bluuebunny/crossref_metadata_2025_split huggingface dataset:
MR Image-Based Attenuation Correction of Brain PET Imaging: Review of Literature on Machine Learning Approaches for Segmentation
Authors: Mecheter Imene , Alic Lejla , Abbod Maysam , Amira Abbes , Ji Jim 
Published: June 2020

AbstractRecent emerging hybrid technology of positron emission tomography/magnetic resonance (PET/MR) imaging has generated a great need for an accurate MR image-based PET attenuation correction. MR image segmentation, as a robust and simple method for PET attenuation correction, has been clinically adopted in commercial PET/MR scanners. The general approach in this method is to segment the MR image into different tissue types, each assigned an attenuation constant as in an X-ray CT image. Machine learning techniques such as clustering, classification and deep networks are extensively used for brain MR image segmentation. However, only limited work has been reported on using deep learning in brain PET attenuation correction. In addition, there is a lack of clinical evaluation of machine learning methods in this application. The aim of this review is to study the use of machine learning methods for MR image segmentation and its application in attenuation correction for PET brain imaging. Furthermore, challenges and future opportunities in MR image-based PET attenuation correction are discussed.
Tree mortality in the dynamics and management of uneven-aged Norway spruce stands in southern Finland
Authors: Valkonen Sauli , Aulus Giacosa Lucie , Heikkinen Juha 
Published: June 2020

AbstractThis study focused on tree mortality in spruce-dominated stands managed using the single-tree selection method in southern Finland. Together with regeneration and tree growth, mortality is one of the basic elements of the stand structure and dynamics in selection stands. The study was based on data acquired from a set of 20 permanent experimental plots monitored with repeated measurements for 20 years. The average mortality in the number of stems (N) was 4.45 trees ha−1a−1, in basal area (G) 0.07 m2 ha−1a−1, and in stemwood volume (V) 0.56 m3 ha−1a−1. In relative terms it was 0.50% of N, 0.30% of G and 0.27% of V, respectively. Wind and snow were the most common causes of mortality, while deaths by biotic causes (mammals, insects, pathogens) were extremely rare. Some 6–10% of the total loss in the number of stems and volume was attributable to the loss or removal of trees that sustained serious damage in harvesting. Most of the mortality occurred in the smallest diameter classes of up to 20 cm. Such a high mortality among small trees can have an adverse influence on the sustainability of selection structures if not successfully checked in harvesting and management.
Double Quasi-Poisson Brackets: Fusion and New Examples
Authors: Fairon Maxime 
Published: June 2020

AbstractWe exhibit new examples of double quasi-Poisson brackets, based on some classification results and the method of fusion. This method was introduced by Van den Bergh for a large class of double quasi-Poisson brackets which are said differential, and our main result is that it can be extended to arbitrary double quasi-Poisson brackets. We also provide an alternative construction for the double quasi-Poisson brackets of Van den Bergh associated to quivers, and of Massuyeau–Turaev associated to the fundamental groups of surfaces.
Students’ knowledge of emerging technology and sustainability through a design activity in technology education
Authors: Lind Johan , Pelger Susanne , Jakobsson Anders 
Published: June 2020

AbstractThe purpose of this study is to explore whether, and if so how, a design activity could encourage students to express and develop knowledge on emerging technology in relation to issues about sustainability. Several researchers have asserted that, in today’s technologically dependent society, it is important to be able to control technology and make informed decisions connected to technology. Design activities could make a significant contribution to technology education while students are developing their knowledge about technology. Thus, the present study aims to analyze students’ verbal interactions as they work in a design project, which includes designing a model of a house, regarding their ability to develop technological literacy with the support of a physical model. The study is based on several small-group interactions that were recorded, transcribed, analyzed, and discussed. This research project was conducted as an observation of technology education in a Swedish compulsory school. The students (aged 13–14) negotiated and shared knowledge about technology as they interacted with their fellow students. The results indicate that, in a relatively large number of situations, the students expressed knowledge about emerging technology and adopted a sustainability perspective while working in a design activity, and thereby, successively developed technological literacy. This meant that the students were able to integrate knowledge on emerging technology like graphene, nanotechnology, and algae batteries in their models. Furthermore, the results indicate that, during technical development work, students were able to develop reasoning, communication, and collaboration skills.
Risk Taking by Adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD): a Behavioral and Psychophysiological Investigation of Peer Influence
Authors: Dekkers Tycho J. , Popma Arne , Sonuga-Barke Edmund J.S. , Oldenhof Helena , Bexkens Anika , Jansen Brenda R. J. , Huizenga Hilde M. 
Published: June 2020

AbstractAdolescents with ADHD demonstrate increased risk-taking behavior (RTB) like substance abuse and dangerous traffic conduct. RTB in adolescence is more likely under peer influence. The current investigation (1) tests the hypothesis that adolescents with ADHD are particularly susceptible to such influence and (2) tests whether groups differed in autonomic reactivity to peer influence. Adolescent boys between 12 and 19 years with (n = 81) and without (n = 99) ADHD performed the Balloon Analogue Risk Task twice. In the peer condition, a highly credible virtual peer manipulation that encouraged risk taking was added, in the solo condition this was absent. Autonomic reactivity was indexed by heart rate (HR), pre-ejection period (PEP) and respiratory sinus arrhythmia (RSA).Alladolescents engaged in more risk taking in the peer condition relative to solo condition. Autonomic differences between groups were only found on PEP: a stronger sympathetic response to peer influence was observed in typically developing adolescents relative to adolescents with ADHD. Increased physiological stress (as indexed by PEP) in the peer relative to the solo condition predicted peer-induced risk taking in all adolescents. We conclude that susceptibility to peer influence is not exaggerated in ADHD but rather reflects a general tendency of adolescents. As adolescents experiencing peer influence as stressful are most susceptible to peer influence, we suggest that increasing resistance to peer influence may be an important treatment aim for these adolescents specifically.
Revisiting afro-alpine Lake Garba Guracha in the Bale Mountains of Ethiopia: rationale, chronology, geochemistry, and paleoenvironmental implications
Authors: Bittner L. , Bliedtner M. , Grady D. , Gil-Romera G. , Martin-Jones C. , Lemma B. , Mekonnen B. , Lamb H. F. , Yang H. , Glaser B. , Szidat S. , Salazar G. , Rose N. L. , Opgenoorth L. , Miehe G. , Zech W. , Zech M. 
Published: June 2020

AbstractPrevious paleolimnological studies demonstrated that the sediments of Garba Guracha, situated at 3950 m asl in the afro-alpine zone of the Bale Mountains of Ethiopia, provide a complete Late Glacial and Holocene paleoclimate and environmental archive. We revisited Garba Guracha in order to retrieve new sediment cores and to apply new environmental proxies, e.g. charcoal, diatoms, biomarkers, and stable isotopes. Our chronology is established using 210Pb dating and radiocarbon dating of bulk sedimentary organic matter, bulk n-alkanes, and charcoal. Although bedrock was not reached during coring, basal ages confirm that sedimentation started at the earliest ~ 16 cal kyr BP. The absence of a systematic age offset for the n-alkanes suggests that “pre-aging” is not a prominent issue in this lake, which is characterised by a very small afro-alpine catchment. X-ray fluorescence scans and total organic carbon contents show a prominent transition from minerogenic to organic-rich sediments around 11 cal kyr BP coinciding with the Holocene onset. While an unambiguous terrestrial versus aquatic source identification seems challenging, the n-alkane-based Paq proxy, TOC/N ratios, δ13C values, and the sugar biomarker patterns suggest a predominantly autochthonous organic matter source. Supraregional climate events, such as the African Humid Period, the Younger Dryas (YD), a 6.5 cal kyr BP short drying event, and the 4.2 cal kyr BP transition to overall drier climate are recorded in our archive. The Garba Guracha record suggests that northern hemisphere forcings played a role in the Eastern African highland paleoclimate.
A decomposition heuristic for rotational workforce scheduling
Authors: Becker Tristan 
Published: June 2020

AbstractIn rotational workforce planning, a schedule is constructed from a sequence of work and rest periods. Each employee starts at a different part of the schedule, and after a certain amount of time, the schedule repeats. The length of the schedule increases with a higher number of employees. At the same time, various constraints on work sequences and days off have to be considered. For a large number of employees, it is difficult to construct a schedule that meets the requirements. It is important to ensure low solution times independently of the problem instance characteristics. In this work, a novel decomposition approach for rotational shift scheduling is proposed. The decomposition exploits the fact that most constraints in rotational workforce scheduling are imposed on the work shift sequence. By considering a fixed set of blocks to cover the demand, the problem complexity can be greatly reduced. Given a fixed set of blocks, we propose a network model that determines whether a feasible sequence of shift blocks exists. The decomposition approach is applied to the problem structure of the Rotating Workforce Scheduling Problem but may be extended to different problem structures. In a computational study, the decomposition approach is compared to a mathematical formulation and previous exact and heuristic approaches. Computational results show that the decomposition approach greatly outperforms previous heuristics on the standard benchmarks.
A systematic review of pharmacist input to metabolic syndrome screening, management and prevention
Authors: Al AdAwi Rana Moustafa , Stewart Derek , Ryan Cristin , Tonna Antonella Pia 
Published: June 2020

AbstractBackground Metabolic syndrome is a cluster of factors that increase the risk of cardiovascular disease and include: diabetes and prediabetes, abdominal obesity, elevated triglycerides, low high-density lipoprotein cholesterol and high blood-pressure. However, the role of the pharmacist in the metabolic syndrome has not yet been fully explored. Aim of the review This systematic review aimed to critically appraise, synthesise, and present the available evidence on pharmacists’ input to the screening, prevention and management of metabolic syndrome. Method The final protocol was based on the “Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P)”. Studies published in English from January 2008 to March 2020 reporting any pharmacist activities in the screening, prevention or management of metabolic syndrome were included. Databases searched were Medline, Cumulative Index to Nursing and Allied Health Literature, International Pharmaceutical Abstracts, Cochrane and Google Scholar. Studies were assessed for quality by two researchers, data extracted and findings synthesised using a narrative approach. Results Of the 39,430 titles reviewed, ten studies were included (four were randomised controlled trials). Most studies focused on pharmacist input to metabolic syndrome screening and management. Screening largely involved communicating metabolic parameters to physicians. Management of metabolic syndrome described pharmacists collaborating with members of the multidisciplinary team. A positive impact was reported in all studies, including achieving metabolic syndrome parameter goals, reverting to a non-metabolic syndrome status and, improved medication adherence. The populations studied were paediatrics with risk factors, adults with comorbidities and psychiatric patients. Integration of the pharmacist within the multidisciplinary team, an easy referral process and accessibility of service were potential facilitators. Inadequate funding was the key barrier. Conclusion The studies describing pharmacist input in metabolic syndrome provide limited evidence of positive outcomes from screening and management as part of collaborative practice. Further work is required to provide more robust evidence of effectiveness and cost-effectiveness while considering key barriers.
Disability: a justice-based account
Authors: Begon Jessica 
Published: June 2020

AbstractMost people have a clear sense of what they mean by disability, and have little trouble identifying conditions they consider disabling. Yet providing a clear and consistent definition of disability is far from straightforward. Standardly, disability is understood as the restriction in our abilities to perform tasks, as a result of an impairment of normal physical or cognitive human functioning (in combination with our social, political, and environmental context, and our resource share). However,which inabilities matter? We are all restricted by our bodies, and are all incapable of performing some tasks, but most of these inabilities are not considered disabilities. If, then, we are to avoid the category of disability becoming overly broad—and thus politically and practically useless—we need some way of picking out the specific inabilities that are disabling. I argue that our answer should be informed by an account of the opportunities individuals are entitled to be able to perform as a matter of justice. Thus, to be disabled is to havetheseopportunities restricted, and not to deviate from the species norm or lack any ability that might improve our well-being.
The sharing economy and the job market: the case of ride-hailing drivers in Chile
Authors: Fielbaum Andrés , Tirachini Alejandro 
Published: June 2020

AbstractRide-hailing (ridesourcing) companies such as Uber, Lyft, and Didi Chuxing have been a disruptive force in the urban mobility landscape around the world during the past decade. In this paper, we analyse the working conditions, earnings, and job satisfaction of ride-hailing drivers. We begin by discussing the regulatory, labour, financial, and urban mobility effects of ride-hailing companies. Then, we present the results of a self-administered survey to ride-hailing drivers in Chile, which is complemented with the use of online tools for the estimation of driving earnings. Our findings show that the flexibility to choose work times is the most appreciated attribute of this job, even though most drivers follow a somewhat fixed routine each week. By contrast, the level of transparency with which ride-hailing apps determine driver pay is the attribute with the lowest satisfaction score. A large number of respondents drive for long daily and weekly periods, which is a health and safety hazard. Current drivers are not concerned about the future deployment of driverless vehicles for on-demand mobility services. Ordered probit models for job satisfaction show that ride-hailing was better evaluated by drivers who use it as a complement to another part-time job, by those who earn more money per week, and by those who have not experienced undesirable situations while working, such as harassment or traffic crashes.
DVT incidence and risk factors in critically ill patients with COVID-19
Authors: Chen Shujing , Zhang Dingyu , Zheng Tianqi , Yu Yongfu , Jiang Jinjun 
Published: June 2020

AbstractFew data are available on the incidence of deep vein thrombosis (DVT) in critically ill COVID-19 with thrombosis prophylaxis. This study retrospectively included 88 patients in the ICU with critically ill COVID-19 at Jinyintan Hospital in Wuhan, China. All patients underwent compression ultrasonography for identifying DVT. Firth logistic regression was used to examine the association of DVT with sex, age, hypoalbuminemia, D-dimer, and SOFA score. The median (interquartile range [IQR]) age and SOFA score of 88 patients were 63 (55–71) years old and 5 (4–6), respectively. Despite all patients receiving guideline-recommended low-molecular-weight heparin (LMWH) thromboprophylaxis, the incidence of DVT was 46% (95% CI 35–56%). Proximal DVT was recognized in 9% (95% CI 3–15%) of the patients, while 46% (95% CI 35–56%) of patients had distal DVT. All of the proximal DVT combined with distal DVT. Risk factors of DVT extension occurred in all distal DVT patients. As Padua score ≥ 4 or IMPROVE score ≥ 2, 53% and 46% of patients had DVT, respectively. Mortality was higher in patients with acute DVT (30%) compared with non-DVT (17%), but did not reach statistical significance. Hypoalbuminemia (odds ratio [OR], 0.17; 95% CI 0.06–0.05, P = 0.001), higher SOFA score (OR per IQR, 2.07; 95% CI 1.38–3.39, P = 0.001), and elevated D-dimer (OR per IQR, 1.04; 95% CI 1.03–1.84, P = 0.029) were significant DVT risk factors in multivariable analyses. High incidence of DVT was identified in patients with critically ill COVID-19, despite the use of guideline-recommended pharmacologic thromboprophylaxis. The presence of hypoalbuminemia, higher SOFA score, and elevated D-dimer were significantly independent risk factors of DVT. More effective VTE prevention and management strategies may need to be addressed.
Betriebliche Gesundheitsförderung in der Pflege
Authors: Mojtahedzadeh Natascha , Neumann Felix Alexander , Rohwer Elisabeth , Augustin Matthias , Zyriax Birgit-Christiane , Harth Volker , Mache Stefanie 
Published: June 2020

Zusammenfassung
Hintergrund
In der Pflegebranche nehmen Arbeitsunfähigkeitstage durch verschiedene Fehlbelastungen zu, welches die Relevanz der Betrieblichen Gesundheitsförderung (BGF) hervorhebt.

Ziel der Arbeit
Der Artikel soll die Thematik der BGF in der Pflege beleuchten und zudem eine Übersicht von bestehenden betrieblichen Gesundheitsförderungsmaßnahmen im Setting Pflege bieten.

Material und Methoden
In einer explorativen Literaturrecherche werden bisher verfügbare Erkenntnisse aus der BGF in der Pflege recherchiert und zusammengefasst. Aus diesen Forschungserkenntnissen werden Maßnahmenvorschläge für die Pflege-BGF abgeleitet. Die Vorschläge sollten aktualisiert werden, wenn derzeit laufende arbeitspsychologische Studien neue Erkenntnisse hervorgebracht haben.

Ergebnisse
Bestehende Interventionen in der Pflegebranche, welche beispielsweise Achtsamkeitstrainings, Maßnahmen zur Stress‑/Tabakkonsumreduzierung sowie die Förderung gesunder Ernährungsweise und körperlichen Aktivität beinhalten, werden dargestellt.

Diskussion
Studienergebnisse zeigen, dass Interventionen zur Stressreduzierung aus der stationären Pflege effektiv das Stresserleben der Pflegekräfte senken konnten. Web-basierte Interventionen scheinen darüber hinaus für das ambulante Pflegesetting als erstrebenswert. Mögliche Herausforderungen, wie fehlende Fachkenntnisse und -kräfte, für die BGF-Umsetzung werden diskutiert.
Retention Management im Krankenhaus – Arbeiten im Spannungsfeld der Gesundheitsversorgung
Authors: Kempny Christian , Breimann Christian 
Published: June 2020

ZusammenfassungDieser Beitrag der Zeitschrift „Gruppe. Interaktion. Organisation. (GIO)“ beschreibt Herausforderungen für das Retention Management in Krankenhäusern und belegt diese mit Daten aus einer empirischen Studie. Die Arbeit in einem Krankenhaus beschreibt einen besonderen Arbeitskosmos, in dem nicht nur die Motive der Mitarbeiter, sondern auch die besondere Stellung des Patienten, die Organisationsform „Krankenhaus“ wesentlich von anderen Organisationen im wirtschaftlichen Kontext abgrenzt. Dennoch müssen sich auch Krankenhäuser dem Fachkräftemangel und der demografischen Entwicklung in Deutschland stellen. Um ein funktionierendes Retention Management in ein Krankenhaus zu integrieren und den Problemen vorzubeugen, müssen zunächst die drei Spannungsfelder „Wirtschaftlichkeit“, „Interkulturalität“ und „Stress“ betrachtet werden. Diese stellen Mitarbeiter in einem Krankenhaus immer wieder, im ohnehin arbeitsintensiven Alltag, vor große Herausforderungen. Es konnten verschiedene Handlungskonzepte entwickelt werden, welche es der Organisation „Krankenhaus“ ermöglicht, gegen die Spannungsfelder zu arbeiten und Mitarbeiter langfristig an das eigene Unternehmen zu binden.
Stability analysis and flight control design of the winged reusable launch vehicle ReFEx
Authors: Kiehn Daniel 
Published: June 2020

AbstractThe German Aerospace Center (DLR) is currently studying different technologies for reusable launch vehicles (RLVs) to evaluate and compare their benefits. The project CALLISTO (Cooperative Action Leading to Launcher Innovation in Stage Toss-back Operations) investigates a VTVL (vertical takeoff, vertical landing) concept. In the DLR project ReFEx (reusability flight experiment), in the context of which this paper is presented, a winged VTHL (vertical takeoff, horizontal landing) concept is investigated to develop the key technologies for future winged RLV applications, culminating in a flight experiment to demonstrate the capability of controlled autonomous return flight from supersonic to subsonic speeds. In this paper, analysis of stability and controllability is used on a three-dimensional envelope of points to derive a suitable flight corridor for the re-entry. Second, a controller concept based on inversion of the rotational equations of motion is derived. The validity of the presented controller concept is shown on a preliminary level via comparison of open-loop and closed-loop dynamics at two representative flight points and a time simulation which includes a segment of the planned mission.
Pedagogical dilemmas in dynamic assessment situations: perspectives on video data from simulator-based competence tests
Authors: Sellberg Charlott 
Published: June 2020

AbstractThis study investigates navigation instructors’ explanations of dynamic assessment practices during simulator-based competency tests, adopting a video-stimulated recall method. Episodes of authentic video materials from simulator-based competency tests are selected and subjected to interaction analysis. In the next step, the episodes are used for conducting stimulated recall interviews with navigation instructors (n = 11) in two focus groups. The results reveal the dynamic nature of assessing competence as well as how instructors participating in focus groups identified and critically discussed a variety of pedagogical dilemmas related to these dynamics. These are related to aspects that relate to what constitutes a valid exam question, how to assess students’ responses, and consistency and fairness of competence tests. In particular, the results indicate the complexity of conducting valid and reliable assessments of knowledge-in-action in situ as well as how thoughtful scenario designs could reduce inconsistencies and unequal treatment of students. The results also highlight how a repeated and collaborative viewing of videos was helpful for instructors to identify potential problems in the dynamic assessment situations they viewed. The implications of the results highlight the need for conducting high-stake assessments for maritime certificates based only on observable behavior and video records of competence tests rather than during ongoing simulator tests. Lastly, the need for continuous and structured pedagogical development of instructors is identified in order to support their complex work of training and assessing competence.