Negative / Null Result ReportOpen accessComputer Science
N. Metwally, M. Abdel-Aty, M. Sebawe Abdalla · 2008 · arXiv
The speed of quantum computation is investigated through the time evolution of the speed of the orthogonality. The external field components for classical treatment beside the detuning and the coupling parameters for quantum treatment play important roles on the computational speed. It has been shown that the number of photons has no significant effect on the speed of computation. However, it is very sensitive to the variation in both detuning and the interaction coupling parameters.
Negative / Null Result ReportOpen accessPhysics
M. A. G. Maia, C. N. A. Willmer, L. N. da Costa · 1997 · arXiv
We examine the H1 content of spiral galaxies in groups by using a catalog of loose groups of galaxies identified in a magnitude limited sample m < 15.7 spanning the range 8 h to 18 h in right ascension and +9 to +15 in declination. The redshift completeness of the galaxy sample is ~95%. No significant effect of H1 depletion is found, although there may be a hint that the earliest type spirals are slightly deficient.
Negative / Null Result ReportOpen accessEngineering
Nina R Benway, Jonathan L Preston, Asif Salekin et al. · 2023 · arXiv
Mispronunciation detection tools could increase treatment access for speech sound disorders impacting, e.g., /r/. We show age-and-sex normalized formant estimation outperforms cepstral representation for detection of fully rhotic vs. derhotic /r/ in the PERCEPT-R Corpus. Gated recurrent neural networks trained on this feature set achieve a mean test participant-specific F1-score =.81 (σx=.10, med = .83, n = 48), with post hoc modeling showing no significant effect of child age or sex.
Negative / Null Result ReportOpen accessPhysics
P. B. Jones · 2008 · arXiv
Calculations have been made of fall-back disk heating by the pulsar wind as distinct from the soft X-rays emitted by the neutron-star surface. The relation between these heating rates and measured near-infrared fluxes in the K and Ks bands places severe constraints on the inner radii of any fall-back disks that may be present in radio pulsars and in some anomalous X-ray pulsars. The lower limits found are so large that the disks concerned can have no significant effect on pulsar spin-down.
Negative / Null Result ReportOpen accessPhysics
Cristina Bena, Leon Balents · 2001 · arXiv
We study the effect of electron-electron backscattering interactions on spin transport in a quantum wire. Even if these interactions have no significant effect on charge transport, they strongly influence the transport of spin. We use the quantum Boltzmann equation in the collision approximation to derive equations of motion for spin current and magnetization. In the limit of small perturbations from equilibrium, we explain the existence of `precessional' and `diffusive' behaviors. We also discuss the low-temperature non-linear decay of an uniform spin current outside the hydrodynamic regime.
Negative / Null Result ReportOpen accessComputer Science
Tsutomu Kobayashi · 2006 · arXiv
We study the spectrum of gravitational waves generated from inflation in the Randall-Sundrum braneworld. Since the inflationary gravitational waves are of quantum-mechanical origin, the initial configuration of perturbations in the bulk includes Kaluza-Klein quantum fluctuations as well as fluctuations in the zero mode. We show, however, that the initial fluctuations in Kaluza-Klein modes have no significant effect on the late time spectrum, irrespective of the energy scale of inflation and the equation of state parameter in the post-inflationary stage. This is done numerically, using the Wron
Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Claudiu Albulescu · 2020 · arXiv
This paper investigates the effect of the novel coronavirus and crude oil prices on the United States (US) economic policy uncertainty (EPU). Using daily data for the period January 21-March 13, 2020, our Autoregressive Distributed Lag (ARDL) model shows that the new infection cases reported at global level, and the death ratio, have no significant effect on the US EPU, whereas the oil price negative dynamics leads to increased uncertainty. However, analyzing the situation outside China, we discover that both new case announcements and the COVID-19 associated death ratio have a positive influe
Negative / Null Result ReportOpen accessPhysics
Takashi Hamana · 1998 · arXiv
Weyl focusing effects on the image magnifications are investigated by using the multiple gravitational lens theory. We focus on the gravitational lensing effects due to the small scale virialized objects, such as galaxies and clusters of galaxies. We consider a simple model of an inhomogeneous universe. The matter distribution in the universe is modeled by randomly distributed isothermal objects. We found that, for the majority of the random lines of sight, the Weyl focusing has no significant effect and the image magnification of a point like source within redshift of 5 is dominated by the Ri
Negative / Null Result ReportOpen accessPhysics
Sarbani Basu, H. M. Antia · 2004 · arXiv
Recent analyses of solar photospheric abundances suggest that the oxygen abundance in the solar atmosphere needs to be revised downwards. In this study we investigate the consequence of this revision on helioseismic analyses of the depth of the solar convection zone and the helium abundance in the solar envelope and find no significant effect. We also find that the revised abundances along with the current OPAL opacity tables are not consistent with seismic data. A significant upward revision of the opacity tables is required to make solar models with lower oxygen abundance consistent with sei
Negative / Null Result ReportOpen accessComputer Science
Thomas M. Breuel · 2015 · arXiv
LSTM (Long Short-Term Memory) recurrent neural networks have been highly successful in a number of application areas. This technical report describes the use of the MNIST and UW3 databases for benchmarking LSTM networks and explores the effect of different architectural and hyperparameter choices on performance. Significant findings include: (1) LSTM performance depends smoothly on learning rates, (2) batching and momentum has no significant effect on performance, (3) softmax training outperforms least square training, (4) peephole units are not useful, (5) the standard non-linearities (tanh a
Negative / Null Result ReportMedicine
Makkar RR, Chakravarty T, Gupta A et al. · 2025 · Journal of the American College of Cardiology
Background In the ACURATE IDE (Safety and Effectiveness Study of ACURATE Valve for Transcatheter Aortic Valve Replacement) randomized controlled trial, ACURATE neo2 failed to show noninferiority to commercially available balloon-expandable…
View details →DOI: 10.1016/j.jacc.2025.05.011 Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
S. Meghna, N. Suresh, J. C. Usha · 2022 · arXiv
This study examines the impact of dividend policy on the performance of initial public offerings in India. The period of study is from the year 2011-2014. Monthly returns of the IPOs issued in the considered period and the Indian Stock Market Index (Nifty 50) were considered for the long-run performance study. The methodological tools used are long-run performance statistics and the GARCH model. The Dummy variable was used to measure the effect of dividends on the IPOs. The study reveals that the dividend policy has no significant effect on the stock prices of IPO.
Negative / Null Result ReportOpen accessPhysics
Patryk Mach · 2004 · arXiv
An analysis of the propagation of non stationary waves in the adiabatic region of stellar interior is presented. An equation of motion with an effective potential is derived, similar to the Zerilli equation known in the propagation of gravitational waves. The Huyghens principle is violated in this case and the energy diffusion outward null cones is expected. Numerical calculations demonstrate that the diffusion is weak for the case of standard Solar model; thus no significant effect corresponding to quasinormal modes can be expected. The likely reason for the absence of stronger features is th
Negative / Null Result ReportOpen accessPhysics
G. Rosenberg, H. -M. Guo, M. Franz · 2010 · arXiv
An infinitely thin solenoid carrying magnetic flux Phi (a `Dirac string') inserted into an ordinary band insulator has no significant effect on the spectrum of electrons. In a strong topological insulator, remarkably, such a solenoid carries protected gapless one-dimensional fermionic modes when Phi=hc/2e. These modes are spin-filtered and represent a distinct bulk manifestation of the topologically non-trivial insulator. We establish this `wormhole' effect by both general qualitative considerations and by numerical calculations within a minimal lattice model. We also discuss the possibility o
Negative / Null Result ReportOpen accessComputer Science
M. U. Ashraf, Junaid Tariq, A. M. Khan · 2022 · arXiv
We report the transverse momentum $p_T$ spectra of identified hadrons ($π^\pm$, $K^\pm$ and $p(\bar p)$) in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7 - 39 GeV from A Multi Phase Transport Model with string melting effect (AMPT-SM). During this study, a new set of parameters are explored to study the effect of hadronic cascade by varying hadronic cascade time $t_{max}$ = 30 $f$m/$c$ and 0.4 $f$m/$c$. No significant effect of this change is observed in the $p_T$ spectra of light hadrons and the AMPT-SM model reasonably reproduces the experimental data. To investigate the kinetic freeze-out prope
Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Ruiwu Liu · 2021 · arXiv
Acemoglu and Johnson (2007) put forward the unprecedented view that health improvement has no significant effect on income growth. To arrive at this conclusion, they constructed predicted mortality as an instrumental variable based on the WHO international disease interventions to analyse this problem. I replicate the process of their research and eliminate some biases in their estimate. In addition, and more importantly, we argue that the construction of their instrumental variable contains a violation of the exclusion restriction of their instrumental variable. This negative correlation betw
Negative / Null Result ReportOpen accessComputer Science
Chathura Rajapakse, Wathsala Ariyarathna, Shanmugalingam Selvakan · 2024 · arXiv
This study investigates Sri Lankan ICT teachers' readiness to teach AI in schools, focusing on self-efficacy. A survey of over 1,300 teachers assessed their self-efficacy using a scale developed based on Bandura's theory. PLS-SEM analysis revealed that teachers' self-efficacy was low, primarily influenced by emotional and physiological states and imaginary experiences related to AI instruction. Mastery experiences had a lesser impact, and vicarious experiences and verbal persuasion showed no significant effect. The study highlights the need for a systemic approach to teacher professional devel
Negative / Null Result ReportOpen accessComputer Science
Muon g-2 Collaboration, :, G. W. Bennett · 2007 · arXiv
The spin precession frequency of muons stored in the $(g-2)$ storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for: a nonzero $Δω_{a}$ (=$ω_{a}^{μ^{+}}-ω_{a}^{μ^{-}}$); and a sidereal variation of $ω_{a}^{μ^{\pm}}$. No significant effect is found, and the following limits on the standard-model extension parameters are obtained: $b_{Z} =-(1.0 \pm 1.1)\times 10^{-23}$ GeV; $(m_μd_{Z0}+H_{XY}) = (1.8 \pm 6.0 \times 10^{-23})$ GeV; and the 95% confidence level limits $\check{b}_{\perp}^{μ^{+}}< 1.4 \times 10^{-24}$ GeV
Negative / Null Result Report
Cui L, Harrison L, Liu J · 2022 · Preprint
Many studies have failed to replicate the disfluency effect (i.e. disfluent font better than fluent font) on Cognitive Reflection Test (CRT) performance shown in Alter et al. (2007). Those studies manipulated perceptual disfluency using…
View details →DOI: 10.31234/osf.io/qdxw3 Negative / Null Result ReportOpen accessPhysics
Saloome Siavoshi, Ashish V. Orpe, Arshad Kudrolli · 2005 · arXiv
We investigate the effective friction encountered by a mass sliding on a granular layer as a function of bed thickness and boundary roughness conditions. The observed friction has minima for a small number of layers before it increases and saturates to a value which depends on the roughness of the sliding surface. We use an index-matched interstitial liquid to probe the internal motion of the grains with fluorescence imaging in a regime where the liquid has no significant effect on the measured friction. The shear profiles obtained as a function of depth show decrease in slip near the sliding
Negative / Null Result ReportOpen accessComputer Science
Amjad Ashoorioon, Mohammad Bagher Jahani Poshteh, Robert B. Mann · 2022 · arXiv
Accelerating supermassive black holes, connected to cosmic strings, could contribute to structure formation and get captured by galaxies if their velocities are small. This would mean that the acceleration of these black holes is small too. Such a slow acceleration has no significant effect on the shadow of such supermassive black holes. We also show that, for slowly accelerating black holes, the angular position of images in the gravitational lensing effects do not change significantly. We propose a method to observe the acceleration of these black holes through the gravitational lensing. The
Negative / Null Result ReportOpen accessPhysics
K. Langanke, G. Martinez-Pinedo, B. Mueller et al. · 2007 · arXiv
Based on the shell model for Gamow-Teller and the Random Phase Approximation for forbidden transitions, we have calculated reaction rates for inelastic neutrino-nucleus scattering (INNS) under supernova (SN) conditions, assuming a matter composition given by Nuclear Statistical Equilibrium. The rates have been incorporated into state-of-the-art stellar core-collapse simulations with detailed energy-dependent neutrino transport. While no significant effect on the SN dynamics is observed, INNS increases the neutrino opacities noticeably and strongly reduces the high-energy tail of the neutrino s
Negative / Null Result ReportOpen accessComputer Science
Samir D. Mathur · 2019 · arXiv
The vacuum must contain virtual fluctuations of black hole microstates for each mass $M$. We observe that the expected suppression for $M\gg m_p$ is counteracted by the large number $Exp[S_{bek}]$ of such states. From string theory we learn that these microstates are extended objects that are resistant to compression. We argue that recognizing this `virtual extended compression-resistant' component of the gravitational vacuum is crucial for understanding gravitational physics. Remarkably, such virtual excitations have no significant effect for observable systems like stars, but they resolve tw
Negative / Null Result ReportOpen accessPhysics
L. S. R. Cavalcante, D. R. da Costa, G. A. Farias et al. · 2021 · arXiv
The effect of an external in-plane electric field on neutral and charged exciton states in two-dimensional (2D) materials is theoretically investigated. These states are argued to be strongly bound, so that electron-hole dissociation is not observed up to high electric field intensities. Trions in the anisotropic case of monolayer phosphorene are demonstrated to especially robust under electric fields, so that fields as high as 100 kV/cm yield no significant effect on the trion binding energy or probability density distribution. Polarizabilities of excitons are obtained from the parabolicity o
Negative / Null Result ReportOpen accessMedicine
Yang W, Li Z, Chen X et al. · 2026 · Clinics (Sao Paulo, Brazil)
Background Diet plays a key role in regulating the gut microbiota. This study aimed to investigate the association between the Dietary Index of the Gut Microbiome (DI-GM) ‒ a score designed to reflect the potential of a diet to support a…
View details →DOI: 10.1016/j.clinsp.2026.100995 Negative / Null Result ReportOpen access
Hamilton F, Mitchell R, Constantinescu A et al. · 2022 · Preprint
Introduction Severe malaria remains a deadly disease for many young children in low- and middle-income countries. Levels of Interleukin-6 (IL-6) have been shown to identify cases of severe malaria and associate with severity, but it is…
View details →DOI: 10.1101/2022.11.04.22281934 Negative / Null Result ReportOpen accessMedicine
Rajaraman R, Kassaye I, Sharma SS et al. · 2026 · Antimicrobial agents and chemotherapy
The aim of this study was to determine the antiamoebic efficacy of povidone-iodine when used as an adjunct to topical biguanide therapy for Acanthamoeba keratitis. Patients with smear- or culture-positive Acanthamoeba keratitis received…
View details →DOI: 10.1128/aac.01512-25 Negative / Null Result Report
Makin AD, Rahman A, Bertamini M · 2020 · Preprint
Previous work has shown that symmetrical or regular stimuli are judged as lasting longer than asymmetrical or irregular ones, even when actual duration is matched. This effect has been replicated with different methods and stimuli types,…
View details →DOI: 10.1101/2020.08.20.258871 Negative / Null Result ReportOpen accessMedicine
Pinto R, Ferreira R, Alves P et al. · 2025 · Healthcare (Basel, Switzerland)
Background : Healthcare-associated infection drives morbidity and unplanned hospital use in haemodialysis. We aimed to determine whether an adapted British Renal Society Infection Risk Screening Tool, applied during a nurse-led vascular…
View details →DOI: 10.3390/healthcare13233058 Negative / Null Result ReportOpen accessMedicine
Andrade G, Gamboa L, Campo-Redondo M · 2026 · Frontiers in psychology
Background Beliefs about free will are central to philosophical and scientific conceptions of agency, and experimental work suggests that weakening such beliefs can reduce honesty, self-control, and helping. Yet little is known about how…
View details →DOI: 10.3389/fpsyg.2026.1748028 