bluuebunny/crossref_metadata_2025 huggingface dataset:
Versorgung älterer Patienten durch Gemeindenotfallsanitäter
Authors: Seeger Insa , Günther Ulf , Schmiemann Guido , Hoffmann Falk
Published: September 2021

Hintergrund

Notaufnahmen und Rettungsdienste werden zunehmend durch nicht vital bedrohlich erkrankte Patienten belastet. Ein großer Anteil der Rettungsdiensteinsätze entfällt auf ältere Menschen. Um eine unnötige Disponierung höherwertiger Rettungsmittel zu reduzieren, wurde das Modellprojekt Gemeindenotfallsanitäter (G-NFS) entwickelt.

Ziel der Arbeit

Ziel dieser Arbeit war es herauszufinden, ob sich spezifische Einsatzschwerpunkte des G‑NFS in der Versorgung älterer Menschen in häuslicher Umgebung und im Pflegeheim zeigen.

Material und Methoden

Es handelt sich um eine retrospektive Beobachtungsstudie auf Basis der Einsatzdokumentation vom 01.07.2019 bis zum 30.06.2020. Es wurden G‑NFS Einsätze bei älteren Menschen (≥ 65 Jahre) analysiert, unterteilt nach den Einsatzorten Pflegeheim oder Häuslichkeit.

Ergebnisse

Es wurden 2358 Protokolle ausgewertet (Durchschnittsalter: 80,8 Jahre; 52,9 % weiblich). Vor Ort wurden 55 % der Patienten versorgt. Die durchgeführten Maßnahmen umfassten Beratungsgespräche (79,4 %), Hilfe bei Selbstmedikation (16,7 %) und Medikamentengabe (23,2 %). Auf Pflegeheimbewohner entfielen 329 (14,0 %) Einsätze. Maßnahmen in Bezug auf Urindauerkatheter wurden häufiger bei Pflegeheimbewohnern als in der Häuslichkeit durchgeführt (32,2 % bzw. 5,7 % aller Einsätze). Bei Patienten mit Katheterproblemen erfolgte im Vergleich zu anderen Einsätzen nahezu immer eine Versorgung vor Ort (84,3 % bzw. 52,2 %).

Diskussion

Durch G‑NFS können die Mehrzahl der älteren Patienten ambulant versorgt und andere Ressourcen entlastet werden. Allerdings führen G‑NFS auch Maßnahmen durch, die im Verantwortungsbereich der hausärztlichen Versorgung liegen, und gleichen somit strukturelle Defizite in der medizinisch-pflegerischen Versorgung aus.
Chirurgische Nadeln in Orthopädie und Unfallchirurgie
Authors: Dresing Klaus , Langer Martin Franz , Slongo Theddy
Published: September 2021

Für Chirurgen in der Klinik und Praxis ist der Umgang mit Nahtmaterial das „tägliche Brot“. Daher könnte man annehmen, dass die Kenntnisse dieses Materials kompetent und umfassend sind. Die tägliche Erfahrung zeigt indes ein anderes Bild. Oft sind die Kenntnisse bezüglich Nadelform, Nadelbeschaffenheit sowie Nadelgröße nur marginal und der Chirurg muss sich auf die Kenntnisse seiner OP-Pflegefachkraft verlassen. Die Wahl der Nadel ist für jeden Operationsschritt und jedes Gewebe ausschlaggebend. Die Verwendung des korrekten Nahtmaterials in Bezug auf das zu nähende Gewebe ist jedoch essenziell, einerseits hinsichtlich der Qualität der Naht, aber auch hinsichtlich der Traumatisierung des Gewebes andererseits. Je nach Gewebe sind an Nadel wie auch an Fäden verschiedene Anforderungen zu stellen respektive zu berücksichtigen. Mit diesem Beitrag sollen die wesentlichsten und grundlegendsten Kenntnisse vermittelt werden wie Einfluss der Nadelform und Dimension, Auswirkung von atraumatischen respektive traumatischen (sog. scharfe) Nadeln auf das Gewebe, die Form der Nadelspitze. Das Zusammenspiel zwischen Nadelhalter und Nadel und der Hand des Operateurs bei verschiedenen Anwendungen wird dargestellt. In diesem Beitrag wird das Hauptaugenmerk auf Nadel und Nadelhalter gelegt. In Planung ist ein Nachfolgebeitrag, der sich speziell dem Nahtmaterial widmet. Der Beitrag erhebt nicht den Anspruch auf 100 %ige Vollständigkeit, es sollen jedoch die wesentlichsten, alltäglich vorkommenden Fragen geklärt werden.
Mathematical modeling of the elastic properties of cubic crystals at small scales based on the Toupin–Mindlin anisotropic first strain gradient elasticity
Authors: Lazar Markus , Agiasofitou Eleni , Böhlke Thomas
Published: September 2021

In this work, a mathematical modeling of the elastic properties of cubic crystals with centrosymmetry at small scales by means of the Toupin–Mindlin anisotropic first strain gradient elasticity theory is presented. In this framework, two constitutive tensors are involved, a constitutive tensor of fourth-rank of the elastic constants and a constitutive tensor of sixth-rank of the gradient-elastic constants. First, $$3+11$$

3
+
11

material parameters (3 elastic and 11 gradient-elastic constants), 3 characteristic lengths and $$1+6$$

1
+
6

isotropy conditions are derived. The 11 gradient-elastic constants are given in terms of the 11 gradient-elastic constants in Voigt notation. Second, the numerical values of the obtained quantities are computed for four representative cubic materials, namely aluminum (Al), copper (Cu), iron (Fe) and tungsten (W) using an interatomic potential (MEAM). The positive definiteness of the strain energy density is examined leading to 3 necessary and sufficient conditions for the elastic constants and 7 ones for the gradient-elastic constants in Voigt notation. Moreover, 5 lattice relations as well as 8 generalized Cauchy relations for the gradient-elastic constants are derived. Furthermore, using the normalized Voigt notation, a tensor equivalent matrix representation of the two constitutive tensors is given. A generalization of the Voigt average toward the sixth-rank constitutive tensor of the gradient-elastic constants is given in order to determine isotropic gradient-elastic constants. In addition, Mindlin’s isotropic first strain gradient elasticity theory is also considered offering through comparisons a deeper understanding of the influence of the anisotropy in a crystal as well as the increased complexity of the mathematical modeling.
Anaerobic 3-methylhopanoid production by an acidophilic photosynthetic purple bacterium
Authors: Mayer Marisa H. , Parenteau Mary N. , Kempher Megan L. , Madigan Michael T. , Jahnke Linda L. , Welander Paula V.
Published: September 2021

Bacterial lipids are well-preserved in ancient rocks and certain ones have been used as indicators of specific bacterial metabolisms or environmental conditions existing at the time of rock deposition. Here we show that an anaerobic bacterium produces 3-methylhopanoids, pentacyclic lipids previously detected only in aerobic bacteria and widely used as biomarkers for methane-oxidizing bacteria. Both Rhodopila globiformis, a phototrophic purple nonsulfur bacterium isolated from an acidic warm spring in Yellowstone, and a newly isolated Rhodopila species from a geochemically similar spring in Lassen Volcanic National Park (USA), synthesized 3-methylhopanoids and a suite of related hopanoids and contained the genes encoding the necessary biosynthetic enzymes. Our results show that 3-methylhopanoids can be produced under anoxic conditions and challenges the use of 3-methylhopanoids as biomarkers of oxic conditions in ancient rocks and as prima facie evidence that methanotrophic bacteria were active when the rocks were deposited.
Lernende Entscheidungsbäume
Authors: Knuth Tobias
Published: September 2021

Entscheidungsbäume bereichern moderne künstliche Intelligenz durch vielseitige Weiterentwicklungen. Lernende Entscheidungsbäume sind seit Jahrzehnten ein tradiertes Werkzeug zur Erstellung von erklärbaren Modellen zu Klassifikation und Regression. Während moderne Trends wie Deep Learning die Aufmerksamkeit der KI-Entwicklung auf sich ziehen, werden Entscheidungsbäume kontinuierlich weiterentwickelt, in neuen Bereichen eingesetzt und mit scheinbar im Wettstreit stehenden Methoden verschmolzen. Der Artikel stellt die Funktionsweise von Entscheidungsbäumen dar und zeigt Entwicklungen der aktuellen Forschung auf.
Impact of DMEK on visual quality in patients with Fuchs’ endothelial dystrophy
Authors: Ademmer Vanessa , Agha Bishr , Shajari Mehdi , Kohnen Thomas , Schmack Ingo
Published: September 2021

Purpose

To investigate short-term (3 months follow-up) changes in visual quality following Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy (FED).

Methods

In this prospective institutional case series, 51 patients that underwent DMEK for FED were included. Assessment included the Quality of Vision (QoV) questionnaire preoperatively, at 1 month, and 3 months after surgery. Secondary outcome measures were anterior segment parameters acquired by Scheimpflug imaging, corrected distance visual acuity (CDVA), and endothelial cell density (ECD).

Results

Glare, hazy vision, blurred vision, and daily fluctuation in vision were the symptoms mostly reported preoperatively. All symptoms demonstrated a significant reduction of item scores for severity, frequency, and bothersome in the course after DMEK (P < 0.01). Glare and fluctuation in vision remained to some extent during the follow-up period (median score = 1). Preoperatively, corneal densitometry correlated moderately to weakly with severity of hazy vision (rs = 0.39; P = 0.03) and frequency (rs = 0.26; P = 0.02) as well as severity (rs = 0.27; P = 0.03) of blurry vision. CDVA and central corneal thickness (CCT) did not correlate with visual complains.

Conclusions

Following DMEK for FED, patient-reported visual symptoms assessed by the QoV questionnaire represent a useful tool providing valuable information on the impact of DMEK on visual quality that cannot be directly estimated by morphological parameters and visual acuity only.
Factors affecting the oral health of inpatients with advanced cancer in palliative care
Authors: Furuya Junichi , Suzuki Hiroyuki , Hidaka Rena , Koshitani Nei , Motomatsu Yuko , Kabasawa Yuji , Tohara Haruka , Sato Yuji , Minakuchi Shunsuke , Miyake Satoshi
Published: September 2021

Purpose

Patients with terminal cancer undergoing multidisciplinary palliative care often have oral health problems, but these details are still unclear. This cross-sectional study aimed to elucidate the oral health of patients with terminal-stage cancer who are inpatient recipients of acute-phase palliative care, and to unveil the factors affecting their oral health.

Methods

Participants were 121 patients with terminal-stage cancer (68 males, 53 females, mean age: 73.6 ± 11.1 years) and oral health complaints. They received palliative care at Tokyo Medical and Dental University Medical Hospital between April 2017 and August 2019. Their demographic and medical details were extracted, retrospectively, from their medical records, and their oral health status, such as the number of natural teeth, removable denture usage, Oral Health Assessment Tool (OHAT), and Dysphagia Severity Scale, were evaluated. All outcomes were assessed by a dentist from the palliative care team.

Results

The problems with soft tissue, saliva, and oral cleanliness were observed. The absence of posterior occlusal support was common, and the use of removable dentures was often inadequate. In contrast, swallowing function was relatively well-conserved and 46.3% of the participants were capable of nutrition intake solely by mouth. Multiple regression analysis revealed a significant association between total OHAT score and age, consciousness level, prognostic level, and method of nutritional intake.

Conclusion

The results revealed that the oral health of terminal cancer patients under palliative care declined despite receiving routine oral care from nurses, and suggest the importance of including dental professionals in multidisciplinary palliative care.
Existence and nonexistence in the liquid drop model
Authors: Frank Rupert L. , Nam Phan Thành
Published: September 2021

We revisit the liquid drop model with a general Riesz potential. Our new result is the existence of minimizers for the conjectured optimal range of parameters. We also prove a conditional uniqueness of minimizers and a nonexistence result for heavy nuclei.
Fast Evaluation of Caprock Strength Sensitivity to Different CO2 Solutions Using Small Sample Techniques
Authors: Edvardsen Laura , Bhuiyan Mohammad H. , Cerasi Pierre R. , Bjørge Ruben
Published: September 2021

The Draupne shale is a rock formation functioning as overburden for gas reservoirs in the Norwegian Sea and potentially as caprock for future CO2 storage locations as well. In this paper, the Draupne shale was exposed to several fluids: CO2 gas, supercritical CO2, CO2 gas dissolved in brine, supercritical CO2 dissolved in brine, as well as brine and dry air. The motivation for the exposure tests was to investigate whether injected CO2 in a reservoir coming into contact with the caprock could change the caprock’s mechanical properties and increase the risk for leakage of the stored CO2. In addition, a systematic exposure study will provide more insight into the various processes susceptible of altering the shale’s shear strength and acoustic velocity, such as clay hydration, mineral dissolution, and capillary forces. Due to the low permeability of the shale, experiments were conducted on mm-sized disk samples, reducing fluid diffusion into the shale, and allowing for many repeated tests on disks close by in the original core. The punch method, where a small circle is punched out of the shale, was used to assess shear strength, while continuous wave technique was used to assess ultrasonic velocity. Results show that the shale is not noticeably sensitive to CO2, in the sense that no additional weakening is observed in the presence of CO2 as compared to brine exposure. This last weakening effect is probably due to poor matching between pore fluid salinity and exposure brine strength.
Can the crowd judge truthfulness? A longitudinal study on recent misinformation about COVID-19
Authors: Roitero Kevin , Soprano Michael , Portelli Beatrice , De Luise Massimiliano , Spina Damiano , Mea Vincenzo Della , Serra Giuseppe , Mizzaro Stefano , Demartini Gianluca
Published: September 2021

Recently, the misinformation problem has been addressed with a crowdsourcing-based approach: to assess the truthfulness of a statement, instead of relying on a few experts, a crowd of non-expert is exploited. We study whether crowdsourcing is an effective and reliable method to assess truthfulness during a pandemic, targeting statements related to COVID-19, thus addressing (mis)information that is both related to a sensitive and personal issue and very recent as compared to when the judgment is done. In our experiments, crowd workers are asked to assess the truthfulness of statements, and to provide evidence for the assessments. Besides showing that the crowd is able to accurately judge the truthfulness of the statements, we report results on workers’ behavior, agreement among workers, effect of aggregation functions, of scales transformations, and of workers background and bias. We perform a longitudinal study by re-launching the task multiple times with both novice and experienced workers, deriving important insights on how the behavior and quality change over time. Our results show that workers are able to detect and objectively categorize online (mis)information related to COVID-19; both crowdsourced and expert judgments can be transformed and aggregated to improve quality; worker background and other signals (e.g., source of information, behavior) impact the quality of the data. The longitudinal study demonstrates that the time-span has a major effect on the quality of the judgments, for both novice and experienced workers. Finally, we provide an extensive failure analysis of the statements misjudged by the crowd-workers.
Notes on {a,b,c}-Modular Matrices
Authors: Glanzer Christoph , Stallknecht Ingo , Weismantel Robert
Published: September 2021

Let $A \in \mathbb {Z}^{m \times n}$
A
∈

ℤ

m
×
n

be an integral matrix and a, b, $c \in \mathbb {Z}$
c
∈
ℤ
satisfy a ≥ b ≥ c ≥ 0. The question is to recognize whether A is {a,b,c}-modular, i.e., whether the set of n × n subdeterminants of A in absolute value is {a,b,c}. We will succeed in solving this problem in polynomial time unless A possesses a duplicative relation, that is, A has nonzero n × n subdeterminants k1 and k2 satisfying 2 ⋅|k1| = |k2|. This is an extension of the well-known recognition algorithm for totally unimodular matrices. As a consequence of our analysis, we present a polynomial time algorithm to solve integer programs in standard form over {a,b,c}-modular constraint matrices for any constants a, b and c.
Manufacture of High-Performance Tidal Turbine Blades Using Advanced Composite Manufacturing Technologies
Authors: Finnegan William , Allen Ronan , Glennon Conor , Maguire James , Flanagan Michael , Flanagan Tomas
Published: September 2021

After wind and solar energy, tidal energy presents the most prominent opportunity for generating energy from renewable sources. However, due to the harsh environment that tidal turbines are deployed in, a number of design and manufacture challenges are presented to engineers. As a consequence of the harsh environment, the loadings on the turbine blades are much greater than that on wind turbine blades and, therefore, require advanced solutions to be able to survive in this environment. In order to avoid issues with corrosion, tidal turbine blades are mainly manufactured from fibre reinforced polymer composite material. As a result, the main design and manufacture challenges are related to the main structural aspects of the blade, which are the spar and root, and the connection between the blade and the turbine hub. Therefore, in this paper, a range of advanced manufacturing technologies for producing a 1 MW tidal turbine blade are developed. The main novelty in this study comes with the challenges that are overcome due to the size of the blade, resulting in thickness composite sections (> 130 mm in places), the fast changes in geometry over a short length that isn’t the case for wind blades and the required durability of the material in the marine environment. These advances aim to increase the likelihood of survival of tidal turbine blades in operation for a design life of 20 + years.
Are citizen juries and assemblies on climate change driving democratic climate policymaking? An exploration of two case studies in the UK
Authors: Wells Rebecca , Howarth Candice , Brand-Correa Lina I.
Published: September 2021

In light of increasing pressure to deliver climate action targets and the growing role of citizens in raising the importance of the issue, deliberative democratic processes (e.g. citizen juries and citizen assemblies) on climate change are increasingly being used to provide a voice to citizens in climate change decision-making. Through a comparative case study of two processes that ran in the UK in 2019 (the Leeds Climate Change Citizens’ Jury and the Oxford Citizens’ Assembly on Climate Change), this paper investigates how far citizen assemblies and juries are increasing citizen engagement on climate change and creating more citizen-centred climate policymaking. Interviews were conducted with policymakers, councillors, professional facilitators and others involved in running these processes to assess motivations for conducting these, their structure and the impact and influence they had. The findings suggest the impact of these processes is not uniform: they have an indirect impact on policy making by creating momentum around climate action and supporting the introduction of pre-planned or pre-existing policies rather than a direct impact by truly being citizen-centred policy making processes or conducive to new climate policy. We conclude with reflections on how these processes give elected representatives a public mandate on climate change, that they help to identify more nuanced and in-depth public opinions in a fair and informed way, yet it can be challenging to embed citizen juries and assemblies in wider democratic processes.
Biodegradable, metal-chelating compounds as alternatives to EDTA for cultivation of marine microalgae
Authors: Sauvage Justine , Wikfors Gary H. , Sabbe Koen , Nevejan Nancy , Goderis Steven , Claeys Philippe , Li Xiaoxu , Joyce Alyssa
Published: September 2021

Iron (Fe) is an essential nutrient for microalgal metabolism. The low solubility of Fe in oxic aquatic environments can be a growth-limiting factor for phytoplankton. Synthetic chelating agents, such as ethylenediaminetetraacetic acid (EDTA), are used widely to maintain Fe in solution for microalgal cultivation. The non-biodegradable nature of EDTA, combined with sub-optimal bioavailability of Fe-EDTA complexes to microalgae, indicates opportunity to improve microalgal cultivation practices that amplify production efficiency and environmental compatibility. In the present study, the effects of four organic chelating ligands known to form readily bioavailable organic complexes with Fe in natural aquatic environments were investigated in relation to growth and biochemical composition of two marine microalgae grown as live feeds in shellfish hatcheries (Chaetoceros calcitransandTisochrysis lutea). Three saccharides, alginic acid (ALG), glucuronic acid (GLU), and dextran (DEX), as well as the siderophore desferrioxamine B (DFB), were compared to EDTA. Organic ligands characterized by weaker binding capacity for cationic metals (i.e., ALG, GLU, DEX) significantly improved microalgal growth and yields in laboratory-scale static batch cultures or bubbled photobioreactors. Maximal microalgal growth enhancement relative to the control (e.g., EDTA) was recorded for GLU, followed by ALG, with 20–35% increase in specific growth rate in the early stages of culture development ofC. calcitransandT. lutea. Substitution of EDTA with GLU resulted in a 27% increase in cellular omega 3-polyunsaturetd fatty acid content ofC. calcitransand doubled final cell yields. Enhanced microalgal culture performance is likely associated with increased intracellular Fe uptake efficiency combined with heterotrophic growth stimulated by the organic ligands. Based upon these results, we propose that replacement of EDTA with one of these organic metal-chelating ligands is an effective and easily implementable strategy to enhance the environmental compatibility of microalgal cultivation practices while also maximizing algal growth and enhancing the nutritional quality of marine microalgal species commonly cultured for live-feed applications in aquaculture.
The Mean Single Molecule Rate (mSMR) in the Analysis of Fluorescence Fluctuations: Measurements on DNA Mixtures of Defined Composition
Authors: Sparrenberg Lorenz T. , Greiner Benjamin , Mathis Harald P.
Published: September 2021

We present a method for the evaluation of fluorescence fluctuations on the basis of Mandel’s Q parameter, using sampling time-dependent factorial cumulants. By relating the Q parameter to the sampling time, we obtain the mean single molecule rate (mSMR), an easy to interpret expression that provides both brightness and diffusion information. The model is suitable for the widely used confocal setups with single photon excitation and a single detection channel. We present a way to correct the mSMR for afterpulsing, dead time and background noise. To account for photokinetic effects at short sampling times, we expand the model by a simple on/off isomerization term, which is similar to the well-known triplet model. The functionality of the mSMR is shown using Monte Carlo simulations. The correction mechanisms and the experimental applicability of the model are then demonstrated by DNA measurements of defined composition. By systematically analyzing DNA mixtures, we can show that at large sampling times, the mSMR correctly describes the single molecule brightness rates and the diffusive properties of DNA molecules. At short sampling times, the photokinetic effects of isomerization are accurately described by the mSMR model. Since additionally the mSMR can easily be corrected for measurement artefacts such as detector dead time, afterpulsing and background noise, this is a valuable advantage over the standard method of fluorescence correlation spectroscopy.
Spanish Science Teacher Educators’ Preparation, Experiences, and Views About Nature of Science in Science Education
Authors: García-Carmona Antonio
Published: September 2021

The obstacles and difficulties that science teachers face when teaching the nature of science (NOS) are well-known. Nonetheless, little is known of what science teacher educators (STEs) know, do, and think about this issue. Thus, a study with 142 Spanish STEs was conducted. This was aimed at analysing (i) what preparation the STEs have to teach NOS, (ii) what educational experience they have about NOS, (iii) what importance they give to NOS in their training plans, (iv) when NOS should be taught, (v) how to integrate NOS in science education, (vi) how to teach NOS, (vii) what to teach about NOS, and (viii) the influences interconnecting the STEs’ preparation, experience, and opinions regarding NOS teaching. Among the results, it was found that most STEs state that they have ample knowledge of NOS, are well prepared pedagogically to teach it, and have extensive experience in teaching it. However, there was some mismatch between their stated preparation and their experience teaching NOS. In addition, they think that NOS should be taught from early ages and be treated as cross-cutting content in science education. They also consider that, when teaching NOS, an implicit approach is just as effective as an explicit-reflective one. As for their selection of NOS content to include, they are fundamentally divided into two groups — those who select only epistemic aspects of NOS and those who select a balanced proportion of both epistemic and non-epistemic aspects. The limitations of the study are reported along with the issues that require further research.
Material Characterization and Modeling for Finite Element Simulation of Press Hardening with AISI 420C
Authors: Behrens Bernd-Arno , Rosenbusch Daniel , Wester Hendrik , Stockburger Eugen
Published: September 2021

The process of press hardening is gaining importance in view of the increasing demand for weight reduction combined with higher crash safety in cars. An alternative to the established manganese-boron steel 22MnB5 is hot-formed martensitic chromium steels such as AISI 420C. Strengths of 1850 MPa and elongations of 12% are possible, exceeding those of 22MnB5. In industrial manufacturing, FE-simulation is commonly used in order to design car body parts cost-efficiently. Therefore, the characterization and the modeling of AISI 420C regarding flow stress, phase transformations as well as failure behavior are presented in this paper. Temperature-depended flow curves are determined, showing the low flow stress and hardening behavior at temperatures around 1000 °C. Cooling experiments are carried out, and a continuous cooling diagram is generated. Observed phases are martensite and retained austenite for industrial relevant cooling rates above 10 K/s. In addition, tests to investigate temperature-dependent forming limit curves are performed. As expected, the highest forming limit is reached at 1050 °C and decreases with falling temperature. Finally, a simulation model of a press-hardening process chain is set up based on the material behavior characterized earlier and compared to experimental values. The forming force, phase transformation and forming limit could be calculated with good agreement to the experiment.
Enhanced aquathermolysis of extra-heavy oil by application of transition metal oxides submicro-particles in relation to steam injection processes
Authors: Zhang Xian , Che Hongchang , Liu Yongjian
Published: September 2021

In order to investigate the catalytic effects of transition metal oxides submicro-particles on aquathermolysis of Liaohe extra-heavy crude oil, the catalysts NiO, α·Fe2O3 and Co3O4 are used and evaluated during the experiments. The optimum mass fraction of the catalyst and water was determined to be 5.0 wt% and 30 wt%, respectively. The optimum reaction time for aquathermolysis was 24 h, and the optimum reaction temperature was 240 °C. The analysis results showed the heavy oil was upgraded dramatically by addition of the catalysts based upon viscosity reduction, saturate/aromatics/resins/asphaltenes analyses, elemental analysis, Fourier transform infrared spectroscopy and gas chromatography. All results show the heavy oil is in situ updated dramatically by catalytic aquathermolysis under the optimum operating conditions. A five-lump model is proposed for estimating kinetic parameters of aquathermolysis and agrees well with the experimental data.
Applying Model-Driven Engineering to Stimulate the Adoption of DevOps Processes in Small and Medium-Sized Development Organizations
Authors: Sorgalla Jonas , Wizenty Philip , Rademacher Florian , Sachweh Sabine , Zündorf Albert
Published: September 2021

Microservice architecture (MSA) denotes an increasingly popular architectural style in which business capabilities are wrapped into autonomously developable and deployable software components called microservices. Microservice applications are developed by multiple DevOps teams each owning one or more services. In this article, we explore the state of how DevOps teams in small and medium-sized organizations (SMOs) cope with MSA and how they can be supported. We show through a secondary analysis of an exploratory interview study comprising six cases, that the organizational and technological complexity resulting from MSA poses particular challenges for small and medium-sized organizations (SMOs). We apply model-driven engineering to address these challenges. As results of the second analysis, we identify the challenge areas of building and maintaining a common architectural understanding, and dealing with deployment technologies. To support DevOps teams of SMOs in coping with these challenges, we present a model-driven workflow based on LEMMA—the Language Ecosystem for Modeling Microservice Architecture. To implement the workflow, we extend LEMMA with the functionality to (i) generate models from API documentation; (ii) reference remote models owned by other teams; (iii) generate deployment specifications; and (iv) generate a visual representation of the overall architecture. We validate the model-driven workflow and our extensions to LEMMA through a case study showing that the added functionality to LEMMA can bring efficiency gains for DevOps teams. To develop best practices for applying our workflow to maximize efficiency in SMOs, we plan to conduct more empirical research in the field in the future.
The Structure of d.r.e. Degrees
Authors: Liu Yong
Published: September 2021

This dissertation is highly motivated by d.r.e. Nondensity Theorem, which is interesting in two perspectives. One is that it contrasts Sacks Density Theorem, and hence shows that the structures of r.e. degrees and d.r.e. degrees are different. The other is to investigate what other properties a maximal degree can have.

In Chapter 1, we briefly review the backgrounds of Recursion Theory which motivate the topics of this dissertation.

In Chapter 2, we introduce the notion of
$(m,n)$
-cupping degree. It is closely related to the notion of maximal d.r.e. degree. In fact, a
$(2,2)$
-cupping degree is maximal d.r.e. degree. We then prove that there exists an isolated
$(2,\omega )$
-cupping degree by combining strategies for maximality and isolation with some efforts.

Chapter 3 is part of a joint project with Steffen Lempp, Yiqun Liu, Keng Meng Ng, Cheng Peng, and Guohua Wu. In this chapter, we prove that any finite boolean algebra can be embedded into d.r.e. degrees as a final segment. We examine the proof of d.r.e. Nondensity Theorem and make developments to the technique to make it work for our theorem. The goal of the project is to see what lattice can be embedded into d.r.e. degrees as a final segment, as we observe that the technique has potential be developed further to produce other interesting results.

Abstract prepared by Yong Liu.

E-mail: liuyong0112@nju.edu.cn
Gravity–capillary multi-component wave patterns generated by a single-frequency wave-maker oscillation and subsequent resonances
Authors: Xu Chang , Perlin Marc
Published: September 2021

Cross-waves are standing waves with crests perpendicular to a wave-maker; they are subharmonic waves excited by parametric instability. The modulational and chaotic behaviours of nonlinear cross-waves have been studied widely since the 1970s. Most of the previous work has focused on gravity waves where surface tension can be neglected. In this work we study cross-waves that are highly dependent on surface tension as well as gravity. By oscillating a planar wave-maker either vertically or horizontally with frequencies of 25 Hz through 40 Hz at one end of a rectangular basin, two-dimensional multi-component surface patterns are realized. Using the free-surface synthetic Schlieren technique to measure the surface elevations, multi-dimensional Fourier transforms are utilized to track the evolutionary spectrum of the water surface in both the temporal and spatial domains. Wavelet transforms are implemented to show the development of the various frequency components. Three-wave resonances with and without first subharmonics are observed for small nonlinearity. Three-dimensional oblique propagating cross-waves are generated at higher nonlinearity; unlike most previous cross-wave experiments, this staggered pattern propagates far downstream. Experimental evidence shows that two oblique propagating waves form a two-dimensional short-crested pattern, and that the lateral component of the waves develops into parametric sloshing modes corresponding to the width of the tank. Two regimes of nonlinear wave patterns, resonant triads and oblique propagating cross-waves, are delineated.
Subgeometric ergodicity and β-mixing
Authors: Meitz Mika , Saikkonen Pentti
Published: September 2021

It is well known that stationary geometrically ergodic Markov chains are
$\beta$
-mixing (absolutely regular) with geometrically decaying mixing coefficients. Furthermore, for initial distributions other than the stationary one, geometric ergodicity implies
$\beta$
-mixing under suitable moment assumptions. In this note we show that similar results hold also for subgeometrically ergodic Markov chains. In particular, for both stationary and other initial distributions, subgeometric ergodicity implies
$\beta$
-mixing with subgeometrically decaying mixing coefficients. Although this result is simple, it should prove very useful in obtaining rates of mixing in situations where geometric ergodicity cannot be established. To illustrate our results we derive new subgeometric ergodicity and
$\beta$
-mixing results for the self-exciting threshold autoregressive model.
Computing minimal signature of coherent systems through matrix-geometric distributions
Authors: Eryilmaz Serkan , Tank Fatih
Published: September 2021

Signatures are useful in analyzing and evaluating coherent systems. However, their computation is a challenging problem, especially for complex coherent structures. In most cases the reliability of a binary coherent system can be linked to a tail probability associated with a properly defined waiting time random variable in a sequence of binary trials. In this paper we present a method for computing the minimal signature of a binary coherent system. Our method is based on matrix-geometric distributions. First, a proper matrix-geometric random variable corresponding to the system structure is found. Second, its probability generating function is obtained. Finally, the companion representation for the distribution of matrix-geometric distribution is used to obtain a matrix-based expression for the minimal signature of the coherent system. The results are also extended to a system with two types of components.
Estimating tails of independently stopped random walks using concave approximations of hazard functions
Authors: Lehtomaa Jaakko
Published: September 2021

This paper considers logarithmic asymptotics of tails of randomly stopped sums. The stopping is assumed to be independent of the underlying random walk. First, finiteness of ordinary moments is revisited. Then the study is expanded to more general asymptotic analysis. Results are applicable to a large class of heavy-tailed random variables. The main result enables one to identify if the asymptotic behaviour of a stopped sum is dominated by its increments or the stopping variable. As a consequence, new sufficient conditions for the moment determinacy of compounded sums are obtained.
Summer’s Gone: Late Style and Popular Music
Authors: GRAHAM STEPHEN
Published: September 2021

The Beach Boys’ 2012 album That’s Why God Made the Radio is typically nostalgic, filled with seemingly sunny reminiscences and retreads that hark back to the 1960s. And yet other parts of the album look back in a more critical fashion, exploring unresolved melancholy through a rich musical language. What makes this even more complicated is the fact that it is possible to hear these two ‘sides’ of the album differently, for the retreads to feel like eerie simulations and the melancholy parts to align with earlier, similarly complicated Beach Boys music. This ambivalence embodies the album’s dual relationship with what I describe as the primary strains of late style: Goethean serenity and Adornian intransigence. In exploring this contention and in applying late style to other examples of popular music, notably David Bowie’s 2016 album Blackstar, I argue that the late-style lens helps to shed new light on popular music’s increasingly complicated knots of nostalgia, ageing and death.
Geographic variations and determinants of EPA plus DHA and EPA alone in pregnant and lactating women from China
Authors: Yin Shaohua , Zhou Yu-bo , Li Hongtian , Meng Ying , Liu Jian-Meng
Published: September 2021

EPA and DHA are essential for maternal and fetal health, but epidemiological data are sparse in China. We examined the trends of EPA alone and a combination of EPA plus DHA in pregnant and lactating women in three distinct geographic regions in China and explored their potential influencing factors. A total of 1015 healthy women during mid-pregnancy, late pregnancy or lactation were recruited from Weihai (coastland), Yueyang (lakeland) and Baotou (inland) cities of China between May and July of 2014. Maternal EPA and DHA concentrations (percentage of total fatty acids) in plasma and erythrocytes were measured by capillary GC. Adjusted EPA plus DHA concentrations in both plasma and erythrocytes significantly declined from mid-pregnancy (2·92 %, 6·95 %) to late pregnancy (2·20 %, 6·42 %) and lactation (2·40 %, 6·29 %) (Ptrend < 0·001); and both concentrations were highest in coastland, followed by lakeland, and lowest in inland (P < 0·001). Regarding EPA alone, the concentrations were higher in women during lactation or late pregnancy and in women in coastland and inland areas. Moreover, concentrations of EPA or EPA plus DHA were higher in women with older age, higher education, higher annual family income per capita and higher dietary intake of marine aquatic product and mutton. In lactating women, erythrocyte EPA concentration was higher in those having breast-feeding partially v. exclusively. In conclusion, maternal plasma and erythrocyte concentrations of EPA plus DHA or EPA alone differed with geographic regions, physiological periods and maternal characteristics, indicating a need of population-specific health strategies to improve fatty acids status in pregnant and lactating women.
Understanding pre- and syn-orogenic tectonic evolution in western Himalaya through age and petrogenesis of Palaeozoic and Cenozoic granites from upper structural levels of Bhagirathi Valley, NW India
Authors: Sen Aranya , Sen Koushik , Chatterjee Amitava , Choudhary Shubham , Dey Alosree
Published: September 2021

The Himalaya is characterized by the presence of both pre-Himalayan Palaeozoic and syn-Himalayan Cenozoic granitic bodies, which can help unravel the pre- to syn-collisional geodynamics of this orogen. In the Bhagirathi Valley of Western Himalaya, such granites and the Tethyan Himalayan Sequence (THS) hosting them are bound to the south by the top-to-the-N extensional Jhala Normal Fault (JNF) and low-grade metapelite of the THS to its north. The THS is intruded by a set of leucocratic dykes concordant to the JNF. Zircon U–Pb laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) geochronology of the THS and one leucocratic dyke reveals that the two rocks have a strikingly similar age distribution, with a common and most prominent age peak at ~1000 Ma. To the north of the THS lies Bhaironghati Granite, a Palaeozoic two-mica granite, which shows a crystallization age of 512.28 ± 1.58 Ma. Our geochemical analysis indicates that it is a product of pre-Himalayan Palaeozoic magmatism owing to extensional tectonics in a back-arc or rift setting following the assembly of Gondwana (500–530 Ma). The Cenozoic Gangotri Leucogranite lies to the north of Bhaironghati Granite, and U–Pb dating of zircon from this leucogranite gives a crystallization age of 21.73 ± 0.11 Ma. Our geochemical studies suggest that the Gangotri Leucogranite is a product of muscovite-dehydration melting of the lower crust owing to flexural bending in relation to steepening of the subducted Indian plate. The leucocratic dykes are highly refracted parts of the Gangotri Leucogranite that migrated and emplaced along extensional fault zones related to the JNF and scavenged zircon from the host THS during crystallization.
ON WARING’S PROBLEM IN SUMS OF THREE CUBES FOR SMALLER POWERS
Authors: PLIEGO JAVIER
Published: September 2021

We give an upper bound for the minimum s with the property that every sufficiently large integer can be represented as the sum of s positive kth powers of integers, each of which is represented as the sum of three positive cubes for the cases
$2\leq k\leq 4.$
Abrupt Implementation of Telework in the Public Sector During the COVID-19 Crisis
Authors: Liebermann Susanne Christina , Blenckner Katharina , Diehl Jan-Hendrik , Feilke Joschka , Frei Christina , Grikscheit Sophie , Hünsch Swantje , Kohring Kristin , Lay Joya , Lorenzen Gotje , Reinhardt Julia
Published: September 2021

Abstract. Lockdown regulations during the COVID-19 outbreak resulted in abrupt changes to work situations and presented new leadership challenges. This short report explores how leaders perceived their options for leading transformationally when their teams were forced to rapidly switch to virtual collaboration. We interviewed 20 supervisors using semistructured telephone interviews who described their general leadership behavior before the lockdown and the evaluated possibilities and difficulties of leading transformationally during the lockdown. The article provides insights into the preconditions for transformational leadership in the public sector during change processes. High workload, time pressure, and role conflicts, combined with restricted freedom of action, restrained their options of transformational leadership. Communicative problems further hindered the transfer of transformational leadership behavior to new working arrangements during the Covid-19-crisis. The article derives implications for ways of helping managers to employ the potentials of transformational leadership in virtual settings and during change processes in the public sector.
Modeling Anthropogenic and Environmental Influences on Freshwater Harmful Algal Bloom Development Detected by MERIS Over the Central United States
Authors: Iiames J. S. , Salls W. B. , Mehaffey M. H. , Nash M. S. , Christensen J. R. , Schaeffer B. A.
Published: September 2021

Human and ecological health have been threatened by the increase of cyanobacteria harmful algal blooms (cyanoHABs) in freshwater systems. Successful mitigation of this risk requires understanding the factors driving cyanoHABs at a broad scale. To inform management priorities and decisions, we employed random forest modeling to identify major cyanoHAB drivers in 369 freshwater lakes distributed across 15 upper Midwest states during the 2011 bloom season (July–October). We used Cyanobacteria Index (CI_cyano)—A remotely sensed product derived from the MEdium Resolution Imaging Spectrometer (MERIS) aboard the European Space Agency's Envisat satellite—as the response variable to obtain variable importance metrics for 75 landscape and lake physiographic predictor variables. Lakes were stratified into high and low elevation categories to further focus CI_cyano variable importance identification by anthropogenic and natural influences. “High elevation” watershed land cover (LC) was primarily forest or natural vegetation, compared with “low elevation” watersheds LC dominated by anthropogenic landscapes (e.g., agriculture and municipalities). We used the top ranked 25 Random Forest variables to create a classification and regression tree (CART) for both low and high elevation lake designations to identify variable thresholds for possible management mitigation. Mean CI_cyano was 3 times larger for “low elevation” lakes than for “high elevation” lakes, with both mean values exceeding the “High” World Health Organization recreational guidance/action level threshold for cyanobacteria (100,000 cells/mL). Agrarian‐related variables were prominent across all 369 lakes and low elevation lakes. High elevation lakes showed more influence of lakeside LC than for the low elevation lakes.
Joint Inversion of Receiver Functions and Apparent Incidence Angles for Sparse Seismic Data
Authors: Joshi Rakshit , Knapmeyer‐Endrun Brigitte , Mosegaard Klaus , Igel Heiner , Christensen Ulrich R.
Published: September 2021

The estimation of crustal structure and thickness is essential in understanding the formation and evolution of terrestrial planets. Initial planetary missions with seismic instrumentation on board face the additional challenge of dealing with seismic activity levels that are only poorly constrained a priori. For example, the lack of plate tectonics on Mars leads to low seismicity, which could, in turn, hinder the application of many terrestrial data analysis techniques. Here we propose using a joint inversion of receiver functions and apparent incidence angles, which contain information on absolute S‐wave velocities of the subsurface. Since receiver function inversions suffer from a velocity depth trade‐off, we in addition exploit a simple relation that defines apparent S‐wave velocity as a function of observed apparent P‐wave incidence angles to constrain the parameter space. We then use the Neighborhood Algorithm for the inversion of a suitable joint objective function. The resulting ensemble of models is then used to derive uncertainty estimates for each model parameter. In preparation for the analysis of data from the InSight mission, we show the application of our proposed method on Mars synthetics and sparse terrestrial data sets from different geological settings using both single and multiple events. We use information‐theoretic statistical tests as model selection criteria and discuss their relevance and implications in a seismological framework.
Mean‐State Dependence of CO2‐Forced Tropical Atlantic Sector Climate Change
Authors: Imbol Nkwinkwa A. S. N. , Latif M. , Park W.
Published: September 2021

Twenty‐first‐century climate change projections are uncertain, especially on regional scales. An important source of uncertainty is that climate models exhibit biases, which limits their ability to predict climate. One of the largest biases is the too warm sea surface temperature (SST) in the eastern tropical Atlantic (TA), reflecting deficient atmospheric and oceanic circulation. Here, we show that CO2‐forced TA‐sector climate changes simulated by state‐of‐the‐art climate models exhibit a strong mean‐state dependence. In particular, models simulating largest SST warming in the eastern TA, consistent with the warming observed since the mid‐20th century, typically exhibit a more realistic mean state than models simulating largest warming in the western TA. The former models exhibit a larger climate sensitivity, and predict stronger and in part qualitatively different climate changes over the TA sector, for example in precipitation. These findings may help to reducing uncertainty in TA‐climate change projections.