bluuebunny/crossref_metadata_2025 huggingface dataset:
Taxonomy Development for Business Research: A Hands-On Guideline
Authors: Steininger Dennis M. , Trenz Manuel , Veit Daniel J.
Published: April 2021

Classification schemes are important groundwork for research on many topics of different business disciplines such as information systems (IS). They make investigating topics manageable by allowing researchers to delimit their work to certain taxa or types (e.g., of artifacts or firms) and provide a basis for generalization. Opposed to theoretically grounded typologies, taxonomies are empirically derived from entities of a phenomenon and therefore have several advantages, such as more detailed and exhaustive coverage. Initial guidelines for developing taxonomies in business have been proposed; however, research is still missing a clear set of applicable procedures to empirically build taxonomies. We tackle this topic by suggesting an inductive approach based on the procedures of content and cluster analysis. Each of the proposed six steps is amended with comprehensive state-of-the-art guidelines, suggestions, and formative measures of reliability and validity.
Studying Conceptual Modeling Processes: A Modeling Tool, Research Observatory, and Multimodal Observation Setup
Authors: Strecker Stefan , Rosenthal Kristina , Ternes Benjamin
Published: April 2021

What do (non-)experienced modelers reason while conceptual modeling and how do they arrive at modeling decisions, which modeling and learning difficulties do they face and why, and how do they overcome these difficulties by tailored modeling tool support are questions of relevance and importance to practicing modelers and, likewise, to conceptual modeling research. For the past 7 years, we have been designing, developing, and evaluating a modeling tool integrating a research observatory aimed at studying individual modeling processes online, in the field, and under laboratory conditions—to contribute to a richer understanding of modeler reasoning and decision-making, to identify common modeling and learning difficulties, and, ultimately, to design tool support to mitigate difficulties and to improve assistance for (non-)experienced modelers. We present an overview of the modeling observatory and of a corresponding multimodal observation setup.
Squashing, mass, and holography for 3d sphere free energy
Authors: Chester Shai M. , Kalloor Rohit R. , Sharon Adar
Published: April 2021

Abstract

We consider the sphere free energy F(b; mI) in $$ \mathcal{N} $$
N
= 6 ABJ(M) theory deformed by both three real masses mI and the squashing parameter b, which has been computed in terms of an N dimensional matrix model integral using supersymmetric localization. We show that setting $$ {m}_3=i\frac{b-{b}^{-1}}{2} $$

m
3

=
i

b
−

b

−
1

2

relates F(b; mI) to the round sphere free energy, which implies infinite relations between mI and b derivatives of F(b; mI) evaluated at mI = 0 and b = 1. For $$ \mathcal{N} $$
N
= 8 ABJ(M) theory, these relations fix all fourth order and some fifth order derivatives in terms of derivatives of m1, m2, which were previously computed to all orders in 1/N using the Fermi gas method. This allows us to compute $$ {\partial}_b^4F\left|{}_{b=1}\right. $$

∂
b
4

F

b
=
1

and $$ {\partial}_b^5F\left|{}_{b=1}\right. $$

∂
b
5

F

b
=
1

to all orders in 1/N, which we precisely match to a recent prediction to sub-leading order in 1/N from the holographically dual AdS4 bulk theory.
Proof-theoretic uniform boundedness and bounded collection principles and countable Heine–Borel compactness
Authors: Kohlenbach Ulrich
Published: April 2021

In this note we show that proof-theoretic uniform boundedness or bounded collection principles which allow one to formalize certain instances of countable Heine–Borel compactness in proofs using abstract metric structures must be carefully distinguished from an unrestricted use of countable Heine–Borel compactness.
Peculiarities of promiscuous l-threonine transaldolases for enantioselective synthesis of β-hydroxy-α-amino acids
Authors: Wang Shan , Deng Hai
Published: April 2021

The introduction of β-hydroxy-α-amino acids (βHAAs) into organic molecules has received considerable attention as these molecules have often found widespread applications in bioorganic chemistry, medicinal chemistry and biomaterial science. Despite innovation of asymmetric synthesis of βHAAs, stereoselective synthesis to control the two chiral centres at Cα and Cβ positions is still challenging, with poor atomic economy and multi protection and deprotection steps. These syntheses are often operated under harsh conditions. Therefore, a biotransformation approach using biocatalysts is needed to selectively introduce these two chiral centres into structurally diverse molecules. Yet, there are few ways that enable one-step synthesis of βHAAs. One is to extend the substrate scope of the existing enzyme inventory. Threonine aldolases have been explored to produce βHAAs. However, the enzymes have poor controlled installation at Cβ position, often resulting in a mixture of diastereoisomers which are difficult to be separated. In this respect, l-threonine transaldolases (LTTAs) offer an excellent potential as the enzymes often provide controlled stereochemistry at Cα and Cβ positions. Another is to mine LTTA homologues and engineer the enzymes using directed evolution with the aim of finding engineered biocatalysts to accept broad substrates with enhanced conversion and stereoselectivity. Here, we review the development of LTTAs that incorporate various aldehyde acceptors to generate structurally diverse βHAAs and highlight areas for future developments.

Key points

• The general mechanism of the transaldolation reaction catalysed by LTTAs

• Recent advances in LTTAs from different biosynthetic pathways

• Applications of LTTAs as biocatalysts for production of βHAAs
3,3′-Thiodipropionic acid (TDP), a possible precursor for the synthesis of polythioesters: identification of TDP transport proteins in Variovorax paradoxus TBEA6
Authors: Reddy M. Venkateswar , Steinbüchel Alexander
Published: April 2021

3,3′-Thiodipropionic acid (TDP) is an antioxidant, which can be used as precursor carbon source to synthesize polythioesters. The bacterium Variovorax paradoxus TBEA6 strain can use TDP as a single source of carbon and energy. In the present study, experiments were carried out to identify proteins involved in the transport of TDP into the cells of strain TBEA6. Hence, eight putative tctC genes, which encode for the TctC proteins, were amplified from genomic DNA of TBEA6 strain using polymerase chain reaction and expressed in E. coli BL21 cells. Cells were grown in auto-induction medium, and protein purification was done using His Spin Trap affinity columns. Purity and molecular weight of each protein were confirmed by SDS-PAGE analysis. Protein-ligand interactions were monitored in thermoshift assays using the real-time PCR system. Two TctC proteins (locus tags VPARA-44430 and VPARA-01760) out of eight proteins showed a significant shift in their melting temperatures when they interact with the ligand (TDP or gluconate). The responsible genes were deleted in the genome of TBEA6 using suicide plasmid pJQ200mp18Tc, and single deletion mutants of the two candidate genes were subsequently generated. Finally, growth of the wild-type strain (TBEA6) and the two mutant strains (ΔVPARA-44430 and ΔVPARA-01760) were monitored and compared using TDP or gluconate as carbon sources. Wild type strains were successfully grown with TDP or gluconate. From the two mutant strains, one (ΔVPARA-44430) was unable to grow with TDP indicating that the tctC gene with locus tag VPARA-44430 is involved in the uptake of TDP.

Key Points

• Putative tctC genes from V. paradoxus TBEA6 were heterologously expressed in E. coli.

• Protein-ligand interactions monitored in thermoshift assays using the real-time PCR.

• tctC gene with locus tag VPARA-44430 is involved in the uptake of TDP.
Enhanced anti-melanoma efficacy through a combination of the armed oncolytic adenovirus ZD55-IL-24 and immune checkpoint blockade in B16-bearing immunocompetent mouse model
Authors: Hu Hai-Jun , Liang Xiu , Li Hai-Lang , Wang Huai-Yuan , Gu Jin-Fa , Sun Lan-Ying , Xiao Jing , Hu Jin-Qing , Ni Ai-Min , Liu Xin-Yuan
Published: April 2021

Although the recent treatment in melanoma through the use of anti-PD-1 immunotherapy is successful, the efficacy of this approach remains to be improved. Here, we explore the feasibility of combination strategy with the armed oncolytic adenovirus ZD55-IL-24 and PD-1 blockade. We find that combination therapy with localized ZD55-IL-24 and systemic PD-1 blockade leads to synergistic inhibition of both local and distant established tumors in B16-bearing immunocompetent mouse model. Our further mechanism investigation reveals that synergistic therapeutic effect is associated with marked promotion of tumor immune infiltration and recognition in both local and distant tumors as well as spleens. PD-1 blockade has no obvious effect on promotion of tumor immune infiltration and recognition. Localized therapy with ZD55-IL-24, however, can help PD-1 blockade to overcome the limitation of relatively low tumor immune infiltration and recognition. This study provides a rationale for investigation of such combination therapy in the clinic.
Quality Improvement to Address Surgical Burden of Disease at a Large Tertiary Public Hospital in Peru
Authors: Iverson Katherine R. , Roa Lina , Shu Sebastian , Wong Milagros , Rubenstein Shayna , Zavala Paloma , Caddell Luke , Graham Cole , Colina Jorge , Leon Segundo R. , Lecca Leonid , Mody Gita N.
Published: April 2021

Background

In resource‐limited settings, there is a unique opportunity for using process improvement strategies to address the lack of access to surgical care. By implementing organizational changes in the surgical admission process, we aimed to decrease wait times, increase surgical volume, and improve patient satisfaction for elective general surgery procedures at a public tertiary hospital in Lima, Peru.

Methods

During the first phase of the intervention, Plan‐Do‐Study‐Act (PDSA) cycles were performed to ensure the surgery waitlist included up‐to‐date clinical information. In the second phase, Lean Six Sigma methodology was used to adapt the admission and scheduling process for elective general surgery patients. After six months, outcomes were compared to baseline data using Wilcoxon rank‐sum test.

Results

At the conclusion of phase one, 87.0% (488/561) of patients on the new waitlist had all relevant clinical data documented, improved from 13.3% (2/15) for the pre‐existing list. Time from admission to discharge for all surgeries improved from 5 to 4 days (p<0.05) after the intervention. Median wait times from admission to operation for elective surgeries were unchanged at 4 days (p=0.076) pre‐ and post‐intervention. There was a trend toward increased weekly elective surgical volume from a median of 9 to 13 cases (p=0.24) and increased patient satisfaction rates for elective surgery from 80.5 to 83.8% (p=0.62), although these were not statistically significant.

Conclusion

The process for scheduling and admitting elective surgical patients became more efficient after our intervention. Time from admission to discharge for all surgical patients improved significantly. Other measured outcomes improved, though not with statistical significance. Main challenges included gaining buy‐in from all participants and disruptions in surgical services from bed shortages.
Velocity data-based determination of airfoil characteristics with circulation and fluid momentum change methods, including a control surface size independence test
Authors: Olasek Krzysztof , Karczewski Maciej
Published: April 2021

An experimental method for determination of aerodynamic loads is presented. It is based on velocity vector field results obtained with Particle Image Velocimetry (PIV). As PIV is an optical measurement technique, the developed method for load determination can be defined as noninvasive. It is shown that the only information needed to estimate the lift and drag forces exerted on a body placed in the flow is a velocity distribution measured around the investigated object. Therefore, PIV results provide sufficient input experimental data to be used. Fundamental fluid mechanics theories were employed to develop algorithms for load estimation. Determination of the lift force is based on velocity circulation calculations. It is obtained by integrating the velocity field along a closed-loop encircling the body. An essential achievement made is the development of a procedure for finding an optimal size of the integration curve used for lift calculations. In the case of the drag force estimation, an analysis of fluid momentum changes has been used. The momentum deficit, within a given control volume containing the analysed aerofoil, is determined and related to the reaction drag force exerted on the body. Additionally, pressure field reconstruction based on velocity data, which enabled an application of small control surfaces and kept the drag estimation error at a satisfactorily low level, was introduced. The developed method was tested and verified with the reference computational fluid dynamics simulation results and applied further to the wind tunnel experimental data. A flow around the standard NACA0012 aerofoil at two flow regimes was investigated (Re=$$0.7\times 10^5$$

0.7
×

10
5

and Re=$$1.4\times 10^5$$

1.4
×

10
5

). Lift and drag coefficient characteristics as a function of the angle of attack were obtained. An exceptional agreement between the experimental and reference numerical lift characteristics was attained (relative differences no larger than 5%). In the case of drag estimation, an acceptable level of similarity was observed (max. discrepancies below 20%).

Graphic abstract
Electrical storm reveals worse prognosis compared to myocardial infarction complicated by ventricular tachyarrhythmias in ICD recipients
Authors: Müller Julian , Behnes Michael , Schupp Tobias , Ellguth Dominik , Taton Gabriel , Reiser Linda , Engelke Niko , Borggrefe Martin , Reichelt Thomas , Bollow Armin , El-Battrawy Ibrahim , Weidner Kathrin , Kim Seung-Hyun , Barth Christian , Ansari Uzair , Große Meininghaus Dirk , Akin Muharrem , Mashayekhi Kambis , Akin Ibrahim
Published: April 2021

Both acute myocardial infarction complicated by ventricular tachyarrhythmias (AMI–VTA) and electrical storm (ES) represent life-threatening clinical conditions. However, a direct comparison of both sub-groups regarding prognostic endpoints has never been investigated. All consecutive implantable cardioverter-defibrillator (ICD) recipients were included retrospectively from 2002 to 2016. Patients with ES apart from AMI (ES) were compared to patients with AMI accompanied by ventricular tachyarrhythmias (AMI–VTA). The primary endpoint was all-cause mortality at 3 years, secondary endpoints were in-hospital mortality, rehospitalization rates and major adverse cardiac event (MACE) at 3 years. A total of 198 consecutive ICD recipients were included (AMI–VTA: 56%; ST-segment elevation myocardial infarction (STEMI): 22%; non-ST-segment myocardial infarction (NSTEMI) 78%; ES: 44%). ES patients were older and had higher rates of severely reduced left ventricular ejection fraction (LVEF) < 35%. ES was associated with increased all-cause mortality at 3 years (37% vs. 19%; p = 0.001; hazard ratio [HR] = 2.242; 95% CI 2.291–3.894; p = 0.004) and with increased risk of first cardiac rehospitalization (44% vs. 12%; p = 0.001; HR = 4.694; 95% CI 2.498–8.823; p = 0.001). This worse prognosis of ES compared to AMI–VTA was still evident after multivariable adjustment (long-term all-cause mortality: HR = 2.504; 95% CI 1.093–5.739; p = 0.030; first cardiac rehospitalization: HR = 2.887; 95% CI 1.240–6.720; p = 0.014). In contrast, the rates of MACE (40% vs. 32%; p = 0.326) were comparable in both groups. At long-term follow-up of 3 years, ES was associated with higher rates of all-cause mortality and rehospitalization compared to patients with AMI–VTA.
Molecular characterization of the Yp11.2 region deletion in the Chinese Han population
Authors: Pang Qianqian , Lin Qingai , Wang Di , Sun Zhenghao , Wang Junfang
Published: April 2021

The Y chromosome is male-specific and is important for spermatogenesis and male fertility. However, the Y chromosome is poorly characterized due to massive palindromes and inverted repeats, which increase the likelihood of genomic rearrangements, resulting in short tandem repeats on the Y chromosome or long fragment deletions. The present study reports a large-scale (2.573~2.648 Mb) deletion in the Yp11.2 region in a Chinese population based on the analysis of 34 selected Y-specific sequence-tagged sites and subsequent sequencing of the breakpoint junctions on the Y chromosome from 5,068,482–5,142,391 bp to 7,715,462–7,716,695 bp. The results of sequence analysis indicated that the deleted region included part or all of the following five genes: PCDH11Y, TSPY, AMELY, TBL1Y, and RKY. These genes are associated with spermatogenesis or amelogenesis and various other processes; however, specific physiological functions and molecular mechanisms of these genes remain unclear. Notably, individuals with this deletion pattern did not have an obvious pathological phenotype but manifested some degree of amelogenesis imperfecta.
A case series of intracranial dural arteriovenous fistulae mimicking cervical myelitis: a diagnosis not to be missed
Authors: Whittam Daniel , Huda Saif , Gibbons Emily , Pullicino Richard , Solomon Tom , Chandran Arun , Puthuran Mani , Jacob Anu
Published: April 2021

Objective

To describe the diagnostic features of intracranial dural arteriovenous fistulae (DAVF) presenting with cervical cord or brainstem swelling.

Methods

Retrospective case note and neuroimaging review of patients with angiographically confirmed DAVF diagnosed during January 2015–June 2020 at a tertiary neuroscience centre (Walton Centre NHS Foundation Trust, Liverpool, UK).

Results

Six intracranial DAVF causing cervical cord or brainstem oedema (all males aged 60–69 years) and 27 spinal DAVF (88% thoracolumbar) were detected over a 5.5-year period. Significantly more patients with intracranial DAVF received steroids for presumed inflammatory myelitis than those with spinal DAVF (5/6 vs 1/27, p = 0.0001, Fisher’s exact test). Several factors misled the treating clinicians: atypical rostral location of cord oedema (6/6); acute clinical deterioration (4/6); absence (3/6) or failure to recognise (3/6) subtle dilated perimedullary veins on MRI; intramedullary gadolinium enhancement (2/6); and elevated CSF protein (4/5). Acute deterioration followed steroid treatment in 4/5 patients. The following features may suggest DAVF rather than myelitis: older male patients (6/6), symptomatic progression over 4 or more weeks (6/6) and acellular CSF (5/5).

Conclusion

Intracranial DAVF are uncommon but often misdiagnosed and treated as myelitis, which can cause life-threatening deterioration. Neurologists must recognise suggestive features and consider angiography, especially in older male patients. Dilated perimedullary veins are an important clue to underlying DAVF, but may be invisible or easily missed on routine MRI sequences.
Investigating the neurochemistry of the human visual system using magnetic resonance spectroscopy
Authors: Ip I. Betina , Bridge Holly
Published: April 2021

Biochemical processes underpin the structure and function of the visual cortex, yet our understanding of the fundamental neurochemistry of the visual brain is incomplete. Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive brain imaging tool that allows chemical quantification of living tissue by detecting minute differences in the resonant frequency of molecules. Application of MRS in the human brain in vivo has advanced our understanding of how the visual brain consumes energy to support neural function, how its neural substrates change as a result of disease or dysfunction, and how neural populations signal during perception and plasticity. The aim of this review is to provide an entry point to researchers interested in investigating the neurochemistry of the visual system using in vivo measurements. We provide a basic overview of MRS principles, and then discuss recent findings in four topics of vision science: (i) visual perception, plasticity in the (ii) healthy and (iii) dysfunctional visual system, and (iv) during visual stimulation. Taken together, evidence suggests that the neurochemistry of the visual system provides important novel insights into how we perceive the world.
ORi™: a new indicator of oxygenation
Authors: Ishida Yusuke , Okada Toshio , Kobayashi Takayuki , Uchino Hiroyuki
Published: April 2021

In the perioperative period, hypoxemia and hyperoxia are crucial factors that require attention, because they greatly affect patient prognoses. The pulse oximeter has been the only noninvasive monitor that can be used as a reference of oxygenation in current anesthetic management; however, in recent years, a new monitoring method that uses the oxygen reserve index (ORi™) has been developed by Masimo Corp. ORi is an index that reflects the state of moderate hyperoxia (partial pressure of arterial oxygen [PaO2] between 100 and 200 mmHg) using a non-unit scale between 0.00 and 1.00. ORi monitoring performed together with percutaneous oxygen saturation (SpO2) measurements may become an important technique in the field of anesthetic management, for measuring oxygenation reserve capacity. By measuring ORi, it is possible to predict hypoxemia and to detect hyperoxia at an early stage. In this review, we summarize the method of ORi, cautions for its use, and suitable cases for its use. In the near future, the monitoring of oxygen concentrations using ORi may become increasingly common for the management of respiratory function before, after, and during surgery.
Korovkin-type theorems on $$B({\mathcal {H}})$$ and their applications to function spaces
Authors: Bauer Wolfram , Kumar V. B. Kiran , Rajan Rahul
Published: April 2021

We prove Korovkin-type theorems in the setting of infinite dimensional Hilbert space operators. The classical Korovkin theorem unified several approximation processes. Also, the non-commutative versions of the theorem were obtained in various settings such as Banach algebras, $$C^{*}$$

C

∗

-algebras and lattices etc. The Korovkin-type theorem in the context of preconditioning large linear systems with Toeplitz structure can be found in the recent literature. In this article, we obtain a Korovkin-type theorem on $$B({\mathcal {H}})$$

B
(
H
)

which generalizes all such results in the recent literature. As an application of this result, we obtain Korovkin-type approximation for Toeplitz operators acting on various function spaces including Bergman space $$A^{2}({\mathbb {D}})$$

A
2

(
D
)

, Fock space $$F^{2}({\mathbb {C}})$$

F
2

(
C
)

etc. These results are closely related to the preconditioning problem for operator equations with Toeplitz structure on the unit disk $${\mathbb {D}}$$
D
and on the whole complex plane $${\mathbb {C}}$$
C
. It is worthwhile to notice that so far such results are available for Toeplitz operators on circle only. This also establishes the role of Korovkin-type approximation techniques on function spaces with certain oscillation property. To address the function theoretic questions using these operator theory tools will be an interesting area of further research.
Creation and validation of the Postpartum Specific Anxiety Scale Research Short-Form (PSAS-RSF)
Authors: Davies Siân M. , Christiansen Paul , Harrold Joanne A. , Silverio Sergio A. , Fallon Victoria
Published: April 2021

The Postpartum Specific Anxiety Scale (PSAS) is a valid, reliable measure of postpartum anxiety (PPA). However, it contains 51 items, so is limited by its length. This study aimed to reduce the number of items in the PSAS, produce a small number of high-performing short-form tools, and confirm the factor structure of the most statistically and theoretically meaningful model. A pooled sample of English-speaking mothers (N = 2033) with infants up to 12 months were randomly split into three samples. (1) A principal component analysis (PCA) was conducted to initially reduce the items (n = 672). (2) Four short-form versions of varying length (informed by statistical, theoretical, lay-person, and expert-guided feedback) were developed and their factor structure examined (n = 673). (3) A final confirmatory factor analysis (CFA) was performed to confirm the factor structure of the PSAS Research Short-Form (PSAS-RSF) (n = 688). PCA and theoretical review reduced the items from 51 to 34 (version 1). Statistical review retained 22 items (version 2). Quantitative expert panel data retained 17 items (version 3). Qualitative expert panel data retained 16 items (version 4). The 16-item version was deemed the most theoretically and psychometrically robust. The resulting 16-item PSAS-RSF demonstrated good psychometric properties and reliability. The PSAS-RSF is the first brief research tool which has been validated to measure PPA. Our findings demonstrate it is theoretically meaningful, statistically robust, reliable, and valid. This study extends the use of the measure up to 12 months postpartum, offering broader opportunity for measurement while further enhancing accessibility through brevity.
A qualitative investigation of LGBTQ+ young people’s experiences and perceptions of self-managing their mental health
Authors: Town Rosa , Hayes Daniel , Fonagy Peter , Stapley Emily
Published: April 2021

There is evidence that young people generally self-manage their mental health using self-care strategies, coping methods and other self-management techniques, which may better meet their needs or be preferable to attending specialist mental health services. LGBTQ+ young people are more likely than their peers to experience a mental health difficulty and may be less likely to draw on specialist support due to fears of discrimination. However, little is known about LGBTQ+ young people’s experiences and perceptions of self-managing their mental health. Using a multimodal qualitative design, 20 LGBTQ+ young people participated in a telephone interview or an online focus group. A semi-structured schedule was employed to address the research questions, which focussed on LGBTQ+ young people’s experiences and perceptions of self-managing their mental health, what they perceived to stop or help them to self-manage and any perceived challenges to self-management specifically relating to being LGBTQ+ . Reflexive thematic analysis yielded three key themes: (1) self-management strategies and process, (2) barriers to self-management and (3) facilitators to self-management. Participants’ most frequently mentioned self-management strategy was ‘speaking to or meeting up with friends or a partner’. Both barriers and facilitators to self-management were identified which participants perceived to relate to LGBTQ+ identity. Social support, LGBTQ+ youth groups and community support were identified as key facilitators to participants’ self-management of their mental health, which merits further investigation in future research. These findings also have important implications for policy and intervention development concerning LGBTQ+ young people’s mental health.
Coriolis-induced instabilities in centrifuge modeling of granular flow
Authors: Leonardi A. , Cabrera M. A. , Pirulli M.
Published: April 2021

Granular flows are typically studied in laboratory flumes based on common similarity scaling, which create stress fields that only roughly approximate field conditions. The geotechnical centrifuge produces stress conditions that are closer to those observed in the field, but steady conditions can be hardly achieved. Moreover, secondary effects induced by the apparent Coriolis acceleration, which can either dilate or compress the flow, often obscure scaling. This work aims at studying a set of numerical experiments where the effects of the Coriolis acceleration are measured and analyzed. Three flow states are observed: dense, dilute, and unstable. It is found that flows generated under the influence of dilative Coriolis accelerations are likely to become unstable. Nevertheless, a steady dense flow can still be obtained if a large centrifuge is used. A parametric group is proposed to predict the insurgence of instabilities; this parameter can guide experimental designs and could help to avoid damage to the experimental apparatus and model instrumentation.

Graphic abstract
Establishing Sustainable Cell Lines of a Coral, Acropora tenuis
Authors: Kawamura Kaz , Nishitsuji Koki , Shoguchi Eiichi , Fujiwara Shigeki , Satoh Noriyuki
Published: April 2021

Planula larvae of the scleractinian coral, Acropora tenuis, consist of elongated ectodermal cells and developing inner endodermal cells. To establish in vitro cell lines for future studies of cellular and developmental potential of coral cells, larvae were successfully dissociated into single cells by treating them with a tissue dissociation solution consisting of trypsin, EDTA, and collagenase. Brown-colored cells, translucent cells, and pale blue cells were the major components of dissociated larvae. Brown-colored cells began to proliferate transiently in the culture medium that was devised for the coral, while translucent cells and pale blue cells decreased in number about 1 week after cell dissociation. In addition, when a modular protease, plasmin, was added to the cell culture medium, brown-colored cells extended pseudopodia and assumed amorphous shapes. They then continued to proliferate in clumps for more than 6 months with a doubling time of approximately 4–5 days. From 3 weeks of cell culture onward, brown-colored cells often aggregated and exhibited morphogenesis-like behavior to form flat sheets, and blastula-like clusters or gastrula-like spheres. Single cells or cell-clusters of the cell lines were analyzed by RNA-seq. This analysis showed that genes expressed in these cells in vitro were A. tenuis genes. Furthermore, each cell line expressed a specific set of genes, suggesting that their properties include gastroderm, secretory cells, undifferentiated cells, neuronal cells, and epidermis. All cell properties were maintained stably throughout successive cell cultures. These results confirm the successful establishment of a coral in vitro cell line.
Direct oral anticoagulants vs. low-molecular-weight heparin for pulmonary embolism in patients with glioblastoma
Authors: Dubinski Daniel , Won Sae-Yeon , Voss Martin , Keil Fee , Miesbach Wolfgang , Behmanesh Bedjan , Dosch Max , Baumgarten Peter , Bernstock Joshua D. , Seifert Volker , Freiman Thomas M. , Gessler Florian
Published: April 2021

Glioblastoma (GBM) is a cancer type with high thrombogenic potential and GBM patients are therefore at a particularly high risk for thrombotic events. To date, only limited data on anticoagulation management after pulmonary embolism (PE) in GBM is available and the sporadic use of DOACs remains off-label. A retrospective cohort analysis of patients with GBM and postoperative, thoracic CT scan confirmed PE was performed. Clinical course, follow-up at 6 and 12 months and the overall survival (OS) were evaluated using medical charts and neuroradiological data. Out of 584 GBM patients, 8% suffered from postoperative PE. Out of these, 30% received direct oral anticoagulants (DOACs) and 70% low-molecular-weight heparin (LMWH) for therapeutic anticoagulation. There was no significant difference in major intracranial hemorrhage (ICH), re-thrombosis, or re-embolism between the two cohorts. Although statistically non-significant, a tendency to reduced mRS at 6 and 12 months was observed in the LMWH cohort. Furthermore, patients receiving DOACs had a statistical benefit in OS. In our analysis, DOACs showed a satisfactory safety profile in terms of major ICH, re-thrombosis, and re-embolism compared to LMWH in GBM patients with postoperative PE. Prospective, randomized trials are urgent to evaluate DOACs for therapeutic anticoagulation in GBM patients with PE.
Craniotomy size for traumatic acute subdural hematomas in elderly patients—same procedure for every age?
Authors: Pinggera Daniel , Bauer Marlies , Unterhofer Michael , Thomé Claudius , Unterhofer Claudia
Published: April 2021

Surgical treatment of acute subdural hematoma (aSDH) is still matter of debate, especially in the elderly. A retrospective study to compare two different surgical approaches, namely standard (SC, craniotomy size > 8 cm) and limited craniotomy (LC, craniotomy size < 8 cm), was conducted in elderly patients with traumatic aSDH to identify the role of craniotomy size in terms of clinical and radiological outcome. Sixty-four patients aged 75 or older with aSDH as sole lesion were retrospectively analyzed. Data were collected pre- and postoperatively including clinical and radiological criteria. The primary outcome parameter was 30-day mortality. Secondary outcome parameters were radiological. The mean age was 79.2 (± 3.1) years with no difference between groups and almost equal distribution of craniotomy size. Mortality rate was significantly higher in the SC group in comparison to the LC group (68.4% vs. 31.6%; p = 0.045). The preoperative HD (p = 0.08) and the MLS (p = 0.09) were significantly higher in the SC group, whereas postoperative radiological evaluation showed no significant difference in HD or MLS. A limited craniotomy is sufficient for adequate evacuation of an aSDH in the elderly achieving the same radiological and clinical outcome.
Differences in the expression of SSTR1–5 in meningiomas and its therapeutic potential
Authors: Behling Felix , Fodi Christina , Skardelly Marco , Renovanz Mirjam , Castaneda Salvador , Tabatabai Ghazaleh , Honegger Jürgen , Tatagiba Marcos , Schittenhelm Jens
Published: April 2021

Beyond microsurgical resection and radiation therapy, there are currently no established treatment alternatives for meningioma patients. In selected cases, peptide radio receptor therapy (PRRT) can be implemented. For this purpose, a radionuclide is bound to a substance targeting specific receptors in meningiomas. One of them is somatostatin receptor 2, which can be found in most meningiomas. However, other somatostatin receptors (SSTR) exist, but their expressions have only been described in small case series. In this study, we analyzed the expression of SSTR1, 2A, 3, 4, and 5 in a large cohort of meningiomas in order to enable further refinement of this innovative treatment option. Overall, 726 tumor samples were processed into tissue microarrays and stained for SSTR1, 2A, 3, 4, and 5 immunohistochemically. Microscopic evaluation was done with an established semiquantitative score regarding percentual quantification and staining intensity, and results were correlated with clinical data. There was a significant lower rate of SSTR1 expression in meningiomas of male patients. Older age was associated with higher expression of SSTR1, 2A, and 5 and lower scores for SSTR3 and 4. Tumors treated with radiotherapy before resection showed lower rates of SSTR1 and 5 expression, while recurrent meningiomas had lower SSTR1 scores. Tumor tissue from patients suffering from neurofibromatosis type 2 had lower expression scores for SSTR1, 2, and 5. For SSTR3 and 4, NF2 patients showed higher scores than sporadic tumors. Spinal meningiomas had higher scores for SSTR1, 4, and 5 compared tumor location of the skull base and convexity/falx. Overall, higher WHO grade was associated with lower SSTR scores. While all SSTRs were expressed, there are marked differences of SSTR expression between meningioma subgroups. This has the potential to drive the development of more selective PRRT substances with higher treatment efficacy.
A New Upper Bound for Sampling Numbers
Authors: Nagel Nicolas , Schäfer Martin , Ullrich Tino
Published: April 2021

We provide a new upper bound for sampling numbers $$(g_n)_{n\in \mathbb {N}}$$

(

g
n

)

n
∈
N

associated with the compact embedding of a separable reproducing kernel Hilbert space into the space of square integrable functions. There are universal constants $$C,c>0$$

C
,
c
>
0

(which are specified in the paper) such that $$\begin{aligned} g^2_n \le \frac{C\log (n)}{n}\sum \limits _{k\ge \lfloor cn \rfloor } \sigma _k^2,\quad n\ge 2, \end{aligned}$$

g
n
2

≤

C
log
(
n
)

n

∑

k
≥
⌊
c
n
⌋

σ
k
2

,

n
≥
2
,

where $$(\sigma _k)_{k\in \mathbb {N}}$$

(

σ
k

)

k
∈
N

is the sequence of singular numbers (approximation numbers) of the Hilbert–Schmidt embedding $$\mathrm {Id}:H(K) \rightarrow L_2(D,\varrho _D)$$

Id
:
H

(
K
)

→

L
2

(
D
,

ϱ
D

)

. The algorithm which realizes the bound is a least squares algorithm based on a specific set of sampling nodes. These are constructed out of a random draw in combination with a down-sampling procedure coming from the celebrated proof of Weaver’s conjecture, which was shown to be equivalent to the Kadison–Singer problem. Our result is non-constructive since we only show the existence of a linear sampling operator realizing the above bound. The general result can for instance be applied to the well-known situation of $$H^s_{\text {mix}}(\mathbb {T}^d)$$

H
mix
s

(

T

d

)

in $$L_2(\mathbb {T}^d)$$

L
2

(

T

d

)

with $$s>1/2$$

s
>
1
/
2

. We obtain the asymptotic bound $$\begin{aligned} g_n \le C_{s,d}n^{-s}\log (n)^{(d-1)s+1/2}, \end{aligned}$$

g
n

≤

C

s
,
d

n

-
s

log

(
n
)

(
d
-
1
)
s
+
1
/
2

,

which improves on very recent results by shortening the gap between upper and lower bound to $$\sqrt{\log (n)}$$

log
(
n
)

. The result implies that for dimensions $$d>2$$

d
>
2

any sparse grid sampling recovery method does not perform asymptotically optimal.
Physically distant but socially close? Changes in non-physical intergenerational contacts at the onset of the COVID-19 pandemic among older people in France, Italy and Spain
Authors: Arpino Bruno , Pasqualini Marta , Bordone Valeria
Published: April 2021

Physical distancing is intended to mitigate the spread of the SARS-CoV-2 virus. However, the impact of a decrease in face-to-face contacts on non-physical social contacts of older people remains unclear. In particular, we focus on intergenerational contacts that are especially relevant for older people’s mental health. Our analyses rely on an online quota sampling survey conducted in France, Italy and Spain during April 14–24, 2020. We considered the subsample of individuals aged 50 + (N = 4207). We calculated post-stratification weights based on official statistics and used logistic regressions to analyze how changes in intergenerational contacts differed by socioeconomic factors and to what extent non-physical contacts (via phone, social media, etc.) have compensated the reduction in face-to-face contacts. Finally, the change in digital devices’ use has been explored as a consequence of both decreased physical intergenerational contacts (PIC) and increased non-physical intergenerational contacts (NPIC). We found that about 50% of older people have increased their NPIC during the first lockdown. Younger individuals, those with medium level of education, and those economically better off displayed higher probabilities of increased NPIC as compared to their counterparts. NPIC increased especially for individuals whose face-to-face contacts decreased, particularly so if this happened with respect to contacts with children. A large share of older people has increased their use of video calls and instant messages, while only some increased the use of social media. These findings are relevant to understand how intergenerational contacts changed during the pandemic and may be central to better plan future outbreak responses.
Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster
Authors: Turnell Biz R. , Kumpitsch Luisa , Reinhardt Klaus
Published: April 2021

Sperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.
A space mission to map the entire observable universe using the CMB as a backlight
Authors: Basu Kaustuv , Remazeilles Mathieu , Melin Jean-Baptiste , Alonso David , Bartlett James G. , Battaglia Nicholas , Chluba Jens , Churazov Eugene , Delabrouille Jacques , Erler Jens , Ferraro Simone , Hernández-Monteagudo Carlos , Hill J. Colin , Hotinli Selim C. , Khabibullin Ildar , Madhavacheril Mathew , Mroczkowski Tony , Nagai Daisuke , Raghunathan Srinivasan , Martin Jose Alberto Rubino , Sayers Jack , Scott Douglas , Sugiyama Naonori , Sunyaev Rashid , Zubeldia Íñigo
Published: April 2021

This Science White Paper, prepared in response to the ESA Voyage 2050 call for long-term mission planning, aims to describe the various science possibilities that can be realized with an L-class space observatory that is dedicated to the study of the interactions of cosmic microwave background (CMB) photons with the cosmic web. Our aim is specifically to use the CMB as a backlight – and survey the gas, total mass, and stellar content of the entire observable Universe by means of analyzing the spatial and spectral distortions imprinted on it. These distortions result from two major processes that impact on CMB photons: scattering by free electrons and atoms (Sunyaev-Zeldovich effect in diverse forms, Rayleigh scattering, resonant scattering) and deflection by gravitational potential (lensing effect). Even though the list of topics collected in this White Paper is not exhaustive, it helps to illustrate the exceptional diversity of major scientific questions that can be addressed by a space mission that will reach an angular resolution of 1.5 arcmin (goal 1 arcmin), have an average sensitivity better than 1 μK-arcmin, and span the microwave frequency range from roughly 50 GHz to 1 THz. The current paper also highlights the synergy of our Backlight mission concept with several upcoming and proposed ground-based CMB experiments.
Using Micro-Scale and Solid Material Data for Modelling Heat Transfer in Stone Wool Composites Under Heat Exposures
Authors: Andres B. , Livkiss K. , Bhargava A. , van Hees P.
Published: April 2021

Modelling capabilities have drastically improved in the last decade. However, in most of the cases the fire response of building elements is predicted by fitting input material properties to the models in order to match test data. This paper presents models developed to predict the unexposed side temperature of stone wool layered composites with stainless steel or gypsum claddings exposed to severe heat conditions. The suitability of material thermal properties from literature and reaction kinetic parameters obtained at bench scale (e.g. thermogravimetric analysis, bomb calorimeter, slug test) to model composites at different heat exposures is studied. Modelling efforts include: (1) the combustion of the organic content of the wool, (2) diffusion term to account for the passage of hot air through the wool, (3) calcination reactions in the gypsum plasterboard, (4) energy released by burning of the paper lining of gypsum plasterboard. The models are compared against experimental data. Results show that material thermal properties of gypsum plasterboard and stone wool retrieved from the literature and obtained at a bench scale provide accurate model predictions under different heat exposures. Furthermore, reactions schemes for the dehydration of gypsum plasterboard and organic content combustion in the wool also provide good modelling results. Further analysis is necessary to understand the environmental conditions inside the layered composites in fire exposures in order to achieve better modelling predictions.
The Devil Burns Gold There: The Heritage of Nazi Germany Crimes in Death Valley, Chojnice, Poland
Authors: Kobiałka Dawid
Published: April 2021

This paper is about Death Valley – a site of mass killings orchestrated by Nazi Germany that took place on the outskirts of Chojnice during the Second World War. I begin by referring to some examples of conflict archaeology that persuasively demonstrate how what has so far been the domain of history is transforming into archaeology. I then present historical information concerning Death Valley. Following this, the paper presents the results of archaeological investigations into material traces of mass killings in Death Valley. Finally, I present an ethnography of Death Valley, scrutinizing the contemporary role of the site among local communities.
Eberlein decomposition for PV inflation systems
Authors: Baake Michael , Strungaru Nicolae
Published: April 2021

The Dirac combs of primitive Pisot–Vijayaraghavan (PV) inflations on the real line or, more generally, in$${\mathbb {R}}^d$$Rdare analysed. We construct a mean-orthogonal splitting for such Dirac combs that leads to the classic Eberlein decomposition on the level of the pair correlation measures, and thus to the separation of pure point versus continuous spectral components in the corresponding diffraction measures. This is illustrated with two guiding examples, and an extension to more general systems with randomness is outlined.