bluuebunny/crossref_metadata_2025 huggingface dataset:
Tolerance to salinity and thermal stress by larvae and adults of the serpulid annelid Ficopomatus enigmaticus
Authors: Peria Jessica , Pernet Bruno
Published: November 2019

The serpulid annelid Ficopomatus enigmaticus is a widely distributed invader of shallow‐water, brackish habitats in subtropical and temperate regions, where it has numerous damaging ecological and economic effects. Its distributional pattern suggests that temperature and salinity play important roles in limiting its distribution, but because other factors often covary with these, drawing strong conclusions from these patterns is difficult. In an effort to more clearly identify the effects of these factors, we examined tolerance to acute thermal (16–28°C) and salinity (0–35 psu) stress by larvae (5‐day exposure, unfed) and adults (14‐day exposure, unfed) of F. enigmaticus in the laboratory experiments. Larvae showed higher mortality at the highest temperature tested 28°C; adult survival was unaffected by temperature. Neither larvae nor adults survived exposure to pure freshwater (0 psu), but survived well at salinities ranging 3.5–35 psu. In addition, high salinity did not slow tube growth in adults. These results suggest that salinity stress, in particular, does not directly limit the distribution of F. enigmaticus to low‐salinity habitats. Experimental work on the distribution of F. enigmaticus is uncommon in the literature, but is likely needed to identify the abiotic or biotic factors that limit the distribution of this frequently invasive species.
EFFECTS OF INTRAVENOUS ABT‐870 (IRON (III)‐HYDROXIDE OLIGOSACCHARIDE) ON MEAN ARTERIAL PRESSURE AND HEART RATE IN THE ANAESTHETIZED BEAGLE: COMPARISON WITH OTHER IRON‐CONTAINING HAEMATINIC AGENTS
Authors: Preusser Lee C , Fryer Ryan M , Gerhardt Armin , Hu Yanhui , Delgado‐Herrera Leticia , Melnick Joel Z , Williams Laura A , Cox Bryan F , Reinhart Glenn A
Published: November 2019

Iron‐deficiency anaemia, a complication of end‐stage renal disease (ESRD), is often treated with parenteral iron therapies that have been shown to produce dose‐limiting hypotension in patients. ABT‐870 (iron‐(III)hydroxide‐oligosaccharide) is comprised of elemental iron complexed with oligosaccharide, a composition that we hypothesised would allow the hypotensive effects of parenteral iron therapy to be overcome, thus allowing a rapid rate of infusion to be well tolerated.

Mean arterial pressure (MAP) and heart rate (HR) were monitored in anaesthetized dogs following the infusion of ABT‐870 and iron sucrose administered at doses of 7.1 and 21.3 mg/kg using a rapid 30 s infusion. ABT‐870 and iron sucrose were also monitored at doses of 7.1, 21.3 and 50 mg/kg administered over a 10 min period. Sodium ferric gluconate complex (SFGC) was administered in an identical fashion at doses of 12.5 and 31.2 mg/kg.

A 30 s rapid infusion of ABT‐870 at doses of 7.1 and 14.3 mg/kg or a 10 min infusion of ABT‐870 at doses of 7.1 and 21.3 mg/kg produced little effect on MAP and HR. Infusion of the highest dose of ABT‐870 (50 mg/kg) produced no consistent hypotension, but did produce an increase in HR (maximal increase 35 ± 9 b.p.m.), an effect that lasted only 15 min. A 30 s rapid infusion of iron sucrose at 7.1 mg/kg produced modest increases in MAP and HR (5 ± 1 mmHg and 5 ± 2 b.p.m., respectively). However, rapid infusion of iron sucrose at 14.3 mg/kg produced hypotension (to ‐8 ± 1 mmHg below baseline) and exerted variable, biphasic effects on HR ranging from ‐16 to +50 b.p.m. Although 10 min infusion of iron sucrose at 7.1 mg/kg exerted little effect on MAP and HR, at doses of 21.3 and 50 mg/kg iron sucrose elicited a profound dose‐dependent decrease in MAP (‐34 ± 11 and ‐83 ± 5 mmHg, respectively) and a pronounced increase in HR ranging from 32 to 49 b.p.m. above baseline. A 10 min infusion of SFGC at doses of 12.5 and 31.2 mg/kg produced a dose‐dependent decrease in MAP (‐28 ± 18 and ‐67 ± 12 mmHg below baseline) and a marked increase in HR (26 ± 11 and 94 ± 15 b.p.m. above baseline).

In conclusion, unlike iron sucrose and SFGC, high doses of ABT‐870 failed to exert consistent hypotensive effects. These data demonstrate that ABT‐870 may have a substantial therapeutic window and considerable clinical potential for iron‐replacement therapy.
The effects of stricter regulation on the going public decision of small and knowledge‐intensive firms
Authors: Engelen Peter‐Jan , Meoli Michele , Signori Andrea , Vismara Silvio
Published: November 2019

This paper studies the impact of increased securities regulation on the IPOs of small and high‐tech, knowledge‐intensive firms. We take advantage of the adoption of European SOX‐like provisions, staggered at different dates across European countries, to test its influence on the going public decision. Starting from the population of European private firms during 1995–2012, we find that the likelihood of going public has decreased among small and high‐tech, knowledge‐intensive firms. Consistently, we document a 6% and 8.5% decrease in the industry‐adjusted Tobin's Q of small and knowledge‐intensive firms that go public after the regulatory change.
Association between gut microbiota composition and glycoalbumin level during pregnancy in Japanese women: Pilot study from Chiba Study of Mother and Child Health
Authors: Sakurai Kenichi , Kato Tamotsu , Tanabe Hiromi , Taguchi‐Atarashi Naoko , Sato Yumi , Eguchi Akifumi , Watanabe Masahiro , Ohno Hiroshi , Mori Chisato
Published: November 2019

Aims/Introduction

Gut microbiota have various effects on human health. Some previous reports have shown that gut microbiota change during pregnancy and affect metabolism, but others have shown that microbiota do not change. Here, we examined the gut microbiota and glycoalbumin levels of 45 healthy Japanese women during pregnancy.

Materials and Methods

We carried out 16S rRNA gene sequencing analyses of maternal stool samples and compared the gut microbiota composition of samples from women in early and late pregnancy. We also examined the association between gut microbiota and maternal characteristics, including glycoalbumin.

Results

Microbiota composition in early and late pregnancy did not differ, according to principal coordinate analysis of weighted and unweighted UniFrac distances. Shannon indices were not different between early and late pregnancy. The proportion of one phylum, TM7, significantly decreased in late pregnancy compared with early pregnancy, but the proportions of other major phyla did not change. The Shannon index of late pregnancy was negatively associated with pregestational body mass index and positively correlated with glycoalbumin level, with adjustment of covariates.

Conclusions

We concluded that Japanese women did not show obvious differences in gut microbiota during pregnancy, except for TM7, and that the diversity of gut microbiota might affect maternal metabolism. As this study had limited statistical power, further large‐scale studies are required.
Competition, patent protection, and innovation with heterogeneous firms in an endogenous market structure
Authors: Suzuki Keishun
Published: November 2019

This paper revisits the relationship between competition and innovation by incorporating the heterogeneity of R&D efficiency across firms and an endogenous market structure in a dynamic general equilibrium model. Using an analytically tractable model, we show that competition and innovation can have either an inverted‐U or a negative relationship, as reported by several empirical studies. Furthermore, we show that the effect of strengthening patent protection on innovation depends on the competition level. In particular, we find a complementary relationship between competition policy and the strengthening of patent protection.
Allosteric modulators restore orthosteric agonist binding to mutated CB1 receptors
Authors: Dopart Rachel , Kendall Debra A
Published: November 2019

Objectives

To determine if diminished orthosteric agonist binding due to mutations in extracellular loops 1 or 2 of the cannabinoid receptor 1 (CB1) can be overcome by an allosteric modulator and restore agonist binding.

Methods

Binding assays were performed using a range of concentrations of orthosteric compound, in the presence or absence of a set concentration of the allosteric modulator PSNCBAM-1 to determine the EC50 in its absence or presence.

Key findings

Single mutations in extracellular loop 1 or 2 of CB1 showed weak or no binding of agonist CP55940 to the receptor. Interestingly, upon addition of the allosteric modulator PSNCBAM-1, this binding was restored typically to wild-type CB1 levels. In a few cases, the allosteric modulator ORG27569 was compared with PSNCBAM-1 for CP55940 binding and it also restored binding. Further, wild-type levels of inverse agonist bound the CB1 mutants in the absence of modulator, suggesting the mutants were originally folded like the wild type.

Conclusions

Based on our findings, we provide evidence of a therapeutic application for allosteric modulators in situations where a mutation in the receptor may hinder its function. By utilizing allosteric modulators, restoration of orthosteric binding may be possible.
Phosphorus excretion by mares post‐lactation
Authors: Fowler Ashley L. , Pyles Morgan B. , Hayes Susan H. , Crum Andrea D. , Lawrence Laurie M.
Published: November 2019

Across the equine literature, estimates of true P digestibility range from −23% to 79%. This large range cannot be explained by differences in P intake or phytate‐P intake alone. However, differences in endogenous P secretion into the GI tract may explain the variation. In horses, excess absorbed P is not excreted in the urine but is re‐secreted into the GI tract, increasing faecal P and leading to estimates of low P digestibility. Thus, accurate estimates of P digestibility can only be obtained if absorbed P is retained in the horse. The objective of this study was to examine P digestibility in post‐lactational mares and control mares that were fed similar amounts of P. It was hypothesized that post‐lactational mares would have greater P retention and higher apparent P digestibility than control mares. Prior to the study, four lactating and four non‐lactating mares were fed a diet that provided 100% of the control mares’ P requirement, but only 55% of the lactating mares’ P requirement. During the study, both groups were fed P at the rate recommended for non‐lactating mares. Post‐lactational mares did not retain more P than control mares but tended to excrete more P than control mares (p = .082), presumably due to differences in endogenous P secretion into the GI tract. Metabolic changes occurring during mammary gland involution may have contributed to the increase in P excretion. However, faecal P excretion exceeded P intake in both groups (p = .08) and both groups lost weight during the study. Tissue mobilization during weight loss may have influenced P secretion into the GI tract.
Digital Transformation and Public Service Delivery in Brazil
Authors: Filgueiras Fernando , Flávio Cireno , Palotti Pedro
Published: November 2019

This article analyzes the digital transformation process of public services in the Brazilian federal government. Based on a survey with 85 federal organizations, 1,740 public services are examined according to different factors that explain why a certain public service is digitalized. We discuss the transition from an e‐government to a digital policy, listing the limits related to agent preferences in public policies. The article discusses digital transformation in governments as a process of institutional change in public organizations, taking into account the role of agents, the contexts of choices, and the factors that explain the decision to digitize public services.
Epigenetic accounting of a previous harvest
Authors: Hoijemberg Mauro , Cerdán Pablo D.
Published: November 2019

This article is a Commentary on Agustí et al., 225: 376–384.
Efficacy and safety of catheter ablation combined with left atrial appendage occlusion for nonvalvular atrial fibrillation: A systematic review and meta‐analysis
Authors: Jiang Ying , Li Fanghui , Li Dongze , Cheng Yisong , Jia Yu , Fu Hua , Pu Xiaobo , Hu Hongde , Jiang Jian , Zeng Rui
Published: November 2019

Atrial fibrillation (AF) is currently the most prevalent arrhythmia in clinical practice, with stroke being one of its major complications. Combining catheter ablation and percutaneous left atrial appendage occlusion (LAAO) into a “one‐stop” intervention could reduce stroke incidence in selected high‐risk patients and, at the same time, relieve AF symptoms in a single procedure. This meta‐analysis analyzed the efficacy and safety of catheter ablation combined with LAAO for nonvalvular AF. PubMed, EMBASE, and the Cochrane Library were searched from inception to April 2019 to identify relevant citations. Efficacy indexes were procedural success, AF recurrence, stroke/transient ischemic attacks (TIA), and device‐related thrombus (DRT). Safety indexes were all‐cause death, major hemorrhagic complications, and pericardial effusion/cardiac tamponade. The incidence rate of events (ratio of events to patients) and 95% confidence interval (CI) were calculated as summary results. A forest plot was constructed to present pooled rates. Eighteen studies (two randomized controlled trials and 16 observational studies) were included. The results showed that one‐stop intervention has significant efficacy and safety, with procedural success of .98 (95% CI, .97‐1.00), AF recurrence of .24 (95% CI, .15‐.35), stroke/TIA of .01 (95% CI, .00‐.01), DRT of .00 (95% CI, .00‐.01), all‐cause mortality of .00 (95% CI, .00‐.00), cardiac/neurological mortality of .00 (95% CI, .00‐.00), major hemorrhagic complications of .01 (95% CI, .00‐.02), and pericardial effusion/cardiac tamponade of .01 (95% CI, .00‐.01). A single procedure with catheter ablation and LAAO in AF is a feasible strategy with significant efficacy and safety.
An improved RANSAC algorithm for extracting roof planes from airborne lidar data
Authors: Canaz Sevgen Sibel , Karsli Fevzi
Published: November 2019

The extraction of building roof planes from lidar data has become a popular research topic with random sample consensus (RANSAC) being one of the most commonly adopted algorithms. RANSAC extracts full planes, which is problematic when there are other points outside the plane boundary but within the plane space. This study proposes an improved RANSAC (I‐RANSAC) algorithm by removing points that do not belong to the roof plane. I‐RANSAC selects a random point from the extracted roof plane and then searches for its neighbours within a given threshold to identify and remove outliers. The new algorithm was tested with 14 buildings from two datasets, where quality control measures showed significant improvement over standard RANSAC.
MicroRNA evolution provides new evidence for a close relationship of Diplura to Insecta
Authors: Liu Ai‐Min , Chen Wan‐Jun , Huang Cheng‐Wang , Qian Chang‐Yuan , Liang Yan , Li Sheng , Zhan Shuai , Luan Yun‐Xia
Published: November 2019

The phylogenetic interrelationships among four hexapod lineages (Protura, Collembola, Diplura and Insecta) are pivotal to understanding the origin of insects and the early diversification of Hexapoda, but they have been difficult to clarify based on the available data. In this study, we identified 91 conserved microRNA (miRNA) families from 36 panarthropod taxa, including seven newly sequenced non‐insect hexapods. We found major clade differentiation accompanied by the origin of novel miRNA families, and most miRNA clusters are conserved with a high degree of microsynteny. Importantly, we were able to identify two miRNA families unique to Hexapoda, and four miRNA families and a miRNA cluster that exist exclusively in Diplura and Insecta, suggesting a close relationship between Diplura and Insecta as well as the monophyly of Hexapoda. Combined with a phylogenetic analysis based on the presence/absence matrix of miRNA families, our study demonstrates the effectiveness of miRNA in resolving deep phylogenetic problems.
Can we use structural knowledge to design a protective vaccine against HIV‐1?
Authors: Bjorkman Pamela J.
Published: November 2019

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) remains one of the most important current threats to global public health. Since its identification in the early 1980s, at least 75 million people have been infected with HIV‐1, the virus that causes AIDS. Although antiretroviral drugs are effective at prolonging life after infection in the developed world, they are associated with significant side effects and are not in widespread use in the developing world. The best way to control the AIDS epidemic would be a vaccine that protects against infection by HIV‐1. Most vaccines work by inducing antibodies in serum or mucosa that block infection or prevent invasion of the bloodstream. Here, I describe background related to my laboratory's attempts to develop an immunogen that would elicit protective antibodies against HIV‐1.
Detection of an HLA‐DRB1*14 variant, HLA‐DRB1*14:141, in a Taiwanese individual
Authors: Yang Kuo‐Liang , Lin Py‐Yu
Published: November 2019

Nucleotide substitutions in 14 codons of HLA‐DRB1*14:03:01 result in a novel allele HLA‐DRB1*14:141.
The Weaver's House: Ethnography, Translation, and Video in the Highlands of Mindanao
Authors: Quizon Cherubim
Published: November 2019

When short video embedded in museum exhibitions aims to present the voice of Indigenous artists, what constrains desired outcomes? This ethnographic study examines the processes behind one such video that focused on Lang Dúlay, a T'boli weaver from Mindanao, the Philippines. Written from the perspective of the researcher/director/producer newly using video in the field, it examines overlaps in ethnographic and visual anthropological theory and uses them to analyze video‐mediated events in the field. The failure to tell the story that the weaver cared most about along with responses and modes of resistance by filmed Indigenous interlocutors is also presented and analyzed.
The MINDBODYSTRONG Intervention for New Nurse Residents: 6‐Month Effects on Mental Health Outcomes, Healthy Lifestyle Behaviors, and Job Satisfaction
Authors: Sampson Marlene , Melnyk Bernadette Mazurek , Hoying Jacqueline
Published: November 2019

Background

In 2017, the National Academy of Medicine convened its Action Collaborative for Clinician Well‐being and Resilience in an effort to stem the epidemic levels of burnout, depression, and suicide among healthcare clinicians. Nurses report higher rates of substance abuse, depression, and suicide than the national average. Newly licensed registered nurses (NLRNs) report high levels of burnout and stress. Suboptimal health in nurses is linked to medical errors. Few studies address the mental health and lifestyle behaviors of NLRNs or provide evidence‐based solutions to improve these outcomes.

Aims

This study evaluated the 6‐month effects of the MINDBODYSTRONG for Healthcare Professionals program on the mental health, healthy lifestyle behaviors, and job satisfaction of NLRNs participating in a nurse residency program.

Methods

A two‐group randomized controlled trial was conducted with 89 NLRNs at a large, Midwestern academic medical center. The intervention group received eight 30– to 35‐min weekly sessions as part of the MINDBODYSTRONG program, a cognitive behavioral skill‐building program incorporating strategies to improve mental and physical health. The control group acted as the attention control group receiving eight weekly 30– to 35‐min debriefing sessions as part of the normal nurse residency program.

Results

Data were collected at baseline, immediately postintervention, 3 months postintervention, and 6 months postintervention. The intervention group scored better on mental health outcomes, healthy lifestyle behaviors, and job satisfaction at 6 months postintervention than the control group. Significant improvements were found for depressive symptoms and job satisfaction; there were moderate to large positive effects for the MINDBODYSTRONG program on all variables.

Linking Evidence to Action

The MINDBODYSTRONG program sustained its positive effects across time and has excellent potential as an evidence‐based intervention for improving the mental health, healthy lifestyle behaviors, and job satisfaction in NLRNs.
Fabricating Fe nanocrystals via encapsulation at the graphite surface
Authors: Lii-Rosales Ann , Han Yong , Lai King C. , Jing Dapeng , Tringides Michael C. , Evans James W. , Thiel Patricia A.
Published: November 2019

In this paper, the authors describe the conditions under which Fe forms encapsulated nanocrystals beneath the surface of graphite, and they characterize these islands (graphite + Fe) thoroughly. The authors use the experimental techniques of scanning tunneling microscopy (STM) plus x-ray photoelectron spectroscopy (XPS) and the computational technique of density functional theory (DFT). Necessary conditions for encapsulation are preexisting ion-induced defects in the graphite substrate and elevated deposition temperature of 875–900 K. Evidence of encapsulation consists of atomically resolved STM images of a carbon lattice, both on top of the islands and on the sloping sides. The nature of the images indicates that this carbon lattice corresponds to a graphene blanket consisting of more than one graphene sheet that drapes continuously from the top of the island to the graphite substrate. The formation of iron carbide is not observed based on XPS. Shapes of the island footprints are consistent with metallic Fe, predominantly in the hcp or fcc form, though larger islands tend toward bcc. Island structures with hexagonally close-packed lateral hcp or fcc planes are stabilized by their excellent lattice match with the graphite substrate. Evolution of island density with prolonged deposition time provides evidence of coarsening, perhaps via Smoluchowski ripening. The encapsulated Fe clusters are stable in air at room temperature, protected by smaller Fe clusters that decorate defect sites and block permeation of gases. DFT shows that two configurations of Fe are more stable within the gallery than adsorbed on top of the surface: a single atom of Fe and a film (slab) of metallic Fe. Comparison with other metals shows that encapsulated Fe is similar to Cu but dissimilar to Ru or Dy, leading the authors to conclude that carbon dissolution in the metal does not play a role in encapsulation.
Psychoacoustic measurement of phase and level for cross-talk cancellation using bilateral bone transducers: Comparison of methods
Authors: Mcleod Robert W. J. , Culling John F.
Published: November 2019

Two bone-conduction hearing aids (BCHAs) could deliver improved stereo separation using cross-talk cancellation. Sound vibrations from each BCHA would be cancelled at the contralateral cochlea by an out-of-phase signal of the same level from the ipsilateral BCHA. A method to measure the level and phase required for these cancellation signals was developed and cross-validated with an established technique that combines air- and bone-conducted sound. Three participants with normal hearing wore bone transducers (BTs) on each mastoid and insert earphones. Both BTs produced a pure tone and the level and phase were adjusted in the right BT in order to cancel all perceived sound at that ear. To cross-validate, one BT was stimulated with a pure tone and participants cancelled the resultant signal at both cochleae via adjustment of the phase and level of signals from the earphones. Participants achieved cancellation using both methods between 1.5 and 8 kHz. Levels measured with each method differed by <1 dB between 3 and 5 kHz. The phase results also corresponded well for the cancelled ear (11° mean difference) but poorly for the contralateral ear (38.4° mean difference). The first method is transferable to patients with middle-ear dysfunction, but covers a limited frequency range.
A paradigm to explore bistatic matching in the bottlenose dolphin (Tursiops truncatus)
Authors: Houser Dorian S. , Mulsow Jason , Tormey Megan , Wu Teri , Crafton Leah , Simmons Rachel , Xitco Mark J. , Finneran James J.
Published: November 2019

Match-to-sample (MTS) has been demonstrated in dolphins using echolocation and across sensory modalities (e.g., visual to echolocation and vice-versa). To assess potential for bistatic MTS, a pilot study was conducted in which a dolphin listened to one of three recorded playbacks of echoes obtained from targets of different shape and material composition and was then asked to echo locate on a set of physical alternatives and choose the corresponding target. Training began with two alternatives and 50% errorless trials, where only the matching physical target was presented. The proportion of errorless trials was progressively reduced to 25%, 12.5%, and then 0% as a criterion of three sessions with >80% correct matching was met. Thereafter, all three alternatives were presented with 0% errorless trials. The dolphin consistently performed above chance over 34 sessions—average correct matching rate was 76% (range 67%–96%)—even though the projected sample echoes did not faithfully reproduce echoes obtained when the dolphin insonified the targets with echolocation clicks. Future testing with novel stimulus sets would be required to determine if and how a dolphin might spontaneously generalize between projected echo facsimiles and real world targets.
Active infotaxis as a model for echolocation
Authors: Lee Wu-Jung , Buck John R. , Tyack Peter L. , Shinn-Cunningham Barbara
Published: November 2019

Recent literature established the highly adaptive nature of echolocation: both toothed whales and bats modify their signals and sonar beam movements dynamically based on echoes from previous emissions in a task-depending manner. However, no theoretical framework systematically interprets these search processes across varying taxa and experimental conditions. To address this need, we cast the “infotaxis” model originally proposed for simulating moth odor tracking into the context of echolocation-based target search. Infotaxis posits that the animal chooses their next action to maximize the expected information gain. By doing so, the searching animal balances the exploration of new information about its environment with exploitation of existing information. The echolocator chooses the next sonar beam location and signal content based on its internal representations of the search space and sensory uncertainty. We model the echolocator’s internal representation of the search space, the echo signatures of the target and clutter objects, and information acquired from echoes as probabilistic distributions and employ a Bayesian update of the target distribution after each echolocation reception. Simulations show the repeated inspection and switching among objects commonly observed in behavioral experiments of echolocation search. [Work supported by ONR MURI program.]
Acoustic characteristics near the living pool of captive belugas whale
Authors: Cao Zhengliang , Song Liming , Chen Zhong
Published: November 2019

Belugas are widely known for their diverse and frequent calls and have been given the nickname, “sea canaries.” As the number of belugas has been living in aquariums and ocean parks, it is very important for us to provide a comfortable environment for these creatures. That means we should understand how sounds made by belugas vocalization and environmental noise related to belugas habitats, therefore designing the most suitable artificial pool for these creatures. This study is on sound acquisition and acoustic estimation near the living pool of captive belugas whales in a new Ocean Park. Besides different hydrophones using for passive acoustic recording, accelerometer sensors and sound meters are deployed to obtain structural vibrations and airborne noises, respectively. Acoustic signals in different sites and pools were recorded, and their characteristics are analyzed and compared to mainly understand the relationship between underwater acoustics and structural vibrations. In the future, more detail tests will design to find out what is the main noise source which may be influencing belugas’ living. This study is also helpful to apply appropriate and reasonable methods for noise reduction. [Work supported by National Natural Science Foundation of China (Grant No. 41374147).]
Advances in technology and signal processing for ocean acoustic tomography
Authors: Worcester Peter F. , Dzieciuch Matthew A.
Published: November 2019

The acoustic source and receiver technologies used to make large-scale tomographic measurements have advanced significantly in recent years. High-efficiency, swept-frequency sources in the 200–300 band have been developed by Teledyne Webb Research. Ultra-low frequency sources in the 30–40 Hz band required for measurements in ice-covered regions have been developed by GeoSpectrum Technologies, Inc. Acoustic receiver technology has also improved. Early instruments were complicated devices because of the scientific requirements for precision timekeeping, measurement of the motion of the moored instruments, and the storage of large amounts of acoustic data. Modern developments in data acquisition systems and data storage have now made the required instrumentation more user friendly. Distributed Vertical Line Array (DVLA) receivers made up of distributed, self-recording Hydrophone Modules and a small number of central controllers now allow large vertical receiving arrays to be deployed. Of equal importance to the hardware developments, the processing of tomographic data has become much more routine. Estimator-correlator processing explicitly accounts for scattering in the receptions. The Viterbi algorithm is used for automated peak tracking to obtain time series of travel times. Finally, travel times (and other data) are now being used to directly constrain ocean circulation models to estimate the state of the ocean.
In situ measurements of compressional and shear wave properties during gravity coring operations
Authors: Ballard Megan S. , Lee Kevin M. , McNeese Andrew R. , Wilson Preston S.
Published: November 2019

Sediment cores provide valuable insight about the physical properties of the seabed, and laboratory measurements of sediment wave speed from cores are often considered “ground truth.” However, sound-speed estimates obtained from cores can be inaccurate due to changes in pressure, temperature, and mechanical properties of the sediment caused by the removal of the core from the seabed and its subsequent transport to the laboratory. To address these issues, the Acoustic Coring System (ACS) was developed. The system uses sets of transducers mounted below the penetrating tip of a sediment corer to make in situ measurements of geoacoustic properties as the corer penetrates the seabed. Compressional wave measurements are obtained with rod-mounted piezoelectric cylinders, and shear wave measurements are obtained with bender elements mounted in flat blades. The ACS was deployed during the environmental survey for ONR Seabed Characterization Experiment (SBCEX) in 2016 and in support of the ONR Canada Basin Acoustic Propagation Experiment (CANAPE) in 2017. In both cases, the system provided measurements of the sediment sound-speed profile as a function of depth within the seabed. On-going work focused on the measurement of shear wave speed profiles and compressional and shear wave attenuation will also be presented. [Work supported by ONR.]
Long range intensity fluctuations on the Chukchi continental shelf measured during the year-long Canada Basin Acoustic Propagation Experiment 2017
Authors: Badiey Mohsen , Wan Lin , Escobar Christian D. , Pecknold Sean , Krishfield Richard A. , Proshutinsky Andrey Y. , Colosi John A. , Worcester Peter F. , Dzieciuch Mathew
Published: November 2019

Analysis of one-year-long broadband transmissions from five deep water sound sources recorded on shelf during the Canada Basin Acoustic Propagation shows strong azimuthal variability. Broadband chirp signals (140–325 Hz) transmitted every 4 h were received on spatially distributed receiver arrays on the Chukchi shelf from October 2016 through 2017. Here, we present spatial, temporal, and azimuthal correlations by four receiver arrays with source-receiver distances ranging from 228.6 to 524.4 km in a cross-the-shelf orientation. Temporal fluctuations in received field are related to water column variability for each source-receiver pair. Received signals from the same source to each receiver on the shelf, separated from 15.8 to 49.63 km in “along-the-shelf” direction show large intensity fluctuation. This is related to the turbulence that signals have experienced in their path. Temporal and spatial variations of temperature profiles were measured on the shelf, however, from deep water sources to the shelf break region, there is little information. Analysis are conducted for three time zones, from fully frozen seas, transition from full ice, and ice-free conditions. The parabolic equation model is used to report the propagation of field for the ice-free condition. Limitations of the acoustic modeling due to spatially under-sampled input environmental parameters are discussed. [Work supported by ONR-322 OA.]
Horses for courses (or something much smaller!): The design, development and acoustic testing of sub-micron cavitation nucleation agents for biomedical applications
Authors: Mannaris Christophoros , Bau Luca , Kwan James J. , Teo Boon , Gray Michael , Elbes Delphine , Smith Cameron , Paverd Catherine , Carlisle Robert , Stride Eleanor P. , Coussios Constantin
Published: November 2019

Lipid and protein-shelled microbubbles have been the mainstay of cavitation nucleation strategies for therapeutic applications for several decades. However, a growing number of therapeutic ultrasound applications require nuclei that (i) are significantly smaller in size, in order to overcome a particular biological barrier such as the leaky vasculature of tumours or the stratum corneum; (ii) offer greatly increased cavitation persistence, both during a single extended ultrasound pulse and in terms of extended circulation following intravenous administration; and (iii) have better resilience to sudden ambient pressure changes in order to enable direct injection without nuclei destruction into tissue targets via a needle and syringe. We will review a range of novel cavitation agents currently under development, including sub-micron gas-stabilizing solid particles and nanodroplets, and provide an overview of their known characteristics in terms of acoustic emissions, activation and cavitation thresholds, cavitation persistence, and circulation. Where possible, the relevant performance of these cavitation nucleation agents will be compared to microbubbles for applications ranging from drug delivery to nucleated tissue fractionation.
Impact of microphone configuration on sonic boom recordings
Authors: Novakovich Daniel J. , Gee Kent L. , Rasband Reese D. , Loubeau Alexandra
Published: November 2019

Because different measurement setups can affect sonic boom recordings, this paper compares different microphone configurations employed during NASA’s Quiet Supersonic Flights 2018(QSF18) research campaign in Galveston, TX. Hardware was deployed at two geographically unique locations that reasonably represented the three different measurement approaches across QSF18. Analysis of several booms points to acoustically relevant differences in the various configurations, most likely caused by microphone height and windscreen type. An elevated microphone has measurable multipath interference effects (also observed in complementary laboratory measurements) and is subjected to increased wind. Additionally, sensors with more compact wind screens have less wind-noise rejection. The multipath effects, in particular, can cause bias errors in relevant metric calculations. Thus, this comparison is useful in the design and planning of similar, future measurements. [Work supported by NASA Langley Research Center through the National Institute of Aerospace.]
Towards 3-D thermoacoustic plasma confinement
Authors: Pree Seth , Koulakis John P. , Putterman Seth
Published: November 2019

Standing wave acoustic fields can segregate partially ionized gas by temperature via a generalized acoustic radiation pressure that we have called the pycnoclinic acoustic force. Thus far, these sound fields have been excited and sustained with a microwave source pulsed near the resonance frequency of a cavity. Consideration of the temperature and luminosity oscillations due to the adiabatic compression of a sound wave suggests an alternative method of driving the sound field necessary for confinement. Acoustic temperature oscillations in the presence of continuous (i.e., not pulsed) microwave fields may cause variable microwave absorption in phase with the acoustic oscillation so as to add energy to the sound field. If the energy added by microwave absorption exceeds that lost to acoustic damping, amplification, and possibly self-oscillation will occur. We give theoretical criteria for amplification and present the apparatus and measurements intended to find signatures of plasma thermoacoustics.
Integrated in situ and ex situ ultrasonic characterization of Ti6Al4V parts made with directed energy deposition additive manufacturing with hybrid capabilities
Authors: Turner Joseph A. , Sotelo Luz D. , Karunakaran Rakeshkumar , Kanger Cody J. , Sealy Michael P.
Published: November 2019

Metal additive manufacturing (AM) is employed to make highly complex low volume components, which often have demanding performance requirements. Current challenges in the metal AM field include control of porosity and microstructure, development of process-structure-property relationships, and simplification of the AM parameter space. These challenges are exacerbated in multiphase materials, such as Ti6Al4V, that are important for the biomedical, aerospace, and energy industries. Integrated in situ and ex situ non-destructive evaluation methods are proposed to address these challenges. In this work, in situ and ex situ ultrasound measurements are conducted on Ti6Al4V parts made using a hybrid Directed Energy Deposition (DED) system. The hybrid capabilities of the system are exploited to quantify part geometry, while ultrasound is used to measure phase velocity and attenuation in situ on a layer-by-layer basis. Furthermore, the phase velocity, attenuation, and backscatter responses of these AM and Hybrid AM parts are quantified ex situ and compared with those from conventionally manufactured Ti6Al4V parts to evaluate the role of microstructural complexity. The results highlight the improved geometric information offered by a hybrid AM system to quantify microstructure and elastic properties of parts in situ. The need for realistic complex microstructures to be integrated within model-based ultrasonic microstructural predictions is also discussed.
Acoustic signals associated with laser-substrate interaction in powder bed fusion additive manufacturing process
Authors: Smith Robert W. , Corbin David J. , Petrich Jan , Reutzel Edward W.
Published: November 2019

During the Powder Bed Fusion Additive Manufacturing Process, flaws are sometimes produced in the component. It is desirable to detect these flaws during the deposition process, so that they might be remediated before they become captured within the part. A pilot study was conducted to see if acoustic data might show some signature or variation when such flaws are produced. This paper will provide some observations on acoustic data recorded during such an additive manufacturing deposition process. Acoustic data were collected within the chamber during the Powder Bed Fusion Additive Manufacturing Process in a 3D Systems Launches Pro-X 320 Direct Metal Printer. A PCB ¼ inch model 378A14 pre-polarized piezo-electric pressure microphone with an integrated preamplifier was the sensor used to detect acoustic signals. Tonal noise associated with pumps obscured the spectral region below 10 kHz, but significant acoustic output associated with the laser-substrate interaction was present from this lower limit. A small cylinder was produced for test, during which intentional process variations were introduced. A CT scan of the cylinder was used to locate flaws, and to register these locations, and thus to attempt to correlate these flaw locations with time windows in the acoustic data.
Perceptual biases in consonant perception—Where do we find them? What is behind them?
Authors: Polka Linda
Published: November 2019

There is no doubt that language experience has an early and profound impact on the perception of phonetic segments. There is now clear evidence that phonetic perception is also shaped by universal perceptual biases that can be exposed as directional asymmetries in phonetic discrimination. Much of this work has focused on vowel perception in which we observe robust perceptual asymmetries in infant and adult L2 perception. To explain these patterns, Polka and Bohn (2003) and (2011) outlined the Natural Referent Vowel (NRV) framework which proposes that vowel perception is shaped by both generic (universal) and language-specific processing. In this talk, I will present data showing perceptual biases in consonant perception which suggest that we can extend NRV principles to consonant perception.
Characterization of the effects of ground boards on acoustic signals
Authors: Anderson Mark , Stephenson James H. , Zawodny Nikolas S. , Gee Kent L.
Published: November 2019

International and Federal regulations stipulate the acquisition of aircraft noise shall be conducted using inverted pressure microphones over a round ground board. These ground boards are used to provide an acoustically hard reflecting surface, limiting the effects of the potentially absorptive ground local to the test location. The microphone location is also specified to be offset from the center of the board to limit the effects of acoustic diffraction off the board edge. In order to determine the effects of the ground board on the measured acoustic signal, a comprehensive measurement campaign was undertaken at NASA Langley Research Center. The experimental setup included multiple ground board configurations placed on top of a sand pit, in an otherwise anechoic chamber. Ground board configurations included a microphone inverted and offset over the round ground board, a microphone offset and flush mounted in the ground board, and a microphone flush mounted in the sand. A detailed frequency sweep from a known source was then used to investigate the ground board effects on the recorded signal. Normal impedance measurements were also acquired to determine the reflection coefficients of the sand and ground boards. Experimental results are discussed, along with implications for future research and development.
Sparse representation of the sound field in a room with dictionary learning
Authors: Fernandez-Grande Efren , Hahmann Manuel , Verburg Samuel A.
Published: November 2019

Phased array measurements of the sound pressure in a room enable to reconstruct the sound field, i.e., to estimate pressure, velocity and sound intensity in positions that have not been measured. Typically, analytical wave functions are used to expand the measured data and interpolate the wave field. However, these bases are often redundant and lead to non-sparse solutions, as multiple basis functions are required to represent the measured data. In this study, we examine the use of dictionary learning to obtain a sparse representation of the sound field in a room, using atoms learned from experimental data. The aim is to obtain a model of reduced dimensionality that can represent optimally the spatial properties of the sound field in a room. We analyse the properties of the extracted dictionaries, their ability to reconstruct the sound field, and their generality. A broader question is the suitability of a given dictionary, which has been extracted from a particular room, to represent the sound field in another room.
Hard surface flooring policy for residential condominiums
Authors: Lilly Jerry G.
Published: November 2019

A majority of the residential condominiums in the USA were originally constructed with wall to wall carpet flooring in the living rooms, bedrooms, and hallways. Removing the carpet and replacing it with various types of hard surface flooring is a recent popular trend. Converting these areas from carpet to hard surface flooring will result in a significant increase in impact sound transmission to the floor below as well as adjacent living units on the same floor. Unfortunately, some condominium homeowner’s associations do not have a written policy for accepting these modifications. Those that do often set the floor acceptance criterion as a field tested FIIC (now called AIIC) rating (typically in the 50 to 55 range), tested after the hard surface flooring is installed. This can result in significant financial impacts to the homeowner installing the flooring if final testing reveals that the floor does not meet the criterion set by the homeowner’s association. This presentation will discuss the complicated issues facing all three parties (homeowner, neighbor, and HOA Board) and presents a recommendation for a written policy that is fair to all.
Introduction in the Russian federation of international standards in the field of measurement and evaluation of sound insulation
Authors: Tsukernikov Ilya E. , Shubin Igor , Nevenchannaya Tatiana
Published: November 2019

The features of the introduction in the Russian Federation of international standards for measurement and evaluation of sound insulation are considered. Over the past eight years, a system for measuring and evaluating the sound insulation of buildings and their elements has been created on the basis of international standards. In 2012, a series of international standards ISO 10140 for methods of laboratory measurements of airborne and impact sound insulation was introduced as the national standards of Russia GOST R ISO. In 2016, the standards ISO 717 were introduced as modified national standards GOST R 56769-2015 and GOST R 56770-2015, setting the rules for single-number rating of airborne and impact sound insulation. In 2018, the international standard ISO 12999-1 was introduced as a modified national standard GOST R 57900-2017 for determining and applying the uncertainties in measuring sound insulation. In 2019, a draft national standard was prepared for field measurement of sound insulation of facades and their elements, which is a modified edition of the ISO 16283-3. Single-numeric parameters of airborne and impact insulation determined using these standards are subject to comparison with the normative values regulated by the national regulatory document—the set of rules SP 51.13330.
Vocal behavior in spotted seals (Phoca largha)
Authors: Sills Jillian , Reichmuth Colleen
Published: November 2019

Captive studies can inform passive acoustic monitoring efforts by describing fundamental features of species-typical vocalizations emitted by known individuals. These include acoustic parameters as well as developmental, seasonal, and sex-based patterns in vocal behavior. Here, two male spotted seals were studied in captivity from age 3 months through 8 years. Vocal behavior was scored daily and opportunistically recorded. The production of underwater calls emerged with presumed sexual maturity (age 4). To evaluate vocal repertoire and fine-scale temporal patterns of sound production in adult seals, an underwater acoustic recorder was continuously deployed with these seals at age 7–8 years. The spotted seals produced a variety of underwater calls—including roars, knocks, and moans—with dominant energy below 1 kHz. There was a marked annual peak in vocal activity in spring, prior to the yearly molt. This period coincided with increased aggressive behavior and musky odor indicative of heightened reproductive activity. These results from developing male spotted seals, obtained in the absence of conspecific females, confirm the production of recognizable, stereotypic underwater calls associated with the breeding season. These findings can be used to inform the use of autonomous acoustic recorders to track the presence and movements of free-ranging seals in remote habitats.