Negative / Null Result ReportOpen accessPhysics
Tanech Klangburam, Chakrit Pongkitivanichkul · 2025 · arXiv
We investigate the effects of the ALP-mediated dark matter (DM) model on neutron star properties using the Quantum Hadrodynamics model (QHD). Using the relativistic mean-field approximation with the QHD-ALP-DM framework, we compute the equation of state (EoS) of neutron stars. Based on our previous study, we find that typical ALP parameter values have no significant effect on the EoS. We then explore various parametrizations of this model by varying the DM Fermi momentum, $q_f$, and DM mass, $m_χ$. Our results show that increasing $q_f$ or $m_χ$ shifts the energy density to higher values while
View details →Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Misha Perepelitsa · 2022 · arXiv
In this paper we give an elementary analysis of economics of Bitcoin that combines the transaction demand by the consumers and the supply of hashrate by miners. We argue that the decreasing block reward will have no significant effect on the exchange rate (price) of Bitcoin and thus the network will be transitioning to a regime where transaction fees will play a bigger part of miners' revenue. We consider a simple model where consumers demand bitcoins for transactions, but not for hoarding bitcoins, and we analyze market equilibrium where the demand is matched with the hashrate supplied by min
View details →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
View details →Negative / Null Result ReportOpen accessPhysics
Xiao-ke xu, Jie Zhang, Ping Li et al. · 2011 · arXiv
Traditionally, there is no evidence suggesting that there are strong ties between the rich-club property and the function of complex networks. In this study, we find that whether a very small portion of rich nodes connected to each other or not can strongly affect the frequency of occurrence of basic building blocks (motif) within networks, and therefore the function, of a heterogeneous network. Conversely whether a homogeneous network has a rich-club property or not generally has no significant effect on its structure and function. These findings open the possibility to optimize and control t
View details →Negative / Null Result ReportOpen accessPhysics
Vikrant Yadav, Rajpal, Pardeep et al. · 2024 · arXiv
In this letter, we report the observational constraints on a Bianchi type I anisotropic extension of $w$CDM model with spatial curvature from observational data including Baryon Acoustic Oscillations (BAO), Cosmic chronometers (CC), Big Bang nucleosynthesis (BBN), Pantheon+ (PP) compilation of SNe Ia and SH0ES Cepheid host distance anchors. The anisotropy is found to be of the order $10^{-13}$, which interplay with spatial curvature to reduce $H_0$ tension by $\sim 1σ$ as found in the analyses with BAO+CC+BBN+PP combination of data, while no significant effect of anisotropy is observed with BA
View details →Negative / Null Result ReportOpen accessPhysics
Andrey A. Kistanov, Yongqing Cai, Kun Zhou et al. · 2016 · arXiv
We investigate the electronic structure and chemical activity of rippled phosphorene induced by large compressive strains via first-principles calculation. It is found that phosphorene is extraordinarily bendable, enabling the accommodation of ripples with large curvatures. Such highly rippled phosphorene shows a strong anisotropy in electronic properties. For ripples along the armchair direction, the band gap changes from 0.84 to 0.51 eV for the compressive strain up to -20% and further compression shows no significant effect, for ripples along the zigzag direction, semiconductor to metal tra
View details →Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Markus Dertwinkel-Kalt, Max R. P. Grossmann · 2025 · arXiv
When environmental regulations are unpopular, policymakers often attribute resistance to information frictions and poor communication. We test this idea in the context of a major climate policy: Germany's Heating Law of 2023, which mandates the phase-out of fossil fuel heating. Through a survey experiment with property owners, we examine whether providing comprehensive information about the regulation's costs, requirements, and timeline affects adoption decisions and policy support. Despite successfully increasing factual knowledge, information provision has no significant effect on intended t
View details →Negative / Null Result ReportOpen accessPhysics
Benjamin Poole, Bartosz Barzdajn, Daniele Dini et al. · 2019 · arXiv
The thermal effects of plastic and frictional heat generation and elevated temperature were examined along with the role of adhesion in the context of galling wear, using a representative crystal plasticity, normally loaded, sliding surface model. Galling frequency behaviour was predicted for 316L steel. Deformation of the surfaces was dominated by the surface geometry, with no significant effect due to variations in frictional models. Plastic and frictional heating were found to have a minimal effect on the deformation of the surface, with the rapid conduction of heat preventing any highly lo
View details →Negative / Null Result ReportOpen accessComputer Science
Varun Kotte · 2026 · arXiv
Prompt-only, single-step LLM query rewriting, where a rewrite is generated from the query alone without retrieval feedback, is commonly used in production RAG pipelines, but its effect on dense retrieval is poorly understood. We present a systematic empirical study across three BEIR benchmarks, two dense retrievers, and multiple training configurations, and find strongly domain-dependent behavior: rewriting degrades nDCG@10 by 9.0 percent on FiQA, improves it by 5.1 percent on TREC-COVID, and has no significant effect on SciFact. We identify a consistent mechanism: degradations co-occur with r
View details →Negative / Null Result ReportOpen accessAgricultural and Biological Sciences
Anna Seigal, Portia Mira, Bernd Sturmfels et al. · 2016 · arXiv
Nosocomial outbreaks of bacteria are well-documented. Based on these incidents, and the heavy usage of antibiotics in hospitals, it has been assumed that antibiotic resistance evolves in hospital environments. To test this assumption, we studied resistance phenotypes of bacteria collected from patient isolates at a community hospital over a 2.5-year period. A graphical model analysis shows no association between resistance and patient information other than time of arrival. This allows us to focus on time course data. We introduce a Hospital Transmission Model, based on negative binomial delay
View details →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
View details →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
View details →Negative / Null Result ReportMedicine
Mohammed Abdul, Bernard, Yates · 2026 · Cureus
Background The optimal choice of polyethylene insert in total knee arthroplasty (TKA) continues to cause contention. Rotating platform bearings (RP) have theoretical advantages but have failed to demonstrate a functional difference…
View details →Negative / Null Result ReportMedicine
Geysenbergh, Debrock, Lie Fong et al. · 2026 · Human reproduction (Oxford, England)
Does a natural cycle result in higher clinical pregnancy rates (CPR) with foetal heartbeat compared to an artificial cycle for frozen-thawed embryo transfer (FET) preparation in ovulatory women? The CPR with foetal heartbeat did not differ…
View details →Negative / Null Result ReportMedicine
El-Tanani, Wali, Rabbani et al. · 2026 · Pharmaceuticals (Basel, Switzerland)
In spite of plausible biology, the majority of oncology trials involving drug repurposing have failed to demonstrate any efficacy. Numerous factors can potentially cause failure, including issues with dosing, drug strength, the trial…
View details →Negative / Null Result ReportOpen accessMicrobiology
Ruliaty Lisa, Amalia Indrian Rizka, Nur Abidin et al. · 2023 · BIO Web of Conferences
This study was aimed to know the effect of hatching and survival rate of milkfish larvae (Chanos chanos) treated with nanosilver. Three concentrations of nanosilver such as 0.25 ppm, 0.5 ppm and 0.75 ppm were applied to culture media at least an hour before stocking. Newly hatched larvae were stocked at the density of 50 pcs l-1, and it was reared for 25 days in 5 m3 of concrete tank. Result of the study found that no significant effect (p>0.05) of the treatments given on hatching rate and survival of milkfish larvae. However, larvae treated with nanosilver tend to gain higher hatching rate (6
View details →Negative / Null Result ReportOpen accessNaval architecture. Shipbuilding. Marine engineering
Chenfang Wang, Longxi Han, Yi Zhang et al. · 2023 · Journal of Marine Science and Engineering
The natural dispersion of oil depends on the oil types, wave-mixing energy, and the temperature and salinity of water. Laboratory experiments were conducted to investigate the effects of these factors on oil dispersion. The results demonstrated that the increase in temperature significantly enhanced the oil dispersion efficiency, particularly for low-viscosity oils. At 30 °C, the dispersion efficiency is 2 times higher than that at 15 °C, while salinity has no significant effect on dispersion efficiency. Nonlinear fitting results revealed an exponential increase in dispersion efficiency with t
View details →Negative / Null Result ReportOpen accessMedicine
Diptasree Maitra Ghosh, Dinesh Kumar, Sridhar Poosapadi Arjunan et al. · 2017 · PLoS ONE
This study has described and experimentally validated the differential electrodes surface electromyography (sEMG) model for tibialis anterior muscles during isometric contraction. This model has investigated the effect of pennation angle on the simulated sEMG signal. The results show that there is no significant effect of pennation angle in the range 0° to 20° to the single fibre action potential shape recorded on the skin surface. However, the changes with respect to pennation angle are observed in sEMG amplitude, frequency and fractal dimension. It is also observed that at different levels o
View details →Negative / Null Result ReportOpen accessAgriculture
Yasen H. Al tahan · 2005 · Mesopotamia Journal of Agriculture
In this study a specific gravity separator has been used in order to consider the effect of three levels of: longitudinal slop angles, vibration speeds, outlets for the produce and their effect on specific weight, productivity and seed purity. The results show the longitudinal horizontal slop angle (0) surpassed significantly in recording the greatest values for all characteristics of the study. While the second vibration speed surpassed significantly in specific weight and productivity and there were no significant effect in seed purity. in the product out lets, the first out lets achieved th
View details →Negative / Null Result ReportOpen accessNeurology. Diseases of the nervous system
Bilge Kocer, Hayat Guven, Isik Conkbayir et al. · 2016 · Parkinson's Disease
Factors related with hyperhomocysteinemia (HHcy) and the impact of HHcy in Parkinson’s disease (PD) are not well understood. We investigated the factors associated with increased levels of homocysteine (Hcy) and the relationship between HHcy and motor symptoms, cognitive status, and vascular risk in patients with Parkinson’s disease. Among 60 patients (29 males, 48.3%) with PD, the stage of the disease, the severity of clinical symptoms, and the patients’ cognitive status were measured using a modified Hoehn and Yahr Staging Scale (mHY), Unified Parkinson’s Disease Rating Scale (UPDRS) II and
View details →Negative / Null Result ReportOpen accessSpecial aspects of education
Brahma Wahyu Kurniawan, Beny Mahyudi Saputra · 2022 · Aksara
This study aims to find out about consumer satisfaction directly and indirectly in terms of the brand ambassador and e-word of mouth variables as well as purchasing decisions as a moderating variable. Using path analysis techniques and 125 people as respondents who have used online media (marketplace) to make transactions. The results obtained in this study are that there is no significant effect indirectly, but it has a significantly positive effect when viewed from the direct influence of each variable. Indicates that consumers who are respondents are not too concerned with many consideratio
View details →Negative / Null Result ReportOpen accessBiology (General)
Qiaoli Wang, Wenpei Wang, Yonghui Wang et al. · 2024 · Journal of Fungi
Manganese is one of the trace elements necessary for organisms to maintain normal biological activities and is also a cofactor for manganese superoxide dismutase (Mn-SOD) and manganese peroxidase (MnP). In order to find a simple and effective method to rejuvenate the degenerated V. volvacea strains, we explored the effect of the exogenous addition of MnSO 4 on the antioxidant vigour and productivity of degenerated strains of V. volvacea . The results showed that the exogenous MnSO 4 had no significant effect on the non-degenerated strain T0, but it could effectively increase the mycelial growt
View details →Negative / Null Result ReportOpen accessScience
Karlos Edmundo Orozco Durán, José Segura Correa, Jessica Herrera Ojeda et al. · 2022 · Nova Scientia
The aim of the study was to evaluate the effect of body condition score (BCS) at lambing over the resumption of ovarian and estrous postpartum activity in lactating Pelibuey ewes. Twenty ewes were assigned to two groups, according to the BCS at lambing: Low BCS (LBC, n = 10) and High BCS (HBC, n = 10). Ovarian and estrous activities were daily monitored from day 3 postpartum until the first estrous or 90 days postpartum. Continuous variables were analyzed using Student´s t test and binary responses with the exact Fisher test. No significant effect of BCS at lambing on ewes in estrous, lambing
View details →Negative / Null Result ReportOpen accessEnvironmental sciences
Chandini Palakkunnel Kuttappan, Sasankan Prasanth Narayanan, Syamkumar Reghu Nandanan Pillai et al. · 2025 · Natural Built Social Environment Health
This study assessed the toxic effects of pesticide exposure on four earthworm species: Perionyx excavatus Perrier, 1872; Megascolex konkanensis Fedarb, 1898; Dichogaster affinis (Michaelsen, 1890); and Metaphire houlleti (Perrier, 1872). The organisms were exposed to pesticide-treated soil. Biomass reduction, immunotoxicity, and enzyme biomarkers were used as endpoints. Among the tested species, M. konkanensis, a native species, appeared more sensitive than the others. In biomass tests, chlorpyrifos showed no significant effect on final body mass (p > 0.05). P. excavatus showed a significant r
View details →Negative / Null Result ReportOpen accessChemistry
Vincent J. Farage, Désimir Janjic · 1981 · CHIMIA
In certain cases, and particularly for the BrO3-/Ce4+/malonic acid system, oxygen seems to inhibit oscillations and the mechanical stirring in a N2 atmosphere has no significant effect on the oscillations. However, for the BrO3-/Ce4+/Cyclohexanon and BrO3-/Ce4+/Cyclopentanon systems under specific experimental conditions, stirring plays a determining part and oxygen has no notable effect on the oscillations.
View details →Negative / Null Result ReportOpen accessAccounting. Bookkeeping
Hutapea Lastiar Hutapea, Aristanti Widyaningsih · 2017 · Jurnal ASET (Akuntansi Riset)
Abstract. The variables tested in the study consist of Good Government Governance measured by the rank of Indonesia Governance Index (IGI) and the size of the legislative by using the number of members of the provincial parliament, and also local government performance measured by three proxies, the GDP per capita, Poverty Rates, and independence Ratios. The study is conducted in 33 provinces in Indonesia in 2012. The results show that there is no significant effect of good government governance on local government performance by proxy of GDP per capita. There is significant impact of good gov
View details →Negative / Null Result ReportOpen accessEngineering (General). Civil engineering (General)
Tkachenko Egor M., Zaitsev Dmitry V. · 2016 · MATEC Web of Conferences
Intensively evaporating liquid films moving under the action of the cocurrent gas flow in a microchannel are promising for the use in modern cooling systems of semiconductor devices with high local heat release. This work has studied the dependence of the critical heat flux on the inclination angle of the channel. It has been found that the inclination angle in the plane parallel to the flow has no significant effect on the critical heat flux. Whereas the inclination angle in the plane perpendicular to the flow, on the contrary, significantly changes the value of the critical heat flux. Howeve
View details →Negative / Null Result ReportMedicine
Suzuki Y, Matsui M, Munir M et al. · 2025 · Zoological science
Using mitochondrial DNA and genome-wide SNP, phylogenetic relationships in Chalcorana were investigated. Phylogenetic analyses based on subregions of mtDNA found possible lineages of several cryptic species, but did not support the…
View details →Negative / Null Result ReportOpen accessPhysics
Chuan-Ren Chen, Yu-Kuang Chu, Ho-Chin Tsai · 2015 · Physics Letters B
Even though the sensitivity of direct dark matter search experiments reaches the level of about 10−45 cm2, no confident signal of dark matter has been observed. We point out that, if dark matter is a vector boson, the null result in direct dark matter search experiments may be due to the destructive effects in dark-matter–nucleon elastic scattering. We illustrate the scenario using a modified Higgs portal model that includes exotic quarks. The significant cancellation can occur for a certain mass gap between new heavy quark and dark matter. As a result, the spin-independent dark-matter–nucleon
View details →Negative / Null Result ReportOpen accessEducation
Yuli Christiana Yoedo, Anita Octaviani, Dani Puspitasari · 2025 · Journal of Digital Learning and Education
This study aims to determine the influence of MindMeister on 4C skills in the Indonesian language subject in grade 6 elementary school in Surabaya. A combined research method was used, involving data collection carried out through in-depth interviews with students, observation, taking pre-test and post-test scores 3 times each in the control class and experimental class. Quantitative results showed no significant effect of using MindMeister on 4C skills (significance values of 0,100 > 0,05). However, the qualitative result based on the student's perspective gained through interviews and observ
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