bluuebunny/crossref_metadata_2025 huggingface dataset:
Innovative groundwater management in industrial park: Optimization and modelling of extraction system
Authors: Baroková Dana , Šoltész Andrej , Červeňanská Michaela , Čubanová Lea
Published: May 2024

The research presented in this paper focuses on the optimization and modelling of an innovative groundwater extraction system and addresses the challenge of managing the increased groundwater level in Nitra Industrial Park, where the Land Rover Jaguar car manufacturer is located. The primary objective of this research was to determine the optimal pumping rate of the system, ensuring the maintenance of the groundwater level at the required elevation without depleting the surrounding water resources. To achieve this goal, a numerical groundwater modelling approach was utilized, employing the TRIWACO simulation package and the finite element method (FEM). The study involved various simulations under steady and unsteady flow conditions, using hydrological, geological and hydrogeological data, including the results of three proposed pumping tests conducted by INGEO, Ltd. Company, as well as measured groundwater level data from boreholes monitored by the Slovak Hydrometeorological Institute (SHMI). Implementing transient groundwater flow simulations considered the impact of a 1000-year flash flood wave (Q1000). This paper presents results of numerical modelling results, offering insights into maintaining the required groundwater elevation while considering key parameters and uncertainties for design purposes. Additionally, on-site optimization was performed to ensure efficient system operation and minimize associated costs. In conclusion, this research contributes to sustainable groundwater management in the Nitra Industrial Park, addressing the challenge of the increased groundwater level and providing valuable findings to optimize the extraction system’s performance.
Expansion and bonded anchors in (shallow) fixings in concrete substrate reinforced with steel and polypropylene fibres
Authors: Konieczny Kazimierz , Dudek Daniel , Kukiełka Alfred
Published: May 2024

Along with the development of engineering construction techniques, the interest in the issue of fastenings increases. In the construction of new facilities as well as in renovation works, a wide range of fasteners is currently used, enabling quick connections and safe fastening of various types of structural and installation elements. This progress is particularly visible in fixings made in concrete substrates. During assembly and during operation, the fasteners are subject to the influence of many external factors that may significantly affect their load capacity. Such factors include the type and nature of the load to be transferred, the strength and condition of the substrate, the temperature at which the fasteners will be installed and used. The technical parameters of fasteners determined by means of theoretical calculations still do not provide adequate accuracy, so that this method can be used to determine their impact on the behaviour of fasteners during their long-term operation. Therefore, their experimental verification is still required. In the countries of the European Union, the development of the rules for the use and assessment of expansion and bonded fasteners has been entrusted to the European Organization for Technical Assessment - EOTA. This organization groups bodies authorized by EU Member States to provide European technical assessments on the terms set out in Regulation No. 305/2011 (CPR) 2013. The current list of EOTA guidelines for expansion and bonded anchors used in the construction industry, specifying the basis for their use as well as standards for the design of fasteners. The scope and methods of fastener testing are presented in the EOTA guidelines. The purpose of these tests is to determine whether the behavior of the fasteners during their use will be safe and effective, taking into account the unfavourable conditions that can be encountered both during its installation and use. The publication will present the basic structural properties of fasteners made in drilled holes in concrete substrates reinforced with steel and polypropylene fibres.
Influence of embedded steel mesh inserts on post-breakage capacity of laminated glass
Authors: Kozłowski Marcin , Wasik Dominik
Published: May 2024

Glass, as a building material, has been known for a long time. The first glass uses were limited to filling window frames. However, in recent years, the popularity of glass in construction has increased significantly. All this is due to the growing trend to bring as much natural sunlight into the buildings as possible. The increasingly popular treatment of glass as a construction material requires using laminated glass, in which a film permanently joins together two or more glass panes. This unique behaviour is because the film between the glass sheets holds the glass fragments in place when they are fractured. In this way, avoiding the risk of injury to people in the vicinity is possible. As part of the ongoing project, “Innovative solution for point-fixed laminated glass with improved capacity after glass fracture” financed by the National Center for Research and Development (NCBR) within the LIDER XI Program, an idea of laminating a steel woven mesh to glass laminates is being investigated. The steel mesh insert is designed to increase the load-bearing capacity of the sample in the post-breakage phase, thus increasing the safety of building occupants. The article deals with the post-breakage capacity of laminated glass elements subjected to three types of loading: in-plane, out-of-plane and combined actions.
The geometric shape of the transported material batches in the vertical branch of a belt conveyor
Authors: Hrabovský Leopold , Blata Jan
Published: May 2024

Transport above the limit angle of transport inclination provided using belt conveyors can be done in several ways. If we omit the methods based on an increase in the contact force of the transported material in relation to the surface of the conveyors belt and increase in the coefficient of friction, we will focus only on the method based on the principle of preventing the movement of the transported grains on the surface of the conveyors belt. This principle uses transverse cleats that prevent the movement (sliding or rotation) of material grains along the entire length of the conveyor belt, which is inclined at a high angle to the horizontal plane. Material grains are transported on the surface of a conveyor with cleats, distributed with a regular spacing along the entire length of the endless loop of the conveyor belt. To prevent material grains from falling of such a belt, corrugated sidewalls are fitted on both edges of the conveyor belt. This paper describes two variants that take into account the mutual position of the cleats in relation to the corrugated sidewalls. For each of the variant, the relationship is given with which it is possible to analytically quantify the volume of the bulk loose material batch that is spread over the area of the cleat in the vertical section of this conveyor belt design. The results of the measured values concerning the height of the loose material pile that were taken using laboratory instruments are listed in the tables and compared with the theoretically calculated values. Key data that must be known to calculate the pile height, and the volume of the transported material batch represent the exact value of the angle of repose for the loose material. The angle of repose of a particular loose material does not acquire a constant size, as it changes from its maximum (static angle of repose) depending on the shaking, flattening or absorbing liquid to its minimum (surcharge angle). The paper presents geometric shapes of batches for the transported material used for both limit values of the angle of repose.
The colonial village of Radomierowice and its sacral buildings as an example of typical rural architecture during the Frederick colonization
Authors: Fiutak Marcin , Bajno Dariusz , Grzybowska Agnieszka
Published: May 2024

The article presents an overview of half-timbered construction in Opole Silesia (south Poland). Its unique forms on the example of the church of N.M.P. in Radomierowice. It shows the genesis of the Prussian colonial style (log construction). Influence of colonial settlements and types of wooden folk architecture in Opole Silesia from the 17th century. The article presents an analysis of frame structures on the example of the church of N.M.P. in Radomierowice by architect Christian Isemer. Which were used in religious architecture during the Friderite colonization (the turn of the 18th and 19th centuries). Was presented a result of the analysis, the problem of the disappearance of the historical substance of monuments from the landscape of the Silesian countryside.
Exploring isovist fields: A comparative study of churches in reconstruction plans for post-earthquake Lisbon
Authors: Sampayo Mafalda , Sousa-Rodrigues David
Published: May 2024

Following the Lisbon 1755 earthquake, Manuel da Maia (1677-1768), chief engineer of King D. José I (1714-1777), commissioned six plans for the city’s reconstruction. We analyze these plans weighing how they addressed the challenges of building a modern city of the XVIII century. In them, churches had different roles in the urban morphology of the city. We investigate their interplay over the plans. The analysis of the importance of religious buildings in the city plan was made through the visual impact that those buildings had in the public space. Using isovists, we examine the visual impact of religious buildings on public space. Our results indicate that all plans, except the chosen one, promoted a greater visual impact of churches in public space. Plan 6 proposed a patriarchal church in Terreiro do Paço, with an extreme impact on the city’s visual landscape. Conversely the chosen plan presented a similar visual impact of churches in the plan as the pre-1755 city. This resulted from the removal of churches from the main streets and their integration inside the city blocks. This plan presented a similar level of visual impact, comparable to the pre-1755, but with a completely different approach to the street drawing. Overall, this study sheds light on how different reconstruction options for the city of Lisbon could have impacted the city being rebuilt. The aftermath of the 1755 earthquake provided an opportunity not only to rebuild the city, but also to redefine the power balance within the kingdom and to shift the importance of the church as a central aspect of city life.
The paradigm of the diachronic Greek stilt house type as an answer to the climate change
Authors: Cheirchanteri Georgia
Published: May 2024

As a matter of fact, climate change is transforming the contemporary way of building. Stilt houses constitute another yet glamorous mystery of prehistoric “small/big world”. It is about permanent human constructions in water areas (usually lakes or lagoons), which appeared 8.000 years ago. People live up to now, in such a dwelling type, located on shallow water areas such as seaside, lakes or rivers worldwide. Although in Greece, the first stilt settlements appeared in the Neolithic era, the later stilt settlements in Mesologgi Lagoon area, are also important. The aim of this research is to discuss how this Greek diachronic stilt house type, in Mesologgi Lagoon area, will be the solution to the climate change constructions. Nowadays, stilt or floating architecture is linked to the usable land’s deficiency for building structures, which due to residential evolution, economic growth and transportation, belongs to the most important environmental pressures on landscapes worldwide, especially in urbanized areas. According to climate change progress and temperature increase, usable land in urban areas will be limited due to the continuous development expansion for residence. Concluding, the stilt house type is the future worldwide type of residence, as an answer to the climate change and the environmental damage.
A low-tech approach to nZEB dwellings in developing countries - case study Romania
Authors: Simiraş-Babic Mihnea
Published: May 2024

This paper, based on a larger research, focuses on evaluating the feasibility and challenges of implementing the nearly Zero-Energy Building (nZEB) standard on dwellings in Romania. It is proposed that implementing this new set of regulations and national strategies should be context-specific, adapted to several factors which are common to a particular area in regard to the characteristics of housing and dwelling: the culture of dwelling, the dynamics of dwelling (occupancy, maintenance, use), household finances and expenses, demographics, building habits and the construction market and climate considerations. These realities are however a product of long periods of evolution and a result of certain habits. The new paradigm, oriented towards energy efficiency, is in some regards divergent to these. As such, before using advanced technological means for a more energy efficient building, these traditions and habits should be addressed. There should be a focus on the initial stages of the design (regarding the future building) and on the way it is used, which means that the architect and the end-user (the dweller) are central to the process. Initial decisions about the appearance of the building and how it is built (orientation, building materials, internal layout etc.) and involving the future dwellers and their dwelling habits in the process affect the overall energy footprint of the building in a more decisive manner than later technological additions. As a result, a context-specific lowtech approach to energy-efficient dwellings begins to take shape. Rather than being localized, it will be shown that these new strategies can affect much larger areas, even involving shifts in the way human settlements are designed and managed.
“Urban ruins” The strategical importance of abandoned buildings in the process of urban reanimation
Authors: Goleac Gabriel-Eugene
Published: May 2024

Entire generations of people, separated by time, through history, are mentally connected through the memories stored in those buildings which had survived to become imposing reminiscences of our past, through which we are able to connect with our ancestors and, therefore, our history. Urban ruins are a natural urban phenomenon. They represent a consequence of time and space, and also the direct result of the rapid urban development of the city, shaped constantly by internal and external social, political and economic conditions. They are usually those abandoned buildings and constructions, who lost their physical integrity due to their advanced state of physical degradation, caused by the lack of periodic maintenance, due to the abandonment of their owners, mostly due to economic reasons. They are usually found in abandoned or contaminated sites, better known as Brownfields and Greyfields. These old abandoned industrial and large commercial urban sites had formed in time disused urban tissues which had caused morphological and technical problems to the entire existing urban fabric of the city. Their lack of activity and advanced state of decay parasitizes the space they occupy within the city, endangers the urban hygiene and the safety of citizens, and overall damages the urban image of the city. The current PhD thesis aims to document the presence of all urban ruins, by mapping all the abandoned buildings and constructions in Bucharest City and analyse their strategic value and importance, in order to establish applicable theoretical principles regarding the urban morphological peculiarities of other cities which also may constitute the subject of this global phenomenon.
Principles and technologies of historical structures consolidation, case study of Banloc castle complex
Authors: Moșiu Alina , Vanciu-Rău Adina , Gheboianu Anca Irina , Slamnoiu-Teodorescu Sofia , Moșoarcă Marius , Ion Rodica-Mariana , Lungu Mihail
Published: May 2024

Historical monuments (palaces, churches, protected urban areas, so on) are integral part of the national cultural heritage which need activities and measures to protect them. The Banloc complex, located in the west of Romania, encompasses five buildings: the castle, the hunting pavilion, the kitchen, housekeeper house, and the stall. This study involves historical, architectural, structural and physical-chemical investigations with the aim of finding the correct restoration solutions, in good agreement with the Venice Charter, respectively the Nara Charter. Being affected by time and by the seismic sequence (Mw 5.6), the restoration of the building is absolutely necessary for recovering the functionality, structural solution and highlighting the artistic elements. Some analytical techniques, as: X-ray diffraction (XRD), Wavelength Dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), and zoom microscopy, Infrared spectroscopy Fourier Transformed (FTIR), and Raman spectroscopy, have been used in this paper in order to clarify the main aspects about the structure, composition and morphological of the samples collected from Pavilion building. The oxides composition, and the possible organic impurities has been identified by WDXRF amd FTIR/Raman spectra, respectively. The microscopy images revealed the colours, fissures, cracks and even holes due to the time weathering processes, and damages they suffered in time.
Recent methods of visualization used in the diagnosis and consolidation of historic structures
Authors: Gigi Olariu , Marius Nemet Florin
Published: May 2024

The subject addresses heritage objects that are subject to degradation processes caused by both natural and anthropogenic factors. One of the current solutions is directed towards a varied range of scientific instruments, thus facilitating the analysis and diagnosis of the concerned buildings, contributing also to the identification of materials and techniques used and providing information about any previous interventions of conservation attempts. Recent visualization methods used in the diagnosis and consolidation of historic structures can utilize both three-dimensional laser scanning technology and laser interferometry as a diagnostic method, as well as alternative methods such electrometry, magnetometry and ground penetrating radar devices. The subject aims to address how heritage objects can be secured using 3D scanning technologies. The case studies were conducted on the Bezdin Monastery Complex, the ”Saint Martyr Gheorghe” Church, the ”Saint Martyr Filimon” Monastery and the former Metropolitan Summer Residence in Sibiu. The selected case studies illustrate the methodology for obtaining and processing field data, as well as the use of this data in the diagnosis process and in selecting appropriate consolidation options for these historical structures based on obtained results. These technologies have provided specialists with the possibility of extracting vital information both in the diagnostic phase and throughout the implementation of restoration works. Advanced scanning technologies of today have enabled the creation of a database with the capability of providing pertinent information about a building’s past, starting from its initial stage, up to the completion of execution works, which significantly aids in facilitating the process of diagnostic analysis and structural calculation.
Common issues regarding the churches of Banat
Authors: Gosta Mihai
Published: May 2024

Banat is a south-western region of Romania in which all villages contain orthodox churches. The churches in question were constructed during the end of the 18th century – beginning of the 19th. It is important mentioning that the religious activity was uninterrupted during this time. The churches are located in the following villages: Poganesti, Voiteg, Zgribesti, Balint, Sanmihaiu Roman, Hezeris, Unip, Capat, Saravale, Hodoni, Igris, Babsa, Ficatari, jebel, Visma, Cadar, Hodos, Olosag. The aim of the study is to identify the primary issues, deteriorations, which became apparent with time and present during evaluation and identifying the cause of this. The observations were made during 2022-2023. The majority of the orthodox churches from Banat consist of a central area (naos), sometimes accompanied by transepts on both sides, a sanctuary in the eastern part and a bell tower in the western part. The primary structural degradation consists of cracks in the walls, the arches and domes. The causes of all this are unequal leaning of the walls, uneven weight exerted by the structure, foundations with insufficient width and depth, and the effects of earthquakes from the past. In addition, there is an overall exfoliation and peeling of the plaster, also excessive humidity among the lower part of the walls. This has happened due to capillary ascent of water and the frosting-defrosting process. Most of the time, improper interventions and the use of cementbased materials have accelerated the process of deterioration. Sometimes, local destructions of the roof and wooden extremities are present because of ageing and lack of maintenance of the roof’s cover, the effects can be noticed on the sheets of metal or ceramic tiles. All of this inevitably leads to a partial or complete destruction of internal mural pictures, often times of great artistic value. The major conclusion represents a centralization of the damaging factors and the proposal of few measures of mitigating the effects of them.
Round-trip hub location problem
Authors: Kemmar Omar , Bouamrane Karim , Gelareh Shahin
Published: May 2024

In this paper, we introduce a novel network design for the Hub Location Problem, inspired by the round-trip structure commonly used by transport service providers. Our design integrates spoke nodes assigned to a central hub node, creating round-trips where the hub node serves as the starting point, visits all assigned spoke nodes, and returns to the hub. To enhance transportation services and provide additional redundancy, we introduce a new type of nodes called runaway nodes to the network. The motivation for this research arises from two real-life cases encountered during consultancy projects, underscoring the necessity for an optimized network design in transportation services. To address the proposed problem, we introduce a mixed-integer linear programming (MIP) mathematical model. However, due to the problem’s complexity, the feasibility of the MIP model is limited to small-scale instances. To tackle medium and large-scale instances, we introduce two hyper-heuristic approaches based on reinforcement learning. These hyper-heuristic approaches harness the power of reinforcement learning to guide the selection of low-level heuristics and improve solution quality. We conduct extensive computational experiments to evaluate the efficiency and effectiveness of the proposed approaches. The results of our experiments affirm the efficiency of the proposed hyper-heuristic approaches, showcasing their ability to discover high-quality solutions for the Hub Location Problem.
Acute Appendicitis in Children with Hematological Malignancies: The Need for Early Diagnosis and Prompt Treatment—A Single-Center Case Series
Authors: Kakkar Shruti , Jain Arihant , Jain Evani , Gupta Anubhavv , Kaur Navneet , Jain Anirudh , Grewal Alka , Budhiraja Sushil , Kakkar Chandan
Published: May 2024

Introduction Appendicitis in patients with hematological malignancies presents with vague symptoms, thus requiring a high degree of suspicion for early diagnosis and treatment to prevent complications.

Objectives The aim of this article was to describe the demographic, clinicoradiological, operative findings, and outcomes in patients with acute appendicitis with underlying hematological malignancies.

Materials and Methods A retrospective review of pediatric patients with hematological malignancy who developed acute appendicitis was conducted. Medical records of patients were reviewed for patient demographics, disease status, signs, and symptoms at the time of diagnosis of acute appendicitis, and outcome. The laboratory, radiological, and histological findings were retrieved from the hospital records.

Results Six (2.4%) patients developed acute appendicitis over the past 8 years among a total of 254 patients treated for hematological malignancies in the unit. Five patients had underlying acute lymphoblastic leukemia (ALL) and one had acute myeloid leukemia (AML). Of the five patients, three were in postremission consolidation, one each in the delayed intensification and maintenance phase of chemotherapy. The child with AML was on induction chemotherapy for the first relapse at the time of diagnosis. Fever and abdominal pain were the common presenting symptoms. Diagnosis was made on ultrasound abdomen in five patients, and one patient was diagnosed on computed tomography. All patients underwent open appendectomy. Two patients had evidence of appendiceal perforation. Three patients had neutropenia at the time of developing appendicitis and underwent appendectomy regardless of the absolute neutrophil count (ANC). Five patients recovered well, and chemotherapy was restarted within 2 weeks of appendectomy. One patient developed a superficial surgical site infection. and one patient with relapsed AML expired due to refractory septic shock.

Conclusion Acute appendicitis in patients with hematological malignancies can present with subtle signs and symptoms. Appendectomy can be safely performed irrespective of the ANC.
A multi-criteria simulation of European coastal shipping routes in the ‘age of sail’
Authors: Litvine Alexis D. , Lewis Joseph , Starzec Arthur W.
Published: May 2024

This article introduces a new method to model sailing routes before the age of steam based on real-world sailing conditions. Using a broad range of historical meteorological data, it offers monthly routing predictions for historical shipping corridors and tests them against historical evidence. In this article the model was applied to French and British ports. The output reveals the presence of historical shipping corridors and offer the first journey-time metrics to and from all European ports.
How does narcissistic leadership influence change-oriented organizational citizenship behavior? Empirical evidence from China
Authors: Fang Yangchun , Liu Yonghua , Yu Peiling , Chen Nuo
Published: May 2024

Based on conservation of resources theory and the work–home resources model, this study examines how and when narcissistic leadership influences employees’ change-oriented organizational citizenship behavior. A total of 363 employees from 61 teams across numerous enterprises based in central China were surveyed using a questionnaire. The study hypotheses were tested using structural equation modeling and Monte Carlo simulation analysis. The findings revealed that narcissistic leadership results in the development of a negative team climate, termed “team chaxu climate,” which, in turn, hinders employees’ change-oriented organizational citizenship behavior. Furthermore, this study explored the moderating role of leaders’ family affective support in the relationship between narcissistic leadership and team chaxu climate. This study contributes to our understanding of the relationship between narcissistic leadership and employee organizational citizenship behavior and empirically validates the work–home resources model.
Automated mathematics and the reconfiguration of proof and labor
Authors: Ochigame Rodrigo
Published: May 2024

This essay examines how automation has reconfigured mathematical proof and labor, and what might happen in the future. It discusses practical standards of proof, distinguishes between prominent forms of automation in research, provides critiques of recurring assumptions, and asks how automation might reshape economies of labor and credit.
Working with machines in mathematics
Authors: Davies Alex
Published: May 2024

Machine learning is making significant contributions to many fields but how can it be used as a tool for mathematicians? This article explores the emerging role of machine learning in mathematical research, highlighting how its perceptual capabilities can augment human intuition and lead to new discoveries.
Linear rates of asymptotic regularity for Halpern-type iterations
Authors: Cheval Horaţiu , Leuştean Laurenţiu
Published: May 2024

In this note we apply a lemma due to Sabach and Shtern to compute linear rates of asymptotic regularity for Halpern-type nonlinear iterations studied in optimization and nonlinear analysis.
Properties of discrete sliced Wasserstein losses
Authors: Tanguy Eloi , Flamary Rémi , Delon Julie
Published: May 2024

The Sliced Wasserstein (SW) distance has become a popular alternative to the Wasserstein distance for comparing probability measures. Widespread applications include image processing, domain adaptation and generative modelling, where it is common to optimise some parameters in order to minimise SW, which serves as a loss function between discrete probability measures (since measures admitting densities are numerically unattainable). All these optimisation problems bear the same sub-problem, which is minimising the SW energy. In this paper we study the properties of

E

:
Y
⟼

S
W

2
2

(

γ
Y

,

γ
Z

)

\mathcal {E}: Y \longmapsto \mathrm {SW}_2^2(\gamma _Y, \gamma _Z)

, i.e. the SW distance between two uniform discrete measures with the same amount of points as a function of the support

Y
∈

R

n
×
d

Y \in \mathbb {R}^{n \times d}

of one of the measures. We investigate the regularity and optimisation properties of this energy, as well as its Monte-Carlo approximation

E

p

\mathcal {E}_p

(estimating the expectation in SW using only

p
p

samples) and show convergence results on the critical points of

E

p

\mathcal {E}_p

to those of

E

\mathcal {E}

, as well as an almost-sure uniform convergence and a uniform Central Limit result on the process

E

p

\mathcal {E}_p

. Finally, we show that in a certain sense, Stochastic Gradient Descent methods minimising

E

\mathcal {E}

and

E

p

\mathcal {E}_p

converge towards (Clarke) critical points of these energies.
Symmetric periodic Reeb orbits on the sphere
Authors: Abreu Miguel , Liu Hui , Macarini Leonardo
Published: May 2024

A long standing conjecture in Hamiltonian Dynamics states that every contact form on the standard contact sphere

S

2
n
+
1

S^{2n+1}

has at least

n
+
1

n+1

simple periodic Reeb orbits. In this work, we consider a refinement of this problem when the contact form has a suitable symmetry and we ask if there are at least

n
+
1

n+1

simple symmetric periodic orbits. We show that there is at least one symmetric periodic orbit for any contact form and at least two symmetric closed orbits whenever the contact form is dynamically convex.
Centralizers of Hamiltonian finite cyclic group actions on rational ruled surfaces
Authors: Chakravarthy Pranav , Pinsonnault Martin
Published: May 2024

Let

M
=
(
M
,
ω
)

M=(M,\omega )

be either

S
2

×

S
2

S^2 \times S^2

or

C

P
2

#

C

P
2

¯

\mathbb {C}P^2\# \overline {\mathbb {C}P^2}

endowed with any symplectic form

ω
\omega

. Suppose a finite cyclic group

Z

n

\mathbb {Z}_n

is acting effectively on

(
M
,
ω
)

(M,\omega )

through Hamiltonian diffeomorphisms, that is, there is an injective homomorphism

Z

n

↪
H
a
m
(
M
,
ω
)

\mathbb {Z}_n\hookrightarrow Ham(M,\omega )

. In this paper, we investigate the homotopy type of the group

S
y
m

p

Z

n

(
M
,
ω
)

Symp^{\mathbb {Z}_n}(M,\omega )

of equivariant symplectomorphisms. We prove that for some infinite families of

Z

n

\mathbb {Z}_n

actions satisfying certain inequalities involving the order

n
n

and the symplectic cohomology class

[
ω
]

[\omega ]

, the actions extend to either one or two toric actions, and accordingly, that the centralizers are homotopically equivalent to either a finite dimensional Lie group, or to the homotopy pushout of two tori along a circle. Our results rely on

J
J

-holomorphic techniques, on Delzant’s classification of toric actions, on Karshon’s classification of Hamiltonian circle actions on

4
4

-manifolds, and on the Chen-Wilczyński classification of smooth

Z

n

\mathbb {Z}_n

-actions on Hirzebruch surfaces.
What do we mean by British architecture?
Authors: Arnold Dana
Published: May 2024

This chapter introduces the key concepts of British architecture. It provides an overview with examples of what is understood by the term architect, and how this has been diversified. The different ways in which histories of British architecture have been written and approached influence the understanding of the field, including women’s involvement with architecture. Additionally, the National Heritage List for England presents another way in which historic architecture in Britain has been evaluated and recorded. The chapter explains that the social and cultural value of a building can assume equal significance to its architectural style or authorship when assessing its merit.
Testis-Specific Protein, Y-Encoded-Like 2 Activates JAK2/STAT3 Pathway in Hypothalamic Paraventricular Nucleus to Sustain Hypertension
Authors: Li Ying , Xu Yang-Fei , Chi Hong-Li , Yu Jia-Yue , Gao Ya-Nan , Li Hong-Bao , Kang Yu-Ming , Yu Xiao-Jing
Published: May 2024

BACKGROUND

In the hypothalamic paraventricular nucleus (PVN) of spontaneously hypertensive rats (SHRs), the expression of the testis-specific protein, Y-encoded-like 2 (TSPYL2) and the phosphorylation level of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) are higher comparing with the normotensive Wistar Kyoto rats (WKY). But how they are involved in hypertension remains unclear. TSPYL2 may interact with JAK2/STAT3 in PVN to sustain high blood pressure during hypertension.

METHODS

Knockdown of TSPYL2 via adeno-associated virus (AAV) carrying shRNA was conducted through bilateral microinjection into the PVN of SHR and WKY rats. JAK2/STAT3 inhibition was achieved by intraperitoneally or PVN injection of AG490 into the SHRs. Blood pressure (BP), plasma norepinephrine (NE), PVN inflammatory response, and PVN oxidative stress were measured.

RESULTS

TSPYL2 knock-down in the PVN of SHRs but not WKYs led to reduced BP and plasma NE, deactivation of JAK2/STAT3, decreased expression of pro-inflammatory cytokine IL-1β, and increased expression of anti-inflammatory cytokine IL-10 in the PVN. Meanwhile, AG490 administrated in both ways reduced the BP in the SHRs and deactivated JAK2/STAT3 but failed to change the expression of TSPYL2 in PVN. AG490 also downregulated expression of IL-1β and upregulated expression of IL-10. Both knockdown of TSPYL2 and inhibition of JAK2/STAT3 can reduce the oxidative stress in the PVN of SHRs.

CONCLUSION

JAK2/STAT3 is regulated by TSPYL2 in the PVN of SHRs, and PVN TSPYL2/JAK2/STAT3 is essential for maintaining high BP in hypertensive rats, making it a potential therapeutic target for hypertension.
Plasmatic NT-proBNP is strongly associated with atrial fibrillation in patients with Implantable cardioverter defibrillator
Authors: Allgaier R , Strack C , Wallner S , Hubauer U , Lehn P , Luchner A , Maier L , Jungbauer C
Published: May 2024

Background and objectives

Atrial fibrillation is common in patients with chronic heart failure and associated with poor outcome in these patients. Plasmatic NT-proBNP represents the gold standard biomarker for chronic heart failure. Further, recent studies showed prognostic impact of urinary NT-proBNP. Aim of the study was to assess the association of plasmatic as well as urinary NT-proBNP and atrial fibrillation in a cohort of patients with implantable cardioverter defibrillator (ICD).

Methods

412 patients were included in the study. Fresh spot urine and blood samples were used to assess urinary as well as plasmatic NT-proBNP. Urinary NT-proBNP was normalized to urinary creatinine. Follow-up was performed after 45 months. Heart rhythm history was evaluated and a 12-lead electrocardiogram was performed at enrollment (sinus rhythm (SR, n = 306), atrial fibrillation (AFib, n = 79)).

Results

Patients suffering from atrial fibrillation showed significant higher age, reduced left ventricular ejection fraction (LVEF), higher rates of chronic kidney disease, hypertension and urinary as well as plasmatic NT-proBNP compared to patients with sinus rhythm (each p < 0.05). There were no differences regarding Diabetes, primary prevention ICD indication, coronary artery disease and dilatative cardiomyopathy (each p = n.s.).

In ROC analysis, plasmatic NT-proBNP showed promising predictive values regarding AFib (AUC: 0.80, IQR 0.76-0.85, p < 0.001) as well as urinary NT-proBNP (AUC: 0.76, IQR 0.71-0.81, p < 0.001). There was no significant difference between plasmatic and urinary NT-proBNP according to ROC analysis (p = n.s.).

Plasmatic NT-proBNP was shown as a significant predictor regarding existence of atrial fibrillation in binary logistic regression analysis, beside age (p < 0.05). Diabetes, hypertension, serum creatinine, LVEF, coronary artery disease and primary prevention ICD indication were no significant predictors (p = n.s.). Urinary NT-proBNP was not shown as a significant predictor regarding existence of atrial fibrillation in binary logistic regression analysis (p = n.s.).

Conclusion

Elevated levels of plasmatic NT-proBNP are strongly associated with the prevalence of atrial fibrillation in a cohort of ICD patients.
Association of brain infarcts and cardiac autonomic dysfunction using entropy functions in patients with atrial fibrillation
Authors: Meyer-Zurn C , Schier J , Schlageter V , Knecht S , Aeschbacher S , Paladini R E , Coslovsky M , Conen D , Krisai P , Osswald S , Kuhne M , Hammerle P
Published: May 2024

Background

Cardiac autonomic dysfunction after brain infarcts is a strong predictor of adverse outcome.

Purpose

The aim of this study was to investigate the association of large cortical or non-cortical brain infarcts (LNCCI) with multiscale (MSE) and sample entropy (SE), which characterize the complexity of RR interval time series in atrial fibrillation patients.

Methods

In this cross-sectional analysis, we enrolled 1085 patients (mean age 72±9 years, 29% female) from the Swiss-AF cohort study with baseline brain MRI and without a paced rhythm on a 5-minute resting 12-lead ECG (61% in SR and 39% in AF). We constructed linear regression models to analyze the association between presence of LNCCI and entropy markers, adjusted for age, gender, intake of betablockers, diabetes and heart failure.

Results

On brain MRI, LNCCI were present in 220 patients (20.3%). 53% of these brain infarcts were clinically silent. Patients with LNCCI had a higher MSE (median 11.4 (IQR 6.5-13.3) vs. 8.5 (IQR 5.2-12.6), p<0.001) and SE (median 2.6 (IQR 1.0-3.4) vs. 1.6 (IQR 0.8-3.2), p<0.001) compared to patients without LNCCI. After adjustment for possible confounders, the presence of LNCCI was independently associated with a higher MSE (β=0.77; 95% CI 0.19-1.35, p=0.010). This association persisted when patients with a history of stroke/TIA were excluded.

Conclusions

Brain infarcts, irrespective if clinically overt or silent, are associated with higher entropy markers in AF patients, which indicates cardiac autonomic disturbances.
Definition and management of arrhythmia-induced cardiomyopathy: findings from the EHRA SIC survey
Authors: Serban T , Badertscher P , Du Fay De Lavallaz J , Providencia R , Migliore F , Mugnai G , Penela D , Perrotta L , Kuehne M , Sticherling C , Chun K R J
Published: May 2024

Background

Arrhythmia-induced Cardiomyopathy (AiCM) represents a subtype of heart failure (HF) in the context of a sustained arrhythmia. However, clear definitions and management recommendations for AiCM are lacking.

Purpose

The European Heart Rhythm Association Scientific Initiatives Committee (EHRA SIC) conducted a survey to determine the current definitions and management of patients with AiCM among European and non-European electrophysiologists.

Methods

A 25-item online questionnaire was developed and distributed among EP research network centres between September 4th and October 5th 2022.

Results

Out of the 206 respondents, 16% were females and the most (33%) were between 40-49 years old. Most of the respondents were EP-Specialists (81%) working at a University Hospital (47%). While most participants (67%) agreed that AiCM should be defined as a left ventricular ejection fraction (LVEF) impairment after new onset of an arrhythmia and/or LVEF recovery after treatment of the culprit arrhythmia, only 35% identified a specific LVEF drop/improvement to diagnose AiCM, the majority (50%) agreeing with a 10% change in LVEF (Figure) but with the rest of the experts choosing a wide range of values (from 5 to 20% LVEF drop). Most respondents used all available therapies in AiCM patients: catheter ablation was chosen by 93%, electrical cardioversion by 83%, antiarrhythmic drugs by 76% and adjuvant HF treatment were used by 76%. 83% of respondents indicated that adjuvant HF treatment should be started at first diagnosis of HF prior to antiarrhythmic treatment and 84% agreed that the therapy should be stopped within six months after LVEF normalization. Responses for the optimal time point for the first reassessment of LVEF during FU varied markedly (1 day to over 6 months after antiarrhythmic treatment).

Conclusion

This EHRA Survey reveals varying practices in defining and managing AiCM among European and non-European physicians. There is an unmet need for a consensus in the definition and management of AiCM patients to improve patient care.Figure
Clinical impact of catheter ablation for atrial fibrillation on heart failure parameters
Authors: Hashiguchi N , Tamura N , Matsuyama T , Hattori K , Tachibana M , Matsuoka T , Ohno Y , Aoki Y
Published: May 2024

Background

Catheter ablation for atrial fibrillation have already been an established therapy to maintain sinus rhythm in patients with or without heart failure. Atrial fibrillation is often associated with functional valve regurgitations, left ventricular dysfunction and biomarkers of HF. However, it is still unclear how often such parameters improve after catheter ablation.

Purpose

The aim of this study is to clarify the clinical impact of catheter ablation on heart failure in patients with atrial fibrillation.

Methods

We retrospectively analysed 139 consecutive patients who underwent catheter ablation for atrial fibrillation and cardiac echocardiography before and one-year after catheter ablation. Patients who underwent hemodialysis or previous valve surgery were excluded.

Results

Mean age was 69.8±9.5 years and 84(60.4%) patients had persistent atrial fibrillation before ablation procedure. Fourteen (10.1%) patients had severe left ventricular dysfunction (EF<40%). Thirty-four (24.5%) and 37(26.6%) patients had moderate or greater mitral and tricuspid valve regurgitation (MR and TR), respectively. BNP or NTproBNP was significantly elevated in 93(66.9%) patients before catheter ablation.

During one-year follow-up, 11 (7.9%) patients underwent second procedure and atrial fibrillation were remained in 2 (1.4%) patients. Additional medications for heart failure were prescribed in 19 (13.7%) of patients after initial procedure.

One year after catheter ablation, 19/34(55.9%) and 20/37(54.1%) of moderate or greater functional MR and TR improved to mild or less. Furthermore, 5/14 (35.7%) patients with severe left ventricular dysfunction improved to normal with combined optimal medical treatment. In 64/93 (68.8%) with elevated BNP or NTproBNP, the increase was no longer significant. Even in patients with still elevated BNP or NTproBNP one-year after catheter ablation, their values were decreased by more than 50% in 17/29 (58.6%) patients.

Conclusion

Catheter ablation for atrial fibrillation can improve heart failure parameters including valve function, systolic ventricular function and biomarkers.
AV nodal ablation in atrial fibrillation: long term outcomes
Authors: Sogandji N , Ding W , Fynn S P , Heck P M , Begley D A , Virdee M S , Gajendragadkar P , Mellor G , Zachariah D , Agarwal S
Published: May 2024

Background

Ablation of the atrioventricular (AV) node, following the insertion of a permanent pacemaker, is a treatment option for symptomatic atrial fibrillation (AF) where rate control is poor, despite maximally tolerated pharmacological intervention or percutaneous AF ablation [1], and yet there is limited data on long-term outcomes.

Purpose

The purpose of this study is to investigate post AV node ablation follow up outcomes, including the incidence and timeframe of conversion of paroxysmal to persistent AF; incidence and timeframe of upgrade to biventricular pacemakers; and mortality.

Methods

This observational descriptive study looked at the post-procedure follow-up outcomes of patients who underwent AV node ablation at our centre between March 2015 and June 2019. Retrospective analysis of prospectively collected data was analysed. The demographics of the patients, including their age, gender, co-morbidities, pre-ablation left ventricular ejection fraction (LVEF) and medications were recorded. The follow up outcomes investigated included the change in LVEF, the proportion of patients whose AF converted from paroxysmal to persistent, the proportion of patients requiring upgrade to biventricular devices, and deaths within 6 months of ablation. Outcomes were compared between those who had a biventricular pacemaker pre-ablation and those who had single/dual chamber pacemakers.

Results

296 patients with a mean age of 72.7± 8.5 years and a female to male ratio of 54.1% : 45.9% were included. 94 patients (31.8%) had paroxysmal AF pre- ablation. 51.6% of those who had paroxysmal AF pre-ablation converted to persistent AF over a median period of 3 years (interquartile range, 3 years). Among those who had a biventricular pacemaker pre-ablation, 56.5% of those with paroxysmal AF converted to persistent, compared to 47.4% of those with a dual pacemaker pre-ablation p=ns Among patients with dual chamber pacemakers, those who remained in paroxysmal AF post-ablation had a mean CHADVASC score of 3.2 (range of 1-6) compared to 3.7 (range of 2-6) in those whose AF converted to persistent (p=0.19). 9 patients (3%) died within less than 6 months of the procedure, with 1 patient dying within 6 days. 13% of the patients originally having a single or dual chamber pacemaker required an upgrade to a biventricular pacemaker over a median period of 1.25 years (interquartile range 1.1 years). All the patients who required an upgrade to a biventricular pacemaker had normal LVEF pre-ablation except for one patient who had mild LV impairment.

Conclusions

A significant proportion of patients with paroxysmal AF converted to persistent AF following AV node ablation and having a biventricular pacemaker did not offer benefit in keeping people in paroxysmal AF.A considerable number of people required an upgrade to biventricular pacemaker over a short time frame even though they had normal LVEF pre AV nodal ablation.