8,483 research outputs found
Spacetime geometries and light trapping in travelling refractive index perturbations
In the framework of transformation optics, we show that the propagation of a
locally superluminal refractive index perturbation (RIP) in a Kerr medium can
be described, in the eikonal approximation, by means of a stationary metric,
which we prove to be of Gordon type. Under suitable hypotheses on the RIP, we
obtain a stationary but not static metric, which is characterized by an
ergosphere and by a peculiar behaviour of the geodesics, which are studied
numerically, also accounting for material dispersion. Finally, the equation to
be satisfied by an event horizon is also displayed and briefly discussed.Comment: 14 pages, 7 figure
Cladribine Tablets Mode of Action, Learning from the Pandemic: A Narrative Review
Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system, characterized by chronic, inflammatory, demyelinating, and neurodegenerative processes. MS management relies on disease-modifying drugs that suppress/modulate the immune system. Cladribine tablets (CladT) have been approved by different health authorities for patients with various forms of relapsing MS. The drug has been demonstrated to deplete CD4+ and CD8+ T-cells, with a higher effect described in the former, and to decrease total CD19+, CD20+, and naive B-cell counts. COVID-19 is expected to become endemic, suggesting its potential infection risk for immuno-compromised patients, including MS patients treated with disease-modifying drugs. We report here the available data on disease-modifying drug-treated-MS patients and COVID-19 infection and vaccination, with a focus on CladT. MS patients treated with CladT are not at higher risk of developing severe COVID-19. While anti-SARS-CoV-2 vaccination is recommended in all MS patients with guidelines addressing vaccination timing according to the different disease-modifying drugs, no vaccination timing restrictions seem to be necessary for cladribine, based on its mechanism of action and available evidence. Published data suggest that CladT treatment does not impact the production of anti-SARS-CoV-2 antibodies after COVID-19 vaccination, possibly due to its relative sparing effect on naïve B-cells and the rapid B-cell reconstitution following treatment. Slightly lower specific T-cell responses are likely not impacting the risk of breakthrough COVID-19. It could be stated that cladribine’s transient effect on innate immune cells likely contributes to maintaining an adequate first line of defense against the SARS-CoV-2 virus
Reply to Comment on: Hawking radiation from ultrashort laser pulse filaments
A comment by R. Schutzhold et al. raises possible concerns and questions
regarding recent measurements of analogue Hawking radiation. We briefly reply
to the opinions expressed in the comment and sustain that the origin of the
radiation may be understood in terms of Hawking emission
Inventory of GIS-Based Decision Support Systems Addressing Climate Change Impacts on Coastal Waters and Related Inland Watersheds
A Decision Support System (DSS) is a computer-based software that can assist decision
makers in their decision process, supporting rather than replacing their judgment and, at
length, improving effectiveness over efficiency. Environmental DSS are models based
tools that cope with environmental issues and support decision makers in the sustainable
management of natural resources and in the definition of possible adaptation and mitigation
measures [2]. DSS have been developed and used to address complex decision-based
problems in varying fields of research. For instance, in environmental resource
management, DSS are generally classified into two main categories: Spatial Decision
Support Systems (SDSS) and Environmental Decision Supports Systems (EDSS) [3-5]. SDSS
provide the necessary platform for decision makers to analyse geographical information in a
flexible manner, while EDSS integrate the relevant environmental models, database and
assessment tools – coupled within a Graphic User Interface (GUI) – for functionality within
a Geographical Information System (GIS) [1,4-6]. In some detail, GIS is a set of computer
tools that can capture, manipulate, process and display spatial or geo-referenced data in
which the enhancement of spatial data integration, analysis and visualization can be
conducted [8-9]. These functionalities make GIS-tools useful for efficient development and
effective implementation of DSS within the management process. For this purpose they are
used either as data managers (i.e. as a spatial geo-database tool) or as an end in itself (i.e. media to communicate information to decision makers)
Business Model validation for a marketplace of lab network initiatives
In the field of science, technology, engineering, and mathematics (STEM) the use of laboratories to support teaching is a common requirement, not just a possibility. With the rise of the internet, teaching laboratories have changed from 'traditional' hands-on equipment to configurations that allow remote use of the experiment materials. In recent years, online labs (e.g., laboratories of universities or research institutes) have gradually been integrated into 'networks' of labs, with the objective of making them more economically viable, otherwise they would have been short-lived due to the high cost for their development and maintenance. While research on online labs has focused on didactic and technical aspects, there seem to be no in-depth studies on the financial sustainability of technical solutions developed. Moreover, online solutions subvert the traditional pattern of access being limited to individuals engaged in the practice of organizations. Indeed, online laboratories can also be used by professionals and companies interested in research and development, testing, and training activities. The authors of this article frame the problem from the perspective of the servitization of labs of universities and research institutions, through a new business model of a marketplace capable of coordinating the network of labs. To do this, an analysis of the intention to use an online lab marketplace and the activities made available by the online labs is conducted. The analysis involves entrepreneurs and practitioners of various companies from diverse industries in the northern Italy. The analysis is twofold. Firstly, it proposes a survey of intention to use university labs and LNIs in business environment. Second, it seeks to assess the usefulness of a marketplace service that technically manages the relationship between service provider and buyer beyond the mere educational aspects
Chapter Inventory of GIS-Based Decision Support Systems Addressing Climate Change Impacts on Coastal Waters and Related Inland Watersheds
Cosmology & the univers
On the Application of GIS-based Decision Support Systems to study climate change impacts on coastal systems and associated ecosystems
One of the most remarkable achievements by scientists in the field of global change in recent years is the improvedunderstanding of climate change issues. Its effects on human environments, particularly coastal zones and associated watersystems, are now a huge challenge to environmental resource managers and decision makers. International and regionalregulatory frameworks have been established to guide the implementation of interdisciplinary methodologies, useful toanalyse water-related systems issues and support the definition of management strategies against the effects of climatechange. As a response to these concerns, several decision support systems (DSS) have been developed and applied toaddress climate change through geographical information systems (GIS) and multi-criteria decision analysis (MCDA)techniques; linking the DSS objectives with specific functionalities leading to key outcomes, and aspects of the decisionmaking process involving coastal and waters resources. An analysis of existing DSS focusing on climate change impacts oncoastal and related ecosystems was conducted by surveying the open literature. Consequently, twenty DSS were identifiedand are comparatively discussed according to their specific objectives and functionalities, including a set of criteria (generaltechnical, specific technical and applicability) in order to better inform potential users and concerned stakeholders throughthe evaluation of a DSS’ actual application.Key words: Climate change, Decision support, GIS, regulations, Environmen
Locality hypothesis and the speed of light
The locality hypothesis is generally considered necessary for the study of
the kinematics of non-inertial systems in special relativity. In this paper we
discuss this hypothesis, showing the necessity of an improvement, in order to
get a more clear understanding of the various concepts involved, like
coordinate velocity and standard velocity of light. Concrete examples are
shown, where these concepts are discussed.Comment: 23 page
S. aureus and IgE-mediated diseases: pilot or copilot? A narrative review
Introduction: S. aureus is a major opportunistic pathogen that has been implicated in the pathogenesis of several chronic inflammatory diseases including bronchial asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), chronic spontaneous urticaria (CSU), and atopic dermatitis. S. aureus can induce the production of both polyclonal and specific IgE that can elicit an inflammatory cascade.
Areas covered: The link between the sensitization to S. aureus enterotoxins and the severity of several chronic inflammatory diseases is reviewed in detail, as well as its therapeutic implications.
Expert opinion: An anti-IgE strategy to inhibit S. aureus enterotoxins would be a valid approach to treat several endotypes of severe asthma, CRSwNP and CSU in which IgE against S. aureus enterotoxins should represent, not only a marker of severity of the diseases but also a target of a treatment
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