Negative / Null Result ReportOpen accessComputer Science
Ruhollah Majdoddin · 2014 · arXiv
AFP Algorithm is a learning algorithm for Horn formulas. We show that it does not improve the complexity of AFP Algorithm, if after each negative counterexample more that just one refinements are performed. Moreover, a canonical normal form for Horn formulas is presented, and it is proved that the output formula of AFP Algorithm is in this normal form.
Negative / Null Result ReportOpen accessComputer Science
OFM Riaz Rahman Aranya, Kevin Desai · 2026 · arXiv
Synthetic data, an appealing alternative to extensive expert-annotated data for medical image segmentation, consistently fails to improve segmentation performance despite its visual realism. The reason being that synthetic and real medical images exist in different semantic feature spaces, creating a domain gap that current semi-supervised learning methods cannot bridge. We propose SRA-Seg, a framework explicitly designed to align synthetic and real feature distributions for medical image segmentation. SRA-Seg introduces a similarity-alignment (SA) loss using frozen DINOv2 embeddings to pull s
Negative / Null Result ReportOpen accessComputer Science
Andrei Liviu Nicolicioiu, Mohammad Pezeshki, Aaron Courville · 2026 · arXiv
On-policy self-distillation achieves strong pass@1 accuracy by using a single model as both teacher and student, with the teacher conditioned on a correct demonstration to provide dense token-level feedback. We show that this could come at a hidden cost: rollout diversity decreases and pass@k curves flatten (i.e., generating more rollouts fails to improve accuracy). We trace this to compounding biases in the design of self-distillation with sampled demonstrations. The teacher scores each student rollout while conditioned on a sampled correct rollout, channeling its feedback through the model's
Negative / Null Result ReportOpen accessDiseases of the digestive system. Gastroenterology
Olga Maria Nardone, Giulio Calabrese, Alessia La Mantia et al. · 2025 · Therapeutic Advances in Gastroenterology
Background: Managing extraintestinal manifestations (EIMs) in inflammatory bowel disease (IBD) patients remains challenging due to considerable heterogeneity in diagnostic criteria and the lack of a standardised definition and validated diagnostic pathways. Delays in recognising and treating EIMs can lead to significant disease progression. Therefore, early detection and treatment are crucial. Objectives: We aimed to assess the effectiveness of a dedicated immune-mediated inflammatory diseases (IMIDs) clinic in reducing EIM diagnostic delays and improving patients’ outcomes. Design: A single-c
View details →DOI: 10.1177/17562848251323529 Negative / Null Result ReportOpen accessComputer Science
Lennart Luettgau, Vanessa Cheung, Magda Dubois et al. · 2025 · arXiv
People increasingly seek personal advice from large language models (LLMs), yet whether humans follow their advice, and its consequences for their well-being, remains unknown. In a longitudinal randomised controlled trial with a representative UK sample (N = 6,474), we found that up to 79% of participants who had a 20-minute discussion with one of three AI chatbots (GPT-4o, LLama-3.3-70B, Gemini 3 Pro) about health, careers or relationships subsequently reported following its advice. Advice-following remained above 60% even for high-stakes recommendations, suggesting that users only weakly cal
Negative / Null Result ReportOpen accessOrthopedic surgery
Michał Maciejewski, Piotr Janusz, Michalina Dudkiewicz et al. · 2023 · Chirurgia Narządów Ruchu i Ortopedia Polska
Introduction. Radial neck fractures in children are rare and account for 1-3% of all childhood trauma. Severe displacement of the fracture can lead to a higher incidence of complications, such as limited range of motion (ROM), pain, instability, neurovascular trauma, premature physeal closure, cubitus valgus, radial head overgrowth, avascular necrosis and improper ossification. The treatment outcome depends on the injury type, treatment method and presence of complications.Aim. The purpose of the study was to assess the outcome of patients treated with elastic-stable intramedullary nailing (ES
View details →DOI: 10.31139/chnriop.2023.88.3.4 Negative / Null Result ReportOpen accessMedicine
Gerda Trutnovsky, MD, Brigitte Bliem, MD, Elfriede Greimel, PhD et al. · 2021 · Sexual Medicine
ABSTRACT: Introduction: Treatment for vulvodynia is challenging and a multidisciplinary approach is recommended. Aim: To examine the effectiveness, safety and treatment satisfaction of vulvovaginal microablative laser treatment for vulvodynia. Methods: Case study of women who received laser treatment as part of a multidisciplinary treatment program for vulvodynia. Subjective improvement was compared to a retrospective cohort of women treated for vulvodynia without LASER therapy. LASER treatment was offered to women with vulvodynia presenting to a gynecologic pain clinic of a tertiary universit
View details →DOI: 10.1016/j.esxm.2021.100432 Negative / Null Result ReportOpen accessSurgery
Samah Abdelfatah Eshiaty, Shimaa Abdelsattar, Dina Sweed et al. · 2023 · Egyptian Liver Journal
Abstract Background Early detection of biliary atresia (BA) is a great challenge providing the main useful way to improve its clinical consequence. Promising metabolomics provides an effective method for determining innovative biomarkers and biochemical ways for improving early diagnosis. This study aimed to determine the benefit of serum and urinary potential bile acid metabolites in the differentiation of BA from non-biliary atresia (non-BA) cases using tandem mass spectrometry (MS/MS). Fourteen bile acids metabolites were measured quantitively by MS/MS in serum and urine samples from 102 ch
View details →DOI: 10.1186/s43066-023-00244-0 Negative / Null Result ReportOpen accessComputer Science
Ruth Cohen, Lu Feng, Ayala Bloch et al. · 2026 · arXiv
While natural-language explanations from large language models (LLMs) are widely adopted to improve transparency and trust, their impact on objective human-AI team performance remains poorly understood. We identify a Persuasion Paradox: fluent explanations systematically increase user confidence and reliance on AI without reliably improving, and in some cases undermining, task accuracy. Across three controlled human-subject studies spanning abstract visual reasoning (RAVEN matrices) and deductive logical reasoning (LSAT problems), we disentangle the effects of AI predictions and explanations u
Negative / Null Result ReportOpen accessScience
Hans IJzerman, Jaap J. A. Denissen · 2019 · Royal Society Open Science
We report a replication and extension of a finding from Studies 1 and 2 of Van Lange et al.'s influential paper (Van Lange et al. 1997 J. Pers. Soc. Psychol. 73, 733–746. (doi:10.1037/0022-3514.73.4.733)), which showed an association between Social Value Orientation (SVO) and attachment security. We report a close replication but with measures of attachment that are considered superior in comparison to measures used by Van Lange et al., due to subsequent psychometric improvements. Psychometric analyses indeed showed that our attachment measures were reliable and valid, demonstrating theoretica
View details →DOI: 10.1098/rsos.181575 Negative / Null Result ReportOpen accessComputer Science
Amanpreet Singh, Mike D'Arcy, Arman Cohan et al. · 2022 · arXiv
Learned representations of scientific documents can serve as valuable input features for downstream tasks without further fine-tuning. However, existing benchmarks for evaluating these representations fail to capture the diversity of relevant tasks. In response, we introduce SciRepEval, the first comprehensive benchmark for training and evaluating scientific document representations. It includes 24 challenging and realistic tasks, 8 of which are new, across four formats: classification, regression, ranking and search. We then use this benchmark to study and improve the generalization ability o
Negative / Null Result ReportOpen accessMedicine (General)
Madeleine M. Southey, Trent Rees, Margaret Rolfe et al. · 2019 · Addiction Science & Clinical Practice
Abstract Background Residential opioid rehabilitation aims to improve the mental health and quality of life of opioid users through abstinence and residential program participation. This study aimed to determine the depression, anxiety, stress and quality of life amongst maintenance to abstinence (MTA) program residents. Secondary study aims were to assess the personal characteristics of MTA clients, addiction and risk taking behaviours, factors associated with program completion, as well as to assess the reliable change in participants’ mental health and quality of life on exit. Methods Retro
View details →DOI: 10.1186/s13722-019-0132-x Negative / Null Result ReportOpen accessComputer Science
Chunliang Li, Tianze Cao, Sanyuan Zhao · 2026 · arXiv
Visual Autoregressive (VAR) modeling inefficiently applies a fixed computational depth to each position when generating high-resolution images. While existing methods accelerate inference by pruning tokens using frequency maps, their binary hard-pruning approach is fundamentally limited and fails to improve quality even with better frequency estimation. Observing that VAR models possess significant depth redundancy, we propose a paradigm shift from pruning entire tokens to adaptively allocating per-token computational depth. To this end, we introduce DepthVAR, a training-free framework that dy
Negative / Null Result ReportOpen accessMedicine
Hanzaleh Jour Ebrahimiyan, Nafise Ansarinejad, Farshid Fardad · 2023 · Disease and Diagnosis
Background: Chemotherapy-induced peripheral neuropathy is one of the most common side effects of chemotherapy. This study aimed to determine the effectiveness of venlafaxine and duloxetine in improving chronic neurotoxicity induced by chemotherapy in cancer patients. Materials and Methods: The study was performed on cancer patients undergoing outpatient chemotherapy or hospitalization in Rasoul Akram hospital. The admitted patients were blindly divided into two groups. The first group was treated with venlafaxine, and the second group was treated with duloxetine. The treatment lasted up until
View details →DOI: 10.34172/ddj.2023.389 Negative / Null Result ReportOpen accessMedicine
Abu Sadat Mohammad Sayeem Bin Shahid, Shahnawaz Ahmed, Tanzina Tazul Renesa et al. · 2022 · PLoS ONE
Background Fibersol-2 has some beneficial effects on human health. We aimed to evaluate the digestive tolerability and acceptability of Fibersol-2 in healthy and diarrheal children, as well as improvement in stool consistencies in young diarrheal children. Methods Sixty children of either sex, aged 1-3 years having four groups (healthy children/low dose, healthy children/high dose, children with diarrhea/low dose and children with diarrhea/high dose) were enrolled into this exploratory study between 1st August to 23rd October 2017. Two presumptive doses, low (2.5g) and high (5g), twice daily w
View details →DOI: 10.1371/journal.pone.0274302 Negative / Null Result ReportOpen accessVeterinary medicine
ali kargarirezapour, somayye ghobadi, afshin zakeri · 2013 · Āsīb/shināsī-i Darmāngāhī-i Dāmpizishkī
Glucans derived from yeast cell wall are promising alternatives to antibiotics, as they have been shown to improve growth performance and stimulate the immune system of immature broilers. In this study we evaluated the effect of different levels of yeast beta-glucan (YBG) on some blood parametrs of broiler chickens. In a factorial experiment based on completely randomized design (the first factor: YBG levels: 0, 0.04 and 0.08% of basal diet and sex as a second factor) 144 day old chicks (72 male and 72 female) were selected and allocated to different treatments (three replicates of each treatm
Negative / Null Result ReportOpen accessComputer Science
Adam Byerly, Daniel Khashabi · 2024 · arXiv
Self-consistency (SC) improves the performance of large language models (LLMs) across various tasks and domains that involve short content. However, does this support its effectiveness for long-context problems? We challenge the assumption that SC's benefits generalize to long-context settings, where LLMs often struggle with position bias, the systematic over-reliance on specific context regions-which hinders their ability to utilize information effectively from all parts of their context. Through comprehensive experimentation with varying state-of-the-art models, tasks, and SC formulations, w
Negative / Null Result ReportOpen accessComputer Science
Aaron B. Wagner, Nirmal V. Shende, Yücel Altuğ · 2019 · arXiv
We introduce a novel mechanism, called timid/bold coding, by which feedback can be used to improve coding performance. For a certain class of DMCs, called compound-dispersion channels, we show that timid/bold coding allows for an improved second-order coding rate compared with coding without feedback. For DMCs that are not compound dispersion, we show that feedback does not improve the second-order coding rate. Thus we completely determine the class of DMCs for which feedback improves the second-order coding rate. An upper bound on the second-order coding rate is provided for compound-dispersi
Negative / Null Result ReportOpen accessAgricultural and Biological Sciences
Denis Boyer, Peter D. Walsh · 2010 · arXiv
Thanks to recent technological advances, it is now possible to track with an unprecedented precision and for long periods of time the movement patterns of many living organisms in their habitat. The increasing amount of data available on single trajectories offers the possibility of understanding how animals move and of testing basic movement models. Random walks have long represented the main description for micro-organisms and have also been useful to understand the foraging behaviour of large animals. Nevertheless, most vertebrates, in particular humans and other primates, rely on sophistic
Negative / Null Result ReportOpen accessSurgery
Eric R. Bain, Bistees George, Syed H. Jafri et al. · 2024 · Journal of Cardiothoracic Surgery
Abstract Background Patients with severe aortic stenosis (AS) and left ventricular (LV) dysfunction demonstrate improvement in left ventricular injection fraction (LVEF) after aortic valve replacement (AVR). The timing and magnitude of recovery in patients with very low LVEF (≤ 25%) in surgical or transcatheter AVR is not well studied. Objective Determine clinical outcomes following transcatheter aortic valve replacement (TAVR) and surgical aortic valve repair (SAVR) in the subset of patients with severely reduced EF ≤ 25%. Methods Single-center, retrospective study with primary endpoint of LV
View details →DOI: 10.1186/s13019-024-02724-9 Negative / Null Result ReportOpen accessComputer Science
Fırat Öncel, Matthias Bethge, Beyza Ermis et al. · 2024 · arXiv
In the last decade, the generalization and adaptation abilities of deep learning models were typically evaluated on fixed training and test distributions. Contrary to traditional deep learning, large language models (LLMs) are (i) even more overparameterized, (ii) trained on unlabeled text corpora curated from the Internet with minimal human intervention, and (iii) trained in an online fashion. These stark contrasts prevent researchers from transferring lessons learned on model generalization and adaptation in deep learning contexts to LLMs. To this end, our short paper introduces empirical ob
Negative / Null Result ReportOpen accessComputer Science
Piyawat Lertvittayakumjorn, David Kinney, Vinodkumar Prabhakaran et al. · 2025 · arXiv
Generative large language models (LLMs) have demonstrated gaps in diverse cultural awareness across the globe. We investigate the effect of retrieval augmented generation and search-grounding techniques on LLMs' ability to display familiarity with various national cultures. Specifically, we compare the performance of standard LLMs, LLMs augmented with retrievals from a bespoke knowledge base (i.e., KB grounding), and LLMs augmented with retrievals from a web search (i.e., search grounding) on multiple cultural awareness benchmarks. We find that search grounding significantly improves the LLM p
Negative / Null Result ReportOpen accessEngineering
Haoyang Li, Yuchen Hu, Chen Chen et al. · 2024 · arXiv
Deep neural network (DNN)-based speech enhancement (SE) usually uses conventional activation functions, which lack the expressiveness to capture complex multiscale structures needed for high-fidelity SE. Group-Rational KAN (GR-KAN), a variant of Kolmogorov-Arnold Networks (KAN), retains KAN's expressiveness while improving scalability on complex tasks. We adapt GR-KAN to existing DNN-based SE by replacing dense layers with GR-KAN layers in the time-frequency (T-F) domain MP-SENet and adapting GR-KAN's activations into the 1D CNN layers in the time-domain Demucs. Results on Voicebank-DEMAND sho
Negative / Null Result ReportOpen accessMedicine
Sung Hee Lim, Jong-Mu Sun, Joohyun Hong et al. · 2021 · The Korean Journal of Internal Medicine
Background/Aims Clinical trials have not consistently supported the use of induction chemotherapy (IC) for locally advanced head and neck squamous cell cancer. Hypopharynx and base of tongue (BOT) cancer has shown relatively poor survival. We investigated the role of IC in improving outcome over current chemoradiotherapy (CRT) in patients with hypopharynx and BOT cancer. Methods Treatment-naïve patients with stage III/IV (M0) hypopharynx or BOT cancer were randomly assigned to receive CRT alone (CRT arm: cisplatin 100 mg/m2 on D1 3-weekly, two times plus radiotherapy 68.4 Gy/30 fractions on we
View details →DOI: 10.3904/kjim.2019.161 Negative / Null Result ReportOpen accessComputer Science
Àlex Miranda-Pascual, Javier Parra-Arnau, Thorsten Strufe · 2026 · arXiv
Sampling is renowned for its privacy amplification in differential privacy (DP), and is often assumed to improve the utility of a DP mechanism by allowing a noise reduction. In this paper, we further show that this last assumption is flawed: When measuring utility at equal privacy levels, sampling as preprocessing consistently yields penalties due to utility loss from omitting records over all canonical DP mechanisms -- Laplace, Gaussian, exponential, and report noisy max -- , as well as recent applications of sampling, such as clustering. Extending this analysis, we investigate suppression as
Negative / Null Result ReportOpen accessMedicine
Cherubino Paolo, Sala Andrea, Casalone Rosario et al. · 2005 · Journal of Translational Medicine
Abstract Background Local myogenesis, neoangiogenesis and homing of progenitor cells from the bone marrow appear to contribute to repair of the infarcted myocardium. Implantation into heart tissues of autologous skeletal myoblasts has been associated with improved contractile function in animal models and in humans with acute myocardial ischemia. Since heart infarction is most prevalent in individuals of over 40 years of age, we tested whether culture methods available in our laboratory were adequate to obtain sufficient numbers of differentiated skeletal myoblasts from muscle biopsy specimens
View details →DOI: 10.1186/1479-5876-3-21 Negative / Null Result ReportOpen accessComputer Science
Hanbing Liu, Haoyang Li, Xiaokang Zhang et al. · 2025 · arXiv
Direct Preference Optimization (DPO) has proven effective in complex reasoning tasks like math word problems and code generation. However, when applied to Text-to-SQL datasets, it often fails to improve performance and can even degrade it. Our investigation reveals the root cause: unlike math and code tasks, which naturally integrate Chain-of-Thought (CoT) reasoning with DPO, Text-to-SQL datasets typically include only final answers (gold SQL queries) without detailed CoT solutions. By augmenting Text-to-SQL datasets with synthetic CoT solutions, we achieve, for the first time, consistent and
Negative / Null Result ReportOpen accessAgriculture
Leila Sahampoor, Fatemeh Zaker Tavallaie, Seyed Reza Fani et al. · 2020 · Journal of Crop Protection
Trichoderma is very important as a bio control agent and probably a good alternative for chemical fungicides. Fusarium oxysporum is a plant pathogen that causes wilt in a wide range of plants. The use of gamma irradiation can be employed to increase Trichoderma efficiency against F. oxysporum. The induced mutation provides genetic changes in Trichoderma and in some of the mutated isolates the efficiency of bio control may be improved. In this study the efficiency of mutated T. harzianum CS5 against the F. oxysporum f.sp. radicis-cucumerinum was evaluated. Among 16 wild isolates of Trichoderma,
Negative / Null Result ReportOpen accessMathematics
Oliver J. Hines, Christian L. Hines · 2026 · arXiv
Gradient boosted decision trees require a stopping rule to avoid overfitting. The standard rule monitors a validation loss and stops if the loss fails to improve for a fixed patience period. However, the patience parameter has no interpretable scale and validation losses can be noisy or implicitly defined by a user-specified gradient. We propose ScoreStop, a gradient-based early-stopping rule that casts the stopping decision at each iteration as a test of the null hypothesis that the current predictor is the population risk minimizer. We use a functional score test, computed on validation data
Negative / Null Result ReportOpen accessComputer Science
Zelu Deng, Yujie Zhong, Sheng Guo et al. · 2021 · arXiv
This work aims at improving instance retrieval with self-supervision. We find that fine-tuning using the recently developed self-supervised (SSL) learning methods, such as SimCLR and MoCo, fails to improve the performance of instance retrieval. In this work, we identify that the learnt representations for instance retrieval should be invariant to large variations in viewpoint and background etc., whereas self-augmented positives applied by the current SSL methods can not provide strong enough signals for learning robust instance-level representations. To overcome this problem, we propose InsCL
