bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploiting the drag reduction characteristics of dense pastes transporting in pipe with boundary liquids injection
Authors: Chunzhi Li , Fuyan Lyu , Di Jiang , Minjun Zhang , Qingguang Chen
Published: June 2021

When dense paste transports in pipe, the pressure loss is enormous. To make use of the wall slip phenomenon, different liquids were injected into the boundary layer in horizontal pipe and pressure loss per unit reduces. Through the pipe transportation tests, the effect of different factors to the resistance was analysed respectively, such as the thickness of boundary layer, the concentration of material, the type of drag reducer, the transport velocity and the flow rate. Results show that the drag reduction effect is much better with a higher thickness and lower transport velocity, and also obtains that PEO (Polyethylene oxide) solution as boundary layer is much more effective than water. With analysis of variance and significance test, the influence degree of the three main factors on the transport resistance is sorted as the thickness of the boundary layer, paste concentration, pipe diameter. The thickness of boundary layer has the greatest influence on the transport resistance. All conclusions provide a basis for how to use the boundary layer rationally in engineering paste pipeline transportation system.
Linear Shape Memory Polyester with Programmable Splitting of Crystals
Authors: Zhou Ziting , Meng Yue , Wei Cong , Bai Ying , Wang Xiaoying , Quan Daping , Zhou Jing
Published: June 2021

Shape memory polymers (SMPs)are widely used owing to their ability to change shapes under external stimuli. Conventional covalently crosslinked SMPs have limitations in biomedical applications. This article presents a linear shape memory biodegradable polyester without chemical crosslinks or multiblock structures. A new programming protocol is developed to split the crystals into two parts with different melting transitions through partial melting/recrystallization. The split crystals play different roles in fixation and recovery process to complete a shape memory cycle. The ratio between the partitioned crystals affects the fixed rate and recovery rate. The shape memory performance can be optimized by controlling the partial melting temperature and pre‐stretching of the sample. Examples of complicated shape changes demonstrate the effectiveness of the proposed technique. The method is applicable to crystallizable linear polymers and has potential applications in implantation devices.
Spectral CT using a fine grid structure and varying x‐ray incidence angle
Authors: Stayman J. Webster , Tivnan Matthew , Wang Wenying , Shapira Nadav , Gang Grace J. , Noël Peter B.
Published: June 2021

Purpose

Interest in spectral computed tomography (CT) for diagnostics and therapy evaluation has been growing. Data acquisitions with distinct spectral sensitivities provide the ability to discriminate multiple materials, quantitative density estimates, and reduced artifacts due to energy dependencies. We introduce a novel spectral CT concept that includes a fine‐pitch grid structure for prefiltration of the x‐ray beam.

Methods

We develop physical models for grid designs and illustrate the basic operating principles wherein small angulations of the incident x rays results significant filtration and spectral shaping of the beam. We fabricate a prototype grid with tungsten lamellae. We compare x‐ray spectra induced by this filter as a function of incidence angle in both simulation students and in physical measurements. The grid is also integrated onto a CT test bench where we scanned an iodinated phantom with clinically relevant concentrations (5, 10, 20, and 50 mgI/mL) to demonstrate the ability to perform spectral CT acquisitions and material decomposition.

Results

X‐ray spectrometer measurements reveal diverse and controllable spectral shaping with small angle changes that are in agreement with simulation studies. Critical angles where the characteristics of the induced spectrum changes dramatically are identified. Reconstructions of projection data for two angulations separated by 2° was reconstructed and material decomposition into iodine and water images shows good agreement with the known iodine concentrations.

Conclusions

This work demonstrates the feasibility of the grid‐based approach to enable spectral CT data acquisitions and accurate material decompositions. On‐going and future studies will investigate the potential of this novel concept as a relatively simple upgrade to standard energy‐integrating CT.
Social stratification during the Eastern Zhou Dynasty of China (771–476 bce): Mortuary and stable isotopic analyses of the Shangshihe cemetery
Authors: Zhou Yawei , Fu Rongyu , Zheng Lichao , Yan Fei , Wang Qian
Published: June 2021

Historic records for the Zhou Dynasty of China (1046–256 bce) defined distinct differentiation of social classes, in which ways of life and the afterlife were put into written form to regulate funerary and dietary practices. The presence of social stratification would suggest differences in nutrition during life and in ceremonial values for the afterlife. In this study, we examined grave goods and human skeletons from people of different social classes in the Guo State (虢) during the Spring–Autumn Period of the Eastern Zhou Dynasty (771–476 bce). Specimens were excavated from the Shangshihe cemetery in Yima County, Henan Province, China. Differences in total burial values and diet structure between different social ranks, sex, and age groups were assessed using mortuary and isotopic analyses. Our mortuary analysis indicated that there were significant differences in grave size, complexity, and values of grave goods between people of different social classes. The stable carbon and nitrogen isotopic analysis indicated a trend that people buried with two or three coffin layers consumed more animal‐derived, protein‐rich food than people who were buried with one layer of coffin. The elderly might have had better nutrition than younger people did. However, there was no sex‐based difference in nutrition between males and females. Results of these paralleled mortuary and isotopic analyses conform to historic records of social stratification in the Zhou Dynasty of China. Evidence of social stratification and its impact on nutrition and health should be considered while assessing the nutrition and health of ancient human individuals and communities.
Capacity for increased surface area in the hydrophobic core of β‐sheet peptide bilayer nanoribbons
Authors: Jones Christopher W. , Morales Crystal G. , Eltiste Sharon L. , Yanchik‐Slade Francine E. , Lee Naomi R. , Nilsson Bradley L.
Published: June 2021

Amphipathic peptides with amino acids arranged in alternating patterns of hydrophobic and hydrophilic residues efficiently self‐assemble into β‐sheet bilayer nanoribbons. Hydrophobic side chain functionality is effectively buried in the interior of the putative bilayer of these nanoribbons. This study investigates consequences on self‐assembly of increasing the surface area of aromatic side chain groups that reside in the hydrophobic core of nanoribbons derived from Ac‐(XKXE)2‐NH2 peptides (X = hydrophobic residue). A series of Ac‐(XKXE)2‐NH2 peptides incorporating aromatic amino acids of increasing molecular volume and steric profile (X = phenylalanine [Phe], homophenylalanine [Hph], tryptophan [Trp], 1‐naphthylalanine [1‐Nal], 2‐naphthylalanine [2‐Nal], or biphenylalanine [Bip]) were assessed to determine substitution effects on self‐assembly propensity and on morphology of the resulting nanoribbon structures. Additional studies were conducted to determine the effects of incorporating amino acids of differing steric profile in the hydrophobic core (Ac‐X1KFEFKFE‐NH2 and Ac‐(X1,5KFE)‐NH2 peptides, X = Trp or Bip). Spectroscopic analysis by circular dichroism (CD) and Fourier transform infrared (FT‐IR) spectroscopy indicated β‐sheet formation for all variants. Self‐assembly rate increased with peptide hydrophobicity; increased molecular volume of the hydrophobic side chain groups did not appear to induce kinetic penalties on self‐assembly rates. Transmission electron microscopy (TEM) imaging indicated variation in fibril morphology as a function of amino acid in the X positions. This study confirms that hydrophobicity of amphipathic Ac‐(XKXE)2‐NH2 peptides correlates to self‐assembly propensity and that the hydrophobic core of the resulting nanoribbon bilayers has a significant capacity to accommodate sterically demanding functional groups. These findings provide insight that may be used to guide the exploitation of self‐assembled amphipathic peptides as functional biomaterials.
Lipemic aqueous humor and suspected xanthomas associated with primary hypertriglyceridemia in a cat
Authors: Barachetti Laura , Fanton Natalia , Savov Stefan , Cancelli Irene , Miller Paul E.
Published: June 2021

A 1‐year‐old, male neutered, European Shorthair cat presented for bilateral lipemic aqueous humour and mildly increased intraocular pressure in the left eye. Laboratory evaluations showed hypertriglyceridemia and elevation of alpha‐1‐globulins and serum amyloid‐A. The initial treatment plan consisted of topical flurbiprofen, tobramycin‐dexamethasone, dorzolamide and low‐fat diet. Lipemic aqueous resolved within 72 hours without recurrence. Presumed lipemic droplets were observed in the vitreous. Two months after the initial diagnosis the cat returned with dermatological changes, consisting of pale pink papules and erosions on the neck and ear pinna with pruritus. Cytology of these lesions was consistent with cutaneous xanthoma. A primary familial hypertriglyceridemia was confirmed by exclusion on the basis of normal abdominal ultrasound, urine test and repeated blood work after the change of the diet. The xanthomas resolved two weeks after further restriction of the diet. At 74‐weeks after initial presentation posterior subcapsular lenticular opacities appeared in both eyes.
The Bethe-Ansatz approach to the $$ \mathcal{N} $$ = 4 superconformal index at finite rank
Authors: Lezcano Alfredo González , Hong Junho , Liu James T. , Pando Zayas Leopoldo A.
Published: June 2021

Abstract

We investigate the Bethe-Ansatz approach to the superconformal index of $$ \mathcal{N} $$
N
= 4 supersymmetric Yang-Mills with SU(N) gauge group in the context of finite rank, N. We explicitly explore the role of the various types of solutions to the Bethe-Ansatz Equations in recovering the exact index for N = 2, 3. We classify the Bethe-Ansatz Equations solutions as standard (corresponding to a freely acting orbifold T2/ℤm× ℤn) and non-standard. For N = 2, we find that the index is fully recovered by standard solutions and displays an interesting pattern of cancellations. However, for N ≥ 3, the standard solutions alone do not suffice to reconstruct the index. We present quantitative arguments in various regimes of fugacities that highlight the challenging role played by the continuous families of non-standard solutions.
Graphical Modelling of Hoop Force Distribution for Equilibrium Analysis of Masonry Domes
Authors: Paris Vittorio , Ruscica Giuseppe , Mirabella Roberti Giulio
Published: June 2021

The behaviour of axisymmetric masonry shells can be simulated by a system of forces constituted by meridian forces acting in the vertical planes, and by hoop forces acting circumferentially. A crucial component for the assessment of these structures using the Modified Thrust Line Method (MTLM) is the determination of hoop forces, whose computation is strenuous, limiting the practical application of MTLM. Working around this limitation, the current research introduces a strategy to manipulate the hoop forces by graphically implementing a function describing their distribution. The adaptiveness of this distribution function not only allows the application of MTLM for the analysis of a range of geometries, but also enables the simulation of membrane behaviour, arch behaviour and their combination, for considering partially cracked structures. Taking this into account, the approach is applied in the case studies illustrated within the current research.
Stromal interaction molecule 1 (STIM1) knock down attenuates invasion and proliferation and enhances the expression of thyroid-specific proteins in human follicular thyroid cancer cells
Authors: Asghar Muhammad Yasir , Lassila Taru , Paatero Ilkka , Nguyen Van Dien , Kronqvist Pauliina , Zhang Jixi , Slita Anna , Löf Christoffer , Zhou You , Rosenholm Jessica , Törnquist Kid
Published: June 2021

Stromal interaction molecule 1 (STIM1) and the ORAI1 calcium channel mediate store-operated calcium entry (SOCE) and regulate a multitude of cellular functions. The identity and function of these proteins in thyroid cancer remain elusive. We show that STIM1 and ORAI1 expression is elevated in thyroid cancer cell lines, compared to primary thyroid cells. Knock-down of STIM1 or ORAI1 attenuated SOCE, reduced invasion, and the expression of promigratory sphingosine 1-phosphate and vascular endothelial growth factor-2 receptors in thyroid cancer ML-1 cells. Cell proliferation was attenuated in these knock-down cells due to increased G1 phase of the cell cycle and enhanced expression of cyclin-dependent kinase inhibitory proteins p21 and p27. STIM1 protein was upregulated in thyroid cancer tissue, compared to normal tissue. Downregulation of STIM1 restored expression of thyroid stimulating hormone receptor, thyroid specific proteins and increased iodine uptake. STIM1 knockdown ML-1 cells were more susceptible to chemotherapeutic drugs, and significantly reduced tumor growth in Zebrafish. Furthermore, STIM1-siRNA-loaded mesoporous polydopamine nanoparticles attenuated invasion and proliferation of ML-1 cells. Taken together, our data suggest that STIM1 is a potential diagnostic and therapeutic target for treatment of thyroid cancer.
On Pleijel’s Nodal Domain Theorem for Quantum Graphs
Authors: Hofmann Matthias , Kennedy James B. , Mugnolo Delio , Plümer Marvin
Published: June 2021

We establish metric graph counterparts of Pleijel’s theorem on the asymptotics of the number of nodal domains $$\nu _n$$

ν
n

of the nth eigenfunction(s) of a broad class of operators on compact metric graphs, including Schrödinger operators with $$L^1$$

L
1

-potentials and a variety of vertex conditions as well as the p-Laplacian with natural vertex conditions, and without any assumptions on the lengths of the edges, the topology of the graph, or the behaviour of the eigenfunctions at the vertices. Among other things, these results characterise the accumulation points of the sequence $$(\frac{\nu _n}{n})_{n\in \mathbb {N}}$$

(

ν
n

n

)

n
∈
N

, which are shown always to form a finite subset of (0, 1]. This extends the previously known result that $$\nu _n\sim n$$

ν
n

∼
n

generically, for certain realisations of the Laplacian, in several directions. In particular, in the special cases of the Laplacian with natural conditions, we show that for graphs any graph with pairwise commensurable edge lengths and at least one cycle, one can find eigenfunctions thereon for which $${\nu _n}\not \sim {n}$$

ν
n

≁
n

; but in this case even the set of points of accumulation may depend on the choice of eigenbasis.
Bigrassmannian permutations and Verma modules
Authors: Ko Hankyung , Mazorchuk Volodymyr , Mrđen Rafael
Published: June 2021

We show that bigrassmannian permutations determine the socle of the cokernel of an inclusion of Verma modules in type A. All such socular constituents turn out to be indexed by Weyl group elements from the penultimate two-sided cell. Combinatorially, the socular constituents in the cokernel of the inclusion of a Verma module indexed by $$w\in S_n$$

w
∈

S
n

into the dominant Verma module are shown to be determined by the essential set of w and their degrees in the graded picture are shown to be computable in terms of the associated rank function. As an application, we compute the first extension from a simple module to a Verma module.
Variation propagation modeling in multistage machining processes considering form errors and N-2-1 fixture layouts
Authors: Yacob Filmon , Semere Daniel , Anwer Nabil
Published: June 2021

Variation propagation modeling of multistage machining processes enables variation reduction by making an accurate prediction on the quality of a part. Part quality prediction through variation propagation models, such as stream of variation and Jacobian-Torsor models, often focus on a 3-2-1 fixture layout and do not consider form errors. This paper derives a mathematical model based on dual quaternion for part quality prediction given parts with form errors and fixtures with N-2-1 (N>3) layout. The method uses techniques of Skin Model Shapes and dual quaternions for a virtual assembling of a part on a fixture, as well as conducting machining and measurement. To validate the method, a part with form errors produced in a two-stationed machining process with a 12-2-1 fixture layout was considered. The prediction made following the proposed method was within 0.4% of the prediction made using a CAD/CAM simulation when form errors were not considered. These results validate the method when form errors are neglected and partially validated when considered.
New preconditioners for the Laplace and Helmholtz integral equations on open curves: analytical framework and numerical results
Authors: Alouges François , Averseng Martin
Published: June 2021

Helmholtz wave scattering by open screens in 2D can be formulated as first-kind integral equations which lead to ill-conditioned linear systems after discretization. We introduce two new preconditioners in the form of square-roots of on-curve differential operators both for the Dirichlet and Neumann boundary conditions on the screen. They generalize the so-called “analytical” preconditioners available for Lipschitz scatterers. We introduce a functional setting adapted to the singularity of the problem and enabling the analysis of those preconditioners. The efficiency of the method is demonstrated on several numerical examples.
Amendment to: populations in environments with a soft carrying capacity are eventually extinct
Authors: Jagers Peter , Zuyev Sergei
Published: June 2021

This sharpens the result in the paper Jagers and Zuyev (J Math Biol 81:845–851, 2020): consider a population changing at discrete (but arbitrary and possibly random) time points, the conditional expected change, given the complete past population history being negative, whenever population size exceeds a carrying capacity. Further assume that there is an $$\epsilon > 0$$

ϵ
>
0

such that the conditional probability of a population decrease at the next step, given the past, always exceeds $$\epsilon $$
ϵ
if the population is not extinct but smaller than the carrying capacity. Then the population must die out.
Meat consumption and cancer of unknown primary (CUP) risk: results from The Netherlands cohort study on diet and cancer
Authors: Hermans Karlijn E. P. E. , van den Brandt Piet A. , Loef Caroline , Jansen Rob L. H. , Schouten Leo J.
Published: June 2021

Purpose

Cancer of unknown primary (CUP) is a metastasised cancer for which no primary lesion could be identified during life. Research into CUP aetiology with respect to dietary factors is particularly scarce. This study investigates whether meat consumption is associated with CUP risk.

Methods

Data was utilised from the prospective Netherlands cohort study that includes 1,20,852 participants aged 55–69 years. All participants completed a self-administered questionnaire on diet and other cancer risk factors at baseline. Cancer follow-up was established through record linkage to the Netherlands Cancer Registry and the Dutch Pathology Registry. A total of 899 CUP cases and 4111 subcohort members with complete and consistent dietary data were available for case–cohort analyses after 20.3 years of follow-up. Multivariable adjusted hazard ratios (HRs) were calculated using proportional hazards models.

Results

We found a statistically significant positive association with beef and processed meat consumption and CUP risk in women (multivariable adjusted HR Q4 vs. Q1 1.47, 95% CI 1.04–2.07, Ptrend = 0.004 and Q4 vs. Q1 1.53, 95% CI 1.08–2.16, Ptrend = 0.001, respectively), and a non-significant positive association with processed meat consumption and CUP risk in men (multivariable adjusted HR Q4 vs. Q1 1.33, 95% CI 0.99–1.79, Ptrend = 0.15). No associations were observed between red meat (overall), poultry or fish consumption and CUP risk.

Conclusion

In this cohort, beef and processed meat consumption were positively associated with increased CUP risk in women, whereas a non-significant positive association was observed between processed meat consumption and CUP risk in men.
Application of platelet-rich plasma in rectovaginal fistulas in the patients with ulcerative colitis
Authors: Hermann Jacek , Cwaliński Jarosław , Banasiewicz Tomasz
Published: June 2021

Background

There is a need for other than surgical methods of therapy for small and low rectovaginal fistulas (RVF) in the course of inflammatory bowel diseases (IBD), such as application of fibrin sealants, stem cells, biological therapy, or platelet-rich plasma. The aim of this study was to evaluate the results of the treatment after local application of PRP in aforementioned fistulas, exclusively in the patients with ulcerative colitis (UC).

Patients and methods

Medical records of 13 patients with small and low-lying, active RVF in the course of UC, and after restorative proctocolectomy for UC were evaluated. Curettage of fistulous tracts was performed with the following application of PRP in all patients.

Results

Complete closure of RVF was achieved after the first injection in 4 patients, 3 women healed their fistulas following the second application, and two of them closed RVF after 3 injections. To sum up, the complete closure of RVF was achieved in 9 (69%) patients. Fistulas remained closed from 6 to 12 months.

Conclusions

The application of PRP in small, low, and recurrent IBD anal fistulas is effective, simple, and safe with an acceptable rate of healing. This therapy might also precede any further, surgical methods of treatment.
Interleukin-10-592 polymorphism: impact on relapse and survival after allogeneic hematopoietic stem cell transplantation in children with hematological malignancies
Authors: Schwenk Laura , Wittig Susan , Gruhn Bernd
Published: June 2021

Purpose

Interleukin-10 (IL-10) potentially can promote the development of alloimmunity. The aim of this study was to investigate if the IL-10-592 CC genotype in the donor reduces the risk of relapse after hematopoietic stem cell transplantation (HSCT) and if that has an impact on event-free survival (EFS) and overall survival (OS).

Methods

A cohort of 211 children with acute lymphoblastic leukemia (n = 99), acute myeloid leukemia (n = 69), myelodysplastic syndrome (n = 31) or chronic myeloid leukemia (n = 12) who underwent hematopoietic stem cell transplantation (HSCT) in a single center and their respective donors were genotyped of IL-10 gene for rs1800872 using TaqMan real-time polymerase chain reaction.

Results

The IL-10-592 CC genotype was detected in 107 of the 211 donors (50.7%) and in 106 of the 211 patients (50.2%). Genotype AC was found in 95 donors (45.0%) and in 90 patients (42.7%). Nine donors (4.3%) and 15 patients (7.1%) were homozygous for AA. Ultimately, we observed a significantly reduced incidence of relapse rate (RR) in patients who were transplanted from a donor with the IL-10-592 CC genotype (19% versus 43% (AC) versus 49% (AA);P = 0.0007). In addition, a significant increase of EFS (P = 0.004) and OS (P = 0.006) was detected if the IL-10-592 CC genotype is present in the donor. The occurrence of the IL-10-592 CC genotype, in either donors or recipients, had no significant impact on acute and chronic graft-versus-host disease. In addition, the IL-10-592 genotype of the recipients was not relevant for the RR (P = 0.47434), the EFS (P = 0.840), and the OS (P = 0.535).

Conclusion

The IL-10-592 CC genotype in the donor was associated with a significant decrease of RR which led to a significant increase of EFS and OS after HSCT. This is the first study to describe an association of the IL-10 gene polymorphism with RR, EFS, and OS after HSCT. Selecting a donor with the IL-10-592 CC genotype could be a useful therapeutic strategy for improving the outcome after allogeneic HSCT.
Ecological traps: evidence of a fitness cost in a cavity-nesting bird
Authors: Krams Ronalds , Krama Tatjana , Brūmelis Guntis , Elferts Didzis , Strode Linda , Dauškane Iluta , Luoto Severi , Šmits Agnis , Krams Indrikis A.
Published: June 2021

Habitat quality has direct effects on the evolutionary fitness of breeding organisms, which is why it is believed that animals tend to have an evolved preference for the best possible habitats. However, some animals may mistakenly choose to reproduce in habitats that decrease their fitness, resulting in ‘ecological traps’. In this study, we tested whether great tits (Parus major) attracted to areas affected by outbreaks of the great web-spinning sawfly (Acantholyda posticalis) had fitness detriments characteristic of ecological traps. Sawfly larvae consume pine needles, which decreases resource availability for birds co-habiting the forest. Using artificial nesting sites, we found that great tits inhabiting areas of sawfly outbreaks had similar clutch sizes as tits breeding in healthy forest patches; however, the fledgling number was significantly lower, and fledgling condition was worse in the damaged forests. While moth larvae are the most important food for bird nestlings, the forest patches damaged by sawflies had lower larval biomass. Although most ecological traps occur in environments altered by humans, this study shows that pest insects can lower habitat quality, forming ecological traps. Our results indicate that attracting cavity-nesting birds should be done with caution because it may negatively impact birds’ nutritional status and reproductive fitness.
Linear or circular: Anastomotic ulcer after gastric bypass surgery
Authors: Schäfer Aline , Gehwolf Philipp , Kienzl-Wagner Katrin , Cakar-Beck Fergül , Wykypiel Heinz
Published: June 2021

Background

After laparoscopic Gastric Bypass Procedure (GBP), anastomotic ulcers (AU) at the gastrojejunostomy (GJ) occur in up to 16% of the patients. Surgical techniques seem to influence the development of AU, but this is still a matter of discussion. This study aims to compare the incidence of AU in circular-stapled (CS) versus linear-stapled (LS) gastrojejunostomy.

Methods

Single-centre retrospective analysis of 241 (m 77 /f 164) consecutive patients (126 CS, 115 LS) with primary or revisional GBP including Roux-Y-Gastric Bypass (RYGB) and One-Anastomosis Gastric Bypass (OAGB) between 01/2014 and 01/2018. Follow-up with oesophagogastroduodenoscopy was only performed in symptomatic patients. Age, body mass index (BMI), comorbidities, smoking and medication were analyzed in both groups. The data are reported as total numbers (%) and mean ± standard deviation.

Results

AU occurred significantly more often in the CS group than in the LS group (p = 0.0034). Moreover, refractory AU and the need for revisional surgery were higher in the CS group. Smoking correlates significantly with the development of AU, whereas other risk factors had no impact on its incidence.

Conclusion

Linear-stapled gastrojejunostomy with a long and narrow pouch should be the preferable procedure for reducing AU development risk. Smoking cessation minimizes the risk for AU and is a necessary part of the treatment.
A simulator for both manual and powered wheelchairs in immersive virtual reality CAVE
Authors: Genova C. , Biffi E. , Arlati S. , Redaelli D. F. , Prini A. , Malosio M. , Corbetta C. , Davalli A. , Sacco M. , Reni G.
Published: June 2021

A large number of people in the world need to use a wheelchair because of different disabilities. Driving a wheelchair requires complex physical and cognitive abilities which need to be trained. Virtual training helps users acquire driving skills in a safe environment. The aim of this paper is to describe and technically validate simulation models for both manual (MW) and powered wheelchairs (PW) based on immersive virtual reality CAVE (VR). As VR system, the Gait Real-time Analysis Interactive Lab (GRAIL) was used, a CAVE equipped with a motion platform with two degrees of freedom and an optoelectronic motion capture system. A real wheelchair was positioned onto the motion platform with rear wheels free to turn in MW modality, and a commercial joystick was installed on an armrest to simulate the PW modality. Passive markers were used to track the wheel rotation, the joystick and the user hand motion. Custom D-flow applications were developed to manage virtual scene response to user actions. Overground tests, based on single wheel rotation, were performed to verify the simulation model reliability. Quantitative results demonstrated that the MW simulator kinematics was consistent with a real wheelchair overground in the absence of wheel slip and inertia (median error for MW 0.40 °, no systematic bias p = 0.943, high correlation rho > 0.999, p < 0.01). The proposed solution is flexible and adaptable to different wheelchairs, joysticks and optoelectronic systems. The main limitation is the absence of force feedback. Nevertheless, it is a reliable prototype that can be used to validate new virtual scenarios as well as for wheelchair training. The next steps include the system validation with real end users and assessment of the simulator effectiveness as a training tool.
Silvicultural prescriptions for mixed-species forest stands. A European review and perspective
Authors: Pretzsch Hans , Poschenrieder Werner , Uhl Enno , Brazaitis Gediminas , Makrickiene Ekaterina , Calama Rafael
Published: June 2021

Compared with far-developed measures and methods for mono-specific forest stands, the silvicultural prescriptions for mixed-species stands are at their early beginning. However, they are essential for the well-conceived establishment, design, and control of mixed-species stands, currently promoted in many countries worldwide. Here, we review the state of the art and we further develop silvicultural prescriptions for mixed-species stands for steering of experiments, stand modeling, and silviculture. We review which aspects of tree species mixing are most relevant for management goal achievement. We found the maintenance of species diversity and structural heterogeneity for ecological purpose, stabilizing productivity, and social-economic performance as main objectives. We give an overview of quantitatively formulated silvicultural prescriptions for steering mixed-species stands for forest practice, long-term experiments, forest stand models. Compared with the sophisticated guidelines for mono-specific stands, prescriptions for mixed stand are often mainly qualitative and vague. Then, we introduce methodological approaches in development for steering mixture: measures for spatial and temporal separation, species-specific growing space requirements for crop trees, coefficients for equivalence and density modification, and basic relationships for steering tree number and area-based mixing proportions. Finally, we draw conclusions for further development of methodological approaches for silvicultural steering of experiments, implementation in stand simulators, and for silvicultural operations. We see the need for improving the quantitative spatially explicit rules based at tree or cohort level, for substantiating the knowledge on species-specific allometry, growing area, tree-to-tree distances, and position-dependent competition indices for steering tree removal. We discuss the prospects and limitations of establishing silvicultural prescriptions for mixed-species stands that inevitably will be more complicated than those for mono-specific stands, and we draw conclusions for next steps in science and practice.
On the Sensitivity Analysis of Porous Finite Element Models for Cerebral Perfusion Estimation
Authors: Józsa T. I. , Padmos R. M. , El-Bouri W. K. , Hoekstra A. G. , Payne S. J.
Published: June 2021

Computational physiological models are promising tools to enhance the design of clinical trials and to assist in decision making. Organ-scale haemodynamic models are gaining popularity to evaluate perfusion in a virtual environment both in healthy and diseased patients. Recently, the principles of verification, validation, and uncertainty quantification of such physiological models have been laid down to ensure safe applications of engineering software in the medical device industry. The present study sets out to establish guidelines for the usage of a three-dimensional steady state porous cerebral perfusion model of the human brain following principles detailed in the verification and validation (V&V 40) standard of the American Society of Mechanical Engineers. The model relies on the finite element method and has been developed specifically to estimate how brain perfusion is altered in ischaemic stroke patients before, during, and after treatments. Simulations are compared with exact analytical solutions and a thorough sensitivity analysis is presented covering every numerical and physiological model parameter. The results suggest that such porous models can approximate blood pressure and perfusion distributions reliably even on a coarse grid with first order elements. On the other hand, higher order elements are essential to mitigate errors in volumetric blood flow rate estimation through cortical surface regions. Matching the volumetric flow rate corresponding to major cerebral arteries is identified as a validation milestone. It is found that inlet velocity boundary conditions are hard to obtain and that constant pressure inlet boundary conditions are feasible alternatives. A one-dimensional model is presented which can serve as a computationally inexpensive replacement of the three-dimensional brain model to ease parameter optimisation, sensitivity analyses and uncertainty quantification. The findings of the present study can be generalised to organ-scale porous perfusion models. The results increase the applicability of computational tools regarding treatment development for stroke and other cerebrovascular conditions.
How Do Trees Grow in Girth? Controversy on the Role of Cellular Events in the Vascular Cambium
Authors: Wilczek-Ponce Anna , Włoch Wiesław , Iqbal Muhammad
Published: June 2021

Radial growth has long been a subject of interest in tree biology research. Recent studies have brought a significant change in the understanding of some basic processes characteristic to the vascular cambium, a meristem that produces secondary vascular tissues (phloem and xylem) in woody plants. A new hypothesis regarding the mechanism of intrusive growth of the cambial initials, which has been ratified by studies of the arrangement of cambial cells, negates the influence of this apical cell growth on the expansion of the cambial circumference. Instead, it suggests that the tip of the elongating cambial initial intrudes between the tangential (periclinal) walls, rather than the radial (anticlinal) walls, of the initial(s) and its(their) derivative(s) lying ahead of the elongating cell tip. The new concept also explains the hitherto obscure mechanism of the cell event called ‘elimination of initials’. This article evaluates these new concepts of the cambial cell dynamics and offers a new interpretation for some curious events occurring in the cambial meristem in relation to the radial growth in woody plants.
The Structure of the Sarvadarśanasaṃgraha
Authors: Bronkhorst Johannes
Published: June 2021

This article shows in detail that the widely held view according to which the Sarvadarśanasaṃgraha has a hierarchical structure is mistaken. It further argues that at least some parts of the texts were independent essays before being incorporated into the Sarvadarśanasaṃgraha.
$$L^2$$-Betti numbers arising from the lamplighter group
Authors: Ara Pere , Claramunt Joan
Published: June 2021

We apply a construction developed in a previous paper by the authors in order to obtain a formula which enables us to compute $$\ell ^2$$

ℓ
2

-Betti numbers coming from a family of group algebras representable as crossed product algebras. As an application, we obtain a whole family of irrational $$\ell ^2$$

ℓ
2

-Betti numbers arising from the lamplighter group algebra $${\mathbb Q}[{\mathbb Z}_2 \wr {\mathbb Z}]$$

Q
[

Z
2

≀
Z
]

. This procedure is constructive, in the sense that one has an explicit description of the elements realizing such irrational numbers. This extends the work made by Grabowski, who first computed irrational $$\ell ^2$$

ℓ
2

-Betti numbers from the algebras $${\mathbb Q}[{\mathbb Z}_n \wr {\mathbb Z}]$$

Q
[

Z
n

≀
Z
]

, where $$n \ge 2$$

n
≥
2

is a natural number. We also apply the techniques developed to the generalized odometer algebra $${\mathcal {O}}({\overline{n}})$$

O
(

n
¯

)

, where $${\overline{n}}$$

n
¯

is a supernatural number. We compute its $$*$$

∗

-regular closure, and this allows us to fully characterize the set of $${\mathcal {O}}({\overline{n}})$$

O
(

n
¯

)

-Betti numbers.
Writers and politics: Gisèle Sapiro’s advances within the Bourdieusian sociology of the literary field
Authors: Fowler Bridget
Published: June 2021

This article undertakes a critical analysis of the work of Gisèle Sapiro, with reference to sociology of literature. From 1999 (Sapiro, 2014a), Sapiro has developed the Bourdieusian research tradition, amplifying especially Bourdieu’s theory of crisis. Focusing on the antagonisms between literary “prophets” and “priests”, she has drawn on a rich sample of 184 writers to elucidate the struggles inherent in World War II between writers from different field positions and literary habitus. Further, her historical analyses of the ethical commitments of nineteenth century writers via a fresh microsociology of literary trials (Sapiro, 2011) has reminded us of the importance of popular poets in articulating the suffering of the subordinate classes. Her most recent book (Sapiro, 2018) has expanded on her earlier themes, whilst identifying the recuperation of certain 1930s’ fascist worldviews within contemporary literature. This article notes that there is a telling divergence between Bourdieu and Sapiro on the issue of interests behind disinterestedness, exemplified in the case of Zola. On this issue, Sapiro’s reading (Sapiro, 2011) is found convincing. Finally, the dialectic of avant-garde consecration and routinisation is questioned as a universal structure. It is suggested that certain avant-garde – the Harlem Renaissance, for example – did not undergo swift consecration or routinisation, although this contention deserves greater research. The paper concludes by showing that Sapiro’s conception of writers’ responsibility owes its origins less to Sartre than to the Durkheimian/ Bourdieusian notion of the expertise of the “specific intellectual”. It welcomes Sapiro’s concern for literature as a potential force for social change.
The clinical significance of anomalous experience in the explanation of monothematic delusions
Authors: Noordhof Paul , Sullivan-Bissett Ema
Published: June 2021

Monothematic delusions involve a single theme, and often occur in the absence of a more general delusional belief system. They are cognitively atypical insofar as they are said to be held in the absence of evidence, are resistant to correction, and have bizarre contents. Empiricism about delusions has it that anomalous experience is causally implicated in their formation, whilst rationalism has it that delusions result from top down malfunctions from which anomalous experiences can follow. Within empiricism, two approaches to the nature of the abnormality/abnormalities involved have been touted by philosophers and psychologists. One-factor approaches have it that monothematic delusions are a normal response to anomalous experiences whilst two-factor approaches seek to identify a clinically abnormal pattern of reasoning in addition to anomalous experience to explain the resultant delusion. In this paper we defend a one-factor approach. We begin by making clear what we mean by atypical, abnormal, and factor. We then identify the phenomenon of interest (monothematic delusion) and overview one and two-factor empiricism about its formation. We critically evaluate the cases for various second factors, and find them all wanting. In light of this we turn to our one-factor account, identifying two ways in which ‘normal response’ may be understood, and how this bears on the discussion of one-factor theories up until this point. We then conjecture that what is at stake is a certain view about the epistemic responsibility of subjects with delusions, and the role of experience, in the context of familiar psychodynamic features. After responding to two objections, we conclude that the onus is on two-factor theorists to show that the one-factor account is inadequate. Until then, the one-factor account ought to be understood as the default position for explaining monothematic delusion formation and retention. We don’t rule out the possibility that, for particular subjects with delusions there may be a second factor at work causally implicated in their delusory beliefs but, until the case for the inadequacy of the single factor is made, the second factor is redundant and fails to pick out the minimum necessary for a monothematic delusion to be present.
Knowledge and reasoning
Authors: Simion Mona
Published: June 2021

This paper develops a novel, functionalist, unified account of the epistemic normativity of reasoning. On this view, epistemic norms drop out of epistemic functions. I argue that practical reasoning serves a prudential function of generating prudentially permissible action, and the epistemic function of generating knowledge of what one ought to do. This picture, if right, goes a long way towards normatively divorcing action and practical reasoning. At the same time, it unifies reasoning epistemically: practical and theoretical reasoning will turn out to be governed by the same epistemic norm—knowledge—in virtue of serving the same epistemic function: generating knowledge of the conclusion.
Should I Stay, or Should I Go? Job satisfaction as a moderating factor between outcome expectations and entrepreneurial intention among academics
Authors: Blaese Richard , Noemi Schneider , Brigitte Liebig
Published: June 2021

Both psychological and entrepreneurship research have highlighted the pivotal role of job satisfaction in the process of entrepreneurial career decisions. In support of this, mounting evidence point to inter-relationships between entrepreneurial intention, job satisfaction, and organizational commitment. Prior research operationalized entrepreneurial careers as an escape from poor work environments; thus, there is a lack of understanding regarding how job-satisfaction can trigger entrepreneurship within and related to the environment of universities. This study, draws on Social Cognitive Career Theory and the concept of entrepreneurial intention, to address whether the role of job satisfaction is a moderating factor between outcome expectations and entrepreneurial intention. Furthermore, we examine to what extent (I) entrepreneurial intention and (II) spin-off intention are determined by certain outcome expectations and perceived behavioral control. To address these questions this study examined academic researchers in specialized and non-technical fields and builds on a survey of 593 academic researchers at Swiss Universities of Applied Science. The results showed that outcome expectations are a significant predictor for entrepreneurial intentions, in general, and spin-off intentions, in particular. A multi-group analysis corroborated that job satisfaction operates as a motivational factor in entrepreneurial transition and interactions with entrepreneurial outcome expectations. In conclusion, the concept of job satisfaction and Social Cognitive Career Theory were powerful constructs to better the understand the process of entrepreneurial career decisions by academic researchers.
Krisendiagnosen aus sozialpädagogischer Sicht
Authors: Dollinger Bernd
Published: June 2021

Krisendiagnosen begleiten die Soziale Arbeit seit ihren Anfängen. Gerade derzeit wird umfassend von Krisen gesprochen. Allerdings sollte beachtet werden, welche Voraussetzungen und – möglicherweise unbeabsichtigten – Folgen dies mit sich bringt.
Current Status of Human Papillomavirus-Related Head and Neck Cancer: From Viral Genome to Patient Care
Authors: Dong Haoru , Shu Xinhua , Xu Qiang , Zhu Chen , Kaufmann Andreas M. , Zheng Zhi-Ming , Albers Andreas E. , Qian Xu
Published: June 2021

Human papillomavirus (HPV) infection identified as a definitive human carcinogen is increasingly being recognized for its role in carcinogenesis of human cancers. Up to 38%–80% of head and neck squamous cell carcinoma (HNSCC) in oropharyngeal location (OPSCC) and nearly all cervical cancers contain the HPV genome which is implicated in causing cancer through its oncoproteins E6 and E7. Given by the biologically distinct HPV-related OPSCC and a more favorable prognosis compared to HPV-negative tumors, clinical trials on de-escalation treatment strategies for these patients have been studied. It is therefore raised the questions for the patient stratification if treatment de-escalation is feasible. Moreover, understanding the crosstalk of HPV-mediated malignancy and immunity with clinical insights from the proportional response rate to immune checkpoint blockade treatments in patients with HNSCC is of importance to substantially improve the treatment efficacy. This review discusses the biology of HPV-related HNSCC as well as successful clinically findings with promising candidates in the pipeline for future directions. With the advent of various sequencing technologies, further biomolecules associated with HPV-related HNSCC progression are currently being identified to be used as potential biomarkers or targets for clinical decisions throughout the continuum of cancer care.
Field observations on the behavioural ecology of the stout bobtail squid Rossia macrosoma (Cephalopoda: Sepiolidae) from Scottish waters
Authors: Drerup Christian , Jackson Andy , Rickard Chris , Skea Mark , Cooke Gavan M.
Published: June 2021

Bobtail squids (Cephalopoda: Sepiolidae) are emerging model organisms for a wide range of genetic, anatomical, neurophysiological and behavioural studies. However, the knowledge about their behavioural ecology is scarce and derives mainly from laboratory-based studies, whereas observations from the wild are rare. Here, we use photo and video footage collected through the Cephalopod Citizen Science Project to describe the hunting, burying, mating and spawning behaviour of the stout bobtail squid Rossia macrosoma (Delle Chiaje, 1830) from Scottish waters. Based on our long-term observations, we were able to determine a spawning period from August to November based on different behavioural traits for this species. Furthermore, we observed R. macrosoma to be able to adhere a sand grain layer (‘sand coat’) to its dorsal mantle. This behavioural feature has only been reported for two genera of the sepiolid subfamily Sepiolinae so far, and therefore represents the first of this kind for the subfamily Rossiinae. Lastly, we identified a local sea urchin species as an active predator of egg batches of R. macrosoma and discussed the cryptic egg laying behaviour of this bobtail squid species in terms of its protective traits to avoid egg predation.