bluuebunny/crossref_metadata_2025 huggingface dataset:
Designing a New Leaning Tower Demonstration
Authors: Greenslade Thomas B.
Published: September 2021

The Leaning Tower is a long-time staple of the demonstration room. I can trace it as far back as apparatus catalogues from the 1850s. Some years ago, while teaching myself how to use a new wood lathe, I made a replica of the original design, shown on the left-hand side of Fig. 1. With the top removed, the tower is stable, but once the top is added, the line of action passing through the center of mass falls outside the area of the base and over it goes.
The On-Axis Magnetic Field for a Single, Helical Turn Coil
Authors: Taylor Richard
Published: September 2021

Science and engineering students in the second semester of a calculus-based physics sequence typically study and measure the on-axis magnetic field for a multiple, circular turn coil. There are four benefits to this approach: 1) an analytical solution is easily obtained, 2) the coil is easily constructed using tightly wound, high-gauge wire where each turn is approximately circular, 3) the magnetic field along the axis of symmetry is parallel to that axis, which simplifies the placement of a magnetic field sensor, and 4) the magnetic field strength can be increased by increasing the number of turns, which increases the signal to “noise” ratio. This approach is fine as an introduction, but it doesn’t address several practical questions. How does one calculate the magnetic field for a current-carrying wire that isn’t in the shape of a line, circle, or multiple concentric circles? Are all coils made of high-gauge wire? Aren’t coils helical? Under what conditions can a circular coil in theory be used to represent a helical coil in practice? How does one measure small magnetic fields in the presence of other magnetic fields? This paper presents a secondary approach that begins to address these questions. It determines the on-axis magnetic field for a single, helical turn coil and then details the setup and procedures used for an experimental confirmation. It is presented to students as a guided experiment.
Wien’s Displacement Law and Blackbody Radiation Quartiles
Authors: González de Arrieta I.
Published: September 2021

The conventional approach to teaching blackbody radiation in introductory modern physics courses relies on an oversimplified explanation of Wien’s displacement law, which does not uphold students’ conceptual understanding of Planck’s law and can lead to well-known misconceptions. Thus, there is a need to clarify the pedagogical role of this concept, while trying to make it more useful for making unambiguous estimates of spectral distributions of blackbodies. This necessarily requires the use of displacement laws, which are independent from the spectral scale of choice.
A Simple Estimation of the Size of Carbon Atoms Using a Pencil Lead
Authors: Medel-Esquivel Ricardo , Gómez-Vargas Isidro , García-Salcedo Ricardo , Vázquez J. Alberto
Published: September 2021

One of the main topics of elementary physics is the idea that every material is composed of “little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one other.” These particles could be atoms or molecules. Atoms are the smallest part into which any material can be divided, and when several atoms are joined together, molecules are formed. Some interesting experiments that do not require sophisticated equipment have been performed to estimate the size of such atoms or molecules. One of these early experiments was conducted by Lord Rayleigh (1842-1919), which consisted of a small drop of oil spread to form a circular patch on the surface of the water. With a few simple calculations it is possible to determine the size of the oil molecule composition and therefore to provide an estimate of the diameter of the carbon atom. The main aim of this article is that students, from middle school to high school, even at the undergraduate level, gain a quantitative understanding of the size of atoms by performing a simple experiment easily designed within the classroom.
Methods to Select the Scales and Starting Values for Axes in Linear Graphs
Authors: Hernandez Joel , Korzun Barys
Published: September 2021

Graphs are an important component in physics laboratory reports. We have noticed that our students have difficulty selecting the scale and the starting value for an axis while generating graphs on graph paper. Recommendations concerning convenient scales and starting values are found in textbooks, laboratory manuals, and papers. Methods to select the scale are found in web sources; however, they are inadequate, because as illustrated later in this paper, they are explained by means of particular numerical examples (instead of as a general formulation) or trial and error. In this paper, the existing methods to select the scale are reformulated and expanded in a general form involving equations and variables, but no trial and error. Methods to select the starting value of an axis are not documented. In this paper, a general method is presented to select the starting value.
Systematic Errors and the Chappaquiddick Accident
Authors: Cross Rod
Published: September 2021

A common procedure when conducting physics experiments is to repeat a measurement several times to calculate the mean and standard deviation. That might be the only instruction we give to students as a means to minimize random errors. However, that technique does not guarantee that the answer will be correct. It might give the same wrong answer every time. How then can we teach students to avoid systematic errors? We don’t focus on that problem enough when teaching physics. Part of the problem is that we and the students usually know the correct answers in advance, since student experiments have usually been repeated thousands of times by others.
Better interactive astronomy lectures using the Laser-Assisted Student Engagement Routine
Authors: Berryhill Katie J. , Slater Timothy F.
Published: September 2021

In support of teaching astronomy as a human enterprise, modern astronomy teaching often emphasizes visuals—whether heavenly telescope images of the cosmos or graphs depicting the relationships between physical process variables. Well-known suggestions of how to have students individually interact with images and graphics pepper earlier AstroNotes columns: teaching strategies that challenge students to provide missing labels to diagrams or to create their own graphical representations using small, individual whiteboards. We suggest here a method of intellectually engaging large groups of students with a large image or graphic that is projected in the front of the room.
Evidence-Based Principles for Worksheet Design
Authors: Burkholder Eric , Mohamed-Hinds Nicel , Wieman Carl
Published: September 2021

Substantial research in teaching and learning has supported the use of active learning strategies in the classroom to improve student learning of fundamental physics concepts and problem-solving skills. The use of worksheets in class has become a widespread successful practice. In this paper, we analyzed numerous completed student worksheets to discover ways to improve their design. We find that worksheet prompts should be precise and focused, one activity should be required per question, students should be given targeted practice with new concepts, and individual accountability is required for students to complete in-class worksheets.
Meeting Laboratory Course Learning Goals Remotely via Custom Home Experiment Kits
Authors: Howard Daniel , Meier Mariel
Published: September 2021

Cost-effective, custom home experiment kits were developed and used for remote teaching of first-semester introductory physics labs. The kit experiments were designed to match the existing onsite lab course learning goals. A revised group project approach optimized for remote use was also developed that leverages the kits. Student survey results at the end of the summer 2020 semester indicate that the critical learning goals were met, student satisfaction with the remote course was maintained, and successful collaboration via video conferencing breakout rooms was achieved.
The Tacoma Narrows Bridge Collapse Revisited
Authors: Kilty Kevin
Published: September 2021

This November marks another anniversary of the collapse of the Tacoma Narrows Bridge, an example appropriate to introductory science or physical sciences courses from grade school to university. The purpose of this brief submission is to add an element to this story, which, despite having been mentioned before, has not received the prominence it deserves either as explanation for the event or for its cautionary lesson for design engineers. Specifically these are broken cable stays observed on the north side of the bridge prior to the bridge collapse.
The integrated stress response contributes to tRNA synthetase–associated peripheral neuropathy
Authors: Spaulding E. L. , Hines T. J. , Bais P. , Tadenev A. L. D. , Schneider R. , Jewett D. , Pattavina B. , Pratt S. L. , Morelli K. H. , Stum M. G. , Hill D. P. , Gobet C. , Pipis M. , Reilly M. M. , Jennings M. J. , Horvath R. , Bai Y. , Shy M. E. , Alvarez-Castelao B. , Schuman E. M. , Bogdanik L. P. , Storkebaum E. , Burgess R. W.
Published: September 2021

Defeating peripheral neuropathy

The mechanisms underlying peripheral neuropathies are not well understood. Spaulding
et al
. studied mouse models of the inherited Charcot-Marie-Tooth (CMT) disease, which is caused by mutations in transfer RNA (tRNA) synthetases. Changes in gene expression and the rate of protein synthesis in neurons in the spinal cord triggered the cell stress response activated by the protein sensor GCN2. When GCN2 was genetically deleted or inhibited with drugs, the stress response was blocked, and the neuropathy was much milder. Zuko
et al
. found that mutant glycyl-tRNA synthetases bind tRNA
Gly
but fail to release it, thus depleting the cellular tRNA
Gly
pool. This process caused stalling of translating ribosomes on glycine codons and activated the integrated stress response. Transgenic tRNA
Gly
overexpression prevented peripheral neuropathy and protein synthesis defects in mouse and fruit fly models. Thus, elevating tRNA
Gly
levels or targeting GCN2 may have therapeutic potential for this currently untreatable disease (see the Perspective by Mellado and Willis). —SMH
Developmental chromatin programs determine oncogenic competence in melanoma
Authors: Baggiolini Arianna , Callahan Scott J. , Montal Emily , Weiss Joshua M. , Trieu Tuan , Tagore Mohita M. , Tischfield Sam E. , Walsh Ryan M. , Suresh Shruthy , Fan Yujie , Campbell Nathaniel R. , Perlee Sarah C. , Saurat Nathalie , Hunter Miranda V. , Simon-Vermot Theresa , Huang Ting-Hsiang , Ma Yilun , Hollmann Travis , Tickoo Satish K. , Taylor Barry S. , Khurana Ekta , Koche Richard P. , Studer Lorenz , White Richard M.
Published: September 2021

Chromatin state and oncogenic competence

Although specific DNA mutations can lead to tumor generation, they are not transforming in all cellular contexts. This may be due to the intrinsic transcriptional program present in the cell of origin. Using zebrafish and human pluripotent stem cell cancer models, Baggiolini
et al
. report that neural crest cells and melanoblasts (precursors to melanocytes) are susceptible to specific mutation of the
BRAF
gene, whereas melanocytes are relatively resistant (see the Perspective by Vredevoogd and Peeper). The competent cells display higher levels of chromatin factors such as the protein ATAD2 compared with the less competent ones. ATAD2 forms a complex with the neural crest transcription factor SOX10 and establishes a chromatin state that makes them permissive to BRAF mutagenesis. These data indicate that developmental chromatin programs are a determinant of how cells respond to DNA mutations. —BAP
Generalized hydrodynamics in strongly interacting 1D Bose gases
Authors: Malvania Neel , Zhang Yicheng , Le Yuan , Dubail Jerome , Rigol Marcos , Weiss David S.
Published: September 2021

Monitoring quantum dynamics

Reducing the dimensionality of a quantum system of interacting particles can simplify its physics. Such reduction is possible in ultracold atomic gases, where a lattice of one-dimensional (1D) gases can be generated using optical potentials. Malvania
et al
. studied the dynamics of 1D rubidium-87 atomic gases after a sudden increase in the axial trapping potential. Normally, these dynamics would be difficult to describe theoretically, but the researchers found that a theory called generalized hydrodynamics captured the behavior of their 1D system over a long time evolution. —JS
Three-megadalton complex of methanogenic electron-bifurcating and CO
2
-fixing enzymes
Authors: Watanabe Tomohiro , Pfeil-Gardiner Olivia , Kahnt Jörg , Koch Jürgen , Shima Seigo , Murphy Bonnie J.
Published: September 2021

Methanogenesis megacomplex

An important first step in methanogenesis is the conversion of carbon dioxide to a reduced one-carbon formyl unit that is a substrate for downstream steps. This reaction is catalyzed by a complex of enzymes, including components for oxidizing hydrogen or formate and splitting two electrons along different energetic paths. Watanabe
et al
. carefully purified and prepared anaerobic cryo–electron microscopy samples of the enzyme complex responsible, resulting in a three-megadalton hexameric structure at 3- to 3.5-ångström resolution. The arrangement of iron–sulfur cofactors provides an explanation for how electron bifurcation is coupled to large protein motions, which are expected from the multiple conformational states present. —MAF
Linking Arctic variability and change with extreme winter weather in the United States
Authors: Cohen Judah , Agel Laurie , Barlow Mathew , Garfinkel Chaim I. , White Ian
Published: September 2021

Cold weather disruptions

Despite the rapid warming that is the cardinal signature of global climate change, especially in the Arctic, where temperatures are rising much more than elsewhere in the world, the United States and other regions of the Northern Hemisphere have experienced a conspicuous and increasingly frequent number of episodes of extremely cold winter weather over the past four decades. Cohen
et al
. combined observations and models to demonstrate that Arctic change is likely an important cause of a chain of processes involving what they call a stratospheric polar vortex disruption, which ultimately results in periods of extreme cold in northern midlatitudes (see the Perspective by Coumou). —HJS
U.S. astronomers weigh fate of giant telescopes
Authors: Clery Daniel
Published: September 2021

“Decadal survey” could recommend bailout for struggling projects
Neurorobotic fusion of prosthetic touch, kinesthesia, and movement in bionic upper limbs promotes intrinsic brain behaviors
Authors: Marasco Paul D. , Hebert Jacqueline S. , Sensinger Jonathon W. , Beckler Dylan T. , Thumser Zachary C. , Shehata Ahmed W. , Williams Heather E. , Wilson Kathleen R.
Published: September 2021

Multiperspective analysis reveals neurorobotic sensory and motor fusion in a bionic system promotes intrinsic neural behaviors.
Engineering and surgical advancements enable more cognitively integrated bionic arms
Authors: Ortiz-Catalan Max
Published: September 2021

Integrating tactile and kinesthetic feedback in a bionic arm results in performance closer to able-bodied individuals.
CISH attenuates homeostatic cytokine signaling to promote lung-specific macrophage programming and function
Authors: Shoger Karsen E. , Cheemalavagu Neha , Cao Yuqi M. , Michalides Brandon A. , Chaudhri Virendra K. , Cohen Jonathan A. , Singh Harinder , Gottschalk Rachel A.
Published: September 2021

The protein CISH fine-tunes homeostatic lung cytokine signaling to maintain alveolar macrophage identity and function.
Oncogenic switch and single-agent MET inhibitor sensitivity in a subset of
EGFR
-mutant lung cancer
Authors: Eser Pınar Özden , Paranal Raymond M. , Son Jieun , Ivanova Elena , Kuang Yanan , Haikala Heidi M. , To Ciric , Okoro Jeffrey J. , Dholakia Kshiti H. , Choi Jihyun , Eum Yoonji , Ogino Atsuko , Missios Pavlos , Ercan Dalia , Xu Man , Poitras Michael J. , Wang Stephen , Ngo Kenneth , Dills Michael , Yanagita Masahiko , Lopez Timothy , Lin Mika , Tsai Jeanelle , Floch Nicolas , Chambers Emily S. , Heng Jennifer , Anjum Rana , Santucci Alison D. , Michael Kesi , Schuller Alwin G. , Cross Darren , Smith Paul D. , Oxnard Geoffrey R. , Barbie David A. , Sholl Lynette M. , Bahcall Magda , Palakurthi Sangeetha , Gokhale Prafulla C. , Paweletz Cloud P. , Daley George Q. , Jänne Pasi A.
Published: September 2021

A subset of drug-resistant
EGFR
-mutant
MET
-amplified lung cancer switches oncogenic dependence to MET and is treatable with MET inhibitor monotherapy.
Temporal multi-omics identifies LRG1 as a vascular niche instructor of metastasis
Authors: Singhal Mahak , Gengenbacher Nicolas , Abdul Pari Ashik Ahmed , Kamiyama Miki , Hai Ling , Kuhn Bianca J. , Kallenberg David M. , Kulkarni Shubhada R. , Camilli Carlotta , Preuß Stephanie F. , Leuchs Barbara , Mogler Carolin , Espinet Elisa , Besemfelder Eva , Heide Danijela , Heikenwalder Mathias , Sprick Martin R. , Trumpp Andreas , Krijgsveld Jeroen , Schlesner Matthias , Hu Junhao , Moss Stephen E. , Greenwood John , Augustin Hellmut G.
Published: September 2021

A temporal systems biology screen of premetastatic endothelial cells identified LRG1 as a therapeutic target for restricting metastases.
A Cell Culture Model of BK Polyomavirus Persistence, Genome Recombination, and Reactivation
Authors: Zhao Linbo , Imperiale Michael J.
Published: September 2021

BK polyomavirus (BKPyV) generally establishes a persistent subclinical infection in healthy individuals but can cause severe disease in transplant recipients. While an
in vitro
model to study acute replication exists, no practical model with which to study BKPyV persistence is currently available.
Complete Genome Sequence of Pseudomonas aeruginosa CMC-097, Isolated from a Ventilator-Associated Pneumonia Patient, Containing a Novel Carbapenem Resistance Class 1 Integron
Authors: Rao Jayasimha , Adenikinju Adenike , Kerkering Thomas M. , Garner Dorothy C. , Jensen Roderick V.
Published: September 2021

We report the complete genome of a clinical strain of
Pseudomonas aeruginosa
, CMC-097, which was isolated from a ventilator-associated pneumonia patient with a chronic infection. Illumina sequence reads were assembled using Geneious to yield a 7,044,064-bp circular chromosome containing a carbapenem resistance integron, In
2020
.
Perinatal outcomes among births to women with infection during pregnancy
Authors: Baguiya Adama , Bonet Mercedes , Cecatti José Guilherme , Brizuela Vanessa , Curteanu Ala , Minkauskiene Meile , Jayaratne Kapila , Ribeiro-do-Valle Carolina Carvalho , Budianu Mihaela-Alexandra , Souza João Paulo , Kouanda Séni
Published: September 2021

Objective

This study is part of the Global Maternal Sepsis Study (GLOSS). It aimed to estimate neonatal near-miss (NNM) and perinatal death frequency and maternal risk factors among births to women with infection during pregnancy in low-income and middle-income countries (LMIC).

Design

We conducted a 1-week inception hospital-based cohort study.

Setting

The study was carried out in 408 hospitals in 43 LMIC of all the WHO regions in 2017.

Patients

We included women with suspected or confirmed infection during pregnancy with at least 28 weeks of gestational age up to day-7 after birth. All babies born to those women were followed from birth until the seventh day after childbirth. Perinatal outcomes were considered at the end of the follow-up.

Main outcome measures

Perinatal outcomes were (i) babies alive without severe complication, (ii) NNM and (iii) perinatal death (stillbirth and early neonatal death).

Results

1219 births were analysed. Among them, 25.9% (n=316) and 10.1% (n=123) were NNM and perinatal deaths, respectively. After adjustment, maternal pre-existing medical condition (adjusted odds ratios (aOR)=1.5; 95% CI 1.1 to 2.0) and maternal infection suspected or diagnosed during labour (aOR=1.9; 95% CI 1.2 to 3.2) were the independent risk factors of NNM. Maternal pre-existing medical condition (aOR=1.7; 95% CI 1.0 to 2.8), infection-related severe maternal outcome (aOR=3.8; 95% CI 2.0 to 7.1), mother’s infection suspected or diagnosed within 24 hours after childbirth (aOR=2.2; 95% CI 1.0 to 4.7) and vaginal birth (aOR=1.8; 95% CI 1.1 to 2.9) were independently associated with increased odds of perinatal death.

Conclusions

Overall, one-third of births were adverse perinatal outcomes. Pre-existing maternal medical conditions and severe infection-related maternal outcomes were the main risk factors of adverse perinatal outcomes.
Long term exposure to low level air pollution and mortality in eight European cohorts within the ELAPSE project: pooled analysis
Authors: Strak Maciej , Weinmayr Gudrun , Rodopoulou Sophia , Chen Jie , de Hoogh Kees , Andersen Zorana J , Atkinson Richard , Bauwelinck Mariska , Bekkevold Terese , Bellander Tom , Boutron-Ruault Marie-Christine , Brandt Jørgen , Cesaroni Giulia , Concin Hans , Fecht Daniela , Forastiere Francesco , Gulliver John , Hertel Ole , Hoffmann Barbara , Hvidtfeldt Ulla Arthur , Janssen Nicole A H , Jöckel Karl-Heinz , Jørgensen Jeanette T , Ketzel Matthias , Klompmaker Jochem O , Lager Anton , Leander Karin , Liu Shuo , Ljungman Petter , Magnusson Patrik K E , Mehta Amar J , Nagel Gabriele , Oftedal Bente , Pershagen Göran , Peters Annette , Raaschou-Nielsen Ole , Renzi Matteo , Rizzuto Debora , van der Schouw Yvonne T , Schramm Sara , Severi Gianluca , Sigsgaard Torben , Sørensen Mette , Stafoggia Massimo , Tjønneland Anne , Verschuren W M Monique , Vienneau Danielle , Wolf Kathrin , Katsouyanni Klea , Brunekreef Bert , Hoek Gerard , Samoli Evangelia
Published: September 2021

Objective

To investigate the associations between air pollution and mortality, focusing on associations below current European Union, United States, and World Health Organization standards and guidelines.

Design

Pooled analysis of eight cohorts.

Setting

Multicentre project Effects of Low-Level Air Pollution: A Study in Europe (ELAPSE) in six European countries.

Participants

325 367 adults from the general population recruited mostly in the 1990s or 2000s with detailed lifestyle data. Stratified Cox proportional hazard models were used to analyse the associations between air pollution and mortality. Western Europe-wide land use regression models were used to characterise residential air pollution concentrations of ambient fine particulate matter (PM
2.5
), nitrogen dioxide, ozone, and black carbon.

Main outcome measures

Deaths due to natural causes and cause specific mortality.

Results

Of 325 367 adults followed-up for an average of 19.5 years, 47 131 deaths were observed. Higher exposure to PM
2.5
, nitrogen dioxide, and black carbon was associated with significantly increased risk of almost all outcomes. An increase of 5 µg/m
3
in PM
2.5
was associated with 13% (95% confidence interval 10.6% to 15.5%) increase in natural deaths; the corresponding figure for a 10 µg/m
3
increase in nitrogen dioxide was 8.6% (7% to 10.2%). Associations with PM
2.5
, nitrogen dioxide, and black carbon remained significant at low concentrations. For participants with exposures below the US standard of 12 µg/m
3
an increase of 5 µg/m
3
in PM
2.5
was associated with 29.6% (14% to 47.4%) increase in natural deaths.

Conclusions

Our study contributes to the evidence that outdoor air pollution is associated with mortality even at low pollution levels below the current European and North American standards and WHO guideline values. These findings are therefore an important contribution to the debate about revision of air quality limits, guidelines, and standards, and future assessments by the Global Burden of Disease.
Place of death in Parkinson’s disease: trends in the USA
Authors: Kumar Pankaj , Yasmin Farah , Khan Muhammad Shahzeb , Shahid Izza , Diwan Mufaddal Najmuddin , Leiter Richard E , Warraich Haider J
Published: September 2021

Background

Parkinson’s disease (PD) is a significant cause of mortality but little is known about the place of death for patients with PD in the USA, a key metric of end-of-life care.

Methodology

A trend analysis was conducted for years 2003–2017 using aggregated death certificate data from the Centers for Disease Control and Prevention Wide-ranging OnLine Data for Epidemiologic Research) database, with individual-level mortality data from the Mortality Multiple Cause-of-Death Public Use Record available between 2013 and 2017. All natural deaths for which PD was identified as an underlying cause of death were identified. Place of death was categorised as hospital, decedent home, hospice facility, nursing home/long-term care and other.

Results

Between 2003 and 2017, 346141 deaths were attributed to PD (59% males, 93.7% White). Most deaths occurred in patients aged 75–84 years (43.9%), followed by those aged ≥85 years (40.9 %). Hospital and nursing home deaths decreased from 18% (n=3240) and 52.6% (n=9474) in 2003 to 9.2% (n=2949) and 42% (n=13 429) in 2017, respectively. Home deaths increased from 21.1% (n=3804) to 32.4% (n=10 347) and hospice facility deaths increased from 0.3% (n=47) in 2003 to 8.6% (n=2739) in 2017. Female sex, being married and college education were associated with increased odds of home deaths while Hispanic ethnicity and non-white race were associated with increased odds of hospital deaths.

Conclusion

Home and hospice facility deaths are gradually increasing in patients with PD. Particular attention should be provided to vulnerable socioeconomic groups that continue to have higher rates of hospital deaths and decreased usage of hospice facilities.
Red cell transfusion benefits in oncology, haematology and palliative medicine populations: a narrative review
Authors: Duffy Ed , O’Mahony Frances , Burke Caroline , Conneely Aoibheann , O’Connell Helen , Twomey Feargal
Published: September 2021

Due to the heterogenous nature of the palliative medicine patient population, assessment of benefit, and thus choice of appropriate patient for consideration of transfusion, can be challenging. This can be confounded by the use of both liberal and restrictive transfusion thresholds. The multifactorial nature of many symptoms of anaemia, particularly in patients with advanced malignancy, can further complicate. As such, there is a paucity of data supporting the subjective, objective and clinical benefit of red cell transfusion in the palliative medicine setting. This narrative review summarises the research and evidence surrounding the benefits of red cell transfusion, with a particular emphasis on the oncological, haematological and palliative medicine population. There is a lack of a validated, reproducible patient-reported outcome measures (PROM) to assess response to red cell transfusions in the palliative medicine population with outcome measures varying from objective improvement in haemoglobin level post-transfusion, to subjective response in primary symptom(s). Further investigation is required regarding the development of effective PROMs assessing response to red cell transfusion in the palliative medicine population, to ensure judicious use of this scarce and valuable resource.
Why is there variation in test ordering practices for patients presenting to the emergency department with undifferentiated chest pain? A qualitative study
Authors: Li Julie , Dahm Maria R , Thomas Judith , Wabe Nasir , Smith Peter , Georgiou Andrew
Published: September 2021

Introduction

Up to one-third of laboratory tests ordered in the ED for adults presenting with undifferentiated chest pain are generally not indicated by current Australian guidelines. This study set out to undertake a qualitative investigation of clinician perceptions to identify the reasons for variations in pathology requesting.

Methods

For this study, we draw on data from semistructured interviews (n=38) conducted in the EDs and laboratories across three hospitals as part of a larger study on the test result management process from test request to result follow-up. Thematic analysis was conducted to determine what aspects of the clinical routines and environment might contribute to variations in pathology requesting. Informed by the findings from the analysis, targeted questions were developed and further focus groups (n=5) were held with clinicians, hospital management and electronic medical record (eMR) analysts to investigate in more detail the reasons for requesting outside of guidelines.

Results

Participants cited four main reasons for ordering outside of guidelines. Clinicians requested tests outside of guidelines and the ED scope of practice to facilitate the patient journey along the broader continuum of care, including admission to hospital or transfer to another site. Clinicians were also faced with multiple and inconsistent guidelines regarding appropriate test selection. Limited access to in-house specialty and diagnostic services also influenced ordering patterns in smaller non-referral hospitals. Finally, certain features of the current electronic ordering framework within the eMR facilitated overordering and failed to impose any real restrictions on ordering inappropriately or outside of scope of practice.

Conclusion

Beyond the standardisation of pathology requesting advice across electronic decision support, order sets and guidelines, attempts to address issues related to the appropriateness and variation of laboratory test ordering should consider local and systemic factors which also shape the ordering process.
Predictors of futile recanalization in patients undergoing endovascular treatment in the DIRECT-MT trial
Authors: Zhou Tengfei , Yi Tingyu , Li Tianxiao , Zhu Liangfu , Li Yucheng , Li Zhaoshuo , Wang Meiyun , Li Qiang , He Yingkun , Yang Pengfei , Zhang Yongwei , Li Zifu , Zhang Yongxin , Ye Xiaofei , Chen Wenhuo , Wang Shouchun , Liu Jianmin
Published: September 2021

Background

Futile recanalization—when patients have a successful recanalization but fail to achieve a satisfactory functional outcome— is a common phenomenon of endovascular treatment of acute ischemic stroke (AIS). The present study aimed to identify the predictors of futile recanalization in AIS patients who received endovascular treatment.

Methods

This is a post-hoc analysis of the DIRECT-MT trial. Demographics, clinical characteristics, acute stroke workflow interval times, biochemical parameters, and imaging characteristics were compared between futile and meaningful recanalization groups. Multivariate analysis was performed to identify the predictors of futile recanalization.

Results

Futile recanalization was observed in 277 patients. In multivariable logistic regression analysis, older age (p<0.001), higher baseline systolic blood pressure (SBP) (p=0.032), incomplete reperfusion defined by extended Thrombolysis In Cerebral Infarction (eTICI) grades (p=0.020), and larger final infarct volume (FIV) (p<0.001) were independent predictors of futile recanalization.

Conclusions

Old age, high baseline SBP, incomplete reperfusion defined by eTICI, and large FIV were independent predictors of futile recanalization after endovascular therapy for AIS.
Public health impact of a US ban on menthol in cigarettes and cigars: a simulation study
Authors: Levy David T , Meza Rafael , Yuan Zhe , Li Yameng , Cadham Christopher , Sanchez-Romero Luz Maria , Travis Nargiz , Knoll Marie , Liber Alex C , Mistry Ritesh , Hirschtick Jana L , Fleischer Nancy L , Skolnick Sarah , Brouwer Andrew F , Douglas Cliff , Jeon Jihyoun , Cook Steven , Warner Kenneth E
Published: September 2021

Introduction

The US Food and Drug Administration most recently announced its intention to ban menthol cigarettes and cigars nationwide in April 2021. Implementation of the ban will require evidence that it would improve public health. This paper simulates the potential public health impact of a ban on menthol in cigarettes and cigars through its impacts on smoking initiation, smoking cessation and switching to nicotine vaping products (NVPs).

Methods

After calibrating an established US simulation model to reflect recent use trends in cigarette and NVP use, we extended the model to incorporate menthol and non-menthol cigarette use under a status quo scenario. Applying estimates from a recent expert elicitation on the behavioural impacts of a menthol ban, we developed a menthol ban scenario with the ban starting in 2021. We estimated the public health impact as the difference between smoking and vaping-attributable deaths and life-years lost in the status quo scenario and the menthol ban scenario from 2021 to 2060.

Results

As a result of the ban, overall smoking was estimated to decline by 15% as early as 2026 due to menthol smokers quitting both NVP and combustible use or switching to NVPs. These transitions are projected to reduce cumulative smoking and vaping-attributable deaths from 2021 to 2060 by 5% (650 000 in total) and reduce life-years lost by 8.8% (11.3 million). Sensitivity analyses showed appreciable public health benefits across different parameter specifications.

Conclusions and relevance

Our findings strongly support the implementation of a ban on menthol in cigarettes and cigars.
Monitoring compliance with Kenya’s shisha ban in select public hospitality venues in Nairobi
Authors: Fukuda Simone , Nyambura Salome , Gitali Joel , Lindi Thomas , Otieno Samson , Beem Alexandra , Camara Bityeki Bintou , Carmona Maria G , Sebrie Ernesto Marcelo
Published: September 2021

Introduction

Seven countries in the WHO African Region have banned the sale and/or use of shisha. In 2017, Kenya implemented a comprehensive ban on shisha, including the use, import, manufacture, sale, offer of sale, advertising, promotion, distribution and encouraging or facilitating its use. The objective of this study was to assess compliance with the ban of shisha use in select public hospitality venues in Nairobi, Kenya.

Methods

Observational study that used a purposive sampling to select restaurants, bars and nightclubs where shisha use took place before the ban. A total of 200 venues were visited in seven areas of Nairobi City County, Kenya. Shisha use was defined as at least one person smoking shisha in any indoor or outdoor area of the venue accessible to the public, and indicators of shisha use as the display of any shisha equipment.

Results

Overall, 81.5% of the venues visited were in compliance. Shisha smoking was observed in 16.5% of all venues and shisha equipment alone was observed in 2.0%. Among the different venue types, 94.6% of restaurants were compliant, 79.7% of bars and 75.6% of nightclubs.

Discussion

The overall high compliance indicates that Kenya’s shisha ban is well implemented in Nairobi, and may be explained by the comprehensive nature of the shisha ban and the low prevalence in the general population. The variation in compliance may be due to the higher rates of use in university students and the additional resources required to enforce the ban in areas with high rates of crime.
Comparison of multiple monitoring techniques for the testing of a scale model timber Warren truss
Authors: Helmer-Smith Henry , Vlachopoulos Nicholas , Dagenais Marc-André , Forbes Bradley
Published: September 2021

This paper outlines the testing and monitoring procedure of a scale model Warren truss constructed of 2 inch × 4 inch (38 mm × 89 mm) members and bolted connections within a laboratory environment. Several forms of deflection monitoring and strain monitoring instrumentation were utilized throughout this laboratory testing phase of a longer-term research program. Instruments included: an automatic total station, linear variable differential transducers, light detection and ranging, electric strain gauges, and distributed optical fibre sensors. The distributed point load-testing regime included two configurations: ( i) the original truss configuration and ( ii) the installation of intermediate columns beneath the truss. Objectives of this phase included identifying instrument capabilities, limitations, and overall reliability/effectiveness with respect to representing the behaviour of the truss system. In addition, members of interest and critical monitoring locations along the Warren truss were determined. The purpose of this laboratory endeavour was to determine an optimized structural-health monitoring program prior to implementation in a heritage timber Warren truss structure within the infrastructure inventory of the Department of National Defence (DND). An options analysis of monitoring techniques was conducted whereby the effectiveness of each instrumentation type was evaluated according to relevant metrics/factors to determine an effective monitoring technique for this heritage building and other similar DND truss structures.
Acceleration in quantum mechanics and electric charge quantization
Authors: Ahmad El-Nabulsi Rami , Anukool Waranont
Published: September 2021

In this study, we have discussed the implications of acceleration in quantum mechanics by means of a generalized derivative operator (GDO). A new Schrödinger equation is obtained which depends on the reduced Compton wavelength of the particle. We have discussed its implications in quantum mechanics for different types of potentials mainly the infinite wall potential, the gravitational linear field potential, the Cornell potential and the Coulomb repulsive potential. The corresponding wave functions and discrete energies are modified and differ from the results obtained in the conventional formalism. The major results obtained concerned the large improvement of the ground energy of the electron subject to the gravitational acceleration in addition to Cornell potential and the emergence of quantized electric charge in the theory without including Dirac monopoles or using gauge theories.
Stability and Bifurcations of Equilibria in Networks with Piecewise Linear Interactions
Authors: Duncan William , Gedeon Tomas
Published: September 2021

In this paper, we study equilibria of differential equation models for networks. When interactions between nodes are taken to be piecewise constant, an efficient combinatorial analysis can be used to characterize the equilibria. When the piecewise constant functions are replaced with piecewise linear functions, the equilibria are preserved as long as the piecewise linear functions are sufficiently steep. Therefore the combinatorial analysis can be leveraged to understand a broader class of interactions. To better understand how broad this class is, we explicitly characterize how steep the piecewise linear functions must be for the correspondence between equilibria to hold. To do so, we analyze the steady state and Hopf bifurcations which cause a change in the number or stability of equilibria as slopes are decreased. Additionally, we show how to choose a subset of parameters so that the correspondence between equilibria holds for the smallest possible slopes when the remaining parameters are fixed.
The Bifurcations of the Critical Points and the Role of Depth in a Symmetric Caldera Potential Energy Surface
Authors: Geng Y. , Katsanikas M. , Agaoglou M. , Wiggins S.
Published: September 2021

In this work, we continue the study of the bifurcations of the critical points in a symmetric Caldera potential energy surface. In particular, we study the influence of the depth of the potential on the trajectory behavior before and after the bifurcation of the critical points. We observe two different types of trajectory behavior: dynamical matching and the nonexistence of dynamical matching. Dynamical matching is a phenomenon that limits the way in which a trajectory can exit the Caldera based solely on how it enters the Caldera. Furthermore, we discuss two different types of symmetric Caldera potential energy surface and the transition from the one type to the other through the bifurcations of the critical points.
Data-Driven Mathematical Modeling and Dynamical Analysis for SARS-CoV-2 Coinfection with Bacteria
Authors: Zhou Yu , Huang Mingzhan , Jiang Ying’an , Zou Xiufen
Published: September 2021

The ongoing coronavirus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has serious influences on human health and economy. The available clinical data suggest that patients infected by SARS-CoV-2 have the possibility of simultaneous infection of bacteria. In this study, we present a data-driven mathematical model for coinfection of SARS-CoV-2 and bacteria to investigate the dynamics of COVID-19 progress. Specifically, based on the statistical analysis of different clinical data from China and some other countries, a system model with ordinary differential equations (ODEs) in four variables, i.e. SARS-CoV-2, bacteria, neutrophils and lymphocytes, is established. We further validate our model through theoretical analysis and fitting of different clinical data. Moreover, through numerical simulations and bifurcation analysis, we find that bacterial infection and immune-related parameters in certain ranges lead to the system transitions among three steady states, i.e. mild, severe and death. We also analyzed the influence of the time it takes for patients to switch from a high-risk area to a low-risk area on the recovery time. These results reveal that the coinfection of viruses and bacteria can explain the changes in neutrophils and lymphocytes, and that initial bacterial infection and immune-related parameters have great influences on the severity degree and mortality in COVID-19 patients. Together, our model and quantitative analysis suggest that preventing bacterial infection and enhancing immune ability during the early phase of infections could be a potential treatment option for high-risk COVID-19 patients.
Bifurcations in Twinkling Patterns for the Lengyel–Epstein Reaction–Diffusion Model
Authors: Sarría-González J. , Sgura Ivonne , Ricard M. R.
Published: September 2021

Conditions for the emergence of strong Turing–Hopf instabilities in the Lengyel–Epstein CIMA reaction–diffusion model are found. Under these conditions, time periodic spatially inhomogeneous solutions can be induced by diffusive instability of the spatially homogeneous limit cycle emerging at a supercritical Bautin–Hopf bifurcation about the unstable steady state of the reaction system. We report numerical simulations by an Alternating Directions Implicit (ADI) method that show the formation of twinkling patterns for a chosen parameter value, thus confirming our theoretical results.
Studying the Complexity of Multichannel Supply Chain with Different Power Structures Under Carbon Subsidy Policy
Authors: Ma Junhai , Tian Yi , Chengjin Liu
Published: September 2021

The game characteristics and equilibrium strategies of a triple-channel supply chain under the carbon subsidy policy are studied in this work with three different game power structures. There are simultaneous decision-making, manufacturer-dominated market and retailer-dominated market. The decision mechanism for order quantity of manufacturer and dual-channel retailer, is discussed. Meanwhile, their complex dynamic characteristics are studied. It is found that when the government implements dual low-carbon subsidies, the supply chain system in which the manufacturer dominates the market is more stable. The government should pay attention to the power structure of the market to determine an appropriate subsidy rate. The over-adjustment of order quantity from manufacturer’s direct sales channel and retailer’s online channel both will lead to large periodical fluctuations in the system, and even bifurcation and chaos. These will cause substantial fluctuations and even loss in the profits of supply chain companies. This analysis shows that delayed feedback can effectively stabilize the periodic bifurcation and chaos in the system.
Artificial Intelligence, Chaos, Prediction and Understanding in Science
Authors: Sanjuán Miguel A. F.
Published: September 2021

Machine learning and deep learning techniques are contributing much to the advancement of science. Their powerful predictive capabilities appear in numerous disciplines, including chaotic dynamics, but they miss understanding. The main thesis here is that prediction and understanding are two very different and important ideas that should guide us to follow the progress of science. Furthermore, the important role played by nonlinear dynamical systems is emphasized for the process of understanding. The path of the future of science will be marked by a constructive dialogue between big data and big theory, without which we cannot understand.
PERMEABILITY MODELS FOR TWO-PHASE FLOW IN FRACTAL POROUS-FRACTURE MEDIA WITH THE TRANSFER OF FLUIDS FROM POROUS MATRIX TO FRACTURE
Authors: MIAO TONGJUN , CHEN AIMIN , XU YAN , CHENG SUJUN , ZHANG LIWEI , YAN CHANGBIN , YU BOMING
Published: September 2021

Study of transport mechanism of two-phase flow through porous-fracture media is of considerable importance to deeply understand geologic behaviors. In this work, to consider the transfer of fluids, the analytical models of dimensionless relative permeabilities for the wetting and non-wetting phases flow are proposed based on the fractal geometry theory for porous media. The proposed models are expressed as functions of micro-structural parameters of the porous matrix and fracture, such as the fractal dimension ([Formula: see text] for pore area, the fractal dimensions [Formula: see text] for wetting phase and for non-wetting phase, porosity ([Formula: see text], the total saturations ([Formula: see text], the porous matrix saturation ([Formula: see text] of the wetting and non-wetting phases, fractal dimension ([Formula: see text] for tortuosity of tortuous capillaries, as well as the ratio ([Formula: see text] of the maximum pore size in porous matrix to fracture aperture. The ratio ([Formula: see text] has a significant impact on the relative permeabilities and total saturations of wetting phases. The results reveal that the flow contribution of wetting phase from the porous matrix to both the seepage behavior of the fracture and total wetting phase saturation can be neglected as [Formula: see text]. The models may shed light on the fundamental mechanisms of the wetting and non-wetting phase flow in porous-fracture media with fluid transfer.
The Price Discovery Processes in China, India, and Russia’s Stock Index Futures Markets
Authors: Liu Qingfeng Wilson , Sono Hui , Zhang Wei
Published: September 2021

In this paper, we examine the price discovery patterns in the three BRICS countries’ stock index futures markets which were launched after 2000 – China, India, and Russia. We find the futures market dominates the price discovery process in China and India, but less so in Russia. A closer examination reveals the dynamic nature of the price discovery process, and the significant impacts on futures’ price discovery functions from China’s regulatory changes in September 2015 and Russia’s economic sanctions in March 2014. The results also show a more balanced and bidirectional volatility spillover between futures and spots in China and India than in Russia.
Successful Outcome Following Hysteroscopic Septoplasty in a Woman with Seven Consecutive Pregnancy Losses
Authors: Banu Jesmine , Amir Mumtahena , Ishrat Shakeela , Munmun Sadia Afrin , Sultana Nighat
Published: September 2021

Anomalies of the reproductive tract are common and present in about 3%–5% of the general population and in about 3% of infertile women. In general, they are asymptomatic, but they can also be associated with recurrent abortions or infertility. This is the case of a 27-year-old nulliparous woman presenting with the history of seven consecutive first trimester spontaneous abortions. Since her marriage 10 years back she conceived on repeated times but all the pregnancies ended in spontaneous miscarriage at around 10–12 weeks. Hysterosalpingography revealed a bicornuate/septate uterus. Hysteroscopic septoplasty with concurrent laparoscopy was planned after normalization of the endocrine parameters. She conceived spontaneously 7 months after the surgery. She had luteal phase support with progesterone, cervical cerclage and management of gestational diabetes, and pregnancy-induced hypertension. At 37 weeks of gestation, elective caesarean section was done with the delivery of a healthy female baby.