1,721,038 research outputs found
Sense and Sensitivity: Data Utility and User Privacy in Differentially Private Machine Learning
Full text linkThis thesis explores existing and novel methods for extracting knowledge from datawhile preserving users' private information through differentially private machine learning. The central challenge addressed here is handling the sensitivity-utility tradeoff that arises when privatizing queries involving vector averages, which are found everywhere in gradient-based optimization and data science in general. New approaches are thus proposed to provide researchers and practitioners with additional tools to prioritize the use of one strategy over the other,depending on the specific learning context, the privacy expectations, and the accuracy of the resulting model. First, metric privacy concepts are applied to collaborative model training, providing distance-dependent privacy guarantees without pre-defining sensitivity. An online optimization method is then introduced for tuning the clipping threshold concurrently with model training, reducing privacy exposure and computational requirements while improving utility. Efficient strategies for empirically verifying privacy results in the training of large language models are also developed, encouraging practical privacy auditing.Finally, a new perspective is offered on the definition of differential privacy,suggesting that sensitivity with respect to record replacement rather thanaddition/removal could yield increased utility in federated learning settings.Through theoretical analyses, algorithms, and experimental evaluations, this work presents ideas and actual techniques for optimizing the privacy-utility tradeoff inherent in differentially private machine learning
NK cell imaging by in vitro and in vivo labelling approaches
No full textNatural killer (NK) cells are a particular lymphocyte subset with a documented cytotoxic activity against cancer cells. Evidence of NK antitumoral effect led researchers to focus on the development of immunotherapies aimed at augmenting NK recruitment and infiltration into tumor and their anti-cancer functions. Studies in animal models proved that the right combination of drugs, cytokines, chemokines and other factors might be used to enhance or suppress tumor targeting by NK cells. Therefore, it would be necessary to have a tool to non-invasively monitor the efficacy of such novel therapies. Available imaging techniques comprise magnetic resonance, optical and nuclear medicine imaging with a pool of compounds that ranges from radiolabelled nanoparticles and radiopharmaceuticals to fluorescent probes. Each tracer and technique has its own pros and cons, but till now, no one emerged as superior among the others
Radiolabelled probes targeting infection and inflammation for personalized medicine.
No full textInflammatory and infectious diseases include many different clinical conditions not often well recognised and characterized with conventional radiology and biochemical tests. Radiological techniques (TC, MRI, US) show anatomical changes that usually occur in chronic stages of the disease leading to a delayed diagnosis and therapy. The possibility of Nuclear Medicine imaging to detect biological and biochemical changes in the earliest phases of diseases, allow the clinician not only to promptly identify the infective or inflammatory focus, but also to establish the best therapeutic approach for the patient. The recent availability of different monoclonal antibodies and analogues of growth and signalling factors offers physicians a wide spectrum of promising radiopharmaceuticals as markers for different pathological events. Therefore, NM may help in therapy decision making, management and follow-up through the evaluation of the expression of these specific molecules, leading to the development of personalized therapies. The appeal to Nuclear Medicine imaging is becoming, indeed, more and more widespread not only for diagnostic purposes, but also for monitoring drug efficacy. Several advances have been observed in this field, and they seem to be very promising for a tailored medicine
Extending OpenStack Monasca for Predictive Elasticity Control
Full text linkTraditional auto-scaling approaches are conceived as reactive automations, typically triggered when predefined thresholds are breached by resource consumption metrics. Managing such rules at scale is cumbersome, especially when resources require non-negligible time to be instantiated. This paper introduces an architecture for predictive cloud operations, which enables orchestrators to apply time-series forecasting techniques to estimate the evolution of relevant metrics and take decisions based on the predicted state of the system. In this way, they can anticipate load peaks and trigger appropriate scaling actions in advance, such that new resources are available when needed. The proposed architecture is implemented in OpenStack, extending the monitoring capabilities of Monasca by injecting short-term forecasts of standard metrics. We use our architecture to implement predictive scaling policies leveraging on linear regression, autoregressive integrated moving average, feed-forward, and recurrent neural networks (RNN). Then, we evaluate their performance on a synthetic workload, comparing them to those of a traditional policy. To assess the ability of the different models to generalize to unseen patterns, we also evaluate them on traces from a real content delivery network (CDN) workload. In particular, the RNN model exhibites the best overall performance in terms of prediction error, observed client-side response latency, and forecasting overhead. The implementation of our architecture is open-source
Imaging T-lymphocytes in inflammatory diseases: a nuclear medicine approach.
No full textIncreasing interest and research efforts have been made in search of specific radiolabelled probes for imaging different immune cells (including T-lymphocytes) in inflammation and infection. This has led to early detection of lymphocyte infiltration, and the deepening of our understanding of pathogenesis of immune mediated diseases. In-vivo imaging of T-lymphocytes with radiolabelled specific probes may provide an important piece of information about inflammatory lesions, which could be very important to understand the molecular mechanism of action of any drug and/or their effect on the microenvironment of the immune system of the body. The present review focuses on radiolabelled T-lymphocytes and different monoclonal antibodies, peptides, cytokines, chemokine used for scintigraphic imaging of T-lymphocytes and their subsets
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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