bluuebunny/crossref_metadata_2025 huggingface dataset:
Robustness of CT radiomics features: consistency within and between single-energy CT and dual-energy CT
Authors: Chen Yong , Zhong Jingyu , Wang Lan , Shi Xiaomeng , Lu Wei , Li Jianying , Feng Jianxing , Xia Yihan , Chang Rui , Fan Jing , Chen Liwei , Zhu Ying , Yan Fuhua , Yao Weiwu , Zhang Huan
Published: February 2022

Objectives

To evaluate inter- and intra- scan mode and scanner repeatability and reproducibility of radiomics features within and between single-energy CT (SECT) and dual-energy CT (DECT).

Methods

A standardized phantom with sixteen rods of clinical-relevant densities was scanned on seven DECT-capable scanners and three SECT-only scanners. The acquisition parameters were selected to present typical abdomen-pelvic examinations with the same voxel size. Images of SECT at 120 kVp and corresponding 120 kVp-like virtual monochromatic images (VMIs) in DECT which were generated according to scanners were analyzed. Regions of interest were drawn with rigid registrations to avoid variations due to segmentation. Radiomics features were extracted via Pyradiomics platform. Test-retest repeatability was evaluated by Bland-Altman analysis for repeated scans. Intra-scanner reproducibility for different scan modes was tested by intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC). Inter-scanner reproducibility among different scanners for same scan mode was assessed by coefficient of variation (CV) and quartile coefficient of dispersion (QCD).

Results

The test-retest analysis presented that 92.91% and 87.02% of the 94 assessed features were repeatable for SECT 120kVp and DECT 120 kVp-like VMIs, respectively. The intra-scanner analysis for SECT 120kVp vs DECT 120 kVp-like VMIs demonstrated that 10.76% and 10.28% of features were with ICC > 0.90 and CCC > 0.90, respectively. The inter-scanner analysis showed that 17.09% and 27.73% of features for SECT 120kVp were with CV < 10% and QCD < 10%, and 15.16% and 32.78% for DECT 120 kVp-like VMIs, respectively.

Conclusions

The majority of radiomics features were non-reproducible within and between SECT and DECT.

Key Points

• Although the test-retest analysis showed high repeatability for radiomics features, the overall reproducibility of radiomics features within and between SECT and DECT was low.

• Only about one-tenth of radiomics features extracted from SECT images and corresponding DECT images did match each other, even their average photon energy levels were considered alike, indicating that the scan mode potentially altered the radiomics features.

• Less than one-fifth of radiomics features were reproducible among multiple SECT and DECT scanners, regardless of their fixed acquisition and reconstruction parameters, suggesting the necessity of scanning protocol adjustment and post-scan harmonization process.
Management of chronic anal fissure: results of a national survey among gastrointestinal surgeons in the Netherlands
Authors: van Reijn-Baggen Danielle A. , Dekker Lisette , Elzevier Henk W. , Pelger Rob C. M. , Han-Geurts Ingrid J. M.
Published: February 2022

Background

Chronic anal fissure (CAF) is a common, bothersome condition frequently accompanied by pelvic floor complaints. Despite current guidelines, optimal management is challenging. The aim of this study is to evaluate current management of CAF among gastrointestinal surgeons in the Netherlands.

Methods

Dutch gastrointestinal surgeons and residents were sent a survey invitation by email, which was available online between June 2021 and September 2021. The questionnaire consisted of 21 questions concerning work experience, physical examination, diagnostic and surgical techniques, and follow-up.

Results

Overall, 106 (33%) respondents completed the survey. Most respondents (59%) had at least 10 years of experience in treating CAF. Only 23% always addressed pelvic floor complaints. Fifty-one percent performed digital rectal examination and 22% always, or almost always, examined the pelvic floor muscles. Most respondents started treatment with fibers and/or laxatives and ointment (96%). Diltiazem was in 90% the preferred ointment. Twenty-two percent referred patients for pelvic floor physical therapy. Botulinum toxin was in 54% performed under general or spinal anesthesia or sedation. The surgical procedure of choice was fissurectomy (71%) followed by lateral internal sphincterotomy (27%). Fissurectomy was in 51% always combined with botulinum toxin. Fifty-seven percent of the respondents preferred a physical follow-up appointment.

Conclusion

Guideline recommendations are largely followed in the Netherlands, starting with conservative measures followed by surgical procedures. Surgeons do not consistently assess pelvic floor complaints, nor do they routinely examine the pelvic floor muscles. Awareness of pelvic floor dysfunctions is important to refer patients for pelvic floor physical therapy.
A sheep model of chronic cervical compressive myelopathy via an implantable wireless compression device
Authors: Li Zihe , Zhai Shuheng , Liu Shanshan , Chen Chunhua , Guo Xinhu , Hu Panpan , Wang Ben , Zhang Youyu , Wei Feng , Liu Zhongjun
Published: February 2022

Purpose

This study aimed to establish an animal model in which we can precisely displace the spinal cord and therefore mimic the chronic spinal compression of cervical spondylotic myelopathy.

Methods

In vivo intervertebral compression devices (IVCDs) connected with subcutaneous control modules (SCCMs) were implanted into the C2-3 intervertebral disk spaces of sheep and connected by Bluetooth to an in vitro control system. Sixteen sheep were divided into four groups: (Group A) control; (Group B) 10-week progressive compression, then held; (Group C) 20-week progressive compression, then held; and (Group D) 20-week progressive compression, then decompression. Electrophysiological analysis (latency and amplitude of the N1-P1-N2 wave in somatosensory evoked potentials, SEP), behavioral changes (Tarlov score), imaging test (encroachment ratio (ER) of intraspinal invasion determined by X-ray and CT scan), and histological examinations (hematoxylin and eosin, Nissl, and TUNEL staining) were performed to assess the efficacy of our model.

Results

Tarlov scores gradually decreased as compression increased with time and partially recovered after decompression. The Pearson correlation coefficient between ER and time was r = 0.993 (p < 0.001) in Group B at 10 weeks and Groups C and D at 20 weeks. And ER was negatively correlated with the Tarlov score (r = -0.878, p < 0.001). As compression progressed, the SEP latency was significantly extended (p < 0.001), and the amplitude significantly decreased (p < 0.001), while they were both partially restored after decompression. The number of abnormal motor neurons and TUNEL-positive cells increased significantly (p < 0.001) with compression.

Conclusion

Our implantable and wireless intervertebral compression model demonstrated outstanding controllability and reproducibility in simulating chronic cervical spinal cord compression in animals.
Frequency response of swarm deformation with control barrier function
Authors: Origane Y. , Hattori Y. , Kurabayashi D.
Published: February 2022

In this study, we focused on robotic swarms, allowing multiple anonymous autonomous robots to gather and move mutually in tasks. We proposed a method to design a parameter of the control barrier function (CBF) in a robotic swarm so that the swarm can achieve collision-free deformation considering the environmental conditions. We analyzed the responses to perturbations of swarming robots, to which we applied the CBF. Although we can guarantee a safe distance between mobile robots, the CBF limits their actions and prevents swarm deformation. Through analysis of the frequency domain, we investigated the effects of a selected parameter in the CBF on the deformability of a swarm. We obtained an appropriate range of parameters that realize both distance maintenance and deformability retention.
Overall readmissions and readmissions related to dehydration after creation of an ileostomy: a systematic review and meta-analysis
Authors: Vogel I. , Shinkwin M. , van der Storm S. L. , Torkington J. , A.Cornish J. , Tanis P. J. , Hompes R. , Bemelman W. A.
Published: February 2022

Background

Hospital readmissions after creation of an ileostomy are common and come with a high clinical and financial burden. The aim of this review with pooled analysis was to determine the incidence of dehydration-related and all-cause readmissions after formation of an ileostomy, and the associated costs.

Methods

A systematic literature search was conducted for studies reporting on dehydration-related and overall readmission rates after formation of a loop or end ileostomy between January 1990 and April 2021. Analyses were performed using R Statistical Software Version 3.6.1.

Results

The search yielded 71 studies (n = 82,451 patients). The pooled incidence of readmissions due to dehydration was 6% (95% CI 0.04–0.09) within 30 days, with an all-cause readmission rate of 20% (CI 95% 0.18–0.23). Duration of readmissions for dehydration ranged from 2.5 to 9 days. Average costs of dehydration-related readmission were between $2750 and $5924 per patient. Other indications for readmission within 30 days were specified in 15 studies, with a pooled incidence of 5% (95% CI 0.02–0.14) for dehydration, 4% (95% CI 0.02–0.08) for stoma outlet problems, and 4% (95% CI 0.02–0.09) for infections.

Conclusions

One in five patients are readmitted with a stoma-related complication within 30 days of creation of an ileostomy. Dehydration is the leading cause for these readmissions, occurring in 6% of all patients within 30 days. This comes with high health care cost for a potentially avoidable cause. Better monitoring, patient awareness and preventive measures are required.
PM2.5 exceedances and source appointment as inputs for an early warning system
Authors: Rincon Gladys , Morantes Quintana Giobertti , Gonzalez Ahilymar , Buitrago Yudeisy , Gonzalez Jean Carlos , Molina Constanza , Jones Benjamin
Published: February 2022

Between June 2018 and April 2019, a sampling campaign was carried out to collect PM2.5, monitoring meteorological parameters and anthropogenic events in the Sartenejas Valley, Venezuela. We develop a logistic model for PM2.5 exceedances (≥ 12.5 µg m−3). Source appointment was done using elemental composition and morphology of PM by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDS). A proposal of an early warning system (EWS) for PM pollution episodes is presented. The logistic model has a holistic success rate of 94%, with forest fires and motor vehicle flows as significant variables. Source appointment analysis by occurrence of events showed that samples with higher concentrations of PM had carbon-rich particles and traces of K associated with biomass burning, as well as aluminosilicates and metallic elements associated with resuspension of soil dust by motor-vehicles. Quantitative source appointment analysis showed that soil dust, garbage burning/marine aerosols and wildfires are three majority sources of PM. An EWS for PM pollution episodes around the Sartenejas Valley is proposed considering the variables and elements mentioned.
Optimality conditions for invex nonsmooth optimization problems with fuzzy objective functions
Authors: Antczak Tadeusz
Published: February 2022

In this paper, the definitions of Clarke generalized directional $$\alpha $$
α
-derivative and Clarke generalized gradient are introduced for a locally Lipschitz fuzzy function. Further, a nonconvex nonsmooth optimization problem with fuzzy objective function and both inequality and equality constraints is considered. The Karush-Kuhn-Tucker optimality conditions are established for such a nonsmooth extremum problem. For proving these conditions, the approach is used in which, for the considered nonsmooth fuzzy optimization problem, its associated bi-objective optimization problem is constructed. The bi-objective optimization problem is solved by its associated scalarized problem constructed in the weighting method. Then, under invexity hypotheses, (weakly) nondominated solutions in the considered nonsmooth fuzzy minimization problem are characterized through Pareto solutions in its associated bi-objective optimization problem and Karush-Kuhn-Tucker points of the weighting problem.
Revisiting selected ethical aspects of current clinical in vitro fertilization (IVF) practice
Authors: von Schondorf-Gleicher Anja , Mochizuki Lyka , Orvieto Raoul , Patrizio Pasquale , Caplan Arthur S. , Gleicher Norbert
Published: February 2022

Ethical considerations are central to all medicine though, likely, nowhere more essential than in the practice of reproductive endocrinology and infertility. Through in vitro fertilization (IVF), this is the only field in medicine involved in creating human life. IVF has, indeed, so far led to close to 10 million births worldwide. Yet, relating to substantial changes in clinical practice of IVF, the medical literature has remained surprisingly quiet over the last two decades. Major changes especially since 2010, however, call for an updated commentary. Three key changes deserve special notice: Starting out as a strictly medical service, IVF in recent years, in efforts to expand female reproductive lifespans in a process given the term “planned” oocyte cryopreservation, increasingly became more socially motivated. The IVF field also increasingly underwent industrialization and commoditization by outside financial interests. Finally, at least partially driven by industrialization and commoditization, so-called add-ons, the term describing mostly unvalidated tests and procedures added to IVF since 2010, have been held responsible for worldwide declines in fresh, non-donor live birthrates after IVF, to levels not seen since the mid-1990s. We here, therefore, do not offer a review of bioethical considerations regarding IVF as a fertility treatment, but attempt to point out ethical issues that arose because of major recent changes in clinical IVF practice.
The Visible Spectro-Polarimeter of the Daniel K. Inouye Solar Telescope
Authors: de Wijn A. G. , Casini R. , Carlile A. , Lecinski A. R. , Sewell S. , Zmarzly P. , Eigenbrot A. D. , Beck C. , Wöger F. , Knölker M.
Published: February 2022

The Daniel K. Inouye Solar Telescope (DKIST) Visible Spectro-Polarimeter (ViSP) is a traditional slit-scanning spectrograph with the ability to observe solar regions up to a $120\times 78~\mbox{arcsec}^{2}$
120
×
78

arcsec
2

area. The design implements dual-beam polarimetry, a polychromatic polarization modulator, a high-dispersion echelle grating, and three spectral channels that can be automatically positioned. A defining feature of the instrument is its capability to tune anywhere within the 380 – 900 nm range of the solar spectrum, allowing for a virtually infinite number of combinations of three wavelengths to be observed simultaneously. This enables the ViSP user to pursue well-established spectro-polarimetric studies of the magnetic structure and plasma dynamics of the solar atmosphere, as well as completely novel investigations of the solar spectrum. Within the suite of first-generation instruments at the DKIST, ViSP is the only wavelength-versatile spectro-polarimeter available to the scientific community. It was specifically designed as a discovery instrument to explore new spectroscopic and polarimetric diagnostics and test improved models of polarized line formation through high spatial-, spectral-, and temporal-resolution observations of the Sun’s polarized spectrum. In this instrument article, we describe the science requirements and design drivers of ViSP and present preliminary science data collected during the commissioning of the instrument.
Beyond Dents and Scratches: Logical Constraints in Unsupervised Anomaly Detection and Localization
Authors: Bergmann Paul , Batzner Kilian , Fauser Michael , Sattlegger David , Steger Carsten
Published: February 2022

The unsupervised detection and localization of anomalies in natural images is an intriguing and challenging problem. Anomalies manifest themselves in very different ways and an ideal benchmark dataset for this task should contain representative examples for all of them. We find that existing datasets are biased towards local structural anomalies such as scratches, dents, or contaminations. In particular, they lack anomalies in the form of violations of logical constraints, e.g., permissible objects occurring in invalid locations. We contribute a new dataset based on industrial inspection scenarios that evenly covers both types of anomalies. We provide pixel-precise ground truth data for each anomalous region and define a generalized evaluation metric that addresses localization ambiguities that can arise for logical anomalies. Furthermore, we propose a novel algorithm that improves over the state of the art in the joint detection of structural and logical anomalies. It consists of a local and a global network branch. The first one inspects confined regions independent of their spatial locations in the input image and is primarily responsible for the detection of entirely new local structures. The second one learns a globally consistent representation of the training data through a bottleneck that enables the detection of violations of long-range dependencies, a key characteristic of many logical anomalies. We perform extensive evaluations on our new dataset to corroborate our claims.
Developing a real-time social distancing detection system based on YOLOv4-tiny and bird-eye view for COVID-19
Authors: Saponara Sergio , Elhanashi Abdussalam , Zheng Qinghe
Published: February 2022

COVID-19 is a virus, which is transmitted through small droplets during speech, sneezing, coughing, and mostly by inhalation between individuals in close contact. The pandemic is still ongoing and causes people to have an acute respiratory infection which has resulted in many deaths. The risks of COVID-19 spread can be eliminated by avoiding physical contact among people. This research proposes real-time AI platform for people detection, and social distancing classification of individuals based on thermal camera. YOLOv4-tiny is proposed in this research for object detection. It is a simple neural network architecture, which makes it suitable for low-cost embedded devices. The proposed model is a better option compared to other approaches for real-time detection. An algorithm is also implemented to monitor social distancing using a bird’s-eye perspective. The proposed approach is applied to videos acquired through thermal cameras for people detection, social distancing classification, and at the same time measuring the skin temperature for the individuals. To tune up the proposed model for individual detection, the training stage is carried out by thermal images with various indoor and outdoor environments. The final prototype algorithm has been deployed in a low-cost Nvidia Jetson devices (Xavier and Jetson Nano) which are composed of fixed camera. The proposed approach is suitable for a surveillance system within sustainable smart cities for people detection, social distancing classification, and body temperature measurement. This will help the authorities to visualize the fulfillment of the individuals with social distancing and simultaneously monitoring their skin temperature.
Mobile First? Ein Vergleich von Lese‑/Rechtschreibtests in traditionellem Papier-und-Bleistift-Format versus App-Format
Authors: Rothe Josefine , Visser Linda , Görgen Ruth , Kalmar Julia , Schulte-Körne Gerd , Hasselhorn Marcus
Published: February 2022

Digitale Medien haben mittlerweile einen festen Platz im Alltag von Schülerinnen und Schülern. Sie dienen nicht nur der Vermittlung von Lehrinhalten, sondern werden zunehmend auch für das Erbringen von Leistungsnachweisen und zur Diagnostik eingesetzt. Für die Durchführung und Auswertung etablierter Testverfahren zur Erfassung schulischer Leistungen wäre es wünschenswert, wenn sie in einem digitalen Format vorliegen. Aber sind diese Testleistungen vergleichbar? Um dies zu prüfen, wurden verbreitete Papier- und Bleistift-Testverfahren zur Erfassung der Lesegenauigkeit (Verlaufsdiagnostik sinnerfassenden Lesens, VSL), Dekodiergeschwindigkeit (Würzburger Leise Leseprobe – Revision, WLLP-R) und Rechtschreibung (Weingartener Grundwortschatz Rechtschreib-Test, WRT 3+/4+) digitalisiert und in eine kindgerechte Rahmengeschichte eingebettet. Insgesamt führten 237 Kinder der dritten und vierten Klassenstufe aus Bayern und Hessen die Testverfahren zuerst in digitaler Version (via App am Tablet oder Smartphone) und danach als Papier-und-Bleistift-Version durch. Es zeigt sich ein hoher Zusammenhang zwischen den Testleistungen der beiden Testformate, der unterschiedliche Interpretationen zulässt. Chancen und Grenzen digitalisierter Leistungstests werden diskutiert.
The Changing Climate and Pregnancy Health
Authors: Ha Sandie
Published: February 2022

Purpose of Review

Climate change is the biggest public health threat of the twenty-first century but its impact on the perinatal period has only recently received attention. This review summarizes recent literature regarding the impacts of climate change and related environmental disasters on pregnancy health and provides recommendations to inform future adaptation and mitigation efforts.

Recent Findings

Accumulating evidence suggests that the changing climate affects pregnancy health directly via discrete environmental disasters (i.e., wildfire, extreme heat, hurricane, flood, and drought), and indirectly through changes in the natural and social environment. Although studies vary greatly in design, analytic methods, and assessment strategies, they generally converge to suggest that climate-related disasters are associated with increased risk of gestational complication, pregnancy loss, restricted fetal growth, low birthweight, preterm birth, and selected delivery/newborn complications. Window(s) of exposure with the highest sensitivity are not clear, but both acute and chronic exposures appear important. Furthermore, socioeconomically disadvantaged populations may be more vulnerable.

Policy, clinical, and research strategies for adaptation and mitigation should be continued, strengthened, and expanded with cross-disciplinary efforts. Top priorities should include (a) reinforcing and expanding policies to further reduce emission, (b) increasing awareness and education resources for healthcare providers and the public, (c) facilitating access to quality population-based data in low-resource areas, and (d) research efforts to better understand mechanisms of effects, identify susceptible populations and windows of exposure, explore interactive impacts of multiple exposures, and develop novel methods to better quantify pregnancy health impacts.
Evolution characteristics of precursor information of coal and gas outburst in deep rock cross-cut coal uncovering
Authors: Tang Jupeng , Zhang Xin , Sun Shengjie , Pan Yishan , Li Liping
Published: February 2022

As mines become deeper, the potential for coal and gas outbursts in deep rock cross-cut coal uncovering is enhanced. The outburst precursors are unclear, which restricts the effectiveness and reliability of warning systems. To reveal the evolution characteristics of coal and gas outburst precursor information in deep rock cross-cut coal uncovering, briquette specimens are constructed and experiments are conducted using a self-developed true triaxial outburst test system. Using acoustic emission monitoring technology, the dynamic failure of coal is monitored, and variations in the root mean square (RMS) of the acoustic emissions allow the effective cracking time and effective cracking gas pressure to be defined. These characteristics are obviously different in deep and shallow coal. The characteristic parameters of gas outburst exhibit stepwise variations at different depths. The RMS and cumulative RMS have stepped failure characteristics with respect to changes in gas pressure. The characteristic parameters of coal failure are negatively correlated with the average in-situ stress and effective stress, but positively correlated with the lateral pressure coefficient of in-situ stress and the critical gas pressure. The transition characteristics are highly sensitive in all cases. The critical depth between deep and shallow coal and gas outbursts is 1700 m. The expansion multiple of acoustic emission intensity from the microfracture stage to the sharp-fracture stage of coal is defined as the outburst risk index, N1. For depths of 1100–1700 m, N1 ≥ 7 denotes a higher risk of outburst, whereas at depths of 1700–2500 m, N1 ≥ 3 indicates enhanced risk.
Employment effects of immigration to Germany in the period of migration policy liberalization, 2005–2018
Authors: Erol Isil , Unal Umut
Published: February 2022

Germany has undergone a significant migration policy shift since the early 2000s. This paper examines the total employment effect of immigration during the liberalization of migration policies from 2005 to 2018 using a regional approach. A set of methods, along with static and dynamic macro-econometric models, were applied on a balanced panel formed by a unique and first-hand-collected data for 156 statistical regions based on the definition of the German Federal Employment Agency. We find suggestive evidence that there has been a significant adverse impact of new immigrants on the overall employment rate, and this negative effect is substantially larger than those reported in previous studies on the employment effect of immigration in the German labor market. In a further step, we divide our sample into two subsamples to capture the employment effect of the massive humanitarian inflows that began in 2015. Our results indicate that, in addition to the new immigrants' lower rate of integration into the local labor markets, a sudden influx of asylum seekers may possibly lead to a substantial fall in the employment rates, because asylum seekers are not immediately allowed to work in the country.
A Feedforward Neural Network for Modeling of Average Pressure Frequency Response
Authors: Pettersson Klas , Karzhou Andrei , Pettersson Irina
Published: February 2022

The Helmholtz equation has been used for modeling the sound pressure field under a harmonic load. Computing harmonic sound pressure fields by means of solving Helmholtz equation can quickly become unfeasible if one wants to study many different geometries for ranges of frequencies. We propose a machine learning approach, namely a feedforward dense neural network, for computing the average sound pressure over a frequency range. The data are generated with finite elements, by numerically computing the response of the average sound pressure, by an eigenmode decomposition of the pressure. We analyze the accuracy of the approximation and determine how much training data is needed in order to reach a certain accuracy in the predictions of the average pressure response.
Aflatoxin B1 Sorption and Safety of Dietary Sodium Bentonite in Sprague-Dawley Rats
Authors: Marroquín-Cardona Alicia G. , Deng Youjun , Garcia-Mazcorro Jose F. , Johnson Natalie M. , Mitchell Nicolle J. , Tang Lili , Wang Jia-Sheng , Harvey Roger B. , Phillips Timothy D.
Published: February 2022

Bentonites are readily available clays used in the livestock industry as feed additives to reduce aflatoxin (AF) exposure; their potential interaction with nutrients is the main concern limiting their use, however. The objective of the present study was to determine the safety of a dietary sodium-bentonite (Na-bentonite) supplement as a potential AF adsorbent, using juvenile Sprague Dawley (SD) rats as a research model. Animals were fed either a control diet or a diet containing Na-bentonite at 0.25% and 2% (w/w) inclusion rate. Growth, serum, and blood biochemical parameters, including selected serum vitamins (A and E) and elements such as calcium (Ca), potassium (K), iron (Fe), and zinc (Zn) were measured. The mineral characteristics and the aflatoxin B1 sorption capacity of Na-bentonite were also determined. By the end of the study, males gained more weight than females in control and Na-bentonite groups (p ≤ 0.0001); the interaction between treatment and sex was not significant (p = 0.6780), however. Some significant differences between the control group and bentonite treatments were observed in serum biochemistry and vitamin and minerals measurements; however, parameters fell within reference clinical values reported for SD rats and no evidence of dose-dependency was found. Serum Na and Na/K ratios were increased, while K levels were decreased in males and females from Na-bentonite groups. Serum Zn levels were decreased only in males from Na-bentonite treatments. Overall, results showed that inclusion of Na-bentonite at 0.25% and 2% did not cause any observable toxicity in a 3-month rodent study.
Numerical Methods for Atmospheric and Oceanic Sciences
Authors: Chandrasekar A
Published: February 2022

Numerical Methods for Atmospheric and Oceanic Sciences caters to the needs of students of atmospheric and oceanic sciences in senior undergraduate and graduate courses as well as students of applied mathematics, mechanical and aerospace engineering. The book covers fundamental theoretical aspects of the various numerical methods that will help both students and teachers in gaining a better understanding of the effectiveness and rigour of these methods. Extensive applications of the finite difference methods used in the processes involving advection, barotropic, shallow water, baroclinic, oscillation and decay are covered in detail. Special emphasis is given to advanced numerical methods such as Semi-Lagrangian, Spectral, Finite Element and Finite Volume methods. Each chapter includes various exercises including Python codes that will enable students to develop the codes and compare the numerical solutions obtained through different numerical methods.
Handbook on Legal Methodology
Authors: Kestemont Lina
Published: February 2022

Legal scholarship is one of the oldest academic disciplines, and the study of law has been passed on from generation to generation as an implicit 'savoir faire'. It was presumed that all legal scholars understood the methodology of legal research, making its explicit clarification and justification unnecessary. Over the last decade, the lack of an explicit methodological tradition has become problematic due to the growing interdisciplinary collaboration at universities and the increased importance of external funding, often granted by mixed experts panels. It is therefore time for legal scholarship to make its implicit methodology explicit.
Markov chain Monte Carlo for a hyperbolic Bayesian inverse problem in traffic flow modeling
Authors: Coullon Jeremie , Pokern Yvo
Published: February 2022

As a Bayesian approach to fitting motorway traffic flow models remains rare in the literature, we empirically explore the sampling challenges this approach offers which have to do with the strong correlations and multimodality of the posterior distribution. In particular, we provide a unified statistical model to estimate using motorway data both boundary conditions and fundamental diagram parameters in a motorway traffic flow model due to Lighthill, Whitham, and Richards known as LWR. This allows us to provide a traffic flow density estimation method that is shown to be superior to two methods found in the traffic flow literature. To sample from this challenging posterior distribution, we use a state-of-the-art gradient-free function space sampler augmented with parallel tempering.
Approaches to healthcare personnel exemption requests from coronavirus disease 2019 (COVID-19) vaccination: Results of a national survey
Authors: Talbot Thomas R. , Beekmann Susan E. , Babcock Hilary M. , Polgreen Philip M.
Published: February 2022

Objective:

Although a growing number of healthcare facilities are implementing healthcare personnel (HCP) coronavirus disease 2019 (COVID-19) vaccination requirements, vaccine exemption request management as a part of such programs is not well described.

Design:

Cross-sectional survey.

Participants:

Infectious disease (ID) physician members of the Emerging Infections Network with infection prevention or hospital epidemiology responsibilities.

Methods:

Eligible persons were sent a web-based survey focused on hospital plans and practices around exemption allowances from HCP COVID-19 vaccine requirements.

Results:

Of the 695 ID physicians surveyed, 263 (38%) responded. Overall, 160 respondent institutions (92%) allowed medical exemptions, whereas 132 (76%) allowed religious exemptions. In contrast, only 14% (n = 24) allowed deeply held personal belief exemptions. The types of medical exemptions allowed varied considerably across facilities, with allergic reactions to the vaccine or its components accepted by 145 facilities (84%). For selected scenarios commonly used as the basis for religious and deeply held personal belief exemption requests, 144 institutions (83%) would not approve exemptions focused on concerns regarding right of consent or violations of freedom of personal choice, and 140 institutions (81%) would not approve exemptions focused on introducing foreign substances into one’s body or the sanctity of the body. Most respondents noted plans for additional infection prevention interventions for HCP who received an exemption for COVID-19 vaccination.

Conclusions:

Although many respondent institutions allowed exemptions from HCP COVID-19 vaccination requirements, the types of exemptions allowed and how the exemption programs were structured varied widely.
‘Society Is Watching You Very Carefully’: Smuggling, the State and Athlete Attempts to Assert Agency in People's Poland
Authors: Lash Christopher
Published: February 2022

This article focuses on the most renowned smuggling case concerning Polish athletes during the Polish People's Republic (Polska Rzeczpospolita Ludowa; PRL). In the early 1970s, several Polish football and basketball players were caught smuggling dollars out of Poland and importing gold into the country for profit. The article discusses the roles states devised for athletes in the countries of real socialism and how athletes attempted to assert agency within these confines. It draws on work by Robert Edelman and Sylvain Dufraisse to show how athletes often did not behave in the way Eastern bloc states wished them to.
Taming Abundance: Doing Digital Archival Research (as Political Scientists)
Authors: Kim Diana S.
Published: February 2022

Political scientists are increasingly using digitized documents from archives. This article is a practical introduction to doing digital archival research. First, it explains when and why political scientists use evidence from archival research. Second, it argues that the remote accessibility of digitized records provides new opportunities for comparative and transnational research. However, digital archival research also risks aggravating five types of biases that pose challenges for qualitative, quantitative, interpretive, and mixed-methods research:survival,transfer,digitization, andreinforcement biasat the level of record collection andsource biasat the level of record creation. Third, this article offers concrete strategies for anticipating and mitigating these biases by walking readers through the experience of entering, being in, and leaving an archive, while also underscoring the importance of learning the structure of an archive. The article concludes by addressing the ethical implications to archival research as a type of field research for political scientists.
House Republican Decision Making Following the Capitol Riot
Authors: Strawbridge Michael G. , Lau Richard R.
Published: February 2022

Former President Donald Trump’s unsubstantiated vote-fraud claims following the 2020 presidential election divided the Republican Party. Numerous Republicans supported Trump’s efforts to overturn the election, others did not. These futile attempts reached a flashpoint during the January 6 attack on the United States Capitol. Even in the wake of such violence, many House Republicans continued to amplify Trump’s baseless claims by voting to exclude the election results from Arizona and Pennsylvania. This article analyzes these roll-call votes to determine the likely motivations for why some House Republicans were still willing to support Trump’s position following the Capitol riot. We then replicate our analysis with the January 13 impeachment and the May 19 vote to establish a bipartisan National Commission to Investigate the January 6 Attack on the United States Capitol Complex (January 6 Commission) to investigate the insurrection. Our findings indicate the relevance of constituent preferences, Trump’s popularity, legislator ideology, and the racial diversity of constituents represented by Republicans.
SEM Nano: An Electron Wave Optical Simulation for the Scanning Electron Microscope
Authors: Kamal Surya , Hailstone Richard K.
Published: February 2022

The simulation program “SEM Nano” is introduced to explain and visualize probe formation in field-emission scanning electron microscopes (SEMs). The program offers an easy and intuitive graphical user interface (GUI) to provide input in terms of understandable SEM parameters and visualization of the output. The simulations are based on wave optics treatment of the electron beam in the SEM column. Based on input parameters provided by the user, the spatial intensity distribution of electrons is calculated at the specimen by incorporating the effects of diffraction, aberrations, coherence, and noise. Given the specimen structure signal (So), the program has the capability to produce an image of the specimen using the electron probe intensity distribution. Finally, a feature is provided to reconstruct the electron probe intensity from the noisy image using a Wiener filter-based deconvolution.
Constraints on Absolute Magma Chamber Volume From Geodetic Measurements of Trapdoor Faulting at Sierra Negra Volcano, Galapagos
Authors: Zheng Yujie , Blackstone Laura , Segall Paul
Published: February 2022

Magma chamber volume is critical for volcano hazards assessment and forecasting. Standard geodetic methods constrain volume change, not the total volume. Here, we show that the deformation response of the magma chamber to trapdoor faulting events at Sierra Negra volcano, Galapagos, depends on the product of the absolute chamber volume and the magma compressibility. Bubble‐free magma provides the lower limit on compressibility, thus an upper bound on the chamber volume of 13.6–20.6 km3, depending on fault dip. We estimate an upper limit on compressibility using a conduit model relating volatile content to lava fountain height, compared with observations from the 2005 eruption, constrained by volatile content of olivine melt inclusions. This yields a lower bound on chamber volume roughly half the upper bound. We find that the best fitting trapdoor fault is near‐vertical; reverse dips are slightly favored (88°).
Increasing Nutrient Fluxes and Mixing Regime Changes in the Eastern Arctic Ocean
Authors: Schulz K. , Lincoln B. , Povazhnyy V. , Rippeth T. , Lenn Y.‐D. , Janout M. , Alkire M. , Scannell B. , Torres‐Valdés S.
Published: February 2022

Primary productivity in the Arctic Ocean is experiencing dramatic changes linked to the receding sea ice cover. The vertical transport of nutrients from deeper water layers is the limiting factor for primary production. Here, we compare coincident profiles of turbulence and nutrients from the Siberian Seas in 2007, 2008, and 2018. In all years, the water column structure in the upstream region of the Arctic Boundary Current promotes upward nutrient transport, in contrast to the regions further downstream, and there are first indications for an eastward progression of these conditions. In summer 2018, strongly enhanced vertical nitrate flux and primary production above the continental slope were observed, likely related to a remote storm. The estimated contribution of these elevated fluxes above the slope to the Pan‐Arctic vertical nitrate supply is comparable with the basin‐wide transport, and is predicted to increase with declining sea ice cover in the future.
A Weak Precipitation Sensitivity of Glacier Runoff
Authors: Banerjee Argha
Published: February 2022

A clear understanding of the influence of glaciers on the climate sensitivity of catchment runoff is critical to unravel the ongoing and future changes in runoff regimes of glacierized catchments in a warming climate. We demonstrate that irrespective of the climate setting, annual glacier runoff is relatively insensitive to the precipitation variability. A temperature‐dependent runoff from the glaciers and a precipitation‐dependent runoff from the non‐glacierized parts determine the climate response of the runoff of glacierized catchments at different time scales. The buffering effect of glaciers against extreme droughts and the multidecadal runoff peak in catchments with shrinking glaciers, both follow from the above properties of glacier runoff. The empirically observed “glacier‐compensation effect” is caused by an inhibited (amplified) response of the catchment runoff to the interannual precipitation (temperature) variability due to the glaciers present in the catchment.
Quantification of Electric Fields in Fast Breakdown During Lightning Initiation From VHF‐UHF Power Spectra
Authors: Pu Yunjiao , Liu Ningyu , Cummer Steven A.
Published: February 2022

This work applies a new remote sensing approach to indirectly probe the electric fields in the discharge region of fast breakdown (FB) processes during lightning initiation. A VHF‐UHF broadband (1–750 MHz) measurement system is used to record the radiation spectra of FB. The average spectrum over 4 FB events exhibits a −10 dB spectral cutoff at 430 MHz, which yields an electrical field of 1.96–2.02 times the conventional breakdown field at 8–9 km altitudes. This in turn implies a localized field enhancement inside the region dominating the VHF‐UHF emissions of >7 times the expected pre‐discharge background field for lightning initiation. Such a high field has implications for the dynamics of individual streamers and their impact on the immediate environment, and also constrains the geometry of parts of the FB structure, suggesting that streamers initiate continuously in the enhanced field ahead of a narrow (aspect ratio >4) and conducting region.
Euler Potentials for Dungey Magnetosphere With Axisymmetric Ring and Field‐Aligned Currents
Authors: Romashets E. , Vandas M.
Published: February 2022

Euler potentials are found for the magnetic field in the inner magnetosphere, consisting of the Earth's dipole field, the Dungey term, ring current (RC), and field‐aligned current (FAC). The magnetic field in this approximation is axially symmetric. One Euler potential for the dipole, Dungey term, and RC is the same, while that for the magnetic field induced by FAC is different and calculated in this work under the condition that all four field contributions have the same second Euler potential. The Euler potentials are determined for quiet, severe, and superstorm geomagnetic conditions. The restriction of the model is its axial symmetry, so changes of the location and intensity of the currents with azimuthal angle are not explicitly present. On the other hand, these parameters can be changed in the model, and one can study local distributions.
Spatial and Temporal Origins of the La Perouse Low Oxygen Pool: A Combined Lagrangian Statistical Approach
Authors: Sahu Saurav , Allen Susan E. , Saldías Gonzalo S. , Klymak Jody M. , Zhai Li
Published: February 2022

A shortage of dissolved oxygen in seawater can adversely impact marine life and ecosystems. Low oxygen conditions at depth occur in many coastal regions, driven by both local productivity and remote changes in the source waters. A low‐oxygen dense pool of water is observed every summer over the mid‐shelf off southwest Vancouver Island in the Juan de Fuca Eddy region. We trace the dense pool waters back to their source using Lagrangian Particle tracking in an ocean model. The model accuracy is evaluated against a set of dense observations collected in August 2013. Only locations where the model represents water properties well are used as starting locations for the tracking. These locations are selected using a K‐Means clustering algorithm. Tracking particles backwards in time showed that the low oxygen dense pool is primarily composed of water from the California Undercurrent, shallower water from further offshore of the Washington shelf, and offshore water. Waters from the northern shelf were not a primary source even though summer currents are from the north. Correspondingly, the water primarily arrived in the south Vancouver Island region in spring, months before the cruise. A kernel density estimate shows the final water properties of the dense pool are well represented by this mixture. The dense water pathways up and onto the shelf are primarily through coastal submarine canyons in early summer. Combining high spatial resolution observations, a carefully evaluated numerical model, Lagrangian tracking, and statistical techniques reveal detailed answers not obtainable through a single method.
Experiment and Simulation of One Deep Sewage Discharge Type: Transport of Low‐Salinity Sediment‐Laden Flow Discharged
Authors: Shen Xia , Li Ran , Cai Huanjie , Feng Jingjie
Published: February 2022

Deep sewage discharge leads to inestimable damage to the ambient water (lakes, oceans and reservoirs), which has caused widespread social concern. In the current paper, a three‐dimensional (3D) buoyancy plume model for deep sewage discharge was developed. It simulates sediment‐laden flow with the effects of temperature and salinity differences. Taking the turbulent diffusion coefficient of salinity (αsal) as the calibration parameter, a comparison between the RNG k‐ε and the standard k‐ε models was performed. The proposed model was verified well and agreement with experiment, which proved that the RNG model with the αsal value of 0.4 was the optimal calibration. Then the model was applied to quantify the behavior of the buoyant plume in the ambient fluid (salt water) with respect to different contours of turbulent kinetic energy (k), temperature, salinity and sediment. The dimensionless centerline trajectory positions and boundary positions of them were determined. The results indicated that the discharge of low‐salinity sediment‐bearing water influenced the deep ambient water spatially, both near the free surface and in the vertical plane. Different diffusion and spreading shapes (butterfly, Ginkgo biloba, bean) can be observed on the surface. Accurately evaluating the impact of deep discharge on ambient water has great significance for maintaining healthy and sustainable environments in offshore areas, deep lakes and reservoirs.
Population-based incidence and risk factors for cholestasis in hemolytic disease of the fetus and newborn
Authors: Teng Jonas , Wickman Linnéa , Reilly Marie , Nemeth Antal , Fischler Björn , Bohlin Kajsa , Tiblad Eleonor
Published: February 2022

Objective

To estimate the incidence of cholestasis in neonates with hemolytic disease of the fetus and newborn (HDFN) and investigate risk factors and long-term liver disease.

Study design

A population-based cohort study of all infants born with HDFN within the Stockholm region between 2006 and 2015. The study period was the first 90 days of life, and presence of any chronic liver disease was evaluated at two years of age.

Results

Cholestasis occurred in 7% (11/149). Median age at detection was 1.1 days. Intrauterine blood transfusions and maternal alloimmunization with multiple red blood cell antibodies including D-, c- or K-antibodies were independent risk factors for cholestasis. No infant had chronic liver disease at two years of age.

Conclusions

Infants with severe HDFN have increased risk for cholestasis, particularly those requiring multiple intrauterine transfusions. Early and repeated screening for conjugated hyperbilirubinemia in the first week of life is needed to ensure adequate management.