ICA-Based Algorithm Applied to Image Coding

©2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.International audienceRecently, Narozny et al [1] proposed a new viewpoint in variable high-rate transform coding. They showed that the problem of finding the optimal 1-D linear block transform for a coding system employing entropy-constrained uniform quantization may be viewed as a modified independent component analysis (ICA) problem. By adopting this new viewpoint, two new ICA-based algorithms, called GCGsup and ICAorth, were then derived for computing respectively the optimal linear transform and the optimal orthogonal transform. In this paper, we show that the transforms returned by GCGsup and ICAorth can achieve better visual image quality(better preservation of lines and contours) than the KLT and 2-D Discrete Cosine Transform (DCT) when applied to the compression of well-known grayscale images

Design and synthesis of novel classes of HDACs and KMTs inhibitors

For long, scientists thought that our body was driven only by our genetic code that we inherited at birth. However, this determinism was shattered entirely and proven as false in the second half of the 21st century with the discovery of epigenetics. Instead, cells turn genes on and off using reversible chemical marks. With the tremendous progression of epigenetic science, it is now believed that we have a certain power over the expression of our genetic traits. Over the years, these epigenetic modifications were found to be at the core of how diseases alter healthy cells, and environmental factors and lifestyle were identified as top influencers. Epigenetic dysregulation has been observed in every major domain of medicine, with a reported implication in cancer development, neurodegenerative pathologies, diabetes, infectious disease and even obesity. Substantially, an epigenetic component is expected to be involved in every human disease. Hence, the modulation of these epigenetics mechanisms has emerged as a therapeutic strategy. Histone deacetylases (HDAC) are silencing epigenetic markers involved in the mediation of the acetylation system. Aberrant HDAC activities have been associated with the development of a broad range of pathologies, and HDAC inhibition is highly regarded as a potential therapeutic target. This approach became successful with the approval by the FDA of several epidrugs. However, they present undesired side effects. Lack of selectivity was identified as a principal suspect and, therefore, the development of novel compounds that would target more selectively the epigenetics enzymes represent a major axis of research for future pharmacological applications. Accordingly, this work focus on designing new classes of HDAC inhibitors. A variety of structures, build around the use of amino acids, were explored and potential inhibitors were produced with different cores. These series were then evaluated in enzymatic inhibition assays on HDAC and in cell growth inhibition assays on leukaemia cell lines. Additionally, we were also involved in the international consortium A-ParaDDisE that aimed to develop epigenetic modulators as drug candidates against the main parasitic diseases: malaria, schistosomiasis, leishmaniasis and Chagas disease. This collaboration resulted in the identification of critical targets for the different parasites and the development of testing methods to move compounds toward clinical development. The antischistosomal effect of some of our inhibitors was, thus, evaluated. Finally, a side project was carried at the University of Salerno in Italy in a short-term scientific mission that aimed to develop a new class of SETD8 methyltransferase inhibitors

Exploring the Relationship Between a ‘Facebook Group’ and Face-to-Face Interactions in ‘Weak-Tie’ Residential Communities

Using Facebook Groups to connect otherwise anonymous people that live in a single urban development is a relatively new phenomenon. Within residential developments there are a number of common management and performance issues experienced by many isolated inhabitants that are identified through building performance evaluation studies. Facebook is a ubiquitous social network tool and powerful communication platform, particularly popular among young adults. This paper explores the use of Facebook in relation to management and performance issues in two cases of Facebook Group usage within residential communities in the UK. Data was collected through longitudinal digital and physical visits to the residential communities and to the Facebook Group sites. Findings are presented in relation to home learning, site/neighbourhood and self-organising initiatives. We propose that weak-tie residential communities can develop collective efficacy and work together for the overall good of the residential development through communicating on a Facebook Group. This helps to improve the physical environment, facilitating further collective action. There is a clear overlap between social media narrative and the physical experience of daily life, which can help to empower residents

ICA based algorithms for computing optimal 1-D linear block transforms in variable high-rate source coding

International audienceThe Karhunen-Loève Transform (KLT) is optimal for transform coding of Gaussian sources, however, it is not optimal, in general, for non-Gaussian sources. Furthermore, under the high-resolution quantization hypothesis, nearly everything is known about the performance of a transform coding system with entropy constrained scalar quantization and mean-square distortion. It is then straightforward to find a criterion that, when minimized, gives the optimal linear transform under the abovementioned conditions. However, the optimal transform computation is generally considered as a difficult task and the Gaussian assumption is then used in order to simplify the calculus. In this paper, we present the abovementioned criterion as a contrast of independent component analysis modified by an additional term which is a penalty to non-orthogonality. Then we adapt the icainf algorithm by Pham in order to compute the transform minimizing the criterion either with no constraint or with the orthogonality constraint. Finally, experimental results show that the transforms we introduced can (1) outperform the KLT on synthetic signals, (2) achieve slightly better PSNR for high-rates and better visual quality (preservation of lines and contours) for medium-to-low rates than the KLT and 2-D DCT on grayscale natural images

Service controls interfaces in housing: usability and engagement tool development

Domestic buildings are increasingly complex, saturated with services that need coherent control if design and inhabitants’ goals are to be achieved. The evidenced inappropriate use of controls linked with a performance gap suggests that effective methods for assessing the inhabitants’ relationship with control interfaces for services are needed within building performance evaluation and practice studies. The development of a bespoke domestic usability tool over two iterations is presented, demonstrating new insights into the relationship between design and inhabitant engagement with controls. Deep contextual development came from trialling the tool in four UK domestic case studies. Understanding the purpose of a control interface and the inhabitants’ role was found to be a fundamental diagnostic for inhabitant engagement. The tool became a prompt for immediate action or further information-seeking for one-quarter of households involved in its application. However, the affordances and physical issues identified could not be addressed without major physical changes, which should have been picked up at the design and construction stages. Organizational learning based on the tool findings was triggered in one of four developers involved. The challenges for developing usability studies are discussed with recommendations provided for different actors in the housing and construction industry on how to progress them

Elemental boron doping behavior in silicon molecular beam epitaxy

Boron-doped Si epilayers were grown by molecular beam epitaxy (MBE) using an elemental boron source, at levels up to 2×1020 cm−3, to elucidate profile control and electrical activation over the growth temperature range 450–900 °C. Precipitation and surface segregation effects were observed at doping levels of 2×1020 cm−3 for growth temperatures above 600 °C. At growth temperatures below 600 °C, excellent profile control was achieved with complete electrical activation at concentrations of 2×1020 cm−3, corresponding to the optimal MBE growth conditions for a range of Si/SixGe1−x heterostructures

Lincolnshire mud and stud. The impact of a grass roots network on the perception of architectural heritage

Context The Lincolnshire Mud and Stud is one of several vernacular earth building techniques on the British Isles. For a long time it was probably the least known and the least praised one. Unlike more acknowledged English traditions, such as Cob or Wattle and Daub, this one was not treated as a separate important part of English heritage. 30 years ago something changed dramatically. A small group of enthusiasts - architects, historians and practitioners – who called themselves EMESS (East Midlands Earth Structure Society) rediscovered this technique and dedicated their work to learning about its uniqueness and disseminating their findings. They started collecting data, getting involved in renovation and new builds, and most of all spread the knowledge of this technique among local residents. Research: main objectives, Today, 3 decades on, research led by Universities of Lincoln and Sheffield involving interviews with inhabitants of those historic buildings brings insight into the long-lasting and transforming impact on the perception of Lincolnshire architecture resulting from EMESS activity. This gives a valuable and useful lesson on how a relatively small grass roots organisation can change the perception and effectively change the role of vernacular architecture

Exploring the efficacy of Facebook groups for collective occupant learning about using their homes

The need for quality learning about how to use a home has been an issue gradually emerging from building performance evaluation (BPE) studies carried out in occupied energy efficient homes (Brown & Cole, 2009; Day & Gunderson, 2014). The BPE gap between the internal environment control as intended by designers and the actual inhabitant practices is associated with unpredicted energy consumption and poor indoor air quality (Balvers et al., 2012). The key inhabitant related causes of the ‘performance gap’ are a discrepancy between user needs and design intentions, lack of user understanding and skills to interact with the available controls and insufficient maintenance. These findings indicate that modifying tacit home use practices, adjusting them to new, more technically advanced contexts, is still not sufficiently addressed by the current learning opportunities offered by the professional actors. This paper explores how self-organised closed Facebook Groups set up independently by the residents of two UK case study urban developments have become supportive environments for such learning

Is BPPV a Prognostic Factor in Idiopathic Sudden Sensory Hearing Loss?

Objectives. The prognostic significance of vertigo in patients with idiopathic sudden sensorineural hearing loss (SSNHL) remains a matter of debate because vertigo is associated with many different vestibular disorders. The purpose of this study is to determine the role of benign paroxysmal positional vertigo (BPPV) as a prognostic factor in patients with SSNHL. Methods. We conducted a retrospective study of 298 patients with SSNHL. Hearing outcomes were evaluated by assessments of pre-treatment hearing and hearing gain. Comparative multivariate analyses between prognostic factors and hearing outcome were conducted. Results. Thirty-eight (12.7%) SSNHL patients were found to also have BPPV. BPPV showed significant negative prognostic factors in hearing outcome on multivariate analysis (odds ratio, 0.15). In comparison to average pure tone audiometry (PTA), patients diagnosed with SSNHL with BPPV exhibited poorer hearing in pre- and post-treatment PTA compared to SSNHL without BPPV. Old age (>60 years), pre-treatment hearing, and canal paresis were significant outcome predictors