bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability estimation for unsupervised clustering: A review
Authors: Liu Tianmou , Yu Han , Blair Rachael Hageman 
Published: January 2022

AbstractCluster analysis remains one of the most challenging yet fundamental tasks in unsupervised learning. This is due in part to the fact that there are no labels or gold standards by which performance can be measured. Moreover, the wide range of clustering methods available is governed by different objective functions, different parameters, and dissimilarity measures. The purpose of clustering is versatile, often playing critical roles in the early stages of exploratory data analysis and as an endpoint for knowledge and discovery. Thus, understanding the quality of a clustering is of critical importance. The concept of stability has emerged as a strategy for assessing the performance and reproducibility of data clustering. The key idea is to produce perturbed data sets that are very close to the original, and cluster them. If the clustering is stable, then the clusters from the original data will be preserved in the perturbed data clustering. The nature of the perturbation, and the methods for quantifying similarity between clusterings, are nontrivial, and ultimately what distinguishes many of the stability estimation methods apart. In this review, we provide an overview of the very active research area of cluster stability estimation and discuss some of the open questions and challenges that remain in the field.This article is categorized under:
Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and Classification
Sparse 3D contrast-enhanced whole-heart imaging for coronary artery evaluation
Authors: Ansari Uzair , Janssen Sonja , Baumann Stefan , Borggrefe Martin , Waldeck Stephan , Schönberg Stefan , Papavassiliu Theano , Overhoff Daniel 
Published: January 2022

Abstract
Background
We investigated the feasibility of evaluating coronary arteries with a contrast-enhanced (CE) self-navigated sparse isotropic 3D whole heart T1-weighted magnetic resonance imaging (MRI) study sequence.

Methods
A total of 22 consecutive patients underwent coronary angiography and/or cardiac computed tomography (CT) including cardiac MRI. The image quality was evaluated on a 3-point Likert scale. Inter-reader variability for image quality was analyzed with Cohen’s kappa for the main coronary segments (left circumflex [LCX], left anterior descending [LAD], right coronary artery [RCA]) and the left main trunk (LMT).

Results
Inter-reader agreement for image quality of the coronary tree ranged from substantial to perfect, with a Cohen’s kappa of 0.722 (RCAmid) to 1 (LCXprox). The LMT had the best image quality. Image quality of the proximal vessel segments differed significantly from the mid- and distal segments (RCAprox vs. RCAdist, p < 0.05). The LCX segments showed no significant difference in image quality along the vessel length (LCXprox vs. LCXdist, p = n.s.). The mean acquisition time for the study sequence was 553 s (±46 s).

Conclusion
Coronary imaging with a sparse 3D whole-heart sequence is feasible in a reasonable amount of time producing good-quality imaging. Image quality was poorer in distal coronary segments and along the entire course of the LCX.
Behandlung von Hepatitis-C-Infektionen im Zeitalter direkt wirkender antiviraler Medikamente (DAAs)
Authors: Peiffer Kai-Henrik , Zeuzem Stefan 
Published: January 2022

ZusammenfassungDie chronische Hepatitis-C-Infektion kann unbehandelt zu schwerwiegenden und potenziell lebensbedrohlichen leberassoziierten Komplikationen führen. Grundsätzlich stellt damit jede chronische Infektion mit dem Hepatitis-C-Virus (HCV) eine Indikation zur antiviralen Therapie dar. Besonders dringlich ist sie jedoch bei Patient*innen mit fortgeschrittener Lebererkrankung. In diesem Beitrag werden Indikation, Therapieziele und Grundprinzipien der direkt antiviralen Therapie beschrieben. Verschiedene Therapieregime und Möglichkeiten der Überwachung von Therapie und Therapieerfolg werden vorgestellt.Heutzutage wird die chronische HCV-Infektion interferonfrei mit direkt antiviral wirksamen Medikamenten („direct acting antivirals“ – DAA) behandelt, wobei die Wahl der Medikamente von HCV-Genotyp, Vortherapie und Fibrosestatus abhängt. Patient*innen mit kompensierter Leberzirrhose und solche ohne Leberzirrhose weisen unter Behandlung vergleichbar hohe Viruseradikationsraten auf. Auch bei dekompensierter Leberzirrhose oder dialysepflichtiger Niereninsuffizienz und selbst bei Kindern ab einem Alter von 3 Jahren ist heutzutage eine sichere und hocheffiziente antivirale Behandlung möglich. Medikamenteninteraktionen sind zu beachten, können aber einfach und schnell im Internet überprüft werden. Auch wenn sich die Prognose nach HCV-Eradikation deutlich verbessert, sollten Patient*innen mit fortgeschrittener Leberfibrose bzw. einer Leberzirrhose lebenslang weiterbeobachtet werden, um die Entstehung eines hepatozellulären Karzinoms rechtzeitig zu erkennen (HCC-Surveillance).
An Observational Study of Paediatric Preoperative Transfusion Practice in a Resource‐Limited Setting
Authors: Charuvila Somy , Aziz Tasmiah Tahera , Davidson Sarah E. , Naznin Ummay , Sinha Shiuly , Ahmed Sabbir , Lakhoo Kokila , Banu Tahmina 
Published: January 2022

AbstractBackgroundPaediatric anaemia is highly prevalent in low–middle‐income countries and can negatively impact postoperative outcomes. Currently, there are no guidelines for the management of paediatric preoperative anaemia. To ensure optimal care in resource‐limited settings: balancing the risks of anaemia and using resources such as blood transfusion, we first need to understand current practices. To address this, a joint UK–Bangladesh team conducted an observational study at a paediatric surgical centre in Bangladesh.MethodsA total of 464 patients ≤16 years who underwent elective and emergency surgery were categorised into major (351/464), moderate (92/464) and minor (21/464) surgery groups according to anticipated blood loss. Preoperative anaemia testing and transfusion was assessed retrospectively through patient notes.ResultsMedian age was 4 years and 73% were male. 32.5% (151/464) patients had preoperative blood testing for anaemia. 17.5% (81/464) children were transfused preoperatively. Of those children transfused, 40.7% (33/81) underwent transfusion solely based on visible signs of anaemia on clinical examination. Seventy‐five percentage (36/48) of children who underwent transfusion after blood testing had haemoglobin ≥80 g/L. Major surgery category had the highest proportion of children who were transfused and tested for anaemia.ConclusionA liberal transfusion approach is evident here. Discussion with local clinicians revealed that this was due to limitations in obtaining timely blood results and reduction in laboratory costs incurred by families when clinical suspicion of anaemia was high. Further research is needed to analyse the potential of using bedside haemoglobin testers in conjunction with patient blood management strategies to limit blood transfusions and its associated risks.
Despite Major Therapeutic Advances, Vena Caval Trauma Remains Associated with Significant Morbidity and Mortality
Authors: Khan Muhammad Zafar , Khan Afroz , Mbebe Dalina Thembisile , Bruce John Lambert , Bekker Wanda , Clarke Damian Luiz 
Published: January 2022

AbstractBackgroundPenetrating inferior vena caval injuries remain a challenging operative entity. This study reviews our local experience with the injury over a nine‐year period and attempts to contextualize it within the published literature that emanates from South Africa on the topic.MethodsA single‐centre retrospective review of prospectively collected data was performed of all patients who underwent a laparotomy for a penetrating IVC injury. Descriptive statistics were calculated for demographics, clinical and biochemical parameters, intraoperative data, ICU admission and outcomes.
ResultsDuring the nine‐year period, thirty‐five patients sustained penetrating injuries to the IVC. Mechanism of injury included 25 low velocity gunshots (71%) and 10 stab wounds (29%). The anatomical location included two (6%) supra‐renal, six (17%) juxta‐renal and 27 (77%) infra‐renal injuries. Venorrhaphy was performed in 22 cases (63%) and ligation in 13 (37%). Average ICU stay was 5.4 days. Thirteen patients died (37%), of which six (46%) died within 24 h of arrival.ConclusionDespite dramatic improvements in surgical trauma care over the last four decades, penetrating injury to the IVC carries a high mortality rate ranging from 31 to 37%. It is unlikely that further improvements can be achieved by refining operative techniques and approaches to resuscitation. Future endeavours must focus on applying the burgeoning understanding of endovascular surgery to these injuries.
Informal input suppliers, quality choice and welfare
Authors: Daga Sergio , Mendi Pedro 
Published: January 2022

AbstractThis paper proposes a theoretical model in which a formal upstream firm competes against informal input suppliers, which constitute an alternative, albeit lower-quality input source for formal downstream firms. The existence of an alternative source increases competition in the industry, which tends to be welfare-increasing. However, it may also distort the incentives of the formal upstream firm to invest in quality upgrading. Assuming quantity competition downstream, we analyze how these incentives change and whether the negative welfare effect of a reduced investment by the upstream firm may more than offset the positive welfare effect of increased competition brought about by informal input suppliers. We find that there are parameter values such that this is the case, and welfare decreases if informal input suppliers are present. We analyze the robustness of this result to alternative modeling assumptions, such as price competition downstream and the use of two-part tariffs by the formal upstream firm.
Bestimmung der Grundwasserneubildungshöhen für Festgesteinsgebiete in Niedersachsen
Authors: Ertl Gabriele , Herrmann Frank , Elbracht Jörg 
Published: January 2022

ZusammenfassungDie Grundwasserneubildung in Festgesteinsbereichen ist aufgrund der hydrogeologischen Eigenschaften der Gesteine im Allgemeinen geringer als in den Porengrundwasserleitern der Lockergesteine. Durch das Zusammenspiel dieser Eigenschaften mit der Topographie der Mittelgebirgslandschaften Niedersachsens, findet dort neben der Grundwasserneubildung auch ein signifikanter Zwischenabfluss statt. Methodisch können in Wasserhaushaltsmodellen im Rahmen einer Abflussseparation diese Größen mithilfe von flächendifferenzierten BFI-Werten berechnet werden. Dabei geben die BFI-Werte das Verhältnis von Grundwasserneubildung zum Gesamtabfluss wieder. Für die Abflussseparation mit dem Modell mGROWA wurden BFI-Werte für das Festgestein von Niedersachsen mit im Vergleich zu vorhergehenden Modellversionen höherem Detaillierungsgrad auf Basis der Geologischen Karte 1:50.000 (GK50) integriert. Dafür wurden 455 geologische Einheiten der GK50 hydrogeologisch analysiert und parametrisiert. Vor allem wasserwirtschaftlich relevante geologische Einheiten geringerer Ausdehnung konnten so besser in der Karte der Grundwasserneubildung berücksichtigt werden. Diesbezüglich werden fünf geologische Einheiten detaillierter diskutiert. Für diese fünf Fallbeispiele wurden mittels eines U‑Tests die Zeitreihen der simulierten jährlichen Grundwasserneubildung auf signifikante Veränderungen geprüft. Es resultiert für alle Zeitreihen eine signifikant veränderte Verteilung der jährlichen Grundwasserneubildung auf einem geringeren Niveau in den gerade vergangenen beiden Dekaden.
Einsatz neuronaler Netze in der Notaufnahme
Authors: Weberskirch Carolin , Pigorsch Uta , Tralls Patric , Rachuba Sebastian 
Published: January 2022

Zusammenfassung
Hintergrund
Krankenhäuser generieren einen Teil ihrer stationären Fälle aus ungeplanten Einweisungen über die zentrale Notfallambulanz (ZNA). Die Vorbereitung der Aufnahme benötigt üblicherweise eine ärztliche Entscheidung. Die resultierende Vorbereitungszeit für die Normalstation ist mitunter nicht ausreichend und es entstehen Verzögerungen.

Ziel der Arbeit/Fragestellung
Anhand der Prognose der Wahrscheinlichkeit einer stationären Aufnahme soll der potenzielle Nutzen des Einsatzes künstlicher neuronaler Netze (KNN) in der ZNA aufgezeigt werden. Dabei stellt sich die Frage, ob Routinedaten, welche in fast jeder ZNA bereits zum Zeitpunkt der Ersteinschätzung zur Verfügung stehen, einen Beitrag zur Reduktion von Verzögerungen bei der stationären Aufnahme leisten können.

Material und Methoden
Auf Grundlage von beschränkten und anonymisierten Routinedaten aus einem Krankenhausinformationssystem wird für eine ZNA ein KNN entwickelt, das die Vorhersage der stationären Aufnahme ermöglicht. Die Implementierung des KNN erfolgt über die Open-Source-Software R.

Ergebnisse
Unter Anwendung von Routinedaten erzielt das KNN eine Genauigkeit von 76,64 %. Die Sensitivität, d. h. der Anteil korrekt vorhergesagter Patientenaufnahmen, liegt bei 66,93 % und damit niedriger als die Spezifität (Anteil korrekt vorhergesagter Nichtaufnahmen), die 82,13 % beträgt.

Diskussion
Bereits unter Verwendung von Routinedaten können KNN einen wertvollen Beitrag für die Ablaufplanung in der ZNA leisten. Es ist zu erwarten, dass zusätzliche Variablen, wie z. B. das Patientenalter, die Prognosegüte steigern.
Towards a rapid assessment of highway slope disasters by using multidisciplinary techniques
Authors: Weng Meng-Chia , Lin Cheng-Han , Shiu Wen-Jie , Chao Wei-An , Chiu Chia-Chi , Lee Ching-Fang , Huang Wei-Kai , Yang Che-Ming 
Published: January 2022

AbstractMega-earthquakes and extreme climate events accompanied by intrinsic fragile geology lead to numerous landslides along mountain highways in Taiwan, causing enormous life and economic losses. In this study, a system for rapid slope disaster information integration and assessment is proposed with the aim of providing information on landslide occurrence, failure mechanisms, and subsequent landslide-affected areas to the highway authority rapidly. The functionality of the proposed system is deployed into three units: (1) geohazard rapid report (GeoPORT I), (2) multidisciplinary geological survey report (GeoPORT II), and (3) site-specific landslide simulation report (GeoPORT III). After landslide occurrence, the seismology-based monitoring network rapidly provides the initial slope disaster information, including preliminary location, event magnitude, earthquake activity, and source dynamics, within an hour. Within 3 days of the landslide, a multidisciplinary geological survey is conducted to collect high-precision topographical, geological, and remote-sensing data to determine the possible failure mechanism. After integrating the aforementioned information, a full-scale three-dimensional landslide simulation based on the discrete element method is performed within 10 days to reveal the failure process and to identify the areas potentially affected by subsequent disasters through scenario modeling. Overall, the proposed system can promptly provide comprehensive and objective information to relevant authorities after the event occurrence for hazard assessment. The proposed system was validated using a landslide event in the Central Cross-Island Highway of Taiwan.
A new global landslide dam database (RAGLAD) and analysis utilizing auxiliary global fluvial datasets
Authors: Wu Hang , Trigg Mark A. , Murphy William , Fuentes Raul 
Published: January 2022

AbstractTo address the current data and understanding knowledge gap in landslide dam inventories related to geomorphological parameters, a new global-scale landslide dam dataset named River Augmented Global Landslide Dams (RAGLAD) was created. RAGLAD is a collection of landslide dam records from multiple data sources published in various languages and many of these records we have been able to precisely geolocate. In total, 779 landslide dam records were compiled from 34 countries/regions. The spatial distribution, time trend, triggers, and geomorphological characteristic of the landslides and catchments where landslide dams formed are summarized. The relationships between geomorphological characteristics for landslides that form river dams are discussed and compared with those of landslides more generally. Additionally, a potential threshold for landslide dam formation is proposed, based on the relationship of landslide volume to river width. Our findings from our analysis of the value of the use of additional fluvial datasets to augment the database parameters indicate that they can be applied as a reliable supplemental data source, when the landslide dam records were accurately and precisely geolocated, although location precision in smaller river catchment areas can result in some uncertainty at this scale. This newly collected and supplemented dataset will allow the analysis and development of new relationships between landslides located near rivers and their actual propensity to block those particular rivers based on their geomorphology.
Successful application of pulsed electromagnetic fields in a patient with post-COVID-19 fatigue: a case report
Authors: Wagner Barbara , Steiner Margarete , Markovic Lovro , Crevenna Richard 
Published: January 2022

Summary
Background
Post-COVID-19 fatigue is a frequent symptom in COVID-19 survivors, which substantially limits patients to achieve full recovery and potentially restrains return to work. The previous literature has not yet reported the use of pulsed electromagnetic fields in this indication.

Methods
Over the course of 5 weeks, 10 sessions of pulsed electromagnetic field treatment with a high magnetic flux density were applied to a patient suffering from post-COVID-19 fatigue syndrome. Fatigue, work ability, quality of life as well as anxiety, depression, stress level, and resilience were evaluated using validated patient-reported outcome measures.

Results
Fatigue, work ability, quality of life, and psychological well-being improved clearly over the course of the treatment and showed stable results 6 weeks later.

Conclusion
The use of pulsed electromagnetic field therapy with a device that allows sufficient penetration of the body tissue might be a promising physical modality to manage post-COVID-19 fatigue syndrome, which could reduce clinical and economic health consequences. Clinical sham-controlled studies are needed to evaluate the effect of pulsed electromagnetic fields in this indication.
Prognostic implications of impaired longitudinal left ventricular systolic function assessed by tissue Doppler imaging prior to transcatheter aortic valve implantation for severe aortic stenosis
Authors: Gallone Guglielmo , Bruno Francesco , Trenkwalder Teresa , D’Ascenzo Fabrizio , Islas Fabian , Leone Pier Pasquale , Nicol Philipp , Pellegrini Costanza , Incaminato Enrico , Jimenez-Quevedo Pilar , Alvarez-Covarrubias Hector Alfonso , Bragato Renato , Andreis Alessandro , Salizzoni Stefano , Rinaldi Mauro , Kastrati Adnan , Conrotto Federico , Joner Michael , Stefanini Giulio , Nombela-Franco Luis , Xhepa Erion , Escaned Javier , De Ferrari Gaetano M. 
Published: January 2022

AbstractChange in longitudinal left ventricular (LV) systolic function serves as an early marker of the deleterious effect of aortic stenosis (AS) and other cardiac comorbidities on cardiac function. We explored the prognostic value of tissue Doppler imaging (TDI)-derived longitudinal LV systolic function, defined by the peak systolic average of lateral and septal mitral annular velocities (average S’) among symptomatic patients with severe AS undergoing transcatheter aortic valve implantation (TAVI). 297 consecutive patients with severe AS undergoing TAVI at three european centers with available average S’ at preprocedural echocardiography were retrospectively included. The primary endpoint was the Kaplan Meier estimate of all-cause mortality. After a median 18 months (IQR 12–18) follow-up, 36 (12.1%) patients had died. Average S’ was associated with all-cause mortality (per 1 cm/sec decrease: HR 1.29, 95%CI 1.03–1.60, p = 0.025), the cut-off of 6.5 cm/sec being the most accurate. Patients with average S’ < 6.5 cm/sec (55.2%) presented characteristics of more advanced LV remodeling and functional impairment along with higher burden of cardiac comorbidities, and experienced higher all-cause mortality (17.6% vs. 7.5%, p = 0.007), also when adjusted for in-study outcome predictors (adj-HR: 2.69, 95%CI 1.22–5.93, p = 0.014). Results were consistent among patients with preserved ejection fraction, normal-flow AS, high-gradient AS and in those without LV hypertrophy. Longitudinal LV systolic function assessed by average S’ is independently associated with long-term all-cause mortality among TAVI patients. An average S’ below 6.5 cm/sec best defines clinically meaningful reduced longitudinal systolic function and may aid clinical risk stratification in these patients.
A recurrent neural network architecture to model physical activity energy expenditure in older people
Authors: Paraschiakos Stylianos , de Sá Cláudio Rebelo , Okai Jeremiah , Slagboom P. Eline , Beekman Marian , Knobbe Arno 
Published: January 2022

AbstractThrough the quantification of physical activity energy expenditure (PAEE), health care monitoring has the potential to stimulate vital and healthy ageing, inducing behavioural changes in older people and linking these to personal health gains. To be able to measure PAEE in a health care perspective, methods from wearable accelerometers have been developed, however, mainly targeted towards younger people. Since elderly subjects differ in energy requirements and range of physical activities, the current models may not be suitable for estimating PAEE among the elderly. Furthermore, currently available methods seem to be either simple but non-generalizable or require elaborate (manual) feature construction steps. Because past activities influence present PAEE, we propose a modeling approach known for its ability to model sequential data, the recurrent neural network (RNN). To train the RNN for an elderly population, we used the growing old together validation (GOTOV) dataset with 34 healthy participants of 60 years and older (mean 65 years old), performing 16 different activities. We used accelerometers placed on wrist and ankle, and measurements of energy counts by means of indirect calorimetry. After optimization, we propose an architecture consisting of an RNN with 3 GRU layers and a feedforward network combining both accelerometer and participant-level data. Our efforts included switching mean to standard deviation for down-sampling the input data and combining temporal and static data (person-specific details such as age, weight, BMI). The resulting architecture produces accurate PAEE estimations while decreasing training input and time by a factor of 10. Subsequently, compared to the state-of-the-art, it is capable to integrate longer activity data which lead to more accurate estimations of low intensity activities EE. It can thus be employed to investigate associations of PAEE with vitality parameters of older people related to metabolic and cognitive health and mental well-being.