Negative / Null Result ReportOpen access
Akerley, Wallace, Herndon, James E. 2nd, Vokes, Everett E. et al. · 2017
BACKGROUND: In Cancer and Leukemia Group B 39801, we evaluated whether induction chemotherapy before concurrent chemoradiotherapy would result in improved survival and demonstrated no significant benefit from the addition of induction…
View details →DOI: 10.1097/jto.0b013e3181b27b33. Negative / Null Result ReportOpen access
Akerley, Wallace, Vokes, Everett E., Cicchetti, M Giulia et al. · 2009
BackgroundIn Cancer and Leukemia Group B 39801, we evaluated whether induction chemotherapy before concurrent chemoradiotherapy would result in improved survival and demonstrated no significant benefit from the addition of induction…
View details →DOI: 10.1097/jto.0b013e3181b27b33 Negative / Null Result ReportOpen access
Macleod, Malcolm R.; id_orcid, Donnan, Geoffrey A., Traystman, RJ et al. · 2009
Background and Purpose—As a research community, we have failed to demonstrate that drugs which show substantial efficacy in animal models of cerebral ischemia can also improve outcome in human stroke. Summary of Review—Accumulating…
View details →DOI: 10.1038/jcbfm.2008.101 Negative / Null Result ReportOpen access
Marc Fisher, Ulrich Dirnagl, Geoffrey A Donnan et al. · 2020
Background and Purpose-As a research community, we have failed to demonstrate that drugs which show substantial efficacy in animal models of cerebral ischemia can also improve outcome in human stroke. Summary of Review-Accumulating…
Negative / Null Result ReportOpen access
Claire L. Gibson (6162488), Philip M. Bath (3111867) · 2015
Two multi-centre phase III clinical trials examining the protective potential of progesterone following traumatic brain injury have recently failed to demonstrate any improvement in outcome. Thus, it is timely to consider how this impacts…
Negative / Null Result ReportOpen access
Claire L. Gibson (6162488), Philip M. Bath (3111867) · 2015
Two multi-centre phase III clinical trials examining the protective potential of progesterone following traumatic brain injury have recently failed to demonstrate any improvement in outcome. Thus, it is timely to consider how this impacts…
Negative / Null Result ReportOpen access
N. Stocchetti · 2014
Aggressive therapy after traumatic brain injury, for instance surgical decompression of the skull, is effective in reducing intracranial pressure. However in a randomized trial it has failed to improve outcome. Careful identification of…
Negative / Null Result ReportOpen access
Dr. Abu Elias Sarker, Dr. Mohammad Habibur Rahman · 2014
In spite of different approaches being experimented over the past six decades, poverty alleviation programs in the developing world have largely failed to improve poverty situation. Of all the factors responsible for the growing trend of…
Negative / Null Result ReportOpen access
Sharafuddin, Melhem, Katz, Daniel, Reddy, Geeta et al. · 2005
Monthly access flow monitoring with increased prophylactic angioplasty did not improve fistula patency.BackgroundRegular access monitoring is recommended to detect and treat access stenosis in order to prevent access thrombosis and…
View details →DOI: 10.1111/j.1523-1755.2005.00697.x Negative / Null Result ReportOpen accessEngineering
Amritanshu Pandey, Marko Jereminov, Gabriela Hug et al. · 2017 · arXiv
Recent advances in power system simulation have included the use of complex rectangular current and voltage (I-V) variables for solving the power flow and three-phase power flow problems. This formulation has demonstrated superior convergence properties over conventional polar coordinate based formulations for three-phase power flow, but has failed to replicate the same advantages for power flow in general due to convergence issues with systems containing PV buses. In this paper, we demonstrate how circuit simulation techniques can provide robust convergence for any complex I-V formulation tha
Negative / Null Result ReportOpen accessComputer Science
James Kirby, Ioana Krehan, Michele Gubian · 2026 · arXiv
This study examines the extent to which the wav2vec2.0 architecture exhibits evidence of compensation for phonological context. We conducted a pseudo-replication of a perceptional compensation experiment on Mandarin Chinese tones, and compared the embedding similarities and probing classifier outputs between a purely self-supervised pre-trained model and a model fine-tuned for Mandarin ASR. No evidence of compensation was found in the embedding similarities of the purely pre-trained model. Probing classifiers showed some evidence of compensation in addition to the expected layer-wise improveme
Negative / Null Result ReportOpen accessComputer Science
Jaroslaw Kornowicz · 2024 · arXiv
This study empirically examines the "Evaluative AI" framework, which aims to enhance the decision-making process for AI users by transitioning from a recommendation-based approach to a hypothesis-driven one. Rather than offering direct recommendations, this framework presents users pro and con evidence for hypotheses to support more informed decisions. However, findings from the current behavioral experiment reveal no significant improvement in decision-making performance and limited user engagement with the evidence provided, resulting in cognitive processes similar to those observed in tradi
Negative / Null Result ReportOpen accessPhysics
Agnès Ferté, Kevin Hong · 2023 · arXiv
We highlight the role of weak lensing measurements from current and upcoming stage-IV imaging surveys in the search for cosmic inflation, specifically in measuring the scalar spectral index $n_s$. To do so, we combine the Dark Energy Survey 3 years of observation weak lensing and clustering data with BICEP/Keck, Planck and Sloan Digital Sky Survey data in $rΛ$CDM where $r$ is the tensor-to-scalar ratio. While there is no significant improvement in constraining power, we obtain a 1$σ$ shift on $n_s$. Additionally, we forecast a weak lensing and clustering data vector from the 10-year Legacy Sur
Negative / Null Result ReportOpen accessComputer Science
Karam Ahmed, Sherif Abuelenin, Heba Soliman et al. · 2015 · arXiv
V-BLAST detection method suffers large computational complexity due to its successive detection of symbols. In this paper, we propose a modified V-BLAST algorithm to decrease the computational complexity by reducing the number of detection iterations required in MIMO communication systems. We begin by showing the existence of a maximum number of iterations, beyond which, no significant improvement is obtained. We establish a criterion for the number of maximum effective iterations. We propose a modified algorithm that uses the measured SNR to dynamically set the number of iterations to achieve
Negative / Null Result ReportOpen accessComputer Science
Alp Atici · 2003 · arXiv
It is an established fact that for many of the interesting problems quantum algorithms based on queries of the standard oracle bring no significant improvement in comparison to known classical algorithms. It is conceivable that there are other oracles of algorithmic importance acting in a less intuitive fashion to which such limitations do not apply. Thus motivated this article suggests a broader understanding towards what a general quantum oracle is. We propose a general definition of a quantum oracle and give a classification of quantum oracles based on the behavior of the eigenvalues and ei
Negative / Null Result ReportOpen accessComputer Science
James Large, Paul Southam, Anthony Bagnall · 2018 · arXiv
tl;dr: no, it cannot, at least not on average on the standard archive problems. We assess whether using six smoothing algorithms (moving average, exponential smoothing, Gaussian filter, Savitzky-Golay filter, Fourier approximation and a recursive median sieve) could be automatically applied to time series classification problems as a preprocessing step to improve the performance of three benchmark classifiers (1-Nearest Neighbour with Euclidean and Dynamic Time Warping distances, and Rotation Forest). We found no significant improvement over unsmoothed data even when we set the smoothing param
Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Dimitrios Exadaktylos, Massimo Riccaboni, Armando Rungi · 2020 · arXiv
In this paper, we test the contribution of foreign management on firms' competitiveness. We use a novel dataset on the careers of 165,084 managers employed by 13,106 companies in the United Kingdom in the period 2009-2017. We find that domestic manufacturing firms become, on average, between 7% and 12% more productive after hiring the first foreign managers, whereas foreign-owned firms register no significant improvement. In particular, we test that previous industry-specific experience is the primary driver of productivity gains in domestic firms (15.6%), in a way that allows the latter to ca
Negative / Null Result ReportOpen accessPhysics
F. M. Brunbauer, R. Aleksan, Y. Angelis et al. · 2026 · arXiv
The combination of a Cherenkov radiator with a semi-transparent photocathode and a Micromegas based amplification stage allows PICOSEC Micromegas detectors to achieve a time resolution of better than 15ps. While tileable prototypes with 10x10 channels feature 1x1 cm^2 readout pads, finer readout granularity can be used to improve the spatial resolution. We report on the study of high readout granularity PICOSEC Micromegas prototypes which achieve around 0.5mm spatial resolution with 3.5mm large pads. No significant improvement was found when readout pad size was further reduced to 2.2mm. The t
Negative / Null Result ReportOpen accessComputer Science
Hao Guo, Han Wang, Di Zhu et al. · 2025 · arXiv
Modeling spatial heterogeneity in the data generation process is essential for understanding and predicting geographical phenomena. Despite their prevalence in geospatial tasks, neural network models usually assume spatial stationarity, which could limit their performance in the presence of spatial process heterogeneity. By allowing model parameters to vary over space, several approaches have been proposed to incorporate spatial heterogeneity into neural networks. However, current geographically weighting approaches are ineffective on graph neural networks, yielding no significant improvement
Negative / Null Result ReportOpen accessPhysics
Filip K. Malinowski, Frederico Martins, Peter D. Nissen et al. · 2017 · arXiv
We operate a resonant exchange qubit in a highly symmetric triple-dot configuration using IQ-modulated RF pulses. At the resulting three-dimensional sweet spot the qubit splitting is an order of magnitude less sensitive to all relevant control voltages, compared to the conventional operating point, but we observe no significant improvement in the quality of Rabi oscillations. For weak driving this is consistent with Overhauser field fluctuations modulating the qubit splitting. For strong driving we infer that effective voltage noise modulates the coupling strength between RF drive and the qubi
Negative / Null Result ReportOpen accessPhysics
Guoliang Shang, Lukas Maiwald, Hagen Renner et al. · 2018 · arXiv
Non-iridescent structural colors based on disordered arrangement of monodisperse spherical particles, also called photonic glass, show low color saturation due to gradual transition in reflectivity. No significant improvement is usually expected from particles optimization, as the Mie resonances are broad for small dielectric particles with moderate refractive index. Moreover, the short range order of a photonic glass alone is also insufficient to cause sharp spectral features. We show here, that the combination of a well-chosen particle geometry with the short range order of a photonic glass
Negative / Null Result ReportOpen accessComputer Science
Hoyeon Chang, Jinho Park, Seonghyeon Ye et al. · 2024 · arXiv
Despite the recent observation that large language models (LLMs) can store substantial factual knowledge, there is a limited understanding of the mechanisms of how they acquire factual knowledge through pretraining. This work addresses this gap by studying how LLMs acquire factual knowledge during pretraining. The findings reveal several important insights into the dynamics of factual knowledge acquisition during pretraining. First, counterintuitively, we observe that pretraining on more data shows no significant improvement in the model's capability to acquire and maintain factual knowledge.
Negative / Null Result ReportOpen accessEngineering
Junwei Yang, Xiao-Xin Li, Feihong Liu et al. · 2021 · arXiv
Recent studies on T1-assisted MRI reconstruction for under-sampled images of other modalities have demonstrated the potential of further accelerating MRI acquisition of other modalities. Most of the state-of-the-art approaches have achieved improvement through the development of network architectures for fixed under-sampling patterns, without fully exploiting the complementary information between modalities. Although existing under-sampling pattern learning algorithms can be simply modified to allow the fully-sampled T1-weighted MR image to assist the pattern learning, no significant improveme
Negative / Null Result Report
· 2022 · The Brown University Psychopharmacology Update
Eight infusions of ketamine administered over 4 weeks did not significantly improve symptoms of post‐traumatic stress disorder (PTSD) in a group of veterans and active‐duty military who had failed on prior antidepressant treatment, a…
View details →DOI: 10.1002/pu.30864 Negative / Null Result ReportOpen accessComputer Science
Ivan Silajev, Niels Victor, Phillip Mortimer · 2022 · arXiv
This paper presents an application of the LayoutLMv3 model for semantic table detection on financial documents from the IIIT-AR-13K dataset. The motivation behind this paper's experiment was that LayoutLMv3's official paper had no results for table detection using semantic information. We concluded that our approach did not improve the model's table detection capabilities, for which we can give several possible reasons. Either the model's weights were unsuitable for our purpose, or we needed to invest more time in optimising the model's hyperparameters. It is also possible that semantic inform
Negative / Null Result ReportOpen accessComputer Science
Bob de Ruiter · 2021 · arXiv
The goal of this study was to improve the post-processing of precipitation forecasts using convolutional neural networks (CNNs). Instead of post-processing forecasts on a per-pixel basis, as is usually done when employing machine learning in meteorological post-processing, input forecast images were combined and transformed into probabilistic output forecast images using fully convolutional neural networks. CNNs did not outperform regularized logistic regression. Additionally, an ablation analysis was performed. Combining input forecasts from a global low-resolution weather model and a regiona
Negative / Null Result ReportOpen accessComputer Science
Haresh Rengaraj Rajamohan, Yuxuan Chen, Kyunghyun Cho et al. · 2026 · arXiv
This study assesses whether self-supervised learning (SSL) improves knee osteoarthritis (OA) modeling for diagnosis and prognosis relative to ImageNet-pretrained initialization. We compared (i) image-only SSL pretrained on knee radiographs from the OAI, MOST, and NYU cohorts, and (ii) multimodal image-text SSL pretrained on hospital knee radiographs paired with radiologist impressions. For diagnostic Kellgren-Lawrence (KL) grade prediction, SSL yielded mixed results. While image-only SSL improved accuracy during linear probing (frozen encoder), it did not outperform ImageNet pretraining during
Negative / Null Result ReportOpen accessComputer Science
N. J. Ayres · 2018 · arXiv
We report on a search for ultra-low-mass axion-like dark matter by analysing the ratio of the spin-precession frequencies of stored ultracold neutrons and $^{199}$Hg atoms for an axion-induced oscillating electric dipole moment of the neutron and an axion-wind spin-precession effect. No signal consistent with dark matter is observed for the axion mass range $10^{-24}~\textrm{eV} \le m_a \le 10^{-17}~\textrm{eV}$. Our null result sets the first laboratory constraints on the coupling of axion dark matter to gluons, which improve on astrophysical limits by up to 3 orders of magnitude, and also im
Negative / Null Result ReportOpen accessPhysics
Michael Blomqvist, Edvard Mortsell, Serena Nobili · 2008 · arXiv
We discuss the possibility to identify anisotropic and/or inhomogeneous cosmological models using type Ia supernova data. A search for correlations in current type Ia peak magnitudes over a large range of angular scales yields a null result. However, the same analysis limited to supernovae at low redshift, shows a feeble anticorrelation at the two sigma level at angular scales of about 40 degrees. Upcoming data from, e.g., the SNLS (Supernova Legacy Survey) and the SDSS-II (SDSS: Sloan Digital Sky Survey) supernova searches will improve our limits on the size of - or possibly detect - possible
Negative / Null Result Report
· 2019 · The Brown University Psychopharmacology Update
Augmenting sertraline with eicosapentaenoic acid (EPA) for 10 weeks did not improve depressive symptoms relative to placebo in a group of 144 patients with major depressive disorder and existing or high risk of heart disease, a randomized…
View details →DOI: 10.1002/pu.30472 