Negative / Null Result ReportOpen accessPhysics
Narayan Khadka, Michal Zajaček, Swayamtrupta Panda et al. · 2022 · arXiv
We use observations of 66 reverberation-measured \Mgii\ quasars (QSOs) in the redshift range $0.36 \leq z \leq 1.686$ -- a subset of the 78 QSOs we previously studied that also have \rfe\ (flux ratio parameter of UV \Feii\ to \Mgii\ that is used as an accretion-rate proxy) measurements -- to simultaneously constrain cosmological model parameters and QSO 2-parameter and 3-parameter radius-luminosity ($R-L$) relation parameters in six different cosmological models. We find that these QSO $R-L$ relation parameters are independent of the assumed cosmological model and so these QSOs are standardiza
Negative / Null Result ReportOpen accessPhysics
Rabiah A. Rahmat, Melissa A. Humphries, Jeremy J. Austin et al. · 2020 · arXiv
Heat alters colour and crystallinity of teeth by destruction of the organic content and inducing hydroxyapatite crystal growth. The colour and crystallite changes can be quantified using spectrophotometric and x-ray diffraction analyses, however these analyses are not commonly used in combination to evaluate burned dental remains. In this study, thirty-nine teeth were incinerated at 300-1000$^\circ$C for 15 and 30 minutes and then measured using a spectrophotometer and an x-ray diffractometer. Response variables used were lightness, L$^\ast$, and chromaticity a$^\ast$ and b$^\ast$ and luminanc
Negative / Null Result ReportOpen accessPhysics
E. Forgacs-Dajka · 2006 · arXiv
We present detailed numerical calculations of the fast solar tachocline based on the assumption that the dynamo field dominates over the dynamics of the tachocline. In the present paper of the series, we focus on three shortfalls of the earlier models. First, instead of the simple oscillating dipole poloidal field we study the more general magnetic field structures reminiscent of the butterfly diagram. The migrating field is prescribed as the observed axisymmetric radial magnetic field Stenflo (1988, 1994). Our results are in good agreement with our analitical estimate and our previous works i
Negative / Null Result ReportOpen accessPhysics
M. Joyce, M. Montuori, F. Sylos Labini · 1999 · arXiv
We report our analysis of the properties of galaxy clustering for a new redshift sample of galaxies, the CfA2-South catalog, using statistical methods which do not rely on the assumption of homogeneity. We find that, up to ~ 20 Mpc/h, which is the largest scale to which correlation properties can be reliably inferred, the galaxy clustering is scale-invariant and characterized by a fractal dimension D=1.9 \pm 0.1. Further there is no statistical evidence for homogeneity at any of the larger scales (up to ~150 Mpc/h) probed more weakly by the catalog. These results means that characteristic ``co
Negative / Null Result ReportOpen accessPhysics
Vadim V. Bobylev, Maxim Yu. Khovritchev · 2006 · arXiv
Based on the Ogorodnikov-Milne model, we analyze the proper motions of Tycho-2 and UCAC2 stars. We have established that the model component that describes the rotation of all stars under consideration around the Galactic y axis differs significantly from zero at various magnitudes. We interpret this rotation found using the most distant stars as a residual rotation of the ICRS/Tycho-2 system relative to the inertial reference frame. For the most distant ($d\approx900$ pc) Tycho-2 and UCAC2 stars, the mean rotation around the Galactic y axis has been found to be $M_{13}=-0.37\pm0.04$ mas yr$^{
Negative / Null Result ReportOpen accessPhysics
K. Pradeesh, C. J. Oton, V. K. Agotiya et al. · 2007 · arXiv
A new class of Erbium doped glasses with compositions xNa2O - (60-x)PbCl2 - 40P2O5 (x=0, 10, 20 and 30) were fabricated and characterized for optical properties. Absorption spectra were analyzed for important Judd-Ofelt parameters from the integrated intensities of various Er3+ glass absorption bands. Photoluminescence (PL) and its decay behavior studies were carried out for the transition 4I13/2 -> 4I15/2. A systematic correlation between the Judd-Ofelt parameter {omega}2 and the covalent nature of the glass matrix was observed, due to increased role of bridging oxygens in the glass network.
Negative / Null Result ReportOpen accessPhysics
Dongsu Ryu, Jongsoo Kim, Seung Soo Hong et al. · 2003 · arXiv
The Parker instability, which has been considered as a process governing the structure of the interstellar medium, is induced by the buoyancy of magnetic field and cosmic rays. In previous studies, while the magnetic field has been fully incorporated in the context of isothermal magnetohydrodynamics, cosmic rays have been normally treated with the simplifying assumption of infinite diffusion along magnetic field lines but no diffusion across them. The cosmic ray diffusion is, however, finite. In this work, we take into account fully the diffusion process of cosmic rays in a linear stability an
Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Mohammad Hassan Shakil, Arne Johan Pollestad, Khine Kyaw et al. · 2025 · arXiv
With European Union initiatives mandating gender quotas on corporate boards, a key question arises: Is greater board gender diversity (BGD) associated with better emissions performance (EP)? To answer this question, we examine the influence of BGD on EP across a sample of European firms from 2016 to 2022. Using panel regressions, advanced machine learning algorithms, and explainable AI, we reveal a non-linear relationship. Specifically, EP improves with BGD up to an optimal level of approximately 35 %, beyond which further increases in BGD yield no additional improvement in EP. A minimum BGD t
Negative / Null Result ReportOpen accessComputer Science
Pappu Kumar Yadav, J. Alex Thomasson, Robert G. Hardin et al. · 2022 · arXiv
Plastic shopping bags that get carried away from the side of roads and tangled on cotton plants can end up at cotton gins if not removed before the harvest. Such bags may not only cause problem in the ginning process but might also get embodied in cotton fibers reducing its quality and marketable value. Therefore, it is required to detect, locate, and remove the bags before cotton is harvested. Manually detecting and locating these bags in cotton fields is labor intensive, time-consuming and a costly process. To solve these challenges, we present application of four variants of YOLOv5 (YOLOv5s
Negative / Null Result ReportMedicine
Özel, Efiloğlu, Cim et al. · 2026 · Neurourology and urodynamics
This study aimed to evaluate the association between gestational diabetes mellitus and urinary incontinence during pregnancy, including symptom subtype, symptom severity, and incontinence-related quality of life. This cross-sectional study…
View details →DOI: 10.1002/nau.70360 Negative / Null Result ReportMedicine
van Driel, Swartjes, Lemmens et al. · 2026 · The British journal of surgery
Colorectal cancer (CRC) incidence is rising, consequentially traditional follow-up care models are increasingly unsustainable. Patient-led, home-based follow-up (PHFU) may offer a promising alternative to reduce hospital visits while…
View details →DOI: 10.1093/bjs/znag081 Negative / Null Result ReportOpen accessPhysics
Chong Yang Du, André Guerra, Adam McElligott et al. · 2023 · arXiv
Reversible addition-fragmentation chain-transfer polymerization with a switchable chain-transfer agent was employed to synthesize amphiphilic block copolymers poly(styrene-b-vinylpyrrolidone) and poly(pentafluorostyrene-b-vinylpyrrolidone) at 10 wt.% hydrophobic content as kinetic hydrate inhibitors for methane hydrates. The dynamic viscosity of methane hydrate slurries was measured in a high-pressure rheometer up to 15 MPag. At 700 ppm of additives in aqueous media, the relative time for slurries to grow to 200 mPa s was 2.2-2.4 times longer than water reference values for the block copolymer
Negative / Null Result ReportOpen accessPhysics
Linda Qerimi, Sarah Malone, Eva Rexigel et al. · 2025 · arXiv
Visual-graphical qubit representations offer a means to introduce abstract quantum concepts - such as quantum state, superposition, or measurement - in an accessible manner, particularly for learners with low prior knowledge. Building on a previous expert rating of mechanisms of qubit representations, this study compared two representations - Bloch sphere and Quantum Bead - in terms of learning outcomes, task performance, cognitive load, and mid-term retention. The study was conducted with N=149 school students. The study assessed conceptual understanding, application-oriented task performance
Negative / Null Result ReportOpen accessComputer Science
Jun-Shuai Wang, Chang Liu, Ju Chen et al. · 2025 · arXiv
In this work, we systematically investigate the capability of space-based gravitational wave detectors in constraining parameters of non-tensor polarization modes. Using Bayesian inference and Fisher Information Matrix methods, we analyze gravitational wave signals from the inspiral phase of supermassive binary black hole mergers. By starting with time-domain signals and applying Fourier transforms, we avoid the use of the stationary phase approximation. We found an asymmetry in the estimation of the vector-mode parameter $α_x$ at inclination angles $ι= 0$ and $ι= π$, which has not been explic
Negative / Null Result ReportOpen accessComputer Science
Jingchao Fang, Victoria Xiaohan Wen, Mina Lee · 2026 · arXiv
The growing capability of artificial intelligence (AI) leads to its increasing adoption in writing, spurring discussions around whether writers should disclose their AI use in writing. What influences the perceived necessity of disclosure? We look into this question from three dimensions: perspective (reader or writer of the text), purpose (the goal of reading or writing), and procedural factors (how AI was used in the writing process in terms of replaceability, effortfulness, intentionality, and directness). In a vignette study (N = 727), we find that readers consider disclosure to be more ne
Negative / Null Result ReportOpen accessPhysics
A. Mainzer, J. Bauer, R. M. Cutri et al. · 2014 · arXiv
NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft has been brought out of hibernation and has resumed surveying the sky at 3.4 and 4.6 um. The scientific objectives of the NEOWISE reactivation mission are to detect, track, and characterize near-Earth asteroids and comets. The search for minor planets resumed on December 23, 2013, and the first new near-Earth object (NEO) was discovered six days later. As an infrared survey, NEOWISE detects asteroids based on their thermal emission and is equally sensitive to high and low albedo objects; consequently, NEOWISE-discovered NEOs tend to
Negative / Null Result ReportOpen accessMathematics
H. Sherry Zhang, Dianne Cook, Nicolas Langrené et al. · 2024 · arXiv
The projection pursuit (PP) guided tour optimizes a criterion function, known as the PP index, to gradually reveal projections of interest from high-dimensional data through animation. Optimization of some PP indexes can be non-trivial, if they are non-smooth functions, or when the optimum has a small "squint angle", detectable only from close proximity. Here, measures for calculating the smoothness and squintability properties of the PP index are defined. These are used to investigate the performance of a recently introduced swarm-based algorithm, Jellyfish Search Optimizer (JSO), for optimiz
Negative / Null Result ReportOpen accessComputer Science
Wenqing Zhang, Trang Nguyen, Elizabeth A. Stuart et al. · 2025 · arXiv
Systematic reviews are crucial for synthesizing scientific evidence but remain labor-intensive, especially when extracting detailed methodological information. Large language models (LLMs) offer potential for automating methodological assessments, promising to transform evidence synthesis. Here, using causal mediation analysis as a representative methodological domain, we benchmarked state-of-the-art LLMs against expert human reviewers across 180 full-text scientific articles. Model performance closely correlated with human judgments (accuracy correlation 0.71; F1 correlation 0.97), achieving
Negative / Null Result ReportMedicine
Ni, Adams, Momenaei et al. · 2026 · Ophthalmology. Retina
To assess the effect of prophylactic treatment of lattice degeneration on retinal break and rhegmatogenous retinal detachment (RRD) risk in fellow eyes of patients with bilateral lattice degeneration treated for retinal break(s) without RD…
View details →DOI: 10.1016/j.oret.2026.06.016 Negative / Null Result ReportOpen accessComputer Science
Mohammed Alsobay, David M. Rothschild, Jake M. Hofman et al. · 2025 · arXiv
Group decision-making often suffers from uneven information sharing, hindering decision quality. While large language models (LLMs) have been widely studied as aids for individuals, their potential to support groups of users, potentially as facilitators, is relatively underexplored. We present a pre-registered randomized experiment with 1,475 participants assigned to 281 five-person groups completing a hidden profile task--selecting an optimal city for a hypothetical sporting event--under one of four facilitation conditions: no facilitation, a one-time message prompting information sharing, a
Negative / Null Result ReportOpen accessPhysics
Leonard Göke, Mario Kendziorski, Claudia Kemfert et al. · 2021 · arXiv
The current governance process to plan the German energy system omits two options to substitute grid expansion: First, placing renewables closer to demand instead of where site conditions are best. Second, utilizing storage instead of additional transmission infrastructure to prevent grid congestion. In the paper, we apply a comprehensive capacity expansion model based on the AnyMOD modelling framework to compare the status quo to alternative planning approaches for a fully renewable energy system. To represent spatiality and fluctuations of renewables, the German electricity sector is modelle
Negative / Null Result ReportOpen accessMathematics
Birgul Koc, Muhammad Mohebujjaman, Changhong Mou et al. · 2018 · arXiv
For reduced order models (ROMs) of fluid flows, we investigate theoretically and computationally whether differentiation and ROM spatial filtering commute, i.e., whether the commutation error (CE) is nonzero. We study the CE for the Laplacian and two ROM filters: the ROM projection and the ROM differential filter. Furthermore, when the CE is nonzero, we investigate whether it has any significant effect on ROMs that are constructed by using spatial filtering. As numerical tests, we use the Burgers equation with viscosities $ν=10^{-1}$ and $ν=10^{-3}$ and a 2D flow past a circular cylinder at Re
Negative / Null Result ReportOpen accessComputer Science
Xinyi Liu, Weiguang Wang, Hangfeng He · 2025 · arXiv
With the growing adoption of Large Language Models (LLMs) for open-ended tasks, accurately assessing epistemic uncertainty, which reflects a model's lack of knowledge, has become crucial to ensuring reliable outcomes. However, quantifying epistemic uncertainty in such tasks is challenging due to the presence of aleatoric uncertainty, which arises from multiple valid answers. While bias can introduce noise into epistemic uncertainty estimation, it may also reduce noise from aleatoric uncertainty. To investigate this trade-off, we conduct experiments on Visual Question Answering (VQA) tasks and
Negative / Null Result ReportOpen accessComputer Science
Lennart Meincke, Ethan Mollick, Lilach Mollick et al. · 2025 · arXiv
This is the third in a series of short reports that seek to help business, education, and policy leaders understand the technical details of working with AI through rigorous testing. In this report, we investigate two commonly held prompting beliefs: a) offering to tip the AI model and b) threatening the AI model. Tipping was a commonly shared tactic for improving AI performance and threats have been endorsed by Google Founder Sergey Brin (All-In, May 2025, 8:20) who observed that 'models tend to do better if you threaten them,' a claim we subject to empirical testing here. We evaluate model p
Negative / Null Result ReportOpen accessComputer Science
Danai Korre · 2023 · arXiv
Embodied conversational agents (ECAs) are paradigms of conversational user interfaces in the form of embodied characters. While ECAs offer various manipulable features, this paper focuses on a study conducted to explore two distinct levels of presentation realism. The two agent versions are photorealistic and animated. The study aims to provide insights and design suggestions for speech-enabled ECAs within serious game environments. A within-subjects, two-by-two factorial design was employed for this research with a cohort of 36 participants balanced for gender. The results showed that both th
Negative / Null Result ReportOpen accessPhysics
Ludovic Huguet, Victor Lherm, Renaud Deguen et al. · 2025 · arXiv
Turbulent thermals emerge in a wide variety of geophysical and industrial flows, such as atmospheric cumulus convection and pollutant dispersal in oceans and lakes. When a buoyant fluid mass rises, or sinks, heat and mass transfers occur by the engulfment of the fresh surrounding fluid inside the thermal - a process that spans over multiple scales from macroscopic entrainment of ambient fluid to microscopic diffusive processes. Turbulent thermals are typically investigated through their integral properties (radius, depth, entrainment rate). However, mixing processes depend on the internal dist
Negative / Null Result ReportOpen accessPhysics
Ozgur Akarsu, Suresh Kumar, Shivani Sharma et al. · 2019 · arXiv
We consider the simplest anisotropic generalization, as a correction, to the standard $Λ$CDM model, by replacing the spatially flat Robertson-Walker metric by the Bianchi type-I metric, which brings in a new term $Ω_{σ0}a^{-6}$ (mimicking the stiff fluid) in the average expansion rate $H(a)$ of the Universe. From Hubble and Pantheon data, relevant to the late Universe ($z\lesssim 2.4$), we obtain the constraint $Ω_{\sigma0}\lesssim10^{-3}$, in line with the model-independent constraints. When the baryonic acoustic oscillations and cosmic microwave background (CMB) data are included, the constr
Negative / Null Result ReportOpen accessComputer Science
Arif Ahmed, Gondy Leroy, Agrim Sachdeva et al. · 2026 · arXiv
Background: Generative artificial intelligence (GenAI) is increasingly used for health information, yet its influence on users' trust calibration remains unclear. Objective: This study examines whether learned dependency on GenAI influences trust in AI-generated health information and whether text highlighting reduces overreliance on incorrect outputs. Methods: Two randomized controlled experiments were conducted with 338 college students and 563 Amazon Mechanical Turk participants. Both experiments used a 2 by 2 between-subjects design manipulating information accuracy (correct versus incorre
Negative / Null Result ReportOpen accessPhysics
Sina Feldmann, Juliane Adrian, Maik Boltes · 2025 · arXiv
Impulse propagation in crowds is a phenomenon that is crucial for understanding collective dynamics, but has been scarcely addressed so far. Therefore, we have carried out experiments in which persons standing in a crowd are pushed forward in a controlled manner. Variations of experimental parameters include (i) the intensity of the push, (ii) the initial inter-person distance, (iii) the preparedness of participants and (iv) the crowd formation. Our analysis links the intensity of an impulse recorded by a pressure sensor with individual movements of participants based on head trajectories reco
Negative / Null Result ReportOpen accessEngineering
Yanyu Cheng, Chongjun Ouyang, Yuanwei Liu et al. · 2025 · arXiv
This paper conducts a comprehensive performance analysis for pinching-antenna systems (PASS) under both orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) transmission. Given the cost of waveguides, we consider a scenario where the waveguide is not deployed in all rooms, i.e., some users are beyond the line-of-sight (LoS) link service area of the PASS. Specifically, we consider a PASS where a pinching antenna in one room serves two users located in separate rooms. The wireless transmissions between the pinching antenna and the users are performed via LoS and non-line-of
