bluuebunny/crossref_metadata_2025 huggingface dataset:
The dynamics of open populations: integration of top–down, bottom–up and supply–side influences on intertidal oysters
Authors: Kimbro David L. , White J. Wilson , Grosholz Edwin D.
Published: October 2018

Most communities are structured not by a single process but by some combination of top–down, bottom–up and supply–side (i.e. juvenile recruitment) factors. However, establishing how multiple processes interact remains a fundamental challenge. For example, the recruitment, growth, and mortality of estuarine species can vary along the steep and numerous environmental and biological gradients typical of these habitats, but the relative importance of those gradients is generally unknown. We took a novel approach to this question by coupling long‐term field observations of the Olympia oyster Ostrea lurida in a central California estuary with a state–space integral projection model. This approach revealed that the most parsimonious description of oyster population dynamics involved spatial variation in growth and adult mortality – but not juvenile mortality – as well as spatiotemporal variation in recruitment. These patterns match the available short‐term estimates of each of those processes from field studies, and reveal a synthetic view of oyster population dynamics. Larval recruitment has an interannual ‘boom and bust’ pattern, and during good recruitment years most larvae settle in the inner bay where water residence time is highest. Adult oyster mortality is also highest in the inner bay, where several invasive predators are abundant and lowest in the mid‐bay, where oyster growth is greatest (due to bottom–up factors), likely leading to a size refuge from native predators. Surprisingly, juvenile mortality was constant across the bay, possibly because of a lack of size refuge from native and invasive predators. Our research approach represents an important advance in disentangling the contributions of spatio–temporal variation in top–down, bottom–up and supply–side forces to the dynamics of populations with open recruitment.
Corticosteroid phobia (corticophobia) in parents of young children with atopic dermatitis and their health care providers
Authors: Bos Bernies , Antonescu Ioana , Osinga Hilda , Veenje Sietske , de Jong Kim , de Vries Tjalling W.
Published: October 2018

Background

Adherence to topical corticosteroids is low among atopic dermatitis patients and their parents. This can lead to treatment failure and decreased quality of life.

Objective

To assess and compare the worries and beliefs concerning topical corticosteroids among parents of children with atopic dermatitis, involved health care professionals, and between different professionals. Also, we identify factors associated with corticosteroid phobia (corticophobia) in professionals.

Methods

Parents and health care professionals were invited to complete a questionnaire about corticophobia (Topicop). Higher questionnaire scores, expressed as a percentage, indicate more severe corticophobia. Professionals were asked to answer the questions as though they were using topical corticosteroids on their own child.

Results

The scores for 29 parents and 31 public health care nurses were equal: 44%. The score for 51 general practitioners was 39%. The score for 33 public health care physicians and of 47 pediatricians was 31%. The differences between parents and these professionals were statistically significantly different (P = 0.001). Type of profession and having a child with atopic dermatitis were significantly associated factors for the score.

Conclusion

Corticophobia is present among parents of children with atopic dermatitis and among health care professionals involved in caring for children with atopic dermatitis. Health care nurses express the same level of corticophobia as parents. The presence of corticophobia among health care professionals may affect parental perspectives and topical corticosteroids adherence negatively.
In utero development of epidermolysis bullosa acquisita
Authors: Dewan Anna K. , Braue Jonathan , Danford Brandon , Stack Lawrence B. , Boyd Alan S. , Fine Jo‐David , Albers Sharon E.
Published: October 2018

We report the case of an infant born with perioral vesicles that rapidly spread to involve his mouth and the majority of his body. Histopathology, immunofluorescence, and enzyme‐linked immunohistochemistry assays confirmed a diagnosis of epidermolysis bullosa acquisita (EBA). His mother had no history of EBA, and serum indirect immunofluorescence was negative. The patient improved rapidly with local wound care and oral dapsone.
Hybrid stage 1 palliation as a bridge to cardiac transplantation in patients with high‐risk single ventricle physiology
Authors: Morray Brian H. , Albers Erin L. , Jones Thomas K. , Kemna Mariska S. , Permut Lester C. , Law Yuk M.
Published: October 2018

Background

The hybrid stage 1 palliation for hypoplastic left heart syndrome (HLHS) was first described in 1993 as a bridge to heart transplant for HLHS. There are limited data on this strategy as primary heart transplantation for HLHS has become less common.

Methods

This is an observational, single‐center study comparing pre‐ and post‐transplant outcomes of patients listed for transplant following hybrid palliation with those following surgical stage 1 palliation.

Results

From 2004 to 2017, 21 patients underwent hybrid palliation as a bridge to heart transplant and 28 patients were listed for transplant following surgical stage 1 palliation or aortic arch repair and pulmonary artery band placement. Premature birth and the presence of genetic or anatomic abnormalities were more common in the hybrid group. Need for extracorporeal membrane oxygenation (ECMO) support and ventricular dysfunction was more common in the surgical group. There was a trend toward shorter waitlist times in the surgical cohort (36 days vs 70 days, P = 0.06). There was no difference in waitlist mortality (19% vs 21%, P = 0.61). Survival at 1 and 5 years post‐transplant was similar for the hybrid and surgical cohorts (5‐year survival, 80% vs 85%, P = 0.94, respectively). There was no difference in the number of post‐transplant interventions.

Conclusions

Although the hybrid patients represented a higher risk cohort and demonstrated longer wait times, the waitlist and post‐transplant mortality was equivalent between the two groups. For high‐risk patients, the hybrid palliation as a bridge to transplant appears to be a reasonable strategy.
Doppler ultrasound predictors of transplant hepatic venous outflow obstruction in pediatric patients
Authors: Monroe Eric J. , Jeyakumar Arthie , Ingraham Christopher R. , Shivaram Giri , Koo Kevin S. H. , Hsu Evelyn K. , Dick Andre A. S.
Published: October 2018

Objective

To investigate Doppler US and catheter venogram correlates to improve detection of transplant HVOO and avoid unnecessary invasive imaging procedures.

Materials and methods

A retrospective review was performed in all pediatric OLT patients undergoing catheter venography of the hepatic veins between 2007 and 2017 at a single large tertiary pediatric liver transplant institution.

Results

Forty‐four transplant hepatic venograms in 32 OLT patients were included (mean 1.38, range 1‐4 venograms per patient). All venograms were preceded by an independent Doppler US examination. Twenty‐one (47.7%) venograms were performed for the investigation of suspected HVOO based on Doppler US alone, 19 (43.2%) were performed for TJLB without suspected HVOO, 4 (9.1%) were performed for both. Sixteen (36.3%) instances of >50% anastomotic stenosis were identified. Mean peak anastomotic velocities were 208 cm/s and 116 cm/s in the presence and absence of a >50% venographic stenosis, respectively (P < 0.004). In all cases where there was a monophasic waveform seen on Doppler US, there was a > 50% stenosis seen on hepatic vein venogram. In all cases where a triphasic waveform was seen on Doppler US, there was no stenosis seen on hepatic vein venogram.

Conclusion

While a Doppler US velocity threshold providing both high sensitivity and specificity has yet to be identified, increasing peak anastomotic velocity and decreasing intrahepatic venous velocity correlate strongly with venographic outflow stenosis. The presence of a triphasic intrahepatic waveform provides good NPV.
Enhanced Production of Hypocrellin A in Submerged Cultures of Shiraia bambusicola by Red Light
Authors: Ma Yan Jun , Sun Chun Xiao , Wang Jian Wen
Published: October 2018

Hypocrellin A (HA), a promising photosensitizer for anticancer photodynamic therapy (PDT), is a fungal perylenequinone pigment from the fruiting body of Shiraia bambusicola, a traditional Chinese medicine for treating skin diseases. The mycelial cultures are becoming a biotechnological alternative for HA production. In this study, light of different wavelengths was investigated to develop an effective eliciting strategy for HA production in the cultures. Under red LED light (627 nm) at 200 lux, the maximum HA production (175.53 mg L−1) in mycelium cultures was reached after 8 days, about 3.82‐fold of the dark control. Red light not only promoted HA biosynthesis in mycelia (intracellular HA), but also stimulated HA secretion into the medium (extracellular HA). We found 14 of 310 transcripts differentially expressed under red light treatment were possible candidate genes for HA biosynthetic pathway. Gene ontology (GO) analysis revealed that red light treatment could change the gene expressions responsible for HA biosynthesis and the transmembrane activity, suggesting both intracellular HA and its secretion could contribute to the enhancement of total HA production in the cultures. The results provided new insights of red light elicitation and effective strategy for HA production in mycelium cultures.
Improving, but could do better: Trends in gestation‐specific stillbirth in Australia, 1994‐2015
Authors: Hilder Lisa , Flenady Vicki , Ellwood David , Donnolley Natasha , Chambers Georgina M.
Published: October 2018

Background

Stillbirth remains a public health concern in high‐income countries. Over the past 20 years, stillbirth rates globally have shown little improvement and large disparities. The overall stillbirth rate, which measures risk among births at all gestations, masks diverging trends at different gestations. This study investigates trends over time in gestation‐specific risk of stillbirth in Australia.

Methods

Analytical epidemiological study using nationally reported gestational age data for births in Australia, 1994‐2015. Average annual change in gestation‐specific prospective risk of stillbirth (per 1000 fetuses at risk [FAR]) was calculated among births in 1994‐2009 and 2010‐2015 at term (37‐41 weeks) and for preterm gestational age subgroups: 28‐36, 24‐27, and 20‐23 weeks.

Results

The decline in risk of stillbirth at term from 2010 to 2015 from 1.43 to 1.16 per 1000 FAR was more rapid than from 1994 to 2009; for preterm gestations from 24 to 27 weeks, there were no discernible trends; from 28 to 36 weeks, the decline between 1994 and 2009 was not sustained; among births from 20 to 23 weeks, the risk of stillbirth plateaued in 2010‐2015, fluctuating around 3.3 per 1000 FAR.

Conclusions

Improvement in the stillbirth rate from 28 weeks’ gestation aligns with changes in other high‐income countries, but more work is needed in Australia to achieve the levels of reduction seen elsewhere. Gestation‐specific risk of stillbirth is more informative than the overall stillbirth rate. The message that the overall risk of stillbirth is not changing disregards gains at different stages of pregnancy.
Attitudes to ageing and their relationship with quality of life in older adults in Turkey
Authors: Korkmaz Aslan Gülbahar , Kulakçı AltıntaŞ Hülya , Özen Çınar İlgün , Veren Funda
Published: October 2018

Aim

With the increase in life expectancy, it has become necessary to expand our knowledge of how older individuals perceive their own ageing and how ageing affects their quality of life. The aim of the study was to determine older adults’ attitudes towards ageing and the relationship between attitudes and quality of life among community‐dwelling older adults in Turkey.

Methods

This cross‐sectional and correlational study was conducted in Zonguldak, Turkey. The sample included 999 community‐dwelling older adults, who were selected from five family health centres. The data were collected between April and June 2015 by using the Attitudes to Aging Questionnaire and the World Health Organization Quality of Life Instrument‐Older Adults Module. A hierarchical multiple regression analysis was conducted to test the predictive value of attitude to ageing on quality of life.

Results

Multiple regression analysis revealed that the subscales of Attitudes to Ageing Questionnaire (psychosocial loss (β = −0.289), physical change (β = 0.296), and psychological growth (β = 0.279)) were statistically significant predictors of quality of life. Attitudes to ageing explained 46.6% of the quality of life among community‐dwelling older adults in Turkey (R2 = 0.466).

Conclusion

The significant impact of attitudes to ageing on quality of life suggests the need for better recognition of attitudes to ageing in older adults.
Gone in sixty (milli)seconds: Disentangling the effects of location context on attention bias
Authors: Rubin Mikael , Telch Michael J.
Published: October 2018

Attention bias is associated with a broad range of emotional disorders. Because of its transportability, attention bias modification (ABM) training can be administered outside of the laboratory; however, some evidence suggests that ABM training may be less effective when conducted in the individual's natural environment. The aim of this study was to examine factors that might account for the attenuated effects of attentional bias (AB) when assessed remotely. One hundred fifty‐eight undergraduate psychology students completed the Emotional Stroop Task on two occasions – once in the laboratory and once remotely. To help disentangle the influences of emotional state and location on attention bias, participants were randomized to view either an emotionally provocative clip or an emotionally neutral clip prior to completing the emotional Stroop task. Results showed evidence of an attentional bias only in the laboratory, among participants in the neutral emotion condition (b = –19.67, P = .008, 95% CI [–34.18, –5.15]). Exploratory analyses revealed that emotion provocation was associated with attentional bias among individuals with greater symptoms of depression, but only remotely (b = –15.70, P = 0.046, 95% CI [–31.15, –0.25]). These findings suggest that caution should be used when conducting attention bias research remotely. Limitations and future directions are discussed.
What IF? Building interactive fiction for teaching and learning religious studies
Authors: Lester G. Brooke
Published: October 2018

Games offer unique possibilities for learning, and text‐based interactive fiction (“IF”) in particular lends itself as a low barrier to entry for instructors and students wishing to build interactive narrative games. Understanding by Design provides a framework by which to determine the best possible places for instructor‐ and learner‐built IF in any given course, whether face‐to‐face or online. A thick description of how an instructor conceived and developed two IF games follows, explicitly tied to course‐design considerations like learning goals and assessment performances. The value of IF as a student project is explored, and finally an appendix provides resources for instructors and students to begin building their own interactive fiction.
War and Peace in Canaan: Connecting geography with political and military affairs in ancient Israel through a classroom game
Authors: Trimm Charlie
Published: October 2018

This essay provides a brief overview of an educational board game developed by the author for use in upper division Old Testament classes. The game, extending in stages across the semester, heightens student learning by requiring strategic thinking about various historical, political, and geographical relationships. Appendices and links to online material provide full details necessary to adapt the game in local classrooms.
Excision in algebraic -theory revisited
Authors: Tamme Georg
Published: October 2018

By a theorem of Suslin, a Tor-unital (not necessarily unital) ring satisfies excision in algebraic$K$-theory. We give a new and direct proof of Suslin’s result based on an exact sequence of categories of perfect modules. In fact, we prove a more general descent result for a pullback square of ring spectra and any localizing invariant. Our descent theorem contains not only Suslin’s result, but also Nisnevich descent of algebraic$K$-theory for affine schemes as special cases. Moreover, the role of the Tor-unitality condition becomes very transparent.
On multi-pointed non-commutative deformations and Calabi–Yau threefolds
Authors: Kawamata Yujiro
Published: October 2018

We will develop a theory of multi-pointed non-commutative deformations of a simple collection in an abelian category, and construct relative exceptional objects and relative spherical objects in some cases. This is inspired by a work by Donovan and Wemyss.
Constructing elliptic curves from Galois representations
Authors: Snowden Andrew , Tsimerman Jacob
Published: October 2018

Given a non-isotrivial elliptic curve over an arithmetic surface, one obtains a lisse $\ell$-adic sheaf of rank two over the surface. This lisse sheaf has a number of straightforward properties: cyclotomic determinant, finite ramification, rational traces of Frobenius elements, and somewhere not potentially good reduction. We prove that any lisse sheaf of rank two possessing these properties comes from an elliptic curve.
Inharmonic Spectra with a Rock Guitar Effects Pedal
Authors: Ruiz Michael J. , Hobbs Lowell
Published: October 2018

Students in introductory physics courses encounter harmonics when they study standing waves on strings and in pipes. The Fourier spectrum, which plots amplitude against harmonic number, can describe all periodic tones imaginable. However, most sounds are aperiodic and therefore have additional spectral components. A real-world application that includes frequencies outside the harmonic series can be found in guitar pedal effects used by rock musicians. A four-minute video accompanying this paper includes the exotic sound of guitar playing when the guitar pedal adds inharmonic frequency components. The principle underlying the pedal effects discussed in this paper is balanced modulation. Some inharmonic spectra based on balanced modulation can easily be sketched after students have learned about timbre and Fourier spectra.
Real-time Visualization of Equipotential Lines Using the IOLab
Authors: Nair Abhilash , Sawtelle Vashti
Published: October 2018

Drawing equipotential and electric field lines is an activity commonly found in most second-semester introductory physics courses. Unfortunately, current commercial lab offerings are expensive and do not afford the opportunity for real-time graphical visualization of the trends in voltage in different regions. In this brief article, we describe a flexible alternative that utilizes the Interactive Online Lab (IOLab) device and easy-to-acquire supplies to create an experiment that yields robust results and has resulted in a positive response from our students.
Aerodynamic Lift, Part 1: The Science
Authors: McLean Doug
Published: October 2018

Every so often an article appears in the popular press pointing to the apparent confusion surrounding the topic of aerodynamic lift and alleging that even the “experts” don’t fully understand it. This makes attention-grabbing copy, but it overstates the case. Actually, the science of lift is not in dispute. It is well understood in terms of a quantitative mathematical theory that is based on established laws of physics, produces accurate predictions, and has been agreed on by the science and engineering communities since the early 20th century. Confusion arises only in connection with explaining lift in qualitative terms.
Using Capacitors to Measure Charge in Electrostatic Experiments
Authors: Vera Francisco , Ortiz Manuel , Romero-Maltrana Diego , Horta-Rangel Francisco Antonio
Published: October 2018

In this work we describe a simple setup for measuring electrostatic charge and polarity in electrostatic experiments. This low-cost detector only requires a graphite pencil, a capacitor, two switches, and a voltmeter, and holds the promise of transforming qualitative activities that are commonly used to teach electrostatics into quantitative activities. In order to measure the charge and polarity of charged objects, a pencil is used as an antenna to collect charge from the object under study. The collected charge is transferred to a capacitor, and the resulting voltage at the capacitor is measured using a voltmeter. In contrast to other devices, our detector can be used to measure the amount of charge stored in objects at several thousand volts, as for example Van de Graaff domes.
A 3D-Printed Wheel with Constant Mass and Variable Moment of Inertia for Lab and Demonstration
Authors: Hazlett Eric , Aragoneses Andrés
Published: October 2018

We present a versatile experimental apparatus for exploring rotational motion through the interplay between the moment of inertia, torque, and rotational kinetic energy of a wheel. The heart of this experiment uses a 3D-printed wheel along with easily accessible stock components that allow for the adjustment of the moment of inertia while keeping the total mass of the wheel constant. The wheel can act as a massive pulley of variable moment of inertia that allows students to measure the moment of inertia of the bare wheel by applying a constant torque to the system. The wheel can also be used to explore rotational kinetic energy in the form of races down ramps. The 3D-printed aspect of this wheel allows anyone with access to a 3D printer to create, explore, and modify this wheel at a low cost, allowing for more flexibility and accessibility for student and instructor exploration and modification. In the study of linear kinematics, it is easy to investigate how systems evolve with variable mass. With rotational motion the situation is more complicated due to the fact that the moment of inertia depends not only on the mass, but also on the distribution of the mass. This can be demonstrated in the form of massive pulleys in Atwood machines and in a rolling race of objects of varying mass and moment of inertia. For lab explorations it is best to isolate a single variable that can be changed. For rotational motion it is difficult to find a wheel with constant mass but different moments of inertia. There do exist examples that solve this problem, but they require workshop access and cannot act as pulleys. To address this issue we have designed a wheel whose moment of inertia can easily be created and manipulated while the mass of the system remains constant, providing an accessible, flexible, and robust apparatus to explore the interplay between moment of inertia and torque and rotational kinetic energy.
Feezya, my love!
Authors: Nadji Taoufik
Published: October 2018

Newton married her, Einstein eloped with her, and many a physicist fell head over heels for her beauty, charm, and heavenly elegance! This paper is a heartfelt personal attempt to make sense of the indescribable love many physicists have for their subject matter, physics. My muse’s nickname is Feezya and this is how she shall be referred to for the remainder of this essay. What you are about to read is not an educational nor a scientific article. Rather, it is an essay that I hope will rekindle the love of the subject matter within the hearts of many of us whose day-to-day teaching loads and experimental and research obligations may have caused our passion to whither and our genuine affection to wash away. The article may at times poke some fun at math, chemistry, or other noble sciences; it is never out of disrespect but rather out of normal and harmless sibling rivalry amongst equally valuable fields of human knowledge and inquiry.
Looking for patterns in eclipses: Saros series
Authors: Brown Todd , Brown Katrina
Published: October 2018

The excitement around the 2017 Great American Eclipse shows that people are fascinated by such events. If they were not expecting such an eclipse to happen, however, it would undoubtedly be surprising and possibly even disconcerting to many people. Millennia ago, a full moon turning red over the course of a night or the blotting out of the Sun were often considered omens. Astronomers in early civilizations such as Babylonia, Mesopotamia, and China all paid note to eclipses, which were often used for the divination of earthly events. There is the possibly allegorical but often-told story of two Chinese astronomers who were beheaded for failing to predict an eclipse that occurred several thousand years BCE.
Infrared light revisited
Authors: Lincoln James
Published: October 2018

The unique properties of infrared light, both in the near and far infrared, have always fascinated me and my students. As I have long had access to a thermographic camera, I have used it for many original experiments and demonstrations. Yet, I have also noticed there are many other familiar tools that can be used to investigate infrared light which I have frequently employed. In this article, I revisit both near and far infrared light and offer some new activities to help students appreciate the specific properties of these wavelengths.
Introduction to and implementation of the WELL sound concept
Authors: Bourdeau Ethan
Published: October 2018

The latest revision of the WELL rating system relocates all previous acoustic related features from the Comfort concept into the new Sound concept. The new iteration of WELL reassesses the importance of all features in terms of substantiation, evidence, best practice, and feasibility, most notably for implementation within existing spaces where minimal mitigation can be anticipated. This paper introduces the new feature set of the Sound concept with a brief introduction of the new WELL rating system platform, provides an example of implementation through a case study of the new International WELL Building Institute (IWBI) headquarters, and serves as a continuation to the discussion of acoustics in ratings systems that address IEQ, health, and well-being.
Evaluating acoustical performance of existing offices as part of a WELL feasibility service
Authors: Bessey Ryan , Roy Jessie
Published: October 2018

While the WELL building standard is typically applied during the design of new offices, it can also be applied retroactively to existing offices. Before undertaking such an endeavour, some companies are interested in evaluating performance with respect to the standard. This paper describes how a WELL feasibility assessment can be performed for the acoustically focused WELL features. This allows companies to know where their existing space stands with respect to the WELL building standard and what it might take to achieve the different levels of certification.
Continued Summer Sound Lab Academic Research: Developing thin shell precast systems for acoustical environments
Authors: Butko Daniel
Published: October 2018

This paper presentation continues progress of an active multiphase acoustical research project emphasizing implementation of adaptive interactive acoustical responses in multiuse spaces to transform unhealthy learning environments. Building upon the December 2017 paper presentation, slotted and pocketed thin shell precast systems are being explored as a viable option to decrease excessive reverberation and flutter echo while increasing clarity and speech intelligibility within a multiuse space on campus. The project, launched Spring 2017, is spanning multiple phases and disciplines as faculty and students are analyzing and validating findings in both computer and physical form. Collected data will lead researchers to design applications for adaptive and resilient learning environments with minimized acoustical distractions and improved speech intelligibility. The work presented here defines prototypical concepts to inform final full-scale built form, providing scholarly merit applicable to similar spaces and/or functions.
Auditory threshold in fishes: Towards international standard measurement procedures
Authors: Halvorsen Michele B. , Ainslie Michael A.
Published: October 2018

Fish rely on their auditory system for survival to detect and interpret sounds in their surroundings, especially those originating from predators, prey, and conspecifics. The sensitivity of fish hearing can be impaired, for example, by masking or temporary threshold shifts. To understand and quantify the impact of noise in the oceans, we need a quantitative and comparable understanding of fishes’ impaired and unimpaired hearing sensitivities to sound pressure and sound particle motion. Historically, hearing sensitivities were measured to generate an audiogram for a fish species of interest. Therefore, audiograms are only available for a few individuals representing a few species. Crucially, differences between measurement protocols leave existing audiograms mostly incomparable. The goldfish (Carassius auratus) is a species for which many audiograms have been measured and the reported hearing thresholds exceed a 40 dB spread, largely attributed to differences in methodology rather than in hearing sensitivity [Ladich & Fay, 2013; Maruska & Sisneros, 2016]. These large differences indicate a need to harmonize measurement procedures. Standardization of hearing sensitivity measurements is therefore essential if we are to achieve environmental management goals in the United States, Europe, and worldwide. We propose a path that leads to the development of suitable international standards.
Listening in the dark—Auditory evoked potential measurements and novel imaging techniques elucidate the role of hearing in deep sea fishes
Authors: Lucke Klaus , Collin Shaun P. , Kerr Caroline , Camilieri-Asch Victoria , Krieg Joanna , McCauley Robert , Chapuis Lucille
Published: October 2018

In the aphotic zone of the deep ocean, mechanisms for conveying information to conspecifics or gathering information about the environment and potential predators are subject to the same physical and ecological limitations as near to the sea surface with the addition of no available light. Passive or active communication often utilises bioluminescent visual, olfactory, or acoustic signals. The sensitivity of deep sea fish to sound has never been tested. In a multi-disciplinary study, deep sea fishes were sampled in the Indian Ocean and examined for acoustic sensitivity. Acoustic signals were generated in a tubular steel tank using a calibrated sound source with pressure and particle motion of generated signals measured. The auditory sensitivity was tested using the auditory brainstem responses to amplitude modulated stimuli. To determine if the pressure or particle motion component of the acoustic signals was most relevant, specimens of all species tested were imaged in a micro-CT using a modified contrast enhancing method. This method provides increased image quality of in-situ morphological features, including the swim bladder and ancillary structures possibly related to for sound perception. Correlating these physiological and morphological results provides the key for an ecologically meaningful assessment of hearing capabilities of deep sea fishes.
Resilience exemplified-drum fish spawning doesn't miss a beat in the eye of a hurricane
Authors: Biggs Christopher , Erisman Brad
Published: October 2018

Spawning locations, timing, and periodicity are important aspects of productivity and resilience in fish because they are directly related to reproductive success. Passive acoustic monitoring can be used to study these aspects of spawning for species that produce spawning associated vocalizations. Drumming sounds produced by spotted seatrout Cynoscion nebulosus during spawning have been extensively described and the sound pressure level (SPL) is correlated to the intensity of spawning. We monitored spawning in seatrout April-September 2017, which coincided with a category 4 hurricane and caused a major acute disturbance. Spawning sounds within the peak frequency bandwidth of seatrout chorusing (251-500 Hz) were observed on every day of the study with an average SPL of 121.8 (CI95 121.6-122.0) dBrms re: 1 μPa, which was significantly higher than the background noise level of 103.9 (CI95 103.8-104.0) dBrms re 1 μPa (w = 0.894, p<0.01). Spawning was also confirmed at two sites within the eye of the hurricane. The onset of spawning shifted 2.2 hours earlier (t = 13.91, df = 36, p < 0.01) for five days after the hurricane. These results illustrate that spotted seatrout are extremely resilient, which indicates a primary reason they are able to thrive in highly disturbed estuarine environments.
Discovery of sound in the sea: Webinars as a means of communicating current underwater acoustics research to decision makers
Authors: Vigness-Raposa Kathleen J. , Scowcroft Gail , Knowlton Christopher , Morin Holly , Ketten Darlene R. , Popper Arthur N. , Miller James H.
Published: October 2018

Underwater sound used for anthropogenic activities is reviewed and restricted under a variety of environmental regulations. Decision makers must often synthesize rapidly new scientific research results to inform their assessments of potential impacts of proposed projects. To assist this need, the University of Rhode Island Graduate School of Oceanography has teamed with Marine Acoustics, Inc., in the Discovery of Sound in the Sea (DOSITS) project to provide accurate scientific information on underwater sound through a diversity of resources and digital platforms, including webinars. Building on the foundation of the successful 2015-2016 DOSITS webinar series and informed by the results of three international regulatory community needs assessments, the DOSITS project is hosting throughout 2018 a four-part webinar series on the fundamentals of underwater hearing and potential impacts of underwater sound on marine animals, particularly marine mammals (April–May) and fishes (November). Evaluation results from the first two webinars on marine mammals showed that 90% of survey respondents were very satisfied or satisfied with the content coverage, and 97% were extremely or very likely to attend future DOSITS webinars. The webinar approach has provided much needed on-the-job training for decision makers to effectively incorporate new scientific research into their evaluation processes.
Low–frequency acoustic transmissions under sea ice as measured in the Beaufort Sea
Authors: Dzieciuch Matthew , Worcester Peter F. , Colosi John A. , Proshutinsky Andrey Y. , Krishfield Richard A. , Nash Jonathan D. , Kemp John N.
Published: October 2018

A tomography array was deployed in the Beaufort Sea for a year beginning in late summer 2016 during the Office of Naval Research sponsored project called the Canada Basin Acoustic Propagation Experiment (CANAPE.) This talk will look in detail at the propagation characteristics of broadband sound transmitted at 250 Hz over 108 km to 285 km ranges as measured on a 60 element vertical line array. Over the year, the heat content and vertical stratification of the ocean change as heat is gained and lost to the atmosphere and as the momentum transfer from the wind mixes the upper layers. The changes in heat content and stratification over the year affects the travel-time of the sound as well as its fluctuations. Examples will be shown of each. Sea-ice roughness adds scattering loss as the ice thickness increases. Thus, the seasonal ice-cover modulates the transmission loss of the acoustic paths. The losses on deep turning paths are different from the sound trapped in the surface duct. The ambient noise level also changes as the seasons progress.
An overview of Beaufort Sea eddies, internal waves, and spice from several recent field efforts and implications for acoustic propagation
Authors: Colosi John A. , Kucukosmanoglu Murat , Worcester Peter F. , Dzieciuch Matthew , Proshutinsky Andrey Y. , Krishfield Richard A. , Nash Jonathan D.
Published: October 2018

Several recent field efforts have revealed surprisingly complex and dynamic thermohaline structure in the upper ocean of the Beaufort Sea. Solitary and compact eddies with strong temperature contrasts and currents have been observed in multiple locations and are associated with vigorous mixing, staircase structure and intrusive feature formation. While many of the eddies are primarily found in the upper 300-m of the water column, rare deep eddies with cores near 500 to 1000-m depth have also been observed. Internal waves are generally weak with energies an order of magnitude less than mid-latitude values and they show marked dominance by near inertial waves, intermittency, spatial inhomogeneity, and deviations from the Garrett-Munk model. Strong intrusive structure, termed spice, is observed in the upper 150-m of the water column and is associated with the mixed layer and eddy activity. Acoustic implications of the associated sound speed structure will be discussed.
A year-long record of low-frequency, long-range, ducted sound propagation from the Canada Basin to the Chukchi Shelf
Authors: Ballard Megan S. , Sagers Jason D. , Badiey Mohsen , Colosi John A. , Turgut Altan , Pecknold Sean , Lin Ying-Tsong , Proshutinsky Andrey Y. , Krishfield Richard A.
Published: October 2018

The Pacific Arctic Region, has experienced decadal changes in atmospheric conditions, seasonal sea-ice coverage, and seawater temperature. From the October 2016 to September 2017, the Canada Basin Acoustic Propagation Experiment (CANAPE) was conducted to understand the changing soundscape and to explore the use of acoustic signals as a remote sensing tool in the modern Arctic. During the experiment, low-frequency signals from five tomographic sources located in the Canada Basin were recorded by an array of hydrophones with both horizontal and vertical apertures located on the Chukchi Shelf at the 150 m isobath. The propagation distances ranged from 240 km to 520 km, and the propagation conditions changed from persistently ducted in the basin to seasonally upward refracting on the continental shelf. The water column properties and ice draft were measured by oceanographic sensors on the basin tomography moorings and by an array of oceanographic moorings on the continental shelf and slope to characterize the temporal and spatial variability of the environment. This talk examines the range-dependent measurements and explains the observed variability in the received signals through propagation modeling using the oceanographic measurements. [Work sponsored by ONR.]
Seabed properties at the 150 m isobath as observed during the 2016–2017 Canada Basin Acoustic Propagation Experiment
Authors: Sagers Jason D. , Ballard Megan S.
Published: October 2018

Seabed layering and sediment properties impact sound propagation in ocean waveguides, particularly in environments where sound propagation paths repeatedly interact with the seafloor. As part of the 2016–2017 Canada Basin Acoustic Propagation Experiment (CANAPE), experiments were designed to investigate seabed layering and sediment properties on the Chukchi Shelf. First, the shallow water experimental region was surveyed with a subbottom profiler to provide information about the overall sediment layering. Second, ship-radiated noise from a research vessel sailing specifically designed tracks was received on the Persistent Acoustic Observation System (PECOS). These recordings provide an opportunity for short- to mid-range geoacoustic inversion for sediment properties. Third, in-situ acoustic sound speed measurements were made with the Acoustic Coring System (ACS) while two to five meter long core samples were simultaneously collected. This talk presents initial findings of the seabed layering and sediment properties from these three experiments. [Work sponsored by ONR.]
Lung ultrasound surface wave elastography
Authors: Zhang Xiaoming
Published: October 2018

Lung ultrasound surface wave elastography (LUSWE) was developed for noninvasively measuring superficial lung tissue stiffness. In LUSWE, a 0.1 second harmonic vibration is generated on the chest wall of a subject using a handheld vibrator. An ultrasound probe is aligned with the vibration excitation in the same intercostal space to measure the generated surface wave propagation on the lung. A human subject is examined in a sitting position. The lung is tested at the total lung volume and through three intercostal spaces on each lung. In a prospective clinical study, we measure the lung surface wave speeds at 100 Hz, 150 Hz, and 200 Hz on 91 patients with interstitial lung disease (ILD) and 30 healthy control subjects. Significant differences of wave speed between patients and controls were found in all 6 lung regions and for 3 frequencies. We also found positive correlation between LUSWE and clinical assessments including CT and pulmonary function tests. LUSWE is used to track the changes of surface wave speed for patients. LUSWE is a safe and noninvasive technique for generating and measuring surface wave propagation on the lung. LUSWE may complement the clinical standard high-resolution computed tomography for assessing ILD.
On the artefactual information of ultrasound lung images
Authors: Demi Marcello , Soldati Gino , Demi Libertario
Published: October 2018

In standard B mode imaging, a probe transmits brief pulses and receives the echoes reflected by every structure of the explored medium. A set of consecutive pulses are used to reconstruct a two-dimensional image even though some of the assumptions needed to do this are not exactly satisfied. Consequently, numerous visual artefacts are present in ultrasound images and physicians are aware that significant discrepancies between the ultrasound images and the anatomy of the examined medium may exist. Nonetheless, such artefacts are usually analyzed accurately since they provide clinical information and understanding of the physical mechanisms which are at the basis of their formation is important. In the case of lung images, everything we see beyond the chest wall represents artefactual information since the aerated spaces of the lung reflect most of the energy of the ultrasound pulses. Herein, we will describe the genesis of the most important lung artefacts by means of mathematical models. We will discuss how the so called A lines, B lines, and White Lung may be generated by the reverberation effects between the probe and the pleura, by the trapped and subsequently re-radiated acoustic energy and by the multiple reflections between randomly distributed aerated spaces.
Beamforming of crackle-related events in supersonic jet noise
Authors: Vaughn Aaron , Swift S. Hales , Gee Kent L. , Downing Micah , James Michael M. , Wall Alan T.
Published: October 2018

Crackle is an annoying component of supersonic jet noise. In the far field, crackle is related to the presence of acoustic shocks that develop due to nonlinear propagation; however, the intermittent source events that drive crackle generation are not well understood. This study investigates the apparent source locations of events related to crackle, which could include high-amplitude or steepened, shock-like waveforms. The measured data were obtained through ground-array measurements near a high-performance military aircraft, which was run at different engine powers. The apparent source regions corresponding to different event triggers, such as pressure amplitude, derivative amplitude, and spectral characteristics, are compared. The crackle-related event beamforming is also compared against the results of time-averaged, frequency-domain source localization. [Funded by an AFRL SBIR.]
Improvement of aero-vibro acoustic simulation technique for prediction of acoustic loading at lift-off
Authors: Tsutsumi Seiji , Maruyama Shinichi , Sarae Wataru , Terashima Keita , Hiraiwa Tetsuo , Ishii Tatsuya
Published: October 2018

Aero-vibro acoustic simulation for the prediction of harmful acoustic loading at lift-off of launch vehicle is developed. In this simulation technique, high-fidelity large-eddy simulation with computational aeroacoutics based on full-Euler equations is employed for computing jet aeroacoustics and their propagation to the outside of payload fairing. Acoustic field inside the payload fairing is computed by the coupled vibro-acoustic simulation based on finite element method. A simplified fairing model is used for the validation of the present method. An impact hammer test and acoustic vibration test using a loudspeaker in an anechoic chamber are conducted for validating the structural model. Then, the accuracy of this method is validated by using the acoustic vibration test result with a subscale rocket engine.
Spectral analysis of jet turbulence and radiated sound
Authors: Schmidt Oliver T. , Colonius Tim , Towne Aaron , Rigas Georgios , Brès Guillaume A.
Published: October 2018

Informed by LES data and resolvent analysis of the mean flow, we examine the structure of turbulence in jets in the subsonic, transonic, and supersonic regimes. Spectral (frequency-space) proper orthogonal decomposition is used to extract energy spectra and decompose the flow into energy-ranked coherent structures. We demonstrate that two distinct mechanisms, which can be distinguished by their characteristic frequency scaling and spatial support, lead to the formation of wavepackets—coherent structures that are known for their acoustic importance in the aft-angle radiation of high subsonic and supersonic jets. We compare these characteristics to acoustic source features extracted from hologram sound pressure measurements in a recent publication. The evidence strongly suggests that both mechanisms are active in full-scale jets and comprise the experimentally educed sources of sound.
Experimental study of acoustic reduction technique for H3 launch vehicle
Authors: Sarae Wataru , Terashima Keita , Tsutsumi Seiji , Takegoshi Masao , Kobayashi Hiroaki
Published: October 2018

A subscale Acoustic test, the H3-scaled Acoustic Reduction Experiments (HARE), was conducted to predict liftoff acoustic environments of the H3 launch vehicle currently being developed in Japan. The HARE is based on 2.5% scale H3 vehicle models, which is composed with a GOX/GH2 engine and solid rocket motors, Movable Launcher (ML) models with upper deck water injection system and Launch Pad (LP) models with deflector and lower deck water injection systems. Approximately 20 instruments measured far/near field acoustic and pressure data. Last year the results of the first campaign of the HARE, which aims at understanding the effects of elevation, the shape of ML, were presented. This year, the results of the second campaign which aims at studying the effects of acoustic reduction techniques such as acoustic shields and water injection will be presented.
Acoustic imaging with a metamaterial Luneburg lens
Authors: Cummer Steven , Xie Yangbo , Fu Yangyang , Li Junfei , Jia Zhetao , Shen Chen , Xu Yadong , Chen Huanyang
Published: October 2018

The Luneburg lens is a spherically symmetrical gradient refractive index device with unique imaging properties. Its wide field-of-view and minimal aberration have led it to be successfully applied in microwave antennas. However, only limited realizations of this type of image formation have been demonstrated in acoustics. Here, we apply a new design method for scalable and self-supporting metamaterials to experimentally demonstrate Luneburg lenses for airborne ultrasound. Experimental imaging results are demonstrated.