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
H. C. Eggers, B. Buschbeck · 2013 · arXiv
A detailed understanding of all effects and influences on higher-order correlations is essential. At low charged multiplicity, the effect of a nonpoissonian multiplicity distribution can significantly distort correlations. Evidently, the reference samples with respect to which correlations are measured should yield a null result in the absence of correlations. We show how the careful specification of desired properties necessarily leads to an average-of-multinomials reference sample. The resulting internal cumulants and their averaging over several multiplicities fulfil all requirements of cor
Negative / Null Result ReportOpen accessPhysics
K. E. Belle, N. Sanghi, S. B. Howell et al. · 2004 · arXiv
Circumbinary (CB) disks have been proposed as a mechanism to extract orbital angular momentum from cataclysmic variables (CVs) during their evolution. As proposed by Taam & Spruit, these disks extend outwards to several a.u. and should be detected observationally via their infrared flux or by absorption lines in the ultraviolet spectra of the CV. We have made use of archival HST/STIS spectra as well as our own near-IR imaging to search for observational evidence of such CB disks in seven CVs. Based on the null result, we place an upper limit on the column density of the disk of N_H~10^17 cm^-2
Negative / Null Result ReportOpen accessPhysics
Peter R. Allen, David W. Koerner, Michael W. McElwain et al. · 2006 · arXiv
We present the results of a deep-imaging search for wide companions to low-mass stars and brown dwarfs using NSFCam on IRTF. We searched a sample of 132 M7-L8 dwarfs to magnitude limits of $J \sim 20.5$ and $K \sim 18.5$, corresponding to secondary-primary mass ratios of $\sim 0.5$. No companions were found with separations between $2{\arcsec}$ to $31{\arcsec}$ ($\sim$40 AU to $\sim$1000 AU). This null result implies a wide companion frequency below 2.3% at the 95% confidence level within the sensitivity limits of the survey. Preliminary modeling efforts indicate that we could have detected 85
Negative / Null Result ReportOpen accessPhysics
P. N. Wilkinson, D. R. Henstock, I. W. A. Browne et al. · 2001 · arXiv
Using Very Long Baseline Interferometry we have searched a sample of 300 compact radio sources for examples of multiple imaging produced by gravitational lensing; no multiple images were found with separations in the angular range 1.5--50 milliarcsec. This null result allows us to place a limit on the cosmological abundance of intergalactic supermassive compact objects in the mass range $\sim 10^{6}$ to $\sim 10^{8}$M$_{\odot}$; such objects cannot make up more than $\sim 1%$ of the closure density (95% confidence). A uniformly distributed population of supermassive black holes forming soon af
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 accessEngineering
Rancy Chepchirchir, Jill Sunday, Raymond Confidence et al. · 2025 · arXiv
In Sub-Saharan Africa (SSA), the utilization of lower-quality Magnetic Resonance Imaging (MRI) technology raises questions about the applicability of machine learning methods for clinical tasks. This study aims to provide a robust deep learning-based brain tumor segmentation (BraTS) method tailored for the SSA population using a threefold approach. Firstly, the impact of domain shift from the SSA training data on model efficacy was examined, revealing no significant effect. Secondly, a comparative analysis of 3D and 2D full-resolution models using the nnU-Net framework indicates similar perfor
Negative / Null Result ReportOpen accessPhysics
Peter Erwin, Linda S. Sparke · 2002 · arXiv
We present results from an imaging survey of an unbiased sample of thirty-eight early-type (S0--Sa), low-inclination, optically barred galaxies in the field. Our goal was to find and characterize central stellar and gaseous structures: secondary bars, inner disks, and nuclear rings. Bars inside bars are surprisingly common: at least one quarter of the sample galaxies (possibly as many as 40%) are double-barred, with no preference for Hubble type or the strength of the primary bar. A typical secondary bar is ~12% of the size of its primary bar and 240--750 pc in radius. We see no significant ef
Negative / Null Result ReportOpen accessPhysics
D. Apai, M. R. Meyer, P. Hinz et al. · 2007 · arXiv
We present results from two high-contrast imaging surveys that exploit a novel technique, L-band angular differential imaging. Our first survey targeted 21 young stars in the Beta Pic and Tuc-Hor moving groups with VLT/NACO reaching typical sensitivities of 20 AU. The statistical analysis of the null result demonstrates that the giant planet population is truncated at 30 AU or less (90% confidence level). Our second, on-going MMT/Clio survey utilizes the unique sensitivity achieved in the L-band for old planets to probe all M-dwarf stars within 6 pc. The proximity of these targe
Negative / Null Result ReportOpen accessPlant culture
J. Harb, A. A. Saquet, R. Bisharat et al. · 2012 · Journal of Applied Botany and Food Quality
Biochemical and quality changes of sweet cherries cv. Regina were assessed over three consecutive years after storage in different modified atmosphere packaging (MAP) liners, with or without hydrocooling, compared to regular atmosphere (RA) storage. All plastic liners used in the experiment resulted in CO2-enrichment and O2-reduction inside packages, with the following impact on fruit quality after five weeks of storage: improved retention of fruit firmness and red color of skin, no significant effect on acidity and total soluble solids, and minimal loss of fruit weight. Fruit decay was absent
Negative / Null Result ReportOpen accessPhysics
H. C. Eggers, B. Buschbeck · 2013 · Advances in High Energy Physics
A detailed understanding of all effects and influences on higher-order correlations is essential. At low charged multiplicity, the effect of a non-Poissonian multiplicity distribution can significantly distort correlations. Evidently, the reference samples with respect to which correlations are measured should yield a null result in the absence of correlations. We show how the careful specification of desired properties necessarily leads to an average-of-multinomials reference sample. The resulting internal cumulants and their averaging over several multiplicities fulfill all requirements of c
View details →DOI: 10.1155/2013/230515 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 →DOI: 10.12890/2025_005235 Negative / Null Result ReportMedicine
Van Gent JM, Clements TW, Gurney JM et al. · 2025 · The journal of trauma and acute care surgery
Background Empiric cryoprecipitate administration has recently failed to show survival benefit in hemorrhaging trauma patients. However, a recent Trauma Quality Improvement Program query suggested a survival benefit in massive transfusions…
View details →DOI: 10.1097/ta.0000000000004643 Negative / Null Result Report
Perdue MV, Geeraert BL, Manning KY et al. · 2024 · Preprint
Numerous studies have linked reading ability to white matter microstructure using diffusion tensor imaging, but recent large studies have failed to show consistency. Fiber-specific diffusion-weighted magnetic resonance imaging (dMRI)…
View details →DOI: 10.1101/2024.09.24.614799 Negative / Null Result ReportMedicine
Taheri F, Tanha AS, Aboutorabi RB et al. · 2026 · Clinical nuclear medicine
A 78-year-old woman with medullary thyroid carcinoma (MTC) demonstrated persistently elevated serum calcitonin despite prior surgery and radiotherapy. 99mTc-octreotide imaging failed to detect skeletal metastases, while 68Ga-FAPI PET/CT…
View details →DOI: 10.1097/rlu.0000000000006450 Negative / Null Result ReportMedicine
Diz-Lopes M, Rovetta CF, Pollastri F et al. · 2026 · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA
We evaluated how romosozumab affects bone structure, density, and strength at the wrist over 12 months. Volumetric bone mineral density did not increase, but high-resolution quantitative computed tomography imaging showed modest…
View details →DOI: 10.1007/s00198-026-08113-3 Negative / Null Result ReportMedicine
Hüther A, Sherman CL, Sumaroka A et al. · 2026 · Ophthalmic genetics
Purpose To describe the phenotype of a patient with bi-allelic pathogenic variants in NR2E3 that did not result in an overt enhanced S-cone syndrome (ESCS) phenotype. Methods The patient underwent a comprehensive ophthalmic exam, imaging…
View details →DOI: 10.1080/13816810.2026.2635611 Negative / Null Result ReportOpen accessMedicine
Caio Gonçalves de Souza, Márcio Passini Gonçalves de Souza, Vanda Jorgetti et al. · 2015 · Acta Ortopédica Brasileira
OBJECTIVE: To determine whether there is a difference on the bone architecture in patients with femoral neck fracture compared to patients with intertrochanteric fractures and assess the importance of aging on bone microarchitecture in patients with proximal femoral fracture.METHODS: Biopsy of the iliac crest was made in seventeen patients between 55 and 90 years old who were admitted to the emergency room with fractures of the proximal end of the femur. After a small fragment was removed, we made a histomorphometric analysis of it.RESULTS: There was no significant difference between patients
View details →DOI: 10.1590/1413-78522015230201056 Negative / Null Result ReportMedicine
Kaman, Stork, Okumus et al. · 2026 · Langenbeck's archives of surgery
Segmentectomy is offered in selected patients with clinical T1a-b N0 M0 lung cancer. In case of positive N1 lymph node at fresh frozen section, conversion to lobectomy is recommended. Indication for redo surgery and completion lobectomy in…
View details →DOI: 10.1007/s00423-026-04089-0 Negative / Null Result Report
Hwang Tan, Pramod Chandru · 2026 · Emergency Medicine Australasia
ABSTRACT Objective Overuse of CT Pulmonary Angiography (CTPA) remains a challenge in emergency medicine. Some institutions resort to radiologist vetting to reduce unnecessary imaging. This is a pilot study that aims to investigate the…
View details →DOI: 10.1111/1742-6723.70237 Negative / Null Result Report
W Reay · 2025 · International Journal of Neuropsychopharmacology
Abstract Background One mechanism that holds great promise to drive drug development or drug repurposing in schizophrenia is through leveraging human genetics. Recent retrospective analyses of decades of clinical trial data have…
View details →DOI: 10.1093/ijnp/pyaf052.095 Negative / Null Result Report
William Zhang, Wan Shen Lim, Andrew Pavlo · 2026 · Proceedings of the ACM on Management of Data
Tuning database management systems (DBMSs) is challenging due to trillions of possible configurations and evolving workloads. Recent advances in tuning have led to breakthroughs in optimizing over the possible configurations. However, due…
View details →DOI: 10.1145/3786704 Negative / Null Result Report
Anna Prucnal · 2025 · International Journal of Business & Management Studies
This study examines the effectiveness of the monetary policy of the European Central Bank (ECB) in managing inflation in the Euro Area compared to the independent monetary policy of seven European Union Member States outside the Economic…
View details →DOI: 10.56734/ijbms.v6n1a7 Negative / Null Result Report
Daniel I. Rhon, Tina A. Greenlee, Rachel Mayhew et al. · 2022 · Journal of the American Academy of Orthopaedic Surgeons
Introduction: After elective orthopaedic surgery, many individuals go on to become long-term opioid users. Mitigating this risk has become a priority for surgeons, other members of the medical care team, and healthcare systems. The purpose…
View details →DOI: 10.5435/jaaos-d-21-00603 Negative / Null Result Report
Bill Cheuk Long Chan, Billy Lee · 2024 · Studia sportiva
Managing the balance of academic and athletic responsibilities at university is a serious challenge for student athletes. This phenomenological case study illuminates how one individual successfully managed his study-sport balance at…
View details →DOI: 10.5817/sts2023-2-6 Negative / Null Result ReportOpen accessComputer Science
Xin Ding, Yongwei Wang, Zuheng Xu · 2023 · arXiv
Continuous Conditional Generative Adversarial Networks (CcGANs) enable generative modeling conditional on continuous scalar variables (termed regression labels). However, they can produce subpar fake images due to limited training data. Although Negative Data Augmentation (NDA) effectively enhances unconditional and class-conditional GANs by introducing anomalies into real training images, guiding the GANs away from low-quality outputs, its impact on CcGANs is limited, as it fails to replicate negative samples that may occur during the CcGAN sampling. We present a novel NDA approach called Dua
Negative / Null Result ReportOpen accessComputer Science
Nilesh Kumar Sahu, Snehil Gupta, Haroon R Lone · 2025 · arXiv
Social Anxiety Disorder (SAD) is a widespread mental health condition, yet its lack of objective markers hinders timely detection and intervention. While previous research has focused on behavioral and non-verbal markers of SAD in structured activities (e.g., speeches or interviews), these settings fail to replicate real-world, unstructured social interactions fully. Identifying non-verbal markers in naturalistic, unstaged environments is essential for developing ubiquitous and non-intrusive monitoring solutions. To address this gap, we present AnxietyFaceTrack, a study leveraging facial video
Negative / Null Result ReportOpen accessPhysics
David M. Hernandez, Eric Agol, Matthew J. Holman et al. · 2021 · arXiv
Symplectic integrators are widely used for the study of planetary dynamics and other $N$-body problems. In a study of the outer Solar system, we demonstrate that individual symplectic integrations can yield biased errors in the semi-major axes and possibly other orbital elements. The bias is resolved by studying an ensemble of initial conditions of the outer Solar system. Such statistical sampling could significantly improve measurement of planetary system properties like their secular frequencies. We also compared the distributions of action-like variables between high and low accuracy integr
Negative / Null Result ReportOpen accessComputer Science
Keith Harrigian, Tina Tang, Anthony Gonzales et al. · 2023 · arXiv
Diabetic eye disease is a major cause of blindness worldwide. The ability to monitor relevant clinical trajectories and detect lapses in care is critical to managing the disease and preventing blindness. Alas, much of the information necessary to support these goals is found only in the free text of the electronic medical record. To fill this information gap, we introduce a system for extracting evidence from clinical text of 19 clinical concepts related to diabetic eye disease and inferring relevant attributes for each. In developing this ophthalmology phenotyping system, we are also afforded
Negative / Null Result ReportOpen accessPhysics
Michael A. Cole, Aristeidis Lamprianidis, Ilya V. Shadrivov et al. · 2018 · arXiv
Metasurfaces are an enabling technology for complex wave manipulation functions, including in the terahertz frequency range, where they are expected to advance security, imaging, sensing, and communications technology. For operation in transmission, Huygens' metasurfaces are commonly used, since their good impedance match to the surrounding media minimizes reflections and maximizes transmission. Recent theoretical work has shown that Huygens' metasurfaces are non-optimal, particularly for large angles of refraction, and that to eliminate reflections and spurious diffracted beams it is necessar
