissimilarity. Acoustical correlates are sought for the dimensions of these timbre spaces in order to quantify them psychophysically. An important question concerns the extent to which the results obtained with one stimulus set generalize to other stimulus sets. A meta-analytic study of data from several timbre spaces using musical tones was performed with the same multidimensional scaling algorithm. The effect of changing a subset of the sounds on the perceptual relations among common sounds was evaluated in conditions where the degree of variation along perceptual dimensions across sets was similar or different (new salient dimensions added). A change in the sounds present in the stimulus set, keeping salient dimensions constant, had little effect on perceptual structure of the common sounds in the two sets. Changing salient acoustical correlates present, while resulting in new dimensions, did not strongly affect the perceptual structure of the common sounds. Results demonstrate that, while a change in stimulus set may introduce new perceptual dimensions, the perceptual structure among sounds common to two sets remains similar.
Fine-tuning the acoustics of libraries at colleges and universities
Authors: Rosenbaum Joyce E. , Krumhansl Carol L. , Hove Michael J.
Published: October 2013

New technology and changing student work habits challenge academic libraries to accommodate different types of study by designing different rooms for distinct purposes. This requires not only a variety of technologies, room setups, and seating, but also acoustic conditions that stimulate efficient and comfortable productivity—whether with computers, textbooks, or interactive study groups. Acoustic recordings were taken in 13 different ‘‘favorite’’ rooms, with diverse characteristics and personalities, within the two main libraries at Cornell University. The acoustic measurements were compared with observations of student activity within these spaces to determine relationships between acoustic measurements and student behavior. Factor analysis revealed three types of student-activity categories: quiet concentration, relaxing and socializing, and computer use. The analysis also revealed three categories of room type: quiet study rooms, rooms with computer use, and cafés. These categories of activities and room types correlate with acoustic measurements, pointing to the existence of distinct niches within the library system. Examining the acoustic conditions conducive to certain activities may help future designers of academic libraries to optimize the acoustics of study spaces for different purposes.
Assessing saccular (otolith) function in man
Authors: Colebatch James G.
Published: October 2013

Scattered observations have suggest that the vestibular apparatus may have retained sound sensitivity in man and primates [e.g., Young et al., Acta Otolaryngol. 84, 352–360 (1977)]. In 1964 Bickford et al. [Ann. N.Y. Acad. Sci. 112, 204–218 (1964)] reported the properties of the ‘‘inion response,’’ evoked by clicks and which in subsequent publications they deduced was likely to be arising from the saccule. Colebatch et al. [Colebatch, et al. J. Neurol. Neurosurg. Psychiatry 57, 190–197 (1994)] reported a new method which reliably demonstrated a short latency vestibulocollic reflex evoked by clicks and recorded from sternocleidomastoid EMG. Consistent with previous evidence, the saccule was thought to be the most likely receptor to mediate the response, a conclusion for which there has been further experimental support. Bone-conducted acoustic stimulation can also evoke a similar reflex and, although saccular receptors are probably excited, this may not be the sole vestibular receptor activated under these conditions. The vestibular apparatus is relatively more sensitive to bone-conducted sound than to air-conducted sound, when compared to the cochlea. [Work supported by NH&MRC Australia.]
Acoustic backscatter from a diving dolphin
Authors: Au Whitlow W. L. , Houser Dorian S. , Dankiewicz Lois A.
Published: October 2013

The acoustic backscatter of a diving Atlantic bottlenose dolphin (Tursiops truncatus) was measured using Simrad EK-60 echosounders operating at 70, 120, and 200 kHz. The animal was trained to dive to a small platform suspended with a nylon rope from a small boat to various depths, with the maximum depth being 100 m. When the dolphin reached the platform, it was required to station on a bite plate attached to the platform until an acoustic signal was sent to release the animal. A video camera on the platform with the signal sent up on a separate line was used to monitor the animal on the bite plate. A time-depth recorder was also attached to the dolphin to determine the average rate of decent and ascent. Echosounding records were collected while the dolphin descended to and ascended from the platform. A total of 15 echosounding records with the dolphin swimming within the beam of the transducers were collected. Preliminary analysis of the data indicated that target strength varied from about −26 dB to −40 dB with a slight frequency dependency. The echoes from the dolphin were structured with the maximum echoes originating from the vicinity of the lungs.