bluuebunny/crossref_metadata_2025 huggingface dataset:
Establishing the prevalence of common tissue-specific autoantibodies following severe acute respiratory syndrome coronavirus 2 infection
Authors: Richter Alex G , Shields Adrian M , Karim Abid , Birch David , Faustini Sian E , Steadman Lora , Ward Kerensa , Plant Timothy , Reynolds Gary , Veenith Tonny , Cunningham Adam F , Drayson Mark T , Wraith David C
Published: June 2021

Coronavirus 19 (COVID-19) has been associated with both transient and persistent systemic symptoms that do not appear to be a direct consequence of viral infection. The generation of autoantibodies has been proposed as a mechanism to explain these symptoms. To understand the prevalence of autoantibodies associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we investigated the frequency and specificity of clinically relevant autoantibodies in 84 individuals previously infected with SARS-CoV-2, suffering from COVID-19 of varying severity in both the acute and convalescent setting. These were compared with results from 32 individuals who were on the intensive therapy unit (ITU) for non-COVID reasons. We demonstrate a higher frequency of autoantibodies in the COVID-19 ITU group compared with non-COVID-19 ITU disease control patients and that autoantibodies were also found in the serum 3–5 months post-COVID-19 infection. Non-COVID patients displayed a diverse pattern of autoantibodies; in contrast, the COVID-19 groups had a more restricted panel of autoantibodies including skin, skeletal muscle and cardiac antibodies. Our results demonstrate that respiratory viral infection with SARS-CoV-2 is associated with the detection of a limited profile of tissue-specific autoantibodies, detectable using routine clinical immunology assays. Further studies are required to determine whether these autoantibodies are specific to SARS-CoV-2 or a phenomenon arising from severe viral infections and to determine the clinical significance of these autoantibodies.
Cardiorespiratory findings during iohexol contrast myelography in horses under total intravenous anaesthesia
Authors: Loomes K.
Published: June 2021

Background

Iohexol myelography is used to investigate cervical vertebral pathology in horses but the cardiorespiratory changes during the procedure under total intravenous anaesthesia (TIVA) have not yet been reported.

Objectives

To analyse heart rate (HR), arterial blood pressure (ABP) and respiratory rate (RR) changes in horses during iohexol contrast myelography under TIVA.

Study design

Retrospective review of anaesthetic records.

Methods

Anaesthetic records from 70 horses undergoing iohexol contrast myelography under TIVA were reviewed. Heart rate, arterial blood pressure and respiratory rate at six time points; baseline (10 min prior to needle insertion), needle insertion, withdrawal of cerebrospinal fluid (CSF), iohexol contrast injection, needle removal and post‐procedure (10 min after needle removal) were analysed. Data were analysed using paired and two‐sample t‐tests, Mann–WhitneyUtest, Wilcoxon signed rank test, ANOVA, Pearson’s correlation and logistic regression.

Results

Forty‐five records contained complete data. Mean HR and ABP were not significantly different from baseline at any time point during the procedure. Overall, median RR was significantly higher during contrast injection (p < 0.001), at needle removal (p < 0.001) and post‐procedure (p < 0.001) compared to baseline. Premedication with acepromazine, romifidine and butorphanol (ARB) was associated with a significantly lower RR at needle removal compared to premedication with romifidine (R), romifidine and butorphanol (RB) or acepromazine and romifidine (AR) (p < 0.05). Premedication with ARB or AR was associated with a lower incidence of tachypnoea (RR >20 breaths/min) at needle removal compared to R and RB (p = 0.005).

Main limitations

Retrospective design and small sample size.

Conclusions

There was little fluctuation in HR and ABP during iohexol myelography in healthy horses under TIVA. Tachypnoea occurred during or after subarachnoid iohexol administration in 55% of horses. Acepromazine premedication reduced the incidence of tachypnoea, however, the cause of this respiratory response requires further investigation.
Regimes of primary production and their drivers in Alpine streams
Authors: Boix Canadell Marta , Gómez‐Gener Lluís , Ulseth Amber J. , Clémençon Mélanie , Lane Stuart N. , Battin Tom J.
Published: June 2021

Primary production is a fundamental ecosystem process that influences nutrient and carbon cycling, and trophic structure in streams. The magnitude and timing of gross primary production (GPP) are typically controlled by hydrology, light, nutrient availability and grazers. Estimates of GPP and its drivers in high‐mountain streams remain elusive at present.

We estimated GPP in streams typical for high‐mountain catchments, namely a glacier‐fed, groundwater‐fed (krenal) and a snowmelt‐fed (nival) stream. Using high‐resolution sensor data over 2 years in combination with numerical simulations of stream hydraulics, we studied the periods of GPP characteristic for these streams, as well as their major drivers.

Favourable windows for GPP were constrained to periods at the onset of the snowmelt and its recession, when photosynthetic active radiation at the streambed and streambed stability facilitated GPP.

During these windows of opportunity, GPP was higher in the nival stream (3.7 ± 3.4 g O2 m−2 day−1), followed by the glacier‐fed (1.5 ± 1.6 g O2 m−2 day−1) and the krenal streams (0.6 ± 0.6 g O2 m−2 day−1). GPP was largely controlled by photosynthetic active radiation at the stream bottom, however, we were not able to establish an unequivocal relationship between flow‐induced bed movement and GPP.

Our results highlight the capacity of primary producers to exploit the discrete and relatively predictable windows of opportunities in high‐mountain streams. We propose that climate‐driven change in snow and glacier melt reduction may ameliorate stream environmental conditions, thereby enhancing the potential autochthonous organic matter supply within the catchment.
Supply potential of lignocellulosic energy crops grown on marginal land and greenhouse gas footprint of advanced biofuels—A spatially explicit assessment under the sustainability criteria of the Renewable Energy Directive Recast
Authors: Vera Ivan , Hoefnagels Ric , Junginger Martin , van der Hilst Floor
Published: June 2021

Advanced biofuels produced from lignocellulosic crops grown on marginal lands can become an important part of the European Union (EU) climate change mitigation strategy to reduce CO2 emissions and meet biofuel demand. This study quantifies spatially explicit the availability of marginal land in the EU, its production biomass potentials for eight different crops, and the greenhouse gas (GHG) performance of advanced biofuel supply chains. Available land is mapped based on land marginality and Renewable Energy Directive Recast (REDII) land‐related sustainability criteria. Biomass potentials are assessed with a water‐use‐to‐biomass‐production approach while considering the available land, location‐specific biophysical conditions and crop‐specific phenological characteristics. The GHG balance of advanced biofuels from energy crops produced on marginal lands is assessed considering both land‐related carbon stock changes and supply chain emissions with the carbon footprint approach from the REDII. Available marginal land that meets REDII criteria is projected at 20.5–21 Mha 2030 and 2050, respectively. Due to biophysical limitations, not all available land is suitable for energy crop production. The maximum biomass potential of lignocellulosic energy crops (optimal crop choice with maximum yield for each available location) varies between 1951 PJ year−1 in 2030 and 2265 PJ year−1 in 2050. The GHG emission performance (net emissions) of different advanced biofuel supply chains varies on average between −32 g CO2‐eq MJfuel−1 for poplar/willow diesel to 38 g CO2‐eq  for reed canary grass renewable jet fuel. The large variability in GHG performance is strongly determined by the spatial heterogeneity, which dictates the type of feedstock produced under specific local biophysical conditions, the crop characteristics, and the best conversion pathway. Negative GHG emissions are related to increased carbon stocks for the biomass and soil organic carbon pools compared to the land prior to conversion. When for each location, the advanced biofuel supply chain with the highest GHG performance (lowest net GHG emissions) is selected, 618 PJ year−1 of advanced biofuels can be produced by 2030. Under REDII GHG emission criteria, slightly less (552 PJ year−1) is viable. Smart choices on location, crop type and supply chain design are paramount to achieve maximum benefits of bioenergy systems.
Synthesis of nonstoichiometric NiO nanocatalysts and growth of bamboo‐like carbon nanotubes
Authors: Kim Taewoo , Lee Jaekwang , Park Gwanhee , Lee Heesoo
Published: June 2021

The growth behavior of carbon nanotubes from NiO nanoparticles was investigated in terms of vacancy concentration and nanostructure. The NiO nanoparticles were prepared using anhydrous ethanol as a solvent to lower hydroxyl groups, compared to distilled water. The Ni vacancies in NiO via less hydrolysis were confirmed by lattice expansion and the increased mean oxidation state of Ni3+ through X‐ray absorption spectroscopy. The increased Ni3+ ratio determined from the photoelectron spectrum and ferromagnetism implied a high concentration of Ni vacancies on the surface. Nonstoichiometric NiO exhibited a small particle size of 10.13 nm and a narrow size distribution. For the growth of CNTs, the NiO nanocatalysts with vacancies resulted in thinner CNTs. The internal structures of the CNTs obtained from the defective particles were grown into bamboo‐like CNTs, identifying the variation in the carbon diffusion path.
Numerical abundance and biomass reveal different temporal trends of functional diversity change in tropical fish assemblages
Authors: Fontrodona‐Eslava Ada , Deacon Amy E. , Ramnarine Indar W. , Magurran Anne E.
Published: June 2021

Understanding how the biodiversity of freshwater fish assemblages changes over time is an important challenge. Until recently most emphasis has been on taxonomic diversity, but it is now clear that measures of functional diversity (FD) can shed new light on the mechanisms that underpin this temporal change. Fish biologists use different currencies, such as numerical abundance and biomass, to measure the abundance of fish species. Nonetheless, because they are not necessarily equivalent, these alternative currencies have the potential to reveal different insights into trends of FD in natural assemblages. In this study, the authors asked how conclusions about temporal trends in FD are influenced by the way in which the abundance of species has been quantified. To do this, the authors computed two informative metrics, for each currency, for 16 freshwater fish assemblages in Trinidad's Northern Range that had been surveyed repeatedly over 5 years. The authors found that numerical abundance and biomass uncover different directional trends in these assemblages for each facet of FD, and as such inform hypotheses about the ways in which these systems are being restructured. On the basis of these results, the authors concluded that a combined approach, in which both currencies are used, contributes to our understanding of the ecological processes that are involved in biodiversity change in freshwater fish assemblages.
Age and growth of the bull shark (Carcharhinus leucas) around Reunion Island, South West Indian Ocean
Authors: Hoarau Florian , Darnaude Audrey , Poirout Thomas , Jannel Lou‐Anne , Labonne Maylis , Jaquemet Sébastien
Published: June 2021

Sharks exhibit varied demographic strategies depending on both the species and the population location, which make them more or less vulnerable to fishing. Accurate evaluation of local age and growth parameters is therefore fundamental for the sustainable management of their stocks. Although demographic parameters have been assessed for bull shark (Carcharhinus leucas) populations in several locations of the world, this information is missing so far around Reunion Island, in the south‐west Indian Ocean. To fill this gap of knowledge, age and growth data were gathered from the vertebrae of 140 individuals of C. leucas (77 females and 63 males, mostly adults) fished around the island between 2012 and 2019. After verification of the annual deposition of growth band pairs on these structures using relative marginal increment analysis on 40 individuals, band pairs were counted along the vertebral centrum for each individual. Thanks to this approach, growth was shown to significantly differ between male and female C. leucas around Reunion Island, with respective von Bertalanffy growth model equations of Lt =  and Lt = . Indeed, the females of the species fished in this area were significantly (P < 0.001) larger than local males, with an estimated difference in size of ~16.1 cm at 20 years old. They also apparently reach older ages, with an estimated maximum age of 33.50 years, against 29.75 years only for the males. The estimated size at birth around the island is larger than elsewhere in the world, varying from 92.30 to 100.00 cm depending on the method used. These results confirm that the population of C. leucas around Reunion Island exhibits a K‐selected strategy, which makes it highly vulnerable to fishing pressure.
Putting quality food on the tray: Factors associated with patients’ perceptions of the hospital food experience
Authors: Trinca Vanessa , Duizer Lisa , Keller Heather
Published: June 2021

Introduction

Perceptions of hospital meal quality can influence patient food intake. Understanding what patients prioritise and what they think of current meals can support menu development. The present study assessed patients’ food and food‐related priorities for hospital meals and their sensory experience using the Hospital Food Experience Questionnaire (HFEQ). Factors independently associated with the HFEQ were determined.

Methods

Cross‐sectional study (n = 1087 patients; 16 Ontario hospitals). Patients completed the HFEQ at a single meal. Descriptive statistics determined the importance of food traits and ratings of a served meal using 22 HFEQ questions (five‐point Likert scales, total score 110). Bivariate and multivariable linear regression tested the association between patient and hospital characteristics and HFEQ score.

Results

Most food traits were rated as ‘important’ (4) or ‘very important’ (5) by two‐thirds or more of patients. Patients typically rated served meal items as ‘good’ (4). Mean HFEQ score was 90.60 (SD 10.83) and was associated with patient and hospital traits in multivariable analyses (F42,556 = 2.34, p < 0.001). Older and woman‐identifying patients were more likely to have a higher score. Foodservice models were associated with HFEQ. Cold‐plated rethermed food resulted in the lowest HFEQ. Local food use > 10% was associated with lower HFEQ score, whereas larger hospitals had a higher score.

Conclusions

Patients prioritised taste, freshness and food that met their dietary needs. Meal sensory ratings were average. A gap exists between what patients want in hospital meals and what they receive. Attention to patient demographics and food delivery that retains sensory properties and supports choice may increase HFEQ score.
Assessment of the impacts of sample preparation on the use of EDS for analysing recycled asphalt blending
Authors: Pape Sonja Ellen , Castorena C. A.
Published: June 2021

Several past studies have demonstrated merit to using tracer‐based energy dispersive X‐ray spectroscopy (EDS) analysis to investigate blending between virgin and recycled materials in asphalt mixtures. However, these past studies have focused on proof of concept and did not establish robust fabrication and microscopy procedures. This study rigorously evaluates the ability to form a stable blend between the tracer and virgin asphalt binder, and the potential for tracer smearing during the preparation of EDS specimens. The results demonstrate that a high shear mixer can be used to prepare homogeneous, stable blends of a titanium dioxide tracer and virgin binder. A critical evaluation of an asphalt mixture specimen prepared to contain specific areas with and without the tracer demonstrates no evidence of tracer smearing due to sample preparation. The results demonstrate that tracer‐based EDS analysis of asphalt mixtures can measure local recycled material availability.
COVID‐19 public health measures and respiratory viruses in children in Melbourne
Authors: Abo Yara‐Natalie , Clifford Vanessa , Lee Lai‐Yang , Costa Anna‐Maria , Crawford Nigel , Wurzel Danielle , Daley Andrew J
Published: June 2021

Aim

To describe the epidemiology of respiratory viruses in children before and during the 2020 SARS‐CoV‐2 pandemic and the relationship to public health measures instituted by the Victorian government.

Methods

Retrospective audit of respiratory viruses at a tertiary paediatric hospital in Melbourne from January 2015 up to week 47, 2020 in children under 18 years of age. The proportion of positive cases in weeks 1–47 in 2015–2019 (period 1) were compared to weeks 1–47, 2020 (period 2), and reviewed in the context of public health restrictions in Victoria.

Results

An annual average of 4636 tests were performed in period 1 compared to 3659 tests in period 2. Proportions of positive influenza A virus, influenza B virus, respiratory syncytial virus (RSV) and human parainfluenza virus were significantly reduced in period 2 compared to period 1: 77.3, 89.4, 68.6 and 66.9% reductions, respectively (all P < 0.001). From week 12–47, 2020, 28 893 SARS‐CoV‐2 tests were performed with a 0.64% positivity rate. Influenza viruses were not detected after week 17, RSV was not detected after week 35.

Conclusions

Strict public health measures and border closures were successful in eliminating community transmission of SARS‐CoV‐2 in Melbourne. This was associated with a significant reduction in other respiratory virus infections in children. Identifying sustainable and effective ongoing public health interventions to reduce transmission of RSV and influenza could result in reduced morbidity and mortality in children and requires further research.
Standing variation rather than recent adaptive introgression probably underlies differentiation of the texanus subspecies of Helianthus annuus
Authors: Owens Gregory L. , Todesco Marco , Bercovich Natalia , Légaré Jean‐Sébastien , Mitchell Nora , Whitney Kenneth D. , Rieseberg Loren H.
Published: June 2021

The origins of geographic races in wide‐ranging species are poorly understood. In Texas, the texanus subspecies of Helianthus annuus has long been thought to have acquired its defining phenotypic traits via introgression from a local congener, H. debilis, but previous tests of this hypothesis were inconclusive. Here, we explore the origins of H. a. texanus using whole genome sequencing data from across the entire range of H. annuus and possible donor species, as well as phenotypic data from a common garden study. We found that although it is morphologically convergent with H. debilis, H. a. texanus has conflicting signals of introgression. Genome wide tests (Patterson's D and TreeMix) only found evidence of introgression from H. argophyllus (sister species to H. annuus and also sympatric), but not H. debilis, with the exception of one individual of 109 analysed. We further scanned the genome for localized signals of introgression using PCAdmix and found minimal but nonzero introgression from H. debilis and significant introgression from H. argophyllus in some populations. Given the paucity of introgression from H. debilis, we argue that the morphological convergence observed in Texas is probably from standing genetic variation. We also found that genomic differentiation in H. a. texanus is mostly driven by large segregating inversions, several of which have signatures of natural selection based on haplotype frequencies.
An (in)effective tax and expenditure limit (TEL): Why county governments do not utilize their maximum allotted property tax rate
Authors: Decker John W.
Published: June 2021

Tax and expenditure limits (TELs) are restrictions placed on governments limiting their ability to collect and spend revenue. Residents support these TELs, as they desire lower tax burdens and more government efficiency; yet, residents still desire the same level of public services. Property tax rate limits, a specific type of TEL, are placed upon local governments to limit their ability to collect revenue and expand authority. Rate limits were implemented on the assumption that governments would tax at their highest maximum possible rate, but this is not always the case. This article studies why some local governments choose not to utilize their maximum allotted property tax rate. Using an open systems governance approach, a panel data analysis was conducted using data from 67 Florida counties from 2008 to 2017. Results of the analysis show that the use of special districts and the age of the residential population have significant effects on property tax rate decisions.
Volumetric differences in gray and white matter of cerebellar Crus I/IIacross the different clinical stages of schizophrenia
Authors: Morimoto Chie , Uematsu Akiko , Nakatani Hironori , Takano Yosuke , Iwashiro Norichika , Abe Osamu , Yamasue Hidenori , Kasai Kiyoto , Koike Shinsuke
Published: June 2021

Aim

Schizophrenia is considered to be a disorder of progressive structural brain abnormalities. Previous studies have indicated that the cerebellar Crus I/II plays a critical role in schizophrenia. We aimed to investigate how specific morphological features in the Crus I/II at different critical stages of the schizophrenia spectrum contribute to the disease.

Methods

The study involved 73 participants on the schizophrenia spectrum (28 with ultra‐high risk for psychosis [UHR], 17 with first‐episode schizophrenia [FES], and 28 with chronic schizophrenia) and 79 healthy controls. We undertook a detailed investigation into differences in Crus I/II volume using a semiautomated segmentation method optimized for the cerebellum. We analyzed the effects of group and sex, as well as their interaction, on Crus I/II volume in gray matter (GM) and white matter (WM).

Results

Significant group × sex interactions were found in WM volumes of the bilateral Crus I/II; the males with UHR demonstrated significantly larger WM volumes compared with the other male groups, whereas no significant group differences were found in the female groups. Additionally, WM and GM volumes of the Crus I/II had positive associations with symptom severity in the UHR group, whereas, in contrast, GM volumes in the FES group were negatively associated with symptom severity.

Conclusions

The present findings provide evidence that the morphology of Crus I/II is involved in schizophrenia in a sex‐ and disease stage–dependent manner. Additionally, alterations of WM volumes of Crus I/II may have potential as a biological marker of early detection and treatment for individuals with UHR.
Induction of reproductive activity and egg production by gonadotropin‐releasing hormone in non‐laying hens
Authors: Hanafy Ahmed M. , Elnesr Shaaban Saad
Published: June 2021

The current study was conducted to evaluate the effects of gonadotropin‐releasing hormone (GnRH) analogue (Receptal) injection on reproductive traits of fully mature layers hens (32 weeks) suffered from inactive ovaries. Ninety‐six non‐laying hens (TETRA‐SL brown egg layers), selected from a commercial flock, with similar body weight, were randomly assigned to four groups (n = 24). Hens in the 1st group served as a control. Hens of the 2nd, 3rd and 4th groups were individually intramuscularly injected every 4 days with 50, 100 and 150 µl of Receptal solution, respectively, for two times. The results stated that the injection of Receptal induced the non‐laying hens to produce eggs, but control birds did not produce eggs during the experimental period. The distance between pelvic bones and between the pelvic bone and keel bone of hens was significantly improved (p < .001) in groups received different GnRH levels compared with the control group. The best results were observed in the group injected with 100 µl Receptal. Levels of LH, FSH, oestrogen and progesterone hormones were significantly (p < .05) higher in Receptal‐treated groups than in the control group. Hens injected with Receptal had an increase in ovary%, yellow follicles number, oviduct% and oviduct length (p < .001) compared with the control. It was concluded that treating inactive ovaries in non‐laying hens with GnRH injections for two times, 4‐day intervals, is an effective procedure for inducing egg production and useful in cost reduction in layer farms, and the group treated with 100 µl Receptal had the best results.
Computational Fluid Dynamics—Machine Learning Prediction of Machinery Coupling Windage Heating and Power Loss
Authors: Dawahdeh Ahmad , Oh Joseph , Zhai Tianbo , Palazzolo Alan
Published: June 2021

Couplings connect the spinning shafts of driving and driven machines in the industry. A coupling guard encloses the coupling to protect personnel from the high-speed rotating coupling. The American Petroleum Institute API publishes standards that restrict the overheating of the coupling guards due to windage caused by the spinning shaft. Based on the most recent version of API 671, the peak temperature for the coupling guard should not exceed 60 °C. This paper proposes a machine learning (ML) model and an empirical formula to predict the maximum guard temperature and power loss. The ML models use a database obtained from simulated computational fluid dynamics (CFD) cases for different coupling guards under various conditions. Also, the paper provides validation for the CFD models with experimental tests for different cases. The proposed ML model uses eight different input parameters to predict temperature and power loss. The model shows an accurate prediction for a varied number of CFD cases. The performance of the generated model has been verified with the experimental results. Also, an empirical formula has been created using the same database from CFD results. The results show that the ML model has better prediction accuracy than the empirical formula for predicting peak temperature and power loss for all cases.
Dynamic Modeling of Spent Fuel Rack Pool Subjected to Seismic Excitation Considering Fluid–Structure Interaction
Authors: Ricciardi Guillaume , Kang Heung Seok , Oh Dong Seok , Lee Kang Hee
Published: June 2021

The spent fuel of a nuclear power plant is generally stored in a wet storage pool. In case of a seismic event, one has to ensure the integrity of the spent fuel and structures holding them called spent fuel racks. In this study, a simple model accounting for 12 racks is proposed and compared with experimental results involving reduced scale racks. Fluid–structure interactions are modeled in terms of added coupling mass and damping, and free surface effects are accounted for. Comparison between simulations and experimental results showed good agreement. In spite of the simplicity of the model, simulations succeed to give a reasonable estimation of racks accelerations and were able to reproduce the effect of excitation amplitude and water level.
A Burst Capacity Model for Corroded Pipelines Subjected to Combined Internal Pressure and Longitudinal Compression
Authors: Zhang Shulong , Zhou Wenxing
Published: June 2021

The present study proposes a new semi-empirical burst capacity model for corroded oil and gas pipelines under combined internal pressure and longitudinal compression. The proposed model evaluates the burst capacity of a corroded pipeline under combined loads as the burst capacity of the pipeline under internal pressure only, which is developed in a recently completed study, multiplied by a correction factor to account for the effect of the longitudinal compression. Extensive parametric elastoplastic finite element analyses (FEA) are carried out, the results of which are used as the basis to develop the correction factor as a function of the corrosion defect sizes and magnitude of the longitudinal compressive stress. The proposed model is validated by a large set of parametric FEA and full-scale burst tests reported in the literature and is shown to provide marked improvements over two existing models, the DNV and RPA-PLLC models, for corroded pipelines under combined loads.
Peridynamics for Numerical Analysis
Authors: Madenci Erdogan , Dorduncu Mehmet , Barut Atila
Published: June 2021

Discrete data analysis and numerical solutions to boundary and initial value problems of ordinary/partial differential equations are essential in almost every branch of science. Although the differentiation process is usually more direct than integration in analytical mathematics, the reverse is true in computational mathematics, especially in the presence of a jump discontinuity or a singularity. Integration is a nonlocal process because it depends on the entire range of integration. However, differentiation is a local process.
Advances in the Stochastic Modeling of Constitutive Laws at Small and Finite Strains
Authors: Staber Brian , Guilleminot Johann
Published: June 2021

The characterization and identification of uncertainties in the physical properties of complex materials have been the subjects of longstanding interest in both research and engineering. These efforts were supported by the growing interest in Uncertainty Quantification (UQ) where predominating system-parameter and model-form uncertainties are integrated in a unified mathematical treatment to endow predictions with some statistical measure of uncertainty (fidelity) [7] (see also [23, 30]). Once properly modeled and calibrated, these uncertainties can then be propagated to the structural response, following for instance the spectral approach introduced in the celebrated monograph by Ghanem and Spanos [8] (see also [13]). Such stochastic simulations are then purposely used in order to increase the robustness of the computational models and design procedures, especially when the mechanical models are highly nonlinear (in which case small variations in the inputs can have dramatic effects on the predicted outputs and thus, on design procedures). They also enable a deeper understanding of the critical mechanisms governing the physics (associated with damage propagation, for instance) at relevant scales.
Novel and Efficient Mathematical and Computational Methods for the Analysis and Architecting of Ultralight Cellular Materials and their Macrostructural Responses
Authors: Tabatabaei Maryam , Atluri Satya N.
Published: June 2021

Nature benefits from high stiffness and strength low-weight materials by involving architected cellular structures. For example, trabecular bone, beaks and bones of birds, plant parenchyma, and sponge optimize superior mechanical properties at low density by implementing a highly porous, complex architected cellular core [25]. The same engineering and architectural principles at the material scale have been used by humankind to develop materials with higher mechanical efficiency and lower mass in many weight-critical applications. The emergence of advanced manufacturing technologies such as additive manufacturing and three-dimensional (3D) laser lithography offer the opportunity to fabricate ultralight metallic and composite materials with intricate cellular architecture to location-specific requirements. For example, the world’s lightest metal [26,32], Fig. 7.1, and reversibly assembled ultralight carbon-fiber-reinforced composite materials [4], Fig. 7.2, with architected cellular structures have been recently fabricated at Hughes Research Laboratories (HRL) in California and MIT Media Lab-Center for Bits and Atoms, respectively.
Magnetic resonance/ultrasound fusion targeted biopsy of the prostate can be improved by adding systematic biopsy
Authors: Cauni Victor Mihail , Stanescu Dan , Tanase Florin , Mihai Bogdan , Persu Cristian
Published: June 2021

Aim: Magnetic resonance/ ultrasound fusion targeted biopsy (Tbs) is widely used for diagnosing prostate cancer (PCa). The aim of our study was to compare the cancer detection rate (CDR) and the clinically significant prostate cancer detection rate (csPCa) of the magnetic resonance/ultrasound fusion targeted biopsy with those of the standard systematic biopsy (Sbs) and of the combination of both techniques.Material and methods: A total of 182 patients underwent magnetic resonance/ultrasound fusion Tbs on the prostate for PCa suspicion based on multiparametric magnetic resonance imaging (mMRI) detection of lesions with PI-RADSv2 score ≥3. A total of 78 patients had prior negative biopsies. Tb was performed by taking 2-4 cores from each suspected lesion, followed by Sb with 12 cores. We evaluated the overall detection rate of PCa and clinically significant prostate cancer, defined as any PCa with Gleason score ≥3+4.Results: Median prostate specific antigen (PSA) level pre-biopsy was 7.4 ng/ml and median free-PSA/PSA ratio was 10.2%. Patient median age was 62 years old. PIRADSv2 score was 3 in 54 cases, 4 in 96 cases and 5 in 32 cases. PI-RADS-dependent detection rate of Tbs for scores 3, 4 and 5 was 25.9%, 65.6% and 84.4%, respectively, with csPCa detection rates of 24.1%, 54.2%, and 71.9%. Overall detection rate was 57.1% for Tbs, which increased to 60.4% by adding Sbs results. Detection rate for clinically significant prostate cancer (csPCa) was 48.4% and increased to 51.1% by adding Sbs. Overall detection rate for repeated biopsy was 50% and 68.3% for biopsy in naïve patients. Sbs detection rate was 55.5%, 8 patients having a negative biopsy on Tbs.Conclusions: When Tbs is considered due to a PI-RADS ≥3 lesion on mMRI, combined Tbs + Sbs increases the overall CDR and csPCa detection rates.
Stress formulation of elastic wave motion
Authors: Kube Christopher M. , Norris Andrew N.
Published: June 2021

Propagation of elastic waves in anisotropic solids is solved through a pure stress formalism. The stress solutions lead to the three wave solutions expected from the displacement formulation plus three non-propagating stresses with zero wave speed which do not satisfy the strain compatibility conditions. This work provides a different perspective to modeling elastic waves and is expected to be better suited for certain types of problems.
Acoustical transmission of face coverings used to reduce coronavirus transmission in a classroom environment
Authors: Ruhala Laura A. , Ruhala Richard J. , Hadjimirzaei Anaheeta , Hernandez-Borjas Danny , Pierce Andrew P. , Crimm Lance
Published: June 2021

The COVID-19 pandemic has caused many communities to require the wearing of face coverings, masks, and/or shields indoors to reduce the transmission rate of the virus, which includes educators and students in classroom settings. Several types of face coverings are studied, including standardized N95 and KN95, assorted cloth, and clear plastic face shields. They are evaluated on an acoustical head and torso simulator (HATS) setup in a classroom with two different locations for monitoring via a sound level meter. The HATS is used as a controlled and repeatable artificial voice or sound source, which creates white noise, artificial speech, and real speech signals. Sound levels throughout the classroom are measured to determine the direct field and reverberant field regions, and they are compared to a room acoustics model. Attenuation at octave band frequencies due to the face coverings are evaluated at a location of 2.0 m from the HATS, which is within the direct field to reduce the room acoustical effects, with evaluations repeated at a location near the back of the classroom (6.2 m) to include those room acoustical effects. The acoustic effects of the face coverings are compared to reported droplet transmission rates.
Ending the day with a song: Patterns of calling behavior in a species of rockfish
Authors: Kok Annebelle , Bishop Kelly M. , Kim Ella B. , Margolina Tetyana , Joseph John E. , Peavey Reeves Lindsey , Hatch Leila , Baumann-Pickering Simone
Published: June 2021

Similar to birds, fish produce sound to attract mates and repel rivals. At the height of the mating season, these calls form a significant part of the marine soundscape. Even though this phenomenon is widespread in fish species, not much is known about fish calling behavior. We investigated the seasonal, lunar and diel patterns of calling behavior of bocaccio (Sebastes paucispinis), a species of rockfish, in the Channel Islands National Marine Sanctuary, on the west coast of the United States. We deployed acoustic recorders at five sites in the Sanctuary, at depths of 21–156 m, for a period of a year. We extracted bocaccio calls using a detection algorithm and related calling patterns to time of day, lunar illumination and time of year. Besides showing correlations with season and lunar illumination, bocaccio calls were mostly produced at night, with clear peaks at crepuscular time periods. The diel calling pattern showed correlations with site depth, possibly due to vertical migration of fish through the course of the night. Describing and understanding patterns of fish calling behavior can provide insight into communication, habitat preference, mating behavior, or animal density of these species as well as help characterize the acoustic environment that sustains them.
Grouper source levels and aggregation dynamics inferred from passive acoustic localization at a multispecies spawning site
Authors: Wilson Katherine , Širović Ana , Semmens Brice X. , Gittings Stephen , Pattengill-Semmens Christy , McCoy Croy
Published: June 2021

Red hind (Epinephelus guttatus) and Nassau (E. striatus), black (Mycteroperca bonaci), and yellowfin grouper (M. venenosa) form spawning aggregations in Little Cayman, Cayman Islands and produce sound during these aggregations. Continuous observation of these aggregations is challenging because traditional methods are limited in time and space. Passive acoustic localization can overcome some of these challenges in case of sound-producing species, allowing observations over long durations and fine spatial scales. A hydrophone array was deployed in February 2017 over a nine-day period that included Nassau grouper spawning. Hyperbolic localization was used to find positions of the grouper producing calls during this time, to measure call source levels, and evaluate spatiotemporal aspects of calling. During the days Nassau grouper spawned, calling peaked after sunset from 19:00 to 21:00. Similarly, when red hind calls were most abundant, they peaked from 16:00 to 21:00. The mean peak-to-peak source levels of calls was 143.7 dB for yellowfin grouper and 154.9 dB for Nassau grouper (re: 1 μPa at 1 m for 70 to 170 Hz). The measured source levels can be used to determine communication and detection ranges and develop passive acoustic density estimation methods for these fishes.
Unravelling the sound-induced motion of fish auditory structures: A non-invasive synchrotron radiation-based approach
Authors: Schulz-Mirbach Tanja , Ladich Friedrich , Schlepütz Christian M. , Mittone Alberto , Olbinado Margie , Bravin Alberto , Maiditsch Isabelle P. , Melzer Roland , Krysl Petr , Heß Martin
Published: June 2021

Modern bony fishes display a high morphological diversity in their auditory structures. Yet, unraveling the sound-induced in situ interaction of the auditory structures has been challenging. Synchrotron radiation-based imaging techniques with high spatial and temporal resolutions now provide a powerful tool to study the functional morphology of such structures in a non-invasive way. We investigated two species representing two types of otophysic connections, namely, goldfish (Weberian apparatus) and Etroplus canarensis (swimbladder extensions contacting the inner ears) asking how different ancillary auditory structures affect otolith motion. Fishes were subjected to a 200 Hz pure tone in a 2L-standing wave tube-like setup while performing 2D radiography based on hard x-ray phase-contrast imaging. The shakers at each end of the tube were either driven 0° in-phase or 180° out-of-phase resulting in maximized sound pressure or sound-induced particle motion in the tube center, respectively. In both species, saccular otolith motion was more pronounced when the swimbladder walls oscillated under 0° in-phase condition and the motion patterns mainly matched the respective orientation patterns of ciliary bundles on the sensory epithelia. In future, we will quantify the motion patterns of fish auditory structures by applying “sound tomography” to cover the three-dimensional aspect of the moving structures.
Automatic detection and classification of fish calls in the Northern Gulf of Mexico using energy detectors and a convolutional neural network
Authors: Waddell Emily , Frasier Kait , Hildebrand John , Sirovic Ana
Published: June 2021

Long-term passive acoustic monitoring datasets can require substantial effort for manual analysis; therefore, automatic methods are a more effective way to conduct these analyses and extract calls of interest. In this study, acoustic recordings from the northern Gulf of Mexico, about 60 km north of the 2010 Deepwater Horizon oil spill location, collected between July 2010 and May 2017 were analyzed to determine if fish call abundance has changed after the oil spill. An energy detector was created to extract six likely fish calls found in these data and a neural network was subsequently applied to classify the detections into different call categories. Data augmentation and iterative training were used to optimize classification and compensate for the low number of training images for a couple call types. Daily, monthly, and yearly patterns in calls were investigated and a hypothesis was tested that there was an increase in call abundance over time, indicating recovery of fish populations since the oil spill. Such long-term studies demonstrate that PAM can be used as a population assessment tool for fisheries management.
Tom Norris’s contributions to the acoustic density estimation of minke whales near Kauai, Hawaii
Authors: Martin Stephen W.
Published: June 2021

Tom Norris was involved in many collaborative efforts involving passive acoustic monitoring to study marine mammals. In the spring of 2010, he and his team conducted 1520 km of acoustic/visual line-transect surveys over 13 days of effort for minke whales (Balaenoptera acutorostrata) using the R/V Dariabar towing multiple hydrophones. The surveys were performed at the U.S. Navy Pacific Missile Range Facility’s offshore underwater range located north-west of Kauai, Hawaii. Minke whales have low observables and are rarely sighted in the Hawaii area which limits the available knowledge on their ecology. However they produce the distinctive boing vocalizations in the winter and spring seasons in the area, presumably for breeding purposes, which makes PAM methods attractive. Simultaneous with the acoustic line-transect surveys, the PMRF hydrophone data were also collected to estimate the boing vocalization density in a collaborative effort. Combining the minke whale density from the acoustic line-transect survey with the minke whale boing vocalization density provided an estimate for the call rate for boing calling minke whales which was a major accomplishment at the time.
Pre-clinical models for therapeutic ultrasound
Authors: Simon Julianna
Published: June 2021

Before clinical translation, all therapeutic ultrasound therapies require testing in pre-clinical models that can be broadly categorized as in vitro (cells), tissue-mimicking phantoms, ex vivo (tissues), and in vivo (animals) to establish safety and effectiveness. Choice of pre-clinical models is governed by the target application, the desired bioeffect, and the types of data that can be collected; other considerations include cost, access, and time. In this tutorial session, an overview of the four main pre-clinical categories will be presented, including common formulations used for therapeutic ultrasound. Within each category, experimental design considerations as well as the relative advantages and disadvantages to each will be discussed.
Reconstruction of arrays of acoustic vortices using holograms for multiple particle trapping
Authors: Jiménez Noé , Sánchez-Rodríguez Gabriela , Jiménez-Gambín Sergio , Andrés Diana , Camarena Francisco
Published: June 2021

Arrays of acoustic vortices are synthesised using 3D printed holograms in the ultrasound regime. This technique paves the way for simultaneous trapping of multiple particles and such as arrays of cells, microbubbles or drug-delivery carriers using a low-cost device.
Ultrasound imaging simulations using Fullwave
Authors: Pinton Gianmarco
Published: June 2021

The latest advancements in diagnostic ultrasound imaging simulations based on the first principles of nonlinear attenuating propagation and reflection in the human body are presented.
An immersed-boundary approach to time-domain simulation of acoustic propagation in complex geometries and media
Authors: Zheng Zhongquan C. , Hou Jiacheng
Published: June 2021

With the advent of computing power in recent decades, time-domain simulation of acoustic propagation has become practically feasible. In this presentation, we present an immersed-boundary approach implemented in TSPACE, a simulation for time-domain acoustic propagation in complex geometries. Because TSPACE is based on conservation laws in the physical domain (both time and space), the primary advantage is its ability to accommodate a wide spectrum of realistic physics in the ambient of acoustic propagation, including complex geometries, media, and environmental conditions. The immersed-boundary approach in TSPCE is to use simple structured Cartesian grid mesh to simulate acoustic propagations, where the time-domain simulation is coupled with the immersed-boundary method to accommodate complicated geometries. Properties such as interface between different acoustic propagation media can be effectively modeled. In the presentation, the mathematical formulation and numerical algorithm of TSPACE will be explained, followed by several examples of simulation including sound propagation around arbitrary-shaped porous barriers, noise from unmanned aerial vehicles, diffractions near buildings, array arrangements in sonic crystals in both two and three dimensions, ultrasonic wave propagation in a lossy medium, and acoustic scattering around bubbles. It will also be demonstrated that the simulation results are verified/validated by comparisons to the analytical solutions and measured data in the literature.
Mode coupling and sound field variability in near-coastal area in the presence of internal Kelwin waves
Authors: Uzhansky Ernest , Lunkov Andrey , Katsnelson Boris
Published: June 2021

In this paper, propagation of the sound waves in near-coastal wedge-like area is studied in the presence of Internal Kelwin waves (IKW), which cause periodic changes of the thermocline level with daily period. These oscillations initiate variation of the sound field interference structure at the receiving system. In the paper theoretical analysis and numerical modeling of these fluctuations are carried out, it is shown that physical reason of variability of the sound field is specific mode coupling in area where time and range depending eigen values of adiabatic modes are closing to each other (quasi-crossection) in a wedge-like waveguide, periodical displacement of place of this quasi-crossection initiates fluctuations of the sound field. Calculations of modal amplitudes and in turn structure and spatio-temporal variability of the sound field in a waveguide was carried out within the framework of parabolic equation and solution of system of equations of mode coupling. Results are compared with experimental data. [Work was supported by RFBR, Grant 20-05-00119.]