bluuebunny/crossref_metadata_2025 huggingface dataset:
How Multidimensional Is the Purchasing Job?
Authors: Jackson Ralph W.
Published: June 2017

This article examines the issue of how multidimensional the buying job actually is. The results of a study of firms in five industries is reported and discussed in light of the need for job enrichment. The findings indicate that the buying job is less diversified than might have been assumed—and that it is entirely possible that this may have a detrimental impact on overall buyer performance.
Scaling Evaluative Criteria and Supplier Performance Estimates in Weighted Point Prepurchase Decision Models
Authors: Thompson Kenneth N.
Published: June 2017

This article recommends the Thurstone Case V scaling technique as an extremely useful tool for scaling the importance weights associated with evaluative criteria and the probable performance of suppliers on these criteria. Thurstone scaling eliminates the need for traditional point estimates of these values when employing weighted point supplier evaluation models. Instead, decision makers simply rank order the relative importances of evaluative criteria and then rank order the projected performance of suppliers on these criteria. Thurstone scaling is then used to transform the rank ordered data into appropriate numeric scales for inclusion in the weighted point model. The appropriate use of Thurstone Case V scaling can greatly simplify the supplier rating process and instill in decision makers greater confidence that the results of weighted point evaluations reflect reality. The article demonstrates how Thurstone Case V scaling can be employed for supplier evaluation. Applications considerations and potential limitations for its use are also discussed.
Managing Inventories in a JIT Environment
Authors: Joshi Kailash , Campbell James F.
Published: June 2017

The advent of JIT systems requires a new approach to inventory management. This article identifies the characteristics of JIT purchasing environments and suggests an alternative formulation to the traditional EOQ model for managing inventories. The article proposes that at any point in time inventory costs can be minimized by fully utilizing the available delivery receiving capacity. A model is developed to determine the optimal delivery frequency for individual items in an organization that receives hundreds or thousands of different items. The model optimally allocates the delivery receiving capacity among individual items to minimize the total inventory costs. The optimal delivery frequency for each item depends on the total delivery receiving capacity and the square root of the annual consumption of the item. This model provides guidelines for JIT purchasing by materials managers and can easily be applied in practice.
International Purchasing Strategies of Multinational U.S. Firms
Authors: Min Hokey , Galle William P.
Published: June 2017

As the global marketplace continues its relentless growth, international purchasing strategy assumes greater significance for many firms. Nevertheless, relatively few studies have reported on the general practice of purchasing professionals in international purchasing situations. This study identifies and analyzes the distinctive, dynamic, and complex aspects of international purchasing strategies prevalent among the nation's typical multinational firms. The findings should assist purchasing professionals in understanding the key principles of international purchasing and in formulating effective international purchasing strategies for their firms.
Redefining the Purchasing Function: An Entrepreneurial Perspective
Authors: Morris Michael H. , Calantone Roger J.
Published: June 2017

Turbulence in the external environments of companies is producing a number of changes in the roles and responsibilities of the purchasing function. Capitalizing on the opportunities created under such conditions requires that purchasing be approached as a potential source of competitive advantage that adds value to the corporate operation. One perspective is that functions such as purchasing must become more entrepreneurial if they are to make significant strategic contributions in the future.

This article summarizes the results of a study directed at purchasing managers regarding the nature of entrepreneurship and its applicability within the purchasing function. The results suggest that managers are placing increasing importance on the need for entrepreneurship, and are able to identify specific activities within purchasing where entrepreneurship is most critical. Major obstacles in achieving an entrepreneurship focus are identified, and examples of entrepreneurial behavior within purchasing are provided.
Lease‐Buy Decision Analysis
Authors: Holmes B. J.
Published: June 2017

This article considers the application of discounting techniques to the decision faced by a firm in determining whether to lease or buy capital equipment. Integral to the analysis is the notion of the internal rate of return. The article concludes by considering the interpretation of the concept, demonstrating that it provides a measure of the opportunity cost associated with a purchase decision.
A Bayesian Approach to Managing Foreign Exchange in International Sourcing
Authors: Vickery Shawnee K. , Carter Joseph R. , D'Itri Michael
Published: June 2017

The cost of a firm's finished goods is affected by exchange rates whenever a firm purchases imported goods or goods that are in turn produced with imported materials. As American firms source abroad, changes in currency values can erode the profitability of established products and markets. This article describes a Bayesian approach to managing foreign exchange which combines the use of a forward rate forecast and an economic forecast in determining a viable strategy. The approach was specifically designed for firms whose principal international activity is foreign sourcing.
Material Cost Sensitivity: Some Consequences and Antecedents
Authors: Perdue Barbara C.
Published: June 2017

This article reports the results of a national survey of purchasing managers that focused on the emphasis buying firms place on reducing the cost of their purchased materials. The findings suggest that this factor has a significant influence on a buyer's approach to negotiations. The findings also suggest that several descriptive characteristics of the buying firm and its competitive environment are useful predictors of its propensity to attempt to reduce material costs.
JIT Implementation: A Growth Opportunity for Purchasing
Authors: Dion Paul A. , Banting Peter M. , Picard Sharon , Blenkhorn David L.
Published: June 2017

This article reports the results of an investigation of the changes in the role of the professional buyer that result from JIT implementation. The researchers interviewed two samples of buyers, totaling 60 respondents, either face‐to‐face or by telephone. From an operating point of view, the study found that higher product quality and supplier service levels as well as closer buyer‐supplier relationships developed. The role of the buyer was found to expand into other functions of the business, such as production and marketing, focusing less on specific transaction details and more on the maintenance of supplier relationships. Implications for practitioners, educators, and researchers are discussed.
Unknown Intracardiac Electrogram
Authors: PRYSTOWSKY ERIC N.
Published: June 2017

Watch a video presentation of this article.

For additional educational resources, please visit Medtronic Academy .
Tumstatin regulates the angiogenic and inflammatory potential of airway smooth muscle extracellular matrix
Authors: Harkness Louise Margaret , Weckmann Markus , Kopp Matthias , Becker Tim , Ashton Anthony Wayne , Burgess Janette Kay
Published: June 2017

The extracellular matrix (ECM) creates the microenvironment of the tissue; an altered ECM in the asthmatic airway may be central in airway inflammation and remodelling. Tumstatin is a collagen IV‐derived matrikine reduced in the asthmatic airway wall that reverses airway inflammation and remodelling in small and large animal models of asthma. This study hypothesized that the mechanisms underlying the broad asthma‐resolving effects of tumstatin were due to autocrine remodelling of the ECM. Neutrophils and endothelial cells were seeded on decellularized ECM of non‐asthmatic (NA) or asthmatic (A) airway smooth muscle (ASM) cells previously exposed to tumstatin in the presence or absence of a broad matrix metalloproteinase inhibitor, Marimastat. Gene expression in NA and A ASM induced by tumstatin was assessed using RT‐PCR arrays. The presence of tumstatin during ECM deposition affected neutrophil and endothelial cell properties on both NA and A ASM‐derived matrices and this was only partly due to MMP activity. Gene expression patterns in response to tumstatin in NA and A ASM cells were different. Tumstatin may foster an anti‐inflammatory and anti‐angiogenic microenvironment by modifying ASM‐derived ECM. Further work is required to examine whether restoring tumstatin levels in the asthmatic airway represents a potential novel therapeutic approach.
Oral fluoropyrimidine versus intravenous 5‐fluorouracil for the treatment of advanced gastric and colorectal cancer: Meta‐analysis
Authors: Zhang Linlin , Xing Xiaoli , Meng Fanlu , Wang Yan , Zhong Diansheng
Published: June 2017

Background and Aim

5‐Fluorouracil (5‐Fu) is one of the most commonly prescribed antineoplastic agents against gastric and colorectal cancers. Continuous infusion would be the optimal way of its administration, however, may usually cause thrombosis, infection, and prolonged hospital stay. Oral fluoropyrimidines would be an attractive alternative, but their efficiency and toxicities for the treatment of gastric and colorectal cancer are still obscure as compared with infusion 5‐Fu.

Methods

Literature retrieval, trials selection and assessment, data collection, and statistic analysis were performed according to the Cochrane Handbook. The outcome measures were tumor response rate, progression‐free survival, overall survival, and adverse effects.

Results

Twenty‐nine randomized controlled trials, comprising totally 15 154 patients, were included. Meta‐analysis showed similar overall outcome in terms of response rate (1.01; 95% confidence interval [CI], 0.92–1.12), progression‐free survival (hazard ratio 1.00; 95%CI, 0.94–1.06), and overall survival (hazard ratio 0.96; 95%CI, 0.92–1.01) between oral fluoropyrimidine‐based and intravenous 5‐Fu‐based regimens in gastric and colorectal cancer patients. The risk of grade 3/4 neutropenia, thrombocytopenia, and stomatitis was more prominent in intravenous 5‐Fu‐based regimens; while more frequent grade 3/4 hand‐foot syndrome, diarrhea, and anorexia were detected in oral fluoropyrimidine‐based regimens.

Conclusions

Oral‐fluoropyrimidines showed equivalent response and similar survival outcomes, but different toxicity profiles, as compared with intravenous 5‐Fu. Thus, it would be a more convenient and adjustable alternative in treatment of advanced gastric and colorectal cancer.
Physiological effects of anterior repositioning splint on temporomandibular joint disc displacement: a quantitative analysis
Authors: Chen H.‐M. , Liu M.‐Q. , Yap A. U‐J. , Fu K.‐Y.
Published: June 2017

Anterior repositioning splints (ARS) are used primarily for the management of temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). However, the exact physiological effects of ARS are still unclear. This study investigated the short and long‐term effects of ARS on disc and condyle angles/positions by metric analysis. Twenty‐two subjects diagnosed with ADDwR were recruited. Maxillary full‐coverage ARS were fabricated, and MRI of TMJs was obtained before splint treatment, immediate post‐insertion and 6 months after splint treatment. Disc–condyle relationship was determined by disc–condyle angle measurement. Disc and condyle positions were described as X‐Y coordinates with the summit of glenoid fossa as the origin of the coordinates. Thirty‐two TMJs were classified as ADDwR and 12 were normal. Upon ARS insertion, all TMJs with ADDwR got normal disc–condyle relationships. The condyles moved significantly forward and downward, while the discs moved significantly backward and upward. MRI at 6 months after treatment (without ARS insertion) indicated that only 40·6% (13/32) of the joints were maintained in the normal disc–condyle relationship. The majority of condyles returned to their pre‐treatment positions, while the discs generally moved anteriorly again. The use of ARS resulted in forward and downward condyle movement, and a concurrent backward movement of the disc resulting in ideal spatial disc–condyle relationship. The stability of this relationship, however, could not be maintained in the majority of TMJs upon ARS removal. Findings explain the good short‐term clinical outcomes with ARS and their relatively lower efficacy in the long term.
Squamous cell carcinoma antigen as a prognostic marker and its correlation with clinicopathological features in head and neck squamous cell carcinoma: Systematic review and meta‐analysis
Authors: Travassos Daphine Caxias , Fernandes Darcy , Massucato Elaine Maria Sgavioli , Navarro Cláudia Maria , Bufalino Andreia
Published: June 2017

Background

Several studies investigate the prognostic value of squamous cell carcinoma antigen (SCC‐Ag) in head and neck squamous cell carcinoma (HNSCC) patients, with contradicting findings. Considering this, the aim of this study was to evaluate the prognostic value of high SCC‐Ag levels and its association with clinicopathological features of HNSCC.

Material and Methods

PubMed, SCOPUS, and Cochrane Library were searched for relevant studies up to December 2015. English‐language publications assessing clinicopathological features of HNSCC and the prognostic significance of SCC‐Ag in this disease were included. A meta‐analysis was performed using Review Manager 5.3 and STATA version 14 software to clarify a possible association between SCC‐Ag and clinical outcomes.

Results

A total of 11 studies met inclusion criteria, comprising 1901 cases of HNSCC. The results of the meta‐analysis showed that there was significant correlation between high SCC‐Ag levels and males (odds ratio [OR]=2.99, 95% CI: 1.18‐7.57, P=.02 fixed‐effect), and advanced TNM stages (OR=3.18, 95% CI: 1.88‐5.38, P<.0001 random‐effect). The survival meta‐analysis showed a pooled hazard ratio for disease‐free survival (DFS) and overall survival (OS) of 1.01 (95% CI: 0.70‐1.31) and 0.86 (95% CI: 0.54‐1.17), respectively.

Conclusion

Our meta‐analysis suggests that elevated SCC‐Ag levels have a significant correlation with males and TNM stage, but may not be used as predictive marker for OS and DFS in HNSCC patients.
Plant elicitor peptides promote plant defences against nematodes in soybean
Authors: Lee Min Woo , Huffaker Alisa , Crippen Devany , Robbins Robert T. , Goggin Fiona L.
Published: June 2017

Plant elicitor peptides (Peps) are widely distributed among angiosperms, and have been shown to amplify immune responses in multiple plant families. Here, we characterize three Peps from soybean (Glycine max) and describe their effects on plant defences against two damaging agricultural pests, the root‐knot nematode (Meloidogyne incognita) and the soybean cyst nematode (Heterodera glycines). Seed treatments with exogenous GmPep1, GmPep2 or GmPep3 significantly reduced the reproduction of both nematodes. Pep treatment also protected plants from the inhibitory effects of root‐knot nematodes on above‐ground growth, and up‐regulated basal expression levels of nematode‐responsive defence genes. GmPep1 induced the expression of its propeptide precursor (GmPROPEP1), a nucleotide‐binding site leucine‐rich repeat protein (NBS‐LRR), a pectin methylesterase inhibitor (PMEI), Respiratory Burst Oxidase Protein D (RBOHD) and the accumulation of reactive oxygen species (ROS) in leaves. In addition, GmPep2 and GmPep3 seed treatments up‐regulated RBOHD expression and ROS accumulation in roots and leaves. These results suggest that GmPeps activate plant defences through systemic transcriptional reprogramming and ROS signalling, and that Pep seed treatments represent a potential strategy for nematode management.
Association between resistance to erythropoiesis‐stimulating agents and carnitine profile in patients on maintenance haemodialysis
Authors: Kamei Daigo , Tsuchiya Ken , Nitta Kosaku , Mineshima Michio , Akiba Takashi
Published: June 2017

Objective

Patients on dialysis are in a chronic carnitine‐deficient state. This condition may be associated with abnormalities in fatty acid and organic acid metabolism; however, the details are unknown. We investigated the association between carnitine profiles before and after dialysis and the erythropoiesis‐stimulating agent (ESA) resistance index (ERI), which is a significant prognostic factor in patients on maintenance haemodialysis.

Methods

This was a cross‐sectional study. We measured the carnitine profile of 79 patients on maintenance haemodialysis before and after dialysis using liquid chromatography–tandem mass spectrometry (LC–MS/MS). The associations between the ERI and pre‐dialysis carnitine profile, removal rate of various carnitines, and previously‐reported ERI‐related factors were investigated. Significant factors were determined with stepwise multiple regression analysis and validated with the bootstrap method. SPSS version 22.0 was used for analysis, and P < 0.05 was considered statistically significant.

Results

The removal rate of long‐chain acylcarnitine with dialysis was lower than that of short‐chain or medium‐chain acylcarnitines. Stepwise multiple regression analysis (n = 79) demonstrated that 3‐hydroxy isovalerylcarnitine (C5‐OH, P < 0.001, β = −0.469) and stearoylcarnitine (C18, P < 0.001, β = 0.390) were independent significant factors (R2 = 0.239) of ERI. The bootstrap method similarly indicated these two to be significant factors.

Conclusion

ERI positively correlated with long‐chain C18 acylcarnitine and negatively correlated with short‐chain C5‐OH acylcarnitine. C5‐OH and C18 acylcarnitines at baseline might be contributing factors in distinguishing responders from nonresponders after L‐carnitine administration.
Degenerative Politics and Youth Criminal Justice Policy in Canada
Authors: Heinmiller B. Timothy , Hennigar Matthew A. , Kopec Sandra
Published: June 2017

The purpose of this article is to determine whether degenerative politics, a central proposition of democratic policy design theory or social constructivism, has been evident in Canadian youth criminal justice policy. Using a synchronic and diachronic case study design, the article conducts a rigorous content analysis of the legislative debates leading to theYoung Offenders Actin 1982 and theYouth Criminal Justice Actin 2002. Policy makers’ social constructions of violent and nonviolent young offenders are measured, along with the benefit/burden content of the legislation, to determine whether young offenders have been caught in the downward spiral of degenerative politics. It finds evidence of degenerative politics for violent young offenders but not for nonviolent young offenders and explores some of the reasons for this divergence.

Related Articles

Dauda,Carol L.2010. “.”Politics & Policy38():1159‐1185.http://onlinelibrary.wiley.com/doi/10.1111/j.1747-1346.2012.00394.x/full

Dyck,Joshua J., andAnnikaHagley.2012. “.”Politics & Policy40():195‐220.http://onlinelibrary.wiley.com/doi/10.1111/j.1747-1346.2012.00346.x/full

Traut,Carol A., andCraig F.Emmert.2003. “.”Politics & Policy31():296‐312.http://onlinelibrary.wiley.com/doi/10.1111/j.1747-1346.2003.tb00150.x/full

Related Media

.2013. “Youth Criminal Justice in Action.”https://www.youtube.com/watch?v = KdZacGdgJrs

.2015. “Public Policy Theory and Democracy.”http://www.ippapublicpolicy.org/teaching-ressource/public-policy-theory-and-democracy/9
The Identity Construction of Nationally Mixed People: The Impact of Parental Transmission and Socialization Outside the Family
Authors: Unterreiner Anne
Published: June 2017

A nationally mixed person, defined as an individual whose parents were born in different countries, may have plural socialization and identify with different nations. Studying this population allows us thus to investigate the process of national identification. From ninety‐seven qualitative interviews of mixed people living in France, Germany, and the United Kingdom, we learn that parental transmission and socialization outside the family interact in the production of the national identification of mixed people. The intermingling of these dimensions leads the national identity of mixed people to turn towards four identity poles: a rooted identity, a mixed identity based on heritage, a foreigner identity, or an identity other than national. Analysing national self‐identification through identity poles has important theoretical implications. First, it shows that national belonging is characterized by fluidity and plurality throughout the entire life course of the respondents. Second, the definition of these different poles of identification highlights the determinants of national self‐identification.
Submicroscopic malaria infections in pregnant women from six departments in Haiti
Authors: Elbadry Maha A. , Tagliamonte Massimiliano S. , Raccurt Christian P. , Lemoine Jean F. , Existe Alexandre , Boncy Jacques , Weppelmann Thomas A. , Dame John B. , Okech Bernard A.
Published: June 2017

Objectives

To describe the epidemiology of malaria in pregnancy in Haiti.

Methods

Cross‐sectional study among pregnant women in six departments of Haiti. After obtaining informed consent, whole blood samples and demographic surveys were collected to investigate malaria prevalence, anaemia and socio‐behavioural risk factors for infection, respectively. A total of 311 pregnant women were screened for Plasmodium falciparum infection using a rapid diagnostic test (RDT), microscopy and a novel, quantitative reverse transcriptase polymerase chain reaction method (qRT‐PCR).

Results

Overall, 1.2% (4/311) of pregnant women were tested positive for malaria infection by both microscopy and RDT. However, using the qRT‐PCR, 16.4% (51/311) of pregnant women were positive. The prevalence of malaria infection varied with geographical locations ranging between 0% and 46.4%. Additionally, 53% of pregnant women had some form of anaemia; however, no significant association was found between anaemia and submicroscopic malaria infection. The socio‐behavioural risk factors identified to be protective of malaria infection were marital status (P < 0.05) and travel within one month prior to screening (P < 0.05).

Conclusion

This study is the first to document the high prevalence of submicroscopic malaria infections among pregnant women in Haiti and identify social and behavioural risk factors for disease transmission.
How sukuk shapes firm performance
Authors: Klein Paul‐Olivier , Weill Laurent , Godlewski Christophe J.
Published: June 2017

With the large expansion of Islamic finance in the recent years, sukuk, which are the Sharia‐compliant substitute to conventional bonds, are now becoming more prominent. The aim of this study was to examine the impact of sukuk issuance on firm performance. To do so, we analyse how stock market performance and operating performance (OP) are influenced by issuance of sukuk and bonds on a sample of Malaysian listed companies. We consider the short‐term and medium‐term stock market reaction through the computation of cumulative abnormal returns and buy‐and‐hold abnormal returns. We investigate the impact on OP by performing regressions and by calculating abnormal operating performance (AOP) so that we can compare how issuance affects similar firms. We find that sukuk issuance generates a negative stock market reaction both in the short term and in the medium term. We also find evidence that issuing sukuk hampers OP. The analysis of AOP shows that sukuk issuers have better performance than their matched bond issuers, but that sukuk contributes to reduce the gap in performance over time. Overall, our results support the view that sukuk issuance hampers stock market performance, but that it is not attributable to a signalling effect on the bad financial situation of the issuer. We interpret our findings as evidence of adverse selection taking place on the financed projects and agency problems stemming from the specific sukuk structuring with stock market investors more reluctant to invest in sukuk issuers.
Investigate echolocation with non-disabled individuals
Authors: Tonelli Alessia , Brayda Luca , Gori Monica
Published: June 2017

Vision is the most important sense on the domain of spatial perception. Congenital blind individuals, that cannot rely on vision, show impairments in performing complex spatial auditory tasks. The echolocation technique allows blind people to compensate the audio spatial deficit. Here, we present an overview of our works. First, we show that also sighted people can acquire spatial information through echolocation, i.e., localize an aperture or discriminate the depths of an object locate in front of them. Second, we identified some kinematic variables that can predict the echolocation performance. Third, we show that echolocation, not only helps to understand the external space, but can influence internal models of the body-space relation, such as the peripersonal space (PPS). We discuss all these aspects showing that human beings are sensitive to echoes. Spatial information can be acquired by echolocation when vision is not available also in people that normally would acquire the same information through it. We finally discuss our results in term of rehabilitation technique for visually impaired people.
Triton: Practical pre-computed sound propagation for games and virtual reality
Authors: Raghuvanshi Nikunj , Tennant John , Snyder John
Published: June 2017

Triton is a pre-computed wave-based acoustics system recently shipped in the game “Gears of War 4.” Games and VR present exciting new opportunities for virtual acoustics by providing the player with scene-dependent reverberation cues and conveying information about visually occluded areas. Several technical challenges must be met. Scenes containing millions of polygons are common, with mixed indoor-outdoor spaces like broken buildings, courtyards, caves, and rocks. A viable technique must handle this complex visual geometry without users' intervention. The emphasis is on ensuring the resulting auralization is perceptually convincing, varying smoothly on source and listener motion in such scenes. Highly occluded cases with salient paths undergoing multiple edge-diffraction and scattering are common. Computational requirements are quite stringent. A fraction of a single CPU core must be used for acoustic calculations for many tens of moving sources. We discuss how these challenges shape Triton’s design. Pre-computation is used to minimize runtime cost. Wave simulation provides complete automation for complex scene geometry. The produced fields contain billions of responses that take terabytes of memory. A key contribution is compact encoding of this data in less than hundred megabytes: objective room acoustic parameters are approached from a novel perspective to aid in spatial compression. The resulting parametric framework is fast and practical for current games and VR applications. Video demonstrations will be shown.
Graphical processing units (GPU)-accelerated acoustic simulation for interactive experiences
Authors: Scudiero Tony
Published: June 2017

The importance of incorporating acoustic effects to the quality of immersion in virtual reality experiences has been the subject of considerable attention recently due to a resurgence of interest in virtual reality. This work discusses advantages and challenges of using graphical processing units (GPU) in real-time ray-based acoustic simulations for interactive applications, especially virtual reality. Existing ray-tracing libraries such as NVIDIA’s OptiX library can be used to create interactive-time simulations which can be applied to audio for virtual reality experiences and games. This work additionally discusses some of the challenges present in creating an accessible library which aims to allow non-experts to easily make use of acoustic simulations to enhance auditory immersion in new virtual reality experiences and games.
Exploring ocean ecosystems and dynamics through sound
Authors: Miksis-Olds Jennifer L.
Published: June 2017

Acoustic signals propagate long distances in the ocean and provide a means for marine life and humans to gain information about the environment and for marine animals to exchange critical information. Innovation in underwater acoustic technology now permits the remote monitoring of marine life and the environment without the need to rely on human observers, the physical presence of an observation vessel, or adequate visibility and sampling conditions. Passive recordings of the underwater soundscape provide information to better understand the influence of environmental parameters on local acoustic processes, to assess habitat quality and health, and to better understand the risks of ocean noise on marine life. Active acoustic technology provides a high-resolution measure of biological and physical oceanographic processes through time series of backscatter measurements. The ability to obtain passive and active acoustic measurements contemporaneously, along with ancillary data to validate and enhance interpretations, is a powerful tool facilitating insight into ocean and ecosystem dynamics. Knowledge gained and questions raised from the integration of acoustic and oceanographic data in rapidly changing environments will be shared, along with a preview of the Atlantic Deepwater Ecosystem Observatory Network (ADEON) program being launched off the South Atlantic Outer Continental Shelf.
Optimal beamforming using higher order statistics for passive acoustic mapping
Authors: Lyka Erasmia , Coviello Christian , Coussios Constantin
Published: June 2017

Passive Acoustic Mapping (PAM) of sources of nonlinear acoustic emissions has been extensively investigated for monitoring ultrasound therapies. Optimal data-adaptive beamforming algorithms, such as Robust Capon Beamformer (RCB), were readily proposed as a means of improving source localization, accounting simultaneously for array configuration and calibration errors. RCB, however, assumes that signal samples follow a Gaussian distribution. Aiming at improving the spatial resolution of PAM, especially in the axial direction with respect to the array, we propose an alternative beamforming approach, Robust Beamforming by Linear Programming (RLPB). This method makes no assumptions on the statistical distribution of the received signals, and exploits not only the variance but also higher-order-statistics (HOS) of the received signals. Performance evaluation on simulated and in vitro experimental data suggests improvement in spatial resolution on the order of 20% and 15% in the axial and transverse directions respectively. This facilitates real-time mapping of disjoint cavitating regions over biologically relevant lengthscales on the order of 2 mm in the axial direction. It is expected that the proposed beamforming approach will provide the necessary improvement in PAM spatial resolution required in several clinically relevant situations, where a single array is used and the ratio of depth to aperture becomes large.
Ultrasound enhanced delivery of cisplatin loaded nanoparticles
Authors: Browning Richard J. , Bian Shuning , Reardon Philip J. , Parhizkar Maryam , Harker Anthony H. , Vassileva Vessela , Daly Dan , Pedley Barbara R. , Edirisinghe Mohan , Knowles Jonathan C. , Stride Eleanor P.
Published: June 2017

Cisplatin forms the basis for many chemotherapy regimens, however the maximum permissible dose is limited by its systemic toxicity. Nanoencapsulation of drugs has been shown to reduce off-target side effects and can potentially improve treatment burden on patients. However, uptake of nanoformulations at tumor sites is minimal without some form of active delivery. We have developed a submicron, polymeric nanoparticle based on biocompatible and degradable poly(lactic-co-glycolic acid) (PLGA) capable of encapsulating cisplatin and which can be bound to the surface of a phospholipid coated microbubble. The acoustic behavior and stability of the resulting nanoparticle loaded microbubbles will be compared with those of unloaded microbubbles. Results will also be presented on the extravasation of particles in a tissue mimicking phantom using a novel long working distance confocal microscope that enables particle distributions to be measured in situ and in real time.
Optimizing gold nanorod volume for minimum cell toxicity and maximum photoacoustic response
Authors: Knights Oscar B. , Cowell David , McLaughlan James R. , Freear Steven
Published: June 2017

Plasmonic nanoparticles show great potential for molecular-targeted photoacoustic (PA) imaging. To maximize light absorption, the gold nanorods (AuNRs) are illuminated at their surface plasmon resonance (SPR), which for biomedical application is typically in the “optical window” of 700-900 nm. For AuNRs, one of the main factors that determines the SPR is their aspect ratio. Since it is possible to have a similar aspect ratio, but different size of the particle the choice of particle could have a critical effect on a number of factors, such as photoacoustic emissions, cell toxicity, and therapeutic efficacy. For example, a particular sized AuNR may produce a higher PA response, for an equivalent laser fluence, but be more toxic to cell populations. In this study, the PA response of AuNRs with four different volumes but similar aspect ratios (~4) are compared. A linear relationship between incident laser fluence and PA amplitude is shown and results indicate that AuNRs with larger volumes produce stronger PA emissions. In-vitro cell studies were performed on a lung cancer cell line to assess the cell toxicity of the different sized AuNRs via a colorimetry assay.
Ultrasound-mediated blood-brain barrier disruption: Correlation with acoustic emissions
Authors: Aron Miles M. , Barnsley Lester , Shrivastava Shamit , Van der Helm Marinke , Segerink Loes , Stride Eleanor P.
Published: June 2017

Blood-brain barrier (BBB) disruption mediated by ultrasound and microbubbles (US-BBBD) is a promising strategy for non-invasive and targeted delivery of therapeutics to the brain. In US-BBBD, treatment control is achieved by externally monitoring acoustic emissions (AE) and adjusting ultrasound parameters in real-time to avoid AE associated with damage. Recent work suggests that AE may also provide insight regarding the extent of BBB opening and BBB recovery time. The mechanisms underlying BBB opening and recovery, however, are largely not understood. To investigate US-BBBD mechanisms with regard to AE, we developed an in vitro platform for monitoring both BBB integrity and AE during US-BBBD. Temporally resolved BBB integrity monitoring was achieved using a microfluidic BBB-on-a-chip device with integrated trans-endothelial electrical resistance (TEER) measurements. Well-characterized ultrasound exposure and AE monitoring were achieved using a focally aligned high-intensity focused ultrasound transducer and passive cavitation detector. In addition to recording TEER and AE data, our platform is compatible with fluorescence microscopy during ultrasound exposure, providing further insight into US-BBBD mechanisms. This work further demonstrates potential for in vitro screening of cavitation agents and/or therapeutics for novel US-BBBD applications and strategies.
Status and plans for NASA’s Quiet SuperSonic Technology (QueSST) aircraft design
Authors: Coen Peter , Richwine David
Published: June 2017

Innovation in Commercial Supersonic Technology is one of six thrusts that guide NASA’s Aeronautics Research Strategy. The near term objective of this activity is the establishment of a standard for acceptable overland supersonic flight, in cooperation with international standards organizations. In support of this objective, NASA supersonics research has had two focus areas in recent years. The first is the design of aircraft that can fly at supersonic speeds without creating a loud sonic boom, and the second is to understand the community response to the relatively quiet sound of the overflight of such aircraft. Based on the recent successes in this research, NASA has determined that the next steps in both these areas and in continued progress toward the near term objective is a flight demonstration. NASA, in cooperation with industry partners, has initiated the preliminary design of a Low Boom Flight Demonstration Aircraft, named QueSST for Quiet Supersonic Technology. This paper will describe the development of the design requirements for QueSST, and provide an overview of the design progress to date and future plans for the Flight Demonstration Project.
Exploring the phenomenon of ultrasonic atomization for viscous fluids
Authors: Friend James
Published: June 2017

We consider the choice of vibration modes and piezoelectric materials for acoustically driven atomization, an attractive method for a broad range of applications, particularly pulmonary drug delivery. Whether by the definition of a figure of merit, a product of the resonator quality factor and electromechanical coupling coefficient, its output vibration displacement at a given input power, or the fluid flow rate during atomization, we find that the combination of single-crystal 127.86-deg. Y-rotated lithium niobate and thickness-mode vibration produces an order of magnitude greater atomization flow rate and efficiency in comparison to classic lead zirconate-based devices and newer, Rayleigh wave or Rayleigh/Lamb spurious-mode based devices alike. For the first time, fluids with viscosities up to 48 cP are reported to be atomized, and we define an atomization Reynolds number ReA that can be used to both predict the atomization flow rate for ReA>40 and the inability to atomize a given fluid at a particular vibration amplitude when ReA<40.
Predicting droplet sizes and production rates in ultrasonic atomization as a strongly nonlinear phenomena
Authors: Friend James
Published: June 2017

Atomization of fluids using ultrasonic irradiation of a fluid interface is well-known, yet the underlying physics is surprisingly complex and rather poorly understood. We review classical and modern theories of capillary wave formation and droplet atomization, from Michael Faraday in 1831 onwards, and show how the atomization process occurs via induction of bulk turbulence that in turn engenders capillary wave production and turbulence. We show the clear separation of droplet generation rate from the frequency of the excitation ultrasound, and instead show the existence of a specific atomization frequency dependent upon the ratio of the fluid's surface tension to its viscosity.
Acoustic radiation force expansions in terms of partial-wave scattering phase shifts: Extended applications
Authors: Marston Philip L. , Zhang Likun
Published: June 2017

When evaluating radiation forces on spheres in sound fields, the interpretation of analytical results is greatly simplified by retaining the use of s-function notation for partial-wave coefficients imported into acoustics from quantum scattering theory. This facilitates easy interpretation of various scattering efficiency factors [L. Zhang and P. Marston, J. Acoust. Soc. Am. 140, EL178 (2016)]. This also facilitates the correction of certain plane-wave results [H. Olsen et al., J. Acoust. Soc. Am. 30, 633 (1958)] and the force parameterization for a broader class of wavefields. For situations in which dissipation is negligible, each partial-wave s-function becomes characterized by a single parameter: a phase shift. These partial-wave phase shifts are associated with scattering by plane traveling waves; the incident wavefields of interest (progressive and standing wavefields and beams) are separately parameterized. (When considering outcomes, the method of fabricating symmetric objects having a desirable set of phase shifts becomes a separate issue.) The existence of negative radiation force “islands” for beams reported in 2006 by Marston is manifested. Elementary standing and traveling wave force expressions are also recovered. This approach also manifests the utility of conservation theorems [P. Marston and L. Zhang, J. Acoust. Soc. Am. 139, 3139 (2016)]. [Work supported by ONR.]
Beyond acoustophoresis: Particle manipulation near oscillating interfaces
Authors: Hilgenfeldt Sascha , Rallabandi Bhargav , Agarwal Siddhansh , Raju David
Published: June 2017

Inertial effects in microfluidics afford an interesting set of tools for the control of particle positions. The gradients of steady channel flows, as well as the gradients of acoustic field amplitudes, have been used prominently to this purpose, the latter in acoustofluidics. Here, we investigate directly the effect of an oscillating interface on the fluid surrounding it and particles suspended in the fluid. The fast oscillatory motion gives rise to strong inertial effects, while the method allows for versatile force actuation because of the variety of flow fields, frequencies, and length scales under the experimentalist's control. We show in experiment and theory that oscillating bubbles simultaneously (i) guide particles close to the bubble interface by streaming flow, and (ii) exert strong lift forces that can be used to sort the particles by size or density. The lift forces and the ensuing particle displacement constitute an effect separate from streaming and can be understood analytically on the time scale of oscillation and that of averaged, steady motion; unlike classical acoustofluidics, it does not rely on density or compressibility contrasts. Comparison with experiments confirms that particle displacements scale more favorably and flexibly with the dimensions of particle and microfluidic set-up than in traditional inertial microfluidics. Size sorting with micrometer resolution can be accomplished within a millisecond, while the same device can exert controlled repulsive and attractive forces.
“Flat” vowel spectra revisited in vowel synthesis
Authors: Maurer Dieter , Suter Heidy
Published: June 2017

Some studies of natural and of synthesized vowel sounds indicate “flat” vowel-related spectral envelopes or envelope parts in terms of vowel-related frequency ranges with harmonics equal in amplitude. The present investigation addresses this question in a vowel synthesis experiment in which sounds related to series of harmonics, multiples of 200 Hz in frequency and equal in amplitude, were created. Thereby, for various frequency ranges, the number of harmonics was increased stepwise from a single lower harmonic to an increasingly broader harmonic series, and, inversely, it was also decreased from a broad series of harmonics to a single higher harmonic. The entire frequency range of investigation was 0.2-4 kHz. Vowel recognition was investigated by means of a listening test in which five phonetic expert listeners were asked to assign the synthesized sounds to Standard German vowel qualities. The results of the experiment reveal that synthesized sounds with frequency bands of series of two or more equal-amplitude harmonics allow for a perceptual differentiation of the Standard German vowels /i-y-e-ɛ-a-ɔ-o/. Methodological issues concerning future investigations as well as implications for the acoustics and perception of vowels are discussed.
Finite element simulation of diphthongs in three-dimensional realistic vocal tracts with flexible walls
Authors: Arnela Marc , Guasch Oriol
Published: June 2017

During the production of diphthongs, acoustic waves propagate along a time-varying three-dimensional (3D) vocal tract of complex geometry. The shape of the vocal tract walls does not only change because of the action of the articulators to produce a given sound, but also experience an elastic back reaction to the inner acoustic pressure. In this work the Finite Element Method (FEM) is used to simulate these phenomena. The mixed wave equation for the acoustic pressure and acoustic particle velocity expressed in an Arbitrary Lagrangian-Eulerian (ALE) frame of reference is solved to account for acoustic wave propagation in moving domains. The flexibility of walls is considered by solving a mass-damper-stiffness auxiliary equation for each boundary node. Dynamic vocal tract geometries are generated from the interpolation of static 3D vocal tract geometries of vowels, obtained from Magnetic Resonance Imaging (MRI). Some diphthong sounds are generated as examples
Soundscape of washroom equipment and its application
Authors: Tsaih Lucky S. , Tedja Yosua W.
Published: June 2017

The soundscape of the three washrooms at NTUST with equipment such as toilets, urinals, wash basins, showers, hand dryers, and tissue dispensers have been studied. The acoustical attributes of each type of washroom equipment have been measured, recorded and analyzed with LZFmax values for the 12.5 Hz to 20K Hz frequency bands. Despite the intermittent occurrence of equipment sounds, the overall maximum sound pressure level for the full frequency spectrum has been identified as 92 dB/ 83 dBA. It is aligned with a NC 74 curve. Such high transient sounds could disrupt sleeping in adjacent dormitory rooms and possibly reduce the quality of lecturing in adjacent classrooms. Light weight gypsum board and metal stud partitions, concrete masonry unit and concrete are the typical partitions used in washrooms of the residential, healthcare, hospitality, and schools. The transmission loss values of the partitions were calculated with Insul in the initial study. It was found that the majority of partitions studied have sufficient transmission loss values in the 100 Hz and above frequency bands, but the transmission loss will not be sufficient to reduce washroom equipment noise levels in the frequency bands between 50 Hz and 100 Hz.
Investigation of heavy-soft impact noise transmission in fitness facilities
Authors: LoVerde John , Dong David W. , Rawlings Samantha , Silva Richard
Published: June 2017

Fitness applications within a mixed-use building can disturb other occupants of the building and, as a result, require assessment and mitigation. There are not currently established standards for conducting repeatable measurement of noise or vibration from fitness activities. The focus of recent work in heavy impacts has been weights, as these are frequently used and typically expected to represent the worst-case scenario. However, fitness programs encompass a variety of activities that are dissimilar from heavy weight impacts, such as use of the human body as an impact source (running, jumping, and dropping) and use of soft and limp materials as an impact source (ropes, medicine balls). This paper presents measurement and application of the predictive methods developed for a heavy rigid impact source to a heavy soft impact source for comparison.
Mapping speech transmission index (STI) and background noise in university classrooms
Authors: Hulva Andrew , Ermann Michael , Rynes Jeffrey , Rehfuss Randall J. , Kanapesky Aaron , Reardon Alexander
Published: June 2017

Noise and intelligibility measurements were taken in dozens of classrooms at approximately every-meter resolution and are presented as heat maps. In doing so we hope to determine (1) the largest (and loudest) classrooms that do not require loudspeaker speech amplification and (2) the radius of muddled intelligibility circumscribed around noise sources such as air diffusers and fan coil units.