bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing ALP lepton flavor violation at
μTRISTAN
Authors: Calibbi Lorenzo , Li Tong , Mukherjee Lopamudra , Yang Yiming
Published: December 2024

Axionlike particles (ALPs) with lepton flavor-violating (LFV) interactions are predicted within a wide range of flavored ALP models. The proposed μTRISTAN high-energy e−μ+ and μ+μ+ collider will provide a good opportunity to explore flavor physics in the charged lepton sector. In this work, based on a model-independent effective Lagrangian describing the ALP leptonic interactions, we investigate the potential of μTRISTAN to probe ALP LFV couplings. We analyze the testability of selected ALP production channels with potential sensitivity at μTRISTAN, considering different beams and collision energies, including e−μ+→aγ, e−μ+→e−τ+a, μ+μ+→μ+τ+a, and e−μ+→τ−μ+a. The produced ALP a is either long-lived or can promptly decay to flavor-violating or flavor-conserving charged lepton final states. In particular, combining the above LFV ALP production modes with a suitable LFV decay mode, one can identify signatures that are virtually free of Standard Model background. We show the resulting sensitivity of μTRISTAN to LFV ALP couplings and compare it with multiple low-energy leptonic constraints and the future improvements thereof. We find that μTRISTAN can be generally complementary to searches for low-energy LFV processes and measurements of the leptonic magnetic dipole moments and has the capability to explore unconstrained parameter space for ALP masses in the O(1)–O(100)  GeV range. In the light ALP regime, however, the parameter space that μTRISTAN is sensitive to has been already excluded by low-energy searches for LFV decays.

Published by the American Physical Society
2024
Casimir energy on the sphere and 6D CFT trace anomaly
Authors: Aros Rodrigo , Bugini Fabrizzio , Diaz Danilo E. , Núñez-Barra Camilo
Published: December 2024

We elucidate the dependence of the Casimir energy on the trace anomaly coefficients for a six-dimensional (6D) conformal field theory on R×S5. This extends the universal dependence on the central charge in two dimensions and the relation by Cappelli and Coste in four dimensions, unveiling the role of the trivial total derivatives in the anomaly that renders the Casimir energy scheme dependent. We obtain Ec=−158a6−512(g5+14g7+12g8−10g9+g10), with a6 being the type A central charge and the g’s, the coefficients of five out of six terms that form a basis for trivial total derivatives. The derivation is based on the Polyakov formulas (conformal primitive) resulting from the integration of the trace anomaly. Alternatively, on a 6D conformally flat background the above basis is redundant, and one can simplify further to get, in terms of the Schouten scalar J and the Schouten tensor V, Branson’s basis for trivial total derivatives

∇

2

∇

2

J

, ∇2J2, and ∇2|V|2+2∇·(V·∇J) with coefficients γ1, γ2, and γ3, respectively, Ec=−158a6−124(γ1−γ2−18γ3). For completeness, we also report the energy-momentum tensor in full generality, which leads to an alternative derivation of the above relation.

Published by the American Physical Society
2024
Quantization of Carrollian conformal scalar theories
Authors: Chen Bin , Sun Haowei , Zheng Yu-fan
Published: December 2024

In this work, we study the quantization of Carrollian conformal scalar theories, including two-dimensional (2D) magnetic scalar and three-dimensional (3D) electric and magnetic scalars. We discuss two different quantization schemes, depending on the choice of the vacuum. We show that the standard canonical quantization corresponding to the induced vacuum yields a unitary Hilbert space and the 2-point correlation functions in this scheme match exactly with the ones computed from the path integral. In the canonical quantization, the BMS symmetry can be realized without anomaly. On the other hand, for the quantization based on the highest-weight vacuum, it does not have a unitary Hilbert space. In 2D, the correlators in the highest-weight vacuum agree with the ones obtained by taking the c→0 limit of the 2D CFT, and there is an anomalous term in the commutation relations between the Virasoso generators, whose form is similar to the one in 2D CFT. In 3D, there is no good definition of the highest-weight vacuum without breaking the rotational symmetry. In our study, we find that the usual state-operator correspondence in CFT does not hold in the Carrollian case.

Published by the American Physical Society
2024
Bulk viscosity, speed of sound, and contact structure at intermediate coupling
Authors: Kushwah Shivam Singh , Misra Aalok
Published: December 2024

Thermal QCD systems like strongly coupled quark gluon plasma require not only a large ’t Hooft coupling but also a finite gauge coupling [Natsuume, ] in the large-N gravity dual. Unlike almost all top-down holographic models in the literature, holographic large-N thermal QCD models based on this assumption, therefore, necessarily require addressing this limit from M theory. In the context of strongly coupled (very large ’t Hooft coupling) thermal QCD-like theories, the bulk-viscosity(ζ)-to-shear-viscosity(η) ratio using the type-IIA-theory dual of thermal QCD-like theories was shown to vary like 13−cs2 [Czajka , Bulk viscosity at extreme limits: From kinetic theory to strings, ] (cs being the speed of sound), and the same (

ζ

η

) at weak coupling using kinetic theory and finite temperature field theory was shown and is known to vary like (13−cs2)2 [Czajka , Bulk viscosity at extreme limits: From kinetic theory to strings, , and references therein]. The novelties of the results of this paper are that we not only show for the first time from M theory that at intermediate coupling, with the inclusion of the O(R4) corrections, the result obtained for ζη interpolates between the strong- and weak-coupling results in a way consistent with lattice computations of SU(3) gluodynamics [Meyer, Calculation of the bulk viscosity in SU(3) gluodynamics, ] within statistical errors (and within the temperature range permissible by our M-theory uplift), but also observe that this behavior is related to the existence of contact 3-structures that exist only at intermediate coupling effected by the intermediate-N “MQGP” limit of Misra and Yadav []. We also obtain an explicit dependence of ζη on (fractional powers of) the temperature-dependent and running gauge coupling (and its temperature derivative) and verify that the weak-coupling result dominates at large temperatures. We further conjecture that the aforementioned fractional-power dependence of ζη on the gauge coupling is related to the lack of “N-connectedness” in the parameter space of contact 3-structures (as shown in ).

Published by the American Physical Society
2024
Susceptible-infected-recovered-susceptible processes competing on simplicial complexes
Authors: Zhao Lina , Wang Haiying , Yang Huijie , Gu Changgui , Moore Jack Murdoch
Published: December 2024

Contagions do not exist in isolation but in the presence of other propagating quantities, with which they may compete. Furthermore, higher-order interactions (interactions involving more than two nodes) are widely represented in real-world systems. We propose a stochastic model for susceptible-infected-recovered-susceptible (SIRS) processes competing in a simplicial complex that accommodates higher-order interactions. We also propose deterministic microscopic Markov chain (MMC) and mean-field (MF) forms of this model, which we analyze to reveal conditions for the persistence of each infection. We verify our analysis via numerical simulations, which also unveil critical mass effects, discontinuous phase transitions, and bistability. The stochastic model exhibits eight distinct classes of dependence of final state on initial conditions. All eight of these classes can be approximately reproduced with MMC, but only seven are seen under MF. The class observed in MMC and approximated in the stochastic model, but missing from MF, involves three distinct steady states for a single set of parameter values. However, in the absence of higher-order interactions MF exhibits an additional class, not observed in MMC or the stochastic model, corresponding to an infinite spectrum of steady states, in which the ratio of infection levels remains at its initial level. Both MMC and MF models can exhibit sustained oscillations in which one contagion disappears while the other tends to a limit cycle.

Published by the American Physical Society
2024
Observation of an Inverse Turbulent-Wave Cascade in a Driven Quantum Gas
Authors: Karailiev Andrey , Gazo Martin , Gałka Maciej , Eigen Christoph , Satoor Tanish , Hadzibabic Zoran
Published: December 2024

We observe an inverse turbulent-wave cascade, from small to large length scales, in a driven homogeneous 2D Bose gas. Starting with an equilibrium condensate, we drive the gas isotropically on a length scale much smaller than its size, and observe a nonthermal population of modes with wavelengths larger than the drive one. At long drive times, the gas exhibits a steady nonthermal momentum distribution. At length scales increasing from the drive one to the system size, this distribution features in turn: (i) a power-law spectrum with an exponent close to the analytical result for a particle cascade in weak-wave turbulence, and (ii) a spectrum reminiscent of a nonthermal fixed point associated with universal coarsening in an isolated 2D gas. In further experiments, based on anisotropic driving, we reveal the complete qualitative picture of how the steady-state cascade forms.

Published by the American Physical Society
2024
Detecting and Attributing Change in Climate and Complex Systems: Foundations, Green’s Functions, and Nonlinear Fingerprints
Authors: Lucarini Valerio , Chekroun Mickaël D.
Published: December 2024

Detection and attribution (DA) studies are cornerstones of climate science, providing crucial evidence for policy decisions. Their goal is to link observed climate change patterns to anthropogenic and natural drivers via the optimal fingerprinting method (OFM). We show that response theory for nonequilibrium systems offers the physical and dynamical basis for OFM, including the concept of causality used for attribution. Our framework clarifies the method’s assumptions, advantages, and potential weaknesses. We use our theory to perform DA for prototypical climate change experiments performed on an energy balance model and on a low-resolution coupled climate model. We also explain the underpinnings of degenerate fingerprinting, which offers early warning indicators for tipping points. Finally, we extend the OFM to the nonlinear response regime. Our analysis shows that OFM has broad applicability across diverse stochastic systems influenced by time-dependent forcings, with potential relevance to ecosystems, quantitative social sciences, and finance, among others.

Published by the American Physical Society
2024
Resolving the Corbino Shockley-Ramo paradox for hydrodynamic current noise
Authors: Hui Aaron
Published: December 2024

Johnson noise thermometry enables direct measurement of the electron temperature, a valuable probe of many-body systems. Practical use of this technique calls for nonequilibrium generalizations of the Johnson-Nyquist theorem. For a hydrodynamic Corbino device, however, a naive use of the Shockley-Ramo theorem alongside the “Corbino paradox” leads to yet another paradox: current noise through the contacts would seem to be completely insensitive to bulk fluctuations. In this work, we resolve the unphysical “Corbino Shockley-Ramo paradox” by correctly formulating the hydrodynamic Shockley-Ramo problem. This allows us to properly formulate the problem of current noise in a hydrodynamic multiterminal device of arbitrary geometry, as well as validate a previously unjustified assumption for rectangular geometry results. As an example, we compute the Johnson noise in a hydrodynamic Corbino device, where we find a suppression of Johnson noise with magnetic field. This unusual characteristic serves as a qualitative signature of viscous hydrodynamic behavior.

Published by the American Physical Society
2024
The AHEAD leadership development program: an illustrative case example in a unique healthcare context
Authors: Cumberland Denise M. , Ellinger Andrea D. , McKinley Tara , Immekus Jason C. , McCart Andrew
Published: December 2024

Purpose

Leadership development programs (LDPs) have emerged relatively recently in the healthcare context as a mechanism not only to develop capable and competent leaders but also to retain them. The purpose of this paper is to describe a perspective on practice by illustrating a case example that showcases a pilot LDP for newly promoted healthcare leaders. The details about how it was developed and implemented collaboratively by a healthcare consortium and higher education institution (HEI) to address shared healthcare leadership talent pipeline and retention challenges are provided.

Design/methodology/approach

This perspective on practice describes how a consortium of competitive healthcare organizations, a type of branded Inter-organizational Relationship referred to as “Coopetition,” contracted with a HEI to design, develop and launch a pilot LDP, referred to as the Academy for Healthcare Education and Development program, using the analyze, design, develop, implement and evaluate model.

Findings

The significance of this illustrative case example is discussed along with some initial lessons learned based upon this pilot LDP that 24 program participants completed. Implications for research, theory and practice are presented, followed by limitations and a conclusion.

Originality/value

Inter-organizational relationships, particularly coopetition, are relatively new in the healthcare sector, along with collaboration with HEIs to develop interventions to solve compelling industry problems. This illustrative case example offers insights that address scholars’ calls and practitioners’ needs to explicate different approaches for LDPs to build the healthcare leadership talent pipeline.
Project leadership and representation: powering purposive social value
Authors: Clegg Stewart , Skyttermoen Torgeir , Vaagaasar Anne Live
Published: December 2024

Purpose

The paper discusses sustainability, in terms of creating purposive social value, which is increasingly an inherent characteristic of project leading and doing. Consequently, project scholars are currently grappling with what purposive social value creation means to initiation and execution of projects.

Design/methodology/approach

In line with recent development we offer reflections on the empowering nature of leadership enabling social value, its underlying forms of power and the dilemmas involved. Our theorizing is based on recent developments in literature on the value of sustainability in the context of projects, combined with literature on project leadership and reflections on the processes of power.

Findings

Based on a process ontology, we suggest that leadership for purposive social value creation calls for a rethinking of leadership as an inclusive patterning of actions, making it relational, boundary spanning and socialized in nature and essentially entailing a politics of representation.

Research limitations/implications

The paper is conceptual, so it has all the limitations of any conceptual paper that innovates a new field of inquiry. It is a not a hypothetic-deductively structured paper but is abductive in nature, combining disparate literary studies in a conceptual framework for further inquiry.

Practical implications

The legitimacy of leadership for purposive social value does not reside in the singular formal position of a project leader but in its broader vesting and representation.

Social implications

The paper calls for a rethinking of the nature of project leadership power relations, processes oriented toward the achievement of purposive social value and representation of interests.

Originality/value

This paper fulfills an identified need to study how purposive social value can be enabled by socialized and distributed project leadership that represents a broad-based and coherent conception of interests.
Appreciation of primary preservice teachers about the potential educational use of citizen science in environmental education
Authors: Diez-Ojeda María , Queiruga-Dios Marián , Queiruga-Dios Miguel Ángel
Published: December 2024

Purpose

This study aims to determine prior knowledge regarding the term “citizen science” (CS) and evaluate preservice teachers’ appreciation of the educational potential of CS.

Design/methodology/approach

Following the pedagogical framework of Experiential Learning Theory, a training program was designed for the subject of Environmental Education (EE) of the Primary Teacher Degree, incorporating CS activities. A quasi-experimental research was carried out with 36 primary preservice teachers who participated in this study, with a qualitative approach and without a control group. Two ad hoc surveys were defined for this study, the first one is related to prior knowledge about the term CS and a questionnaire was conducted to assess the educational potential of the CS after the implementation of the training program. The results showed a great initial lack of knowledge about CS but the appreciation of the preservice teachers after the educational intervention reveals the advantages and educational potential of CS.

Findings

Preservice teachers consider that CS can and should be incorporated, as part of the course syllabus, into the teaching system and this can be done in scientific-technological subjects or in all subjects with an interdisciplinary and transversal approach, with the majority of responses indicating that the development of generic skills would be the greatest perceived benefit for students.

Originality/value

There has been an increase in CS initiatives and projects in recent decades. However, despite the advantages for the participants and actors involved, its incorporation into higher education curricula is scarce.
Unveiling the mechanisms between project manager leadership competencies and team performance: an empirical study
Authors: Wang Peng , Haron Nuzul Azam , Law Teik Hua , Alias Aidi Hizami , Qi Yuewu
Published: December 2024

Purpose

This study aims to explore the influence of construction project manager competencies on team performance, using structural equation modeling (SEM) within the framework of social information processing theory. It investigates the multidimensional nature of project manager competencies and their impact on team processes and outcomes. Additionally, the study examines the mediating role of team processes in the relationship between competencies and team performance.

Design/methodology/approach

Drawing on data collected from 483 construction professionals in China, this study uses SEM to analyze the relationships among project manager competencies, team processes and team performance.

Findings

The results demonstrate a significant and positive effect of competencies on team performance. Specifically, task-related competencies directly contribute to performance, while people-related competencies enhance leader-member relations, and self-related competencies exert a gradual, cumulative influence. Moreover, the research confirms a three-factor competency structure and elucidates the nuanced mediating roles of team learning, monitoring and climate in the competency-performance relationship, shedding light on how specific competencies affect different stages of team development.

Originality/value

This study contributes to project management literature by applying social information processing theory to elucidate how project managers influence team cognition through competencies. From a practical standpoint, it advocates for a competency-based approach to project manager selection and training, aiming to enhance team performance. Overall, this research advances the understanding of the intricate interplay between project manager competencies and team performance, using SEM and a theoretical perspective rooted in social information processing theory.
A study of c-suite leaders’ individualistic and collectivistic decision-making styles: elaborating on leaders’ efficacy during crises
Authors: Bansal Anjali , Saini Damini , Yaqub Muhammad Zafar , Gupta Pragya
Published: December 2024

Purpose

This study investigated leaders’ decision-making during crises. Using grounded theory research, we explored whether leaders’ use of either individualistic or collectivistic decision-making styles is based on the context of a crisis. In addition, the authors looked into the components of building leaders’ efficacy during a crisis event and gauged their attitudinal and behavioral reactions to the crisis.

Design/methodology/approach

The authors conducted interviews with 30 C-suite executives during the first wave of the COVID-19 pandemic to determine their responses to crises. The authors then used open, axial, and selective coding to examine their data, which was then extracted for representative themes and overarching dimensions. In total, The authors received 12 major themes largely summarizing into 6 overarching dimensions – context of decision-making, leaders’ efficacy, individualistic approach to decision-making, collectivistic approach to decision-making, process of decision-making, and outcomes.

Findings

The research presents a decision-making framework clearly bifurcating situations with the need for individualistic and collectivistic decision-making. While, a high level of urgency and scarce resources encouraged leaders to adopt an individualistic approach in which most of the decisions were intuition-based and only high-level stakeholders were involved, the less time urgent and uncertain situation allowed leaders to put significant effort into building their own knowledge systems and involving others. In addition, leaders’ efficacy is understood in terms of their attitudes, readiness and reactions, which further elaborated upon their knowledge systems to allow them to excel in decision-making irrespective of the approaches they chose.

Originality/value

The research has implications for leaders in the decision-making roles to be effective during both individualistic and collectivistic decision-making.
Is the interplay among O2O platform businesses always equal? Evidence of attribute weight changes in the hospitality sector
Authors: Wen Tianhao , Ha Hong-Youl
Published: December 2024

Purpose

A crossover effect exists in the relationship between recommendation apps and restaurants in the online-to-offline (O2O) service platform context. Yet, how this effect evolves across subsequent consumption episodes, from the initial stage of information searching to the final stage of loyalty to a service provider, remains unclear.

Design/methodology/approach

This study utilizes a two-time-lag interval approach to test changes in temporal and carryover effects and attribute weights.

Findings

While there is no crossover effect between restaurant satisfaction and recommendation app loyalty during two time-lag interval periods, the crossover effect between recommendation app satisfaction and restaurant loyalty intentions is significant. These findings indicate that the satisfaction–loyalty intentions linkage operates systematically within the O2O consumption domain and increases over time. Particularly, the initial selection of a restaurant based on an app’s recommendation strengthens the intention to use the app again and increases loyalty toward the restaurant.

Originality/value

This study contributes to the literature by demonstrating the crossover effects of the two consumption systems on consumer evaluations. It underscores the importance of changes in individual attribute weights between the two systems as behavioral responses occur during initial and subsequent consumption phases.
Enhancing digital currency adoption: examining user experiences
Authors: Bhatnagr Puneett
Published: December 2024

Purpose

This study aimed to analyse user experiences and perceptions of eRupee banking applications in India, focussing on understanding the key factors driving user satisfaction and dissatisfaction.

Design/methodology/approach

A comprehensive text-mining approach was employed to analyse 5,176 user reviews collected from the Google Play Store. Sentiment analysis and latent Dirichlet allocation (LDA) were used to classify reviews and uncover prevailing themes.

Findings

The analysis revealed that positive reviews highlighted the themes of usefulness, convenience, satisfaction, app attributes, and ease of use. Negative reviews emphasise issues related to lack of trust, faulty updates, unreliability, security concerns, and inadequate customer support. The Logistic Regression model demonstrated superior performance in predicting user sentiments, achieving an AUC of 0.7926 and an accuracy rate of 77.90%.

Research limitations/implications

This study was limited to reviews from a single-platform source. Future research could incorporate data from multiple online sources and employ qualitative methods to gain deeper insight. Additionally, longitudinal studies and cross-cultural analyses are recommended to capture evolving user sentiments and global perspectives.

Practical implications

The findings provide actionable insights for bank managers, app developers and policymakers to enhance eRupee applications by addressing identified issues and leveraging positive aspects to improve overall user experience and satisfaction.

Originality/value

This study makes a novel contribution to the literature on digital currency and advanced text-mining techniques using machine-learning models to analyse user feedback in the context of an emerging economy. The proposed conceptual model and practical recommendations serve as the foundation for future research and practical development in digital financial services.
Unveiling user responses to AI-powered personalised recommendations: a qualitative study of consumer engagement dynamics on Douyin
Authors: Ding Liang , Antonucci Gianluca , Venditti Michelina
Published: December 2024

Purpose

This study aims to explore the impact of artificial intelligence-powered personalised recommendations (AI-PPRs) on user engagement, browsing behaviour and purchase intentions on TikTok (Douyin in China), focusing on how these recommendations affect user satisfaction and purchase intention, while also addressing potential privacy concerns. In addition, the research investigates the influence of AI-recommended product presentation, timing and placement, as well as social factors such as key opinion leaders’ (KOLs) influence on consumer decision-making.

Design/methodology/approach

Using the expectancy-value theory and the stimulus-organism-response model, this research used a qualitative methodology through interviews with Douyin users to explore their experiences and perceptions of AI-PPRs.

Findings

The findings indicate that Douyin’s proactive “push” mechanism of AI-PPRs enhances user engagement by effortlessly integrating product discovery into the entertainment experience. Content-driven AI-PPRs align with user preferences, decrease search time and increase satisfaction and purchase intentions through engaging short videos and live streaming. However, privacy concerns emerge when personalisation is perceived as excessively intrusive, leading to negative emotions and avoidance behaviours. Recommendation timing and cultural context significantly influence receptiveness, with inappropriate timing (e.g. during holidays) causing negative reactions. Technical challenges, such as network issues during live streaming, negatively impact user experience and engagement. Content quality is crucial, and poor or irrelevant content leads to negative perceptions and disengagement. While KOLs face scepticism due to perceived commercialisation, endorsements from trusted figures and authentic influencers are better received. Innovative payment methods, like “Douyin Monthly Payment”, enhance financial flexibility and promote customer loyalty. This study highlights the need to balance personalisation with privacy, emphasising the importance of content quality and authenticity in influencer marketing. For businesses using AI-PPRs, maintaining this balance is essential for preserving trust and sustaining consumer engagement and loyalty.

Originality/value

This study contributes valuable insights to the field by unravelling the intricate dynamics between AI-PPRs, user preferences and social influences. The findings provide practical implications for companies aiming to optimise personalised recommendation algorithms and enhance user engagement, thereby facilitating business growth in the dynamic short video e-commerce market.
Digital transformation and talent management in industry 4.0: a systematic literature review and the future directions
Authors: Banerjee Pramit , Sharma Naman
Published: December 2024

Purpose

This study aims to explore the relationship between digital transformation and talent management during the current industrial revolution (Industry 4.0). Talent management is a critical strategic focus for human resource (HR) managers, evolving with changing approaches over time. The paper seeks to guide talent management in Industry 4.0 by advocating a collaborative approach between employees and HR managers amidst technological transformations.

Design/methodology/approach

A systematic method of finding the literature using the PRISMA framework, through databases like Scopus, EBSCO, Emerald Insights and Science Direct was applied. A total of 629 papers were initially identified, which were filtered down to 42 papers for the review, leading to identification of research gaps, formulation of different research questions and proposal of a conceptual framework.

Findings

The literature highlights varied HR practices in Industry 4.0 and the corresponding transformation initiatives. It underscores that Industry 4.0 technologies empower employees to leverage creative, digital and interpersonal skills, fostering continuous learning. HR managers, through coaching and a commitment to sustainable practices, further motivate employees to acquire new skills. This collaborative effort propels the digital transformation of talent management, significantly impacting the overall talent pool.

Research limitations/implications

Although the literature review was conducted using prominent databases, some papers in regional languages were excluded, along with few articles whose full texts were not available, which may be a limitation of this paper.

Originality/value

This research represents a pioneering exploration of the interdisciplinary intersections between talent management and technological transformations. Initially, it surveys digital transformation practices, followed by a systematic review presenting various authors’ perspectives on talent management in Industry 4.0. The paper concludes by identifying research gaps and articulating key variables shaped by the intentions of HR managers and employees, thus, driving the transformation of talent.
Measuring overall functional diversity by aggregating its multiple facets: Functional richness, biomass evenness, trait evenness and dispersion
Authors: Wojcik Laurie Anne , Gaedke Ursula , van Velzen Ellen , Klauschies Toni
Published: December 2024

Human activities induce environmental changes, which can affect individuals' traits thereby leading to changes in functional diversity and finally in ecosystem functioning. Measuring functional diversity is thus of utmost importance to understand the consequences of such activities on ecosystem functioning. Functional diversity is composed of several facets, but these facets are almost always measured individually, and we lack a common metric integrating the multifaceted nature of functional diversity.

Consequently, we developed an index defined as the geometric mean of four independent facets: functional richness (the classic measure of the coverage of the trait axis), biomass evenness and trait evenness (quantifying how evenly distributed the biomass and traits are among species and within the feasible trait range, respectively) and dispersion (quantifying the spread around the biomass‐weighted mean trait). and each of its underlying facet take values between 0 and 1, and they assume the uniform distribution to yield maximal diversity.

We compared to other, more classic metrics measuring fewer facets of functional diversity by calculating all these indices for randomly and non‐randomly generated communities. We showed that overcomes several limitations of other indices (e.g. lack of accuracy, not computable for simple communities, unclear ecological interpretation) and is strongly correlated with ecosystem functions in simulated predator–prey communities. In addition, decomposing into its underlying facets revealed that ecosystem functions can be driven by different facets of on different trophic levels.

The strength of our index lies in being the only index that measures accurately the overall functional diversity by combining several facets and providing the option to decompose into them. This notably yields mechanistic insights about which facets are more important for driving changes in functional diversity and ecosystem functioning.
Beyond pathology: Patient experiences of laparoscopy for persistent pelvic pain with no identifiable cause found
Authors: McCaughey Tristan , Younes Melissa M , Raoofi Mooska , Hicks Lauren , Amir Michal , Reddington Charlotte , Cheng Claudia , Healey Martin , Peate Michelle
Published: December 2024

Background

Laparoscopy has often been considered a core part of the workup for pelvic pain. However, many of these laparoscopies find no pathology.

Aims

To evaluate the experiences of patients following laparoscopy for pelvic pain when there is no diagnosis found.

Materials and Methods

This descriptive qualitative study reviewed patients who underwent a diagnostic laparoscopy for persistent pelvic pain with no pathology found. Participants completed a written questionnaire and an in‐depth semi‐structured interview. Interview data were thematically analysed.

Results

Fifteen patients were interviewed with a median age of 30 years. Six themes were identified: desire for a diagnosis, hope as a coping strategy, inadequate communication, having ‘next steps’ of management offered, mental health impacts, and system issues. Participants wanted a diagnosis to help understand their condition, to enable connection with others, and believed that clinicians viewed pain with a diagnosis more seriously. Participants who were confident preoperatively that laparoscopy would lead to a diagnosis reported this contributing to poorer postoperative mental health. Participants discussed diagnoses not listed in the medical records, which provided hope for future management options. Participants reported worse mental health following the laparoscopy.

Conclusion

This study provides insight into the experiences of patients following a laparoscopy without an identifiable diagnosis. It highlights the importance of pre‐ and postoperative counselling, including discussing the potential for no findings at laparoscopy; the language used around other potential diagnoses; and the value in considering a patient's pre‐existing mental health. The findings of this study are relevant for all clinicians counselling people with persistent pelvic pain where endometriosis is suspected.
The sitting men: A systematic review of spare and working time exposure to sedentariness in relation to semen parameters
Authors: Sterpi Vittoria , Ricci Elena , Chiaffarino Francesca , Fedele Francesco , Esposito Giovanna , Parazzini Fabio , Viganò Paola , Cipriani Sonia
Published: December 2024

Background

Over the past few decades, several studies have found that semen quality parameters have steadily declined over time. Many hypotheses have been made to explain this finding, among which a sedentary lifestyle has been investigated. To synthesize the current evidence, we performed a systematic review of published papers reporting on the relationship between sedentary habits and semen parameters.

Methods

Embase and PubMed were systematically searched for papers published in English up to May 2023. We included all full‐text observational papers that reported the relationship between sedentariness and semen parameters. Article selection adhered to the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis (PRISMA) guidelines.

Results

Sixteen observational studies were ultimately included, six in healthy men and ten in men from Fertility Clinics. They encompassed a total of 13,509 men, with 9877 being healthy men and 3632 presenting at Fertility Clinics for initial assessment. In terms of semen volume, no association emerged in the six studies involving healthy men: however, results in men referring to fertility clinics mainly showed no association, with one indicating a decline and one higher volume. Twelve studies did not report differences in sperm concentration, while one study in men from Fertility Clinics and two in healthy men observed a decline in this parameter with increasing time spent on TV watching or sedentary posture in spare time. Total sperm count was found to be similar across groups of inactivity, except for one study that showed a significant decrease when men from Fertility Clinics spent more time watching TV. No significant differences were reported in sperm motility across all studies, with only one study, among those addressing sperm morphology, indicating a lower percentage of normal forms in men watching TV more than 3 h per day. Finally, three studies conducted in men referring to Fertility Clinics analyzed the sperm DNA fragmentation index. Two of these studies found a higher DNA fragmentation index in men spending more time per day in a sitting posture.

Conclusions

This review suggests a weak association between time spent sitting during spare time and sperm concentration, but the findings are inconsistent, highlighting the need for further research.
Nuclear lipids in chromatin regulation: Biological roles, experimental approaches and existing challenges
Authors: Sayed Ahmed , Eswara Karthik , Teles Kaian , Boudellioua Ahlem , Fischle Wolfgang
Published: December 2024

Lipids are crucial for various cellular functions. Besides the storage of energy equivalents, these include forming membrane bilayers and serving as signaling molecules. While significant progress has been made in the comprehension of the molecular and cellular biology of lipids, their functions in the cell nucleus remain poorly understood. The main role of the eukaryotic cell nucleus is to provide an environment for the storage and regulation of chromatin which is a complex of DNA, histones, and associated proteins. Recent studies suggest that nuclear lipids play a role in chromatin regulation and epigenetics. Here, we discuss various experimental methods in lipid‐chromatin research, including biophysical, structural, and cell biology approaches, pointing out their strengths and weaknesses. We take the view that nuclear lipids have a far more widespread impact on chromatin than is currently acknowledged. This gap in comprehension is mostly due to existing experimental challenges in the study of lipid‐chromatin biology. Several new, interdisciplinary approaches are discussed that could aid in elucidating the roles of nuclear lipids in chromatin regulation and gene expression.
Impact and Mechanisms of Action of BDNF on Neurological Disorders, Cancer, and Cardiovascular Diseases
Authors: Lei Min , Liu Qiwen , Nie Jinxia , Huang Rongyi , Mei Yan , Pan Dan , Chen Yong , Liu Wu
Published: December 2024

Brain‐derived neurotrophic factor (BDNF), which is primarily expressed in the brain and nervous tissues, is the most abundant neurotrophic factor in the adult brain. BDNF serves not only as a major neurotrophic signaling agent in the human body but also as a crucial neuromodulator. Widely distributed throughout the central nervous system (CNS), both BDNF and its receptors play a significant role in promoting neuronal survival and growth, thereby exerting neuroprotective effects. It is further considered as a guiding medium for the functionality and structural plasticity of the CNS. Increasingly, research has indicated the critical importance of BDNF in understanding human diseases. Activation of intracellular signaling pathways such as the mitogen‐activated protein kinase pathway, phosphatidylinositol 3‐kinase/protein kinase B/mammalian target of rapamycin pathway, and phospholipase C γ pathway by BDNF can all potentially enhance the growth, survival, proliferation, and migration of cancer cells, influencing cancer development. The loss of BDNF and its receptor, tropomyosin receptor kinase B, in signaling pathways is also associated with increased susceptibility to brain and heart diseases. Additionally, reduced BDNF levels in both the central and peripheral systems have been closely linked to various neurogenic diseases, including neuropathic pain and psychiatric disorders. As such, this review summarizes and analyzes the impact of BDNF on neurogenic diseases, cancer, and cardiovascular diseases. This study thereby aimed to elucidate its effects on these diseases to provide new insights and approaches for their treatment.
Influence of Donor Transfusion on Heart Transplantation Outcomes: A United Network for Organ Sharing Registry Analysis
Authors: Tavolacci Sooyun Caroline , Gregory Vasiliki , Okumura Kenji , Isath Ameesh , Shimamura Junichi , Spielvogel David , Ohira Suguru
Published: December 2024

Introduction

There is a lack of evidence regarding the impact of donor blood transfusion on heart transplant (HT) outcomes. We sought to elucidate the influence of donor transfusion on HT outcomes using the national database.

Methods

From January 2004 to March 2023, donor transfusion information was available for 40 538 recipients for HT in the United Network for Organ Sharing (UNOS) database. We used the UNOS 4‐level designation of transfusion (no blood [N = 18 575], 1–5 units [N = 14 098], 6–10 units [N = 4766], and massive transfusion of > 10 units [N = 3099]).

Results

Among this cohort, 53.2% of donors (N = 20 220) received a blood transfusion during the same admission. Donors who required blood transfusion commonly had head trauma as a cause of death (no‐blood, 22% vs. 1–5 units, 61%, 6–10 units, 88%, massive, 89%, p < 0.001). An increased amount of donor blood transfusion did not affect rates of acute rejection (no‐blood, 18% vs. 1–5 units, 19%, 6–10 units, 17%, massive, 19%, p = 0.13). The number of units transfused also did not affect 1‐year survival rates. The Cox hazard model showed no effect of massive transfusion on mortality following transplant (no‐blood, reference vs. 1–5 units; HR, 1.02 [p = 0.35], 6–10 units; HR, 1.10 [p = 0.01], massive transfusion; HR 1.04 [p = 0.3]).

Conclusions

Massive transfusion in donors was not associated with increased recipient mortality. Additionally, the amount of donor blood transfusion did not affect rejection rates following HT. The present study suggests that a history of donor blood transfusion, as well as the amount of transfusion, should not preclude donor heart utilization.
Translational findings support regimen selection for first‐in‐human study of ubamatamab (MUC16 × CD3 bispecific antibody) in patients with recurrent ovarian cancer
Authors: Zhu Min , Madia Priyanka , Crawford Alison , Brouwer‐Visser Jurriaan , Krueger Pamela , Haber Lauric , Peterman Mary , Uldrick Thomas S. , Miller Elizabeth , Davis John D. , Retter Marc W.
Published: December 2024

Ubamatamab, a Mucin 16 (MUC16) × cluster of differentiation 3 (CD3) bispecific antibody that promotes T‐cell‐mediated cytotoxicity of MUC16‐expressing cells, is being investigated for the treatment of ovarian cancer. Intravenous administration of ubamatamab, with or without the anti‐programmed cell death‐1 inhibitor cemiplimab, is being evaluated in a first‐in‐human study in patients with recurrent ovarian cancer. In vitro cytotoxicity and cytokine data and projected ubamatamab human pharmacokinetic (PK) profiles scaled with monkey PK parameters enabled starting‐dose selection in humans. Mouse tumor regression studies identified ubamatamab effective concentrations. Preclinical and clinical PK, cytokine, safety, and efficacy data from dose escalation were integrated to determine expansion regimens. A starting dose of 0.1 mg was selected, which showed acceptable safety in patients. A step‐up dosing approach was used to effectively manage cytokine release syndrome. Mouse tumor regression models suggested an ubamatamab efficacious concentration range of 0.4–50 mg/L, consistent with clinical activity observed at ubamatamab trough concentrations ≥5 mg/L. Integrating preclinical and clinical data determined a target trough concentration range of 5–30 mg/L, which supports evaluation of ubamatamab 250 mg with or without cemiplimab and 800 mg monotherapy once every 3 weeks in expansion cohorts. Preclinical data (cytokine release, tumor regression, monkey PK) had translational value in supporting regimen selection in dose escalation and subsequently in dose expansion after integration with patient data from dose escalation.
Establishment size and the task content of jobs: evidence from 46 countries
Authors: De Vera Micole , Garcia‐Brazales Javier
Published: December 2024

Using a mix of household‐ and employer‐based survey data from 46 countries, we provide novel evidence that workers in larger establishments perform more non‐routine analytical tasks, even within narrowly defined occupations. Moreover, workers in larger establishments rely more on the use of information and communication technologies to perform these tasks. We also document a 15% raw wage premium that workers in larger establishments enjoy relative to their counterparts in smaller establishments. A mediation analysis shows that our novel empirical facts on the task content of jobs are able to explain 5–20% of the establishment size wage premium, a similar fraction to what can be explained by selection of workers on education, gender and age.