bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the convergence rate of the Kačanov scheme for shear-thinning fluids
Authors: Heid Pascal , Süli Endre 
Published: November 2021

AbstractWe explore the convergence rate of the Kačanov iteration scheme for different models of shear-thinning fluids, including Carreau and power-law type explicit quasi-Newtonian constitutive laws. It is shown that the energy difference contracts along the sequence generated by the iteration. In addition, an a posteriori computable contraction factor is proposed, which improves, on finite-dimensional Galerkin spaces, previously derived bounds on the contraction factor in the context of the power-law model. Significantly, this factor is shown to be independent of the choice of the cut-off parameters whose use was proposed in the literature for the Kačanov iteration applied to the power-law model. Our analytical findings are confirmed by a series of numerical experiments.
CMR-derived myocardial strain analysis differentiates ischemic and dilated cardiomyopathy—a propensity score-matched study
Authors: Vietheer Julia , Lehmann Lena , Unbehaun Claudia , Fischer-Rasokat Ulrich , Wolter Jan Sebastian , Kriechbaum Steffen , Weferling Maren , von Jeinsen Beatrice , Hain Andreas , Liebetrau Christoph , Hamm Christian W. , Keller Till , Rolf Andreas 
Published: November 2021

AbstractLeft ventricular (LV) longitudinal, circumferential, and radial motion can be measured using feature tracking of cardiac magnetic resonance (CMR) images. The aim of our study was to detect differences in LV mechanics between patients with dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) who were matched using a propensity score-based model. Between April 2017 and October 2019, 1224 patients were included in our CMR registry, among them 141 with ICM and 77 with DCM. Propensity score matching was used to pair patients based on their indexed end-diastolic volume (EDVi), ejection fraction (EF), and septal T1 relaxation time (psmatch2 module L Feature tracking provided six parameters for global longitudinal, circumferential, and radial strain with corresponding strain rates in each group. Strain parameters were compared between matched pairs of ICM and DCM patients using paired t tests. Propensity score matching yielded 72 patients in each group (DCM mean age 58.6 ± 11.6 years, 15 females; ICM mean age 62.6 ± 13.2 years, 11 females, p = 0.084 and 0.44 respectively; LV-EF 32.2 ± 13.5% vs. 33.8 ± 12.1%, p = 0.356; EDVi 127.2 ± 30.7 ml/m2 vs. 121.1 ± 41.8 ml/m2, p = 0.251; native T1 values 1165 ± 58 ms vs. 1167 ± 70 ms, p = 0.862). There was no difference in global longitudinal strain between DCM and ICM patients (− 10.9 ± 5.5% vs. − 11.2 ± 4.7%, p = 0.72), whereas in DCM patients there was a significant reduction in global circumferential strain (− 10.0 ± 4.5% vs. − 12.2 ± 4.7%, p = 0.002) and radial strain (17.1 ± 8.51 vs. 21.2 ± 9.7%, p = 0.039). Our data suggest that ICM and DCM patients have inherently different myocardial mechanics, even if phenotypes are similar. Our data show that GCS is significantly more impaired in DCM patients. This feature may help in more thoroughly characterizing cardiomyopathy patients.
Effect of Embedded Careers Education in Science Lessons on Students’ Interest, Awareness, and Aspirations
Authors: Kang Jingoo , Salonen Anssi , Tolppanen Sakari , Scheersoi Annette , Hense Jonathan , Rannikmäe Miia , Soobard Regina , Keinonen Tuula 
Published: November 2021

AbstractIn the last decades, secondary school students have indicated a low interest in science and a lack of awareness of authentic science careers that may impede their aspiration to work in science-related fields in future. To raise students’ aspirations, several studies used context-based approaches, but few integrated career aspects into the school curricula. Accordingly, this study aimed to promote lower secondary school students’ interest in and awareness of science careers by introducing science career-related scenarios reflected in a real-world context as embedded careers education in science lessons. In this study, we explored the effect of the interventions on students’ interest, awareness, and aspirations towards science careers using Estonian, Finnish, and German datasets. According to the results, the students participating in the project indicated a higher interest in science, aspiration towards science careers, and awareness of future careers than those who did not experience the embedded science career interventions. Also, the results showed that when students got more information about science careers at school, their interest in science was more easily transferred to their aspirations in science studies and careers. Thus, this result emphasizes the importance of fostering awareness of science careers at lower secondary schools in order to inspire young learners to engage in science studies and works in future.
In situ extraction (milking) of the two promising Botryococcus braunii strains Showa and Bot22 under optimized extraction time
Authors: Kleinert Christian , Griehl Carola 
Published: November 2021

AbstractIn situ extraction or “milking” of microalgae is a promising approach to reduce downstream costs in order to produce low-value substances such as lipids from microalgae in an economical way. Due to its ability to secrete high amounts of long-chain hydrocarbons to an extracellular matrix, the green microalga Botryococcus braunii is suitable for the process of in situ extraction as the cost intensive steps of harvesting, dewatering, and cell disruption could be omitted. Based on a previous study investigating various B. braunii strains in terms of growth, lipid accumulation, and solvent compatibility, the B. braunii strains Showa and Bot22 (both B race) were identified as potential candidates for the process of in situ extraction. In order to prove the suitability of these two strains for the process of in situ extraction, this study first determined the optimal extraction time using short-term in situ extraction over 7 days at different starting biomass concentrations of 1.5 and 2.5 g L−1. Furthermore, both strains were treated applying the optimal extraction time in long-term in situ extractions for 30 days to confirm the results from the short-term extractions. The results indicate a strain-dependent optimal extraction time of 300 min day−1 for strain Showa and 200 min day−1 for strain Bot22. During long-term in situ extraction for 30 days, hydrocarbon productivity was 16.99 mg L−1 day−1 (10.53 mg gDW−1 day−1) for strain Showa and 14.53 mg L−1 day−1 (10.48 mg gDW−1 day−1) for strain Bot22. Furthermore, a direct correlation between hydrocarbon productivity achieved by in situ extraction and the hydrocarbon concentration in the biomass of the respective strain could be established. It could be shown that the consideration of the effective extraction time and the phase boundary area is required to calculate an extraction system independent value for the comparison of different extraction setups.
How One can Repair Non-integrable Kahan Discretizations. II. A Planar System with Invariant Curves of Degree 6
Authors: Schmalian Misha , Suris Yuri B. , Tumarkin Yuriy 
Published: November 2021

AbstractWe find a novel one-parameter family of integrable quadratic Cremona maps of the plane preserving a pencil of curves of degree 6 and of genus 1. They turn out to serve as Kahan-type discretizations of a novel family of quadratic vector fields possessing a polynomial integral of degree 6 whose level curves are of genus 1, as well. These vector fields are non-homogeneous generalizations of reduced Nahm systems for magnetic monopoles with icosahedral symmetry, introduced by Hitchin, Manton and Murray. The straightforward Kahan discretization of these novel non-homogeneous systems is non-integrable. However, this drawback is repaired by introducing adjustments of order $$O(\epsilon ^2)$$

O
(

ϵ
2

)

in the coefficients of the discretization, where $$\epsilon $$
ϵ
is the stepsize.
Would you Bribe your Lecturer? A Quasi-experimental Study on Burnout and Bribery in Higher Education
Authors: Weißmüller Kristina S. , De Waele Lode 
Published: December 2021

AbstractBribery is a complex and critical issue in higher education (HE), causing severe economic and societal harm. Traditionally, most scholarship on HE corruption has focused on institutional factors in developing countries and insights into the psychological and motivational factors that drive HE bribery on the micro-level mechanisms are virtually non-existent. To close this research gap, this study investigates the connection between study-related burnout and university students’ willingness to offer bribes to their lecturers to pass important exams. Conducting a vignette-based quasi-experimental replication study with 624 university students in Germany, Belgium, and the Netherlands we find that university students in three countries differentiate sharply between different shades of bribery and that a majority accept using emotional influence tactics to pass (failed) exams. In contrast, offering a helping hand or money (i.e., darker shades of bribery) to their lecturer was less acceptable. Study-related burnout is associated with a higher likelihood of engaging in these darker shades of bribery and students’ commitment to the public interest is but a weak factor in preventing unethical behavior. In summary, this study provides solid empirical evidence that university students are likely to use emotional influence tactics violating both the ethical codes of conduct and the formalized bureaucratic procedures of HE examination, particularly if they suffer from study-related burnout. However, the accelerating effect of burnout on bribery is conditional in that it only holds for darker shades of bribery. HE institutions may benefit from implementing the four-eye principle and from launching awareness campaigns that enable lecturers to better recognize these tactics and engage students in creating a transparent environment for testing, grading, and collaboration that is resistant to bribery.
A de Rham decomposition type theorem for contact sub-Riemannian manifolds
Authors: Grochowski Marek 
Published: November 2021

AbstractIn this paper we prove a result which can be regarded as a sub-Riemannian version of de Rham decomposition theorem. More precisely, suppose that (M, H, g) is a contact and oriented sub-Riemannian manifold such that the Reeb vector field $$\xi $$
ξ
is an infinitesimal isometry. Under such assumptions there exists a unique metric and torsion-free connection on H. Suppose that there exists a point $$q\in M$$

q
∈
M

such that the holonomy group $$\Psi (q)$$

Ψ
(
q
)

acts reducibly on H(q) yielding a decomposition $$H(q) = H_1(q)\oplus \cdots \oplus H_m(q)$$

H

(
q
)

=

H
1

(
q
)

⊕
⋯
⊕

H
m

(
q
)

into $$\Psi (q)$$

Ψ
(
q
)

-irreducible factors. Using parallel transport we obtain the decomposition $$H = H_1\oplus \cdots \oplus H_m$$

H
=

H
1

⊕
⋯
⊕

H
m

of H into sub-distributions $$H_i$$

H
i

. Unlike the Riemannian case, the distributions $$H_i$$

H
i

are not integrable, however they induce integrable distributions $$\Delta _i$$

Δ
i

on $$M/\xi $$

M
/
ξ

, which is locally a smooth manifold. As a result, every point in M has a neighborhood U such that $$T(U/\xi )=\Delta _1\oplus \cdots \oplus \Delta _m$$

T

(
U
/
ξ
)

=

Δ
1

⊕
⋯
⊕

Δ
m

, and the latter decomposition of $$T(U/\xi )$$

T
(
U
/
ξ
)

induces the decomposition of $$U/\xi $$

U
/
ξ

into the product of Riemannian manifolds. One can restate this as follows: every contact sub-Riemannian manifold whose holonomy group acts reducibly has, at least locally, the structure of a fiber bundle over a product of Riemannian manifolds. We also give a version of the theorem for indefinite metrics.
Ionic liquids as boundary additives in water-based and PAO lubricants
Authors: Wijanarko Wahyu , Khanmohammadi Hamid , Espallargas Nuria 
Published: November 2021

AbstractIonic liquids have been widely discussed as potential lubricants, however, their properties make them also very good potential candidates as lubricant additives (e.g., friction modifiers and anti-wear). In this work, the tribological study of two ionic liquids (tributylmethylphosphonium dimethylphosphate (PP), and 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate (BMP)) as lubricant additives has been performed on stainless steel (AISI 316L) exposed to polar (water-glycol) and non-polar (polyalphaolefin) based lubricants under boundary lubricating conditions. The performance of these ionic liquids as lubricant additives has been compared to a classical organic friction modifier (dodecanoic acid (C12)). The water-glycol lubricant formulated with the two ionic liquids showed friction values higher than the same base lubricant formulated with dodecanoic acid, however, opposite results were observed for polyalphaolefin (PAO). A detailed surface chemical analysis using X-ray photoelectron spectroscopy (XPS) revealed differences in the passive/tribofilm thickness and chemical composition of the stainless steel surface tested in all lubricants. In the case of the polar lubricant additivated with ionic liquids, the tribochemical reaction accompanied by a tribocorrosion process led to the formation of an unstable passive/tribofilm resulting in high friction and wear. However, in the absence of tribocorrosion process (polyalphaolefin base lubricant), the tribochemical reaction led to the formation of a stable passive/tribofilm resulting in low friction and wear. A detailed surface and subsurface investigation of the microstructure using scanning electron microscopy equipped with a focused ion beam (SEM-FIB) showed that high wear rates resulted in thicker recrystallization region under the wear track surface. Among all lubricant additives tested in this work, BMP in non-polar lubricant media showed the best tribological performance.
Stigmatisierungserfahrungen strafrechtlich verurteilter Männer im Reintegrationsprozess. Ergebnisse einer qualitativen Längsschnittstudie in der Schweiz
Authors: Zahradnik Franz 
Published: November 2021

ZusammenfassungStrafrechtlich verurteilte Personen machen während einer Freiheitsstrafe sowie nach der Entlassung häufig Stigmatisierungserfahrungen, die den Reintegrationsprozess herausfordern und durchkreuzen können. Auf der Grundlage von Längsschnittinterviews mit strafrechtlich verurteilten Männern in der Schweiz werden deren subjektive Erfahrungen in Hinblick auf Stigmatisierung, die sie über mehrere Jahre hinweg in unterschiedlichen sozialen Kontexten gemacht haben, sowie ihre Verarbeitungsweisen derselben untersucht. In der kategorialen Auswertung des Gesamtsamples zeigt sich eine Korrespondenz von gehäuften Stigmatisierungserfahrungen und tendenziell sich stabilisierenden Reintegrationsverläufen. Es deutet sich an, dass gerade diejenigen, die eine ausgeprägte Reintegrationsorientierung zeigen, Situationen mit Stigmatisierungspotenzial etwa im Bereich der Arbeits- und Wohnungssuche nicht von vornherein auszuweichen versuchen, sondern diesen aktiv entgegentreten. Die dauerhafte Bewältigung solch herausfordernder und teils diskreditierender Situationen ist aber voraussetzungsvoll und gelingt nicht allen interviewten Männern gleichermaßen. Des Weiteren wird herausgearbeitet, welche Stigmatisierungserfahrungen die Interviewten in unterschiedlichen sozialen Kontexten und Phasen des Reintegrationsprozesses machen. Dabei zeigt sich, dass Stigmatisierungen nicht immer offen zutage treten, sondern von den Interviewten häufig antizipiert werden. Aktenkundige Stigmaeigenschaften hingegen werden dann offensichtlich, wenn ein Strafregisterauszug vorgelegt werden muss. Die damit verbundene Diskriminierung aber bleibt auf der Interaktionsebene zumeist verdeckt.
Representing Uncertainty in Physical Security Risk Assessment
Authors: Lichte Daniel , Witte Dustin , Termin Thomas , Wolf Kai-Dietrich 
Published: November 2021

AbstractThe importance of (physical) security is increasingly acknowledged by society and the scientific community. In light of increasing terrorist threat levels, numerous security assessments of critical infrastructures are conducted in practice and researchers propose new approaches continuously. While practical security risk assessments (SRA) use mostly qualitative methods, most of the lately proposed approaches are based on quantitative metrics. Due to little evidence of actual attacks, both qualitative and quantitative approaches suffer from the fundamental problem of inherent uncertainties regarding threats and capabilities of security measures as a result from vague data or the usage of expert knowledge. In quantitative analysis, such uncertainties may be represented by, e.g., probability distributions to reflect the knowledge on security measure performance available. This paper focuses on the impact of these uncertainties in security assessment and their consideration in system design. We show this influence by comparing the results of a scalar evaluation that does not take into account uncertainties and another evaluation based on distributed input values. In addition, we show that the influence is concentrated on certain barriers of the security system. Specifically, we discuss the robustness of the system by conducting quantitative vulnerability assessment as part of the SRA process of an airport structure example. Based on these results, we propose the concept of a security margin. This concept accounts for the uncertain knowledge of the input parameters in the design of the security system and minimizes the influence of these uncertainties on the actual system performance. We show how this approach can be used for vulnerability assessment by applying it to the initially assessed configuration of the airport structure. The results of this case study support our assumptions that the security margin can help in targeted uncertainty consideration leading to reduced system vulnerability.
Compassion fatigue in pediatric hematology, oncology, and bone marrow transplant healthcare providers: An integrative review
Authors: Berger Rebecca S. , Wright Rebecca J. , Faith Melissa A. , Stapleton Stacie 
Published: December 2021

AbstractObjectiveCompassion fatigue (CF), which includes burnout and secondary traumatic stress, is highly prevalent among healthcare providers (HCPs). Ultimately, if left untreated, CF is often associated with absenteeism, decreased work performance, poor job satisfaction, and providers leaving their positions. To identify risk factors for developing CF and interventions to combat it in pediatric hematology, oncology, and bone marrow transplant (PHOB) HCPs.MethodsAn integrative review was conducted. Controlled vocabulary relevant to neoplasms, CF, pediatrics, and HCPs was used to search PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, and Web of Science MEDLINE. Inclusion criteria were the following: English language and PHOB population. Exclusion criteria were the following: did not address question, wrong study population, mixed study population where PHOB HCPs were only part of the population, articles about moral distress as this is a similar but not the same topic as CF, conference abstracts, and book chapters.ResultsA total of 16 articles were reviewed: 3 qualitative, 6 quantitative, 3 mixed methods, and 4 non research. Three themes were explored: (1) high-risk populations for developing CF, (2) sources of stress in PHOB HCPs, and (3) workplace interventions to decrease CF.Significance of resultsPHOB HCPs are at high risk of developing CF due to high morbidity and mortality in their patient population. Various interventions, including the use of a clinical support nurse, debriefing, support groups, respite rooms, and retreats, have varying degrees of efficacy to decrease CF in this population.
Insomnia with physiological hyperarousal is associated with lower weight: a novel finding and its clinical implications
Authors: Ren Rong , Zhang Ye , Yang Linghui , Sanford Larry D. , Tang Xiangdong 
Published: November 2021

AbstractPrevious studies on the association of insomnia with body mass index (BMI) have been controversial. Physiological hyperarousal, the key pathological mechanism of insomnia, may be an important reason for different findings. We explored whether insomnia with physiological hyperarousal measured by the multiple sleep latency test (MSLT) is associated with body-weight differences. A total of 185 normal sleepers and 440 insomniacs were included in this study. Insomnia was defined by standard diagnostic criteria with symptoms lasting ≥6 months. All subjects underwent one night of laboratory polysomnography followed by a standard MSLT. We used the median MSLT value (i.e., ≥14 min) to define physiological hyperarousal. BMI was based on measured height (cm) and weight (kg) during the subjects’ sleep laboratory visit. BMI > 25 kg/m2 was defined as overweight, while BMI < 18.5 kg/m2 was defined as underweight. After controlling for confounders, the odds of lower weight rather than overweight were significantly increased among insomnia patients with increased MSLT: insomnia with MSLT 14–17 min and MSLT > 17 min increased the odds of lower weight by approximately 89% (OR = 1.89, 95% CI 1.00–4.85) and 273% (OR = 3.73, 95% CI 1.51–9.22) compared with normal sleepers, respectively. In contrast, insomnia in patients with MSLT 11–14 min and 8–11 min was not different from normal sleepers in terms of body weight. Insomnia associated with physiological hyperarousal, the most severe phenotype of chronic insomnia, is associated with higher odds of lower weight and underweight compared with normal sleepers. This is a novel finding consistent with previous physiologic data and has significant clinical implications.
Exposure and risk characterizations of ochratoxins A and aflatoxins through maize (Zea mays) consumed in different agro-ecological zones of Ghana
Authors: Kortei Nii Korley , Annan Theophilus , Kyei-Baffour Vincent , Essuman Edward Ken , Okyere Harry , Tettey Clement Okraku 
Published: December 2021

AbstractMycotoxin contamination of foodstuffs is a serious food safety concern globally as the prolonged ingestion of these toxins has the tendency to worsen the risk of hepatocellular carcinoma. This study aimed at estimating ochratoxin A (OTA) and aflatoxin (AF) levels above international (European Food Safety Authority, EFSA) and local (Ghana Standards Authority, GSA) standards as well as the health risks associated with the consumption of maize (n = 180) sampled from six (6) regions representing the agro-ecological zones of Ghana. OTA and AF were measured with High-Performance Liquid Chromatography with a Fluorescence detector. Out of the 180 samples analyzed for total aflatoxins (AFtotal), 131/180 tested positive and 127 (70.50%) exceeded the limits of EFSA and ranged 4.27–441.02 µg/kg. While for GSA, 116 (64.44%) of samples exceeded this limit and ranged between 10.18 and 441.02 µg/kg. For OTA, 103/180 tested positive and 94 (52.22%) of samples between the range 4.00–97.51 µg/kg exceeded the tolerable limit of EFSA, whereas 89 (49.44%) and were in the range of 3.30–97.51 µg/kg exceeded the limits of GSA. Risk assessment values for total aflatoxins (AFtotal) ranged between 50 and 1150 ng/kg bw/day, 0.4–6.67, 0–0.0323 aflatoxins ng/kg bw/day and 1.62–37.15 cases/100,000 person/year for Estimated Daily Intake (EDI), Margin of Exposure (MOE), Average Potency, and Cancer Risks respectively. Likewise, ochratoxin (OTA) values were in the ranges of 8.6 × 10–3–450 ng/kg bw/day, 0.05–2059.97, 0–0.0323 ochratoxins ng/kg bw/day and 2.78 × 10–4–14.54 cases/100,000 person/year. Consumption of maize posed adverse health effects in all age categories of the locations studied since the calculated MOE values were less than 10,000.