On the lower semicontinuous envelope of functionals defined on polyhedral chains

In this note we prove an explicit formula for the lower semicontinuous envelope of some functionals defined on real polyhedral chains. More precisely, denoting by $H \colon \mathbb{R} \to \left[ 0,\infty \right)$ an even, subadditive, and lower semicontinuous function with $H(0)=0$, and by $\Phi_H$ the functional induced by $H$ on polyhedral $m$-chains, namely \Phi_{H}(P) := \sum_{i=1}^{N} H(\theta_{i}) \mathcal{H}^{m}(\sigma_{i}), \quad\mbox{for every }P=\sum_{i=1}^{N} \theta_{i} [[ \sigma_{i} ]] \in\mathbf{P}_m(\mathbb{R}^n), we prove that the lower semicontinuous envelope of $\Phi_H$ coincides on rectifiable $m$-currents with the $H$-mass \mathbb{M}_{H}(R) := \int_E H(\theta(x)) \, d\mathcal{H}^m(x) \quad \mbox{ for every } R= [[ E,\tau,\theta ]] \in \mathbf{R}_{m}(\mathbb{R}^{n}). Comment: 14 page

Parallel waveform extraction algorithms for the Cherenkov Telescope Array Real-Time Analysis

The Cherenkov Telescope Array (CTA) is the next generation observatory for the study of very high-energy gamma rays from about 20 GeV up to 300 TeV. Thanks to the large effective area and field of view, the CTA observatory will be characterized by an unprecedented sensitivity to transient flaring gamma-ray phenomena compared to both current ground (e.g. MAGIC, VERITAS, H.E.S.S.) and space (e.g. Fermi) gamma-ray telescopes. In order to trigger the astrophysics community for follow-up observations, or being able to quickly respond to external science alerts, a fast analysis pipeline is crucial. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a fast and automated science alert trigger system, becoming a key system of the CTA observatory. Among the CTA design key requirements to the RTA system, the most challenging is the generation of alerts within 30 seconds from the last acquired event, while obtaining a flux sensitivity not worse than the one of the final analysis by more than a factor of 3. A dedicated software and hardware architecture for the RTA pipeline must be designed and tested. We present comparison of OpenCL solutions using different kind of devices like CPUs, Graphical Processing Unit (GPU) and Field Programmable Array (FPGA) cards for the Real-Time data reduction of the Cherenkov Telescope Array (CTA) triggered data.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

Clustering and classifying images with local and global variability

A procedure for clustering and classifying images determined by three classification variables is presented. A measure of global variability based on the singular value decomposition of the image matrices, and two average measures of local variability based on spatial correlation and spatial changes. The performance of the procedure is compared using three different databases

Be Eaten to Stay Healthy: Elucidating the Mechanisms of Mitochondrial Quality Control by Mitophagy

Mitochondria are essential organelles that provide the cell with energy and are involved in many housekeeping processes. Maintaining a healthy population of mitochondria is vital for the proper functioning of cells and the presence of dysfunctional mitochondria may lead to cellular damage and cell death. Neurons are particularly susceptible to the consequences of mitochondrial damage as they have high energy needs and are post-mitotic. The clearance of damaged mitochondria by autophagy, or mitophagy, has emerged as an important quality control mechanism. The Parkinson's disease related proteins phosphatase and tensin homolog-induced putative kinase 1 (PINK1) and Parkin have been identified as important regulators of mitophagy in mammalian cells, directly linking mitophagy to neurodegeneration. The role of these two proteins in this mitophagy is further explored in the first part of this dissertation. We propose a model whereby a cleavage product of PINK1 in the cytosol binds Parkin and prevents its translocation to mitochondria, which is regarded as the initiating step in Parkin/PINK1 mitophagy. Upon the occurrence of mitochondrial damage, however, full-length PINK1 accumulates on the mitochondrial outer membrane (MOM) and recruits Parkin, marking the damaged mitochondria for mitophagy. In the second part, we assess mitophagy in a cellular model based on disease caused by mutations in mitochondrial DNA (mtDNA). We find that the mere presence of damaged mitochondria in the cell does not activate mitophagy. Rather, this process is a complex interplay between mitochondrial membrane potential, levels of PINK1/Parkin and the activation of general macroautophagy. The final part of this dissertation describes the development and validation of a new method to study mitophagy. MitophaGFP, a red-green tandem fluorescent protein targeted to the MOM, changes color from yellow to red once mitochondria enter lysosomes, the final step of the mitophagy process. This new probe allows us to quantitatively and qualitatively assess mitophagy and fulfills a need in the mitophagy field. The work described in this dissertation contributes to elucidate the mechanisms underlying mitophagy regulation in mammalian cells. Its findings can serve as a basis to further explore the importance of mitophagy as a quality control mechanism and the role of its defect in neurodegeneration

ISAC6+ Delivering Smarter Administration through innovation - a Benefits Realisation approach to ensuring success.

The paper describes how the Project Management discipline of benefits realisation has been applied to an EU funded E-government initiative. It explores the benefits of using this approach, the challenges to be addressed, and suggest a framework for applying the approach to other local and national e-government initiatives. One of the key project objectives is to demonstrate through the pilot that implementation of the iSAC6+ system will provide value for money by delivering the desired benefits both to government office users and citizens. The approach described here focuses on costs and benefits generated by use of the system. There are staff costs for training, support and operation, technical costs for integrating iSAC6+ in to existing systems and websites, and more significantly organisational costs for designing and implementing new procedures and working practices. Citizens too will incur costs to access and use the service. In iSAC6+ we have created a model of costs and benefits which can be applied in the short term to the pilot, and in the longer term to a much larger number of public organisations. The aim of the Benefits Realisation model is to demonstrate that iSAC6+ is capable of delivering value for money, and thus to justify the investment needed for expanding its use. Information Technology project success or failure is traditionally judged against objectives set during initial project planning. Enterprises, both public and private sector, have found this approach inadequate because long term costs and benefits do not occur until after the project has completed. Benefits Realisation emerged in the 1990s and developed two roles: a discipline for anticipating and quantifying the expected value of a project in terms of the costs and benefits which will accrue after the project itself is complete; and an over-arching project management philosophy. The paper uses the case study experience to comment upon these two different perspectives. The model developed within the project is based upon the recognised public sector costing formula, the Standard Cost model (SCM) but goes much further by integrating it into a Benefits Realisation tool which creates an audit trail from organisational strategic aims through to detailed cost measures for both quantitative and qualitative incidences

Experimenting in circles: Agfa, amateur cinema, and the art of R&D

Focusing on small-gauge film technology, the article moves from 16 mm film practices to develop a twofold exploration of film and camera as conceptually interlinked in what we term a mutual cycle of experimentation. In this interesting dynamics, the industrial complex’ influences are negotiated by the filmmakers’ creativity, leading to the production of relevant yet unresearched experiments. Italian filmmaker Ubaldo Magnaghi’s city symphonies provide a rather illustrative example: active in the early 1930s as an independent filmmaker, between 1930 and 1933 he produced 5 films sponsored by Agfa, who was expanding its market in Italy. Symphony of Life and Work (1933), the most astonishing film of this series, was rewarded with the first prize in the first experimental and amateur film contest at the Venice Biennale in 1934. Magnaghi’s experimental films were thought to stress the material resistance of cameras (an Agfa Movex 30) and the filmstock (Agfa Isopan reverse), and they were meant to promote Agfa technology, to the extent that even the projector Agfa Movector was mentioned in the credits of each film as an integral part of the promotional technical equipment. The article will shed light on the affordances offered to the filmmaker both in terms of the specificities of the film stock and of the camera involved in the production process. Such a virtuous cycle connecting production and creativity is metaphorically reinforced on the aesthetics level in Magnaghi’s film, characterised by a reiterated circling camera movement. In fact, these formal circles made evident extreme gestures of bodily adaptation to the Agfa Movex 30 ergonomics (with a highly innovative oval shape), meant to expand the range of its operability and to stress the industrial improbability of its technical components. Inspired by this, we aim at crafting a study that assembles the various components of the filmmaker’s work in a rounded film experience, underlining the nature of small-gauge cinema as a non-neutral yet empowering practice able to create a complex room for critical analysis eliciting new ways of looking, problematizing and therefore thinking reality

Ampliação da jornada escolar e atividades artísticas: análise da produção científica entre 2000 e 2012 no Brasil

This study addresses the inclusion of artistic activities in the context of after-school programs. We consider it important to map and investigate how the inclusion of these activities, as well as relationships between young individuals and education institutions, have been discussed. Theses and dissertations, available on the CAPES platform between 2000 and 2012, the themes of which were artistic activities included in after-school programs, were analyzed. The method used is defined as “State of the Art”. A total of 49 theses and dissertations were found and categories such as main topic and results were analyzed. This analysis highlights new ways of doing research and current opportunities of aesthetic education directed to young individuals. The results show changes in the lives of young individuals participating in educational projects that include Art. Enabling access to aesthetic knowledge within formal educational institutions is essential.Este estudio trata de la inclusión de actividades artísticas en contextos de ampliación del tiempo educativo. Consideramos relevante mapear e investigar el modo como se discuten tanto la presencia de esas actividades artísticas en eses espacios como las relaciones entre jóvenes e instituciones formadoras. Analiza investigaciones disponibles en el banco de tesis y disertaciones de la CAPES entre los años de 2000 y 2012 que presentan como temática las actividades artísticas en programas de ampliación del tiempo educativo. La metodología se caracteriza como “estado del arte”. Por eso, fueron identificados y analizados 49 tesis y disertaciones a partir de categorías, tales como: temática principal de investigación y resultados alcanzados. En el análisis, se destacan nuevas formas de hacer investigaciones en el contexto de la educación y las oportunidades de educación estética a los jóvenes actualmente. Las investigaciones indicaron en sus resultados cambios ocurridos en la vida de los jóvenes al participar en proyectos educativos. Se considera fundamental dar la oportunidad de acceder a los conocimientos estéticos por medio de los espacios educativos formales.Este estudo tem como temática as atividades artísticas em contextos de ampliação da Jornada Escolar. Consideramos relevante mapear e investigar o modo como discutem tanto a presença dessas atividades artísticas nesses espaços como também, as relações entre jovens e instituições formadoras. Analisa pesquisas disponíveis no banco de teses e dissertações da CAPES entre 2000 e 2012 que apresentam como temática as atividades artísticas em programas de ampliação do tempo educativo. A metodologia caracteriza-se como “estado da arte”. Por isso, realizou-se levantamento e análise de 49 teses e dissertações a partir de categorias, tais como: temática principal de pesquisa e resultados obtidos. Na análise, destacam-se novos modos de fazer pesquisa e às oportunidades de educação estética aos jovens na atualidade. As investigações indicaram, em seus resultados, mudanças ocorridas na vida dos jovens ao participarem de projetos educativos com Arte. Considera-se fundamental oportunizar o acesso aos conhecimentos estéticos por meio dos espaços educativos formais

ALS mutant FUS proteins are recruited into stress granules in induced pluripotent stem cells- derived motoneurons

Patient-derived induced Pluripotent Stem Cells (iPSCs) provide an opportunity to study human diseases mainly in those cases where no suitable model systems are available. Here we have taken advantage of in vitro iPSCs derived from patients affected by Amyotrophic Lateral Sclerosis and carrying mutations in the RNA-binding proteins FUS to study the cellular behavior of the mutant proteins in the appropriate genetic background. Moreover, the ability to differentiate iPSCs into spinal cord neural cells provides an in vitro model mimicking the physiological conditions. iPSCs were derived from FUS(R514S) and FUS(R521C) patients' fibroblasts, while in the case of the severe FUS(P525L) mutation, where fibroblasts were not available, a heterozygous and a homozygous iPSC lines were raised by TALEN-directed mutagenesis. We show that aberrant localization and recruitment of FUS into stress granules (SGs) is a prerogative of the FUS mutant proteins and occurs only upon induction of stress in both undifferentiated iPSCs and spinal cord neural cells. Moreover, we show that the incorporation into SGs is proportional to the amount of cytoplasmic FUS, nicely correlating with the cytoplasmic delocalization phenotype of the different mutants. Therefore, the available iPSCs represent a very powerful system for understanding the correlation between FUS mutations, the molecular mechanisms of SG formation and ALS ethiopathogenesis

Metodo di Edge-Detection basato sul calcolo di aree parziali

In questo lavoro, viene proposto un metodo di Edge-Detection, in immagini rumorose e con sfuocamento. Il problema è stato posto da Marposs, che fornisce sistemi di misura di alta precisione, quindi è stato necessario applicare un metodo di detezione di edges a livello subpixel. È stato utilizzato il funzionale di Perona Malik per il metodo di denoising e un metodo basato sul calcolo di aree parziali per il subpixed edge detection. Il metodo raggiunge dei buoni risultati anche in situazioni di alto di rumore e sfocamento. Verranno mostrati risultati sia riguardo all'accuratezza dell'edge-detection di contorni rettilinei, con varie inclinazioni, che riguardo la ripetibilità. Infine verranno accennati alcuni risultati nel caso di edge curvilinei e possibili sviluppi futuri per migliorarne le prestazioni