Negative / Null Result ReportOpen accessEcology
Sánchez-Ledesma Judith A., Águila Bernardo, Garibay-Orijel Roberto et al. · 2025 · Folia Oecologica
Using ITS1-based metabarcoding, we investigated the structure of the soil fungal communities in the central and peripheral zones of a 25-hectare pecan nut (Carya illinoinensis) orchard located in the arid region of Coahuila, Mexico. While environmental conditions such as soil moisture and temperature varied between zones, physicochemical soil properties (pH, organic carbon, total carbon, organic matter, electrical conductivity, and zinc) remained homogeneous. A total of 4,443 fungal OTUs were detected at 97% similarity. Alpha diversity indices did not differ significantly between zones. The fu
View details →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
View details →Negative / Null Result Report
Creamer MS, Leifer AM, Pillow JW · 2024 · Preprint
A fundamental goal of neuroscience is to understand how anatomy determines the functional properties of the nervous system. However, previous work has failed to show how the functional connections between neurons are derived from the…
View details →Negative / Null Result ReportOpen accessComputer Science
G. Kaelbermann, J. M. Eisenberg, Andreas Schaefer · 1994 · arXiv
It is well known that in lowest order the skyrmion model of the nucleon gives vanishing spin content. With new data indicating a proton spin content $ΔΣ= 0.22\pm 0.14,$ it is an increasing challenge to find ways in which the skyrmion can move away from the null result. We show here that a particular term in the skyrmion lagrangian in SU(3) involving six derivatives of the field can, with plausible parameters, yield a spin content consistent with present experiment.
View details →Negative / Null Result ReportOpen accessMedicine
Chaudhari A, Rosenstein ZM, Kamal R et al. · 2026 · Stroke (Hoboken, N.J.)
Background Intracranial atherosclerotic disease is associated with up to 10% of ischemic strokes and a high risk of recurrence. Endovascular treatments including percutaneous transluminal angioplasty and stenting have failed to demonstrate…
View details →Short NoteOpen accessMedicine
Jennifer Huberty, Lara Baez, Kelsey McAlister et al. · 2026 · JMIR Formative Research
AbstractThe digital mental health (DMH) industry has grown drastically over the last decade; yet, many DMH products have failed to demonstrate meaningful clinical outcomes, in large part due to lack of scientific evidence. This viewpoint paper highlights an example of how early-stage DMH companies can prioritize science as a strategic advantage. We discuss Moment for Parents, an artificial intelligence–driven maternal mental health app built entirely with support from the National Institutes of Health (NIH) Small Business Innovation Research (SBIR) program. We illustrate the advantages and cha
View details →Abandoned HypothesisOpen accessImmunologic diseases. Allergy
John P. Veluchamy, John P. Veluchamy, Nina Kok et al. · 2017 · Frontiers in Immunology
Natural killer (NK) cells are critical immune effector cells in the fight against cancer. As NK cells in cancer patients are highly dysfunctional and reduced in number, adoptive transfer of large numbers of cytolytic NK cells and their potential to induce relevant antitumor responses are widely explored in cancer immunotherapy. Early studies from autologous NK cells have failed to demonstrate significant clinical benefit. In this review, the clinical benefits of adoptively transferred allogeneic NK cells in a transplant and non-transplant setting are compared and discussed in the context of re
View details →Methods Dead-EndOpen accessMedical emergencies. Critical care. Intensive care. First aid
Leslie Bilello, Andrew Ketterer, Shaked Yarza et al. · 2021 · Clinical and Experimental Emergency Medicine
Objective Optimal training methods remain controversial for rarely performed emergency procedures. Previous research has failed to demonstrate the superiority or inferiority of live anesthetized animal models (LAA) as compared to other modalities. Most of the data on LAA use comes from military contexts; less information is available for civilian emergency medicine (EM) training. We sought to characterize the prevalence of LAA use among civilian EM residency programs and reasons for its use or discontinuation. Methods Survey study of program directors of EM residency programs accredited by the
View details →Negative / Null Result ReportOpen accessSpecial aspects of education
Ning Zhang, Fan Ouyang · 2023 · International Journal of Educational Technology in Higher Education
Abstract Collaborative knowledge construction (CKC) involved students’ sharing of information, improvement of ideas, and construction of collective knowledge. In this process, knowledge extraction and analysis can provide valuable insights into students’ knowledge capacities, depths, and levels in order to improve the CKC quality. However, existing studies tended to extract and analyze knowledge from a single perspective (e.g., the number of certain knowledge types and knowledge structures), which failed to demonstrate the complexity and dynamics of knowledge construction and advancement. To f
View details →Negative / Null Result ReportOpen accessImmunologic diseases. Allergy
Richard Morter, Alfred B. Tiono, Alfred B. Tiono et al. · 2022 · Frontiers in Immunology
The experimental malaria vaccine ChAd63 MVA ME-TRAP previously showed protective efficacy against Plasmodium falciparum infection in Phase IIa sporozoite challenge studies in adults in the United Kingdom and in a Phase IIb field efficacy trial in Kenyan adults. However, it failed to demonstrate efficacy in a phase IIb trial in 5-17 month-old children in an area of high malaria transmission in Burkina Faso. This secondary analysis investigated whether exposure to malaria or nutritional status might be associated with reduced responses to vaccination in this cohort. Parasite blood smears and ant
View details →Negative / Null Result ReportOpen accessPhysics
G. He, R. Belanger, P. H. Hguyen et al. · 2018 · arXiv
The influence of long-range dipole interactions on two dimensional magnetism has been studied extensively in the spin-reorientation transition of ferromagnetic ultrathin films. Although there is a great deal of experimental information on the perpendicular domain phase that is stabilized by dipole interactions, the transitions to or from the domain phase are subtle and difficult to characterize experimentally. Magnetic susceptibility measurements show no divergence in the vicinity of the spin-reorientation transition as a function of thickness -- a null result that is difficult to interpret wi
View details →Negative / Null Result ReportOpen accessComputer Science
Bob de Ruiter · 2023 · arXiv
In many fields of experimental science, papers that failed to replicate continue to be cited as a result of the poor discoverability of replication studies. As a first step to creating a system that automatically finds replication studies for a given paper, 334 replication studies and 344 replicated studies were collected. Replication studies could be identified in the dataset based on text content at a higher rate than chance (AUROC = 0.886). Additionally, successful replication studies could be distinguished from failed replication studies at a higher rate than chance (AUROC = 0.664).
View details →Negative / Null Result ReportOpen accessComputer Science
Andy Hocker · 1999 · arXiv
The most recently available results from searches conducted by the four LEP experiments at 189 GeV center-of-mass energy for Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) are presented. No evidence for a signal has been observed, and the null result is used by the experiments, both individually and collectively, to exclude regions of the MSSM parameter space and to set lower limits on Higgs boson masses at 95% confidence level in constrained MSSM scenarios.
View details →Negative / Null Result Report
· 2021 · The Brown University Psychopharmacology Update
A new study that confirmed the effect of topiramate in reducing heavy‐drinking days in patients with alcohol use disorder (AUD) did not find a moderating effect of the rs2832407 genotype on study outcomes. The latter finding contradicted…
View details →Failed Experiment ReportOpen accessMedicine
Wallon S, Williamsson C, Karlsson V et al. · 2026 · Trials
Background Routine use of surgical drains after abdominal operations has largely been abandoned over the past decades. Studies have failed to demonstrate benefits of routine drainage following liver, gallbladder, gastric, and colorectal…
View details →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…
View details →Short NoteOpen accessMedical physics. Medical radiology. Nuclear medicine
Farhana Ebrahim Suleman, Margaret Kisansa · 2010 · South African Journal of Radiology
Macrodystrophia lipomatosa (MDL) is described as a rare, non-hereditary, congenital condition presenting with localized macrodactyly and a proliferation of mesenchymal elements. There is in particular a marked increase in fibroadipose tissue(1). We describe two cases presenting to our department in a six month period, with a history of disproportionately large limbs since birth. While our first case demonstrated all the typical features of MDL, our second case failed to demonstrate osseous gigantism although the other features of MDL were present. An extensive search of the literature failed t
View details →Negative / Null Result ReportOpen accessPhysics
Pedro Augusto, Peter N. Wilkinson · 2000 · arXiv
A radio-based search for strong gravitational lensing, with image separations in the range 160-300 milliarcsec (mas), has yielded a null result for a sample of 1665 sources (Augusto, Wilkinson & Browne 1998) whose mean redshift is estimated to be ~1.3. The lensing rate for this previously-unexplored separation range, <1:555 at the 95% confidence level, is less than on arcsecond-scales - as expected from models of lensing galaxy populations. Lensing on 160-300 mas scales is expected to arise predominantly from spiral galaxies at a rate dependent on the disk-halo mass ratio and the evolving numb
View details →Failed Experiment ReportOpen accessMedical physics. Medical radiology. Nuclear medicine
Ma Li, Men Yu, Feng Lingling et al. · 2019 · Radiology and Oncology
The mainstay therapy for locally advanced non-small cell lung cancer is concurrent chemoradiotherapy. Loco-regional recurrence constitutes the predominant failure patterns. Previous studies confirmed the relationship between increased biological equivalent doses and improved overall survival. However, the large randomized phase III study, RTOG 0617, failed to demonstrate the benefit of dose-escalation to 74 Gy compared with 60 Gy by simply increasing fraction numbers.
View details →Negative / Null Result ReportOpen accessPhysics
Daniel Lima Nascimento · 2013 · arXiv
A reanalisis of the effect of a moving frame of reference is done, showing that the null result of the Michelson-Morley's experimente of 1887 on the possibility of detecting the variation of the velocity of light with respect to a moving observer, na observer at the Earth, was already implied in these equations; thereforewith no need of new ad hoc hypotheses to explain it in the classical framework. In fact, it will be shown that behind those equations is hidden the fascinating phenomenon of the absolute motion.
View details →Negative / Null Result ReportOpen accessPhysics
D. L. Khokhlov · 2008 · arXiv
It is revisited the Michelson-Morley experiment within the quantum mechanics framework. One can define the wave function of photon in the whole space at a given moment of time. The phase difference between the source and receiver is a distance between the source and receiver at the time of reception hence it does not depend on the velocity of the frame. Then one can explain the null result of the Michelson-Morley experiment within the quantum mechanics framework.
View details →Abandoned HypothesisOpen accessPhilosophy (General)
Mostafa Taqavi · 2019 · Journal of Philosophical Investigations
There are two main sections in this paper. First, we will show that some of the chief 20th-century theories of science either have failed to demonstrate that value judgments do not influence the context of consolidation and determination of science or have accepted the role of value judgments in the context of consolidation and determination of science and theorized accordingly. For this purpose, the ideas of logical positivists, Willard Quine, Karl Popper, Thomas Kuhn, Imre Lakatos, Paul Feyerabend, and Roy Bhaskar on science are briefly reviewed. Finally, the validity of the following statem
View details →Negative / Null Result ReportOpen accessDiseases of the circulatory (Cardiovascular) system
Oh Young Bang, Mi Ji Lee, Sookyung Ryoo et al. · 2015 · Journal of Stroke
Patent foramen ovale (PFO) is growing in clinical interest because of a renewed focus on embolic stroke of undetermined source (ESUS), the PFO attributable fraction (the 10-point Risk of Paradoxical Embolism score), technical advances in PFO diagnosis, and the emergence of endovascular device closure as a treatment option. However, recent randomized controlled trials of the management of patients with ESUS and PFO failed to demonstrate the superiority of closure over medical treatment. The mechanisms of stroke other than paradoxical embolism may be important in patients with ESUS and PFO. This
View details →Null DatasetOpen accessMaterials of engineering and construction. Mechanics of materials
· 2009 · eXPRESS Polymer Letters
The thermal and reaction to fire characteristics of a flame retardant unsaturated polyester (UP) ternary system are presented here. Thermal gravimetric analysis showed an improved thermal stability between 200–600°C with the addition of ammonium polyphosphate (APP) and aluminium trihydroxide (ATH) formulation. Cone calorimetry tests indicated that ATH is more efficient than calcium carbonate at delaying the ignition time, lowering the carbon monoxide yield and lowering the peak heat release (PHRR). However the addition of APP and ATH to the formulation failed to demonstrate any significant syn
View details →Negative / Null Result ReportOpen accessAnimal culture
Samadi F, Sahneh M · 2015 · Poultry Science Journal
A total of 240, one-day-old quail chicks (Coturnix coturnix japonica) were used to study the effects of Artichoke leaf meal (ALM) and vitamin E in diet on growth performance, ileal microbial populations and intestinal morphology in a 42-d trial. This experiment was performed as a completely randomized design with 4 replicates of 15 quails each, using a 4 × 2 factorial arrangement with diet and gender as the main effects. Four dietary treatments were formulated by addition of 2 levels (1.5 and 3 percent) of ALM and 300 mg/Kg vitamin E to the basal diet. Supplementing basal diet with ALM did not
View details →Negative / Null Result ReportOpen accessComputer Science
L. Cooper, G. E. Stedman · 1995 · arXiv
A ring-laser experiment, similar to the Canterbury ring laser, to detect axion- and {\sc qed}-induced vacuum birefringence is proposed. It uses a slowly modulated magnetic field and a novel polarization geometry. Both axion coupling and vacuum birefringence would modulate the Sagnac beat frequency. A null result could place sensitive bounds on the axion mass and on two-photon coupling.
View details →Negative / Null Result ReportMedicine
Beck QM, Sachet J, Cargnelli C et al. · 2026 · The Journal of clinical psychiatry
Objectives: Unwanted intrusive thoughts (UITs) of intentional infant-related harm are common among birthing parents. Evidence to date has failed to find any association with physical aggression toward the infant. However, the relationship…
View details →Negative / Null Result ReportOpen accessPhysics
Anand Bhattacharya, Igor Zutic, Oriol T. Valls et al. · 1998 · arXiv
In a recent Letter (Phys. Rev. Lett. 81, p.5640 (1998), cond-mat/9808249 v3), it was suggested that nonlocal effects may prevent observation of the nonlinear Meissner effect in YBCO. We argue that this claim is incorrect with regards to measurements of the nonlinear transverse magnetic moment, and that the most likely reason for a null result lies elsewhere.
View details →Negative / Null Result ReportOpen accessMedicine
Xavier Jannot, Alpha Oumar Diallo, Judicaelle Didierjean et al. · 2025 · European Journal of Case Reports in Internal Medicine
We report the case of a 75-year-old woman admitted to the emergency department for confusion, gait disturbances and mutism associated with an inflammatory syndrome occurring 3 weeks after acute carbon monoxide intoxication. The main hypothesis upon arrival was infectious meningoencephalitis, and the patient was put on acyclovir and antibiotics in meningeal doses. After a short stay in intensive care, the patient’s condition did not improve, and the revaluation of her case history and imaging studies led to the diagnosis of post-interval syndrome secondary to carbon monoxide intoxication after
View details →Negative / Null Result ReportOpen accessDiseases of the blood and blood-forming organs
Daniel A. Ermann, Victoria A. Vardell, Lindsey Fitzgerald et al. · 2026 · eJHaem
ABSTRACT Introduction B‐cell prolymphocytic leukemia (B‐PLL) is a rare, aggressive leukemic B‐cell malignancy historically associated with poor outcomes and recently reclassified in the WHO Fifth Edition but retained as a distinct entity in the ICC. Methods We analyzed 950 patients labeled as B‐PLL in the National Cancer Database (2004–2019), identified using ICD‐O‐3 morphology code 9833/3. Results Median age was 72 years, and 72% received systemic therapy at diagnosis. Median overall survival (OS) was poor (2.8 years) and did not improve over time. Patients initially managed with active surve
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