bluuebunny/crossref_metadata_2025 huggingface dataset:
Commercial hostages in international business disputes
Authors: Carr Chris , Harris Dan
Published: April 2021

A “commercial hostage” or “debt hostage” situation involves a dispute between a foreign company and its local partner over such matters as payment, the closing of a local office or facility, the laying off of local employees, or the transfer or ownership of intellectual property. Rather than file a lawsuit seeking money damages or an injunction, the local partner takes extra‐judicial steps to detain the foreigner against their will, so as to pressure the foreign company into resolving the dispute. The local police may even actively assist the local partner by way of inaction when the foreign company asks for help. While this activity occurs in a number of countries, this study focuses on China. One challenge in studying commercial hostage situations is gathering enough cases to be able to gauge the factors that drive them. Stated differently, how can scholars shift the study of this important topic from the anecdotal to a data‐based approach? This study is an initial attempt to do just that—it mainly attempts to gauge the frequency of recent commercial hostage activity in the P.R.C. Secondarily, it sheds light on where that activity occurs, why, and the identity of its victims. To accomplish this, Freedom of Information Act requests were submitted to six Western countries (including the U.S.) with significant China trade. English and Chinese business and legal media reports were also searched for commercial hostage cases involving foreigners. Between these two sources, dozens of commercial hostage incidents were identified. The vast majority occurred in or near Tier 1 cities and/or coastal regions, a significant number involved foreign firms operating in the commodity goods space, and a disproportionate percentage involved ethnic Chinese. Building on these findings, we conclude by providing a risk assessment matrix that foreign businesspersons can use to evaluate the risk of travelling to the P.R.C. for business. As trade tensions rise between the U.S. and China, the importance of this issue and evaluating commercial hostage risk may only increase.
Amyloid beta cleavage by ANA‐TA9, a synthetic peptide from the ANA/BTG3 Box A region
Authors: Hatakawa Yusuke , Nakamura Rina , Konishi Motomi , Sakane Toshiyasu , Tanaka Akiko , Matsuda Akira , Saito Motoaki , Akizawa Toshifumi
Published: April 2021

Introduction

We recently discovered a short synthetic peptide derived from the ANA/BTG3 protein Box A region called ANA‐TA9 (SKGQAYRMI), which possesses catalytic activity. Herein we demonstrated the proteolytic activity of ANA‐TA9 against amyloid beta 42 (Aβ42).

Methods

The proteolytic activity of ANA‐TA9 against both the authentic soluble form Aβ42 (a‐Aβ42) and the solid insoluble form Aβ42 (s‐Aβ42) was analyzed by high‐performance liquid chromatography and mass spectrometry. Plasma clearance, brain uptake, and cell viability were examined.

Results

ANA‐TA9 cleaved not only a‐Aβ42 but also s‐Aβ42. Proteolytic activity was partially inhibited by 4‐(2‐aminoethyl) benzenesulfonyl fluoride hydrochloride, a serine protease inhibitor. Plasma clearance was very rapid, and the brain concentration indicated efficient brain delivery of ANA‐TA9 via nasal application. Cell viability analysis indicated that ANA‐TA9 did not display toxicity.

Discussion

ANA‐TA9 is an attractive potential candidate for the development of novel peptide drugs in Alzheimer's disease treatment.
Getting the Short End of the Stick: Power Relations and Their Distributive Outcomes for Lower-Income Countries in Transfer Pricing Governance
Authors: Vet Cassandra , Cassimon Danny , Van de Vijver Anne
Published: April 2021

It is widely recognized that international corporate taxation holds a distributional bias toward advanced economies and that developing countries only play a marginal role in tax governance-making. Yet, it is the ambition of both the G20 and the Organisation for Economic Co-operation and Development (OECD) to integrate developing countries in the BEPS Inclusive Framework. The Base Erosion and Profit Shifting (BEPS) action is the latest global initiative to update the international framework of corporate taxation and curb corporate tax avoidance. On one hand, the integration for developing countries within the policy-making forums remains incomplete and focused on the implementation of the global tax rules. On the other, even when lower-income countries have a seat at the table, uneven power relations shape the distributional outcomes of the G20-OECD tax reform project. This analysis of the power relations at play during the revision of the transactional profit split method (TPSM) reveals how dominant logics on value creation work against the material interests of developing countries in the distribution of taxing rights. Therefore, for a tax reform to be truly legitimate for developing countries, it should emancipate and even “decolonize” the discourse and ideas of the international tax regime. While the updated OECD guidelines on transfer pricing expanded the size of the overall cake of taxable profits, the dominant logics and criteria of the guidance make it difficult for lower-income countries to obtain a decent slice of the cake and actually eat it.
Tax Incentives in Pacific Alliance Countries, the BEPS Project (Action 5), and the 2030 Sustainable Development Agenda
Authors: Lozano Rodríguez Eleonora
Published: April 2021

The chapter provides a theoretical and conceptual approach to tax incentives and their desirable and problematic characteristics. It then presents the objectives that, from the international scenario, the OECD’s BEPS Project and the Sustainable Development Agenda seek from their good design and implementation. Finally, it presents the current panorama of such incentives in Latin American countries in general, and in those of the Pacific Alliance in particular, analysing, based on a sample of income and value-added tax incentives, their difficulties in meeting international standards. Finally, it proposes a series of public policy recommendations for improvement.
Cognitive Assistance to Support Maintenance and Assembly Tasks: Results on Technology Acceptance of a Head-Mounted Device
Authors: Gerdenitsch Cornelia , Deinhard Lisa , Kern Bettina , Hold Philipp , Egger-Lampl Sebastian
Published: April 2021

This paper presents a study investigating the user acceptance (i.e. the perceived ease of use, willingness to use the system over time, and perceived usefulness) of a smart head-mounted device that can be used as assistive technology for maintenance and assembly. In particular, we focus on the head-mounted display named HMT-1 from RealWear. The uniqueness of this technology is, among other things, that it offers the possibility to fold away the display with the instructions, allowing more control over the appearance of assistive content than in other head-mounted displays. Overall, 48 participants took part in this interview study. They mentioned some advantages (e.g., that the hands are free and that one can see the instructions while working on something else at the same time) and disadvantages of the technology (such as usability issues). They also suggested that the technology is suitable for non-routine tasks and tasks of medium-to-high complexity. Our findings highlight that a cognitive assistive technology is perceived as positive when direct assistance is available (in the visual field of the worker) with a possibility to control the system.
Attention Analysis for Assistance in Assembly Processes
Authors: Paletta Lucas
Published: April 2021

Human attention processes play a major role in the optimization of human-machine interaction (HMI) systems. This work describes a suite of innovative components within a novel framework in order to assess the human factors state of the human operator primarily by gaze and in real-time. The objective is to derive parameters that determine information about situation awareness of the human collaborator that represents a central concept in the evaluation of interaction strategies in collaboration. The human control of attention provides measures of executive functions that enable to characterize key features in the domain of human-machine collaboration. This work presents a suite of human factors analysis components (the Human Factors Toolbox) and its application in the assembly processes of a future production line. Comprehensive experiments on HMI are described which were conducted with typical tasks including collaborative pick-and-place in a lab based prototypical manufacturing environment.
Towards the Automated Coverlay Assembly in FPCB Manufacturing: Concept and Preliminary Tests
Authors: Valori Marcello , Basile Vito , Negri Simone Pio , Scalmati Paolo , Renghini Chiara , Fassi Irene
Published: April 2021

In modern electronics, flexible and rigid-flex PCBs are largely used due to their intrinsic versatility and performance, allowing to increase the available volume, or enabling connection between unconstrained components. Rigid-flex PCBs consists of rigid board portions with flexible interconnections and are commonly used in a wide variety of industrial applications. However, the assembly process of these devices still has some bottlenecks. Specifically, they require the application of cover layers (namely, coverlays), to provide insulation and protection of the flexible circuits. Due to the variability in planar shape and dimensions, the coverlay application is still performed manually, requiring troublesome manipulation steps and resulting in undetermined time-cycle and precision.

This paper aims at the improvement of the industrial process currently performed, by proposing an approach for the automation of Kapton coverlay manipulation and application. Since these products are commercially provided as a film with a protective layer to be removed, the peeling issue is addressed, representing a challenging step of the automated process; the results of a systematic series of tests, performed in order to validate the peeling strategy, are reported in the paper. The overall assembly strategy relies on the development of a customized multi-hole vacuum gripper, whose concept is presented and contextualized in the proposed assembly process by outlining a suitable workcell architecture.
Improving Automated Insertion Task in Robotics by Reducing Registration Error
Authors: Cheok Geraldine S. , Franaszek Marek , Van Wyk Karl , Marvel Jeremy A.
Published: April 2021

A peg-in-hole operation is representative of common tasks performed in assembly lines by robots. It requires registration of the coordinate frame where a part resides to the robot frame where it is acted upon. Poor registration causes misalignment of the peg and the hole which will result in a failed insertion of the peg. In this study, the dependence of the outcome of the insertion task on the quality of registration is investigated. It was shown in earlier studies that Restoring Rigid-Body Condition (RRBC) leads to decreased target registration error. This study quantifies the improvement in the Pass/Fail rate when the target registration error is reduced for a given peg-hole tolerance. A robot arm operated in position control mode was used to perform the insertion without performing any search algorithms or force/torque sensing. Results show that use of the RRBC method yielded substantial reduction in failed insertions, especially for tighter tolerances.
Introduction: What Goes Wrong in Our Understanding of the Strategy Concept?
Authors: Yu Xiu-bao
Published: April 2021

The term strategy in Chinese originated from war, and the bookThe Art of Warby Sun wu in the Spring and Autumn Period.
Implications for Future Research
Authors: Yu Xiu-bao
Published: April 2021

On the basis of the three elements of strategy, this chapter puts forward some follow-up research questions and prospects mainly from the following aspects. The first is the study of factors that have influences on the quality of strategic decision. Factors include individual aspects of decision-maker, strategic decision-making information factors, approaches of strategic decision-making, etc. The second is about normative studies. They are about how the world ought to be or how strategy decisions ought to be in given situations. Outcomes of the studies can provide guidance to industry decision makers when facing development issues. Future research includePerhaps the impact of strategic decision-makers on the quality of strategies is far beyond our imagination.
Why Are There Over 90 Definitions of the Strategy Concept?
Authors: Yu Xiu-bao
Published: April 2021

Outline: Based on the Three-multiple problem of literature on strategy definition, this chapter analyses literature on strategy definition based on a special research approach developed by the author. The reasons for the aforesaid Three-multiple problem are examined with a sample over 30 definitions. It is found that there are mainly four reasons contributing to the Three-multiple problem. (1) different wordings are used to express the same meaning; (2) a variety of wordings are used to illustrate the content of different sub-classes that are under the same category; (3) different understandings of the strategy concept cause the use of various wordings; (4) extensions of concept are included in literature on strategy definition.
Phase relaxation and pattern formation in holographic gapless charge density waves
Authors: Andrade Tomas , Baggioli Matteo , Krikun Alexander
Published: April 2021

Abstract

We study the dynamics of spontaneous translation symmetry breaking in holographic models in presence of weak explicit sources. We show that, unlike conventional gapped quantum charge density wave systems, this dynamics is well characterized by the effective time dependent Ginzburg-Landau equation, both above and below the critical temperature, which leads to a “gapless” algebraic pattern of metal-insulator phase transition. In this framework we elucidate the nature of the damped Goldstone mode (the phason), which has earlier been identified in the effective hydrodynamic theory of pinned charge density wave and observed in holographic homogeneous lattice models. We follow the motion of the quasinormal modes across the dynamical phase transition in models with either periodic inhomogeneous or helical homogeneous spatial structures, showing that the phase relaxation rate is continuous at the critical temperature. Moreover, we find that the qualitative low-energy dynamics of the broken phase is universal, insensitive to the precise pattern of translation symmetry breaking, and therefore applies to homogeneous models as well.
Consistent treatment of rapidity divergence in soft-collinear effective theory
Authors: Chay Junegone , Kim Chul
Published: April 2021

Abstract

In soft-collinear effective theory, we analyze the structure of rapidity divergence due to the collinear and soft modes residing in disparate phase spaces. The idea of an effective theory is applied to a system of collinear modes with large rapidity and soft modes with small rapidity. The large-rapidity (collinear) modes are integrated out to obtain the effective theory for the small-rapidity (soft) modes. The full SCET with the collinear and soft modes should be matched onto the soft theory at the rapidity boundary, and the matching procedure becomes exactly the zero-bin subtraction. The large-rapidity region is out of reach for the soft mode, which results in the rapidity divergence. The rapidity divergence in the collinear sector comes from the zero-bin subtraction, which ensures the cancellation of the rapidity divergences from the soft and collinear sectors. In order to treat the rapidity divergence, we construct the rapidity regulators consistently for all the modes. They are generalized by assigning independent rapidity scales for different collinear directions. The soft regulator incorporates the correct directional dependence when the innate collinear directions are not back-to-back, which is discussed in the N-jet operator. As an application, we consider the Sudakov form factor for the back-to-back collinear current and the soft-collinear current, where the soft rapidity regulator for a soft quark is developed. We extend the analysis to the boosted heavy quark sector and exploit the delicacy with the presence of the heavy quark mass. We present the resummed results of large logarithms in the form factors for various currents with the light and the heavy quarks, employing the renormalization group evolution on the renormalization and the rapidity scales.
SU(2/1) superchiral self-duality: a new quantum, algebraic and geometric paradigm to describe the electroweak interactions
Authors: Thierry-Mieg Jean , Jarvis Peter
Published: April 2021

Abstract

We propose an extension of the Yang-Mills paradigm from Lie algebras to internal chiral superalgebras. We replace the Lie algebra-valued connection one-form A, by a superalgebra-valued polyform $$ \tilde{A} $$

A
˜

mixing exterior-forms of all degrees and satisfying the chiral self-duality condition $$ \tilde{A} =^{\ast }{\tilde{A}}_{\chi } $$

A
˜

=

∗

A
˜

χ

, where χ denotes the superalgebra grading operator. This superconnection contains Yang-Mills vectors valued in the even Lie subalgebra, together with scalars and self-dual tensors valued in the odd module, all coupling only to the charge parity CP-positive Fermions. The Fermion quantum loops then induce the usual Yang-Mills-scalar Lagrangian, the self-dual Avdeev-Chizhov propagator of the tensors, plus a new vector-scalar-tensor vertex and several quartic terms which match the geometric definition of the supercurvature. Applied to the SU(2/1) Lie-Kac simple superalgebra, which naturally classifies all the elementary particles, the resulting quantum field theory is anomaly-free and the interactions are governed by the super-Killing metric and by the structure constants of the superalgebra.
Inclusive and exclusive neutrino-nucleus cross sections and the reconstruction of the interaction kinematics
Authors: Bourguille B. , Nieves J. , Sánchez F.
Published: April 2021

Abstract

We present a full kinematic analysis of neutrino-nucleus charged current quasielastic interactions based on the Local Fermi Gas model and the Random Phase Approximation. The model was implemented in the NEUT Monte Carlo framework, which allows us to investigate potentially measurable observables, including hadron distributions. We compare the predictions simultaneously to the most recent T2K and MINERvA charged current (CC) inclusive, CC0πand transverse kinematic-imbalance variable results. We pursuit a microscopic interpretation of the relevant reaction mechanisms, with the aim to achieving in neutrino oscillation experiments a correct reconstruction of the incoming neutrino kinematics, free of conceptual biasses. Such study is of the utmost importance for the ambitious experimental program which is underway to precisely determine neutrino properties, test the three-generation paradigm, establish the order of mass eigenstates and investigate leptonic CP violation.
Cadherins in early neural development
Authors: Punovuori Karolina , Malaguti Mattias , Lowell Sally
Published: April 2021

During early neural development, changes in signalling inform the expression of transcription factors that in turn instruct changes in cell identity. At the same time, switches in adhesion molecule expression result in cellular rearrangements that define the morphology of the emerging neural tube. It is becoming increasingly clear that these two processes influence each other; adhesion molecules do not simply operate downstream of or in parallel with changes in cell identity but rather actively feed into cell fate decisions. Why are differentiation and adhesion so tightly linked? It is now over 60 years since Conrad Waddington noted the remarkable "Constancy of the Wild Type” (Waddington in Nature 183: 1654–1655, 1959) yet we still do not fully understand the mechanisms that make development so reproducible. Conversely, we do not understand why directed differentiation of cells in a dish is sometimes unpredictable and difficult to control. It has long been suggested that cells make decisions as 'local cooperatives' rather than as individuals (Gurdon in Nature 336: 772–774, 1988; Lander in Cell 144: 955–969, 2011). Given that the cadherin family of adhesion molecules can simultaneously influence morphogenesis and signalling, it is tempting to speculate that they may help coordinate cell fate decisions between neighbouring cells in the embryo to ensure fidelity of patterning, and that the uncoupling of these processes in a culture dish might underlie some of the problems with controlling cell fate decisions ex-vivo. Here we review the expression and function of cadherins during early neural development and discuss how and why they might modulate signalling and differentiation as neural tissues are formed.
Consistency Proof for Multi-time Schrödinger Equations with Particle Creation and Ultraviolet Cut-Off
Authors: Lill Sascha , Nickel Lukas , Tumulka Roderich
Published: April 2021

For multi-time wave functions, which naturally arise as the relativistic particle-position representation of the quantum state vector, the analog of the Schrödinger equation consists of several equations, one for each time variable. This leads to the question of how to prove the consistency of such a system of PDEs. The question becomes more difficult for theories with particle creation, as then different sectors of the wave function have different numbers of time variables. Petrat and Tumulka (2014) gave an example of such a model and a non-rigorous argument for its consistency. We give here a rigorous version of the argument after introducing an ultraviolet cut-off into the creation and annihilation terms of the multi-time evolution equations. These equations form an infinite system of coupled PDEs; they are based on the Dirac equation but are not fully relativistic (in part because of the cut-off). We prove the existence and uniqueness of a smooth solution to this system for every initial wave function from a certain class that corresponds to a dense subspace in the appropriate Hilbert space.
Modelling European regional FDI flows using a Bayesian spatial Poisson interaction model
Authors: Krisztin Tamás , Piribauer Philipp
Published: April 2021

This paper presents an empirical study of spatial origin and destination effects of European regional FDI dyads. Recent regional studies primarily focus on locational determinants, but ignore bilateral origin- and intervening factors, as well as associated spatial dependence. This paper fills this gap by using observations on interregional FDI flows within a spatially augmented Poisson interaction model. We explicitly distinguish FDI activities between three different stages of the value chain. Our results provide important insights on drivers of regional FDI activities, both from origin and destination perspectives. We moreover show that spatial dependence plays a key role in both dimensions.
Prediction of laser drilled hole geometries from linear cutting operation by way of artificial neural networks
Authors: Baiocco Gabriele , Genna Silvio , Leone Claudio , Ucciardello Nadia
Published: April 2021

This paper deals on artificial intelligence (AI) application for the estimation of kerf geometry and hole diameters for laser micro-cutting and laser micro-drilling operations. To this aim laser cutting and laser drilling operation were performed on NIMONIC 263 superalloy sheet, 0.38 mm in nominal thickness, by way of a 100 W fibre laser in modulated wave regime. Linear cuts and holes (by trepanning) were performed fixing the average power at 80 W and changing the pulse duration, the cutting speed, the focus depth and the laser path (the latter only for the drilling operations). Kerf width and the holed diameter, at the upper and downsides, were measured by digital microscopy. Different artificial neural networks (ANNs) were developed and tested to predict the kerf widths and the diameters (at the upper and downside). Two ANNs were addressed to the linear cutting process modelling; also, two further ANNs were developed for micro-drilling on the base of the linear cutting process features. The networks were trained with a subset of data containing the process conditions and the kerf/hole geometry. The ANN test was performed with the remaining data. The results show that ANNs can model the cut and hole geometry as a function of the process parameters. Moreover, the ANN trained with kerf geometry is more efficient. Therefore, a functional correlation between the kerf geometries achievable in the linear cutting process and micro-drilling was assessed.
Effect of clad height, substrate thickness and scanning pattern on cantilever distortion in direct metal deposition
Authors: Soffel Fabian , Eisenbarth Daniel , Wegener Konrad
Published: April 2021

In metal additive manufacturing, moving heat sources cause spatial and time-dependent variations of temperature and strain that can lead to part distortions. Distortion prediction and optimized deposition parameters can increase the dimensional accuracy of the generated components. In this study, an analytical approach for modeling the effect of clad height and substrate thickness is experimentally validated. Additionally, the influence of the scanning pattern as a function of clad height and substrate thickness is determined experimentally. The analytical model is based on the cool-down phase mechanism and assumes the formation of constant thermal shrinking forces for each deposited layer. The model accurately predicts longitudinal cantilever distortion after experimental calibration when compared with similar experimental conditions. For multi-layer deposition, the scanning pattern has the largest influence on distortion for thin-walled substrates. An optimized deposition strategy with longitudinal scanning vectors leads to a distortion reduction of up to 86%. The results highlight the potential of mechanical modeling and scanning strategy optimizations to increase the shape accuracy for industrial applications in the field of additive manufacturing.
Revisiting Amyand's Hernia: A 20‐Year Systematic Review
Authors: Manatakis Dimitrios K. , Tasis Nikolaos , Antonopoulou Maria Ioanna , Anagnostopoulos Petros , Acheimastos Vasileios , Papageorgiou Dimitrios , Fradelos Evangelos , Zoulamoglou Menelaos , Agalianos Christos , Tsiaoussis John , Xynos Evaghelos
Published: April 2021

Purpose

Protrusion of the appendix within an inguinal hernia is termed an Amyand's hernia. A systematic review of case reports and case series of Amyand's hernia was performed, with emphasis on surgical decision‐making.

Methods

The English literature (2000–2019) was reviewed, using PubMed and Embase, combining the terms “hernia”, “inguinal”, “appendix”, “appendicitis” and “Amyand”. Overall, 231 studies were included, describing 442 patients.

Results

Mean age of patients was 34 ± 32 years (adults 57.5%, children 42.5%). 91% were males, while a left‐sided Amyand's hernia was observed in 9.5%. Of 156 elective hernia repairs, 38.5% underwent appendectomy and 61.5% simple reduction of the appendix. 88% of the adult patients had a mesh repair, without complications. Of 281 acute cases, hernial complications (76%) and acute appendicitis (12%) were the most common preoperative surgical indications. Appendectomy was performed in 79%, more extensive operations in 8% and simple reduction in 13% of cases. A mesh was used in 19% of adult patients following any type of resection and in 81% following reduction of the appendix. Among acute cases, mortality was 1.8% and morbidity 9.2%. Surgical site infections were observed in 3.6%, all of which in patients without mesh implantation.

Conclusion

In elective Amyand's hernia cases, appendectomy may be considered in certain patients, provided faecal spillage is avoided, to prevent mesh infection. In cases of appendicitis, prosthetic mesh may be used, if the surgical field is relatively clean, whereas endogenous tissue repairs are preferred in cases of heavy contamination.
An Updated Overview of Gender Dysphoria and Gender Affirmation Surgery: What Every Plastic Surgeon Should Know
Authors: Hamidian Jahromi Alireza , Boyd Louisa C. , Schechter Loren
Published: April 2021

Gender dysphoria refers to the medical condition experienced by individuals whose physical anatomy is not consistent with their gender identity. Surgery is a safe and effective treatment for many individuals, yet the current demand for surgery exceeds the number of trained surgeons. This article reviews gender‐affirming surgical procedures and emphasizes an individualized approach within the context of a multidisciplinary team. We review pre‐, intra‐, and postoperative care including the preoperative requirements for surgery.
Bosworth fracture complicated by unrecognized compartment syndrome: a case report and review of the literature
Authors: Bartoníček Jan , Rammelt Stefan , Kostlivý Karel
Published: April 2021

Introduction

Compartment syndrome (CS) is exceedingly rare in ankle fractures. However, the risk of CS development seems to be increased in the presence of a Bosworth fracture-dislocation (BF), a rare variant of locked dislocation of the fibula behind the tibia.

Materials and methods

Here, we report the case of a 39-year old man with delayed diagnosis of CS after having sustained a BF and failed attempts on closed reduction. The patient developed a flexion contracture of the hallux necessitating secondary fusion.

Results

At 3 years after the injury, the patient was capable of running, but had 10 degrees limitation of ankle dorsiflexion, persisting decreased sensation on the plantar surface and clawing of the lesser toes. A thorough review of the literature revealed nine cases of CS after 167 reported BF resulting in a calculated prevalence of 5.4%.

Conclusions

Given the extreme paucity of CS in malleolar fractures, CS in BF has a relatively high prevalence. Risk factors include severe dislocations, repeated attempts on closed reduction, and a long interval to definite surgery. A high index of suspicion is required because delayed diagnosis leads to lasting functional restrictions.
Effect of transcranial direct current stimulation on post-stroke fatigue
Authors: De Doncker William , Ondobaka Sasha , Kuppuswamy Annapoorna
Published: April 2021

Background

Fatigue is one of the most commonly reported symptoms post-stroke, which has a severe impact on the quality of life. Post-stroke fatigue is associated with reduced motor cortical excitability, specifically of the affected hemisphere.

Objective

The aim of this exploratory study was to assess whether fatigue symptoms can be reduced by increasing cortical excitability using anodal transcranial direct current stimulation (tDCS).

Methods

In this sham-controlled, double-blind intervention study, tDCS was applied bilaterally over the primary motor cortex in a single session in thirty stroke survivors with high severity of fatigue. A questionnaire-based measure of trait fatigue (primary outcome) was obtained before, after a week and 5 weeks post stimulation. Secondary outcome measures of state fatigue, motor cortex neurophysiology and perceived effort were also assessed pre, immediately post, a week and 5 weeks post stimulation.

Results

Anodal tDCS significantly improved fatigue symptoms a week after real stimulation when compared to sham stimulation. There was also a significant change in motor cortex neurophysiology of the affected hemisphere and perceived effort, a week after stimulation. The degree of improvement in fatigue was associated with baseline anxiety levels.

Conclusion

A single session of anodal tDCS improves fatigue symptoms with the effect lasting up to a week post stimulation. tDCS may therefore be a useful tool for managing fatigue symptoms post-stroke.

Trial registration

NCT04634864

Date of registration

17/11/2020–“retrospectively registered”.
Binding of gephyrin to microtubules is regulated by its phosphorylation at Ser270
Authors: Zhou Lin , Kiss Eva , Demmig Rebecca , Kirsch Joachim , Nawrotzki Ralph Alexander , Kuhse Jochen
Published: April 2021

Gephyrin is a multifunctional scaffolding protein anchoring glycine- and subtypes of GABA type A- receptors at inhibitory postsynaptic membrane specializations by binding to the microtubule (MT) and/or the actin cytoskeleton. However, the conditions under which gephyrin can bind to MTs and its regulation are currently unknown. Here, we demonstrate that during the purification of MTs from rat brain by sedimentation of polymerized tubulin using high-speed centrifugation a fraction of gephyrin was bound to MTs, whereas gephyrin phosphorylated at the CDK5-dependent site Ser270 was detached from MTs and remained in the soluble protein fraction. Moreover, after collybistin fostered phosphorylation at Ser270 the binding of a recombinant gephyrin to MTs was strongly reduced in co-sedimentation assays. Correspondingly, upon substitution of wild-type gephyrin with recombinant gephyrin carrying alanine mutations at putative CDK5 phosphorylation sites the binding of gephyrin to MTs was increased. Furthermore, the analysis of cultured HEK293T and U2OS cells by immunofluorescence-microscopy disclosed a dispersed and punctuated endogenous gephyrin immunoreactivity co-localizing with MTs which was evidently not phosphorylated at Ser270. Thus, our study provides additional evidence for the binding of gephyrin to MTs in brain tissue and in in vitro cell systems. More importantly, our findings indicate that gephyrin-MT binding is restricted to a specific gephyrin fraction and depicts phosphorylation of gephyrin as a regulatory mechanism of this process by showing that soluble gephyrin detached from MTs can be detected specifically with the mAb7a antibody, which recognizes the Ser270 phosphorylated- version of gephyrin.
Changes in sleep EEG with aging in humans and rodents
Authors: Campos-Beltrán Diana , Marshall Lisa
Published: April 2021

Sleep is one of the most ubiquitous but also complex animal behaviors. It is regulated at the global, systems level scale by circadian and homeostatic processes. Across the 24-h day, distribution of sleep/wake activity differs between species, with global sleep states characterized by defined patterns of brain electric activity and electromyography. Sleep patterns have been most intensely investigated in mammalian species. The present review begins with a brief overview on current understandings on the regulation of sleep, and its interaction with aging. An overview on age-related variations in the sleep states and associated electrophysiology and oscillatory events in humans as well as in the most common laboratory rodents follows. We present findings observed in different studies and meta-analyses, indicating links to putative physiological changes in the aged brain. Concepts requiring a more integrative view on the role of circadian and homeostatic sleep regulatory mechanisms to explain aging in sleep are emerging.
The effect of pain on reference memory for duration
Authors: Piovesan Andrea , Mirams Laura , Poole Helen , Ogden Ruth
Published: April 2021

Previous research has consistently reported that pain related stimuli are perceived as lasting longer than non-pain related ones, suggesting that pain lengthens subjective time. However, to date, the investigation has been limited to the immediate effects of pain on time perception. The current study aims to investigate whether pain affects how a duration is recalled after a period of delay. In two experiments, participants were asked to complete four temporal generalisation tasks, where they were required first to remember the duration of a standard tone (learning phase) and then to compare the standard duration to a series of comparison durations (testing phase). Using a 2 × 2 design, the four tasks differed in terms of whether participants were exposed to a painful or non-painful stimulus during the learning phase, and whether the testing phase started immediately or 15 min after the learning phase. Participants were exposed to low pain in Experiment 1 and high pain in Experiment 2. Two possible results were expected: pain could decrease temporal accuracy, because pain disrupts cognitive processes required for accurate timing, or pain could increase temporal accuracy, because pain facilitates memory consolidation. Contrary to expectations, results from both Experiments indicated that participants’ temporal performances were similar in the pain and no-pain conditions when testing occurred 15 min after the learning phase. Findings, therefore, suggest that pain neither disrupts nor enhances long-term memory representations of duration.
The risks associated with tourniquet use in lower limb trauma surgery: a systematic review and meta-analysis
Authors: Farhan-Alanie Muhamed M. , Dhaif Fatema , Trompeter Alex , Underwood Martin , Yeung Joyce , Parsons Nick , Metcalfe Andy , Wall Peter D. H.
Published: April 2021

Purpose

Tourniquet use in lower limb fracture surgery may reduce intra-operative bleeding, improve surgical field of view and reduce length of procedure. However, tourniquets may result in pain and the production of harmful metabolites cause complications or affect functional outcomes. This systematic review aimed to compare outcomes following lower limb fracture surgery performed with or without tourniquet.

Methods

We searched databases for RCTs comparing lower limb fracture surgery performed with versus without tourniquet reporting on outcomes pain, physical function, health-related quality of life, complications, cognitive function, blood loss, length of stay, length of procedure, swelling, time to union, surgical field of view, volume of anaesthetic agent, biochemical markers of inflammation and injury, and electrolyte and acid–base balance. Random-effects meta-analysis was performed. PROSPERO ID CRD42020209310.

Results

Six RCTs enabled inclusion of 552 procedures. Pooled analysis demonstrated that tourniquet use reduced length of procedure by 6 minutes (95% CI −10.12 to −1.87; p < 0.010). We were unable to exclude increased harms from tourniquet use. Pooled analysis showed post-operative pain score was higher in tourniquet group by 12.88 on 100-point scale (95% CI −1.25–27.02; p = 0.070). Risk differences for wound infection, deep venous thrombosis and re-operation were 0.06 (95% CI −0.00–0.12; p = 0.070), 0.05 (95% CI −0.02–0.11; p = 0.150) and 0.03 (95% CI -0.03–0.09; p = 0.340).

Conclusion

Tourniquet use was associated with a reduced length of procedure. It is possible that tourniquets also increase incidence of important complications, but the data are too sparse to draw firm conclusions. Methodological weaknesses of the included RCTs prevent any solid conclusions being drawn for outcomes investigated. Further studies are required to address these limitations.
Weight-scheduling for linear time-variant model predictive wind turbine control toward field testing
Authors: Wintermeyer-Kallen Thorben , Dickler Sebastian , Zierath János , Konrad Thomas , Abel Dirk
Published: April 2021

Modern multi-megawatt wind turbines require powerful control algorithms which consider several control objectives at the same time and respect process constraints. Model predictive control (MPC) is a promising control method and has been a research topic for years. So far, very few studies evaluated MPC algorithms in field tests. This work aims to prepare a real-time MPC system for a full-scale field test in a 3 MW wind turbine. To this end, we introduce a weight-scheduling scheme for a linear time-variant MPC in order to ensure control operation over the entire operating range from the partial to the full load range. We use a rapid control prototyping process, in particular with comprehensive software-in-the-loop (SiL) tests, in order to design and validate the MPC system for the field test.

In this contribution, we present the implementation of the linear time-variant MPC with weight-scheduling to be tested in the field test. With the weight-scheduling for the optimization problem inside the MPC, we achieved good performance over the entire operating range of the wind turbine. In the SiL tests, the proposed MPC algorithm achieved loads, comparable to the baseline controller of the wind turbine and improved the reference tracking of the power output and the rotational speed. The proposed linear time-variant MPC with weight-scheduling is fully validated in the presented software-in-the-loop tests and is ready for full-scale field test in the 3 MW wind turbine. We present the experimental field test results of the introduced MPC system in a separated contribution.
First comparison of the electrical properties of two grid emulators for UVRT test against field measurement
Authors: Frehn Anica , Azarian Soroush , Quistorf Gesa , Adloff Stephan , Santjer Fritz , Monti Antonello
Published: April 2021

The technical rules for connecting turbines to the medium, high or extra-high voltage grid in Germany require the certification of the UVRT characteristics of wind turbines. The state-of-art voltage divider-based test equipment, also named UVRT-Container, is well equipped for executing UVRT tests in field. To conduct the UVRT in field the full wind turbine should be already installed. A second option to perform UVRT tests are system level test benches. They enable the testing of the nacelle. The components that are not actually present, such as the turbine tower or the blades, are emulated via a mechanical hardware in the loop (HiL) system. In this work, for the first time, the performance of two different grid simulators installed at the DyNaLab at Fraunhofer IWES and at the CWD at RWTH Aachen University is compared with a field measurement of the same type of wind turbine. Thus, not only a system test bench measurement is compared to a field measurement. Rather, two system test benches with individual technical approaches are additionally compared with each other. The focus of this work is to investigate the characteristics of the grid simulators within the steady-state range of the UVRT tests to replicate identical fault shapes on the test benches and in the field.
The spherical primitive and perlin noise method to recreate realistic aggregate shapes
Authors: Michot-Roberto S. , Garcia-Hernández A. , Dopazo-Hilario S. , Dawson A.
Published: April 2021

An algorithm to re-create virtual aggregates with realistic shapes is presented in this paper. The algorithm has been implemented in the Unity 3D platform. The idea is to re-create realistically the virtual coarse and crushed aggregates that are normally used as a material for the construction of roads. This method consists of two major procedures: (i) to combine a spherical density function with a noise matrix based on the Perlin noise to obtain shapes of appropriate angularity and, (ii) deform the shapes until their minor ferret, aspect ratio and, thickness are equivalent to those wanted. The efficiency of the algorithm has been tested by reproducing nine types of aggregates from different sources. The results obtained indicate that the method proposed can be used to realistically re-create in 3D coarse aggregates.

Graphic abstract
T2-weighted, apparent diffusion coefficient and 18F-FDG PET histogram analysis of rectal cancer after preoperative chemoradiotherapy
Authors: Crimì F. , Stramare R. , Spolverato G. , Aldegheri V. , Barison A. , D’Alimonte L. , Bao Q. R. , Spimpolo A. , Albertoni L. , Cecchin D. , Campi C. , Quaia E. , Pucciarelli S. , Zucchetta P.
Published: April 2021

Background

The aim of our study was to investigate the correlation among T2-weighted (T2w) images, apparent diffusion coefficient (ADC) maps, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) images, histogram analysis and the pathological response in locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (pCRT).

Methods

Patients with LARC were prospectively enrolled between February 2015 and August 2018 and underwent PET/magnetic resonance imaging (MRI). MRI included T2w and diffusion-weighted imaging (DWI)-sequences. ADC maps and PET images were matched to the T2w images. Voxel-based standardized uptake values (SUVs,) ADC and T2w-signal-intensity values were collected from the volumes of interest (VOIs) and mean, skewness and kurtosis were calculated. Spearman’s correlation coefficient was applied to evaluate the correlation among the variables and tumor regression grade (TRG), T stage, N stage and fibrosis.

Results

Twenty-two patients with biopsy-proven LARC in the low or mid rectum were enrolled [17 males, mean age was 69 years (range 49–85 years)]. Seven patients experienced complete regression (TRG1). A significant positive correlation was found between SUV mean values (ρ = 0.480; p = 0.037) and TRG. No other significant correlations were found.

Conclusions

Histogram analysis of SUV values is a predictor of TRG in LARC.
All-case Japanese post-marketing surveillance of the real-world safety and efficacy of rituximab treatment in patients with refractory nephrotic syndrome
Authors: Kobayashi Mana , Kageyama Yutaro , Ando Takashi , Sakamoto Junko , Kimura Shohji
Published: April 2021

Background

Rituximab is conditionally approved in Japan for use in patients with refractory nephrotic syndrome. To meet the conditions of approval, an all-case post-marketing surveillance study was conducted to confirm the real-world safety and efficacy of rituximab in patients of all ages with refractory nephrotic syndrome.

Methods

All patients scheduled to receive rituximab treatment for refractory nephrotic syndrome were eligible to register (registration: August 29, 2014 through April 15, 2016); the planned observation period was 2 years from the initiation of rituximab treatment (intravenous infusion, 375 mg/m2 once weekly for four doses). The study was conducted at 227 hospitals throughout Japan. Adverse drug reactions (ADRs) were collected for safety outcomes. The efficacy outcomes were relapse-free period and the degree of growth in pediatric (< 15 years) patients.

Results

In total, 997 (447 pediatric) patients were registered; 981 (445) were included in the safety analysis set; 852 (402) completed the 2-year observation period; and 810 (429) were included in the efficacy analysis set. Refractory nephrotic syndrome had developed in childhood for 85.0% of patients, and 54.6% were aged ≥15 years. ADRs were observed in 527 (53.7%) patients, treatment-related infection/infestation in 235 (24.0%) patients, and infusion reactions in 313 (31.9%) patients. The relapse-free period was 580 days (95% confidence interval, 511–664). There was a significant change in height standard deviation score (pediatric patients; mean change, 0.093; standard deviation, 0.637; P = 0.009).

Conclusion

The safety and efficacy of rituximab treatment in patients with refractory nephrotic syndrome were confirmed in the real-world setting.

Clinical trial registration

UMIN000014997.