174 research outputs found
Adaptive query-based sampling of distributed collections
As part of a Distributed Information Retrieval system a de-scription of each remote information resource, archive or repository is usually stored centrally in order to facilitate resource selection. The ac-quisition ofprecise resourcedescriptionsistherefore animportantphase in Distributed Information Retrieval, as the quality of such represen-tations will impact on selection accuracy, and ultimately retrieval per-formance. While Query-Based Sampling is currently used for content discovery of uncooperative resources, the application of this technique is dependent upon heuristic guidelines to determine when a sufficiently accurate representation of each remote resource has been obtained. In this paper we address this shortcoming by using the Predictive Likelihood to provide both an indication of thequality of an acquired resource description estimate, and when a sufficiently good representation of a resource hasbeen obtained during Query-Based Sampling
Critical role of the disintegrin metalloprotease ADAM-like Decysin-1 (ADAMDEC1) for intestinal immunity and inflammation
BACKGROUND AND AIMS: ADAM (A Disintegrin And Metalloproteinase) is a family of peptidase proteins, which have diverse roles in tissue homeostasis and immunity. Here, we study ADAM-like Decysin-1 (ADAMDEC1) a unique member of the ADAM family. ADAMDEC1 expression is restricted to the macrophage/dendritic cell populations of the gastrointestinal tract and secondary lymphoid tissue. The biological function of ADAMDEC1 is unknown but it has been hypothesised to play a role in immunity. The identification of reduced ADAMDEC1 expression in Crohn's disease patients has provided evidence of a potential role in bowel inflammation. METHODS: Adamdec1(-/-) mice were exposed to dextran sodium sulphate or infected orally with Citrobacter rodentium or Salmonella typhimurium The clinical response was monitored. RESULTS: The loss of Adamdec1 rendered mice more susceptible to the induction of bacterial and chemical induced colitis, as evidenced by increased neutrophil infiltration, greater IL-6 and IL-1β secretion, more weight loss and increased mortality. In the absence of Adamdec1, greater numbers of Citrobacter rodentium were found in the spleen, suggestive of a breakdown in mucosal immunity which resulted in bacteraemia. CONCLUSION: In summary, Adamdec1 protects the bowel from chemical and bacterial insults, failure of which may predispose to Crohn's disease
Deep Sequential Models for Task Satisfaction Prediction
Detecting and understanding implicit signals of user satisfaction are essential for experimentation aimed at predicting searcher satisfaction. As retrieval systems have advanced, search tasks have steadily emerged as accurate units not only to capture searcher's goals but also in understanding how well a system is able to help the user achieve that goal. However, a major portion of existing work on modeling searcher satisfaction has focused on query level satisfaction. The few existing approaches for task satisfaction prediction have narrowly focused on simple tasks aimed at solving atomic information needs.
In this work we go beyond such atomic tasks and consider the problem of predicting user's satisfaction when engaged in complex search tasks composed of many different queries and subtasks. We begin by considering holistic view of user interactions with the search engine result page (SERP) and extract detailed interaction sequences of their activity. We then look at query level abstraction and propose a novel deep sequential architecture which leverages the extracted interaction sequences to predict query level satisfaction. Further, we enrich this model with auxiliary features which have been traditionally used for satisfaction prediction and propose a unified multi-view model which combines the benefit of user interaction sequences with auxiliary features.
Finally, we go beyond query level abstraction and consider query sequences issued by the user in order to complete a complex task, to make task level satisfaction predictions. We propose a number of functional composition techniques which take into account query level satisfaction estimates along with the query sequence to predict task level satisfaction. Through rigorous experiments, we demonstrate that the proposed deep sequential models significantly outperform established baselines at both query and task satisfaction prediction. Our findings have implications on metric development for gauging user satisfaction and on designing systems which help users accomplish complex search tasks
Serum overexpression of miR-301a and miR-23a in patients with colorectal cancer
BACKGROUND: Extracellular vesicles (EVs) are a heterogeneous group of membrane-bound vesicles with complex cargoes including proteins, lipids, and nucleic acids. EVs have received significant attention due to their specific features including stability under harsh conditions and involvement in cell-to-cell communication. Circulating EVs and the molecules associated with them are important in the diagnosis and prognosis of cancers. MicroRNAs (miRNAs) are a group of small noncoding RNAs that have a role in regulating gene expression. Current literature shows that circulating miRNAs can be used as noninvasive biomarkers for early detection of cancers. The present study was set to investigate the potential role of serum exosomal miRNA expression levels in colorectal cancer (CRC) patients and evaluate their correlation with clinicopathologic features. METHODS: Exosome-enriched fractions were isolated from the serum of 25 CRC patients and 13 age- and sex-matched healthy controls using a polymer-based precipitation method. During the pilot phase, real-time polymerase chain reaction (RT-PCR) was carried out on 12 CRC patients and eight healthy participants to evaluate the expression difference of 11 candidate miRNAs between CRC patients and tumor free subjects. Finally, the results were validated in a separate group, which was similar in size to the pilot group. The clinicopathologic data were also collected and the relationship between aberrant miRNA expression and clinicopathological parameters were investigated. RESULTS: There were high expressions of exosomal miR-23a and miR-301a in serum samples of CRC patients compared to normal controls in training and validation phases; these differences were not significantly correlated with clinicopathologic features. Receiver operating characteristic curve analysis showed that miR-301a and miR-23a were able to discriminate CRC patients from normal subjects. CONCLUSION: The findings provide evidence on the roles of miR-301a and miR-23a in CRC development and their potential roles as noninvasive biomarkers for early detection of CRC
Assessment of the impact of the scanner-related factors on brain morphometry analysis with Brainvisa.
BACKGROUND: Brain morphometry is extensively used in cross-sectional studies. However, the difference in the estimated values of the morphometric measures between patients and healthy subjects may be small and hence overshadowed by the scanner-related variability, especially with multicentre and longitudinal studies. It is important therefore to investigate the variability and reliability of morphometric measurements between different scanners and different sessions of the same scanner. METHODS: We assessed the variability and reliability for the grey matter, white matter, cerebrospinal fluid and cerebral hemisphere volumes as well as the global sulcal index, sulcal surface and mean geodesic depth using Brainvisa. We used datasets obtained across multiple MR scanners at 1.5 T and 3 T from the same groups of 13 and 11 healthy volunteers, respectively. For each morphometric measure, we conducted ANOVA analysis and verified whether the estimated values were significantly different across different scanners or different sessions of the same scanner. The between-centre and between-visit reliabilities were estimated from their contribution to the total variance, using a random-effects ANOVA model. To estimate the main processes responsible for low reliability, the results of brain segmentation were compared to those obtained using FAST within FSL. RESULTS: In a considerable number of cases, the main effects of both centre and visit factors were found to be significant. Moreover, both between-centre and between-visit reliabilities ranged from poor to excellent for most morphometric measures. A comparison between segmentation using Brainvisa and FAST revealed that FAST improved the reliabilities for most cases, suggesting that morphometry could benefit from improving the bias correction. However, the results were still significantly different across different scanners or different visits. CONCLUSIONS: Our results confirm that for morphometry analysis with the current version of Brainvisa using data from multicentre or longitudinal studies, the scanner-related variability must be taken into account and where possible should be corrected for. We also suggest providing some flexibility to Brainvisa for a step-by-step analysis of the robustness of this package in terms of reproducibility of the results by allowing the bias corrected images to be imported from other packages and bias correction step be skipped, for example.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Digital outpatient health solutions as a vehicle to improve healthcare sustainability—a United Kingdom focused policy and practice perspective
IntroductionIn the midst of a global climate emergency and with health care systems across the world facing extreme pressure, interest in digital approaches as a potential part-solution to these challenges has increased rapidly. The evidence base to support the role that digitalization can play in moving towards more sustainable models of healthcare is growing, as is the awareness of this key area of healthcare reform amongst policy makers, clinicians and the public.Method and ResultsIn this policy and practice review we explore four domains of healthcare sustainability-environmental, economic, and patient and clinician, delineating the potential impact that digitally enabled healthcare can have on each area. Real-world examples are provided to illustrate the impact individual digital interventions can have on each pillar of sustainability and demonstrate the scale of the potential benefits which can be achieved.DiscussionDigitally enabled healthcare solutions present an approach which offer numerous benefits, including environmental sustainability, economic benefits, and improved patient experience. There are also potential drawbacks such as the risk of digital exclusion and the need for integration with existing technology platforms. Overall, it is essential to strike a balance between the benefits and potential drawbacks of digital healthcare solutions to ensure that they are equitable, effective, and sustainable
Recent publications from the Alzheimer's Disease Neuroimaging Initiative: Reviewing progress toward improved AD clinical trials
INTRODUCTION:
The Alzheimer's Disease Neuroimaging Initiative (ADNI) has continued development and standardization of methodologies for biomarkers and has provided an increased depth and breadth of data available to qualified researchers. This review summarizes the over 400 publications using ADNI data during 2014 and 2015.
METHODS:
We used standard searches to find publications using ADNI data.
RESULTS:
(1) Structural and functional changes, including subtle changes to hippocampal shape and texture, atrophy in areas outside of hippocampus, and disruption to functional networks, are detectable in presymptomatic subjects before hippocampal atrophy; (2) In subjects with abnormal β-amyloid deposition (Aβ+), biomarkers become abnormal in the order predicted by the amyloid cascade hypothesis; (3) Cognitive decline is more closely linked to tau than Aβ deposition; (4) Cerebrovascular risk factors may interact with Aβ to increase white-matter (WM) abnormalities which may accelerate Alzheimer's disease (AD) progression in conjunction with tau abnormalities; (5) Different patterns of atrophy are associated with impairment of memory and executive function and may underlie psychiatric symptoms; (6) Structural, functional, and metabolic network connectivities are disrupted as AD progresses. Models of prion-like spreading of Aβ pathology along WM tracts predict known patterns of cortical Aβ deposition and declines in glucose metabolism; (7) New AD risk and protective gene loci have been identified using biologically informed approaches; (8) Cognitively normal and mild cognitive impairment (MCI) subjects are heterogeneous and include groups typified not only by "classic" AD pathology but also by normal biomarkers, accelerated decline, and suspected non-Alzheimer's pathology; (9) Selection of subjects at risk of imminent decline on the basis of one or more pathologies improves the power of clinical trials; (10) Sensitivity of cognitive outcome measures to early changes in cognition has been improved and surrogate outcome measures using longitudinal structural magnetic resonance imaging may further reduce clinical trial cost and duration; (11) Advances in machine learning techniques such as neural networks have improved diagnostic and prognostic accuracy especially in challenges involving MCI subjects; and (12) Network connectivity measures and genetic variants show promise in multimodal classification and some classifiers using single modalities are rivaling multimodal classifiers.
DISCUSSION:
Taken together, these studies fundamentally deepen our understanding of AD progression and its underlying genetic basis, which in turn informs and improves clinical trial desig
Pulse velocity assessment of early age creep of concrete
Creep of concrete can have damaging effects by inducing deformations that may contribute or eventually lead to cracks, which influence concrete durability, steel reinforcement exposure to corrosion, and aesthetic damage to architectural buildings. This research investigated the early age creep deformation in concrete samples made with normal, lightweight (Lytag), recycled concrete, and recycled asphalt aggregates using ultrasonic pulse velocity measurements. Creep was achieved by applying a load corresponding to 30% of the strength of concrete to 100 × 250 mm prisms. The compressive load was applied from 24 h after mixing and up to 27 days. The results and analysis of measurements obtained for stress development, specific creep (creep strain per unit stress), and ultrasonic pulse velocity measured up to 27 days after load application are presented. Empirical models that allow the assessment of creep of concrete using ultrasonic pulse velocity measurements are also presented.
Early age specific creep is higher for recycled asphalt aggregate than Lytag aggregate and recycled concrete aggregate concretes, which are higher than gravel concrete. Measurements of ultrasonic pulse velocity could be used to determine creep but further work to refine this technique is required
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