The importance of camera calibration and distortion correction to obtain measurements with video surveillance systems

Video surveillance systems are commonly used as important sources of quantitative information but from the acquired images it is possible to obtain a large amount of metric information. Yet, different methodological issues must be considered in order to perform accurate measurements using images. The most important one is the camera calibration, which is the estimation of the parameters defining the camera model. One of the most used camera calibration method is the Zhang's method, that allows the estimation of the linear parameters of the camera model. This method is very diffused as it requires a simple setup and it allows to calibrate cameras using a simple and fast procedure, but it does not consider lenses distortions, that must be taken into account with short focal lenses, commonly used in video surveillance systems. In order to perform accurate measurements, the linear camera model and the Zhang's method are improved in order to take nonlinear parameters into account and compensate the distortion contribute. In this paper we first describe the pinhole camera model that considers cameras as central projection systems. After a brief introduction to the camera calibration process and in particular the Zhang's method, we give a description of the different types of lens distortions and the techniques used for the distortion compensation. At the end some numerical example are shown in order to demonstrate the importance of the distortion compensation to obtain accurate measurements

Emulsion polymerization of butyl acrylate: safe optimization using topological criteria

Fast and strongly exothermic emulsion polymerization processes are particularly difficult to be optimized from both safety and productivity point of view because of the occurrence of a number of side undesired reactions (e.g. propagation of tertiary radicals, chain transfer to monomer, backbiting, termination by disproportion etc.) and the triggering of boiling phenomena with consequent stable foams formation under atmospheric pressure. Therefore, it would be useful to develop a suitable combined theoretical and experimental procedure able to detect both the optimum process dosing time and initial reactor temperature. In this work, it is discussed how an extended version of the topological criterion theory, originally developed for isoperibolic semibatch reactors, can be used to safely optimize indirectly cooled isothermal semibatch reactor. Moreover, such a methodology is applied to a case-study represented by the synthesis of polybutyl acrylate through the radical emulsion polymerization of butyl acrylate

Batchsize and topological criteria: a combined approach to safely optimize hazardous polymerization processes

Small and medium chemical enterprises are widely diffused in Italy. Particularly, they operate batch and semi-batch processes working on job orders and making a massive use of multipurpose reactors having an Emergency Relief System (ERS) already installed. A batchsize approach is a method focused on finding the reactor fill level that can lead to a single phase vapor flow whether an external fire occurs, so that the installed ERS can protect the reactor from overpressures. In this work, such an approach has been revised, by choosing a runaway reaction as design incidental scenario, and integrated with a suitable optimization procedure based on topological criteria. The new batchsize approach allows for computing a reactor fill level which is much more reasonable for industrial applications with respect to that one predicted by the older method, while the topological approach permits to identify the minimum dosing time capable of guaranteeing both reactor safety and high productivity. Theoretical results have been experimentally validated using data obtained by reaction calorimetry experiments, carried out in an isoperibolic RC1 equipment (1 L, Mettler Toledo), implementing the relevant case study of the solution homopolymerization of butyl acrylate

Impairment of platelet function in both mild and severe COVID-19 patients

Abnormalities of platelet function were reported in patients with severe COVID-19 (severe-C), but few data are available in patients with mild COVID-19 (mild-C) and after COVID-19 recovery. The aim of this study was to investigate platelet parameters in mild-C patients (n = 51), with no evidence of pneumonia, and severe-C patients (n = 49), during the acute phase and after recovery, compared to 43 healthy controls. Both mild-C and severe-C patients displayed increased circulating activated platelets, low d-granule content (ADP, serotonin), impaired platelet activation by collagen (light transmission aggregometry) and impaired platelet thrombus formation on collagen-coated surfaces under controlled flow conditions (300/s shear rate). The observed abnormalities were more marked in severe-C patients than in mild-C patients. Overall, 61% (30/49) of mild-C and 73% (33/45) of severe-C patients displayed at least one abnormal platelet parameter. In a subgroup of just 13 patients who showed no persisting signs/symptoms of COVID-19 and were re-evaluated at least 1 month after recovery, 11 of the 13 subjects exhibited normalization of platelet parameters. In conclusion, mild abnormalities of platelet parameters were present not only in severe-C but also, albeit to a lesser extent, in mild-C patients during the acute phase of COVID-19 and normalized in most tested patients after clinical recovery

Thermochemical stability: A comparison between experimental and predicted data

The first step to be performed during the development of a new industrial process should be the assessment of all hazards associated to the involved compounds. Particularly, the knowledge of all substances thermochemical parameters is a primary feature for such a hazard evaluation. CHETAH (CHEmical Thermodynamic And Hazard evaluation) is a prediction software suitable for calculating potential hazards of chemicals, mixtures or a single reaction that, using only the structure of the involved molecules and Benson's group contribution method, is able to calculate heats of formation, entropies, Gibbs free energies and reaction enthalpies. Because of its ability to predict the potential hazards of a material or mixture, CHETAH is part of the so-called \u201cdesktop methods\u201d for early stage chemical safety analysis. In this work, CHETAH software has been used to compile a complete risk database reporting heats of decomposition and Energy Release Potential (ERP) for 342 common use chemicals. These compounds have been gathered into classes depending on their functional groups and similarities in their thermal behavior. Calculated decomposition enthalpies for each of the compounds have also been compared with experimental data obtained with either thermoanalytic or calorimetric techniques (Differential Scanning Calorimeter \u2013 DSC \u2013 and Accelerating Rate Calorimeter \u2013 ARC)

Maximizing the Products Display for Purchaser Lucidity and Alleviation in Circulation to Augment the Sale of Supermarket: Milieu of Bangladesh

The purpose of this study is to appraise the accessible products display for the purchaser lucidity which may maximizes offers and actions of business with the alleviation in circulation to augment the random sale in the arena of supermarket. The study scrutinizes a fundamental research on the context of Bangladesh and especially for the Dhaka zone. A supermarket, a large form of the traditional grocery store, is a self-service shop offering a wide variety of food and household products, organized into aisles. It is larger in size and has a wider selection than a traditional grocery store, but is smaller and more limited in the range of merchandise than a hypermarket or big-box market. The traditional supermarket occupies a large amount of floor space, usually on a single level. It is usually situated near a residential area in order to be convenient to consumers. The basic appeal is the availability of a broad selection of goods under a single roof, at relatively low prices. Other advantages include ease of parking and frequently the convenience of shopping hours that extend far into the evening or even 24 hours a day. Key words: Circulation, Supermarket, Alleviation, Sale, Products, Variation, Lucidit

Post-natal cardiomyocytes can generate iPS cells with an enhanced capacity toward cardiomyogenic re-differentation

Adult mammalian cells can be reprogrammed to a pluripotent state by forcing the expression of a few embryonic transcription factors. The resulting induced pluripotent stem (iPS) cells can differentiate into cells of all three germ layers. It is well known that post-natal cardiomyocytes (CMs) lack the capacity to proliferate. Here, we report that neonatal CMs can be reprogrammed to generate iPS cells that express embryonic-specific markers and feature gene-expression profiles similar to those of mouse embryonic stem (mES) cell and cardiac fibroblast (CF)-derived iPS cell populations. CM-derived iPS cells are able to generate chimeric mice and, moreover, re-differentiate toward CMs more efficiently then either CF-derived iPS cells or mES cells. The increased differentiation capacity is possibly related to CM-derived iPS cells retaining an epigenetic memory of the phenotype of their founder cell. CM-derived iPS cells may thus lead to new information on differentiation processes underlying cardiac differentiation and proliferation

MariX, an advanced MHz-class repetition rate X-ray source for linear regime time-resolved spectroscopy and photon scattering

The need of a fs-scale pulsed, high repetition rate, X-ray source for time-resolved fine analysis of matter (spectroscopy and photon scattering) in the linear response regime is addressed by the conceptual design of a facility called MariX (Multi-disciplinary Advanced Research Infrastructure for the generation and application of X-rays) outperforming current X-ray sources for the declared scope. MariX is based on the original design of a two-pass two-way superconducting linear electron accelerator, equipped with an arc compressor, to be operated in CW mode (1 MHz). MariX provides FEL emission in the range 0.2–8 keV with 108 photons per pulse ideally suited for photoelectric effect and inelastic X-ray scattering experiments. The accelerator complex includes an early stage that supports an advanced inverse Compton source of very high-flux hard X-rays of energies up to 180 keV that is well adapted for large area radiological imaging, realizing a broad science programme and serving a multidisciplinary user community, covering fundamental science of matter and application to life sciences, including health at preclinical and clinical level

Inflammatory biomarkers in Alzheimer's disease plasma

Introduction: Plasma biomarkers for Alzheimer's disease (AD) diagnosis/stratification are a \u201cHoly Grail\u201d of AD research and intensively sought; however, there are no well-established plasma markers. Methods: A hypothesis-led plasma biomarker search was conducted in the context of international multicenter studies. The discovery phase measured 53 inflammatory proteins in elderly control (CTL; 259), mild cognitive impairment (MCI; 199), and AD (262) subjects from AddNeuroMed. Results: Ten analytes showed significant intergroup differences. Logistic regression identified five (FB, FH, sCR1, MCP-1, eotaxin-1) that, age/APO\u3b54 adjusted, optimally differentiated AD and CTL (AUC: 0.79), and three (sCR1, MCP-1, eotaxin-1) that optimally differentiated AD and MCI (AUC: 0.74). These models replicated in an independent cohort (EMIF; AUC 0.81 and 0.67). Two analytes (FB, FH) plus age predicted MCI progression to AD (AUC: 0.71). Discussion: Plasma markers of inflammation and complement dysregulation support diagnosis and outcome prediction in AD and MCI. Further replication is needed before clinical translation

From sea monsters to charismatic megafauna: changes in perception and use of large marine animals

Marine megafauna has always elicited contrasting feelings. In the past, large marine animals were often depicted as fantastic mythological creatures and dangerous monsters, while also arousing human curiosity. Marine megafauna has been a valuable resource to exploit, leading to the collapse of populations and local extinctions. In addition, some species have been perceived as competitors of fishers for marine resources and were often actively culled. Since the 1970s, there has been a change in the perception and use of megafauna. The growth of marine tourism, increasingly oriented towards the observation of wildlife, has driven a shift from extractive to non-extractive use, supporting the conservation of at least some species of marine megafauna. In this paper, we review and compare the changes in the perception and use of three megafaunal groups, cetaceans, elasmobranchs and groupers, with a special focus on European cultures. We highlight the main drivers and the timing of these changes, compare different taxonomic groups and species, and highlight the implications for management and conservation. One of the main drivers of the shift in perception, shared by all the three groups of megafauna, has been a general increase in curiosity towards wildlife, stimulated inter alia by documentaries (from the early 1970s onwards), and also promoted by easy access to scuba diving. At the same time, environmental campaigns have been developed to raise public awareness regarding marine wildlife, especially cetaceans, a process greatly facilitated by the rise of Internet and the World Wide Web. Currently, all the three groups (cetaceans, elasmobranchs and groupers) may represent valuable resources for ecotourism. Strikingly, the economic value of live specimens may exceed their value for human consumption. A further change in perception involving all the three groups is related to a growing understanding and appreciation of their key ecological role. The shift from extractive to non-extractive use has the potential for promoting species conservation and local economic growth. However, the change in use may not benefit the original stakeholders (e.g. fishers or whalers) and there may therefore be a case for providing compensation for disadvantaged stakeholders. Moreover, it is increasingly clear that even non-extractive use may have a negative impact on marine megafauna, therefore regulations are needed.SFRH/BPD/102494/2014, UID/MAR/04292/2019, IS1403info:eu-repo/semantics/publishedVersio