bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic intestinal pseudo‐obstruction: Progress in management?
Authors: Di Nardo G. , Karunaratne T. B. , Frediani S. , De Giorgio R.
Published: November 2017

Chronic intestinal pseudo‐obstruction (CIPO) is a severe form of gastrointestinal dysmotility (often due to derangement of the innervation/smooth muscle/interstitial cells of Cajal) with recurrent episodes of intestinal subocclusion mimicking a mechanical obstruction. Because of its complexity and heterogeneity, CIPO is often misdiagnosed or remains unrecognized until advanced stages. Management is a critical aspect in CIPO patient care. So far, most prokinetic drugs have not proven efficacy in restoring intestinal propulsion, thus nutritional support, fluid/electrolyte replacement, and antibiotics are the mainstay of treatment. In this issue of the journal, Ohkubo et al showed promising data indicating that percutaneous endoscopic gastro‐jejunostomy (PEG‐J) can be proposed as a measure for intestinal decompression, thereby improving CIPO‐associated abdominal symptoms, including pain. In addition to a concise update of clinical and diagnostic features, the present minireview tackles management options, with a major emphasis on PEG‐J, for CIPO patients.
Identification of swallowing disorders in early and mid‐stage Parkinson's disease using pattern recognition of pharyngeal high‐resolution manometry data
Authors: Jones C. A. , Hoffman M. R. , Lin L. , Abdelhalim S. , Jiang J. J. , McCulloch T. M.
Published: November 2017

Background

Parkinson's disease (PD) can cause severe dysphagia, especially later in disease progression. Early identification of swallowing dysfunction may lead to earlier intervention. Pharyngeal high‐resolution manometry (HRM) provides complementary information to videofluoroscopy, with advantages of being quantitative and objective. Artificial neural network (ANN) classification can examine non‐linear relationships among multiple variables with relatively low bias. We evaluated if ANN techniques could differentiate between patients with PD and healthy controls.

Methods

Simultaneous videofluoroscopy and pharyngeal HRM were performed on 31 patients with early to mid‐stage PD and 31 age‐ and sex‐matched controls during thin‐liquid swallows of 2 cc, 10 cc and comfortable sip volume. We performed multilayer‐perceptron analyses on only videofluoroscopic data, only HRM data or a combination of the two. We also evaluated variability‐based parameters, representing variability in manometric parameters across multiple swallows. We hypothesized that patients with PD and controls would be classified with at least 80% accuracy, and that combined videofluoroscopic and HRM data would classify participants better than either alone.

Key Results

Classification rates were highest with all parameters considered. Maximum classification rate was 82.3 ± 5.2%, recorded for 2 cc swallows. Inclusion of variability‐based parameters improved classification rates. Classification rates using only manometric parameters were similar to those using all parameters, and rates were substantially lower for the comfortable sip volumes.

Conclusions & Inferences

Results from these classifications highlight the differences between swallowing function in patients with early and mid‐stage PD and healthy controls. Early identification of swallowing dysfunction is key to developing preventative swallowing treatments for those with PD.
The role of glucagon in weight loss‐mediated metabolic improvement: a systematic review and meta‐analysis
Authors: Silvestre M. P. , Goode J. P. , Vlaskovsky P. , McMahon C. , Tay A. , Poppitt S. D.
Published: November 2017

Aims

This meta‐analysis aimed to investigate the role of glucagon suppression in regulating glucose homeostasis following diet or bariatric surgery.

Methods

A comprehensive search of intervention and observational studies was conducted in Medline, Scopus, Web of Science, PubMed and Embase. Random effects model meta‐analysis was performed. Primary outcomes were (i) body weight change, (ii) fasting glucagon, (iii) fasting glucose and (iv) fasting insulin concentrations.

Results

Twenty articles reporting data from 29 interventions were eligible for analysis. Bariatric surgery caused greater weight loss than diet (bariatric −29.7 kg [CI:‐36.8, −22.6]; diet −5.8 kg [CI: −8.4, −3.3]; P < 0.00001), an effect that remained significant after adjusting for study duration (P < 0.05). Mean fasting glucagon decreased in parallel with weight loss (−11.8 ng/L [CI: −15.9, −7.8]; P < 0.00001) with no difference between bariatric and diet intervention. Both fasting glucose, and insulin decreased following weight loss (both P < 0.00001; glucose −1.7 mmol/L [CI: −2.0, −1.3]; insulin −50.6 pmol/L [CI: −66.5, −34.7] with greater decrease in fasting insulin between bariatric versus diet (P = 0.01).

Conclusions

Synergistic suppression of fasting glucagon and insulin resistance may act together to restore normoglycaemia following weight loss. Whether suppression of plasma glucagon may contribute to increased hunger after weight loss and gradual weight regain is not yet known.
Evaluation of patient satisfaction in pediatric dermatology
Authors: Ahmed Sarah , Miller Jonathan , Burrows James F , Bertha Ben Khallouq , Rosen Paul
Published: November 2017

Background/Objectives

There remains a lack of investigation into which factors patients and families value the most in their experience at pediatric dermatology clinics. Most of the current literature on quality improvement in dermatology does not encompass the pediatric population. To determine the drivers that are most predictive of a positive patient experience, we observed the indirect relationship between several factors of the patient experience and their role in patient satisfaction.

Methods

Patient satisfaction surveys were distributed after their visits to patients at four pediatric dermatology clinics in one children's academic health system. Data were collected and organized into the top 30 survey variables with which patients expressed satisfaction on a 5‐point Likert scale. Pearson product‐moment correlation coefficients (r) for each variable with regard to “likelihood of your recommending our practice to others” were calculated.

Results

A total of 516 families completed patient satisfaction surveys. Analyses of top box scores showed that the strongest predictors of patient satisfaction were the likelihood of recommending care provider (r = .77, P = <.001), cheerfulness of practice (r = .76, P = <.001), care provider spoke using clear language (r = .73, P = <.001), patient confidence in care provider (r = .70, P = <.001), and our sensitivity to patient needs (r = .70, P = <.001).

Conclusion

The patient‐physician relationship, along with the environment of the practice and its sensitivity to patients’ personal needs, contributes most to the patient experience in pediatric dermatology. Identifying such variables that shape patients’ assessments of their experience can guide future quality improvement plans in the specialty.
Treatment and biology of pediatric acute lymphoblastic leukemia
Authors: Kato Motohiro , Manabe Atsushi
Published: November 2017

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. In the past ALL was intractable but now the survival probability is as high as 80–90%. Improved supportive care, treatment stratification based on relapse risk, biological features of leukemic cells, and optimization of treatment regimens by nationwide and international collaboration have contributed to this dramatic improvement. While including traditional risk factors (e.g. age and leukocyte count at diagnosis), the treatment has been modified based on biological characteristics (aneuploidy and translocation) and treatment response (assessed by minimal residual disease). Treatment for pediatric ALL typically consists of induction therapy with steroids, vincristine, and asparaginase with or without anthracycline, followed by multi‐agent consolidation including high‐dose methotrexate and re‐induction therapy. After consolidation, less intensive maintenance therapy is required for 1–2 years to maintain event‐free survival. Recently, using advanced genomic analysis technology, novel sentinel genomic alterations that may provide more precise stratification or therapeutic targets, were identified. Moreover, in the last decade germline variations have been recognized as similarly important contributors to understanding the etiology and sensitivity of ALL to treatment. A more individualized approach based on genomic features (somatic and germline) and treatment response, the introduction of newly developed agents such as molecular targeted drugs or immunotherapy, and social support including long‐term follow up are required for further improvement.
The Facebook President: Oil, Citizenship, and the Social Mediation of Politics in Nigeria
Authors: Adunbi Omolade
Published: November 2017

On June 28, 2010, Nigerian President Jonathan announced that he had set up a Facebook page. Within a few days, his first post garnered 1,344 likes and more than 2,139 comments. This article examines how Nigerians use social media to interact with the state. It asks: How does social media facilitate conversations on what constitutes a national resource? How is social media creating citizens who are simultaneously anonymous and visible? It suggests that Facebook and other sites on which Jonathan established online presences were constructed as political spaces to interact with the youth of Nigeria, molding that constituency into loyal social media citizens ready to align with his aspirations. It also describes social media as sites on which the politics of claim‐making produce the social mediation of oil as a commonwealth in Nigeria. The use of the term “social media citizens” is anchored in the fluidity of citizenship. Jonathan's use of Facebook as both public and political spaces elevated the site to a national forum on a resource whose distribution must benefit all Nigerians: oil. The article suggests further that social media can serve as a site on which social media citizens can critique how the state manages and distributes oil.
The Persistence of Prosocial Work Effort as a Function of Mission Match
Authors: Resh William G. , Marvel John D. , Wen Bo
Published: November 2017

The authors use an online experiment to test the proposal that “mission match” leads to persistent prosocial work effort, whereby employees go above and beyond remunerated job responsibilities to deliver a public good. First, the importance of mission match to persistent prosocial work effort in public and nonprofit organizations is discussed. Then a real‐effort experiment is used to test whether mission match is associated with the persistence of individual work effort under conditions of unreasonable performance expectations. Findings show that subjects’ narrow identification with the mission of the particular organization on whose behalf they are working is a more important determinant of persistence than the extent to which one reports self‐sacrifice as a motivation toward service. Moreover, reported self‐sacrifice does not appear to reinforce the relationship between mission match and persistent prosocial work behavior.
Polo‐like kinase 1 inhibition results in misaligned chromosomes and aberrant spindles in porcine oocytes during the first meiotic division
Authors: Liao Y , Lin D , Cui P , Abbasi B , Chen C , Zhang Z , Zhang Y , Dong Y , Rui R , Ju S
Published: November 2017

Contents

Polo‐like kinase 1 (Plk1), a type of serine/threonine protein kinase, has been implicated in various functions in the regulation of mitotic processes. However, these kinase's roles in meiotic division are not fully understood, particularly in the meiotic maturation of porcine oocytes. In this study, the expression and spatiotemporal localization of Plk1 were initially assessed in the meiotic process of pig oocytes by utilizing Western blotting with immunofluorescent staining combined with confocal microscopy imaging technique. The results showed that Plk1 was expressed and exhibited a dynamic subcellular localization throughout the meiotic process. After germinal vesicle breakdown (GVBD), Plk1 was detected prominently around the condensed chromosomes and subsequently exhibited a similar subcellular localization to α‐tubulin throughout subsequent meiotic phases, with particular enrichment being observed near spindle poles at MI and MII. Inhibition of Plk1 via a highly selective inhibitor, GSK461364, led to the failure of first polar body extrusion in porcine oocytes, with the majority of the treated oocytes being arrested in GVBD. Further subcellular structure examination results indicated that Plk1 inhibition caused the great majority of oocytes with spindle abnormalities and chromosome misalignment during the first meiotic division. The results of this study illustrate that Plk1 is critical for the first meiotic division in porcine oocytes through its influence on spindle organization and chromosome alignment, which further affects the ensuing meiotic cell cycle progression.
Region‐dependent hamstrings activity in Nordic hamstring exercise and stiff‐leg deadlift defined with high‐density electromyography
Authors: Hegyi A. , Péter A. , Finni T. , Cronin N. J.
Published: November 2017

Recent studies suggest region‐specific metabolic activity in hamstring muscles during injury prevention exercises, but the neural representation of this phenomenon is unknown. The aim of this study was to examine whether regional differences are evident in the activity of biceps femoris long head (BFlh) and semitendinosus (ST) muscles during two common injury prevention exercises. Twelve male participants without a history of hamstring injury performed the Nordic hamstring exercise (NHE) and stiff‐leg deadlift (SDL) while BFlh and ST activities were recorded with high‐density electromyography (HD‐EMG). Normalized activity was calculated from the distal, middle, and proximal regions in the eccentric phase of each exercise. In NHE, ST overall activity was substantially higher than in BFlh (d = 1.06 ± 0.45), compared to trivial differences between muscles in SDL (d = 0.19 ± 0.34). Regional differences were found in NHE for both muscles, with different proximal‐distal patterns: The distal region showed the lowest activity level in ST (regional differences, d range = 0.55‐1.41) but the highest activity level in BFlh (regional differences, d range = 0.38‐1.25). In SDL, regional differences were smaller in both muscles (d range = 0.29‐0.67 and 0.16‐0.63 in ST and BFlh, respectively) than in NHE. The use of HD‐EMG in hamstrings revealed heterogeneous hamstrings activity during typical injury prevention exercises. High‐density EMG might be useful in future studies to provide a comprehensive overview of hamstring muscle activity in other exercises and high‐injury risk tasks.
Resident versus faculty member simulation debriefing
Authors: Adams Traci , Newton Chad , Patel Hetal , Sulistio Melanie , Tomlinson Andrew , Lee Won
Published: November 2017

Background

Near‐peer teaching is effective in graduate medical education, but it has not been compared with faculty member teaching in resident simulation. In this study, we sought to compare debriefing sessions of internal medicine (IM) intern simulation sessions led by academic faculty doctors with those led by senior IM residents in order to measure the effectiveness of near‐peer teaching in this setting.

Near‐peer teaching is effective in graduate medical education, but has not been compared with faculty member teaching in resident simulation

Method

Internal medicine interns participated in four simulation cases, two of which were debriefed by faculty members and two of which were debriefed by residents. Pre‐simulation knowledge assessment was completed prior to the case. Following each debriefing, interns completed a Debriefing Assessment for Simulation in Healthcare (DASH) survey. Post‐simulation knowledge assessments were completed 6 months after simulation. Debriefings were recorded and transcribed. Each statement made during debriefing was classified as either correct or erroneous by blinded reviewers.

Results

Fifty interns participated in simulation, and the response rate on the DASH survey was 88%. There was no difference between DASH scores (p = 0.13), post‐simulation knowledge assessments or error rates during debriefing (p = 0.31) for faculty member and resident instructors.

Conclusion

Our study suggests that residents and faculty members provide a similar quality of simulation instruction based on qualitative and quantitative evaluation.
What can strike‐slip fault spacing tell us about the plate boundary of western North America?
Authors: Zuza Andrew V. , Carlson Chad W.
Published: November 2017

The spacing of parallel continental strike‐slip faults can constrain the mechanical properties of the faults and fault‐bounded crust. In the western US, evenly spaced strike‐slip fault domains are observed in the San Andreas (SA) and Walker Lane (WL) fault systems. Comparison of fault spacing (S) vs. seismogenic zone thickness (L) relationships of the SA and WL systems indicates that the SA has a higher S/L ratio (~8 vs. 1, respectively). If a stress‐shadow mechanism guides parallel fault formation, the S/L ratio should be controlled by fault strength, crustal strength, and/or regional stress. This suggests that the SA‐related strike‐slip faults are relatively weaker, with lower fault friction: 0.13–0.19 for the SA vs. 0.20 for WL. The observed mechanical differences between the San Andreas and Walker Lane fault systems may be attributed to variations in the local geology of the fault‐hosting crust and/or the regional boundary conditions (e.g. geothermal gradient or strain rate).
Sustained cardiac programming by short‐term juvenile exercise training in male rats
Authors: Asif Y. , Wlodek M. E. , Black M. J. , Russell A. P. , Soeding P. F. , Wadley G. D.
Published: November 2017

Key points

Cardiac hypertrophy following endurance‐training is thought to be due to hypertrophy of existing cardiomyocytes.

The benefits of endurance exercise on cardiac hypertrophy are generally thought to be short‐lived and regress to sedentary levels within a few weeks of stopping endurance training.

We have now established that cardiomyocyte hyperplasia also plays a considerable role in cardiac growth in response to just 4 weeks of endurance exercise in juvenile (5–9 weeks of age) rats.

The effect of endurance exercise on cardiomyocyte hyperplasia diminishes with age and is lost by adulthood.

We have also established that the effect of juvenile exercise on heart mass is sustained into adulthood.

The aim of this study was to investigate if endurance training during juvenile life ‘reprogrammes’ the heart and leads to sustained improvements in the structure, function, and morphology of the adult heart. Male Wistar Kyoto rats were exercise trained 5 days week−1 for 4 weeks in either juvenile (5–9 weeks of age), adolescent (11–15 weeks of age) or adult life (20–24 weeks of age). Juvenile exercise training, when compared to 24‐week‐old sedentary rats, led to sustained increases in left ventricle (LV) mass (+18%; P < 0.05), wall thickness (+11%; P < 0.05), the longitudinal area of binucleated cardiomyocytes (P < 0.05), cardiomyocyte number (+36%; P < 0.05), and doubled the proportion of mononucleated cardiomyocytes (P < 0.05), with a less pronounced effect of exercise during adolescent life. Adult exercise training also increased LV mass (+11%; P < 0.05), wall thickness (+6%; P < 0.05) and the longitudinal area of binucleated cardiomyocytes (P < 0.05), despite no change in cardiomyocyte number or the proportion of mono‐ and binucleated cardiomyocytes. Resting cardiac function, LV chamber dimensions and fibrosis levels were not altered by juvenile or adult exercise training. At 9 weeks of age, juvenile exercise significantly reduced the expression of microRNA‐208b, which is a known regulator of cardiac growth, but this was not sustained to 24 weeks of age. In conclusion, juvenile exercise leads to physiological cardiac hypertrophy that is sustained into adulthood long after exercise training has ceased. Furthermore, this cardiac reprogramming is largely due to a 36% increase in cardiomyocyte number, which results in an additional 20 million cardiomyocytes in adulthood.
An Object-Oriented Modeling Approach to Virtual Prototyping of Marine Operation Systems Based on Functional Mock-Up Interface Co-Simulation
Authors: Chu Yingguang , Hatledal Lars Ivar , Æsøy Vilmar , Ehlers Sören , Zhang Houxiang
Published: November 2017

This paper presents an object-oriented modeling (OOM) approach to model development of marine operation systems, specifically the hydraulic systems of marine cranes. Benefited from the rapid development of computation technology, many modeling and simulation techniques and software tools have proved to be very useful during the product and system development process. However, due to the increasing complexity of the physical systems, many challenges still exist regarding model flexibility, model integration, simulation accuracy, stability, and efficiency. The goal of introducing OOM to complex dynamic systems is to provide flexible, effective, and efficient models for different simulation applications. Previous work presented a virtual prototyping (VP) framework based on the functional mock-up interface (FMI) standard. The advantage of using FMI co-simulation is that modeling and simulation of stiff and strongly coupled systems can be distributed. As a result, the modeling tradeoffs between simulation accuracy and efficiency can be evaluated. The essential features of OOM and its application within dynamic operation system domain are highlighted through a case study. These features include model causality, model encapsulation, and inheritance that facilitate the decomposition and coupling of complex system models for co-simulation. The simulation results based on the proposed VP framework showed speedups in the computation efficiency at the cost of moderate accuracy loss.
Adaptive cubature Kalman filtering for distant speech tracking using a circular microphone array
Authors: Pan Xiang , Bao Yue , Zhu Yiting , Cheng Zefeng , Yang T. C.
Published: November 2017

A joint processing framework for distant speech tracking is proposed based on combination of an adaptive cubature Kalman Filter with a 80-element circular microphone array. The deconvolved convention beamforming (DCB) [T. C. Yang, 10.1109/JOE.2017.2680818] is carried out over the distant speech data for speech enhancement and bearing estimate. DCB provides superdirective beams and offers the same robustness as conventional beamforming. With the estimated speech bearing, a “current” statistical (CS) motion model is combined with a cubature Kalman filter to track the speech of interest. The CS model assumes a modified Rayleigh distribution for the acceleration probability density (of the moving source) whose mean value is the current acceleration. Based on this model, we utilize a zoom factor achieved by computing the norm of the tracking innovation to adjust the dynamic state model adaptively. Both numerical simulation and the outdoor experimental results show that the proposed framework in this paper can effectively track a maneuvering speech source.
Improving the evaluation of soundscape variability via blind source separation
Authors: Lin Tzu-Hao , Akamatsu Tomonari , Tuanmu Mao-Ning , Huang Chun-Chia , Yao Chiou-Ju , Fang Shih-Hua , Tsao Yu
Published: November 2017

Evaluation of soundscape variability is essential for acoustic-based biodiversity monitoring. To study biodiversity change, many researchers tried to quantify the complexity of biological sound. However, the analysis of biological sound remains difficult because the soundscape is made up of multiple sound sources. To facilitate the acoustic analysis, we have applied non-negative matrix factorization (NMF) to separate different sound sources in an unsupervised manner. NMF is a self-learning algorithm which factorizes a non-negative matrix as a basis matrix and an encoding matrix. Based on the periodicity information learned from the encoding matrix, biological chorus and the other noise sources can be efficiently separated. Besides, vocalizations of different species can also be separated by using the encoding information learned from multiple layers of NMF and convolutive NMF. In this presentation, we will demonstrate the application of NMF-based blind source separation in the analysis of long-duration field recordings. Our preliminary results suggest that NMF-based blind source separation can effectively recognize biological and non-biological sounds without any learning database. It can also accurately separate different vocalizing animals and improve acoustic-based biodiversity monitoring in a noisy environment.
Before there was a National Center for Physical Acoustics: Memories of the first employee
Authors: Gilbert Kenneth E.
Published: November 2017

New laboratories, like newborn babies, usually come into the world along with a mix of excitement, joy, anxiety, and pain. Most of these feelings were present in the Ole Miss physics department when I arrived on the campus in August of 1985. Over the next few years, I watched what started as an attempt to obtain a metal building for acoustics research, evolve into what is today the National Center for Physical Acoustics (NCPA). In this presentation, I will tell some stories about the birth and early days of the NCPA as seen by a newly arrived outsider. Some of the stories are funny and others are not. I hope to convey what it was like to know something important was happening even though no one, especially me, seemed to know exactly where things were headed.
Student-centered acoustical engineering education at the University of Hartford
Authors: Celmer Robert
Published: November 2017

The University of Hartford has provided the author with a fulfilling métier, shepherding two undergraduate engineering programs in the area of acoustics: (1) the Bachelor of Science in Mechanical Engineering (BSME) with Acoustics Concentration and (2) the Bachelor of Science in Engineering with a major in Acoustical Engineering & Music. The first is part of our BSME degree program that has required courses in Vibration as well as Engineering Acoustics since the 1960's. The Acoustical Engineering & Music degree is a unique program instituted in 1976, where applicants must meet engineering’s math and science entrance requirements as well as pass the audition requirements of our music conservatory (The Hartt School). Both ABET-accredited programs encompass the same engineering vibrations and acoustics courses, as well as the same acoustics projects sequence, beginning in the sophomore year. Alumni of both undergraduate programs have successfully obtained positions in consulting (architectural and environmental), audio product and A/V design, musical instrument design, hearing- and psychoacoustic-related design, noise/vibration control of machines, as well as graduate degrees. The use of real world industry-sponsored acoustic projects for engineering design courses throughout the curriculum will be described, as well as the programs’ Service Learning components and High Impact Practices.
On identifying the accidental sudden acceleration of an SUV vehicle by engine sound
Authors: Bae Jihye , Bae Myungjin
Published: November 2017

A major accident occurred when an SUV vehicle of the company A that recently ran the road was flooded with roadside trees on the road. It was suspected of a sudden accident, but Company A judged the driver immature because the driver did not step on the brake paddle at that moment. The situation before and after the accident was recorded in the black box video, but the engine sound was not heard well. However, we analyzed the curve of the change in engine sound while emphasizing the change of the engine sound at the moment of the accident by recording the voice in the black box video. In particular, when comparing the curve of the engine sound change below 1,000 Hz with the rapid acceleration curve of the existing engine sound, for 5 seconds before the accident, the rotation sound of the engine changed 1.7 times faster than the rapid acceleration, and the highest rpm lasted 3 seconds. After all, in terms of the engine sound change curve of the black box video, this was a sudden velocity accident. In this paper, we proposed a new method to identify the accident through engine sound.
Digital design of cellular solids for noise and vibration mitigation
Authors: Cops Mark J. , McDaniel James G. , Magliula Elizabeth A.
Published: November 2017

Cellular solids are of large interest in structural vibration due to their high strength-to-weight ratio and ability for high energy absorption. This presentation describes concepts for digitally designing cellular solids and demonstrates the ability of this design method for tuning effective material properties for noise and vibration mitigation applications. The designs can be created by defining a complete topology mathematically or by specifying section cut-outs from a solid host material. The digital designs are then analyzed with finite element software to determine effective material properties. This approach is advantageous because it allows for an automated computer procedure for designing and characterizing materials. In addition, resulting designs can be fabricated through either 3D printing processes or CNC milling. In this presentation, the relationship between geometrical/physical properties and effective static material properties (such as Young's modulus and Poisson ratio) of cellular solids will be discussed for the digital designs, with reference to existing theory.
Noseleaf motions impart dynamic signatures on bat biosonar pulses
Authors: Zhang Liujun , Zhang Ru , Zhang Shuxin , Yang Luhui , Müller Rolf
Published: November 2017

Old-World leaf-nosed bats (Hipposideridae) are echolocating bats with nasal biosonar pulse emission. The nostrils in these animals are surrounded by baffle shapes (“noseleaves”) that have been shown to function as beamforming devices. In addition to their elaborate static geometries, the noseleaves can also undergo non-rigid shape changes that coincide with biosonar pulse emission. Prior work by the authors based on biomimetic baffle shapes has demonstrated that baffle motions similar to the ones seen in bat noseleaves can result in time-variant device properties, i.e., distributions of signal power over direction and frequency that also change with time. However, it remained to be established whether similar effects occur in bats. To answer this question, biosonar pulse emission in hipposiderid bats (Hipposideros armiger and Hipposideros pratti) has been studied with synchronized arrays of high-speed video cameras and ultrasonic microphones. Noseleaf motion was characterized by tracking the position of nine landmark points on the noseleaf. Temporal variability in the distribution of signal energy across spatial directions and ultrasonic frequencies was quantified using pair-wise measures of similarity applied to time-windowed segments of the pulse waveforms. Pulses that were accompanied by unequivocal noseleaf motions showed a significantly larger variability across time than those that were not.
The role of familiarity in audiovisual speech perception
Authors: Lee Chao-Yang , Harrison Margaret , Wiener Seth
Published: November 2017

Speech perception involves processing a spoken message’s linguistic content and information about the talker's voice carrying the message. Speech perception is also affected by visual information, e.g., the McGurk effect. Familiarity with a talker's voice facilitates auditory speech perception (Nygaard & Pisoni, 1998), but it is not clear whether visual familiarity with a talker's face affects audiovisual speech perception (Walker, Bruce, & O'Malley, 1995). In this study we investigated how visual familiarity with a talker affects the perception of the English sibilants /s/ and /ʃ/, which involve visible lip-rounding contrasts. Participants identified syllable-initial sibilants from stimuli that were audio-only, visual-only, audiovisual-congruent, or audiovisual-incongruent (e.g., audio “save” paired with visual “shave”). We also examined whether visual familiarity affects the occurrence of the McGurk effect. Participants identified syllable-initial stops from syllables that were audiovisual-congruent or incongruent (e.g., audio /bɑ/ paired with visual /gɑ/). The results indicated that participants familiar with the talker identified sibilants faster in all conditions and more accurately in the visual-only condition; no accuracy difference was found between the two groups in the other conditions or in the number of McGurk responses. These results are discussed in the context of processing intersensory information.
Examining the effect of first formant transition on perception of dynamic spectral change in the second formant
Authors: Roten Amie , Molis Michelle R.
Published: November 2017

Speech perception studies using methods such as formant-flattening and the silent-center paradigm have demonstrated that vowel-inherent spectral change (VISC) in speech-like stimuli adds significant information aiding in accurate phoneme identification. For listeners to reliably utilize this cue, formant extent thresholds must be smaller than transitions occurring in natural syllables. Although natural speech always involves movement of multiple formants over time, limited studies have determined formant transition thresholds in the context of competing formant movement. The purpose of this study was to begin to examine these interactions by determining the effect of F1-region transitions on perception of change in F2 (ΔF2). Listeners were presented 120 ms, two-formant stimuli approximating a vocoid F1/F2 configuration using a 4-interval, 2AFC, two-down/one-up adaptive paradigm. The first formant pivoted around a 500 Hz center frequency, and the second around 1500Hz. Thresholds for detection of both upward and downward ΔF2 were determined in the context of a flat F1, and an F1 transitioning linearly up or down by 1 ERB. Differences in performance were observed depending on F1 context, as well as direction of ΔF2, which may have bearing on speech perception ability. [Work supported by NIH/NIDCD.]
Using nonlinear time warping to estimate North Pacific right whale calling depths and propagation environment in the Bering Sea
Authors: Thode Aaron , Bonnel Julien , Thieury Margaux , Fagan Aileen , Verlinden Christopher M. , Wright Dana , Crance Jessica , Berchok Catherine L.
Published: November 2017

Calling depth distributions and ranges are estimated for two types of calls produced by critically endangered eastern North Pacific right whales (NPRW) in the Bering Sea, using passive acoustic data collected with bottom-mounted single-hydrophone recorders in 50–90 m water depths. Nonlinear time resampling of 12 NPRW “upcalls” and 20 broadband “gunshots” typically isolated 3 to 4 individual mode arrivals below 200 Hz. Matched-mode processing (MMP) methods were used to remove the unknown source phase and amplitude structure, but incoherently averaging MMP ambiguity surfaces across frequency yielded many local minima when inverting for sediment properties. Instead, the ambiguity surfaces were plotted as a function of range and frequency, which revealed the type and degree of environmental mismatch present in initial waveguide models. This qualitative approach revealed the existence of large sound speed gradients in the sediment, along with downward-refracting sound speed profiles during the summer months. Gunshot sounds were generally produced at a few meters depth, while upcall depths clustered between 10 and 25 m, consistent with previously published bioacoustic tagging results from North Atlantic right whales.
The 2016–2017 deep-water Canada Basin Acoustic Propagation Experiment (CANAPE): A preliminary report
Authors: Worcester Peter F. , Dzieciuch Matthew A. , Colosi John A. , Proshutinsky Andrey Y. , Krishfield Richard A. , Nash Jonathan D. , Kemp John N.
Published: November 2017

The Arctic Ocean is undergoing dramatic changes in both ice cover and ocean structure. The Canada Basin Acoustic Propagation Experiment (CANAPE), which includes both deep and shallow water components, was designed to understand the effects of changing Arctic conditions on low-frequency propagation and ambient noise. The deep-water component, which is reported on here, includes a yearlong experiment in the Canada Basin during 2016–2017, preceded by a short Pilot Study during July–August 2015. During 2016-2017, a Distributed Vertical Line Array (DVLA) receiver with 60 Hydrophone Modules was moored within a six-element acoustic transceiver array with a 150-km radius. Environmental measurements on the DVLA include 28 Sea-Bird MicroCATs and upward- and downward-looking Acoustic Doppler Current Profilers (ADCPs) located below the hydrophone array. The acoustic transceivers had sources at 175-m depth and 15 Hydrophone Modules located above the sources. Environmental measurements on the transceiver moorings include ice-profiling sonars, upward-looking ADCPs on the subsurface floats, and 10 temperature sensors located below the acoustic transceivers. The one-year deployment provides measurements at least partially in open water during summer, in the marginal ice zone (MIZ) as it transitions across the array during the spring and autumn, and under complete ice cover during winter.
Effect of acoustic computer model precision on auralization perception
Authors: Westergaard Brandon M. , Hsu Timothy
Published: November 2017

Most modern acoustic simulation programs use geometric acoustics to auralize the sound within a space, providing acceptable results in a relatively quick manner. Still, because of the limitations of geometric acoustics in computer simulations, it is of particular interest to investigate the relationship between model geometry, simulation parameters, and the listener’s perception of auralizations created from iterations of an acoustic model. In the context of this study, differences between auralizations were investigated from a perceptual standpoint, using the subjective judgment of listeners. A modified version of the Multiple Stimulus test with Hidden Reference and Anchor methodology was used to define a threshold at which an increase in model precision no longer results in perceived differences between auralizations, aiming to inform efficient modeling practices in practical applications. Acoustic simulations were performed on a set of speech and music venues modeled at incremental geometrical precision regarding their real-life counterparts, ultimately resulting in a series of auralizations that reflected changes in modeling precision. Single factor analysis of variance and a series of two-sample t-tests indicate that increasing acoustic model precision may not always result in perceptually relevant differences.
Absorption: The misunderstandings about what can be measured and the newest ideas of how to perform these measurements
Authors: Sauro Ronald
Published: November 2017

We will present the latest research into the measurement of absorption, the pitfalls, and some possible ways out of the these pits. We will also present new information on methods derived from the measuring of diffusion that can be applied to measuring absorption.
In vivo investigation of high-intensity focused ultrasound combined with thermally triggered chemotherapy for liver cancer treatment
Authors: Halliburton Gray , Murad Hakm Y. , Kala Monica , Zhang Yueheng , Sholl Andrew , John Vijay , Khismatullin Damir
Published: November 2017

High-Intensity Focused Ultrasound (HIFU) induces rapid tissue heating and mechanical disruption and also provides noninvasive release of chemotherapy from temperature-sensitive-liposomes (TSLs). We evaluated the combination of Sorafenib-loaded TSLs (SfTSLs) and HIFU via analysis of cell viability, tumor growth, and long-term survival. Liposomes were encapsulated with Sorafenib at 10μM with a glass transition temperature of 43°C. Hep3B human liver cancer cells were placed in PCR tubes to mimic dense tumor aggregates. Aggregates were treated with HIFU alone, SfTSLs alone, or SfTSLs + HIFU. HIFU exposure was applied for 30 seconds at acoustic output powers of 8.7 and 12W. Cell viability and proliferation were measured over 4 days post-treatment via AnnexinV/PI and WST-8 staining. Xenografted tumors were created via injection of 1.0×106 Hep3B cells within Matrigel into flanks of athymic-nude mice. Tumors at 8–10 mm were separated into the following groups: Control (sham), HIFU, SfTSLs, and SfTSLs + HIFU. Tumors were measured daily with endpoints at 5 days, 14 days, or long-term survival. Dissected tumors were H&E stained and evaluated by a blinded pathologist. The in vitro data indicates that Hep3B cells exposed to SfTSLs + HIFU have a significantly lower viability and proliferation rate. Similarly, in vivo results show SfTSLs + HIFU reduces tumor growth and increases survival.
Nonlinear softening of unconsolidated granular earth materials
Authors: Lieou Charles , Daub Eric , Guyer Robert , Johnson Paul A.
Published: November 2017

Unconsolidated granular earth materials exhibit softening behavior due to external perturbations such as seismic waves, namely, the wave speed and elastic modulus decrease upon increasing the strain amplitude. In this letter, we describe a theoretical model for such behavior. The model is based on the idea that shear transformation zones (STZs)—clusters of grains that are loose and susceptible to contact changes and rearrangement—are responsible for plastic deformation and softening of the material. We apply the theory to experiments on simulated fault gouge composed of glass beads, and demonstrate that the theory predicts nonlinear resonance shifts and reduction of the P-wave modulus, in agreement with experiments. The theory thus offers insights on the nature of the critical state prior to failure on earthquake faults.
Phonological neighborhood density and speech production in L1 and L2 English speakers
Authors: Vasandani Veera S. , Baese-Berk Melissa M. , Kim Jennifer S. , Munson Benjamin
Published: November 2017

Phonological Neighborhood Density (PND) affects speech production latencies, word durations, and acoustic-phonetic detail (e.g., Baese-Berk & Goldrick, 2009; Buz & Jaeger, 2016; Fox, Reilly, & Blumstein, 2015; Munson, 2013; Munson & Solomon, 2004; Wright, 2004). The nature of these effects has been debated actively. Some have argued that these effects reflect intentional articulatory modifications to increase intelligibility, while others have suggested that they are the consequence of planning processes. The purpose of this presentation is to examine whether these effects are present in second-language speakers of English whose first language is Korean. Because the mechanisms underlying these effects are unclear, examining whether non-native speakers also show sensitivity to PND will inform our understanding of the mechanisms that drive them. Moreover, studying non-native speakers of varying proficiency allows us to infer whether PND-driven variation in production emerges over the course of second-language acquisition. The production of multiple repetitions of high- and low-PND CVC words was collected from 17 native adult speakers of English and 19 adult L2 speakers of English whose L1 was Korean. Estimates of vocabulary size were also collected for both groups. Analyses of production latencies and vowel acoustics are ongoing. [Funding provided by a University of Minnesota Multicultural Summer Research Opportunity Program award to the first author.]
Eigenanalysis-based adaptive interference suppression for underwater target estimation
Authors: Ren Suiling , Guo Lianghao , Chen Yanli
Published: November 2017

It is generally difficult for a passive sonar system to localize a weak source due to the complexity and variability of the ocean environment, especially in the presence of strong interferences. In this paper, an eigenanalysis-based adaptive interference suppression method (EAAIS) is presented for estimating the weak source bearing. Assuming the target of interest (TOI) is in a known bearing sector, we first define a contribution ratio for each eigenvector of the cross-spectral density matrix (CSDM). The eigenvectors not dominated by the TOI are adaptively identified and removed for interference suppression. The remaining eigenvectors are then used to reconstruct the CSDM for TOI bearing estimation with adaptive beamforming methods. In comparison with the basic ECA method, the proposed method has better interference rejection capability and wider fields of application. Simulation and experimental results also show that the proposed method can achieve accurate localization estimates even in the presence of strong interferences.
Influence of microphone position error on generating spatial null sensitivity point by line microphone array
Authors: Ando Akio
Published: November 2017

We developed a method that picked up a sound of a target source located beyond the noise source [1]. It used an end-fire line microphone array whose direction was toward the noise source and created a spatial null sensitivity point at the noise source position. This method relied on the assumption that the precise distance between microphones was known so that all microphone outputs from the noise source became in phase by using the delay calculated by the distance. In this study, we analyzed the influence of the error of microphone distance on the performance of the method. As a result, if the real distance was larger than that of the system’s knowledge, the dip of sensitivity at the noise position was separated along the direction normal to that of the line of the microphones. On the other hand, it the distance was smaller than that of the system’s knowledge, the dip did not separate and just became shallower. Based on these results, we will propose how to compensate the microphone position error. [1] A. Ando, et al., 3pSP3, Acoustics ’17 Boston, 2017.
Efficient algorithm for active noise control of impulsive noise
Authors: Mirza Allina , Zeb Ayesha
Published: November 2017

Active Noise Control (ANC) systems employing adaptive filters suffer from stability issues in the presence of impulsive noise. Due to its simplicity and less computational complexity, the Filtered-x Least Mean Square (FxLMS) algorithm is the most widely used ANC algorithm which minimizes the mean square error of noise, but it lacks robustness and stability in presence of high impulses. To overcome this limitation, new methods must be investigated. A robust adaptive algorithm (Bhagyashri algorithm) for impulsive noise suppression is already proposed in literature. In this paper, Bhagyashri algorithm is tested in ANC domain and thus Filtered-x Bhagyashri (FxBhag) algorithm is proposed. Computer simulations are executed to verify the enhanced performance of the FxBhag algorithm. The statistics of impulsive noise is modeled by Symmetric α-stable (SαS) distributions. The suggested solution exhibits better stability and faster convergence with almost same computational complexity as that of standard FxLMS algorithm and its variants.
Motion planning based on matched field processing with Bayesian filtering
Authors: Bogdan Caitlin , Nelson Kenric , Andersson Sean , McDaniel James G.
Published: November 2017

Matched Field Processing (MFP) has often been used with stationary arrays as a method for developing source location information, but potentially with large amounts of uncertainty. This has been overcome in some cases by using Bayesian Filtering to improve estimates over time of the source location by treating this quantity as a random variable. Here we show how these methods can be applied to an autonomous vehicle for motion planning. The vehicle moving through an acoustic field can provide spatially separated data that can be used in an MFP algorithm to generate an estimated source location, which can be integrated utilizing Bayesian Filtering. Motion planning methods are shown which aim to move the vehicle to the maxima of this probability distribution. This method is demonstrated using ocean acoustic simulations. [Work supported by Raytheon Advanced Studies Fellowship.]