Action Of Group Research Articles

Understanding factors for adhering to health recommendations during COVID-19 among older adults - a qualitative interview study using health belief model as analytical framework

IntroductionThe COVID-19 pandemic has presented a unique possibility to broaden the understanding of people’s reactions to a global crisis. Early on, it became evident that older adults were particularly vulnerable to the virus and that the actions of this age group would be crucial to the outcome. This qualitative interview study uses the Health Belief Model (HBM) framework as an analytical tool to examine older people’s experiences of adherence to recommendations during the initial phase of the COVID-19 pandemic. It is important to view this study in the context of Sweden’s voluntary restrictions, which further highlight the unique nature of this research.MethodIn April-May 2020, 41 adults aged 70–85 participated in unstructured phone interviews. The objective was to investigate older adults’ perceptions of the COVID-19 pandemic, particularly their understanding of the disease and the conditions that influenced their adherence to health recommendations. HBM was used as an analytical framework to guide the analysis of the interviews.ResultsDespite perceiving COVID-19 as a severe threat to health and society, participants did not let fear dominate their responses. Instead, they demonstrated remarkable resilience and a proactive approach. For some, the perceived susceptibility to the disease was the primary motivator for adherence to the Swedish national recommendations. Notably, trust in the authorities and family members’ requests significantly bolstered adherence. Moreover, adherence was found to contribute to feelings of safety. Conversely, potential barriers to adhering to recommendations included missing loved ones and frustration with sometimes ambiguous information from authorities.ConclusionsThe results from this study indicate that older adults are willing to adhere to voluntary restrictions during a global pandemic. Relatives of older people are a resource for communicating information regarding safety and health messages, a message that is preferably thorough and consistent. Further, much can be gained if loneliness during isolation can be mitigated since missing loved ones appears to be a potential barrier to adherence.

Property $\mathrm{(NL)}$ for group actions on hyperbolic spaces (with an appendix by Alessandro Sisto)

We introduce Property \mathrm{(NL)} , which indicates that a group does not admit any (isometric) action on a hyperbolic space with loxodromic elements. In other words, such a group G can only admit elliptic or horocyclic hyperbolic actions, and consequently its poset of hyperbolic structures \mathcal{H}(G) is trivial. It turns out that many groups satisfy this property, and we initiate the formal study of this phenomenon. Of particular importance is the proof of a dynamical criterion in this paper that ensures that groups with “rich” actions on compact Hausdorff spaces have Property \mathrm{(NL)} . These include many Thompson-like groups, such as V, T and even twisted Brin–Thompson groups, which implies that every finitely generated group quasi-isometrically embeds into a finitely generated simple group with Property \mathrm{(NL)} . We also study the stability of the property under group operations and explore connections to other fixed point properties. In the appendix (by Alessandro Sisto), we describe a construction of cobounded actions on hyperbolic spaces starting from non-cobounded ones that preserves various properties of the initial action.

Every noncompact surface is a leaf of a minimal foliation

We show that any noncompact oriented surface is homeomorphic to the leaf of a minimal foliation of a closed 3 -manifold. These foliations are (or are covered by) suspensions of continuous minimal actions of surface groups on the circle. Moreover, the above result is also true for any prescription of a countable family of topologies of noncompact surfaces: they can coexist in the same minimal foliation. All the given examples are hyperbolic foliations, meaning that they admit a leafwise Riemannian metric of constant negative curvature. Many oriented Seifert manifolds with a fibered incompressible torus and whose associated orbifold is hyperbolic admit minimal foliations as above. The given examples are not transversely C^{2} -smoothable.

Improved optimization for the neural-network quantum states and tests on the chromium dimer.

The advent of Neural-network Quantum States (NQS) has significantly advanced wave function ansatz research, sparking a resurgence in orbital space variational Monte Carlo (VMC) exploration. This work introduces three algorithmic enhancements to reduce computational demands of VMC optimization using NQS: an adaptive learning rate algorithm, constrained optimization, and block optimization. We evaluate the refined algorithm on complex multireference bond stretches of H2O and N2 within the cc-pVDZ basis set and calculate the ground-state energy of the strongly correlated chromium dimer (Cr2) in the Ahlrichs SV basis set. Our results achieve superior accuracy compared to coupled cluster theory at a relatively modest CPU cost. This work demonstrates how to enhance optimization efficiency and robustness using these strategies, opening a new path to optimize large-scale restricted Boltzmann machine-based NQS more effectively and marking a substantial advancement in NQS's practical quantum chemistry applications.

[formula omitted]: Isogeny-based Secret Handshakes with friendly communication costs

Secret handshake schemes allow members from the same organization to authenticate each other anonymously. After its proposal, various schemes have been introduced to achieve advanced privacy protection. Regrettably, all the schemes based on number theoretic assumptions are insecure under quantum computers, and the known post-quantum designs are impractical because of the overhead cost (> 10 MB). To fill the gap, we present the first isogeny-based secret handshake scheme (i.e., ISH) with a friendly communication cost (67 KB). In particular, we apply the CSI-FiSh signature scheme to generate group keys and credentials. For each zero-knowledge transcript in the credential, we generate a signature for handshake via the Fiat–Shamir paradigm, while it fails anonymous authentication. To fix the issue, we modify the Fiat–Shamir-type signature by embedding the CSIDH ephemeral private key into the challenge space. After verifying the modified signatures, two users recover the right ephemeral private key if they are in the same group, then they can negotiate a session key and authenticate each other. Our scheme is proved secure under the Group Action Inverse Problems (GAIP) in the random oracle model, and deniability, as an attractive property, also holds for ISH, enabling user’s ability to deny their interactions in the finished handshakes. Via choosing appropriate parameters, the communication cost surpasses all the existing post-quantum secret handshakes.

Symmetry Determining Equations and Lie Groups of the Neutron Transport Equation

The Grigoriev-Meleshko Method, an indirect Lie group theory method, is used to derive the symmetry determining equations (SDEs) of the neutron transport equation (NTE) and the coupled delayed neutron precursor equations (DNPEs). A solution to the SDEs is a Lie group of transformations that can be used to reduce the order of the NTE and DNPEs or outright solve the equations. We found several solutions of the SDEs and worked through the mathematical algorithm to demonstrate relationships of instantiations of the NTE and its known solutions with the Lie groups. Examples of solutions include the Lie group that allows for the transformation of the differential form of the NTE to the integral form of the NTE; the Lie groups that permit Case’s solution; and the Lie group used to transform from the NTE to the α -eigenvalue form of the NTE.

RECURRENCE SETS FOR PARTIAL INVERSE

Two types of recurrence sets are introduced for inverse semigroup partial actions in topological spaces. Some applications to the basic dynamical properties of the action are indicated, covering topics as topological transitivity, limit points and periodic points. We then explore the connections of these recurrence sets with similar notions for related types of imperfect symmetries (prefix inverse semigroup expansions, partial group and groupoid actions).

Novel results for two families of multivalued dominated mappings satisfying generalized nonlinear contractive inequalities and applications

Abstract In this manuscript, we prove new extensions of Nashine, Wardowski, Feng-Liu, and Ćirić-type contractive inequalities using orbitally lower semi-continuous functions in an orbitally complete b b -metric space. We accomplish new multivalued common fixed point results for two families of dominated set-valued mappings in an ordered complete orbitally b b -metric space. Some new definitions and illustrative examples are given to validate our new results. To show the novelty of our results, applications are given to obtain the solution of nonlinear integral and fractional differential equations. Our results expand the hypothetical consequences of Nashine et al. (Feng–Liu-type fixed point result in orbital b-metric spaces and application to fractal integral equation, Nonlinear Anal. Model. Control. 26 (2021), no. 3, 522–533) and Rasham et al. (Common fixed point results for new Ciric-type rational multivalued-contraction with an application, J. Fixed Point Theory Appl. 20 (2018), no. 1, Paper No. 45).

Partition functions for U(1) vectors and phases of scalar QED in AdS

We extend the computation of one-loop partition function in AdSd+1 using the method in [23] and [24] for scalars and fermions to the case of U(1) vectors. This method utilizes the eigenfunctions of the AdS Laplacian for vectors. For finite temperature, the partition function is obtained by generalizing the eigenfunctions so that they are invariant under the quotient group action, which defines the thermal AdS spaces. The results obtained match with those available in the literature. As an application of these results, we then analyze phases of scalar QED theories at one-loop in d = 2, 3. We do this first as functions of AdS radius at zero temperature showing that the results reduce to those in flat space in the large AdS radius limit. Thereafter the phases are studied as a function of the scalar mass and temperature. We also derive effective potentials and study phases of the scalar QED theories with N scalars.

Spherical objects, transitivity and auto-equivalences of Kodaira cycles via gentle algebras

This paper studies the class of spherical objects over any Kodaira n -cycle of projective lines and provides a parametrization of their isomorphism classes in terms of closed curves on the n -punctured torus without self-intersections. Employing recent results on gentle algebras, we derive a topological model for the bounded derived category of any Kodaira cycle. The groups of triangle auto-equivalences of these categories are computed and are shown to act transitively on isomorphism classes of spherical objects. This answers a question by Polishchuk (2002) and extends earlier results by Burban–Kreußler (2012) and Lekili–Polishchuk (2019). The description of auto-equivalences is further used to establish faithfulness of a mapping class group action defined by Sibilla (2014). The final part describes the closed curves which correspond to vector bundles and simple vector bundles. This leads to an alternative proof of a result by Bodnarchuk–Drozd–Greuel (2012) which states that simple vector bundles on cycles of projective lines are uniquely determined by their multi-degree, rank and determinant. As a by-product, we obtain a closed formula for the cyclic sequence of any simple vector bundle on C_{n} as introduced by Burban–Drozd–Greuel (2001).

Non-Virtually Abelian Discontinuous Group Actions vs. Proper SL(2,ℝ) -Actions on Homogeneous Spaces

We develop algorithms and computer programs which verify criteria of properness of discrete group actions on semisimple homogeneous spaces. We apply these algorithms to find new examples of non-virtually abelian discontinuous group actions on homogeneous spaces which do not admit proper SL ( 2 , R ) -actions.

𝐾𝐾-duality for self-similar groupoid actions on graphs

We extend Nekrashevych’s K K KK -duality for C ∗ C^* -algebras of regular, recurrent, contracting self-similar group actions to regular, contracting self-similar groupoid actions on a graph, removing the recurrence condition entirely and generalising from a finite alphabet to a finite graph. More precisely, given a regular and contracting self-similar groupoid ( G , E ) (G,E) acting faithfully on a finite directed graph E E , we associate two C ∗ C^* -algebras, O ( G , E ) \mathcal {O}(G,E) and O ^ ( G , E ) \widehat {\mathcal {O}}(G,E) , to it and prove that they are strongly Morita equivalent to the stable and unstable Ruelle C*-algebras of a Smale space arising from a Wieler solenoid of the self-similar limit space. That these algebras are Spanier-Whitehead dual in K K KK -theory follows from the general result for Ruelle algebras of irreducible Smale spaces proved by Kaminker, Putnam, and the last author.

Enhancing plant fiber antibacterial and antiviral performance through synergistic action of amino and sulfonic acid groups

As the most abundant renewable resource, cellulose fibers are potential candidates for use in health-protective clothing. Herein, we demonstrate a novel strategy for preparing cellulose fiber with prominent antibacterial and antiviral performance by the synergistic effect of amino groups and sulfonic acid groups. Specifically, guanylated chitosan oligosaccharide (GCOS) and N-sulfopropyl chitosan oligosaccharide (SCOS) were synthesized and chemically grafted onto cellulose fibers (CFs) to endow the fibers with antibacterial and antiviral properties. Moreover, a compounding strategy was applied to make the fibers with simultaneously high antibacterial and antiviral activity, especially in short contact time. The bacteriostatic rate (against S. aureus: 95.81 %, against E. coli: 92.07 %, 1 h) of the compounded fibers improved substantially when a few GCOS-CFs were mixed with SCOS-CFs; especially, it was much higher than both the individual GCOS-CFs and SCOS-CFs. By contrast, the improvement of the antiviral properties was less dramatic; however, even a few SCOS-CFs was mixed, the antiviral properties increased pronouncedly. Although the electrostatic interaction between SCOS and GCOS can make the SCOS-GCOS mixture lose some extent of antibacterial activity, the long chains of cellulose restrain the electrostatic interaction between sulfonic and amino groups, leading to their synergistic action and eventually superior antibacterial and antiviral effects.

Influence of bottom protection structures group on the hydraulic characteristics in sharp bends

Bottom protection (BP) is a commonly used engineering measure in river training. A 3D hydrodynamic numerical model is established to study the influence of the overall arrangements of BP structures on the hydraulic characteristics of the sharp bends. Under the action of the BP structures group, the maximum longitudinal flow velocity is closer to the water surface vertically and closer to the concave bank laterally compared with no BP. The high shear stress zones on the riverbed at the exit straight section of the bend do not occur. The so-called primary circulation after the apex of the bend gradually weakens and disappears. If the coverage rate of BP is increased to 1.5 times that of the sequential BP, the average longitudinal flow velocity near the bottom of BP decreases by 10% and the average bed shear stress at the outlet section of the bend decreases by 35%. In the staggered BP condition, the average bed shear stress at the outlet section of the bend is reduced by 23% compared with the sequential BP. Moreover, the results show that the protection effects of the dense BP and the staggered BP are better than that of sequential BP.

Narrative as active inference: an integrative account of cognitive and social functions in adaptation.

While the ubiquity and importance of narratives for human adaptation is widely recognized, there is no integrative framework for understanding the roles of narrative in human adaptation. Research has identified several cognitive and social functions of narratives that are conducive to well-being and adaptation as well as to coordinated social practices and enculturation. In this paper, we characterize the cognitive and social functions of narratives in terms of active inference, to support the claim that one of the main adaptive functions of narrative is to generate more useful (i.e., accurate, parsimonious) predictions for the individual, as well as to coordinate group action (over multiple timescales) through shared predictions about collective behavior. Active inference is a theory that depicts the fundamental tendency of living organisms to adapt by proactively inferring the causes of their sensations (including their own actions). We review narrative research on identity, event segmentation, episodic memory, future projections, storytelling practices, enculturation, and master narratives. We show how this research dovetails with the active inference framework and propose an account of the cognitive and social functions of narrative that emphasizes that narratives are for the future-even when they are focused on recollecting or recounting the past. Understanding narratives as cognitive and cultural tools for mutual prediction in social contexts can guide research on narrative in adaptive behavior and psychopathology, based on a parsimonious mechanistic model of some of the basic adaptive functions of narrative.

Robustly reusable fuzzy extractor from isogeny

Robustly reusable Fuzzy Extractor (rrFE) allows multiple extractions from the same fuzzy source in a reproducible way. The reusability of rrFE asks the pseudo-randomness of the extracted keys, while robustness of rrFE makes sure that active attacks can be detected during the reproduction of the extracted key. With rrFE, we are able to produce cryptographic keys for our cryptosystems from fuzzy sources, like biometrics, physical unclonable functions, etc. There are rrFE schemes from the DDH, LWE and LPN assumptions. However there is no rrFE scheme from isogeny-based assumptions up to now.In this paper, we construct the first rrFE from isogeny. To obtain such an rrFE, we propose a new framework for constructing rrFE with a core technical tool, named Enhanced Effective Group Action (EEGA). EEGA is built upon the basic Effective Group Action (EGA), and is equipped with a sampling algorithm and a derivation algorithm. With such an EEGA, the same random input can be derived to produce different pseudo-random and unpredictable outputs. The EEGA, together with other routine building blocks like secure sketch and extractor, leverages an FE to achieve reusability and robustness. We construct EEGA based on CSI-FiSh, which admits the first rrFE scheme from isogeny. Besides, we also propose another two EEGA instantiations from the DDH assumption, and this provides another approach to DDH-based rrFE, which may be of independent interest.

Regularized mean curvature flow for invariant hypersurfaces in a Hilbert space and its application to gauge theory

In this paper, we investigate a regularized mean curvature flow starting from an invariant hypersurface in a Hilbert space equipped with an isometric and almost free action of a Hilbert Lie group whose orbits are minimal regularizable submanifolds. We prove that, if the initial invariant hypersurface satisfies a certain kind of horizontally convexity condition and some additional conditions, then it collapses to an orbit of the Hilbert Lie group action along the regularized mean curvature flow. In the final section, we state a vision for applying the study of the regularized mean curvature flow to the gauge theory.

Understanding Lorentz Utilizing Galilei: The Emergence of a Friendly Extended Special Relativity Theory that Admits Relativistic Multi-Particle Entanglement

Special relativity theory stems from the Lorentz transformation of signature (1,3). The incorporation into special relativity of the Lorentz transformations of signature (m,n) for all m,n∈ℕ (n = 3 in physical applications) enriches the theory. The resulting enriched special relativity is a friendly extended special relativity that admits multi-particle entanglement, as demanded by relativistic quantum mechanics. The Lorentz transformation of signature (m,n) admits a novel physical interpretation induced by the intuitively clear interpretation of the Galilei transformation of signature (m,n) for all m,n > 1. In this sense we understand Lorentz utilizing Galilei in m temporal and n spatial dimensions, resulting in the emergence of multi-particle entanglement that the enriched special theory of relativity admits. Remarkably, it turns out that, for any m,n∈ℕ, the group of Lorentz transformations of signature (m,n) is the symmetry group that underlies any multi-particle system that consists of m n - dimensional entangled particles.

Functions with a maximal number of finite invariant or internally-1-quasi-invariant sets or supersets

A relaxation of the notion of invariant set, known as $k$-quasi-invariant set, has appeared several times in the literature in relation to group dynamics. The results obtained in this context depend on the fact that the dynamic is generated by a group. In our work, we consider the notions of invariant and 1-internally-quasi-invariant sets as applied to an action of a function $f$ on a set $I$. We answer several problems of the following type, where $k \in \{0,1\}$: what are the functions $f$ for which every finite subset of $I$ is internally-$k$-quasi-invariant? More restrictively, if $I = \mathbb{N}$, what are the functions $f$ for which every finite interval of $I$ is internally-$k$-quasi-invariant? Last, what are the functions $f$ for which every finite subset of $I$ admits a finite superset that is internally-$k$-quasi-invariant? This parallels a similar investigation undergone by C. E. Praeger in the context of group actions.

Non-Hausdorff germinal groupoids for actions of countable groups

We study conditions under which the germinal groupoid associated to a minimal equicontinuous action of a countable group on a Cantor set has non-Hausdorff topology. We develop a new criterion, which serves as an obstruction for the étale topology on the groupoid to be non-Hausdorff. We use this and other criteria to study the topology of germinal groupoids for a few classes of actions. In particular, we give examples of families of contracting and non-contracting self-similar groups, which are amenable and whose actions have associated germinal groupoids with non-Hausdorff topology.