157 research outputs found

    Ransomware Detection Using Federated Learning with Imbalanced Datasets

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    Ransomware is a type of malware which encrypts user data and extorts payments in return for the decryption keys. This cyberthreat is one of the most serious challenges facing organizations today and has already caused immense financial damage. As a result, many researchers have been developing techniques to counter ransomware. Recently, the federated learning (FL) approach has also been applied for ransomware analysis, allowing corporations to achieve scalable, effective detection and attribution without having to share their private data. However, in reality there is much variation in the quantity and composition of ransomware data collected across multiple FL client sites/regions. This imbalance will inevitably degrade the effectiveness of any defense mechanisms. To address this concern, a modified FL scheme is proposed using a weighted cross-entropy loss function approach to mitigate dataset imbalance. A detailed performance evaluation study is then presented for the case of static analysis using the latest Windows-based ransomware families. The findings confirm improved ML classifier performance for a highly imbalanced dataset.Comment: 6 pages, 4 figures, 3 table

    Activity Inference for Ambient Intelligence Through Handling Artifacts in a Healthcare Environment

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    Human activity inference is not a simple process due to distinct ways of performing it. Our proposal presents the SCAN framework for activity inference. SCAN is divided into three modules: (1) artifact recognition, (2) activity inference, and (3) activity representation, integrating three important elements of Ambient Intelligence (AmI) (artifact-behavior modeling, event interpretation and context extraction). The framework extends the roaming beat (RB) concept by obtaining the representation using three kinds of technologies for activity inference. The RB is based on both analysis and recognition from artifact behavior for activity inference. A practical case is shown in a nursing home where a system affording 91.35% effectiveness was implemented in situ. Three examples are shown using RB representation for activity representation. Framework description, RB description and CALog system overcome distinct problems such as the feasibility to implement AmI systems, and to show the feasibility for accomplishing the challenges related to activity recognition based on artifact recognition. We discuss how the use of RBs might positively impact the problems faced by designers and developers for recovering information in an easier manner and thus they can develop tools focused on the user

    First-line therapy for post-traumatic stress disorder : a systematic review of cognitive behavioural therapy and psychodynamic approaches

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    Background: Despite evidence supporting cognitive behavioural therapy (CBT) based interventions as the most effective approach for treating posttraumatic stress disorder (PTSD) in randomised control trials, alternative treatment interventions are often used in clinical practice. Psychodynamic (PDT) based interventions are one example of such preferred approaches, this is despite comparatively limited available evidence supporting their effectiveness for treating PTSD. Aims: Existing research exploring effective therapeutic interventions for PTSD includes trauma-focused CBT involving exposure techniques. The present review sought to establish the treatment efficacy of CBT and PDT approaches, and considers the potential impact of selecting PDT-based techniques over CBT-based techniques for the treatment of PTSD.Results: The evidence reviewed provided examples supporting PDT-based therapy as an effective treatment for PTSD, but confirmed CBT as more effective in the treatment of this particular disorder. Comparable dropout rates were reported for both treatment approaches, suggesting that relative dropout rate should not be a pivotal factor in the selection of a PDT approach over CBT for treatment of PTSD.Conclusion/Implications: The need to routinely observe evidence-based recommendations for effective treatment of PTSD is highlighted and factors undermining practitioner engagement with CBT-based interventions for the treatment of PTSD are identified

    Elimination of the Warburg effect in Chinese hamster ovary (CHO) cells improves cell phenotype as a protein production platform

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    Lactate is a common metabolite and is central to many important processes. One of its more prominent roles is in the Warburg effect, in which cancer cells exhibit high rates of glycolytic flux followed by secretion of lactate, even in the presence of oxygen. This fermentation of pyruvate to lactate via lactate dehydrogenase (Ldh) accompanies increased proliferation of cancer cells and several other types of rapidly proliferating cell types in immune cell activation and embryonic development. Aerobic glycolysis is also prominent in biotherapeutic protein production, where mammalian production cells often secrete high levels of lactate. The accumulation of lactate is deleterious for cell growth, viability, product formation, and quality, both directly via acidification of the media and indirectly through base addition to control culture pH. Despite a clear genetic target, efforts to eliminate lactate secretion via knockout of Ldh(s) in mammalian cells have been unsuccessful, pointing to the essentiality of Ldh mediated NAD regeneration. A wide variety of approaches have been utilized to limit lactate accumulation in culture, including knockdown or inhibition of Ldh, replacement of glucose with alternate sugars, controlled feeding strategies, and many others, however none have proven successful in eliminating the Warburg effect. We report the elimination of the Warburg effect in a CHO cell line by using CRISPR/Cas9-based engineering to simultaneously knockout enzymes responsible for lactate production and ancillary regulators. The resulting cell lines remain proliferative while consuming significantly less glucose and can be used to generate protein producing lines using standard industrial processes. In a pH-controlled fedbatch process, the Warburg null cells require minimal base addition to maintain a stable pH, allowing an extended growth phase. The knockout strategy was also successfully applied to a CHO cell line producing Rituximab, again resulting in a prolonged growth phase. Additionally, protein production was maintained, while product quality was improved with increased glycan galactosylation. Thus, CHO cells without the capacity of Warburg metabolism may be useful for engineering production cell lines with enhanced bioproduction traits

    Roadmap on digital holography [Invited]

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    This Roadmap article on digital holography provides an overview of a vast array of research activities in the field of digital holography. The paper consists of a series of 25 sections from the prominent experts in digital holography presenting various aspects of the field on sensing, 3D imaging and displays, virtual and augmented reality, microscopy, cell identification, tomography, label-free live cell imaging, and other applications. Each section represents the vision of its author to describe the significant progress, potential impact, important developments, and challenging issues in the field of digital holography

    Development of a core outcome set for orthodontic trials using a mixed-methods approach: Protocol for a multicentre study

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    © 2017 The Author(s). Background: Orthodontic treatment is commonly undertaken in young people, with over 40% of children in the UK needing treatment and currently one third having treatment, at a cost to the National Health Service in England and Wales of £273 million each year. Most current research about orthodontic care does not consider what patients truly feel about, or want, from treatment, and a diverse range of outcomes is being used with little consistency between studies. This study aims to address these problems, using established methodology to develop a core outcome set for use in future clinical trials of orthodontic interventions in children and young people. Methods/design: This is a mixed-methods study incorporating four distinct stages. The first stage will include a scoping review of the scientific literature to identify primary and secondary outcome measures that have been used in previous orthodontic clinical trials. The second stage will involve qualitative interviews and focus groups with orthodontic patients aged 10 to 16 years to determine what outcomes are important to them. The outcomes elicited from these two stages will inform the third stage of the study in which a long-list of outcomes will be ranked in terms of importance using electronic Delphi surveys involving clinicians and patients. The final stage of the study will involve face-to-face consensus meetings with all stakeholders to discuss and agree on the outcome measures that should be included in the final core outcome set. Discussion: This research will help to inform patients, parents, clinicians and commissioners about outcomes that are important to young people undergoing orthodontic treatment. Adoption of the core outcome set in future clinical trials of orthodontic treatment will make it easier for results to be compared, contrasted and combined. This should translate into improved decision-making by all stakeholders involved. Trial registration: The project has been registered on the Core Outcome Measures in Effectiveness Trials (COMET) website, January 2016

    What is the value of orthodontic treatment?

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    Orthodontic treatment is as popular as ever. Orthodontists frequently have long lists of people wanting treatment and the cost to the NHS in England was ÂŁ258m in 2010-2011 (approximately 10% of the NHS annual spend on dentistry). It is important that clinicians and healthcare commissioners constantly question the contribution of interventions towards improving the health of the population. In this article, the authors outline some of the evidence for and against the claims that people with a malocclusion are at a disadvantage compared with those without a malocclusion and that orthodontic treatment has significant health benefits. The authors would like to point out that this is not a comprehensive and systematic review of the entire scientific literature. Rather the evidence is presented in order to stimulate discussion and debate

    Fatigue life of machined components

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    A correlation between machining process and fatigue strength of machined components clearly exists. However, a complete picture of the knowledge on this is not readily available for practical applications. This study addresses this issue by investigating the effects of machining methods on fatigue life of commonly used materials, such as titanium alloys, steel, aluminium alloys and nickel alloys from previous literature. Effects of turning, milling, grinding and different non-conventional machining processes on fatigue strength of above-mentioned materials have been investigated in detail with correlated information. It is found that the effect of materials is not significant except steel in which phase change causes volume expansion, resulting in compressive/tensile residual stresses based on the amounts of white layers. It is very complex to identify the influence of surface roughness on the fatigue strength of machined components in the presence of residual stresses. The polishing process improves the surface roughness, but removes the surface layers that contain compressive residual stresses to decrease the fatigue strength of polished specimens. The compressive and tensile residual stresses improve and reduce fatigue strength, respectively. Grinding process induces tensile residual stresses on the machined surfaces due to high temperature generation. On the other hand, milling and turning processes induce compressive residual stresses. High temperature non-conventional machining generates a network of micro-cracks on the surfaces in addition to tensile residual stresses to subsequently reduce fatigue strength of machined components. Embedded grits of abrasive water jet machining degrade the fatigue performance of components machined by this method

    On the Introduction of an Agile, Temporary Workforce into a Tandem Queueing System

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    We consider a two-station tandem queueing system where customers arrive according to a Poisson process and must receive service at both stations before leaving the system. Neither queue is equipped with dedicated servers. Instead, we consider three scenarios for the fluctuations of workforce level. In the first, a decision-maker can increase and decrease the capacity as is deemed appropriate; the unrestricted case. In the other two cases, workers arrive randomly and can be rejected or allocated to either station. In one case the number of workers can then be reduced (the controlled capacity reduction case). In the other they leave randomly (the uncontrolled capacity reduction case). All servers are capable of working collaboratively on a single job and can work at either station as long as they remain in the system. We show in each scenario that all workers should be allocated to one queue or the other (never split between queues) and that they should serve exhaustively at one of the queues depending on the direction of an inequality. This extends previous studies on flexible systems to the case where the capacity varies over time. We then show in the unrestricted case that the optimal number of workers to have in the system is non-decreasing in the number of customers in either queue.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47647/1/11134_2005_Article_2441.pd
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