bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence and type of peripheral intravenous catheter complications documented in hospitalised dogs
Authors: Simpson S. E. , Zersen K. M.
Published: November 2022

Objective

To report the incidence and type of peripheral intravenous catheter complications in hospitalised dogs.

Methods

A prospective, observational trial was performed. Peripheral intravenous catheters were monitored for complications. Complications were documented and classified as extravasation, phlebitis, dislodgement, occlusion and line breakage. If phlebitis was present, the Visual Infusion Phlebitis Scale was used to assign a grade (0 to 5). Fisher's exact test was used to compare the type of complications between the critical care unit and the intermediate care unit. A univariate logistic model was used to compare the incidence of complications between the critical care unit and the intermediate care unit and adjusted odds ratios were used to compare the groups.

Results

The incidence of peripheral intravenous catheter complications was 24.2% in the Critical Care Unit and 13.1% in the Intermediate Care Unit, with an overall incidence of 19.9%. Phlebitis was the most common peripheral intravenous catheter complication in the Critical Care Unit, and line breakage was the most common complication in the Intermediate Care Unit. Length of hospitalisation and weight had a significant effect on the likelihood of complication. In a multivariable logistic regression model, the odds of a peripheral intravenous catheter complication was not significantly higher in CCU than IMCU, accounting for length of hospitalisation and weight (adjusted odds ratio, 1.84; 95% confidence interval, 0.98 to 3.48).

Clinical Significance

Peripheral intravenous catheter complications are common in hospitalised dogs and may result in an increased expense for owners, failure to deliver prescribed treatments, venous depletion (lack of peripheral vessels for intravenous catheter placement) and pain experienced by the patient. Techniques to reduce peripheral intravenous catheter complications should be further evaluated and may include the use of peripheral intravenous catheter placement and maintenance checklists, use of force‐activated separation devices, or patient sedation.
Does the employment effect of national minimum wage vary by non‐employment rate? A regression discontinuity approach
Authors: Xu Lei , Zhu Yu
Published: November 2022

We extend the Regression Discontinuity model to evaluate the procyclicality of employment effect of minimum wage and show that previous estimates may be biased due to failure to account for the local non‐employment rate. The results suggest that the positive employment effect of increasing minimum wage is strongly procyclical, that is, is more pronounced in areas with low non‐employment rates. Under an assumption that employers have no direct impact around the cut‐off point, the results suggest that a higher minimum wage increases labour supply of young workers.
Mapping the root systems of individual trees in a natural community using genotyping‐by‐sequencing
Authors: Osborne Owen G. , Dobreva Mariya P. , Papadopulos Alexander S. T. , de Moura Magna S. B. , Brunello Alexandre T. , de Queiroz Luciano P. , Pennington R. Toby , Lloyd Jon , Savolainen Vincent
Published: November 2022

The architecture of root systems is an important driver of plant fitness, competition and ecosystem processes. However, the methodological difficulty of mapping roots hampers the study of these processes. Existing approaches to match individual plants to belowground samples are low throughput and species specific. Here, we developed a scalable sequencing‐based method to map the root systems of individual trees across multiple species. We successfully applied it to a tropical dry forest community in the Brazilian Caatinga containing 14 species.

We sequenced all 42 individual shrubs and trees in a 14 × 14 m plot using double‐digest restriction site‐associated sequencing (ddRADseq). We identified species‐specific markers and individual‐specific haplotypes from the data. We matched these markers to the ddRADseq data from 100 mixed root samples from across the centre (10 × 10 m) of the plot at four different depths using a newly developed R package.

We identified individual root samples for all species and all but one individual. There was a strong significant correlation between belowground and aboveground size measurements, and we also detected significant species‐level root‐depth preference for two species.

The method is more scalable and less labour intensive than the current techniques and is broadly applicable to ecology, forestry and agricultural biology.
Deciphering the “obesity paradox” in the elderly: A systematic review and meta‐analysis of sarcopenic obesity
Authors: Liu Chaoran , Wong Pui Yan , Chung Yik Lok , Chow Simon Kwoon‐Ho , Cheung Wing Hoi , Law Sheung Wai , Chan Juliana Chung Ngor , Wong Ronald Man Yeung
Published: November 2022

Aging and obesity are two global concerns in public health. Sarcopenic obesity (SO), defined as the combination of age‐related sarcopenia and obesity, has become a pressing issue. This systematic review and meta‐analysis summarize the current clinical evidence relevant to SO. PubMed, Embase, and Web of Science were searched, and 106 clinical studies with 167,151 elderlies were included. The estimated prevalence of SO was 9% in both men and women. Obesity was associated with 34% reduced risk of sarcopenia (odds ratio [OR] 0.66, 95% CI 0.48–0.91; p < 0.001). The pooled hazard ratio (HR) of all‐cause mortality was 1.51 (95% CI 1.14–2.02; p < 0.001) for people with SO compared with healthy individuals. SO was associated with increased risk of cardiovascular disease and related mortality, metabolic disorders, cognitive impairment, arthritis, functional limitation, and lung diseases (all ORs > 1.0, p < 0.05). The attenuated risk of sarcopenia in elderlies with obesity (“obesity paradox”) was dependent on higher muscle mass and strength. Apart from unifying the diagnosis of SO, more research is needed to subphenotype people with obesity and sarcopenia for individualized treatment. Meanwhile, the maintenance of proper body composition of muscle and fat may delay or attenuate the adverse outcomes of aging.
Fear of falling from the perspective of affected persons—A systematic review and qualitative meta‐summary using Sandelowski and Barroso's method
Authors: Baltes Marion , Herber Oliver Rudolf , Meyer Gabriele , Stephan Astrid
Published: November 2022

Background

Fear of falling (FoF) affects a large number of older people, whether they have a history of falls or not. This has an impact on their lives. FoF is a potentially modifiable factor, which has been identified as one of the most important threats to older people's autonomy.

Objectives

To gain a comprehensive understanding of the phenomenon, we conducted a systematic review and meta‐summary. The available evidence from qualitative research exploring how people experience FoF and how FoF affects daily living was aggregated.

Methods

We followed the approach by Sandelowski and Barroso (2007) as a method to aggregate knowledge based on an exhaustive literature search. We searched the databases CINAHL, MEDLINE, PsycINFO and SSCI systematically for relevant articles as well as grey literature until September 2020. Out of the included studies, findings were extracted, edited, grouped and abstracted into meta‐findings. Finally, the manifest frequency effect size of each abstracted meta‐finding was calculated.

Results

Out of 2978 identified studies, 15 met our inclusion criteria, which were published between 1993 and 2017 and included a total of 276 participants. We extracted 578 findings, and the abstraction process resulted in 183 meta‐findings. We identified three main topics: ‘Triggers and reasons for FoF identified by affected people’, ‘Consequences attributed to FoF’ and ‘Strategies to manage FoF in daily life’.

Conclusion

Our findings demonstrate that FoF has a far‐reaching impact on the lives of those affected. With the aggregation of the existing qualitative data with the application of the frequency effect size, we were able to identify three areas of particular importance to those affected: (1) controlling the risk, (2) creating a safe environment and (3) staying independent. Implications for practice these three areas of particular importance to those affected should be taken into account when revisiting or creating new interventions to prevent or reduce FoF.
A Randomized Study on the Prophylactic Use of Acetaminophen to Prevent Fever after the Removal of Drainage Tubes for Lumbar Surgery
Authors: Ye Kaifeng , Li Yan , Xing Yong , Liu Kaixi , Zhou Fang , Tian Yun , Zhang Yanping
Published: November 2022

Background

Many inpatients encounter a fever in the first 24 h after drainage removal. It is costly to exclude the possibility of deep infection and cultures usually fail to identify the etiology. We hypothesize that the fever is caused by a normal inflammatory response and tested whether the prophylactic use of acetaminophen could reduce the fever rate.

Methods

This was a prospectively randomized clinical trial performed from July 2019 to January 2020. A total of 183 consecutive patients undergoing lumbar spine surgery were prospectively randomized into two groups. Ninety‐one patients were randomized into the study group; they received oral acetaminophen before removal of the drainage tubes and a second dose at 8 p.m. on the same day. The remaining 92 patients were placed in the control group, and they were given routine treatment without acetaminophen. The two groups were compared for differences in age, sex, height, weight, BMI, surgical segments, surgical time, blood loss, blood transfusion, ASA score, duration of drainage, total volume of the drainage, variation of WBC and CRP, hospital stay after the removal of the drainage tube and the rate of fever. Student's t‐test and the Mann–Whitney U test were used to analyze the continuous data, while the chi‐square test was used for the analysis of the ranked data.

Results

Regarding the comparisons of basic information, there were no significant differences between the two groups for age, height, weight, BMI, surgical segments, surgical time, blood loss, blood transfusion, total drainage volume, duration of drainage, hospital stay, WBC, and CRP variation or the duration of hospital stay after removal of the drainage tube (all p > 0.05). However, the fever rate was significantly different (p = 0.006), and the fever rate of the study group (14/91, 15.38%) was significantly lower than that of the control group (30/92, 32.61%). In the study group, there were no complications related to the use of acetaminophen during the hospital stay or during the outpatient follow‐up period.

Conclusion

Fever after removal of tube drainage is caused by a normal inflammatory response, and a small dose of acetaminophen could significantly reduce the possibility of fever.
Study on the Optimal Surgical Scheme for Very Severe Osteoporotic Vertebral Compression Fractures
Authors: Wen Zhenxing , Mo Xiaoyi , Ma Hangzhan , Li Haonan , Liao Changhe , Fu Dan , Cheung Wing Hoi , Qi Zhichao , Zhao Shengli , Chen Bailing
Published: November 2022

Objective

Therapy of very severe osteoporotic compression fractures (VSOVCF) has been a growing challenge for spine surgeons. Opinions vary regarding the optimal surgical procedure for the treatment of VSOVCF and which internal fixation method is more effective is still under debate, and research on this topic is lacking. This retrospective study was conducted to compare the efficacy and safety of various pedicle screw fixation methods for treating VSOVCF.

Methods

This single‐center retrospective comparative study was conducted between January 2015 and September 2020. Two hundred and one patients were divided into six groups according to different surgical methods: 45 patients underwent long‐segment fixation (Group 1); 39 underwent short‐segment fixation (Group 2); 30 received long‐segment fixation with cement‐reinforced screws (Group 3); 32 received short‐segment fixation with cement‐reinforced screws (Group 4); 29 had long‐segment fixation combined with kyphoplasty (PKP) (Group 5); and 26 cases had short‐segment fixation combined with PKP (Group 6). The clinical records were reviewed and the visual analogue scale (VAS) score and the Oswestry Disability Index (ODI) score were used for clinical evaluation. The vertebral height (VH), fractured vertebral body height (FVBH), and Cobb's angle were objectively calculated and analyzed on lateral plain radiographs. Student's t‐tests and one‐way ANOVA among groups were conducted to analyze the continuous, and the chi‐squared test was used to compare the dichotomous or categorical variables. The difference was considered statistically significant when the P‐value was less than 0.05.

Results

The six groups had similar distributions in age, gender, course of the disease, follow‐up period, and injured level. In the postoperative assessment of the VAS score, the surgical intervention most likely to rank first in terms of pain relief was the short‐segment fixation with cement‐reinforced screws (Group 4). For the functional evaluation, the surgical intervention that is most likely to rank first in terms of ODI score was a short‐segment fixation with cement‐reinforced screws (Group 4), followed by long‐segment fixation (Group 1). The long‐segment fixation with cement‐reinforced screws was the first‐ranked surgical intervention for the maintenance of Cobb's angle and vertebral height, whereas the short‐segment fixation performed the worst. The highest overall complication rate was in Group 6 with an incidence of 42.3% (11/26), followed by Group 2 with an incidence of 38.5% (15/39).

Conclusion

For the treatment of VSOVCF, the short‐segment fixation with cement‐reinforced screws is the most effective and optimal procedure, and should be used as the preferred surgical method if surgeons are proficient in using cemented screws; otherwise, directly and unquestionably use long‐segment fixation to achieve satisfactory clinical results.
Grafting‐induced seed gossypol levels by demethylation of (+)‐delta‐cadinene synthase genes in upland cotton
Authors: Karaca Mehmet , Ince Ayse Gul
Published: November 2022

Two‐year‐grafting experiments within and between Gossypium barbadense and Gossypium hirsutum accessions were conducted to study the source, transfer, and alteration of gossypol and methylation of (+)‐δ‐cadinene synthase (CDN) genes along with whole chromosomes of A01, A04, A11, D01, D05, and D11, harbouring the cotton CDNs, using the whole genome bisulfite sequencing (WGBS) method. The results revealed that although a glandless line used in this study had a low level of gossypol in the seeds, it did not contain any pigment glands, indicating that expression pathways of gland and gossypol were under genetic control of different loci in cotton. Grafts with glandless rootstocks produced significant amounts of total gossypol in the seeds, clearly demonstrating that the source of gossypol biosynthesis was not specific to the root. Heterografts consisting of scion GN, a glandless line, and scion TM‐1 grafted on Pima 3‐79 rootstocks caused increased total seed gossypol levels whereas homograft TT had decreased total seed gossypol levels. Alteration of total gossypol levels was also associated with gland density, and DNA demethylation levels of (+)‐δ‐cadinene synthase genes.
Genetic variability and phylogenetic characterization of different populations of Meloidogyne izalcoensis and reaction of coffee genotypes to this new species detected in Brazil
Authors: Almeida Sheila F. , Santos Marcilene F. A. , Stefanelo Daniela , Mattos Vanessa S. , Rodrigues‐Silva Paolo L. , Sousa Gleiciane P. , Salgado Sônia M. L. , Sera Gustavo H. , Castagnone‐Sereno Philippe , Cares Juvenil E. , Carneiro Regina M. D. G.
Published: November 2022

A new root‐knot nematode (RKN), Meloidogyne izalcoensis, was detected on coffee in Brazil. This species was first described on coffee from El Salvador and later detected in Asia and Africa. There are no reports on the genetic diversity of this species and resistance to M. izalcoensis has not yet been studied in coffee cultivars. All populations were identified by esterase phenotype and sequence‐characterized amplified region (SCAR) species‐specific markers. Based on random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers, low intraspecific variability was detected among M. izalcoensis populations from Africa, Vietnam and Brazil, but the population from El Salvador showed fewer genetic differences from the other populations. Phylogenetically, all populations of M. izalcoensis from different locations (El Salvador, Kenya, Tanzania, Vietnam and Brazil) grouped with 90% and 69% bootstrap support for COII and HSP90 regions, respectively, indicating that these markers are highly conserved for the species. In addition, both markers enabled separation of M. izalcoensis populations from other important coffee Meloidogyne species, including M. exigua, M. paranaensis, M. incognita, M. arabicida and M. lopezi. In resistance studies, most genotypes tested that had resistance to other Meloidogyne spp. (Amphillo × Catuaí, Hybrid of Timor, IAPAR 59, IPR 99, IPR 100, IPR 102, IPR 103, IPR 105, IPR 106, IPR 107 and IPR 108) were found to be susceptible to M. izalcoensis, except for the rootstock cv. Apoatã IAC 2258, which proved to be moderately resistant, with a genetic segregation for this character of 43.8%.
A Bayesian Improvement of the Proportionality Principle
Authors: Pecaric Mirko
Published: November 2022

The principle of proportionality is seen as the highest peak of structural, logical thinking that enables balancing between constitutional principles and their interferences. So far, Alexy's weight formula has been the most advanced approach in structured balancing of proportionalitystricto sensu, while this paper shows it as still too subjective. Despite judicial tests—or different, manifestly inappropriate reasonableness tests—proportionalitystricto sensuhides some form of the jumping‐to‐conclusions bias, because the inference is made through a subjective lens. The paper presents structured legal balancing (and hence reasoning) based on Bayes’ theorem. This paper, based on the connection between probability and hypothetical legal norms, transfers the four‐part structure of proportionality into the relevant four‐part structure of the Bayes tree. This transfer shows the first as flawed due to its failing to consider means that can have the same effects as the considered ones. Only by inclusion of the latter can the total probability of a considered case be established. Numerical proportionalityà laBayes can be further improved through the use of public‐value weights that are obtained from surveys or online communities of people giving weights in the real time (collective wisdom). The Bayesian approach can also be used in adjudication as a control in assessing judicial standards in use.
Coeval Miocene exhumation of the Cycladic Blueschist Unit and the Cycladic Basement in the southern Cyclades, Ios and Sikinos, Greece
Authors: Flansburg Megan E. , Poulaki Eirini M. , Stockli Daniel F. , Soukis Konstantinos
Published: November 2022

Miocene extension in the back arc of the retreating Hellenic subduction zone resulted in metamorphic core complex formation and exhumation of the Cycladic HP‐LT rocks. The extension was accommodated by bivergent detachment systems, generally occupying the interface between the Cycladic Blueschist Unit (CBU) and overlying Pelagonian units. However, the nature and kinematic history of the contact between the CBU and underlying Cycladic Basement (CB) in the southern Cyclades remains debated due to the presence of both top‐to‐the‐N and top‐to‐the‐S kinematics and ambiguities dating the final exhumation stages. Zircon and apatite (U‐Th)/He data and thermal modelling for the CB and CBU on Ios and Sikinos show that both units were likely exhumed as a coherent footwall block in response to rapid slip along the bivergent Miocene Santorini and Naxos‐Paros detachment systems.
Suppression of the tonoplast sugar transporter, StTST3.1, affects transitory starch turnover and plant growth in potato
Authors: Liu Tengfei , Kawochar Md Abu , Liu Shengxuan , Cheng Yunxia , Begum Shahnewaz , Wang Enshuang , Zhou Tingting , Liu Tiantian , Cai Xingkui , Song Botao
Published: November 2022

Transitory starch and vacuolar sugars function as highly dynamic pools of instantly accessible metabolites in plant leaf cells. Their metabolic regulation is critical for plant survival. The tonoplast sugar transporters (TSTs), responsible for sugar uptake into vacuoles, regulate cellular sugar partitioning and vacuolar sugar accumulation. However, whether TSTs are involved in leaf transient starch turnover and plant growth is unclear. Here, we found that suppressing StTST3.1 resulted in growth retardation and pale green leaves in potato plants. StTST3.1‐silenced plants displayed abnormal chloroplasts and impaired photosynthetic performance. The subcellular localization assay and the oscillation expression patterns revealed that StTST3.1 encoded a tonoplast‐localized protein and responded to photoperiod. Moreover, RNA‐seq analyses identified that starch synthase (SS2 and SS6) and glucan water, dikinase (GWD), were downregulated in StTST3.1‐silenced lines. Correspondingly, the capacity for starch synthesis and degradation was decreased in StTST3.1‐silenced lines. Surprisingly, StTST3.1‐silenced leaves accumulated exceptionally high levels of maltose but low levels of sucrose and hexose. Additionally, chlorophyll content was reduced in StTST3.1‐silenced leaves. Analysis of chlorophyll metabolic pathways found that Non‐Yellow Coloring 1 (NYC1)‐like (NOL), encoding a chloroplast‐localized key enzyme that catalyzes the initial step of chlorophyll b degradation, was upregulated in StTST3.1‐silenced leaves. Transient overexpression of StNOL accelerated chlorophyll b degradation in tobacco leaves. Our results indicated that StTST3.1 is involved in transitory starch turnover and chlorophyll metabolism, thereby playing a critical role in normal potato plant growth.
The Reversal Characteristics of GABAergic Neurons: A Neurovascular Model
Authors: David Tim , Morillo Robin , Howarth Clare , Berwick Jason , Lee Llywelyn
Published: November 2022

Neurovascular coupling (NVC) is the ability to locally adjust vascular resistance as a function of neuronal activity. Recent experiments have illustrated that NVC is partially independent of metabolic signals. In addition, nitric oxide (NO) has been shown in some instances to provide an important mechanism in altering vascular resistance. An extension to the original model of NVC [1] has been developed to include the activation of both somatosensory neurons and GABAergic interneurons and to investigate the role of NO and the delicate balance of GABA and neuronal peptide enzymes (NPY) pathways. The numerical model is compared to murine experimental data that provides time-dependent profiles of oxy, de-oxy, and total-hemoglobin. The results indicate a delicate balance that exists between GABA and NPY when nNOS interneurons are activated mediated by NO. Whereas somatosensory neurons (producing potassium into the extracellular space) do not seem to be effected by the inhibition of NO. Further work will need to be done to investigate the role of NO when stimulation periods are increased substantially from the short pulses of 2 s as used in the above experiments.
Nucleation and growth mechanism for atomic layer deposition of Al2O3 on two-dimensional WS2 monolayer
Authors: Lee Tsu-Ting , Chiranjeevulu Kashi , Pedaballi Sireesha , Cott Daire , Delabie Annelies , Dee Chang-Fu , Chang Edward Yi
Published: November 2022

Nanoelectronics holds significant promise for two-dimensional (2D) semiconducting transition metal dichalcogenide (TMD) applications. On a polycrystalline WS2 monolayer created by metal-organic chemical vapor deposition (MOCVD) at 950 °C, we studied the nucleation, growth, and development of Al2O3 atomic layer deposition (ALD) on a SiO2/Si substrate. In this investigation, we used various complementary characterization methods, such as Raman spectroscopy, elastic recoil detection, atomic force microscopy, and time-of-flight secondary ion mass spectrometry, to understand thoroughly the intrinsic reactivity of WS2. Strong peak intensity changes at the interfaces in the Raman line scans of the SiO2/Si patterns suggest extremely crystalline WS2. After multiple ALD cycles, triangular WS2 crystals were decorated to provide a two-dimensional growth mode with a great selectivity for grain boundaries and step edges. The results of this work can be used for further exploration of the TMD monolayer structure and properties, which is essential for tailoring 2D materials for a specific application in devices.
Autopsy of a failed extension policy
Authors: McCoy Bradley “Peanut”
Published: November 2022

There is a challenge as an instructor to balance the tension between flexibility and accountability in assignment due dates. I have long used an extension policy in my classes out of a desire to give students some flexibility on due dates. Students may have many good reasons that warrant extensions: work schedules, athletics, family crises, exams or major assignments in other courses, and more. After using a relatively generous extension policy in my courses for several years, I became concerned that some students may not be served well by this policy and reviewed the policy and its effects on student grades. In this article I describe how student extension usage correlates with grades.
Cultivating community
Authors: Wachowski Shannon
Published: November 2022

When I started out as a teacher, over 15 years ago, I was what might be categorized as “traditional.” I gave PowerPoint lectures, assigned homework, and supported my students to perform confirmatory labs demonstrating what I had already told them was true in the lecture. I was seen as a “good” teacher. Evaluations from administrators, along with anecdotal comments from students and parents, supported this label. But something didn’t feel right. My students were not all demonstrating mastery on assessments, and I didn’t feel like I was connecting with and supporting each student every day. About five years into my teaching career, at the annual Colorado Association of Science Teachers’ Conference in November, I learned about Flipped Learning at a presentation by Aaron Sams and Jon Bergmann. The general idea of Flipped Learning is that students need support on the more challenging aspects of learning (application) and can receive the direct instruction parts (lecture) on their own time. While this model has evolved over time, it started out as an emphasis on doing exploratory and application-like activities with students in class (labs, practice problems, etc.) and providing students with the information, either as an introduction or wrap-up to the lesson, through video for students to watch on their own time. Feeling like this might be a way to better meet the needs of my students, over the holiday break, I revamped my entire Chemistry course, making videos of all my lectures, writing a grant to secure some technology, and preparing to launch my Flipped Chemistry course upon return to school in January. Much to my surprise, students did not readily embrace this change in the way I had hoped. I received comments such as “you’re not teaching me,” and parents started complaining to the administration. I learned a lot from that experience. Change takes time and must be well thought out and planned. Stakeholders, in this case students, parents, and administrators, needed to be brought into the planning and needed to understand the purpose and motivation behind the change. And most importantly, I needed a community of other teachers to exchange ideas with, share challenges with, and receive support from. I had decided to implement this change without a network of support, and without consulting others to determine possible roadblocks and challenges. When we pursue the path less taken, it can often feel scary and lonely. Finding individuals who share similar choices can often be reassuring and motivate us to push past moments of difficulty when we believe this uncharted path really is the best one for us. This is why community is so important, especially in education.
The Cross Diagram for Kinematics Problems
Authors: Sinkovits Daniel Wilhelm
Published: November 2022

The cross diagram is a way to illustrate and plan the solutions for all kinds of constant-acceleration kinematics problems—including projectile motion, multistage, and multiple-object problems. The cross diagram arranges the kinematic variables in a logical way, making the kinematic relationships between them easy to identify. Combined with a method to visually mark known information and equations, it provides a framework to plan out which equations will be used in the solution of a problem. This paper introduces the cross diagram through its use in a series of example problems.
Take-Home Labs at the University of Chicago
Authors: Greenslade Thomas B.
Published: November 2022

In the 1930s, the teaching staff of the University of Chicago devised a clever way to deliver experimental data to their introductory students without meeting them in the laboratory. The university’s curriculum included a required Introductory Course in the Physical Sciences. There were probably too many students to allow for a standard face-to-face laboratory experience. In this article, I will discuss the solution that was reached about 80 years ago, and muse on how it can be used during a time when a pandemic makes regular laboratory instruction impossible. Their approach may be useful to present-day teachers trying to deliver a laboratory experience to students in introductory physics courses without face-to-face instruction.
Time-reversal in phononic crystal-based water filled pipe
Authors: Ahmed Utban , Nasroui Saber , Louati Moez , Ghidaoui Mohamed S.
Published: November 2022

Time-reversal based source localization in a conventional water-filled pipe using acoustic waves is hamstrung by the diffraction limit (λ/2). In this paper, time reversal in a novel metamaterial-based water pipeline is studied where a conventional rigid pipe is modified to have periodic square corrugations. Based on the choice of periodicity, such a novel waveguide can support subwavelength resonance in the low frequency regime while exhibiting Bragg resonance, avoided crossing of modes and forbidden bands in diffraction regime. This paper focuses on the latter such that a band structure is obtained. Full wave simulation performed on COMSOL verifies the phononic crystal-like properties in the diffraction regime. Time reversal refocusing is performed by placing a point source in the middle of the corrugated section while a receiver outside the said section records the response of the system. The receiver acts as a Time Reversal Mirror (TRM) such that it flips and reinjects the recorded signal into the system which retraces its path and focuses on its source. Time-reversal refocusing is found to be sensitive to the recorded frequency grains in addition to the energy propagated from the source such that if the source encompasses a band gap, the time reversal quality deteriorates.
Ultra-stiff and ultra-light architected metamaterial for vibration mitigation
Authors: Huang Edward , Oudich Mourad , Heo Hyeonu , Jing Yun
Published: November 2022

We designed, fabricated, and experimentally validated an architected mechanical metamaterial vibration shielding while ensuring high effective stiffness with low density. The structure is made of a periodic succession of octet truss units with alternating circular strut diameters. The octet truss endows the meta-structure with a high effective stiffness and a low effective density, while alternating the units with different struts radii enables the opening of a wide band-gap for elastic waves. Samples were 3D printed and experimentally validated using a shaker and accelerometer. Unidirectional compression test was also performed to characterize the mechanical properties of the metamaterial. The results are in good agreement with the numerical prediction.
Lombard effect and speech intelligibility by frequency content
Authors: Bottalico Pasquale , Murgia Silvia
Published: November 2022

The Lombard Effect is an increase in vocal effort in response to rising noise levels and disturbance in the communication environment. The objective of this study is to evaluate the Lombard Effect during four intensity levels from 45dB(A) to 75dB(A) of low-frequency, medium-frequency, and high-frequency energy noise to measure the effect of disturbance and vocal discomfort on the speaker’s intent to communicate, as well as the effect on speech intelligibility. Twelve conditions were randomly presented and recorded for each participant with the three types of noise and levels. At each condition, 20 participants were asked to read a passage. Immediately following each reading, participants were asked to rate the amount of noise disturbance and vocal comfort they had experienced. After, the speech intelligibility was evaluated by asking the participants to repeat the sentences of the QuickSin test emitted by a Head and Torso Simulator. The medium-frequency energy noise showed the highest Lombard Effect and the stronger decrease in intelligibility. In the conditions with noise with mid-frequency energetic content, the decrease in intelligibility was drastic with the increase in noise level. Low-frequency noises minimally impact speech intelligibility. High-frequency noises show little change in intelligibility with the increase in noise level.
Predicting talker intelligibility: Contrasting talkers’ racialized identities and listeners’ racializations
Authors: Tripp Alayo , Lyons Tatiana , Munson Benjamin
Published: November 2022

Recent studies have found that speech intelligibility can be manipulated by changing the race of a person whose face is used as a visual prime presented with a spoken sentence (Babel & Russell, 2015; McGowan, 2015; Kutlu et al., 2022). These findings suggest that the differences in racializing faces—the process whereby people ascribe a race to an individual an explanation for observed traits and behaviors and to predict future behavior–may mediate speech intelligibility. However, other data suggests that the contrastive effect arises more from perceived differences in vocal behavior (McLaughlin et al., 2022). In this study, we address this discrepancy in previous research. We examine variability in the process of racialization from faces and voices by contrasting the predictive power of talkers’ self-reported racialized identities on speech intelligibility with that of racializations reported by listeners. We examine this in an experiment assessing the audio-only and audio-visual intelligibility in noise of 28 talkers of various racialized identities by 242 listeners. The listeners both reported the speech they heard, and indicated what they believed the talkers’ racialized identities to be. Data collection is complete, and analysis is ongoing. [Funded by NIH grant R21 DC018070]
Predicting cross-barrier communication disruption using adaptive Support Vector Machines
Authors: McCormick Cameron A. , Aquino Wilkins , Smith Chandler , Walsh Timothy
Published: November 2022

Certain applications may exist where it is necessary to transmit data between two sides of a physical barrier without compromising the structure of the barrier itself. This may be the case when the barrier separates personnel from dangerous conditions or when sensitive electronics are hermetically sealed. One solution is to use mechanical waves to transmit data across the barrier directly. However, this solution is susceptible to new environmental disruptions that can compromise the data stream, such as mechanical vibrations from components in contact with the barrier. Comprehensively evaluating the entire range of expected environmental disruptions can be prohibitive. This work will present the application of Support Vector Machines (SVMs) to adaptively predict environments in which data disruption is expected to occur. The problem is cast as a binary classification problem, for which SVMs are one of the leading machine learning algorithms. The adaptive SVM approach is able to accurately predict disruptive environmental conditions while exploring only a small subset of the entire range. Knowledge of the environmental conditions that lead to data disruption will then enable the design of experiments for validation.SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
Categorical perception of Mandarin tones in neurotypical adults with subclinical autistic traits
Authors: Li Yu , Jiang Sabrina Y. , Wang Yuanyuan , Zhang Linjun
Published: November 2022

Early studies have revealed that categorical speech perception is impaired in individuals with autism spectrum disorders. However, it remains unclear whether categorical speech perception ability is associated with subclinical autistic traits in neurotypical populations. The current study sought to address this question by examining categorical perception of Mandarin tones (T1, high-level; T4, falling) in young adults. One hundred and thirty-one college students were recruited to participate in two classic categorical perception task, identification and discrimination, and to fill in the Autism-Spectrum Quotient (AQ; Baron-Cohen et al., 2001) for measuring subclinical autistic traits. The results showed that identification slope and categorical boundary width were not significantly correlated with the overall AQ score and the scores of the five subscales. However, between-category discrimination accuracy was significantly correlated with the social subscale score, indicating that individuals with less social skills have heightened between-category discrimination ability. Possible theoretical and practical implications of this association in subclinical populations are discussed. The current study adds to a better understanding of the associations between subclinical autistic traits and categorical speech perception in neurotypical individuals. [Work supported by the Humanities and Social Sciences Foundation of Ministry of Education of China 20YJCZH079.]
Show your scattering coefficients
Authors: Vorlaender Michael , Feistel Stefan
Published: November 2022

Absorption and scattering coefficients of surfaces are crucial components of room-acoustic simulations. The random-incidence scattering coefficient is the most uncertain metric applied in geometrical acoustics. Databases of scattering coefficients are rare. Their impact on auditory perception in auralizations, however, is relatively well studied. Research directions in developing improved scattering metrics can focus on their relevance for auditory effects, their influence on the spatial sound energy flow, their characterization in angular decomposition, and their estimation with simple rules of thumb. This paper will highlight the state of the art in determining and using scattering coefficients, and it will discuss possible improvements.
Fiber Bragg grating technology for biomedical ultrasound applications
Authors: Shekhar Himanshu , Jajoria Kuldeep , Jha Chandan K. , Chakraborty Arup L.
Published: November 2022

Fiber Bragg gratings (FBGs) are a class of optical sensors that have been used widely in non destructive testing and monitoring. These sensors are compact, robust, inexpensive and immune to electromagnetic interference. FBGs serve as wavelength selective mirrors that reflect light at the Bragg wavelength. An applied strain results in a shift in the Bragg wavelength, which can be used to detect physical parameters such as temperature and pressure. Recent work suggests that FBGs could have potential for measurements in the biomedical ultrasound frequency range. In this presentation, I will provide an overview of ongoing work in our group on employing FBGs for applications in therapeutic ultrasound. Specifically, I will discuss calibration of these sensors along with their use in passive cavitation detection. I will also present recent results on detecting nonlinear waveforms relevant to focused ultrasound along with temperature measurement for thermal therapy. We envisage that these sensors will be useful in laboratory research environments, and for specialized therapy applications in the clinical setting.
Effects of multilingual and monolingual social networks on speech perception
Authors: Kutlu Ethan , Fell Alexandra , Apfelbaum Keith , McMurray Bob
Published: November 2022

Speech perception is gradient—listeners track continuous acoustic differences within a category (McMurray et al., 2022; Kapnoula & McMurray, 2022). Listeners use this gradiency to adjust subphonetic details (McMurray & Jongman, 2011), recover from ambiguity (McMurray et al., 2009), and aid learning and adaptation (McMurray & Farris-Trimble, 2012; Clayards et al., 2008). However, it is unclear whether gradiency is a developmental product of linguistic experience, particularly the variability of speech that is experienced. This ongoing project (current n = 31, planned n = 60) is testing school-aged children (6–11 years old) using the visual analogue scaling task (Kong & Edwards, 2011). Children hear tokens from a speech continuum (e.g., beach/peach) and make continuous ratings about how /b/- or /p/- like the sound is. This is related to social network information regarding children’s language and social background. Preliminary results suggest that linguistic diversity impacts speech perception gradiency. The implications of bilingual education and linguistic environment in development will be discussed.
Joint range-velocity estimation with continuous active sonar
Authors: Krolik Jeffrey , Hickman Granger
Published: November 2022

Active sonars using linear frequency-modulated (LFM) continuous waveforms are typically processed in sub-bands to facilitate high target range update rates. Target range-rate is then estimated using incoherently processed matched-filter outputs from each sub-band as input to a tracker. Target returns can easily be confused with clutter because sub-band width is typically chosen to avoid decoherence caused by target and/or platform motion. In this paper, we present methods for joint range-velocity estimation which allows for coherent combination of sub-band outputs and accounts for target/platform motion. The approach involves pre-filtering beamformed sub-band outputs using the transmitted LFM waveform, match-filtering each frequency-domain pre-filtered sub-band under a range-velocity hypothesis, and coherently combining the results. A maximum likelihood estimate (MLE) of range-velocity is formed which involves adaptively suppressing clutter and noise using an estimate of sub-band clutter covariance matrices. Simulation results are presented which indicate that joint range-velocity estimation using coherent processing across sub-bands offers a significant improvement over conventional methods and allows for more flexible selection of sub-band processing bandwidth. Moreover, the approach lends itself to handling the case of partial coherence across sub-bands and offers the potential for improved discrimination of slowly moving targets versus clutter discretes. Work supported by ONR.
Jammer robust model-aided deep learning-based target detection for cognitive sonar
Authors: Ali Touseef , Richmond Christ D.
Published: November 2022

This work extends the development of an adaptive deep learning-based target detection algorithm for a channel matrix-based cognitive sonar framework that makes use of both a primary and secondary dataset. The channel matrix-based framework models all waveform dependent components, i.e. the sonar echo and clutter, via transfer function matrices, whereas all other waveform independent noise is characterized via the data covariance. By leveraging "lessons learned" from a derived model-based generalized likelihood ratio test (GLRT), a data driven deep learning algorithm was made adaptive to waveform dependent clutter returns in our previous work. The algorithm, however, remains fragile to waveform independent jamming and interference, and the extensive training required to obtain robust performance is practically infeasible. Thus, in this work further modifications are included to robustify the algorithm against these waveform independent components by leveraging knowledge from the model-based GLRT. The performance of the proposed algorithm is tested using various scenarios with jamming and interference signals.
Monitoring cavitation activity through bone: Passive acoustic mapping for monitoring ultrasound therapy in the central nervous system
Authors: Frizado Andrew , Farbin Grace , O'Reilly Meaghan
Published: November 2022

The blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB) are major impediments to the pharmacological treatment of central nervous system disorders. Focused ultrasound in combination with intravenously administered microbubbles can transiently increase the permeability of the BBB and BSCB to enable passage of therapeutics from the blood pool to the brain and spinal cord tissues. Safely controlling these treatments relies on information such as the cavitation state (i.e., stable vs. inertial), and location. Passive acoustic mapping (PAM) is a beamforming approach that does not require absolute time of flight knowledge and is therefore well suited for monitoring ultrasound therapy where therapy pulses are long, ranging from several cycles to milliseconds in length. PAM applied with large receiver arrays can enable three-dimensional monitoring of cavitation activity through the bone for non-invasive treatment monitoring. This talk will discuss the application of PAM in brain and spinal cord and the challenges posed by the skull and vertebral bony geometry, with a focus on recent in silico and experimental work in transvertebral PAM.
Normal mode extraction using sparse Bayesian learning in shallow water
Authors: Niu Haiqiang , Gerstoft Peter
Published: November 2022

The low-frequency signals propagating in the shallow-water waveguides are dispersive. They are composed of several normal modes according to the normal mode theory. For the vertical array data, the horizontal wavenumbers and the associated multi-frequency modal depth functions were estimated using block sparse Bayesian learning (Niu et al., JASA 2020), while a priori knowledge of sea bottom, moving source, and source locations is not needed. For the impulsive or known-form signals received by one hydrophone, the sparse Bayesian learning (SBL) approach can be also used to extract the modes (Niu et al., JASA 2021). It uses the approximate modal dispersion relation, connecting the horizontal wavenumbers (phase velocities) for multiple frequencies, to build the dictionary matrix for SBL. Different from warping transforms based on the group slowness (or group speed) dispersion curves, mode separation using SBL is performed in frequency domain based on the phase speed (or equivalently horizontal wavenumbers) dispersion relation. The simulation results demonstrate that the proposed approach is adapted to the environment where both the reflected and refracted modes coexist, whereas the performance of the time warping transformation degrades significantly in this scenario.
Structural Elements Involved in ATP Hydrolysis Inhibition and ATP Synthesis of Tuberculosis and Nontuberculous Mycobacterial F-ATP Synthase Decipher New Targets for Inhibitors
Authors: Wong Chui Fann , Saw Wuan-Geok , Basak Sandip , Sano Mio , Ueno Hiroshi , Kerk Hwee Wen , Litty Dennis , Ragunathan Priya , Dick Thomas , Müller Volker , Noji Hiroyuki , Grüber Gerhard
Published: November 2022

The F
1
F
O
-ATP synthase is required for the viability of tuberculosis (TB) and nontuberculous mycobacteria (NTM) and has been validated as a drug target. Here, we present the cryo-EM structures of the
Mycobacterium smegmatis
F
1
-ATPase and the F
1
F
O
-ATP synthase with different nucleotide occupation within the catalytic sites and visualize critical elements for latent ATP hydrolysis and efficient ATP synthesis.