30472 research outputs found
Sort by
Perseveration and shifting in Obsessive-Compulsive Disorder as a function of uncertainty, punishment, and Serotonergic medication
Get PDFBackground: The nature of cognitive flexibility deficits in obsessive-compulsive disorder (OCD), which historically have been tested with probabilistic reversal learning tasks, remains elusive. Here, a novel deterministic reversal task and inclusion of unmedicated patients in the study sample illuminated the role of fixed versus uncertain rules/contingencies and of serotonergic medication. Additionally, our understanding of probabilistic reversal was enhanced through theoretical computational modeling of cognitive flexibility in OCD.
Methods: We recruited 49 patients with OCD, 21 of whom were unmedicated, and 43 healthy control participants matched for age, IQ, and gender. Participants were tested on 2 tasks: a novel visuomotor deterministic reversal learning task with 3 reversals (feedback rewarding/punishing/neutral) measuring accuracy/perseveration and a 2-choice visual probabilistic reversal learning task with uncertain feedback and a single reversal measuring win-stay and lose-shift. Bayesian computational modeling provided measures of learning rate, reinforcement sensitivity, and stimulus stickiness.
Results: Unmedicated patients with OCD were impaired on the deterministic reversal task under punishment only at the first and third reversals compared with both control participants and medicated patients with OCD, who had no deficit. Perseverative errors were correlated with OCD severity. On the probabilistic reversal task, unmedicated patients were only impaired at reversal, whereas medicated patients were impaired at both the learning and reversal stages. Computational modeling showed that the overall change was reduced feedback sensitivity in both OCD groups.
Conclusions: Both perseveration and increased shifting can be observed in OCD, depending on test conditions including the predictability of reinforcement. Perseveration was related to clinical severity and remediated by serotonergic medication
Recent speciation and adaptation to aridity in the ecologically diverse Pilbara region of Australia enabled the native tobaccos (Nicotiana; Solanaceae) to colonize all Australian deserts
Get PDFOver the last 6 million years, the arid Australian Eremaean Zone (EZ) has remained as
dry as it is today. A widely accepted hypothesis suggests that the flora and fauna of
arid regions were more broadly distributed before aridification began. In Australia, this
process started around 20 million years ago (Ma), leading to gradual speciation as the
climate became increasingly arid. Here, we use genomic data to investigate the biogeography and timing of divergence of native allotetraploid tobaccos, Nicotiana section
Suaveolentes (Solanaceae). The original allotetraploid migrants from South America
were adapted to mesic areas of Australia and recently radiated in the EZ, including in
sandy dune fields (only 1.2 Ma old), after developing drought adaptations. Coalescent
and maximum likelihood analyses suggest that Nicotiana section Suaveolentes arrived
on the continent around 6 Ma, with the ancestors of the Pilbara (Western Australian)
lineages radiating there at the onset of extreme aridity 5 Ma by locally adapting to
these various ancient, highly stable habitats. The Pilbara thus served as both a mesic
refugium and cradle for adaptations to harsher conditions, due to its high topographical diversity, providing microhabitats with varying moisture levels and its proximity to
the ocean, which buffers against extreme aridity. This enabled species like Nicotiana
to survive in mesic refugia and subsequently adapt to more arid conditions. These
results demonstrate that initially poorly adapted plant groups can develop novel adaptations in situ, permitting extensive and rapid dispersal despite the highly variable
and unpredictable extreme conditions of the EZ
Why it’s worth avoiding as many viruses/common colds as possible: mine led to permanent disability
No full textPeople are obsessed with the short-term effects of Covid, prioritising them over the longer-term impacts. “It was just like a minor cold, really”, they say, perhaps not realising that even mild cases of Covid have been shown to cause lasting cognitive impairment. But I also take exception with this comparison to the common cold. Because, for me, a simple cold led to lifelong disability and severe chronic health problems
On Complexity Bounds and Confluence of Parallel Term Rewriting
Get PDFWe revisit parallel-innermost term rewriting as a model of parallel computation on inductive data structures and provide a corresponding notion of runtime complexity parametric in the size of the start term. We propose automatic techniques to derive both upper and lower bounds on parallel complexity of rewriting that enable a direct reuse of existing techniques for sequential complexity. Our approach to find lower bounds requires confluence of the parallel-innermost rewrite relation, thus we also provide effective sufficient criteria for proving confluence. The applicability and the precision of the method are demonstrated by the relatively light effort in extending the program analysis tool AProVE and by experiments on numerous benchmarks from the literature
Empirical and experimental perspectives on big data in recommendation systems: a comprehensive survey
Get PDFThis survey paper provides a comprehensive analysis of big data algorithms in recommendation systems, addressing the lack of depth and precision in existing literature. It proposes a two-pronged approach: a thorough analysis of current algorithms and a novel, hierarchical taxonomy for precise categorization. The taxonomy is based on a tri-level hierarchy, starting with the methodology category and narrowing down to specific techniques. Such a framework allows for a structured and comprehensive classification of algorithms, assisting researchers in understanding the interrelationships among diverse algorithms and techniques. Covering a wide range of algorithms, this taxonomy first categorizes algorithms into four main analysis types: user and item similarity based methods, hybrid and combined approaches, deep learning and algorithmic methods, and mathematical modeling methods, with further subdivisions into sub-categories and techniques. The paper incorporates both empirical and experimental evaluations to differentiate between the techniques. The empirical evaluation ranks the techniques based on four criteria. The experimental assessments rank the algorithms that belong to the same category, sub-category, technique, and sub-technique. Also, the paper illuminates the future prospects of big data techniques in recommendation systems, underscoring potential advancements and opportunities for further research in this fields
Modulation of Vibrio cholerae gene expression through conjugative delivery of engineered regulatory small RNAs
Get PDFThe increase in antibiotic resistance in bacteria has prompted the efforts in developing new alternative strategies for pathogenic bacteria. We explored the feasibility of targeting Vibrio cholerae by neutralizing bacterial cellular processes rather than outright killing the pathogen. We investigated the efficacy of delivering engineered regulatory small RNAs (sRNAs) to modulate gene expression through DNA conjugation. As a proof of concept, we engineered several sRNAs targeting the type VI secretion system (T6SS), several of which were able to successfully knockdown the T6SS activity at different degrees. Using the same strategy, we modulated exopolysaccharide production and motility. Lastly, we delivered an sRNA targeting T6SS into V. cholerae via conjugation and observed a rapid knockdown of the T6SS activity. Coupling conjugation with engineered sRNAs represents a novel way of modulating gene expression in V. cholerae opening the door for the development of novel prophylactic and therapeutic applications
A visual analytics framework for explainable malware detection in Edge computing networks
Get PDFThe emergence of new technologies for the fifth/sixth generation (5G/6G) wireless networks has led to the development of new services, resulting in an increase in malicious activities and cyber-attacks targeting various network layers. Edge computing, a crucial technology enabler for 6G, is expected to facilitate traffic optimisation and support new ultra- low latency services. By integrating computing power from supercomputing servers into devices at the network edge in a distributed manner, edge computing can provide consistent quality-of-service, even in remote areas, which will drive the growth of associated applications. However, the complex environment created by edge computing also poses challenges for detecting malware. Therefore, this paper proposes a novel approach to malware detection using explainability via visualization and a multi-labelling technique. An object detection algorithm is used to identify malware families within the dataset which is created by emphasizing key regions. Using features from different malware categories in an image, this model displays a thorough malware recipe. Our experiments using real malware data demonstrate that identifying malware by its visible characteristics can significantly improve the interpretability of the detection process, enhancing transparency and trustworthiness
Coordination and optimization decision of assembly building supply chain under supply disruption risk
Get PDFIn the context of the low-carbon transformation of the construction industry, assembly buildings have better results in reducing carbon emissions, improving building standardization, and optimizing the use of resources compared to traditional buildings. But the assembly building supply chain is characterized by high vulnerability and time-sensitive requirements. Therefore, this paper considers the disruption risk and capacity constraints of the assembly building supply chain under the supply disruption risk and constructs a three-tier assembly building supply chain consisting of primary suppliers of components, backup suppliers, assembly manufacturers, and retailers, comparing the optimal decision-making and supply chain coordination of the supply chain members under the centralized, decentralized, and joint pacts, respectively. On this basis, the supply chain dual-source procurement decision coordination model is constructed by integrating the capacity constraints, and the impacts of supply disruption probability, repurchase coefficient, revenue sharing coefficient, cost and other parameters on the expected profits of the supply chain members are analyzed by arithmetic simulation. Studies have shown that an increase in the risk of disruption leads to a decrease in the expected profit of the primary provider and an increase in the expected profit of the backup provider. With a joint contract, the expected profits of the assembly manufacturer and the parts backup supplier would be much higher than in the decentralized decision-making model. The revenue sharing coefficient affects the expected profits of retailers and assembly manufacturers to a greater extent than the repurchase coefficient. The selection bias between NA and NB strategies under capacity constraints stems mainly from the aggressiveness of the wholesale asking prices of low-cost suppliers of components, with assembly manufacturers increasingly favoring the NA strategy. The research in this paper can effectively realize the contractual coordination of the assembly building supply chain, enhance the resilience of the assembly building supply chain, and promote the long-term sustainable development of the assembly building supply chain
Auditory processing as perceptual, cognitive, and motoric abilities underlying successful second language acquisition: interaction model.
Get PDFA growing amount of attention has been given to examining the domain-general auditory processing of individual acoustic dimensions as a key driving force for adult L2 acquisition. Whereas auditory processing has traditionally been conceptualized as a bottom-up and encapsulated phenomenon, the interaction model (Kraus & Banai, 2007) proposes auditory processing as a set of perceptual, cognitive, and motoric abilities—the perception of acoustic details (acuity), the selection of relevant and irrelevant dimensions (attention), and the conversion of audio input into motor action (integration). To test this hypothesis, we examined the relationship between each component and the L2 outcomes of 102 adult Chinese speakers of English who varied in age, experience, and working memory background. According to the results of the statistical analyses, (a) the tests scores tapped into essentially distinct components of auditory processing (acuity, attention, and integration), and (b) these components played an equal role in explaining various aspects of L2 learning (phonology, morphosyntax) with large effects, even after biographical background and working memory were controlled for
Introduction - Shaping Film Festivals In a Changing World: Practice and Methods
Get PDFThis is an introductory section to the edited volume Shaping Film Festivals In a Changing World: Practice and Methods. This volume is a collective attempt on the part of a community of academics, film festival curators, and archivists to come to terms with practical and intellectual challenges of the pandemic and post-pandemic realities affecting cultures of film festivals. The collection draws contours of critical inquiry orienting current film festival research and practice to explore new directions in archiving and decolonizing practices and big data analysis in the post-Covid-19 context and beyond. The four-part study gathers the voices of academics and practitioners who engage in a dialogue to articulate critical areas for both study and practice of film festivals, and identifies conceptual tools to address them: “Archival Turn,” “Decolonizing Film Festival Studies,” “Post-Covid-19 and Film Festival Studies” and “Data Visualization and Film Festival Research and Practice.
Data sources:
Access Repository Dashboard
Do you manage Birkbeck Institutional Research Online? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!