bluuebunny/crossref_metadata_2025 huggingface dataset:
Lymphoepithelioma‐like neoplasm of the biliary tract with ‘probable low malignant potential’
Authors: Khandakar Binny , Liu Jun‐Ru , Thung Swan , Li Ying , Rhee Hyungjin , Kagen Alexander C , Sun‐Wing Tong Tommy , Nyun Park Young , Theise Neil , Ng Irene Oi‐Lin
Published: October 2021

Aims

Lymphoepithelioma‐like carcinomas (LELCs) are uncommon epithelial cancers characteristically showing two distinct components consisting of malignant epithelial cells and prominent dense lymphoid infiltrate. Hepatic LELCs consist of two types, the lymphoepithelioma‐like hepatocellular carcinoma and lymphoepithelioma‐like cholangiocarcinoma (LEL‐CCA), with the latter being strongly associated with Epstein–Barr virus (EBV).

Methods and results

We present a series of three cases of intrahepatic biliary EBV‐associated LEL tumours in which the biliary epithelial component showed a distinctly benign appearance, instead of the usual malignant epithelial features of a typical CCA or EBV‐associated LEL‐CCA. In the lesions, the biliary epithelium showed interconnecting glands or cords of cells. All had a very low proliferation (Ki‐67) index. Immunohistochemistry for IDH1 and TP53 performed on two cases was negative and molecular tests for EGFR and KRAS gene mutations performed on one were negative. Prognosis was very good in all three cases, with patients alive with no evidence of disease 24–62 months after surgery. Intriguingly, all three cases had co‐infection of HBV and EBV. These cases are also discussed in the context of the 63 cases of LEL‐CCA available in the literature, with a focus on epidemiology, clinicopathological features and potential research interests.

Conclusions

Based on the distinct clinicopathological features and unique survival benefits, we believe these tumours represent the benign end of the spectrum of EBV‐associated lymphoepithelial biliary carcinomas. Whether these tumours require a revision of the current nomenclature to ‘lymphoepithelioma‐like neoplasm of the biliary tract with probable low malignant potential’ will require more detailed analysis with larger case‐series.
The implementation of a professional practice model to improve the nurse work environment in a Dutch hospital: A quasi‐experimental study
Authors: Bloemhof Janet , Knol Jeannette , Van Rijn Marjon , Buurman Bianca M.
Published: October 2021

Aims

To evaluate the effects of the implementation of a professional practice model based on Magnet principles on the nurse work environment in a Dutch teaching hospital.

Design

A quasi‐experimental study.

Methods

Data were collected from registered nurses working on the clinical wards and outpatient clinics of the hospital in June/July 2016 (baseline) and in June/September 2019 (measurement of effects). Participants completed the Dutch Essentials of Magnetism II survey, which was used to measure their perception of their work environment. After baseline measurements were collected, interventions based on a professional practice model incorporating Magnet principles were implemented to improve the nurse work environment. Descriptive statistics and independent t‐tests were conducted to examine differences between survey outcomes in 2016 and 2019.

Results

Survey outcomes revealed significant changes in the nurse work environment between 2016 and 2019. Seven of the eight subscales (essentials of magnetism) improved significantly. Score for overall job satisfaction increased from 7.3 to 8.0 and score for quality of care increased from 7.0 to 7.6. On unit level, 17 of the 19 units showed improvement in the nurse work environment.

Conclusion

The implementation of a professional practice model positively affects the nurse work environment, job satisfaction and quality of care.

Impact

Nowadays, the quality of care is threatened by workload pressure and the low autonomy experienced by nurses. Considering the global shortage of nurses and growing complexity of healthcare, it is important to invest in improving the nurse work environment. The Magnet concept created a work environment in which nurses can deliver optimal quality of care. Knowledge of how Magnet principles affect the nurse work environment in the Netherlands is missing. These study results, including the description of how the interventions were implemented, will assist other hospitals to develop improvement strategies by focusing on the nurse work environment.
Plant height and lifespan predict range size in southern African grasses
Authors: Mashau Aluoneswi C. , Hempson Gareth P. , Lehmann Caroline E. R. , Vorontsova Maria S. , Visser Vernon , Archibald Sally
Published: October 2021

Aim

To understand the geographical distribution of grasses in sub‐Saharan Africa with reference to key plant traits thought to affect range size in this family (Poaceae). Specifically, to test hypotheses on the importance of plant height and lifespan in determining range size and invasion potential in the context of their evolutionary history.

Location

Sub‐Saharan Africa.

Taxon

Poaceae.

Methods

The range sizes of 757 grass species native to southern Africa were estimated for the sub‐Saharan African region from geo‐referenced herbarium records using the alpha hull function. Phylogenetic generalised least squares models and linear mixed effects models were fitted to test whether grass range size was related to plant height and lifespan. Tribe‐level relationships between range size and plant height were assessed with linear models. For species introduced to other continents, generalised linear mixed effects models were fitted to test whether invasiveness was related to native range size, plant height and lifespan. Differences in native range size among species in four invasion‐related categories were assessed with linear mixed effects models.

Results

Grass range sizes are larger for taller species and for species with shorter lifespans. The relationship between plant height and range size varies widely among tribes, with some range‐restricted tribes having a non‐significant effect on plant height. Grasses with larger native range sizes and shorter lifespans are more likely to become invasive after being introduced to other continents. Grass species introduced to other continents have larger native range sizes than those that have not, and native range size increases along the introduced‐naturalised‐invasive continuum.

Main conclusions

The increased dispersal opportunities of annual‐biannual grasses appear to have a greater positive effect on range size than do the longer generation times of perennial grasses. Grass height has and continues to be an important driver of grass biogeography, with implications for understanding the spread of certain grass tribes over the Miocene. Factors that promote large native range sizes are also likely to increase the probability of a species becoming invasive.
Long‐term continuity of steppe grasslands in eastern Central Europe: Evidence from species distribution patterns and chloroplast haplotypes
Authors: Willner Wolfgang , Moser Dietmar , Plenk Kristina , Aćić Svetlana , Demina Olga N. , Höhn Maria , Kuzemko Anna , Roleček Jan , Vassilev Kiril , Vynokurov Denys , Kropf Matthias
Published: October 2021

Aim

The steppe grasslands of eastern Central Europe are exceptionally species rich and valuable from a nature conservation point of view. However, their historical biogeography is still poorly understood. Here we use the regional diversity of habitat specialists and chloroplast DNA data to investigate potential long‐term refugia of steppe species in this region.

Location

Pannonian Basin and adjacent regions; SW Russia.

Taxon

Vascular plants.

Methods

After identifying habitat specialists of the three main steppe types (meadow steppes, grass steppes and rocky steppes), we compiled their regional presence–absence in grid cells of 75 km × 75 km. We analysed the dependency of habitat specialist diversity to climate, topographic heterogeneity and geographical distance to potential refugia. For genetic analysis, we sampled three or four habitat specialists of each steppe type and used cpDNA markers to investigate intraspecific diversity and geographical distribution of haplotypes. We also tested for correspondence between the number of habitat specialists and haplotype diversity.

Results

Climate and topography explained between 40% and 63% of the variance in habitat specialist diversity. Adding geographical distance to potential refugia increased the explained variance in the models for all steppe types. Chloroplast haplotypes featured a complex pattern across the study area. Several species showed a strong geographical differentiation, suggesting migration waves from multiple refugia with only limited subsequent genetic intermixture. Maximum haplotype diversity in a region showed a better correlation with the number of habitat specialists per steppe type than mean haplotype diversity.

Main conclusions

We can clearly reject the scenario of a late‐Holocene immigration of steppe species from areas outside the Pannonian Basin. Most species must have been present in the region since at least the early Holocene, highlighting the importance of the lower mountain ranges surrounding the Pannonian Basin as long‐term refugia for European steppe species. Dispersal limitation and resulting migration lags seem to have a strong influence on the distribution of steppe species in Central Europe.
The oxytocin system and early‐life experience‐dependent plastic changes
Authors: Onaka Tatsushi , Takayanagi Yuki
Published: October 2021

Early‐life experience influences social and emotional behaviour in adulthood. Affiliative tactile stimuli in early life facilitate the development of social and emotional behaviour, whereas early‐life adverse stimuli have been shown to increase the risk of various diseases in later life. On the other hand, oxytocin has been shown to have organizational actions during early‐life stages. However, the detailed mechanisms of the effects of early‐life experience and oxytocin remain unclear. Here, we review the effects of affiliative tactile stimuli during the neonatal period and neonatal oxytocin treatment on the activity of the oxytocin–oxytocin receptor system and social or emotional behaviour in adulthood. Both affiliative tactile stimuli and early‐life adverse stimuli in the neonatal period acutely activate the oxytocin–oxytocin receptor system in the brain but modulate social behaviour and anxiety‐related behaviour apparently in an opposite direction in adulthood. Accumulating evidence suggests that affiliative tactile stimuli and exogenous application of oxytocin in early‐life stages induce higher activity of the oxytocin–oxytocin receptor system in adulthood, although the effects are dependent on experimental procedures, sex, dosages and brain regions examined. On the other hand, early‐life stressful stimuli appear to induce reduced activity of the oxytocin–oxytocin receptor system, possibly leading to adverse actions in adulthood. It is possible that activation of a specific oxytocin system can induce beneficial actions against early‐life maltreatments and thus could be used for the treatment of developmental psychiatric disorders.
Rubus aetnicus Cupani ex Weston and R. canescens DC. (Rosaceae): an analysis
Authors: van de Beek Abraham , Domina Gianniantonio
Published: October 2021

Beek (2016) argued that Rubus aetnicus Cupani ex Weston was the correct name of the taxon that was then called R. canescens DC., and which was previously known as R. tomentosus Borkh. Moreover, R. canescens was stated to be not identical with R. aetnicus, but rather a form of R. × collinus DC. Matzke‐Hajek (2016) raised objections to both statements. Therefore, the aim of this study was to thoroughly analyse both names and support this analysis with field work at the type localities and by DNA data. Despite the correspondence at the investigated conservative DNA loci, the investigation showed that the two species are morphologically different and must be conceived as separate taxa. According to the rules of the ICN, R. aetnicus, as the earliest available legitimate name, must be accepted as the correct name for R. tomentosus auct. non Borkh. There is no reason not to use the name R. aetnicus, which has not been commonly used until now. It is unambiguous, while any other name could cause confusion if it would be conserved. Other scientific names clarified in this study are R. aetnaeus Tornab. (= R. ulmifolius Schott), R. aetnensis Tornab. (= R. aetnicus) and R. argenteus Gmel.
Transient hypopharyngeal intrabolus pressurization patterns: Clinically relevant or normal variant?
Authors: Omari Taher , Rommel Nathalie , Jan Tack , Szczesniak Michal , Wu Peter , Schar Mistyka , Doeltgen Sebastian , Cock Charles
Published: October 2021

Introduction

In oropharyngeal dysphagia, impaired pharyngoesophageal junction (PEJ) opening is reflected by an elevated hypopharyngeal intrabolus pressure (IBP), quantifiable using pharyngeal high‐resolution manometry with impedance (P‐HRM‐I). Transient intrabolus pressurization (TP) phenomena are not sustained and last for only a brief period. We hypothesized that TP patterns reflect impaired coordination between timing of hypopharyngeal bolus arrival and PEJ relaxation.

Methods

A retrospective audit was conducted of P‐HRM‐I datasets; 93 asymptomatic Controls and 214 Patients with differing etiological/clinical backgrounds were included. TP patterns were examined during 10ml liquid swallows. TP was defined by a simultaneous, non‐sustained, pressurization wave spanning from the velo‐/meso‐pharynx to PEJ. The coordination between deglutitive pharyngeal bolus distension and PEJ relaxation timing was assessed using timing variables; (i) Distention‐Contraction Latency (DCL, s) and (ii) PEJ Relaxation Time (RT, s). Resultant flow resistance was quantified (IBP, mmHg).

Results

TP swallows were observed in 87 (28%) cases. DCL was not significantly different in relation to TP, while PEJ relaxation time was shorter, and IBP was higher during TP swallows. In Patients RT‐DCL time difference correlated with IBP (r −0.368, p < 0.01).

Conclusion

Bolus distension and PEJ relaxation were miss‐timed during TP swallows, impeding bolus flow and leading to a brief period of pressurization of the pharyngeal chamber by muscular propulsive forces. While TP swallows were identified in both Controls and Patients, increased IBPs were most apparent for Patient swallows indicating that the extent of IBP increase may differentiate pathological TP swallows.
NLRP3‐mediated dysfunction of mitochondria leads to cell death in CFT073‐stimulated macrophages
Authors: Verma Vivek , Kumar Parveen , Gupta Surbhi , Yadav Sonal , Dhanda Rakesh Singh , Yadav Manisha
Published: October 2021

Urinary tract infections (UTIs) are commonly caused by uropathogenic E coli (UPEC), which uses different mechanisms to invade and damage hosts. NLRP3 inflammasome activation is a double‐edged sword, although beneficial in the clearance of dysfunctional cells or pathogens but results in severe pathologies, if unchecked. NLRP3 inflammasome plays a critical role in UPEC‐mediated inflammatory cell death during UPEC infection, though the effects of its activation are not clearly understood yet. Inflammatory response usually involves Signal‐I (MyD88, TRIF and NF‐κB signalling) and Signal‐II (Inflammasome oligomerization) which is induced by the pathogen‐associated molecular patterns during infection. We observed that proIL‐1β and mature IL‐1β remained unchanged on inhibition of MyD88 and TRIF‐dependent signalling in CFT073‐insulted THP‐1m. However, inhibition of NF‐κB pathway resulted in concomitant reduction in both pro‐ and cleaved forms of IL‐1β in cellular extracts but there was no change in IL‐1 β secretion. Interestingly, inhibition of NLRP3 completely abolished the maturation and release of cleaved form of IL‐1β. Additionally, NLRP3‐mediated mitochondrial dysfunction (increased mito‐ROS and mitochondrial hyperpolarization) resulting in cell death was induced in CFT073‐insulted THP‐1m, which was rescued upon inhibition of NLRP3 activation. Therefore, we have concluded that UPEC uses a different signal‐I pathway (other than MyD88 and TRIF), while NLRP3 inflammasome is the major signal‐II for the induction of inflammatory response. Further, this study signifies the importance of NLRP3‐mediated mitochondrial dysfunction in CFT073‐induced inflammatory cell death of macrophages, which could be rescued through inhibition of NLRP3 activation.
Studying European Radical Left Parties since the Fall of the Berlin Wall (1990–2019): A Scoping Review
Authors: Lourenço Pedro
Published: October 2021

The 2008 economic crisis brought an increasing support for some European radical left parties (RLPs) and renewed academic attention to this party family. This article retrospectively assesses the literature on RLPs by conducting a scoping review under the following research question: How have European radical left parties been studied since the fall of the Berlin Wall (1989)? Using an adapted version of the PRISMA framework, it analyzes 197 articles published between 1990 and 2019 to show that, despite the growing scholarship, significant gaps persist in the literature. Important aspects of RLPs have yet to be explored (e.g. party organization, policy impact), while uneven geographic coverage has left some relevant countries and parties in the background. By providing an overview of the field, it identifies new avenues for future research on the topic and shows how scoping reviews can be a method of interest also for political scientists.
Making Home(s) in Displacement
Authors: Heynen Hilde
Published: October 2021

Making Home(s) in Displacement critically rethinks the relationship between home and displacement from a spatial, material, and architectural perspective. Recent scholarship in the social sciences has investigated how migrants and refugees create and reproduce home under new conditions, thereby unpacking the seemingly contradictory positions of making a home and overcoming its loss. Yet, making home(s) in displacement is also a spatial practice, one which intrinsically relates to the fabrication of the built environment worldwide. Conceptually the book is divided along four spatial sites, referred to as camp, shelter, city, and house, which are approached with a multitude of perspectives ranging from urban planning and architecture to anthropology, geography, philosophy, gender studies, and urban history, all with a common focus on space and spatiality. By articulating everyday homemaking experiences of migrants and refugees as spatial practices in a variety of geopolitical and historical contexts, this edited volume adds a novel perspective to the existing interdisciplinary scholarship at the intersection of home and displacement. It equally intends to broaden the canon of architectural histories and theories by including migrants' and refugees' spatial agencies and place-making practices to its annals. By highlighting the political in the spatial, and vice versa, this volume sets out to decentralise and decolonise current definitions of home and displacement, striving for a more pluralistic outlook on the idea of home.
Fluctuation theorems with retrodiction rather than reverse processes
Authors: Aw Clive Cenxin , Buscemi Francesco , Scarani Valerio
Published: October 2021

Irreversibility is usually captured by a comparison between the process that happens and a corresponding “reverse process.” In the last decades, this comparison has been extensively studied through fluctuation relations. Here, we revisit fluctuation relations from the standpoint, suggested decades ago by Watanabe, that the comparison should involve the prediction and the retrodiction on the unique process, rather than two processes. We identify a necessary and sufficient condition for a retrodictive reading of a fluctuation relation. The retrodictive narrative also brings to the fore the possibility of deriving fluctuation relations based on various statistical divergences, and clarifies some of the traditional assumptions as arising from the choice of a reference prior.
Colloidal Nanocrystal Shape and Size Control: The Case of Cobalt
Authors: Puntes Victor F. , Krishnan Kannan M. , Alivisatos A. Paul
Published: October 2021

We show that a relatively simple approach for controlling the colloidal synthesis of anisotropic cadmium selenide semiconductor nanorods can be extended to the size-controlled preparation of magnetic cobalt nanorods as well as spherically shaped nanocrystals. This approach helps define a minimum feature set needed to separately control the sizes and shapes of nanocrystals. The resulting cobalt nanocrystals produce interesting two- and three-dimensional superstructures, including ribbons of nanorods.
Cultural Responses to Climate Change During the Late Holocene
Authors: deMenocal Peter B.
Published: October 2021

Modern complex societies exhibit marked resilience to interannual-to- decadal droughts, but cultural responses to multidecadal-to-multicentury droughts can only be addressed by integrating detailed archaeological and paleoclimatic records. Four case studies drawn from New and Old World civilizations document societal responses to prolonged drought, including population dislocations, urban abandonment, and state collapse. Further study of past cultural adaptations to persistent climate change may provide valuable perspective on possible responses of modern societies to future climate change.
Magnetic Twisters on Mercury
Authors: Glassmeier Karl-Heinz
Published: October 2021

Observations of Mercury during the recent MESSENGER spacecraft flybys reveal a complex magnetosphere.
Vibrio cholerae,Vibrio parahaemolyticus, and Other Vibrios: Occurrence and Distribution in Chesapeake Bay
Authors: Colwell R. R. , Kaper J. , Joseph S. W.
Published: October 2021

Vibrio choleraewas isolated at several locations in Chesapeake Bay in fall 1976 and spring 1977. Strains induced fluid accumulation in rabbit ileal loops and positive activity in Y-1 adrenal cells.Vibrio cholerae,Vibrio parahaemolyticus, and related vibrios show a spatial and temporal distribution characteristic ofVibriospecies in an estuary. TheVibrio choleraestrains isolated from Chesapeake Bay represent serotypes other than O-group I—that is, so-called nonagglutinable vibrios—and are not recognized as a serious epidemic threat, although they have caused choleralike diarrhea sporadically.
New University Breaks the Mold
Authors: Kahn Patricia
Published: October 2021

Cottbus—A new university of science and technology, the Technical University of Cottbus, established 5 years ago in this coal-mining region near the Polish border, is attempting to break out of the straitjacket of German university policy. Courses are multidisciplinary, students can get involved in projects focusing on the problems of the local region, and instruction is mostly by small group teaching—a far cry from the huge, overcrowded lectures common in other universities. If this educational experiment works, it could provide a model for other German universities.
An Elite System Struggles With Mass Education
Authors: Balter Michael
Published: October 2021

A fundamental tenet of French education is that universities should be open to all who graduate from secondary school. As a result, the number of university students almost doubled between 1980 and 1995. But the universities themselves have remained elitist, with a rigorous assessment at the end of each year that determines whether a student can progress to the next year. One result has been frustration and a high dropout rate. These problems are compounded by the fact that funding has not kept pace with the growth in student numbers. Now some academics are arguing that it is time to be more selective in admitting students in the first place.
Universities Feel the Heat of Competition
Authors: Williams Nigel
Published: October 2021

London—Britain's system of higher education has gone through perhaps the most radical changes of any in Europe in the past few years. The government promoted an entire tier of colleges to university status and changed funding systems to reward universities for attracting—and retaining—students. This has promoted competition among universities for both teaching and research funding, while increasing school leavers’ access to university education. But it has also increased the pressures on universities at a time when funding has not kept pace with the growth in student numbers.
The Computer as Lab Assistant
Authors: Williams Nigel
Published: October 2021

Cambridge, U.K.—As the British government ratchets up the pressure on universities to educate more students for less money, many institutions are turning to a new type of teaching assistant: computers. A government-funded project, the Teaching and Learning Technology Program, has resulted in the development of software packages that can substitute for laboratory instruction.
Government Pushes Students Onto the Fast Track
Authors: Hellemans Alexander
Published: October 2021

Amsterdam—Faced with budget constraints, the government announced a round of reforms in 1994 designed to shorten the time it takes students to complete their studies. Dutch universities have also begun to move away from a system based on equality among institutions to one in which universities specialize in particular fields and offer courses geared more to excellence.
Hungary: Industry and Foundations Help Out
Authors: Milligan Susan
Published: October 2021

Budapest—Like other Central European education systems, Hungary's universities are struggling to shake off the shackles of the country's communist past. Budapest Technical University is getting some outside help. Representatives from Hungary's leading industrial countries are offering advice and giving support for reforms aimed at providing students with a broader education that will be more useful for their careers. And financier George Soros has helped fund Central Europe's first independent graduate school, the Central European University.
Mesenchymal Stromal Cells: an Antimicrobial and Host-Directed Therapy for Complex Infectious Diseases
Authors: Shaw Timothy D. , Krasnodembskaya Anna D. , Schroeder Gunnar N. , Zumla Alimuddin , Maeurer Markus , O’Kane Cecilia M.
Published: October 2021

There is an urgent need for new antimicrobial strategies for treating complex infections and emerging pathogens. Human mesenchymal stromal cells (MSCs) are adult multipotent cells with antimicrobial properties, mediated through direct bactericidal activity and modulation of host innate and adaptive immune cells.
Advances in acute myeloid leukemia
Authors: Newell Laura F , Cook Rachel J
Published: October 2021

Acute myeloid leukemia (AML) is an uncommon but potentially catastrophic diagnosis with historically high mortality rates. The standard of care treatment remained unchanged for decades; however, recent discoveries of molecular drivers of leukemogenesis and disease progression have led to novel therapies for AML. Ongoing research and clinical trials are actively seeking to personalize therapy by identifying molecular targets, discovering patient specific and disease specific risk factors, and identifying effective combinations of modalities and drugs. This review focuses on important updates in diagnostic and disease classifications that reflect new understanding of the biology of AML, its mutational heterogeneity, some important genetic and environmental risk factors, and new treatment options including cytotoxic chemotherapy, novel targeted agents, and cellular therapies.
Influence of stress history on undrained cyclic shear strength evolution
Authors: Sahdi Fauzan , Tom Joe , Hou Zhechen , Bransby Fraser , Gaudin Christophe , Watson Phillip
Published: October 2021

Offshore infrastructure often interacts cyclically with the seabed over the operational life of a project. Previous research on the evolution of soil’s undrained strength under long-term, large-amplitude cyclic loading has focused on contractile clays and demonstrated that this cyclic interaction can lead to the initial generation and later dissipation of positive excess pore pressure in the soil. This process generally leads to an initial strength reduction, with subsequent densification and soil strength gains that can have consequences on the performance of seabed infrastructure during its design life. In this paper, new experimental data from T-bar penetrometer testing in kaolin and reconstituted Gulf of Mexico clays is presented. The data illustrate how the stress history, quantified via the overconsolidation ratio, affects soil strength changes during large-amplitude cyclic loading. The experiments explore both long-term continuous loading cycles and episodic loading with packets of undrained cycles followed by quiescent consolidation periods. A critical state-based framework is used to interpret the experimental data and provide predictions of the long-term steady-state strength of both soils as a function of the initial in situ state of the soil.
Analysis of charged gravastar in f(R,G) gravity
Authors: Bhatti M. Z. , Yousaf Z. , Rehman A.
Published: October 2021

This paper is dedicated to inspecting the appearance of electromagnetic field, which is caused by the presence of charge in the highly compact object named gravastar in the background of [Formula: see text] theory. According to conjecture introduced by Mazur and Mottola gravastar must be consisted of three sectors. We have interpreted these sectors by using specific equations of states. Spherically static metric, perfect fluid and the isotropic pressure have been used in order to calculate a singularity free solution. Gravitational mass present in the inner sector of gravastar is changed into electromagnetic mass in the existence of charge. The electromagnetic mass model of inner sector is responsible for stability by providing balance to the repulsive pressure, which is caused by the presence of charge. It is observed that the presence of electrical charge has a significant effect on energy content, entropy and proper length of the shell that is demonstrated with the help of graphs.
A tachyon field around the black hole
Authors: Rashidi Narges
Published: October 2021

In this paper, we study the effects of the presence of the tachyon field around the black hole. We show that in presence of the tachyon field, unlike the ordinary canonical scalar field, the time evolution of the black hole mass depends on the potential of this field. By considering several types of potential, we study the behavior of the black hole mass and its time evolution and find some interesting results. We find that the presence of the tachyon field causes the accretion of the mass into the black hole. We also show that with linear and hilltop potentials, in some ranges of the parameters space, the mass of the black hole can decrease even without any Hawking radiation.
Thermodynamics of Bardeen regular black hole with generalized uncertainty principle
Authors: Merriam Areeba , Sarwar M. Zain
Published: October 2021

This study explores the emission of massive charged spin-1 particles from the background of Bardeen regular spacetime by the semi-classical method used to study the Hawking radiation spectrum. We employed the Hamilton–Jacobi method and Wentzel–Kramers–Brillouin approximation technique with the suitable form of the wave function to solve the Proca field equation. We calculated the tunneling probability of outgoing spin-1 particles and the corresponding thermodynamic temperature. Furthermore, we obtained the modified thermodynamic quantities like temperature, entropy as well as heat capacity by utilizing the quadratic form of generalized uncertainty principle (GUP) and minimal length. In the end, we investigated the local stability as well as phase transitions of the Bardeen black hole in the context of GUP-modified heat capacity.
Reducing ω-model reflection to iterated syntactic reflection
Authors: Pakhomov Fedor , Walsh James
Published: October 2021

In mathematical logic there are two seemingly distinct kinds of principles called “reflection principles.” Semantic reflection principles assert that if a formula holds in the whole universe, then it holds in a set-sized model. Syntactic reflection principles assert that every provable sentence from some complexity class is true. In this paper, we study connections between these two kinds of reflection principles in the setting of second-order arithmetic. We prove that, for a large swathe of theories, [Formula: see text]-model reflection is equivalent to the claim that arbitrary iterations of uniform [Formula: see text] reflection along countable well-orderings are [Formula: see text]-sound. This result yields uniform ordinal analyzes of theories with strength between [Formula: see text] and [Formula: see text]. The main technical novelty of our analysis is the introduction of the notion of the proof-theoretic dilator of a theory [Formula: see text], which is the operator on countable ordinals that maps the order-type of [Formula: see text] to the proof-theoretic ordinal of [Formula: see text]. We obtain precise results about the growth of proof-theoretic dilators as a function of provable [Formula: see text]-model reflection. This approach enables us to simultaneously obtain not only [Formula: see text], [Formula: see text] and [Formula: see text] ordinals but also reverse-mathematical theorems for well-ordering principles.
Boundedness and compactness of commutators associated with Lipschitz functions
Authors: Guo Weichao , He Jianxun , Wu Huoxiong , Yang Dongyong
Published: October 2021

Let [Formula: see text], [Formula: see text] and [Formula: see text] be a singular or fractional integral operator with homogeneous kernel [Formula: see text]. In this paper, a CMO type space [Formula: see text] is introduced and studied. In particular, the relationship between [Formula: see text] and the Lipchitz space [Formula: see text] is discussed. Moreover, a necessary condition of restricted boundedness of the iterated commutator [Formula: see text] on weighted Lebesgue spaces via functions in [Formula: see text], and an equivalent characterization of the compactness for [Formula: see text] via functions in [Formula: see text] are obtained. Some results are new even in the unweighted setting for the first-order commutators.
Sparse representation of approximation to identity
Authors: Qu Wei , Chui Charles K. , Deng Guan-Tie , Qian Tao
Published: October 2021

The Dirac-[Formula: see text] distribution may be realized through sequences of convolutions, the latter being also regarded as approximation to the identity. This paper proposes the real form of pre-orthogonal adaptive Fourier decomposition (POAFD) method to realize fast approximation to the identity. It belongs to sparse representation of signals having potential applications in signal and image analysis.
Nonlinear Forced Vibration of Spinning Pipes Conveying Fluid Under Lateral Harmonic Excitation
Authors: Liang Feng , Qian Yu , Chen Yao , Gao An
Published: October 2021

As a crucial offshore drilling equipment, the drill strings often encounter instability due to various external excitations. In order to deeply understand the dynamical mechanism of such issues, in this paper, the working drill strings are modeled as a spinning pipe conveying fluid, and the forced vibration characteristics of such system under an equivalent lateral excitation are studied analytically and numerically. The system considered is essentially under triple excitations: the fluid–structure interaction (FSI), spinning motion and external force. The viscoelastic material and geometrical nonlinearity due to extensible pipe axis are taken into account. The governing equation is derived by the Hamilton principle and then treated by the numerical simulation. The Lissajous trajectory and whirling motion shape of the pipe are obtained, in which the subcritical and supercritical cases are both discussed. It is revealed that the system conducts periodic or quasi-periodic motion at subcritical state, while presents chaotic motion at supercritical flow velocity. Perturbation analysis is also carried out to investigate the nonlinear frequency–amplitude features of the system. Comprehensive parametric studies are performed and the flow velocity, spinning speed, nonlinearity, excitation and damping are all found to have significant effects on the moving trajectory and frequency response of the pipe.
The Gogo Formation Lagerstätte: a view of Australia's first great barrier reef
Authors: Trinajstic Kate , Briggs Derek E. G. , Long John A.
Published: October 2021

Discoveries from the Late Devonian Gogo Formation in the Canning Basin, Western Australia, have provided insights into the origin and evolution of many unique gnathostome features such as the origins of teeth, internal fertilization, air-breathing, transitional tissues between bone and cartilage, and insights into the fin-to-limb transition. Although vertebrate studies have dominated evolutionary work, invertebrate studies have added important insights into the palaeoecology of the site and demonstrated close faunal affinities along the margins of northern Gondwana and China. Geochemical analyses have broadened our understanding of the pathways involved in the exceptional preservation of this Devonian Konservat-Lagerstätte. Fossils from the Gogo Formation show extensive soft tissue preservation through phosphatization, recording anatomical details not normally obtained from fossil sites.
Origin of Fe–Ni–Cu (Co) sulfide and Fe–Ti oxide minerals in the
c.
1.77 Ga dolerite dyke, Singhbhum Craton (eastern India)
Authors: Dey Arnab , Mondal Sisir K.
Published: October 2021

Dolerite dyke swarms are widespread within the Singhbhum Craton (eastern India) that emplaced from the Neoarchean to Paleoproterozoic era just after the stabilization of crust before
c.
3 Ga. These dyke swarms are oriented in NE–SW to NNE–SSW, NW–SE to WNW–ESE, east–west and north–south directions. The WNW–ESE-trending
c.
1.77 Ga Pipilia dyke swarm is sampled from the Satkosia area of Orissa state. The dyke shows a noticeable disparity in terms of the modal proportion and grain size of pyroxenes, plagioclase, Fe–Ti oxide minerals and texture across the trend. In places the primary silicates are altered to secondary hydrated mineral assemblages of amphibole, chlorite and sericite. The primary silicates are clinopyroxene (augite – Mg# = 65.7–82.6; En
37–48
Fs
11–17
Wo
36–41
), orthopyroxene (clinoenstatite – Mg# = 68.5–78; En
63–70
Fs
20–29
Wo
4–5
) and plagioclase (An
11–39
Ab
44–82
Or
1–7
) and the Fe–Ti oxides are titanomagnetite (FeO, 34.38–39.50 wt%; Fe
2
O
3
, 48.26–56.21 wt%; TiO
2
, 5.05–9.60 wt%) and ilmenite (FeO, 40.75–43.79 wt%; Fe
2
O
3
, 3.54–10.03 wt%; TiO
2
, 47.82–50.87 wt%). Application of two-pyroxene thermometry yields an equilibration temperature range of 1065–978°C, and coexisting titanomagnetite–ilmenite pairs reveal 731.39–573.37°C under the oxygen fugacity (
f
O
2
) condition NNO + 0.3 to FMQ − 1.03. The dyke contains disseminated sulfides at the interstices of Fe–Ti oxides and silicates. Major sulfide minerals are pyrite, chalcopyrite and vaesite; pyrite–vaesite assemblages occur in association with secondary silicate minerals. Pyrite grains contain variable concentrations of Co (0.01–5.70 wt%) and Ni (0.02–1.95 wt%). Coexisting vaesite contains Co (2.42–10.44 wt%), Ni (26.40–47.88 wt%) and Fe (7.32–26.55 wt%). Texture, sulfide–silicate assemblage and the presence of low metal/S sulfides such as the pyrite–vaesite assemblage indicate that primary Fe–Ni sulfides (pyrrhotite–pentlandite) that segregated from immiscible sulfide liquid at high temperature are modified by late magmatic/hydrothermal fluid activities. Numerous sulfide-bearing deposits hosted in ultramafic–mafic intrusions of Paleoproterozoic age have been recorded globally and the occurrence of Fe–Ni sulfides in the
c.
1.77 Ga Pipilia dyke swarm in the Singhbhum Craton enhances the exploration potential of this craton in eastern India.
Motivating Players to Perform an Optional Strenuous Activity in a Virtual Reality Exergame Using Virtual Performance Augmentation
Authors: Born Felix , Rygula Adrian , Masuch Maic
Published: October 2021

Research on VR Exergaming is mostly conducted with participants who are not presented a choice whether or not to play the exergame and thus to perform a certain strenuous activity. Whether players would engage in such activity if it were optional and how they could be motivated to do so is mostly neglected. Therefore, we have developed a novel controller and implemented a VR exergame that utilizes Virtual Performance Augmentation (VPA) to motivate players to engage in an optional strenuous activity. The motivational impact of three different conditions (VPA vs. Points vs. No Motivator) was evaluated in a study with 47 participants. Our results suggest that using VPA can significantly increase the time the players engage in the strenuous activity enriched by VPA, while in contrast to our hypotheses, no significant differences for the players' enjoyment and perceived exertion between the conditions were found. We discuss our findings in the context of motivation, exertion, and the resulting implications for further VR exergames research.
Game-based Climate Change Engagement
Authors: Fernández Galeote Daniel , Hamari Juho
Published: October 2021

Video games have risen as a popular medium with the potential to become a powerful tool for public climate change engagement. However, little is known about how existing digital games can fulfill this role. This study systematically compiles 150 video games that represent climate change, including serious (n = 109) and for entertainment (n = 41). The games are analyzed by adapting an existing framework (15 dimensions: achievable, challenging, concrete, credible, efficacy-enhancing, experiential learning, feedback-oriented, fun, identity-driven, levelling-up, meaningful, narrative-driven, reward-driven, simulating, social) and statistically compared. The analysis reveals that most games comply with most recommended attributes, but credibility, achievability, meaningfulness, and social features are uncommon or rare. Statistical results comparing serious games and games for entertainment associate six attributes with serious games (achievable, challenging, credible, efficacy-enhancing, experiential learning, feedback-oriented), and one (narrative-driven) with games for entertainment. The findings suggest that researchers would benefit from widening their lens to detect previously overlooked opportunities for game-based climate change engagement, communication, and education. The study also provides a systematic mapping of extant games depicting climate change for interested developers, designers and educators.
Play for Real(ism) - Using Games to Predict Human-AI interactions in the Real World
Authors: Guttman Rotem D. , Hammer Jessica , Harpstead Erik , Smith Carol J.
Published: October 2021

AI-enabled decision support systems have repeatedly failed in real world applications despite the underlying model operating as designed. Often this was because the system was used in an unexpected manner. Our goal is to enable better prediction of how systems will be used prior to their implementation as well as to improve existing designs, by taking human behavior into account. There are several challenges to collecting such data. Not having access to an existing prediction engine requires the simulation of such a system's behavior. This simulation must include not just the behavior of the underlying model but also the context in which the decision will be made in the real world. Additionally, collecting statistically valid samples requires that test subjects make repeated choices under slightly varied conditions. Unfortunately, in such repetitious conditions fatigue can quickly set in. Games provide us the ability to address both of these challenges by providing both systems context and narrative context. Systems context can be used to convey some or all of the information the player needs to make a decision in the game environment itself, which can help avoid the onset of fatigue. Narrative context can provide a broader environment within which the simulated system operates, adding a sense of progress, showing the effect of decisions, adding perceived social norms, and setting incentives and stakes. This broader environment can further prevent player fatigue while replicating many of the external factors that might affect choices in the real world. In this paper we describe the design of the Human-AI Decision Evaluation System (HADES), a test harness capable of interfacing with a game environment, simulating the behavior of an AI-enabled decision support system, and collecting the results of human decision making based upon such a system's predictions. Additionally, we present an analysis of data collected by HADES while interfaced with a visual novel game focused on software cyber-risk assessment.
Predicting Game Difficulty and Engagement Using AI Players
Authors: Roohi Shaghayegh , Guckelsberger Christian , Relas Asko , Heiskanen Henri , Takatalo Jari , Hämäläinen Perttu
Published: October 2021

This paper presents a novel approach to automated playtesting for the prediction of human player behavior and experience. We have previously demonstrated that Deep Reinforcement Learning (DRL) game-playing agents can predict both game difficulty and player engagement, operationalized as average pass and churn rates. We improve this approach by enhancing DRL with Monte Carlo Tree Search (MCTS). We also motivate an enhanced selection strategy for predictor features, based on the observation that an AI agent's best-case performance can yield stronger correlations with human data than the agent's average performance. Both additions consistently improve the prediction accuracy, and the DRL-enhanced MCTS outperforms both DRL and vanilla MCTS in the hardest levels. We conclude that player modelling via automated playtesting can benefit from combining DRL and MCTS. Moreover, it can be worthwhile to investigate a subset of repeated best AI agent runs, if AI gameplay does not yield good predictions on average.
Little Computer People
Authors: Azad Sasha , Martens Chris
Published: October 2021

Bolstered by a growing interest in simulating believable non-player characters (NPCs), work on NPC models has spanned topics such as planning, procedural storytelling, decision-making, and social dynamics. However, research groups work in isolation, designing and discussing their character models with disparate approaches, often using project-specific terminology. This makes it challenging to identify, classify, and accumulate existing knowledge. It is our position that since modelling of virtual characters has become an integral part of the scientific practice in our field, we must develop a common taxonomy to discuss these models. With this goal in mind, we conduct an in-depth analysis of a selection of projects, categorizing existing agent social interactions, and comparing results from research-based and commercial social simulation works in the entertainment domain. We conceptualize a taxonomy that classifies agent interactions by their social behaviours, inter-agent communication, knowledge flow, and the change in their relationships. We posit such a taxonomy would allow scientists to reproduce and evaluate existing models, collaborate on standards, share advances with other researchers and practitioners, allow for better communication and methodologies developed for new techniques, and allow for a more rigorous model-to-model analysis.