bluuebunny/crossref_metadata_2025 huggingface dataset:
An investigation of main meal preferences in nursing home residents
Authors: Okkels Signe L. , Dybdal Ditte R. , Beck Anne M. , Bügel Susanne , Klausen Tobias W. , Olsen Annemarie
Published: April 2019

Nursing home residents are at high risk of undernutrition. Their nutritional status could possibly be improved by identifying and serving meals according to their preferences. Thus, the aim of the current study was to investigate basic sensory customization factors of most preferred main meals in nursing home residents. In total, 40 popular Danish meals from two hospital kitchens and one meals‐on‐wheels kitchen were chosen for the study. Thirty of the meals contained meat (pork, beef, mixed meat, chicken, and fish) and the rest were plant‐based. Twenty‐nine nursing home residents evaluated liking of appearance, flavor, and texture on a five‐point liking scale. The test was divided in eight tasting sessions, where the participants tested five food samples per session at 10.30–11.30 a.m. Prior to the tasting sessions, the participants were screened for nutritional risk and eating problems and level of appetite was tested on a five‐point category scale. The sensory meal preferences included meals containing fish, beef, and pork and could be related to meal familiarity and chewing and swallowing difficulties of old adults, which should be kept in mind when making further adjustments in the meal preparation before served the target group.

Practical applications

Product development and sensory meal customization are used in various ways to improve food intake indifferent populations. When focusing on nursing home residents, customization of meals could be a way to improve the nutritional status of this target group. Before determining the exact way of customization, the actual acceptance of the meal types available for nursing home residents should be identified. In this way the sensory factors of high and low liked meals could be found, and the product development initiated. To gain in sight into meal preferences from the target group of focus, meal tasting sessions with nursing home residents could be used.
The signaling peptide NprX controlling sporulation and necrotrophism is imported into Bacillus thuringiensis by two oligopeptide permease systems
Authors: Dubois Thomas , Lemy Christelle , Perchat Stéphane , Lereclus Didier
Published: April 2019

The infectious cycle of Bacillus thuringiensis in the insect host is regulated by quorum sensors of the RNPP family. The activity of these regulators is modulated by their cognate signaling peptides translocated into the bacterial cells by oligopeptide permeases (Opp systems). In B. thuringiensis, the quorum sensor NprR is a bi‐functional regulator that connects sporulation to necrotrophism. The binding of the signaling peptide NprX switches NprR from a dimeric inhibitor of sporulation to a tetrameric transcriptional activator involved in the necrotrophic lifestyle of B. thuringiensis. Here, we report that NprX is imported into the bacterial cells by two different oligopeptide permease systems. The first one is Opp, the system known to be involved in the import of the signaling peptide PapR in B. thuringiensis and Bacillus cereus. The second, designated as Npp (NprX peptide permease), was not previously described. We show that at least two substrate binding proteins (SBPs) are able to translocate NprX through OppBCDF. In contrast, we demonstrate that a unique SBP (NppA) can translocate NprX through NppDFBC. We identified the promoter of the npp operon, and we showed that transcription starts at the onset of stationary phase and is repressed by the nutritional regulator CodY during the exponential growth phase.
The Wnt signaling pathway: a potential therapeutic target against cancer
Authors: Ghosh Noyel , Hossain Uday , Mandal Ankita , Sil Parames C.
Published: April 2019

The role of the evolutionarily conserved Wnt signaling pathway is well documented in several cellular processes, such as cell proliferation, differentiation, cell motility, and maintenance of the stem cell niche. The very first indication that aberrant Wnt signaling can cause carcinogenesis came from a finding that the mutation of the adenomatous polyposis coli gene (APC) predisposes a person to colorectal carcinoma. Later, with progressing research it became clear that abnormal activation or mutation of the genes related to this pathway could drive tumorigenesis. Here, we review recent advances in research regarding Wnt signaling regulation and its role in several cancer subtypes. Additionally, the utility of Wnt pathway–targeted cancer therapy intervention is also highlighted, with an overview of current approaches to target the Wnt pathway in oncogenesis and the future scopes and challenges associated with them.
Repressive Compassion: Deportation Caseworkers Furnishing an Emotional Comfort Zone in Encounters with Illegalized Migrants
Authors: Kalir Barak
Published: April 2019

The treatment of illegalized migrants in Western liberal states has been often characterized by a duality of compassion and repression. Within this dyad, repression is said to be applied with the right hand of the state by the police, border control, refugee status determination units, etc., and compassion with its left hand by social workers, medical staff, as well as civil society organizations and humanitarian agencies. Drawing on the toil of deportation caseworkers in the Netherlands, this article argues that compassion is prevalent not only among those who show benevolence and support illegalized migrants but also among many who work on the repressive side of the divide. However, expressions of compassion by deportation caseworkers do not seem to mitigate an otherwise repressive bureaucratic work. Instead, compassion often helps caseworkers to furnish a comfort zone in which emotions can be discharged and from which caseworkers neutralize potentially disruptive affective dynamics by experiencing them as intrinsic to the law they implement. Compassion not only fails to produce vertical commonality with deportable migrants in vulnerable positions; it also willfully fosters the self‐image of civil servants as humane and sensitive actors as they effectively implement controversial state policies.
Power transitions and global trade governance: The impact of a rising China on the export credit regime
Authors: Hopewell Kristen
Published: April 2019

The existing liberal international economic order was constructed during the era of American hegemony and has been heavily shaped by US power. How is the rise of China affecting global economic governance? This article analyzes the case of export credit, which has long been considered a highly effective international regulatory regime and an important component of global trade governance. I show that the rise of China is profoundly altering the landscape of export credit and undermining its governance arrangements. State‐backed export credit is a key tool of China's development strategy, yet I argue that an explosion in China's use of export credit is eroding the efficacy of existing international rules intended to prevent a competitive spiral of state subsidization via export credit. The case of export credit highlights a fundamental tension between liberal institutions of global governance and the development objectives of emerging powers.
Zebrafish fin regeneration involves transient serotonin synthesis
Authors: König Désirée , Jaźwińska Anna
Published: April 2019

The zebrafish is a vertebrate organism capable of regenerating many of its organs. Notably, it can undergo epimorphic regeneration of its fins after amputation. This process occurs through the formation of a wound epithelium and the dedifferentiation of mesenchymal and bone‐forming cells, which form a proliferative blastema. Here, we report that the entry into the regenerative process involves the local synthesis of serotonin (5‐hydroxytryptamine, 5‐HT) in the injury‐associated tissue. One day after wounding, intracellular accumulation of serotonin was induced in the stump below the amputation plane. During blastema formation, serotonin was detected in the mesenchyme at the vicinity of the amputation plane and in the apical wound epithelium. During the advanced outgrowth phase, this monoamine was no longer present in the blastema, suggesting a temporal involvement of serotonin in the postinjury area. We show the expression of two serotonin synthesizing enzymes, tryptophan hydroxylase 1a and 1b in the blastema, suggesting the local production of this monoamine. Neither depletion of serotonin by chemical inhibition of tryptophan hydroxylase, nor ectopic administration of this monoamine affected fin regeneration, indicating it does not play a role during this process. Finally, we found that the presence of serotonin during regeneration depends on fibroblast growth factor and retinoic acid signaling. Overall, our study demonstrates that the initiation of fin regeneration is associated with a transient synthesis of serotonin in the regrowing tissue.
Insufficient sleep is associated with a pro‐atherogenic circulating microRNA signature
Authors: Hijmans Jamie G. , Levy Ma'ayan , Garcia Vinicius , Lincenberg Grace M. , Diehl Kyle J. , Greiner Jared J. , Stauffer Brian L. , DeSouza Christopher A.
Published: April 2019

New Findings

What is the central question of the study

Is habitual short sleep associated with altered circulating levels of specific inflammation‐ and vascular‐related microRNAs?

What is the main finding and its importance?

Circulating levels of miR‐125a, miR‐126 and miR‐146a were significantly lower in the short sleep compared with the normal sleep group. Altered circulating profiles of these vascular‐related microRNAs have been linked to vascular inflammation, dysfunction and increased cardiovascular disease events. Sleep‐related changes in these microRNAs are consistent with, and might play a role in, the aberrant vascular physiology and increased vascular risk associated with short sleep.

Habitual short sleep duration (<7 h night−1) is associated with increased morbidity and mortality attributable, in large part, to increased inflammatory burden and endothelial dysfunction. MicroRNAs (miRNAs) play a key role in regulating vascular health, and circulating levels are now recognized to be sensitive and specific biomarkers of cardiovascular function, inflammation and disease.  The aim of this study was to determine whether the expression of circulating miR‐34a, miR‐92a, miR‐125a, miR‐126, miR‐145, miR‐146a and miR‐150 is disrupted in adults who habitually sleep <7 h night−1 (short sleep). These were chosen based upon their well‐established links with vascular inflammation, function and, in turn, cardiovascular risk. Twenty‐four adults were studied: 12 with normal nightly sleep duration (six men and six women; age, 55 ± 3 years old; sleep duration, ≥7.0 h night−1) and 12 with short nightly sleep duration (seven men and five women; 55 ± 2 years old; sleep duration, <7 h night−1), and circulating miRNA expression was assayed by RT‐PCR. All subjects were non‐smokers, normolipidaemic, non‐medicated and free of overt cardiovascular disease. Circulating levels of miR‐125a (3.07 ± 1.98 versus 7.34 ± 5.34 a.u.), miR‐126 [1.28 (0.42–2.51) versus 1.78 (1.29–4.80) a.u.] and miR‐146a [2.55 (1.00–4.80) versus 6.46 (1.50–11.44) a.u.] were significantly lower (∼60, 40 and 60%, respectively) in the short compared with the normal sleep group. However, there were no significant group differences in circulating levels of miR‐34a, miR‐92a, miR‐145 and miR‐150. In summary, chronic short sleep is associated with a marked reduction in circulating levels of miR‐125a, miR‐126 and miR‐146a. Dysregulation of these miRNAs might contribute to the increased inflammatory burden and endothelial dysfunction associated with habitual insufficient sleep.
“Efecto del consumo habitual de café en la salud cardiovascular de la población adulta: protocolo de una revisión de revisiones sistemáticas de la literatura”
Authors: Alba Talero Luz Helena , Peñaloza Maylin Johanna , Gutiérrez Vanesa , Castillo Juan Sebastian
Published: April 2019

Introducción: El café es una de las bebidas más consumidas en el mundo, aunque no están claramente establecidos sus efectos en la salud. En particular, aún hay controversia sobre sus efectos cardiovasculares. El objetivo de este trabajo es sintetizar evidencia acerca de los efectos del consumo habitual de café, en la salud cardiovascular. Métodos: Se llevó a cabo una revisión de revisiones sistemáticas de la literatura, de artículos obtenidos de las bases Medline, Embase, Cochrane y LILACS, publicados en inglés, español, francés o portugués. La búsqueda fue complementada manualmente con las referencias de las revisiones incluidas. Una pareja de investigadores seleccionó y extrajo información de manera independiente, y las discrepancias se resolvieron por consenso. Las revisiones incluidas se clasificaron según el año de publicación, desenlaces, diseño de los estudios primarios y calidad. Se utilizó el instrumento Assessing Methodological Quality for Systematic Reviews para calificar la calidad, y la información se sintetizó en formatos sistematizados. Discusión: La revisión sintetizó la evidencia del efecto del café sobre la salud cardiovascular y estimó la relación dosis-respuesta.
Regression Models for the Erector Spinae Muscle Mass (ESMM) Cross-Sectional Area: Asymptomatic Populations
Authors: Gungor Celal , Tang Ruoliang , Sesek Richard F. , Davis Gerard A. , Gallagher Sean
Published: April 2019

Understanding low back muscle morphology is critical to understanding spinal loading and the underlying injury mechanisms, which help in characterizing risk and, therefore, minimize low back pain injuries. Individualized erector spinae muscle mass (ESMM) cross-sectional area (CSA) allows biomechanics practitioners to calculate individualized force generating capacities and spinal loadings for given tasks. The objective is to perform morphological analyses and then provide regression models to estimate the ESMM CSA of an individual with his/her subject characteristics. Thirty-five subjects (13 females and 22 males) without low back pain (LBP) history were included in this magnetic resonance imaging (MRI) study. Axial-oblique scans of low back region were used to measure the ESMM CSA. Subject demographics and anthropometrics were obtained and regressed over the ESMM CSA. Best-subset regression analyses were performed. Lean body mass (LBM) and the ankle, wrist, and head indexes were the most frequent predictive variables. Regression models with easy-to-measure variables showed smaller predictive power and increased estimation error compared to other regression models. Practitioners should consider this trade-off between model accuracy and complexity. An individual's ESMM CSA could be estimated by his/her individual characteristics, which enables biomechanical practitioners to estimate individualized low back force capacity and spinal loading.
Instability of Incompatible Bilayered Soft Tissues and the Role of Interface Conditions
Authors: Emuna Nir , Durban David
Published: April 2019

Mechanical stability analysis is instructive in explaining biological processes like morphogenesis, organogenesis, and pathogenesis of soft tissues. Consideration of the layered, residually stressed structure of tissues, requires accounting for the joint effects of interface conditions and layer incompatibility. This paper is concerned with the influence of imposed rate (incremental) interface conditions (RICs) on critical loads in soft tissues, within the context of linear bifurcation analysis. Aiming at simplicity, we analyze a model of bilayered isotropic hyperelastic (neo-Hookean) spherical shells with residual stresses generated by “shrink-fitting” two perfectly bonded layers with radial interfacial incompatibility. This setting allows a comparison between available, seemingly equivalent, interface conditions commonly used in the literature of layered media stability. We analytically determine the circumstances under which the interface conditions are equivalent or not, and numerically demonstrate significant differences between interface conditions with increasing level of layer incompatibility. Differences of more than tenfold in buckling and 30% in inflation instability critical loads are recorded using the different RICs. Contrasting instability characteristics are also revealed using the different RICs in the presence of incompatibility: inflation instability can occur before pressure maximum, and spontaneous instability may be excluded for thin shells. These findings are relevant to the growing body of stability studies of layered and residually stressed tissues. The impact of interface conditions on critical thresholds is significant in studies that use concepts of instability to draw conclusions about the normal development and the pathologies of tissues like arteries, esophagus, airways, and the brain.
Three-Dimensional Kinematic Coupling of the Healthy Knee During Treadmill Walking
Authors: Koo Young-Jun , Koo Seungbum
Published: April 2019

Accurate joint kinematics plays an important role in estimating joint kinetics in musculoskeletal simulations. Biplanar fluoroscopic (BPF) systems have been introduced to measure skeletal kinematics with six degrees-of-freedom. The purpose of this study was to model knee kinematic coupling using knee kinematics during walking, as measured by the BPF system. Seven healthy individuals (mean age, 23 ± 2 yr) performed treadmill walking trials at 1.2 m/s. Knee kinematics was regressed separately for the swing and stance phases using a generalized mixed effects model. Tibial anterior translation function was y=0.20x−3.09 for the swing phase and y=0.31x−0.54 for the stance phase, where x was the flexion angle and y was the tibial anterior translation. Tibial lateral and inferior translation were also regressed separately for the stance phase and the swing phase. Tibial external rotation was y=−0.002x2+0.19x−0.64 for the swing phase and y=−0.19x−1.22 for the stance phase. The tibial adduction rotation function was also calculated separately for the stance and swing phase. The study presented three-dimensional coupled motion in the knee during the stance and swing phases of walking, and demonstrated the lateral pivoting motion found in previous studies. This expanded understanding of secondary knee motion functions will benefit musculoskeletal simulation and help improve the accuracy of calculated kinetics.
Sweeping Jets Issuing From the Face of a Backward-Facing Step
Authors: Bohan Brian T. , Polanka Marc D. , Rutledge James L.
Published: April 2019

This study quantified the performance and fluid disbursal capabilities of several fluidic oscillator variations injecting from the face of a backward-facing step. These devices were designed as a replacement for a pair of nonoscillating fuel injector jets in an ultra-compact combustor. However, these results have relevance whenever fluid is injected from the face of a backward-facing step making the oscillator performance widely applicable. The oscillators were tested with and without coflow and at varying coflow velocities, which controlled the strength of the recirculation behind the backward-facing step. The fluidic oscillators investigated included single as well as paired oscillators that produced in-phase and out-of-phase synchronized jets. The injected fluid disbursal was found to be dependent on the velocity ratio of the freestream air and the injecting jet velocity. Additionally, the oscillation angle was found to be a function of Reynolds number due to the interaction of the oscillating jet with the walls of the models used in the present study. Finally, the oscillation frequency was found to be independent of Reynolds number, throat aspect ratio, working gas, and model scale, which resulted in a Strouhal number of 0.017. This result was supported by nondimensionalizing the published data from several other studies.
Design of a Passive Self-Regulating Gravity Compensator for Variable Payloads
Authors: Chew Dexter X. H. , Wood Kristin L. , Tan U.-Xuan
Published: April 2019

Most passive gravity balancing mechanisms (GBMs) require manual adjustment or actuators to alter its parameters for different payloads. The few balancers that passively self-regulate employ regulation at the end-effector, which makes the end-effector bulky. Additionally, there is a lack of systematic approach to design such compensators. Hence, this paper provides a review of current work which serves as the basis for a systematic design approach to solve the problem. Unlike previous designs, an independent self-regulating mechanism is mounted onto the proximal link of the GBM achieving better safety, larger range of motion, and loading at intermediate angles. The GBM is designed using design tools like functional modeling and morphological analysis with existing literature. This approach reveals design considerations of current GBMs and areas for innovation. Design approaches from the literature are organized and serve as a reference for innovation. A prototype is developed, and experiments are performed to illustrate the capability.
Buckling Analysis of Toroidal Shell by Rayleigh-Ritz Method
Authors: Senjanović Ivo , Alujević Neven , Ćatipović Ivan , Čakmak Damjan , Vladimir Nikola , Cho Dae-Seung
Published: April 2019

The energy approach is used to analyze the buckling stability of toroidal shells. A closed and an open toroidal shell, as well as a shell segment are considered. Linear strain energy and nonlinear strain energy due to a uniform external pressure are formulated. Variations of the in-surface and normal displacement components in the circumferential and meridional directions are assumed in the form of a double Fourier series. The eigenvalue problem for the determination of the critical pressure is formulated by the Rayleigh–Ritz method (RRM). The proposed procedure is evaluated by numerical examples: one for a closed and another one for a simply supported open toroidal shell. The obtained results are validated by a comparison with results obtained by the finite strip method (FSM) and the finite element method (FEM), which shows a very good agreement.
Designing a Mobility Solution for Fully Autonomous Welding of Double-Hull Blocks
Authors: Goh Chun Fan , Hinduja Akshay , Ajmani Divish , Song Robin , Zhang Lei , Shimada Kenji
Published: April 2019

Automating the double-hull block welding improves the shipbuilding efficiency and mitigates health risk to the welders. Due to the unique challenge posed by the internal structures, existing technologies are at most semi-autonomous. Believing that mobility is key to full autonomy, we employ mobile robot technology to transport the welding manipulator, treating the internal structures as obstacles. Though many robot designs for obstacle scaling exist, there is no selection guideline. To this end, we surveyed existing robots and came out with a taxonomy to explain the design philosophies behind them. From the survey, it is ascertained that there are two suitable philosophies: bridging and conforming. Bridging mechanisms create links between points on obstacles while conforming mechanisms have the robot’s body attuned to the surface contour of obstacles. Understanding the pros and cons, we conclude that having a hybrid mechanism with tracked arms and articulated body would be ideal for the structured environment. Subsequently, we studied the feasibility of the design in terms of configuration, geometry, kinematics, and stability. Lastly, the proposed design was tested by building a 1/3 scale prototype robot. It was made to perform the expected motions in a mock double-hull block setup. The experiment proved that the design achieves the mobility objectives of the robot. With this mobility design, we solved the most challenging issue in enabling fully autonomous welding in double-hull blocks. The taxonomy is instrumental in our design selection and could be helpful for other robot designers too.
Well Clean-Up Using a Combined Thermochemical/Chelating Agent Fluids
Authors: Mahmoud Mohamed
Published: April 2019

The well clean-up process involves the removal of impermeable filter cake from the formation face. This process is essential to allow the formation fluids to flow from the reservoir to the wellbore. Different types of drilling fluids such as oil- and water-based drilling fluids are used to drill oil and gas wells. These drilling fluids are weighted with different weighting materials such as bentonite, calcium carbonate, and barite. The filter cake that forms on the formation face consists mainly of the drilling fluid weighting materials (around 90%), and the rest is other additives such as polymers or oil in the case of oil-base drilling fluids. The process of filter cake removal is very complicated because it involves more than one stage due to the compatibility issues of the fluids used to remove the filter cake. Different formulations were used to remove different types of filter cake, but the problem with these methods is the removal efficiency or the compatibility. In this paper, a new method was developed to remove different types of filter cakes and to clean-up oil and gas wells after drilling operations. Thermochemical fluids that consist of two inert salts when mixed together will generate very high pressure and high temperature in addition to hot water and hot nitrogen. These fluids are sodium nitrate and ammonium chloride. The filter cake was formed using barite and calcite water- and oil-based drilling fluids at high pressure and high temperature. The removal process started by injecting 500 ml of the two salts and left for different time periods from 6 to 24 h. The results of this study showed that the newly developed method of thermochemical removed the filter cake after 6 h with a removal efficiency of 89 wt% for the barite filter cake in the water-based drilling fluid. The mechanisms of removal using the combined solution of thermochemical fluid and ethylenediamine tetra-acetic acid (EDTA) chelating agent were explained by the generation of a strong pressure pulse that disturbed the filter cake and the generation of the high temperature that enhanced the barite dissolution and polymer degradation. This solution for filter cake removal works for reservoir temperatures greater than 100 °C.
Kinetic model for color-center formation in TiO2 film using femtosecond laser irradiation
Authors: Kato Susumu , Sunahara Atsushi , Tsukamoto Masahiro
Published: April 2019

The authors investigate the formation of color centers (CC) using a femtosecond laser, which causes the darkening of TiO2 film surfaces and reduction of their electrical resistance under visible-light illumination. They propose a kinetic model to explain the CC formation from femtosecond laser irradiation. The kinetic model treats three components, which are conduction-band electrons, self-trapped excitons or polarons, and color centers. The CC formation coefficient is assumed to be expressed by the Arrhenius equation. The laser fluence dependence on the decrease of the electrical resistance is well explained by the kinetic model.
Resolution improving filter for time-reversal (TR) with a switching TR mirror in a halfspace
Authors: Goh Heedong , Koo Seungbum , Kallivokas Loukas F.
Published: April 2019

This paper addresses the issue of using a switching time-reversal (TR) mirror for wave energy focusing to subsurface targets. The motivation stems from applications in geophysics, hydro-geology, environmental engineering, and even in therapeutic medicine. Using TR concepts, wave-focusing is straightforward and efficient, but only under ideal conditions that are, typically, unattainable in practice. The unboundedness of the subsurface that hosts the target, the TR mirror's limited aperture, and, worse, the practical need for a switching TR mirror, where recorded Dirichlet data are time-reversed as Neumann data (switching mirror), all contribute to the deterioration of the focusing resolution at the target. Herein, the development of a data filter is discussed, which is shown to be capable of overcoming the switching mirror's shortcoming, leading to improved focusing resolution. The filter's effect is demonstrated with numerical examples.
Statistical distribution of ambient noise levels compiled from building acoustics measurements
Authors: Loverde John , Dong David W.
Published: April 2019

One of the primary factors affecting speech privacy is the background noise level. During the course of building acoustics testing by the authors’ company, the background noise level has been measured in hundreds of locations nationwide in a wide variety of site conditions and building types. This information is compiled and analyzed. The effect of the statistical expectation of the background noise level on the required level of sound reduction is discussed.
The prognostic role of ultrasonographic air bronchogram in the management of community acquired pneumoniae in children
Authors: Inchingolo Riccardo , Smargiassi Andrea , Copetti Roberto , Soldati Gino
Published: April 2019

Chest ultrasound is a non-invasive method for evaluating children with suspected community-acquired pneumonia (CAP), allowing close follow-up and reduction of ionizing radiation. We studied the prognostic role of the change of ultrasonographic (US) air bronchogram in the management of CAP in terms of rate of complicated CAP, change in empiric antibiotic therapy, relationship to defervescence time, and length of hospitalization. Patients with diagnosis of CAP and radiographic evidence of lung consolidation were prospectively enrolled. The first chest US examination was performed within 12 h from admission and after 48 h. A new grading system (USINCHILD score) based on the presence and features of air bronchogram was adopted. Thirty six patients (mean age of 5 years) were stratified into two groups according to the presence of an increase in at least 1 grade of US score (Δ US grade), expression of an improvement of lung consolidation. The US grade after 48 h < 1 was associated with an increased risk of complicated CAP (OR: 160.88, p-value: 0.0109) and a longer defervescence time (70 h, p-value: 0.0047). Moreover, Δ US grade ≥ 1 was predictive of a short hospitalization (7 days, p-value: 0.0061). USINCHILD score could be an innovative biotechnology tool for the management of pediatric CAP.
Experimental study on effect of background noise on deep sleep in bedroom
Authors: Yan Xiang , Wang Jianghua , Li Hui , Chen Yuxiao
Published: April 2019

One of the most important external factors for sleep quality is noise. Previous studies show that deep sleep is disturbed strongly by noise, resulting in insufficient cerebral cortex deep resting, in delaying the growth and development, and in reducing immunity and brain functions. In the past, all the research studies added artificial noise into the bedroom, and how background noise affects sleep was still unknown. In this paper, the difference in the deep sleep length between the normal bedroom and the 0-dB(A) silence room which excludes the background noise during subject’s sleep was compared. Continuously two night sleeps of 35 random subjects, wearing the EEG brainwave Zeo headband, were recorded, one in the silence room and another in subject’s self-home bedroom. The result shows that comparing 29–35 dBA with the 0 dB extreme silence condition, deep sleep length increased. The best value locates about 31 dBA, which may be related to the masking of breathing sounds. Below 31 dBA, with noise reducing, the deep sleep length is reduced because of the excessive quietness reduces the masking effect, highlighting the effects of incidental noise. Between 31 and 48 dBA, as the noise increases, the length of deep sleep would decrease, by 4% for each additional 1 dB noise.
Experimental studies of sound propagation over vertical and slanted paths in a turbulent atmosphere
Authors: Ostashev Vladimir E. , Wilson D. Keith , Kamrath Matthew , Hart Carl R. , White Michael J. , Swearingen Michelle E. , Lyons Gregory W.
Published: April 2019

Sound propagation over vertical and slanted paths differs from horizontal paths due to the height dependence of turbulence parameters and atmospheric stratification. Vertical and slanted paths are important for several applications, such as localization of unattended aerial systems (UASs) with ground-based acoustic microphone arrays, detection of ground-based sources with elevated arrays, and the effect of atmospheric turbulence on sonic booms. This paper describes a comprehensive experiment on near-vertical sound propagation conducted over five days in September 2018 at the National Wind Technology Center (NWTC), located near Boulder, CO. The experiment involved the NWTC 135-m meteorological tower with meteorological instruments installed at 17 heights. Nine microphones were located on three horizontal booms attached to the tower at different heights, and a speaker was placed on the ground. Two reference microphones where located near the speaker. About 65% of the time, the speaker transmitted nine or twelve tones. During the remaining time, 6-ms chirps were transmitted. A preliminary analysis of the signal statistics is presented and compared with theoretical predictions.
Developing extrapolated pressure level maps from firearms
Authors: Rasband Reese D. , Gee Kent L. , Wall Alan T. , Wagner Caleb M. , Murphy William J.
Published: April 2019

This paper describes the development of spatial maps for both peak and A-weighted equivalent sound levels from various firearms, as measured with different spatial resolutions. Two outdoor datasets that adhered to the MIL-STD-1474E weapon noise measurement standard are considered. First is an extensive measurement of the M16A4 rifle at U.S. Marine Corps Base Quantico that included several shooter configurations and a circular measurement arc with 15-deg spacing and 3.67 m radius [R. D. Rasband et al., J. Acoust. Soc. Am. 143, 1935 (2018)]. Second is a measurement of many different firearms using an array with 30-deg spacing and 3.0 m radius, performed in Rudyard Michigan [W.J. Murphy et al., J. Acoust. Soc. Am. 132, 1905 (2012)]. Using these levels and conservative estimates based on spherical spreading and symmetry, level maps are created based on shooter position, weapon used, and number of shots fired. The fidelity of the extrapolation procedure and possible future improvements is discussed. [Work supported by ONR, WTB Quantico, and AFRL through ORISE.]
Optimal vibration suppression in adaptable acoustic metamaterials by a complex wavenumber
Authors: Stearns Aaron J. , Beck Benjamin
Published: April 2019

Acoustic metamaterials are composite materials exhibiting effective properties and acoustic behavior not found in traditional materials. Through periodic subwavelength resonant inclusions, acoustic metamaterials enable steering, cloaking, lensing, and frequency band control of acoustic waves. A common drawback of acoustic metamaterials is that the properties are limited to narrow frequency bands. Investigation of practical active and adaptable acoustic metamaterials is valuable in achieving wider operation frequency bands. Here, a one dimensional metamaterial is analyzed using a finite element method. The purpose of the metamaterial is to minimize vibration. From the finite element method formulation, a complex wavenumber is calculated. The unit cell considered is active and adaptable via piezoelectric actuators attached to negative capacitance shunt circuits. Therefore, the stiffness of the unit cell is tunable through selection of the circuit parameters. Choosing the negative capacitance shunt circuit elements to maximize the attenuative part of the complex wavenumber leads to maximum vibration suppression. So far, it has been found that maximizing the attenuative part of the wavenumber gives unrealizable specifications for the shunt circuit. To prevent this, the goal of this work is to constrain the optimization problem using experimentally obtained circuit stability bounds. The experimental stability results and optimization results will be presented.
Reconfigurable valley acoustic phononic crystals based on a fluidic system
Authors: Shen Chen , Tian Zhenhua , Li Junfei , Reit Eric , Huang Tony Jun , Cummer Steven
Published: April 2019

Valley serves as a new degree of freedom in controlling wave dynamics. Here, we present a design of valley acoustic phononic crystals (PCs) composed of a hybrid channel-cavity structure. Valley states for both waveguide and surface acoustic modes can be realized, and the mode transition is enabled by adjusting the channel height. Reconfigurable valley Hall phase transition in a wide range of frequencies is allowed by tuning the cavity sizes based on a fluidic system. By injecting/withdrawing fluid into/out of the cavities, the dispersion relation, phase transition, and edge states can be controlled conveniently in the two-dimensional PCs. Frequency-dependent acoustic routing, tunable refraction, topological switching, wave splitting, and reconfigurable acoustic pathways with suppressed backscattering are demonstrated both numerically and experimentally through acoustic field scanning. The reconfigurable valley PCs can serve as a versatile platform for exploring valley-related physics and achieving tunable wideband acoustic devices.
Seismic isolation in advanced Virgo gravitational wave detector
Authors: Boschi Valerio
Published: April 2019

We will present an overview of the seismic isolation systems used in an AdVirgo gravitational wave interferometer. We will concentrate on the the so-called super-attenuator, the seismic isolator used for all the detector main optical components. This complex mechanical device is able to provide more than 12 orders of magnitude of attenuation above a few Hz. We will also describe its high-performance digital control system and the control algorithms implemented with it.
A performance metric for screen selection with the acoustic single pixel imager
Authors: Ramirez Juan , Rogers Jeffrey S. , Edelmann Geoffrey F.
Published: April 2019

In the recent literature, an Acoustic Single-Pixel Imager has been successfully developed for source localization in a two-dimensional waveguide. Source bearing angle estimation was carried out by applying sparse recovery techniques on sensor measurements taken over dierent imaging screens. In this paper, we show that the mutual coherence of the sensing matrix can be used as a metric to predict the source localization capability of the single-pixel imaging system. In particular, our analysis focuses on the sparsity of open cells within the imaging screen and the number of imaging screens used to maximize the probability of correct detection over varying levels of source sparsity. In this work, we develop a simulation environment to demonstrate how the mutual coherence of the sensing matrix correlates with source localization performance over source sparsity, sparsity of open screen cells, and number of measurements used for sparse recovery. Our analysis shows that the leading factor in source localization performance gains is primarily from the number of imaging screens used to measure the acoustic wave-field.
Lung ultrasound surface wave elastography for assessing interstitial lung disease
Authors: Zhang Xiaoming , Zhou Boran , Zhou Jinling , Bartholmai Brian , Osborn Thomas , Kalra Sanjay
Published: April 2019

Many lung diseases including interstitial lung disease (ILD) are associated with changes in the lung’s biomechanical properties. ILD comprises a number of serious diseases in which fibrosis stiffens and damages lung tissue. Most ILDs are typically distributed in the lung’s peripheral and subpleural regions. Pulmonary function test (PFT) and high-resolution computed tomography (HRCT) are used to assess ILD. Ultrasonography is not widely used for lung assessment because ultrasound cannot image deep lung tissue. We have developed lung ultrasound surface wave elastography (LUSWE) for measuring superficial lung wave speed. In LUSWE, a 0.1-s 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 six intercostal spaces. Significant differences of surface wave speed between patients and controls were found in 6 lung regions and for 3 excitation frequencies. A positive correlation between LUSWE and clinical tests including HRCT and PTF was found. LUSWE may complement the clinical standard HRCT for assessing ILD.
A comparison of hyperelastic constitutive models applicable to Shear Wave Elastography (SWE) data in tissue-mimicking materials
Authors: Rosen David , Jiang Jingfeng
Published: April 2019

Shear wave elastography (SWE) techniques have received substantial attention in recent years. Strong experimental data in SWE suggest that shear wave speed changes significantly due to the known acoustoelastic effect (AE). This presents both challenges and opportunities toward the in vivo characterization of biological soft tissues. In this work, under the framework of continuum mechanics, we model a tissue-mimicking material as a homogeneous, isotropic, incompressible, hyperelastic material. Our primary objective is to quantitatively and qualitatively compare experimentally measured acoustoelastic data with model-predicted outcomes using multiple strain energy functions. Our analysis indicated that the classic neo-Hookean and Mooney-Rivlin models are inadequate for modeling the AE in tissue-mimicking materials. However, a subclass of strain energy functions containing both high-order/exponential term(s) and second-order invariant dependence showed good agreement with experimental data. Based on data investigated, we also found that discrepancies may exist between parameters inversely estimated from uniaxial compression, and SWE data though Mooney plots were consistent between the uniaxial compression and AE results. Overall, our findings may improve our understanding of the clinical SWE results.
An ultrasound surface wave elastography technique for non-invasive measurement of scar tissue
Authors: Zhou Boran , Wyles Saranya P. , Meves Alexander , Moran Steven , Zhang Xiaoming
Published: April 2019

Hypertrophic scars and keloids are characterized by excessive fibrosis and can be functionally problematic. Indeed, hypertrophic scarring is characterized by wide, raised scars that remain within the original borders of injury and have a rapid growth phase. There is a need for quantitative scar measurement modalities to effectively evaluate and monitor treatments. We aim to assess the role of the non-invasive scar-measuring device, ultrasound surface wave elastography (USWE), in accurately evaluating scar metrics. Two sites of breast tissue were tested control and scar portions. In USWE, a small, local, and 0.1-s harmonic vibration at three excitation frequencies (100, 150, and 200 Hz) was generated on these sites, and the resulting surface wave speed was measured via an ultrasound probe with a central frequency of 6.4 MHz. There was a statistically significant difference in the wave speed at three frequencies of the scar portion between prior and after treatment, suggesting that the scar portion was softener after treatment. USWE provides an objective assessment of the reaction of the scar to injury and treatment response.
Detecting articulations in clarinet playing
Authors: Gabriel Jack D. , Coyle Whitney L.
Published: April 2019

A method is suggested to automatically distinguish slurred transitions from tongued transitions in clarinet playing based on the mouth pressure signal. Player data will be presented from musicians playing a clarinet with a sensor-equipped mouthpiece. Playing parameters such as blowing pressure and pressure in the mouthpiece were captured, and data recorded in controlled tests and musical passages will be presented. Possible future applications of the method will be discussed, such as automatic detection of the quality clarinet and clarinet accessories.
Imaging of transient and steady-state flow in organ pipes
Authors: Moore Thomas , Coyle Whitney L.
Published: April 2019

The transient and steady-state flow at the flue and open end of organ pipes has been studied using high-speed electronic speckle pattern interferometry. We show that the flow at the flue is similar to square and round organ pipes; however, at the open end, the flow depends on the pipe shape. There is a significant flow from a square pipe and no detectable flow from a round pipe. These results can be directly compared to the results of simulations recently developed by Thacker and Giordano. [Work supported by NSF Grant #PHY-160749.]
Hearing on the battlefield: The challenge of protecting hearing while enabling the mission
Authors: Thompson Eric R. , Simpson Brian
Published: April 2019

The auditory sense plays a critical role in human performance on the battlefield. Effective verbal communication is key to the success of all military operations, the ability to detect and localize sounds in the immediate environment is critical for supporting situation awareness, and the ability to identify sound sources is required for labeling items and events as hostile or friendly. However, operational environments tend to be extremely noisy, and most warfighters are regularly exposed to hazardous noise levels, necessitating the use of hearing protection to reduce the chance of experiencing temporary or permanent hearing loss. Unfortunately, the use of hearing protection can have a deleterious effect on communication, sound source identification, and overall situation awareness. For this reason, operators often choose to perform all, or part, of their mission without the appropriate hearing protection in place. In order to protect warfighters’ hearing, appropriate hearing protection needs to be selected that will provide enough protection from the expected hazardous sounds, while also enabling the hearing-critical tasks that are required for the mission. This presents a great challenge for those who make the decisions on what hearing protection to prescribe.
Nonlinear tuning curve demonstration: Comparing a buried mine simulant with a clamped elastic plate—Cylindrical soil column oscillator
Authors: Twitty Ava B. , Korman Murray S.
Published: April 2019

Experiments using soil-plate-oscillators (SPO) involve a cylindrical column of granular media (masonry sand) supported by a clamped circular elastic acrylic plate (12.7 cm diameter, 3.2 mm thick). The plate is clamped between two 20.3 cm O.D., 12.7 cm I.D., 6.4 cm thick flat toroidal brass “rings.” Two 15 cm diameter subwoofers (10 cm above the soil) are driven by an amplified swept sinusoidal chirp which drives the 2.5-cm soil column. A spectrum analyzer measures the laser Doppler vibrometer particle velocity versus frequency near the center of the column. The resonant frequency decreases with the increasing amplitude—representing softening in the nonlinear system. The back-bone curve (locus of the resonant frequency versus corresponding peak velocity coordinates) has a distinct arching shape where the slope of the velocity increases with the decreasing frequency. Here, the resonant frequency goes from 247 to 203 Hz. A lumped element bilinear hysteresis model describes the shape of the tuning curves and backbone curve. Next, a drum-like simulant (made by replacing the upper toroidal ring by a 0.64-cm thick ring) is buried 2.5-cm deep in an open square concrete tank (57 cm). Nonlinear tuning curve experiments “on” and “off” the mine are compared with the SPO results.