bluuebunny/crossref_metadata_2025 huggingface dataset:
Safeguarding Patients with End-Stage Kidney Disease From Climate-driven Extreme Heat and Hurricanes
Authors: Shakour Rebecca L. , Mithani Zain , Kopp Jeffrey B. , Shepherd J. Marshall , Nogueira Leticia M. , Espinel Zelde , Shultz James M.
Published: September 2024

5wPatients with end stage kidney disease (ESKD) who receive in-center hemodialysis are disproportionately vulnerable to extreme weather events, including hurricanes and heat waves, that may disrupt access to healthcare providers, and life-sustaining treatments. This current era of climate-driven compounding disasters is progressively elevating the level of threat to the health and well-being of patients with ESKD. This analysis brings together multi-disciplinary expertise to explore the contours of this increasingly complex risk landscape. Despite the challenges, important advances have been made for safeguarding this medically high-risk patient population. Hemodialysis services providers have devised innovative systems for preparing their patients and sustaining, or rapidly reestablishing, hemodialysis services in the aftermath of a disaster, and maintaining open lines of communication with their caseloads of ESKD patients throughout all phases of the event. A description of lessons learned along the path towards improved patient support in disasters, is provided. The article concludes with a detailed case example, describing dialysis providers’ effective response throughout Hurricane Ian’s passage across the State of Florida in 2022. Based on lessons learned, this analysis outlines strategies for protecting patients with ESKD that may be adapted for future climate-potentiated disaster scenarios.
Non-concentration property of Patterson–Sullivan measures for Anosov subgroups
Authors: KIM DONGRYUL M. , OH HEE
Published: September 2024

Let G be a connected semisimple real algebraic group. For a Zariski dense Anosov subgroup
$\Gamma <G$
with respect to a parabolic subgroup
$P_\theta $
, we prove that any
$\Gamma $
-Patterson–Sullivan measure charges no mass on any proper subvariety of
$G/P_\theta $
. More generally, we prove that for a Zariski dense
$\theta $
-transverse subgroup
$\Gamma <G$
, any
$(\Gamma , \psi )$
-Patterson–Sullivan measure charges no mass on any proper subvariety of
$G/P_\theta $
, provided the
$\psi $
-Poincaré series of
$\Gamma $
diverges at its abscissa of convergence. In particular, our result also applies to relatively Anosov subgroups.
The impact of the COVID-19 pandemic on individuals with pre-existing diabetes mellitus
Authors: Farrell A. , Srikumar K. , Farmer G. , Liew A. , Hallahan B.
Published: September 2024

Objectives:

To examine the psychosocial impact of the COVID-19 pandemic on patients with a diagnosis of diabetes mellitus (DM).

Methods:

Semi-structured interviews were conducted with 31 individuals with DM attending a diabetes clinic to determine the impact of the COVID-19 restrictions on anxiety and depressive symptoms, social and occupational functioning and quality of life. Anxiety symptoms were correlated with functioning, quality of life and diabetes self-management.

Results:

Likert data demonstrated that social functioning (mean = 5.5, SD = 3.7) and quality of life (mean = 4.1, SD = 3.1) were most impacted by the COVID-19 pandemic. Anxiety symptoms were prevalent with 13 individuals (41.9%) scoring above cut-off scores for the presence of anxiety symptoms based on the Beck Anxiety Inventory. Diabetes self-management was significantly correlated with functioning (r = 0.51, p = 0.006) and inversely correlated with anxiety symptoms (r = −0.51, p = 0.007). A prior history of a depressive or anxiety disorder was associated with significantly increased anxiety symptoms, as well as impaired global functioning (p < 0.01), poorer self-care of diabetes (p = 0.014) and satisfaction with diabetes treatment (p = 0.03).

Conclusions:

The psychological and social impact of COVID-19 restrictions on individuals with DM was significant, with poorer management of diabetes correlated with anxiety symptom severity.
Searching for Traces of the Shi in Tombs of the Jin Dynasty
Authors: Hsu Ya-hwei
Published: September 2024

Scholars of Jin history have noted a flourishing literati culture after the mid-Jin period, but excavated tombs suggest a more complicated picture. The shi, referring to literati without official titles, constituted a prominent group in Northern Song tombs, as evidenced by their epitaphs, but this group appears to have nearly vanished from the Jin tombs. To search for traces of the shi, this article comprehensively examines the social elites’ tombs with burial inscriptions and ink writings, where the shi would most likely be laid to rest. It shows that the text and paratext of epitaphs, as well as the tombs that yielded them, contain direct information about the shi and their interactions with other officials and non-official elites. Analysis of ink writings suggests that the shi played a role in the advanced literary expression in the tombs of some non-literati local elites. Examining these traces of the shi in tombs allows us to reintegrate them into broader society, investigate their interactions with other elites, and attain a more holistic understanding of Jin elite society and culture.
Internal heating profiles for which downward conduction is impossible
Authors: Arslan Ali , Fantuzzi Giovanni , Craske John , Wynn Andrew
Published: September 2024

We consider an internally heated fluid between parallel plates with fixed thermal fluxes. For a large class of heat sources that vary in the direction of gravity, we prove that

$\smash { \smash {{\langle {\delta T} \rangle _h}} } \geq \sigma R^{-1/3} - \mu$

, where

$\smash { \smash {{\langle {\delta T} \rangle _h}} }$

is the average temperature difference between the bottom and top plates,

$R$

is a ‘flux’ Rayleigh number and the constants

$\sigma,\mu >0$

depend on the geometric properties of the internal heating. This result implies that mean downward conduction (for which

$\smash { \smash {{\langle {\delta T} \rangle _h}} }< 0$

) is impossible for a range of Rayleigh numbers smaller than a critical value

$R_0:=(\sigma /\mu )^{3}$

. The bound demonstrates that

$R_0$

depends on the heating distribution and can be made arbitrarily large by concentrating the heating near the bottom plate. However, for any given fixed heating profile of the class we consider, the corresponding value of

$R_0$

is always finite. This points to a fundamental difference between internally heated convection and its limiting case of Rayleigh–Bénard convection with fixed-flux boundary conditions, for which

$\smash {{\langle {\delta T} \rangle _h}}$

is known to be positive for all

$R$

.
Crowding accelerates the rotation of a bacterial rotor
Authors: Huang Haoxin , Zhang Bokai , Guo Shuo
Published: September 2024

Understanding the propulsion of a swimmer in a large group of individuals holds the key to unravelling the intriguing dynamics of active matter collective motion. Here, we develop a two-dimensional (2-D) self-assembled rotor, powered by bacterial flagella. At a water–air interface, the average direction of rotation of a rotor is fixed. When the chiral rotor is put into a 2-D bacterial suspension, we examine the average and fluctuation of the angular velocity of the rotor. Remarkably, the average angular velocity of a rotor is found to increase up to 3 times when the density of surrounding bacterial suspension increases and the increase is nonlinear. In a dense suspension of bacteria, the existence of a rotor disrupts vortices in the surrounding active turbulence, and the acceleration of the rotor is independent of the activity level of the surrounding free bacteria. The nonlinear acceleration thus results from hydrodynamic interaction with surrounding crowdedness that can be quantitatively explained by hydrodynamic simulation. The simultaneity between the acceleration of rotor and free bacteria in active turbulence suggests that crowding-induced acceleration may promote the onset of instability. The result will inspire new active-matter-based microfluidic devices with improved transport properties.
Attracting dynamical modes of highly elastic fibres settling under gravity in a viscous fluid
Authors: Melikhov Yevgen , Ekiel-Jeżewska Maria L.
Published: September 2024

The dynamics of a single highly elastic fibre settling under gravity in a very viscous fluid is studied numerically. We employ the bead model and multipole expansion of the Stokes equations, corrected for lubrication that is implemented in the precise Hydromultipole numerical codes. Four attracting regular dynamical modes of highly elastic fibres are found: two stationary shapes (one translating and the other rotating and translating), and two periodic oscillations around such shapes. The phase diagram of these modes is presented. It illustrates that the existence of each mode depends not only on the elasto-gravitation number but also on the fibre aspect ratio. Characteristic time scales, fibre deformation patterns and motion in the different modes are determined.
Experimental investigation of three-dimensional Rayleigh–Taylor instability of a gaseous interface
Authors: Liang Yu , Alkindi Ahmed , Alzeyoudi Khalid , Liu Lili , Ali Mohamed , Masmoudi Nader
Published: September 2024

Validating the theoretical work on Rayleigh–Taylor instability (RTI) through experiments with an exceptionally clean and well-characterized initial condition has been a long-standing challenge. Experiments were conducted to study the three-dimensional RTI of an SF

$_6$

–air interface at moderate Atwood numbers. A novel soap film technique was developed to create a discontinuous gaseous interface with controllable initial conditions. Spectrum analysis revealed that the initial perturbation of the soap film interface is half the size of an entire single-mode perturbation. The correlation between the initial interface perturbation and Atwood numbers was determined. Due to the steep and highly curved feature of the initial soap film interface, the early-time evolution of RTI exhibits significant nonlinearity. In the quasi-steady regime, various potential flow models accurately predict the late-time bubble velocities by considering the channel width as the perturbation wavelength. Differently, the late-time spike velocities are described by these potential flow models using the wavelength of the entire single-mode perturbation. These findings indicate that the bubble evolution is influenced primarily by the spatial constraint imposed by walls, while the spike evolution is influenced mainly by the initial curvature of the spike tip. Consequently, a recent potential flow model was adopted to describe the time-varying amplitude growth induced by RTI. Furthermore, the self-similar growth factors for bubbles and spikes were determined from experiments and compared with existing studies, revealing that a large amplitude in the initial soap film interface promotes the spike development.
Efficiency of reversible MCMC methods: elementary derivations and applications to composite methods
Authors: Neal Radford M. , Rosenthal Jeffrey S.
Published: September 2024

We review criteria for comparing the efficiency of Markov chain Monte Carlo (MCMC) methods with respect to the asymptotic variance of estimates of expectations of functions of state, and show how such criteria can justify ways of combining improvements to MCMC methods. We say that a chain on a finite state space with transition matrix P efficiency-dominates one with transition matrix Q if for every function of state it has lower (or equal) asymptotic variance. We give elementary proofs of some previous results regarding efficiency dominance, leading to a self-contained demonstration that a reversible chain with transition matrix P efficiency-dominates a reversible chain with transition matrix Q if and only if none of the eigenvalues of
$Q-P$
are negative. This allows us to conclude that modifying a reversible MCMC method to improve its efficiency will also improve the efficiency of a method that randomly chooses either this or some other reversible method, and to conclude that improving the efficiency of a reversible update for one component of state (as in Gibbs sampling) will improve the overall efficiency of a reversible method that combines this and other updates. It also explains how antithetic MCMC can be more efficient than independent and identically distributed sampling. We also establish conditions that can guarantee that a method is not efficiency-dominated by any other method.
The structure of finite groups whose elements outside a normal subgroup have prime power orders
Authors: Shao Changguo , Jiang Qinhui
Published: September 2024

The structure of groups in which every element has prime power order (CP-groups) is extensively studied. We first investigate the properties of group

$G$

such that each element of

$G\setminus N$

has prime power order. It is proved that

$N$

is solvable or every non-solvable chief factor

$H/K$

of

$G$

satisfying

$H\leq N$

is isomorphic to

$PSL_2(3^f)$

with

$f$

a 2-power. This partially answers the question proposed by Lewis in 2023, asking whether

$G\cong M_{10}$

? Furthermore, we prove that if each element

$x\in G\backslash N$

has prime power order and

${\bf C}_G(x)$

is maximal in

$G$

, then

$N$

is solvable. Relying on this, we give the structure of group

$G$

with normal subgroup

$N$

such that

${\bf C}_G(x)$

is maximal in

$G$

for any element

$x\in G\setminus N$

. Finally, we investigate the structure of a normal subgroup

$N$

when the centralizer

${\bf C}_G(x)$

is maximal in

$G$

for any element

$x\in N\setminus {\bf Z}(N)$

, which is a generalization of results of Zhao, Chen, and Guo in 2020, investigating a special case that

$N=G$

for our main result. We also provide a new proof for Zhao, Chen, and Guo's results above.
Combined AMS 14C and archaeological dating of the Rouran period cemetery of Choburak-I (Northern Altai)
Authors: Seregin N N , Svyatko S V , Barrett G , Matrenin S S , Reimer P J
Published: September 2024

This paper presents a detailed chronological study of the previously undisturbed burial ground of Choburak-I of the Bulan-Koby Culture in the Northern Altai using a program of comprehensive dating, including AMS 14C dating of human and animal remains (26 14C dates from 12 kurgans in total), and archaeological dating of the associated artifacts. This completely excavated cemetery contained numerous grave goods and various organic remains (anthropological and archaeozoological) critical for understanding the social and chronological dynamics of this culture during the Rouran period in Altai (second half of the 4th–first half of the 6th century CE). The results of archaeological dating, supported by the largest set of AMS 14C dates for the Bulan-Koby Culture, and further aided by Bayesian analysis, demonstrate the likely continuous existence of the necropolis within the period of 310–400 cal CE, which broadly corresponds to the beginning of the Rouran period in the history of Altai, with a maximum duration of 66 years. The presented results make it possible to consider the necropolis of Choburak-I as a chronologically defining monument of the Rouran period of Northern Altai and permit a new level of relative and absolute chronological reconstructions for archaeological sites of this region and adjacent territories at the turn of late antiquity and the early Middle Ages.
EARLY GREEK MYTHOGRAPHY AND EPIC POETRY: A REASSESSMENT
Authors: Pàmias Jordi
Published: September 2024

Studies of early mythography have stressed the dependent relationship between the so-called logographers and epic archaic poetry. Better knowledge of archaic and classical mythography in recent years has provided more accurate details of the context of the production and purposes of the fragmentary works by Hecataeus, Acusilaus, Pherecydes and Hellanicus. Each of them has his own agenda and programme, which have to be explained within their context and not, from a purely historic-literary perspective, as an appendix, a continuation or an exegesis of the epic tradition. This article argues that conditions of preservation, and means of transmission, of fragmentary mythographers have shaped the way we approach them. In other words, the process of reception of epic poetry through the exegetic and grammarian tradition distorts our view and leads the modern reader to see mythography as being dependent on Homer or Hesiod.
MORE AND LESS EVIDENCE FOR THE TEXT OF JULIUS EXUPERANTIUS
Authors: Welsh Jarrett T.
Published: September 2024

This paper examines a neglected fifteenth-century manuscript of the opusculum of Julius Exuperantius. It argues that that manuscript (Bologna, Biblioteca Universitaria, 748) is a sibling of Vatican City, BAV, Vat. lat. 3334, and situates the new manuscript in the stemma established by the last editor. It then proposes a modification to that editor's stemma, arguing that those two fifteenth-century manuscripts in fact descend from Milan, BA, H 37 sup., once owned by Francesco Pizolpasso. Finally, it considers the implications of those arguments for the editing and the history of the text.
Experiencing Exclusion: Scholarship after Inquisition
Authors: Davis Natalie Zemon , Hanß Stefan
Published: September 2024

In 1952, while working on my Ph.D. at the University of Michigan, two men from the Department of State came to our apartment and picked up my passport and that of my husband, Chandler Davis. In 1962, Chandler was finally allowed to immigrate to Canada with his family and take up a professorship at the University of Toronto. The ten years in between were packed with politics: Chandler’s refusal to answer questions before the House Un-American Activities Committee (HUAC); his firing from the University of Michigan; his court case challenging HUAC; his six months’ prison term for contempt of Congress; and throughout, his inability to get a tenure-track appointment at any American university. I myself was not called to confess my political views or memberships but investigations against Chandler were based on the publication of Operation mind – a pamphlet which I had co-authored together with Elizabeth Douvan and which is presented here. I was without a passport and not part of a university community for years. This article reflects on the impact of this experience of persecution on my work as a historian, and the relationship between politics, activism, and what Marc Bloch and Lucien Febvre called ‘the historian’s craft’ and ‘consciousness’.
The Hidden Labour of Digital Capitalism: Changes, Continuities, Critical Issues
Authors: Pizzolato Nico
Published: September 2024

Rapid technological development means that the ground on which recent academic studies and public debates about the future of work organisation are based is shifting too rapidly for predictions to be credible. Organisational studies scholars have provided a counterpoint to this futuristic, speculative debate about the world of tomorrow with studies that contextualise seemingly new trends within a longer history of industrial capitalism. In this article, using Moritz Altenried's The Digital Factory (2022) as a starting point, I further explore the historical contextualisation of two aspects of platform capitalism: its de-spatialisation and its use of “autonomy”.
Mapping the Social Relations of Labor in Contemporary Algorithmic Society
Authors: Downey Greg
Published: September 2024

Moritz Altenried's The Digital Factory (2022) accomplishes in just under two hundred pages what many other books twice that length have struggled with: assembling a concise yet readable introductory map to the global, fragmented, and too-often hidden landscape of digitally-mediated capitalism. But the digital factory itself is an incomplete concept, almost always requiring us to look for the external and contingent labor support hidden just outside of its supposedly totalizing network of logistics, robotics and algorithms.
Introduction to the Review Dossier on The Digital Factory: Continuing a Long-Standing Debate
Authors: Akgöz Görkem , Blok Aad
Published: September 2024

Theories about the impact of digital technology on society and the development of capitalism and debates about the influence of digital information technologies on the future of work have been abundant since the end of the twentieth century. Most of the academic debate has taken place outside labour history, leaving the actual effects of digital technologies on human work and labour relations often overlooked. Moritz Altenried's The Digital Factory: The Human Labor of Automation focuses precisely on these effects, and as such provides a good opportunity to engage with these debates from a labour history perspective. This Review Dossier includes four comments on Altenried's book, by Bridget Kenny, Nico Pizzolato, Görkem Akgöz, and Greg Downey, to which the author responds. The contributors focus on different aspects of The Digital Factory depending on their own perspective on recent developments in the digital economy in the larger context of global capitalism.
Disciplining Citizens and Commodities: Economic Crimes and Accusations in 1970s Uganda
Authors: Donovan Kevin P.
Published: September 2024

In 1975, the Ugandan state established an Economic Crimes Tribunal to investigate and penalize smuggling, hoarding, overcharging, and other commercial malfeasance. In the coming years, innumerable Ugandans were arrested and charged with contravening the state's economic regulations. Prior observers have seen this as another instance of a capricious state, but in this article, I demonstrate the popular investment in economic regulation. Ugandans demanded better stewardship of money and things because they were aghast at the ungovernable world of commodities. For one thing, the inaccessibility of so-called “essential commodities” — sugar and salt, preeminently — impeded ethical expectations surrounding social reproduction, hospitality, and masculine respectability. More troubling, essential commodities were not completely unavailable; rather, they were available on exclusionary and confusing terms. Relative deprivation was more upsetting than absolute scarcity because it offended a sense of consumptive entitlement. As a result, it was not only the state that accused citizens of economic crimes. There were widespread accusations in which allegation and denunciation circulated among neighbors, families, and bureaucrats in an urgent effort to discipline commodities and people.
Nonlinear solution of classical three-wave interaction via finite-dimensional quantum model
Authors: May Michael Q. , Qin Hong
Published: September 2024

The quantum three-wave interaction, the lowest-order nonlinear interaction in plasma physics, describes energy–momentum transfer between three resonant waves in the quantum regime. We describe how it may also act as a finite-degree-of-freedom approximation to the classical three-wave interaction in certain circumstances. By promoting the field variables to operators, we quantize the classical system, show that the quantum system has more free parameters than the classical system and explain how these parameters may be selected to optimize either initial or long-term correspondence. We then numerically compare the long-time quantum–classical correspondence far from the fixed point dynamics. We discuss the Poincaré recurrence of the system and the mitigation of quantum scrambling.
Improved axial confinement in the open trap by the combination of helical and short mirrors
Authors: Sudnikov Anton V. , Ivanov Ivan A. , Inzhevatkina Anna A. , Kozhevnikov Aleksey V. , Postupaev Vladimir V. , Tolkachev Mikhail S. , Ustyuzhanin Viktor O.
Published: September 2024

The paper presents experimental results from the SMOLA device, which was built in the Budker Institute of Nuclear Physics for the verification of the helical mirror confinement idea. This concept involves active control of axial losses from the confinement zone in an open magnetic trap through the use of multiple mirrors that move in the plasma frame of reference. The discussed experiments focused on determining the cumulative effect of a helical mirror system in combination with a short segment of a stronger magnetic field. Combination of these two methods of axial flow suppression results in higher efficiency compared with each method individually. Different combinations of the mirrors were tested. The most effective flow suppression was observed if the short mirror was placed between the confinement region and the helical mirror. In this configuration, an effective mirror ratio of

$R_{{\rm eff}} = 32.6\pm 7.8$

was achieved, along with a more than three-fold increase in plasma density within the confinement region. The possibility of a cumulative effect of different types of magnetic mirrors offers a way to improve the confinement performance of the reactor-grade mirror confinement devices.
A foreign settler: the anthropogenic displacement of sea cucumbers through fisheries discards
Authors: Castro Nuno , Romão Filipe , Félix Pedro M.
Published: September 2024

This study describes the presence of the royal cucumber Parastichopus regalis (Cuvier, 1817) in The Natural Park of Ria Formosa (NPRF), Portugal. A single individual was observed during a monitoring scuba dive at a depth of 3 m inside this shallow mesotidal lagoon. The most plausible explanation for this occurrence is attributed to the rejection by trawlers when returning to their home port from their fishing grounds. This marine species has a deeper distribution outside the lagoon and is commonly captured as by-catch and subsequently discarded. This study also alerts us to the growing presence of non-indigenous species and the emergent threat of new invasions, highlighting the need to adopt biosecurity measures, like good practices for fishers when dealing with discards to avoid new species introductions in this fragile coastal marine habitat.
Design of a traction neck brace with two degrees-of-freedom via a novel architecture of a spatial parallel mechanism
Authors: Zhou Jingzong , Kulkarni Priya , Zhao Xincheng , Agrawal Sunil K.
Published: September 2024

Traction of the head-neck is important in the treatment of patients suffering from neck pain due to degeneration of the intervertebral discs. Conventional neck traction is provided manually by experienced physical therapists who maintain a desired orientation of the head-neck relative to the trunk while applying the traction. It is postulated that innovative designs of neck exoskeletons can provide the same function both flexibly and accurately. This article presents a novel architecture of a parallel mechanism whose base sits on the human shoulders with 4 parallel chains, each chain having a revolute-revolute-universal-revolute (RRUR) structure, while the end-effector is connected rigidly to the human head. Each chain has five degrees-of-freedom (DOF) and applies a constraint on the motion of the end-effector. As a result, this parallel mechanism allows two DOFs to the end-effector. These are (i) forward flexion or lateral bending of the head and (ii) vertical translation. An important motivation for the current design with RRUR structure is to characterize the range of forward flexion/lateral bending of the head-neck with this structure and the vertical translation to the end-effector. A physical prototype was constructed and tested to evaluate the performance of this mechanism in hardware for the proposed application.
Prediction of abnormal gait behavior of lower limbs based on depth vision
Authors: Liu Tie , Bai Dianchun , Yi Hongyu , Yokoi Hiroshi
Published: September 2024

As a kind of lower-limb motor assistance device, the intelligent walking aid robot plays an essential role in helping people with lower-limb diseases to carry out rehabilitation walking training. In order to enhance the safety performance of the lower-limb walking aid robot, this study proposes a deep vision-based abnormal lower-limb gait prediction model construction method for the problem of abnormal gait prediction of patients’ lower limbs. The point cloud depth vision technique is used to acquire lower-limb motion data, and a multi-posture angular prediction model is trained using long and short-term memory networks to build a model of the user’s lower-limb posture characteristics during normal walking as well as a real-time lower-limb motion prediction model. The experimental results indicate that the proposed lower-limb abnormal behavior prediction model is able to achieve a 97.4% prediction rate of abnormal lower-limb movements within 150 ms. Additionally, the model demonstrates strong generalization ability in practical applications. This paper proposes further ideas to enhance the safety performance of lower-limb rehabilitation robot use for patients with lower-limb disabilities.
RGB-D visual odometry by constructing and matching features at superpixel level
Authors: Yang Meiyi , Xiong Junlin , Li Youfu
Published: September 2024

Visual odometry (VO) is a key technology for estimating camera motion from captured images. In this paper, we propose a novel RGB-D visual odometry by constructing and matching features at the superpixel level that represents better adaptability in different environments than state-of-the-art solutions. Superpixels are content-sensitive and perform well in information aggregation. They could thus characterize the complexity of the environment. Firstly, we designed the superpixel-based feature SegPatch and its corresponding 3D representation MapPatch. By using the neighboring information, SegPatch robustly represents its distinctiveness in various environments with different texture densities. Due to the inclusion of depth measurement, the MapPatch constructs the scene structurally. Then, the distance between SegPatches is defined to characterize the regional similarity. We use the graph search method in scale space for searching and matching. As a result, the accuracy and efficiency of matching process are improved. Additionally, we minimize the reprojection error between the matched SegPatches and estimate camera poses through all these correspondences. Our proposed VO is evaluated on the TUM dataset both quantitatively and qualitatively, showing good balance to adapt to the environment under different realistic conditions.
Obstacle avoidance control of UGV based on adaptive-dynamic control barrier function in unstructured terrain
Authors: Guo Liang , Zhang Suyu , Zhao Wenlong , Liu Jun , Liu Ruijun
Published: September 2024

The widely used model predictive control of discrete-time control barrier functions (MPC-CBF) has difficulties in obstacle avoidance for unmanned ground vehicles (UGVs) in complex terrain. To address this problem, we propose adaptive dynamic control barrier functions (AD-CBF). AD-CBF is able to adaptively select an extended class of functions of CBF to optimize the feasibility and flexibility of obstacle avoidance behaviors based on the relative positions of the UGV and the obstacle, which in turn improves the obstacle avoidance speed and safety of the MPC algorithm when integrated with MPC. The algorithmic constraints of the CBF employ hierarchical density-based spatial clustering of applications with noise (HDBSCAN) for parameterization of dynamic obstacle information and unscaled Kalman filter (UKF) for trajectory prediction. Through simulations and practical experiments, we demonstrate the effectiveness of the AD-CBF-MPC algorithm in planning optimal obstacle avoidance paths in dynamic environments, overcoming the limitations of the point-by-point feasibility of MPC-CBF.
Kinematic analysis and advanced control of a vectored thruster based on 3RRUR parallel manipulator for micro-size AUVs
Authors: Liu Tao , Zhao Jintao , Huang Junhao
Published: September 2024

Autonomous underwater vehicles (AUVs) have played a pivotal role in advancing ocean exploration and exploitation. However, traditional AUVs face limitations when executing missions at minimal or near-zero forward velocities due to the ineffectiveness of their control surfaces, considerably constraining their potential applications. To address this challenge, this paper introduces an innovative vectored thruster system based on a 3RRUR parallel manipulator tailored for micro-sized AUVs. The incorporation of a vectored thruster enhances the performance of micro-sized AUVs when operating at minimal and low forward speeds. A comprehensive exploration of the kinematics of the thrust-vectoring mechanism has been undertaken through theoretical analysis and experimental validation. The findings from theoretical analysis and experimental confirmation unequivocally affirm the feasibility of the devised thrust-vectoring mechanism. The precise control of the vector device is studied using Physics-informed Neural Network and Model Predictive Control (PINN-MPC). Through the adoption of this pioneering thrust-vectoring mechanism rooted in the 3RRUR parallel manipulator, AUVs can efficiently and effectively generate the requisite motion for thrust-vectoring propulsion, overcoming the limitations of traditional AUVs and expanding their potential applications across various domains.
Type synthesis of a new parallel mechanism with complete separation of constraints and drives
Authors: Wang Yu , Qiu Can , He Xiaoyu , Wu Jiabin , Xu Yundou , Zhao Yongsheng
Published: September 2024

Currently, there is an increasing demand for parallel mechanisms with fewer inputs and more outputs in aerospace, antennas, and recreational facilities. Therefore, this paper proposes a new parallel mechanism (PM) with a separation of constraints and drives, facilitating centralized drive management. Based on screw theory, the type synthesis of new parallel mechanisms with 3T (T representing translation), 3R (R representing revolute), 2T1R, and 2R1T is proposed. Three-degree-of-freedom (3-DOF) parallel mechanisms with fewer inputs and multiple outputs are proposed. Taking the 3RPS-PPPS parallel mechanism as an example, the closed-loop vector method is employed to solve for the lengths of actuated branches. A complete Jacobi matrix is constructed. The motion/force transmission performance of the 3RRS/PPPS parallel mechanism is better than the 3RRS parallel mechanism. Centralized management of drive branches greatly reduces the number of drives, making maintenance and repair easier. It has many application scenarios in antennas, recreational facilities, and other occasions.
X-ray powder diffraction data for mosapride dihydrogen citrate dihydrate
Authors: Dugarte-Dugarte Analio J. , Toro Robert A. , Henao José Antonio , Díaz de Delgado Graciela , Delgado José Miguel
Published: September 2024

The previously unindexed laboratory X-ray powder diffraction data of mosapride dihydrogen citrate dihydrate, an API used to stimulate gastrointestinal motility, has been recorded at room temperature. Using these data, the crystal structure of this API has been refined in space group P21/c (No. 14) with a = 18.707(4) Å, b = 9.6187(1) Å, c = 18.2176(4) Å, β = 114.164(1)°, V = 2990.74(8) Å3, and Z = 4. The structure of this material corresponds to the phase associated with CSD Refcode LUWPOL determined at 93 K. The Rietveld refinement, carried out with TOPAS-Academic, proved the single nature of the sample and the quality of the data recorded.
A new formula for the determinant and bounds on its tensor and Waring ranks
Authors: Houston Robin , Goucher Adam P. , Johnston Nathaniel
Published: September 2024

We present a new explicit formula for the determinant that contains superexponentially fewer terms than the usual Leibniz formula. As an immediate corollary of our formula, we show that the tensor rank of the
$n \times n$
determinant tensor is no larger than the
$n$
-th Bell number, which is much smaller than the previously best-known upper bounds when
$n \geq 4$
. Over fields of non-zero characteristic we obtain even tighter upper bounds, and we also slightly improve the known lower bounds. In particular, we show that the
$4 \times 4$
determinant over
${\mathbb{F}}_2$
has tensor rank exactly equal to
$12$
. Our results also improve upon the best-known upper bound for the Waring rank of the determinant when
$n \geq 17$
, and lead to a new family of axis-aligned polytopes that tile
${\mathbb{R}}^n$
.
Effect of temperature on the embryonic and larvae development of discus fish Symphysodon aequifasciatus and time of first feeding
Authors: Mattos Douglas da Cruz , Cardoso Leonardo Demier , Oliveira Adriano Teixeira de , Screnci-Ribeiro Rafaela , Mattos Bruno Olivetti de , Aride Paulo Henrique Rocha , Radael Marcella Costa , Motta Jonas Henrique de Souza , Vidal Manuel Vazquez
Published: September 2024

This study aimed to analyze the influence of different temperatures on the embryonic and larval development of discus fish Symphysodon aequifasciatus and determine the time required for the beginning of exogenous feeding. Eggs and larvae were obtained from natural spawns and distributed in five treatments: 24.0, 26.0, 28.0, 30.0, and 32.0 °C. To assess the developmental stages and embryonic structures, samples were taken at regular intervals and checked under an optical microscope. At the end of the experimental period, statistical analysis was performed, followed by Tukey’s test. As a result, it was possible to observe the significant effects of temperature on the variables. It was noted that the temperature accelerated the embryonic and larval development of the discus and also contributed to a reduction in the time between the incubation period and the feeding transition. It was also noted that the incubation of eggs and larvae at a temperature of 24.0 °C can cause damage to embryos, such as malformation of the body as well as anomalies in the circulatory system.
Central bank digital currencies: an old tale with a new chapter
Authors: Bordo Michael D. , Roberds William
Published: September 2024

We consider the debut of a new monetary instrument, central bank digital currencies (CBDCs). Drawing on examples from monetary history, we argue that a successful monetary transformation must combine microeconomic efficiency with macroeconomic credibility. A paradoxical feature of these transformations is that success in the micro dimension can encourage macro failure. Overcoming this paradox may require politically uncomfortable compromises. We propose that such compromises will be necessary for the success of CBDCs.
Cognitive reserve as residual variance in cognitive performance: Latent dimensionality, correlates, and dementia prediction
Authors: Aichele Stephen R.
Published: September 2024

Objectives:

Cognitive reserve (CR) is typically operationalized as episodic memory residualized on brain health indices. The dimensionality of more generalized models of CR has rarely been examined.

Methods:

In a sample of N = 113 dementia-free older adults (ages 62–86 years at MRI scan; 58.4% women), the domain-specific representation of general cognition (COG) before vs. after residualization on brain indices (brain volume loss, cerebral blood flow, white matter hyperintensities) was compared (i.e., COG vs. CR). COG and CR were assessed by 15 tasks spanning five domains: processing speed, verbal memory, visuospatial memory, fluid reasoning, and vocabulary. Measurement invariance and item-construct representation were tested in a series of structural factor analyses. COG and CR were then examined in relation to 22 risk and protective factors and dementia status at time of death.

Results:

Item-factor loadings differed such that CR more strongly emphasized fluid reasoning. More years of education, higher occupational class, more hobbies/interests, and fewer difficulties with personal mobility similarly predicted better COG and CR. Only the sub-domain of visuospatial memory (both before and after residualization) was associated with conversion to dementia by end-of-life (r = −.30; p = .01).

Conclusions:

Results provide tentative support for the role of fluid reasoning (intelligence) as a potential compensatory factor for age- and/or neuropathology-related reductions in processing speed and memory. Intellectually stimulating work, efforts to preserve personal mobility, and a diversity of hobbies and interests may attenuate age- and/or pathology-related reductions in cognitive functioning prior to dementia onset.
Exploring fluctuations and interconnected movements in stock, commodity, and cryptocurrency markets
Authors: Akin Isik , Akin Meryem , Ozturk Zafer , Hameed Affan , Opara Victoria , Satiroglu Hakan
Published: September 2024

This research employs a vector autoregression (VAR) analysis to explore the volatility and dynamic interactions between stock, commodity, and cryptocurrency markets. It focuses on the returns of the S&P 500, gold, crude oil, and Bitcoin to analyse their interconnections. Our results indicate that Bitcoin returns positively affect S&P 500 and crude oil, but negatively impact gold. Conversely, crude oil returns have a positive influence on gold but lead to decreased returns for Bitcoin and the S&P 500. Similarly, higher gold returns correspond to increased returns in crude oil and S&P 500 but decreased returns in Bitcoin. The rise of the S&P 500 negatively influences Bitcoin and crude oil returns, while gold returns remain unaffected. However, these relationships exhibit weak and limited strength. Including these assets in a portfolio can help risk mitigation, as Bitcoin diversifies crude oil, gold, and S&P 500, and crude oil diversifies S&P 500. These findings contribute to our understanding of global financial dynamics and inform decision-making in risk assessment, portfolio management, risk mitigation, and diversification strategies.
A case for the moral duty of specific human germline genetic engineering
Authors: Szocik Konrad , MacKay Matthew , Mason Christopher E.
Published: September 2024

Germline gene editing (GGE) is a controversial procedure, prohibited by most intergovernmental and scientific bodies and is not currently medically utilized. However, given circumstances where GGE would be essential for human survival, it is possible that GGE could be ideal, ethical and even necessary. One such possible instance of this circumstance could be long-term presence of humans on other planets. In our paper, we point out that there is a strong case for genetically modifying humans, including through GGE, for a future settlement in space directed at preserving human (and other) species. To avoid unnecessarily suffering and death from such difficult missions and environments, GGE enhancements should be considered, although only if shown to be safe, well-regulated and efficacious. We also examine and detail how major ethical frameworks can be shown to support, rather than prohibit, such procedures.
The association of compassion with dignity and symptoms in end-of-life cancer patients
Authors: Bovero Andrea , Di Girolamo Irene , Botto Rossana , Geminiani Giuliano Carlo
Published: September 2024

Objectives

Compassion is essential in palliative care; however, there is a lack of evidence of the association between this construct and patients’ dignity-related distress. The present study aimed to investigate the association between end-of-life cancer patients’ sense of dignity, the level of compassion of the healthcare professionals (HCPs) noticed and perceived by the patients, and levels of compassion that HCPs felt they had toward patients, investigating through specific attitudes and behaviors. Furthermore, the relationship between compassion and patients’ physical and psychological symptoms, such as levels of anxiety and depression, was also investigated.

Methods

The study was cross-sectional. The sample consisted of 105 end-of-life cancer patients and 40 HCPs. Patients had a Karnofsky Performance Status of 50 or lower and a life expectancy of less than 4 months. For each patient, sociodemographic data were collected, and a set of rating scales assessing compassion, dignity as well as physical and psychological symptoms were administered.

Results

The results showed significant negative associations between patients’ perception of compassion and dignity-related distress as well as significant negative associations between patients’ perception of compassion and patients’ symptoms.

Significance of results

Compassion seems to be involved in diminishing dignity-related distress and alleviating physical and psychological symptoms. Other studies are needed to understand whether patients’ symptoms or whether specific HCPs’ conditions influence compassion. Exploring compassion and at the end-of-life could encourage a dignity-conserving care.
Modern arable and diverse ley farming systems can increase soil organic matter faster than global targets
Authors: Gantlett Richard , Bishop Jacob , Jones Hannah E. , Lukac Martin
Published: September 2024

Agriculture can be pivotal in mitigating climate change through soil carbon sequestration. Land conversion to pasture has been identified as the most effective method to achieve this. Yet, it creates a perceived trade-off between increasing soil carbon and maintaining arable food crop production. In this on-farm study, we assessed the potential of incorporating a 2-year diverse ley (consisting of 23 species of legumes, herbs, and grasses) within a 7-year arable crop rotation for soil organic matter accumulation. We established upper and lower boundaries of soil organic matter accumulation by comparing this approach to positive (permanent ley, akin to conversion to permanent pasture) and negative (bare soil) references. Our findings in the 2-year diverse ley treatment show greater soil organic matter accumulation in plots with lower baseline levels, suggesting a potential plateau of carbon sequestration under this management practice. In contrast, the positive reference consistently showed a steady rate of organic matter accumulation regardless of baseline levels. Moreover, we observed a concurrent increase in labile carbon content in the 2-year ley treatment and positive reference, indicating improved soil nutrient cycling and ecological processes that facilitate soil carbon sequestration. Our results demonstrate that incorporating a 2-year diverse ley within arable rotations surpasses the COP21 global target of a 0.4% annual increase in soil organic carbon. These findings, derived from a working farm's practical and economic constraints, provide compelling evidence that productive arable agriculture can contribute to climate change mitigation efforts.
Generalized Poisson random variable: its distributional properties and actuarial applications
Authors: Faroughi Pouya , Li Shu , Ren Jiandong
Published: September 2024

Generalized Poisson (GP) distribution was introduced in Consul & Jain ((1973). Technometrics, 15(4), 791–799.). Since then it has found various applications in actuarial science and other areas. In this paper, we focus on the distributional properties of GP and its related distributions. In particular, we study the distributional properties of distributions in the
$\mathcal{H}$
family, which includes GP and generalized negative binomial distributions as special cases. We demonstrate that the moment and size-biased transformations of distributions within the
$\mathcal{H}$
family remain in the same family, which significantly extends the results presented in Ambagaspitiya & Balakrishnan ((1994). ASTINBulletin: the Journal of the IAA, 24(2), 255–263.) and Ambagaspitiya ((1995). Insurance Mathematics and Economics, 2(16), 107–127.). Such findings enable us to provide recursive formulas for evaluating risk measures, such as Value-at-Risk and conditional tail expectation of the compound GP distributions. In addition, we show that the risk measures can be calculated by making use of transform methods, such as fast Fourier transform. In fact, the transformation method showed a remarkable time advantage over the recursive method. We numerically compare the risk measures of the compound sums when the primary distributions are Poisson and GP. The results illustrate the model risk for the loss frequency distribution.